Volume 1 No. 2, June 2005 Journal of Paediatric Respirology and Critical Care Journal of Paediatric Respirology and Critical Care (JPRCC) is the official peer-reviewed publication of the Hong Kong Society of Paediatric Respirology, and is published quarterly by Medcom Limited. ISSN 1814-4527. Website: www.hkspr.org. Printed in Hong Kong. An official Publication of Hong Kong Society of Paediatric Respirology The opinions expressed in the JPRCC are those of the authors and do not necessarily reflect the official policies of the Hong Kong Society of Paediatric Respirology, the institutions to which the authors are affiliated, or those of the publisher. Dr. Daniel NG Copyright @2005 by the Hong Kong Society of Paediatric Respirology. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the editor or the publisher. Editorial Board Advertisements Enquiries should be addressed to: Dr. Daniel KK Ng, Department of Paediatrics, Kwong Wah Hospital, 25 Waterloo Road, Kowloon, Hong Kong. Email: dkkng@ha.org.hk. Editor Dr. Ka-Li KWOK Dr. Ting-Fan LEUNG Dr. Sou-Chi SIT Dr. Nai-Shun TSOI Dr. Tat-Kong WONG Dr. Tak-Wai WONG Subscription JPRCC is distributed to members of the Hong Kong Society of Paediatric Respirology. It is also available to non-members on subscription. The price of four issues is HK$400 for delivery within Hong Kong or US$100 for airmail delivery outside Hong Kong. Subscription enquiries should be address to Dr. Daniel KK Ng, Department of Paediatrics, Kwong Wah Hospital, 25 Waterloo Road, Kowloon, Hong Kong. Email: dkkng@ha.org.hk. Instructions to Authors Council of Hong Kong Society of Paediatric Respirology President Dr. Alfred TAM Vice-President Dr. Daniel NG JPRCC publishes original research papers, review articles, case reports, editorials, commentaries, letters to the editor and conference proceedings. Topics of interest will include all subjects that relate to clinical practice and research in paediatrics and child health. Manuscripts are accepted on the condition that they are submitted solely to the JPRCC and have not been published elsewhere previously and are not under consideration by another journal. A complete report following presentation or publication of preliminar y findings elsewhere can be considered. Hon. Secretary Categories of articles include the following: Dr. Ting-Yat MIU Original Articles The text should not usually exceed 5,000 words; the number of tables, figures, or both should normally be not more than six, and references not more than 50. Review Articles Reviews are usually invited systematic critical assessments of literature. Case Reports Length should not exceed 1,500 words; the number of tables or figures used should not be more than two, and references should not be more than 10. Commentaries Commentary on current topics are welcome. Length should not exceed 1,200 words; no tables or figures allowed, and references should not be more than 20. Letters to the Editor Letters discussing a recent article in the JPRCC are welcome. Original letters that do not refer to an JPRCC article may also be considered. Letters should not exceed 500 words and have no more than five references. Published letters may be edited. Hon. Treasurer Dr. Grace CHAN Council Members Dr. Kwan-Tong SO (Ex-President) Dr. Kam-Lau CHEUNG Dr. Wa-Keung CHIU Dr. Pok-Yu CHOW Dr. Siu-Ngan CHOW Dr. Daniel Wai-Tai KO Dr. Ping LAM Dr. Shu-Yan LAM Dr. Theresa LEUNG Dr. Ting-Fan LEUNG Dr. Wan-Cheong MAK Dr. Sou-Chi SIT Dr. Nai-Shun TSOI Dr. Tak-Wai WONG Dr. Gary Wing-Kin WONG Hon. Legal Advisor Miss Kitty SO Hon. Auditor Mr. Kai-Man WONG Address Department of Paediatrics Queen Elizabeth Hospital 30 Gascoigne Road Kowloon 1 Manuscript Preparation 1. Use Arabic numerals for numbers above nine, for designators (e.g. case 5, day 2, etc.) and for units of measure; numbers should be spelled out if below 10, at the beginning and end of sentences, and for fractions below one. 2. Manuscripts should be word-processed or typed doublespaced on one side of good quality A4 (210 x 297 mm) paper. Pages should have margins of 1 inch (25 mm). Three copies of the manuscript should be sent. If possible, a floppy disc (preferably 3.5") prepared on IBM-compatible personal computer can be sent as well. Authors must use a common software program. Discs should be labelled with: manuscript number; author names; manuscript title; program and file name. 3. Do not use abbreviations in the title or abstract and limit their use in the text. Standard abbreviations may be used and should be defined on first mention in the text unless it is a standard unit of measurement. Ethics Ethical considerations will be taken into account in the assessment of papers that have experimental investigations of human or animal subjects. An appropriate institutional review board approval should be obtained. The manuscript should usually be arranged as follows: Title page This page should include the full names, and affiliations of all authors. A short title of no more than 40 characters should also be given. Up to three academic degrees for each author are allowed. If an author’s affiliation has changed since the work was done, list the new affiliations as well. Abstract and Key words The abstract should be no more than 150 words summarising the purpose, methods, findings and conclusions. Authors should provide no more than five key words to assist with crossindexing of the paper. Key words should be taken from Index Medicus. Introduction Methods Results Discussion References Number references in the order they appear in the text. References should follow the Vancouver style and should appear in the text, tables and legends as arabic numerals in superscript. Journal titles should be abbreviated in accordance with Index Medicus. List all authors and/or editors up to six; if more than six, list the first six and “et al”. Tables Type or print out each table double-spaced on a separate sheet of A4 paper. Number tables consecutively in the order of their first citation in the text and supply a brief title for each. Give each column a short or abbreviated heading. Place explanatory matter in footnotes, not in the heading. Vertical rules and horizontal rules should be omitted. Illustrations (Figures) Submit 3 complete sets of figures. Illustrations include photographs, photomicrographs, charts and diagrams, and these should be camera-ready. Freehand or typewritten lettering is unacceptable. Illustrations should be sharp, glossy black-and-white photographic prints, and no larger than 210 x 297 mm. Letters, numbers and symbols should be clear and of sufficient size to retain legibility when reduced. Titles and detailed explanations should be confined to legends and not included in illustrations. Costs of colour printing will be charged to auhtors. Number illustrations consecutively according to the order in which they have been first cited in the text. Each figure should be identified clearly on the back with a label which states its number, name of first author, short form of title, and an arrow to show orientation. Photomicrographs must have internal scale markers and include magnification. Photographs of persons must be retouched to make the subject unidentifiable, or be accompanied by written permission from the subject to use the photograph. All illustrations require legends, typed on a separate page, double-spaced and with arabic numbers corresponding to the illustrations. Explain the internal scale and identify the method of staining in photomicrographs. Correspondence All manuscripts, correspondence and subscription should be addressed to:Dr. Daniel KK Ng, Department of Paediatrics, Kwong Wah Hospital, 25 Waterloo Road, Kowloon. Fax: (852) 3517 5261, email: dkkng@ha.org.hk Editorial Journal of Paediatric Respirology and Critical Care Paediatic respirology training in Hong Kong: where are we heading? Kwan-Tong SO Department of Paedaitrics & Adolescent Medicine, Tuen Mun Hospital, Hong Kong This first issue of the newsletter marks an important milestone of the development of our society and provide an opportunity for the council to update its members on the development of our subspecialty training. Since the Hong Kong College of Paediatricians has announced its plan to launch subspecialty accreditation several years ago, our Society has been active in having paediatric respirology recognised as a subspecialty in the College. A Working Group on Post-graduate Training was formed under the Council and we have taken every opportunity to tap on the expertise of internal leaders in this field. The Forum on Paediatric Respirology Training during the 2004 IPRAIC Meeting in Hong Kong provided the most unique and invaluable opportunity for us to learn from the rest of the world. However, at the end of the day, we will have to decide a training programme that is suitable for Hong Kong. I believe the task of developing and implementing a training programme is particularly challenging for a society like Hong Kong which is not as well developed and resourceful (in terms of richness of clinical materials and research activities as most developed countries) and yet with a high standard of expectation. The task however, will be easier if we are right in two critical areas: a) what type of paediatric respirology specialist do we need and b) what are the critical elements for success and making sure that they are in place. The rest I believe can be further fine tuned as we go along. What type of specialist do we need? I, same as many others, believe that we need to train up paediatric respirology specialists who will be able to tackle a full range of paediatric respirology problems, some of these will be rare and complex. We need such highly skilled specialists to render services to our children so that children with such respiratory problems can be well taken care of, just like their counterparts in well developed countries. However, the requirement for such type of specialist is probably small and limited to perhaps one or two special centres in Hong Kong. These centres will need referrals from all the paediatric Email: sokt@ha.org.hk depar tments and also from the private sector to development and maintain a high level of expertise. Perhaps a great majority of children, especially those with common diseases like asthma or pneumonia will continue to be cared for by other paediatricians, who may well have completed the respiratory training programme but have settled down in places other than the specialised centres mentioned above. If this is going to be the case, the training programme will need to be designed to produce these types of products, and trainees should be fully aware of their career options. What are the critical elements for success? For the training programme to be successful, the following intrinsic and extrinsic factors are of vital importance. Efforts should be made to ensure that they are in place: a) Its end products must meet the needs of our society, i.e. the needs our patients, paediatric departments and the private sector. It is perhaps easier said than done and requires careful thinking. b) Sufficient resources to be given to training centres to ensure a high quality of training. c) Stability of training staff should be ensured or the programme may collapse if the key persons leave the programme for one reason or another. This may mean obtaining commitment from the training depar tments to have such vacancies filled by qualified trainers in respirology. d) Sending trainees to training should not mean significant loss of manpower strength, unless compensated. e) An effective referral system for complex cases ought to be put into place to ensure concentration of cases and a high level of activities. f) And lastly, and perhaps the most important prerequisite is the determination and conjoint effort from the entire paediatric community of Hong Kong to make it a success. It is hoped that this short article will stimulate the thinking of our learned members and the author will be obliged for any suggestions or comments on these issues. 2 Volume 1 No. 2, June 2005 Allergic rhinitis and asthma : two ends of one airway Daniel Kwok-Keung NG * and Pok-Yu CHOW Department of Paedaitrics, Kwong Wah Hospital, Hong Kong Asthma is a worldwide health problem causing significant morbidity and mortality. Hong Kong has witnessed a significant increase in the prevalence of asthma over the past two decades. It is timely that the Society released the childhood asthma treatment guideline for Hong Kong in May this year and a more detailed account of the guideline is published in the current issue of the Jour nal. Complicating the picture is the often co-exisiting allergic rhinitis in the same patient. Up to 80% of asthma patients have concomitant allergic rhinitis. On 17th Apr il 2005, a forum on management of paediatric asthma and allergic rhinitis was held in Prince of Wales Hospital, Hong Kong with support from this Society, the close relationship of these two diseases were emphasized. The "One Airway" concept, meaning allergic inflammation often a f fe c t s b o t h t h e u p p e r a n d l owe r a i r w ay, a s proposed by the WHO's allergic rhinitis and its impact on asthma (ARIA) guidelines was discussed. depression, anxiety, fearfulness and fatigue than those without the condition. Allergic rhinitis is classified as either inter mittent or persistent. Persistent means symptoms are present more than 4 days a week and lasting more than 4 weeks a year. The characteristics of asthma include the following findings: recurrent cough, wheeze or shor tness of breath. Clinical signs are often absent between attacks. Although in chronic asthmatics, there may be Harrison's sulci and an increase in chest AP diameter from air-trapping. Allergic rhinitis is a condition character ized by sneezing, which is f r e q u e n t l y p a r ox y s m a l , p r o f u s e c l e a r w a t e r y rhinorrhoea and nasal obstruction leading to mouth breathing. Recurrent cough, especially on lying down or rising, is a common feature in allergic rhinitis children. Clinical signs include pale and swollen nasal mucosa, post-nasal drip and allergic shiners. Approximately 20% of allergic rhinitis cases are accompanied by symptoms of asthma. In severe cases, it has been shown that sufferers of allergic rhinitis are more likely to exhibit shyness; For those with persistent allergic rhinitis, treatment with topical nasal corticosteroids and/or systemic anti-histamines would be advised. Intranasal cor ticosteroids are effective in controlling all symptoms of allergic rhinitis. Satisfactory control can be achieved in over 90% of patients. The overall symptom control is superior to any other m o n o t h e r a p y. T h e e f f e c t o f i n t r a n a s a l cor ticosteroids on the early and the late phase d e p e n d o n t h e d u r a t i o n o f t r e a t m e n t b e fo r e exposure. Therefore, for maximal effect, it should be given regular ly and commenced before expected exposure to allergen. Studies have shown a consistent reduction in the early phase reaction after 1 to 2 weeks of treatment. This may be related to the lowering of histamine release. A once daily dose is usually sufficient in most cases. A twice daily regime may be necessary in severe cases and during exacerbations. The aim of therapy is to use the minimal dose necessary to control symptoms. S e ve r a l s y n t h e t i c n a s a l c o r t i c o s t e r o i d s a r e *Author to whom correspondence should be addressed. Email: dkkng@ha.org.hk 3 For children with concomitant allergic rhinitis and asthma, monitoring with asthma and allergic rhinitis diar y would be helpful to quantify the control. Identification of allergens and avoidance of the offending allergens would be helpful. This identification could be done by either skin prick test or radioallergosorbent test (RAST). Management of asthma in children is covered in the asthma guideline published in the current issue. For those with mild persistent asthma and inter mittent allergic rhinitis with mild symptoms, preliminar y evidence suggested that montelukast was effective for controlling both diseases. Fur ther studies are required. Editorial Journal of Paediatric Respirology and Critical Care available for use in young children like mometasone for over 2 years old and budesonide for over 6 years old. Studies have shown that intranasal corticosteroids have no effect on the hypothalamic pituitar y adrenal axis if used in recommended dosages because of the limited systemic bioavailability. However, growth suppression in children has been repor ted in some studies with the use of intranasal corticosteroids. The clinical importance of these findings in terms of final adult height is not presently known. Second generation antihistamines are lipophobic w i t h a l a r g e m o l e c u l a r s i ze a n d p o s s e s s a n electrostatic charge. They generally do not cross the blood-brain barr ier and exhibit little CNS effects. One of the major advantages of second generation antihistamine is its non-sedating or low sedating effects. The longer duration of action also means infrequent dosing which makes adherence to treatment easier. Other advantages include preferential binding to peripheral H 1 receptors and minimal antimuscar inic, adrenergic and a n t i c h o l i n e r g i c e f fe c t s. E x a m p l e s o f s e c o n d generation antihistamines include loratadine, c e t i r i z i n e a n d fex o fe n a d i n e . L o r a t a d i n e a n d c e t i r i z i n e a r e c u r r e n t l y ava i l a bl e fo r t r e a t i n g children less than 12 years of age. Antihistamines are more effective if occupation of H 1 receptors occurs before histamine is released; consequently the maximum benefit from antihistamine is a c h i eve d w i t h p r o p hy l a c t i c t r e a t m e n t b e fo r e exposure to allergen. Antihistamines are less efficacious than topical cor ticosteroids. By combining with a decongestant or a topical c o r t i c o s t e r o i d , e f f i c a c y m ay b e e n h a n c e d . Alternative treatments for allergic rhinitis included sublingual immunotherapy for those with monoallergen and acupuncture. Conclusion Childhood asthma and allergic rhinitis often occur together in the same child. Compared with asthma, allergic rhinitis severity is often underdiagnosed and untreated leading to unnecessary suffer ing. As allergic rhinitis often aggravates asthma control and symptoms of allergic rhinitis overlap with that of asthma, it is important to treat both diseases. References are available on request. ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Acknowledgement AstraZeneca Hong Kong Limited GlaxoSmithKline Merck Sharp & Dohme (Asia) Limited 4 Volume 1 No. 2, June 2005 Upper airway obstruction in children Chung-Mo CHOW and Kam-Lun HON *, Kam-Lau CHEUNG Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Introduction Table 1. Acute and chronic causes of upper airway obstruction Upper airway obstruction in children is one of the most challenging acute emergencies, which requires urgent management in order to prevent fatal outcome. Severe upper airway obstruction accounts for 3.3% of all admission to paediatric intensive care unit (PICU). 1 There are many causes of upper airway obstr uction that can be fur ther classified as acute or chronic causes (Table 1). In this review, the characters of children who are a d m i t t e d t o P I C U w i t h s e ve r e u p p e r a i r w ay obstruction will be discussed further. Difficulties of intubation, indications and complications of tracheotomy will be discussed afterwards. Angioedema, bacterial tracheitis, acute epiglottitis and croup will be discussed with details separately. Laryngomalacia will also be discussed because it is one of the most common causes of stridor in infant. Patients with other anatomical abnormalities of the upper airway will not be discussed in this review, as most of them are under cared by the surgeons rather than paediatricians. Cause of upper airway obstruction • Acute • Acute laryngotracheitis • Acute epiglottitis • Suppurative tracheitis • Laryngeal foreign body • Diphtheria • Acute Angioneurotic oedema • Retropharyngeal abscess • Chronic • Laryngeal: Laryngomalacia, Subglottic stenosis/hemagioma, Vocal cord paralysis, Laryngeal web, Cyst (posterior tongue, aryepiglottic, subglottic, larygoceles, laryngeal cleft), laryngeal papillomas • Trachea: Vascular ring, Tracheal stenosis, trachemalacia Difficulty in intubation will be encountered in 43%.1 However, tracheostomy is not common among children who required PICU admission. Regarding the prognosis, non-survivors have a higher Paediatric Risk of Mortality (PRISM) II score although the outcome is generally favorable. The conditions are similar in Hong Kong according to our experience in a teaching hospital (unpublished data). Intubation PICU admission with severe upper airway obstruction There is marked heterogeneity in the causes of upper airway obstruction that requires PICU admission. According to studies conducted in Malaysia 1 and London,2 congenital causes account for 6-23%, which include lar yngomalacia, vascular ring, subglottic haemangioma, laryngeal cyst and web of pharynx. Acquired causes account for 77-94%, which include infection and anatomical problems. Viral croup is the most common diagnosis and it accounts for about 30% to 50% of all PICU admissions. Acute epiglottitis is extremely rare in Asia and also not common in Western countries. Bacterial tracheitis and subglottic stenosis are the most likely diagnosis requiring ventilation, as these patients are usually more sick and ill. Anatomical causes include tracheal compression, subglottic granuloma, subglottic stenosis and foreign body are other causes of PICU admission. *Author to whom correspondence should be addressed. Email: kl-cheung@cuhk.edu.hk 5 Difficulty in intubation will be encountered in half of the cases during intubations of severe upper airway obstruction patients. There are some characteristics of patients that we should pay special attention during intubation in order to facilitate the procedure. Delay in intubation in those critical ill patients could have very serious complication and even fatal. Pierre-Robin syndrome, Treacher-Collins syndrome, Goldenhar syndrome and mucopolysaccharidosis (Hurler, Hunter, Maroteaux-Lamy) are commonly associated with significant cranio-facial abnormalities, and these patients may have problems dur ing i n t u b a t i o n . T h ey h ave m i c r o g n a t h i a , r e l a t i ve m a c r o g l o s s i a , hy p o p l a s i a o f t h e fa c i a l b o n e, m a c r o s t o m i a a n d eve n s h o r t i m m o b i l e n e ck . Mucopolysaccharidosis has excessive intra-lysosomal accumulation of glycosaminoglycans that causes generalised thickening of soft tissues. All these features make the procedure of intubation more difficult. Inhalation injury makes visualisation of the normal airway anatomy more difficult. Epiglottitis is another Review Ar ticle Journal of Paediatric Respirology and Critical Care potential life-threatening cause for difficult intubation. Trauma can distort the normal anatomy of the upper airway and make the intubation more complicated. For these patients, an anesthetic approach should be adopted. Atropine pre-medication should be administered to dry up secretions, and oxygen should be given. It is better to use ketamine for sedation for these patients. Muscle relaxants should be withheld until the airway is secured. Intubation should be performed under deep inhalational anaesthesia. Surgical airway should be performed rapidly if the above methods fail. complication of tracheotomy is 44%, with granuloma formation being the most common. 3 Table 2 shows the common complications associated with tracheostomy. In the same study, the overall mortality rate is 19% (Figure 3), with the vast majority of deaths are due to the child’s primary illness. Only 3.6% was known to be directly due to tracheotomy. Most of them have plugging of the tracheotomy tube with resultant respiratory arrests occurring between 0.3 and 30.8 months after the tracheotomy. Misplacement of the tube after operation has been reported. Tracheotomy Angioedema D u r i n g 1 9 7 0 s, i n fe c t i o n s u c h a s l a r y n g o tracheobronchitis and epiglottitis were the common causes for tracheotomy in children. With the popular use of endotracheal intubation, fewer tracheotomies and decannulations were performed. Figures 1 and 2 show the common indications for tracheotomy and the associated decannulation rate. According to Carron et al, the overall decannulation rate is 41%. The overall Angioedema is an anatomically limited non-pitting edema that may result in life-threatening airway obstruction.4 Facial swelling is present in 80% of cases. Other common symptoms include tenderness, dyspnea, dysphagia or hoarseness. Food allergy accounts for about 40% of the causes, and insect bites, infection and drugs are the other common causes. These patients seldom require PICU admission, as the symptoms of t h e s e p a t i e n t s u s u a l l y r e s o l ve s o o n a f t e r p h a r m a c o l o g i c a l t r e a t m e n t w i t h a d r e n a l i n e, antihistamine or steroid. Bacterial tracheitis Bacterial tracheitis is not a common disease but can be very serious. The clinical presentation is similar to that of severe viral croup, epiglottitis, or foreign-body aspiration. It can range from mild stridor to even Table 2. Complications of tracheotomy Primary indications for tracheotomy by grouping. PI=prolonged intubation; NI=neurologically impaired; T=trauma; VFP=vocal fold paralysis; UAO=upper airway obstruction; CF=craniofacial abnormality. Figure 1. Primary indications for tracheotomy (adapted from reference [3]). • Stomal granuloma 20% • Tracheo-cutaneous fistula 13% • Tracheal stenosis 2% • Tube plugging with respiratory arrest 2% • Accidental decannulation 1.5% • False passage creation 1% • Stomal keloid formation 1% Figure 2. Decannulations rates by group (adapted from reference [3]). Figure 3. Mortality rates by group (adapted from reference [3]). 6 Volume 1 No. 2, June 2005 cardio-respirator y arrest. The clinical course is generally less acute than that of epiglottitis and also with prodromal symptoms. Patients exhibit high fever, appear more ill, and are less responsive to nebulised epinephrine and other supportive measures than c h i l d r e n w i t h v i r a l c r o u p. D r o o l i n g a n d n e ck hyperextension are uncommon in bacterial tracheitis. Tracheal secretions are copious, thick, and tenacious which persist for 3 to 5 days and even up to 3 weeks. Once these patients are admitted to PICU, 57% of them will be intubated.5 Intubated patients are usually younger than the non-intubated patients. The most common pathogens in bacterial tracheitis are Staphylococcus aureus and Haemophilus influenzae. However, there are reports of bacterial tracheitis caused by Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus viridans, Pseudomonas aeruginosa, Escherichia coli, Moraxella catarrhalis, non-group A streptococci, and Neisseria spp. Patients may be extubated safely when their body temperature returns to normal, detection of air leaking around the nasotracheal tube, and when the amount of secretions markedly decreases. Acute epiglottitis Paediatric epiglottitis is a serious, potentially lifethreatening condition although it is extremely rare in Asia. After Haemophilis influenza (Hib) vaccination in Western countries, the annual incidence of children below 5 years of age decreases from 20.9 per 100,000 in 1987 to 0.9 per 100,000 in 1996.6 In adults a tendency toward a decrease in incidence is also evidence initially but then rises from a low in 1998 to reach pre-vaccine levels in 2003. 7 Immunisation programme in children may have unexpected effects on the epidemiology of disease. The presentations of the patients remained static but a decrease in Hib cases (especially the number of ampicillin-resistant organism) are seen. Affected children are, on average, much older after the implementation of universal vaccination programme. Vaccine failures still occur but are rare. Acute epiglottitis should still need to be considered when a child presents with severe upper airway obstruction even after Hib vaccination. laryngomalacia, coming from the Greek malakia with the meaning of morbid softening of part of an organ. Jackson clearly defined it as softness, flabbiness, or loss of consistency of the laryngeal tissues.10 In affected patients, inspiratory stridor is usually present since bir th. In some cases, stridor may become apparent few weeks or even months later. Stridor may be exacerbated in some cases by an upper respiratory infection. It is often intermittent and is aggravated when the child is active and crying. On the other hand, symptoms may also be precipitated by supination and head flexion and are relieved by pronation and head extension. For most of the cases, the symptoms will disappear with time. In 10% of cases, however, upper airway obstruction is so severe that patients develop apnoea or failure to thrive. 11 In these situations, surgery or tracheotomy may be needed. Croup Acute respiratory illness caused by inflammation and narrowing of the subglottic region of the larynx is defined as croup.12 Barking cough, hoarseness, stridor and respiratory distress are the usual presentations. Croup is usually self-limiting and symptoms usually last for 3-7 days. Yet, it still can cause severe upper airway obstructions that result in intubation or even mortality. For those patients with very severe croup, other causes of upper airway obstructions, especially epiglottitis, should be ruled out. If the diagnosis is not cer tain, patients must be treated empirically as epiglottitis, and intubation should be performed by experienced anaesthetists under deep inhalation induction. Surgical airway should be performed rapidly if the above methods fail. Neck radiograph is usually not necessary for the diagnosis but if taken, it would show the steeple sign (narrowing of the subglottic area) in patients with croup. The incidence of croup is 1.5-6 per 100 children per year. The admission rate for croup varies from 1.5% to 30%. This wide range of admission rate reflects different criteria for admission. In the United States, croup has been estimated to cause 41,000 hospitalisations annually.13 The intubation rate is about 0.5-1.5% for those patients admitted to hospital. The re-intubation rate is 5-16%. Laryngomalacia Congenital stridor was first reported in 1853 by two French physicians, Rilliet and Barthez. 8 Sutherland and Lack published the first review of this condition in 1 8 9 7 . 9 I n 1 9 4 2 , Ja ck s o n f i r s t u s e d t h e t e r m 7 Parainfluenza virus type 1 is the main virus causing croup. 14 The parainfluenza virus 1, 2 and 3 can be isolated in all age groups, and altogether account for about 2/3 of all cases. For patients younger than 5 years old, respiratory syncytial virus (RSV) tends to Review Ar ticle be isolated more commonly. On the other hand, influenza virus and Mycoplasma pneumoniae affect children older than 6 years of age. 15 Moreover, influenza virus tends to cause more serious illness as compared with parainfluenza virus.16 Mortality rate for croup is less than 0.5% in intubated patients. 17 According to Sacenkova et al, 92.5% of these cases die of severe pneumonia, 7.5% die of sepsis; 70% of them are 0-2 year old, 75% are boy and nearly all patients had aggravated pre-morbid background.18 In this study, virus and resistant strains of staphylococci and streptococci (penicillin, ampicillin and cefazoline) could be isolated in the sputum or organ tissues from most of the death cases. The authors concluded that children with croup died of severe pneumonia complications with a low systemic reactivity and high antibacterial resistance. Tr e a t m e n t s o f c r o u p i n c l u d e g l u c o c o r t i c o i d s , nebulised epinephrine, humidification and heliox. S i n c e l a t e 1 9 8 0 s, g l u c o c o r t i c o i d s h ave b e e n recognised to provide some clinical benefit for children with croup. Kairys et al published a metaanalysis of clinical trials examining the benefit of glucocorticoids in 1989. 19 The Cochrane Database o f S y s t e m i c R ev i ew s i n 2 0 0 4 s h owe d t h a t glucocor ticoid treatment is effective in improving symptoms of croup in children as early as six hours and for up to at least 12 hours after treatment, and the efficacy was suppor ted by improvement in croup score, decrease in return visit or admission, reduction in length of stay and epinephrine use as an additional intervention. 20 With the introduction of steroid, less croup patients need intubation and intensive care, 21 and the duration of intubation and need for re-intubation also decreased. 22 Regarding the administration for glucocorticoid, oral route is preferred as this is easily given and the efficacy for oral route is the same as with intramuscular injection. Some children find nebulised therapy distressing. The standard dose for glucocorticoid is dexamethasone at 0.6 mg per kilogram body weight per dose, with a maximum of 10 mg although some authors suggest that lower dose is also effective. Epinephrine (adrenaline) is a potent agonist of alphaand beta-adrenergic receptors. Since early 1970s, epinephrine has been used to treat croup. It helps to reduce bronchial and tracheal secretions and oedema. Following nebulised therapy, these effects are noted within 10-30 min and last for about one hour. However, 35% of patients who received epinephrine had a relapse of their symptoms within 2 hours of treatment.23 Racemic epinephrine, a mixture of equal amounts of Journal of Paediatric Respirology and Critical Care dextro(d) and levo(l)-isomer, was traditionally used because this was believed to have fewer side effects and better effectiveness. However, with more published data, racemic epinephr ine and levoepinephrine were found to be the same for their effectiveness and side effect profile. 24 In fact, levoepinephrine is cheaper and more easily available. Therefore, levo-epinephrine is recommended for treatment of croup instead of racemic epinephrine. Humidification was a routine therapy in early 1990s. It was believed that this therapy relieved discomfort and prevented the dr ying of inflamed lar yngeal mucosa. However, there is no evidence for these effects. During the therapy, children need to stay inside mist tents. They can become wet and cold. These patients may be quite irritated during isolation. It was also difficult to observe the general conditions of these children in mist tents. With the introduction of steroid therapy, humidification therapy is no longer use as a standard therapy for croup. Heliox is an experimental treatment. It is a metabolically inert, non-toxic gas that combines helium with oxygen. It has low viscosity and low specific gravity, and these properties allow for greater laminar airflow through the respiratory tract. Heliox is well tolerated, and some studies suggested that it decreased the croup score. In summary, glucocorticoid reduces croup score, rate and duration of intubation. However, there is no conclusion on the best route and dosage of its administration. Nebulised epinephrine can relieve the symptoms of croup transiently but symptoms will recur following transient improvement. Humidification is no longer a routine treatment for croup. Heliox is still an experimental treatment, and more evidence is needed to support its routine clinical use. Summary Severe upper airway obstruction in children requires urgent management. Rapid and effective management can prevent severe complications and even fatality. Tracheotomy is rarely needed. Infections such as croup remain the most common cause of severe upper airway obstr uction that requires intensive care management. Acute epiglottitis and bacterial tracheitis are rare, but should be the differential diagnoses in critically ill patients. Patients with angioedema are rarely admitted to PICU, and most of them resolve soon after medical treatment. Laryngomalacia is common but most of them will be resolved without treatment. Steroid is very effective for croup, and much less patients with croup require intubation following the use of steroid treatment. 8 Volume 1 No. 2, June 2005 References 1. Chan PWK, Goh AYT, Lum LCS. Severe upper airway obstruction in the tropics requiring intensive care. Pediatr Int 2001;43:53-7. 2. Durward AD, Nicoll SJB, Oliver J, Tibby SM, Murdoch IA. The outcome of patients with upper airway obstruction transported to a regional paediatric intensive care unit. Eur J Pediatr 1998;157:907-11. 3. Carron JD, Derkay CS, Strope GL, Nosonchuk JE, Darrow DH. Pediatric tracheotomies: changing indications and outcomes. Laryngoscope 2000;110:1099-104. 4. Shah UK, Jacobs IN. Pediatric angioedema: ten years’ experience. Arch Otolaryngol Head Neck Surg 1999;125:791-5. 5. Bernstein T, Brilli R, Jacobs B. Is bacterial tracheitis changing? A 14-month experience in a pediatric intensive care unit. Clin Infect Dis 1998;27:458-62. 6. Garpenholt O, Hugosson S, Fredlund H, Bodin L, Olcen P. Epiglottitis in Sweden before and after introduction of vaccination against Haemophilus influenzae type b. Pediatr Infect Dis J 1999;18:490-3. 7. McVernon J, Trotter CL, Slack MP, Ramsay ME. Trends in Haemophilus influenzae type b infections in adults in England and Wales: surveillance study. Br Med J 2004;329:655-8. 8. Rilliet F, Barthez E. Traite Clinique et Pratique des Maladies des Enfants. Vol. 1. Paris: Germer Bailliere, 1853:484-8. 9. Sutherland GA, Lack HL. Congenital laryngeal obstruction. Lancet 1897;2:653-5. 10. Jackson C. Diseases and Injuries of the Larynx. New York: MacMillan, 1942:63-8. 11. Kavanagh KT, Babin RW. Endoscopic surgical management for laryngomalacia. Case report and review of the literature. Ann Otol Rhinol Laryngol 1987;96:650-3. 12. Brown JC. The management of croup. Br Med Bull 2002;61: 189-202. 13. Marz A, Torok TJ, Holman RC, Clarke MJ, Anderson LJ. Pediatric hospitalizations for croup (laryngotracheobronchitis): 9 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. biennial increases associated with human parainfleunza virus 1 epidemics. J Infect Dis 1997;176:1423-7. Henrickson KJ, Kuhn SM, Savatski LL. Epidemiology and cost of infection with human parainfluenza virus type 1 and 2 in young children. Clin Infect Dis 1994; 18:770-9. Denny FW, Murphy TF, Clyde WA Jr, Collier AM, Henderson FW. Croup: an 11-year study in a pediatric practice. Pediatrics 1983;71:871-6. Peltola V, Heikkinen T, Ruuskanen O. Clinical courses of croup caused by influenza and parainfluenza viruses. Pediatr Infect Dis J 2002;21:76-8. McEniery J, Gillis J, Kilham H, Benjamin B. Review of intubation in severe laryngotracheobronchitis. Pediatrics 1991; 87:847-53. Savenkova MS, Korobko LM, Kotsyganova GG, Legkova TP, Afanas’eva AA, Golubtova EE. Causes of lethal outcomes in croup syndrome in children. Vestn Otorinolaringol 2002;3:50-1. Kairys SW, Olmstead EM, O’Connor GT. Steroid treatment of laryngotracheitis: a meta-analysis of the evidence from randomised trials. Pediatrics 1989;83:683-93. Russell K, Wiebe N, Saenz A, Ausejo SM, Johnson D, Hartling L, et al. Glucocor ticoids for croup (Cochrane Review). Cochrane Database Syst Rev 2004(1):CD001955. Geelhoed GC. Sixteen years of croup in a western Australian teaching hospital: effects of routine steroid treatment. Ann Emerg Med 1996;28:621-6. Tibballs J, Shann FA, Landau LI. Placebo-controlled trial of prednisolone in children intubated for croup. Lancet 1992; 340:745-48. Fogel JM, Berg IJ, Gerber MA, Sherter CB. Racemic epinephrine in the treatment of croup: nebulization alone versus nebilization with intermittent positive pressure breathing. J Pediatr 1982;101:1028-31. Waisman Y, Klein B, Boenning D et al. Prospective randomised double-blinded study comparing L-epinephrine aerosols in the treatment of lar yngotracheitis (croup). Pediatrics 1992;89:302-6. Revie w Ar ticle Journal of Paediatric Respirology and Critical Care Exercise therapy in the correction of pectus excavatum Steward Ying-Kit CHEUNG Senior Physiotherapist, Physiotherapy Department, Kwong Wah Hospital, Hong Kong Introduction Pectus deformities are common abnormalities of the thorax and affect an estimate of 6 to 8 per 1000 children.1 The cause of pectus deformities is accepted to be an abnormal overgrowth of cartilage between the ribs and sternum that pushes the sternum inward (pectus excavatum) or outward (pectus carinatum) causing a funnel-chest or pigeon-chest respectively. Pectus excavatum is more commonly encountered and it may impact on the pulmonary and cardiac functions in severe cases. Surgical intervention is an accepted practice of intervention for severe pectus excavatum.2, 3 Other than surgical intervention, exercise is another treatment alternative. 4 Clinically, a number of patients were observed to benefit from exercise training although the long term effect and its physiological benefits are still unknown. Therapeutic exercises to improve pectus excavatum deformity In theory, the main question in managing pectus excavatum is how to pull the sunken anterior chest wall outward and forward. The inspiratory muscles that help in pulling up the chest wall should be considered. This includes the scalenus anterior and medius, and the sternocleidomastoid. The serratus anterior and pectoralis minor also par ticipate during forced inspiration. Intercostal muscles help the elevation of the chest wall only when the first ribs fixed and elevated. All these mentioned muscles, however, cannot directly add their pull of force on the lower sternum and sunken ribs, which are commonly encountered in pectus excavatum. Their effect of pull seems limited and mainly affects the upper chest wall. However, if the upper limbs can be supported by grasping a chair back or table, the sternal origin of the pectoralis major muscles can also assist the elevation process of the chest wall. Pectoralis major is a thick and powerful triangular muscle. Its fibers are inserted by a bilaminar tendon into the lateral lip of the bicipital groove of the humerus. It originates from the sternal half of the clavicle, the anterior sternal surface to the level of the sixth or seventh costal cartilage, the first to seventh costal cartilages, the sternal end of the sixth rib and the aponeurosis of obliquus extenus abdominus. If the insertion of the arm can be put and fixed in an upward Email: cheungyk1@ha.org.hk stretched position, all these origins especially the latter four can directly and forcibly pull the sunken sternum and infolding ribs up during the muscle contraction. The concept of “reverse origin and insertion” of this muscle action is applied. The direction of pull from the stretched arm position along the sternocostal fibers of the pectoralis major acts effectively on the depressed chest wall. Pectoralis major situated in its mid range of length enables it to recruit the greatest amount of muscle fibers to exert powerful pulling force. With these in mind, it provides the direction for the design of the following suggested exercise program. With an increase in strength and muscle tone by training, the chest wall deformity may be diminished or at least maintained. In addition, the increase in intensity of training, especially to the anterior chest wall may help to build up larger muscle bulk and a better cosmetic outlook. Steps to improve the chest wall appearance In order to improve the chest wall appearance, the patient need to follow the following steps in sequence in their daily exercise program. They are: 1. To increase the mobility and flexibility of the spine and chest wall. 2. To lengthen any tightened and shortened structures. 3. To strengthen muscles in elevating and expanding the depressed chest wall. 4. To restore normal posture. The first two steps are to mobilize the articulating joints and to lengthen any tight soft tissue around the chest wall so that less impedance will be encountered during the elevation of depressed chest. Exercises of these two steps can, at the same time, serve as a warm-up. They condition the musculo-skeletal in preparing for the following vigorous exercises. These exercises will be done with intensive training to strengthen inspiratory muscles, which are essential in elevating the depressed chest wall. Training of pectoralis major, especially the sternocostal fibres, will be of utmost importance. With better chest wall mobility and muscle tone after these preparatory steps, the patient will be conditioned to learn the postural correction exercises. It is important that the patient must persist in performing these exercises. Suggested exercise program Mobilizing and stretching exercise 1. Forward arm stretching in pone kneeling The patient is positioned in an inclined prone kneeling position with hands stretching forward and 10 Volume 1 No. 2, June 2005 supported by wall bar (about 2 to 3 feet high from ground) (Figure 1). Slowly lower his upper body and press his scapula towards the floor. Experience the stretch feeling at the front axilla and shoulder. Hold 8 seconds (may get a deep breathe and hold to increasingly stretch the chest wall) and release. Repeat for 20 times and 4 sessions per day. Purpose: Stretch all anterior chest wall muscles especially pectoralis major and extend the upper back. chest wall) and then return to the original position. Take a rest and repeat on the other side. Repeat for 20 times and 4 sessions per day. Purpose: Similar to the 2nd exercise. Figure 3. Upper trunk side flexion in sitting. Figure 1. Forward arm stretching in pone kneeling. 2. Upper trunk rotation in standing The patient is to stand obliquely to a wall. The near hand is put on the wall a bit higher than the shoulder level. The patient’s pelvis turns to the opposite side while still leaving the hand fixed on the wall (Figure 2). A stretch is felt at the anterior shoulder and upper chest wall. Hold 8 second, then release and return to the original position. Take a rest and repeat on the other side. Repeat for 20 cycles and 4 sessions per day. Purpose: Rotation gives the greatest range of movement for thoracic vertebrae allowing stretch to ligaments, muscles and joints Figure 2. Upper trunk rotation in around the chest standing. wall in a different direction. 3. Upper trunk side flexion in sitting The patient is seated on a chair. Side bend to one side with the opposite hand crossing over the head to another side (Figure 3). A stretching feeling is felt on the other side of trunk. Hold 8 seconds (may get a deep breathe and hold to increasingly stretch the 11 Strengthening exercise 1. Weight lifting in stretch supine lying The patient is positioned in supine with the upper trunk on a small foam roll around 2 to 3 inches in diameter (if patient can’t tolerate, just lie flat). The arms are put in an upward stretched position. The hands should hold on a fixed wall bar (Figure 4) or hardly movable weight about 10 inches from the surface of the bed (pillows may be used to support the weight) (Figure 5). Deeply inspire and exert maximal force in lifting the wall bar or weight. Hold Figure 4. Lifting wall bar in stretch supine lying (with foam roll). Figure 5. Weight lifting in stretch supine lying (pillow support the weight). Review Ar ticle 8 seconds and relax. Repeat 10 times as 1 lot. Take rest then and repeat another 2 lots performing a total of 30 repetitions and 4 sessions per day. Purpose: By the technique of “reverse origin and insertion”, the arms are being fixed and the anterior chest wall is lifted up mainly by the pectoralis major and minor. Maximal force exertion allows recruitment of surrounding respiratory muscles for training. The foam roll under the upper to middle part of the trunk exerts postero-anterior force to the thoracic spine helping in extension, which mobilizes and corrects any thoracic kyphosis . The depressed chest will also be “opened” up facilitating the elevation of the chest wall. Arms, being in a mid-length muscle range, are capable to exert the greatest force to elevate the depressed chest. Tone of pectorlis major is built up for better posture and outlook. 2. Upper trunk extension in prone lying The patient is positioned in prone lying with one or two pillows under the tummy (avoiding the lower anterior chest pressing on the pillow) (Figure 6). The hands are placed behind the head. The feet may be fixed on wall bar. Deeply inspire and extend the upper trunk with arms arching back. Stay and hold 8 seconds and then relax. Repeat 10 times as 1 lot. Take rest then and repeat another 2 lots. Perform a total of 30 repetitions and 4 sessions per day. Purpose: The strengthened upper back muscles help to balance the improved muscle force of the anterior chest wall muscle. This prevents the development of thoracic kyphosis due to strong anterior muscle pull and keeps a good posture. Journal of Paediatric Respirology and Critical Care Purpose: The exercise aims at general strengthening of the chest wall. Moreover, the high intensity but low frequency impacting force may be advantageous to stimulate remodeling and shaping of the chest wall deformity. Bone mineralization may also be enhanced. Figure 7. Push up. 4. Hands up and down movement behind and by the sides of body (with theraband) The patient is positioned in sitting or standing with both arms in a stretched position. Each hand holds one end of a theraband or a spring (resistance should be set at 10 repetitive maximum, RM, i.e. the resistance that one can perform 10 repetitions but no more). Then stretch the theraband and maintain the elbows straight (Figure 8). Slowly put the hands behind and pass by the sides of body and then down below buttock. After 3 seconds rest, the hands slowly go up and along the same track to the starting position. Repeat 10 times as 1 lot. Take rest and then repeat another 2 lots performing a total 30 repetitions and 4 sessions per day. Figure 6. Upper trunk extension in prone lying. 3. Push up The patient is positioned in prone lying and both hands are used to push up his body (Figure 7). The level of difficulty depends on the actual ability of the patients (1st level – upper trunk pushed up, 2nd level – whole body pushed up in one piece, 3rd level – push and clap both hands in mid air). Start with the 1st level and when the patient is able to finish the level easily, he may proceed to next level). Repeat 10 times as 1 lot. Take rest and then repeat another 2 lots performing a total of 30 repetitions and 4 sessions per day. Figure 8. Hands up and down behind and by the sides of body (with theraband). 12 Volume 1 No. 2, June 2005 Purpose: The exercise is used to strengthen the neck, shoulder, upper back and anterior upper chest muscles. It can be treated as a kind of stabilization exercise to the upper thorax. Postural correction The above exercises help correct the depressed chest wall deformity and also the thoracic kyphosis. However, as the postural problems of individual patients may have different clinical presentations and causes. It is impossible to have one exercise program to suit all patients for postural correction. It would be best to consult doctors or physiotherapists in postural exercises. On the whole, the exercises should mainly concentrate on realignment of good posture, both static and dynamic. To maintain a sense of good posture in both static and dynamic work is another area to be tackled. Proprioceptive exercise training should also be introduced. In addition, the final postural exercises can act as some cool down activities. Although some exercises have been suggested, they should preferably be done within the patient’s tolerance. The suggested intensity and frequency of treatment should act as a beginning reference. The parameters should be modified whenever the conditions seem necessary. With improvement in exercise performance and effect, patients may increase their treatment frequency and intensity, under the advice from a doctor or a physiotherapist. For young patients, who can’t perform these exercises, their parents may help passively to stretch their limbs similar to the described moblising and stretching exercises. For the strengthening exercises, they can try swimming in free-style. The alternate climbing action of both hands is good training for pectoralis major. Discussion Perfor mance of the above exercises will see immediate elevation of chest wall. The long term effect of the exercises is unknown. However, some reviews throw light of hope that throughout life, the skeleton is continuously changing to adapt its form and structure to suit their functional needs.5 Bone growth and maintenance is always a process between osteoblastic and osteoclastic activities. If the former activity is greater than the latter, bone grows. Otherwise bone will be resorbed and the mineral will be redistributed to build up bone against load stress in other areas. 6 This is reflected by the Wolff’s law, a principle assuming that mechanical stresses influence the remodeling process of bone and subsequently the structure and strength of bone.7 All cells participating in the remodeling process have been termed the bone multicellular unit and are thought to proceed through activation, resorption, and formation, during which a quantum of bone is exchanged. The alteration in bone shape was evidenced in a study using immature Holstein bull calves as a model, short-duration but 13 high-intensity exercise to stimulate bone formation and altering bone shape was observed in comparison with the stalled and group-housed calves. 8 Dynamic loads trigger the adaptive response in bone.9 Whether the shape and deformity of pectus excavatum be improved with the above exercises require further study. Most studies show that mineralisation of bone can be developed through impacting exercises 10 to increase the bone mass density of the weight bearing bone. There is also evidence that bone developmental changes in bone strength might also be secondary to the increasing loads imposed by larger muscle forces. The results of this study are compatible with the view that bone development might be driven by muscle development. 11 This gives an implication that high intensity loading during exercise design may help to increase mineralization of the bone to maintain a reformed shape. From the skeletal point of view, bone shaping should be done early before it is mature. Since the ossification of the chest wall begins in utero and continues to approximately the 25th year, and even earlier for the rib as ossification is completed by age 20.12 Therefore the best training period should be started earlier than this age and childhood is probably the ideal period. References 1. Clark JB, Grenville-Mathers R. Pectus excavatum. Br J Dis Chest 1962; 56:202-5. 2. Williams AM, Crabbe DC. Pectus deformities of the anterior chest wall. Paediatr Respir Rev 2003; 4(3):237-42. 3. Edwards CRW, Bouchier IAD, Haslett C, Chilvers ER. (ed.) Davidiom’s Priniciples and Practice of Medicine (7th Ed.) Churchill Livingstone, New York 1995; 404. 4. http://www.users.bigpond.com/conover/PE/exercise.htm 5. Mow Van C, Ratcliffe A, Woo Savio L-Y (ed.). Biomechanics of diathrodial joints (Vol II). New York: Springer-Verlag, 1990; 119. 6. Rauch F, Schoenau E. The developing bone: slave or master of its cells and molecules? Pediatr Res 2001; 50(3):309-14 7. Mow Van C, Ratcliffe A, Woo, Savio L-Y (ed.). Biomechanics of diathrodial joints (Vol II). New York: Springer-Verlag, 1990; 61. 8. Hiney KM, Nielsen BD, Rosenstein D, Orth MW, Marks BP. High-intensity exercise of short duration alters bovine bone density and shape. J Anim Sci 2004; 82:1612-20. 9. Robling AG, Duijvelaar KM, Geevers JV, Ohashi N, Turner CH. Modulation of appositional and longitudinal bone growth in the rat ulna by applied static and dynamic force. Bone 2001; 29(2):105-13. 10. Kotha SP, Hsieh YF, Strigel RM, Muller R, Silva MJ. Experimental and finite element analysis of the rat ulnar loading model-correlations between strain and bone formation following fatigue loading. J Biomech 2004; 37:541-8. 11. Rauch F, Bailey DA, Baxter-Jones A, Mirwald R, Faulkner R. The ‘muscle-bone unit’ during the pubertal growth spurt. Bone 2004; 34:771-5. 12. Taussig LM, Landau LI (ed.). Paediatric respiratory medicine St. Louis: Mosby, 1999; 1154. Society Guideline Journal of Paediatric Respirology and Critical Care Childhood asthma treatment guildeline 2005 Hong Kong Society of Paediatric Respirology Childhood asthma: diagnosis Asthma is usually diagnosed on the basis of the history of symptoms along with physical examination. In selected cases, measurement of lung function, reversibility of airway obstruction may enhance diagnostic accuracy. The following are important diagnostic hints of asthma: History 1. 2. 3. 4. Coughing is the commonest symptom of asthma especially in young children. Wheezing: a common symptom of asthma but the absence of wheezing attacks does not exclude the diagnosis. Breathing difficulty. The chance of asthma increases if the above symptoms occur: - recurrently or persistently - interrupting sleep at night - during or after a cold - when the weather changes - on exercise - when in contact with some known allergens - when in contact with animals - when in contact with smoke or other irritants - when in contact with pollen or some plants 5. A family history of atopy and allergic diseases. 6. Past history of atopic diseases. Physical examination 1. Signs of airway obstruction: - chest hyperinflation - obstructed expiration: spontaneous wheeze or forced expiratory wheeze - diminished air movement in the chest - physical examination may be normal in children with mild asthma 2. Signs of other allergies or complication: - eczema, allergic rhinitis, growth failure, sinusitis, chest deformity Investigations 1. In older children (6 or above) who are able to perform simple lung function testing (peak flow rate or spirometry), demonstrate variable airflow obstruction with diary cards and peak flow monitoring, or use bronchodilator inhalation to demonstrate improvement in spirometry. 2. In younger children, demonstrate immediate improvement of signs with bronchodilator inhalation, or a therapeutic trial of asthma medications to look for improvement over time. 3. Other supportive diagnostic modalities: Exhaled Nitric oxide measurement, skin-prick test, infant lung function measurement if available. Special note 1. Often a period of observation is required to ascertain the diagnosis. 2. Asthma is a chronic disease and patients have to be reassessed on a regular basis to adjust the prescribed treatment. Correspondence to Prof. Gary Wing-Kin Wong Email: wingkinwong@cuhk.edu.hk 14 Volume 1 No. 2, June 2005 Treatment Guideline for Managing Asthma in Children Older Than 5 years of Age: Treatment Classify Severity: Clinical Features Before Treatment or Adequate Control Recommended Medications Required To Maintain Long-Term Asthma Control Symptoms/Day Symptoms/Nights PEF or FEV1 Daily Medications PEF Variability Continual Frequent ≤60% >30% • Preferred treatment: - High-dose inhaled corticosteroids (>800 mcg of budesonide or equivalent) AND - Long-acting inhaled beta2-agonists AND if needed, - Corticosteroid tablets: a short course of steroid may be needed to suppress airway inflammation • Alternative treatment: - High dose inhaled corticosteroids AND either leukotriene modifier or theophylline Step 3 Daily Moderate Persistent >1 night/week >60% - <80% >30% • Preferred treatment: - Low to medium dose inhaled corticosteroids (200-800 mcg of budesonide or equivalent) and long- acting inhaled beta2agnoists. • Alternative treatment: - Increase inhaled corticosteroids within medium-dose range OR - Low-to-medium dose inhaled corticosteroids and either leukotriene modifier or theophylline Step 2 Mild Persistent >2/week but <1x/day > 2 nights/month ≥80% 20-30% • Preferred treatment: - Low-dose inhaled corticosteroids (<400 mcg of budesonide or equivalent). • Alternative treatment options: cromolyn, leukotriene modifier, nedocromil, OR sustained-release theophylline to keep serum concentration of 5-15 mcg/mL. Step 1 Mild Intermittent ≤2 days/week ≤2 nights/month ≥80% <20% • No daily medication needed. • Inhaled (preferred) or oral bronchodilators may be prescribed and use as needed Step 4 Severe Persistent Quick Relief • Short-acting bronchodilator: 2-4 puffs short-acting inhaled beta2-agonists as needed for symptoms. All Patients • Intensity of treatment will depend on severity of exacerbation; up to 3 treatments at 20-minute intervals treatment as needed. Course of systemic corticosteroids may be needed. MDI with spacer is just as effective as the nebulizer in most situations of mild to moderate attacks. • Use of short-acting beta2-agonists >2 times a week in intermittent asthma (daily, or increasing use in persistent asthma) may indicate the need to start long-term-control therapy. ↓ Step down Review treatment every 1 to 6 months; a gradual stepwise reduction in treatment may be possible. ↑ Step up If control is not maintained, consider step up. First, review patient medication technique, adherence, and environmental control. Goals of Therapy: Optimal Asthma Control • Minimal or no chronic symptoms day or night • Maintain (near) normal pulmonary function • Minimal or no exacerbations • Minimal use of short-acting inhaled beta2-agonist • No limitations on activities; no school/work missed • Minimal or no adverse effects from medications 15 Society Guideline Journal of Paediatric Respirology and Critical Care Treatment Guideline for Managing Infants and Young Children (5 years of Age and Younger) with Asthma Classify Severity: Clinical Features Before Treatment or Adequate Control Medications Required To Maintain Long-Term Control Symptoms/Day Symptoms/Nights Daily Medications Step 4 Severe Persistent Continual Frequent • Preferred treatment: - High-dose inhaled corticosteroids (>800 mcg of budesonide or equivalent) AND - Long-acting inhaled beta2-agonists AND if needed, - Corticosteroid tablets: a short course of steroid may be needed to suppress airway inflammation (2 mg/kg/day) Step 3 Moderate Persistent Daily >1 night/week • Preferred treatment: - Low-dose inhaled corticosteroids (<400 mcg of budesonide or equivalent) and long-acting inhaled beta2-agnoists OR - Medium-dose inhaled (400-800 mcg of budesonide or equivalent) corticosteroids. • Alternative treatment: - Low-dose inhaled corticosteroids and either leukotriene receptor antagonist or theophylline. Step 2 Mild Persistent >2/week but <1x/day >2 nights/month • Preferred treatment: - Low-dose inhaled corticosteroids (with MDI with holding chamber with or without face mask or nebulizer). • Alternative treatment (listed alphabetically): - Cromolyn (MDI with holding chamber or nebulizer) OR oral leukotriene receptor antagonist. Step 1 Mild Intermittent ≤2 days/week ≤2 nights/month • No daily medication needed. • Inhaled (preferred) or oral bronchodilators may be prescribed and use as needed. Quick Relief All Patients ↓ • Bronchodilator as needed for symptoms. Intensity of treatment will depend upon severity of exacerbation. - Preferred treatment: Short-acting inhaled beta2-agonists by face mask and space/holding chamber or nebulizer - Alternative treatment: Oral beta2-agonist • With viral respiratory infection - Bronchodilator q 4-6 hours up to 24 hours - Consider systemic corticosteroid if exacerbation is severe or patient has history of previous severe exacerbations • Use of short-acting beta2-agonists >2 times a week in intermittent asthma (daily, or increasing use inpersistent asthma) may indicate the need to start long-term-control therapy. Step down Review treatment every 1 to 6 months; a gradual stepwise reduction in treatment may be possible ↑ Step up If control is not maintained, consider step up. First, review patient medication technique, adherence, and environmental control. Goals of Therapy: Optimal Asthma Control • Minimal or no chronic symptoms day or night • Minimal use of short-acting inhaled beta2-agonist • Minimal or no exacerbations • Minimal or no adverse effects from medications • No limitations on activities; no school/parent's work missed 16 Society Volume 1 No. 2, June 2005 Guideline Steroid equivalent table: Estimated Comparative Daily Dosages for Inhaled Glucocorticosteroids µg) Low Daily Dose (µ µg) Medium Daily Dose (µ µg) High Daily Dose (µ Adult Child Adult Child Adult Child Beclomethasone 200-500 100-250 500-1000 250-500 >1000 >500 Budesonide-DPI 200-600 100-200 600-1000 200-600 >1000 >600 Drug Budesonide-Neb 250-500 500-1000 >1000 Inhalation suspension Fluticasone 100-250 Mometasone furoate 200-400 100-200 250-500 400-800 200-400 >500 >400 >800 Notes: The most important determinant of appropriate dosing is the clinician’s judgment of the patient’s response to therapy. The clinician must monitor the patient’s response in terms of a combination of clinical parameters and adjust the dose accordingly. The stepwise approach to therapy emphasizes that once control of asthma is achieved, the dose of medication should be carefully titrated to the minimum dose required to maintain control, thus reducing the potential for adverse effects. Actual delivered dose may vary according to the device used for delivery of inhaled steroids. 17 Jour nal Watch/ Coming Activities Journal of Paediatric Respirology and Critical Care Reliability of scoring arousals in normal children and children with obstructive sleep apnea syndrome The six-minute walk test in healthy children: reliability and validity Wong TK, Galster P, Lau TS, Lutz JM, Marcus CL Sleep 2004;27:1139-45 Li AM, Yin J, Yu CCW, Tsang T, So HK, Wong E, Chan D, Hon EKL, Sung R. Eur Respir J 2005; 25:1057-60 Assessment of the Pediatric Index of Mortality (PIM) and the Pediatric Risk of Mortality (PRISM) III score for prediction of mortality in a paediatric intensive care unit in Hong Kong Choi KMS, Ng DKK, Wong SF, Kwok KL, Chow PY, Chan CH, Ho JCS HKMJ 2005;11:97-103 The official website of Hong Kong Society of Paediatric Respirology is now online. Welcome to our website: http://www.hkspr.org. Time-table for HKSPR Clinical Meetings 2005-6 (Revised as of June 2005) Date 29 Jun 2005 Hospital(s) / Organization(s) TMH Title(s) of Presentation A New Treatment for a Newborn with Speaker(s) Dr. Siu Luen Yee Chairperson Dr. TY Miu Respiratory Distress 27 Jul 2005 AHNH + NDH 31 Aug 2005 CMC + OLMH Cases presentation in Asthma Dr Chow Siu Ngai Dr. Grace Chan A child with tracheal stenosis presented as Dr Lam Ping Dr. WK Chiu Dr. Eric Chan Dr. SY Lam recurrent wheezing 28 Sep 2005 KWH Chronic Cough in Children Dr. PY Chow ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ World Asthma Day, 3 May 2005 World Asthma Day (WAD) is a yearly event initiated by Global Initiative for Asthma (GINA) to arouse asthma awareness and care throughout the world. In the years before, WAD activities in Hong Kong was mainly hosted by the Hong Kong Asthma Society (HKAS). This year, your Society has joined hands with Hong Kong Medical Association (HKMA) and HKAS to host a press conference, announcing some joint activities against asthma. The Childhood Asthma Guideline for Hong Kong, produced by HKSPR, will be the theme of a series of lecture to front line doctors in various districts in Hong Kong in the coming year. While HKMA will organize the luncheon lectures, HKSPR will provide the speakers and contents. The Guideline will therefore have a chance to reach doctors working in the frontline, hopefully helping them to deal with childhood wheezing and asthma effectively. Such lectures will also provide a chance for feedback from the doctors so that the Guideline can be made more useful and appropriate for Hong Kong in the future. The first of these lectures were given on WAD to over 250 front line doctors by Dr. Alfred Tam and Prof. Gary Wong at Langham Hotel. Hong Kong Asthma Society will be hosting a series of lectures, and training workshops for parents and teachers this year, focused on asthma and allergies. These will be very good training for the lay public. HKSPR Medical Advisors will be invited to be speakers of these events. 18