Search PubMed⌕ Search

Biomedical subjects

A B Chang

Publications and source records attributed to A B Chang.

At least 55 records · Page 3Linked to original sources
PubMed2000

A modified nasopharyngeal tube to relieve high upper airway obstruction.

Infants with high upper airway obstruction (UAO) are managed with a variety of techniques to relieve their UAO. Among these techniques, the least invasive and safest is the nasopharyngeal tube (NPT). However, the traditional NPT is not always satisfactory, and tracheostomies need to be done. We recently described a modified NPT technique that, in contrast to the traditional tube, does not add airway dead space and resistance, is easy to use, is well-tolerated, has proven highly successful, and allows the simultaneous use of oxygen nasal prongs. This modified NPT has many advantages over the traditional NPT as a temporary management of high UAO that resolves with growth of the infant. This report highlights the respiratory care of 10 infants with high UAO (Pierre Robin syndrome, Down syndrome, Goldenhar syndrome, isolated microngathia, and idiopathic hypotonia) who were managed with a modified NPT. The modified NPT described potentially reduces the need for surgical intervention to relieve high UAO in infants.

Airway Obstruction↗
PubMed2000

Severe obstructive sleep apnoea secondary to pressure garments used in the treatment of hypertrophic burn scars.

Obstructive sleep apnoea (OSA) secondary to pressure garments used to treat hypertrophic scarring of burns has never been reported. The present study describes two children who presented with OSA following introduction of such garments for management of hypertrophic scars following severe facial and upper body burns. Complex sleep polysomnography confirmed severe OSA with desaturations sufficient to result in physiological dysfunction that significantly improved on removal of the garments. As there is little evidence to suggest that the use of such garments alters the end result, the potentially serious side effect of obstructive sleep apnoea should be considered before their use is advised.

Adolescent↗
PubMed2000

Asthma management in indigenous children of a remote community using an indigenous health model.

OBJECTIVE: To describe the management of asthma in children in a remote indigenous community and the delivery of subspecialist service through the indigenous health-care model. METHODOLOGY: Children referred by indigenous health-care workers were evaluated prospectively by paediatric respiratory physicians, based on a standardized protocol, at a primary health care setting at Thursday Island, Queensland. RESULTS: Forty of the 54 children referred with a provisional diagnosis of asthma did have asthma, with 30% having persistent asthma. Only 59% of parents knew the dose of the medication prescribed and 80% had minimal knowledge of the medications. In 88% of children, the management of asthma was improved by introduction of an appropriate spacer device and changing the dose and type of medications. CONCLUSIONS: The management of children with asthma in the Torres region can be improved substantially by the use of age appropriate delivery devices and medications, and improving knowledge of asthma. Specialist delivery service to remote indigenous communities can be effectively delivered in partnership with the indigenous health service. The high proportion of persistent asthma in the Torres Straits community in comparison to urbanised Australia raises issues of inequity of appropriate medical service delivery to remote indigenous communities.

Adolescent↗
PubMed1999

Cough, cough receptors, and asthma in children.

This review discusses current general concepts on cough and the relationship between cough, cough receptor sensitivity, and asthma in children. It presents models of the relationship between cough and bronchoconstriction, and proposes a new model outlining the relationship between cough receptor sensitivity, airway hyperresponsiveness, and the clinical issues of cough, wheeze, and dyspnea in children with and without asthma. Cough is very common in children, with a prevalence of 15-20%. Those with non-specific cough (dry cough in the absence of identifiable respiratory illness) are often treated with a variety of drugs, in particular, medications for asthma and gastroesophageal reflux. However, there is little evidence to use these medications for the sole symptom of cough in children. Clinical studies on cough need to be interpreted in light of inherent methodological problems in studying cough. These methodological problems include the nonrepeatable nature of questions on cough, the unreliability of subjective measurements of cough, the lack of objective measurements to quantify cough severity, and the period effect (spontaneous resolution of cough). Although cough can be troublesome, cough serves as an important function for maintaining normal health of the respiratory system. The importance of cough in maintaining respiratory health is reflected in the development of lung atelactasis/collapse from retained secretions and recurrent pneumonia in clinical situations where the cough reflex is ineffective. The cough reflex is complex and still poorly understood. In this article the simplified cough pathway is presented and involves cough receptors, mediators of sensory nerves and the afferent pathway, the vagus nerve, the cough centre, efferent pathway, and cough effectors.

Adolescent↗
PubMed1999

Modified nasopharyngeal tube for upper airway obstruction.

A modified nasopharyngeal tube is described that does not add airway dead space and resistance, is well tolerated, highly successful, and allows simultaneous use of oxygen prongs. This potentially reduces the need for surgical intervention to relieve high upper airway obstruction from Pierre-Robin syndrome and other causes.

Airway Obstruction↗
PubMed1998

Post-infectious bronchiolitis obliterans: clinical, radiological and pulmonary function sequelae.

Background. There are few data on clinical, chest radiograph (CXR) or pulmonary function sequelae in children with post-infectious bronchiolitis obliterans (BO) (pulmonary crepitations, abnormalities on CXR, CT, nuclear medicine scans, or bronchography, with a history of past pulmonary infection and in the absence of other underlying pathology). Objective. To analyse the methodology of diagnosis, long-term clinical imaging and pulmonary function sequelae of post-infectious BO in children. Materials and methods. Imaging (CXRs, CT and nuclear lung scans) and clinical histories of 19 children were analysed. Results. Clinical follow-up (mean 6.8 years), revealed a high incidence of continuing problems (asthma and bronchiectasis). Fixed airway obstruction was the most common pulmonary function sequela. The sequelae on follow-up (mean 5.8 years) CXR were classified into five patterns which are illustrated: unilateral hyperlucency of an enlarged lung/part of lung; complete collapse of the affected lobe; unilateral hyperlucency of a small or normal-sized lung; bilateral hyperlucent lungs and a mixed pattern of persistent collapse, hyperlucency and peribronchial thickening. Conclusion. Long-term observations in children with post-infectious BO should be undertaken to detect bronchiectasis and obstructive airway disease. Sequelae evident on CXR, other than those previously described, can be found. Bronchography and/or lung biopsy are not usually required for the diagnosis of post-infectious BO.

Bronchiolitis Obliterans↗
PubMed1998

Renal tuberculosis in an Australian-born child.

This report describes a case of renal tuberculosis, complicated by hypertension and ureteric obstruction, in a previously well Australian born child. Despite antituberculous chemotherapy and ureteric stenting, there was a progressive loss of renal function in the right kidney until surgical nephrectomy allowed full recovery. A high level of clinical suspicion is necessary for a diagnosis of genitourinary tuberculosis. Ureteric cicatrisation and obstruction occasionally may occur with healing, and therefore serial renal tract imaging during treatment is necessary to detect this complication.

Child↗
PubMed1998

A randomised, placebo controlled trial of inhaled salbutamol and beclomethasone for recurrent cough.

AIMS: To test the hypothesis that inhaled salbutamol or beclomethasone will reduce the frequency of cough in children with recurrent cough. A secondary aim was to determine if the presence of airway hyperresponsiveness (AHR) can predict the response. DESIGN: Randomised, double blind, placebo controlled trial. METHODS: During a coughing phase, 43 children (age 6-17 years) with recurrent cough were randomised to receive inhaled salbutamol or placebo (phase I) for 5-7 days and then beclomethasone or placebo (phase II) for 4-5 weeks, and in a subgroup of children for 8-9 weeks. The children used an ambulatory cough meter, kept cough diaries, and performed the capsaicin cough sensitivity, hypertonic saline bronchoprovocation, and skin prick tests. RESULTS: Salbutamol or beclomethasone had no effect on cough frequency or score, irrespective of the presence of AHR. CONCLUSIONS: Most children with recurrent cough without other evidence of airway obstruction, do not have asthma and neither inhaled salbutamol nor beclomethasone is beneficial.

Administration, Inhalation↗
PubMed1998

Subjective scoring of cough in children: parent-completed vs child-completed diary cards vs an objective method.

Cough is often used as an outcome measure, although the reporting of cough is unreliable. Using a 24 h ambulatory cough meter to measure cough frequency, the aim of this study was to compare: 1) the correlation of child-completed diary cards to the objective measurement, with that of parent-completed diary cards; and 2) the visual analogue scale (VAS) to the verbal category descriptive (VCD) score. The cough meter consisted of a previously validated Holter monitor and a cough processor. Eighty four children (39 with recurrent cough and 45 controls, aged 6-17 yrs) used a cough meter at least once. Thirty three subjects used the cough meter twice. Parents and children completed separate diary cards using the VAS and VCD scores. The strength of the relationship between the subjective scores and the objective recordings was analysed by spearman's rank correlation coefficient. For daytime cough, child-completed diary cards and the VCD correlated better to the objective measurement than parent-completed diary cards and the VAS, respectively. In subjects that used the cough meter twice, the difference between the cough frequency correlated to the difference in the subjective scores. The confidence intervals for the correlation coefficients were wide. The agreement between the objective and subjective presence of daytime cough was good but that for night-time cough was poor. We conclude that the severity of cough defined on diary cards may not represent cough frequency. Objective readings are first choice but currently not yet practical. The verbal category descriptive diary card completed by children and assisted by parents has the highest correlation to cough frequency measured objectively.

Adolescent↗
PubMed1998

Non-specific cough in children: diagnosis and treatment.

Cough is a common reason for parents to seek medical attention. When the history, examination, chest X-ray and, if possible, spirometry are normal, the cough can be classified as non-specific, which is often found. This article focuses on non-specific cough, addresses common questions and gives a simple approach to evaluating the child with a cough.

Asthma↗
PubMed1997

Effect of capsaicin on airway responsiveness to hypertonic saline challenge in asthmatic and non-asthmatic children.

Recurrent cough and asthma are common problems in children. In the evaluation of children with recurrent cough, the sequential measurements of airway responsiveness (AR) and capsaicin cough receptor sensitivity may be useful. However, the effect of capsaicin on AR induced by an indirect stimulus such as hypertonic saline (HS) is not known. Current evidence suggests that a common pathway is involved in both capsaicin and HS challenges. This study was designed to determine whether inhalation of capsaicin for the cough receptor sensitivity test before HS challenge will alter AR of asthmatic and non-asthmatic children to that challenge. Twenty-one children (12 asthmatics, 9 non-asthmatics; mean age, 11.3 years) performed the HS challenge alone or 2 min after capsaicin inhalation on 2 different days in random order. The end point of the capsaicin inhalation was when > or = 5 coughs were stimulated from a single inhalation. The power of the study was > 90% at a significance level of 0.05. Capsaicin inhalation prior to HS challenge did not alter the AR of normal children. In the asthmatic group, the PD15 (provocation dose causing a fall in forced expiratory volume in 1 s of > or = 15% from the baseline) without prior inhalation of capsaicin (mean, 2.44 +/- SEM 1.21 ml) was not significantly different from that when HS challenge was performed after capsaicin inhalation (mean, 2.19 +/- SEM 0.83 ml). The mean of the difference in log PD15 of the HS challenge with and without capsaicin was -0.02 (95% CI, -0.16, 0.12), i.e. within the equivalence range of the HS challenge in children with asthma. We conclude that in normal and asthmatic children, capsaicin inhalation does not alter AR to HS; consequently the capsaicin cough sensitivity test can be performed validly before an HS challenge.

Adolescent↗
PubMed1997

Pulmonary diseases in children with severe combined immune deficiency and DiGeorge syndrome.

Pulmonary disease is a common presenting feature and complication of T-cell immunodeficiency. We retrospectively reviewed 15 children with severe combined immune deficiency (SCID) and 19 children with DiGeorge syndrome at the time of their first presentation to the Royal Children's Hospital in the 15-year period from 1981 to 1995. In children with SCID, pulmonary disease was a common (67%) presenting feature and the organisms identified were Pneumocystis carinii (PCP) (n = 7), bacteria (n = 4), viruses (n = 3), and a fungus (n = 1). Late pulmonary complications included lower respiratory tract infections, bronchiolitis obliterans, and lymphointerstitial pneumonitis. Pulmonary infections were common (17 occasions) and the organisms identified were bacteria (n = 7), viruses (n = 6), fungi (n = 3), and Mycobacterium tuberculosis (n = 1). Pulmonary complications were responsible for 5 of 9 deaths. PCP was not identified as a late complication in any child, presumably as a result of effective prophylactic therapy. Although pulmonary disease was not a major presenting feature in children with DiGeorge syndrome, pulmonary complications were common. These included recurrent bacterial and viral infections and bronchomalacia, which complicated management and predisposed to morbidity and mortality, even in those without a T-cell defect. We conclude that pulmonary disease is a common manifestation in children with SCID and DiGeorge syndrome.

CD4 Lymphocyte Count↗
PubMed1997

Cough sensitivity in children with asthma, recurrent cough, and cystic fibrosis.

In adults, cough sensitivity is influenced by gender and is heightened in those with non-productive cough. This study examined if cough sensitivity is (i) altered in children with asthma, recurrent cough, and cystic fibrosis and (ii) influenced by age, gender, or forced expiratory volume in one second (FEV1). Cough sensitivity to capsaicin and spirometry were performed on 209 children grouped by the diagnosis of asthma, recurrent dry cough, cystic fibrosis, and controls. Cough sensitivity was increased in children with recurrent cough, and lower in children with cystic fibrosis when compared with children with asthma and controls. Age influenced cough sensitivity in the controls. In the asthmatics, FEV1 (% predicted) correlated to cough sensitivity measures. There was no gender difference in cough sensitivity. It is concluded that cough sensitivity is different among children with recurrent dry cough, asthma, and cystic fibrosis. In children, age, but not gender, influences cough sensitivity measures and when cough sensitivity is used in comparative studies, children should be matched for age and FEV1.

Adolescent↗