A prospective study of tracheal intubation in an emergency department in Hong Kong.

Emergency department (ED) doctors often intubate patients, however no data was available in Hong Kong on this aspect. Our study was to assess the competency of ED doctors in intubating critical patients in a typical ED in Hong Kong. Between March and August 1999, in an urban hospital with an emergency physician training programme, all doctors, after performing any tracheal intubation, were required to fill in a pro forma designed for the study. Data collected included the training status of the intubator, the number of intubation attempts, intubation methods and complications. A total of 214 ED patients required advanced airway management including 87 (41%) patients in cardiopulmonary arrest; 207 (97%) of them were successfully intubated by ED doctors (76 by specialists, 61 by trainees, 70 by residents) and 90% were successful in the first attempt. The remaining seven patients' airway control was eventually managed by anaesthetists who successfully intubated six patients and performed cricothyrotomy for one patient. Rapid sequence intubation was performed in 70 (33%) patients by ED doctors and specialists. There were 30 (14%) patients successfully intubated using sedative agents alone. Twenty-two (10%) patients were found to have a total of 32 complications including 13 patients with oesophageal intubation, seven with soft tissue damage, four with desaturation, three with bronchial intubation, three with hypotension, one with dental trauma, one with dysrhythmia. The majority of ED intubations for critically ill patients were performed by ED doctors with high success rate and few major complications.

Comparison between two districts of the effects of an air pollution intervention on bronchial responsiveness in primary school children in Hong Kong.

STUDY OBJECTIVE: This study examined the impact on children's respiratory health of a government air quality intervention that restricted the sulphur content of fuels to 0.5% from July 1990 onwards. DESIGN/SETTING/PARTICIPANTS: This study examined the changes, one and two years after the introduction of the intervention, in airway hyperreactivity of non-asthmatic and non-wheezing, primary 4, 5, and 6, school children aged 9-12 years living in a polluted district compared with those in a less polluted district. Bronchial hyperreactivity (BHR)(a 20% decrease in FEV1 provoked by a cumulative dose of histamine less than 7.8 mumol) and bronchial reactivity slope (BR slope) (percentage change in logarithmic scale in FEV1 per unit dose of histamine) were used to estimate responses to a histamine challenge. The between districts differences after the intervention were studied to assess the effectiveness of the intervention. MAIN RESULTS: In cohorts, comparing measurements made before the intervention and one year afterwards, both BHR and BR slope declined from 29% to 16% (p = 0.026) and from 48 to 39 (p = 0.075) respectively in the polluted district; and from 21% to 10% (p = 0.001) and 42 to 36 (p > 0.100) in the less polluted district. Comparing measurements made in 1991 (one year after intervention) with those in 1992 (two years after intervention), only the polluted district showed a significant decline from 28% to 12% (p = 0.016) and from 46 to 35 (p = 0.014), for BHR and BR slope respectively, with a greater decline in both responses (p = 0.018 and 0.073) than in the less polluted district. CONCLUSION: Bronchial hyperresponsiveness tests can be used to support the evaluation of an air quality intervention. The demonstrated reduction in bronchial hyperresponsiveness is an indication of the effectiveness of the intervention.

Breath hydrogen (H2) analysis in southern Chinese children and infants by gas chromatography and a novel automatic sampling system.

Breath hydrogen (H2) analysis was used to study lactose malabsorption in Southern Chinese children and infants. End-expired air was collected in 85 children using a modified anaesthesia bag system; while in infants, a novel automated end-expired sampling device was constructed and tested on 45 term and 27 preterm infants. Hydrogen and other respiratory gases were measured in the expired air using standard gas chromatograph equipped with a thermal conductivity detector. The system was found to have a detection limit of 0.5 ppm for H2. Both sampling methods were found to be reproducible, with intra-individual coefficient variations of less than 10%. Using 5% carbon dioxide as the expected alveolar concentration, the samples obtained by the bag system represented 85% of the end-expired air, while those obtained by the automated machine corresponded to 75%-100% end-tidal air. Taking 20 ppm rise in breath H2 as a cutoff criterion, the incidence of lactose malabsorption in the children was 78%; while in term and preterm infants this was 17.8% and 63% respectively.

Bronchial responsiveness in children exposed to atmospheric pollution in Hong Kong.

Bronchial responsiveness was studied by histamine challenge in 423 school children with mean (SEM) age of 10.85 (0.05) years living in two districts of Hong Kong with contrasting levels of air pollution. Differences between districts of residence were observed, with a higher prevalence of bronchial hyperreactivity (BHR) in children living in the more polluted district (chi 2 = 7.74, df = 3, p = 0.052). Bronchial hyperreactivity was defined as a 20 percent or greater drop in FEV1. The district effect remained after exclusion of children with a history of wheeze and those diagnosed asthmatic for prevalence of BHR (chi 2 = 8.93, df = 3, p = 0.030) and for degree of bronchial reactivity (BR) after adjustment for other socioeconomic factors and smoking in the home (z = 1.97, p = 0.049). Bronchial reactivity was defined as the percentage drop in FEV1 per cumulative histamine dose from postsaline to end dose. The results demonstrate that studies on bronchial responsiveness can be used to assess the effects of air quality on the respiratory health of children and will be employed to measure the impact of new air quality control measures in Hong Kong.

Systemic fungal infections in neonates.

The 50,000 or so known species of fungi are present in a large part of our environment and are common in soil, decaying vegetable matter, animals and air. Despite this diversity the actual spectrum of fungal infections in man is limited and in neonates is limited even further.

Response of preterm infants to hepatitis B vaccine.

Ninety-nine preterm infants with birth weights < 1750 gm had three doses of hepatitis B vaccine. Fifty-seven received the first dose when they weighed > or = 1000 gm (group 1) and 42 when they weighed > or = 2000 gm (group 2). The final seropositive rates and geometric mean titers of group 1 infants (79%, 61 mIU/ml) and group 2 infants (91%, 262 mIU/ml) were less than that of 43 normal term infants (100%, 679 mIU/ml).

Antineutrophil cytoplasmic antibody and gallium lung scintiscan in usual interstitial pneumonitis.

A 2 year old Chinese boy was reported in whom there was an association between usual interstitial pneumonitis (UIP) and serum antineutrophil cytoplasmic antibody of the classical cytoplasmic type (cANCA). The concentration of cANCA reflected disease activity and decreased during a 6-week course of prednisolone. The gallium lung scintiscan index correlated with his disease activity. Both the serum cANCA concentration and the gallium lung scan could be used to monitor responses to treatment in this patient with UIP.

Effects of anticoagulants and incubation time on neutrophil nitroblue tetrazolium score.

We studied the effect of anticoagulants and incubation time on neutrophil nitroblue tetrazolium (NBT) scores. Heparin (10 IU/ml) and EDTA (1.5 mg/ml) were used, and the preparations were incubated for periods ranging from 20 to 180 min. Heparin, in contrast to EDTA, was found to be associated with cell destruction, cell aggregates and higher NBT scores; the effects were more profound with endotoxin stimulation. The duration of incubation significantly affects NBT scores in both the heparin- and EDTA-anticoagulated samples, and the effect is more marked with heparin. Cell destruction and cell clumping are both enhanced with incubation, again more so with heparin. It is concluded that when performing NBT tests, blood samples would best be anticoagulated with EDTA to ensure more consistent results.

IgG4-anti-IgE antibodies in Chinese allergic children.

IgG4-anti-IgE antibodies have been identified in normal nonatopic subjects, as well as in allergic patients. Their potential role remains controversial. We studied 44 Chinese children with allergic symptoms, and measured their IgG4-anti-IgE serum levels using a modified IgG4 FAST assay. The levels of IgG4-anti-IgE antibodies did not correlate with clinical status. The usefulness and relevance of these measurements remain questionable in allergic patients.

Evaluation of serum total IgE in Chinese allergic children using different assays.

Since differences in HLA groups have been found in Chinese populations, as well as differences in the values of total IgE in China, Japan and Thailand, a study has been done in 44 Chinese children, all of them with a history of atopic conditions divided into five groups: asthma, rhinitis, conjunctivitis, allergic bronchitis and atopic dermatitis. 34 of them were positive against D. pteronyssimus, 8 against cats, 3 against dogs and 3 against fish. The only adult patient studied was positive against gramineal plants (all positivities were tested with the prick test). IVT ELISA Screen is performed against 10 allergens, as well as 3 M FAST-Test and 3 M Total IgE FAST Plus Test. The results show that the majority of children had an elevation of the total IgE in the three tests. There is quite a good agreement between FAST and IgE-IVT and a better correlation between IgE-IVT and IgE FAST Plus. The correlation between IgE FAST and IgE FAST Plus was excellent.

Suppression of adrenal function in children on inhaled steroids.

Inhaled steroid therapy is one of the mainstays of treatment of asthma in children. Side effects, including suppression of the hypothalamic-pituitary-adrenal (HPA) axis, have been noted with high doses of inhaled steroids. Most studies concerning side effects have been done with mechanical nebulization devices or hand-held metered-dose inhalers. The present study attempts to ascertain if dry powder inhalation of beclomethasone dipropionate is associated with any significant suppression of the HPA axis. Fifteen children (10 male and 5 female) between the ages of 4 and 14 years were followed for several years in our outpatient department. They were on inhaled beclomethasone dipropionate at dosages ranging from 6.9 to 25 micrograms/kg per day for 4-24 months. The short adrenocorticotrophic hormone (ACTH) test was used to evaluate function of the HPA axis. Mild suppression of the HPA axis was noted in one of the cases. The study therefore concludes that at therapeutic doses of dry powder beclomethasone dipropionate, suppression of the HPA axis can occur. However, the extent of this complication does not appear to be greater than with hand-held or mechanical nebulization devices.

Studies on the respiratory health of primary school children in urban communities of Hong Kong.

The first stage of a 2-year survey of respiratory morbidity in primary school children was conducted in two districts of Hong Kong in April/May 1989. One group (2009) of children was from Kwai Tsing District, which had high levels of exhaust emission from factories. The other group (1837) was from Southern District where atmospheric pollution was considered to be relatively low. After adjustment for gender, age, socioeconomic factors, child smoking and exposure to parental smoking, the prevalence ratios of sore throat, evening cough, cough for more than 3 months, morning phlegm and wheezing were found to be significantly higher in Kwai Tsing. The difference between the districts is likely to be related to the environmental air quality. The study, which is continuing, will provide the basis for an evaluation of the impact of new low sulphur fuel regulations introduced in July 1990.

Pseudomonas septicaemia in apparently healthy children.

Among 27 cases of Pseudomonas septicaemia in the Department of Paediatrics of Queen Mary Hospital from 1981 to 1988, we have identified 10 children without known predisposing causes before presentation and report their clinical features. Six were infants, of whom 4 developed shock on admission and died. Ecthyma gangrenosum was present in 4 patients. Pseudomonas aeruginosa was isolated in 8 patients. All isolates, except Ps. cepacia, were sensitive to gentamicin. One patient had cyclical neutropenia. Another had an appendicular abscess. Salmonella was cultured from the stool in one patient. Although Pseudomonas septicaemia is normally considered to be associated with underlying immunodeficiency, in 22% it occurred in previously healthy children. Mortality is high especially in infants who develop septicaemic shock. It is advisable to cover for Pseudomonas septicaemia with aminoglycosides or ceftazidime in sick septic infants.

Automatic end-expiratory air sampling device for breath hydrogen test in infants.

An automatic electronically operated end-expiratory air sampler has been developed for use in small infants. Upon expiration, which is detected by a hot-wire sensor, a small portion of the end-expiratory air is automatically collected into a syringe mounted on a syringe driver. The sampler obtained 87% of the end-expiratory air sample. Additionally, highly reproducible and consistent results were obtained for the respiratory gases (O2, N2, CO2). The sampler has been applied for studying breath hydrogen excretion to detect lactose malabsorption. It may also be applicable to study other expiratory gases in infants.

Haemorrhagic shock encephalopathy.

Three children suffered from acute onset of convulsions and progressive coma associated with hyperpyrexia, profound shock and generalized bleeding tendency. No causative agent could be identified. Despite aggressive resuscitation they all died. Post-mortem examination revealed cerebral oedema, petechial haemorrhages of the gut, lungs and kidneys, and a generalized depletion of lymphocytes in the lymphoid organs. Features were compatible with haemorrhagic shock encephalopathy, which is a highly fatal disease. The possible role of hyperpyrexia in its pathophysiology is discussed. More careful case identification and research in various possible aetiological factors may help elucidate its pathogenesis.