Original Article

TH Tan, JT Heng, KY Wong
Correspondence: Dr Tan Teng Hong, tanth@kkh.com.sg

ABSTRACT
The aim of this study is to establish the norms for pulmonary arterial diameters in the premature infants. One hundred and thirty cross-sectional echocardiograms were performed on 62 premature neonates (23.4 weeks to 36 weeks gestation) in the Neonatal Intensive Care Unit. Except for small atrial septal defects/patent foremen ovale (< or =3 mm) or patent ductus arteriosus (PDA), babies with structural heart defects were excluded. The weight at echocardiography ranges from 470 grams to 2,445 grams, with a mean of 1,157 grams. The diameter of the pulmonary annulus (PA), left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured at peak systole at predetermined sites. Sizes of the atrial septal defect and PDA were also measured, if present. There was no difference in the diameter between the left and right pulmonary arteries (p=0.254, paired t-test) in the same patient. After controlling for weight, the mean diameters of the LPA and RPA were larger in patients with PDA (p=0.002) compared to those without PDA (p=0.002), while their pulmonary annulus were comparable in size (p=0.691). Between the gestational ages of 23 and 36 weeks, the diameter of PA, LPA and RPA correlated linearly with weight (Pearson R = 0.84, 0.82, 0.65 and 0.71, respectively; p<0.0005). Prediction graphs and regression equations are given. These normal ranges can be used for assessment of pulmonary artery diameters in premature neonates.

Keywords: Prematurity, patent ductus arteriosus, regression equations, congenital heart disease
Singapore Med J 2001; 42(3): 102-106

WS Lee, KP Ng
Correspondence: Dr W S Lee, leews@medicine.med.um.edu.my

ABSTRACT
A pilot study to determine the seroprevalence of anti-HCV among children from Kuala Lumpur, Malaysia, was conducted using microparticle enzyme immunoassay. Serum samples were obtained randomly from children, aged between one to 16 years of age, admitted to the paediatric unit of University of Malaya Medical Centre, Kuala Lumpur for various medical reasons. Of the 179 samples assayed, only one was positive, giving the prevalence rate of 0.6%. It is reasonable to conclude that the seroprevalence of anti-HCV among children from Kuala Lumpur is low, less than 1%.

Keywords: seroprevalence, anti-HCV, child population
Singapore Med J 2001; 42(3): 100-101

CY Chan, CHJ Tan
Correspondence: Dr John Tan, jtan@md_sh.com

ABSTRACT
Despite advances in surgical technique and peri-operative care, mortality from ruptured abdominal aortic aneurysm presenting to a hospital remains around 50%. This is in contrast to the mortality rate of < 5% for elective repair. In a two and a half year period,the principal surgeon operated on 10 patients with ruptured AAA, with a peri-operative and overall mortality of 30%. One of the ten patients had a ruptured mycotic aneurysm. We present our experience with these patients and also correlate this with recent publications.

Keywords: ruptured abdominal aortic aneurysm, mycotic aneurysm
Singapore Med J 2001; 42(2): 73-76

TL Tan, YY Ding, A Lee
Correspondence: Dr T L Tan, thai_lian_tan@notes.ttsh.gov.sg

ABSTRACT
Objectives To study the profile of older persons with impaired mobility.
Methods A retrospective observational study that reviewed the case records of patients with impaired mobility at a geriatric assessment clinic. Data on mobility status, duration of decline in mobility, functional status, causes, intervention and short-term outcome (up to 16 weeks) were extracted and analysed.
Results The study included 78 patients (42 males) with the median age of 78 years (61 to 96). About 80% had independent premorbid mobility. At presentation, this declined to 45%. Delayed consultations (more than 2 years) were found in 17% of patients. One third had associated decline in transfer, dressing, toileting or bathing, while 19% also had decline in feeding. In each patient, cause(s), many which were potentially reversible, were identified to have contributed to the immobility. More than one cause was identified in half of the patients. Interventions were prescribed in 88% of these patients. Short-term follow-up (median 7 weeks) showed that 21 had an improvement, 35 had the same and 8 had decline in mobility. There was a significant trend towards better outcome when patient presented early during their course of decline in mobility (p=0.005, linear by linear association = 0.013).
Conclusion Impaired mobility is a common pathway for many diseases, and is associated with significant functional decline. With proper evaluation, the offending causes can be identified. Early consultation is important for the application of appropriate intervention and can result in better outcome.

Keywords: aged, elderly, geriatric syndrome, geriatric assessment, intervention
Singapore Med J 2001; 42(2): 68-72

R Mahendran
Correspondence: Dr R Mahendran

ABSTRACT
Aim To study the socio-demographic profile, symptomatology, prior treatment and treatment response of patients seen in an Insomnia Clinic.
Method Information was gathered by case-note review from eighty-five consecutive cases referred to the clinic.
Findings There were almost equal numbers of males and females and they were predominantly Chinese, married and almost equally distributed in the 31 to 60 years age range. More than half (54.2%) had sleep problems for more than a year and almost three quarters (74.1%) had prior treatment for sleep problems. The main presenting complaints were of difficulty initiating sleep (92.9%). About 60.7% reported that their sleep problems were transient episodes and 39.3% reported it as persistent. 92.9% of the cases received pharmacotherapy. All patients received psychological treatment. For those treated with pharmacotherapy, 44.7% received benzodiazepines and 37.6% received non-benzodiazepine hypnotics. The majority, 77.5% were on treatment for less than six months. 48.2% improved and ended treatment themselves.
Conclusion The patients in this sample sought treatment or were referred for treatment much earlier compared to other samples studied. Importantly, 29.5% of the patients referred had an undiagnosed psychiatric condition.

Keywords: Patient Characteristics, Insomnia Clinic, Psychiatry Setting
Singapore Med J 2001; 42(2): 64-67

LKD Koh, PC Ip-Yam, ASA Tan
Correspondence: Dr L K D Koh

ABSTRACT
Congenital disorders of neuromuscular transmission are commonly referred to as congenital myasthenia gravis because of their clinical similarity to the immune-mediated disease. Differentiation between the immune-mediated and congenital forms of the disease is important, because therapy established for the former may not be appropriate for patients with the latter presentation. The course of this rare neuromuscular disorder during pregnancy and its influence on anaesthesia remain largely unknown. We report on the case of a 32-year-old parturient suffering from congenital myasthenia gravis scheduled for elective caesarean section. The perioperative management of this patient who underwent the operation under spinal anaesthesia was reviewed. The effects of anaesthetic agents and techniques on the course of congenital myasthenic patients may need further review in the light of latest findings in the electrophysiology, genetic and therapeutic studies of this syndrome.

Keywords: Anaesthesia, pregnancy, myasthenia gravis, congenital, caesarean section, subarachnoid
Singapore Med J 2001; 42(2): 61-63

WS Lee, SD Puthucheary
Correspondence: Dr W S Lee, leews@medicine.med.um.edu.my

ABSTRACT
Aims To describe the patterns of isolation of Aeromonas spp. and the resulting spectrum of infection, intestinal and extra-intestinal,from infants and children in an urban area in a hot and humid country from SoutheastAsia.
Materials and Methods Retrospective review of all bacterial culture records from children below 16 years of age, from the Department of Medical Microbiology, University of Malaya Medical Centre, Kuala Lumpur, from January 1988 to December 1997. Review of all stool samples and rectal swabs obtained from children during the same period were carried out to ascertain the isolation rate of Aeromonas sp. from stools and rectal swabs. The case records of those with a positive Aeromonas culture were retrieved and reviewed.
Results During the study period, 84 culture samples were positive of Aeromonas spp. (stools 48, rectal swabs 36). During the same period, 1,352 stool samples were positive for at least one enteropathogen. Aeromonas spp. constituted 0.62% of all stool samples. Of the 61 cases reviewed,four patterns of colonization were observed: (a) 17 cases of mostly asymptomatic nursery newborns with a positive rectal swab; (b) 9 children with no diarrhoea; (c) 23 cases, of who seven were immunocompromised, had acute, brief watery diarrhoea without severe dehydration or disturbances of serum electrolytes. No chronic diarrhoea or bacteraemia was noted. (d) 12 cases had a mixed infection with a second enteropathogen isolated from stool samples. Three had chronic diarrhoea No extra-intestinal infection attributed to Aeromonas spp. was identified in this study.
Conclusion Aeromonas was a rare cause of gastroenteritis in urban Malaysian children. It was isolated almost exclusively from gastro-intestinal tract, caused mostly by mild gastroenteritis with no serious complications. Asymptomatic stool carriage among newborns admitted to special care nursery and older children with no diarrhoea were observed.

Keywords: Aeromonas, gastroenteritis, childhood
Singapore Med J 2001; 42(2): 57-60

F Lateef, AB Storrow, K Malone, T Liu, BW Gibler
Correspondence: Dr Fatimah Lateef, f_lateef@hotmail.com; gaefal@sgh.gov.sg

ABSTRACT
Objective To compare the 30-day outcomes of patients enrolled in a 6-hour and 9-hour emergency department (ED)-based chest pain centre (CPC) protocol.
Methods All patients with the chief complaint of chest pain, who were older than 25 years, or with cocaine usage within 96 hours of initial presentation, were eligible for enrolment. Exclusion criteria included acute ST-segment elevation or depression >1 mm in 2 contiguous leads, history of coronary artery disease (CAD), haemodynamic instability or clinical syndromes consistent with unstable angina. Outcomes included ED disposition and cardiac events at 30 days (defined as acute myocardial infarction (AMI), percutaneous trans-luminal coronary angiography (PTCA), coronary artery bypass graft surgery (CABG),ventricular tachycardia or fibrillation (VT/VF) arrest, congestive heart failure (CHF) admission or cardiac-related death). The 9-hour protocol consisted of ST-segment monitoring,serial CK-MB draws at 0, 3,6 and 9 hours as well as a graded exercise test (GXT) prior to ED disposition. The 6-hour protocol eliminated the 9-hour serum marker determination, included cardiac Troponin-I (cTn-I) and allowed a GXT, 3 hours earlier. Follow-up was obtained by medical record review, phone contact, letter and also review of national and state death registries.
Results The 9-hour protocol (October 1991-December 1997) included 2,133 patients and the 6-hour protocol (January 1998- August 1998) had 184 patients enrolled. The 6-hour protocol was not different from the 9-hour one in terms of percentage admissions (9-hour: 310, 14.5%; 6-hour: 33, 17.9%; p=0.213), Coronary Care Unit admission (9-hour: 59, 2.8%; 6-hour: 5, 2.7%; p=0.303) or 30-day cardiac events (9-hour: 38, 1.9%; 6-hour: 2, 1.3%; p=0.605).
Conclusion The 6-hour CPC strategy is an effective and safe evaluation method for patients at low to moderate risk for acute coronary syndromes.

Keywords: Chest pain centre, acute coronary syndrome
Singapore Med J 2001; 42(2): 52-56

W Luman, HS Ng
Correspondence: W Luman

ABSTRACT
Introduction Dyspepsia is a common complaint and represents an important health problem in the community. The aim of the study was to survey the diagnostic approach and management of dyspepsia and Helicobacter pylori (H. pylori) infection by primary care physicians.
Methods Questionnaires were given to 70 medical officers (MO) working in government polyclinics and 70 general practitioners (GP) in private practice.
Results Questionnaires were returned from 68 MO's (response rate 97%) and 61 GP's (response rate 87%). Only 20% of MO and 50% of GP prescribed H. pylori eradication therapy. Of those who have prescribed eradication therapy, 70% would confirm H. pylori infection before therapy (50% for gastroscopy, 19% for Urea Breath test, 25% for laboratory based serology, 6% for office based serology test kits). 85% would prescribe triple therapy against 15% for dual therapy. Proton pump inhibitor (PPI) is the acid suppression agent most commonly prescribed (77%) in regimens of eradication therapy; the remaining would prescribe either bismuth subcitrate or H2 antagonists. Only 8% of respondents would confirm eradication after therapy.
Conclusion Less than half of the primary care physicians surveyed prescribed H. pylori eradication therapy. The main reason given for not prescribing therapy was lack of facility for testing the infection. Of those who prescribed eradication therapy, majority would order the correct and reliable investigations to confirm the infection. Most of them would prescribe triple therapy which is the recommended eradication regimens.

Keywords: Dyspepsia, Helicobacter pylori
Singapore Med J 2001; 42(1): 26-29

AS Devnani
Correspondence: Dr A S Devnani, devnani@kb.usm.my

ABSTRACT
Aim Internal fixation with a plate in the management of non-union for shaft of long bones has been condemned but the review of the literature does not provide such unequivocal evidence. Also there are certain situations where it is either technically not feasible or contraindicated to do closed intramedullary nailing. This study was done to see the outcome of plate-fixation for the treatment of non-union of the shaft of long bones.
Method The non-union was treated by freshening the fracture ends, opening the medullary canal, re-aligning and stabilizing the fracture with a plate and packing autogenous cancellous bone grafts around the non-union site. There were 25 patients with an average age of 35 years. The non-union involved 7 femurs, 8 humerii and 10 tibiae. The initial treatment was operative in 11 patients, by plaster cast in 5, by traction in 1 and by traditional practitioner in 8. There was no pathological fractures or infected cases. The average delay prior to operation was 14 months and the average follow up was 30 months.
Results All non-unions healed on an average in 18 weeks. There was neither incidence of infection nor any complications at the bone graft donor site. Three cases of transient nerve paralysis recovered spontaneously. One femoral plate broke at 12 weeks, which required replating. In another patient the distal screws of the femoral plate pulled out, this was managed successfully with a cast brace.
Conclusion Plate fixation is useful and effective in the management of non-union, more so in situations where it is technically not feasible to do closed intramedullary nailing. The incidence of infection, success of union and time to union are comparable with other methods.

Keywords: aseptic non-union, shaft of long bones, plating and bone grafting
Singapore Med J 2001; 42(1): 20-25