Original Article

AC Kor, HS Lee, CBE Chee, YT Wang
Correspondence: Dr Kor Ai Ching, Ai_Ching_Kor@notes.ttsh.gov.sg

ABSTRACT
Aim Since the first notified case of occupational asthma in 1983, a total of 90 cases were confirmed as on 31st December 1999. In this study, demographic data, causative agents and impact on the workers were described.
Methods The data was derived from notifications to the Ministry of Manpower and referrals to the Occupational Lung Disease Clinic jointly run with Department of Respiratory Medicine, Tan Tock Seng Hospital.
Results Of the 90 cases, 19 (21%) were females and 71 (79%) were males. There were 48 (53%) Chinese, 22 (24%) Malays, 14 (16%) Indians and 6 (7%) of other ethnic origins. The mean age at diagnosis was 35.8 +/- 9.3 yrs. The mean duration of exposure prior to onset of symptoms was 34.9 +/- 57.3 months. The most common causative agent was isocyanates (28 cases, 31%) followed by solder flux (12 cases, 13%) and welding fumes (8 cases, 9%) respectively. Thirteen (14.4%) workers were assessed to have permanent disability under the Workmen's Compensation Act.
Conclusion Since 1990, occupational asthma has overtaken silicosis and asbestosis as the most common occupational lung disease in Singapore. The most common causative agent is isocyanates. Occupational asthma is a condition associated with disability in the workplace and may still be largely under-reported.

Keywords: occupational asthma, isocyanates
Singapore Med J 2001; 42(8): 373-377

MD Kamaliah, LD Sanjay
Correspondence: Dr M D Kamaliah, kamalia@kb.usm.my

ABSTRACT
Drug induced myopathy has been reported with the use of fibric acid derivatives, hydroxymethylglutaryl coenzyme A (HMG-CoA)reductase inhibitors and nicotinic acid. Over the last three decades, hypolipemiants like fibric acid derivatives and statins have been increasingly recognised as causes of rhabdomyolysis and acute renal failure especially during combination therapy and in the presence of underlying renal impairment. We report two cases of bezafibrate-induced rhabdomyolysis in patients with underlying coronary artery disease and pre-existing renal impairment. Both patients developed rhabdomyolysis leading to acute renal failure soon after their hyperlipidaemia treatment was changed from gemfibrozil to bezafibrate. There were no intercurrent illnesses or co-administration of other lipid lowering drugs in both patients. Even though both drugs belong to the same fibric acid derivatives group, these patients developed the complication only after a switchover of therapy.

Keywords: rhabdomyolysis, acute renal failure, lipid-lowering drugs
Singapore Med J 2001; 42(8): 368-372

Satyender Singh Yadav
Correspondence: Satyender Singh Yadav, ssyadav@hotmail.com

ABSTRACT
Singapore's elderly population has been growing rapidly and is expected to constitute more than 25 percent of the total population by the year 2030. The ageing process brings with it a host of health problems. Here the question arises--Are the increasing years of life going to create a high proportion of sick and disabled elderly people, or a rich human resource of healthy senior citizens? Since more women are living longer than men, who would face a higher risk of disability and handicap? These questions are yet to be answered in Singapore. This paper seeks answers to these questions. The study is based on a sample survey of 1209 elderly Singaporeans living in Kampong Glam, Kreta Ayer and Bukit Merah parliamentary constituencies which have some of the highest proportions of the aged population. The results revealed that more than half of the aged had a disability and the rate of disability was significantly higher among the women as compared to the men. More than one-third of the elderly had a handicap and the rate of handicap among the women was twice as much as that among the men. Severity of handicap was directly correlated with age.

Keywords: Ageing, Disability, Handicap, Area of Handicap, Severity of Handicap
Singapore Med J 2001; 42(8): 360-367

J Ho, for the Malaysian Very Low Birth Weight Study Group
Correspondence: Jacqueline Ho, jackie@perakmed.edu.my

ABSTRACT
Objective To compare the neonatal course of small for gestational age (SGA) and appropriate for gestational age (AGA) preterm infants 1500 g or less birthweight.
Method A total of 116 infants SGA infants 32 weeks or less were matched with 116 AGA infants of the same gestation, ethnic group, sex and where possible inborn or outborn status.
Results Significantly more SGA infants had a 1-minute Apgar scores of 3 or less, odds ratio (OR) 2.54 (95% Confidence Interval (CI) 1.25, 5.20) and a Critical Risk Index in Babies (CRIB) score > 5, OR 2.09 (95% CI 1.07, 4.09). They were significantly more likely to have hypotension, 35.5 versus 22.3%, OR 1.90 (95% CI 1.01, 3.59). There was no difference in the frequency of respiratory distress syndrome, mechanical ventilation, infection or rate of congenital malformation. Mortality before hospital discharge was significantly greater for the SGA infant (52.6 versus 28.4%, OR 2.79 (95% CI 1.56, 5.02)). This difference remained significant after exclusion of congenital abnormalities. Survivors had a longer mean duration of stay, (54.4 versus 41.2 days, p < 0.001).
Conclusion The higher mortality seen in SGA infants appears to be due to a poorer condition at birth. There is no evidence that SGA infants have more mature lungs so antenatal corticosteroids should not be withheld on these grounds.

Keywords: small for gestational age, preterm, very low birth weight, Malaysia, mortality, morbidity
Singapore Med J 2001; 42(8): 355-359

V Singh, A Sehgal, A Parashari, P Sodhani, L Satyanarayana
Correspondence: Dr. Veena Singh, icpo@icmricpo.ren.nic.in

ABSTRACT
Objective To assess the sensitivity and specificity of visual inspection of cervix for detection of precancerous and early cancerous lesions of cervix.
Methods In a Maternal and Child Health Care setting of New Delhi women underwent a detailed pelvic examination, visual inspection of cervix after 5% acetic acid application, cytology (pap smear), detailed colposcopic examination and colposcopic directed biopsy when indicated.
Results Findings of aided visual inspection using 5% acetic acid and of cytology were evaluated among symptomatic 402 women against colposcopic findings and/or histologic reports. Seventy-three mild dysplasias, 50 moderate dysplasias, 45 severe dysplasias/Carcinoma in-situ and 40 early invasive cancerous cases were diagnosed histologically. The sensitivity of cytology (75.3%) was higher compared to that of acetic acid application (52.0%) for mild dysplasias. On the other hand, the sensitivity for detecting moderate dysplasias was 78% for cytology and 81.6% for acetic acid; for severe dysplasias/carcinoma in-situ it was 73.3% for cytology and 86.7% for acetic acid. For invasive cancers sensitivity for acetic acid application and cytology (95% for both modalities) was comparable. The specificity of cytology (99%) was higher compared to that of acetic acid application (94.3%). The false positive rate for cytology was 1.0% as against 5.7% for acetic acid application. The results of acetic acid application also showed a remarkable improvement in the sensitivity of unaided visual inspection for early cancerous lesion which was about 60% for early cancerous lesion and only 12% for mild dysplastic and 20% for moderate and severe dysplastic lesions in our earlier experience. It also reduced the false positive rates from 12% by unaided visual inspection to 5.7% by acetic acid application. Furthermore, cost of detection of one true lesion through acetic acid application (Rs.1689.00) was much lower as compared to the cost involved in cytology detected true lesions (Rs.2227.00). Visual inspection without acetic acid incurred Rs.6608.60 for detection of true lesion.
Conclusion Screening for cervical precancerous and cancerous lesions using visual inspection aided by acetic acid may be a suitable low-cost and a feasible alternative modality for control of cervical cancer in a resource poor setting.

Keywords: Visual Inspection, Aided visual inspection, Acetic acid application
Singapore Med J 2001; 42(8): 351-354

LG Lau, KO Kong, PH Chew
Correspondence: L G Lau, LauLG@nuh.com.sg

ABSTRACT
Aims To study the demographic and clinical features as well as outcomes of tetanus patients at the Sarawak General Hospital, Kuching from 1990 to 1999.
Methods All cases of tetanus from January 1990 to September 1999 were identified from the computer record at the hospital and these were then restrospectively reviewed.
Results A total of 22 cases of tetanus was seen at the Sarawak General Hospital in the ten-year period with a mean of 2.2 cases per year. There were 15 male (68.2%) and 7 female (31.8%) patients. Most cases occurred in the age group 60-69. Eighteen patients (81.8%) had a reasonably identifiable injury prior to the onset; all had their wounds debrided. Body stiffness, trismus and dysphagia were the three commonest presenting complaints. Twenty-one patients (95.5%) were admitted to the intensive care unit (ICU), with an average length of ICU stay of 21.4 days. Nineteen patients (86.4%) required mechanical ventilation for a varying period of time in the ICU. All patients (100%) had tracheostomy performed and intravenous diazepam infusion as part of their management. Twenty patients (90.9%) received intravenous crystalline penicillin as the treatment antibiotics. Twenty-one patients (95.5%) received intramuscular human antitetanus immunoglobulin. There were four deaths, accounting for a mortality of 18.2%.
Conclusion In general, tetanus remains in Sarawak an important disease with substantial mortality and morbidity that primarily affects unvaccinated or inadequately vaccinated individuals. It is, however, highly preventable through both routine vaccination and appropriate wound management. Our case series show comparable pattern and outcome with other case series reported in the literatures.

Keywords: Retrospective study, Tetanus, Demography, Clinical features, Sarawak General Hospital
Singapore Med J 2001; 42(8): 346-350

KL Ling, W Luman, B Ho, HS Ng
Correspondence: Dr Ling Khoon Lin, lingkhoonlin@yahoo.com.sg

ABSTRACT
Background There has been a gradual increase in the proportion of Singapore patients with metronidazole resistant strains of Helicobacter pylori. We studied the efficacy of a nitroimidazole containing regime in eradicating H. pylori.
Methods Consecutive treatment naive patients with peptic ulcer disease and culture proven H. pylori were recruited. From each patient, two antral biopsies were taken for rapid urease test and two for histology. Two biopsies each from the gastric antrum and corpus were taken for H. pylori culture. Antibiotic sensitivity to amoxycillin, metronidazole, clarithromycin and tetracycline were tested using the disc diffusion method. Patients were treated with lansoprazole 30 mg bd, tinidazole 500 mg bd and clarithromycin 500 mg bd for seven days. Successful eradication was defined as either negative urea breath tests 4 and 12 weeks after treatment, or negative histology and culture at least four weeks after the end of treatment.
Results A total of 64 patients were culture positive (51 males, 13 females). Forty-two patients had duodenal ulcers (DU), 17 gastric ulcers (GU), and 5 DU and GU. Metronidazole resistance was detected in 16 patients (25%). Three of the 16 patients (19%) had a mixed population of resistant and sensitive strains of H. pylori. None of the H. pylori isolates were resistant to amoxycillin, tetracycline or clarithromycin. Overall, eradication was achieved in 51/64 patients (80%). Eradication rate was 88% (42/48) among those with metronidazole sensitive strains, and 56% (9/16) among those with metronidazole resistant strains (p < 0.02).
Conclusion A high proportion of our patients with metronidazole resistant strains of H. pylori failed eradication therapy when a nitroimidazole containing regime was used. It may not be appropriate to use a nitroimidazole containing without prior knowledge of the antibiotic sensitivity pattern of the H. pylori isolate.

Keywords: Helicobacter pylori, antimicrobial susceptibility testing, treatment failure
Singapore Med J 2001; 42(7): 317-321

P Mok, RS Seshadri, JK Siow, SMF Lim
Correspondence: Dr Paul Mok, paul_mok@notes.ttsh.gov.sg

ABSTRACT
We present three patients with Nasopharyngeal Carcinoma (NPC) developing swallowing problems after radiotherapy as the primary modality of treatment. All patients had advanced stage NPC presenting with enlarged neck nodes and underwent radical external beam radiotherapy. All three patients had both CN X and CN XII palsies and had difficulty in both the oral and pharyngeal phases of swallowing. None of them has any clinical or radiological evidence of local recurrence in the post nasal space and neck or metastasis to the skull base. One patient underwent cricopharyngeal myotomy with epiglottopexy and hyoid suspension which failed and subsequently underwent laryngectomy. Another patient had medialisation thyroplasty and the third underwent a percutaneous endoscopic gastrostomy (PEG).

Keywords: swallowing problems, post irradiation, nasopharyngeal carcinoma
Singapore Med J 2001; 42(7): 312-316

WY Pek, A Johan, SS Tan, P Lee, CBE Chee, YT Wang
Correspondence: Dr Azman Johan, azman_johan@notes.ttsh.gov.sg

ABSTRACT
Introduction There is a lack of data on the prevalence of deep vein thrombosis and pulmonary embolism in patients admitted to hospital for exacerbation of chronic obstructive pulmonary disease. Studies have found that most pulmonary embolism originate from deep vein thrombosis in the lower limbs, thus the prevalence of deep vein thrombosis may give an accurate reflection of the prevalence of pulmonary embolism. The aim of our study was to determine the prevalence of deep vein thrombosis in these patients, using duplex ultrasound of the lower limbs as the screening tool.
Methods Thirty-three male patients admitted to the general ward for exacerbation of chronic obstructive pulmonary disease were screened for presence of deep vein thrombosis of the lower limbs using duplex ultrasound scan.
Result No patient in this study was found to have deep vein thrombosis of the lower limbs.
Conclusion The prevalence of deep vein thrombosis in local patients admitted for exacerbation of chronic obstructive pulmonary disease is likely to be low. We do not recommend the use of duplex ultrasound to screen for deep vein thrombosis in this group of patients.

Keywords: chronic obstructive pulmonary disease, deep vein thrombosis, pulmonary embolism, venous thromboembolism, duplex scan
Singapore Med J 2001; 42(7): 308-311

BSC Woo, G Parker, MI Loh
Correspondence: Dr Bernardine S C Woo, bernardine_woo@imh.com.sg

ABSTRACT
We report a retrospective study examining the prevalence, demographic profile and pattern of psychiatric morbidity of theft offenders remanded for psychiatric assessment by the Singapore courts. Case records of 100 male and 100 female consecutively remanded theft offenders were reviewed. There was a high rate of psychopathology, with schizophrenia as the commonest disorder. Sex differences were identified in demographic profiles, psychiatric diagnoses, types of offences committed and likely psychiatric determinants of the offence. Depression was more common in females while substance abuse and antisocial personality disorder were diagnosed more frequently in males.

Keywords: Schizophrenia, depression, substance abuse, antisocial personality disorder
Singapore Med J 2001; 42(7): 304-307