Original Article

HC Chua, N Venketasubramanian, H Tjia
Correspondence: Dr Chua Hoe Chin

ABSTRACT
Background Heparin is a widely used antithrombotic agent for treatment of ischemic cerebrovascular disease. One of its most important side-effects is thrombocytopenia which may lead to potentially life-threatening haemorrhagic and thrombotic complications.
Methods We performed a prospective study to determine the frequency of heparin induced thrombocytopenia. Heparin induced thrombocytopenia is defined as a platelet count of less than 150 x 10(3)/mm3 or a decrease in platelet count to 30% to 50% from baseline. Daily platelet counts were obtained in 50 adult patients who were treated with the same lot of intravenous bovine heparin. Two patients (4%) developed thrombocytopenia with onset varying from four to seven days after heparin was started. In both cases, platelet counts returned to baseline levels three to five days after cessation of therapy. No ischemic or haemorrhagic complications occurred.
Conclusion Heparin induced thrombocytopenia is a common complication of intravenous heparin treatment. Clinicians treating patients with heparin should determine platelet counts at baseline and henceforth at regular intervals beginning from the fifth day of therapy. We recommend commencement of warfarin therapy concurrently with heparin infusion and discontinuation of heparin once warfarin has become effective. All doctors must be vigilant to this reversible common complication.

Keywords: heparin, thrombocytopenia, platelet, cardiovascular, stroke
Singapore Med J 2001; 42(5): 200-202

Praveen L Basanagoudar, Shivinder S Gill, Mandeep S Dhillon, Ram K Marwaha
Correspondence: Dr Shivinder S Gill, msdhillon@glide.net.in; mandyrima@hotmail.com

ABSTRACT
Aim of Study To analyse the incidence of fractures in beta thalassemia patients and to identify causative factors.
Methods We examined all cases of transfusion dependent beta thalassemia (TDBT) seen at our institute over a two-year period. The transfusion records, incidence of fractures, cause of fracture and Hb levels were recorded. Radiographs of the involved parts were taken in cases with fractures only.
Results and Conclusion Amongst 105 cases of TDBT assessed, 14 sustained a total of 28 fractures. Seven patients sustained more than one fracture. Two thirds of these fractures were caused by trivial trauma. All fractures, except one, were of the closed type. Radiologically, fractures frequently showed minimal or no displacement. All fractures were successfully treated by closed modalities of treatment. Majority of the fractures healed within normal union time for a given bone. Permanent deformities and gross limb length discrepancies were uncommon. On reviewing the literature, we noted that the incidence of fractures in our series and in the latest reports was lesser than previously reported. We postulate that this is a result of better and earlier control of hemoglobin status by improved transfusion techniques, and earlier recognition of the disease. Difficulties arise due to inadequate blood transfusion facilities in developing countries.

Keywords: Beta Thalassemia, fractures
Singapore Med J 2001; 42(5): 196-199

WH Wong, KF Cheong
Correspondence: Dr K F Cheong

ABSTRACT
Propofol is frequently associated with pain on injection. We evaluated the effect of tramadol in a randomised, double-blind study using a tourniquet venous retention technique. Normal saline placebo was given intravenously to patients in Group 1 (n = 30),tramadol 50 mg to Group 2 (n = 30), and lignocaine 50 mg to Group 3 (n = 30). The venous retention of drugs was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol. Pain assessment was made immediately after propofol injection. There was a significant reduction in the incidence of pain associated with propofol administration in patients pretreated with lignocaine and tramadol (P < 0.05). In addition, pretreatment with tramadol was as effective as lignocaine in reducing pain on propofol injection.

Keywords: Anaesthetics, Intravenous: Propofol, Narcotics: Tramadol, Anaesthesia, Complications: pain
Singapore Med J 2001; 42(5): 193-195

HL Yap, R Mahendran, D Lim, PH Liow, A Lee, S Phang, A Tiong
Correspondence: Dr Yap Hwa Ling

ABSTRACT
Objective To evaluate the efficacy and safety of risperidone in Singapore patients with first-episode psychosis in an eight-week open label prospective study.
Method Previously untreated male and female patients aged 18 - 65 with DSM IV schizophreniform disorder or DSM IV schizophrenia for no longer than 12 months were recruited from Woodbridge Hospital and Geylang Psychiatric Outpatient Clinic. Patients were treated with risperidone for 56 days. Outcome was assessed with the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression scale (CGI). Safety was assessed by monitoring of vital signs and by comparing the frequency of adverse events (AEs) before and after treatment.
Results 24 patients with a mean age of 33.29+/-9.12 years and a mean duration of illness of 166.5+/-111.4 days (median 180 days) were included. The mean risperidone dosage was 2.7 mg +/- 1.0 at day 56. Mean PANSS total scores reduced by 50.21% from 88.29+/-21.55 at baseline to 43.96+/-7.5 at endpoint (p < 0.001). The responder rate (> or = 20% reduction in the total PANSS score) was 87.5%. 13 patients (54.2%) exhibited a 50% or greater reduction in total PANSS score. Except for item G5 (mannerisms and posturing) all single PANSS items were reduced significantly. The CGI scores of all patients improved at endpoint. No serious adverse events were reported.
Conclusion Overall the therapy of first-episode psychosis patients with risperidone was effective and safe.

Keywords: Treatment of first-episode psychosis, risperidone, Asian patients, PANSS, CGI
Singapore Med J 2001; 42(4): 170-173

KB Chuah, CK Yap, HS Ng
Correspondence: Dr Chuah Khoon Beng, khoon_beng_chuah@notes.ttsh.gov.sg

ABSTRACT
Background Although the length of the common bile duct is well documented, the length of extrahepatic biliary tree is less well studied, particularly in among the Asian population. The extrahepatic bile duct (BD) length is defined as the measurement from the hepatic hilum to the papilla.
Objective This study was performed to assess the normal range of extrahepatic BD length, as defined above, in the Singapore population. This information would be useful in assisting the local endoscopy unit in procuring the different lengths of biliary stents.
Method Between 1.8.96 to 1.12.97, 486 cholangiograms were obtained post-ERCP, of which only 100 cholangiograms that were representative of a non-distorted BD were used for analysis. The BD length, taken from the mid-point of the confluence of the left and right hepatic ducts at the hilum to the papilla, was measured with a string placed on the cholangiogram. The true length was obtained after correction for radiological magnification.
Results The range of bile duct lengths followed a normal distribution curve with a mean length of 9.6 cm. The range was from 6.9 cm to 12.6 cm. With respect to the length of stents commonly deployed, the cumulative percentage of BD length less than and equal to 7-, 9-, 10- and 12-cm were 1%, 38%, 57% and 98% respectively.
Conclusion From a practical point of view, this study suggests that endobiliary stent of 5 cm in length should be readily available for drainage of distal CBD strictures as 1% of our population has BD length less than 7 cm. However, as 2% of the population has BD length greater than 12 cm, 15 cm stents should be available in the endoscopy unit for drainage of hilar obstructions/strictures.

Keywords: ERCP, bile duct length, biliary stenting, cholangiogram, extrahepatic
Singapore Med J 2001; 42(4): 165-169

PP Hsu, RH Brett
Correspondence: Dr Hsu Pon Poh

ABSTRACT
The aim of the study is to evaluate the results of multiple level pharyngeal surgery in patients with moderate to severe obstructive sleep apnoea in Changi General Hospital, Singapore. 13 patients who failed non-surgical treatment underwent surgery which includes uvulopharyngopalatoplasty, genioglossal advancement and modified hyoid myotomy and suspension. Epworth sleepiness scale, Cephalometric analysis and Sleep study were performed pre- and post-operatively to evaluate the results. 76.9% of the patients achieved more than 50% reduction in AHI with post-operative AHI of less than 20. Cephalometric analysis showed an average of 5.2 mm increase in posterior airway space. All patients achieved improvement in Epworth sleepiness scale with an average improvement of 11.8 points. The mean follow-up period of the 13 patients is 12.6 months. Our preliminary results suggest that multiple level pharyngeal surgery is an effective option in the treatment of moderate to severe obstructive sleep apnoea.

Keywords: Obstructive sleep apnoea , multiple level pharyngeal surgery
Singapore Med J 2001; 42(4): 160-164

NWC Chee, TY Tan
Correspondence: Dr Nelson Chee, nelson_chee@notes.ttsh.gov.sg

ABSTRACT
Introduction Cholesteatoma is traditionally diagnosed by otoscopic examination and treated by explorative surgery. The need for imaging in an uncomplicated case is contentious. This study assesses the usefulness of a pre-operative high-resolution CT scan in depicting the status of the middle ear structures in the presence of cholesteatoma.
Materials and Methods The surgical findings of 36 ears with cholesteatoma operated on by the first author were retrospectively compared with the CT findings reported on by the second author. The following were analysed: diagnostic features of cholesteatoma on CT, status of the middle ear structures (ossicles, facial nerve canal, semicircular canals and tegmen tympani), and presence of any anatomical variations and disease complications.
Results All cases had at least 1, and 30 cases (83.3%) had all, of the following radiological features: (a) a non-dependent tissue mass, (b) a location typical for cholesteatoma and (c) bony erosion. The radiosurgical agreement was excellent for the malleus (kappa statistics, k=0.83), stapes (0.94) and semicircular canals (0.8), good for the incus (0.62) and tegmen (0.65), but poor for the facial nerve canal (0.3). Potential surgical hazards detected by the scans included: low lying dura, high jugular bulb, anterior lying sigmoid sinus, facial nerve dehiscence and other situations brought about by the destructive nature of the lesion.
Conclusion There is good to excellent radiosurgical correlation in cholesteatoma for most middle ear structures except for the integrity of the facial canal. The scan alerts the surgeon to potential surgical dangers and complications of disease. High-resolution CT scan is an important investigative tool prior to cholesteatoma surgery.

Keywords: mastoidectomy, ossicles, facial canal, labyrinthine fistula
Singapore Med J 2001; 42(4): 155-159

CYV Chiu, WK Wong, HLJ Mak, CSS Chan, CHP Kwok, CHS Chan, MK Chan
Correspondence: Dr Vivian Chiu, kingjoin@hongkong.com

ABSTRACT
Twelve women with symptomatic fibroids were treated with transcatheter uterine artery embolisation with the use of polyvinyl alcohol (PVA) particles. For the nine women who were due for follow-up, reduction in uterine volume and dominant fibroid size were observed on magnetic resonance imaging. All the nine women had normal luteinising hormone (LH) and follicle stimulating hormone (FSH) levels before the procedure and during the follow-up. Seven of the nine women reported noticeable symptomatic improvement during the follow-up. Pain experienced was of variable level, but well controlled. Adequate analgesia is essential for the procedure. Longer follow-up and prospective fertility studies are required to evaluate the long-term effects before this procedure could be safely extended to younger age groups.

Keywords: Leiomyoma, magnetic resonance imaging, therapeutic embolisation, uterine arteries, uterus
Singapore Med J 2001; 42(4): 148-154

YM Lai, CPH Hong, CYI Chee
Correspondence: Dr Lai Yew Min

ABSTRACT
Background Psychiatric patients carry the additional burden of stigma.
Methods The views of 300 psychiatric out-patients and day-patients and 100 mental health workers concerning stigma were sought. The control group comprised 50 cardiac out-patients.
Results A fair proportion of patients with schizophrenia or depression perceived that stigma had a negative effect on their self-esteem, relationships and job opportunities. The majority felt a need for an increase in public awareness of mental illness. In contrast, the cardiac patients reported very little stigmatization.
Conclusion The diagnostic label of mental illness may render the person vulnerable to stigmatization. Possible causes of stigma and ways of reducing stigma are discussed.

Keywords: mental illness, negative perception, stigma
Singapore Med J 2001; 42(3): 111-114

JL Yu, SX Wu, HQ Jia
Correspondence: Dr Yu Jia Lin

ABSTRACT
Objective The method of Manual of Clinical Microbiology was used to identify bacteria. We investigated the epidemiological characteristics of bacterial agents and their antimicrobial susceptibility as empirical treatment for neonatal infections. Disk diffusion tests were also done for antimicrobial susceptibility.
Results From January 1987 to December 1998, 2,244 bacterial strains were isolated in our neonatal ward. The first three predominant species were Staphylococcus epidermidis (23.9%), Staphylococcus saprophyticus (19.9%) and Escherichia coli (12.6%) in group I (infections acquired outside of hospital). Escherichia coli, Klebsiella and Pseudomonas aeruginosa accounted for 18%, 15.2% and 12.6% respectively in group II (nosocomial infections). The sensitivity rates of those antimicrobials that are seldom used for newborns were found to be higher, while the resistant rates of the commonly used antimicrobial drugs have increased significantly. The resistant rates of bacterial isolate from group II to antimicrobial agents including penicillin and ampicillin were significantly higher than those isolated from group I (p<0.05)The sensitivity rate was 82.2% (717/833) by using amikacin only, when combined with penicillin, rose to 89%(741/833).
Conclusion Gram-negative bacteria were mainly responsible for nosocomial infections of neonates in our hospital. Infections acquired outside the hospital were mainly caused by Gram-positive bacteria. Nosocomial pathogens produced drug resistance easily. Combination of amikacin and penicillin can be recommended as the initial antibiotics for treatment of neonatal infections.

Keywords: infections, nosocomial, antimicrobial susceptibility tests, antimicrobial drugs, China, hospital
Singapore Med J 2001; 42(3): 107-110