2005

A Ngo, SH Lim, RA Charles, SH Goh
Correspondence: Dr Adeline Ngo, Adeline_ngo@singhealth.com.sg

ABSTRACT
A 24-year-old man presented with generalised malaise and myalgia for three days. He presented to the Emergency Department after a fall at his workplace due to weakness. 12-lead electrocardiogram (ECG) showed normal sinus rhythm with ST depression in the leads V4 to V6, with a U wave. The tallest U wave appeared in V3. These ECG features are characteristic of hypokalaemia. ECG changes in hypokalaemia and differential diagnosis are discussed. A second case of thyrotoxic periodic paralysis with similar ECG changes of hypokalaemia is also presented.

Keywords: hypokalaemia, hypokalemic periodic paralysis
Singapore Med J 2005; 46(1): 38-41

YFA Chung, CH Thng, HF Lui, K Mancer, PKH Chow, YM Tan, PC Cheow, LLPJ Ooi
Correspondence: Dr Alexander Y F Chung, gsucyf@sgh.com.sg

ABSTRACT
This pictorial essay aims to show the clinical mimicry of hepatocellular carcinoma (HCC) and its diagnostic difficulty, and to create awareness among clinicians and radiologists of potential diagnostic pitfalls. A selected consecutive series of hepatectomies with proven HCC over a three-year period, identifying clinical presentation, blood results and imaging of patients with difficult preoperative diagnosis, was reviewed. The imaging of the focal liver lesions is presented pictorially with pathological correlation. Six patients out of 34 cases of resected HCC were diagnosed to have benign (three liver abscesses) and neoplastic (one Klatskin tumour, one colorectal liver metastasis, one gallbladder cancer) conditions. Compared to the rest in the series, all six patients had normal serum alpha fetoprotein levels. On computed tomography, the mosaic appearance of HCC mimicked locules of liver abscess while HCC with pseudocapsule (rim enhancement) was misdiagnosed as unilocular abscess or metastatic lesion. Arterial enhancement on contrast-enhanced triphasic computed tomography was useful in diagnosis of HCC. In summary, HCC can mimic benign and neoplastic clinical syndromes. The diagnosis of liver abscess can delay subsequent diagnosis of HCC and potentially complicate the treatment plan. Contrast-enhanced triphasic computed tomography or magnetic resonance imaging is useful to resolve difficult diagnosis, especially when the serum alpha fetoprotein level is not raised.

Keywords: alpha fetoprotein, diagnostic imaging, hepatocellular carcinoma, liver abscess, liver tumour
Singapore Med J 2005; 46(1): 31-37

V Mali, B Liu, K Prabhakaran, D Loh
Correspondence: Dr Vidyadhar Mali, vidyadhar69@yahoo.co.in

ABSTRACT
Since the routine use of antenatal ultrasonography, congenital pelviureteric junction (PUJ) obstruction rarely presents as an incidental diagnosis following renal trauma. Gross haematuria following seemingly trivial trauma should arouse the suspicion of a pre-existing abnormality. We report a 14-year-old girl with previously asymptomatic and undetected PUJ obstruction who first presented with gross haematuria following a trivial fall. The diagnosis was established by an abdominal computed tomography that showed left chronic hydronephrosis, and was subsequently confirmed on a renal isotope scan. Since the pre-existing hydronephrosis has little impact on the recovery from the injury itself, the initial management was non-operative with an aim to conserve the kidney. As standard surgery has a good outcome, once the renal scan confirmed good renal function, a delayed Anderson-Hynes' pyeloplasty was performed following healing of the kidney laceration as seen on ultrasonography.

Keywords: haematuria, occult hydronephrosis, paediatric renal trauma, pelviureteric obstruction
Singapore Med J 2005; 46(1): 28-30

Y Imran, Y Halim
Correspondence: Dr Imran Yusof, drimran93@yahoo.com

ABSTRACT
A 63-year-old man developed acute cauda equina syndrome due to fat graft compression. Following decompressive laminectomy and posterior instrumented fusion with pedicle screw fixation for spinal stenosis of L5 and S1 vertebral levels, free fat grafting was performed to cover the exposed dura. The patient developed gradual neurological deficit three days postoperatively. This started with sensory loss and weakness of the affected dermatomes and myotomes, followed by bowel incontinence on the 12th postoperative day. Intraoperatively, significant dural compression by the fat graft was confirmed. Immediate removal of the fat graft resulted in recovery from cauda equina syndrome.

Keywords: cauda equina syndrome, free fat graft, postoperative complications, spinal surgery
Singapore Med J 2005; 46(1): 25-27

A Mukhopadhyay, TK Lim
Correspondence: Dr Lim Tow Keang, mdclimtk@nus.edu.sg

ABSTRACT
Introduction This prospective audit examines the diagnostic and clinical outcomes of consecutive adult inpatients who were admitted to a university hospital for other reasons and referred for breathlessness to respiratory physicians.
Methods We enrolled all adult inpatients referred for breathlessness from May 2000 to October 2001. We evaluated the clinical features and utility of routine investigations, such as blood tests and radiology. Subsequent investigations were undertaken at the discretion of the physician.
Results Of the 105 patients, 49 were men and 56 were women. Their mean age was 66 plus or minus 18 years. Surgical departments and cardiology were the main referring departments. Respiratory infection (31 percent) was the most common diagnosis. Acute pulmonary embolism (PE) was diagnosed in four patients postoperatively. Chest radiographs were helpful in making a diagnosis in 66 percent of patients. Computed tomography pulmonary angiogram of the thorax was performed in 31 of the 34 patients who were investigated for acute PE. More postoperative than non-postoperative patients were tested for PE (p-value less than 0.0001).
Conclusion In hospitalised patients referred for breathlessness, respiratory infections were the most common diagnosis and the chest radiograph was the most useful initial investigation. Computed tomography pulmonary angiogram was the preferred investigation for acute PE and clinicians were more inclined to investigate for PE in postoperative patients.

Keywords: chest radiograph, computed tomography pulmonary angiogram, dyspnoea, pulmonary embolism
Singapore Med J 2005; 46(1): 21-24

V Ashok, A Nishkantha, KH Leong, HD Luo, RM El-Oakley, CTT Tan, CN Lee, EK Sim
Correspondence: Dr Eugene Sim, sursimkw@nus.edu.sg

ABSTRACT
Introduction Off-pump coronary artery bypass grafting (OPCABG) is gaining widespread acceptance as the preferred choice for myocardial revascularisation. However, no definite data exist as to whether it is better than conventional CABG. We aimed to study the efficacy of the procedure in our patients, which constituted of a predominantly Asian population.
Methods Between January 2000 and December 2002, 1062 patients underwent isolated coronary artery bypass in our institution. 184 patients (17.3 percent) underwent OPCABG. Patients were preoperatively prospectively risk stratified under the EuroSCORE risk assessment model under high, medium and low risk classes thereby making them comparable. Post-operative complications, intensive care unit stay, hospital stay, types of grafts done were then analysed in these different risk classes.
Results The incidence of off-pump procedures showed a gradual increase over the last three years in this institution. A reduction in the number of post-operative complications, hospital stay, intensive care unit stay and mortality in the off-pump group was observed. Certain differences were found to be statistically significant.
Conclusion Off-pump CABG is a safe and viable alternative to conventional CABG as a treatment modality for surgical coronary revascularisation.

Keywords: cardiac disease, coronary artery bypass grafting, myocardial revascularisation, off-pump coronary artery bypass, grafting
Singapore Med J 2005; 46(1): 15-20

MZC Lam, TJ Lee, PY Boey, WF Ng, HW Hey, KY Ho, PY Cheong
Correspondence: Dr Cheong Pak Yean, cpy@cfps.org.sg

ABSTRACT
Introduction We assessed the accuracy of physician trainees in identifying different cardiac sounds and examined the factors influencing their cardiac auscultation proficiency.
Methods A total of 106 physicians in the Family Medicine Training Programme were asked to identify 10 cardiac sounds played sequentially on the Littmann electronic stethoscope, which functioned as a surrogate patient. Their auscultation accuracy was scored numerically out of a maximum of 10. Demographical data of the physicians was collected prospectively.
Results The mean (+/-SD) auscultation proficiency score of the study population was 4.0 +/- 1.7. Physicians who graduated in 1994 or earlier fared significantly poorer than those who obtained their Bachelor of Medicine and Bachelor of Surgery degrees between 1995 and 2000 (p-value equals 0.02). Auscultation proficiency was not related to current practice, previous years of primary care, cardiology, internal medicine or paediatric medicine postings, or cumulative years of postings. Normal heart sounds were most accurately identified. Prosthetic cardiac sounds were better identified than other extra-cardiac sounds while systolic murmurs were more accurately identified than diastolic murmurs. Tachycardia had the lowest identification rate.
Conclusion Our data suggest that cardiac auscultation skill declined with time, being significantly impaired eight years after graduation. We suggest that there is a need for retraining in the form of continuing medical education to address not only new knowledge and skills, but also basic skill competency.

Keywords: basic skill competency, cardiac auscultation, continuing medical education, physician training
Singapore Med J 2005; 46(1): 11-14

NC Tan, SL Cheah, EK Teo
Correspondence: Dr Ngiap-Chuan Tan, Tan.Ngiap.Chuan@singhealth.com.sg

ABSTRACT
Introduction Asymptomatic Hepatitis virus (HBV) carriers are often followed up at primary and secondary care centres in Singapore. Compliance to disease monitoring is perceived to be a barrier in their management. The study used qualitative methods to determine the health-seeking behavior of HBV carriers. Understanding such behavior will enable the attending physicians to optimise their care and promote regular disease surveillance.
Methods Data were collected from 39 HBV carriers from primary and secondary healthcare centres, with different demographic profiles in eight respective focus group discussions (FGD). A nurse conducted the FGDs using a semi-structured guideline. The qualitative data were analysed using standard content analysis technique.
Results There was evidence of doctor hopping among the HBV carriers in seeking the follow-up of their disease. Cost of review and investigations and preference for specialists' care appeared to be determinants of the sites of disease monitoring. Compliance to follow-up seemed to be sub-optimal, arising from apathy, denial, perceived inconvenience and cost of review. A significant proportion of the carriers had tried alternate therapy, took liver supplements but most found them to be ineffective. Most carriers had adopted healthier lifestyle after their diagnosis with regular exercise, smoking cessation and alcohol abstinence.
Conclusion Many HBV carriers' inadequate understanding of the disease resulted in indifferent or inappropriate health-seeking behavior towards their disease management. There is room for health education for these carriers to enhance their awareness of the disease and improve compliance to disease monitoring.

Keywords: chronic Hepatitis B infection, focus group discussion, disease monitoring, health education, health-seeking behavior
Singapore Med J 2005; 46(1): 6-10