Gregory Kaw

Analysis of deaths during the severe acute respiratory syndrome (SARS) epidemic in Singapore: challenges in determining a SARS diagnosis.

CONTEXT An outbreak of severe acute respiratory syndrome (SARS), an infectious disease attributed to a novel coronavirus, occurred in Singapore during the first quarter of 2003 and led to 204 patients with diagnosed illnesses and 26 deaths by May 2, 2003. Twenty-one percent of these patients required admission to the medical intensive care unit. During this period, the Center for Forensic Medicine, Health Sciences Authority, Singapore, performed a total of 14 postmortem examinations for probable and suspected SARS. Of these, a total of 8 were later confirmed as SARS infections. OBJECTIVE Our series documents the difficulties encountered at autopsy during the initial phases of the SARS epidemic, when the pattern of infection and definitive diagnostic laboratory criteria were yet to be established. DESIGN Autopsies were performed by pathologists affiliated with the Center for Forensic Medicine, Health Sciences Authority, Singapore. Tissue was accessed and read at the Tan Tock Seng Hospital, Singapore, and at the Armed Forces Institute of Pathology, Washington, DC. Autopsy tissue was submitted to the Virology Department, Singapore General Hospital, for analysis, and in situ hybridization for the SARS coronavirus was carried out at the National Institute of Infectious Diseases, Tokyo, Japan. RESULTS Thirteen of 14 patients showed features of diffuse alveolar damage. In 8 patients, no precipitating etiology was identified, and in all of these patients, we now have laboratory confirmation of coronavirus infection. Two of the 8 patients presented at autopsy as sudden unexpected deaths, while the remaining 6 patients had been hospitalized with varying lengths of stay in the intensive care unit. In 3 patients, including the 2 sudden unexpected deaths, in situ hybridization showed the presence of virally infected cells within the lung. In 4 of the 8 SARS patients, pulmonary thromboemboli were also recognized on gross examination, while one patient had marantic cardiac valvular vegetations. CONCLUSIONS It is unfortunate that the term atypical pneumonia has been used in conjunction with SARS. Although nonspecific by itself, the term does not accurately reflect the underlying dangers of viral pneumonia, which may progress rapidly to acute respiratory distress syndrome. We observed that the clinical spectrum of disease as seen in our autopsy series included sudden deaths. This is a worrisome finding that illustrates that viral diseases will have a spectrum of clinical presentations and that the diagnoses made for such patients must incorporate laboratory as well as clinical data.

Pulmonary function and exercise capacity in survivors of severe acute respiratory syndrome

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS). At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing. No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment. In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.

Hypocortisolism in survivors of severe acute respiratory syndrome (SARS)

Objective  Following the severe acute respiratory syndrome (SARS) outbreak, many survivors were observed to suffer from psychosomatic symptoms reminiscent of various endocrine disorders. Hence, we sought to determine the existence of any chronic endocrine sequelae in SARS survivors.

1-Year Pulmonary Function and Health Status in Survivors of Severe Acute Respiratory Syndrome

Study objectives To characterize the long-term pulmonary function and health status in a prospectively identified cohort of patients who survived the severe acute respiratory syndrome (SARS). Design Prospective follow-up cohort study. Setting University-affiliated hospital. Patients Ninety-four patients who recovered from SARS were assessed at a uniform time point of 1 year after hospital discharge. Measurements The study included the measurement of static and dynamic lung volumes, the determination of the diffusing capacity of the lung for carbon monoxide (Dlco), and a health status evaluation using the St. George Respiratory Questionnaire (SGRQ). Results Eleven patients (12%) had mild impairment of FVC, 20 (21%) had mild impairment of FEV1, 5 (5%) had mild impairment of the FEV1/FVC ratio, and 17 (18%) had mild impairment of the Dlco. There was one patient (1%) who had moderate impairment of FVC, one patient (1%) who had moderate impairment of the FEV1/FVC ratio, and three patients (3%) who had moderate impairment of the Dlco. No pulmonary function abnormalities were detected in 59 patients (63%). Mean scores were significantly higher (ie, worse) than the population norms in the activity (p < 0.001), impacts (p < 0.001), and total (p < 0.001) domains of the SGRQ. Conclusions One year after recovery from SARS, persistent pulmonary function impairment was found in about one third of patients. The health status of SARS survivors was also significantly worse compared with the healthy population. The main determinants of morbidity in recovered SARS patients need to be further defined.

Comprehensive noninvasive evaluation of bypass grafts and native coronary arteries in patients after coronary bypass surgery: accuracy of 64-slice multidetector computed tomography compared to invasive coronary angiography.

Aims We assessed the accuracy of 64-slice multidetector computed tomography (MDCT) compared with that of invasive coronary angiography (ICA) in the evaluation of symptomatic postcoronary artery bypass graft (post-CABG) patients. Methods MDCT and ICA were performed in 44 consecutive post-CABG patients with chest pain (mean age 66 ± 10 years, mean duration post-CABG 9 ± 5 years). MDCT findings were compared with the corresponding ICA, which was read by an interventional cardiologist blinded to the MDCT findings. Significant stenosis was defined as at least 50% luminal stenosis. Results One hundred and thirty-seven grafts (31 arterial and 106 venous), all evaluable by MDCT, were assessed. In a ‘per graft’ analysis, MDCT could detect significant disease in bypass grafts (graft occlusion or stenosis) with a sensitivity of 98% and specificity of 98%. In a ‘per segment’ analysis, MDCT could detect significant disease in all native coronary arteries with a sensitivity of 91% and specificity of 79% and in clinically relevant native coronary arteries with a sensitivity of 92% and specificity of 84%. In a ‘per vessel’ analysis, MDCT could differentiate native arterial occlusion from nonocclusive stenosis with a sensitivity of 68% and specificity of 70%. In a ‘per patient’ analysis, MDCT could detect significant disease in bypass grafts or clinically relevant native coronary arteries with a sensitivity of 100%, specificity of 40% and accuracy of 93%. Conclusion Sixty-four-slice MDCT allows evaluation of bypass grafts and native coronary arteries in post-CABG patients. Although accurate for detecting bypass graft disease, 64-slice MDCT has significant limitations when evaluating native arteries in post-CABG patients.

Infrared thermographic in identification of human elevated temperature with biostatistical and ROC analysis

This paper evaluates the effectiveness of thermal scanner when it is being used for mass blind screening of potential fever subjects. Both regression and ROC curve are used to analyze the data collected from the SARS hospital in Singapore and conclusive results are drawn from them. These results will be vital in determining two very important information: the best and yet practical region on the face to take readings and optimal pre-set threshold temperature for the thermal imager.

CD99 negative primary sciatic nerve Ewing family tumour in a middle-aged woman: a rare clinical presentation

Sir, Ewing family tumours (EFTs) comprise a group of morphologically heterogeneous small round cell tumours (SRCTs) characterised by a non-random chromosomal translocation involving the Ewing’s sarcoma (EWS) gene and one of several members of the ETS family of transcription factors. A presentation as a primary peripheral nerve tumour lacking CD99 expression is rare, and this case illustrates the importance of corroborating molecular techniques with the clinical, light microscopic and immunohistochemical findings in establishing a correct diagnosis given the unusual clinical context. To the best of our knowledge, this is the first reported case of a primary peripheral nerve EFT where the application of fluorescent in situ hybridisation (FISH) was pivotal in the diagnosis. A previously healthy 39-year-old Malay female was admitted in April and August 2004 and April 2005 for severe, sharp pain over the left posterior thigh radiating to the left foot, which resolved with analgesia after a period of observation during the first two admissions. There was no history of trauma, back pain, bowel and urinary incontinence, or constitutional symptoms. A magnetic resonance imaging (MRI) scan of the lumbar spine performed during her first admission was normal. Although treated symptomatically as for a back strain, the pain became progressively worse in the few months before her third admission. Physical examination and electromyography showed features consistent with a left sciatic peripheral neuropathy, in addition to a tender mass in the posteromedial aspect of the left thigh. A MRI scan revealed an ill-defined, 86464 cm fusiform mass arising from the left sciatic nerve, with displacement of the surrounding muscles (Fig. 1). A biopsy with intra-operative frozen section was performed in July 2005 at another institution. A subsequent bone scintigraphy and computed tomography (CT) scan of the thorax

Ministry of Health Clinical Practice Guidelines: Prevention, Diagnosis and Management of Tuberculosis.

The Ministry of Health (MOH) has developed the clinical practice guidelines on Prevention, Diagnosis and Management of Tuberculosis to provide doctors and patients in Singapore with evidence-based treatment for tuberculosis. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Prevention, Diagnosis and Management of Tuberculosis, for the information of SMJ readers. The chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Pulmonary function and exercise capacity in survivors of Severe Acute Respiratory Syndrome

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS). At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing. No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment. In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.