2005

FJ Ruiz-Ruiz, D Saenz-Abad, AM Hualde-Enguita, JL Morales-Rull
Correspondence: Dr Francisco J Ruiz-Ruiz, fjruizl@terra.es

ABSTRACT
Metastatic cancer of unknown primary site represents approximately three percent of all new cancer diagnoses. Expensive and invasive diagnostic procedures are often performed although the primary tumour is detected in less than 25 percent of cases. We present a 63-year-old woman presenting with low back pain and was found on positron emission tomography (PET) to have lung cancer. The pros and cons of PET in the diagnostic process of patients with metastatic cancer of unknown primary site are reviewed. PET should be considered in the diagnostic process of patients with unknown primaries, and unnecessary invasive procedures may be avoided.

Keywords: cancer, metastases, positron emission tomography, unknown primary neoplasm
Singapore Med J 2005; 46(6): 302-303

SC Ong, DCE Ng, FX Sundram
Correspondence: Dr Seng Chuan Ong, gnmosc@sgh.com.sg

ABSTRACT
Introduction This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in thyroid carcinoma patients with elevated serum thyroglobulin (Tg) but negative iodine-131 (I-131) whole body scans.
Methods 17 patients with differentiated thyroid carcinoma who underwent FDG PET/CT scans were reviewed retrospectively over a period of one year from July 2003 to June 2004. All these patients had completion thyroidectomy and subsequently presented with elevated serum Tg but negative post-therapy I-131 whole body scans. Nine of these patients underwent FDG PET/CT in a hypothyroid state, while the remainder underwent FDG PET/CT while on thyroxine replacement.
Results 15 out of 17 PET/CT scans revealed lesions consistent with metastases, giving a sensitivity of 88.2 percent. Four of these patients were amendable to surgical treatment. Two scans were negative.
Conclusion FDG PET/CT is a sensitive diagnostic tool to detect radioiodine-negative recurrences/metastases in patients with thyroid carcinoma. Our preliminary results are comparable with published results based on PET.

Keywords: computed tomography, fluorine-18-fluorodeoxyglucose, positron emission tomography, thyroglobulin, thyroid cancer
Singapore Med J 2005; 46(6): 297-301

LP Tham, I Chan
Correspondence: Dr Tham Lai Peng, sharonlp@kkh.com.sg

ABSTRACT
Introduction Little information is available regarding the outcome of children in our local population who sustained pre-hospital cardiac arrest. This study was performed to determine the survival rate among children after out-of-hospital cardiac arrest, to describe the epidemiology, and to identify predictors of survival.
Methods The records of 85 children who presented to a paediatric emergency department in cardiac arrest, between 1 June 1997 and 31 September 2001, were reviewed. The characteristics of the patients, cardiac arrest circumstances, and the outcomes of arrest were analysed.
Results 85 children presented to the emergency department in cardiac arrest during the 52-month study period. 26 out of 85 children (30.6 percent) with cardiac arrest had return of spontaneous circulation (ROSC) after resuscitation efforts at the emergency department. Only four (4.7 percent) survived to be discharged from hospital and three of them survived beyond one year. Two of the cardiac arrest survivors had no change in the neurological status, with the remaining two sustaining severe neurological deficits. Emergency medical service was activated in only 63.7 percent of the patients. 34 percent of the arrests were witnessed, and only 22.9 percent of the children received bystander cardiopulmonary resuscitation (CPR). The positive predictors for survival to hospital discharge in a bivariate analysis were witnessed arrest (p-value is equal to 0.012), presence of bystander CPR (p-value is equal to 0.003), and duration of resuscitation (p-value is equal to 0.028). None who had more than 30 minutes of resuscitation in the emergency department survived. In a multivariate analysis with a logistic regression model, the only two independent predictors of ROSC were witnessed arrest (odds ratio is 3.049; 95% confidence interval [CI] is 1.101-8.444; p-value is equal to 0.032) and duration of resuscitation (odds ratio is 0.353; 95% CI is 0.146 - 0.854; p-value is equal to 0.021).
Conclusion Out-of-hospital cardiac arrest in children has a poor prognosis and prolonged resuscitation at the emergency department beyond 30 minutes does not improve survival.

Keywords: cardiac arrest, cardiopulmonary resuscitation, emergency medical service, paediatric cardiac arrest
Singapore Med J 2005; 46(6): 289-296

K Lew, PJ Barlow
Correspondence: Dr Philip John Barlow, chmpjb@nus.edu.sg

ABSTRACT
Introduction This study sets out to investigate any differences in dietary practices between adolescents in Singapore and Malaysia.
Methods An adolescent dietary practices survey was conducted in Singapore and Malaysia involving 200 adolescents (100 from each country) aged 11 to 21 years in order to have a better understanding of the adolescents' dietary practices. Dietary practices were assessed by a self-administered dietary practices questionnaire (DPQ).
Results The major differences identified between adolescents' dietary practices in Singapore and Malaysia are related to alcohol consumption and venue for taking of lunch. More Malaysian adolescents have their lunch prepared at home (32.9 percent), compared with 7.2 percent of Singaporean adolescents. More adolescents in Malaysia drink alcohol (49.4 percent), compared with only 21.7 percent of Singaporean adolescents.
Conclusion From the dietary practices survey of adolescents from Singapore and Malaysia, it may be concluded that while general dietary practices are similar, the major differences identified were significantly (p-value is less than 0.05) higher alcohol consumption by Malaysian adolescents and significantly (p-value is less than 0.05) more Malaysians took their lunch at home compared with Singaporeans. The reasons for the differences are discussed in the paper.

Keywords: adolescent dietary practice, diet, food habits, nutritional behaviour
Singapore Med J 2005; 46(6): 282-288

HY Lee, EL Lee, P Pathy, YH Chan
Correspondence: Dr Lee Huei Yen, gdmlhy@sgh.com.sg

ABSTRACT
Introduction Information regarding the clinical features of patients with anorexia nervosa in Singapore is rare and there have not been any large studies published to date. The aims of this paper were to study the clinical characteristics and features of patients with anorexia nervosa in Singapore, and to compare the clinical features of the early versus the classical later-onset cases.
Methods 126 cases presenting to the Child Guidance Clinic and the Eating Disorder Clinic at the Institute of Mental Health between 1994 and 2002 were identified and studied retrospectively. All presented with anorexia nervosa or had a past history of it. Subjects were further classified into early-onset (younger than 14 years) or classical later-onset (14 years and older), and a comparison was done between the two groups.
Results The large majority were female students with a mean presenting age of 17.6 years. 65.1 percent were of the restricting subtype. 84.1 percent were Chinese, 7.9 percent were Indians and 4.8 percent were Malays. Mean presenting body mass index (BMI) was 15.56. Depression was the most common co-morbid condition affecting 25.4 percent of the sample. The number of new cases increased significantly from six in 1994 to 24 in 2002 (p-value equals 0.002). Commonest precipitating factors were comments from others, school and work stress. 11.1 percent were previously members of trim and fit club in school. 42.7 percent of late-onset cases compared to 16.2 percent of the early-onset were of the binge-purge type (p-value equals to 0.005) and had a higher presenting BMI (15.91 +/- 2.90 versus 14.74 +/- 2.14, p-value equals 0.003).
Conclusion The clinical characteristics of patients with anorexia nervosa in Singapore are similar to that reported in western literature. The Malay population appears to be under-represented. There was a significant increase in numbers presenting over the last two years. The early-onset cases tend to be of the restrictive-type and had a lower presenting BMI than the later-onset group.

Keywords: anorexia nervosa, body mass index, depression, eating disorder
Singapore Med J 2005; 46(6): 275-281

S Green
Correspondence: Dr Sally Green, sally.green@med.monash.edu.au

ABSTRACT
Systematic reviews form a potential method for overcoming the barriers faced by clinicians when trying to access and interpret evidence to inform their practice. This fourth article in the Evidence-Based Medicine and Healthcare series of the Singapore Medical Journal introduces readers to systematic reviews, outlining why they are important, describing their methods and providing readers with the skills to recognise and understand a reliable review.

Keywords: evidence-based medicine, meta-analysis, systematic reviews
Singapore Med J 2005; 46(6): 270-274