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Biomedical subjects

I K Tan

Publications and source records attributed to I K Tan.

At least 19 recordsLinked to original sources

Spinal haematoma following epidural anaesthesia in a patient with eclampsia.

A patient with a twin pregnancy required a Caesarean section for severe pre-eclampsia. Her platelet count was 71 x 10(9).l-1. Epidural anaesthesia was performed after platelet transfusion. A spinal epidural haematoma was diagnosed postoperatively. A generalised tonic-clonic seizure sparing the lower limbs enabled early diagnosis to be made. The patient recovered with no permanent neurological damage after laminectomy and clot removal. The risks and benefits of regional techniques require careful consideration, and postoperative monitoring for recovery of neural blockade is essential.

Adult

Vitamin E status of infants at birth.

Preterm infants may be susceptible to chronic lung disease and retinopathy of prematurity because of deficient antioxidant mechanisms including deficiency of vitamin E. The aim of this study was to evaluate the status of the antioxidant vitamin E among preterm and term livebirths. Umbilical cord blood samples collected from 40 preterm and 180 term babies were analyzed for vitamin E levels using high performance liquid chromatography. Linear regression analysis was used to examine the relationship of vitamin E with gestational age, birth weight and appropriateness of weight for gestational age. The median vitamin E level of preterm babies (2.61 mg/L) was not significantly different from that of term babies (2.77 mg/L), p = 0.2. Linear regression analysis demonstrated a weak but statistically significant correlation between cord blood vitamin E levels and gestational age (r = 0.14, p = 0.046). Vitamin E levels did not correlate with birth weight or weight for gestational age. Preterm babies had a higher incidence of vitamin E deficiency compared to term babies (38% v 19%, p = 0.02). Our findings lead us to conclude that vitamin E accumulates in the fetus throughout the third trimester so that preterm infants are likely to have vitamin E deficiency.

Birth Weight

Rescue from neutropenic fever and a bamboo pole.

We describe a patient admitted to the intensive care unit following a penetrating head injury. This patient developed agranulocytosis and subsequently pancytopenia secondary to an idiosyncratic drug reaction. The possible causative drugs are phenytoin, cloxacillin, ceftriaxone and ceftazidime. The patient was treated with recombinant human granulocyte colony-stimulating factor.

Adult

APACHE II and SAPS II are poorly calibrated in a Hong Kong intensive care unit.

This study seeks to determine if the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the new Simplified Acute Physiology Score (SAPS II) model predictions are well calibrated in our adult Intensive Care Unit (ICU) patient population. 1064 successive ICU discharges were enrolled with 222 deaths at hospital discharge. APACHE II predicted 287.44 deaths, thus giving an APACHE II standardised mortality ratio (SMR) of 0.77 (95% confidence interval +/- 0.07). SAPS II predicted 269.59 deaths, giving a SAPS II SMR of 0.82 (95% confidence interval +/- 0.07). The Hosmer-Lemeshow goodness-of-fit C statistic was 43.96 for APACHE II and 49.06 for SAPS II (P < 0.001 for both, inferring significant departures from the null hypotheses of good calibration). The area under the Receiver Operating Characteristic plot for SAPS II risk of death was 0.87 (95% confidence interval +/- 0.028) while that for APACHE II risk of death was 0.88 (95% confidence interval +/- 0.026). Although the APACHE II and SAPS II models provide good discriminatory performance this study finds the APACHE II and SAPS II models to be poorly calibrated in that they over-predict mortality in our ICU population.

APACHE

Airway obstruction following internal jugular vein cannulation.

A patient developed neck swelling following removal of an internal jugular vein cannula. Although tracheal extubation was delayed, severe airway obstruction occurred resulting in a cardiac arrest. He was successfully resuscitated. Doppler ultrasonography revealed a huge cervical haematoma surrounding a carotid artery pseudoaneurysm. The carotid artery pseudoaneurysm was obliterated using radiological intervention.

Aged

Case report: recurrent hyperammonaemic encephalopathy due to citrullinaemia in a 52 year old man.

The present report describes a Chinese male who presented for the first time with recurrent encephalopathy and hyperammonaemia at the age of 52 years. He was found to have citrullinaemia. To our knowledge, this is the first Chinese with citrullinaemia and the first non-Japanese who has the variant form of presentation. The patient also has the longest asymptomatic period for citrullinaemia so far described. The patient's biochemical derangement, clinical features and the postulation of his late presentation are discussed. It is noteworthy that simple therapeutic measures, such as lactulose and dietary protein restriction, controlled his symptoms well.

Amino Acid Metabolism, Inborn Errors

Phaeochromocytoma--a rare cause of hypertension in an 11-year-old girl.

Severe sustained hypertension occurs in only 0.1% of the paediatric population and only about 2% of these patients will have an underlying endocrine cause. Phaeochromocytoma as a catecholamine-secreting tumour causing severe hypertension is exceedingly rare in children. A high index of suspicion and an awareness of the clinical spectrum are therefore necessary to make the diagnosis. Phaeochromocytomas can have protean manifestations which may be mistaken for a variety of clinical conditions. We highlight the problems encountered in making the diagnosis in an 11-year-old Chinese girl who presented with sustained hypertension, heart failure and transient renal impairment with two normal 24-hour urinary vanillyl mandelic acid (VMA) results before a third produced the diagnosis. We emphasize that total reliance on a single biochemical urinary screening is not acceptable. The measurement of urinary catecholamines or their metabolites increases the sensitivity of diagnosis. We recommend that in situations where biochemical screening is doubtful, appropriate imaging should be undertaken to exclude the diagnosis.

Adrenal Gland Neoplasms

Inborn errors of metabolism in Singapore.

Between 1992 and 1994 the Paediatric Metabolic Centre screened 403 patients for inherited metabolic disease. Seventeen patients were diagnosed, including 7 with organic acidurias, 5 with mucopolysaccharidoses, 2 with amino acid disorders, 2 with carbohydrate disorders and 1 with hyperlipidaemia. The ethnic distribution of disorders in Singapore is compared with incidences reported by others in this part of the world. It is likely that further studies will indicate which diagnostic or screening tests would best serve this community.

Adolescent

Superimposed inspiratory work of the Siemens Servo 300 ventilator during continuous positive airway pressure.

OBJECTIVE: To compare the superimposed inspired work of breathing (SIW) of the Siemens Servo 300 ventilator with the Siemens Servo 900 C ventilator. DESIGN: Comparisons made at continuous positive airway pressure (CPAP) levels of 0, 4, and 8 cmH2O, and at trigger sensitivities of -1 and -2 cmH2O, and flow triggering. SETTING: General intensive care unit in a University teaching hospital. PATIENTS: 7 patients receiving CPAP. At all levels of CPAP, the SIW was significantly less with the Siemens Servo 300 ventilator as compared to the Siemens Servo 900 C ventilator despite similar trigger sensitivities. No significant difference was found in the SIW of the Servo 300 ventilator when comparing trigger sensitivities of -1 cmH2O, -2 cmH2O, and flow triggering. Different levels of CPAP had no effect on SIW. CONCLUSIONS: The Siemens Servo 300 ventilator entails less superimposed inspiratory work of breathing than the Siemens Servo 900 C ventilator.

Adult

The effect of recombinant growth hormone on nitrogen balance in malnourished patients after major abdominal surgery.

The effect of recombinant growth hormone (rGH) on nitrogen balance was studied in malnourished patients receiving total parenteral nutrition after major abdominal surgery. Fifteen patients were randomized to receive either subcutaneous rGH (0.2 iu/kg) or placebo (saline) injection daily for seven days after surgery. Positive nitrogen balance was achieved throughout the treatment period with rGH administration and was significant on days 3 and 6. This was associated with increase in mid-arm muscle circumference and significant weight gain. Plasma insulin-like growth factor-1 (IGF-1) concentration was significantly raised in the rGH group at day 7, suggesting its role in the anabolic effect of growth hormone. Plasma pre-albumin and retinol-binding protein concentrations were raised in both the rGH and control groups, indicating improvement in the nutritional status. We conclude that the postoperative catabolic response can be attenuated using recombinant growth hormone.

Abdomen