Oxidative burden in prediabetic and diabetic individuals: evidence from plasma coenzyme Q(10).

AIM: Individuals with diabetes and prediabetes are at risk of vascular injury. However, the exact mechanisms are unclear. The mitochondria mobile electron carrier coenzyme Q(10) (CoQ(10)) is a potent lipophilic antioxidant. We hypothesize that oxidative stress, detectable as changes in plasma CoQ(10) concentrations and composition, plays an important role in vascular disease in diabetes. METHODS: We measured plasma CoQ(10) concentrations (including reduced ubiquinol and oxidized ubiquinone subfractions) in 60 subjects with normal glucose tolerance [NGT; fasting plasma glucose (FPG) < 5.5 mmol/l], 63 with impaired fasting glucose (IFG; FPG 5.6-6.9 mmol/l) and 69 with Type 2 diabetes (DM; FPG > 6.9 mmol/l). RESULTS: In men and women, the total CoQ(10)/total cholesterol ratio was reduced in DM (mean +/-sd) [male (M) 0.09 +/- 0.04; female (F) 0.07 +/- 0.04] compared with NGT (0.29 +/- 0.08; 0.21 +/- 0.07) and IFG (0.27 +/- 0.07; 0.23 +/- 0.07) (DM vs. NGT and IFG P = 0.001). A stepwise reduction in the plasma ubiquinol fraction (ubiquinol/total CoQ10) was observed from NGT (M 0.93 +/- 0.06; F 0.95 +/- 0.06) compared with IFG (0.43 +/- 0.25; 0.41 +/- 0.15) and DM (0.24 +/- 0.11; F 0.29 +/- 0.16) (DM vs. IFG vs. NGT P = 0.001). In contrast, the plasma ubiquinone/ubiquinol ratio increased from NGT (M 0.08 +/- 0.07, F 0.06 +/- 0.08) to IFG (2.14 +/- 1.84, 1.75 +/- 1.04) to DM (4.77 +/- 4.88, 3.81 +/- 3.71) (DM vs. IFG vs. NGT P = 0.001). These differences remained after adjusting for age, body mass index and FPG. CONCLUSIONS: The change in CoQ(10) with increasing FPG concentration suggests an increase in oxidative burden, already evident in the prediabetic IFG individuals. This increase in oxidative stress might contribute to the increased risk of vascular disease.

Tetramine poisoning.

We report on two patients who presented with status epilepticus due to ingestion of rat poison containing tetramine. Both had eaten the same meal, subsequently presumed to be the source of the poison. Physical examination and investigation were unremarkable and diagnosis was based on patient history. Seizures were ultimately controlled with ketamine, after unsuccessful attempt of benzodiazepine and sodium thiopentone. One week after poisoning, both patients underwent one session of high-volume haemofiltration followed by charcoal haemoperfusion to eliminate the toxin from the body. Plasma tetramine levels then decreased from 0.95 microgram/mL to 0.35 microgram/mL and from 0.53 microgram/mL to 0.40 microgram/mL, respectively.

Anaemia in the critically ill--the optimal haematocrit.

INTRODUCTION: The optimal haematocrit for the critically ill patient is undetermined. METHODS: This review focuses on clinical and experimental papers regarding the aetiology and management of anaemia from the Medline database. Data from our intensive care unit (ICU) were also included. RESULTS: Anaemia may result from frequent blood sampling, gastrointestinal bleeding, surgical blood loss, impaired erythropoeitic response, and nutritional deficiencies of iron, vitamin B12 and folate. Available data on the minimum tolerated Hct are conflicting. There has been emphasis that transfusions should not be based on a single "trigger". Recent data suggest a linear relationship between Hct and cerebral oxygen delivery (DO2). There is evidence that anaemia increases the mortality, and the risk is higher in patients with cardiovascular disease. Conversely, transfusions are not without risks, which include transmission of infections, incompatibility reactions and immunomodulation. Restricting blood transfusion has been shown to result in lower 30-day mortality in certain patient groups. Minimising blood loss and nutritional support are important. Alternative strategies to transfusion include erythropoeitin and blood substitutes like cell-free haemoglobin, perfluorocarbon emulsions and liposome-encapsulated Hb. Hyperbaric oxygen has also been tried. CONCLUSION: Oxygen consumption requires oxygen delivery. Haematocrit delivers oxygen. However, if oxygen delivery is not limited by haematocrit or is achieved by other means, then the concept of the optimal haematocrit is irrelevant. There are currently no guidelines for the management of anaemia in the critically ill.

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.

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.

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.

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.

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.

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.

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.

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.

Use of prostate specific antigen (PSA) and transrectal ultrasound (TRUS) in the diagnosis of prostate cancer--a local experience.

Prostate specific antigen (PSA) and transrectal ultrasound (TRUS) are two new modalities added to improve our ability to diagnose prostate cancer at an early stage. We reviewed our own experience of 100 cancers among 579 men from August 1991 to October1994. The detection rate was 17.3%. Digital rectal examination (DRE) alone had a positive predictive value (PPV) of 39.9%. The PPV for PSA was 23%. The combination of PSA and DRE gave a PPV of 47.2%. TRUS had a PPV of 30.6%. Features of cancer on TRUS may be both hypoechoic or hyperechoic nodules which appeared to have almost equal proportions associated with cancer. The addition of age-specific ranges did not affect the PPV of PSA. The PPV of the combination of TRUS and DRE was 53%. With all 3 modalities combined, the PPV was 58.8%. An interesting finding from the study was the higher average PSA for benign and malignant disease in the local population and cases of acute retention of urine. There was a higher incidence of prostatitis and lower incidence of cancer in cases with retention of urine.