HAEMODYNAMIC EFFECTS FOLLOWING SURGICAL RELEASE OF INCREASED INTRA-ABDOMINAL PRESSURE

The haemodynamic indices of three patients, who developed abdominaltamponade as a result of intra-abdominal bleeding followingliver transplantation, were measured on four occasions as theincreased intra-abdominal pressure was released. Hypotensionfollowed the release of the tamponade in all patients and wasthe result of a decrease in systemic vascular resistance. Thiswas treated with vasoconstrictors; the response to various agentswas monitored. Treatment of hypotension following release ofabdominal tamponade by volume replacement alone may be inappropriateand may lead to over-transfusion; adrenaline may be the treatmentof choice. Intensivemonitoring is advisable.     

The anaphylaxis hypothesis of sudden infant death syndrome (SIDS): mast cell degranulation in cot death revealed by elevated concentrations of tryptase in serum

A series of cases of sudden unexpected post-neonatal deaths from two centres in the UK have been investigated for evidence of mast cell activation using the biochemical markers tryptase and 9α,11β-PGF₂. Tryptase was selected as a possible marker because it is a component of mast cell secretory granules and, unlike histamine, it is not released from basophils. The prostaglandin 9α,11β-PGF₂ is an initial and pharmacologically active metabolite of PGD₂, the major mast cell-derived cyclo-oxygenase product. This prostaglandin was chosen to serve as a marker of newly generated mediator release. In the study, unexplained infant deaths were associated with a higher concentration of tryptase in serum compared with cases of unexpected, but subsequently explained death. However, 9α,11β-PGF₂ was found to be an unsuitable post mortem marker in this situation. These results provide direct evidence that mast cell degranulation, possibly as a result of anaphylaxis, may be occurring around the time of death in some cases of cot death.     

Does conception before marriage matter?

Summary. Data from the 1970 British Births survey were used to compare 1380 births conceived before marriage (women who were delivered less than 6 months after marriage) with 13845 births to women who had been married for at least 6 months before delivery. Infants in the premarital conception group were at increased risk because of maternal youth, primiparity and maternal health behaviour such as smoking. Once these factors had been taken into account there was no residual risk of perinatal death or low birthweight. There was a slight excess of preterm deliveries.     

Effect of different doses of omeprazole on 24-hour oesophageal acid exposure in patients with gastro-oesophageal reflux

To define the optimum doses of omeprazole appropriate for acute and long-term therapy of patients with gastro-oesophageal reflux disease, 24-h oesophageal pH was measured in 12 patients with symptomatic reflux and an abnormal 24-h oesophageal acid exposure time (greater than 6%) in a randomized, double-blind, four-way crossover study comparing the effects of omeprazole 10, 20, or 40 mg/day and placebo. Total reflux time over 24 hours, number of reflux episodes per hour, and the number of reflux episodes lasting greater than 5 minutes were measured by ambulatory 24-h oesophageal pH monitoring. All doses of omeprazole were superior to placebo in decreasing gastro-oesophageal reflux as measured by each index. With placebo, oesophageal acid exposure was 16.3% of the 24 hours, 10 mg omeprazole/day reduced that to 6.3%, 20 mg/day lowered acid exposure to 0.9%, and 40 mg/day to 0.6%. Thus only the 20 and 40 mg doses reduced acid exposure to within the normal range. Similar results were obtained with the other indices of reflux. These data suggest that a rational dose regimen for reflux oesophagitis is 20 mg/day, a regimen that has proved effective in clinical trials. The present study indicates that 24-hour oesophageal pH monitoring is a practical approach to the determination of drug dosage in patients with gastro-oesophageal reflux.     

ORIGINAL ARTICLE: Are 10 min of seating enough to guarantee stable haemoglobin and haematocrit readings for the athlete’s biological passport?

Haemoglobin (Hb) and haematocrit (Hct) are measured as indirect markers of doping in athletes. We studied the effect of posture on these parameters in a typical antidoping setting. Venous blood samples were obtained from nine endurance athletes (six males, three females) and nine control subjects (six males, three females) immediately and after 5, 10, 15, 20 and 30 min after having adopted a seated position from normal daily activity. Hb (CV 0.72%) and Hct (CV 0.87%) were determined using an automated cell counter, plasma volume changes were calculated. Differences between the time points, gender and groups were calculated using a mixed-model procedure. Significant changes were observed in the first 10 min after sitting down but no further changes were noted between 10 and 30 min. Mean directional change for Hb and Hct between 0 min and the average of the period from 10 to 30 min was −2.4% (−0.35 g/dl) for Hb and −2.7% (−1.2%) for Hct. Plasma volume increased accordingly. Neither group nor gender had significant effects. Under typical conditions encountered during blood testing in doping control, a period of 10 min in a seated position is sufficient for the vascular volumes to re-equilibrate and to adapt to the new posture.