Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of non-selective, non-steroidal anti-inflammatory drugs and cyclo-oxygenase-2 selective inhibitors on the PFA-100 closure time.
The place of cyclo-oxygenase (COX)-2 selective non-steroidal anti-inflammatory drugs (NSAIDs) in the peri-operative period remains under discussion. Due to the absence of COX-2 in platelets, the risk of bleeding in patients who use selective NSAIDs is thought to be decreased. We studied the influence of aspirin, diclofenac, lornoxicam and rofecoxib on the in vitro bleeding time using the platelet function analyser (PFA-100). ⋯ Measurements in 43 volunteers were performed at three time points: before, 3 h, and 12 h after oral ingestion of one of the randomly assigned study medications. Aspirin, diclofenac and lornoxicam had a significant effect on the in vitro closure time, while rofecoxib did not show this effect. This supports the use of COX-2 selective drugs in the peri-operative period to minimise the risk of bleeding.
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Caesarean section carries a high risk of awareness, especially in the period prior to neonatal delivery. We investigated the concentration of sevoflurane required to maintain bispectral index (BIS) < 60 until delivery occurred. We enrolled 23 parturients into an up-down sequential allocation study. ⋯ The EC(50) for sevoflurane was 1.22% (1.08-1.33, 95% CI). The probability of maintaining BIS < 60 was < 55% at a concentration of < 1.1%; this increased to 80% at concentrations of 1.2-1.3%. We conclude that sevoflurane concentrations of at least 1.2-1.3% should be administered in uncomplicated Caesarean section, so as to minimise the risk of awareness and recall.
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Infusion devices for continuous and precise drug administration are indispensable tools in anaesthesia and critical care medicine. Problems such as start-up delays, non-continuous flow and susceptibility to hydrostatic pressure changes at low infusion rates resulting in accidental bolus release or prolonged flow interruption are inherent to current infusion technology. ⋯ The performance of the MVIP prototype has been evaluated and compared with standard syringe infusion pump assemblies. The novel MVIP concept has thereby proven to eliminate most problems during infusion start-up, steady state flow and vertical pump displacement, and has the potential of revolutionising infusion technology and setting a new dimension in patient safety.
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Alterations of electrolytes and albumin cause metabolic acid-base disorders. It is unclear, however, to what degree these plasma components affect the overall metabolic acid-base state in the course of critical illness. We performed serial analyses of the metabolic acid-base state in 30 critically ill patients over the course of 1 week. ⋯ Changes in serum chloride and unmeasured anions were responsible for changes of 41% and 22% in the metabolic acid-base state, respectively. Sodium and albumin played a minor role. In conclusion, chloride is the major determinant of metabolic acid-base state in critical illness.
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Comparative Study Clinical Trial Controlled Clinical Trial
Continuous assessment of right ventricular ejection fraction: new pulmonary artery catheter versus transoesophageal echocardiography.
In 25 cardiac surgical patients, right ventricular ejection fraction was continuously measured with a new pulmonary artery catheter and transoesophageal echocardiography, scanning the 'fractional area change' in a standardised transatrial cross section area. Measurements were recorded at three predefined time points (pre-, intra-, and postoperatively). ⋯ Bias and precision significantly improved when the heart rate was less than 100 beats.min(-1), pulmonary artery pressures were low and cardiac performance adequate. In conclusion, the new continuous pulmonary artery catheter system appears to be a valid and useful bedside monitoring device in the haemodynamic management of critically ill patients.