British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Influence of different anticoagulation regimens on platelet function during cardiac surgery.
Qualitative platelet defects are of great importance as a cause of bleeding in cardiac surgery. We have studied the effects of different anticoagulation regimens on platelet function in 60 patients undergoing elective aorto-coronary bypass grafting with cardiopulmonary bypass (CPB). Patients were allocated randomly to four groups (each group n = 15) to receive either: bovine heparin 300 u. kg-1 (standard); heparin 300 u. kg-1 followed by a continuous infusion of 10,000 u. kg-1 until the end of CPB; heparin 600 u. kg-1; or heparin 600 u. kg-1 in addition to high-dose aprotinin 2 million iu before CPB, 500,000 iu h-1 until the end of operation and 2 million iu added to the prime. ⋯ Mean total dose of heparin given in groups 2, 3 and 4 was more than 50,000 u. and differed significantly from that of group 1 (28,150 (SD 4700)u.). Platelet aggregation variables were most depressed during CPB and until the end of surgery in groups 2 and 3 (maximum aggregation - 54% to - 75% of baseline values). In the postoperative period, platelet function recovered but did not completely reach baseline values in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Continuous monitoring of depth of sedation by EEG spectral analysis in patients requiring mechanical ventilation.
Twenty-three patients undergoing intensive therapy had continuous EEG recording in an attempt to assess depth of sedation using spectral analysis. Median power frequency (MPF) and spectral edge frequency (SEF) were calculated and correlated with the clinical sedation score and blood concentration of sedative drug. ⋯ There was no correlation between MPF or SEF and sedation score or blood concentration of drug. These results suggest that no simple measure of the EEG is likely to correlate with depth of sedation in critically ill patients.
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Randomized Controlled Trial Clinical Trial
Effects of oral nizatidine on preoperative gastric fluid pH and volume in children.
We have studied the effect of oral nizatidine 6 mg kg-1 in total on preoperative gastric fluid pH and volume in children. One hundred and four healthy children, aged 4-11 yr, were allocated randomly to four groups (n = 26): placebo administered at 21:00 and 06:30 the night before and on the day of surgery, respectively (placebo-placebo: control); nizatidine 6 mg kg-1 at 21:00 and placebo at 06:30 (nizatidine-placebo); placebo at 21:00 and nizatidine 6 mg kg-1 at 06:30 (placebo-nizatidine); and nizatidine 3 mg kg-1 at 21:00 and 06:30 (nizatidine-nizatidine). Each child ingested a large volume of apple juice 3 h before estimated induction of anaesthesia. ⋯ Mean pH in the placebo-nizatidine and nizatidine-nizatidine groups was significantly higher than that in the placebo-placebo group (5.7 (SEM 0.3), 6.0 (0.3) vs 1.8 (0.2), respectively) (P < 0.05). Mean pH in the nizatidine-placebo group was similar to that in the control group (2.3 (0.3) vs 1.8 (0.2)). The number of children with pH < 2.5 and volume > 0.4 ml kg-1 in the nizatidine-nizatidine (0%) and placebo-nizatidine (4%) groups was reduced compared with the control (46%) or nizatidine-placebo (38%) group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Extradural analgesia in labour: complications of three techniques of administration.
We have studied the complications associated with three techniques used to maintain extradural analgesia in labour: midwife top-up doses of 0.25% bupivacaine 10 ml, continuous infusion of 0.125% bupivacaine 10 ml h-1 and patient-controlled extradural analgesia (PCEA) with self-administered 3-ml bolus doses of 0.25% bupivacaine. A significantly higher intervention rate by an anaesthetist was required in the continuous infusion group. ⋯ Uneventful hypotension occurred in three women; two receiving PCEA and one receiving continuous infusion. Ten women experienced sensory blocks extending above T7 with no ill effects; seven receiving PCEA and three continuous infusion.