British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of alfentanil, fentanyl and sufentanil for total intravenous anaesthesia with propofol in patients undergoing coronary artery bypass surgery.
We have studied the pharmacokinetics and pharmacodynamics of alfentanil, fentanyl and sufentanil together with propofol in patients undergoing coronary artery bypass graft surgery (CABG). Sixty patients (age 40-73 yr, 56 male) were assigned randomly to receive alfentanil, fentanyl or sufentanil and propofol. Plasma concentrations of these drugs and times for the plasma concentration to decrease by 50% (t50) and 80% (t80) after cessation of the infusion were determined. ⋯ However, the t50 values for these opioids were similar and did not correlate with recovery time. In conclusion, patients undergoing CABG and who were anaesthetized with fentanyl and propofol needed mechanical ventilatory support for a significantly longer time than those receiving alfentanil or sufentanil and propofol. On the basis of the interindividual variation observed, the time to tracheal extubation was most predictable in patients receiving alfentanil and most variable in patients receiving fentanyl, a finding which may be important if the patients are transferred to a step-down unit on the evening of the operation.
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Randomized Controlled Trial Comparative Study Clinical Trial
Peripheral lidocaine but not ketamine inhibits capsaicin-induced hyperalgesia in humans.
We examined the effect of the subcutaneous infiltration of ketamine, lidocaine and saline before injury on capsaicin-induced pain and hyperalgesia. Twelve healthy volunteers participated in two separate, randomized, double-blind, placebo-controlled crossover experiments. In experiment 1, 100 micrograms capsaicin was injected intradermally in one volar forearm 10 min after the skin had been pretreated with lidocaine 20.0 mg in 2.0 ml or 0.9% saline 2.0 ml at the capsaicin injection site. ⋯ Pain scores and areas of hyperalgesia were not affected when the contralateral site was infiltrated with ketamine or lidocaine. Lidocaine produced no side-effects, whereas ketamine produced paraesthesia, dizziness and sleepiness in six out of 24 (25%) cases. Blocking peripheral sodium channels with locally administered lidocaine reduces spontaneous pain and capsaicin-induced hyperalgesia but local block with the NMDA-type glutamate receptor antagonist ketamine has no effect on capsaicin-induced pain and hyperalgesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of intubating conditions following propofol and succinylcholine with propofol and remifentanil 2 micrograms kg-1 or 4 micrograms kg-1.
We evaluated the intubating conditions, haemodynamic responses and duration of apnoea in 60 healthy adult patients after propofol 2 mg kg-1 combined with either a bolus of remifentanil 2 micrograms kg-1 or 4 micrograms kg-1, or succinylcholine 1 mg kg-1. Patients intubated following remifentanil showed dose-dependent intubating conditions, similar at 4 micrograms kg-1 to the conditions produced with succinylcholine. Post-induction mean arterial pressure decreased from baseline values by 21% (P < 0.0001), 28% (P < 0.0001) and 8% (P > 0.05) in the remifentanil 2 micrograms kg-1, remifentanil 4 micrograms kg-1 and succinylcholine 1 mg kg-1 groups, respectively. The mean (SD) duration of apnoea following induction was 9.3 (2.6) min and 12.8 (2.9) min in the remifentanil 2 micrograms kg-1 and 4 micrograms kg-1 groups, and 6.0 (0.9) min in the succinylcholine group (P < 0.001 between groups).
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Randomized Controlled Trial Comparative Study Clinical Trial
Clinical comparison of 'single agent' anaesthesia with sevoflurane versus target controlled infusion of propofol.
The introduction of total intravenous anaesthesia (TIVA) and the use of volatile induction/maintenance anaesthesia (VIMA) has led to the rediscovery of 'single agent' anaesthesia, eliminating the transition phase from induction to maintenance. We compared quality, patient acceptability and cost of TIVA using target control infusion (TCI) with propofol and VIMA with sevoflurane. Forty patients undergoing spinal surgery of 1-3 h were assigned to one of two groups. ⋯ Cardiovascular stability was good and comparable in both groups. The majority of patients found either technique acceptable and would choose the same anaesthetic again. Induction and maintenance was substantially cheaper with sevoflurane (28.06 Pounds) compared with propofol (41.43 Pounds).
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The lower inflection point (LIP) of the inspiratory limb of a static pressure-volume (PV) loop is assumed to indicate the pressure at which most lung units are recruited. The LIP is determined by a static manoeuvre with a PV-history that is different from the PV-history of the actual ventilation. ⋯ Volume-dependent dynamic compliance suggested a PEEP reduction (to 15 (13-18) cm H2O). Pulmonary gas exchange remained satisfactory and this change resulted in reduced mechanical stress on the respiratory system, indirectly indicated by volume-dependent compliance being consistently great during the entire inspiration.