British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Addition of oral clonidine to postoperative patient-controlled analgesia with i.v. morphine.
Using a randomized, double-blind, placebo-controlled design, we have investigated, in 40 patients undergoing major abdominal surgery, the effect of oral clonidine 300 micrograms, 1 h before and 12 h after surgery on postoperative morphine requirements (evaluated by PCA). During the 24 h of the study, pain scores measured every 6 h did not differ significantly. ⋯ Heart rate was significantly lower until 18 h after surgery and sedation was significantly more pronounced in patients receiving clonidine. We cannot recommend routine oral administration of clonidine before surgery to improve postoperative analgesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Haemodynamic and catecholamine changes after induction of anaesthesia with either thiopentone or propofol with suxamethonium.
We have compared the haemodynamic and catecholamine responses to laryngoscopy and tracheal intubation in 43 patients after induction of anaesthesia with either thiopentone 5.1 (SD 0.9) mg kg-1 or propofol 2.2 (0.1) mg kg-1, each with suxamethonium and without opioid pretreatment. Heart rate increased significantly above baseline after induction and intubation in both groups, but there were no differences between groups. Arterial pressure increased significantly at 1 min after intubation in both groups and at 2 min in the thiopentone group only. ⋯ Plasma concentrations of adrenaline were significantly greater in the thiopentone group than in the propofol group at both 1 and 2 min after intubation. Plasma concentrations of noradrenaline showed no significant time-based within-group changes, but were significantly greater in the thiopentone group at 1 and 2 min after intubation. We conclude that doses of either thiopentone or propofol sufficient to obtund the eyelash reflex with suxamethonium 1 mg kg-1 alone do not adequately block the catecholamine and hypertensive responses to laryngoscopy and intubation in normal patients and although propofol suppressed increases in catecholamines to a greater extent than thiopentone, there were no clinical advantages.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of preoperative with postoperative lignocaine infiltration on postoperative analgesic requirements.
Ninety patients undergoing appendicectomy were allocated randomly to receive 1.5% lignocaine 15 ml with adrenaline infiltrated into the proposed wound line 3 min before incision, lignocaine 15 ml with adrenaline infiltrated into the wound on closure or no wound infiltration. After operation, all patients received pethidine by patient-controlled analgesia. ⋯ There were no significant differences in the cumulative dose of pethidine required or pain scores between the three groups at any time point after operation. We conclude that pre-incisional infiltration with 1.5% lignocaine had no advantage compared with infiltration at wound closure or no wound infiltration in reducing postoperative analgesic requirements or pain scores after appendicectomy.
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We have studied plasma protein binding of alfentanil in 10 patients given a mean total dose of 949 micrograms kg-1 as the principal anaesthetic agent for coronary artery bypass grafting. The mean unbound fraction of plasma alfentanil increased from 0.09 to 0.16 after administration of heparin and to 0.26 after beginning cardiopulmonary bypass (CPB). ⋯ Within the first 1 min of CPB, total alfentanil concentration had decreased by more than the unbound concentration and the decrease observed in the latter disappeared rapidly. From induction of anaesthesia until awakening of the patient, plasma protein binding of alfentanil was related significantly (P = 0.0166) to the serum concentration of orosomucoid (alpha 1-acid glyco-protein).