Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of regularly dosed oral morphine and on-demand intramuscular morphine in the treatment of postsurgical pain.
A randomized, placebo-controlled, double-blind clinical trial was conducted to compare the use of regularly dosed po morphine and on-demand in morphine in 47 patients undergoing total hip arthroplasty. Patients were randomized to receive either 20 mg (initial dose) of regularly dosed morphine (every four hours po) plus breakthrough pain medication on-demand consisting of both 10 mg morphine po and placebo im, or an equivalent regularly dosed oral placebo (every four hours) with breakthrough pain medication consisting of oral placebo and 5-10 mg morphine im. Subsequent to each request for breakthrough pain medication, the next regularly dosed oral solution was increased by 5 mg (or equivalent volume of placebo) to a maximum of 40 mg po Q4H. ⋯ Fewer patients requested breakthrough pain medication on both days in the oral morphine group. The incidence of nausea and vomiting, and of decreased respiratory rates were similar in both groups. Regularly dosed oral morphine is inexpensive and should be compared to other methods of opioid delivery.
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Randomized Controlled Trial Clinical Trial
Morphine does not affect the awakening concentration of sevoflurane.
This study was designed to determine whether morphine 0.1 mg.kg-1 i.v. given intraoperatively altered the end-tidal concentration of sevoflurane which is associated with eye opening to verbal command. We studied 24 healthy ASA physical status I patients to determine whether morphine, or placebo administered about 60 min before the end of surgery affected recovery from sevoflurane/oxygen anaesthesia. During anaesthesia no other anaesthetics or drugs were given. ⋯ In both groups, the MACawake decreased with age, and the ratio to age-adjusted sevoflurane MAC was 0.31 +/- 0.04 (mean +/- SD) for the control group and 0.30 +/- 0.04 for the morphine group. The ratio had no correlation with age. It is concluded that the awakening concentration of sevoflurane during recovery from anaesthesia is not affected by analgesic doses of morphine 0.1 mg.kg-1 i.v. administered intraoperatively.
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Randomized Controlled Trial Clinical Trial
Preoperative plateletpheresis does not reduce blood loss during cardiac surgery.
Acute preoperative plateletpheresis has been reported to be effective in reducing blood loss and blood component transfusion while improving haematological profiles in patients undergoing open-heart surgery. However, in these studies, the concomitant use of cell saver techniques may have been responsible for the beneficial effects because they remove free haemoglobin and activated procoagulants and, therefore, could mask the deleterious effects of combined plateletpheresis and cardiopulmonary bypass (CPB). In the present study, 40 patients undergoing primary myocardial revascularization were randomly divided into two groups: a control group without plateletpheresis performed, and a second group in which preoperative platelet-rich plasma 10 ml.kg-1 (PRP group) was collected and later reinfused after reversal of heparin. ⋯ Reinfusion of autologous PRP did not improve platelet count and function, nor tests of coagulation. Fibrinogen concentrations were lower in the PRP group on the operative day (P < 0.05), suggesting increased fibrinogen consumption; and more patients in the PRP group had low haptoglobin levels during CPB (8/19 vs 0/20 patients, P < 0.005), which indicated greater haemolysis in this group. We conclude that acute preoperative plateletpheresis offers no advantage in haemostasis during elective primary myocardial revascularization surgery.
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Randomized Controlled Trial Comparative Study Clinical Trial
Patient response to laryngeal mask insertion after induction of anaesthesia with propofol or thiopentone.
The response to insertion of the laryngeal mask airway (LMA) following either propofol 2.5 mg.kg-1 or thiopentone 5 mg.kg-1 was assessed in two groups of patients. The purpose of the study was to ascertain which of these two induction agents provided the better conditions for insertion of the LMA. Anaesthesia was induced by propofol in 35 patients and by thiopentone in 37. ⋯ Thiopentone was associated with an adverse response in 76% of patients, compared with propofol in 26% (P < 0.01). Gagging, laryngospasm and head movement were more common using thiopentone (P < 0.01, P < 0.05 and P < 0.05 respectively) and in 11% (P < 0.05) of the thiopentone group insertion of the LMA was impossible due to inadequate relaxation. We conclude that, using these doses, propofol is superior to thiopentone as an induction agent for insertion of the laryngeal mask airway.
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Randomized Controlled Trial Clinical Trial
Improved peribulbar anaesthesia with alkalinization and hyaluronidase.
A prospective double-blind randomized study was carried out to determine the effect of pH and the addition of hyaluronidase to a mixture of lidocaine and bupivacaine on the efficacy of peribulbar anaesthesia. One hundred patients were assigned to one of five groups. All groups received a solution of two parts bupivacaine (0.75%) and one part lidocaine (2%) (with 1:100,000 adrenaline) as the base components of their anaesthesia. ⋯ The solution containing hyaluronidase and pH adjusted to 6.7 was found to be the most effective (P < 0.025). The presence of hyaluronidase without alkalinization did not improve the efficacy of the mixture; and similarly, alkalinization in the absence of hyaluronidase was ineffective. These results reflected the pH- and temperature-dependent thermodynamic properties of local anaesthetics, and the pH-dependent activity of hyaluronidase.