Effect of informational internet web pages on patients' decision-making: randomised controlled trial regarding choice of spinal or general anaesthesia for orthopaedic surgery.

This study explored whether patients' preference for particular types of anaesthesia could be influenced pre-operatively by giving them the addresses of various relevant websites. Patients at an orthopaedic pre-assessment education clinic completed a questionnaire, which included a short multiple-choice general knowledge quiz about anaesthesia, and also questioned them as to their choice of anaesthesia (general or neuraxial). Patients were randomly assigned to intervention or control groups. Intervention group members were given the addresses of three relevant anaesthesia and health related websites to access at home. All patients were asked to complete the questionnaires on a second occasion, before surgery. Initially, most patients stated a preference for general anaesthesia. Subsequently, the intervention group altered their preference towards neuraxial anaesthesia compared to the control group (p < or = 0.0001). The increase in median (IQR [range]) anaesthesia knowledge test score was greater in the intervention group (from 10.0 (9.0-12.0 [5.0-14.0]) to 13.0 (11.0-14.0 [6.0-14.0])) than in the control group (from 10.0 (9.0-11.5 [3.0-13.0]) to 11.0 (9.0-12.0 [4.0-14.0]); p = 0.0068).

Comparison of the analgesic efficacy and plasma concentrations of high-dose intra-articular and intramuscular morphine for knee arthroscopy.

BACKGROUND AND OBJECTIVE: It is important to provide good postoperative analgesia after discharge from day case surgery. The usefulness of intra-articular morphine for analgesia after day case knee arthroscopy remains controversial. A large dose of morphine intra-articularly may provide a good long-lasting analgesia, but its efficacy and pharmacokinetics are not known and may be no better than intramuscular morphine. We compared the effect of 10 mg intra-articular and intramuscular morphine for 24 h post-injection in a randomized double-blind study. METHODS: Forty adults undergoing knee arthroscopy were recruited and received either 10mg morphine intra-articularly or intramuscularly. Our primary outcome was overall visual analogue assessment of pain (0-100 mm scale where 0 is no pain and 100 is worst possible pain) between 4 h (on discharge) and 24 h (post-operatively). Plasma morphine concentrations were measured at 15 min, and 1, 2, 4 and 24 h. The use of additional analgesia was noted. RESULTS: The assessment of pain experienced between discharge (4 h) and 24 h was significantly better in the intra-articular (n = 20; mean+/-SD: 18+/-19) than the intramuscular (n = 19; mean+/-SD: 34+/-20) group (P = 0.027). The number of patients consuming any additional analgesia between discharge and 24 h was significantly lower in the intra-articular morphine group (P = 0.038), with 4 (20%) patients in the intra-articular group and 11 (60%) patients in the intramuscular group consuming supplementary analgesia. There were no differences in plasma morphine concentrations between the groups. CONCLUSIONS: A large dose of intra-articular morphine provided better analgesia than the same dose of intramuscular morphine, low plasma morphine levels suggesting a peripheral mechanism.

Effects of halothane, enflurane and isoflurane anaesthesia on renal plasma flow.

Effective renal plasma flow (ERPF) and linear cardiac output (aortic blood velocity) were measured in 15 patients who received halothane, enflurane or isoflurane in oxygen. All three agents caused a significant reduction in ERPF (P less than 0.05) and the effect was greater at 1.25 MAC than at 0.75 MAC. No significant difference was demonstrated between the agents. Linear cardiac output did not change significantly during the study, suggesting that the observed reduction in ERPF was not caused by cardiovascular depression.

Comparison of the effects of dopamine, dobutamine, and dopexamine upon renal blood flow: a study in normal healthy volunteers.

1. We compared the effects of dopexamine, dopamine and dobutamine on the heart rate, blood pressure and renal blood flow of six healthy volunteers in an open triple crossover trial. 2. The results suggest that at the dose ranges investigated dopamine was the most effective agent for increasing renal blood flow.

Effects of benzodiazepines on laryngeal reflexes. Comparison of lormetazepam and Diazemuls.

Of 20 volunteers, five were given intravenous Diazemuls 15 mg over 15 seconds, and three groups of five were given lormetazepam 2 mg intravenously over 10, 20 and 60 seconds, respectively. Laryngeal reactivity and psychomotor function were tested at intervals from prior to injection until 4 hours after injection. For equivalent degrees of depression of psychomotor function, lormetazepam depressed the laryngeal reflex less than Diazemuls (p = 0.004). Lormetazepam give over 60 seconds depressed the laryngeal reflex more than when given over 10 seconds (p = 0.008) or over 20 seconds (p = 0.048), although a significant difference was not demonstrated between the 10-second and 20-second groups. These results concur with experimental evidence that benzodiazepine receptor multiplicity exists, which allows various members of the benzodiazepine group of drugs to exhibit differing therapeutic ratios for their various effects.