No abstract

No abstract

We have examined the influence of bolus size on efficacy, opioid consumption, side effects and patient satisfaction during i.v. patient-controlled analgesia (PCA) in 60 patients (ASA I-II, aged 32-82 yr) after abdominal surgery. Patients were allocated randomly, in a double-blind manner, to receive PCA with a bolus dose of either piritramide 0.75 mg or 1.5 mg (lockout 5 min) for postoperative pain control. Mean 24 h piritramide consumption differed significantly between groups (11.4 (SD 5.8) mg vs 22.5 (18.3) mg; Pϭ0.001). There were no significant differences in the number of applied bolus doses, pain scores, pain relief (VAS), sedation, nausea, pruritus and patient satisfaction. We conclude that a PCA regimen with a bolus dose of piritramide 0.75 mg and a lockout time of 5 min was effective in the treatment of postoperative pain, but did not reduce the occurrence of side effects.Br J Anaesth 1999; 82: 52-5

No abstract

Controlled decreases in mean arterial pressure to 20%, 40% and 60% of baseline were produced by the administration of increasing concentrations of adenosine triphosphate (ATP) i.v. in five anaesthetized baboons. Indices of the systemic circulation (arterial pressure, right atrial pressure, pulmonary artery pressures, cardiac output) and of the cerebral circulation (cerebral blood flow, cerebral metabolic rate for oxygen, cerebrovascular reactivity) were obtained as arterial pressure was decreased, and following discontinuation of the infusion of ATP. A neuropathological investigation was undertaken at the end of the experimental procedure. The infusion of ATP produced dose-dependent decreases in systemic vascular resistance and mean arterial pressure (MAP). Cardiac output and stroke volume were maintained close to baseline values, or increased slightly. Cerebral blood flow (CBF) increased initially (48 +/- 4 ml min-1/100 g to 68 +/- 9 ml min-1/100 g) and then decreased progressively as MAP was decreased to 40% and 60% of baseline. Cerebrovascular reactivity was shown to be impaired during, and for up to 90 min following, the administration of ATP. However, there was no morphological evidence of ischaemic cell damage in any animal. Tachyphylaxis was not observed during, and there were no instances of rebound hypertension following, the infusion of ATP. The concentration of uric acid had increased significantly by the 40% decrement in MAP, and remained so 60 min after the restoration of the arterial pressure.