A case of prolonged post-operative somnolence is described. The patient was on concurrent benzodiazepine and cimetidine therapy. Cimetidine can cause impairment of metabolism of the benzodiazepines by inhibiting the hepatic microsomal enzyme system and its possible role in causing the prolonged somnolence is discussed.

Aged↗

PubMed1980

Surgical stimulation does not enhance ventilatory chemoreflexes during enflurane anaesthesia in man.

To assess the impact of surgical stimulation on regulation of ventilation in anaesthetized man, we measured ventilation and the ventilatory responses to either hyperoxic hypercapnia or to isocapnic hypoxaemia in fifteen subjects anaesthetized with enflurane 1.1 MAC, just prior to and then during a surgical procedure. Anaesthesia alone reduced ventilation, increased PaCO2, decreased the response to carbon dioxide and virtually abolished the response to hypoxaemia. The addition of operation at the same level of anaesthesia augmented ventilation and reduced PaCO2, but did not improve the anaesthesia-induced impairment of the responses to hypercarbia and hypoxaemia. Over the range of PCO2 and PO2 values studied, the effects of surgery were constant and independent of chemical drive.

Adult↗

PubMedDate not supplied

Correlation between somatosensory evoked potentials and neuronal ischemic changes following middle cerebral artery occlusion.

In an attempt to determine the usefulness of evoked potentials as a measure of focal cerebral ischemia, we examined somatosensory evoked potentials (SEP's) and morphological neuronal changes in cats following unilateral middle cerebral artery (MCA) occlusion. Fifteen adult cats underwent transorbital occlusion of the MCA under halothane anesthesia. In seven cats the ipsilateral SEP's were abolished after middle cerebral artery occlusion, and did not show any recovery after 6 hours. The same seven cats showed the greatest area of moderate and severe ischemic neuronal changes, ranging from 21 to 64% (mean 39 +/- 14%) of the total ipsilateral cortical area. The remaining eight cats showed a complete flattening or decreased amplitude of the SEP after occlusion, but demonstrated a considerable recovery in the amplitude of the primary cortical potential during the six hours of the study. All these cats had ischemic areas of less than 15% (mean 9 +/- 3%) of the total ipsilateral cortex. These results demonstrate that the disappearance of the SEP and their failure to recover correlate with the extent and degree of histological cerebral ischemia.

Animals↗

PubMedDate not supplied

Analgesia following major gynecological laparoscopic surgery--PCA versus intermittent intramuscular injection.

BACKGROUND AND OBJECTIVES: To compare the use of patient-controlled analgesia to intermittent intramuscular injections of morphine following major gynecological laparoscopic procedures in order to assess differences in level of pain, sedation, episodes of nausea and/or vomiting, hospitalization time and patient satisfaction with their postoperative analgesia. METHODS: Seventy-two patients undergoing major gynecological laparoscopic surgery were randomized to receive either postoperative analgesia via intermittent intramuscular injection of morphine (Group 1) or patient controlled analgesia (PCA-Group 2). All patients received anesthesia via a standardized protocol. Postoperative pain levels were recorded via a 10 cm visual analogue scale, and sedation scores were recorded on a standard PCA form. Episodes of nausea and vomiting were also recorded on the same form. RESULTS: There were no statistically significant differences between intramuscular analgesia and PCA for any of the factors studied. Most significantly it was found that most patients ceased to require either form of parenteral analgesia within 24 hours of their procedure, regardless of the operating time. CONCLUSION: It is important for the surgeon to be aware of the effects of postoperative analgesia on his or her patients' level of satisfaction. We do not recommend the use of PCA analgesia following major laparoscopic gynecological surgery.

Adult↗