Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 2002
Cerebrovascular carbon dioxide reactivity in sheep: effect of propofol or isoflurane anaesthesia.
Propofol and isoflurane are commonly used in neuroanaesthesia. Some published data suggest that the use of these agents is associated with impaired cerebral blood flow/carbon dioxide (CO2) reactivity. Cerebrovascular CO2 reactivity was therefore measured in three cohorts of adult merino sheep: awake (n=6), anaesthetized with steady-state propofol (15 mg/min; n=6) and anaesthetized with 2% isoflurane (n=6). ⋯ The slopes of the lines were highly variable between individuals for the awake cohort (mean 4.73, 1.42-7.12, 95% CI). The slopes for the propofol (mean 2.67, 2.06-3.28, 95% CI) and isoflurane (mean 2.82, 219-3.45, 95% CI) cohorts were more predictable. However, there was no significant difference between these anaesthetic agents with respect to the CO2 reactivity of cerebral blood flow.
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Anaesth Intensive Care · Aug 2002
Case ReportsSuccessful use of oral methadone after failure of intravenous morphine and ketamine.
We describe an opioid-tolerant patient with severe acute pain which was unrelieved by morphine and ketamine via intravenous patient-controlled analgesia, but almost totally relieved by methadone. In the previous 24 hours, 509 mg of intravenous morphine and 769 mg of ketamine had been used and this was replaced by 200 mg of oral methadone. This implies that the success of methadone in morphine tolerant patients chiefly involves factors other than its role as an N-methyl-D-aspartate receptor antagonist, and that methadone should be considered as a replacement for morphine when the N-methyl-D-aspartate antagonist ketamine has proved ineffective.
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Anaesth Intensive Care · Aug 2002
Neurolytic celiac plexus block for visceral abdominal malignancy: is prior diagnostic block warranted?
Neurolytic celiac plexus block is a recognised treatment for visceral abdominal pain due to malignancy. The need for a diagnostic celiac plexus block prior to neurolytic blockade is of questionable value, as it may not predict a positive response and may incorrectly predict a lack of response. Our objective is to evaluate the efficacy of diagnostic celiac plexus block. ⋯ Therefore, a positive response to diagnostic block correlates positively with neurolytic celiac plexus block for abdominal visceral pain due to malignancy. However, diagnostic block is a poor predictor when the response is negative. Hence, its clinical role is questionable and may not be warranted for patients with terminal malignancy.