Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 1998
Incidence of phrenic nerve block and hypercapnia in patients undergoing carotid endarterectomy under cervical plexus block.
Deep cervical plexus blockade blocks the second, third and fourth cervical nerve roots. The phrenic nerve arises from C3, C4, C5 and should therefore be commonly blocked with cervical plexus blockade. The aim of this study was to report the incidence of phrenic nerve block and to assess the effect of this on arterial carbon dioxide tension (PaCO2) in premedicated and sedated patients. ⋯ Fluoroscopy showed that 22 patients (55%) had evidence of phrenic nerve block (Group A), 18 patients showed no change (Group B). PaCO2 levels increased in both groups following premedication, from 41 +/- 5 mmHg (mean +/- SD) to 46 +/- 5 mmHg in Group A, and 41 +/- 4 mmHg in Group B; twenty minutes after cervical plexus block the PaCO2 rose to 49 +/- 6 mmHg in Group A, and 48 +/- 6 mmHg in Group B. These changes were not statistically significantly different when the two groups were compared.
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Anaesth Intensive Care · Aug 1998
Induction of anaesthesia with sevoflurane, preprogrammed propofol infusion or combined sevoflurane/propofol for laryngeal mask insertion: cardiovascular, movement and EEG bispectral index responses.
Inhalation induction with sevoflurane was compared with propofol or sevoflurane/propofol in 60 unpremedicated adults. Target concentrations for the three groups (with 60% nitrous oxide) were 3% end-tidal sevoflurane, 12 mg/l propofol and 1.5% sevoflurane/6 mg/l propofol respectively, prior to insertion of a laryngeal mask airway (LMA) at 10 minutes. Induction of anaesthesia was satisfactory in each group, but movement response to LMA insertion was observed in 20 patients (least in the sevoflurane group). ⋯ EEG bispectral index suggested a greater depth of anaesthesia in the inhalation induction group. A bispectral index of 60 separated patients responding to LMA insertion from nonresponders (P = 0.006), and had a sensitivity of 68% and specificity 70%. Movement response was not predicted by cardiovascular changes.
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Anaesth Intensive Care · Aug 1998
Case ReportsAcute hyponatraemia secondary to cerebral salt wasting syndrome in a patient with tuberculous meningitis.
A 30-year-old HIV-positive man presented with acute hydrocephalus secondary to tuberculous meningitis, for which an external ventricular drain was inserted. He developed marked natriuresis in the postoperative period, which resulted in acute hyponatraemia (131 to 122 mmol/l) and a contraction of his intravascular volume. A diagnosis of cerebral salt wasting syndrome was made, and he responded to sodium and fluid loading. This case highlights the differentiation of cerebral salt wasting syndrome from the more commonly occurring syndrome of inappropriate anti-diuretic hormone secretion as the aetiology of the hyponatraemia.
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Anaesth Intensive Care · Aug 1998
The third five-year survey of fellows (by examination) of the Faculty of Intensive Care, Australian and New Zealand College of Anaesthetists.
A questionnaire was sent to 126 Fellows who had passed the Fellowship Examination in Intensive Care up to and including the examination of October, 1995. The major objectives were to assess the continuing involvement of Fellows in Intensive Care and obtain feedback on training and the examinations. Only six Fellows failed to respond. ⋯ Although there was considerable individual variation, the Fellows had not changed their median amount of Intensive Care practice over time. The responders provided feedback on their work patterns in the public and private systems, and their training and examinations. Overall, the training/examination system appears to satisfy Fellows although some fine tuning is required.
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Anaesth Intensive Care · Aug 1998
Reinforcing a "low flow" anaesthesia policy with feedback can produce a sustained reduction in isoflurane consumption.
A three-month audit of isoflurane consumption at Palmerston North Hospital in 1994 showed an averaged vapour flow rate of approx 85 ml per minute of anaesthesia, equivalent to 1.4% isoflurane at six litres per minute. After purchasing volatile agent analysers, a program encouraging low flow anaesthesia and providing a report of the previous month's consumption rate was started in July 1996. The isoflurane averaged vapour flow rate was tracked over the following twenty-month period and fell by a sustained 65% to range around 30 +/- 5 ml/min, producing savings of approximately NZ$104,000 over this period.