British Journal of Anaesthesia, 1973, Vol. 45, No. 7 704-710
© 1973 The Board of Management and Trustees of the British Journal of Anaesthesia
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VALSALVA RESPONSES AND SYSTOLIC TIME INTERVALS DURING ANAESTHESIA AND INDUCED HYPOTENSION
Magill Department of Anaesthetics and Department of Clinical Measurement Westminster Hospital, London
Queen Victoria Hospital, East Grinstead
Passive Valsalva manoeuvres were performed on young healthy patients about to undergo elective plastic surgery requiring induction of hypotension. This challenge was applied both in the supine and 30-degree head-up postures, during light anaesthesia, and after administration of beta-adrenergic blocking and ganglion blocking drugs, halothane and methoxyflurane. The resulting changes in blood pressure, pulse rate and systolic time intervals were recorded. During light anaesthesia more than half the responses were found to be unblocked, despite administration of beta-adrenergic blocking and ganglion blocking agents. Deepening the level of anaesthesia with either halothane or methoxyflurane usually resulted in a blocked response. The response to the manoeuvre could be influenced by posture. Marked alterations in the pre-ejection period occurred during every manoeuvre and were the same whether the manoeuvre was blocked or unblocked.