Prospective study of changes in serum calcium after diethyl-ether anaesthesia.

Changes in serum calcium after diethyl-ether anaesthesia given for various routine surgical operations, were studied in 30 patients. Mean (+/- SD) concentration (mg%) of serum calcium before induction of anaesthesia was 10.37 +/- 0.77. Serum calcium decreased by 0.05 per cent after 10 min of induction and by 3.33 per cent at the end of anaesthesia which was highly significant (P less than 0.001). There was a correlation (r = 0.63; P less than 0.01) between decline in serum calcium and duration of ether anaesthesia. Serum calcium returned to near normal levels after 24 h of ether anaesthesia. In view of the fall in serum calcium, it is emphasized that ether should be either avoided in patients with known or suspected hypocalcaemia or be used for as short a time as possible with due precaution and calcium supplementation.