Subarachnoid anaesthesia with 0.75% bupivacaine in patients with chronic renal failure

Twenty consecutive patients with chronic renal failure (CRF) and 20 control patients received subarachnoid anaesthesia with 3 ml of 0.75% bupivacaine plain for surgery in the lower abdomen. Sensory analgesia (onset) developed significantly more rapidly in the CRF patients: maximum segmental level of pin-prick analgesia was reached in an average of 21 min in the CRF patients and in 35 min in the control patients. An observed tendency to acidosis and a possible reduced intrathecal space in the uraemic patients may account for the more rapid blockade. The mean spread of the sensory block in CRF patients (T4) was two segments higher than that in the control patients, but because of marked inter-individual variation this difference cannot be considered clinically important. Three CRF patients and two control patients had insufficient analgesia for surgery. In the CRF patients, both sensory and motor blockades were of shorter duration than in the control patients. The incidence of complaints of nausea and backache was similar in the groups. One control patient had a headache.