DIRECTION OF INJECTION DOES NOT AFFECT THE SPREAD OF SPINAL BUPIVACAINE IN PARTURIENTS

Purpose: One of the factors that can affect the distribution of local anaesthetic solutions in the subarachnoid space is the direction of th e spinal needle through which injections are made. This study investig ated the effect of the direction of the aperture of the Whitacre needl e on the spread of hype bane bupivacaine in parturients undergoing ele ctive caesarean section. Methods: Forty healthy term parturients sched uled for caesarean delivery under spinal anaesthesia with 12 mg hyperb aric bupivacaine + 0.2 mg morphine were randomly assigned to one of tw o groups; needle orifice cephalad (i) or caudad (II). Spinal blocks we re administered in the sitting position with patients being positioned supine immediately after. A blinded observer assessed the dermatome l evel of analgesia to ice every minute for the first 10 minutes, every three minutes for the following 35 min, then every 15 min until the se nsory level regressed to T-10. Results: There was no difference betwee n the groups regarding the maximal number of segments blocked cephalad to T-11 (11.4 +/- 3.4: group I and 12.0 +/- 3.4: group II), time to h ighest cephalad spread of sensory block (22 +/- 10: group I and 19 +/- 10 min: group II), or time to regression to T-10 (164 +/- 26: group I and 153 +/- 24 min: group II). The maximum decrease in blood pressure (33.9 +/- 9.6: group I and 36.8 +/- 11.8 mmHg: group II) and dosage o f ephedrine administered (14.7 +/- 10.7: group I and 16.2 +/- 11.0 mg: group II) did not differ. Conclusion: The direction of the aperture o f the Whitacre needle does nor influence the spread of hyperbaric bupi vacaine in the term parturient.