She YJ, Zheng X, Zhao BS, Zeng MT, Tan YH, Song XR. Body height and the spread of spinal anaesthesia for caesarean section: a prospective controlled trial.
Acta Anaesthesiol Scand 2017;
61:824-831. [PMID:
28653319 DOI:
10.1111/aas.12928]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 05/23/2017] [Accepted: 05/29/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND
No conclusive evidence exists on the effect of patient height on the spread of spinal anaesthesia. Our aim was to measure the ED50 and ED95 values of intrathecal ropivacaine in taller and shorter patients, and thus investigate the hypothesis that the spinal dose requirement in shorter patients is lower than that in taller patients undergoing caesarean section.
METHODS
In this study, 270 pregnant women were assigned to the taller (Group T) or shorter group (Group S) based on their heights. Subjects in both groups were further randomly assigned to one of nine subgroups based on the dosage of intrathecal isobaric ropivacaine to be administered (7, 8, 9, 10, 11, 12, 13, 14 or 15 mg respectively).
RESULTS
The ED50 and ED95 values of ropivacaine were 9.24 mg and 13.36 mg in Group S, and 10.11 mg and 14.63 mg in Group T, with no inter-group difference (P = 0.886). There was a significant inter-group difference in the incidence of hypotension and the changes in mean arterial pressure after spinal anaesthesia using 15 mg ropivacaine. The dose of ephedrine administered in Group S was higher than that in Group T when 15 mg ropivacaine was administered (P = 0.031).
CONCLUSION
The taller and shorter patients did not respond differently to modest intrathecal doses of ropivacaine. However, a larger dose of ropivacaine was associated with an increased incidence of hypotension in shorter patients compared to that in taller patients.
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