Anesthesia characteristic of an algorithm of bupivacaine dose based on height in caesarean section under spinal anesthesia: a retrospective cohort study

BACKGROUND: An algorithm of bupivacaine dose based on height is applied to reduce maternal hypotension in caesarean section under spinal anesthesia. This study is designed to further verify whether the algorithm of bupivacaine dose based on height is suitable. METHODS: The parturients were grouped according to height. The comparison of anesthesia characteristic among subgroups was carried out. The univariate and multivariate binary logistic regressions were executed to reanalyze the interference factor for the anesthesia characteristic. RESULTS: When the dose of bupivacaine was adjusted by using the height based dosing algorithm, except for weight (P < 0.05), other general data did not present statistical changes with height (P > 0.05); the incidences of complications, characteristics of sensory or motor block, quality of anesthesia and neonatal outcome were of no statistical difference among parturients with different heights (P > 0.05); the height, weight and body mass index were not related with maternal hypotension (P > 0.05). When the dose of bupivacaine is constant, except for weight and body mass index (P > 0.05), the height was the independent risk factor for maternal hypotension (P < 0.05). CONCLUSIONS: Except for weight and body mass index, the height has an influence on the bupivacaine dose. It is reasonable that the bupivacaine dose is adjusted by using this dosing algorithm based on height. TRIAL REGISTRATION: This study was registered at http://clinicaltrials.gov (13/04/2018, NCT03497364).