%0 Journal Article
%T Volume mediano efetivo de cristaloides na preven£¿£¿o de hipotens£¿o arterial em pacientes submetidas ¨¤ cesariana com raquianestesia
%A ShiQin
%A Xu
%A HaiBo
%A Wu
%A QingSong
%A Zhao
%A XiaoFeng
%A Shen
%A XiRong
%A Guo
%A FuZhou
%A Wang
%J Revista Brasileira de Anestesiologia
%D 2012
%I Sociedade Brasileira de Anestesiologia
%R 10.1590/S0034-70942012000300004
%X background and objectives: spinal anesthesia-associated maternal hypotension in cesarean delivery is the most frequent and troublesome complication, posing serious risks to mothers and compromising neonatal well-being. the effective volume of intravenous crystalloid as the preventive strategy in this context has not been estimated. methods: eighty-five parturients with asa physical status i/ii undergoing elective cesarean delivery were screened and 67 eligible women were assigned to receive pre-spinal crystalloid loading. hyperbaric 0.5% bupivacaine 2 ml (10 mg) plus morphine 50 ¦Ìg was given to all patients. the volume of crystalloid was determined by an up-and-down sequential method. the crystalloid was infused at a rate of 100-150 ml.min-1 prior to the spinal anesthetic injection. the initial volume of crystalloid was 5 ml.kg-1. volume-effect data were fitted to a sigmoidal maximum efficacy model and the median effective volume (ev50) and corresponding 95% confidence interval (95% ci) were estimated using maximum likelihood estimation and logistic regression with firth's correction. results: a total of 67 subjects completed the study and were analyzed. twenty-eight (41.8%) patients developed hypotension with their systolic blood pressure (sbp) decreasing > 20% of baseline. the ev50 of crystalloid were 12.6 ml.kg-1 (95% ci, 11.6 to 14.8 ml.kg-1). with firth's correction, the pooled probability of an effective preventive volume of crystalloid at 13 ml.kg-1 was 50.2% (95% ci, 30% to 83.1%). conclusions: the estimated ev50 of the preloaded crystalloid required to prevent spinal anesthesia-induced hypotension in a cesarean section is, approximately, 13 ml.kg-1. however, prophylactic or therapeutic vasoconstrictors should also be prepared and administered at an appropriate time.
%K anesthesia
%K spinal
%K cesarean section
%K isotonic solutions
%K hypotension [prevention and control].
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0034-70942012000300004&lng=en&nrm=iso&tlng=en