Hyperbaric bupivacaine and fentanyl for elective cesarean section: effect of a height and weight adjusting dose

ABSTRACT

There are large varieties of dosage regimens which are in use for spinal anesthesia for Cesarean section [3]. All aiming for limiting the dose of Bupivacaine to reduce incidence of maternal hypotension and vasopressor requirements, decreasing nausea and vomiting, reducing time to discharge from post anesthesia unit, and improving maternal satisfaction [4]. This study was designed to assess the validity of adjusting the dosage of intrathecal hyperbaric bupivacaine according to the patient's height and weight would provide adequate surgical anesthesia for elective cesarean section while decreasing the incidence of maternal hypotension and the use of vasopressor to treat hypotension and consequently fetal outcome. Patients were randomly assigned to be involved into two groups. Group 1 The fixed dose group, patients received fentanyl 20 microgram [0.4ml] added to hyperbaric bupivacaine 0.5% 2.4ml. Group 2 The adjusting dosage group, patients receive fentanyl 20 microgram [0.4ml] added to a volume of hyperbaric bupivacaine 0.5% that is determined by referencing to the dosage regimen detailed Table. All the cardiovascular data measured plus the incidence of nausea and vomiting were statistically significantly lower in the adjusted group compared to the fixed one [p<0.05]. Time to loss of cold [T4] and to pinprick sensation to T64 on both sides were significantly slower in the adjusted group [p<0.05]. There were no significant differences as regard the visual analogue scale, number of patients needed supplementary analgesia, or the fetal outcome between the two groups at different time intervals [p>0.05]. Adjusting the intrathecal hyperbaric Bupivacaine dose to patient's height and weight combined with 20 microgram Fenatnyl provide adequate anesthesia with less maternal side effects for patients undergoing elective cesarean section