Khawaja Kamal Nasir, Erum Shahid, Arshad Saleem Shahani.
Use of hyperbaric and isobaric bupivacaine in elective Cesarean section: a comparison.
Ann Pak Inst Med Sci Jan ;1(1):40-4.

Background: Spinal anaesthesia has recently gained popularity for caesarean section because of the low risk of toxicity of the drug involved, as the volume of local anaesthetic required to perform the block is very small. Hyperbaric or plain isobaric bupivacaine is an appropriate choice of local anaesthetic for caesarean section under spinal anaesthesia. But the cardiovascular effects i.e., changes in heart rate and blood pressure is still controversial. In this study we tried to observe the change in heart rate and blood pressure seen with the use of isobaric or hyperbaric bupivacaine in obstetric patients undergoing elective caesarean section keeping the space and volume constant. Methods: Patients, selected according to inclusion criteria, were randomly divided into two groups of thirty each. Patients were preloaded with 1000 millilitres of lactated ringer solution prior to spinal anaesthesia; pulse rate, non-invasive blood pressure, electrocardiogram, and pulse oximetry were continuously monitored. Two millilitres of hyperbaric bupivacaine 0.75% was injected to group A patients and two millilitres of isobaric bupivacaine 0.5% was injected to group B patients. Patients were given supine position with ten-degree head tilt and left lateral tilt. Haemodynamic changes i.e., changes in pulse and blood pressure were monitored every minute for the first ten minutes. Result: No statistically significant difference was seen in heart rate between the two groups (P >0.05). Systolic and diastolic blood pressure showed statistically significant difference between the two groups after 4 minutes (P <0.05). Conclusion: Haemodynamic stability is more with hyperbaric bupivacaine than isobaric bupivacaine in obstetric patients undergoing elective caesarean section keeping the space and volume constant.

PakMediNet -Pakistan's largest Database of Pakistani Medical Journals - http://www.pakmedinet.com