Hemodynamic Responses for Pre-Eclamptic Patients Undergoing Cesarean Section Under General Anesthesia; Comparative Study between Dexmedetomidine and Fentanyl

Background: The introduction of parenterally administered drugs in the obstetric population encounters many challenges. Such obstacles are imperative, as careless systemic administration of any medication may have a profound effect on both mother and fetus. Dexmedetomidine is associated with a decreased hemodynamic response to intubation, extubation and recovery time after surgery, cause minimal respiratory depression and posses hemodynamic stabilizing effects. Patients and Methods: The present study included 100 parturients of average age 18-45 years, singleton pregnancies of at least 36 weeks gestation with mild or moderate pre-eclampsia. All cases are premeditated by ranitidine 150mg andondansetron 4mg intravenously. All patients received general anesthesia after preoxygenation for 5min, rapid-sequence induction was performed with thiopental 3-5mg/kg and suxamethonium 1.5mg/kg. Cricoid pressure was applied, laryngoscopy was performed and tracheal intubation was done. Maintenance of anesthesia was performed by isoflurane, and atracurium to maintain neuromuscular blockade. The patients were randomly assigned and divided into 2 groups namely Dexmedetomidine group (n=50) and Fentanyl group (n=50), Group (D): Dexmeditomidine group: Patients received dexmeditomidine i.v. loading dose of 1 μg/kg/h in time period 10min before induction of anesthesia and continued after induction in the rate (0.4μg/kg/hr) and reduced to 0.2μg/kg/hr after delivery continued until skin closure. Group (F): Fentanyl group: Patients received an i.v. bolus of 1μg/kg fentanyl before induction of anesthesia. Both groups received 0.5-1 μg/kg fentenyl after delivery of the fetus. Parameters measured in the study were Hemodynamic parameters: Blood pressure and heart rate after induction, at intubation, skin incision, after delivery and extubation, Ventilation time: Time to spontaneous ventilation and Extubation time: After the end of operation and quality of extubation. Results: Group D showed significantly lower heart rate compared to Group F at intubation, skin incision, delivery time, and at extubation. Group D showed lower systolic and diastolic blood pressures than Group F at induction in at intubation, skin incision and at extubation time. These difference were statistically significant p-value 0.05. At delivery time Group D showed also non significant lower systolic and diastolic pressure than Group F. Conclusion: This study demonestrates that dexmedetomidine has attenuated the hemodynamic response caused by anesthesia for pre-eclamptic parturients than fentanyl.