ABSTRACT
BACKGROUND: Despite multiple benefits, laparoscopic surgery always poses anesthetic challenge due to significant alteration of hemodynamics. Various pharmacological agents have been used for the same with variable response. Dexmedetomidine, in addition to sympatholytic effect, diminishes intraoperative requirement of anesthetics including propofol. The present study was conducted to evaluate the effects of intravenous dexmedetomidine on intraoperative hemodynamics and propofol requirement using bispectral index (BIS) in laparoscopic cholecystectomy. METHODS: Forty patients undergoing laparoscopic cholecystectomy were randomly allocated to receive either dexmedetomidine (Group A; n = 20) or normal saline (Group B; n = 20). In Group A, dexmedetomidine was loaded (1 µg/kg) before anesthesia induction and infused (0.6 µg/kg/h) during surgery. Anesthesia was induced with propofol, and maintenance infusion rate was adjusted to a BIS of 55-60 in both groups. Mean arterial pressure (MAP) and heart rate (HR) were recorded at baseline and at various time points from loading of drugs to just after tracheal extubation. All infusions were stopped with removal of scope from abdominal cavity. Recovery time (time from end of all infusions to BIS = 80) and extubation time (time from end of all infusions to extubation) were noted. RESULTS: After intubation, MAP and HR values in Group A were significantly lower than Group B at various time points of study. To achieve similar BIS values, significantly low doses of propofol were required in Group A during induction and intraoperatively. Doses were reduced by 36% and 31%, respectively. Mean recovery time and mean extubation time in Group A were also significantly less. CONCLUSION: During propofol-based anesthesia for laparoscopic cholecystectomy, dexmedetomidine provides stable intraoperative hemodynamics and reduces propofol requirement for induction as well as maintenance, without compromising recovery profile.
ABSTRACT
BACKGROUND: Intubation is known to cause an exaggerated hemodynamic response in the form of tachycardia, hypertension, and dysrhythmias. In cervical spine instability, intubation has to be performed using cervical immobilization to prevent exacerbation of spinal cord injuries. Application of rigid cervical collar may reduce cervical spine movements, but it hinders tracheal intubation with a standard laryngoscope. The aim of this study was to compare the hemodynamic responses to fiberoptic bronchoscope (FOB) and McCoy laryngoscope in patients undergoing elective surgery under general anesthesia with rigid cervical collar simulating cervical spine immobilization in the situation of cervical trauma. METHODS: Thirty-two patients in the age range 20-50 years, of American Society of Anaesthesiologist I-II, and of either sex undergoing elective surgery under general anesthesia were randomly allocated into each group. There were two groups according to the technique used for intubation: Group A (flexible FOB) and Group B (McCoy laryngoscope). Systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and heart rate (HR) were recorded at baseline, intraoperatively, immediately before and after induction, and immediately after intubation. Thereafter, every min for next 5 min. STATISTICAL ANALYSIS: Intergroup comparison of categorical data was done by Chi-square test. P < 0.05 was considered statistically significant. Intergroup comparison of quantitative data was done by the parametric test (unpaired t-test), and probability was considered to be significant if <0.05. RESULTS: Due to intubation response, HR and blood pressure increased significantly (P < 0.05) above preoperative values in McCoy group as compared to the fiberoptic group. CONCLUSION: We suggest that the flexible FOB is an effective and better method of intubation in a situation like traumatic cervical spine injury and provides stable hemodynamics.
