Comparison of the effects of different doses of cisatracurium on appropriate time for endotracheal intubation and hemodynamic changes during anesthesia

Cisatracurium is used to facilitate endotracheal intubation. However, conventional doses have slow onset time. The higher doses of this drug may eliminate this problem but may be associated with significant hemodynamic changes. The present study was designed to compare the effects of three doses of cisatracurium (0.15, 0.20, and 0.25 mg/kg) on hemodynamic parameters and the appropriate time required for endotracheal intubation. One hundred and twenty three patients, aged 20-40 years old with ASA class 1 or 2 were randomly allocated to receive one of the cisatracurium doses: 0.15 mg/kg; 0.20 mg/kg; and 0.25 mg/kg. After induction of anesthesia, the mean arterial pressures and pulse rates were measured at the baseline, after induction of anesthesia, and after endotracheal intubation at one minute interval for 5 minutes. The appropriate time for intubation (time of achieving TOF=0 and PTC=0) and TOF recovery after administration of cisatracurium, were also measured and compared accordingly. After induction of anesthesia, the patients of all three groups showed a significant decrease in their mean arterial pressures (p < 0.001). We also noticed a drop in pulse rates (p>0.05). The changes were more marked in the 0.15 mg/kg, 0.25 mg/kg, and 0.20 mg/kg group, respectively. However, these changes were not clinically significant and did not require any intervention. The time required for endotracheal intubation (to achieve TOF=0) in 0.15, 0.20 and 0.25 mg/k-group were 191.50±35.16, 145.40±25.08 and 100.20±25.59 seconds, respectively (p < 0.001). The time of TOF recovery in 0.15, 0.20 and 0.25 mg/kg-group were 2696.20±324.25, 3422.20 ±253.00 and 3378.90 ±626.15 seconds respectively (p< 0.001). We concluded that doses of 0.20 and 0.25 mg/kg in comparison to 0.15 mg/kg of cisatracurium provide a shorter time required for endotracheal intubation but are associated with more significant changes in blood pressure and pulse rates. However, these changes are not clinically significant and need no intervention.