Impact of Different Stimulation Patterns of Neuromuscular Blockade Monitoring and Clinical Assessment on Intubation Time and Intensity of Hemodynamic Response During Rocuronium Induced Endotracheal Intubation

Introduction and aims: Typical autonomic response to endotracheal intubation manifests itself by increasing blood pressure and heart rate. The aim of this study as to evaluate whether different stimulation patterns of neuromuscular blockade monitoring techniques may impact hemodynamic response. Materials and Methods: Randomized, prospective, double blind study involved 60 patients who underwent elective abdominal surgery. Patients were randomly allocated into 3 groups. Anesthesia was induced with propofol-remifentanil and acceleromyography at adductor pollicis was established before rocuronium (0.6 mg/kg) was given to facilitate endotracheal intubation. Endotracheal intubation was initiated after 95% suppression of 0.1 Hz single twitch (ST group), complete disappearance of responses to train-of-four stimulation (TOF group) or after clinical criteria (good relaxation of the masseter muscle and the lower jaw, easy mask ventilation and the fact that 60 secs had elapsed since rocuronium was administered) were met (control-CL group). Blood pressure and heart rate were measured in five time points: after positioning the patient (HDbas), 30 s after propofol-remifentanyl (HD1), 30 s after rocuronium (HD2), 30 s (HD3) and 2 minutes following initiation (HD4) of endotracheal intubation. Results: The interval between administration of rocuronium and initiation of endotracheal intubation was significantly shorter in CL group (66.5 s), compared to TOF group (75.44 s) and ST group (83.75 s), (p < 0.001). There was statistically significant difference in systolic blood pressure at HD3 and HD4 time point between groups (p < 0.01). Post hoc analysis shows that these values of systolic blood pressure in CL group were significantly higher compared to the other two groups (p < 0.05). Also, systolic blood pressure after the fourth and fifth measurements were significantly higher compared to initial three measurements in CL group (p < 0.01). By comparing the heart rate at HD3and HD4 time points, significant difference between the groups was noted (p < 0.01). At HD3 time heart rate was significantly higher in CL group compared to other groups (p < 0.01). Additionally, at HD4 heart rate was significantly higher in CL group than in TOF group (p < 0.05) and ST group (p < 0.01). Also, heart rate was significantly increased at HD3 time point. Conclusion: Even though objective NMB monitoring prolongs intubating time, its use prevents vacillation of the hemodynamic response associated with endotracheal intubation.