Effectiveness of high dose remifentanil in preventing coughing and laryngospasm in non-paralyzed patients for advanced bronchoscopic procedures

Anesthesia for bronchoscopy presents unique challenges, as constant stimulus due to bronchoscope needs to be obtunded using drugs with a minimal post-procedure residual effect. Remifentanil for maintenance is an ideal choice, but optimal doses are yet to be determined. Bronchoscopic procedures were prospectively evaluated for 4 months studying the frequency of complications and anesthesia techniques. Anesthesia was maintained on remifentanil/propofol infusion avoiding neuromuscular blockers. Laryngeal mask airway was used for the controlled ventilation [with high oxygen concentration] that also served as a conduit for bronchoscope insertions. Anesthesiologists were blinded to the study [avoiding performance bias] and the Pulmonologist was blinded to the anesthesia technique [to document unbiased procedural satisfaction scores]. Procedures were divided into 2 groups based on the dose of remifentanil used for maintenance: Group-H [high dose -0.26 to 0.5 micro g/kg/min and Group-NH [non-high dose <0.25 micro,g/kg/min]. Observed 75 procedures were divided into Group-H [42] and Group-NH [33]. Number of statistical difference was found in demography, procedural profile, hemodynamic parameters and total phenylephrine used. Chi-square test showed Group-NH had significantly higher frequency of laryngospasm [P= 0.047] and coughing [F= 0.002]. The likelihood ratio of patient coughing and developing laryngospasm in Group-NH was found to be 4.56 and 10.97 times respectively. Minimum pulse-oximeter saturation was statistically higher in Group-H [98.80% vs. 96.50% P= 0.009]. Pulmonologist satisfaction scores were significantly better in Group-H. High dose of remifentanil infusion is associated with a lower incidence of coughing and laryngospasms during bronchoscopy. Simultaneously, it improves Pulmonologist's satisfaction and procedural conditions