The Feasibility of Endotracheal Intubation with Subcutaneous Dissociative Conscious Sedation versus General Anesthesia: A Prospective Randomized Trial

Despite outstanding improvements in anesthesia techniques and anesthetics, difficult airway is still a dilemma and is accompanied by morbidity and mortality. The aim of this study is to compare the feasibility of endotracheal intubation with the traditional method of general anesthesia by using muscle relaxants, and “sDCS” (Subcutaneous Dissociative Conscious Sedation) which has been recently reported as an efficient method of anesthesia with the capability of maintaining spontaneous ventilation and providing an appropriate situation for larynxgoscopy and endotracheal intubation. Material and Methods: This randomized clinical trial was conducted on 100 patients who were scheduled for elective laparotomy. Patients were randomly divided into two groups: group A and group B. In group A, patients underwent general anesthesia with thiopental sodium and relaxant. In group B, patients underwent “subcutaneous Dissociative Conscious Sedation” and received low dose subcutaneous ketamine and intravenous narcotic with no relaxant. The feasibility of direct laryngoscopy and tracheal intubation, hemodynamic changes, desaturation (SpO2 < 90%), patient cooperation, patient comfort, hallucination, nausea and vomiting, nystagmus and salivation were evaluated in two groups. Adverse events including apnea and need for positive pressure mask ventilation, additional dose of fentanyl were recorded in group B. The anesthesiologist who performed the procedure was asked about the patient calmness and cooperation during the procedure and the feasibility of laryngoscopy and tracheal intubation. The incidence of nausea and vomiting in post-operative care unit was recorded too. Results: Hemodynamic variables were comparable in two groups. No event of irreversible respiratory depression, desaturation, need for positive pressure ventilation and hallucination was observed in group B. All patients were cooperative and obedient during the laryngoscopy and tracheal intubation. The incidence of nausea was not statistically significant. The anesthesiologist was satisfied by the quality of patient’s cooperation for laryngoscopy in both groups. Conclusion: Subcutaneous dissociative conscious sedation is comparable with general anesthesia to provide desirable situation for laryngoscopy and tracheal intubation.