Dissociative Conscious Sedation versus Airway Regional Blocks in Patients with Predicted Difficult Airway: Advantages and Disadvantages

Background: Establishment of a patent airway and preserving spontaneous ventilation is a necessity in predicted difficult airway. Airway regional blocks are commonly used in predicted difficult airway but the known limitations of these techniques propose the need to suggest alternative methods. This study compares subcutaneous dissociative conscious sedation (sDCS); a recently reported method of conscious sedation versus airway regional blocks in patients with predicted difficult airway. Methods: This study was conducted in 60 patients scheduled for direct laryngoscopic biopsy (DLB). Patients were randomly assigned into two groups: subcutaneous dissociative conscious sedation (sDCS) (n=30) and airway regional blocks (ARB) (n=30).Patients were compared for direct laryngoscopy, insertion of endotracheal tube, hemodynamic changes, oxygen saturation, patient cooperation, patient comfort, hallucination, nystagmus, salivation and event of recall. Results: Direct laryngoscopy was successfully performed in all patients in sDCS group and 28 patients in ARB group. Insertion of endotracheal tube was successfully done in 28 patients of sDCS group and failed in two cases. In group ARB, endotracheal intubation was successfully done in 26 patients. Despite the lower success rate in group, ARB it was not statistically significant. Patient cooperation was significantly higher in sDCS group. No event of recall was observed in sDCS group versus 8 in group ARB. Subcutaneous dissociative conscious sedation (sDCS) is a safe anesthesia method for endotracheal intubation and it is comparable and even superior to airway regional blocks in some aspects.