Dexmedetomidine versus midazolam for sedation of critically ill patients on noninvasive mechanical ventilation

Abstract

Introduction Dexmedetomidine is a highly selective a-2 adrenoceptor agonist and eight times more specific than clonidine. It exerts its major sedative and analgesic effect through stimulation of the a-2 adrenoceptor and the locus coeruleus. Its analgesic effect is also produced by direct stimulation of the a-2 adrenoceptor in the spinal cord. The unique sedative effect of dexmedetomidine that mimics natural sleep makes the postsedative delirium after stopping dexmedetomidine very rare. Moreover, even on the sedative score Richmond Agitation-Sedation Scale (RASS)-1-2, patients can respond easily to verbal command and go back to sleep. The most commonly reported adverse effects are bradycardia and hypotension. Aim of the work This was a comparative prospective double-blind study comparing dexmedetomidine versus midazolam as a sedative agent used in noninvasive ventilation (NIV) and short-term intubation and mechanical ventilation (5 days). Patients and methods In all, 200 patients admitted to King Abd el Aziz Specialist Hospital, Taif, in the ICU with acute hypoxemia with SpO 2 less than 80% were allocated randomly to two groups. All patients in both groups were subjected to NIV for 3 days and if this failed (persistent hypoxemia, became hemodynamically unstable, or showed marked tracheal secretion), intubation and mechanical ventilation was considered for 5 days. Group A included 100 patients who received midazolam as a sedative agent, whereas group B included 100 patients who received dexmedetomidine as a sedative agent. The number of patients who responded to NIV in both groups was recorded and the number of patients who were extubated and weaned from mechanical ventilation in 5 days in both groups was also recorded together with the complications from sedation. Results There was a significant increase in the number of patients who responded to NIV in group B compared with group A. Moreover, there was a significant increase in the number of patients extubated and weaned from mechanical ventilation in the 5-day period in group B compared with group A. Conclusion Dexmedetomidine is a safer agent for sedation of critically ill patients with fewer incidences of delirium, and less morbidity and mortality compared with midazolam with the same efficacy.