Dexmedetomidine Versus Midazolam for Facilitating Extubation

This study is unique because midazolam or dexmedetomidine will be added, in a blinded fashion, to existing sedation and analgesia in an effort to decrease or possibly discontinue these therapies. Objectives: The objectives of this study are to determine if transitioning conventional sedation to dexmedetomidine safely facilitates tracheal extubation after study initiation; alters the amounts of sedative and analgesic agents required after study initiation; influences the levels of sedation and analgesia; alters the adverse event profile (neurologic, hemodynamic, or gastrointestinal) during and after discontinuing sedation; and impacts the total cost of sedation during and after discontinuing sedation. Hypothesis 1: Transitioning conventional sedation to dexmedetomidine expedites tracheal extubation to shorten ventilator time. Specific Aim 1: Comparatively determine the time from study initiation to tracheal extubation with midazolam and dexmedetomidine when the practice of daily awakenings is used. Hypothesis 2: Transitioning conventional sedation to dexmedetomidine reduces the doses of conventional sedatives and analgesics while maintaining equivalent levels of sedation and analgesia and not incurring adverse events. Specific Aim 2a: Comparatively determine the hourly, daily, and cumulative doses of conventional sedatives and analgesics from study initiation to sedation discontinuation with midazolam and dexmedetomidine when the practice of daily awakenings is used. Specific Aim 2b: Comparatively evaluate the quality of sedation and analgesia of midazolam and dexmedetomidine by determining the proportion of Riker sedation scores at 3 - 4 (desired level of sedation) and ≤ 2 or ≥ 5 (undesired levels of sedation) and the proportion of Pain Assessment Behavioral Scores (PABS) ≤ 3 (comfortable) and ≥ 4 (pain). Specific Aim 2c: Comparatively evaluate sedation-related adverse effects (neurologic, hemodynamic, or gastrointestinal) of midazolam and dexmedetomidine when the practice of daily awakenings is used. Hypothesis 3: Transitioning conventional sedation to dexmedetomidine increases the cost of administering sedation but minimizes the incidental costs associated with sedation to counterbalance and possibly reduce the total cost of sedation (sum of administration costs and incidental costs). Specific Aim 3a: Comparatively determine the hourly, daily, and cumulative administration costs of midazolam and dexmedetomidine when the practice of daily awakenings is used. Specific Aim 3b: Comparatively determine the hourly, daily, and cumulative incidental costs of conventional sedatives and dexmedetomidine; including neurologic dysfunction, antipsychotic requirements, cardiovascular dysfunction, constipation or ileus, differences in times to ventilator discontinuation, personnel time, and patient transfer from the ICU after sedation discontinuation.