There are several considerations with regard to sedation and anesthetic use that are essential to ensure optimal conditions for successfully weaning from mechanical ventilation. While providing sedation, one must be cognizant of the numerous factors linked to failure of NIV. Such factors include weak cough reflex, excessive secretions, intolerance and psychomotor agitation, patient–ventilator asynchrony, oxygen impairment, increased respiratory rate and elevated rapid shallow breathing index, hypercapnia, sleep disturbance, and delirium [3]. Failure to optimize these factors makes it increasingly difficult to wean from mechanical ventilation. As such, the goal is to provide adequate sedation and pain control while maintaining arousability, respiratory drive, cough reflex, and airway protection, all while retaining the ability to quickly and safely wean the patient from both sedation and mechanical ventilation. Techniques that are beneficial to improving these conditions include delivering an appropriate level of sedation and analgesia, integrating protocols to guide administration, utilizing sufficient monitoring, using the practice of intermittent sedation, and the proper selection of anesthetic agent.

To maximize the likelihood of success during weaning, it is crucial to incorporate the best practices in regards to the delivery of sedation and analgesia to increase effectiveness while minimizing risks. Reduction of pain and agitation, avoidance of exacerbating factors, and allowing the patient to easily interact with the ventilator will encourage improvement and prevent complications, and ultimately facilitate achieving the desired outcome.

By using methods to ensure that the patient experiences appropriate levels of sedation and analgesia, optimal conditions can be provided to prevent the problems that lead to difficulty in weaning from mechanical ventilation. There is evidence that the use of protocols and algorithms for optimizing sedation and analgesia produces numerous positive effects, including the prevention of oversedation, decreased pain and agitation, less patient-ventilator asynchrony, better detection of delirium, and a reduction in duration of mechanical ventilation and intensive care unit (ICU) and hospital stay [4].

One important consideration to bear in mind when weaning sedation from the mechanically ventilated patient is the temporal manner in which the sedation is delivered. Numerous studies have shown there are a variety of benefits to patients who receive daily interruption of sedation. Such benefits include shorter duration of mechanical ventilation, shorter length of stay, fewer diagnostic imaging tests for mental status changes, better Psychosocial Adjustment to Illness Scale scores, lower incidence of post-traumatic stress disorder, and the potential for reducing the risk of delirium [5].

It is important to monitor depth of sedation to maintain an adequate level, because prolonged and too deep sedation has been associated with worse outcomes. Toward this end, there are several tools available to ensure adequate levels of sedation. For example, the Ramsay Sedation Scale, the Sedation Agitation Scale, and the Richmond Agitation-Sedation Scale can be used to monitor and adjust the depth of sedation [5]. Although the Bispectral Index (BIS©, Aspect Medical Systems, Norwood, MA, USA) represents a novel method of measuring depth of sedation through the use of electroencephalography, more research is likely needed at this time before it sees routine use for this application. In addition to sedation scales, there are also various pain scales that may be employed to guide the administration of adequate analgesia, such as the Numeric Rating Scale, the Behavioral Pain Scale, the Critical Care Pain Observation Tool, and the Nonverbal Pain Scale [6].