Efficacy of Proportional Sedation and Deep Sedation Defined by Sedation Protocols: A Multicenter, Prospective, Observational Comparative Study.

Purpose: To investigate the efficacy of two types of palliative sedation: proportional and deep sedation, defined by sedation protocols.

Methods: From a multicenter prospective observational study, we analyzed the data of those patients who received the continuous infusion of midazolam according to the sedation protocol. The primary endpoint was goal achievement at 4 hours: in proportional sedation, symptom relief (Integrated Palliative care Outcome Scale: IPOS ≤ 1) and absence of agitation (modified Richmond Agitation-Sedation Scale: RASS ≤ 0); in deep sedation, the achievement of deep sedation (RASS ≤ -4). Secondary endpoints included deep sedation as a result of proportional sedation, communication capacity (Communication Capacity Scale item 4 ≤ 2), IPOS and RASS scores, and adverse events.

Results: A total of 81 patients from 14 palliative care units were analyzed: proportional sedation (n = 64) and deep sedation (n = 17). At 4 hours, the goal was achieved in 77% (n = 49; 95% confidence interval: 66-87) with proportional sedation; and 88% (n = 15; 71-100) with deep sedation. Deep sedation was necessary in 45% of those who received proportional sedation. Communication capacity was maintained in 34% with proportional sedation and 10% with deep sedation. IPOS decreased from 3.5 to 0.9 with proportional sedation, and 3.5 to 0.4 with deep sedation; RASS decreased from +0.3 to -2.6, and +0.4 to -4.2, respectively. Fatal events related to the treatment occurred in 2% (n = 1) with proportional and none with deep sedation.

Conclusion: Proportional sedation achieved satisfactory symptom relief while maintaining some patients' consciousness, and deep sedation achieved good symptom relief while the majority of patients lost consciousness.