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

Abstract 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.