Sevoflurane sedation for weaning from mechanical ventilation in pediatric intensive care unit.

BACKGROUND: Light sedation is the prerequisite for weaning from mechanical ventilation. Our aim was to evaluate the technical feasibility and efficacy of sevoflurane delivered by anesthetic conserving device (ACD) for sedation of children during weaning from mechanical ventilation.

METHODS: Prospective observational feasibility study in pediatric ICU. Patients who were identified as ready for weaning from mechanical ventilation and had Withdrawal Assessment Tool version 1 (WAT-1) score of ≥8 were switched from intravenous sedatives to sevoflurane sedation by AnaConDa® ACD (Sedana Medical, Danderyd, Sweden) placed at the inspiratory limb of the ventilator (INSP group) or at Y-piece (Y group). Primary endpoints were proportion of time within a predefined interval on a sedation scale (COMFORT score 17-26) and the time required from discontinuation of sevoflurane until extubation. Secondary endpoints were the short-term (-6 hours to +6 hours) effects on systemic hemodynamics.

RESULTS: We enrolled 40 patients. Proportion of time with COMFORT score 17-26 was 89%, mean time to extubation was 10.2±3.9 min. The sevoflurane flow rate was 7±3 mL/h in INSP group, and 3.5±1.3 mL/h in Y group to obtain median end-tidal sevoflurane concentration (ETsevo) of 0.88 (range: 0.21-1.2) and 1.3 (range: 0.43-1.47) vol%, respectively. Mean arterial pressure (MAP) decreased significantly from 67.2±15 mmHg at -1 hour to 61±13.8 mmHg at +1 hour, and 62.8±14.8 mmHg at +6 hours, necessitating fluid therapy and/or vasopressor increase in eight (20%) patients. Transient psychomotor dysfunction developed in five (12.5%) patients after discontinuation of sevoflurane.

CONCLUSIONS: Sevoflurane administration by ACD is technically feasible in critically ill children. It provides sedation within the desired sedation interval 89% of time, with short time to extubation after termination of administration. Decrease in mean arterial pressure warrants good hemodynamic monitoring and optimization of preload. Longer sevoflurane sedation and higher ETsevo is associated with development of reversible psychomotor dysfunction.