Comparison of isoflurane and propofol sedation in critically ill COVID-19 patients-a retrospective chart review.

PURPOSE: In this retrospective study, we compared inhaled sedation with isoflurane to intravenous propofol in invasively ventilated COVID-19 patients with ARDS (Acute Respiratory Distress Syndrome).

METHODS: Charts of all 20 patients with COVID-19 ARDS admitted to the ICU of a German University Hospital during the first wave of the pandemic between 22/03/2020 and 21/04/2020 were reviewed. Among screened 333 days, isoflurane was used in 97 days, while in 187 days, propofol was used for 12 h or more. The effect and dose of these two sedatives were compared. Mixed sedation days were excluded.

RESULTS: Patients' age (median [interquartile range]) was 64 (60-68) years. They were invasively ventilated for 36 [21-50] days. End-tidal isoflurane concentrations were high (0.96 ± 0.41 Vol %); multiple linear regression yielded the ratio (isoflurane infusion rate)/(minute ventilation) as the single best predictor. Infusion rates were decreased under ECMO (3.5 ± 1.4 versus 7.1 ± 3.2 ml∙h-1 ; p < 0.001). In five patients, the maximum recommended dose of propofol of 4 mg∙hour-1 ∙kg-1 ABW was exceeded on several days. On isoflurane compared to propofol days, neuro-muscular blocking agents (NMBAs) were used less frequently (11% versus 21%; p < 0.05), as were co-sedatives (7% versus 31%, p < 0.001); daily opioid doses were lower (720 [720-960] versus 1080 [720-1620] mg morphine equivalents, p < 0.001); and RASS scores indicated deeper levels of sedation (- 4.0 [- 4.0 to - 3.0] versus - 3.0 [- 3.6 to - 2.5]; p < 0.01).

CONCLUSION: Isoflurane provided sufficient sedation with less NMBAs, less polypharmacy and lower opioid doses compared to propofol. High doses of both drugs were needed in severely ill COVID-19 patients.