Cost-Effectiveness Analysis of Inhaled Isoflurane Sedation in Critically Ill Patients: A Comparison with Intravenous Sedation

Abstract

Background: Sedation in critically ill patients requiring invasive mechanical ventilation is a cornerstone of intensive care. While intravenous sedatives such as propofol, midazolam and fentanyl are widely used, inhaled agents like isoflurane have emerged as alternatives with potential clinical benefits. However, (their) its economic impact remains uncertain, particularly in low- and middle-income healthcare settings.
Objective: To evaluate the cost-effectiveness of inhaled sedation with isoflurane versus conventional intravenous sedation with midazolam and fentanyl in mechanically ventilated ICU patients from the Colombian healthcare system perspective.
Methods: A decision tree model was constructed using clinical effectiveness data from recent studies, including patients with and without COVID-19. Direct medical costs were obtained from national tariff manuals, institutional records, and literature. The model simulated a cohort of 1,000 patients (500 per group), and incorporated key clinical outcomes: ICU length of stay, mechanical ventilation duration, delirium incidence, and sedative/opioid consumption. Sensitivity analyses explored optimistic and pessimistic scenarios. The Incremental Cost-Effectiveness Ratio (ICER) was calculated using weighted differences in ICU stay as the effectiveness measure.
Results: In the base-case scenario, inhaled sedation reduced ICU stay by 4.02 days on average, with a total cost of $ 1.258.580 USD, compared to $ 1.838.040 USD for intravenous sedation-yielding a net saving of $ 579.460 USD. The ICER was -$144.144 USD, indicating inhaled sedation was a dominant strategy (more effective and less costly). In sensitivity analyses, the optimistic scenario showed greater savings ($ 609.920 USD), while the pessimistic scenario-assuming equal ICU stays-still resulted in modest savings ($ 32.000 USD).
Conclusion: Inhaled isoflurane sedation is a cost-effective and clinically advantageous strategy for critically ill patients requiring mechanical ventilation. Despite higher initial costs, it results in net savings through reductions in ICU stay and associated complications. These findings support its adoption in resource-constrained settings, with local cost data adjustments for broader applicability.