Evaluation of preintubation shock index and modified shock index as predictors of postintubation hypotension and other short-term outcomes

Purpose: Preintubation shock index (SI) and modified shock index (MSI) have demonstrated predictive capability for postintubation hypotension in emergency department. The primary aim was to explore this relationship in the critical care environment. The secondary aims were to evaluate the relationship of shock indices with other short-term outcomes like mortality and length of stay in intensive care unit. Materials and methods: This is a nonconcurrent cohort study, conducted in eligible 140 adult intensive care unit (ICU) patients of a tertiary care medical center. Eligibility criterion was emergent endotracheal intubation in apparently hemodynamically stable patients. Results: Preintubation SI ≥ 0.90 had a significant association with postintubation hypotension as defined by systolic blood pressure < 90 mm Hg in the univariate (. P = .03; odds ratio [OR], 2.13; 95% confidence interval [CI], 1.07-4.35) and multivariate analyses (. P = .01; OR, 3.17; 95% CI, 1.36-7.73) after adjusting for confounders. It was also associated with higher ICU mortality in both the univariate (. P = .01; OR, 4.00; 95% CI, 1.26-12.67) and multivariate analyses (. P = .01; OR, 5.75; 95% CI, 1.58-26.48). There was no association of preintubation MSI with postintubation hemodynamic instability and ICU mortality. No association was found between preintubation SI and MSI, with ICU length of stay and 30-day mortality. Conclusions: Our findings indicate that preintubation SI greater than or equal to 0.90 is a predictor of postintubation hypotension (systolic blood pressure <90 mm Hg) and ICU mortality in emergently intubated adult patients in intensive care units.