Early Identification of Patients at Risk for Difficult Intubation in the Intensive Care Unit

TLDR

Difficult intubation in the ICU is a challenging issue that is associated with severe life‑threatening complications. The study aims to develop and validate a simplified score to identify ICU patients at risk of difficult intubation and to report associated complications. The authors performed a prospective multicenter study of 1,000 ICU intubations, then externally validated the MACOCHA score on 400 cases and internally via bootstrap, deriving a seven‑item simplified score from β parameters. The MACOCHA score achieved an AUC of 0.89 (internal) and 0.86 (external), with 73% sensitivity, 89% specificity, and 98% NPV, and identified that difficult intubation (11.3% incidence) was linked to a 51% rate of severe life‑threatening complications versus 36% in nondifficult cases. The study is registered at ClinicalTrials.gov (NCT01532063).

Abstract

Difficult intubation in the intensive care unit (ICU) is a challenging issue.To develop and validate a simplified score for identifying patients with difficult intubation in the ICU and to report related complications.Data collected in a prospective multicenter study from 1,000 consecutive intubations from 42 ICUs were used to develop a simplified score of difficult intubation, which was then validated externally in 400 consecutive intubation procedures from 18 other ICUs and internally by bootstrap on 1,000 iterations.In multivariate analysis, the main predictors of difficult intubation (incidence = 11.3%) were related to patient (Mallampati score III or IV, obstructive sleep apnea syndrome, reduced mobility of cervical spine, limited mouth opening); pathology (severe hypoxia, coma); and operator (nonanesthesiologist). From the β parameter, a seven-item simplified score (MACOCHA score) was built, with an area under the curve (AUC) of 0.89 (95% confidence interval [CI], 0.85-0.94). In the validation cohort (prevalence of difficult intubation = 8%), the AUC was 0.86 (95% CI, 0.76-0.96), with a sensitivity of 73%, a specificity of 89%, a negative predictive value of 98%, and a positive predictive value of 36%. After internal validation by bootstrap, the AUC was 0.89 (95% CI, 0.86-0.93). Severe life-threatening events (severe hypoxia, collapse, cardiac arrest, or death) occurred in 38% of the 1,000 cases. Patients with difficult intubation (n = 113) had significantly higher severe life-threatening complications than those who had a nondifficult intubation (51% vs. 36%; P < 0.0001).Difficult intubation in the ICU is strongly associated with severe life-threatening complications. A simple score including seven clinical items discriminates difficult and nondifficult intubation in the ICU. Clinical trial registered with www.clinicaltrials.gov (NCT 01532063).