Objective. To evaluate the association between the success of extubation and Tobin index (frequency/spontaneous tidal volume), negative inspiratory force (NIF), forced vital capacity (FVC), respiratory rate (RR), oxygenation in patients with mysasthenic crisis and respiratory failure. Methods. Retrospective data of 22 consecutive patients (all female, age 49 ±21 years) admitted to the Neurosciences Critical Care Unit (NCCU) at Johns Hopkins Hospital from 1990 to 1998 were collected. Sixteen patients were Caucasian and 6 were African-American. Results. The patients were intubated for 18 ±24 days, required ICU management for 21 ±23 days. Each patient met the following criteria prior to extubation: absence of fever, no evidence of sepsis or pneumonia, FVC>1.2L, NIF>-25, RR <25, exhale volume > 400, minimum FiO2 of 30-40%, Tobin Index <100 and oxygen saturation > 95% in CPAP mode. Thirteen patients were successfully extubated and 9 patients required reintubation and mechanical ventilation. In African-Americans extubation was more likely to be unsuccessful than in Caucasians (odds ratio 0.155, 95% conf. int. 0.033-0.725, p = .018). Patients without basal atelectasis on chest X-ray had a higher chance of successful extubation (odds ratio 6.601, 95% conf. int. 1.009-43.200, p = .049). Better FVC was trendwise associated with successful extubation but did not reach significance (Punivariate = -074). Neither age, medical history, Tobin index, NIF, RR, exhale volume, oxygenation, nor secretions had predictive value for successful extubation. Conclusion. In mechanically ventilated patients with myasthenic crisis, Tobin Index, NIF, RR, and oxygenation may not be appropriate predictors for successful extubation. Other parameters may be necessary to correctly evaluate the strength of breathing. Radiographic evidence of atelectasis should be excluded before extubation.
|Original language||English (US)|
|Journal||Critical care medicine|
|Issue number||12 SUPPL.|
|State||Published - Dec 1 1999|
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine