Predicting laryngeal edema in intubated patients by portable intensive care unit ultrasound

Abstract

PurposeThe purpose of this study is to determine the diagnostic accuracy of portable ultrasound for detection of laryngeal edema (LE) in intubated patients. Materials and MethodsWe conducted a prospective, observational study from December 2010 to September 2011. We measured air column width differences (ACWD) in planned extubation patients admitted in intensive care unit by ultrasound. The primary outcome was the diagnostic accuracy of ACWD to predict the presence of LE. ResultsA total of 101 patients were enrolled. The prevalence of LE was 16.8%. Baseline characteristics were similar between intubated patients with and without LE. The mean difference of increasing of air column width in patients without LE was higher than in LE group (1.9 vs 1.08 mm, P < .001). The sensitivity and specificity at ACWD higher or equal to 1.6 mm were 0.706 and 0.702, respectively. The positive predictive value and negative predictive value were 0.324 and 0.922, respectively. The area under the receiver operating characteristic curve of laryngeal ultrasound was 0.823 (95% confidence interval, 0.698-0.947) and that of cuff leak test was 0.840 (95% confidence interval, 0.715-0.964). ConclusionPortable intensive care unit ultrasound visualizing ACWD between predeflation and postdeflation cuff balloon is a promising objective tool, which aids in prediction of successful extubation regarding LE.