Severe tracheomalacia in the ICU: identification of diagnostic criteria and risk factor analysis from a case control study.

BACKGROUND: Severe tracheomalacia (STM) is being increasingly recognized as a cause for respiratory failure in the ICU. The diagnosis is often overlooked, as chest radiography appears normal, and the role of invasive diagnostic testing for this diagnosis is not well described in the ICU setting. The prevalence and risk factors for STM are not known, and computed tomography (CT) based diagnostic criteria for ventilated patients are not well studied. METHODS: Patients admitted between January 2008 and December 2010, with respiratory failure and who failed ventilator discontinuation or required reintubation, were screened for the presence of any tracheal collapse, utilizing prior CT of the chest. Bronchoscopically confirmed cases were compared with age and sex matched controls to identify risk factors. RESULTS: Twenty-five subjects were identified as having STM, which represented 0.7% of ICU admissions and 1.6% of subjects with respiratory failure. The mean ICU stay was significantly longer in STM (30 d, 95% CI 19.7-40 d), compared to controls (4.4 d, 95% CI 3.6-5.2 d). Obesity (odds ratio 1.26, 95% CI 1.04-1.54) and gastro-esophageal reflux (odds ratio 31, 1.7- 586) were associated with increased risk for STM. The pre-intubation PaCO2 (68 mm Hg, 95% CI 57-79 mm Hg) was significantly higher in STM, compared to controls (38 mm Hg, 95% CI 35-41). The distal tracheal antero-posterior diameter (2.80 mm, 95% CI 2.15-3.46) was significantly lower in STM. A receiver operating characteristic analysis showed a distal tracheal antero-posterior diameter < 7 mm to be the optimal cutoff measurement to diagnose STM. CONCLUSION: STM was associated with prolonged ICU stay. A distal tracheal antero-posterior diameter < 7 mm on a non-intubated CT chest was suggestive of STM that required a confirmatory bronchoscopy. Gastroesophageal reflux disease and obesity were potential risk factors.

Diagnostic yield and renal complications after computed tomography pulmonary angiograms performed in a community-based academic hospital.

BACKGROUND: Venous thromboembolism and pulmonary embolism (VTE/PE) remain a diagnostic challenge. The computed tomography pulmonary angiogram (CTPA) has emerged as a popular diagnostic test for PE. However, there is limited data on diagnostic yield and complications in actual clinical settings. Our goal was to determine the diagnostic yield for PE and rate of renal complications following CTPA in a large community hospital setting. METHODS: A retrospective chart review of 1,514 patients who underwent CTPA in the emergency department or during the initial 24 hours of admission to a community-based academic hospital. RESULTS: Of 1,514 CTPAs, 125 were positive for VTE/PE yielding a positive diagnosis in 8.2%. Dyspnea was the most common symptom in patients and a normal physical exam was the most common finding. Among the 925 patients with adequate data to calculate the rate of contrast-induced nephropathy (CIN), 25.8% had an increase of at least 25% in serum creatinine following the CTPA. Pre-existing diabetes and age were the most important predictors of CIN. CONCLUSIONS: CTPA has a low diagnostic yield for PE in a community setting, and in some patient populations, the rate of contrast-induced nephropathy may be higher than previously reported in the literature. Due to the retrospective nature of this study we were limited in using pre-test scoring systems and in measuring the impact of alternative CT diagnoses on patient management.