Bedside Abdominal Ultrasound in Evaluating Nasogastric Tube Placement: A Multicenter, Prospective, Cohort Study.

BACKGROUND: Chest radiography is universally accepted as the method of choice to confirm correct positioning of a nasogastric tube (NGT). Considering also that radiation exposure could increase with multiple insertions in a single patient, bedside abdominal ultrasound (BAU) may be a potentially useful alternative to chest radiography in the management of NGTs. RESEARCH QUESTION: What is the accuracy of BAU in confirming the correct positioning of an NGT? STUDY DESIGN AND METHODS: After a specific course consisting of 10 h of training, the authors studied, in a prospective multicenter cohort, the validity of BAU to confirm correct NGT placement. All patients were also evaluated by auscultation (whoosh test) and by chest radiography. Every involved operator was blind to each other. Interobserver agreement and accuracy analyses were calculated. RESULTS: This study evaluated 606 consecutive inpatients with an indication for NGT insertion. Eighty patients were excluded for protocol violation or incomplete examinations and 526 were analyzed. BAU was positive, negative, and inconclusive in 415 (78.9%), 71 (13.5%), and 40 (7.6%), respectively. The agreement between BAU and chest radiography was excellent. Excluding inconclusive results, BAU had a sensitivity of 99.8% (99.3%-100%), a specificity of 91.0% (88.5%-93.6%), a positive predictive value of 98.3% (97.2%-99.5%), and a negative predictive value of 98.6% (97.6%-99.7%). The accuracy of BAU slightly changed according to the different assignments of the uncertain cases and was improved by the exclusion of patients with an altered level of consciousness. INTERPRETATION: These results suggest that BAU has a good positive predictive value and may confirm the correct placement of NGTs when compared with chest radiography. However, considering its suboptimal specificity, caution is necessary before implementing this technique in clinical practice.

Accuracy of Nurse-Performed Lung Ultrasound in Patients With Acute Dyspnea: A Prospective Observational Study.

In clinical practice lung ultrasound (LUS) is becoming an easy and reliable noninvasive tool for the evaluation of dyspnea. The aim of this study was to assess the accuracy of nurse-performed LUS, in particular, in the diagnosis of acute cardiogenic pulmonary congestion. We prospectively evaluated all the consecutive patients admitted for dyspnea in our Medicine Department between April and July 2014. At admission, serum brain natriuretic peptide (BNP) levels and LUS was performed by trained nurses blinded to clinical and laboratory data. The accuracy of nurse-performed LUS alone and combined with BNP for the diagnosis of acute cardiogenic dyspnea was calculated. Two hundred twenty-six patients (41.6% men, mean age 78.7 ±â€Š12.7 years) were included in the study. Nurse-performed LUS alone had a sensitivity of 95.3% (95% CI: 92.6-98.1%), a specificity of 88.2% (95% CI: 84.0-92.4%), a positive predictive value of 87.9% (95% CI: 83.7-92.2%) and a negative predictive value of 95.5% (95% CI: 92.7-98.2%). The combination of nurse-performed LUS with BNP level (cut-off 400 pg/mL) resulted in a higher sensitivity (98.9%, 95% CI: 97.4-100%), negative predictive value (98.8%, 95% CI: 97.2-100%), and corresponding negative likelihood ratio (0.01, 95% CI: 0.0, 0.07). Nurse-performed LUS had a good accuracy in the diagnosis of acute cardiogenic dyspnea. Use of this technique in combination with BNP seems to be useful in ruling out cardiogenic dyspnea. Other studies are warranted to confirm our preliminary findings and to establish the role of this tool in other settings.