Role Of Lung Ultrasound During Weaning In Patient With Mitral Regurgitation Post Angioplasty.

BACKGROUND: We hypothesize that a change in lung ultrasound score (LUS) can assist in the early diagnosis of weaning-induced respiratory failure (RF). The objective of this study was to determine the utility of LUS in weaning patients with mitral regurgitation (MR) from mechanical ventilation (MV). METHODS: This prospective observational study included patients with acute coronary syndrome (ACS) who required invasive MV after angiography/angioplasty. Echocardiography was performed and MR was recorded. When the patient was considered ready for extubation, a spontaneous breathing trial (SBT) was performed and pre- and post-SBT LUS was calculated. Patients who successfully passed the SBT were extubated and followed up for 48 hours for the signs of RF and outcomes. RESULTS: We enrolled 215 patients, out of which MR occurred in 51(23.7%) patients. On post-SBT lung ultrasound, patients with MR were more likely to have B2 lines compared to those without MR; 15.7% vs. 3.7%; p=0.002 and mean LUS was significantly higher for patients with MR as compared to patients without MR; 2.75±3.21 vs. 1.37± 2.02; p<0.001. Post-extubation RF and mean CCU stay were significantly higher in MR patients, 49.0% (25) vs. 32.3% (53); p=0.030 and 3.53±1.54 days vs. 2.41±1.1 days; p<0.001 respectively. However, re-intubation and coronary care unit (CCU) mortality rate were not significantly different between patients with and without MR; 7.8% (4/51) vs. 3.7% (6/164); p=0.215, and 5.9% (3/51) vs. 3% (5/164); p=0.35 respectively. CONCLUSIONS: Bedside LU is a convenient tool to detect changes in cardiopulmonary interactions during weaning for patients with MR post-ACS.

Predicting Post-Extubation Respiratory Failure After Myocardial Infarction Using The Rapid Shallow Breathing Index And Lung Ultrasound Score.

BACKGROUND: The Rapid Shallow Breathing Index (RSBI) has been hypothesized to have discriminating power for categorizing patients at higher risk of post-extubation respiratory failure (RF). Hence aim of this study was to determine the predictive value of RSBI for post-extubation RF in patients after acute myocardial infarction (AMI). METHODS: Consecutive, intubated patients admitted post-revascularization were included. RSBI and lung ultrasound score (LUS) were measured and post-extubation RF within 48 hours was recorded. RESULTS: RF was observed in 36.3% (78/215) patients. For the prediction of RF, RSBI and LUS had area under the curve of 0.670 and 0.635, respectively. The sensitivity, specificity, negative predictive value, and positive predictive value of RSBI >50.5 were 75.6%, 54.7%, 79.8%, and 48.8% respectively, while, the accuracy measures for the combination of RSBI with LUS >1.5 were 44.9%, 84.7%, 73.0%, and 62.5% respectively. CONCLUSIONS: Combined RSBI and LUS measured during spontaneous breathing trial in patients after an AMI, have high predictive abilities for identifying post-extubation RF.

Assessing the Utility of End-Tidal Carbon Dioxide as a Marker for Fluid Responsiveness in Cardiogenic Shock.

Background Preventing end-organ failure in patients with shock requires rapid and easily accessible measurements of fluid responsiveness. Unlike septic shock, not all patients in cardiogenic shock are preload responsive. We conducted this study to determine the discriminant power of changes in end-tidal carbon dioxide (ETCO2), systolic blood pressure (SBP), inferior vena cava (IVC) collapsibility index (IVC-CI), and venous to arterial carbon dioxide (Pv-aCO2) gap after a fluid challenge and compared it to increases in cardiac output. Methodology In a prospective, quasi-experimental design, mechanically ventilated patients in cardiogenic shock were assessed for fluid responsiveness by comparing improvement in cardiac output (velocity time integral) with changes in ETCO2, heart rate, SBP, Pv-aCO2 gap, IVC-CI after a fluid challenge (a crystalloid bolus or passive leg raise). Results Out of 60 patients, with mean age 61.3 ± 14.8 years, mean acute physiology and chronic health evaluation (APACHE) score -14.82 ± 7.49, and median ejection fraction (EF) 25% (25-35), 36.7% (22) had non ST-segment elevation myocardial infarction (NSTEMI) and 60% (36) were ST-segment elevation myocardial infarction (STEMI). ETCO2 was the best predictor of fluid responsiveness; area under the curve (AUC) 0.705 (95% confidence interval (CI) 0.57-0.83), p=0.007, followed by reduction in Pv-aCO2 gap; AUC 0.598 (95% CI; 0.45-0.74), p= 0.202. Changes in SBP, mean arterial pressure (MAP), IVC-CI weren't significant; 0.431 (p=0.367), 0.437 (p=0.410), 0.569 (p=0.367) respectively. The discriminant value identified for ETCO2 was more than equal to 2 mmHg, with sensitivity 58.6%, specificity 80.7%, positive predictive value 73.9% [95% CI; 56.5% to 86.1%], negative predictive value 69.7% [95% CI; 56.7% to 76.9%]. Conclusions Change in ETCO2 is a useful bedside test to predict fluid responsiveness in cardiogenic shock.