Usefulness of lung ultrasound for early detection of hospital-acquired pneumonia in cardiac critically ill patients on venoarterial extracorporeal membrane oxygenation

Background

Hospital-acquired pneumonia (HAP) is the most common and severe complication in patients treated with venoarterial extracorporeal membrane oxygenation (VA ECMO) and its diagnosis remains challenging. Nothing is known about the usefulness of lung ultrasound (LUS) in early detection of HAP in patients treated with VA ECMO. Also, LUS and chest radiography were performed when HAP was suspected in cardiac critically ill adult VA ECMO presenting with acute respiratory failure. The sonographic features of HAP in VA ECMO patients were determined and we assessed the performance of the lung ultrasound simplified clinical pulmonary score (LUS-sCPIS), the sCPIS and bioclinical parameters or chest radiography alone for early diagnosis of HAP.

Results

We included 70 patients, of which 44 (63%) were independently diagnosed with HAP. LUS examination revealed that color Doppler intrapulmonary flow (P = 0.0000043) and dynamic air bronchogram (P = 0.00024) were the most frequent HAP-related signs. The LUS-sCPIS (area under the curve = 0.77) yielded significantly better results than the sCPIS (area under the curve = 0.65; P = 0.004), while leukocyte count, temperature and chest radiography were not discriminating for HAP diagnosis.

Discussion

Diagnosis of HAP is a daily challenge for the clinician managing patients on venoarterial ECMO. Lung ultrasound can be a valuable tool as the initial imaging modality for the diagnosis of pneumonia. Color Doppler intrapulmonary flow and dynamic air bronchogram appear to be particularly insightful for the diagnosis of HAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01013-9.

Predictors and outcomes of postoperative respiratory failure after cardiac surgery

BACKGROUND

Postoperative respiratory failure after cardiac surgery (CS-PRF) is a devastating complication and its incidence and predictors vary depending on how it is defined and the patient population.

AIMS

This study was conducted to determine the incidence, predictors and outcomes of CS-PRF defined as prolonged mechanical ventilation >48 hours and reintubation.

METHODS

This is a retrospective chart review of 1257 patients who underwent cardiac surgery between June 2011 and December 2018. The research questions were addressed through bivariate inferential, descriptive and binary logistic regression.

RESULTS

The overall incidence of CS-PRF was 15.9% and significant regression predictors included diabetes mellitus (OR = 1.77, P = .001), preoperative renal replacement therapy (OR = 2.07, P = .033), need for intraoperative transfusion (OR = 2.35, P = .000), combined coronary bypass/valvular surgery (OR = 2.61, P = .001) and intra-aortic balloon pump (OR = 3.60, P = .000). CS-PRF patients had increased postoperative blood transfusions (69.5% vs 27.9%, P = .000), reoperation for bleeding (9.0 vs 0.4%, P = .000), pleural effusion (13.5% vs 4.1%, P = .000), pneumonia (33.5% vs 1.6%, P = .000), acute kidney injury (70.9% vs 39.9%, P = .000), atrial fibrillation (42.5% vs 26.3%, P = .000), coma/encephalopathy (21.5% vs 3.3%, P = .000) and cerebrovascular accident (6.0% vs 1.3%, P = .000). They also had longer intensive care (262.1 vs 97.4 hours, P = .000) and hospital lengths of stay (17 vs 8 days, P = .000), and increased in-hospital mortality (17.5% vs 0.4%, P = .000). Survivors of CS-PRF were less likely to be discharged home (38.0% vs 84.4%, P = .000).

CONCLUSIONS

Knowledge of predictors for CS-PRF may help identify patients who are at risk for this complication and who may benefit from preventive measures to promote early extubation and to avert reintubation.

Prophylactic Noninvasive Ventilation Versus Conventional Care in Patients After Cardiac Surgery

BACKGROUND

Cardiac surgery can be accompanied by postoperative complications, which are associated with increased postoperative morbidity and mortality. Therefore, it is necessary to investigate the effect of prophylactic noninvasive ventilation (NIV) after extubation versus conventional pulmonary care on complications after cardiac surgery.

MATERIALS AND METHODS

An electronic search of PubMed, Cochrane Library, Ovid, and EMBASE was conducted to find randomized controlled trials which compared the effect of prophylactic NIV with controlled strategies on complications and which were published before April 2018.

RESULTS

Ten studies (1011 patients) were included in the final analysis. The atelectasis rate was 32.6% in the prophylactic-NIV group, which was lower than that in the control group (48.71%). Prophylactic NIV could lower the rate of atelectasis, reintubation, and other respiratory complications (pleural effusion, pneumonia, and hypoxia) (odds ratio = 0.43, 0.33, and 0.45; 95% confidence interval: 0.21-0.88, 0. 13-0.84, 0.27-0.75; P = 0.02, 0.02, and 0.002, respectively). The effect on cardiac and distal organ complications (P = 0.07) and hospital mortality (P = 0.62) might be limited.

CONCLUSIONS

Prophylactic NIV is associated with a lower rate of postoperative pulmonary complications. The effect on the other complications and hospital mortality might be limited. Further evidence with randomized controlled trials can discern the benefits.