Diaphragm Paralysis After Cardiac Surgery: A Frequent Cause of Post-Operative Respiratory Failure

Abstract

BackgroundDiaphragmatic dysfunction (DD) is found in 1.2-60% of patients after cardiac surgery. The aim of this study was to reinvestigate the incidence, risk factors and outcomes of DD with actual cardiac surgery procedures.MethodsThis is an observational study based on a prospectively collected database in one cardiac surgery centre. The DD group included patients with clinically perceptible diaphragmatic paralysis, which was confirmed by chest ultrasound (amplitude of the diaphragm movement in time-motion mode [TM] at rest, after a sniff test). The primary endpoint was the incidence of DD. ResultsA total of 3577 patients were included between January 2016 and September 2019. We found 272 cases of DD (7.6%). Individuals with DD had more arterial hypertension (64.3% vs. 52.6%; p<0.0001), higher body mass index (BMI) (28[25–30] kg/m2 vs. 26[24-29] kg/m2; p<0.0002) and higher incidence of coronary bypass grafting (58.8% vs. 46.6%; p=0.0001). DD was associated with more postoperative pneumonia (23.9% vs. 8.7%; p<0.0001), reintubation (8.8% vs. 2.9%; p<0.0001), tracheotomy (3.3% vs. 0.3%; p<0.0001), non-invasive ventilation (45.6% vs. 5.4%; p<0.0001), duration of mechanical ventilation (5[4-11] h vs. 4[3-6] h; p<0.0001), and ICU and hospital stays (14[11-17] days vs. 13[11–16] days; p<0.0001). In multivariate analysis, DD was associated with coronary artery bypass grafting (OR=1.9[1.5-2.6]; p=0.0001), arterial hypertension (OR=1.4[1.1- 1.9]; p=0.008), and BMI (OR per point =1.04[1.01-1.07] kg/m2; p=0.003).ConclusionThe incidence of symptomatic DD after cardiac surgery was 7.6%, leading to respiratory complications and increased ICU stay. Coronary bypass grafting was the principal factor associated with DD.