Myocardial ischemia during ventilator weaning: a prospective multicenter cohort study

Abstract

Background Weaning-induced cardiac pulmonary edema (WiPO) is one of the main mechanisms of weaning failure during mechanical ventilation. We hypothesized that weaning-induced cardiac ischemia (WiCI) may contribute to weaning failure from cardiac origin. Methods A prospective cohort study of patients mechanically ventilated for at least 24 h who failed a first spontaneous breathing trial (SBT) was conducted in four intensive care units. Patients were explored during a second SBT using multiple tools (echocardiography, continuous 12-lead ST monitoring, biomarkers) to scrutinize the mechanisms of weaning failure. WiPO definition was based on three criteria (echocardiographic signs of increased left atrial pressure, increase in B-type natriuretic peptides, or increase in protein concentration during SBT) according to a conservative definition (at least two criteria) and a liberal definition (at least one criterion). WiCI was diagnosed according to the third universal definition of myocardial infarction proposed by the European Society of Cardiology (ESC) and the American Heart Association (AHA) statement for exercise testing. Results Among patients who failed a first SBT, WiPO occurred in 124/208 (59.6%) and 44/208 (21.2%) patients, according to the liberal and conservative definition, respectively. Among patients with ST monitoring, WiCI was diagnosed in 36/177 (20.3%) and 12/177 (6.8%) of them, according to the ESC and AHA definitions, respectively. WiCI was not associated with WiPO and was not associated with weaning outcomes. Only two patients of the cohort were treated for an acute coronary syndrome after the second SBT, and seven other patients required coronary angiography during the weaning period. Conclusions This observational study showed the common occurrence of pulmonary edema in mechanically ventilated patients who failed a first SBT, but the association with cardiac ischemia and weaning outcomes was weak.

Diaphragm dysfunction, lung aeration loss and weaning-induced pulmonary oedema in difficult-to-wean patients

“…Herein, we report a high rate of spontaneous breathing trial failure that is purposely explained by the specific combination of inclusion criteria that we applied: duration of mechanical ventilation longer than 48 h and failure to the first spontaneous breathing trial. This prevalence is higher than that previously reported (60%) [ 1 , 2 , 27 ], but can presumably be explained by the selection of our patients. The definition of weaning-induced pulmonary oedema used in this study could also explain the high prevalence, as we opted to standardize classification of patients based on objective criteria (echocardiography and/or biomarkers) rather than classify patients based on expert consensus [ 1 , 2 ], which may be subject to bias.…”

“…This prevalence is higher than that previously reported (60%) [ 1 , 2 , 27 ], but can presumably be explained by the selection of our patients. The definition of weaning-induced pulmonary oedema used in this study could also explain the high prevalence, as we opted to standardize classification of patients based on objective criteria (echocardiography and/or biomarkers) rather than classify patients based on expert consensus [ 1 , 2 ], which may be subject to bias. We also used a challenging weaning trial that is likely to have markedly influenced the intrathoracic pressure [ 29 ].…”

“…Weaning-induced pulmonary oedema is a frequent cause of spontaneous breathing trial failure, accounting for up to 60% of weaning failure in two large observational studies [ 1 , 2 ]. Likewise, a strong association has been established between diaphragm dysfunction and spontaneous breathing trial failure [ 3 , 4 ].…”

Critical illness-related corticosteroid insufficiency during difficult weaning from mechanical ventilation

“…This ancillary study, planned a priori, was performed in one (Henri Mondor University hospital, Creteil, France) of the four centers participating in a prospective multicenter study assessment of WiPO and weaning-induced myocardial ischemia (WiCI) [ 11 ]. Patients screened for enrolment were those intubated for at least 24 h with ventilator settings allowing to initiate the weaning process [SpO 2 > 90% or PaO 2 /FiO 2 ≥ 150 mmHg with a fraction of inspired oxygen (FiO 2 ) ≤ 40% and a positive end-expiratory pressure (PEEP) ≤ 8 cmH 2 O].…”

“…Because there is no non-invasive consensual definition of WiPO, we considered three criteria proposed in the recent literature: (i) echocardiographic signs of increased left atrial pressure at the end of the SBT: E / A ratio > 0.95 and E / e ′ ratio > 8.5 [ 19 ]; (ii) an increase of BNP (absolute change ≥ 48 ng/L) or NT-proBNP (absolute change ≥ 21 ng/L) concentration during the SBT [ 20 ]; and (iii) an increase of protein concentration (relative change > 6%) during the SBT [ 21 ]. We further combined these criteria into two definitions of WiPO, as follows: a conservative definition (when at least two criteria were fulfilled), and a liberal definition (when at least one criterion was fulfilled) [ 11 ]. As per our weaning protocol and current guidelines [ 13 ], we performed a cuff leak test in selected patients at high risk of post-extubation stridor; no patient required a preventive or curative steroid treatment for stridor.…”