Acute Left Ventricular Dysfunction during Unsuccessful Weaning from Mechanical Ventilation

Weaning Failure of Cardiac Origin: Recent Advances

“…A marked increase in work of breathing may increase cardiac work and myocardial oxygen demand [5]. Th e increased adrenergic tone may also increase venous return, LV afterload, cardiac work, and myocardial oxygen demand and may thus potentially result in myocardial ischemia in predisposed patients [4,6]. In patients with pre-existing right ventricular (RV) disease, an increase in weaning-induced RV afterload may occur because of hypoxemia or worsening of intrinsic positive end-expiratory pressure (PEEPi) [5].…”

“…However, in the absence of left heart disease, the rise in pulmonary artery occlusion pressure (PAOP) is limited [7,8]. In contrast, marked increases in PAOP have been reported to occur during unsuccessful weaning in patients with left heart disease [4,[9][10][11][12], who can thus be suspected to have failed to wean because of the onset of cardiogenic pulmonary edema.…”

“…Th ere is no defi nite value of PAOP above which cardiogenic pulmo nary edema develops, although 18 mmHg is recognized as a classical cut-off value [15]. Numerous studies have shown increases in PAOP during weaning in patients who failed to wean [4,[9][10][11][12]. Lemaire and colleagues [4] reported an average increase in transmural PAOP from 8 to 25 mmHg in unsuccessful weaning trials in 15 patients with both COPD and left heart disease.…”

“…Numerous studies have shown increases in PAOP during weaning in patients who failed to wean [4,[9][10][11][12]. Lemaire and colleagues [4] reported an average increase in transmural PAOP from 8 to 25 mmHg in unsuccessful weaning trials in 15 patients with both COPD and left heart disease. Interestingly, after diuretic therapy, 60% of these diffi cult-to-wean patients could be suc cessfully weaned with no further increase in PAOP during weaning [4].…”

“…Conversely, cardiac consequences of spontaneous breathing may be responsible for weaning failure in patients with left heart disease, even though the mechanical ventilation was required for respiratory failure of non-cardiac origin. Since its fi rst description more than twenty years ago [4], cardiogenic pulmonary edema has been recognized as a frequent cause of weaning failure in patients with underlying left cardiac dysfunction.…”