The goal of this study was to evaluate possible changes in the left myocardial performance of patients with cardiogenic shock (CS) during ascending levels of positive end-expiratory pressure (PEEP) using speckle-tracking echocardiography.Materials and Methods:
This was an interventional clinical study performed on CS patients under mechanical ventilation. These patients underwent echocardiography after 15 to 30 minutes of progressive increases in PEEP zero end-expiratory pressure (ZEEP) (PEEP 5, PEEP 10, PEEP 15 cm H2O). We evaluated the changes caused by these increasing levels of PEEP on the E/E′ ratio and the parameters of left ventricular systolic and diastolic functions, including longitudinal strain (S) and strain rate (SR). Analyses of mean values were carried out using analysis of variance.Results:
A total of 65 CS patients were included. Their mean age was 68.58±14.61 years. Progressive increases in PEEP induced a significant decrease in the E/E′ ratio (ZEEP=12.87±1.81; PEEP=5, 8.39±3.61; PEEP=10, 6.34±1.73; and PEEP=15, 7.10±0.37; P<0.0001). Although we did not find significant changes in left ventricular ejection fraction, a clear increase in left ventricular S and SR occurred (ZEEP=−13, 15±1.27; PEEP=5, −16.97±4.01; PEEP=10, −16.89±0.46; PEEP=15, −15.39±4.21; and ZEEP=−1.02±0.02; PEEP=5, −1.49±0.13; PEEP=10, −1.57±0.21; PEEP=15, −1.24±0.29, respectively; all values were significant).Conclusions:
Increasing levels of PEEP improve the left ventricular S and SR. PEEP levels could modify the performance of left ventricular fibers.