Influence of positive end-expiratory pressure (PEEP) on left ventricular regional wall motion in patients with acute respiratory distress syndrome (ARDS)

Regional left ventricular wall motion abnormalities have been described at a positive end-expiratory pressure (PEEP) level of 20 cm H₂O [1]. However, no PEEP level has yet been defined, above which RWMA may occur.

Objective

To assess global and regional LV performance in response to PEEP by transoesophageal echocardiography (TOE) in patients with ARDS.

Setting

Surgical ICU in a university hospital.

Patients

Eight critically ill patients with normal systolic LV function requiring mechanical ventilation (tidal volume 6-8 ml/kg, PEEP 12 ± 2 cmH₂O) due to ARDS.

Measurements

Regional and global LV performance were assessed at PEEP levels of 5, 10, 15, 20 and 25 cmH₂O by means of TOE by the centerline method on the transgastric short-axis view.

Results

PEEP =15 cmH₂O produced a significant reduction in systolic septal wall motion (hypokinesia) and a significant augmentation of lateral systolic wall motion (hyperkinesia). Global LV performance - measured as fractional area change - was not significantly affected.

Conclusion and discussion

PEEP levels =15 cmH₂O may be associated with an inhomogeneity of regional wall motion. Most likely, this phenomenon is related to a nonuniform transmission of the increased intrathoracic pressure on the left ventricular wall because of its different relation to the pleural space.