ABSTRACT 524

Abstract

Background and aims: In patients who develop dilated cardiomyopathy (DCM) due to acute fulminant myocarditis, afterload reduction plays a crucial role during management. Although higher levels of intrathoracic pressure (ITP) reduce left ventricular afterload, it is generally acknowledged that elevated ITP causes hemodynamic compromise due to predominance of other complex cardiopulmonary interactions. Aims: Demonstrate that increasing ITP can improve cardiac function in selected patients. Case Report: A 4 year old girl presenting with severe hemodynamic and respiratory compromise was admitted to the PICU with vasopressor, inotropic, ventilator and fluid support while maintaining euvolemia. Echocardiography (ECG) on admission revealed evidence of myocarditis and DCM with an ejection fraction (EF) of 30%. Repeat ECG 24 hours later revealed no improvement. ECG guided adjustment of ventilator settings was decided. No change in medication or dosage was done during the adjustment, eliminating other potential confounders. Case is presented as educational material and is not subject to IRB review (patient is deceased and all attempts to remove identifiable information were made).FigureResults: EF improvement (47%) was noted after gradually increasing positive end-expiratory pressure (PEEP) from 5 to 10 cmH20. Effect was maintained on subsequent ECGs on the following days. Conclusions: This case demonstrates improvement in cardiac function after increasing PEEP. This suggests that PEEP could serve as a ventricular assist mechanism in isolated cases of ventricular failure. Heart-lung interaction during mechanical ventilation needs further study.