Category: Critical Care
Keywords: RV dysfunction, APRV, echo, ultrasound (PubMed Search)
--RV systolic function is negatively affected by high RV afterload
--High mean airway pressures on the ventilator (particularly in modes such as APRV [airway pressure release ventilation]) can induce RV dysfunction
*****CLICK BELOW FOR A GREAT CASE!!!*****
A 25yoF with ARDS is on APRV (36/0 and 5/0.5). She is on norepi to maintain a MAP >65. A bedside echo reveals a dilated, dysfunctional RV.
--Open "A4C end diastole"
Measurement of TAPSE confirms the RV dysfunction, but also reveals the cause.
Every 5th beat, the TAPSE significantly improves to "normal" range. The four beats inbetween are abnormal. The 5th normal beat coincides with the APRV relase, when airway pressures are zero! Thus, this change in RV function is from the ventilator alone. The TAPSE decreases by almost 40%!
--Open "TAPSE measured"
Be careful with high mean airway pressures in patients with known or suspected RV dysfunction. This is why we try to avoid intubation in HD significant pulmonary embolism!