Applications of the Pulsatile Flow Versatile ECLS: In Vivo Studies

Abstract

Introduction

T-PLS (Twin-Pulse Life Support) is the first commercial pulsatile ECLS (Extra Corporeal Life Support) device (1). The dual sac structure of T-PLS can effectively reduce high membrane oxygenator inlet pressure and hemolysis. To verify both the use of T-PLS for ECLS and the advantages of T-PLS, we tested various models.

Method and Results

In the partial CPB (cardio pulmonary bypass) model (swine), T-PLS (N=6), and Biopump (N=2), a single pulsatile pump (N=2), were compared. In the case of single pulsatile flow, during pump systole, pressure increased to 700 - 800 mmHg at the inlet port of the membrane oxygenator. fHb, a hemolysis measurement value, was about 80 mg / dL at 3 hours. On the contrary, because of T-PLS's dual sac system, the pressure of T-PLS had a maximum value of about 250 mmHg and fHb was similar to that of the commercial centrifugal pumps. In the total CPB model (bovine, N=6), the heart was stopped via cardioplegia (Kcl). T-PLS flow was maintained at 3.0 - 4.5 L/min. T-PLS functioned like a natural heart, having a pulse pressure of 26 - 43 mmHg and a pulse rate of 40 - 60 bpm (beats per minute). In the emergency case model (canine, N=6), T-PLS was started 10 minutes after cardiac arrest from electronic shock. In spite of cardiac arrest for a period of 40 minutes, the heart was recovered after defibrillation. In the ARDS (Acute Respiratory Distress Syndrome) model (canine, N=6), minimal ventilator parameters were set: tidal volume 130 ml, respiration rate = bpm, FiO₂ = 10%. Three hours after starting T-PLS, PO₂ of the carotid artery blood (after 2 hours: 195 ±89.4; after 3 hours: 258 ±99.3 mmHg) was above half the value of the femoral artery but was within normal range.

Conclusion

It is suggested that a portable pulsatile ECLS like T-PLS may be used as a CPB device and as an alternative CPR (cardiopulmonary resuscitation) device in the case of cardiac arrest. Due to the pulsatile flow, oxygenated blood is delivered to the patient without overloading the ARDS patient's heart.