Seven-Day Artificial Lung Testing in an In-Parallel Configuration

Abstract

A thoracic artificial lung, the MC3 Biolung, is being developed as a bridge to lung transplantation or as a treatment for acute respiratory insufficiency. The thoracic artificial lung was tested in 10 sheep with the goal of 7 days of respiratory support. The sheep were recovered from surgery and monitored awake for 7 days. Hemodynamics, blood gases, blood cell counts, and organ function were recorded, and after 7 days, all sheep were euthanized and necropsied. Seven sheep survived the full duration. Cardiac output and mean arterial blood pressure were unchanged, averaging 4.7 +/- 0.8 L/min and 98 +/- 10 mm Hg, respectively. Arterial oxygen tension and device oxygen transfer rate were also unchanged, averaging 110 +/- 26 mm Hg and 97.7 +/- 35 mL/min, respectively. Arterial carbon dioxide tension was within normal ranges during the entire experiment, averaging 37.4 +/- 3.8 mm Hg. Artificial lung blood flow decreased from 51% +/- 14% of cardiac output on day 1 to 30% +/- 16% by day 7 because of changes in natural and artificial lung resistance. White blood cell counts were significantly elevated on days 5 and 7, and lastly, kidney and liver function remained normal, although signs of kidney infarction or hemorrhage were noted. The thoracic artificial lung is suitable for 7-day attachment, but improvements in blood biocompatibility are warranted.