Respiratory dialysis with an active-mixing extracorporeal carbon dioxide removal system in a chronic sheep study

• Published in: Intensive care medicine Vol. 38; no. 10; pp. 1705 - 1711
• Main Authors: Wearden, Peter D., Federspiel, William J., Morley, Scott W., Rosenberg, Meir, Bieniek, Paul D., Lund, Laura W., Ochs, Burt D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-10-2012; Springer; Springer Nature B.V
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesiology; Animals; Biological and medical sciences; Blood; Carbon dioxide; Carbon Dioxide - blood; Carbon dioxide removal; Catheters; Chronic obstructive pulmonary disease; Critical Care Medicine; Dialysis - methods; Emergency and intensive respiratory care; Emergency Medicine; Experimental; Extracorporeal Circulation - adverse effects; Extracorporeal Circulation - instrumentation; Extracorporeal Circulation - methods; Extracorporeal membrane oxygenation; Extracorporeal Membrane Oxygenation - adverse effects; Extracorporeal Membrane Oxygenation - instrumentation; Extracorporeal Membrane Oxygenation - methods; Gases; Hemodialysis; Hemoglobin; Intensive; Intensive care medicine; Laboratory animals; Medical prognosis; Medical sciences; Medicine; Medicine & Public Health; Money; Pain Medicine; Pediatrics; Pneumology/Respiratory System; Pulmonary Disease, Chronic Obstructive - blood; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Disease, Chronic Obstructive - therapy; Pulmonary Gas Exchange - physiology; Regenerative medicine; Regulatory approval; Respiratory distress syndrome; Respiratory Distress Syndrome - blood; Respiratory Distress Syndrome - physiopathology; Respiratory Distress Syndrome - therapy; Sheep; Sheep, Domestic; Ventilators; Pennsylvania; United States > US; Pittsburgh Pennsylvania; Chronic obstructive pulmonary disease (COPD); Ventilation; Gas exchange; Acute respiratory distress syndrome (ARDS); Extracorporeal membrane oxygenation (ECMO); Extracorporeal life support (ECLS); Lung disease; Intensive care; Respiratory disease; Hemodialysis; Carbon dioxide; Vertebrata; Chronic; Mammalia; Exeresis; Bronchus disease; Respiratory distress; Sheep; Chronic obstructive pulmonary disease; Dialysis; Artiodactyla; Oxygenation; Ungulata; Resuscitation
• ISSN: 0342-4642; 1432-1238
• DOI: 10.1007/s00134-012-2651-8

Purpose
The objective of this study was to demonstrate the safety and performance of a unique extracorporeal carbon dioxide removal system (Hemolung, ALung Technologies, Pittsburgh, PA) which incorporates active mixing to improve gas exchange efficiency, reduce exposure of blood to the circuit, and provide partial respiratory support at dialysis-like settings.
Methods
An animal study was conducted using eight domestic crossbred sheep, 6–18 months of age and 49–115 kg in weight. The sheep were sedated and intubated, and a 15.5-Fr dual lumen catheter was inserted into the right jugular vein. The catheter was connected to the extracorporeal circuit primed with heparinized saline, and flow immediately initiated. The animals were then awakened and encouraged to stand. The animals were supported in a stanchion and monitored around the clock. Anticoagulation was maintained with heparin to achieve an aPTT of 46–70 s.
Results
Measurements included blood flow rate through the device, carbon dioxide exchange rate, pump speed and sweep gas flow rate. Safety and biocompatibility measurements included but were not limited to plasma-free hemoglobin, hematocrit, white blood cell count, platelet count and fibrinogen. The Hemolung removed clinically significant amounts of carbon dioxide, more than 50 ml/min, at low blood flows of 350–450 ml/min, with minimal adverse effects.
Conclusions
The results of 8-day trials in awake and standing sheep supported by the Hemolung demonstrated that this device can consistently achieve clinically relevant levels of carbon dioxide removal without failure and without significant risk of adverse reactions.