Comparison of a New Miniaturized Extracorporeal Membrane Oxygenation System With Integrated Rotary Blood Pump to a Standard System in a Porcine Model of Acute Lung Injury

Abstract

Extracorporeal membrane oxygenation (ECMO) is used for severe acute respiratory distress syndrome. However, available ECMO systems are large and not well designed for fast delivery, emergency implantation, and interhospital transfer. Therefore, a new miniaturized oxygenator with integrated rotary blood pump (ILIAS) was developed and compared with a standard ECMO system in a large animal model. Acute lung injury was induced with repeated pulmonary saline lavage in 14 pigs until PaO2 /FiO2 -ratio was <100 mm Hg with a positive-end-expiratory-pressure of 5 mbar. Pigs were assigned to the following three groups: group 1 (n = 4): control group with conventional ventilation; group 2 (n = 5): standard vv-ECMO; group 3 (n = 5): vv-ILIAS. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined over a period of 8 h. No device failed during the observation period. PaCO2 decreased from 59.40 ± 4.14 mm Hg to 48.62 ± 4.50 mm Hg after 1 h in the ILIAS group compared with an improvement of PaCO2 from 48.86 ± 7.45 to 40.10 ± 6.02 in the conventional ECMO group (P = not significant [n.s.]). ARDS-induced respiratory acidosis was controlled promptly with a pH of 7.2 ± 0.1 at baseline increasing to 7.4 ± 0.1 in both study groups after 60 min of ECMO support. Mean carbon dioxide transfer was comparable between the conventional ECMO and ILIAS (211.36 ± 78.39 mL/min vs. 219.99 ± 76.72 mL/min, P = n.s.). PaO2 /FiO2 increased from 118.4 ± 15.5 mm Hg to 179.1 ± 72.4 mm Hg in the ILIAS group compared with an improvement of oxygenation from 107.1 ± 24.9 mm Hg to 179.0 ± 45.7 mm Hg in the standard ECMO group (P = n.s.). Mean oxygen transfer was calculated with 136.09 ± 30.25 mL/min for the ILIAS and 129.05 ± 36.28 mL/min for the standard ECMO. Hemodynamic instability or significant activation of the plasmatic coagulation was not observed. However, hemolysis was significantly higher in the ILIAS group compared with the conventional ECMO. As the ILIAS prototype provided excellent gas exchange with hemodynamic stability comparable with a standard ECMO system, we believe this study serves as a proof of concept. Further development and design modifications (optimized rotation speed and surface coating of rotor) are already done and another experiment is projected to reduce hemolysis and platelet consumption for clinical application.

A pH‐based experimental method for carbon dioxide exchange evaluation in cylindrical hollow fiber membrane oxygenators

“…CTR of an HFMO is mainly investigated in vitro using either native animal blood, for example, bovine or porcine blood or normal saline solution . Utilizing animal blood requires a complicated procedure to adjust and manipulate the blood's parameters according to the human mixed venous blood condition based on DIN EN ISO 7199 .…”

Extracorporeal membrane oxygenation (ECMO) and the acute respiratory distress syndrome (ARDS): a systematic review of pre-clinical models

“…Inhalational anesthesia was used in two studies [16, 19]. Only four studies reported a protocolized approach to cardiovascular support [12, 24, 25, 27], while six studies provided data on cumulative fluid balance.…”

“…OA over 30 minP/F < 150 mmHgAraos et al [12]Saline lavage (30 mL/kg at 39 °C) × 4 (2 prone, 2 supine) and 2 h of injurious ventilation (inspiratory pressure 40 cmH 2 O, PEEP 0 cmH 2 O, FiO 2 1.0, RR 10)P/F < 250 mmHgWang et al [28]18–20 μg/kg i.v. E. coli LPS within 1 hP/F ≤ 300 mmHg and 30% decrease in dynamic compliance from baselineNi et al [23]Blunt injury (free fall 0.45 kg weight from 1-m column) to each lateral chest wall (ribs 6–9) and hemorrhage to MAP 40 ± 5 mmHg for 2 h followed by crystalloid/autologous blood resuscitationNot statedPilarczyk et al [25]Saline lavage (1000 mL bilaterally at 37 °C) repeated every 60 mins until injury achievedPaO 2 < 100 mmHg for > 1 hPark et al [24]Saline lavage (1000 mL at 37 °C) repeated until injury achieved and fecal peritonitis (1 g/kg injection of feces into peritoneal cavity)P/F < 50 mmHgKopp et al [20]Hypoxia (FiO 2 reduced to achieve hypoxic inspiratory gas mixture)SaO 2 < 85%Song et al [26]18–20 μg/kg i.v. E. coli LPS within 1 hP/F ≤ 300 mmHg and 30% decrease in dynamic compliance from baselineKopp et al [21]Saline lavage (40 mL/kg) repeated until injury achievedP/F < 100 mmHgHenderson et al [16]0.2 mL/kg i.v.…”

“…A summary of ECMO models and the management of ECMO during experiments are provided in Table 5. In most cases ( n = 14), cannulation was peripheral, with three studies performing surgical cutdown [17, 25, 28]. There were a wide variety of cannulation configurations among studies.…”

Percutaneous cannulation for extracorporeal membrane oxygenation (ECMO): A method for pig experimental models

“…The reported complications of this technique are mainly related to the insertion process, and include insertion failure due to a mismatch between vessel size and diameter of the cannula, as well as potential bleeding complications [5] . Long term complications include infection, limb ischemia and subsequent sensory-motor complications in humans [6 , 7] .…”