Extracorporeal Hyperoxygenation Therapy (EHT) for Carbon Monoxide Poisoning: In-Vitro Proof of Principle

Abstract

Carbon monoxide (CO) poisoning is the leading cause of poisoning-related deaths globally. The currently available therapy options are normobaric oxygen (NBO) and hyperbaric oxygen (HBO). While NBO lacks in efficacy, HBO is not available in all areas and countries. We present a novel method, extracorporeal hyperoxygenation therapy (EHT), for the treatment of CO poisoning that eliminates the CO by treating blood extracorporeally at elevated oxygen partial pressure. In this study, we proof the principle of the method in vitro using procine blood: Firstly, we investigated the difference in the CO elimination of a hollow fibre membrane oxygenator and a specifically designed batch oxygenator based on the bubble oxygenator principle at elevated pressures (1, 3 bar). Secondly, the batch oxygenator was redesigned and tested for a broader range of pressures (1, 3, 5, 7 bar) and temperatures (23, 30, 37 °C). So far, the shortest measured carboxyhemoglobin half-life in the blood was 21.32 min. In conclusion, EHT has the potential to provide an easily available and effective method for the treatment of CO poisoning.

Carboxyhemoglobin predicts oxygenator performance and imminent oxygenator change in extracorporeal membrane oxygenation

“…We consider hemolysis inside the ECMO circuit together with reduced pulmonary elimination due to marginal lung function (V-V ECMO) or bypassing of the lung (V-A ECMO), as the most likely cause of rising COHb levels in our patients. The effectiveness of ECMO in reducing moderately elevated COHb is unclear but the residence time inside the oxygenator may be too short [ 15 , 32 ]. This is probably more important with high blood flow rates in patients already hypoxemic [ 31 ].…”

“…Heme oxygenase further metabolizes heme into biliverdin, free iron, and carbon monoxide [ 12 , 13 ]. Carbon monoxide (CO) then binds with high affinity to hemoglobin (about 250-fold greater as with oxygen) [ 14 , 15 ]. COHb is a promising parameter of overall oxygenator function because it is routinely measured every few hours, and both its production and its elimination are theoretically dependent on oxygenator condition [ 15 ].…”

“…Carbon monoxide (CO) then binds with high affinity to hemoglobin (about 250-fold greater as with oxygen) [ 14 , 15 ]. COHb is a promising parameter of overall oxygenator function because it is routinely measured every few hours, and both its production and its elimination are theoretically dependent on oxygenator condition [ 15 ]. We therefore analyzed the potential use of COHb as a novel parameter predicting oxygenator dysfunction…”