Application value of transcutaneous oximeter and distal perfusion catheter in acute limb ischemia in patients with venoarterial extracorporeal membrane oxygenation

ObjectiveTo investigate the application value of transcutaneous oximeter and distal perfusion catheter (DPC) in acute limb ischemia (ALI) complications of venoarterial extracorporeal membrane oxygenation (VA-ECMO).

MethodsA total of 50 patients who received VA-ECMO treatment were selected as the study subjects.All patients were treated with ultrasound-guided peripheral femoral arteriovenous catheter and indwelling DPC.The patients were divided into ischemia group (n=15) and non-ischemia group (n=35) according to the occurrence of ALI.Transcutaneous oxygen pressure (PtcO₂) and transcutaneous carbon dioxide pressure (PtcCO₂) of lower extremity on the side of arterial catheterization were monitored, and oxygen challenge test (OCT) was performed.The general clinical data, PtcO₂ and PtcCO₂ before and after OCT, 10 min-OCT, and PtcO₂ and PtcCO₂ before and after DPC access were compared between the two groups.The predictive value of PtcO₂ and PtcCO₂ was evaluated by receiver operating characteristic (ROC) curve.

ResultsPtcO₂ was significantly increased after OCT in patients without ischemia, resulting in statistically significant differences in PtcO2 and 10 min-OCT between the two groups (P < 0.01), while there were no significant changes in PtcO₂ and PtcCO₂ after OCT in patients with ischemia (P>0.05).There were statistically significant differences in PtcO₂ and PtcCO₂ between the two groups before DPC access (P < 0.01), but PtcO₂ was significantly increased and PtcCO₂ was significantly decreased in the ischemic group after DPC access, resulting in no statistically significant difference between PtcO₂ and PtcCO₂ between the two groups after DPC access (P>0.05).ROC curve analysis showed that 10 min-OCT, PtcO₂ after OCT, PtcO₂ and PtcCO₂ before DPC access had good predictive value on the occurrence of ALI, and the area under ROC curve was 0.945 (95%CI: 0.934 -1.000), 0.904 (95%CI: 0.821-0.987), 0.939 (95%CI: 0.870-1.000), 0.874 (95%CI: 0.766-0.983), and pairwise comparison of the ROC curves of the above four indicators showed no statistical significance (P>0.05).

ConclusionsTranscutaneous oximeter can be used as an effective means to monitor ALI in VA-ECMO patients, and the occurrence of ALI can be identified earlier by OCT.DPC can significantly improve the lower extremity blood supply of VA-ECMO patients, and it is recommended to be routinely placed during VA-ECMO catheter placement.