Alterations in arterial function after high-voltage electrical injury

INTRODUCTION: The aim of this study was to evaluate the functional changes of the arterial endothelium and smooth muscle after a high-voltage electrical injury (HVEI), using flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD). METHODS: Twenty-five male patients injured in the upper extremities by current due to contact with more than 20,000 volts were enrolled in the study. FMD and NMD were measured on the brachial artery within 48 hours after HVEI, and follow-up FMD and NMD were evaluated six weeks later. In addition, we enrolled an age, sex and body mass index matched healthy control group consisting of 25 individuals. Including FMD and NMD, all the variables of the control group were investigated one time and compared with the initial and six week follow-up data of the HVEI group. RESULTS: A significantly lower initial FMD was seen in the HVEI group compared with the control group (2.1 ± 1.2% versus 13.6 ± 3.4%, P < 0.01). At the six week follow-up, the FMD of the HVEI group had significantly improved compared to the initial FMD (2.1 ± 1.2% versus 5.1 ± 2.1%, P < 0.01), but it was still lower than the FMD of the control group (5.1 ± 2.1% versus 13.6 ± 3.4%, P < 0.01). A significantly lower NMD was seen both initially and at the six week follow-up compared with the NMD of the control group (7.3 ± 4.7% versus 20.4 ± 4.1%, P < 0.01 and 11.4 ± 6.7% versus 20.4 ± 4.1%, P < 0.01, respectively). The FMD study of the contralateral arm which was uninjured by HVEI was available in six patients. In those patients, the six week follow-up FMD was significantly improved in the HVEI arm compared with the initial FMD (1.8 ± 0.6% versus 4.4 ± 1.6%, P < 0.01). However, in the contralateral uninjured arm, there was no difference between the initial and the six week follow-up FMDs (5.5 ± 1.4% versus 6.9 ± 2.2%, P = 0.26). CONCLUSIONS: After HVEI, the endothelial and smooth muscle functions of the brachial artery were significantly decreased for at least six weeks. Long term cautious care might be needed for all victims of HVEI, because there is a chance of increased risk of thrombosis or stenosis in the injured arm.