Blood Flow Changes in Forearm Arteries After Ultrasound-guided Costoclavicular Brachial Plexus Blocks: a Prospective Observational Study

Abstract

BackgroundAs a new approach, an infraclavicular brachial plexus block (BPB) at the costoclavicular space (CCS) has been shown to be effective in achieving a sensory and motor blockade in the forearm. However, no studies have assessed blood flow changes in the forearm arteries after a costoclavicular BPB. The purpose of the present study was to assess blood flow changes in the distal radial artery (RA) and ulnar artery (UA) after a costoclavicular BPB using color Doppler ultrasound.MethodsThirty patients who underwent amputated finger replantation and received an ultrasound-guided costoclavicular BPB were included in the study. The hemodynamic parameters of the RA and UA were recorded before the block and 10 min, 20 min, and 30 min after the block using color Doppler ultrasound to determine the peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vmean), pulsatility index (PI), resistance index (RI) and area. The volumetric flow rate (VFR) was calculated using the formula Q=area×Vmean. The aforementioned parameters were compared not only before and after the BPB but also between the RA and UA.ResultsThere was a significant increase in the PSV, EDV, Vmean, area, and VFR and a significant decrease in the PI and RI of the RA and UA 10 min, 20 min, and 30 min postblock compared with the respective baselines. The increase of 30 min postblock in EDV (258.68% in the RA, 279.63% in the UA) was the most notable, followed by that in the Vmean (183.36% in the RA, 235.24% in the UA), and the PSV (139.11% in the RA, 153.15% in the UA) changed minimally. The Vmean and VFR of the RA were significantly greater than those of the UA before the BPB, howerver, there was no significant difference in VFR between RA and UA after the BPB.ConclusionsA costoclavicular BPB can increase blood flow in the forearm arteries. The RA had a higher volumetric flow rate than the UA before the BPB; however, the potential blood supply capacity of the UA is similar to that of the RA after a BPB.Trial registrationThis study was registered in Chictr.org.cn registry system on 12 June 2019 (ChiCTR1900023796).