PT  - JOURNAL ARTICLE
AU  - Ching-Hsia Hung
AU  - Chong-Chi Chiu
AU  - Chen-Chih Liu
AU  - Yu-Wen Chen
TI  - Local Application of Ultrasound Attenuates Neuropathic Allodynia and Proinflammatory Cytokines in Rats After Thoracotomy
AID  - 10.1097/AAP.0000000000000717
DP  - 2018 Feb 01
TA  - Regional Anesthesia & Pain Medicine
PG  - 193--199
VI  - 43
IP  - 2
4099  - http://rapm.bmj.com/content/43/2/193.short
4100  - http://rapm.bmj.com/content/43/2/193.full
SO  - Reg Anesth Pain Med2018 Feb 01; 43
AB  - Background and Objectives We aimed to investigate the effect of therapeutic ultrasound (TU) on pain sensitivity and the concentration inflammatory cytokines in a thoracotomy rat model.Methods Rats were distributed randomly into 4 groups: (1) sham operated, (2) thoracotomy and rib retraction (TRR), (3) TRR rats that received TU (TRR + TU-1), and (4) TRR rats that received TU with the ultrasound turned off (TRR + TU-0). Ultrasound was set at 1-MHz frequency (1.0-W/cm2 intensity and 100% duty cycle for 5 minutes), began on postoperative day (POD) 10, and then continued once per day, 5 days a week for 3 weeks.Results The TRR and TRR + TU-0 rats encountered tactile hypersensitivity from PODs 10 to 28. Mechanical withdrawal thresholds were increased (all P < 0.05) following 5 days of TU, but thresholds remained significantly lower than baseline values. Therapeutic ultrasound increased the subcutaneous, but not body temperature. All groups receiving TRR demonstrated an increase in concentration of interleukin 1β and tumor necrosis factor α (TNF-α) on POD 14; however, the rise in TNF-α concentration was less in the TU-treated group than in the others. The decrease in concentration was greatest in the TRR + TU-1 group and similar between the TRR and TRR + TU-0 groups.Conclusions Mechanical allodynia was partially resolved with TU. Tissue temperature increased with ultrasound, while TU restricted the up-regulation of interleukin 1β and TNF-α around the injured intercostal nerve.