Popliteal Sciatic Nerve Block May Increase Time to First Opioid Request in Diabetic Peripheral Neuropathy

Patients with type 2 diabetes and diabetic peripheral neuropathy may have an increased time to first opioid request and reduced time to onset of sensory blockade after an ultrasound-guided popliteal sciatic nerve block compared with patients without neuropathy, according to results published in Anaesthesia.

The study included participants with type 2 diabetes and diabetic peripheral neuropathy (n=33) and control patients without diabetes (n=23) scheduled for fore-foot surgery. All participants received an ultrasound-guided popliteal sciatic nerve block with a 20 mL 1:1 mixture of lidocaine 1% and bupivacaine 0.5%. The primary outcome was time to first opioid request after the block procedure, and secondary outcomes were time to onset of sensory blockade and pain score at rest on postoperative day 1, assessed with a 0 to 10 numeric rating scale.

The results indicated that participants with diabetic peripheral neuropathy had a significantly prolonged median time to first opioid request (1440 minutes; interquartile range [IQR], 1140-1440) compared with control patients (710 minutes; IQR, 420-1200; P =.0004). Compared with control patients, participants with neuropathy had a 59% shorter time to the onset of sensory blockade (median time ratio, 0.41; 95% CI, 0.28-0.59; P <.0001). Participants with neuropathy also had lower median pain scores at rest on postoperative day 1 (0; IQR, 0-1) compared with control patients (IQR, 0-5; P =.001).

“These results should help physicians in adjusting peripheral regional anaesthesia in this population,” the researchers wrote.

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Reference

Baeriswyl M, Taffe P, Kirkham KR, et al. Comparison of peripheral nerve blockade characteristics between non-diabetic patients and patients suffering from diabetic neuropathy: a prospective cohort study [published online June 2, 2018]. Anaesthesia. doi:10.1111/anae.14347