Polyethylene Glycol-Mediated Axonal Fusion Promotes Early Sensory Recovery After Digital Nerve Injury: A Randomized Clinical Trial.

BACKGROUND: Peripheral nerve repair is limited by Wallerian degeneration coupled with the slow and inconsistent rates of nerve regrowth. In more proximal injuries, delayed nerve regeneration can cause debilitating muscle atrophy. Topical application of polyethylene glycol (PEG) during neurorrhaphy facilitates the fusion of severed axonal membranes, immediately restoring action potentials across the coaptation site. In preclinical animal models, PEG-fusion resulted in remarkable early functional recovery. METHODS: This is the first randomized clinical trial comparing functional outcomes between PEG-fusion and standard neurorrhaphy. Participants with digital nerve transections were followed up at 2 weeks, 1 month, and 3 months postoperatively. The primary outcome was assessed using the Medical Research Council Classification (MRCC) rating for sensory recovery at each timepoint. Semmes-Weinstein monofilaments and static two-point discrimination determined MRCC ratings. Postoperative quality of life was measured using the Michigan Hand Questionnaire (MHQ). RESULTS: Forty-eight transected digital nerves (25 control, 23 PEG) across twenty-two patients were analyzed. PEG-fused nerves demonstrated significantly higher MRCC scores at 2 weeks (OR 16.95, 95% CI: 1.79 - 160.38, p = 0.008) and 1 month (OR 13.40, 95% CI: 1.64 - 109.77, p = 0.009). Participants in the PEG cohort also had significantly higher average MHQ scores at 2 weeks (Hodge's g 1.28, 95% CI: 0.23 - 2.30, p = 0.0163) and 1 month (Hodge's g 1.02, 95% CI: 0.04 - 1.99, p = 0.049). No participants had adverse events related to the study drug. CONCLUSION: PEG-fusion promotes early sensory recovery and improved patient well-being following peripheral nerve repair of digital nerves.

Randomized Controlled Trial Comparing Liposomal to Plain Bupivacaine in the Transversus Abdominis Plane for DIEP Flap Breast Reconstruction.

BACKGROUND: Pain control after autologous breast reconstruction is important for patient satisfaction and early recovery. Transversus abdominis plane (TAP) blocks are commonly used as part of an enhanced recovery after surgery (ERAS) pathway for breast reconstruction. It is uncertain whether liposomal bupivacaine used in TAP blocks offers additional advantages. This study aimed to compare the efficacy of liposomal bupivacaine versus plain bupivacaine for patients undergoing deep inferior epigastric perforator flap reconstruction. METHODS: This double-blinded randomized controlled trial studied patients undergoing abdominally based autologous breast reconstruction between June of 2019 and August of 2020. Subjects were randomly assigned liposomal or plain bupivacaine, performed using ultrasound-guided TAP block technique. All patients were managed according to an ERAS protocol. Primary outcomes were postoperative narcotic analgesia required, measured in oral morphine equivalents from postoperative days 1 to 7. Secondary outcomes included numeric pain scale score on postoperative days 1 to 7, nonnarcotic pain medication use, time to first narcotic use, return of bowel function, and length of stay. RESULTS: Sixty patients were enrolled: 30 received liposomal bupivacaine and 30 received plain bupivacaine. There were no significant differences in demographics, daily oral morphine equivalent narcotic use, nonnarcotic pain medication use, time to narcotic use, numeric pain scale score, time to bowel function, or length of stay. CONCLUSION: Liposomal bupivacaine does not confer advantages over plain bupivacaine when used in TAP blocks for abdominally based microvascular breast reconstruction in patients under ERAS protocols and multimodal approaches for pain control. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

Panel study using novel sensing devices to assess associations of PM2.5 with heart rate variability and exposure sources.

BACKGROUND/OBJECTIVE: This work applied a newly developed low-cost sensing (LCS) device (AS-LUNG-P) and a certified medical LCS device (Rooti RX) to assessing PM2.5 impacts on heart rate variability (HRV) and determining important exposure sources, with less inconvenience to subjects. METHODS: Observations using AS-LUNG-P were corrected by side-by-side comparison with GRIMM instruments. Thirty-six nonsmoking healthy subjects aged 20-65 years were wearing AS-LUNG-P and Rooti RX for 2-4 days in both Summer and Winter in Taiwan. RESULTS: PM2.5 exposures were 12.6 ± 8.9 µg/m3. After adjusting for confounding factors using the general additive mixed model, the standard deviations of all normal to normal intervals reduced by 3.68% (95% confidence level (CI) = 3.06-4.29%) and the ratios of low-frequency power to high-frequency power increased by 3.86% (CI = 2.74-4.99%) for an IQR of 10.7 µg/m3 PM2.5, with impacts lasting for 4.5-5 h. The top three exposure sources were environmental tobacco smoke, incense burning, and cooking, contributing PM2.5 increase of 8.53, 5.85, and 3.52 µg/m3, respectively, during 30-min intervals. SIGNIFICANCE: This is a pioneer in demonstrating application of novel LCS devices to assessing close-to-reality PM2.5 exposure and exposure-health relationships. Significant HRV changes were observed in healthy adults even at low PM2.5 levels.