Liposomal bupivacaine addition versus standard bupivacaine alone for colorectal surgery: a randomized controlled trial.

Aim: This study evaluated use of liposomal bupivacaine (LB) versus standard bupivacaine (SB) alone in quadratus lumborum (QL) blocks for laparoscopic colorectal surgery. Materials & methods: In this prospective, randomized controlled trial, patients received QL1 blocks with either LB (40 ml 0.125% SB plus 20 ml of LB) or SB (60 ml of 0.25% SB) with 30 ml per side. Opioid usage, pain scores, side effects and other medications were recorded. Results: For 78 patients (38 LB; 40 SB), all parameters were similar between groups, except that the LB group had a higher 48 h need for metoclopramide. Conclusion: LB provided no analgesic benefit over SB alone for QL blocks. Clinical Trials registration number: NCT03702621.

Lay abstract This study evaluated use of extended release bupivacaine (LB) versus standard bupivacaine (SB) alone in nerve blocks for laparoscopic colorectal surgery. Patients undergoing colorectal surgery received nerve blocks with either LB combined with SB, or SB alone. Opioid usage, pain scores, side effects and other medications were recorded. For 78 patients (38 LB + SB; 40 SB), all parameters were similar between groups, except that the LB group had a higher 48 h need for anti-nausea medication. LB provided no pain control benefit over SB alone for nerve blocks in colorectal surgery.

Efficient CdSe nanocrystal diffraction gratings prepared by microcontact molding.

We describe the formation of efficient transmission diffraction gratings created from patterned high quality ligand-capped CdSe nanocrystals (NCs), using a facile microcontact molding procedure. Soft polymer replicas of commercially available master gratings were "inked" with solvated NCs and the resulting pattern transferred to a variety of substrates after drying. Large-area (>0.5 cm(2)), defect free diffraction gratings were prepared with a variety of submicrometer line spacings and feature sizes down to ca. 160 nm. The morphology of the resulting pattern was tuned by controlling the concentration of the NC-based ink. Optimized gratings (1200 g/mm) showed an increase in transmission diffraction efficiency (DE) with increasing nanocrystal diameter. DE = ca. 15% (488 nm) for 2.5 nm diameter NCs versus DE = ca. 25-30% (488 nm) for 7.3 nm nanocrystals. These increases in DE are ascribed to changes in both the real (n) and imaginary (k) components of the complex index of refraction as NC diameter increases. We demonstrate the ability to in- and out-couple incident laser radiation into internal reflection elements using these stamped NC gratings, including single-mode waveguides, offering a novel application of ordered nanocrystal thin films.