Anatomical description of anaesthetic spread after deep erector spinae block at L-4. / Estudio anatómico de la distribución del volumen administrado tras bloqueo en el plano profundo del erector espinal a nivel lumbar.

INTRODUCTION: Thoracic erector spinae plane (ESP) block is now used for postoperative analgesia. However, although reports of lumbar ESP have been published, the anesthetic spread and mechanism of action of this technique remains unclear. We describe the lumbar ESP block technique and evaluate the spread of 20ml of solution administered at the level of the transverse process of L4 in a cadaver model. METHODS: Observational study after 12 lumbar ESP blocks at L4 on a fresh cadaver model (6 bilaterally). The spread of 20ml of injected contrast solution was assessed by computed tomography in all 6 samples. Four of the samples were evaluated by anatomical study, 2 by plane dissection, and 2 others were frozen and cut into 2-2.5cm axial slices. RESULTS: The injected solution spread from L2 to L5 in a cranio-caudal direction in the erector spinae muscle, reaching the facet joints medially and the thoracolumbar fascia laterally. In 33% of cases the solution did not spread anterior to the transverse process; in 51%, spread was minimal and did not affect the corresponding spinal nerves, and in 2 samples (16%), spread was extensive and reached the corresponding spinal nerves. CONCLUSIONS: Lumbar ESP at L4 always acts on the posterior branches of the spinal nerves, but seldom spreads to the paravertebral space to block the spinal nerve.

L4 erector spinal plane block after lumbar spine arthrodesi: A case-series. / Bloqueo del plano del erector espinal en L4 en cirugía de artrodesis lumbar: serie de casos.

INTRODUCTION: Thoracic erector spinae plane block is now performed in many different surgical procedures, including lumbar spinal fusion. We evaluated the analgesic effect of lumbar ESP performed at L4 after lumbar spinal fusion surgery. METHODS AND CASE SERIES: Eight patients scheduled for lumbar spinal fusion were included in the case series. Erector spinae plane block was performed at L4 preoperatively, administering 20ml of 0.2% ropivacaine on each side. We recorded patient-reported pain intensity during the first 48 postoperative hours using a visual analogue scale (VAS) and rescue analgesia requirements. Pain at rest was controlled in all patients (VAS 0 to 3), although pain on movement ranged from mild to severe (VAS 0 to 8). Rescue analgesia consumption ranged from 1 to 22mg morphine. CONCLUSIONS: Lumbar ESP appears to contribute to pain control during the first 48hours after lumbar spinal fusion.

Extruded films of blended chitosan, low density polyethylene and ethylene acrylic acid.

The obtaining of chitosan extruded films was possible by using low density polyethylene (LDPE) as a matrix polymer and ethylene-acrylic acid copolymer as an adhesive, in order to ensure adhesion in the interphase of the immiscible polymers. The obtained blend films were resistant; however, a reduction in the mechanical resistance was observed as chitosan concentration increased. The thermal stability of the films showed a certain grade of interaction between polymers as seen in FTIR spectra. The antifungal activity of the extruded films was assessed against Aspergillus niger and high inhibition percentages were observed, which may be mainly attributed to barrier properties of the extruded films and the limited oxygen availability, resulting in the inability of the fungi to grow. A low adherence of fungal spores to the material surface was observed, mainly in areas with chitosan clumps, which can serve as starting points for material degradation.

Lymphocytosis as a predictor of poor response to treatment of hepatitis C.

BACKGROUND/AIMS: Identification of factors predicting response to therapy is critical in the management of hepatitis C. This study assessed significance of lymphocytosis as a predictor of sustained virological response (SVR). METHODS: Retrospective analysis of lymphocytosis and its correlation with virologic response was performed in 110 subjects with chronic HCV infection, who underwent interferon based therapy. Lymphocytosis was defined as ratio of lymphocytes to neutrophils (L/N) above 0.6. L/N ratios were calculated to avoid the impact of hypersplenism and constitutional leukopenia seen in African Americans (AA). RESULTS: At baseline, L/N of HCV subjects (0.86) as compared to Hepatitis B controls (0.56) was significantly higher (P < 0.01). More AA HCV subjects (81.8%) had lymphocytosis at baseline when compared to Caucasian Americans subjects with HCV (37.9%) or AA controls (39.4%). Nonresponders had a higher frequency of lymphocytosis at baseline compared to subjects that achieved SVR (61.4% vs. 36.0%, p<0.05). More HCV subjects without lymphocytosis at baseline achieved SVR (33.3%) compared to HCV subjects with lymphocytosis (15%). At week 12 of therapy, nonresponders had higher L/N (1.02 vs. 0.86) and frequency of lymphocytosis (73% vs. 48%) compared to subjects that achieved SVR (p<0.05 for both). Only 17.2% of subjects with lymphocytosis at 12 weeks achieved SVR compared to 37.5% without lymphocytosis (p < 0.05). All responders exhibited significant normalization of lymphocytosis after treatment. CONCLUSIONS: HCV induces lymphocytosis, especially in AA, and is associated with lower rate of SVR. Furthermore, lymphocytosis may serve as an inexpensive pre-treatment tool to predict poor virologic response to HCV therapy.