Single-cuff forearm tourniquet in intravenous regional anaesthesia results in less pain and fewer sedation requirements than upper arm tourniquet.

BACKGROUND: A limitation of Bier's block or i.v. regional anaesthesia (IVRA) is tourniquet pain. We hypothesized that tourniquet placement on the forearm vs upper arm during IVRA for distal upper extremity surgery may result in less tourniquet pain, lower the need for analgesic interventions, and decrease post-anaesthesia care unit (PACU) admission. METHODS: Patients for distal upper extremity surgery were randomized into upper or forearm single-cuff tourniquet placement. IVRA was either performed with 15 ml of 2% lidocaine and 20 mg ketorolac in the upper group or 8 ml of 2% lidocaine and 10 mg ketorolac in the forearm group. Vital signs and visual analogue scale (VAS) score were recorded. If VAS score was >4, 50 µg fentanyl was injected. If the patient had VAS scores >6 with fentanyl, deep sedation with propofol was administered. RESULTS: Twenty-eight subjects were in each group. There were no significant differences in patient characteristics, tourniquet time, or pressure between the groups. Ten patients in the forearm vs 27 in the upper arm group had a VAS score >4. The mean fentanyl use was 30 µg in the forearm group vs 104 µg in the upper arm group. One patient in the forearm group required propofol vs 22 in the upper arm group. PACU bypass to phase 2 recovery occurred 19 times in the forearm group vs zero times in the upper arm group (P<0.0001). CONCLUSIONS: Our results indicate that the placement of the tourniquet on the forearm resulted in less discomfort, fewer sedation interventions, and greater likelihood of bypassing the PACU when compared with upper arm tourniquet.

Vein visualization: patient characteristic factors and efficacy of a new infrared vein finder technology.

BACKGROUND: We investigated the patient characteristic factors that correlate with identification of i.v. cannulation sites with normal eyesight. We evaluated a new infrared vein finding (VF) technology device in identifying i.v. cannulation sites. METHODS: Each subject underwent two observations: one using the conventional method (CM) of normal, unassisted eyesight and the other with the infrared VF device, VueTek's Veinsite™ (VF). A power analysis for moderate effect size (ß=0.95) required 54 samples for within-subject differences. RESULTS: Patient characteristic profiles were obtained from 384 subjects (768 observations). Our sample population exhibited an overall average of 5.8 [95% confidence interval (CI) 5.4-6.2] veins using CM. As a whole, CM vein visualization were less effective among obese [4.5 (95% CI 3.8-5.3)], African-American [4.6 (95% CI 3.6-5.5 veins)], and Asian [5.1 (95% CI 4.1-6.0)] subjects. Next, the VF technology identified an average of 9.1 (95% CI 8.6-9.5) possible cannulation sites compared with CM [average of 5.8 (95% CI 5.4-6.2)]. Seventy-six obese subjects had an average of 4.5 (95% CI 3.8-5.3) and 8.2 (95% CI 7.4-9.1) veins viewable by CM and VF, respectively. In dark skin subjects, 9.1 (95% CI 8.3-9.9) veins were visible by VF compared with 5.4 (95% CI 4.8-6.0) with CM. CONCLUSIONS: African-American or Asian ethnicity, and obesity were associated with decreased vein visibility. The visibility of veins eligible for cannulation increased for all subgroups using a new infrared device.

De-repression of the p21 promoter in prostate cancer cells by an isothiocyanate via inhibition of HDACs and c-Myc.

Natural isothiocyanates from cruciferous vegetables have been described as important dietary factors for prostate cancer prevention. Phenethyl isothiocyanate (PEITC), found rich in watercress, induces growth arrest and apoptosis in prostate cancer cells, and also inhibits the testosterone-mediated growth of prostates by regulating the androgen receptor and cell cycle progression in rats. PEITC has been recently identified as an inhibitor of histone deacetylases (HDACs). Herein we describe the mechanism of PEITC-mediated growth attenuation in relation to HDAC inhibition in human prostate cancer cells. Exposure of androgen-dependent prostate cancer cells LNCaP to PEITC resulted in cell cycle arrest and a p53-independent up-regulation of the inhibitors of cyclin-dependent kinases, including p21WAF1 and p27. The mechanism of p21 activation was investigated. PEITC significantly enhanced histone acetylation and induced selective modification of histone methylation for chromatin remodeling. Chromatin immunoprecipitation revealed that the p21 gene was associated with the PEITC-induced hyperacetylated histones. As a result, the chromatin unfolding permitted the transcription activation of the p21 gene. PEITC also significantly reduced the expression of c-Myc which represses p21. Pull-down assays using Sp1 affinity oligo beads of the p21 promoter, showed decreased c-Myc binding to the Sp1 transcriptional complexes in the p21 promoter, resulting in reduced p21 repression. The quantity of PEITC (0.5-1 micro M) effective to mediate cell cycle arrest was less than that for inhibiting c-Myc (2-5 micro M), suggesting that the inhibition of HDACs may be the primary mechanism for p21 activation. The PEITC-mediated growth attenuation of prostate cancer cells includes an interactive mechanism involving HDAC and c-Myc inhibition.