Double-blind comparison of the postoperative respiratory depressant effects of alfentanil and fentanyl

Alfentanil was compared with fentanyl in a double blind study of 90 female patients undergoing laparoscopic sterilizations. The analgesic was combined with droperidol and etomidate for induction and with etomidate, nitrous oxide and occasional increments of succinylcholine for maintenance of anesthesia. Twenty-four percent of the patients required reversal of postoperative respiratory depression after fentanyl compared with 7% after alfentanil (p = 0.042). When the last dose of analgesic had been given more than 10 minutes before the end of the operation, none of the alfentanil patients required reversal of respiratory depression while under the same circumstances 26% of the fentanyl patients required naloxone (p = 0.005). Awakening was delayed in all patients, exceeding a mean time of 20 minutes in both groups. However, 84% of patients were alert on awakening after alfentanil compared with 62% of patients after fentanyl (p = 0.032). Duration and quality of postoperative analgesia were similar in both groups. Cardio-vascular stability was satisfactory in all patients and side effects were minor and infrequent.     

Diffusivity and Solubility of Nitric Oxide in Water and Saline

Aqueous diffusivities and solubilities of NO were determined by using a chemiluminescence detector to measure time-dependent fluxes across stagnant liquid films confined between polydimethylsiloxane membranes. The NO diffusivities in pure water and PBS at 25C were found to be (2.21 ± 0.02) × 10^–5 cm² s^–1 and (2.21 ± 0.04) × 10^–5 cm² s^–1, respectively. Although lower than most previous values for NO at room temperature, these diffusivities are very similar to those for O₂, as one would expect. Extrapolation to 37°C yielded a value of 3.0 × 10^–5 cm² s^–1. The solubility of NO in water at 25°C was (1.94 ± 0.03) × 10^–6 mol cm^–3 atm^–1, in agreement with the literature. This agreement, along with the excellent fits obtained to the transient flux data (<4% rms error in each experiment), supports the validity of the simultaneously measured diffusivity. The solubility of NO in PBS at 25°C was (1.75 ± 0.02) × 10^–6 mol cm^–3 atm^–1. The modest (10%) reduction in solubility relative to that in pure water is consistent with the usual effects of salts on gas solubilities.     

Three systems of insular functional connectivity identified with cluster analysis

Despite much research on the function of the insular cortex, few studies have investigated functional subdivisions of the insula in humans. The present study used resting-state functional connectivity magnetic resonance imaging (MRI) to parcellate the human insular lobe based on clustering of functional connectivity patterns. Connectivity maps were computed for each voxel in the insula based on resting-state functional MRI (fMRI) data and segregated using cluster analysis. We identified 3 insular subregions with distinct patterns of connectivity: a posterior region, functionally connected with primary and secondary somatomotor cortices; a dorsal anterior to middle region, connected with dorsal anterior cingulate cortex, along with other regions of a previously described control network; and a ventral anterior region, primarily connected with pregenual anterior cingulate cortex. Applying these regions to a separate task data set, we found that dorsal and ventral anterior insula responded selectively to disgusting images, while posterior insula did not. These results demonstrate that clustering of connectivity patterns can be used to subdivide cerebral cortex into anatomically and functionally meaningful subregions; the insular regions identified here should be useful in future investigations on the function of the insula.     

Proximal and distal rectal cancers differ in curative resectability and local recurrence

AIM: To evaluate patients with proximal rectal cancer (PRC) (> 6 cm up to 12 cm) and distal rectal cancer (DRC) (0 to 6 cm from the anal verge). METHODS: Two hundred and eighteen patients (120 male, 98 female, median age 58 years, range 19-88 years) comprised 100 with PRC and 118 with DRC. The proportion of T1, T2 vs T3, T4 stage cancers was similar in both groups (PRC: T1+T2 = 29%; T3+T4 = 71% and DRC: T1+T2 = -31%; T3+T4 = 69%). All patients had cancer confined to the rectum -those with synchronous distant metastasis were excluded. Surgical resection was with curative intent with or without pre-operative chemoradiation (c-RT). Follow-up was for a median of 35 mo (range: 12 to 126 mo). End points were: 30 d mortality, complications of operation, microscopic tumour-free margins, resection with a tumour-free circumferential margin (CRM) of 1 to 2 mm and > 2 mm, local recurrence, survival and the permanent stoma rate. RESULTS: Overall 30-d mortality was 6% (12): PRC 7 % and DRC 4%. Postoperative complications occurred in 14% with PRC compared with 21.5% with DRC, urinary retention was the complication most frequently reported (PRC 2% vs DRC 9%, P = 0.04). Twelve percent with PRC compared with 37% with DRC were subjected to preoperative c-RT (P = 0.03). A tumour-free CRM of 1 to 2 mm and > 2 mm was reported in 93% and 82% with PRC and 88% and 75% with DRC respectively (PRC vs DRC, P > 0.05). However, local recurrence was 5% for PRC vs 11% for DRC (P < 0.001). Three and five years survival was 65.6% and 60.2% for PRC vs 67% and 64.3% for DRC respectively. No patient with PRC and 23 (20%) with DRC received an abdomino-perineal resection. CONCLUSION: PRC and DRC differ in the rate of abdomino-perineal resection, post-operative urinary retention and local recurrence. Survival in both groups was similar.     

奥美拉唑与脑卒中相关性肺炎的关系研究

目的探讨无法进食经鼻饲的急性脑卒中患者给予奥美拉唑后胃液pH值、胃腔细菌定植情况以及对应激性消化道溃疡、卒中相关性肺炎（SAP）的影响。方法90例患者依据奥美拉唑应用时间随机分为三组,每8小时抽取胃液,测pH值及潜血试验。留取胃液、深部痰行细菌培养。结果三组胃液pH值、各组SAP发生率差异有统计学意义：三组应激性溃疡的发生率差异无统计学意义。90例患者中31例发生胃腔细菌定植,三组差异有统计学意义。胃腔细菌定植患者pH值与无细菌定植患者胃液pH值差异有统计学意义;发生胃腔细菌定植细菌主要为革兰阴性杆菌;17例SAP患者痰细菌培养主要为革兰阴性杆菌。17例SAP患者pH值与非SAP患者胃液pH值差异有统计学意义;急性脑卒中鼻饲患者,应用奥美拉唑时间延长,胃液pH增加,胃腔细菌定植增多,SAP发生率增加,应激性溃疡发生率下降。结论对于急性脑卒中患者应选择应用奥美拉唑时间,需监测胃液pH值,使胃液pH值保持适当范围。