Limb remote ischemic preconditioning for intestinal and pulmonary protection during elective open infrarenal abdominal aortic aneurysm repair: a randomized controlled trial.

BACKGROUND: Remote ischemic preconditioning (RIPC) may confer the cytoprotection in critical organs. The authors hypothesized that limb RIPC would reduce intestinal and pulmonary injury in patients undergoing open infrarenal abdominal aortic aneurysm repair. METHODS: In this single-center, prospective, double-blinded, randomized, parallel-controlled trial, 62 patients undergoing elective open infrarenal abdominal aortic aneurysm repair were randomly assigned in a 1:1 ratio by computerized block randomization to receive limb RIPC or conventional abdominal aortic aneurysm repair (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff placed on the left upper arm served as RIPC stimulus. The primary endpoint was arterial-alveolar oxygen tension ratio. The secondary endpoints mainly included the intestinal injury markers (serum intestinal fatty acid-binding protein, endotoxin levels, and diamine oxidase activity), the markers of oxidative stress and systemic inflammatory response, and the scores of the severity of intestinal and pulmonary injury. RESULTS: In limb RIPC group, a/A ratio was significantly higher than that in control group at 8, 12, and 24 h after cross-clamp release (66 ± 4 vs. 45 ± 4, P = 0.003; 60 ± 6 vs. 37 ± 4, P = 0.002; and 60 ± 5 vs. 47 ± 6, P = 0.039, respectively). All biomarkers reflecting intestinal injury increased over time, and there was significant differences between limb RIPC and control group (P < 0.001). The severity of intestinal and pulmonary injury was decreased by limb RIPC (P = 0.014 and P = 0.001, respectively). CONCLUSIONS: Limb RIPC attenuates intestinal and pulmonary injury in patients undergoing elective open infrarenal abdominal aortic aneurysm repair without any potential risk.

Alda-1, an ALDH2 activator, protects against hepatic ischemia/reperfusion injury in rats via inhibition of oxidative stress.

Previous studies have proved that activation of aldehyde dehydrogenase two (ALDH2) can attenuate oxidative stress through clearance of cytotoxic aldehydes, and can protect against cardiac, cerebral, and lung ischemia/reperfusion (I/R) injuries. In this study, we investigated the effects of the ALDH2 activator Alda-1 on hepatic I/R injury. Partial warm ischemia was performed in the left and middle hepatic lobes of Sprague-Dawley rats for 1 h, followed by 6 h of reperfusion. Rats received either Alda-1 or vehicle by intravenous injection 30 min before ischemia. Blood and tissue samples of the rats were collected after 6-h reperfusion. Histological injury, proinflammatory cytokines, reactive oxygen species (ROS), cellular apoptosis, ALDH2 expression and activity, 4-hydroxy-trans-2-nonenal (4-HNE) and malondialdehyde (MDA) were measured. BRL-3A hepatocytes were subjected to hypoxia/reoxygenation (H/R). Cell viability, ROS, and mitochondrial membrane potential were determined. Pretreatment with Alda-1 significantly alleviated I/R-induced elevations of alanine aminotransferase and aspartate amino transferase, and significantly blunted the pathological injury of the liver. Moreover, Alda-1 significantly inhibited ROS and proinflammatory cytokines production, 4-HNE and MDA accumulation, and apoptosis. Increased ALDH2 activity was found after Alda-1 administration. No significant changes in ALDH2 expression were observed after I/R. ROS was also higher in H/R cells than in control cells, which was aggravated upon treatment with 4-HNE, and reduced by Alda-1 treatment. Cell viability and mitochondrial membrane potential were inhibited in H/R cells, which was attenuated upon Alda-1 treatment. Activation of ALDH2 by Alda-1 attenuates hepatic I/R injury via clearance of cytotoxic aldehydes.

Risk factors for hypothermia in patients under general anesthesia: Is there a drawback of laminar airflow operating rooms? A prospective cohort study.

INTRODUCTION: The aim of this study was to estimate the prevalence and risk factors of hypothermia under general anesthesia in a large domestic hospital. METHOD: All of the consecutive 1840 patients who underwent scheduled surgery between August and December 2013 were admitted to the study. The nasopharyngeal temperature was measured, and the following variables were also recorded: sex, age, type of surgery, duration of anesthesia, active warming devices and type of operating room. Univariate and multiple regression binary logistic analyses with odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the relationship between each clinical risk factor and hypothermia. RESULTS: The prevalence of hypothermia under general anesthesia was 25.7%. In the univariate analysis, the risk factors of hypothermia were age, the duration of anesthesia, the type of operating room and the type of surgery. Sex was not included. In the multiple logistic regression analysis, the significant risk factors of hypothermia were advanced age, laminar airflow operating rooms and general surgeries. CONCLUSION: Intraoperative hypothermia is still common and should therefore receive serious attention. Advanced age, the use of a laminar airflow operating room and general surgeries are high risk factors of hypothermia.