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Summary Background Surgical site infection (SSI) after colorectal surgery is the leading cause of postoperative morbidity. Opioids induce immunosuppression through activation of μ-opioid receptors expressed on leucocytes, and through opioid withdrawal. A high dose of opioid administered as remifentanil during surgery may induce immunosuppression, leading to the development of SSI. Aim The purpose of this study was to investigate the influence of remifentanil on the development of SSI. Methods Adult patients who underwent elective colorectal surgery from January 2009 to December 2012 ( N = 286) were prospectively investigated according to the guidelines of the US Centers for Disease Control and Prevention. After exclusion of 51 patients, propensity matching was performed in 235 patients. To reduce the influence of selection on SSIs, propensity score pairwise matching was performed for patients maintained with remifentanil and for patients maintained with fentanyl. Findings The number of patients who developed SSI was higher after remifentanil-based anaesthesia compared with fentanyl-based anaesthesia [11.6% (17/146) vs 3.4% (3/89), remifentanil vs fentanyl, P = 0.03] before propensity matching. Propensity matching yielded 61 pairs of patients anaesthetized with remifentanil or fentanyl, and corrected several biases in the preoperative patient characteristics. After propensity matching, the number of patients who developed SSI was still higher after remifentanil-based anaesthesia than after fentanyl-based anaesthesia [16.4% (10/61) vs 3.3% (2/61), remifentanil vs fentanyl, P = 0.029]. Conclusion Remifentanil-based anaesthesia increased the incidence of SSI. A possible reason may be opioid-induced immunosuppression or opioid withdrawal-induced immunosuppression. [ABSTRACT FROM AUTHOR]

Epinephrine has been administered as a drug essential for cardiopulmonary resuscitation (CPR). Recently, vasopressin has been reported to be more effective than epinephrine for CPR in a ventricular fibrillation (VF) model. As a different myocardial pathology is speculated to exist between the VF model and the asphyxia model, we investigated whether vasopressin is also effective in a rat asphyxia model. Twenty-one Sprague–Dawley male rats were divided into three groups: vasopressin 0.8 U/kg (Vaso-Gr), epinephrine 0.05 mg/kg (Epi-Gr), and saline same volume as the other two drugs (Sal-Gr). Five minutes after suffocation induced by obstruction of the tracheal tube, CPR was performed using each drug. Although only one animal survived (17%) in the Sal-Gr, 6/7 (85%) survived in both Vaso-Gr and Epi-Gr (P<0.01). Vasopressin is as effective as epinephrine for CPR in asphyxia-induced rats. [Copyright &y& Elsevier]

Abstract: Argon with an admixture of CF4 is expected to be a good candidate for the gas mixture to be used for a time projection chamber (TPC) in the future linear collider experiment because of its small transverse diffusion of drift electrons especially under a strong magnetic field. In order to confirm the superiority of this gas mixture over conventional TPC gases we carried out cosmic ray tests using a GEM-based TPC operated mostly in Ar–CF4–isobutane mixtures under 0–1T axial magnetic fields. The measured gas properties such as gas gain and transverse diffusion constant as well as the observed spatial resolution are presented. [Copyright &y& Elsevier]

Recently, vasopressin has been reported as a more effective drug than epinephrine (adrenaline) for cardiopulmonary resuscitation (CPR). However, vasopressin decreases myocardial blood flow (MBF) because of its strong vasoconstriction, to maintain better coronary perfusion pressure (CPP) compared with epinephrine. Nitroglycerin is well known to be able to maintain MBF and increase survival rate. In a VF model, vasopressin combined with nitroglycerin maintained CPP; however, low survival rates were observed compared with vasopressin alone. We investigated the effectiveness of the delayed use of nitroglycerin combined with vasopressin in a severe asphyxia model. Fourteen Sprague–Dawley male rats were divided into two groups: vasopressin 0.8 U/kg alone (V-Gr.), and nitroglycerin 0.3 μg/kg 45 s after the administration of 0.8 U/kg vasopressin (VN-Gr.). Six min after asphyxia induced by obstructing the tracheal tube, CPR was performed in two ways. Three animals resuscitated in the V-Gr. (42%) and six/seven (84%) in the VN-Gr. (P<0.05). In the 6 min of asphyxia rat model, vasopressin combined with delayed nitroglycerin is more effective than vasopressin alone. [Copyright &y& Elsevier]