In several recent clinical trials on cardiac surgery patients, remote ischaemic preconditioning (RIPC) showed a powerful myocardial protective effect. However, the effect of RIPC has not been studied in patients undergoing off-pump coronary artery bypass graft surgery. We evaluated whether RIPC could induce myocardial protection in off-pump coronary artery bypass graft surgery patients. Patients undergoing elective off-pump coronary artery bypass graft surgery were randomly allocated to the RIPC (n=65) or control group (n=65). After induction of anaesthesia, RIPC was induced by four cycles of five-minute ischaemia and reperfusion on the upper limb using a pneumatic cuff. Anaesthesia was maintained with sevoflurane, remifentanil and vecuronium. Myocardial injury was assessed by troponin I before surgery and 1, 6, 12, 24, 48 and 72 hours after surgery. There were no statistical differences in troponin I levels between RIPC and control groups (P=0.172). Although RIPC reduced the total amount of troponin I (area under the curve of troponin increase) by 26%, it did not reach statistical significance (RIPC group 53.2∓72.9 hours.ng/ml vs control group 67.4∓97.7 hours.ng/ml, P=0.281). In this study, RIPC by upper limb ischaemia reduced the postoperative myocardial enzyme elevation in offpump coronary artery bypass graft surgery patients, but this did not reach statistical significance. Further study with a larger number of patients may be needed to fully evaluate the clinical effect of RIPC in off-pump coronary artery bypass graft surgery patients.

Inflammation plays a key role in the pathogenesis of vascular occlusive diseases, such as myocardial infarction and stroke. Additionally, these conditions are predicted by C-reactive protein (CRP), a general inflammation marker. We hypothesized that the inflammation induced by surgery itself augments vascular occlusive disease. We retrospectively evaluated the relationship between postoperative CRP elevation and postoperative major adverse cardiovascular and cerebral events (MACCE) in patients undergoing off-pump coronary artery bypass surgery (OPCAB). The electronic medical records of 1046 patients who underwent OPCAB were reviewed retrospectively. The relationship between postoperative serum CRP and long-term postoperative MACCE (median follow-up 28 months) was investigated. Patients were divided into quartiles according to maximum postoperative CRP levels (<18, 18–22, 22–27, ≥27 mg dl⁻¹). The adjusted hazard ratios (HRs) were 2.15, 2.45, and 2.81, respectively (P=0.004), compared with the lowest quartile (<18 mg dl⁻¹). In the multivariate analysis, the postoperative CRP quartile (HR 2.81; P=0.004), postoperative non-use of statins (HR 1.86; P=0.003), and postoperative maximum troponin I (HR 1.02; P<0.001) independently predicted postoperative MACCE, while preoperative CRP did not (P=0.203). Several parameters were correlated with postoperative maximum CRP level: body temperature (P=0.001) and heart rate (P<0.001) at the end of surgery; intraoperative last lactate (P<0.001) and base excess (P<0.001); and red blood cell transfusion (P=0.019). Postoperative CRP elevation was associated with long-term postoperative MACCE in OPCAB patients. This was mitigated by postoperative statin medication. Furthermore, postoperative CRP elevation was associated with intraoperative parameters reflecting hypoperfusion and inflammation.

Introduction: Microvascular reactivity is decreased in patients with septic shock; this is associated with worse clinical outcomes. The objectives of the present study were to investigate microvascular reactivity in cardiac surgery patients and to assess any association with clinical outcomes. Methods: We retrospectively analyzed a prospectively collected registry. In total, 254 consecutive adult patients undergoing cardiac and thoracic aortic surgeries from January 2013 through May 2014 were analyzed. We performed a vascular occlusion test (VOT) by using near-infrared spectroscopy to measure microvascular reactivity. VOT was performed three times per patient: prior to the induction of anesthesia, at the end of surgery, and on postoperative day 1. The primary endpoint was a composite of major adverse complications, including death, myocardial infarction, acute kidney injury, acute respiratory distress syndrome, and persistent cardiogenic shock. Results: VOT recovery slope decreased during the surgery. VOT recovery slope on postoperative day 1 was significantly lower in patients with composite complications than those without (3.1 ± 1.6 versus 4.0 ± 1.5 %/s, P = 0.001), although conventional hemodynamic values, such as cardiac output and blood pressure, did not differ between the groups. On multivariable regression and linear analyses, low VOT recovery slope on postoperative day 1 was associated with increases of composite complications (odds ratio 0.742; 95 % confidence interval (CI) 0.584 to 0.943; P = 0.015) and hospital length of stay (regression coefficient (B) −1.276; 95 % CI −2.440 to −0.112; P = 0.032). Conclusion: Microvascular reactivity largely recovered on postoperative day 1 in the patients without composite complications, but this restoration was attenuated in patients with composite complications. Trial registration: ClinicalTrials.gov NCT01713192. Registered 22 October 2012.

The effects of remote ischemic preconditioning (RIPC) in cardiac surgery have been inconsistent. We investigated whether anesthesia or beta-blockers interfere with RIPC cardioprotection. Fifty patients undergoing cardiac surgery were randomized to receive limb RIPC (four cycles of 5-min of upper arm cuff inflation/deflation) in the awake state (no-anesthesia; n = 17), or under sevoflurane (n = 17) or propofol (n = 16) anesthesia. In a separate crossover study, 11 healthy volunteers received either carvedilol or no medication prior to RIPC. Plasma dialysates were obtained and perfused through an isolated male Sprague–Dawley rat heart subjected to 30-min ischemia/60-min reperfusion, following which myocardial infarct (MI) size was determined. In the cardiac surgery study, pre-RIPC MI sizes were similar among the groups (39.7 ± 4.5% no-anesthesia, 38.9 ± 5.3% sevoflurane, and 38.6 ± 3.6% propofol). However, post-RIPC MI size was reduced in the no-anesthesia group (27.5 ± 8.0%; p < 0.001), but not in the anesthesia groups (35.7 ± 6.9% sevoflurane and 35.8 ± 5.8% propofol). In the healthy volunteer study, there was a reduction in MI size with RIPC in the no-carvedilol group (41.7 ± 4.3% to 30.6 ± 8.5%; p < 0.0001), but not in the carvedilol group (41.0 ± 4.0% to 39.6 ± 5.6%; p = 0.452). We found that the cardioprotective effects of limb RIPC were abolished under propofol or sevoflurane anesthesia and in the presence of carvedilol therapy.

One-lung ventilation during thoracic surgery frequently disturbs normal systemic oxygenation. However, the effect of anesthetics on arterial oxygenation during one-lung ventilation has not been well established in human study. In this clinical trial, we investigated whether a difference between desflurane-remifentanil and propofol-remifentanil anesthesia can be observed with regard to oxygenation during one-lung ventilation for thoracoscopic surgery. Adult patients with lung cancer, scheduled for video-assisted thoracoscopic lobectomy without preoperative oxygen support, were screened and randomized to receive desflurane or propofol, with remifentanil continuous infusion in both groups. Mechanical ventilation was performed with tidal volume of 8 ml/kg and FIO2 0.5 during two-lung ventilation, and 6 ml/kg and 1.0 during one-lung ventilation, both with positive end-expiratory pressure of 5 cmH2O. Arterial blood gas analysis was performed preoperatively, during two-lung ventilation, and after 15, 30, 45, and 60 min of one-lung ventilation. The primary endpoint was PaO2 at 30 min after initiating one-lung ventilation. Statistical analyses included the independent t-test for the primary endpoint and a mixed model with a post-hoc analysis to evaluate the serial changes in values. Patients were recruited between July 9 and December 2, 2014. In total, 103 patients were analyzed (n = 52 in desflurane group and n = 51 in propofol group). The primary endpoint, PaO2 at 30 min of one-lung ventilation was lower in the desflurane group than the propofol group (170 ± 72 vs. 202 ± 82 mmHg; p = 0.039). Serial changes in PaO2 during one-lung ventilation showed lower levels during desflurane anesthesia compared with propofol anesthesia (mean difference, 45 mmHg; 95% confidence interval, 16–75 mmHg; p = 0.003). In conclusion, desflurane-remifentanil anesthesia resulted in decreased arterial oxygenation compared with that of propofol-remifentanil anesthesia during one-lung ventilation for thoracoscopic surgery in patients with lung cancer. ClinicalTrials.gov identifier: NCT02191371 , registered on July 7, 2014