Background: Systemic ␣2 agonists are believed to reduce pain and opioid requirements after surgery, thus decreasing the incidence of opioid-related adverse effects, including hyperalgesia. Methods: The authors searched for randomized placebocontrolled trials testing systemic ␣2 agonists administrated in surgical patients and reporting on postoperative cumulative opioid consumption and/or pain intensity. Meta-analyses were performed when data from 5 or more trials and/or 100 or more patients could be combined. Results: Thirty studies (1,792 patients, 933 received clonidine or dexmedetomidine) were included. There was evidence of postoperative morphine-sparing at 24 h; the

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SummaryThere has been increased interest in the prophylactic and therapeutic use of high‐flow nasal oxygen in patients with, or at risk of, non‐hypercapnic respiratory failure. There are no randomised trials examining the efficacy of high‐flow nasal oxygen in high‐risk cardiac surgical patients. We sought to determine whether routine administration of high‐flow nasal oxygen, compared with standard oxygen therapy, leads to reduced hospital length of stay after cardiac surgery in patients with pre‐existing respiratory disease at high risk for postoperative pulmonary complications. Adult patients with pre‐existing respiratory disease undergoing elective cardiac surgery were randomly allocated to receive high‐flow nasal oxygen (n = 51) or standard oxygen therapy (n = 49). The primary outcome was hospital length of stay and all analyses were carried out on an intention‐to‐treat basis. Median (IQR [range]) hospital length of stay was 7 (6–9 [4–30]) days in the high‐flow nasal oxygen group and 9 (7–16 [4–120]) days in the standard oxygen group (p=0.012). Geometric mean hospital length of stay was 29% lower in the high‐flow nasal group (95%CI 11–44%, p = 0.004). High‐flow nasal oxygen was also associated with fewer intensive care unit re‐admissions (1/49 vs. 7/45; p = 0.026). When compared with standard care, prophylactic postoperative high‐flow nasal oxygen reduced hospital length of stay and intensive care unit re‐admission. This is the first randomised controlled trial examining the effect of prophylactic high‐flow nasal oxygen use on patient‐centred outcomes in cardiac surgical patients at high risk for postoperative respiratory complications.

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The end-systolic pressure-volume relationship (ESPVR) is proposed and used as a reliable index of left ventricular (LV) contractility despite the fact that its afterload independence has been challenged. Furthermore, the physiological relevance of its volume-axis intercept, V 0 , remains unclear. Systemic haemodynamics and pressure-volume loops obtained by inferior vena cava occlusion were recorded in 21 rats anaesthetized by isoflurane inhalation and instrumented with a conductance pressure-volume catheter in response to incremental i.v. doses of adrenaline, dobutamine, phenylephrine, metoprolol, papaverine and isoflurane inhalation. In conditions with large variations (±100%) of both inotropy and afterload, infusion of negative inotropic drugs was associated with a dose-dependent rightward shift of ESPVR accompanied by a decrease in its slope (end-systolic elastance, E es ), whereas positive inotropic agents produced an isolated decrease in V 0 . With the predominant vasoactive drugs, there was a dose-dependent change in E es without major horizontal shifts, demonstrating that this slope mainly represents LV afterload rather than inotropy. When contractility was altered, V 0 was negatively correlated to the preload-adjusted contractility index, PAdP/dt max , demonstrating that a reduced V 0 provides a good reflection of increased LV contractility. From these results, we computed a logarithmically adjusted E es /V 0 ratio, which resulted in reasonably strong concordance with PAdP/dt max , including all the investigated drugs and dosages [n = 288; bias, 0.8 ± 16.2% (SD)]. Concordance with E es (bias, 7.2 ± 58.7%) or V 0 (bias, −0.6 ± 33.4%), used alone or with other commonly used contractility indices, was far less significant. In contrast to E es , V 0 provides a relatively good LV contractility index because it is much less sensitive to afterload. The pressure-volume (PV) loops are used to describe the active and passive mechanical properties of the heart. In particular, the systolic function of the ventricle is analysed by using the end-systolic pressure-volume relationship (ESPVR). The ESPVR is described by a linear slope, the end-systolic elastance (E es ; approximated by maximal elastance, E max ), and by a volume-axis intercept (V 0 ). Suga et al. (1973Suga et al. ( , 1974 showed in the isolated canine heart that E es was load independent, but sensitive to inotropic interventions. This measure of left ventricular myocardial contractility was also applied in conscious dogs (Sagawa et al. 1977;Sodums et al. 1984) and in man (Grossman et al. 1977;Mehmel et al. 1981;Borow et al. 1982).However, these classic notions were later questioned; indeed, the ESPVR has been shown to be afterload dependent (Burkhoff et al. 1993) and, when analysed over wide ranges of contractile states, it was shown to be curvilinear (Burkhoff et al. 1987;Sato et al. 1998). Moreover, logarithmic regression of the ESPVR is superior to linear in estimating the volume-axis intercept (Claessens et al. 2006). Finally, not only the slope of ...

Anaemia is common before cardiac surgery and is associated with increased morbidity and mortality. The World Health Organization (WHO) definition of anaemia is lower for women than for men by 10 g.l , potentially putting women at a disadvantage compared with men with regard to pre-operative optimisation. Our hypothesis was that women with borderline anaemia (defined by us as haemoglobin concentration 120-129 g.l ) would have a higher rate of red cell transfusion, morbidity and mortality than non-anaemic women (haemoglobin ≥ 130 g.l ). This retrospective observational study included all adult patients admitted for elective cardiac surgery from January 2013 to April 2016. During the study period, 1388 women underwent cardiac surgery. Pre-operatively, 333 (24%) had a haemoglobin level < 120 g.l ; 408 (29%) 120-129 g.l ; and 647 (47%) ≥ 130 g.l . Compared with non-anaemic women, women with borderline anaemia were more likely to be transfused (68.6% vs. 44.5%; RR 1.5, 95%CI 1.4-1.7; p < 0.0001) and were transfused with more units of red cells, mean (SD) 1.8 (2.8) vs. 1.3 (3.0); p < 0.0001. Hospital length of stay was significantly longer in the borderline anaemia group compared with non-anaemic women, median (IQR [range]) 8 (6-12 [3-45]) vs. 7 (6-11 [4-60]); p = 0.0159. Short- and long-term postoperative survival was comparable in both groups. Borderline anaemia is associated with increased red cell transfusion and prolonged hospital stay. Future research should address whether correction of borderline anaemia results in improved outcomes.

This article aims at reviewing the currently available evidence about blood conservation strategies in cardiac surgery. Pre-operative anaemia and perioperative allogeneic blood transfusions are associated with worse outcomes after surgery. In addition, transfusions are a scarce and costly resource. As cardiac surgery accounts for a significant proportion of all blood products transfused, efforts should be made to decrease the risk of perioperative transfusion. Pre-operative strategies focus on the detection and treatment of anaemia. The management of haematological abnormalities, most frequently functional iron deficiency, is a matter for debate. However, iron supplementation therapy is increasingly commonly administered. Intra-operatively, antifibrinolytics should be routinely used, whereas the cardiopulmonary bypass strategy should be adapted to minimise haemodilution secondary to circuit priming. There is less evidence to recommend minimally invasive surgery. Cell salvage and point-of-care tests should also be a part of the routine care. Post-operatively, any unnecessary iatrogenic blood loss should be avoided.

Background: Pulmonary hypertension and associated pressure-overload right ventricular (RV) hypertrophy represent a tremendous challenge for the anesthesiologist, as optimal perioperative management is mandatory. However, the ideal anesthetic agent remains unknown because scientific evidence is lacking. Methods: Twenty-eight rats were randomly assigned to a control or a monocrotaline group (60 mg kg −1 ). Four weeks later, animals were anesthetized, instrumented with a RV conductance catheter, and underwent wellcontrolled dose-responses to isoflurane, desflurane, and sevoflurane inhalation (minimum alveolar concentrations 0.5, 1.0, 1.5). Results: Compared with controls, rats injected with monocrotaline presented with RV hypertrophy, increased afterload, and contractility, without change in cardiac output. The ratio of pressures in the right over the left circulation increased. The halogenated volatiles differently altered hemodynamics. Sevoflurane reduced RV contractility (more than 50%) and the right over left pressures ratio increased (from 0.41 ± 0.08 [SD] to 0.82 ± 0.14; P < 0.0001) secondary to profound concomitant systemic vasodilation, demonstrating a critical pressure gradient between right and left circulations. Despite significantly higher RV systolic pressures and afterload, desflurane decreased RV contractility much less (<10%; P < 0.0001 vs. sevoflurane) and maintained the right over left pressures ratio at more favorable values (0.47 ± 0.07; P < 0.0001 vs. sevoflurane). Isoflurane presented intermediate effects. Conclusion: In the presence of pressure-overload RV hypertrophy, hemodynamics are better preserved under desflurane inhalation, whereas sevoflurane-and to a lesser extent isoflurane-cause large discrepancies on the left and right circulations, raising the right over left pressures ratio to critical levels despite a conserved cardiac output. UNDER the denomination of pulmonary hypertension (PH) are grouped five entities (pulmonary arterial hypertension; PH with left heart disease; PH associated with lung diseases and/or hypoxemia; PH due to chronic thrombotic and/or embolic disease; miscellaneous [revised World Health Organization classification])1 that all share in common hemodynamic modifications of the pulmonary vasculature leading to a chronically increased intravascular pressure, defined as a mean pulmonary arterial pressure above 25 mmHg at rest, 2 and resulting in eventual right ventricular (RV) failure.The prevalence of PH in the population is dependent on its etiology. In a French registry, the prevalence of pulmonary arterial hypertension was approximately 15 per million. What This Article Tells Us That Is New• Desflurane produced minimal systemic and right ventricular effects most probably related to its ability to relatively preserve sympathetic tone, whereas sevoflurane-and to a lesser extent, isoflurane-caused large discrepancies in the left and right circulations, characterized by marked reduction in left ventricular afterload combined with reduced right ventricular in...