Pharmacological interventions to reduce edema following cardiopulmonary bypass: A systematic review and meta-analysis

Skin injury: Associations with variables related to perfusion and pressure

Skin injuries are a major healthcare problem that are not well understood or prevented in the critically ill, suggesting that underappreciated variables are contributing. This pilot study tested the hypothesis that perfusion-related factors contribute to skin injuries diagnosed as hospital-acquired pressure injuries (HAPIs). A total of 533 adult patients were followed over 2574 critical care days (mean age 62.4, standard deviation (SD) 14.3 years, mean body mass index 30.4 (SD 7.4) kg/m2, 36.4% female). This was a secondary analysis of prospective, non-randomised clinical data from an intensive care unit at a large urban teaching hospital. Factors related to perfusion, specifically two or more infusions of vasopressors/inotropes, temporary mechanical circulatory support (MCS), extracorporeal membrane oxygenation, and durable MCS, were analysed to determine whether they were more strongly associated with HAPIs than immobility due to prolonged mechanical ventilation (>72 h) or operating room time (>6 h). Patients diagnosed with a HAPI had a statistically significant higher risk of being exposed to variables related to perfusion and immobility (P < 0.05 for each variable). Perfusion-related variables, except durable MCS, had a larger effect on skin breakdown (number needed to harm (NNH) 4-10) than immobility-associated variables (NNH 12-17). The finding that perfusion-related variables predicted HAPIs may warrant consideration of alternative diagnoses, such as skin failure due to impaired perfusion as a pathophysiological process that occurs concurrently with multisystem organ failure. Differentiation of skin injuries primarily from circulatory malfunction, rather than external pressure, may guide the development of more effective treatment and prevention protocols. This pilot study suggests that the contribution of perfusion to skin injuries should be explored further.

Unilateral pulmonary edema after minimally-invasive bentall procedure - Case report

Introduction

Unilateral pulmonary edema (UPE), a life-threatening complication of cardiac surgery, often occurs after prolonged cardiopulmonary bypass and lung collapse, especially in minimally-invasive cardiac surgery (MICS). The present study reported a young patient with severe UPE after the surgery as well as corresponding clinical treatments. In addition to the supportive treatment of extracorporeal membrane oxygenation (ECMO), monitoring changes in cardiopulmonary function and early clinical interventions are crucial.

Conclusion

By weighing the beneficial and detrimental effects of the treatment, it calls for early diagnosis and new therapeutic strategies for the complication.

Right ventricular myocardial edema leading to severe heart failure after open heart surgery - possible effect of high-dose corticosteroid therapy

BACKGROUND

Cardiopulmonary bypass induces a systemic inflammatory response and alterations in fluid homeostasis, resulting in generalized tissue edema. Additionally, ischemia-reperfusion injury following cardioplegic arrest presumably prompts organ-specific myocardial edema.

CASE PRESENTATION

The case report presents a 75-year-old Caucasian male diagnosed with aortic dissection, Stanford type A, who underwent complicated open-heart surgery. Postoperatively, the patient developed excessive myocardial edema, particularly affecting the right ventricle myocardium to an extent where the right ventricle surpassed the sternal rim, making it impossible to close the sternum. Ischemia was ruled out by performing coronary angiography, demonstrating well-calibrated coronary arteries. Transoesophageal echocardiography showed a restrictive right ventricle with free-wall thickness of 30 mm, severely reduced right ventricle systolic function and a volume-depleted left ventricle consistent with right ventricular heart failure due to right ventricular edema. The patient presented with unstable haemodynamics despite use of inotropes and continuation of open sternotomy. In an attempt to reduce myocardial edema, the patient was started on corticosteroid treatment despite of ongoing mediastinitis. Corticosteroid treatment reduced myocardial edema and enabled the closure of sternum on the 44th postoperative day.

CONCLUSIONS

The case report addresses the clinical relevance of corticosteroid treatment in selective cases of intractable haemodynamically significant postoperative myocardial edema.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

Severe noncardiogenic pulmonary edema after cardiopulmonary bypass: Case report

Lung injury is a common complication after cardiopulmonary bypass (CPB). However, cases of noncardiogenic pulmonary edema in which the patient ultimately requires extracorporeal membrane oxygenation (ECMO) support are uncommon. A 54-year-old man was admitted to the hospital with shortness of breath after activity and paroxysmal dyspnoea at night for 3 months. Infective endocarditis and acute heart failure were diagnosed. The patient underwent emergency surgery including aortic valve replacement, mitral valve replacement, tricuspid valve repair, and ventricular septal defect correction. It's noteworthy that the patient experienced significant pulmonary edema during the surgery and within 8 hours postoperatively, with over 3000 mL of yellow-clear fluid aspirated from the trachea and bronchi. The patient eventually recovered through ECMO V-V mode treatment. Inflammatory markers were markedly elevated during the perioperative period, and blood smear revealed Gram-positive bacterial infection. Blood NGS testing detected Streptococcus pneumoniae infection. Despite various factors contributing to the patient's pulmonary edema, it is hypothesized that the edema is related to uncontrolled inflammatory response and cytokine storm. Therefore, when significant pulmonary edema occurs during surgery, swift and decisive actions are necessary to avoid missing the optimal rescue window. If required, the use of ECMO is an effective final treatment option.

Pharmacological Cardioprotection against Ischemia Reperfusion Injury-The Search for a Clinical Effective Therapy

Pharmacological conditioning aims to protect the heart from myocardial ischemia-reperfusion injury (IRI). Despite extensive research in this area, today, a significant gap remains between experimental findings and clinical practice. This review provides an update on recent developments in pharmacological conditioning in the experimental setting and summarizes the clinical evidence of these cardioprotective strategies in the perioperative setting. We start describing the crucial cellular processes during ischemia and reperfusion that drive acute IRI through changes in critical compounds (∆G_ATP, Na⁺, Ca²⁺, pH, glycogen, succinate, glucose-6-phosphate, mitoHKII, acylcarnitines, BH₄, and NAD⁺). These compounds all precipitate common end-effector mechanisms of IRI, such as reactive oxygen species (ROS) generation, Ca²⁺ overload, and mitochondrial permeability transition pore opening (mPTP). We further discuss novel promising interventions targeting these processes, with emphasis on cardiomyocytes and the endothelium. The limited translatability from basic research to clinical practice is likely due to the lack of comorbidities, comedications, and peri-operative treatments in preclinical animal models, employing only monotherapy/monointervention, and the use of no-flow (always in preclinical models) versus low-flow ischemia (often in humans). Future research should focus on improved matching between preclinical models and clinical reality, and on aligning multitarget therapy with optimized dosing and timing towards the human condition.

Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial

INTRODUCTION

Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS

Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS

Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS

Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.

Impact of Steroid on Macrophage Migration Inhibitory Factor During and After Cardiopulmonary Bypass

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine released in response to glucocorticoids, which counter-regulates the effects of glucocorticoids. This study was performed to determine the impact of steroids on the expression of MIF and other pro- and anti-inflammatory cytokines during and after cardiopulmonary bypass (CPB). Twenty adult patients (10 men, 64 ± 8 years old) who underwent elective cardiac surgery by CPB were given either 2000 mg (group-H, n = 10) or 500 mg of methylprednisolone (group-L, n = 10) during CPB. The serum concentrations of MIF, interleukin (IL)-1β, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α) were measured at eight time points until 36 hours after skin closure. The early postoperative course was uneventful for all patients. There were no significant differences in duration of operation, CPB, or aortic cross-clamping (AXC) between the two groups. MIF and IL-10 levels peaked just after the conclusion of CPB and decreased gradually thereafter. IL-1β, IL-8, and TNF-α were undetectable throughout the study period. There were no significant differences in MIF or IL-10 levels between the two groups. Peak levels of MIF in all patients were significantly correlated with the duration of CPB and AXC, whereas no such correlation was observed for IL-10. MIF or IL-10 levels were significantly elevated during and after CPB, but there were no differences between the two doses of steroid administration. Both steroid doses sufficiently suppressed proinflammatory cytokines. MIF better reflected the invasiveness of the operation than IL-10.

Anti-factor X Activity Levels with Continuous Intravenous Infusion and Subcutaneous Administration of Enoxaparin after Coronary Artery Bypass Grafting: a Randomized Clinical Trial

BACKGROUND

Low-molecular-weight heparin enoxaparin is widely used in pharmacological thromboprophylaxis after coronary artery bypass grafting (CABG). The aim of this study was to compare anti-factor X activity (anti-Xa) levels when the thromboprophylactic dose of enoxaparin was provided after CABG, with two different administration routes: continuous intravenous infusion (CIV) and subcutaneous bolus (SCB) injection. We hypothesized that the current standard method of SCB administration might lead to lower anti-Xa levels than recommended in other patient groups, due to reduced bioavailability.

METHODS

In this prospective, randomized, controlled clinical trial, 40 patients scheduled for elective CABG were randomized to receive 40 mg of enoxaparin per day either as CIV or SCB for 72 h. Enoxaparin was initiated 6-10 h after CABG. Anti-Xa levels were measured 12-14 times during the study period. The primary outcome i.e. the maximum anti-Xa concentration over 0-24 h (C_max0-24h ), was calculated from these measured values. Secondary outcomes were C_max25-72h and the trough concentration of anti-Xa after 72 h of enoxaparin initiation (C_72h ).

RESULTS

Twenty patients were randomized to the CIV-group and 19 to the SCB-group. The median anti-Xa C_max0-24h was significantly lower in the CIV-group than in the SCB-group: 0.15 [interquartile range (IQR) 0.13-0.19] IU/mL versus 0.25 (IQR 0.18-0.32) IU/mL, p < 0.005. The median anti-Xa C_max25-72h was 0.12 (IQR, 0.1-0.17) IU/mL versus 0.23 (IQR 0.19-0.31) IU/mL, respectively, p < 0.005. At 72 h, there was no difference between the groups in their anti-Xa levels.

CONCLUSIONS

In this low-risk CABG patient population, SCB administration of a thromboprophylactic dose of enoxaparin provided anti-Xa levels that are considered sufficient for thromboprophylaxis in other patient groups. CIV administration resulted in lower anti-Xa levels compared to the SCB route.

The risk factors for delayed recovery in patients with cardiopulmonary bypass: Why should we care?

Cardiopulmonary bypass (CPB) is very commonly performed among the cardiovascular surgeries, and delayed recovery (DR) is a kind of serious complications in patients with CPB. It is necessary to assess the risk factors for DR in patients with CPB, to provide evidence into the management of CPB patients.Patients undergoing CPB in our hospital from January 2018 to March 2020 were included. Cases that consciousness has not recovered 12 hours after anesthesia were considered as DR. The preoperative and intraoperative variables of CPB patients were collected and analyzed. Logistic regressions were conducted to analyze the potential influencing factor.A total of 756 CPB patients were included, and the incidence of DR was 9.79%. There were significant differences on the age, aspartate aminotransferase (AST), glutamic pvruvic transaminase (ALT), blood urea nitrogen (BUN), and serum creatinine (SCr) between patients with and without DR (all P < .05); there were no significant differences in the types of surgical procedure (all P > .05); there were significant differences on the duration of CPB, duration of aortic cross clamp (ACC), duration of surgery, minimum nasopharyngeal temperature, and transfusion of packed red blood cells between patients with and without DR (all P < .05). Logistic regression analysis indicated that duration of CPB ≥132 minutes (odds ratio [OR] 4.12, 1.02-8.33), BUN ≥9 mmol/L (OR 4.05, 1.37-8.41), infusion of red blood cell suspension (OR 3.93, 1.25-7.63), duration of surgery ≥350 minutes (OR 3.17, 1.24-5.20), age ≥6 (OR 3.01, 1.38-6.84) were the independent risk factors for DR in patients with CPB (all P < .05).Extra attention and care are needed for those CPB patients with duration of CPB ≥132 minutes, BUN ≥9 mmol/L, infusion of red blood cell suspension, duration of surgery ≥350 minutes, and age ≥60.

Microcirculatory perfusion disturbances following cardiopulmonary bypass: a systematic review

Background

Microcirculatory perfusion disturbances are associated with increased morbidity and mortality in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Technological advancements made it possible to monitor sublingual microcirculatory perfusion over time. The goal of this review is to provide an overview of the course of alterations in sublingual microcirculatory perfusion following CPB. The secondary goal is to identify which parameter of sublingual microcirculatory perfusion is most profoundly affected by CPB.

Methods

PubMed and Embase databases were systematically searched according to PRISMA guidelines and as registered in PROSPERO. Studies that reported sublingual microcirculatory perfusion measurements before and after onset of CPB in adult patients undergoing cardiac surgery were included. The primary outcome was sublingual microcirculatory perfusion, represented by functional capillary density (FCD), perfused vessel density (PVD), total vessel density (TVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI).

Results

The search identified 277 studies, of which 19 fulfilled all eligibility criteria. Initiation of CPB had a profound effect on FCD, PVD, or PPV. Seventeen studies (89%) reported one or more of these parameters, and in 11 of those studies (65%), there was a significant decrease in these parameters during cardiac surgery; the other 6 studies (35%) reported no effect. In 29% of the studies, FCD, PVD, or PPV normalized by the end of cardiac surgery, and in 24% percent of the studies, this effect lasted at least 24 h. There was no clear effect of CPB on TVD and a mixed effect on MFI.

Conclusion

CPB during cardiac surgery impaired sublingual microcirculatory perfusion as reflected by reduced FCD, PVD, and PPV. Four studies reported this effect at least 24 h after surgery. Further research is warranted to conclude on the duration of CPB-induced microcirculatory perfusion disturbances and the relationship with clinical outcome.

Trial registration

PROSPERO, CRD42019127798