Acute perioperative heart failure

Functional recovery after accidental deep hypothermic cardiac arrest: Comparison of different cardiopulmonary bypass rewarming strategies

Introduction: Using a porcine model of accidental immersion hypothermia and hypothermic cardiac arrest (HCA), the aim of the present study was to compare effects of different rewarming strategies on CPB on need for vascular fluid supply, level of cardiac restitution, and cerebral metabolism and pressures.

Materials and Methods: Totally sixteen healthy, anesthetized castrated male pigs were immersion cooled to 20°C to induce HCA, maintained for 75 min and then randomized into two groups: 1) animals receiving CPB rewarming to 30°C followed by immersion rewarming to 36°C (CPB₃₀, n = 8), or 2) animals receiving CPB rewarming to 36°C (CPB₃₆, n = 8). Measurements of cerebral metabolism were collected using a microdialysis catheter. After rewarming to 36°C, surviving animals in both groups were further warmed by immersion to 38°C and observed for 2 h.

Results: Survival rate at 2 h after rewarming was 5 out of 8 animals in the CPB₃₀ group, and 8 out of 8 in the CPB₃₆ group. All surviving animals displayed significant acute cardiac dysfunction irrespective of rewarming method. Differences between groups in CPB exposure time or rewarming rate created no differences in need for vascular volume supply, in variables of cerebral metabolism, or in cerebral pressures and blood flow.

Conclusion: As 3 out of 8 animals did not survive weaning from CPB at 30°C, early weaning gave no advantages over weaning at 36°C. Further, in surviving animals, the results showed no differences between groups in the need for vascular volume replacement, nor any differences in cerebral blood flow or pressures. Most prominent, after weaning from CPB, was the existence of acute cardiac failure which was responsible for the inability to create an adequate perfusion irrespective of rewarming strategy.

Cooling to Hypothermic Circulatory Arrest by Immersion vs. Cardiopulmonary Bypass (CPB): Worse Outcome After Rewarming in Immersion Cooled Pigs

Introduction

Cooling by cardiopulmonary bypass (CPB) to deep hypothermic cardiac arrest (HCA) for cardiac surgical interventions, followed by CPB-rewarming is performed on a routine basis with relatively low mortality. In contrast, victims of deep accidental hypothermia rewarmed with CPB generally have a much worse prognosis. Thus, we have developed an intact pig model to compare effects on perfusion pressures and global oxygen delivery (DO₂) during immersion cooling versus cooling by CPB. Further, we compared the effects of CPB-rewarming between groups, to restitute cardiovascular function, brain blood flow, and brain metabolism.

Materials and Methods

Total sixteen healthy, anesthetized juvenile (2–3 months) castrated male pigs were randomized in a prospective, open placebo-controlled experimental study to immersion cooling (IMM_c, n = 8), or cooling by CPB (CPB_c, n = 8). After 75 minutes of deep HCA in both groups, pigs were rewarmed by CPB. After weaning from CPB surviving animals were observed for 2 h before euthanasia.

Results

Survival rates at 2 h after completed rewarming were 4 out of 8 in the IMM_c group, and 8 out of 8 in the CPB_c group. Compared with the CPB_c-group, IMM_c animals showed significant reduction in DO₂, mean arterial pressure (MAP), cerebral perfusion pressure, and blood flow during cooling below 25°C as well as after weaning from CPB after rewarming. After rewarming, brain blood flow returned to control in CPB_c animals only, and brain micro dialysate-data showed a significantly increase in the lactate/pyruvate ratio in IMM_c vs. CPB_c animals.

Conclusion

Our data indicate that, although global O₂ consumption was independent of DO₂, regional ischemic damage may have taken place during cooling in the brain of IMM_c animals below 25°C. The need for prolonged extracorporeal membrane oxygenation (ECMO) should be considered in all victims of accidental hypothermic arrest that cannot be weaned from CPB immediately after rewarming.

Levosimendan for patients with heart failure undergoing major oncological surgery: A randomised blinded pilot study

Background and Aims:

Cardiovascular diseases and cancer are among the leading causes of mortality worldwide. The aim of this study is to evaluate the efficacy and safety of preoperative administration of levosimendan in patients with chronic heart failure (CHF) scheduled for major abdominal oncologic surgery.

Methods:

This study included 60 patients with abdominal malignancy, ejection fraction (EF) <35% and CHF scheduled for surgery under isoflurane-fentanyl anaesthesia and were managed in the surgical intensive care unit perioperatively. They were randomised to receive levosimendan infusion (n = 30) at a dose of 0.1 μg/kg/min or placebo (n = 30) for 24 hours before surgery.

Results:

The risk of hypotension (RR: 0.40, 95% CI: 0.19-0.83) or decompensated heart failure (RR: 0.31, 95% CI: 0.12-0.76) was significantly lower in the levosimendan group. The ejection fraction, cardiac index and stroke volume index were significantly higher in the levosimendan group after surgery (P < 0.001). Duration of postoperative ventilation and hospital stay were significantly shorter in the levosimendan group (P < 0.001) while the frequency of dysrhythmia, deterioration of renal function and sepsis was comparable.

Conclusion:

In patients with low EF <35% and CHF, administration of levosimendan for 24 hours before major abdominal oncologic surgeries may reduce the risk of hypotension and decompensated heart failure and may improve cardiac function.

Gender and racial differences in surgical outcomes among adult patients with acute heart failure

BACKGROUND

Approximately three million U.S. adult women have heart failure (HF), increasing their risk of adverse perioperative outcomes. While gender and racial differences are reported in surgical outcomes, less is known about 30-day perioperative outcomes in HF patients.

OBJECTIVES

To characterize and compare gender and racial differences in 30-day perioperative outcomes in adults with new or acute/worsening HF.

METHODS

The 2012-2013 American College of Surgeons National Surgical Quality Improvement Program database of surgical patients (n = 9458) with HF was analyzed. Logistic regression was used to adjust for gender and racial differences in baseline covariates.

RESULTS

No gender difference in mortality (odds ratio = 0.922, 95% confidence interval = 0.0792-1.073, p = 0.294) was noted. Whites were more likely than Blacks to die 30 days after surgery (14% vs 9%, p < 0.001); after adjustment, Blacks were more likely to experience complications and be readmitted compared to Whites.

CONCLUSIONS

There was no gender difference in mortality. White patients with HF were more likely to die after surgery than Black patients.

Levosimendan as a treatment for acute renal failure associated with cardiogenic shock after hip fracture

Inotropic drugs are part of the treatment of heart failure; however, inotropic treatment has been largely debated due to the increased incidence of adverse effects and increased mortality. Recently levosimendan, an inotropic positive agent, has been proved to be effective in acute heart failure, reducing the mortality and improving cardiac and renal performance. We report the case of a 75-year-old woman with history of heart and renal failure and hip fracture. Levosimendan was used in preoperative preparation as an adjuvant therapy, to improve cardiac and renal function and to allow surgery.

Preoperative optimization with levosimendan in heart failure patient undergoing thoracic surgery

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The use of levosimendan for perioperative optimization of patients undergoing cardiac surgery has been reported in several studies, however it has not been thouroughly evaluated in cardiac failure patients undergoing non cardiac surgery.

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Preoperative levosimendan administration is safe and effective in cardiac failure patient undergoing thoracic surgery.

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Prophylactic preoperative levosimendan treatment in heart failure patients merits further study.

Introduction

We present the case of a patient with dilatative cardiomyopathy waiting for heart transplantation with pleural effusion to be subjected to pleural biopsy, treated with preoperative infusion of levosimendan to improve heart performances.

Presentation of case

A 56-year-old man (BMI 22,49) with dilatative cardiomyopathy (EF 18%) presented right pleural effusion. The levosimendan treatment protocol consisted of 24 h continuous infusion (0,1 ug/kg/min), without bolus. The patient was under continuous hemodynamic monitoring prior, during and after levosimendan administration. The surgery for pleural biopsy was performed with uniportal Video Assisted Thoracoscopic approach (VATS).

Discussion

A significant increase of Cardiac Index (CI) and Stroke Volume Index (SVI) were observed at 4 h after infusion initiation and was sustained during the next 24 h after the end of infusion. Levosimendan administration was safe.

Conclusion

In this case the prophylactic preoperative levosimendan administration is safe and effective in cardiac failure patient undergoing thoracic surgery, but prophylactic preoperative levosimendan treatment in these patients merits further study.

[Levosimendan as a treatment for acute renal failure associated with cardiogenic shock after hip fracture]

Inotropic drugs are part of the treatment of heart failure; however, inotropic treatment has been largely debated due to the increased incidence of adverse effects and increased mortality. Recently levosimendan, an inotropic positive agent, has been proved to be effective in acute heart failure, reducing the mortality and improving cardiac and renal performance. We report the case of a 75-year-old woman with history of heart and renal failure and hip fracture. Levosimendan was used in preoperative preparation as an adjuvant therapy, to improve cardiac and renal function and to allow surgery.

The cardioprotective effects of levosimendan: preclinical and clinical evidence

Levosimendan, a drug used in the treatment of acute and decompensated heart failure, has positive inotropic and antistunning effects mediated by calcium sensitization of contractile proteins, and vasodilatory and antiischemic effects mediated via the opening of ATP-sensitive potassium channels in vascular smooth-muscle cells. Recently, it also has been shown to act on mitochondrial ATP-sensitive potassium (mitoKATP) channels, an action thought to protect the heart against ischemia-reperfusion damage. This finding has suggested a possible application for levosimendan in clinical situations in which preconditioning would be beneficial (eg, in pre- and perioperative settings in cardiac surgery). The demonstration that levosimendan can prevent or limit myocyte apoptosis via the activation of mitoKATP channels provides a potential mechanism whereby this agent might protect cardiac myocytes during episodes of acute heart failure. This finding may explain why short-term treatment with levosimendan may improve longer-term survival. The present article reviews the literature on the cardioprotective actions of levosimendan, with particular emphasis on its recently recognized effects on mitoKATP channels and the putative preconditioning effects of that action. A therapeutic approach to acute heart failure that includes a cardioprotective strategy could have a clinically meaningful benefit on disease progression beyond alleviation of symptoms.

Prospective, randomized trial comparing fluids and dobutamine optimization of oxygen delivery in high-risk surgical patients [ISRCTN42445141]

INTRODUCTION

Preventing perioperative tissue oxygen debt contributes to a better postoperative recovery. Whether the beneficial effects of fluids and inotropes during optimization of the oxygen delivery index (DO2I) in high-risk patients submitted to major surgeries are due to fluids, to inotropes, or to the combination of the two is not known. We aimed to investigate the effect of DO2I optimization with fluids or with fluids and dobutamine on the 60-day hospital mortality and incidence of complications.

METHODS

A randomized and controlled trial was performed in 50 high-risk patients (elderly with coexistent pathologies) undergoing major elective surgery. Therapy consisted of pulmonary artery catheter-guided hemodynamic optimization during the operation and 24 hours postoperatively using either fluids alone (n = 25) or fluids and dobutamine (n = 25), aiming to achieve supranormal values (DO2I > 600 ml/minute/m2).

RESULTS

The cardiovascular depression was an important component in the perioperative period in this group of patients. Cardiovascular complications in the postoperative period occurred significantly more frequently in the volume group (13/25, 52%) than in the dobutamine group (4/25, 16%) (relative risk, 3.25; 95% confidence interval, 1.22-8.60; P < 0.05). The 60-day mortality rates were 28% in the volume group and 8% in the dobutamine group (relative risk, 3.00; 95% confidence interval, 0.67-13.46; not significant).

CONCLUSION

In patients with high risk of perioperative death, pulmonary artery catheter-guided hemodynamic optimization using dobutamine determines better outcomes, whereas fluids alone increase the incidence of postoperative complications.