Risk factors for vasoplegia after coronary artery bypass and valve surgery

Perioperative care in infective endocarditis

Patients undergoing surgery for acute infective endocarditis are among those with the highest risk. Their preoperative condition has significant impact on outcomes. There are specific issues related with the preoperative situation, intraoperative findings, and postoperative management. In this narrative review, focus is placed on the most critical aspects in the perioperative period including the management and weaning from mechanical ventilation, the management of vasoplegia, the management of the chest open, antithrombotic therapy, transfusion, coagulopathy, management of atrial fibrillation, the duration of antibiotic therapy, and pacemaker implantation.

The effect of pituitrin on postoperative outcomes in patients with pulmonary hypertension undergoing cardiac surgery: a study protocol for a randomized controlled trial

Background

The vasoplegic syndrome is one of the major consequences of cardiac surgery. If pulmonary hypertension is additionally involved with vasoplegic syndrome, circulation management becomes much more complicated. According to previous studies, pituitrin (a substitute for vasopressin, which contains vasopressin and oxytocin) not only constricts systemic circulation vessels and increases systemic circulation pressure but also likely decreases pulmonary artery pressure and pulmonary vascular resistance. The aim of this study is to investigate whether pituitrin is beneficial for the postoperative outcomes in patients with pulmonary hypertension undergoing cardiac surgery.

Methods and analysis

The randomized controlled trial will include an intervention group continuously infused with 0.04 U/(kg h) of pituitrin and a control group. Adult patients with pulmonary hypertension undergoing elective cardiac surgery will be included in this study. Patients who meet the conditions and give their consent will be randomly assigned to the intervention group or the control group. The primary outcome is the composite endpoint of all-cause mortality within 30 days after surgery or common complications after cardiac surgery. Secondary outcomes include the incidence of other postoperative complications, length of hospital stay, and so on.

Discussion

Pituitrin constricts systemic circulation vessels, increases systemic circulation pressure, and may reduce pulmonary artery pressure and pulmonary vascular resistance, which makes it a potentially promising vasopressor during the perioperative period in patients with pulmonary hypertension. Therefore, evidence from randomized controlled trials is necessary to elucidate whether pituitrin influences outcomes in patients with pulmonary hypertension following cardiac surgery.

Angiotensin-II for vasoplegia following cardiac surgery

INTRODUCTION

The objective of this study was to describe the implementation and outcomes of a protocol outlining angiotensin-II utilization for vasoplegia following cardiac surgery.

METHODS

This was a retrospective chart review at a single-center university hospital. Included patients received angiotensin-II for vasoplegia refractory to standard interventions, including norepinephrine 20 mcg/min and vasopressin 0.04 units/min, following cardiac surgery between April 2021 and April 2022.

RESULTS

30 patients received angiotensin-II for refractory vasoplegia. Adjunctive agents at angiotensin-II initiation included corticosteroids (26 patients; 87%), epinephrine (26 patients; 87%), dobutamine (17 patients; 57%), dopamine (9 patients; 30%), milrinone (2 patients; 7%), and hydroxocobalamin (4 patients; 13%). At 3 hours, the median mean arterial pressure increased from baseline (70 vs 61.5 mmHg, p = .0006). Median norepinephrine doses at angiotensin-II initiation, 1 hour, 3 hours, and angiotensin-II discontinuation were 0.22, 0.16 (p = .0023), 0.10 (p < .0001), and 0.07 (p < .0001) mcg/kg/min. Median dobutamine doses decreased throughout angiotensin-II infusion from eight to six mcg/kg/min (p = .0313). Other vasoactive medication doses were unchanged. Three patients (10%) subsequently received hydroxocobalamin. Thirteen (43.3%) and five (16.7%) patients experienced mortality by day 28 and venous or arterial thrombosis events, respectively.

CONCLUSIONS

The administration of angiotensin-II to vasoplegic patients following cardiac surgery was associated with increased mean arterial pressure, reduced norepinephrine dosages, and reduced dobutamine dosages.

The gut microbiome and cardiac surgery an unusual symphony

The relationship between the gut microbiome and various organ systems has gained interest throughout the scientific community in recent times. The understanding of these complex relationships has greatly improved with clinical benefits now being seen. Cardiopulmonary bypass (CPB) is a form of extracorporeal circulation that provides circulatory and respiratory support during cardiac surgery. This physiological support facilitates a still and bloodless field facilitating operations on the heart to be performed. Through various mechanisms CPB results in a systemic inflammatory response syndrome (SIRS). This response can vary from mild hypotension to multiple organ failure. It remains difficult to predict the degree to which a patient will experience SIRS post-operatively. The relationship between the composition of the gut microbiome and inflammatory processes associated with disease has been seen across several fields including gastroenterology, neurology, psychiatry and cardiology. To date, minimal research has been undertaken to examine the impact the gut microbiome has on outcomes following cardiac surgery. This review paper explores the pathophysiology behind the SIRS response associated with CPB for cardiac surgery and the hypothesis that a correlation exists between a patients gut microbiome composition and the degree of inflammatory response experienced following cardiac surgery.

Vasoplegia: A Review

Vasoplegia is a condition characterized by persistent low systemic vascular resistance despite a normal or high cardiac index, resulting in profound and uncontrolled vasodilation. Vasoplegia may occur due to various conditions, including cardiac failure, sepsis, and post-cardiac surgery. In the cardiac cohort, multiple risk factors for vasoplegia have been identified. Several factors contribute to the pathophysiology of this condition, and various mechanisms have been proposed, including nitric oxide, adenosine, prostanoids, endothelins, the renin-angiotensin-aldosterone system, and hydrogen sulfide. Early identification and prompt management of vasoplegia is crucial to prevent development of shock. This review expands upon the different vasopressors used in management of vasoplegia, including catecholamines such as norepinephrine, dopamine, epinephrine, phenylephrine, and other agents including vasopressin, methylene blue, angiotensin II, hydroxocobalamin, vitamin C, thiamine, and corticosteroids (ie, hydrocortisone). It also emphasizes the importance of conducting further research and making advancements in treatment regimens for vasoplegia.

Epidemiology, risk factors and outcomes of norepinephrine use in cardiac surgery with cardiopulmonary bypass: a multicentric prospective study

BACKGROUND

The present study was designed to describe the prevalence of norepinephrine use, the factors associated with its use, and the incidence of postoperative complications according to norepinephrine use, in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHOD

We performed a prospective, multicenter, observational study in 4 University-affiliated medico-surgical cardiovascular units. We analyzed all patients treated with cardiac surgery after excluding pre-ECMO surgery, LVAD implantation, heart transplantation and intra-operative hemorrhage.

RESULTS

Of 9316 patients screened during the study period, 2862 were included and 2510 were analyzed. Among them, 1549 (61%) were treated with norepinephrine with a median maximal dose of 0.11 [0.06-0.2] μg.kg^-1.min^-1 and a median duration of 10 h [2-24]. Norepinephrine was most often started in the operating room before cardiopulmonary bypass. The multiple regression logistic analysis identified several modifiable (haematocrit, maintenance of beta-blocker, cardiopulmonary bypass time, glucose-insulin-potassium, Custodiol cardioplegia, Delnido cardioplegia, and fibrinogen transfusion) and non-modifiable factors (age, ASA score, chronic high blood pressure, coronary disease, dyslipidemia, right ventricular dysfunction, left ventricular dysfunction, active endocarditis, and valvular aortic surgery) associated with norepinephrine use. Mortality, morbidity (neurological and renal complications, death) and length of stay in the ICU were higher in patients treated with norepinephrine.

CONCLUSION

Norepinephrine is often used in cardiac surgical patients but for <24 h with a low dose. Many preoperative and surgical factors are associated with norepinephrine use. Patients supported by norepinephrine have a higher incidence of major postoperative events.

Review of Postoperative Care for Heart Transplant Recipients

The early postoperative management strategies after heart transplantation include optimizing the function of the denervated heart, correcting the causes of hemodynamic instability, and initiating and maintaining immunosuppressive therapy, allograft rejection surveillance, and prophylaxis against infections caused by immunosuppression. The course of postoperative support is influenced by the quality of allograft myocardial protection prior to implantation and reperfusion, donor-recipient heart size matching, surgical technique of orthotopic heart transplantation, and patient factors (eg, preoperative condition, immunologic compatibility, postoperative vasomotor tone, severity and reversibility of pulmonary vascular hypertension, pulmonary function, mediastinal blood loss, and end-organ perfusion). This review provides an overview of the early postoperative care of recipients and includes a brief description of the surgical techniques for orthotopic heart transplantation.