Pulmonary vascular and right ventricular dysfunction in adult critical care: current and emerging options for management: a systematic literature review

Association of right ventricular dysfunction and pulmonary hypertension with adverse 30-day outcomes in COVID-19 patients

Background

Cardiac manifestations in COVID-19 are multifactorial and are associated with increased mortality. The clinical utility and prognostic value of echocardiography in COVID-19 inpatients is not clearly defined. We aim to identify echocardiographic parameters that are associated with 30-day clinical outcomes secondary to COVID-19 hospitalization.

Methods

This retrospective cohort study was conducted in a large tertiary hospital in New York City during the COVID-19 pandemic. It included 214 adult inpatients with a laboratory-confirmed diagnosis of COVID-19 by reverse transcriptase polymerase chain reaction assay (RT-PCR) for SARS-CoV-2 on nasopharyngeal swab and had a transthoracic echocardiogram performed during the index hospitalization. Primary outcome was 30-day all-cause inpatient mortality. Secondary outcomes were 30-day utilization of mechanical ventilator support, vasopressors, or renal replacement therapy.

Results

Mild right ventricular systolic dysfunction (odds ratio (OR): 3.51, 95% confidence interval (CI): 1.63–7.57, p = 0.001), moderate to severe right ventricular systolic dysfunction (OR: 7.30, 95% CI: 2.20–24.25, p = 0.001), pulmonary hypertension (OR: 5.39, 95% CI: 1.96–14.86, p = 0.001), and moderate to severe tricuspid regurgitation (OR: 3.92, 95% CI: 1.71–9.03, p = 0.001) were each associated with increased odds of 30-day all-cause inpatient mortality. Pulmonary hypertension and moderate to severe right ventricular dysfunction were each associated with increased odds of 30-day utilization of mechanical ventilator support and vasopressors.

Conclusions

Right ventricular dysfunction, pulmonary hypertension, and moderate to severe tricuspid regurgitation were associated with increased odds for 30-day inpatient mortality. This study highlights the importance of echocardiography and its clinical utility and prognostic value for evaluating hospitalized COVID-19 patients.

Intensive care management of right ventricular failure and pulmonary hypertension crises

Pulmonary hypertension (PH), an often unrelenting disease that carries with it significant morbidity and mortality, affects not only the pulmonary vasculature but, in turn, the right ventricle as well. The survival of patients with PH is closely related to the right ventricular function. Therefore, having an understanding of how to manage right ventricular failure (RVF) and acute pulmonary hypertensive crises is imperative for clinicians who encounter these patients. This review addresses the management of these patients in detail, addressing: (a) the pathophysiology of RVF, (b) intensive care monitoring of these patients in the intensive care unit, (c) imaging of the right ventricle, (d) intubation and mechanical ventilation, (e) inotrope and vasopressor selection, (f) pulmonary vasodilator use, (g) interventional and surgical procedures for the acutely failing right ventricle, and (h) mechanical support for RVF.

Case Report of a 23-year-old first gravida presenting with breathlessness and oxygen saturation of 80

Central principles are interdisciplinary teamwork and keeping the ratio between pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) balanced to avoid vicious circle with right heart failure and hypoxia.

Critical Care of Patients With Cardiopulmonary Complications of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease defined by the presence of aberrant granulomas affecting various organs. Due to its multisystem involvement, care of patients with established sarcoidosis becomes challenging, especially in the intensive care setting. While the lungs are typically involved, extrapulmonary manifestations also occur either concurrently or exclusively within a significant proportion of patients, complicating diagnostic and management decisions. The scope of this review is to focus on what considerations are necessary in the evaluation and management of patients with known sarcoidosis and their associated complications within a cardiopulmonary and critical care perspective.

Assessment of Right Ventricular Function With CT and Echocardiography in Patients With Severe Acute Respiratory Distress Syndrome on Extracorporeal Membrane Oxygenation

Supplemental Digital Content is available in the text.

Changes in right ventricular size and function are frequently observed in patients with severe acute respiratory distress syndrome. The majority of patients who receive venovenous extracorporeal membrane oxygenation undergo chest CT and transthoracic echocardiography. The aims of this study were to compare the use of CT and transthoracic echocardiography to evaluate the right ventricular function and to determine the prevalence of acute cor pulmonale in this patient population.

Vasopressor Therapy in Cardiac Surgery-An Experts' Consensus Statement

Hemodynamic conditions with reduced systemic vascular resistance commonly are observed in patients undergoing cardiac surgery and may range from moderate reductions in vascular tone, as a side effect of general anesthetics, to a profound vasodilatory syndrome, often referred to as vasoplegic shock. Therapy with vasopressors is an important pillar in the treatment of these conditions. There is limited guidance on the appropriate choice of vasopressors to restore and optimize systemic vascular tone in patients undergoing cardiac surgery. A panel of experts in the field convened to develop statements and evidence-based recommendations on clinically relevant questions on the use of vasopressors in cardiac surgical patients, using a critical appraisal of the literature following the GRADE system and a modified Delphi process. The authors unanimously and strongly recommend the use of norepinephrine and/or vasopressin for restoration and maintenance of systemic perfusion pressure in cardiac surgical patients; despite that, the authors cannot recommend either of these drugs with respect to the risk of ischemic complications. The authors unanimously and strongly recommend against using dopamine for treating post-cardiac surgery vasoplegic shock and against using methylene blue for purposes other than a rescue therapy. The authors unanimously and weakly recommend that clinicians consider early addition of a second vasopressor (norepinephrine or vasopressin) if adequate vascular tone cannot be restored by a monotherapy with either norepinephrine or vasopressin and to consider using vasopressin as a first-line vasopressor or to add vasopressin to norepinephrine in cardiac surgical patients with pulmonary hypertension or right-sided heart dysfunction.

Treatment of right ventricular dysfunction and heart failure in pulmonary arterial hypertension

Right heart dysfunction and failure is the principal determinant of adverse outcomes in patients with pulmonary arterial hypertension (PAH). In addition to right ventricular (RV) dysfunction, systemic congestion, increased afterload and impaired myocardial contractility play an important role in the pathophysiology of RV failure. The behavior of the RV in response to the hemodynamic overload is primarily modulated by the ventricular interaction and its coupling to the pulmonary circulation. The presentation can be acute with hemodynamic instability and shock or chronic producing symptoms of systemic venous congestion and low cardiac output. The prognostic factors associated with poor outcomes in hospitalized patients include systemic hypotension, hyponatremia, severe tricuspid insufficiency, inotropic support use and the presence of pericardial effusion. Effective therapeutic management strategies involve identification and effective treatment of the triggering factors, improving cardiopulmonary hemodynamics by optimization of volume to improve diastolic ventricular interactions, improving contractility by use of inotropes, and reducing afterload by use of drugs targeting pulmonary circulation. The medical therapies approved for PAH act primarily on the pulmonary vasculature with secondary effects on the right ventricle. Mechanical circulatory support as a bridge to transplantation has also gained traction in medically refractory cases. The current review was undertaken to summarize recent insights into the evaluation and treatment of RV dysfunction and failure attributable to PAH.

Anesthesia for Pregnant Women with Pulmonary Hypertension

Despite advances in the therapy for pulmonary hypertension over the past decades, the prognosis of pregnant patients with pulmonary hypertension remains poor, with high maternal mortality. This poses a particular challenge for the mother and her medical team. In the present review, the authors have updated the classification and definition of pulmonary hypertension, summarized the current knowledge with regard to perioperative management and anesthesia considerations for these patients, and stressed the importance of a "pregnancy heart team" to improve long-term outcomes of pregnant women with pulmonary hypertension.

The interaction between arterial oxygenation and carbon dioxide and hospital mortality following out of hospital cardiac arrest: a cohort study

BACKGROUND

Outcomes following out of hospital cardiac arrest (OHCA) are poor. The optimal arterial oxygen and carbon dioxide (PaCO₂) levels for managing patients following OHCA are unknown. We hypothesized that abnormalities in arterial oxygenation (PaO₂/FiO₂ ratio or PaO₂) and PaCO₂ would be associated with hospital mortality following OHCA. We hypothesized that PaCO₂ would significantly modify the oxygenation-mortality relationship.

METHODS

This was an observational cohort study using data from OHCA survivors admitted to adult critical care units in England, Wales and Northern Ireland from 2011 to 2018. Logistic regression analyses were performed to assess the relationship between hospital mortality and oxygenation and PaCO₂.

RESULTS

The analysis included 23,625 patients. In comparison with patients with a PaO₂/FiO₂ > 300 mmHg, those with a PaO₂/FiO₂ ≤ 100 mmHg had higher mortality (adjusted OR, 1.79; 95% CI, 1.48 to 2.15; P < 0.001). In comparison to hyperoxemia (PaO₂ > 100 mmHg), patients with hypoxemia (PaO₂ < 60 mmHg) had higher mortality (adjusted OR, 1.34; 95% CI, 1.10 to 1.65; P = 0.004). In comparison with normocapnia, hypercapnia was associated with lower mortality. Hypocapnia (PaCO2 ≤ 35 mmHg) was associated with higher mortality (adjusted OR, 1.91; 95% CI, 1.63 to 2.24; P < 0.001). PaCO₂ modified the PaO₂/FiO₂-mortality and PaO₂-mortality relationships, though these relationships were complex. Patients who were both hyperoxic and hypercapnic had the lowest mortality.

CONCLUSIONS

Low PaO₂/FiO₂ ratio, hypoxemia and hypocapnia are associated with higher mortality following OHCA. PaCO₂ modifies the relationship between oxygenation and mortality following OHCA; future studies examining this interaction are required.

Riociguat, sildenafil and inhaled nitric oxide reduces pulmonary vascular resistance and improves right ventricular function in a porcine model of acute pulmonary embolism

BACKGROUND

Pulmonary vasodilators as add-on to current treatment strategies in acute pulmonary embolism may improve right ventricular unloading and hence improve patient outcome. We aimed to investigate whether stimulation of the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway with riociguat, sildenafil or inhaled NO causes pulmonary vasodilation and improves right ventricular function in a porcine model of acute intermediate risk pulmonary embolism.

METHODS

Two large autologous blood clots were administered to the pulmonary circulation of 28 pigs (60 kg). Animals were randomized to four increasing, clinically equivalent doses of riociguat (n=6), sildenafil (n=6), inhaled NO (n=6) or vehicle (n=6). Sham animals (n=4) did not receive pulmonary embolism or treatment. Haemodynamic responses were evaluated at baseline, after pulmonary embolism and after each dose using invasive pressure measurements, transoesophageal echocardiography, respiratory parameters and blood analysis.

RESULTS

Pulmonary embolism caused a three-fold increase in pulmonary vascular resistance compared with baseline (pulmonary embolism: 352±29 vs. baseline: 107±6 dynes, p<0.0001). All treatments lowered pulmonary vascular resistance compared with vehicle (riociguat: -158±35, sildenafil: -224±35, inhaled NO: -156±35 dynes, p<0.0001). Sildenafil, but neither inhaled NO nor riociguat, caused a decrease in systemic vascular resistance (sildenafil 678±41 vs. vehicle 1081±93 dynes, p=0.02) and increased cardiac output (sildenafil 8.8±0.8 vs. vehicle: 5.9±0.2 L/min, p<0.001). Systemic blood pressure was unaltered in all treatment groups.

CONCLUSION

Stimulation of the NO-sGC-cGMP pathway by riociguat, sildenafil and inhaled NO reduces pulmonary vascular resistance in a porcine model of acute pulmonary embolism without lowering systemic blood pressure.

Terlipressin Increases Systemic and Lowers Pulmonary Arterial Pressure in Experimental Acute Pulmonary Embolism

OBJECTIVES

We investigated whether the vasopressin-analog, terlipressin induces systemic vasoconstriction and pulmonary vasodilation in a porcine model of acute pulmonary embolism.

DESIGN

Controlled, animal study.

SETTING

Tertiary medical center research laboratory.

SUBJECTS

Female pigs (n = 12, Cross of Land Race, Duroc, and Yorkshire ~ 60 kg).

INTERVENTIONS

Acute pulmonary embolism was induced by administration of three large autologous emboli. Animals then received four increasing doses of either terlipressin (n = 6) or vehicle (n = 6).

MEASUREMENTS AND MAIN RESULTS

Effects were evaluated in vivo at baseline, after pulmonary embolism and after each dose by invasive hemodynamic measures, transesophageal echocardiography, and blood analysis. Isolated pulmonary arteries were evaluated ex vivo in a myograph. Pulmonary embolism caused a four-fold increase in pulmonary vascular resistance (p < 0.0001) and a two-fold increase in mean pulmonary arterial pressure (p < 0.0001) compared with baseline. Terlipressin increased mean systemic blood pressure (28 ± 5 mm Hg; p < 0.0001) and systemic vascular resistance (1,320 ± 143 dynes; p < 0.0001) compared with vehicle. In the pulmonary circulation, terlipressin decreased mean pulmonary arterial pressure (-6.5 ± 1.8 mm Hg; p = 0.005) and tended to decrease pulmonary vascular resistance (-83 ± 33 dynes; p = 0.07). Terlipressin decreased cardiac output (-2.5 ± 0.5 L/min; p < 0.0001) and increased plasma lactate (2.7 ± 0.2 mmol/L; p < 0.0001), possibly indicating systemic hypoperfusion. A biomarker of cerebral ischemia, S100b, remained unchanged, suggesting preserved cerebral perfusion (0.17 ± 0.11 µg/L; p = 0.51). Ex vivo, terlipressin relaxed pulmonary and constricted mesenteric arteries.

CONCLUSIONS

Terlipressin caused systemic vasoconstriction and pulmonary vasodilation in a porcine in vivo model of acute pulmonary embolism and vasorelaxation in isolated pulmonary arteries. Despite positive vascular effects, cardiac output declined and plasma lactate increased probably due to a predominantly systemic vasoconstrictor effect of terlipressin. These findings should warrant careful translation to the clinical setting and does not suggest routine use in acute pulmonary embolism.

[Management of right ventricular failure in pulmonary vascular diseases]

Right ventricular failure (RVF) is a common cause of admission to the intensive care unit and its presence is a major prognostic factor in acute pulmonary embolism (PE) and chronic pulmonary hypertension (PH). RVF results from an incapacity of the RV to adapt to an increase in afterload so it can become critical in acute PE and chronic PH. The presence of RVF in cases of acute PE with haemodynamic instability is an indication for thrombolytic therapy. RVF represents the most common cause of death in chronic PH. Factors triggering RV failure in PH, such as infection, PE, arrhythmias, or unplanned withdrawal of pulmonary arterial hypertension (PAH)-targeted therapy, have to be considered and treated if identified. However, RVF may also represent progression to end-stage disease. The management of RVF in patients with PH requires expertise and consists of optimization of fluid balance (with diuretics), cardiac output (with inotropic support such as dobutamine), perfusion pressure (with norepinephrine), and reduction of RV afterload with PAH-targeted therapies. Extracorporeal life support, lung transplantation or heart-lung transplantation should be considered in cases of refractory RVF in eligible patients.

The Right Ventricle-You May Forget it, but It Will Not Forget You

Right ventricular (RV) dysfunction and failure are common and often overlooked causes of perioperative deterioration and adverse outcomes. Due to its unique pathophysiologic underpinnings, RV failure often does not respond to typical therapeutic measures such as volume resuscitation and often worsens when therapy is escalated and mechanical ventilation is begun, with a danger of irreversible cardiovascular collapse and death. The single most important factor in improving outcomes in the context of RV failure is anticipating and recognizing it. Once established, a vicious circle of systemic hypotension, and RV ischemia and dilation is set in motion, rapidly spiraling down into a state of shock culminating in multi-organ failure and ultimately death. Therapy of RV failure must focus on rapidly reestablishing RV coronary perfusion, lowering pulmonary vascular resistance and optimizing volemia. In parallel, underlying reversible causes should be sought and if possible treated. In all stages of diagnostics and therapy, echocardiography plays a central role. In severe cases of RV dysfunction there remains a role for the use of the pulmonary artery catheter. When these mostly simple measures are undertaken in a timely fashion, the spiral of death of RV failure can often be broken or even prevented altogether.

Association between Left Ventricular Systolic Dysfunction and Mortality in Patients with Septic Shock

BACKGROUND

The impact of myocardial damage on the prognosis of patients with septic shock is not clearly elucidated because complex hemodynamic changes in sepsis obscure the direct relationship. We evaluated left ventricular (LV) conditions that reflect myocardial damage independently from hemodynamic changes in septic shock and their influence on the prognosis of patients.

METHODS

We retrospectively enrolled 208 adult patients who were admitted to the intensive care unit and underwent echocardiography within 7 days from the diagnosis of septic shock. Patients who were previously diagnosed with structural heart disease or coronary artery disease were excluded. Left ventricular ejection fraction (LVEF) was divided into four categories: normal, ≥ 50%; mild, ≥ 40%; moderate, ≥ 30%; and severe dysfunction, < 30%. Wall motion impairment was categorized into the following patterns: normal, diffuse, ballooning, and focal.

RESULTS

There were 141 patients with normal LVEF. Among patients with impaired LV wall motion, the diffuse pattern was the most common (34 patients), followed by the ballooning pattern (26 patients). Finally, 102 patients died, and in-hospital mortality was significantly higher in patients with severe LV systolic dysfunction (hazard ratio [HR], 1.97; 95% confidence interval [CI], 1.04-3.75; P = 0.039) and in patients with diffuse pattern of LV wall motion impairment (HR, 2.28; 95% CI, 1.19-4.36; P = 0.013) than in those with a normal LV systolic function.

CONCLUSION

Severe LV systolic dysfunction and diffuse pattern of LV wall motion impairment significantly affected in-hospital mortality in patients with septic shock. Conventional echocardiographic evaluation provides adequate information on the development of myocardial damage and accurately predicts the prognosis of patients with septic shock.

Cardiogenic Shock: Reflections at the Crossroad Between Perfusion, Tissue Hypoxia, and Mitochondrial Function

Cardiogenic shock is classically defined by systemic hypotension with evidence of hypoperfusion and end organ dysfunction. In modern practice, however, these metrics often incompletely describe cardiogenic shock because patients present with more advanced cardiovascular disease and greater degrees of multiorgan dysfunction. Understanding how perfusion, congestion, and end organ dysfunction contribute to hypoxia at the cellular level are central to the diagnosis and management of cardiogenic shock. Although, in clinical practice, increased lactate level is often equated with hypoxia, several other factors might contribute to an elevated lactate level including mitochondrial dysfunction, impaired hepatic and renal clearance, as well as epinephrine use. To this end, we present the evidence underlying the value of lactate to pyruvate ratio as a potential discriminator of cellular hypoxia. We will then discuss the physiological implications of hypoxia and congestion on hepatic, intestinal, and renal physiology. Organ-specific susceptibility to hypoxia is presented in the context of their functional architecture. We discuss how the concepts of contractile reserve, fluid responsiveness, tissue oxygenation, and cardiopulmonary interactions can help personalize the management of cardiogenic shock. Finally, we highlight the limitations of using lactate for tailoring therapy in cardiogenic shock.

Inflammatory Basis of Pulmonary Arterial Hypertension: Implications for Perioperative and Critical Care Medicine

Patients with pulmonary arterial hypertension have exceptionally high perioperative risk. This review summarizes the clinical presentation and therapies for pulmonary arterial hypertension, and it highlights evidence for inflammation as a driver of disease pathogenesis and a therapeutic target.

Use of Levosimendan in Intensive Care Unit Settings: An Opinion Paper

Levosimendan is an inodilator that promotes cardiac contractility primarily through calcium sensitization of cardiac troponin C and vasodilatation via opening of adenosine triphosphate–sensitive potassium (K_ATP) channels in vascular smooth muscle cells; the drug also exerts organ-protective effects through a similar effect on mitochondrial K_ATP channels. This pharmacological profile identifies levosimendan as a drug that may have applications in a wide range of critical illness situations encountered in intensive care unit medicine: hemodynamic support in cardiogenic or septic shock; weaning from mechanical ventilation or from extracorporeal membrane oxygenation; and in the context of cardiorenal syndrome. This review, authored by experts from 9 European countries (Austria, Belgium, Czech republic, Finland, France, Germany, Italy, Sweden, and Switzerland), examines the clinical and experimental data for levosimendan in these situations and concludes that, in most instances, the evidence is encouraging, which is not the case with other cardioactive and vasoactive drugs routinely used in the intensive care unit. The size of the available studies is, however, limited and the data are in need of verification in larger controlled trials. Some proposals are offered for the aims and designs of these additional studies.

Biomarkers and Right Ventricular Dysfunction

Right ventricular failure is common in critically ill patients, as it frequently results from pulmonary embolism or pulmonary hypertension, and can complicate sepsis and the acute respiratory distress syndrome. Right ventricular dysfunction can be challenging to manage and is associated with poor outcomes in this wide array of disease. Laboratory biomarkers are rapid, noninvasive, accurate, and widely available and thus are useful in the diagnosis and management of right ventricular dysfunction in the critically ill patient. This article discusses the pathophysiology of right ventricular failure and reviews the applications of commonly used biomarkers in right ventricular dysfunction in critical care.

Inhaled prostacyclin for the prevention of increased pulmonary vascular resistance in cemented hip hemiarthroplasty-A randomised trial

BACKGROUND

Bone cementation may cause pulmonary vasoconstriction and ventilation/perfusion abnormalities in patients undergoing cemented hip hemiarthroplasty. In this randomised trial, we tested the hypothesis that intra-operative inhalation of prostacyclin could attenuate the increase in pulmonary vascular resistance index (PVRI, primary endpoint) when compared to inhaled saline in this group of patients.

METHODS

Twenty-two patients with displaced femoral neck fractures were allocated to receive inhaled aerosolised prostacyclin (20 ng/kg/min) (n = 11) or inhaled saline (NaCl, 9 mg/mL) (n = 11). All patients received total intravenous anaesthesia and were catheterised with radial and pulmonary artery fast response thermodilution catheters, for measurements of arterial and pulmonary arterial pressures, cardiac output, right ventricular ejection fraction and effective pulmonary arterial elastance. Haemodynamic measurements were performed after induction of anaesthesia, during surgery before and immediately after bone cementation and prosthesis insertion, 10 and 20 min after insertion and during skin closure.

RESULTS

During the surgical procedure, PVRI increased both in the saline (44%, P < 0.001) and the prostacyclin (36%, P = 0.019) groups, with a less pronounced increase in the prostacyclin group (P = 0.031). Effective pulmonary arterial elastance increased both in the saline (44%, P < 0.001) and the prostacyclin groups (29%, P = 0.032), with a trend for a less pronounced increase in the prostacyclin group (P = 0.084). Right ventricular ejection fraction decreased significantly in both groups with no difference between the groups.

CONCLUSION

Inhalation of prostacyclin attenuates the increase in pulmonary vascular resistance in patients undergoing cemented hip hemiarthroplasty and could potentially attenuate/prevent haemodynamic instability induced by an increase in right ventricular afterload seen in this procedure.

A 44-Year-Old Woman With Sudden Breathlessness, Tightness in Chest, and Hypotension After Extubation in the Early Postoperative Period After Liver Transplantation

CASE PRESENTATION

A 44-year-old woman with Child-Pugh class C cirrhosis due to primary biliary cirrhosis and mild portopulmonary syndrome received a liver transplant. Her basal catheterization showed a mean pulmonary arterial pressure (mPAP) of 28 mm Hg, pulmonary artery occlusion pressure (PAOP) of 8 mm Hg, pulmonary vascular resistance (PVR) of 307 dynes.s.cm^-5, and a cardiac output of 5.2 L/min. The echocardiogram did not reveal right ventricular dilatation (mid-diameter of 34 mm). In surgery, hemodynamic assessment showed an mPAP of 25 mm Hg, PAOP of 6 mm Hg, PVR of 262 dynes.s.cm^-5 and cardiac output of 5.8 L/min. During the anhepatic period, the patient required norepinephrine (0.4 μg/kg/min) but had no complications during reperfusion; throughout surgery, her mPAP was never > 30 mm Hg. At the end of surgery, the brain natriuretic peptide level was 66 pg/mL (< 100 pg/mL). One day following transplantation, the patient remained hemodynamically stable and was therefore weaned from mechanical ventilation. However, 6 h following extubation, she reported breathlessness and tightness in chest, and developed sudden arterial hypotension, oxygen desaturation, and oliguria.

Dysrhythmias and heart failure complicating acute myocardial infarction: An emergency medicine review

INTRODUCTION

Patients with acute myocardial infarction (AMI) may suffer several complications after the acute event, including dysrhythmias and heart failure (HF). These complications place patients at risk for morbidity and mortality.

OBJECTIVE

This narrative review evaluates literature and guideline recommendations relevant to the acute emergency department (ED) management of AMI complicated by dysrhythmia or HF, with a focus on evidence-based considerations for ED interventions.

DISCUSSION

Limited evidence exists for ED management of dysrhythmias in AMI due to relatively low prevalence and frequent exclusion of patients with active cardiac ischemia from clinical studies. Management decisions for bradycardia in the setting of AMI are determined by location of infarction, timing of the dysrhythmia, rhythm assessment, and hemodynamic status of the patient. Atrial fibrillation is common in the setting of AMI, and caution is warranted in acute rate control for rapid ventricular rate given the possibility of compensation for decreased ventricular function. Regular wide complex tachycardia in the setting of AMI should be managed as ventricular tachycardia with electrocardioversion in the majority of cases. Management directed towards HF from left ventricular dysfunction in AMI consists of noninvasive positive pressure ventilation, nitroglycerin therapy, and early cardiac catheterization. Norepinephrine is the first line vasopressor for patients with cardiogenic shock and hypoperfusion on clinical examination. Early involvement of a multi-disciplinary team is recommended when caring for patients in cardiogenic shock.

CONCLUSIONS

This review discusses considerations of ED management of dysrhythmias and HF associated with AMI.

Critical Care of Patients After Pulmonary Thromboendarterectomy

Pulmonary thromboendarterectomy (PTE) remains the only curative surgery for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Postoperative intensive care unit care challenges providers with unique disease physiology, operative sequelae, and the potential for detrimental complications. Central concerns in patients with CTEPH immediately after PTE relate to neurologic, pulmonary, hemodynamic, and hematologic aspects. Institutional experience in critical care for the CTEPH population, a multidisciplinary team approach, patient risk assessment, and integration of current concepts in critical care determine outcomes after PTE surgery. In this review, the authors will focus on specific aspects unique to this population, with integration of current available evidence and future directions. The goal of this review is to provide the cardiac anesthesiologist and intensivist with a comprehensive understanding of postoperative physiology, potential complications, and contemporary intensive care unit management immediately after pulmonary endarterectomy.

Pulmonary haemodynamics and right ventricular function in cemented vs uncemented total hip arthroplasty-A randomized trial

BACKGROUND

Bone cement implantation syndrome (BCIS) is a feared complication in orthopaedic surgery with a huge impact on post-operative morbidity. In this randomized trial, we evaluated the effects of bone cement on pulmonary and systemic haemodynamics in patients receiving either cemented or uncemented hip arthroplasty for isolated femoral neck fracture.

METHODS

Twenty-two patients were randomized to receive either cemented (n = 10) or uncemented (n = 12) total hip arthroplasty. Surgery was performed under total intravenous anaesthesia in the lateral position. All patients were catheterized with radial- and pulmonary artery catheters, for continuous measurements of mean arterial pressure (MAP), pulmonary arterial pressure (PAP), cardiac output, right ventricular (RV) end-diastolic volume (RVEDV) and RV ejection fraction (RVEF). Haemodynamic measurements and blood gas analyses were performed after induction of anaesthesia, during surgery before and immediately after bone cementation and prosthesis insertion, 10 and 20 minutes after insertion and during skin closure.

RESULTS

Pulmonary vascular resistance index (PVRI) increased during and after prosthesis insertion by 45% and 20% in the cemented and uncemented group, respectively (P < 0.005). Systolic and mean PAP increased by 18% and 17% in the cemented group, which was not seen in the uncemented group (P < 0.001). There was a trend for a more pronounced fall in RVEF in the cemented group, while there were no differences in cardiac output or stroke volume between groups.

CONCLUSION

The use of bone cement in total hip arthroplasty increases pulmonary vascular resistance and the afterload of the RV with potentially negative effects on RV performance.

Pulmonary Hypertension in Intensive Care Units: An Updated Review

Pulmonary hypertension (PH) is a condition associated with high morbidity and mortality. Patients with PH who require critical care usually have severe right ventricular (RV) dysfunction. Although different groups of PH have different etiologies, pulmonary vascular dysfunction is common in these groups. PH can lead to increased pulmonary artery pressure, which can ultimately cause RV failure. Clinicians should be familiar with the presentations of this disease and diagnostic tools. The contributing factors, if present (e.g., sepsis), and coexisting conditions (e.g., arrhythmias) should be identified and addressed accordingly. The preload should be optimized by fluid administration, diuretics, and dialysis, if necessary. On the other hand, the RV afterload should be reduced to improve the RV function with pulmonary vasodilators, such as prostacyclins, inhaled nitric oxide, and phosphodiesterase type 5 inhibitors, especially in group 1 PH. Inotropes are also used to improve RV contractility, and if inadequate, use of ventricular assist devices and extracorporeal life support should be considered in suitable candidates. Moreover, vasopressors should be used to maintain systemic blood pressure, albeit cautiously, as they increase the RV afterload. Measures should be also taken to ensure adequate oxygenation. However, mechanical ventilation is avoided in RV failure. In this study, we reviewed the pathophysiology, manifestations, diagnosis, monitoring, and management strategies of PH, especially in intensive care units.

Vasoactive Agent Use in Septic Shock: Beyond First-Line Recommendations

Septic shock is a life-threatening disorder associated with high mortality rates requiring rapid identification and intervention. Vasoactive agents are often required to maintain goal hemodynamics and preserve tissue perfusion. However, guidance regarding the proper administration of adjunct agents for the management of septic shock is limited in patients who are refractory to norepinephrine. This review summarizes vasopressor agents and describes the nuanced application of these agents in patients with septic shock, specifically focusing on clinical scenarios with limited guidance including patients who are nonresponsive to first-line agents and individuals with mixed shock states, tachyarrhythmias, obesity, valvular abnormalities, or other comorbid conditions.

Effects of vasopressin during a pulmonary hypertensive crisis induced by acute hypoxia in a rat model of pulmonary hypertension

BACKGROUND

A pulmonary hypertensive crisis (PHC) can be a life-threatening condition. We established a PHC model by exposing rats with monocrotaline (MCT)-induced pulmonary hypertension to acute hypoxia, and investigated the effects of vasopressin, phenylephrine, and norepinephrine on the PHC.

METHODS

Four weeks after MCT 60 mg kg^-1 administration i.v., right ventricular systolic pressure (RVSP), systolic BP (SBP), mean BP (MBP), cardiac index (CI), and pulmonary vascular resistance index (PVRI) were measured. PHC defined as an RVSP exceeding or equal to SBP was induced by changing the fraction of inspiratory oxygen to 0.1. Rats were subsequently treated by vasopressin, phenylephrine, or norepinephrine, followed by assessment of systemic haemodynamics, isometric tension of femoral and pulmonary arteries, cardiac function, blood gas composition, and survival.

RESULTS

PHC was associated with increased RV dilatation and paradoxical septal motion. Vasopressin increased MBP [mean (standard error)] from 52.6 (3.8) to 125.0 (8.9) mm Hg and CI from 25.4 (2.3) to 40.6 (1.8) ml min^-1 100 g^-1 while decreasing PVRI. Vasopressin also improved RV dilatation, oxygenation, and survival in PHC. In contrast, phenylephrine increased MBP from 54.8 (2.3) to 96.8 (3.2) mm Hg without improving cardiac pump function. Norepinephrine did not alter MBP. Vasopressin contracted femoral but not pulmonary arteries, whereas phenylephrine contracted both arterial beds. Hence, improvements with vasopressin in PHC might be associated with decreased PVRI and selective systemic vasoconstriction.

CONCLUSIONS

In this rat model of a PHC, vasopressin, but not phenylephrine or norepinephrine, resulted in better haemodynamic and vascular recovery.

Intensive care, right ventricular support and lung transplantation in patients with pulmonary hypertension

Intensive care of patients with pulmonary hypertension (PH) and right-sided heart failure includes treatment of factors causing or contributing to heart failure, careful fluid management, and strategies to reduce ventricular afterload and improve cardiac function. Extracorporeal membrane oxygenation (ECMO) should be considered in distinct situations, especially in candidates for lung transplantation (bridge to transplant) or, occasionally, in patients with a reversible cause of right-sided heart failure (bridge to recovery). ECMO should not be used in patients with end-stage disease without a realistic chance for recovery or for transplantation. For patients with refractory disease, lung transplantation remains an important treatment option. Patients should be referred to a transplant centre when they remain in an intermediate- or high-risk category despite receiving optimised pulmonary arterial hypertension therapy. Meticulous peri-operative management including the intra-operative and post-operative use of ECMO effectively prevents graft failure. In experienced centres, the 1-year survival rates after lung transplantation for PH now exceed 90%.

Ceramide and Regulation of Vascular Tone

In addition to playing a role as a structural component of cellular membranes, ceramide is now clearly recognized as a bioactive lipid implicated in a variety of physiological functions. This review aims to provide updated information on the role of ceramide in the regulation of vascular tone. Ceramide may induce vasodilator or vasoconstrictor effects by interacting with several signaling pathways in endothelial and smooth muscle cells. There is a clear, albeit complex, interaction between ceramide and redox signaling. In fact, reactive oxygen species (ROS) activate different ceramide generating pathways and, conversely, ceramide is known to increase ROS production. In recent years, ceramide has emerged as a novel key player in oxygen sensing in vascular cells and mediating vascular responses of crucial physiological relevance such as hypoxic pulmonary vasoconstriction (HPV) or normoxic ductus arteriosus constriction. Likewise, a growing body of evidence over the last years suggests that exaggerated production of vascular ceramide may have detrimental effects in a number of pathological processes including cardiovascular and lung diseases.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

Pulmonary hypertension and cardiac anesthesia: Anesthesiologist's perspective

Perioperative management of pulmonary hypertension remains one of the most challenging scenarios during cardiac surgery. It is associated with high morbidity and mortality due to right ventricular failure, arrhythmias, myocardial ischemia, and intractable hypoxia. Therefore, this review article is intended toward the anesthetic considerations in the perioperative period, with particular emphasis on the selection of technique and choice of anesthesia with maintenance, anesthetic drugs, and the recent intraoperative recommendations for prevention and treatment of pulmonary hypertensive crisis.

Positive Pressure Ventilation in the Cardiac Intensive Care Unit

Contemporary cardiac intensive care units (CICUs) provide care for an aging and increasingly complex patient population. The medical complexity of this population is partly driven by an increased proportion of patients with respiratory failure needing noninvasive or invasive positive pressure ventilation (PPV). PPV often plays an important role in the management of patients with cardiogenic pulmonary edema, cardiogenic shock, or cardiac arrest, and those undergoing mechanical circulatory support. Noninvasive PPV, when appropriately applied to selected patients, may reduce the need for invasive mechanical PPV and improve survival. Invasive PPV can be lifesaving, but has both favorable and unfavorable interactions with left and right ventricular physiology and carries a risk of complications that influence CICU mortality. Effective implementation of PPV requires an understanding of the underlying cardiac and pulmonary pathophysiology. Cardiologists who practice in the CICU should be proficient with the indications, appropriate selection, potential cardiopulmonary interactions, and complications of PPV.

Right Ventricular Function in Left Heart Disease

Right ventricular (RV) function is an independent prognostic factor for short- and long-term outcomes in cardiac surgical patients. Patients with mitral valve (MV) disease are at increased risk of RV dysfunction before and after MV operations. Yet RV function is not part of criteria for decision making or risk stratification in this setting. The role of MV disease in the development of pulmonary hypertension (PHTN) and the ultimate impact of PHTN on RV function have been well described. Nonetheless, there are other mechanisms by which MV disease and MV surgery affect RV performance. Research suggests that PHTN may not be the most important determinant of RV dysfunction. Both RV dysfunction and PHTN have independent prognostic significance. This review explores the unique anatomic and functional features of the RV and the pathophysiologic and prognostic implications of RV dysfunction in patients with MV disease in the perioperative period.

Coronary artery bypass graft surgery complications: A review for emergency clinicians

INTRODUCTION

Coronary artery bypass graft (CABG) surgery remains a high-risk procedure, and many patients require emergency department (ED) management for complications after surgery.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of post-CABG surgery complications.

DISCUSSION

While there has been a recent decline in all cardiac revascularization procedures, there remains over 200,000 CABG surgeries performed in the United States annually, with up to 14% of these patients presenting to the ED within 30 days of discharge with post-operative complications. Risk factors for perioperative mortality and morbidity after CABG surgery can be divided into three categories: patient characteristics, clinician characteristics, and postoperative factors. Emergency physicians will be faced with several postoperative complications, including sternal wound infections, pneumonia, thromboembolic phenomena, graft failure, atrial fibrillation, pulmonary hypertension, pericardial effusion, strokes, renal injury, gastrointestinal insults, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the primary surgical team is needed, which improves patient outcomes. This review provides several guiding principles for management of acute complications. Understanding these complications and an approach to the management of hemodynamic instability is essential to optimizing patient care.

CONCLUSIONS

Postoperative complications of CABG surgery can result in significant morbidity and mortality. Physicians must rapidly diagnose these conditions while evaluating for other diseases. Early surgical consultation is imperative, as is optimizing the patient's hemodynamics, including preload, heart rate, cardiac rhythm, contractility, and afterload.

Atrial septal defects and pulmonary arterial hypertension

Atrial septal defects (ASD) are a common congenital heart defect. The majority of patient with ASDs often follow an uncomplicated course of events. However, a proportion of patients with ASDs, may have their condition complicated by pulmonary hypertension (PH), with a subsequent significant impact on management, morbidity and mortality. The presence of PH, influences the suitability for defect closure. In this review we describe the different types of ASDs, the classification of PH related to congenital heart disease (CHD), when ASD closure is contraindicated and the management of patients who develop pulmonary arterial hypertension (PAH), including the most extreme form, Eisenmenger syndrome (ES).

Current Status of Inotropes in Heart Failure

Inotropes are medications that improve the contractility of the heart and are used in patients with low cardiac output or evidence of end-organ dysfunction. Since their initial discovery, inotropes have held promise in alleviating symptoms and potentially increasing longevity in such patients. Decades of intensive study have further elucidated the benefits and risks of using inotropes. In this article, the authors discuss the history of inotropes, their indications, mechanism of action, and current guidelines pertaining to their use in heart failure. The authors provide insight into their appropriate use and related shortcomings and the practical aspects of inotrope use.