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

Cardiooncology in the ICU - Cardiac Urgencies in Cancer Care

Cardiovascular disease is an increasing risk of morbidity and mortality in cancer patients, related to an growing number of aging survivors with pre-existing cardiovascular disease and the use of traditional and novel cancer therapies with cardiotoxic effects. While many cardiac complications are chronic processes that develop over time, there are many acute processes that may arise in hospitalized patients. It is important for hospitalists and critical care physicians to be familiar with the recognition and management of these conditions in this unique population. This article reviews the presentation and management of common cardiac urgencies in critically ill cancer patients including acute decompensated heart failure, acute coronary syndromes, arrhythmias, hypertensive crises, pulmonary embolism, pericardial tamponade and myocarditis.

Assessing Right Ventricle Over Time in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: Insights From Serial Echocardiography

Extracorporeal membrane oxygenation (ECMO) is often used in acute respiratory distress syndrome (ARDS) with refractory hypoxemia. There is limited literature highlighting the development of right ventricular (RV) failure while on ECMO. We conducted a retrospective multicenter observational study including 70 patients who were placed on veno-venous (VV)-ECMO for respiratory failure at Mayo Clinic, Jacksonville, and Mayo Clinic, Rochester, between January 2018 and June 2022 and had at least two post-ECMO transthoracic echoes. The primary outcomes were the incidence and progression of RV dysfunction and dilatation. The secondary outcome was in-patient mortality. Among 70 patients in our cohort, 60.6% had a normal RV function at the time of ECMO placement, whereas only 42% had a normal RV function at the second post-ECMO echo. On multinomial regression, a moderate decrease in RV function was associated with ECMO flow (odds ratio [OR] = 2.32, p = 0.001) and ECMO duration (OR = 1.01, p = 0.01). A moderately dilated RV size was also associated with ECMO flow (OR = 2.62, p < 0.001) and ECMO duration (OR = 1.02, p = 0.02). An increasing degree of RV dysfunction was associated with worse outcomes. Our study showed that the increasing duration and flow of VV-ECMO correlated with progressive RV dilatation and dysfunction, which were associated with poor survival.

Physiologic Comparison of Airway Pressure Release Ventilation and Low Tidal Volume Ventilation in ARDS: A Randomized Controlled Trial

BACKGROUND

The physiologic effects of different ventilation strategies on patients with ARDS)need to be understood better.

RESEARCH QUESTION

In patients with ARDS receiving controlled mandatory ventilation, does airway pressure release ventilation (APRV) improve lung ventilation/perfusion (V˙/Q˙) matching and ventilation homogeneity compared with low tidal volume (LTV) ventilation?

STUDY DESIGN AND METHODS

This study was a single-center randomized controlled trial. Patients with moderate to severe ARDS were ventilated randomly with APRV or LTV ventilation. Electrical impedance tomography (EIT) was used to assess lung ventilation and perfusion. EIT-based data and clinical variables related to respiratory and hemodynamic conditions were collected shortly before randomization (0 hours) and at 12 and 24 hours after randomization.

RESULTS

A total of 40 patients were included and randomized to the APRV or LTV ventilation group (20 per group). During the 24-hour trial period, patients receiving APRV exhibited significantly increased dorsal ventilation (difference value [24 hours minus 0 hours]: median, 10.82% [interquartile range (IQR), 2.62%-13.74%] vs 0.12% [IQR, -2.81% to 4.76%]; P = .017), decreased dorsal shunt (median, -4.67% [IQR, -6.83% to 0.59%] vs 1.73% [IQR, -0.95% to 5.53%]; P = .008), and increased dorsal V˙/Q˙ matching (median, 4.13% [IQR, -0.26% to 10.47%] vs -3.29% [IQR, -5.05% to 2.81%]; P = .026) than those receiving LTV ventilation. No difference in ventral dead space was observed between study groups (P = .903). Additionally, 2 indicators of ventilation distribution heterogeneity, global inhomogeneity index and center of ventilation, significantly decreased and significantly increased, respectively, in the APRV group compared with the LTV ventilation group. Patients receiving APRV showed significantly higher Pao2 to Fio2 ratio, higher respiratory system static compliance (Crs) and lower Paco2 than those receiving LTV ventilation at 24 hours. The cardiac output was comparable in both groups.

INTERPRETATION

APRV, as compared with LTV ventilation, could recruit dorsal region, reduce dorsal shunt, increase dorsal V˙/Q˙ matching, and improve ventilation homogeneity of the lungs, leading to better gas exchange and Crs in patients with moderate to severe ARDS.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT05767125; URL: www.

CLINICALTRIALS

gov.

Non-contrasted computed tomography (NCCT) based chronic thromboembolic pulmonary hypertension (CTEPH) automatic diagnosis using cascaded network with multiple instance learning

Objective.The diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) is challenging due to nonspecific early symptoms, complex diagnostic processes, and small lesion sizes. This study aims to develop an automatic diagnosis method for CTEPH using non-contrasted computed tomography (NCCT) scans, enabling automated diagnosis without precise lesion annotation.Approach.A novel cascade network (CN) with multiple instance learning (CNMIL) framework was developed to improve the diagnosis of CTEPH. This method uses a CN architecture combining two Resnet-18 CNN networks to progressively distinguish between normal and CTEPH cases. Multiple instance learning (MIL) is employed to treat each 3D CT case as a 'bag' of image slices, using attention scoring to identify the most important slices. An attention module helps the model focus on diagnostically relevant regions within each slice. The dataset comprised NCCT scans from 300 subjects, including 117 males and 183 females, with an average age of 52.5 ± 20.9 years, consisting of 132 normal cases and 168 cases of lung diseases, including 88 cases of CTEPH. The CNMIL framework was evaluated using sensitivity, specificity, and the area under the curve (AUC) metrics, and compared with common 3D supervised classification networks and existing CTEPH automatic diagnosis networks.Main results. The CNMIL framework demonstrated high diagnostic performance, achieving an AUC of 0.807, accuracy of 0.833, sensitivity of 0.795, and specificity of 0.849 in distinguishing CTEPH cases. Ablation studies revealed that integrating MIL and the CN significantly enhanced performance, with the model achieving an AUC of 0.978 and perfect sensitivity (1.000) in normal classification. Comparisons with other 3D network architectures confirmed that the integrated model outperformed others, achieving the highest AUC of 0.8419.Significance. The CNMIL network requires no additional scans or annotations, relying solely on NCCT. This approach can improve timely and accurate CTEPH detection, resulting in better patient outcomes.

Definition and management of right ventricular injury in adult patients receiving extracorporeal membrane oxygenation for respiratory support using the Delphi method: a PRORVnet study. Expert position statements

PURPOSE

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an integral part of the management algorithm of patients with severe respiratory failure refractory to evidence-based conventional treatments. Right ventricular injury (RVI) pertaining to abnormalities in the dimensions and/or function of the right ventricle (RV) in the context of VV-ECMO significantly influences mortality. However, in the absence of a universally accepted RVI definition and evidence-based guidance for the management of RVI in this very high-risk patient cohort, variations in clinical practice continue to exist.

METHODS

Following a systematic search of the literature, an international Steering Committee consisting of eight healthcare professionals involved in the management of patients receiving ECMO identified domains and knowledge gaps pertaining to RVI definition and management where the evidence is limited or ambiguous. Using a Delphi process, an international panel of 52 Experts developed Expert position statements in those areas. The process also conferred RV-centric overarching open questions for future research. Consensus was defined as achieved when 70% or more of the Experts agreed or disagreed on a Likert-scale statement or when 80% or more of the Experts agreed on a particular option in multiple-choice questions.

RESULTS

The Delphi process was conducted through four rounds and consensus was achieved on 31 (89%) of 35 statements from which 24 Expert position statements were derived. Expert position statements provided recommendations for RVI nomenclature in the setting of VV-ECMO, a multi-modal diagnostic approach to RVI, the timing and parameters of diagnostic echocardiography, and VV-ECMO settings during RVI assessment and management. Consensus was not reached on RV-protective driving pressure thresholds or the effect of prone positioning on patient-centric outcomes.

CONCLUSION

The proposed definition of RVI in the context of VV-ECMO needs to be validated through a systematic aggregation of data across studies. Until further evidence emerges, the Expert position statements can guide informed decision-making in the management of these patients.

Intraoperative prophylactic right ventricular assist device in prevention of postcardiotomy failure

OBJECTIVES

In patients at risk of developing right ventricular failure after cardiac surgery, right ventricular support with a ventricular assist device may be a promising strategy to reduce mortality. We present our experience with intraoperative right ventricular assist device implantation as a prevention strategy of right ventricular failure after cardiac surgery.

METHODS

Between 2016 and 2022, we implanted four right ventricular assist devices prophylactically in a series of patients with surgical indication for valvular heart disease and high risk of postoperative right ventricular failure. Indications for the right ventricular assist device were suprasystemic pulmonary hypertension or severe right ventricular dysfunction.

RESULTS

Externalization of the device cannulas through intercostal spaces was performed in three patients, allowing early mobilization and withdrawal without resternotomy. Removal of the device ocurred on the eighth postoperative day. ICU and hospital length of stay was 12 (±1.6) and 23 days (±4.2) respectively. Hospital mortality was null. No patient died during follow-up, mean follow-up was 32.5 months [1-72]. Patients improved their NYHA functional class up to grade II during follow-up.

CONCLUSIONS

Acute right ventricular failure after cardiac surgery remains a significant cause of morbidity and mortality. Prophylactic strategies to prevent postoperative right ventricular dysfunction may decrease the incidence of refractory postoperative right ventricular failure. We propose a novel approach to prevent right failure after cardiac surgery with prophylactic intraoperative ventricular assist device implantation.

Arrhythmias in Patients with Pulmonary Hypertension and Right Ventricular Failure: Importance of Rhythm Control Strategies

Arrhythmias frequently complicate the course of advanced pulmonary hypertension, often leading to hemodynamic compromise, functional impairment, and mortality. Given the importance of right atrial function in this physiology, the restoration and maintenance of sinus rhythm are of critical importance. In this review, we outline the pathophysiology of arrhythmias and their impact on right heart performance; describe considerations for antiarrhythmic drug selection, anesthetic and periprocedural management; and discuss the results of catheter ablation techniques in this complex and challenging patient population.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle

PURPOSE OF REVIEW

To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure.

RECENT FINDINGS

Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

The Roles of Venopulmonary Arterial Extracorporeal Membrane Oxygenation

OBJECTIVES

Concise definitive review of the use of venopulmonary arterial extracorporeal membrane oxygenation (V-PA ECMO) support in patients with cardiopulmonary failure.

DATA SOURCES

Original investigations identified through a PubMed search with search terms "percutaneous right ventricular assist device," "oxy-RVAD," "V-PA ECMO," and "veno-pulmonary arterial ECMO" were reviewed and evaluated for relevance.

STUDY SELECTION

Studies that included more than three patients supported with V-PA ECMO were included.

DATA EXTRACTION

Clinically relevant data from included studies, including patient-important outcomes, were summarized and discussed.

DATA SYNTHESIS

We identified four groups of patients where V-PA ECMO has been studied: acute respiratory distress syndrome, right ventricular dysfunction after left ventricular assist device placement, bridge to lung transplantation, and pulmonary embolism. Most identified works are small, single center, and retrospective in nature, precluding definitive conclusions regarding the efficacy of V-PA ECMO. There have been no clinical trials evaluating the efficacy of V-PA ECMO for any indication.

CONCLUSIONS

V-PA ECMO is a promising form of extracorporeal support for patients with right ventricular dysfunction. Future work should focus on identifying the optimal timing and populations for the use of V-PA ECMO.

Inhaled Pulmonary Vasodilators for the Treatment of Right Ventricular Failure in Cardio-Thoracic Surgery: Is One Better than the Others?

Right ventricular failure (RFV) is a potential complication following cardio-thoracic surgery, with an incidence ranging from 0.1% to 30%. The increase in pulmonary vascular resistance (PVR) is one of the main triggers of perioperative RVF. Inhaled pulmonary vasodilators (IPVs) can reduce PVR and improve right ventricular function with minimal systemic effects. This narrative review aims to assess the efficacy of inhaled nitric oxide and inhaled prostacyclins for the treatment of perioperative RVF. The literature, although statistically limited, supports the clinical similarity between them. However, it failed to demonstrate a clear benefit from the pre-emptive use of inhaled nitric oxide in patients undergoing left ventricular assist device implantation or early administration during heart-lung transplants. Additional concerns are related to cost safety and IPV use in pathologies associated with pulmonary venous congestion. The largest ongoing randomized controlled trial on adults (INSPIRE-FLO) is addressing whether inhaled Epoprostenol and inhaled nitric oxide are similar in preventing RVF after heart transplants and left ventricular assist device placement, and whether they are similar in preventing primary graft dysfunction after lung transplants. The preliminary analysis supports their equivalence. Several key points may be achieved by the present narrative review. When RVF occurs in the setting of elevated PVR, IPV should be the preferred initial treatment and they should be preventively used in patients at high risk of postoperative RVF. If severe refractory postoperative RVF occurs, IPVs should be combined with complementary pharmacology (inotropes and inodilators). If unsuccessful, right ventricular mechanical support should be established.

The value of right ventricular to pulmonary arterial coupling in the critically ill: a National Echocardiography Database of Australia (NEDA) substudy

BACKGROUND

Right ventricular (RV) function is tightly coupled to afterload, yet echocardiographic indices of RV function are frequently assessed in isolation. Normalizing RV function for afterload (RV-PA coupling) using a simplified ratio of tricuspid annular plane systolic excursion (TAPSE)/ tricuspid regurgitant velocity (TRV) could help to identify RV decompensation and improve risk stratification in critically ill patients. This is the first study to explore the distribution of TAPSE/TRV ratio and its prognostic relevance in a large general critical care cohort.

METHODS

We undertook retrospective analysis of echocardiographic, clinical, and mortality data of intensive care unit (ICU) patients between January 2012 and May 2017. A total of 1077 patients were included and stratified into tertile groups based on TAPSE/TRV ratio: low (< 5.9 mm.(m/s)-1), middle (≥ 5.9-8.02 mm.(m/s)-1), and high (≥ 8.03 mm.(m/s)-1). The distribution of the TAPSE/TRV ratio across ventricular function subtypes of normal, isolated left ventricular (LV), isolated RV, and biventricular dysfunction was explored. The overall prognostic relevance of the TAPSE/TRV ratio was tested, including distribution across septic, cardiovascular, respiratory, and neurological subgroups.

RESULTS

Higher proportions of ventricular dysfunctions were seen in low TAPSE/TRV tertiles. TAPSE/TRV ratio is impacted by LV systolic function but to a lesser extent than RV dysfunction or biventricular dysfunction. There was a strong inverse relationship between TAPSE/TRV ratio and survival. After multivariate analysis, higher TAPSE/TRV ratios (indicating better RV-PA coupling) were independently associated with lower risk of death in ICU (HR 0.927 [0.872-0.985], p < 0.05). Kaplan-Meier analysis demonstrated higher overall survival in middle and high tertiles compared to low tertiles (log rank p < 0.0001). The prognostic relevance of TAPSE/TRV ratio was strongest in respiratory and sepsis subgroups. Patients with TAPSE/TRV < 5.9 mm (m/s)-1 had a significantly worse prognosis than those with higher TAPSE/TRV ratios.

CONCLUSION

The TAPSE/TRV ratio has prognostic relevance in critically ill patients. The prognostic power may be stronger in respiratory and septic subgroups. Larger prospective studies are needed to investigate the role of TAPSE/TRV in pre-specified subgroups including its role in clinical decision-making.

Left ventricular assist device implantation and concomitant mitral valve surgery: A systematic review and meta-analysis

BACKGROUND

The management of concomitant valvular lesions in patients undergoing left ventricular assist device (LVAD) implantation remains a topic of debate. This systematic review and meta-analysis aimed to evaluate the existing evidence on postoperative outcomes following LVAD implantation, with and without concomitant MV surgery.

METHODS

A systematic database search was conducted as per PRISMA guidelines, of original articles comparing LVAD alone to LVAD plus concomitant MV surgery up to February 2023. The primary outcomes assessed were overall mortality and early mortality, while secondary outcomes included stroke, need for right ventricular assist device (RVAD) implantation, postoperative mitral valve regurgitation, major bleeding, and renal dysfunction.

RESULTS

The meta-analysis included 10 studies comprising 32 184 patients. It revealed that concomitant MV surgery during LVAD implantation did not significantly affect overall mortality (OR:0.83; 95% CI: 0.53 to 1.29; p = 0.40), early mortality (OR:1.17; 95% CI: 0.63 to 2.17; p = 0.63), stroke, need for RVAD implantation, postoperative mitral valve regurgitation, major bleeding, or renal dysfunction. These findings suggest that concomitant MV surgery appears not to confer additional benefits in terms of these clinical outcomes.

CONCLUSION

Based on the available evidence, concomitant MV surgery during LVAD implantation does not appear to have a significant impact on postoperative outcomes. However, decision-making regarding MV surgery should be individualized, considering patient-specific factors and characteristics. Further research with prospective studies focusing on specific patient populations and newer LVAD devices is warranted to provide more robust evidence and guide clinical practice in the management of valvular lesions in LVAD recipients.

Management of Acutely Decompensated Pulmonary Hypertension

Pulmonary arterial hypertension is a severe life-threatening condition associated with increased pulmonary vascular resistance and resulting right heart dysfunction. Admission to intensive care unit with acutely decompensated right heart failure is a significant negative prognostic event with a high risk of multisystem organ dysfunction and death. Presentations are heterogenous and may combine signs of both diastolic and systolic dysfunction complicating management. Renal dysfunction is often present, but other organ systems can be involved resulting in findings such as acute hepatic dysfunction or bowel wall congestion and ischemia. The goals of therapy are to rapidly reverse ventriculo-arterial decoupling and reduce right ventricular afterload to prevent progression to refractory or irreversible right heart failure. Triggering events must be investigated for and addressed urgently if identified. Volume status management is critical and both noninvasive and invasive testing can aid in prognostication and guide management, including the use of inotropes and vasopressors. In cases of refractory right heart dysfunction, consideration of urgent lung transplantation and mechanical circulatory support is necessary. These patients should be managed at expert centers in an intensive care setting with a multidisciplinary team of practitioners experienced in the management of right heart dysfunction given the high short- and long-term mortality resulting from acute decompensated right heart failure.

Medical Emergencies in Pulmonary Hypertension

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Tris-Hydroxymethyl Aminomethane in Critically Ill Adults: A Systematic Review

Tris-hydroxymethyl aminomethane (THAM) is an amino alcohol used clinically to buffer acid loads and raise pH in acidotic conditions. Unlike sodium bicarbonate, which increases plasma sodium levels with use and produces carbon dioxide (CO 2 ) as part of the buffering process, THAM does neither. Although not widely used in modern critical care and unavailable for clinical use in 2016, THAM has been available in the United States since 2020. Clinical experience and existing literature suggest that THAM may have clinical utility in acid-base management in conditions such as liver transplantation where rising sodium levels during perioperative care may be dangerous, and in managing acid-base derangements during care of patients with acute respiratory distress syndrome (ARDS). To clarify the evidence base supporting the clinical use of THAM, we conducted a systematic review to assess the efficacy and safety of THAM as a buffering agent in critically ill adults using Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection. Randomized-, crossover-, retrospective cohort-, parallel-designed clinical trials, case series, and case reports of adult patients who received THAM in the operative or critical care setting were included. Conference abstracts of qualifying study designs were also included. Two independent reviewers extracted the data regarding the study details, demographics, treatment, and outcomes data. A third reviewer adjudicated discrepancies. A total of 21 studies including 3 randomized controlled trials, 5 observational studies, 4 case series, and 9 case reports met inclusion criteria. Eight studies (38%) were abstracts published in conference proceedings. In total, 417 critically ill patients received THAM to treat acidosis in critically ill surgical and nonsurgical patients, during liver transplantation, and in ARDS. In general, THAM corrected acidosis with an efficacy equivalent to sodium bicarbonate and did so with less hypercarbia and hypernatremia. Adverse effects of THAM included hyperkalemia, hypoglycemia, ventilator depression, and tissue damage with extravasation. We conclude that THAM may have potential advantages in some critical care settings, but that clinical evidence is limited, and high-quality evaluations are necessary.

Unrecognized Pulmonary Hypertension in Non-Cardiac Surgical Patients: At-Risk Populations, Preoperative Evaluation, Intraoperative Management and Postoperative Complications

Pulmonary hypertension is a well-established independent risk factor for perioperative complications after elective non-cardiac surgery. Patients undergoing cardiac surgery are routinely evaluated for the presence of pulmonary hypertension in the preoperative period. Better monitoring in the postoperative critical care setting leads to more efficient management of potential complications. Data among patients with pulmonary hypertension undergoing elective non-cardiac surgery are scant. Moreover, the condition may be unidentified at the time of surgery. Also, monitoring after non-cardiac surgery can be very limited in the PACU setting, as opposed to the critical care setting. All these factors can result in a higher postoperative complication rate and poor outcomes.

Pannexin1: insight into inflammatory conditions and its potential involvement in multiple organ dysfunction syndrome

Sepsis represents a global health concern, and patients with severe sepsis are at risk of experiencing MODS (multiple organ dysfunction syndrome), which is associated with elevated mortality rates and a poorer prognosis. The development of sepsis involves hyperactive inflammation, immune disorder, and disrupted microcirculation. It is crucial to identify targets within these processes to develop therapeutic interventions. One such potential target is Panx1 (pannexin-1), a widely expressed transmembrane protein that facilitates the passage of molecules smaller than 1 KDa, such as ATP. Accumulating evidence has implicated the involvement of Panx1 in sepsis-associated MODS. It attracts immune cells via the purinergic signaling pathway, mediates immune responses via the Panx1-IL-33 axis, promotes immune cell apoptosis, regulates blood flow by modulating VSMCs' and vascular endothelial cells' tension, and disrupts microcirculation by elevating endothelial permeability and promoting microthrombosis. At the level of organs, Panx1 contributes to inflammatory injury in multiple organs. Panx1 primarily exacerbates injury and hinders recovery, making it a potential target for sepsis-induced MODS. While no drugs have been developed explicitly against Panx1, some compounds that inhibit Panx1 hemichannels have been used extensively in experiments. However, given that Panx1's role may vary during different phases of sepsis, more investigations are required before interventions against Panx1 can be applied in clinical. Overall, Panx1 may be a promising target for sepsis-induced MODS. Nevertheless, further research is needed to understand its complex role in different stages of sepsis fully and to develop suitable pharmaceutical interventions for clinical use.

The perioperative use of inhaled prostacyclins in cardiac surgery: a systematic review and meta-analysis

PURPOSE

Perioperative pulmonary hypertension (PH) is an independent risk factor for morbidity and mortality in cardiac surgery. While inhaled prostacyclins (iPGI2s) are an established treatment of chronic PH, data on the efficacy of iPGI2s in perioperative PH are scarce.

METHODS

We searched PubMed, Embase, the Web of Science, CENTRAL, and the grey literature from inception until April 2021. We included randomized controlled trials investigating the use of iPGI2s in adult and pediatric patients undergoing cardiac surgery with an increased risk of perioperative right ventricle failure. We assessed the efficacy and safety of iPGI2s compared with placebo and other inhaled or intravenous vasodilators with random-effect meta-analyses. The primary outcome was mean pulmonary artery pressure (MPAP). Secondary outcomes included other hemodynamic parameters and mortality.

RESULTS

Thirteen studies were included, comprising 734 patients. Inhaled prostacyclins significantly decreased MPAP compared with placebo (standardized effect size, 0.46; 95% confidence interval [CI], 0.11 to 0.87; P = 0.01) and to intravenous vasodilators (1.26; 95% CI, 0.03 to 2.49; P = 0.045). Inhaled prostacyclins significantly improved the cardiac index compared with intravenous vasodilators (1.53; 95% CI, 0.50 to 2.57; P = 0.004). In contrast, mean arterial pressure was significantly lower in patients treated with iPGI2s vs placebo (-0.39; 95% CI, -0.62 to 0.16; P = 0.001), but higher than in patients treated with intravenous vasodilators (0.81; 95% CI, 0.29 to 1.33; P = 0.002). With respect to hemodynamics, iPGI2s had similar effects as other inhaled vasodilators. Mortality was not affected by iPGI2s.

CONCLUSION

The results of this systematic review and meta-analysis show that iPGI2s improved pulmonary hemodynamics with similar efficacy as other inhaled vasodilators, but caused a significant small decrease in arterial pressure when compared with placebo, indicating spill-over into the systemic circulation. These effects did not affect clinical outcomes.

STUDY REGISTRATION DATE

PROSPERO (CRD42021237991); registered 26 May 2021.

Echocardiographic profiles and hemodynamic response after vasopressin initiation in septic shock: A cross-sectional study

PURPOSE

Vasopressin, used as a catecholamine adjunct, is a vasoconstrictor that may be detrimental in some hemodynamic profiles, particularly left ventricular (LV) systolic dysfunction. This study tested the hypothesis that echocardiographic parameters differ between patients with a hemodynamic response after vasopressin initiation and those without a response.

METHODS

This retrospective, single-center, cross-sectional study included adults with septic shock receiving catecholamines and vasopressin with an echocardiogram performed after shock onset but before vasopressin initiation. Patients were grouped by hemodynamic response, defined as decreased catecholamine dosage with mean arterial pressure ≥ 65 mmHg six hours after vasopressin initiation, with echocardiographic parameters compared. LV systolic dysfunction was defined as LV ejection fraction (LVEF) <45%.

RESULTS

Of 129 included patients, 72 (56%) were hemodynamic responders. Hemodynamic responders, versus non-responders, had higher LVEF (61% [55%,68%] vs. 55% [40%,65%]; p = 0.02) and less-frequent LV systolic dysfunction (absolute difference  -16%; 95% CI -30%,-2%). Higher LVEF was associated with higher odds of hemodynamic response (for each LVEF 10%, response OR 1.32; 95% CI 1.04-1.68). Patients with LV systolic dysfunction, versus without LV systolic dysfunction, had higher mortality risk (HR(t) = e[0.81-0.1*t]; at t = 0, HR 2.24; 95% CI 1.08-4.64).

CONCLUSIONS

Pre-drug echocardiographic profiles differed in hemodynamic responders after vasopressin initiation versus non-responders.

The Role of the Vasculature in Heart Failure

The contribution of the vasculature in the development and progression of heart failure (HF) syndromes is poorly understood and often neglected. Incorporating both arterial and venous systems, the vasculature plays a significant role in the regulation of blood flow throughout the body in meeting its metabolic requirements. A deterioration or imbalance between the cardiac and vascular interaction can precipitate acute decompensated HF in both preserved and reduced ejection fraction phenotypes. This is characterised by the increasingly recognised concept of ventricular-arterial coupling: a well-balanced relationship between ventricular and vascular stiffness, which has major implications in HF. Often, the cause of decompensation is unknown, with international guidelines mainly centred on arrhythmia, infection, acute coronary syndrome and its mechanical complications as common causes of decompensation; the vascular component is often underrecognised. A better understanding of the vascular contribution in cardiovascular failure can improve risk stratification, earlier diagnosis and facilitate earlier optimal treatment. This review focuses on the role of the vasculature by integrating the concepts of ventricular-arterial coupling, arterial stiffness and venous return in a failing heart.

Right Ventricular Limitation: A Tale of Two Elastances

Right ventricular (RV) dysfunction is a commonly considered cause of low cardiac output in critically ill patients. Its management can be difficult and requires an understanding of how the RV limits cardiac output. We explain that RV stroke output is caught between the passive elastance of the RV walls during diastolic filling and the active elastance produced by the RV in systole. These two elastances limit RV filling and stroke volume and consequently limit left ventricular stroke volume. We emphasize the use of the term "RV limitation" and argue that limitation of RV filling is the primary pathophysiological process by which the RV causes hemodynamic instability. Importantly, RV limitation can be present even when RV function is normal. We use the term "RV dysfunction" to indicate that RV end-systolic elastance is depressed or diastolic elastance is increased. When RV dysfunction is present, RV limitation occurs at lowerpulmonary valve opening pressures and lower stroke volume, but stroke volume and cardiac output still can be maintained until RV filling is limited. We use the term "RV failure" to indicate the condition in which RV output is insufficient for tissue needs. We discuss the physiological underpinnings of these terms and implications for clinical management.

Right ventricle-specific therapies in acute respiratory distress syndrome: a scoping review

OBJECTIVE

To summarize knowledge and identify gaps in evidence regarding treatment of right ventricular dysfunction (RVD) in acute respiratory distress syndrome (ARDS).

DATA SOURCES

We conducted a comprehensive search of MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials.

STUDY SELECTION

Studies were included if they reported effects of treatments on right ventricular function, whether or not the intent was to modify right ventricular function.

DATA EXTRACTION

Data extraction was performed independently and in duplicate by two authors. Data items included the study design, patient population, type of intervention, comparison group, and RV-specific outcomes.

DATA SYNTHESIS

Of 1,430 studies screened, 51 studies reporting on 1,526 patients were included. By frequency, the included studies examined the following interventions: ventilator settings (29.4%), inhaled medications (33.3%), extracorporeal life support (13.7%), intravenous or oral medications (13.7%), and prone positioning (9.8%). The majority of the studies were non-randomized experimental studies (53%), with the next most common being case reports (16%). Only 5.9% of studies were RCTs. In total, 27% of studies were conducted with the goal of modifying RV function.

CONCLUSIONS

Given the prevalence of RVD in ARDS and its association with mortality, the dearth of research on this topic is concerning. This review highlights the need for prospective trials aimed at treating RV dysfunction in ARDS.

Outcomes and Prognostic Factors of Pulmonary Hypertension Patients Undergoing Emergent Endotracheal Intubation

Background: Emergent endotracheal intubations (ETI) in pulmonary hypertension (PH) patients are associated with increased mortality. Post-intubation interventions that could increase survivability in this population have not been explored. We evaluate early clinical characteristics and complications following emergent endotracheal intubation and seek predictors of adverse outcomes during this post-intubation period. Methods: Retrospective cohort analysis of adult patients with groups 1 and 3 PH who underwent emergent intubation between 2005-2021 in medical and liver transplant ICUs at a tertiary medical center. PH patients were compared to non-PH patients, matched by Charlson Comorbidity Index. Primary outcomes were 24-h post-intubation and inpatient mortalities. Various 24-h post-intubation secondary outcomes were compared between PH and control cohorts. Results: We identified 48 PH and 110 non-PH patients. Pulmonary hypertension was not associated with increased 24-h mortality (OR 1.32, 95%CI 0.35-4.94, P = .18), but was associated with inpatient mortality (OR 4.03, 95%CI 1.29-12.5, P = .016) after intubation. Within 24 h post-intubation, PH patients experienced more frequent acute kidney injury (43.5% vs. 19.8%, P = .006) and required higher norepinephrine dosing equivalents (6.90 [0.13-10.6] mcg/kg/min, vs. 0.20 [0.10-2.03] mcg/kg/min, P = .037). Additionally, the median P/F ratio (PaO₂/FiO₂) was lower in PH patients (96.3 [58.9-201] vs. 233 [146-346] in non-PH, P = .001). Finally, a post-intubation increase in PaCO₂ was associated with mortality in the PH cohort (post-intubation change in PaCO₂ +5.14 ± 16.1 in non-survivors vs. -18.7 ± 28.0 in survivors, P = .007). Conclusions: Pulmonary hypertension was associated with worse outcomes after emergent endotracheal intubation than similar patients without PH. More importantly, our data suggest that the first 24 hours following intubation in the PH group represent a particularly vulnerable period that may determine long-term outcomes. Early post-intubation interventions may be key to improving survival in this population.

Perioperative Decision-Making in Pulmonary Hypertension

Pulmonary hypertension (PH) is a haemodynamic manifestation of cardiorespiratory and non-cardiorespiratory pathologies. Cardiorespiratory pathologies account for nearly three-fourths of patients with PH. It is now increasingly being recognised due to routine requests for transthoracic echocardiographic examination in the perioperative setting in patients undergoing intermediate- to high-risk non-cardiac surgery. The increased risks of perioperative morbidity and mortality attributed to PH have been widely acknowledged in the literature. The importance of PH in perioperative decision-making and postoperative outcomes has had little mention in all the guidelines. Understanding the complexity of the pathophysiology of PH may help in anaesthetic and surgical decision-making. Preoperative evaluation and risk assessment are guided by the nature, extent, invasiveness, and duration of surgery. Surgical decision-making and anaesthetic management involve preoperative risk stratification, understanding the interactions between surgical procedures and PH, and understanding the interactions between anaesthetic procedures, PH, and cardiopulmonary interactions. Intraoperative and postoperative monitoring is crucial for maintaining the haemodynamic parameters and helps titrate anaesthetic agents and medication. This narrative review focusses on all issues related to anaesthetic and surgical challenges in patients with PH. This review aimed to suggest a preoperative evaluation plan, surgical decision-making, anaesthetic plan, and anaesthetic management based on the evidence available in the literature.

Pre-Existing Right Ventricular Dysfunction as an Independent Risk Factor for Post Intubation Cardiac Arrest and Hemodynamic Instability in Critically Ill Patients: A Retrospective Observational Study

BACKGROUND

Post intubation cardiac arrest and hemodynamic instability are serious adverse events encountered in critically ill patients. The association of pre-existing right ventricular (RV) dysfunction with post intubation cardiac arrest and hemodynamic instability in critically ill patients is unknown.

METHODS

This is a retrospective matched cohort study of adult critically ill patients who underwent intubation from July 2016 to December 2019. The study was conducted at a quaternary medical center in Houston, Texas. A total of 340 critically ill patients who underwent intubation in the intensive care units, wards, and the emergency room were included. The study cohort was categorized into 4 groups based on the pre-existing RV function: normal function, mild dysfunction, moderate dysfunction, and severe dysfunction. Cardiac arrest and/or hemodynamic instability within one hour post intubation were the primary study outcomes. Secondary outcomes included in hospital and 60-day mortality.

RESULTS

Study patients were of mean age of 61.95 ± 14.28 years, including 132 (39%) females and 208 (61%) males. The primary outcomes were significantly worse in mild, moderate, and severe RV dysfunction groups compared to the normal RV function group (34.12%-P = 0.014, 47.06%-P < 0.001, 51.67%-P < 0.001, vs. 17.56%). In a multivariable logistic regression analysis, pre-existing moderate (OR = 2.65, P = 0.013) and severe RV dysfunction groups (OR = 2.66, P = 0.015) were associated with statistically significant higher cardiac arrest and hemodynamic instability post intubation. Pre-existing severe RV dysfunction was associated with statistically significant higher in hospital mortality (62.35%-P < 0.001). The multivariable Cox-regression analysis showed that pre-existing severe RV dysfunction was associated with a statistically significant higher 60-day mortality (HR = 2.57, P = 0.001).

CONCLUSIONS

Pre-existing moderate and severe RV dysfunctions were independently associated with significantly higher cardiac arrest and/or hemodynamic instability post intubation in critically ill patients. Pre-existing RV function may serve as a mortality predictor in critically ill patients undergoing endotracheal intubation.

The relationship between pre-operative right ventricular longitudinal strain and low-cardiac-output syndrome after surgical aortic valve replacement

Objectives

This study was performed to investigate the relationship between right ventricular free wall longitudinal strain (RVFWSL) and low cardiac output syndrome (LCOS) after surgical aortic valve replacement (SAVR) and to further explore its association with readmission within 2 years in patients who developed LCOS after SAVR.

Methods

This single-center retrospective observational study involved consecutive patients who underwent SAVR at our hospital from May 2018 to June 2020. Preoperative echocardiography was obtained within 3 days before SAVR. The longitudinal strain of the right ventricle was analyzed using the right ventricle as the main section, and the RVFWSL and right ventricular four-chamber longitudinal strain (RV4CSL) were obtained. The primary observation was the occurrence of LCOS. The secondary prognostic indicators were mainly the readmission rates within 2 years.

Results

In total, 146 patients were finally included in this study. The RVFWSL was significantly lower in the LCOS group than in the No-LCOS group (16.63 ± 2.10) vs. (23.95 ± 6.33), respectively; P < 0.001). The multivariate regression analysis showed that the RVFWSL was associated with LCOS (odds ratio, 1.676; 95% confidence interval, 1.258-2.232; P < 0.001). The receiver operating characteristic curve showed that the cut-off value for RVFWSL to predict LCOS was less than -18.3, with an area under the curve of 0.879, sensitivity of 100%, and specificity of 80.47%. The multivariate regression analysis showed that LCOS was an independent risk factor for readmission within 2 years in patients undergoing SAVR.

Conclusion

Patients with RVFWSL (<-18.3%) may be an increased risker for LCOS after SAVR. The occurrence of LCOS after SAVR is Yong-jian Zhang a risk factor for readmission within 2 years. Right ventricular function monitoring may have some predictive value for the postoperative prognosis in patients undergoing SAVR.

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.

Intensive Care Management of the Cardiogenic Shock Patient

Optimal management of patients with cardiogenic shock requires a detailed and systematic assessment of all organ systems, balancing the risks and benefits of any investigation and intervention, while avoiding the complications of critical illness. Overall prognosis depends upon a number of factors, including that of the underlying cardiac disease and its potential reversibility, the severity of shock, the involvement of other organ systems, the age of the patient and comorbidities. As with all intensive care patients, the mainstay of management is supportive, up to and including implementation and management of a number of devices, including acute mechanical circulatory support. The assessment and management of these most critically ill patients therefore demands in-depth knowledge and skill relating to cardiac intensive care, extending well beyond standard intensive care or cardiology practice.

Right heart failure: A narrative review for emergency clinicians

INTRODUCTION

Right heart failure (RHF) is a clinical syndrome with impaired right ventricular cardiac output due to a variety of etiologies including ischemia, elevated pulmonary arterial pressure, or volume overload. Emergency department (ED) patients with an acute RHF exacerbation can be diagnostically and therapeutically challenging to manage.

OBJECTIVE

This narrative review describes the pathophysiology of right ventricular dysfunction and pulmonary hypertension, the methods to diagnose RHF in the ED, and management strategies.

DISCUSSION

Right ventricular contraction normally occurs against a low pressure, highly compliant pulmonary vascular system. This physiology makes the right ventricle susceptible to acute changes in afterload, which can lead to RHF. Patients with acute RHF may present with an acute illness and have underlying chronic pulmonary hypertension due to left ventricular failure, pulmonary arterial hypertension, chronic lung conditions, thromboemboli, or idiopathic conditions. Patients can present with a variety of symptoms resulting from systemic edema and hemodynamic compromise. Evaluation with electrocardiogram, laboratory analysis, and imaging is necessary to evaluate cardiac function and end organ injury. Management focuses on treating the underlying condition, optimizing oxygenation and ventilation, treating arrhythmias, and understanding the patient's hemodynamics with bedside ultrasound. As RHF patients are preload dependent they may require fluid resuscitation or diuresis. Hypotension should be rapidly addressed with vasopressors. Cardiac contractility can be augmented with inotropes. Efforts should be made to support oxygenation while trying to avoid intubation if possible.

CONCLUSIONS

Emergency clinician understanding of this condition is important to diagnose and treat this life-threatening cardiopulmonary disorder.

Cardiac dysfunction and mortality in critically ill patients with COVID-19: A Swedish multicentre observational study

BACKGROUND

The prevalence and importance of cardiac dysfunction in critically ill patients with COVID-19 in Sweden is not yet established. The aim of the study was to assess the prevalence of cardiac dysfunction and elevated pulmonary artery pressure (PAP), and its influence on mortality in patients with COVID-19 in intensive care in Sweden.

METHODS

This was a multicentre observational study performed in five intensive care units (ICUs) in Sweden. Patients admitted to participating ICU with COVID-19 were examined with echocardiography within 72 h from admission and again after 4 to 7 days. Cardiac dysfunction was defined as left ventricular (LV) dysfunction (ejection fraction <50% and/or regional hypokinesia) or right ventricular (RV) dysfunction (defined as TAPSE <17 mm or visually assessed moderate/severe RV dysfunction).

RESULTS

We included 132 patients, of whom 127 (96%) were intubated. Cardiac dysfunction was found in 42 (32%) patients. Most patients had cardiac dysfunction at the first assessment (n = 35) while a few developed cardiac dysfunction later (n = 7) and some changed type of dysfunction (n = 3). LV dysfunction was found in 21 and RV dysfunction in 19 patients, while 5 patients had combined dysfunction. Elevated PAP was found in 34 patients (26%) and was more common in patients with RV dysfunction. RV dysfunction and elevated PAP were independently associated with an increased risk of death (OR 3.98, p = .013 and OR 3.88, p = .007, respectively).

CONCLUSIONS

Cardiac dysfunction occurs commonly in critically ill patients with COVID-19 in Sweden. RV dysfunction and elevated PAP are associated with an increased risk of death.

Causes and outcomes of ICU hospitalisations in patients with pulmonary arterial hypertension

Rationale

Pulmonary arterial hypertension (PAH) is a rare disease characterised by limited survival despite remarkable improvements in therapy. The causes, clinical burden and outcomes of patients admitted to the intensive care unit (ICU) remain poorly characterised. The aim of this study was to describe patient characteristics, causes of ICU hospitalisation, and risk factors for ICU and 1-year mortality.

Methods

Data from patients enrolled in the Johns Hopkins Pulmonary Hypertension Registry were analysed for the period between January 2010 and December 2020. Clinical, functional, haemodynamic and laboratory data were collected.

Measurements and main results

102 adult patients with 155 consecutive ICU hospitalisations were included. The leading causes for admission were right heart failure (RHF, 53.3%), infection (17.4%) and arrhythmia (11.0%). ICU mortality was 27.1%. Mortality risk factors included Na <136 mEq·mL-1 (OR: 3.10, 95% CI: 1.41-6.82), elevated pro-B-type natriuretic peptide (proBNP) (OR: 1.75, 95% CI: 1.03-2.98), hyperbilirubinaemia (OR: 1.40, 95% CI: 1.09-1.80), hyperlactaemia (OR: 1.42, 95% CI: 1.05-1.93), and need for vasopressors/inotropes (OR: 5.29, 95% CI: 2.28-12.28), mechanical ventilation (OR: 3.76, 95% CI: 1.63-8.76) and renal replacement therapy (OR: 5.57, 95% CI: 1.25-24.76). Mortality rates at 3, 6 and 12 months were 17.5%, 27.6% and 39.0%, respectively. Connective tissue disease-associated PAH has lower 1-year survival compared to idiopathic PAH (51.4% versus 79.8%, log-rank test p=0.019).

Conclusions

RHF is the most common cause for ICU admission. In-hospital and 1-year mortality remain exceedingly high despite improved ICU care. Recognising specific risk factors on admission can help identifying patients at risk for poor outcomes.

Advanced Circulatory Support and Lung Transplantation in Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive fatal disease. Although medical therapies have improved the outlook for these patients, there still exists a cohort of patients with PAH who are refractory to these therapies. Lung transplantation (LT), and in certain cases heart-lung transplantation (HLT), is a therapeutic option for patients with severe PAH who are receiving optimal therapy yet declining. ECMO may serve as a bridge to transplant or recovery in appropriate patients. Although, the mortality within the first 3 months after transplant is higher in PAH recipients than the other indications for LT, and the long-term survival after LT is excellent for this group of individuals. In this review, we discuss the indications for LT in PAH patients, when to refer and list patients for LT, the indications for double lung transplant (DLT) versus HLT for PAH patients, types of advanced circulatory support for severe PAH, and short and long-term outcomes in transplant recipients with PAH.

The use of point-of-care assessments and advanced hemodynamic monitoring in a patient with Eisenmenger syndrome for cesarean section: A case report

INTRODUCTION

Eisenmenger syndrome should be diagnosed before pregnancy and surgically corrected if possible. Cesarean section in a patient with Eisenmenger syndrome is high risk as morbidity and mortality are very high. Delivery in hospitals with intensive care units should be recommended. Use of point-of-care assessments and advanced monitors allow accurate management.

CASE PRESENTATION

A primigravid with congestive heart failure from a patent ductus arteriosus in Eisenmenger syndrome, presented with threatened preterm labor and uncontrolled hypertension prompting cesarean delivery under epidural anesthesia. Pre-induction focused echocardiography revealed normal right ventricular function and severe pulmonary hypertension. Intraoperatively, hemodynamics became unstable. The decision to use fluids, vasopressor and inotrope was guided by analyses of arterial pulse contour, central venous pressure waveform and blood exams. Hemodynamics improved and a live baby was delivered. Postoperative course was unremarkable.

DISCUSSION

The cause of hemodynamic instability must be accurately determined as inappropriate use of fluid or medication may be detrimental to a patient with Eisenmenger syndrome. In this case, advanced hemodynamic monitoring showed changes in central venous pressure, cardiac output and systemic vascular resistance which differentiated the causes of hypotension and desaturation. Point-of-care blood analysis showed acidosis and hypoxia which may have worsened the right-to-left shunt, contributing to the desaturation. Fluid and drug infusions to address identified problems were then guided by advanced monitors.

CONCLUSION

The use of point-of-care assessments and advanced hemodynamic monitoring allowed accurate diagnoses and goal-directed therapies leading to improved patient safety and outcomes. The need for prolonged intensive care in this case was prevented.

Critical Care Management of Decompensated Right Heart Failure in Pulmonary Arterial Hypertension Patients - An Ongoing Approach

Despite substantial advancements in diagnosis and specific medical therapy in pulmonary arterial hypertension patients’ management, this condition continues to represent a major cause of mortality worldwide. In pulmonary arterial hypertension, the continuous increase of pulmonary vascular resistance and rapid development of right heart failure determine a poor prognosis. Against targeted therapy, patients inexorable deteriorate over time. Pulmonary arterial hypertension patients with acute right heart failure who need intensive care unit admission present a complexity of the disease pathophysiology. Intensive care management challenges are multifaceted. Awareness of algorithms of right-sided heart failure monitoring in intensive care units, targeted pulmonary hypertension therapies, and recognition of precipitating factors, hemodynamic instability and progressive multisystem organ failure requires a multidisciplinary pulmonary hypertension team. This paper summarizes the management strategies of acute right-sided heart failure in pulmonary arterial hypertension adult cases based on recently available data.

Impairment of hypoxic pulmonary vasoconstriction in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a serious complication of severe systemic or local pulmonary inflammation, such as caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. ARDS is characterised by diffuse alveolar damage that leads to protein-rich pulmonary oedema, local alveolar hypoventilation and atelectasis. Inadequate perfusion of these areas is the main cause of hypoxaemia in ARDS. High perfusion in relation to ventilation (V/Q<1) and shunting (V/Q=0) is not only caused by impaired hypoxic pulmonary vasoconstriction but also redistribution of perfusion from obstructed lung vessels. Rebalancing the pulmonary vascular tone is a therapeutic challenge. Previous clinical trials on inhaled vasodilators (nitric oxide and prostacyclin) to enhance perfusion to high V/Q areas showed beneficial effects on hypoxaemia but not on mortality. However, specific patient populations with pulmonary hypertension may profit from treatment with inhaled vasodilators. Novel treatment targets to decrease perfusion in low V/Q areas include epoxyeicosatrienoic acids and specific leukotriene receptors. Still, lung protective ventilation and prone positioning are the best available standard of care. This review focuses on disturbed perfusion in ARDS and aims to provide basic scientists and clinicians with an overview of the vascular alterations and mechanisms of V/Q mismatch, current therapeutic strategies, and experimental approaches.

A Detailed Review of Critical Care Considerations for the Pregnant Cardiac Patient

Maternal cardiovascular disease is a leading cause of maternal death worldwide and recently, maternal mortality has increased secondary to cardiovascular causes. Maternal admissions to critical care encompass 1%-2% of all critical care admissions, and although not common, the management of the critically ill pregnant patient is complex. Caring for the critically ill pregnant cardiac patient requires integration of pregnancy-associated physiologic changes, understanding pathophysiologic disease states unique to pregnancy, and a multidisciplinary approach to timing around delivery as well as antenatal and postpartum care. Herein we describe cardiorespiratory changes that occur during pregnancy and the differential diagnosis for cardiorespiratory failure in pregnancy. Cardiorespiratory diseases that are either associated or exacerbated by pregnancy are highlighted with emphasis on perturbations secondary to pregnancy and appropriate management strategies. Finally, we describe general management of the pregnant cardiac patient admitted to critical care.

Supportive care of right ventricular failure due to fat embolism syndrome

Pulmonary fat embolism is a common phenomenon in cases of traumatic long bone fractures, with only a minority developing the more catastrophic Fat Embolism Syndrome (FES). Diagnosis is clinical and requires a high index of suspicion. Treatment remains under-investigated, with common interventions having low quality level-of-evidence and no mortality benefit. In severe cases, focus should be on supporting the failing right ventricle through use of inotropes, pulmonary vasodilators, and mechanical circulatory support. This requires a thorough understanding of the unique physiology through the pulmonary circulation.

•

Pulmonary fat embolism is a common phenomenon following long bone fracture. Only a minority develop the more serious complication Fat Embolism Syndrome (FES).

•

FES is a diagnosis of exclusion classically characterized by hypoxemia, altered mentation, and petechiae. Mortality is often a result of right ventricular (RV) failure.

•

The failing RV has unique physiology. Treatment focuses on supportive care through use of inotropes, pulmonary vasodilators, and mechanical circulatory devices.

Advanced airway management and respiratory care in decompensated pulmonary hypertension

Meticulous risk stratification is essential when considering intubation of a patient with decompensated pulmonary hypertension (dPH). It is paramount to understand both the pathophysiology of dPH (and associated right ventricular failure) and the complications related to a high-risk intubation before attempting the procedure. There are few recommendations in this area and the literature, guiding these recommendations, is limited to expert opinion and very few case reports/case series. This review will discuss the complex pathophysiology of dPH, the complications associated with intubation, the debates surrounding induction agents, and the available options for the intubation procedure, with specific emphasis on the emerging role for awake fiberoptic intubation. All patients should be evaluated for candidacy for veno-arterial extracorporeal membrane oxygen as a bridge to recovery, lung transplantation, or pulmonary endarterectomy prior to intubation. Only an experienced proceduralist who is both comfortable with high-risk intubations and the pathophysiology of dPH should perform these intubations.

Anesthetic Considerations for Percutaneous Coronary Intervention for Chronic Total Occlusions-A Narrative Review

Advancing stent technology has enabled interventional cardiologists to perform percutaneous coronary intervention (PCI) to open chronic total occlusions (CTOs). Because PCI for CTOs improve patient anginal symptoms and quality of life, these procedures have been increasing over the past decade. Compared to standard PCI, these procedures are technically more difficult, with prolonged procedure time and increased risk of complications. Accordingly, anesthesiologists are increasingly being asked to provide sedation for these patients in the cardiac catheterization suite. In CTO PCI, anesthesiologists are more likely to encounter complications such as coronary artery perforation, malignant arrhythmias, non-target vessel ischemia, bleeding and shock. Additionally, CTO PCI may be supported by mechanical circulatory support devices. Understanding the procedural techniques of these complex PCI procedures is important to enable optimal anesthetic care in these patients. This narrative review discusses the pathophysiology, risks, benefits, procedural steps, and main anesthetic considerations for patients undergoing CTO PCI. Despite a growing body of literature, future research is still required to elucidate optimal anesthetic and mechanical support strategies in patients undergoing CTO PCI.

Amniotic Fluid Embolism Treated With Inhaled Milrinone: A Case Report

We present a patient with sudden cardiovascular collapse during cesarean delivery that was attributed to amniotic fluid embolism (AFE). The syndrome of AFE may be initiated by an anaphylactoid response to amniotic fluid in the maternal circulation that triggers the release of pulmonary vasoconstrictors, with transient pulmonary vasospasm, causing hemodynamic collapse and profound left ventricular failure. Milrinone, a pulmonary vasodilator used in the management of emergent right ventricular failure, was administered via a nebulizer in an effort to decrease pulmonary vascular resistance. If used immediately after AFE, inhaled milrinone may mitigate pulmonary vasoconstriction, providing a bridge to extracorporeal membrane oxygenation.

Interhospital Transfer of Patients With Acute Pulmonary Embolism (PE): Challenges and Opportunities

Acute pulmonary embolism (PE) is associated with significant morbidity and mortality. The management paradigm for acute PE has evolved in recent years with wider availability of advanced treatment modalities ranging from catheter-directed reperfusion therapies to mechanical circulatory support. This evolution has coincided with the development and implementation of institutional pulmonary embolism response teams (PERT) nationwide and internationally. Because most institutions are not equipped or staffed for advanced PE care, patients often require transfer to centers with more comprehensive resources, including PERT expertise. One of the unmet needs in current PE care is an organized approach to the process of interhospital transfer (IHT) of critically ill PE patients. In this review, we discuss medical optimization and support of patients before and during transfer, transfer checklists, defined roles of emergency medical services, and the roles and responsibilities of referring and receiving centers involved in the IHT of acute PE patients.

Cardiogenic shock and acute kidney injury: the rule rather than the exception

Cardiogenic shock (CS) is a life-threatening condition of poor end-organ perfusion, caused by any cardiovascular disease resulting in a severe depression of cardiac output. Despite recent advances in replacement therapies, the outcome of CS is still poor, and its management depends more on empirical decisions rather than on evidence-based strategies. By its side, acute kidney injury (AKI) is a frequent complication of CS, resulting in the onset of a cardiorenal syndrome. The combination of CS with AKI depicts a worse clinical scenario and holds a worse prognosis. Many factors can lead to acute renal impairment in the setting of CS, either for natural disease progression or for iatrogenic causes. This review aims at collecting the current evidence-based acknowledgments in epidemiology, pathophysiology, clinical features, diagnosis, and management of CS with AKI. We also attempted to highlight the major gaps in evidence as well as to point out possible strategies to improve the outcome.