Mechanical Ventilation Outcomes in Patients With Pulmonary Hypertension in the United States: A National Retrospective Cohort Analysis

Management of the peri-intubation period in patients with pulmonary arterial hypertension and respiratory failure

PURPOSE OF REVIEW

The endotracheal intubation of patients with pulmonary arterial hypertension (PAH) in respiratory distress is a highly morbid procedure that can precipitate hemodynamic collapse. Here we review our strategy for confronting this difficult clinical situation.

RECENT FINDINGS

There are no clinical trials that explore best practices in the management of patients with PAH and respiratory failure. Here we provide a practical approach to respiratory support, inopressor and pulmonary vasodilator selection, hemodynamic considerations, point-of-care ultrasound monitoring, and endotracheal intubation in patients with PAH in respiratory failure.

Echocardiographic diagnosis and clinical implications of wide-open tricuspid regurgitation for evaluating right ventricular dysfunction in the emergency department

The tricuspid regurgitation pressure gradient (TRPG) reflects the difference in pressure between the right ventricle and right atrium (ΔPRV-RA). Its estimation by echocardiography correlates well with that obtained using right-heart catheterization. An elevated TRPG is an important marker for identifying right ventricular dysfunction in both the acute and chronic settings. However, in the "wide-open" variant of TR, the TRPG counterintuitively falls. Failure to recognize this potential pitfall and underlying pathophysiology can cause underestimation of the severity of right ventricular dysfunction. This could lead to erroneous fluid tolerance assessments, and potentially harmful resuscitative and airway management strategies. In this manuscript, we illustrate the pathophysiology and potential pitfall of wide-open TR through a series of cases in which emergency physicians made the diagnosis using cardiac point-of-care ultrasound. To our knowledge, this clinical series is the first to demonstrate recognition of the paradoxically-low TRPG of wide-open TR, which guided appropriate management of critically ill patients in the emergency department.

Diagnosis and Management of Pulmonary Hypertension and Right Ventricular Failure in the Cardiovascular Intensive Care Unit

Pulmonary hypertension (PH) encompasses a broad range of conditions, including pulmonary artery hypertension, left-sided heart disease, and pulmonary and thromboembolic disorders. Successful diagnosis and management rely on an integrated clinical assessment of the patient's physiology and right heart function. Right ventricular (RV) heart failure is often a result of PH, but may result from varying abnormalities in preload, afterload, and intrinsic myocardial dysfunction, which require distinct management strategies. Consideration of an individual's hemodynamic phenotype and physiologic circumstances is paramount in management of PH and RV failure, particularly when there is clinical instability in the intensive care setting.

Right Heart Failure in the Intensive Care Unit: Etiology, Pathogenesis, Diagnosis, and Treatment

Right heart (RH) failure carries a high rate of morbidity and mortality. Patients who present with RH failure often exhibit complex aberrant cardio-pulmonary physiology with varying presentations. The treatment of RH failure almost always requires care and management from an intensivist. Treatment options for RH failure patients continue to evolve rapidly with multiple options available, including different pharmacotherapies and mechanical circulatory support devices that target various components of the RH circulatory system. An understanding of the normal RH circulatory physiology, treatment, and support options for the RH failure patients is necessary for all intensivists to improve outcomes. The purpose of this review is to provide clinical guidance on the diagnosis and management of RH failure within the intensive care unit setting, and to highlight the different pathophysiological manifestations of RH failure, its hemodynamics, and treatment options available at the disposal of the intensivist.

High driving pressure ventilation induces pulmonary hypertension in a rabbit model of acute lung injury

BACKGROUND

Mechanical ventilation may cause pulmonary hypertension in patients with acute lung injury (ALI), but the underlying mechanism remains elucidated.

METHODS

ALI was induced in rabbits by a two-hit injury, i.e., hydrochloric acid aspiration followed by mechanical ventilation for 1 h. Rabbits were then ventilated with driving pressure of 10, 15, 20, or 25 cmH2O for 7 h. Clinicopathological parameters were measured at baseline and different timepoints of ventilation. RNA sequencing was conducted to identify the differentially expressed genes in high driving pressure ventilated lung tissue.

RESULTS

The two-hit injury induced ALI in rabbits was evidenced by dramatically decreased PaO2/FiO2 in the ALI group compared with that in the control group (144.5 ± 23.8 mmHg vs. 391.6 ± 26.6 mmHg, P < 0.001). High driving pressure ventilation (20 and 25 cmH2O) significantly elevated the parameters of acute pulmonary hypertension at different timepoints compared with low driving pressure (10 and 15 cmH2O), along with significant increases in lung wet/dry ratios, total protein contents in bronchoalveolar lavage fluid, and lung injury scores. The high driving pressure groups showed more pronounced histopathological abnormalities in the lung compared with the low driving pressure groups, accompanied by significant increases in the cross-sectional areas of myocytes, right ventricular weight/body weight value, and Fulton's index. Furthermore, the expression of the genes related to ferroptosis induction was generally upregulated in high driving pressure groups compared with those in low driving pressure groups.

CONCLUSIONS

A rabbit model of ventilation-induced pulmonary hypertension in ALI was successfully established. Our results open a new research direction investigating the exact role of ferroptosis in ventilation-induced pulmonary hypertension in ALI.

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.

Bedside Ultrasound for Hemodynamic Monitoring in Cardiac Intensive Care Unit

Thanks to the advances in medical therapy and assist devices, the management of patients hospitalized in cardiac intensive care unit (CICU) is becoming increasingly challenging. In fact, Patients in the cardiac intensive care unit are frequently characterized by dynamic and variable diseases, which may evolve into several clinical phenotypes based on underlying etiology and its complexity. Therefore, the use of noninvasive tools in order to provide a personalized approach to these patients, according to their phenotype, may help to optimize the therapeutic strategies towards the underlying etiology. Echocardiography is the most reliable and feasible bedside method to assess cardiac function repeatedly, assisting clinicians not only in characterizing hemodynamic disorders, but also in helping to guide interventions and monitor response to therapies. Beyond basic echocardiographic parameters, its application has been expanded with the introduction of new tools such as lung ultrasound (LUS), the Venous Excess UltraSound (VexUS) grading system, and the assessment of pulmonary hypertension, which is fundamental to guide oxygen therapy. The aim of this review is to provide an overview on the current knowledge about the pathophysiology and echocardiographic evaluation of perfusion and congestion in patients in CICU, and to provide practical indications for the use of echocardiography across clinical phenotypes and new applications in CICU.

Demographics and Risk Factors of Pediatric Pulmonary Hypertension Readmissions

BACKGROUND AND OBJECTIVES

Pulmonary hypertension (PH) leads to significant morbidity and mortality in pediatric patients and increases the readmission rates for hospitalizations. This study evaluates the risk factors and comorbidities associated with an increase in 30-day readmissions among pediatric PH patients.

METHODS

National Readmission Database (NRD) 2017 was searched for patients less than 18 years of age who were diagnosed with PH based on the International Classification of Diseases, 10th Revision (ICD-10). Statistical Package for the Social Sciences (SPSS) software v25.0 (IBM Corp., Armonk, NY) was used for statistical analysis.

RESULTS

Of 5.52 million pediatric encounters, 10,501 patients met the selection criteria. The 30-day readmission rate of 14.43% (p < 0.001) was higher than hospitalizations from other causes {Odds Ratio (OR) 4.02 (3.84-4.20), p < 0.001}. The comorbidities of sepsis {OR 0.75 (0.64-0.89), p < 0.02} and respiratory infections {OR 0.75 (0.67-0.85), p < 0.001} were observed to be associated with lower 30-day readmissions. Patients who required invasive mechanical ventilation via endotracheal tube {OR 1.66 (1.4-1.96), p < 0.001} or tracheostomy tube {OR 1.35 (1.15-1.6), p < 0.001} had increased unplanned readmissions. Patients with higher severity of illness based on All Patients Refined Diagnosis Related Groups (APR-DRG) were more likely to get readmitted {OR 7.66 (3.13-18.76), p < 0.001}.

CONCLUSION

PH was associated with increased readmission rates compared to the other pediatric diagnoses, but the readmission rate in this study was lower than one previous pediatric study. Invasive mechanical ventilation, Medicaid insurance, higher severity of illness, and female gender were associated with a higher likelihood of readmission within 30 days.

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.

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.

Critical Care Management of the Patient with Pulmonary Hypertension

Pulmonary hypertension patients admitted to the intensive care unit have high mortality, and right ventricular failure typically is implicated as cause of or contributor to death. Initial care of critically ill pulmonary hypertension patients includes recognition of right ventricular failure, appropriate monitoring, and identification and treatment of any inciting cause. Management centers around optimization of cardiac function, with a multipronged approach aimed at reversing the pathophysiology of right ventricular failure. For patients who remain critically ill or in shock despite medical optimization, mechanical circulatory support can be used as a bridge to recovery or lung transplantation.

Critical care outcomes in patients with pre-existing pulmonary hypertension: insights from the ASPIRE registry

Pulmonary hypertension (PH) is a life-shortening condition characterised by episodes of decompensation precipitated by factors such as disease progression, arrhythmias and sepsis. Surgery and pregnancy also place additional strain on the right ventricle. Data on critical care management in patients with pre-existing PH are scarce.

We conducted a retrospective observational study of a large cohort of patients admitted to the critical care unit of a national referral centre between 2000–2017 to establish acute mortality, evaluate predictors of in-hospital mortality and establish longer term outcomes in survivors to hospital discharge.

242 critical care admissions involving 206 patients were identified. Hospital survival was 59.3%, 94% and 92% for patients admitted for medical, surgical or obstetric reasons, respectively. Medical patients had more severe physiological and laboratory perturbations than patients admitted following surgical or obstetric interventions. Higher APACHE II (Acute Physiology and Chronic Health Evaluation) score, age and lactate, and lower oxygen saturation measure by pulse oximetry/inspiratory oxygen fraction (S_pO2/F_iO2) ratio, platelet count and sodium level were identified as independent predictors of hospital mortality. An exploratory risk score, OPALS (oxygen (S_pO2/F_iO2) ≤185; platelets ≤196×10⁹·L⁻¹; age ≥37.5 years; lactate ≥2.45 mmol·L⁻¹; sodium ≤130.5 mmol·L⁻¹), identified medical patients at increasing risk of hospital mortality. One (11%) out of nine patients who were invasively ventilated for medical decompensation and 50% of patients receiving renal replacement therapy left hospital alive. There was no significant difference in exercise capacity or functional class between follow-up and pre-admission in patients who survived to discharge.

These data have clinical utility in guiding critical care management of patients with known PH. The exploratory OPALS score requires validation.

Critical care survival is worse in PH patients admitted for medical rather than surgical/obstetric indications. Nevertheless, many show longer term survival and functional recovery. Markers of severity of acute illness at admission are prognostic.https://bit.ly/2YX9Fw9

Evaluation of code-based algorithms to identify pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients in large administrative databases

Large administrative healthcare (including insurance claims) databases are used for various retrospective real-world evidence studies. However, in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension, identifying patients retrospectively based on administrative codes remains challenging, as it relies on code combinations (algorithms) and the accuracy for patient identification of most of them is unknown. This study aimed to assess the performance of various algorithms in correctly identifying patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension in administrative databases. A systematic literature review was performed to find publications detailing code-based algorithms used to identify pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients. PheValuator, a diagnostic predictive modelling tool, was applied to three US claims databases, yielding models that estimated the probability of a patient having the disease. These models were used to evaluate the performance characteristics of selected pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension algorithms. With increasing algorithm complexity, average positive predictive value increased (pulmonary arterial hypertension: 13.4–66.0%; chronic thromboembolic pulmonary hypertension: 10.3–75.1%) and average sensitivity decreased (pulmonary arterial hypertension: 61.5–2.7%; chronic thromboembolic pulmonary hypertension: 20.7–0.2%). Specificities and negative predictive values were high (≥97.5%) for all algorithms. Several of the algorithms performed well overall when considering all of these four performance parameters, and all algorithms performed with similar accuracy across the three claims databases studied, even though most were designed for patient identification in a specific database. Therefore, it is the objective of a study that will determine which algorithm may be most suitable; one- or two-component algorithms are most inclusive and three- or four-component algorithms identify most precise pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension populations, respectively.

Management of Pulmonary Arterial Hypertension in the ICU

Patients with pulmonary arterial hypertension (PAH) who are admitted to the intensive care unit (ICU) pose a challenge to the multidisciplinary health-care team due to the complexity of the pathophysiology of their disease state and the medication considerations that must be made to appropriately manage them. PAH is a progressive disease with the majority of patients ultimately dying as a result of right ventricular (RV) failure. During an acute decompensation, patients must be appropriately managed to optimize volume status, RV function, cardiac output, and systemic perfusion, while treating the underlying cause of the exacerbation. During times of critical illness, the ability to administer medications approved for use in PAH can be impacted by end-organ damage, hemodynamic instability, new drug interactions, or available dosage forms. Balancing the multimodal treatment approach needed to manage an acute exacerbation and the pharmacokinetic and administration concerns impacting baseline PAH therapy as a result of critical illness requires an expert multiprofessional PAH team. The purpose of this review is to evaluate specific management considerations for critically ill patients with PAH in the ICU.

National trends and outcomes of hospitalizations for pulmonary hypertension in Spain (2001-2014)

OBJECTIVE

To assess changes in incidence, diagnostic procedures, comorbidity profiles, length of hospital stay (LOHS), costs, and in-hospital mortality (IHM) for patients hospitalized with pulmonary hypertension (PH).

METHODS

We included patients hospitalized with PH in Spain from 2001 to 2014. The data were collected from the National Hospital Discharge Database.

RESULTS

We included 644,436 discharges (43.31% males and 56.09% females) admitted for primary PH (8.34%) or secondary PH (91.66%). The crude incidence rate increased from 58.67 to 148.32 hospitalizations per 100,000 inhabitants between 2001 and 2002 and 2013-2014 (p < 0.001). The percentage of patients with a Charlson comorbidity index ≥2 was 27.87% in 2001-2002, increasing to 47.02% in 2013-2014 (p < 0.001). IHM was 8.77%, with a reduction in the value yielded by the multivariable analysis between 2009 and 2010 and 2013-2014. Median LOHS was 9 ± 9 days in 2001-2002, which decreased to 7 ± 8 days in 2013-2014 (p < 0.001). The mean cost per patient increased from €3352.4 ± €1495 in the period 2001-2002 to €4198.94 ± €1287.96 in 2013-2014 (p < 0.001).

CONCLUSIONS

Despite the increase over time in hospital admissions for PH, associated comorbidity, and costs, LOHS and IHM decreased, suggesting that the management of PH-related hospitalizations improved in Spain during the study period.

PRactice of VENTilation in Middle-Income Countries (PRoVENT-iMIC): rationale and protocol for a prospective international multicentre observational study in intensive care units in Asia

INTRODUCTION

Current evidence on epidemiology and outcomes of invasively mechanically ventilated intensive care unit (ICU) patients is predominantly gathered in resource-rich settings. Patient casemix and patterns of critical illnesses, and probably also ventilation practices are likely to be different in resource-limited settings. We aim to investigate the epidemiological characteristics, ventilation practices and clinical outcomes of patients receiving mechanical ventilation in ICUs in Asia.

METHODS AND ANALYSIS

PRoVENT-iMIC (study of PRactice of VENTilation in Middle-Income Countries) is an international multicentre observational study to be undertaken in approximately 60 ICUs in 11 Asian countries. Consecutive patients aged 18 years or older who are receiving invasive ventilation in participating ICUs during a predefined 28-day period are to be enrolled, with a daily follow-up of 7 days. The primary outcome is ventilatory management (including tidal volume expressed as mL/kg predicted body weight and positive end-expiratory pressure expressed as cm H₂O) during the first 3 days of mechanical ventilation-compared between patients at no risk for acute respiratory distress syndrome (ARDS), patients at risk for ARDS and in patients with ARDS (in case the diagnosis of ARDS can be made on admission). Secondary outcomes include occurrence of pulmonary complications and all-cause ICU mortality.

ETHICS AND DISSEMINATION

PRoVENT-iMIC will be the first international study that prospectively assesses ventilation practices, outcomes and epidemiology of invasively ventilated patients in ICUs in Asia. The results of this large study, to be disseminated through conference presentations and publications in international peer-reviewed journals, are of ultimate importance when designing trials of invasive ventilation in resource-limited ICUs. Access to source data will be made available through national or international anonymised datasets on request and after agreement of the PRoVENT-iMIC steering committee.

TRIAL REGISTRATION NUMBER

NCT03188770; Pre-results.

Medical Management of Pulmonary Embolism: Beyond Anticoagulation

Pulmonary embolism (PE) is a common medical condition that carries significant morbidity and mortality. Although diagnosis, anticoagulation, and interventional clot-burden reduction strategies represent the focus of clinical research and care in PE, appropriate risk stratification and supportive care are crucial to ensure good outcomes. In this chapter, we will discuss the medical management of PE from the time of presentation to discharge, focusing on the critical care of acute right ventricular failure, anticoagulation of special patient populations, and appropriate follow-up testing after acute PE.