Safety and utility of indwelling pleural catheters in lung transplant recipients.

INTRODUCTION: The safety and efficacy of indwelling pleural catheters (IPCs) in lung allograft recipients is under-reported. METHODS: We performed a multicenter, retrospective analysis between 1/1/2010 and 6/1/2022 of consecutive IPCs placed in lung transplant recipients. Outcomes included incidence of infectious and non-infectious complications and rate of auto-pleurodesis. RESULTS: Seventy-one IPCs placed in 61 lung transplant patients at eight centers were included. The most common indication for IPC placement was recurrent post-operative effusion. IPCs were placed at a median of 59 days (IQR 40-203) post-transplant and remained for 43 days (IQR 25-88). There was a total of eight (11%) complications. Infection occurred in five patients (7%); four had empyema and one had a catheter tract infection. IPCs did not cause death or critical illness in our cohort. Auto-pleurodesis leading to the removal of the IPC occurred in 63 (89%) instances. None of the patients in this cohort required subsequent surgical decortication. CONCLUSIONS: The use of IPCs in lung transplant patients was associated with an infectious complication rate comparable to other populations previously studied. A high rate of auto-pleurodesis was observed. This work suggests that IPCs may be considered for the management of recurrent pleural effusions in lung allograft recipients.

Multiplatform Single-Cell Analysis Identifies Immune Cell Types Enhanced in Pulmonary Fibrosis.

Immune cells have been implicated in idiopathic pulmonary fibrosis (IPF), but the phenotypes and effector mechanisms of these cells remain incompletely characterized. We performed mass cytometry to quantify immune cell subsets in lungs of 12 patients with IPF and 15 organ donors without chronic lung disease and used existing single-cell RNA-sequencing data to investigate transcriptional profiles of immune cells overrepresented in IPF. Among myeloid cells, we found increased numbers of alveolar macrophages (AMØs) and dendritic cells (DCs) in IPF, as well as a subset of monocyte-derived DCs. In contrast, monocyte-like cells and interstitial macrophages were reduced in IPF. Transcriptomic profiling identified an enrichment for IFN-γ response pathways in AMØs and DCs from IPF, as well as antigen processing in DCs and phagocytosis in AMØs. Among T cells, we identified three subsets of memory T cells that were increased in IPF, including CD4+ and CD8+ resident memory T cells (TRM) and CD8+ effector memory cells. The response to the IFN-γ pathway was enriched in CD4 TRM and CD8 TRM cells in IPF, together with T cell activation and immune response-regulating signaling pathways. Increased AMØs, DCs, and memory T cells were present in IPF lungs compared with control subjects. In IPF, these cells possess an activation profile indicating increased IFN-γ signaling and upregulation of adaptive immunity in the lungs. Together, these studies highlight critical features of the immunopathogenesis of IPF.

Left Ventricular Unloading During Extracorporeal Life Support: Current Practice.

Venoarterial extracorporeal life support (VA-ECLS) is a powerful tool that can provide complete cardiopulmonary support for patients with refractory cardiogenic shock. However, VA-ECLS increases left ventricular (LV) afterload, resulting in greater myocardial oxygen demand, which can impair myocardial recovery and worsen pulmonary edema. These complications can be ameliorated by various LV venting strategies to unload the LV. Evidence suggests that LV venting improves outcomes in VA-ECLS, but there is a paucity of randomized trials to help guide optimal strategy and the timing of venting. In this review, we discuss the available evidence regarding LV venting in VA-ECLS, explain important hemodynamic principles involved, and propose a practical approach to LV venting in VA-ECLS.

Pilot Testing of a Lightweight, Pulmonary Assist System in an Ambulatory Sheep Model of Destination Therapy Respiratory Support.

A new, lightweight (2.3 kg), ambulatory pulmonary assist system (PAS) underwent preliminary evaluation in ambulatory sheep. The PAS was purposefully designed for long-term extracorporeal respiratory support for chronic lung disease and utilizes a novel, small (0.9 m 2 surface area) gas exchanger, the pulmonary assist device, with a modified Heart Assist 5 pump fitting in a small wearable pack. Prototype PAS were attached to two sheep in venovenous configuration for 7 and 14 days, evaluating ability to remain thrombus free; maintain gas exchange and blood flow resistance; avoid biocompatibility-related complications while allowing safe ambulation. The PAS achieved 1.56 L/min of flow at 10.8 kRPM with a 24 Fr cannula in sheep one and 2.0 L/min at 10.5 kRPM with a 28 Fr cannula in sheep 2 without significant change. Both sheep walked freely, demonstrating the first application of truly ambulatory ECMO in sheep. While in vitro testing evaluated PAS oxygen transfer rates of 104.6 ml/min at 2 L/min blood flow, oxygen transfer rates averaged 60.6 ml/min and 70.6 ml/min in studies 1 and 2, due to average hemoglobin concentrations lower than humans (8.9 and 10.5 g/dl, respectively). The presented cases support uncomplicated ambulation using the PAS.

Area Deprivation Index and Distress Community Index Scores Are Not Associated With Short-Term and Long-Term Extracorporeal Life Support Outcomes.

Distressed Communities Index (DCI) and Area Deprivation Index (ADI) are two composite ranking scores that report community level socioeconomic status (SES) by ZIP codes. The objective of this study was to evaluate the impact of SES as estimated by DCI and ADI scores on short-term and long-term outcomes after extracorporeal life support (ECLS) at a quaternary medical center. All patients on ECLS between January 1, 2015 and August 31, 2020 (N = 428) at Vanderbilt University Medical Center in Nashville, Tennessee, had their ADI and DCI scores calculated. Primary outcome was mortality during index hospitalization, and secondary outcome was survival to end of study follow-up. There was no significant difference in primary outcome between the top 25% ADI vs . bottom 75% ADI (53.8% vs . 50.6%; p = 0.56) or between top 25% DCI vs . bottom 75% DCI (56.1 vs . 49.2; p = 0.21). Adjusted odds ratio for the primary outcome with ADI and DCI was 1.13 (95% CI, 0.63-2.0; p = 0.67) and 1.28 (95% CI, 0.70-2.34; p = 0.41), respectively. Additionally, there was no significant difference in long-term survival curves based on their ADI or DCI scores. In conclusion, SES as estimated by baseline DCI and ADI scores does not appear to impact short- or long-term survival post-ECLS at a large volume center. http://links.lww.com/ASAIO/A951.

Modifiable Mechanical Ventilation Targets Are Associated With Improved Survival in Ventilated VA-ECLS Patients.

BACKGROUND: In acute respiratory distress syndrome (ARDS), lung protective ventilation (LPV) improves patient outcomes by minimizing ventilator-induced lung injury. The value of LPV in ventilated patients with cardiogenic shock (CS) requiring venoarterial extracorporeal life support (VA-ECLS) is not known, but the extracorporeal circuit provides a unique opportunity to modify ventilatory parameters to improve outcomes. OBJECTIVES: The authors hypothesized that CS patients on VA-ECLS who require mechanical ventilation (MV) may benefit from low intrapulmonary pressure ventilation (LPPV), which has the same end goals as LPV. METHODS: The authors queried the ELSO (Extracorporeal Life Support Organization) registry for hospital admissions between 2009 and 2019 for CS patients on VA-ECLS and MV. They defined LPPV as peak inspiratory pressure at 24 hours on ECLS of <30 cm H2O. Positive end-expiration pressure and dynamic driving pressure (DDP) at 24 hours were also studied as continuous variables. Their primary outcome was survival to discharge. Multivariable analyses were performed that adjusted for baseline Survival After Venoarterial Extracorporeal Membrane Oxygenation score, chronic lung conditions, and center extracorporeal membrane oxygenation volume. RESULTS: A total of 2,226 CS patients on VA-ECLS were included: 1,904 received LPPV. The primary outcome was higher in the LPPV group vs the no-LPPV group (47.4% vs 32.6%; P < 0.001). Median peak inspiratory pressure (22 vs 24 cm H2O; P < 0.001) as well as DDP (14.5 vs 16 cm H2O; P < 0.001) were also significantly lower in those surviving to discharge. The adjusted OR for the primary outcome with LPPV was 1.69 (95% CI: 1.21-2.37; P = 0.0021). CONCLUSIONS: LPPV is associated with improved outcomes in CS patients on VA-ECLS requiring MV.

Extracorporeal Life Support for Cardiogenic Shock in Adult Congenital Heart Disease-An ELSO Registry Analysis.

There are minimal data on the use of venoarterial extracorporeal membrane life support (VA-ECLS) in adult congenital heart disease (ACHD) patients presenting with cardiogenic shock (CS). This study sought to describe the population of ACHD patients with CS who received VA-ECLS in the Extracorporeal Life Support Organization (ELSO) Registry. This was a retrospective analysis of adult patients with diagnoses of ACHD and CS in ELSO from 2009-2021. Anatomic complexity was categorized using the American College of Cardiology/American Heart Association 2018 guidelines. We described patient characteristics, complications, and outcomes, as well as trends in mortality and VA-ECLS utilization. Of 528 patients who met inclusion criteria, there were 32 patients with high-complexity anatomy, 196 with moderate-complexity anatomy, and 300 with low-complexity anatomy. The median age was 59.6 years (interquartile range, 45.8-68.2). The number of VA-ECLS implants increased from five implants in 2010 to 81 implants in 2021. Overall mortality was 58.3% and decreased year-by-year (ß= -2.03 [95% confidence interval, -3.36 to -0.70], p = 0.007). Six patients (1.1%) were bridged to heart transplantation and 21 (4.0%) to durable ventricular assist device. Complications included cardiac arrhythmia/tamponade (21.6%), surgical site bleeding (17.6%), cannula site bleeding (11.4%), limb ischemia (7.4%), and stroke (8.7%). Utilization of VA-ECLS for CS in ACHD patients has increased over time with a trend toward improvement in survival to discharge.

Early Blood Pressure Variables Associated With Improved Outcomes in VA-ECLS: The ELSO Registry Analysis.

BACKGROUND: As utilization of veno-arterial extracorporeal life support (VA-ECLS) in treatment of cardiogenic shock (CS) continues to expand, clinical variables that guide clinicians in early recognition of myocardial recovery and therefore, improved survival, after VA-ECLS are critical. There remains a paucity of literature on early postinitiation blood pressure measurements that predict improved outcomes. OBJECTIVES: The objective of this study is to help identify early blood pressure variables associated with improved outcomes in VA-ECLS. METHODS: The authors queried the ELSO (Extracorporeal Life Support Organization) registry for cardiogenic shock patients treated with VA-ECLS or venovenous arterial ECLS between 2009 and 2020. Their inclusion criteria included treatment with VA-ECLS or venovenous arterial ECLS; absence of pre-existing durable right, left, or biventricular assist devices; no pre-ECLS cardiac arrest; and no surgical or percutaneously placed left ventricular venting devices during their ECLS runs. Their primary outcome of interest was the survival to discharge during index hospitalization. RESULTS: A total of 2,400 CS patients met the authors' inclusion criteria and had complete documentation of blood pressures. Actual mortality during index hospitalization in their cohort was 49.5% and survivors were younger and more likely to be Caucasian, intubated for >30 hours pre-ECLS initiation, and had a favorable baseline SAVE (Survival After Veno-arterial ECMO) score (P < 0.05 for all). Multivariable regression analyses adjusting for SAVE score, age, ECLS flow at 4 hours, and race showed that every 10-mm Hg increase in baseline systolic blood pressure (HR: 0.92 [95% CI: 0.89-0.95]; P < 0.001), and baseline pulse pressure (HR: 0.88 [95% CI: 0.84-0.91]; P < 0.001) at 24 hours was associated with a statistically significant reduction in mortality. CONCLUSIONS: Early (within 24 hours) improvements in pulse pressure and systolic blood pressure from baseline are associated with improved survival to discharge among CS patients treated with VA-ECLS.

Obesity and underweight are associated with an increased risk of death after lung transplantation.

RATIONALE: Obesity is considered a relative contraindication to lung transplantation, based on studies that have not accounted for key confounders. Little is known about the risk of death for underweight candidates after transplantation. OBJECTIVES: To examine the associations of pretransplant obesity and underweight with the risk of death after lung transplantation. METHODS: We examined 5,978 adults with cystic fibrosis, chronic obstructive pulmonary disease, and diffuse parenchymal lung disease who underwent lung transplantation in the United States between 1995 and 2003. We used Cox models and generalized additive models to examine the association between pretransplant body mass index and the risk of death after lung transplantation with adjustment for donor and recipient factors. MEASUREMENTS AND MAIN RESULTS: The median follow-up time was 4.2 years. Compared with normal weight recipients, the multivariable-adjusted rates of death were 15% higher for underweight recipients (95% confidence interval, 3 to 28%), 15% higher for overweight recipients (95% confidence interval, 6 to 26%), and 22% higher for obese recipients (95% confidence interval, 8 to 39%). These relationships persisted when stratified by diagnosis. The multivariable-adjusted population attributable fraction was 12% at 1 year and 8% at 5 years. CONCLUSIONS: Both obesity and underweight are independent risk factors for death after lung transplantation, contributing to up to 12% of deaths in the first year after transplantation. Primary care providers and pulmonologists should promote a healthy weight for patients with lung disease long before transplantation is considered.

Low-dose spironolactone: effects on artery-to-artery vein grafts and percutaneous coronary intervention sites.

The efficacy of vein grafts used in coronary and peripheral artery bypass is limited by excessive hyperplasia and fibrosis that occur early after engraftment. In the present study, we sought to determine whether low-dose spironolactone alleviates maladaptive vein graft arterialization and alters intimal reaction to coronary artery stenting. Yorkshire pigs were randomized to treatment with oral spironolactone 25 mg daily or placebo. All animals underwent right carotid artery interposition grafting using a segment of external jugular vein and, 5 days later, underwent angiography of carotid and coronary arteries. At that time, a bare metal stent was placed in the left anterior descending artery and balloon angioplasty was performed on the circumflex coronary artery. Repeat carotid and coronary angiograms were performed before euthanasia and graft excision at 30 days. Angiography revealed that venous grafts of spironolactone-treated animals had lumen diameters twice the size of controls at 5 days, a finding that persisted at 30 days. However, neointima and total vessel wall areas also were 2- to 3-fold greater in spironolactone-treated animals, and there were no differences in vessel wall layer thicknesses or collagen and elastin densities. In the coronary circulation, there were no differences between treatment groups in any vessel wall parameters in either stented or unstented vessels. Taken together, these observations suggest that low-dose spironolactone may exert a novel protective effect on remodeling in venous arterial grafts that does not depend on the reduction of hyperplastic changes but may involve dilatation of the vessel wall.

Successful pulmonary thromboendarterectomy in a patient with sickle cell disease and associated resolution of a leg ulcer.

Pulmonary hypertension (PH) is a relatively frequent and severe complication of sickle cell disease (SCD). PH associated with SCD is classified as Group 5 PH. The exact pathogenesis of PH in SCD in not known. There are also very limited treatment options available at this time for such patients with Group 5 PH. Patients with SCD are predisposed to a hypercoagulable state and thus can also suffer from chronic thromboembolism. These patients can have associated chronic thromboembolic pulmonary hypertension (CTEPH), thus being classified as Group 4 PH. We present such a case of a patient with SCD diagnosed with severe PH who was found to have CTEPH and successfully underwent a thromboendarterectomy with resolution of his symptoms such as reduction of his oxygen requirements and healing of chronic leg ulcer. This case illustrates the importance of screening patients with SCD and elevated pulmonary artery pressures for CTEPH as this would offer possible treatment options such as pulmonary thromboendarterectomy and/or riociguat in this subset of patients.

The Feasibility of Venovenous ECMO at Role-2 Facilities in Austere Military Environments.

INTRODUCTION: Venovenous extracorporeal membrane oxygenation (VV-ECMO) has been gaining use to bridge the recovery from acute respiratory distress syndrome (ARDS) refractory to conventional treatment. However, these interventions are often limited to higher echelons of military care. We present a case of lung salvage from severe ARDS in an Afghani soldier with VV-ECMO at a Role-2 (R2) facility in an austere military environment in Afghanistan. CASE: A 25-year-old Afghani soldier presented to an R2 facility with blast lung injury and multiple penetrating injuries following an explosion. The patient underwent immediate damage control laparotomy. The abdomen was left open for subsequent washouts and ongoing resuscitation. Due to his ineligibility for evacuation and worsening ARDS, despite 5 d of conventional ventilation strategies, he was started on VV-ECMO. The patient had immediate improvements in oxygenation, which continued for 10 d. Moreover, he underwent three transportations to the operating room without accidental decannulation or disruption of the VV-ECMO device. Despite significant improvements, the patient expired on postoperative day 15, due to an overwhelming intra-abdominal sepsis. CONCLUSION: As future advancements are sought, VV-ECMO may become a consideration for casualties with severe ARDS at the point of injury and at lower echelons of military care.

Increasing Opportunity for Lung Transplant in Interstitial Lung Disease With Pulmonary Hypertension.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation for end-stage interstitial lung disease (ILD) and pulmonary hypertension (PH) has varying results based on ECMO configuration. We compare our experience using venovenous (VV) and venoarterial (VA) ECMO bridge to transplantation for ILD with PH on survival to successful transplantation. METHODS: A single-center retrospective review was done of patients with ILD and secondary PH who were placed on either VV or VA ECMO as bridge to transplantation from 2010 to 2016. Comparisons for factors associated with survival to transplantation between VV and VA ECMO strategies were made using Cox proportional hazards model. Subgroup analysis included comparisons of VV ECMO patients who remained on VV or were converted to VA ECMO. RESULTS: A total of 50 patients with ILD and PH were treated initially with either VV (n = 19) or VA (n = 31) ECMO as bridge to lung transplantation. Initial VA ECMO had a significantly higher survival to transplantation compared with initial VV ECMO (p = 0.03). Cox proportional hazards modeling showed a 59% reduction in risk of death for VA compared with VV ECMO (hazard reduction 0.41, 95% confidence interval: 0.18 to 0.92, p = 0.03). Patients converted from VV to VA ECMO had significantly longer survival awaiting transplant than patients who remained on VV ECMO (p = 0.03). Ambulation on ECMO before transplantation was associated with an 80% reduction in the risk of death (hazard reduction 0.20, 95% confidence interval: 0.08 to 0.48, p < 0.01). CONCLUSIONS: Venoarterial ECMO upper body configuration for patients with end stage ILD and PH significantly improves overall survival to transplantation.

Anesthetic management of the patient with extracorporeal membrane oxygenator support.

The use of short-term mechanical circulatory support in the form of extracorporeal membrane oxygenation (ECMO) in adult patients has increased over the last decade. Cardiothoracic anesthesiologists may care for these patients during ECMO placement and for procedures while ECMO support is in place. An understanding of ECMO capabilities, indications, and complications is essential to the anesthesiologist caring for these patients. Below we review the anesthetic considerations for the implantation of ECMO and concerns when caring for patients on ECMO.

Factors influencing DNR decision-making in a surgical ICU.

BACKGROUND: End-of-life decisions in the surgical ICU can be complicated by the unique characteristics of perioperative illness and the focus on life-extending interventions. We sought to determine whether illness severity correlated with the presence of DNR order in critically ill surgical patients. STUDY DESIGN: All surgical ICU patients who were given a DNR order from May 1, 1991 to May 31, 1998 were identified. Demographic data for all patients were collected prospectively. Patients who died without a DNR order were compared with patients with DNR orders. Variables in the analysis included date of DNR order, age, ICU, and hospital lengths of stay, APACHE II and III scores and maximum multiple organ dysfunction scores, past medical history, and mortality. ANOVA, multivariate ANOVA, and chi-square statistical tests were used to analyze the data, with p

Chronic thromboembolic pulmonary hypertension, pregnancy, and a pulmonary endarterectomy: a rare challenge.

It is well described that patients with group 1 forms of pulmonary arterial hypertension have a high risk of mortality during pregnancy and in the early postpartum period. However, to the authors' knowledge, the diagnosis and management of group 4 pulmonary hypertension due to chronic thromboembolic pulmonary hypertension (CTEPH) during pregnancy with early postpartum pulmonary endarterectomy (PEA) has not been previously reported. We report the case of a 28-year-old woman who received a diagnosis of CTEPH during her pregnancy, was managed as an inpatient by a multidisciplinary team throughout the pregnancy and early postpartum period, and underwent PEA 6 weeks after delivery. While the management of acute pulmonary embolus in pregnancy is well described, this unique case of CTEPH diagnosed during pregnancy illustrates several challenging management issues.

Blood conservation in extracorporeal membrane oxygenation for acute respiratory distress syndrome.

BACKGROUND: Extracorporeal membrane oxygenation support (ECMO) typically requires multiple blood transfusions and is associated with frequent bleeding complications. Blood transfusions are known to increase morbidity and mortality in critically ill patients, which may extend to patients receiving ECMO. Aiming to reduce transfusion requirements, we implemented a blood conservation protocol in adults with severe acute respiratory distress syndrome (ARDS) receiving ECMO. METHODS: This was a retrospective study of adults receiving ECMO for ARDS after initiation of a blood conservation protocol that included a transfusion trigger of hemoglobin of less than 7.0 g/dL, use of low-dose anticoagulation targeting an activated partial thromboplastin time of 40 to 60 seconds, and autotransfusion of circuit blood during decannulation. The primary objective was to evaluate transfusion requirements during ECMO support. Clinical outcomes included survival, neurologic function, renal function, bleeding, and thrombotic complications. RESULTS: The analysis included 38 patients; of these, 24 (63.2%) received a transfusion while receiving ECMO. Median hemoglobin was 8.29 g/dL. A median of 1.0 units (range, 250 to 300 mL) was transfused during ECMO support over a median duration of 9.0 days, equivalent to 0.11 U/d (range, 27.5 to 33.3 mL/d). The median activated partial thromboplastin time was 46.5 seconds. Bleeding occurred in 10 patients (26.3%); severe bleeding occurred in 2 patients (5.3%). Twenty-eight patients (73.7%) survived to hospital discharge. CONCLUSIONS: Implementation of a blood conservation protocol in adults receiving ECMO for ARDS resulted in lower transfusion requirements and bleeding complications than previously reported in the literature and was associated with comparable survival and organ recovery.

Outcomes of cardiac surgery in nonagenarians: a 10-year experience.

BACKGROUND: With an increasing awareness of health issues and greater emphasis on preventive medicine, the general population is living longer and healthier lives than ever before. Physicians are taking care of older patients, many of whom may require cardiac surgical procedures. Improving cardiopulmonary bypass technology allows for safer procedures with reduced morbidity and mortality even in older patients. METHODS: We have performed a retrospective analysis of 42 consecutive nonagenarian patients who underwent open-heart procedures over a 10-year period (1993 to 2002) at our institution. Their demographic profiles, operative data, perioperative results, and long-term outcomes were recorded and analyzed. RESULTS: Twenty-two women and 20 men with an age range of 90 to 97 years (mean, 91.4 years) had open-heart surgery over the study period. The complication rate was 67% overall, consisting of 7% respiratory (pneumonia, respiratory failure, reintubation), 7% hemorrhagic or embolic (postoperative bleeding, cerebral vascular accident), 12% infectious (wound infection, sepsis), and 31% new arrhythmia (atrial fibrillation, atrial flutter, ventricular tachycardia, ventricular fibrillation). Despite these complication rates, average hospital stay was 17.5 days (median, 11 days), with an intensive care unit stay of 12.0 days (median, 5 days). Thirty-day survival was 95% and survival to discharge was 93% (three deaths total; one cardiac arrest at hospital day 134 and two perioperative deaths; one ventricular arrhythmia, one cerebral vascular accident). The only statistically significant risk factor of mortality was emergency surgery. Currently, 81% are still alive an average of 2.53 years since surgery (range, 0.16 to 7.1 years). CONCLUSIONS: With improving techniques and greater attention to detail, the select nonagenarian can safely undergo cardiac surgery.

Resection of a symptomatic pericardial cyst using the computer-enhanced da Vinci Surgical System.

Traditionally, symptomatic pericardial cysts have been treated with thoracotomy and resection. More recently, video-assisted thoracoscopic procedures for pericardial cysts have been reported. We present the case of a 43-year-old man who was suffering from a symptomatic pericardial cyst. He underwent successful resection using a computer-enhanced robotic surgical system. This case is an example of the continued extension of robotic-assisted thoracic surgery.