Acute Kidney Injury in Patients Undergoing Cardiopulmonary Bypass for Lung Transplantation

Early outcomes of lung transplantation with lung allografts from coronavirus disease 2019 (COVID-19)-positive donors

OBJECTIVE

Coronavirus disease 2019 (COVID-19) can be detected for extended periods of time with nucleic acid amplification test even after transmissibility becomes negligible. Lung allografts from COVID-19-positive donors have been used for transplantation in highly selected cases. This study aimed to clarify the early outcomes of lung transplantation with COVID-19-positive donors.

METHODS

The Organ Procurement and Transplantation Network/United Network for Organ Sharing database between April 2020 and June 2022 was retrospectively analyzed.

RESULTS

In the study period, 1297 COVID-19-positive donors were identified and the lungs were transplanted from 47 donors (3.6%). Of 47 donors, 44 donors were positive for COVID-19 NAT with nasopharyngeal swabs and the other 3 were positive with bronchoalveolar lavage. The COVID-19-positive lung donors were younger than the COVID-19-negative donors (28.4 ± 11.6 years vs 35.4 ± 13.6 years, P < .001). Recipients of the COVID-19-positive lungs (n = 47) were more likely have a greater lung allocation score (57.1 ± 22.9 vs 50.5 ± 19.7, P = .057) than recipients of COVID-19-negative lungs (n = 5501). The posttransplant length of hospital stay (39.8 ± 43.6 days vs 30.6 ± 34.5 days, P = .181), need for extracorporeal membrane oxygenation support at 72 hours after transplantation (2.6% [1/38] vs 10.4% [541/5184], P = .18), and 1-year overall survival rate (85.6% vs 87.1%, P = .63) were comparable between the 2 groups.

CONCLUSIONS

Carefully selected lung allografts from COVID-19-positive donors had comparable early posttransplant outcomes to lung allografts from COVID-19-negative donors.

Prediction of mechanical ventilation outcome by early abdominal-visceral-blood-flow-and-function score in critically ill patients after cardiopulmonary bypass in the ICU: A prospective observational study

Background

Abdominal organs are important organs that sense and respond to ischemia and hypoxia, but there are few evaluation methods.We use ultrasonography to evaluate abdominal organ function and blood flow in patients with mechanical ventilation (MV) after cardiopulmonary bypass and to obtain a semiquantitative score for abdominal organ function and blood flow.

Methods

Patients with cardiopulmonary bypass in the Critical Care Department of Peking Union Medical College Hospital in China from March to July 2021 were enrolled in this prospective observational study. The correlation of the abdominal-visceral-blood-flow-and-function score (AVBFS) with the duration of MV, number of days spent in the intensive care unit (ICU), acute physiology and chronic health evaluation II (APACHE-II), sequential organ failure assessment (SOFA), lactate, epinephrine, and norepinephrine use was analyzed, and the results were used to assess the predictive value of the receiver operating characteristic curve (ROC) regression analysis score for the duration of MV.

Results

Of the 92 patients who underwent cardiopulmonary bypass, 41 were finally included. The AVBFS were significantly correlated with the duration of MV, number of days spent in the ICU, APACHE-II score, SOFA score, and norepinephrine use time. The AVBFS in a group of patients using ventilators ≥36 h were significantly higher than those obtained for a group of patients using ventilators <36 h (P <0.05). The evaluation results for the AVBFS at 0-12 h after ICU admission were as follows: area under the ROC curve (AUC)=0.876 (95% confidence interval [CI]: 0.767 to 0.984), cut-off value=2.5, specificity=0.842, and sensitivity=0.773.

Conclusions

Abdominal visceral organ function and blood perfusion can be used to evaluate gastrointestinal function. It is related to early and late extubation after cardiac surgery.

Impact of cerebrovascular accidents on lung transplant survival

BACKGROUND

Cerebrovascular accidents (CVA) are a source of postoperative morbidity. Existing data on CVA after lung transplantation (LT) are limited. We aimed to evaluate the impact of CVA on LT survival.

METHODS

A retrospective analysis of LT recipients at the University of Texas Southwestern Medical Center was performed. Data was obtained from the institutional thoracic transplant database between January 2012 and December 2018, which consisted of 476 patients. Patients were stratified by the presence of a postoperative CVA. Univariate comparisons of baseline characteristics, operative variables, and postoperative outcomes between the cohorts were performed. Survival was analyzed by Kaplan-Meier method. Aalen's additive regression model was utilized to assess mortality hazard over time.

RESULTS

The incidence of CVA was 4.2% (20/476). Lung allocation score was higher in the CVA cohort (46.2 [41.7, 57.3] vs. 41.5 [35.8, 52.2], p = 0.04). There were no significant differences in operative variables. CVA patients had longer initial intensive care unit (ICU) stays (316 h [251, 557] vs. 124 [85, 218], p < 0.001) and longer length of stay (22 days [17, 53] vs. 15 [11, 26], p = 0.007). CVA patients required more ICU readmissions (35% vs. 15%, p = 0.02) and had a lower rates of home discharge (35% vs. 71%, p < 0.001). Thirty-day mortality was higher in the CVA cohort (20% vs. 1.3%, p < 0.001). Overall survival was lower in the CVA cohort (log rank p = 0.044).

CONCLUSIONS

Postoperative CVA following LT was associated with longer ICU stays, more ICU readmissions, longer length of stay, and fewer home discharges. Thirty day and long-term mortality were significantly higher in the CVA group.

XueFu ZhuYu Decoction Alleviates Cardiopulmonary Bypass-Induced NLRP3 Inflammasome-Dependent Pyroptosis by Inhibiting IkB-α/NF-κB Pathway in Acute Lung Injury Rats

XueFu ZhuYu Decoction (XFZYD) is an effective prescription that is widely used to improve blood circulation by removing blood stasis. This study aimed to investigate the effects and the underlying molecular mechanisms of XFZYD on lung pyroptosis in cardiopulmonary bypass- (CPB-) induced acute lung injury (ALI) rats. A rat model of ALI was induced by CPB treatment after XFZYD, Ac-YVAD-CMK, and Bay-11-7082 administration. The respiratory index (RI) and oxygenation index (OI) were determined at each time point. The levels of interleukin (IL)-1β, IL-6, IL-18, and TNF-α in serum and lung were measured by enzyme-linked immunosorbent assays (ELISA). Moreover, the protein levels, neutrophil counts, and total cell of bronchoalveolar lavage fluid (BALF) were detected. Additionally, Myeloperoxidase (MPO) expression was detected by immunohistochemical assay. Lung injury was evaluated with the wet/dry (W/D) ratio and pathologic changes, respectively. Besides, the expression of NLRP3 inflammasome and IkB-α/NF-κB pathway proteins was estimated by immunofluorescence, quantitative real-time PCR (qRT-PCR), and Western blotting assays, respectively. XFZYD pretreatment significantly ameliorated pulmonary ventilation function and reduced the CPB-induced lung histopathological injury, inflammatory cell infiltration in BALF and lung, and the apoptosis of lung cells. Interestingly, XFZYD decreased the CPB-induced NLRP3, ASC, Caspase-1 p20, Pro-GSDMD, GSDMD p30, IL-18, IL-1β p-P65, and p-IKBα mRNA or protein levels in lung tissues in ALI model rats. In summary, these findings suggest that XFZYD effectively mitigates NLRP3 inflammasome-dependent pyroptosis in CPB-induced ALI model rats, possibly by inhibiting the IkB-α/NF-κB pathway in the lung.

Intraoperative support during lung transplantation

The role of intraoperative mechanical support during lung transplantation (LTx) is essential to provide a safe hemodynamic and ventilatory status during critical intraoperative events. This hemodynamic and ventilatory stability is vital to minimize the odds of suboptimal outcomes, especially considering that, due to the scarcity of donors and the fact that more and more patients with significant comorbidities are being considered for this therapy, a more aggressive approach is often needed by the transplant centers. Hence, the attenuation of any potential injury that can happen during this complex event is paramount. While a thorough assessment of the donor and optimization of postoperative care is pursued, certainly protective intraoperative management would also contribute to better outcomes. Understanding each patient’s underlying anatomy and cardiopulmonary physiology, associated with awareness of critical events during a complicated procedure like LTx, is essential for a precise indication and safe use of support. Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation (VA ECMO) have been the most common approaches used, with the latter gaining popularity more recently and we have used VA ECMO exclusively for the last decade. New technologies certainly contributed to more liberal use of VA ECMO intraoperatively, enabling a protecting and physiologic environment for the newly implanted grafts. In this setting, potential prophylactic use for lung protection during a critical period is also considered.

Postoperative acute kidney injury and renal replacement therapy after DCD lung transplantation

Acute kidney injury (AKI) after lung transplantation (LTx) is a common complication. We aimed to assess whether donation after circulatory death (DCD) is associated with an increased risk of AKI and renal replacement therapy (RRT) in the early postoperative period compared to the donation after brain death (DBD). Retrospective data on a cohort (N = 95) of LTx patients (DCD n = 17, DBD n = 78) characterized by no use of ex-vivo lung perfusion were analyzed for the incidence of AKI within 30 postoperative days and incidence of RRT within 7 and 30 days. After optimal full matching, an imbalance remained between the DCD and DBD patients in respect to intraoperative use of cardiopulmonary bypass (CPB). Therefore, a further subset (n = 77) was defined that excluded CPB patients, and matching was repeated (DCD n = 13 vs. DBD n = 63) resulting in a fair balance on a range of preoperative characteristics and intraoperative use of ECMO. In both matched subsets, DCD was associated with around twice higher risk of AKI and RRT within 7 and 30 postoperative days. In conclusion, data suggest that DCD could be associated with worse early renal outcomes in a subset of LTx patients and justify further studies on the topic in order to refine further renal care pathways perioperatively.

Year in Review 2020: Noteworthy Literature in Cardiothoracic Critical Care

This year will be forever marked by the drastic changes COVID-19 wrought on our personal and professional lives. New roles and challenges in critical care have forced us to be constantly nimble and flexible in how we approach medicine. The strain of these challenges is apparent throughout the health care community and our society as a whole. Despite this adversity, 2020 will also be remembered for fantastic advances in research. This article is a collection of influential and exciting studies published in 2020 encompassing a broad swath of critical care with a focus on cardiothoracic critical care. Themes include examinations of early extracorporeal membrane oxygenation support for out-of-hospital cardiac arrest patients, the impact of sedation and other risk factors on perioperative mortality, a novel fluid resuscitation strategy following cardiac surgery, and advances in the fields of heart and lung transplantation as well as how they were affected by COVID-19. Given that many cardiothoracic intensivists were redeployed to the care of SARS-CoV-2 patients, we also discuss important advances in therapeutics for the virus.

Long-term survival after descending thoracic and thoracoabdominal aortic aneurysm repair

OBJECTIVE

Patients with descending thoracic aortic aneurysms (dTAA) or thoracoabdominal aortic aneurysms (TAAA) often have a variety of medical comorbidities. Those that are deemed acceptable for intervention undergo complicated repairs with good early outcomes. The purpose of this study was to identify variables that were associated with mortality over time.

METHODS

This was a retrospective review of a prospectively maintained database at our institution from 1983 to 2015. Patients were included if they underwent open or endovascular repair for dTAA or TAAA. Patients were excluded if they were intervened on for traumatic transections. The primary outcome for the study was long-term survival. Secondary outcomes included aortic-related mortality. We had mortality and survival data on all patients.

RESULTS

A total of 946 patients met our study criteria with a median follow-up of 102.8 months (interquartile range [IQR], 58.9-148.2 months). The median age of the cohort was 71 years (IQR, 63-77 years) with the majority of patients being male (58.1%). The extent of TAAA pathology was as follows: type I (14.2%), type II (21.2%), type III (17.1%), type IV (26.2%), and dTAA (21.2%). A total of 147 patients (15.5%) had a prior dissection. The median diameter of aneurysm was 6.4 cm (IQR, 6.0-7.0 cm). A total of 158 patients (16.7%) underwent endovascular repair over the study period. Variables associated with mortality over time were age, surgical era, acute pathology, dissection, preoperative creatinine, and type IV TAAAs. In addition, experiencing the following complications in the postoperative period was associated with mortality over time: neurological, cardiac, and pulmonary. Aortic-related mortality was 2.1% (n = 20) over the study period. Patients who underwent endovascular repair for acute conditions had better long-term survival when compared with open repair. However, there were no differences in long-term survival between open and endovascular repair for nonacute cases. In addition, repair in the more modern era was associated with improved survival.

CONCLUSIONS

TAAAs can be repaired with reasonable perioperative mortality rates. Once patients undergo repair of their aneurysm, aortic-related mortality remains low. The addition of endovascular options has dramatically changed management of patients with dTAA and TAAA. Further, endovascular repair was associated with decreased perioperative mortality and significantly increased long-term survival in acute patients. Patients undergoing TAAA repair are generally considered high risk and therefore require extensive long-term follow-up for management of their comorbidities and complications, because these are the main contributors to mortality over time.