Acute renal failure after lung transplantation: incidence, predictors and impact on perioperative morbidity and mortality

Perioperative fluid balance and early acute kidney injury after lung transplantation

BACKGROUND

Postoperative acute kidney injury (AKI) after lung transplantation (LTx) is an important factor affecting the short-term outcomes. The focus item of transplantation centers is how to improve the incidence of AKI through optimal management during the perioperative period.

OBJECTIVE

The purpose of the study is to investigate the influence of perioperative volume in the development of early AKI following LTx.

METHOD

The study involved patients who had undergone LTx between October 2018 to December 2021 at China-Japan Friendship Hospital in Beijing. The patients were monitored for AKI occurring within 72 hours after LTx, as well as the renal outcomes within 30 days. The perioperative volumes were compared and analyzed to determine the impact on various clinical outcomes.

RESULTS

248 patients were enrolled in the study ultimately, with almost half of them (49.6 %) experiencing AKI. 48.8 % of AKI patients received continuous renal replacement therapy (CRRT), with 57.7 % recovered by the end of the 30-day follow-up period. A J-shaped relationship was demonstrated between perioperative volume and AKI incidence. Moreover, maintaining a positive fluid balance would increase the 30-day mortality and lead to poor renal outcomes.

CONCLUSION

Perioperative volume is an independent risk factor of early AKI after LTx. Positive fluid balance increases the risk of AKI, 30-day mortality, and adverse renal prognosis. The LTx recipients may benefit from a relatively restrict fluid strategy during and after the lung transplantation.

Interorgan communication networks in the kidney-lung axis

The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.

Postoperative Acute Kidney Injury and Long-Term Outcomes After Lung Transplantation

BACKGROUND

This study sought to characterize perioperative risk factors of acute kidney injury (AKI) and report outcomes associated with its development in the immediate postoperative setting after lung transplantation.

METHODS

Study investigator performed a retrospective analysis of all adult patients undergoing primary lung transplantation at a single institution from January 1, 2011 to December 31, 2021 AKI was defined using Kidney Disease: Improving Global Outcomes (KDIGO) criteria after lung transplantation and was stratified on the basis of whether patients required renal replacement therapy (RRT; AKI-no RRT vs AKI-RRT).

RESULTS

Of the 754 patients included, 369 (48.9%) any AKI developed in the postoperative period (252 AKI-no RRT vs 117 AKI-RRT). Risk factors for postoperative AKI included higher preoperative creatinine levels (odds ratio [OR], 5.15; P < .001), lower preoperative estimated glomerular filtration rate (OR, 0.99; P < 0.018), delayed chest closure (OR, 2.72; P < .001), and higher volumes of postoperative blood products (OR, 1.09; P < .001) in the multivariable analysis. On univariate analysis, both AKI groups were also associated with higher rates of pneumonia (P < .001), reintubation (P < .001), mortality on index admission (P < 0.001), longer ventilator duration (P < .001), longer intensive care unit length of stay (P < .001), and longer hospital length of stay (P < .001), with the highest rates in the AKI-RRT group. In a multivariable survival analysis, postoperative AKI-no RRT (hazard ratio [HR], 1.50; P = .006) and AKI-RRT (HR, 2.70; P < .001) were associated with significantly worse survival independent of severe grade 3 primary graft dysfunction at 72 hours (HR, 1.45; P = .038).

CONCLUSIONS

The development of postoperative AKI was associated with numerous preoperative and intraoperative factors. Postoperative AKI remained significantly associated with poorer posttransplantation survival. Severe cases of AKI necessitating RRT portended the worst survival after lung transplantation.

Retrospective analysis on incidence and risk factors for early acute renal injury after lung transplantation

BACKGROUND

Acute renal injury (AKI) is a common complication of lung transplantation. However, there has been no related research on whether the relationship between fluid balance and input and output influences the occurrence of early AKI. This study aimed to explore the relationship between early fluid balance and input and output on the incidence of early AKI after lung transplantation.

METHODS

Data from 31 patients who underwent lung transplantation in the Department of Intensive Care Medicine of the Sichuan Academy of Medical Sciences, Sichuan People's Hospital, from August 2018 to July 2021 were collected. To summarize the occurrence of early AKI after lung transplantation, The main indicators of lung transplantation patients were collected. The risk factors for early AKI after lung transplantation were analyzed.

RESULTS

Among the 31 patients who underwent lung transplantation, 21 had early postoperative AKI, with an incidence rate of 67.7%. Compared with the non-AKI group, the hospitalization and ICU hospitalization times of the AKI group were longer (P < 0.05). Multivariate regression analysis showed that intraoperative input volume, BMI, and fluid balance on the first day after lung transplantation were independent risk factors for AKI.

CONCLUSION

Intraoperative input volume, BMI, and fluid balance on the first day after lung transplantation were independent risk factors for AKI.

Role of the Nephrologist in Non-Kidney Solid Organ Transplant (NKSOT)

BACKGROUND

Chronic kidney disease (CKD) is a common complication of a non-kidney solid organ transplant (NKSOT). Identifying predisposing factors is crucial for an early approach and correct referral to nephrology.

METHODS

This is a single-center retrospective observational study of a cohort of CKD patients under follow-up in the Nephrology Department between 2010 to 2020. Statistical analysis was performed between all the risk factors and four dependent variables: end-stage renal disease (ESKD); increased serum creatinine ≥50%; renal replacement therapy (RRT); and death in the pre-transplant, peri-transplant, and post-transplant periods.

RESULTS

74 patients were studied (7 heart transplants, 34 liver transplants, and 33 lung transplants). Patients who were not followed-up by a nephrologist in the pre-transplant (p < 0.027) or peri-transplant (p < 0.046) periods and those who had the longest time until an outpatient clinic follow-up (HR 1.032) were associated with a higher risk of creatinine increase ≥50%. Receiving a lung transplant conferred a higher risk than a liver or heart transplant for developing a creatinine increase ≥50% and ESKD. Peri-transplant mechanical ventilation, peri-transplant and post-transplant anticalcineurin overdose, nephrotoxicity, and the number of hospital admissions were significantly associated with a creatinine increase ≥50% and developing ESKD.

CONCLUSIONS

Early and close follow-up by a nephrologist was associated with a decrease in the worsening of renal function.

Conversion to belatacept after lung transplantation: Report of 10 cases

BACKGROUND

Calcineurin inhibitors (CNIs) remain the cornerstone of maintenance immunosuppression (IS) after lung transplantation (LTx), although CNI-related life-threatening toxic effects may occur. Belatacept, a novel immunosuppressant that blocks a T-cell co-stimulation pathway, is a non-nephrotoxic drug indicated as an alternative to CNIs in kidney Tx. In LTx, there are only a few reports of belatacept conversion as a CNI-free or CNI-sparing IS treatment.

METHODS

We reviewed a series of 10 LTx recipients with conversion to a CNI-free belatacept IS regimen within the first year post-LTx (n = 7) or a belatacept/low-dose CNI combination after the first year (n = 3).

RESULTS

Use of belatacept was triggered by severe renal failure in 9 patients and under-IS with previous other IS-related toxicities in 1 patient. Mean estimated glomerular filtration rate after starting belatacept significantly improved at 6 months after initiation and at the last-follow-up (p = 0.006, and p = 0.002 respectively). The incidence of recurrent and/or severe acute cellular rejection (ACR) episodes was high in patients with CNI-free belatacept-based IS (n = 4/7). Chronic graft allograft dysfunction developed in 2 of 9 recipients under belatacept IS. Belatacept was stopped in 6 patients because of recurrent/severe ACR (n = 3), recurrent opportunistic infections (n = 1), center modified policy (n = 1), or other cause (n = 1).

CONCLUSION

Early conversion to CNI-free belatacept-based IS improved renal function in this series but was counterbalanced by a high incidence of recurrent ACR, including life-threatening episodes. Other studies are needed to better determine the indications for its use after LTx, possibly with lower immunological risk IS regimens, such as CNI-sparing belatacept.

Conventional and Novel Approaches to Immunosuppression in Lung Transplantation

Most therapeutic advances in immunosuppression have occurred over the past few decades. Although modern strategies have been effective in reducing acute cellular rejection, excess immunosuppression comes at the price of toxicity, opportunistic infection, and malignancy. As our understanding of the immune system and allograft rejection becomes more nuanced, there is an opportunity to evolve immunosuppression protocols to optimize longer term outcomes while mitigating the deleterious effects of traditional protocols.

Effect of Propofol versus Sevoflurane Anesthesia on Acute Kidney Injury after Lung Transplantation Surgery: A Prospective Randomized Controlled Trial

This prospective randomized controlled trial aimed to compare the effects of sevoflurane and propofol anesthesia on the occurrence of acute kidney injury (AKI) following lung transplantation (LTx) surgery. Sixty adult patients undergoing bilateral LTx were randomized to receive either inhalation of sevoflurane or continuous infusion of propofol for general anesthesia. The primary outcomes were AKI incidence according to the Acute Kidney Injury Network (AKIN) criteria and blood biomarker of kidney injury, including neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C levels within 48 h of surgery. Serum interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and superoxide dismutase were measured before and after surgery. The post-operative 30-day morbidity and long-term mortality were also assessed. Significantly fewer patients in the propofol group developed AKI compared with the sevoflurane group (13% vs. 38%, p = 0.030). NGAL levels were significantly lower in the propofol group at immediately after, 24 h, and 48 h post-operation. IL-6 levels were significantly lower in the propofol group immediately after surgery. AKI occurrence was significantly associated with a lower 5-year survival rate. Total intravenous anesthesia with propofol reduced the AKI incidence in LTx compared with sevoflurane, which is understood to be mediated by the attenuation of inflammatory responses.

Cell-Free Hemoglobin in Acute Kidney Injury after Lung Transplantation and Experimental Renal Ischemia/Reperfusion

Cell-free hemoglobin (CFH), a pro-oxidant and cytotoxic compound that is released in hemolysis, has been associated with nephrotoxicity. Lung transplantation (LuTx) is a clinical condition with a high incidence of acute kidney injury (AKI). In this study, we investigated the plasma levels of CFH and haptoglobin, a CFH-binding serum protein, in prospectively enrolled LuTx patients (n = 20) with and without AKI. LuTx patients with postoperative AKI had higher CFH plasma levels at the end of surgery compared with no-AKI patients, and CFH correlated with serum creatinine at 48 h. Moreover, CFH levels inversely correlated with haptoglobin levels, which were significantly reduced at the end of surgery in LuTx patients with AKI. Because multiple other factors can contribute to AKI development in the complex clinical setting of LuTx, we next investigated the role of exogenous CFH administration in a mouse model of mild bilateral renal ischemia reperfusion injury (IRI). Exogenous administration of CFH after reperfusion caused overt AKI with creatinine increase, tubular injury, and enhanced markers of renal inflammation compared with vehicle-treated animals. In conclusion, CFH is a possible factor contributing to postoperative AKI after LuTx and promotes AKI in an experimental model of mild transient renal ischemia. Targeting CFH might be a therapeutic option to prevent AKI after LuTx.

Kidney disease in non-kidney solid organ transplantation

Kidney disease after non-kidney solid organ transplantation (NKSOT) is a common post-transplant complication associated with deleterious outcomes. Kidney disease, both acute kidney injury and chronic kidney disease (CKD) alike, emanates from multifactorial, summative pre-, peri- and post-transplant events. Several factors leading to kidney disease are shared amongst solid organ transplantation in addition to distinct mechanisms unique to individual transplant types. The aim of this review is to summarize the current literature describing kidney disease in NKSOT. We conducted a narrative review of pertinent studies on the subject, limiting our search to full text studies in the English language. Kidney disease after NKSOT is prevalent, particularly in intestinal and lung transplantation. Management strategies in the peri-operative and post-transplant periods including proteinuria management, calcineurin-inhibitor minimization/ sparing approaches, and nephrology referral can counteract CKD progression and/or aid in subsequent kidney after solid organ transplantation. Kidney disease after NKSOT is an important consideration in organ allocation practices, ethics of transplantation. Kidney disease after SOT is an incipient condition demanding further inquiry. While some truths have been revealed about this chronic disease, as we have aimed to describe in this review, continued multidisciplinary efforts are needed more than ever to combat this threat to patient and allograft survival.

Single Lung Transplant Remains a Viable Option for Patients With Severe Secondary Pulmonary Hypertension

BACKGROUND

Although double lung transplant is recommended in patients with severe secondary pulmonary hypertension (SPH), our institutional experiences suggest a role for single lung transplant in these patients. Here, we review our experience prioritizing single lung transplant in patients with SPH to minimize their surgical burden.

METHODS

We conducted a retrospective review of our lung transplant database to identify patients with SPH who underwent single lung transplant. Patients were stratified as either mild SPH (mean pulmonary artery pressure 25-40 mm Hg) or severe SPH (mean pulmonary artery pressure >40 mm Hg). Singe lung recipients without PH transplanted over the same time were also examined.

RESULTS

Between January 2017 and December 2019, 318 patients underwent single lung transplantation; 217 had mild SPH (68%), and 59 had severe SPH (18.5%). Forty-two patients without PH underwent single lung transplant. When the groups were compared, significantly higher pulmonary vascular resistance was noted in the severe SPH group, and obesity was noted in both the mild and severe SPH groups. Although the severe SPH group required more intraoperative cardiopulmonary support (37.3% versus 10.3% versus 4.7%, P < 0.05), there were no significant differences in most major postoperative parameters, including the duration of postoperative mechanical ventilation or the incidence of severe primary graft dysfunction. Survival 1 y posttransplant was not significantly different among the groups (93.2% versus 89.4% versus 92.9%, P = 0.58).

CONCLUSIONS

Our experience supports the option of single lung transplantation with appropriate intraoperative mechanical circulatory support in patients with SPH. This strategy is worth pursuing, especially with ongoing donor lung shortages.

Nonallograft Complications of Lung Transplantation

Long-term exposure to immunosuppressive therapy may exacerbate pre-existing medical comorbidities or result in the development of new chronic medical conditions after lung transplantation. This article focuses on common nonallograft complications with the highest impact on short- and long-term outcomes after transplantation. These include diabetes mellitus, hypertension, dyslipidemia, kidney disease (acute and chronic), and malignancy. We discuss evidence-based strategies for the prevention, diagnosis, and management of these nonallograft complications in this article.

Kidney injury after lung transplantation: Long-term mortality predicted by post-operative day-7 serum creatinine and few clinical factors

BACKGROUND

Acute kidney injury (AKI) after lung transplantation (LuTx) is associated with increased long-term mortality. In this prospective observational study, commonly used AKI-definitions were examined regarding prediction of long-term mortality and compared to simple use of the serum creatinine value at day 7 for patients who did not receive hemodialysis, and serum creatinine value immediately before initiation of hemodialysis (d7/preHD-sCr).

METHODS

185 patients with LuTx were prospectively enrolled from 2013-2014 at our center. Kidney injury was assessed within 7 days by: (1) the Kidney Disease Improving Global Outcomes criteria (KDIGO-AKI), (2) the Acute Disease Quality Initiative 16 Workgroup classification (ADQI-AKI) and (3) d7/preHD-sCr. Prediction of all-cause mortality was examined by Cox regression analysis, and clinical as well as laboratory factors for impaired kidney function post-LuTx were analyzed.

RESULTS

AKI according to KDIGO and ADQI-AKI occurred in 115 patients (62.2%) within 7 days after LuTx. Persistent ADQI-AKI, KDIGO-AKI stage 3 and higher d7/preHD-sCr were associated with higher mortality in the univariable analysis. In the multivariable analysis, d7/preHD-sCr in combination with body weight and intra- and postoperative platelet transfusions predicted mortality after LuTx with similar performance as models using KDIGO-AKI and ADQI-AKI (concordance index of 0.75 for d7/preHD-sCr vs., 0.74 and 0.73, respectively). Pre-transplant reduced renal function, diabetes, higher BMI, and intraoperative ECMO predicted higher d7/preHD-sCr (r2 = 0.354, p < 0.001).

CONCLUSION

Our results confirm the importance of AKI in lung transplant patients; however, a simple and pragmatic indicator of renal function, d7/preHD-sCr, predicts long-term mortality equally reliable as more complex AKI-definitions like KDIGO and ADQI.

When the Renal (Function) Begins to Fall: A Mini-Review of Acute Kidney Injury Related to Acute Respiratory Distress Syndrome in Critically Ill Patients

Acute kidney injury (AKI) is one of the most frequent causes of organ failure encountered in patients in the intensive care unit (ICU). Because of its predisposition to occur in the most critically ill patients, it is not surprising to observe a high frequency of AKI in patients with acute respiratory distress syndrome (ARDS). However, few studies have been carried out to assess the epidemiology of AKI in subgroups of ARDS patients using recommended KDIGO criteria. Moreover, the mechanisms involved in the physio-pathogenesis of AKI are still poorly understood, in particular the impact of mechanical ventilation on the kidneys. We carried out a review of the literature, focusing on the epidemiology and physiopathology of AKI in patients with ARDS admitted to the ICU. We addressed the importance of clinical management, focusing on mechanical ventilation for improving outcomes, on AKI. Finally, we also propose candidate treatment strategies and management perspectives. Our literature search showed that AKI is particularly common in ICU patients with ARDS. In association with the classic risk factors for AKI, such as comorbidities and iatrogeny, changes in mechanical ventilation parameters, which have been exclusively evaluated for their outcomes on respiratory function and death, must be considered carefully in terms of their impact on the short-term renal prognosis.

Incidence and Perioperative Risk Factors of Acute Kidney Injury Among Lung Transplant Recipients

BACKGROUND

Acute kidney injury (AKI) is a significant burden in an early postoperative period after lung transplantation (LT). The development of severe AKI, including a need for continuous renal replacement therapy (CRRT), is associated with increased mortality among lung transplant recipients. Evaluation of AKI incidence and predictive factors related to the development of severe AKI and with the use of CRRT in the early postoperative period after LT.

METHODS

Retrospective study of 73 consecutive patients after LT operated between 2015 and 2018 in our center. We noted the stage of AKI according to KDIGO guidelines in the 7 postoperative days.

RESULTS

We noted AKI among 62 lung transplant recipients (84.9%). We recognized the first and second stages of AKI in 21 patients (28.8%) and 19 patients 26%, respectively (group A). We identified severe AKI (group C) in 22 recipients (30.1%), 9 of whom needed CRRT postoperatively. There was a nonsignificant difference between groups in baseline serum creatinine (0.69 ± 0.22 mg/dL vs 0.84 ± 0.34; P = .073). Group C subjects statistically more often suffered from pulmonary hypertension (P < .001) and diabetes (P < .001). In both groups, the duration of the procedure was comparable, but, among patients with severe AKI, procedures were performed more often with the use of extracorporeal circulation (50% vs 68%; P = .194) CONCLUSIONS: Pulmonary hypertension and diabetes could be significant risk factors of high-grade AKI development after LT. Identification of factors modifying renal insufficiency development in lung transplant recipients needs further investigations.

Outcomes following lung re-transplantation in patients with cystic fibrosis

PURPOSE

We examined cystic fibrosis (CF) patients and compared their clinical status at the time of primary versus double lung re-transplantation (re-DLTx) in order to better understand lung retransplant practice patterns.

METHODS

We performed a retrospective analysis of the UNOS Database identifying CF patients ≥18 years old undergoing re-DLTx (5/4/2005 and 12/4/2020). Baseline and clinical variables at the primary and re-DLTx were compared utilizing the paired student t-test. Graft survival was defined as time from surgery to retransplant and analyzed using Kaplan-Meier estimates.

RESULTS

277 CF patients who underwent re-DLTx experienced a significantly worse 5-year survival when compared to the primary DLTx cohort (47.9% vs 58.8%, p = 0.00012). The following differences were observed comparing CF re-DLTx group to their primary DLTx: higher LAS score at the time of listing (50.66 vs 42.15, p < 0.001) and transplant (62.19 vs 48.20, p < 0.001), and increase LAS from the time of listing to transplant (+12.22 vs +7.23, p = 0.002). While serum albumin and total bilirubin were similar, CF patients had a higher creatinine (1.05 vs 0.74, p < 0.001), dialysis (4.4% vs 0.6%, p < 0.001), ECMO bridge to transplant rates (7.6% vs 4.0%, p < 0.001), and higher oxygen requirements (5.95 vs 3.93, p < 0.001) at the time of listing for a re-DLTx.

CONCLUSION

Compared to their initial transplant, CF patients experience significant clinical decline in renal, cardiac, and pulmonary function at the time of lung retransplantation. This may indicate that an earlier evaluation and rehabilitation process may be necessary to identify patients earlier for lung retransplantation prior significant clinical decline.

Acute kidney injury following adult lung transplantation

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication following lung transplantation (LTx), and it is associated with high mortality and morbidity. This study assessed the incidence of AKI after LTx and analyzed the associated perioperative factors and clinical outcomes.

METHODS

This retrospective study included all adult LTx recipients at the China-Japan Friendship Hospital in Beijing between March 2017 and December 2019. The outcomes were AKI incidence, risk factors, mortality, and kidney recovery. Multivariate analysis was performed to identify independent risk factors. Survival analysis was presented using the Kaplan-Meier curves.

RESULTS

AKI occurred in 137 of the 191 patients (71.7%), with transient AKI in 43 (22.5%) and persistent AKI in 94 (49.2%). AKI stage 1 occurred in 27/191 (14.1%), stage 2 in 46/191 (24.1%), and stage 3 in 64/191 (33.5%) of the AKI patients. Renal replacement therapy (RRT) was administered to 35/191 (18.3%) of the patients. Male sex, older age, mechanical ventilation (MV), severe hypotension, septic shock, multiple organ dysfunction (MODS), prolonged extracorporeal membrane oxygenation (ECMO), reintubation, and nephrotoxic agents were associated with AKI (P < 0.050). Persistent AKI was independently associated with pre-operative pulmonary hypertension, severe hypotension, post-operative MODS, and nephrotoxic agents. Severe hypotension, septic shock, MODS, reintubation, prolonged MV, and ECMO during or after LTx were related to severe AKI (stage 3) (P < 0.050). Patients with persistent and severe AKI had a significantly longer duration of MV, longer duration in the intensive care unit (ICU), worse downstream kidney function, and reduced survival (P < 0.050).

CONCLUSIONS

AKI is common after LTx, but the pathogenic mechanism of AKI is complicated, and prerenal causes are important. Persistent and severe AKI were associated with poor short- and long-term kidney function and reduced survival in LTx patients.

Kidney Disease After Nonkidney Solid Organ Transplant

Nonkidney solid organ transplants (NKSOTs) are increasing in the United States with improving long-term allograft and patient survival. CKD is prevalent in patients with NKSOT and is associated with increased morbidity and mortality especially in those who progress to end-stage kidney disease. Calcineurin inhibitor nephrotoxicity is a main contributor to CKD after NKSOT, but other factors in the pretransplant, peritransplant, and post-transplant period can predispose to progressive kidney dysfunction. The management of CKD after NKSOT generally follows society guidelines for native kidney disease. Kidney-protective and calcineurin inhibitor-sparing immunosuppression has been explored in this population and warrants a discussion with transplant teams. Kidney transplantation in NKSOT recipients remains the kidney replacement therapy of choice for suitable candidates, as it provides a survival benefit over remaining on dialysis.

Looking Beyond the Allograft Survival: Long-Term, 5-Year Renal Outcome in Lung Transplant Recipients

With the increased incidence and survival of lung transplant (LTx) recipients, the risk for chronic sequelae such as chronic kidney disease (CKD) is on the rise. Data on the long-term renal outcome are scarce. We performed a retrospective chart review of 171 adults with LTx from January 1, 2014, to January 1, 2019. Primary outcomes were prevalence of CKD/end-stage renal disease, acute kidney injury (AKI) as a risk factor for future CKD, and all-cause mortality in recipients with CKD compared with the non-CKD group. Secondary outcomes were frequency of utilization of modalities for CKD (urinalysis, imaging, biopsy, nephrology consultations). Baseline median creatinine and estimated glomerular filtration rate (eGFR) were 0.8 mg/dL and 90 mL/min/1.73 m², respectively. Of the participants, 60% (96 of 161), 67% (102 of 153), 79% (37 of 47), 86% (10 of 12) had CKD at the end of 6, 12, 36, and 60 months, respectively, and 16% were on dialysis at the end of the study period; 3% received a subsequent renal transplant, and 27% mortality was noted over a 5-year follow-up period. The odds of CKD development in patients with an AKI during index hospitalization vs no AKI was 6.22 (2.87 to 13.06, P < .0001). The odds ratio of all-cause mortality in patients with CKD compared with non-CKD was 3.36 (95% confidence interval, 1.44-8.64, P = .005). Measurement of hematuria/proteinuria, imaging, and renal biopsy were infrequently used. Given the high prevalence of AKI and CKD in this population, a multidisciplinary team approach with an early nephrology consultation will be key to improve the overall and renal outcomes in LTx recipients.

Risk factors and mortality of acute kidney injury within 1 month after lung transplantation

After lung transplantation (LT), some patients are at risk of acute kidney injury (AKI), which is associated with worse outcomes and increased mortality. Previous studies focused on AKI development from 72 h to 1 week within LT, and reported main risk factors for AKI such as intraoperative hypotension, need of ECMO support, ischemia time or longer time on waiting list. However, this period interval rarely reflects medical risk factors probably happen in longer post-operative period. So, in this study we aimed to describe the incidence and risk factor of AKI within post-operative 1 month, which is longer follow up duration. Among 161 patients who underwent LT at Severance hospital in Seoul, Korea from October 2012 to September 2017, 148 patients were retrospectively enrolled. Multivariable logistic regression and Cox proportional hazard models were utilized. Among 148 patients, 59 (39.8%) developed AKI within 1-month after LT. Stage I or II, and stage III AKI were recorded in 26 (17.5%) and 33 (22.2%), respectively. We also classified AKI according to occurrence time, within 1 week as early AKI, from 1 week within 1 month was defined as late AKI. AKI III usually occurred within 7 days after transplantation (early vs. late AKI III, 72.5% vs 21.1%). Risk factor for AKI development was pre-operative anemia, higher units of red blood cells transfused during surgery, colistin intravenous infusion for treating multi drug resistant pathogens were independent risk factors for AKI development. Post-operative bleeding, grade 3 PGD within 72 h, and sepsis were more common complication in the AKI group. Patients with AKI III ([24/33] 72.7%) had significantly higher 1-year mortality than the no-AKI ([18/89] 20.2%), and AKI I or II group ([9/26] 34.6%), log-rank test, P < 0.001). AKI was associated with worse post-operative outcome, 3-month, and 1-year mortality after LT. Severity of AKI was usually determined in early post op period (ex. within 7 days) after LT, so optimal post-operative management as well as recipients selection should be considered.

Possible Predictive Factor of Acute Respiratory Distress Syndrome Development After Mild Traumatic Brain Injury: A Single Rural Trauma Center Preliminary Study

Introduction Acute respiratory distress syndrome (ARDS) after mild traumatic brain injury (TBI) can be associated with significant morbidity and mortality. This study aimed to evaluate the potential predictive factors of ARDS development following mild TBI in trauma patients. Methods A retrospective chart review was done for adult trauma patients with mild TBI (GCS 13-15) requiring admission at our center from 2012 to 2020. Linear regression analysis and chi-square test were utilized to identify independent predictors of the association with ARDS in adults with mild TBI.  Results A total of 784 mild TBI patients were admitted during the time of interest; 34 patients developed ARDS during their index hospitalization. Patients who had ARDS were more likely to have acute kidney injury (AKI; p < 0.0001), sepsis (p < 0.01), rib fractures (p < 0.05), use of anticoagulants (p < 0.001), deep vein thrombosis (p < 0.001), transfusion during the first 4four hours upon admission (p = 0.01), intravenous fluid (IVF) resuscitation during the first four hours (p <0.05), the first eight hours (p = 0.01), the first 12 hours (p = 0.03), and intubation upon the admission (p < 0.0001). ARDS associated with mild TBI demonstrated a statistically significant increase in mortality during the index hospitalization (p < 0.0001). Conclusion ARDS after mild TBI can be associated with significant morbidity and mortality. Key risk factors identified include AKI, sepsis, anticoagulant use, deep vein thrombosis (DVT), transfusion in the first four hours, IVF resuscitation in the first four, eight, and 12 hours, and intubation upon admission.

Lung transplantation: candidate selection and timing of transplant

PURPOSE OF REVIEW

Over the past two decades, lung transplant has become the mainstay of treatment for several end-stage lung diseases. As the field continues to evolve, the criteria for referral and listing have also changed. The last update to these guidelines was in 2014 and several studies since then have changed how patients are transplanted. Our article aims to briefly discuss these updates in lung transplantation.

RECENT FINDINGS

This article discusses the importance of early referral of patients for lung transplantation and the concept of the 'transplant window'. We review the referral and listing criteria for some common pulmonary diseases and also cite the updated literature surrounding the absolute and relative contraindications keeping in mind that they are a constantly moving target. Frailty and psychosocial barriers are difficult to assess with the current assessment tools but continue to impact posttransplant outcomes. Finally, we discuss the limited data on transplantation in acute respiratory distress syndrome (ARDS) due to COVID19 as well as extracorporeal membrane oxygenation bridge to transplantation.

SUMMARY

The findings discussed in this article will strongly impact, if not already, how we select candidates for lung transplantation. It also addresses some aspects of lung transplant such as frailty and ARDS, which need better assessment tools and clinical data.

Acute kidney injury after lung transplantation: a narrative review

Acute kidney injury (AKI) is a commonly recognized complication after lung transplantation (LT) and is related to increased mortality and morbidity. With the improvement of survival after LT and the increasing number of lung transplant recipients, the detrimental impact of current management on renal function has become increasingly apparent. Multifarious risk factors in the perioperative setting contribute to the development of AKI, including the preoperative status and complications of the recipient, complex perioperative problems especially hemodynamic fluctuation, and exposure to nephrotoxic agents, mainly calcineurin inhibitors (CNIs) and antimicrobial drugs. Identification and minimization of the effects of these risk factors can relieve AKI severity and incidence in high-risk patients. Close monitoring of urine output and serum creatinine (sCr) levels and of specific biomarkers may promote early recognition of AKI and rapid nephrology intervention to improve outcomes. This review summarizes advances in the epidemiology, diagnostic criteria, biological markers of AKI, and further recommends appropriate treatment strategies for the long-term management of AKI related manifestations in lung transplant recipients. Future work will need to focus on developing more accurate measures of renal function and identifying patients before the occurrence of early renal damage. Combining renal protection strategies with the use of new biomarkers to develop early kidney risk identification and protection protocols is a promising idea that requires further investigation.

Retrospective analysis on incidence and risk factors of early onset acute kidney injury after lung transplantation and its association with mortality

OBJECTIVES

Acute kidney injury (AKI) is a common complication after lung transplantation (LTx) which is closely related to the poor prognosis of patients. We aimed to explore potential risk factors and outcomes associated with early post-operative AKI after LTx.

METHODS

A retrospective study was conducted in 136 patients who underwent LTx at our institution from 2017 to 2019. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guideline. Univariate and multivariate analyses were conducted to identify risk factors related to AKI. The primary outcome was the incidence of AKI after LTx. Secondary outcomes were associations between AKI and short-term clinical outcomes and mortality.

RESULTS

Of the 136 patients analyzed, 110 developed AKI (80.9%). AKI was associated with higher baseline eGFR (odds ratio (OR) 1.01 (95% confidence interval (CI): 1.00-1.03)) and median tacrolimus (TAC) concentration (OR 1.15 (95% CI: 1.02-1.30)). Patients with AKI suffered longer mechanical ventilation days (p = .015) and ICU stay days (p = .011). AKI stage 2-3 patients had higher risk of 1-year mortality (HR 16.98 (95% CI: 2.25-128.45)) compared with no-AKI and stage 1 patients.

CONCLUSIONS

Our results suggested early post-operative AKI may be associated with higher baseline eGFR and TAC concentrations. AKI stage 1 may have no influence on survival rate, whereas AKI stage 2-3 may be associated with increased mortality at 1-year.

The Prevalence, Risk Factors, and Prognosis of Acute Kidney Injury After Lung Transplantation: A Single-Center Cohort Study in China

PURPOSE

The aim of this study is to evaluate the incidence, risk factors, and prognosis of acute kidney injury (AKI) after lung transplantation (LTx).

METHODS

Records of patients who underwent LTx in a single center were retrospectively reviewed. The prevalence of post-transplant AKI, the use of continuous renal replacement therapy (CRRT), and the risk factors for AKI were investigated. The effects of AKI and CRRT on short-term outcomes and long-term survival were measured.

RESULTS

This study included 148 patients, 67 of which developed postoperative AKI. Of these, 31 patients underwent CRRT; the percentage of cases with no AKI was 6.2%, and the percentage of cases with stage 1, 2, and 3 who used CRRT was 0%, 10%, and 86.2%, respectively. Patients with AKI had significantly higher intensive care unit mortality and in-hospital mortality. The 1-year post-LTx survival rate of patients with AKI was 47.8%, significantly lower than those without AKI (74.1%). There was no difference in 1-year survival rate of those with stage 1 and stage 2 AKI, but patients with stage 3 AKI showed the worst survival. Patients who underwent CRRT had an inferior survival outcome (9.7% vs 76.1%, P < .05). We found that higher acute physiologic assessment and chronic health evaluation (APACHE) II scores (odds ratio [OR] 1.082, P = .009) and higher intraoperative fluid balance (OR 1.001, P = .012) were independent risk factors, and female sex (OR 2.539) and pulmonary hypertension (OR 2.869) were potential risk factors for post-LTx AKI. A prediction model integration of the above factors showed a good concordance with actual risks and had a concordance index (C-index) of 0.76 (95% confidence interval [CI], 0.66-0.87).

CONCLUSION

Severe AKI requiring CRRT had a negative impact on the short-term and long-term outcomes of patients.

Application of MR diffusion imaging for non-invasive assessment of acute kidney injury after lung transplantation

To assess whether MR diffusion imaging may be applied for non-invasive detection of renal changes correlating with clinical diagnosis of acute kidney injury (AKI) in patients after lung transplantation (lutx).Fifty-four patients (mean age 49.6, range 26-64 years) after lutx were enrolled in a prospective clinical study and underwent functional MR imaging of the kidneys in the early postoperative period. Baseline s-creatinine ranged from 39 to 112 μmol/L. For comparison, 14 healthy volunteers (mean age 42.1, range 24-59 years) underwent magnetic resonance imaging (MRI) using the same protocol. Renal tissue injury was evaluated using quantification of diffusion and diffusion anisotropy with diffusion-weighted (DWI) and diffusion-tensor imaging (DTI). Renal function was monitored and AKI was defined according to Acute-Kidney-Injury-Network criteria. Statistical analysis comprised one-way ANOVA and Pearson correlation.67% of lutx patients (36/54) developed AKI, 47% (17/36) had AKI stage 1, 42% (15/36) AKI stage 2, and 8% (3/36) severe AKI stage 3. Renal apparent diffusion coefficients (ADCs) were reduced in patients with AKI, but preserved in transplant patients without AKI and healthy volunteers (2.07 ± 0.02 vs 2.18 ± 0.05 vs 2.21 ± 0.03 × 10 mm/s, P < .05). Diffusion anisotropy was reduced in all lutx recipients compared with healthy volunteers (AKI: 0.27 ± 0.01 vs no AKI: 0.28 ± 0.01 vs healthy: 0.33 ± 0.02; P < .01). Reduction of renal ADC correlated significantly with acute loss of renal function after lutx (decrease of renal function in the postoperative period and glomerular filtration rate on the day of MRI).MR diffusion imaging enables non-invasive assessment of renal changes correlating with AKI early after lutx. Reduction of diffusion anisotropy was present in all patients after lutx, whereas marked reduction of renal ADC was observed only in the group of lutx recipients with AKI and correlated with renal function impairment.

Combined Single Lung and Liver Transplantation in a Cystic Fibrosis Patient With Previous Contralateral Pneumonectomy: A Case Report

Combined lung-liver transplantation is a rare life-saving procedure to treat concomitant end-stage lung and liver failure. In this report, we describe the first published case of single lung and liver transplantation in a cystic fibrosis patient who had previously undergone a pneumonectomy for the treatment of an infected and destroyed right lung. We detail the lung first, sequential transplant procedure and surgical difficulties due to mediastinal shift. Emergent intraoperative renal replacement therapy was carried out before liver transplantation to overcome pulmonary edema in the transplanted lung. After fluid balance equilibration, liver transplantation was performed in good conditions. The patient is currently alive with no signs of rejection 8 years after the procedure.

Acute Kidney Injury in Patients Undergoing Cardiopulmonary Bypass for Lung Transplantation

BACKGROUND

Cardiopulmonary bypass (CPB) is often used to support patients undergoing lung transplantation who are intolerant of anatomic manipulation or single lung ventilation during the procedure. However, CPB may be associated with adverse outcomes. We evaluated the hypothesis that CPB is associated with increased acute kidney injury (AKI) and postoperative mortality after lung transplantation.

MATERIALS AND METHODS

This was a retrospective review of our institutional lung transplant database at the University of Texas Southwestern Medical Center from 2012 to 2018. Patients were grouped based on their need for CPB. The primary outcome was AKI within 48 h of transplantation, which was defined as Kidney Disease Improving Global Outcomes stage 1 or greater. Secondary outcomes included all-cause mortality.

RESULTS

A total of 426 patients underwent lung transplantation with 39.0% (n = 166) requiring CPB. There were no differences in demographics and comorbidities, including baseline renal function, between CPB and no CPB. CPB use was higher in recipients with interstitial lung diseases and primary pulmonary hypertension. Median lung allocation score was higher in those needing CPB (47 [interquartile range, 40-59] versus 39 [interquartile range, 35-47]). Patients requiring CPB were significantly more likely to experience AKI (61.44% versus 36.5.3%, P < 0.01) and postoperative hemodialysis (6.6% versus 0.4%, P < 0.01). On multivariable analysis, CPB was significantly associated with postoperative AKI (odds ratio, 1.66; 95% CI, 1.01-2.75; P = 0.04). Thirty-day mortality was higher in patients undergoing CPB (4.2% versus 0.8%, P = 0.03).

CONCLUSIONS

CPB for lung transplantation is associated with a higher incidence of AKI, renal failure requiring hemodialysis, and 30-d mortality. CPB should be used selectively for lung transplantation.

De Novo Belatacept in a Kidney-After-Heart Transplant Recipient

Renal injury almost always accompanies the multisystem organ failure that precedes cardiac transplantation and renal function is further compromised by the nephrotoxicity of calcineurin inhibitors posttransplant. Renal dysfunction in turn causes significant morbidity and mortality. The development of belatacept was motivated by need for an alternative to calcineurin-based immunosuppression, particularly in renal transplantation where the nephrotoxicity of calcineurin inhibitors reduce graft longevity and adverse cardiovascular effects of calcineurin inhibitors increase overall mortality. In 2011, the FDA approved belatacept for use in renal transplantation. Seven-year data from the multicenter randomized phase III BENEFIT trial, which compared belatacept with cyclosporine in renal transplant recipients, show belatacept therapy offers both improved renal function and 43% risk reduction for the combined endpoint of graft loss and death. At present, belatacept use is predominantly confined to renal transplant recipients; however, reports of belatacept use in other transplant settings are emerging. Here, we describe successful long-term use of belatacept in a kidney-after-heart transplant recipient and review use of belatacept in cardiothoracic and other nonrenal transplant settings.

Acute Kidney Injury after Lung Transplantation: A Systematic Review and Meta-Analysis

Background: Lung transplantation has been increasingly performed worldwide and is considered an effective therapy for patients with various causes of end-stage lung diseases. We performed a systematic review to assess the incidence and impact of acute kidney injury (AKI) and severe AKI requiring renal replacement therapy (RRT) in patients after lung transplantation. Methods: A literature search was conducted utilizing Ovid MEDLINE, EMBASE, and Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring RRT, and mortality risk of AKI among patients after lung transplantation. Pooled incidence and odds ratios (ORs) with 95% confidence interval (CI) were obtained using random-effects meta-analysis. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42019134095). Results: A total of 26 cohort studies with a total of 40,592 patients after lung transplantation were enrolled. Overall, the pooled estimated incidence rates of AKI (by standard AKI definitions) and severe AKI requiring RRT following lung transplantation were 52.5% (95% CI: 45.8–59.1%) and 9.3% (95% CI: 7.6–11.4%). Meta-regression analysis demonstrated that the year of study did not significantly affect the incidence of AKI (p = 0.22) and severe AKI requiring RRT (p = 0.68). The pooled ORs of in-hospital mortality in patients after lung transplantation with AKI and severe AKI requiring RRT were 2.75 (95% CI, 1.18–6.41) and 10.89 (95% CI, 5.03–23.58). At five years, the pooled ORs of mortality among patients after lung transplantation with AKI and severe AKI requiring RRT were 1.47 (95% CI, 1.11–1.94) and 4.79 (95% CI, 3.58–6.40), respectively. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring RRT in patients after lung transplantation are 52.5% and 9.3%, respectively. Despite advances in therapy, the incidence of AKI in patients after lung transplantation does not seem to have decreased. In addition, AKI after lung transplantation is significantly associated with reduced short-term and long-term survival.

The association of post-lung transplant acute kidney injury with mortality is independent of primary graft dysfunction: A cohort study

BACKGROUND

Prior studies of post-lung transplant acute kidney injury (AKI) have not accounted for confounding effects of primary graft dysfunction (PGD). We sought to test the impact of PGD on AKI risk factors and on the association of AKI with mortality.

METHODS

We included patients transplanted at the University of Pennsylvania from 2005-12, defined AKI using consensus criteria during transplant hospitalization, and defined PGD as grade 3 at 48-72 hours. We used multivariable logistic regression to test the impact of PGD on AKI risk factors and Cox models to test association of AKI with one-year mortality adjusting for PGD and other confounders.

RESULTS

Of 299 patients, 188 (62.9%) developed AKI with 142 (75%) cases occurring by postoperative day 4. In multivariable models, PGD was strongly associated with AKI (OR 3.76, 95% CI 1.72-8.19, P = .001) but minimally changed associations of other risk factors with AKI. Both AKI (HR 3.64, 95% CI 1.68-7.88, P = .001) and PGD (HR 2.55, 95% CI 1.40-4.64, P = .002) were independently associated with one-year mortality.

CONCLUSIONS

Post-lung transplant AKI risk factors and association of AKI with mortality were independent of PGD. AKI may therefore be a target for improving lung transplant mortality rather than simply an epiphenomenon of PGD.

In-hospital and subsequent mortality among lung transplant recipients with a prolonged initial hospitalization

The care of lung transplant recipients with prolonged index hospitalizations can be ethically complex, with conflicts arising over whether the expected outcomes justify ongoing intensive interventions. There are limited data to guide these conversations. The objective of this study was to evaluate survival to discharge for lung transplant recipients based on length of stay (LOS). This was a retrospective cohort study of adult lung transplant recipients in the Scientific Registry of Transplant Recipients. For each day of the index hospitalization the mortality rate among patients who survived to that length of stay or longer was calculated. Post-discharge survival was compared in those with and without a prolonged hospitalization (defined as the 97th percentile [>90 days]). Among the 19 250 included recipients, the index hospitalization mortality was 5.4%. Posttransplant stroke and need for dialysis were the strongest predictors of index hospitalization mortality. No individual or combination of available risk factors, however, was associated with inpatient mortality consistently above 50%. Recipients with >90 day index hospitalization had a 28.8% subsequent inpatient mortality. Their 1, 3 and 5 year survival following discharge was 53%, 26%, and 16%. These data provide additional context to goals of care conversations for transplant recipients with prolonged index hospitalizations.

Acute Kidney Injury in Children with Kidney Transplantation

BACKGROUND AND OBJECTIVES

AKI is associated with progression of CKD. Little is known about AKI after kidney transplantation in pediatric recipients. We aim to describe the epidemiology, risk factors, consequences, and outcomes of AKI in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective longitudinal analysis of pediatric kidney transplant recipients followed at The Hospital for Sick Children (Toronto, Canada) from 2001 to 2012. AKI was defined as an increase in serum creatinine ≥1.5 times baseline, and a rise of serum creatinine ≥1.25 but <1.5 times baseline defined subacute AKI.

RESULTS

Of 179 children, 122 were eligible for analysis. At baseline (3 months post-transplant), median age of the children was 13 years old (interquartile range, 9-16 years old), and 53% had CKD stage 2. Congenital anomalies of the kidney and urinary tract accounted for 46% of children. Over the study period (12 years), the incidence of AKI was 37% (n=45 children), and 65% (79 children) experienced subacute AKI. Twenty-seven percent (33 children) did not develop AKI or subacute AKI. The main causes of AKI were infections other than urinary tract infections, rejection, and urinary tract infections. In a multivariable Poisson regression analysis, independent risk factors for AKI included younger age, girls, grafts from deceased donors, and lower baseline eGFR. AKI was significantly associated with lower long-term GFR and graft loss independent of rejection episodes. Moreover, subacute AKI was associated with progression of CKD.

CONCLUSIONS

AKI and subacute AKI were common after pediatric kidney transplantation, and they were associated with graft loss, lower eGFR, and more rapid progression of CKD.

Renal Complications Following Lung Transplantation and Heart Transplantation

Renal complications are common following heart and/or lung transplantation and lead to increased morbidity and mortality. Renal dysfunction is also associated with increased mortality for patients on the transplant wait list. Dialysis dependence is a relative contraindication for heart or lung transplantation at most centers, and such patients are often listed for a simultaneous kidney transplant. Several factors contribute to the impaired renal function in patients undergoing heart and/or lung transplantation, including the interplay between cardiopulmonary and renal hemodynamics, complex perioperative issues, and exposure to nephrotoxic medications, mainly calcineurin inhibitors.

[Ageing with cystic fibrosis: Classical and emerging comorbidities in adults with cystic fibrosis]

Cystic fibrosis (CF) is a genetic disease with pulmonary involvement being predominant and often leading to respiratory failure and premature death. Non-pulmonary complications related to CF transmembrane conductance regulator (CFTR) defect are numerous and account for significant morbidity (exocrine pancreatic insufficiency, diabetes, CF-related liver disease, chronic sinusitis, osteoporosis). Improvement in patients' care led to a continuous increase in life expectancy, with a subsequent increase in the number of adult CF patients worldwide. Increased life expectancy comes with increased prevalence of CF-related comorbidities, but also with new emerging complications directly related to ageing (chronic kidney disease, cardiovascular risk factors, cancers). CFTR modulators might also contribute to modify the face of CF epidemiology and prognosis. Ageing with CF has become a challenge for CF patients and caregivers. This review summarizes classic and emerging comorbidities in the context of current growth and ageing of the CF population. It also addresses potential roles of CFTR modulators.

Impact of donor lung pathogenic bacteria on patient outcomes in the immediate post-transplant period

BACKGROUND

Patient outcomes post-lung transplant remain inferior to other types of solid organ transplantation. We investigated whether the presence of potentially pathogenic bacteria (PPB) in donor lung bronchial cultures was associated with adverse outcomes postoperatively.

METHODS

All patients who underwent lung transplantation between August 2015 and April 2017 at the University of Kentucky Medical Center were retrospectively reviewed. Retransplants, patients with bronchiectasis (including cystic fibrosis), and individuals who received organs from donation after cardiac death (DCD) donors were excluded. The remaining subjects were separated into two groups: individuals whose donor bronchial cultures grew PPB, and those whose cultures either returned negative for PPB or were sterile. 30-day mortality rates as well as the incidence of grade 3 primary graft dysfunction (PGD) and acute kidney injury (AKI) at both 24 and 72 hours post-transplant were calculated. The duration of mechanical ventilation postoperatively was also recorded.

RESULTS

Thirty two subjects comprised the study population. 20 patients (63%) had growth of PPB on donor cultures, while 12 (37%) did not. Patients with PPB had a significantly greater number of days on the ventilator postoperatively compared to those with no PPB (mean = 11.3 and median = 5.0 vs mean = 5.8 and median = 3.0, respectively, P = 0.0232). Subsequent regression analysis revealed this association to not be influenced by recipient lung allocation score (LAS), donor age, donor smoking history, recipient mean pulmonary artery pressure (mPAP) value, and/or use of cardiopulmonary bypass at the time of transplantation. Neither 30-day survival nor incidence of Grade 3 PGD and AKI at 24 or 72 hours post-transplant differed between the two groups (P > 0.05).

CONCLUSION

The recovery of PPB in donor lung cultures was associated with a longer duration of mechanical ventilation postoperatively in lung transplant recipients.

Inhaled nitric oxide therapy was not associated with postoperative acute kidney injury in patients undergoing lung transplantation: A retrospective pilot study

Inhaled nitric oxide (iNO) therapy is commonly used in lung transplantation (LT) recipients during the perioperative periods. However, previous studies report that the use of iNO may increase the risk of renal dysfunction. Post-LT acute kidney injury (AKI) can lead to critical situations, including prolonged intensive care unit or hospital stays and increased morbidity and mortality. Accordingly, the aim of this study was to investigate the relationship between iNO therapy and incidence of post-LT AKI in LT recipients.The medical data of 36 patients who underwent LT surgery from January 2012 to July 2017 in a single university hospital setting were retrospectively collected and analyzed. Patients were divided into 2 groups: iNO (n = 14) and control (n = 19). The demographic data, anesthetic methods, complications, and perioperative laboratory test values of each patient were assessed. Patients were categorized according to changes in plasma creatinine (Cr) concentration levels within 48 hours after LT using Acute Kidney Injury Network criteria.There was no significant difference in the occurrence (P = .13) and severity (P = .9) of post-LT AKI between iNO and control groups. The mean serum Cr levels after surgery were 0.91 ± 0.44 and 0.81 ± 0.37 mg/dL in the iNO and control groups, respectively (P = .50).AKI plays a critical role in the prognosis of LT recipients. Our results revealed that iNO therapy was not associated with the incidence of post-LT AKI. Therefore, if iNO treatment is indicated, active use under close monitoring of renal function is recommended in LT-patients concerned about AKI after surgery.

Acute Kidney Injury in Mechanically Ventilated Patients: The Risk Factor Profile Depends on the Timing of Aki Onset

BACKGROUND

Acute kidney injury (AKI) is a frequent complication in patients under mechanical ventilation (MV). We aimed to assess the risk factors for AKI with particular emphasis on those potentially preventable.

STUDY DESIGN, SETTING, AND PARTICIPANTS

Retrospective analysis of a large, multinational database of MV patients with >24 h of MV and normal renal function at admission. AKI was defined according to creatinine-based KDIGO criteria. Risk factors were analyzed according to the time point at which AKI occurred: early (≤48 h after ICU admission, AKIE) and late (day 3 to day 7 of ICU stay, AKIL). A conditional logistic regression model was used to identify variables independently associated with AKI.

RESULTS

Three thousand two hundred six patients were included. Seven hundred patients had AKI (22%), the majority of them AKIE (547/704). The risk factor profile was highly dependent upon the timing of AKI onset. In AKIE risk factors were older age; SAPS II score; postoperative and cardiac arrest as the reasons for MV; worse cardiovascular SOFA, pH, serum creatinine, and platelet count; higher level of peak pressure and Vt/kg; and fluid overload at admission. In contrast, AKIL was linked mostly to events that occurred after admission (lower platelet count and pH; ICU-acquired sepsis; and fluid overload). None ventilation-associated parameters were identify as risk factors for AKIL.

CONCLUSIONS

In the first 48 h, risk factors are associated with the primary disease and the patient's condition at admission. Subsequently, emergent events like sepsis and organ dysfunction appear to be predictive factors making prevention a challenge.

Acute kidney injury among adult patients undergoing major surgery in a tertiary hospital in Nigeria

Background

Acute kidney injury (AKI) is an underreported but major cause of morbidity and mortality among patients undergoing major surgical interventions in sub-Saharan Africa (SSA). Whereas AKI is often seen following major cardiac surgery in high-income countries, a similar spectrum of surgical diseases and interventions is not seen in developing countries. The impacts on surgical outcomes have also not been well characterized in SSA. This study aimed at identifying risk factors, incidence and determinants and short-term outcomes of AKI among patients undergoing major surgery.

Methods

This was a cohort study of adult patients undergoing major surgery at the University College Hospital, Ibadan, Nigeria. Data obtained were sociodemographic details, risk factors for AKI, details of surgery, anaesthesia and intra-operative events and short-term outcomes. Blood samples were obtained for pre-operative (pre-op) full blood count, serum electrolytes, blood urea and creatinine (SCr). Post-operatively (Post-op) SCr was determined at 24 h, Day 7 post-op and weekly until each patient was discharged.

Results

A total of 219 subjects who had major surgery (86.3% elective) were enrolled. The median age of the patients was 46 (range 18-73) years and 72.6% were females. The surgeries performed were mostly simple mastectomies (37.4%), exploratory laparotomies (22.8%) and total thyroidectomies (16.4%). The incidences of AKI were 18.7% at 24 h and 17.4% at Day 7 post-op, while cumulative AKI incidence was 22.5% at 1-week post-op. Pre-op elevated SCr [odds ratio (OR) 3.86], sepsis (OR 2.69), anaemia (OR 2.91) and duration of surgery >120 min (OR 1.75) were independently associated with AKI. In-patient mortality was 20.4% in individuals with AKI and 5.3% in those without AKI (P < 0.01).

Conclusion

Peri-operative risk factors for AKI are common among patients undergoing major surgery in SSA hospitals. The cumulative incidence of AKI was high and independently associated with pre-op sepsis, anaemia, pre-existing kidney dysfunction and duration of surgery >120 min.

Evaluation of Renal Function in Patients Undergoing Lung Transplantation

BACKGROUND

Acute kidney injury and chronic kidney failure are serious complications after lung transplantation. Glomerular filtration rate (GFR) is the primary indicator of renal function. Several equations have been proposed to evaluate the estimated GFR (eGFR). We compared three different equations to determine which has the better correlation with the development of acute and chronic renal failure in lung recipients.

METHODS

Twenty-two patients with a mean age of 54.4 ± 8.5 years underwent lung transplantation from 2010 to 2015. Thirteen (59%) had pulmonary fibrosis, 7 (32%) emphysema, 1 (4.5%) bronchiectasis, and 1 (4.5%) lymphangioleiomyomatosis. In all patients, eGFR was measured preoperatively using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Levey's Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. In 20 patients (90%) eGFR was calculated at 1, 3, and 6 months.

RESULTS

According to CKD-EPI and MDRD, eight patients (36.3%) had preoperative reduction in eGFR, whereas 6 patients (27.2%) had preoperative reduction according to the CG (P = .04). The mean values were higher for the CG (103.2 vs. 102 vs. 94.4). Five patients (22.7%) developed perioperative acute renal failure requesting a dialysis treatment; four of these showed a preoperative eGFR to the highest CG (P = .05). At 1 and 6 months after lung transplantation, the CG, MDRD and CKD-EPI eGFR values were, respectively, 86.6, 84.1 and 76.6 mL/min/1.73m² and 75.8, 72.7, and 72.3 mL/min/1.73m². CKD-EPI eGFR values are more predictable than the other equations of AKI.

CONCLUSIONS

Preoperative assessment of eGFR using the MDRD and CKD-EPI seems to correlate better than the CG to the prediction of acute renal failure, whereas for the chronic form the three equations seem equivalent.

Acute Kidney Injury After Craniotomy Is Associated With Increased Mortality: A Cohort Study

BACKGROUND

Acute kidney injury (AKI) is a serious postoperative complication.

OBJECTIVE

To determine whether AKI in patients after craniotomy is associated with heightened 30-day mortality.

METHODS

We performed a 2-center, retrospective cohort study of 1656 craniotomy patients who received critical care between 1998 and 2011. The exposure of interest was AKI defined as meeting RIFLE (Risk, Injury, Failure, Loss of Kidney Function, and End-stage Kidney Disease) class risk, injury, and failure criteria, and the primary outcome was 30-day mortality. Adjusted odds ratios were estimated by multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both AKI and mortality. Additionally, mortality in craniotomy patients with AKI was analyzed with a risk-adjusted Cox proportional hazards regression model and propensity score matching as a sensitivity analysis.

RESULTS

The incidences of RIFLE class risk, injury, and failure were 5.7%, 2.9%, and 1.3%, respectively. The odds of 30-day mortality in patients with RIFLE class risk, injury, or failure fully adjusted were 2.79 (95% confidence interval [CI], 1.76-4.42), 7.65 (95% CI, 4.16-14.07), and 14.41 (95% CI, 5.51-37.64), respectively. Patients with AKI experienced a significantly higher risk of death during follow-up; hazard ratio, 1.82 (95% CI, 1.34-2.46), 3.37 (95% CI, 2.36-4.81), and 5.06 (95% CI, 2.99-8.58), respectively, fully adjusted. In a cohort of propensity score-matched patients, RIFLE class remained a significant predictor of 30-day mortality.

CONCLUSION

Craniotomy patients who suffer postoperative AKI are among a high-risk group for mortality. The severity of AKI after craniotomy is predictive of 30-day mortality.

ABBREVIATIONS

AKI, acute kidney injuryAPACHE II, Acute Physiology and Chronic Health Evaluation IICI, confidence intervalCPT, Current Procedural TerminologyICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical ModificationRIFLE, risk, injury, failure, loss of kidney function, and end-stage kidney diseaseRPDR, Research Patient Data Registry.

Interaction of pre-transplant recipient characteristics and renal function in lung transplant survival

BACKGROUND

There has been little investigation into the potential interaction of recipient characteristics with the association of pre-transplant renal functions and survival after lung transplantation. In this study we tested the hypothesis that association of pre-transplant renal function and post-transplant mortality varies among recipient subgroups.

METHODS

We queried the United Network for Organ Sharing (UNOS) database for adult patients (≥18 years of age) undergoing lung transplantation between May 2005 and March 2015. The study population (n = 15,540) was split into 3 groups (90 to 150, 60 to 89.9 and 30 to 59.9 ml/min/1.73 m2) based on the estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration equation) at the time of listing. We utilized multivariable inverse probability weighted Cox proportional hazard models to compare the association of glomerular filtration rate (GFR) groups with mortality among recipient subgroups.

RESULTS

Overall, there was an independent and graded inverse association between the estimated GFR (eGFR) and mortality, with the hazard of mortality significantly rising with listing eGFR <60 ml/min/1.73 m2. The association between low eGFR and mortality was more consistent and stronger for older (>45 years), non-African-American and non-diabetic patients as well as those with low lung allocation score (LAS <40). Among the diagnosis groups, patients with vascular diseases had the strongest association between low eGFR and poor survival. Sensitivity analyses conducted using an alternate equation to estimate the GFR (Modification of Diet in Renal Disease) supported these associations.

CONCLUSIONS

Prognostic significance of pre-transplant renal functions varies significantly among recipient subgroups. It may be appropriate to develop a customized approach toward assessing and interpreting renal function to determine transplant candidacy.