Perioperative fluid management in kidney transplantation: a black box

Predicting the risk of pulmonary infection after kidney transplantation using machine learning methods: a retrospective cohort study

PURPOSE

Pulmonary infection is the most common and serious complication after kidney transplantation that affects the survival of the transplanted kidney and the quality of life of patients. This study aims to construct a machine learning model for predicting the risk of pulmonary infection after kidney transplantation.

METHODS

We recruited 857 kidney transplant recipients from January 1, 2016, to December 31, 2021, in the Department of Nephrology, the First Affiliated Hospital of the University of Science and Technology of China. First, the distribution of baseline characteristics between patients with and without postoperative pulmonary infections was analyzed. Subsequently, six machine learning models were constructed to predict the risk of postoperative pulmonary infections. Finally, these models were subjected to external validation using an independent cohort. The performance of the models was evaluated by area under the receiver operating characteristic curve (AUC).

RESULTS

Among kidney transplant recipients, a total of 186 individuals developed pneumonia, with 144 cases in the training cohort and 42 cases in the external validation cohort. The AUC range of the six machine learning models for predicting the risk of postoperative pulmonary infection was 0.758-0.822 for the training cohort and 0.642-0.795 for the testing cohort. Among the models assessed, the gradient boosting machine demonstrated the most favorable predictive accuracy.

CONCLUSIONS

Our study has developed a predictive model for assessing the risk of pulmonary infection after kidney transplantation, thereby providing a valuable foundation for the effective management of kidney transplant recipients.

Intraoperative central venous pressures related to early graft function in deceased donor kidney transplant recipients with low immunological risks

This study aims to analyze data from patients who received kidney transplantation from deceased donors to investigate the anesthetic factors influencing early and late graft outcomes, including the incidence of slow graft function (SGF), delayed graft function (DGF), and 3-year graft outcomes. We retrospectively analyzed 202 recipients who underwent deceased donor kidney transplantation from March 2010 to December 2020. Anesthetic monitoring data during the intraoperative period was analyzed at 5-minute intervals, and basic clinical parameters were evaluated. The mean recipient age was 46.6 ± 10.3 years, and the mean donor age was 41.7 ± 12.7 years. Anesthetic time averaged 285.8 ± 70.2 min, and operation time averaged 223.1 ± 44.0 min. The incidence of SGF was 11.8%, and the incidence of DGF was 3.9%. Mean central venous pressures (CVPs) were higher in recipients with SGF or DGF (11.7 mmHg) compared to those with immediate graft function (9.7 mmHg). Higher CVP was identified as an independent risk factor for SGF or DGF (odds ratio 1.219, p = 0.006). This study suggests that intraoperative monitoring of CVP is crucial for predicting short-term graft function in deceased donor kidney transplantation and should be managed to prevent excessive fluid intake.

Assessment of fluid responsiveness after tidal volume challenge in renal transplant recipients: a nonrandomized prospective interventional study

Background

When applying lung-protective ventilation, fluid responsiveness cannot be predicted by pulse pressure variation (PPV) or stroke volume variation (SVV). Functional hemodynamic testing may help address this limitation. This study examined whether changes in dynamic indices such as PPV and SVV, induced by tidal volume challenge (TVC), can reliably predict fluid responsiveness in patients undergoing renal transplantation who receive lung-protective ventilation.

Methods

This nonrandomized interventional study included renal transplant recipients with end-stage renal disease. Patients received ventilation with a 6 mL/kg tidal volume (TV), and the FloTrac system was attached for continuous hemodynamic monitoring. Participants were classified as responders or nonresponders based on whether fluid challenge increased the stroke volume index by more than 10%.

Results

The analysis included 36 patients, of whom 19 (52.8%) were responders and 17 (47.2%) were nonresponders. Among responders, the mean ΔPPV6-8 (calculated as PPV at a TV of 8 mL/kg predicted body weight [PBW] minus that at 6 mL/kg PBW) was 3.32±0.75 and ΔSVV6-8 was 2.58±0.77, compared to 0.82±0.53 and 0.70±0.92 for nonresponders, respectively. ΔPPV6-8 exhibited an area under the curve (AUC) of 0.97 (95% confidence interval [CI], 0.93-1.00; P≤0.001), with an optimal cutoff value of 1.5, sensitivity of 94.7%, and specificity of 94.1%. ΔSVV6-8 displayed an AUC of 0.93 (95% CI, 0.84-1.00; P≤0.001) at the same cutoff value of 1.5, with a sensitivity of 94.7% and a specificity of 76.5%.

Conclusions

TVC-induced changes in PPV and SVV are predictive of fluid responsiveness in renal transplant recipients who receive intraoperative lung-protective ventilation.

Comparison of two different preload targets of stroke volume variation during kidney transplantation: a randomised controlled trial

INTRODUCTION

Maintaining adequate preload during kidney transplantation (KT) is important for graft function. We evaluated whether a high or low normal target for a dynamic preload index of stroke volume variation (SVV) would impact graft function during living donor KT.

METHODS

We compared haemodynamic management algorithms using two different targets of SVV: SVV6% group (n = 30) versus SVV12% group (n = 30). Crystalloids were administered to achieve SVV less than the assigned target. Neutrophil gelatinase-associated lipocalin (NGAL) level at the end of surgery was compared. We also compared the incidence of delayed graft function (DGF), daily serum creatinine level and glomerular filtration rate (GFR) until 2 weeks postoperatively.

RESULTS

The total amount of crystalloids administered was significantly different between the SVV6% and SVV12% groups (median [interquartile range] 2,250 [1,700-3,600] vs. 1,350 [1,050-1,900], P < 0.001). There was no significant difference in NGAL level at the end of the operation between the SVV6% and SVV12% groups (395 [234-560] vs. 518 [346-654], P = 0.115). The incidence of DGF was not significantly different, and there was no significant difference in the postoperative serum creatinine levels or GFR between the groups.

CONCLUSIONS

Our randomised trial demonstrated that an SVV target of either 6% or 12% could be adequate as a preload management target for postoperative graft function during living donor KT. However, given the low incidence of DGF in living donor KT and type II error, our study should be interpreted carefully and further studies for deceased donor KT are required.

Intraoperative Mean Arterial Pressure and Postoperative Delayed Graft Function in Kidney Transplantation: Evaluating Three Commonly Used Thresholds

BACKGROUND

Delayed graft function (DGF) is a common early complication after kidney transplantation (KT) and is associated with various long-term adverse outcomes. Despite numerous studies on hemodynamic management, the optimal hemodynamic goals during KT remain unclear. In this retrospective study, we aimed to investigate if three mean artery pressure (MAP) thresholds (≤75, 80, and 85 mmHg) that were commonly used in clinical practice were associated with DGF in adult patients undergoing KT.

METHODS

We extracted de-identified data on adult patients who underwent deceased donor KT from our Discovery Data Repository. DGF was defined as the requirement for dialysis within the first 7 days after transplantation. Three MAP thresholds (≤75, 80, and 85 mmHg) and the duration of pressure below the three thresholds were recorded. Multivariable logistic analysis was used to identify risk factors for DGF.

RESULTS

We included 2301 adult KT patients. The mean age was 52.5±12.9 years and 59% were male. DGF occurred in 1066 patients (46.3%). Patients frequently experienced MAP ≤75, 80, and 85 mmHg (approximately 70%, 80%, and 90% of patients experienced 10 min of MAP ≤75, 80, and 85 mmHg, respectively). Patients with DGF spent significantly longer durations below the three MAP thresholds during surgery compared with those without DGF. Further analysis revealed that the minimal time spent on MAP ≤75, 80, and 85 mmHg that were significantly associated with DGF were 6, 23, and 37 min, respectively. After adjusting for non-hemodynamic risk factors (age, basiliximab administration, and urine output), prolonged exposure to the three MAP thresholds remained significant predictors for DGF (for MAP ≤75 mmHg, OR 1.257, 95% CI 1.017-1.554, p = 0.034; MAP ≤80 mmHg, OR 1.220, 95% CI 1.018-1.463, p = 0.031; MAP ≤85 mmHg, OR 1.253, 95% CI 1.048-1.498, p = 0.013).

CONCLUSION

Prolonged exposure to the three common MAP thresholds (≤75, 80, and 85 mmHg) occurred frequently during adult deceased donor KT and was associated with DGF.

Correlation Between Serum Transaminase Levels and Estimated Glomerular Filtration Rate After Living-Donor Kidney Transplantation

BACKGROUND

There is a risk of hypoperfusion during kidney transplantation surgery owing to patients' underlying disease and ischemia-reperfusion injury; further, hypoperfusion may cause injury to major organs. We hypothesized that the decrease in blood pressure after ischemia-reperfusion injury during kidney transplantation may be associated with indicators of liver injury and kidney graft function.

METHODS

Data regarding living-donor kidney transplantations performed at our institution between 2018 and 2022 were retrospectively evaluated. Exclusion criteria included pediatric recipients or donors aged <18 years, multiple organ transplantation, and elevated postoperative serum transaminase levels. Correlations among blood pressure, serum transaminase levels on postoperative days 3 to 5, and estimated glomerular filtration rate (eGFR) on postoperative days 7 and 14 were analyzed. Further, a subgroup analysis was performed based on eGFR.

RESULTS

A total of 276 patients were included in the final analysis. Serum transaminase levels were significantly negatively correlated with eGFR (partial correlation coefficient-0.26, P < .001). The postreperfusion decrease in blood pressure was not correlated with serum transaminase levels. However, the postreperfusion decrease in blood pressure and baseline blood pressure correlated with the eGFR (partial correlation coefficient = -0.18, P = .004).

CONCLUSION

These findings indicate a correlation between intraoperative liver injury and kidney graft function, suggesting the importance of intraoperative management of organ perfusion. Since postreperfusion blood pressure changes did not significantly correlate with liver injury indicators, it is important to consider other causative factors for hypoperfusion in major organs during living-donor kidney transplantation, including microcirculatory failure and organ congestion-related ischemia/reperfusion.

Postoperative cognitive dysfunction in elderly patients with colorectal cancer: A randomized controlled study comparing goal-directed and conventional fluid therapy

To investigate the impact of goal-directed fluid therapy (GDFT) on postoperative cognitive dysfunction (POCD) in elderly patients with colorectal cancer, we conducted a randomized controlled trial. Eighty elderly patients who underwent elective laparoscopic radical resection of colorectal cancer were randomly assigned to either the GDFT group or the conventional fluid therapy group. The primary outcome was the incidence of POCD during the initial 7 postoperative days, while secondary outcomes included inflammatory marker levels such as interleukin-6 (IL-6) and S100β protein, hemodynamics, level of lactic acid, postoperative functional recovery, and complications. Among 88 randomized patients, 80 were evaluable for the primary outcome. The incidence of POCD was significantly lower in the GDFT group (15.0%) compared to the conventional fluid therapy group (30.0%), with the highest occurrence observed on day 3 postoperatively in both groups (P < 0.05). IL-6 and S100β concentrations were consistently lower in the GDFT group than in the conventional fluid therapy group at the corresponding time points (P < 0.05). The GDFT group exhibited more stable perioperative hemodynamics and lower lactate levels (P < 0.05). Moreover, patients in the GDFT group exhibited better postoperative functional recovery indicators and a lower incidence of postoperative complications (P < 0.05). In summary, GDFT appears to reduce the incidence of early POCD, accelerate postoperative recovery, and enhance overall prognosis.

Anesthesia and intensive care unit care in pediatric kidney transplantation: An international survey

BACKGROUND

Despite the high perioperative risk profile, international guidelines for anesthesia and intensive care unit (ICU) care in pediatric kidney transplantation do not exist. Optimizing hemodynamics can be challenging in these patients, while scientific data to guide decisions in hemodynamic monitoring, hemodynamic targets, and perioperative fluid management are lacking. The limited annual number of pediatric kidney transplantations, even in reference centers, necessitates the urge for international collaboration to share knowledge and develop research and guidelines. The aim of this study was to collect data on current perioperative anesthesia and ICU care practices in pediatric kidney transplantation.

METHODS

An international survey with an anonymized link was sent from a validated electronic data capture system (Castor). Inclusion criteria were: medical doctor in anesthesia, (ICU), or pediatric nephrology working in a pediatric kidney transplantation specialized center; and signed informed consent. Data were analyzed using descriptive statistics.

RESULTS

Thirty-three records were analyzed. Responders were anesthesiologists (58%), pediatric nephrologists (30%), and pediatric intensivists (12%), representing 13 countries worldwide. About half of the centers (48%) performed more than 10 pediatric kidney transplantations a year. Perioperative hemodynamic support was guided by intra-arterial blood pressure (88%), central venous pressure (CVP; 88%), and cardiac output (CO; 39%). The most variation was seen in the hemodynamic targets CVP and CO, fluid administration, and inotrope/vasopressor use. The protocolized use of furosemide (46%) and mannitol (61%) also varied between centers. Postoperative care for the youngest recipients occurred in the pediatric intensive care unit at all centers.

CONCLUSION

The results of this survey reveal a large variation in anesthesia and ICU care in pediatric kidney transplantation centers worldwide, particularly in CVP and CO targets, hemodynamic therapy, and the use of furosemide and mannitol. These data identify areas for further research and can be a starting point for international research collaboration and guideline development.

Perioperative management of kidney transplantation in China: A national survey in 2021

Perioperative anaesthesia management has an important significance for kidney transplantation; however, the related consensus remains limited. An electronic survey with 44 questions was developed and sent to the chief anaesthesiologist at 115 non-military medical centres performing kidney transplantation in China through WeChat. A response rate of 81.7% was achieved from 94 of 115 non-military medical centres, where 94.4% of kidney transplants (10404 /11026) were completed in 2021. The result showed an overview of perioperative practice for kidney transplantations in China, identify the heterogeneity, and provide evidence for improving perioperative management of kidney transplantation. Some controversial therapy, such as hydroxyethyl starch, are still widely used, while some recommended methods are not widely available. More efforts on fluid management, hemodynamical monitoring, perioperative anaesthetics, and postoperative pain control are needed to improve the outcomes. Evidence-based guidelines for standardizing clinical practice are needed.

A systematic review and meta-analysis on the effect of goal-directed fluid therapy on postoperative outcomes in renal transplantation surgeries

Introduction

This systematic review and meta-analysis investigated the impact of intraoperative goal-directed therapy (GDT) compared with conventional fluid therapy on postoperative outcomes in renal transplantation recipients, addressing this gap in current literature.

Method

A systematic search of patients aged ≥18 years who have undergone single-organ primary renal transplantations up to June 2022 in PubMed, Embase, Scopus and CINAHL Plus was performed. Primary outcome examined was postoperative renal function. Secondary outcomes assessed were mean arterial pressure at graft reperfusion, intraoperative fluid volume and other postoperative complications. Heterogeneity was tested using I² test. The study protocol was registered on PROSPERO.

Results

A total of 2459 studies were identified. Seven eligible studies on 607 patients were included. Subgroup assessments revealed potential renal protective benefits of GDT, with patients receiving cadaveric grafts showing lower serum creatinine on postoperative days 1 and 3, and patients monitored with arterial waveform analysis devices experiencing lower incidences of postoperative haemodialysis. Overall analysis found GDT resulted in lower incidence of tissue oedema (risk ratio [RR] 0.34, 95% CI 0.15-0.78, P=0.01) and respiratory complications (RR 0.39, 95% CI 0.17-0.90, P=0.03). However, quality of data was deemed low given inclusion of non-randomised studies, presence of heterogeneities and inconsistencies in defining outcomes measures.

Conclusion

While no definitive conclusions can be ascertained given current limitations, this review highlights potential benefits of using GDT in renal transplantation recipients. It prompts the need for further standardised studies to address limitations discussed in this review.

Use of Intramuscular Ephedrine Sulfate During Kidney Transplantation

Hypotension during kidney transplantation can be common. Vasopressor use during these procedures is often avoided, with a fear of decreasing renal perfusion in the transplanted kidney. However, adequate perfusion for the rest of the body is also necessary, and given that these patients often have underlying hypertension or other comorbid conditions, an appropriate mean arterial pressure (MAP) has to be maintained. Intramuscular injections of ephedrine have been studied in the anesthesiology literature in a variety of case types, and it is seen as a safe and effective method to boost MAP. We present a case series of three patients who underwent renal transplantation and who received an intramuscular injection of ephedrine for hypotension control. The medication worked well for increasing blood pressures without apparent side effects. All three patients were followed for more than one year, and all patients had good graft function at the end of that time period. This series shows that while further research is necessary in this arena, intramuscular ephedrine may have a place in the management of persistent hypotension in the operating room during kidney transplantation.

Early Postoperative Volume Overload is a Predictor of 1-Year Post-Transplant Mortality in Pediatric Heart Transplant Recipients

Fluid restriction and diuretic management are mainstays in the postoperative management of cardiac patients, at risk of volume overload and its deleterious effects on primary cardiac function and multi-organ systems. The importance of fluid homeostasis is further emphasized among orthotopic heart transplant recipients (OHT). We sought to investigate the relationship between postoperative volume overload, mortality, and allograft dysfunction among pediatric OHT recipients within 1-year of transplantation. This is a retrospective cohort study from a single pediatric OHT center. Children under 21 years undergoing cardiac transplantation between 2010 and 2018 were included. Cumulative fluid overload (cFO) was assessed as percent fluid accumulation adjusted for preoperative body weight. Greater than 10% cFO defined those with postoperative cFO and a comparison of postoperative cFO vs. no postoperative cFO (< 5%) is reported. 102 pediatric OHT recipients were included. Early cFO at 72 h post-OHT occurred in 14% and overall cFO at 1-week post-OHT occurred in 23% of patients. Risk factors for cFO included younger age, lower weight, and postoperative ECMO. Early cFO was associated with postoperative mortality at 1-year, OR 8.6 (95% CI 1.4, 51.6), p = 0.04, independent of age and weight. There was no significant relationship between cFO and allograft dysfunction, measured by rates of clinical rejection and cardiopulmonary filling pressures within 1-year of transplant. Early postoperative volume overload is prevalent and associated with increased risk of death at 1-year among pediatric OHT recipients. It may be an important postoperative marker of transplant survival, and this relationship warrants further clinical investigation.

Intraoperative Hemodynamic Parameters Associated With Delayed Graft Function in Kidney Transplant Patients

PURPOSE

Intraoperative hemodynamic instability was proven to be associated with delayed graft function (DGF) after kidney transplantation. This retrospective study aims to find the specific intraoperative hemodynamic parameters as an efficient predicting factor of DGF.

MATERIALS AND METHODS

Patients who underwent kidney transplantation between 2020 and 2022 were enrolled and classified into DGF and non-DGF groups. Pediatric and multiorgan recipients were excluded. Hemodynamic parameters such as central venous pressure, mean arterial pressure, cardiac output, and cardiac index (CI) at the timings of wound incision, graft reperfusion, and operation completion were recorded, respectively. A comparison of parameters between these 2 groups was analyzed.

RESULTS

We enrolled 42 recipients, with 26 in the DGF group and 16 in the non-DGF group. Compared with the DGF group, CI around graft reperfusion was significantly higher in the non-DGF group (3.97 vs 4.67 L/min/m², P = .043). Other hemodynamic variables revealed no statistical difference. In the results of multivariate analysis, the deceased donor source, the greater volume of blood loss, and the lower CI around graft reperfusion were considered independent risk factors for DGF. Using CI around graft reperfusion to conduct a receiver operating characteristic (ROC) curve for DGF prediction, the area under the ROC curve achieved a value of 0.739 (95% confidence interval, 0.579-0.900), with the optimal cut-point value at CI = 4.245 L/min/m².

CONCLUSION

The cardiac index value around graft reperfusion was statistically associated with the incidence of DGF and might be used as a valid predicting factor.

Goal-Directed Haemodynamic Therapy Improves Patient Outcomes in Kidney Transplantation

Introduction: Kidney transplant graft function depends on optimised haemodynamics. However, high fluid volumes risk hypervolaemic complications. The Edwards Lifesciences ClearSight™ device permits fluid titration through markers of preload and beat-to-beat blood pressure monitoring. We evaluated the implementation of a novel goal-directed haemodynamic therapy protocol to determine whether patient outcomes had improved. Design: A retrospective evaluation of standard care versus goal-directed haemodynamic therapy in adults undergoing kidney transplantation was performed in a single centre between April 2016 and October 2019. Twenty-eight standard-of-care patients received intraoperative fixed-rate infusion and 28 patients received goal-directed haemodynamic therapy. The primary outcome was volume of fluid administered intraoperatively. Secondary outcomes included blood product and vasoactive drug exposure, graft and recipient outcomes. Results: Intraoperative fluid administered was significantly reduced in the goal-directed haemodynamic therapy cohort (4325 vs 2751 ml, P < .001). Exposure to vasopressor (67.9% vs 42.9%, P = .060) and blood products (17.9% vs 3.6%, P = .101) was unchanged. Immediate graft function (82.1% vs 75.0%, P = .515), dialysis requirement (14.3% vs 21.4%, P = .729) and creatinine changes post-operatively were unchanged. In the goal-directed haemodynamic therapy cohort, 1 patient had pulmonary oedema (3.6%) versus 21.4% in the standard cohort. Patients in the goal-directed haemodynamic therapy group were more likely to mobilise within 48 hours of surgery (number needed to treat = 3.5, P = .012). Conclusions: Protocolised goal-directed haemodynamic therapy in kidney transplantation was safe and may improve patient, graft, and surgical outcomes. Clinical trials assessing goal-directed approaches are needed.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Anesthetic considerations for pediatric abdominal solid organ transplantation

While many pediatric patients undergo abdominal solid organ transplants every year worldwide, each is unique due to varying age, size, and comorbidities; thus, they require a careful anesthesia plan to undergo surgery safely. This article reviews the anesthetic considerations and management of patients undergoing liver and kidney transplantation. Preoperative, intraoperative, and post-operative management are discussed, including induction, access, monitoring, and maintenance. Blood transfusion is also addressed.

Effects of the Type of Intraoperative Fluid in Living Donor Kidney Transplantation: A Single-Center Retrospective Cohort Study

PURPOSE

Perioperative fluid management in kidney transplant recipients is crucial to supporting the fluid, acid-base, and electrolyte balance required for graft perfusion. However, the choice of intraoperative crystalloids in kidney transplantation remains controversial. We conducted a single-center retrospective cohort study to evaluate the impact of intraoperative fluids on acid-base and electrolyte balance and graft outcomes.

MATERIALS AND METHODS

We included 282 living donor kidney transplant recipients from January 2010 to December 2017. Patients were classified into two groups based on the type of intraoperative crystalloids used (157 patients in the half saline group and 125 patients in the balanced crystalloid solutions group, Plasma-lyte).

RESULTS

Compared with the half saline group, the Plasma-lyte group showed less metabolic acidosis and hyponatremia during surgery. Hyperkalemia incidence was not significantly different between the two groups. Changes in postoperative graft function assessed by blood urea nitrogen and creatinine were significantly different between the two groups. Patients in the Plasma-lyte group exhibited consistently higher glomerular filtration rates than those in the half saline group at 1 month and 1 year after transplantation after adjusting for demographic differences.

CONCLUSION

Intraoperative Plasma-lyte can lead to more favorable results in terms of acid-base balance during kidney transplantation. Patients who received Plasma-lyte showed superior postoperative graft function at 1 month and 1 year after transplantation. Further studies are needed to evaluate the superiority of intraoperative Plasma-lyte over other types of crystalloids in relation to graft outcomes.

Influence of Intraoperative Hemodynamic Parameters on Outcome in Simultaneous Pancreas-Kidney Transplant Recipients

Objectives: Adequate organ perfusion, as well as appropriate blood pressure levels at the time of unclamping, is crucial for early and long-term graft function and outcome in simultaneous pancreas−kidney transplantation (SPKT). However, the optimal intraoperative mean arterial pressure (MAP) level has not well been defined. Methods: From a prospectively collected database, the medical data of 105 patients undergoing SPKT at our center were retrospectively analyzed. A receiver operating characteristic (ROC) analysis was preliminarily performed for optimal cut-off value for MAP at reperfusion, to predict early pancreatic graft function. Due to these results, we divided the patients according to their MAP values at reperfusion into <91 mmHg (n = 47 patients) and >91 mmHg (n = 58 patients) groups. Clinicopathological characteristics and outcomes, as well as early graft function and long-term survival, were retrospectively analyzed. Results: Donor and recipient characteristics were comparable between both groups. Rates of postoperative complications were significantly higher in the <91 mmHg group than those in the >91 mmHg group (vascular thrombosis of the pancreas: 7 (14%) versus 2 (3%); p = 0.03; pancreatitis/intraabdominal abscess: 10 (21%) versus 4 (7%); p = 0.03; renal delayed graft function (DGF): 11 (23%) versus 5 (9%); p = 0.03; postreperfusion urine output: 106 ± 50 mL versus 195 ± 45 mL; p = 0.04). There were no significant differences in intraoperative volume repletion, central venous pressure (CVP), use of vasoactive inotropic agents, and the metabolic outcome. Five-year pancreas graft survival was significantly higher in the >91 mmHg group (>91 mmHg: 82% versus <91 mmHg: 61%; p < 0.01). No significant differences were observed in patient and kidney graft survival at 5 years between both groups. Multivariate Cox regression analysis affirmed MAP < 91 mmHg as an independent prognostic predictor for renal DGF (HR 3.49, 1.1−10.8, p = 0.03) and pancreas allograft failure (HR 2.26, 1.0−4.8, p = 0.01). Conclusions: A MAP > 91 mmHg at the time point of reperfusion was associated with a reduced rate of postoperative complications, enhancing and recovering long-term graft function and outcome and thus increasing long-term survival in SPKT recipients.

Balancing the tug of war: intraoperative and postoperative management of multiorgan transplantation

PURPOSE OF REVIEW

Multiorgan heart transplants (MOHT) have steadily increased and account for approximately 4% of all heart transplants performed. Although long-term outcomes of MOHT are similar to heart transplant alone, perioperative management remains an issue with nearly double the rate of prolonged hospitalization. Better understanding of hemodynamic environments encountered and appropriate therapeutic targets can help improve perioperative management.

RECENT FINDINGS

Accurate and precise hemodynamic monitoring allows for early identification of complications and prompt assessment of therapeutic interventions. This can be achieved with a multimodal approach using traditional monitoring tools, such a pulmonary artery catheter and arterial line in conjunction with transesophageal echocardiography. Specific targets for optimizing graft perfusion are determined by phase of surgery and organ combination. In some circumstances, the surgical sequence of transplant can help mitigate or avoid certain detrimental hemodynamic environments.

SUMMARY

With better understanding of the array of hemodynamic environments that can develop during MOHT, we can work to standardize hemodynamic targets and therapeutic interventions to optimize graft perfusion. Effectively navigating this perioperative course with multimodal monitoring including transesophageal echocardiography can mitigate impact of complications and reduce prolonged hospitalization associated with MOHT.

Crystalloid fluids and delayed graft function in kidney transplant: A cohort study

Background:

Normal saline is commonly used in the perioperative kidney transplant period; its high chloride content can cause hyperchloremic metabolic acidosis giving a possible advantage to balanced electrolyte solutions due to their lower chloride content. The evidence regarding the best practices in fluid management during kidney transplantation and its effect on the incidence of delayed graft function (DGF) is still limited.

Materials and Methods:

One hundred thirty-eight patients were included and followed up for seven days after surgery. Administered crystalloid type and volume were compared among patients with and without DGF, along with additional patient and surgical variables. To investigate whether intraoperative fluid type/amount influence DGF, patients were categorized into three groups: those who received mainly (>50%) lactated Ringer's solution, normal saline, or plasmaLyte. A logistic regression analysis was used to define variables independently correlated with DGF, and odds ratios (OR) with a 95% confidence interval (CI) were reported.

Results:

The incidence of DGF was 8.7%. Cold ischemia time independently increased the odds of DGF (OR = 1.006 (95% CI: 1.002–1.011) while fluid type (saline versus PlasmaLyte OR = 5.28, 95% CI: 0.76–36.88) or amount (OR = 1.00, 95% CI: 1.00–1.01) did not significantly modify the odds of DGF. Central venous pressure, systolic blood pressure, and mean arterial pressure were higher in the non-DGF group, but this was not statistically significant (P > 0.05). Significant intraoperative acidosis developed in patients who received normal saline compared to those in PlasmaLyte and lactated Ringer's groups; however, acid–base balance and electrolytes did not vary significantly between the DGF and non-DGF groups.

Conclusion:

DGF was primarily influenced by surgical factors such as cold ischemia time, whereas intraoperative fluid type or amount did not affect DGF incidence.

Anaesthesia for renal transplantation

Renal transplantation is the most common procedure in solid organ transplantation. Compered to dialysis, renal transplantation offers better quality of life and overall survival for patients. Due to the improvement of surgical technique, imunosupressive therapy and medical monitor-ing in general, the outcome of treatment has significantly improved today. The importance of the anesthesiologists and the correct performance of all procedures during this treatment has been shown in many studies related to the outcome. In addition to the correct selection of anesthesia drugs, it is very important to pay attention to the position-ing of the patient, adequate monitoring, careful fluid re-placement and the type of fluid intra-and postoperative, as well as adequate pain control after the procedure.

Effects of Plasma-Lyte® and 0.9% saline in renal function after deceased-donor kidney transplant: a randomized controlled trial

BACKGROUND

The influence of different crystalloid solutions infused during deceased-donor kidney transplant on the incidence of delayed graft function remains unclear. We investigated the influence of Plasma-Lyte® vs. 0.9% saline on the incidence of delayed graft function in deceased-donor kidney transplant recipients.

METHODS

We conducted a single-blind randomized controlled trial of 104 patients aged 18 to 65 years who underwent deceased-donor kidney transplant under general anesthesia. Patients were randomly assigned to receive either Plasma-Lyte® (n = 52) or 0.9% saline (n = 52), at the same infusion volume, for intraoperative fluid replacement. The primary outcome was the occurrence of delayed graft function. Secondary outcomes included metabolic and electrolytic changes at the end of surgery.

RESULTS

Two patients in the Plasma-Lyte® group and one in the 0.9% saline group died postoperatively and were not included for analysis. The incidence of delayed graft function in Plasma-Lyte® and 0.9% saline groups were 60.0% (95% Confidence Interval [95% CI 46.2-72.4]) and 74.5% (95% CI 61.1-84.4), respectively (p = 0.140). Mean (standard deviation) values of immediate postoperative pH and serum chloride levels in Plasma-Lyte® and 0.9% saline groups were 7.306 (0.071) and 7.273 (0.061) (p = 0.013), and 99.6 (4.2) mEq.L^-1 and 103.3 (5.6) mEq.L^-1, respectively (p < 0.001). All other postoperative metabolic and electrolyte variables were not statistically different at the immediate postoperative period (p > 0.05).

CONCLUSION

In deceased-donor kidney transplant recipients, the incidence of delayed graft function is not influenced by Plasma-Lyte® or 0.9% saline used for intraoperative fluid replacement.

Intraoperative fluid management and kidney transplantation outcomes: A retrospective cohort study

BACKGROUND

Patients undergoing kidney transplantation traditionally receive liberal amounts of fluid during surgery. However, excessive fluids can lead to fluid overload and ileus. In this retrospective cohort study, we compared the effect of restrictive versus liberal fluid therapy on kidney transplantation outcomes.

METHODS

Patients who underwent deceased-donor kidney transplantation at Mayo Clinic from January 2014 to March 2019 were included. Those who received <3 L of intravenous fluids intraoperatively were categorized as "restrictive;" those who received ≥3 L were categorized as "liberal." The primary outcome was incidence of delayed graft function (DGF). Secondary outcomes included length of stay, readmission within 30 days, time to return of bowel function, and incidence of postoperative complications.

RESULTS

Of the 1171 patients included, 557 were in the restrictive group and 614 in the liberal group. The mean (SD) fluid intake was 2.17 (.54) L in the restrictive group and 3.67 (.68) L in the liberal group (P<.001). There was no difference in DGF (relative risk, 1.03; P = .56), length of stay (P = .34), readmission (P = .80), return of bowel function (P = .71), or other postoperative complications.

CONCLUSIONS

Intraoperative restrictive fluid therapy during kidney transplantation was not associated with DGF or worse outcomes when compared with liberal fluid therapy.

Fluid overload and renal function in children after living-donor renal transplantation: a single-center retrospective analysis

BACKGROUND

We aimed to compare renal function after kidney transplantation in children who were treated with higher vs. lower fluid volumes.

METHODS

A retrospective analysis of 81 living-donor renal transplantation pediatric patients was performed between the years 2007 and 2018. We analyzed associations of the decrease in serum creatinine (delta creatinine) with fluid balance, central venous pressure (CVP), pulmonary congestion, mean arterial pressure (MAP), and MAP-CVP percentiles in the first 3 postoperative days. After correcting creatinine for fluid overload, we also assessed associations of these variables with the above parameters. Finally, we evaluated the association between delta creatinine and estimated glomerular filtration rate (eGFR) at 3 months follow-up.

RESULTS

Both delta creatinine and delta-corrected creatinine were found to be associated with pulmonary congestion on the second and third postoperative days (p < 0.02). In addition, trends for positive correlations were found of delta creatinine with fluid balance/kg (p = 0.07), and of delta-corrected creatinine with fluid balance/kg and CVP (p = 0.06-0.07) on the second postoperative day. An association was also demonstrated between the accumulated fluid balance of the first 2 days and eGFR at 3 months after transplantation (p = 0.03).

CONCLUSIONS

An association was demonstrated between indices of fluid overload, >80 ml/kg, and greater improvement in renal function.

IMPACT

There is no consensus regarding the optimal fluid treatment after pediatric renal transplantation. In our cohort, indices of fluid overload were associated with better renal function immediately after the transplantation and 3 months thereafter. Fluid overload after living-donor renal transplantation in children may have short- and long-term benefits on renal function.

Fluid Management During Kidney Transplantation: A Consensus Statement of the Committee on Transplant Anesthesia of the American Society of Anesthesiologists

BACKGROUND

Intraoperative fluid management may affect the outcome after kidney transplantation. However, the amount and type of fluid administered, and monitoring techniques vary greatly between institutions and there are limited prospective randomized trials and meta-analyses to guide fluid management in kidney transplant recipients.

METHODS

Members of the American Society of Anesthesiologists (ASA) committee on transplantation reviewed the current literature on the amount and type of fluids (albumin, starches, 0.9% saline, and balanced crystalloid solutions) administered and the different monitors used to assess fluid status, resulting in this consensus statement with recommendations based on the best available evidence.

RESULTS

Review of the current literature suggests that starch solutions are associated with increased risk of renal injury in randomized trials and should be avoided in kidney donors and recipients. There is no evidence supporting the routine use of albumin solutions in kidney transplants. Balanced crystalloid solutions such as Lactated Ringer are associated with less acidosis and may lead to less hyperkalemia than 0.9% saline solutions. Central venous pressure is only weakly supported as a tool to assess fluid status.

CONCLUSIONS

These recommendations may be useful to anesthesiologists making fluid management decisions during kidney transplantation and facilitate future research on this topic.

Early perioperative fluid overload is associated with adverse outcomes in deceased donor kidney transplantation

Kidney transplant recipients are often treated with a large volume of infusion to attain adequate graft perfusion in the early perioperative period. However, it remains unknown whether this fluid therapy is renal responsive or a contributing factor to fluid overload complications. We conducted a retrospective cohort analysis of all recipients who received deceased donor kidney transplantation at an academic teaching hospital from January 2015 to April 2019. Our exposure of interest was early perioperative fluid balance. The primary outcome was graft function at 1, 6, and 12 months after transplantation. The secondary outcome was cardiopulmonary and gastrointestinal complications. Fluid balance was not significantly correlated with graft function in short- or long-term periods. Postoperative complications were higher in recipients with increased fluid balance. Delayed graft function was significantly related to cardiopulmonary and gastrointestinal complications. Cardiovascular disease and high BMI of recipients were strong risk factors for cardiopulmonary complications. Fluid overload was prevalent in the early perioperative period of kidney transplantation. It did not promote renal recovery, but was associated with a high risk of complications. Our findings might be a useful indicator to optimize the perioperative fluid management of kidney transplant recipients.

Recipient pre-existing chronic hypotension is associated with delayed graft function and inferior graft survival in kidney transplantation from elderly donors

BACKGROUND

Pre-existing chronic hypotension affects a percentage of kidney transplanted patients (KTs). Although a relationship with delayed graft function (DGF) has been hypothesized, available data are still scarce and inconclusive.

METHODS

A monocentric retrospective observational study was performed on 1127 consecutive KTs from brain death donors over 11 years (2003-2013), classified according to their pre-transplant Mean Blood Pressure (MBP) as hypotensive (MBP < 80 mmHg) or normal-hypertensive (MBP ≥ 80 mmHg, with or without effective antihypertensive therapy).

RESULTS

Univariate analysis showed that a pre-existing hypotension is associated to DGF occurrence (p<0.01; OR for KTs with MBP < 80 mmHg, 4.5; 95% confidence interval [CI], 2.7 to 7.5). Chronic hypotension remained a major predictive factor for DGF development in the logistic regression model adjusted for all DGF determinants. Adjunctive evaluations on paired grafts performed in two different recipients (one hypotensive and the other one normal-hypertensive) confirmed this assumption. Although graft survival was only associated with DGF but not with chronic hypotension in the overall population, stratification according to donor age revealed that death-censored graft survival was significantly lower in hypotensive patients who received a KT from >50 years old donor.

CONCLUSIONS

Our findings suggest that pre-existing recipient hypotension, and the subsequent hypotension-related DGF, could be considered a significant detrimental factor, especially when elderly donors are involved in the transplant procedure.

Impact of goal-directed hemodynamic management on the incidence of acute kidney injury in patients undergoing partial nephrectomy: a pilot randomized controlled trial

Background

The incidence of acute kidney injury (AKI) remains high after partial nephrectomy. Ischemia-reperfusion injury produced by renal hilum clamping during surgery might have contributed to the development of AKI. In this study we tested the hypothesis that goal-directed fluid and blood pressure management may reduce AKI in patients following partial nephrectomy.

Methods

This was a pilot randomized controlled trial. Adult patients who were scheduled to undergo partial nephrectomy were randomized into two groups. In the intervention group, goal-directed hemodynamic management was performed from renal hilum clamping until end of surgery; the target was to maintain stroke volume variation < 6%, cardiac index 3.0–4.0 L/min/m² and mean arterial pressure > 95 mmHg with crystalloid fluids and infusion of dobutamine and/or norepinephrine. In the control group, hemodynamic management was performed according to routine practice. The primary outcome was the incidence of AKI within the first 3 postoperative days.

Results

From June 2016 to January 2017, 144 patients were enrolled and randomized (intervention group, n = 72; control group, n = 72). AKI developed in 12.5% of patients in the intervention group and in 20.8% of patients in the control group; the relative reduction of AKI was 39.9% in the intervention group but the difference was not statistically significant (relative risk 0.60, 95% confidence interval [CI] 0.28–1.28; P = 0.180). No significant differences were found regarding AKI classification, change of estimated glomerular filtration rate over time, incidence of postoperative 30-day complications, postoperative length of hospital stay, as well as 30-day and 6-month mortality between the two groups.

Conclusion

For patients undergoing partial nephrectomy, goal-directed circulatory management during surgery reduced postoperative AKI by about 40%, although not significantly so. The trial was underpowered. Large sample size randomized trials are needed to confirm our results.

Trial registration

Clinicaltrials.gov identifier: NCT02803372. Date of registration: June 6, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01288-8.

Hemodynamic Management During Kidney Transplantation: A French Survey

BACKGROUND

Hypovolemia or excess fluid load during kidney transplantation may have detrimental effects on the recipient and graft. The aim of our survey was to examine hemodynamic monitoring during kidney transplantation (KT) in French KT centers.

BASIC PROCEDURES

The online survey covered the organization of anesthesia, the type of hemodynamic monitoring available in each center, the frequency of use of each hemodynamic parameter, and the hemodynamic algorithm used to manage fluid administration.

MAIN FINDINGS

Twenty-four centers answered the survey (70% of all the 34 French KT centers) and reported performing 2029 KTs in 2016. Anesthesia for KT was performed either by a general team (n = 12, 48%) or less often, by a specific team during open hours (n = 7, 28%), a specific 24-hour/24-hour team (n = 5, 20%), or an emergency team (n = 1, 4%). The centers reported that up to 8 different hemodynamic monitoring techniques were available for KT. Central venous pressure (CVP) is the most frequently used hemodynamic parameter (1278 KT, 63%). Among the 17 centers using CVP monitoring, 9 had no specific algorithm and the other 8 centers used a different algorithm to manage fluids with CVP. The total fluids administered during KT varied from 1000 mL to 3500 mL.

CONCLUSIONS

CVP was still the main hemodynamic parameter used in France during KT in 2016. Our results suggest that a large randomized controlled trial should be performed to specifically address the question of hemodynamic management during KT.

Intra-abdominal hypertension in early post-kidney transplantation period is associated with impaired graft function

BACKGROUND

Moderate hyperhydration is often achieved in the early post-kidney transplantation period. Whether this strategy could lead to the development of intra-abdominal hypertension (IAH) has never been assessed so far. We aimed to study the incidence of IAH after kidney transplantation and its association with graft function recovery.

METHODS

We conducted a prospective monocentric study among patients undergoing kidney transplantation at the University Hospital of Reims between May 2017 and April 2019. Intravesical pressure (IVP) was monitored every 8 h from Day 0 to 3.

RESULTS

A total of 107 patients were enrolled. Among 55 patients included in the analysis, 74.5% developed IAH. Body mass index >25 kg/m2 was associated with IAH development {odds ratio [OR] 10.4 [95% confidence interval (CI) 2.0-52.9]; P = 0.005}. A previous history of peritoneal dialysis was protective [OR 0.06 (95% CI 0.01-0.3); P = 0.001]. IAH Grades III and IV occurred in 30.9% of patients and correlated with higher Day 3 creatininaemia (419.6 ± 258.5 versus 232.5 ± 189.4 μmol/L; P = 0.02), higher delayed graft function incidence (41.2 versus 7.9%; P = 0.04), lower Kirchner index measured using scintigraphy (0.47 ± 0.09 versus 0.64 ± 0.09; P = 0.0005) and decreased Day 30 estimated glomerular filtration rate (35.8 ± 18.8 versus 52.5 ± 21.3, P = 0.05). IAH patients had higher fluid balance (P = 0.02). Evolution of IVP correlated with weight gain (P < 0.01) and central venous pressure (P < 0.001).

CONCLUSIONS

IAH is frequent after kidney transplantation and IAH Grades III and IV are independently associated with impaired graft function. These results question current haemodynamic objectives and raise for the first time interest in intra-abdominal pressure monitoring in these patients.

CLINICAL TRIAL NOTATION

ClinicalTrials.gov identifier: NCT03478176.

Novel approaches to management of hyperkalaemia in kidney transplantation

PURPOSE OF REVIEW

Medications used frequently after kidney transplantation, including calcineurin inhibitors, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta blockers and antimicrobials, are considered the leading culprit for posttransplant hyperkalaemia in recipients with a well functioning allograft. Other risk factors include comorbidities such as diabetes, hypertension and heart failure; and consumption of a potassium-enriched diet. We review the mechanisms for hyperkalaemia following kidney transplantation that are addressed using nonpharmacological and pharmacological interventions. We also discuss emerging therapeutic approaches for the management of recurrent hyperkalaemia in solid organ transplantation, including newer potassium binding therapies.

RECENT FINDINGS

Patiromer and sodium zirconium cyclosilicate are emerging potassium binders approved for the treatment of hyperkalaemia. Patiromer is a polymer that exchanges potassium for calcium ions. In contrast, sodium zirconium cyclosilicate is a nonpolymer compound that exchanges potassium for sodium and hydrogen ions. Both agents are efficacious in the treatment of chronic or recurrent hyperkalaemia and may result in fewer gastrointestinal side effects than older potassium binders such as sodium polystyrene sulfonate and calcium polystyrene sulfonate. Large-scale clinical studies have not been performed in kidney transplant patients. Patiromer may increase serum concentrations of tacrolimus, but not cyclosporine. Sodium zirconium cyclosilicate does not appear to compromise tacrolimus pharmacokinetics, although it may have a higher sodium burden.

SUMMARY

Patiromer and sodium zirconium cyclosilicate may be well tolerated options to treat asymptomatic hyperkalaemia and have the potential to ease potassium dietary restrictions in kidney transplant patients by maintaining a plant-dominant, heart-healthy diet. Their efficacy, better tolerability and comparable cost with respect to previously available potassium binders make them an attractive therapeutic option in chronic hyperkalaemia following kidney transplantation.

A randomized comparison between pulse pressure variation and central venous pressure in patients undergoing renal transplantation

Background and Aims:

Intraoperative fluid management is important in renal transplant recipients with end-stage renal disease. Conventionally, central venous pressure (CVP) has been used to guide perioperative fluid administration but with high incidence of poor graft outcome. There is a requirement of reliable parameter to guide the fluid therapy in these patients so as to minimize the perioperative complications and improve the outcome. Hence, this study was conducted.

Material and Methods:

This prospective study included 75 patients of chronic kidney disease undergoing renal transplantation. Patients were divided into two groups. Group A (control group): Intraoperative fluids were guided by CVP; Group B: Intraoperative fluids were guided by pulse pressure variation (PPV). Primary outcome measure of this study was incidence of delayed graft functioning, i.e., need of hemodialysis within 7 days of renal transplant. Secondary outcome measures were incidence of perioperative hypotension, post-transplant pulmonary edema, tissue edema, and lactic acidosis.

Results:

Total amount of fluid before reperfusion was significantly greater in the control group (P = 0.005). However, the total amount of fluid required at the end of surgery was comparable. Delayed graft functioning was seen only in CVP group, although it was not statistically significant. The postoperative tissue edema was more in CVP group (P = 0.03). The postoperative nausea and vomiting, pulmonary edema, and mechanical ventilation were more in CVP group but not statistically significant. Increase in lactate value was more in CVP group.

Conclusion:

Perioperative fluid guidance by PPV is better than central venous pressure in renal transplant patients.

To compare intraoperative goal directed fluid therapy by trans-oesophageal Doppler vis-à-vis FloTrac™ in patients undergoing living related renal transplantation-a prospective randomised controlled study

Background:

Optimal intra-operative fluid therapy in renal transplantation (RT) is essential to ensure adequate graft function while preventing fluid overload related complications. This RCT was to compare the intraoperative goal directed fluid therapy (GDFT) based either on corrected flow time (CFT), measured by trans oesophageal Doppler (TED) or on the stroke volume variation (SVV), by FloTrac in patients undergoing living donor RT.

Methods:

This prospective, randomised controlled trial (RCT) was done on 60 end stage renal disease (ESRD) patients, American Society of Anaesthesiologists(ASA) grade III–IV, age 18 to 65 years of either sex, scheduled for living donor RT under general anaesthesia. They were randomly divided into two groups: TED group (n = 30) and FloTrac™ group (n = 30) and administered GDFT, based upon CFT (TED) and SVV (FloTrac™). The primary outcome was to compare the total fluid and number of fluid boluses administered intraoperatively, while the secondary outcomes were to compare any postoperative complications due to fluid overload and allograft function, assessed by serial serum creatinine levels up to 90 days postoperatively.

Results:

The mean total intra-operative fluid [3991.67 ± 856.32 vs. 3543.33 ± 1131.35, P = 0.089] and the amount of fluid administered per kg body weight per hour [13.32 ± 4.67 vs. 11.82 ± 4.76, P = 0.222] were lesser in the FloTrac compared to TED group, though not statistically significant. However, the postoperative incidence of allograft dysfunction, including rejection (P = 0.743) and acute tubular necrosis (ATN) (P = 0.999), and other complications (P = 0.643) were comparable.

Conclusions:

Both TED and FloTrac devices can be used effectively to guide GDFT in RT, However, lesser total fluid was required in the FloTrac group, which may lead to a lesser number of fluid-related postoperative complications.

"Does Perioperative Patient Perfusion Obviate the Need for Kidney Machine Perfusion?" A Retrospective Analysis of Patients Receiving a Kidney From "Donation After Circulatory Death" Donors

BACKGROUND

Delayed graft function (DGF) remains a clinically relevant problem in the post-transplant period, especially in patients with a renal graft from a "donation after cardiac death" (DCD) donor. Controversy exists around the optimal perioperative fluid therapy in such patients. These patients may benefit from a perioperative saline loading fluid protocol, which may reduce the risk of DGF.

METHODS

We compared 2 cohorts of patients who underwent a renal transplantation with a graft from a DCD donor. From January 2003 until December 2012, patients (N = 46) were hemodynamically managed at the discretion of the care-giving physician, without a preoperative fluid administration protocol (first study period). From January 2015 until March 2019 (N = 26), patients received saline loading before, during, and after kidney transplantation according to a well-defined saline loading fluid protocol (second study period). The relationship between the use of this perioperative fluid protocol and DGF was analyzed using univariable and multivariable logistic regression models.

RESULTS

DGF occurred in 11 of 46 (24%) patients in the first study period and in 1 of 26 (4%) in the second study period (P < .05). In a multivariable model, correcting for cold ischemia time and Kidney Donor Risk Index, the use of a saline loading fluid protocol in the perioperative phase was nearly significantly associated with a decrease in DGF (P = .07).

CONCLUSION

In our DCD transplant population, DGF rates were low. Our data further strongly suggest that implementation of a perioperative saline loading fluid protocol was independently associated with a lower risk of DGF.

Approach and Management of Hypertension After Kidney Transplantation

Hypertension is one of the most common cardiovascular co-morbidities after successful kidney transplantation. It commonly occurs in patients with other metabolic diseases, such as diabetes mellitus, hyperlipidemia, and obesity. The pathogenesis of post-transplant hypertension is complex and is a result of the interplay between immunological and non-immunological factors. Post-transplant hypertension can be divided into immediate, early, and late post-transplant periods. This classification can help clinicians determine the etiology and provide the appropriate management for these complex patients. Volume overload from intravenous fluid administration is common during the immediate post-transplant period and commonly contributes to hypertension seen early after transplantation. Immunosuppressive medications and donor kidneys are associated with post-transplant hypertension occurring at any time point after transplantation. Transplant renal artery stenosis (TRAS) and obstructive sleep apnea (OSA) are recognized but common and treatable causes of resistant hypertension post-transplantation. During late post-transplant period, chronic renal allograft dysfunction becomes an additional cause of hypertension. As these patients develop more substantial chronic kidney disease affecting their allografts, fibroblast growth factor 23 (FGF23) increases and is associated with increased cardiovascular and all-cause mortality in kidney transplant recipients. The exact relationship between increased FGF23 and post-transplant hypertension remains poorly understood. Blood pressure (BP) targets and management involve both non-pharmacologic and pharmacologic treatment and should be individualized. Until strong evidence in the kidney transplant population exists, a BP of <130/80 mmHg is a reasonable target. Similar to complete renal denervation in non-transplant patients, bilateral native nephrectomy is another treatment option for resistant post-transplant hypertension. Native renal denervation offers promising outcomes for controlling resistant hypertension with no significant procedure-related complications. This review addresses the epidemiology, pathogenesis, and specific etiologies of post-transplant hypertension including TRAS, calcineurin inhibitor effects, OSA, and failed native kidney. The cardiovascular and survival outcomes related to post-transplant hypertension and the utility of 24-h blood pressure monitoring will be briefly discussed. Antihypertensive medications and their mechanism of actions relevant to kidney transplantation will be highlighted. A summary of guidelines from different professional societies for BP targets and antihypertensive medications as well as non-pharmacological interventions, including bilateral native nephrectomy and native renal denervation, will be reviewed.

[Pulse pressure variation guided fluid therapy during kidney transplantation: a randomized controlled trial]

PURPOSE

Kidney transplantation is the gold-standard treatment for end stage renal disease. Although different hemodynamic variables, like central venous pressure and mean arterial pressure, have been used to guide volume replacement during surgery, the best strategy still ought to be determined. Respiratory arterial Pulse Pressure Variation (PPV) is recognized to be a good predictor of fluid responsiveness for perioperative hemodynamic optimization in operating room settings. The aim of this study was to investigate whether a PPV-guided fluid management strategy is better than a liberal fluid strategy during kidney transplantation surgeries. Identification of differences in urine output in the first postoperative hour was the main objective of this study.

METHODS

We conducted a prospective, single blind, randomized controlled trial. We enrolled 40 patients who underwent kidney transplantation from deceased donors. Patients randomized in the PPV Group received fluids whenever PPV was higher than 12%, patients in the Free Fluid Group received fluids following our institutional standard care protocol for kidney transplantations (10mL.kg^-1.h^-1).

RESULTS

Urinary output was similar at every time-point between the two groups, urea was statistically different from the third postoperative day with a peak at the fourth postoperative day and creatinine showed a similar trend, being statistically different from the second postoperative day. Urea, creatinine and urine output were not different at the hospital discharge.

CONCLUSION

PPV-guided fluid therapy during kidney transplantation significantly improves urea and creatinine levels in the first week after kidney transplantation surgery.

Dynamic 2-deoxy-2[18F] fluoro-D-glucose PET/MRI in human renal allotransplant patients undergoing acute kidney injury

Patients after solid organ kidney transplantation (KTX) often suffer from acute kidney injury (AKI). Parameters as serum creatinine indicate a loss of kidney function, although no distinction of the cause and prognosis can be made. Imaging tools measuring kidney function have not been widely in clinical use. In this observational study we evaluated 2-deoxy-2[18F] fluoro-D-glucose (FDG) PET/MRI in thirteen patients after KTX with AKI as a functional assessment of the graft. Twenty-four healthy volunteers served as control. General kidney performance (GKP), initial flow (IF) and renal response function (RF) were calculated by standardized uptake values (SUV) and time activity curves (TAC). The GKP measured for the total kidney and medulla was significantly higher in healthy patients compared to patients after KTX (p = 0.0002 and p = 0.0004, respectively), but no difference was found for the GKP of the cortex (p = 0.59). The IF in KTX patients correlated with renal recovery, defined as change in serum creatinine 10 days after PET/MRI (r = 0.80, p = 0.001). With regard to the RF, a negative correlation for tubular damage was found (r = -0.74, p = 0.004). In conclusion, parameters obtained from FDG PET/MRI showed a possible predictive feature for renal recovery in KTX patients undergoing AKI.

Pulse pressure variation guided fluid therapy during kidney transplantation: a randomized controlled trial

Purpose

Kidney transplantation is the gold-standard treatment for end stage renal disease. Although different hemodynamic variables, like central venous pressure and mean arterial pressure, have been used to guide volume replacement during surgery, the best strategy still ought to be determined. Respiratory arterial Pulse Pressure Variation (PPV) is recognized to be a good predictor of fluid responsiveness for perioperative hemodynamic optimization in operating room settings. The aim of this study was to investigate whether a PPV guided fluid management strategy is better than a liberal fluid strategy during kidney transplantation surgeries. Identification of differences in urine output in the first postoperative hour was the main objective of this study.

Methods

We conducted a prospective, single blind, randomized controlled trial. We enrolled 40 patients who underwent kidney transplantation from deceased donors. Patients randomized in the “PPV” group received fluids whenever PPV was higher than 12%, patients in the “free fluid” group received fluids following our institutional standard care protocol for kidney transplantations (10 mL.kg^-1. h^-1).

Results

Urinary output was similar at every time-point between the two groups, urea was statistically different from the third postoperative day with a peak at the fourth postoperative day and creatinine showed a similar trend, being statistically different from the second postoperative day. Urea, creatinine and urine output were not different at the hospital discharge.

Conclusion

PPV guided fluid therapy during kidney transplantation significantly improves urea and creatinine levels in the first week after kidney transplantation surgery.

Effect of Perioperative Optimization of Arterial Oxygen Content and Perfusion Pressure on the Function of the Transplanted Kidney in the Retrospective Study of Excretory Function and Assessment of New Markers of Kidney Damage: IL-18, Neutrophil Gelatinase-Associated Lipocalin, and Clusterin

INTRODUCTION

The concept of anesthesia, in which kidney perfusion is optimized, the use of nephrotoxic drugs is avoided, and general anesthesia with protective and preconditioning properties of the graft is applied, is a key element of the therapeutic strategy in kidney transplantation (KTx).

MATERIAL AND METHOD

A total of 86 patients (mean age: 49.4 ± 14.0 years, 66% men) with end-stage renal disease who underwent KTx between 2012 and 2015 were included in this retrospective study. Our aim was to assess the effect of oxygen content in arterial blood and selected hemodynamic parameters on the graft function and the occurrence of delayed graft failure.

RESULTS

No differences were found in baseline characteristics, indication for transplantation, and surgical technique used among study population. No correlation was found between oxygen delivery exponents and both standard markers of renal function and new biochemical markers (eg, IL-18, clusterin, and neutrophil gelatinase-associated lipocalin [NGAL]).

DISCUSSION

In our study, hemodynamic parameters measured at scheduled intervals did not exceed the physiological range, which might have been the reason for the lack of correlation between the function of graft and the described hemodynamic conditions. At the same time, in the observed ranges of perfusion pressure during optimization of the oxygen content, no correlations were found with the postoperative function of the transplanted kidney. That observation could be a valuable conclusion for reducing the tendency of maintaining high blood pressure with the abuse of catecholamines, especially vasoconstrictors, and volume therapy, whose negative effect on tissue perfusion is unequivocal.

Assessment of Hemoglobin Levels in Patients Qualified for Kidney Transplantation in the Perioperative Period and Its Impact on the Occurrence of Delayed Graft Function

BACKGROUND

Anesthesia in patients undergoing kidney transplantation (KTx) should be aimed at creating optimal hemodynamic conditions for the newly implanted kidney. Changes in of blood count, caused mainly by intraoperative hemodilution, may adversely affect the perioperative course by strengthening the pathologic mechanisms of ischemia-reperfusion syndrome.

METHODS

A total of 86 patients (mean age: 49.4 ± 14.0 years, 66% men) with end-stage renal disease who underwent KTx between 2012 and 2015 were included in this retrospective study. Our aim was to assess the hemoglobin level and the effect of fluctuations caused by the implemented fluid therapy on graft function and the occurrence of delayed graft failure.

RESULTS

There was no difference in baseline characteristics, indication for transplantation, and surgical technique used among study population. Among the whole observation group, no correlation was found between fluid therapy causing hemodilution with a decrease in hemoglobin concentration and the occurrence of delayed graft failure.

CONCLUSIONS

In our observations, we paid special attention to the problem of hemodilution in patients undergoing KTx. It is important to emphasize the importance of proper preparation of the patient for KTx by earlier implementation of anemia therapy, thus preventing exacerbation of anemia in the postoperative period, especially because the perioperative use of blood products is associated with numerous complications and a worse prognosis for the newly implanted kidney.

Effect of Intravenous Total Anesthesia on Hemodynamic Changes in Renal Transplant

BACKGROUND

The objective of the transanesthetic management of renal transplant is to achieve graft function and improve its prognosis and quality of life of the patient; total intravenous anesthesia (TIVA) is an attractive alternative for the maintenance of hemodynamic stability, lower immunologic involvement, and prevention of reperfusion ischemia injury, which are fundamental in the success of the transplant. The objective of the study was to determine the effect of TIVA on hemodynamic changes in renal transplant.

METHODS

We performed a retrospective observational study of patients who received transplants under TIVA from March 1, 2014, to March 31, 2019. Baseline vital signs and their variability were analyzed in addition to the times and goals of surgery and anesthesia. The statistical analysis was descriptive and inferential and with χ² test, Student t test, and Fisher exact test.

RESULTS

A total of 30 patients were included, and P < .001 was determined in the variability of hemodynamics during the transanesthetic period and at the end of the surgery (χ² and Student t was applied). In addition, P < .001 was obtained with a mean difference of 6.12 and CI of 5.02 to 7.22 for creatinine at 24 hours post transplant, of 2.42 and CI of 1.89 to 2.95 and P < .001 for creatinine at 48 hours, and P < .001 at 72 hours. There was spontaneous uresis in 90%.

CONCLUSIONS

TIVA and the use of adjuvants could be the best option for the anesthetic management of renal transplant and offers greater benefits compared with traditional management.

Modifiable Risk Factors for Delayed Graft Function After Deceased Donor Kidney Transplantation

PURPOSE

Delayed graft function is a major complication after kidney transplantation affecting patients' long-term outcome. The aim of this study was to identify modifiable risk factors for delayed graft function after deceased donor kidney transplantation.

METHODS

This is a single-center retrospective cohort study of a university transplantation center. Univariate and multivariate step-wise logistic regression analysis of patient-specific and procedural risk factors were conducted.

RESULTS

We analyzed 380 deceased donor kidney transplantation patients between October 30, 2008 and December 30, 2017. The incidence of delayed graft function was 15% (58/380). Among the patient-specific risk factors recipient diabetes (2.8 [1.4-5.9] odds ratio [OR] [95% confidence interval [CI]]), American Society of Anesthesiologist score of 4 (2.7 [1.2-6.5] OR [95% CI]), cold ischemic time >13 hours (2.8 [1.5-5.3] OR [95% CI]) and donor age >55 years (1.9 [1.01-3.6] OR [95% CI]) revealed significance. The significant intraoperative, procedural risk factors included the use of colloids (3.9 [1.4-11.3] OR [95% CI]), albumin (3.0 [1.2-7.5] OR [95% CI]), crystalloids >3000 mL (3.1 [1.2-7.5] OR [95% CI]) and mean arterial pressure <80 mm Hg at the time of reperfusion (2.4 [1.2-4.8] OR [95% CI]).

CONCLUSION

Patients undergoing deceased donor kidney transplantation with a mean arterial pressure >80 mm Hg at the time of transplant reperfusion without requiring excessive fluid therapy in terms of colloids, albumin or crystalloids >3000 mL are less likely to develop delayed graft function.

Systolic Blood Pressure Pattern: The Tick Mark Signal of Delayed Renal Graft Function

BACKGROUND

Delayed graft function (DGF) is a multifactorial clinical entity. The aim of our study was to analyze the role of perioperative fluid and noninvasive hemodynamic parameters in DGF patients.

METHODS

The medical records of 122 adult deceased donor kidney transplant patients were retrospectively analyzed with respect to donor (medical history, kidney donor risk index), recipient (medical history), transplant (cold-warm ischemia time, renal arterial resistive index), and perioperative anesthetic, especially noninvasive hemodynamic management. Patients were grouped as DGF and immediate graft function.

RESULTS

Prevalence of DGF was 21.3% (n = 26). Delayed graft function was related to higher donor body mass index (P = .04), kidney donor risk index higher than 1.6 (P = .008), recipient age older than 65 years (P = .03), and perioperative factors, such as lower residual diuresis of recipient (8.7 [SD, 5.2] mL/kg vs 14.4 [SD, 10.3] mL/kg; P = .005), higher intradialytic weight gain (2.65 [SD, 1.03] kg vs 2.16 [SD, 0.79] kg; P = .07), and higher fluid balance during the first postoperative day (3310 [SD, 1230] mL vs 2354 [1812] mL; P = .01). The curve of change in systolic blood pressure (SBP) showed a tick mark pattern in DGF and a semicircular shape in the immediate graft function group. In the DGF group, SBP change compared with baseline value was higher at reperfusion (-3.16% [SD, 23.37%] vs -12.84% [SD, 23.37%]; P = .047), at the ending of surgery (-5.83% [SD, 26.21%] vs -3.26% [SD, 21.81%]; P = .07), and at the ending of anesthesia (11.81% [SD, 29.77%] vs -1.26% [SD, 21.87%]; P = .01). The postoperative renal arterial resistive index was higher in the DGF group (0.75 [SD, 0.10] vs 0.69 [SD, 0.08]; P = .007).

CONCLUSION

The tick mark pattern of SBP kinetics might help to identify DGF intraoperatively. When detecting this SBP pattern, the excessive fluid therapy should be avoided during the postoperative period to prevent iatrogenic hypervolemia leading to further graft damage.

Abdominal Organ Transplantation: Noteworthy Literature in 2018

A PubMed search revealed 1382 articles on pancreatic transplantation, 781 on intestinal transplantation, more than 7200 on kidney transplantation, and more than 5500 on liver transplantation published between January 1, 2018, and December 31, 2018. After narrowing the list down to human studies, 436 pancreatic, 302 intestinal, 1920 liver, and more than 2000 kidney transplantation studies were screened for inclusion in this review.