Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial

The effect of goal-directed fluid therapy on delayed graft function in kidney transplant recipients: A systematic review and meta-analysis

Delayed graft function (DGF) is a common post-operative complication with potential long-term sequelae for many kidney transplant recipients, and hemodynamic factors and fluid status play a role. Fixed perioperative fluid infusions are the standard of care, but more recent evidence in the non-transplant population has suggested benefit with goal-directed fluid strategies based on hemodynamic targets. We searched MEDLINE, EMBASE, Cochrane Controlled Trials Registry and Google Scholar through December 2022 for randomized controlled trials comparing risk of DGF between goal-directed and conventional fluid therapy in adults receiving a living or deceased donor kidney transplant. Effect estimates were reported with odds ratios (OR) and pooled using random effects meta-analysis. We identified 4 studies (205 participants) that met the inclusion criteria. The use of goal-directed fluid therapy had no significant effect on DGF (OR 1.37 95% CI, 0.34-5.6; p = 0.52; I2 = 0.11). Subgroup analysis examining effects among deceased and living kidney donation did not reveal significant differences in the effects of fluid strategy on DGF between subgroups. Overall, the strength of the evidence for goal-directed versus conventional fluid therapy to reduce DGF was of low certainty. Our findings highlight the need for larger trials to determine the effect of goal-directed fluid therapy on this patient-centered outcome.

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.

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.

Restricted Versus Liberal Versus Goal-Directed Fluid Therapy for Non-vascular Abdominal Surgery: A Network Meta-Analysis and Systematic Review

Optimal perioperative fluid management is crucial, with over- or under-replacement associated with complications. There are many strategies for fluid therapy, including liberal fluid therapy (LFT), restrictive fluid therapy (RFT) and goal-directed fluid therapy (GDT), without a clear consensus as to which is better. We aimed to find out which is the more effective fluid therapy option in adult surgical patients undergoing non-vascular abdominal surgery in the perioperative period. This study is a systematic review and network meta-analysis (NMA) with node-splitting analysis of inconsistency, sensitivity analysis and meta-regression. We conducted a literature search of Pubmed, Cochrane Library, EMBASE, Google Scholar and Web of Science. Only studies comparing restrictive, liberal and goal-directed fluid therapy during the perioperative phase in major non-cardiac surgery in adult patients will be included. Trials on paediatric patients, obstetric patients and cardiac surgery were excluded. Trials that focused on goal-directed therapy monitoring with pulmonary artery catheters and venous oxygen saturation (SvO2), as well as those examining purely biochemical and laboratory end points, were excluded. A total of 102 randomised controlled trials (RCTs) and 78 studies (12,100 patients) were included. NMA concluded that goal-directed fluid therapy utilising FloTrac was the most effective intervention in reducing the length of stay (LOS) (surface under cumulative ranking curve (SUCRA) = 91%, odds ratio (OR) = -2.4, 95% credible intervals (CrI) = -3.9 to -0.85) and wound complications (SUCRA = 86%, OR = 0.41, 95% CrI = 0.24 to 0.69). Goal-directed fluid therapy utilising pulse pressure variation was the most effective in reducing the complication rate (SUCRA = 80%, OR = 0.25, 95% CrI = 0.047 to 1.2), renal complications (SUCRA = 93%, OR = 0.23, 95% CrI = 0.045 to 1.0), respiratory complications (SUCRA = 74%, OR = 0.42, 95% CrI = 0.053 to 3.6) and cardiac complications (SUCRA = 97%, OR = 0.067, 95% CrI = 0.0058 to 0.57). Liberal fluid therapy was the most effective in reducing the mortality rate (SUCRA = 81%, OR = 0.40, 95% CrI = 0.12 to 1.5). Goal-directed therapy utilising oesophageal Doppler was the most effective in reducing anastomotic leak (SUCRA = 79%, OR = 0.45, 95% CrI = 0.12 to 1.5). There was no publication bias, but moderate to substantial heterogeneity was found in all networks. In preventing different complications, except mortality, goal-directed fluid therapy was consistently more highly ranked and effective than standard (SFT), liberal or restricted fluid therapy. The evidence grade was low quality to very low quality for all the results, except those for wound complications and anastomotic leak.

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.

The effect of pulse pressure variation compared with central venous pressure on intraoperative fluid management during kidney transplant surgery: a randomized controlled trial

BACKGROUND

Traditionally, fluid administration during kidney transplant surgery is guided by central venous pressure (CVP) despite its limited reliability as a parameter for assessing intravascular fluid volume, particularly in patients with cardiovascular diseases. The recommended goals at graft reperfusion are a mean arterial pressure of 90 mm Hg and a CVP of 12-14 mm Hg. This approach may increase the risk of significant adverse effects due to volume overload. Perioperative fluid therapy guided by dynamic indices of fluid responsiveness has been shown to optimize intravascular volume and prevent complications associated with overzealous administration of fluids in major abdominal surgeries. We hypothesized that pulse pressure variation (PPV)-guided fluid administration would result in better optimization of intravascular fluid volume compared with a CVP-guided strategy during kidney transplant surgery.

METHODS

In this single-centre randomized double blinded trial, 77 end-stage renal disease patients, who underwent kidney transplant surgery under general anesthesia with epidural analgesia, were randomized to receive either CVP-guided (n = 35) or PPV-guided (n = 35) fluid therapy using predefined hemodynamic endpoints. The primary outcome was the total volume of intraoperative fluids administered. Secondary outcomes were intraoperative hemodynamic changes, serum lactate levels, serum creatinine, need for dialysis within the first week, creatinine elimination ratio, and incidence of immediate and delayed graft dysfunction.

RESULTS

Results were analyzed for 70 patients. Eighty percent of the patients underwent living-related donor allograft kidney transplant. Operative variables related to donor characteristics, duration of surgery, graft cold ischemia time, and blood loss were comparable in both groups. The mean (standard deviation) volume of intravenous fluids administered intraoperatively was 1,346 (337) mL in the PPV-guided group vs 1,901 (379) mL in the CVP-guided group (difference in means, 556 mL; 95% confidence interval, 385 to 727; P = 0.001). There were no significant differences in secondary outcomes between the two groups.

CONCLUSION

Pulse pressure variation -guided fluid administration significantly decreased the total volume of crystalloids compared with CVP-guided fluid therapy during the intraoperative period in patients who underwent kidney transplant surgery. Nevertheless, our study was underpowered to detect differences in secondary outcomes.

TRIAL REGISTRATION

www.ctri.nic.in (CTRI/2018/01/011638); registered 31 January 2018.

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.

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.

[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.

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.

Perioperative considerations for kidney and pancreas-kidney transplantation

Kidney transplantation is the treatment of choice in patients with end-stage renal disease, as it improves survival and quality of life. Living donor kidney transplant prior to pancreas transplantation, or simultaneous pancreas and kidney transplantation are discussed. Patients usually present comorbidities and extensive preoperative workups are recommended, especially cardiac assessment, though type and frequency of surveillance is not established. Nephroprotective strategies include adequate fluid status and goal-directed therapy. The conventional use of diuretics has not demonstrated a real nephroprotective effect at follow-up. Thromboprophylaxis regimes, especially for the pancreatic graft outcome, are of importance. Notably, transplantation in the obese population has increased in recent decades. Strict preoperative evaluation and pulmonary considerations must be kept in mind. Finally, robotic kidney transplant is a recent approach that presents anesthetic challenges, mainly related to steep Trendelenburg position and fluid restriction.

Perioperative restrictive versus goal-directed fluid therapy for adults undergoing major non-cardiac surgery

BACKGROUND

Perioperative fluid management is a crucial element of perioperative care and has been studied extensively recently; however, 'the right amount' remains uncertain. One concept in perioperative fluid handling is goal-directed fluid therapy (GDFT), wherein fluid administration targets various continuously measured haemodynamic variables with the aim of optimizing oxygen delivery. Another recently raised concept is that perioperative restrictive fluid therapy (RFT) may be beneficial and at least as effective as GDFT, with lower cost and less resource utilization.

OBJECTIVES

To investigate whether RFT may be more beneficial than GDFT for adults undergoing major non-cardiac surgery.

SEARCH METHODS

We searched the following electronic databases on 11 October 2019: Cochrane Central Register of Controlled Trials, in the Cochrane Libary; MEDLINE; and Embase. Additionally, we performed a targeted search in Google Scholar and searched trial registries (World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov) for ongoing and unpublished trials. We scanned the reference lists and citations of included trials and any relevant systematic reviews identified.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing perioperative RFT versus GDFT for adults (aged ≥ 18 years) undergoing major non-cardiac surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references for eligibility, extracted data, and assessed risk of bias. We resolved discrepancies by discussion and consulted a third review author if necessary. When necessary, we contacted trial authors to request additional information. We presented pooled estimates for dichotomous outcomes as risk ratios (RRs) with 95% confidence intervals (CIs), and for continuous outcomes as mean differences (MDs) with standard deviations (SDs). We used Review Manager 5 software to perform the meta-analyses. We used a fixed-effect model if we considered heterogeneity as not important; otherwise, we used a random-effects model. We used Poisson regression models to compare the average number of complications per person.

MAIN RESULTS

From 6396 citations, we included six studies with a total of 562 participants. Five studies were performed in participants undergoing abdominal surgery (including one study in participants undergoing cytoreductive abdominal surgery with hyperthermic intraperitoneal chemotherapy (HIPEC)), and one study was performed in participants undergoing orthopaedic surgery. In all studies, surgeries were elective. In five studies, crystalloids were used for basal infusion and colloids for boluses, and in one study, colloid was used for both basal infusion and boluses. Five studies reported the ASA (American Society of Anesthesiologists) status of participants. Most participants were ASA II (60.4%), 22.7% were ASA I, and only 16.9% were ASA III. No study participants were ASA IV. For the GDFT group, oesophageal doppler monitoring was used in three studies, uncalibrated invasive arterial pressure analysis systems in two studies, and a non-invasive arterial pressure monitoring system in one study. In all studies, GDFT optimization was conducted only intraoperatively. Only one study was at low risk of bias in all domains. The other five studies were at unclear or high risk of bias in one to three domains. RFT may have no effect on the rate of major complications compared to GDFT, but the evidence is very uncertain (RR 1.61, 95% CI 0.78 to 3.34; 484 participants; 5 studies; very low-certainty evidence). RFT may increase the risk of all-cause mortality compared to GDFT, but the evidence on this is also very uncertain (RD 0.03, 95% CI 0.00 to 0.06; 544 participants; 6 studies; very low-certainty evidence). In a post-hoc analysis using a Peto odds ratio (OR) or a Poisson regression model, the odds of all-cause mortality were 4.81 times greater with the use of RFT compared to GDFT, but the evidence again is very uncertain (Peto OR 4.81, 95% CI 1.38 to 16.84; 544 participants; 6 studies; very low-certainty evidence). Nevertheless, sensitivity analysis shows that exclusion of a study in which the final volume of fluid received intraoperatively was higher in the RFT group than in the GDFT group revealed no differences in mortality. Based on analysis of secondary outcomes, such as length of hospital stay (464 participants; 5 studies; very low-certainty evidence), surgery-related complications (364 participants; 4 studies; very low-certainty evidence), non-surgery-related complications (74 participants; 1 study; very low-certainty evidence), renal failure (410 participants; 4 studies; very low-certainty evidence), and quality of surgical recovery (74 participants; 1 study; very low-certainty evidence), GDFT may have no effect on the risk of these outcomes compared to RFT, but the evidence is very uncertain. Included studies provided no data on administration of vasopressors or inotropes to correct haemodynamic instability nor on cost of treatment.

AUTHORS' CONCLUSIONS

Based on very low-certainty evidence, we are uncertain whether RFT is inferior to GDFT in selected populations of adults undergoing major non-cardiac surgery. The evidence is based mainly on data from studies on abdominal surgery in a low-risk population. The evidence does not address higher-risk populations or other surgery types. Larger, higher-quality RCTs including a wider spectrum of surgery types and a wider spectrum of patient groups, including high-risk populations, are needed to determine effects of the intervention.

Cardiac output-guided hemodynamic therapy for adult living donor kidney transplantation in children under 20 kg: A pilot study

BACKGROUND

A living-donor (adult) kidney transplantation in young children requires an increased cardiac output to maintain adequate perfusion of the relatively large kidney. To achieve this, protocols commonly advise liberal fluid administration guided by high target central venous pressure. Such therapy may lead to good renal outcomes, but the risk of tissue edema is substantial.

AIMS

We aimed to evaluate the safety and feasibility of the transpulmonary thermodilution technique to measure cardiac output in pediatric recipients. The second aim was to evaluate whether a cardiac output-guided hemodynamic therapy algorithm could induce less liberal fluid administration, while preserving good renal results and achieving increased target cardiac output and blood pressure.

METHODS

In twelve consecutive recipients, cardiac output was measured with transpulmonary thermodilution (PiCCO device, Pulsion). The algorithm steered administration of fluids, norepinephrine and dobutamine. Hemodynamic values were obtained before, during and after transplantation. Results are given as mean (SD) [minimum-maximum].

RESULTS

Age and weight of recipients was 3.2 (0.97) [1.6-4.9] yr and 14.1 (2.4) [10.4-18] kg, respectively. No complications related to cardiac output monitoring occurred. After transplantation, cardiac index increased with 31% (95% CI = 15%-48%). Extravascular lung water and central venous pressure did not change. Fluids given decreased from 158 [124-191] mL kg^-1 in the first 2 patients to 80 (18) [44-106] mL kg^-1 in the last 10 patients. The latter amount was 23 mL kg^-1 less (95% CI = 6-40 mL kg^-1 ) than in one recent study, but similar to that in another. After reperfusion, all patients received norepinephrine (maximum dose 0.45 (0.3) [0.1-0.9] mcg kg^-1  min^-1 ). Patient and graft survivals were 100% with excellent kidney function at 6 months post-transplantation.

CONCLUSION

Transpulmonary thermodilution-cardiac output monitoring appeared to be safe and feasible. Using the cardiac output-guided algorithm led to excellent renal results with a trend toward less fluids in favor of norepinephrine.

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.

Association of conflicts of interest with the results and conclusions of goal-directed hemodynamic therapy research: a systematic review with meta-analysis

PURPOSE

The association between conflicts of interest (COI) and study results or article conclusions in goal-directed hemodynamic therapy (GDHT) research is unknown.

METHODS

Randomized controlled trials comparing GDHT with usual care were identified. COI were classified as industry sponsorship, author conflict, device loaner, none, or not reported. The association between COI and study results (complications and mortality) was assessed using both stratified meta-analysis and mixed effects meta-regression. The association between COI and an article's conclusion (graded as GDHT-favorable, neutral, or unfavorable) was investigated using logistic regression.

RESULTS

Of the 82 eligible articles, 43 (53%) had self-reported COI, and 50 (61%) favored GDHT. GDHT significantly reduced complications on the basis of the meta-analysis of studies with any type of COI, studies declaring no COI, industry-sponsored studies, and studies with author conflict but not on studies with a device loaner. However, no significant relationship between COI and the relative risk (GDHT vs. usual care) of developing complications was found on the basis of meta-regression (p = 0.25). No significant effect of GDHT was found on mortality. COI had a significant overall effect (p = 0.016) on the odds of having a GDHT-favorable vs. neutral conclusion based on 81 studies. Eighty-four percent of the industry-sponsored studies had a GDHT-favorable conclusion, while only 27% of the studies with a device loaner had the same conclusion grade.

CONCLUSIONS

The available evidence does not suggest a close relationship between COI and study results in GDHT research. However, a potential association may exist between COI and an article's conclusion in GDHT research.