Fluid therapy in organ transplantation

Balanced Crystalloids Versus Normal Saline in Kidney Transplant Patients: An Updated Systematic Review, Meta-analysis, and Trial Sequential Analysis

BACKGROUND

The use of balanced crystalloids over normal saline for perioperative fluid management during kidney transplantation and its benefits on acid-base and electrolyte balance along with its influence on postoperative clinical outcomes remains a topic of controversy. Therefore, we conducted this review to assess the impact of balanced solutions compared to normal saline on outcomes for kidney transplant patients.

METHODS

We searched MEDLINE, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) comparing balanced lower-chloride solutions to normal saline in renal transplant patients. Our main outcome of interest was delayed graft function (DGF). Additionally, we examined acid-base and electrolyte measurements, along with postoperative renal function. We computed relative risk (RR) using the Mantel-Haenszel test for binary outcomes, and mean difference (MD) for continuous data, and applied DerSimonian and Laird random-effects models to address heterogeneity. Furthermore, we performed a trial sequential analysis (TSA) for all outcomes.

RESULTS

Twelve RCTs comprising a total of 1668 patients were included; 832 (49.9%) were assigned to receive balanced solutions. Balanced crystalloids reduced the occurrence of DGF compared to normal saline, with RR of 0.82 (95% confidence interval [CI], 0.71-0.94), P = .005; I² = 0%. The occurrence was 25% (194 of 787) in the balanced crystalloids group and 34% (240 of 701) in the normal saline group. Moreover, our TSA supported the primary outcome result and suggests that the sample size was sufficient for our conclusion. End-of-surgery chloride (MD, -8.80 mEq·L -1 ; 95% CI, -13.98 to -3.63 mEq.L -1 ; P < .001), bicarbonate (MD, 2.12 mEq·L -1 ; 95% CI, 1.02-3.21 mEq·L -1 ; P < .001), pH (MD, 0.06; 95% CI, 0.04-0.07; P < .001), and base excess (BE) (MD, 2.41 mEq·L -1 ; 95% CI, 0.88-3.95 mEq·L -1 ; P = .002) significantly favored the balanced crystalloids groups and the end of surgery potassium (MD, -0.17 mEq·L -1 ; 95% CI, -0.36 to 0.02 mEq·L -1 ; P = .07) did not differ between groups. However, creatinine did not differ in the first (MD, -0.06 mg·dL -1 ; 95% CI, -0.38 to 0.26 mg·dL -1 ; P = .71) and seventh (MD, -0.06 mg·dL -1 ; 95% CI, -0.18 to 0.06 mg·dL -1 ; P = .30) postoperative days nor urine output in the first (MD, -1.12 L; 95% CI, -3.67 to 1.43 L; P = .39) and seventh (MD, -0.01 L; 95% CI, -0.45 to 0.42 L; P = .95) postoperative days.

CONCLUSIONS

Balanced lower-chloride solutions significantly reduce the occurrence of DGF and provide an improved acid-base and electrolyte control in patients undergoing kidney transplantation.

Influence of specific thoracic donor therapy on kidney donation and long-term kidney graft survival

OBJECTIVE

To analyze the impact of a specific thoracic donor-treatment protocol (including restrictive fluid balance) on kidney donation and on kidney graft survival.

METHODS

A cohort study. Lung Donors and kidney recipients from 2003 to 2008 were the pre-protocol cohort, and those from 2009 to 2013 were the protocol cohort. The main outcome variables were graft survival and rate of kidney donation.

RESULTS

Kidney donation rates were similar in both periods (86.2 vs. 86.2 %; p > 0.05). Both donors and kidney recipients were older and with more comorbidities in the protocol group and this is the reason there were more cases of delayed graft function (differences not statistically significant) and with higher sequential creatinine levels of kidney recipients during the protocol period. However, graft survival was similar in both groups. The probability of graft survival 5 years after transplantation was 0.75 (95 % confidence interval 0.65-0.85) in the pre-protocol cohort and 0.81 (0.70-0.92) in the protocol cohort.

CONCLUSIONS

Specific treatment for multi-organ donors including restrictive fluid balance does not affect kidney donation or kidney graft loss, and has no impact on long-term viability. Hemodynamics must be closely monitored by medical personnel with specific training.

Normal saline versus lower-chloride solutions for kidney transplantation

BACKGROUND

The ideal intravenous fluid for kidney transplantation has not been defined, despite the common use of normal saline during the peri-operative period. The high chloride content of normal saline is associated with an increased risk of hyperchloraemic metabolic acidosis, which may in turn increase the risk of hyperkalaemia and delayed graft function. Balanced electrolyte solutions have a lower chloride content which may decrease this risk and avoid the need for dialysis due to hyperkalaemia in the immediate post-transplant period. Randomised controlled trials (RCTs) addressing this issue have used biochemical outcomes to compare fluids and have been underpowered to address patient-centred outcomes such as delayed graft function.

OBJECTIVES

To examine the effect of lower-chloride solutions versus normal saline on delayed graft function, hyperkalaemia and acid-base status in kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 26 November 2015 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

RCTs of kidney transplant recipients that compared peri-operative intravenous lower-chloride solutions to normal saline were included.

DATA COLLECTION AND ANALYSIS

Two independent investigators assessed studies for eligibility and risk of bias. Data from individual studies were extracted using standardised forms and pooled according to a published protocol. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes.

MAIN RESULTS

Six studies (477 participants) were included in the review. All participants were adult kidney transplant recipients and 70% of participants underwent live-donor kidney transplantation. The overall risk of bias was low for selection bias and unclear for remaining domains. There was no difference in the risk of delayed graft function (3 studies, 298 participants: RR 1.03, 95% CI 0.62 to 1.70) or hyperkalaemia (2 studies, 199 participants: RR 0.48, 95% CI 0.04 to 6.10) for participants who received balanced electrolyte solutions compared to normal saline. Intraoperative balanced electrolyte solutions compared to normal saline were associated with higher blood pH (3 studies, 193 participants: MD 0.07, 95% CI 0.05 to 0.09), higher serum bicarbonate (3 studies, 215 participants: MD 3.02 mEq/L, 95% CI 2.00 to 4.05) and lower serum chloride (3 studies, 215 participants: MD -9.93 mmol/L, 95% CI -19.96 to 0.11). There were four cases of graft loss in the normal saline group and one in the balanced electrolyte solution group, and four cases of acute rejection in the normal saline group compared to two cases in the balanced electrolyte solution group.

AUTHORS' CONCLUSIONS

Balanced electrolyte solutions are associated with less hyperchloraemic metabolic acidosis compared to normal saline, however it remains uncertain whether lower-chloride solutions lead to improved graft outcomes compared to normal saline.