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

Diagnostic and therapeutic challenges in implementing hypertension management after kidney transplantation

PURPOSE OF REVIEW

Evidence for blood pressure (BP) measurement and hypertension management in kidney transplant recipients (KTR) remains lacking.

RECENT FINDINGS

Accurate BP measurement technique is a critical component of hypertension management, and 24-h ambulatory BP monitoring remains the gold standard for diagnosis of hypertension in KTR. BP target at different periods posttransplant is uncertain, but likely higher than that in nontransplant patients given factors related to long-standing uremic milieu and kidney transplantation such as vascular calcification altering transplant renal hemodynamic and allograft perfusion and immunosuppression. Dividing BP target into immediate, early, and late posttransplant periods can guide differential diagnoses of hypertension and BP control with a target SBP less than 160 mmHg in general and BP 115-135/65-85 mmHg for adult KTR receiving pediatric kidneys during the immediate posttransplant period, 130/80 mmHg during early and late posttransplant periods. Calcium channel blockers were shown to have favorable graft outcomes. Novel antihypertensive medications for resistant and refractory hypertension and device-based therapies are limited due to KTR's ineligibility for participating in clinical trials.

SUMMARY

In KTR, BP measurement and monitoring practice should follow the standard clinical practice guideline for nontransplant patients by considering posttransplant factors and immunosuppressive state. Novel treatment options required further studies.

Effect of perioperative management on early graft function in living donor paediatric kidney transplantation

BACKGROUND

Paediatric kidney transplantation has an increased risk of surgical and vascular complications, with intensive care monitoring required postoperatively. This study aimed to determine if perioperative management affects early graft function in living donor paediatric kidney transplantation.

METHODS

Clinical data was extracted from the electronic medical record for living donor kidney transplants at two paediatric centres covering the state of New South Wales (NSW), Australia from 2009 to 2021. Estimated glomerular filtration rate (eGFR) of 7 days and 1-month post-transplant were calculated as measures of early graft function.

RESULTS

Thirty-nine eligible patients (female n (%) 13 (33%)) with a median (IQR) age of 6 (3-9) years and pre-transplant eGFR of 7 (6-10) mL/min/1.73 m2 were analysed. Mean (SD) central venous pressure (CVP) after revascularisation was 11 (4) mmHg. Intraoperatively, mean volume of fluid administered was 84 (39) mL/kg, and 34 (87%) patients received vasoactive agents. Average systolic blood pressure (BP) in the first 24-h post-transplant was 117 (12) mmHg. Postoperatively, median volume of fluid administered in the first 24 h was 224 (159-313) mL/kg, and 17 (44%) patients received vasoactive agents. Median eGFR 7 days and 1-month post-transplant were 115 (79-148) and 103 (83-115) mL/min/1.73 m2, respectively. Linear regression analyses demonstrated that after adjusting for age, the average CVP after revascularisation and average systolic BP in the first 24-h post-transplant were not associated with eGFR in the first month post-transplant.

CONCLUSIONS

Targeted intraoperative and postoperative fluid and haemodynamic characteristics were achieved but did not correlate with early graft function.

Perioperative fluid management and associated complications in children receiving kidney transplants in the UK

BACKGROUND

Intravenous fluid administration is an essential part of perioperative care for children receiving a kidney transplant. There is a paucity of evidence to guide optimal perioperative fluid management. This study aimed to identify the volume of perioperative fluids administered across 5 UK paediatric kidney transplant centres and explore associations between fluid volume administered, graft function, and fluid-related adverse events.

METHODS

Data were collected from five UK paediatric kidney transplant centres on perioperative fluid volumes administered, and incidence of pulmonary oedema, systemic hypertension, and requirement for intensive care support. Children < 18 years of age who received a kidney-only transplant between 1^st January 2020 and 31^st December 2021 were included.

RESULTS

Complete data from 102 children were analysed. The median total volume of fluid administered in 72 h was 377 ml/kg (IQR 149 ml/kg) with a high degree of variability. A negative relationship between total fluid volume administered and day 7 eGFR was noted (p < 0.001). Association between urine volume post-transplant and day 7 eGFR was also negative (p < 0.001). Adverse events were frequent but no significant difference was found in the fluid volume administered to those who developed an adverse event, vs those who did not.

CONCLUSIONS

This study describes a high degree of variability in perioperative fluid volumes administered to children receiving kidney transplants. Both fluid volume and urine output were negatively associated with short-term graft function. These data contrast traditional interpretation of high urine output as a marker of graft health, and highlight the need for prospective clinical trials to optimise perioperative fluid administration for this group. A higher resolution version of the Graphical abstract is available as Supplementary information.

Changes in graft function after living donor kidney transplantation in children

BACKGROUND

This study aimed to evaluate the change in graft function in two groups stratified by the estimated glomerular filtration rate (eGFR) at 1 month after transplantation (eGFR-1 M) in pediatric living donor kidney transplant recipients.

METHODS

Forty-three pediatric recipients were classified as those with an eGFR-1 M ≥ 90 mL/min/1.73 m² (n = 19; high eGFR group) or those with an eGFR-1 M of 60-89 mL/min/1.73 m² (n = 24; middle eGFR group). In the two groups, changes in the eGFR were retrospectively evaluated for 5 years after kidney transplantation.

RESULTS

The mean recipient age at transplantation in the high/middle eGFR group was 6.1 ± 3.4/7.8 ± 4.0 years (P = 0.14). The mean eGFR-1, -12, and -60 M (mL/min/1.73 m²) in the high/middle eGFR group were 106.8 ± 2.99/78.5 ± 1.52 (P < 0.001), 79.3 ± 3.22/62.7 ± 2.38 (P < 0.001), and 73.1 ± 4.16/59.2 ± 2.79 (P = 0.006), respectively. The change in the mean eGFR remained mostly parallel in the two groups. In both groups, the eGFR significantly decreased only between 1 and 12 months after transplantation (P < 0.0001). Approximately 70% of the patients had an eGFR-60 M ≥ 60 mL/min/1.73 m².

CONCLUSIONS

The high and middle eGFR groups showed a rapid decline in the eGFR by 1 year after transplantation, but the change thereafter was gradual. In pediatric living donor kidney transplant recipients, the eGFR was relatively well maintained up to 5 years after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.