Clinical trial NCT06886191: PuO2 in RenalGuard Pilot Study
Official title: Effects on Urine Oxygenation of Forced Diuresis with Neutral Fluid Balance During Cardiac Surgery, a Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Cardiac Surgery Subjects
Keywords: renal oxygenation
urine oxygen tension
furosemide
balanced diuresis
Lead sponsor: Sahlgrenska University Hospital
Sponsor class: OTHER
First posted: 2025-03-20
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The PuO2 in RenalGuard (PURE) study is planned as a single center, randomized controlled pilot study comparing renal oxygenation during cardiac surgery with cardiopulmonary bypass (CPB) with or without balanced forced diuresis using the RenalGuard (RG) system.

Renal oxygenation will be assessed by urine oxygen tension, continuously measured by optodes placed through the urine catheter. Measurements will start after induction of anesthesia and continue for 24 hours.

In total, 30 patients will be randomized 1:1 to RG or standard of care (SOC) during cardiac surgery with CPB. In the RG group, the forced diuresis with neutral fluid balance will be maintained from before the start of surgery until 3 hours after weaning from CPB.

The primary endpoint is the group difference (RG vs SOC) in delta PuO2, defined as the change in mean PuO2 from baseline to the last 5-minute period at 45 minutes after start of CPB.

The secondary endpoints include

1. Group difference in mean PuO2 before, during and after CPB
2. Group difference in time weighted area under the curve for PuO2
3. Group differences in renal near infrared spectroscopy (NIRS) before, during and after CPB
4. Group difference in urine and blood biochemistry including renal biomarkers
5. Group difference in urine output and fluid balance during surgery and first postoperative day
6. Group differences in postoperative AKI according to the KDIGO criteria
7. Time (minutes) with puO2 ≤ 15 and ≤ 10 mmHg during and after CPB
8. Dynamics of PuO2 during the early postoperative phase

Patients ≥18 years scheduled for cardiac surgery with CPB with estimated glomerular filtration rate ≥50 ml/min are eligible for inclusion. Exclusion criteria include patients on higher doses of furosemide, patients with AKI or under renal replacement therapy.

Patients will be analyzed according to study group. In patients where hemofiltration has been used during CPB, control group patients who has received furosemide and patients in the RG group who do not reach target urine flow will be excluded from the main analysis but will be included in a separate analysis.


Eligibility criteria: Inclusion Criteria:

* Patients ≥18 years of age
* scheduled for cardiac surgery with normothermic CPB
* Estimated glomerular filtration rate ≥50 ml/min as assessed by the CKD-EPI formula

Exclusion Criteria:

* Patient receiving furosemide at a dose\>100 mg/day orally (or the equivalent dose of an alternative loop diuretic) in the last week
* Patient who cannot be urethrally catheterized for any reason
* Patient already dialysis dependent
* Known or suspected AKI (KDIGO criteria) at the time of screening
* Any condition which, in the judgement of the investigator, might increase the risk to the patient

Primary outcomes:
measure: Delta PuO2
timeFrame: Baseline (before start of surgery) to 45 minutes after start of CPB
Secondary outcomes:
measure: Repeated PuO2
timeFrame: baseline, 30, 45 minutes on CPB and at 30, 60 and 240 minutes after CPB
measure: PuO2 AUC
timeFrame: From baseline before start of surgery until 4 hours after CPB
measure: PuO2 sub threshold
timeFrame: From baseline before surgery until 4 hours after CPB
measure: Diuresis and fluid balance
timeFrame: 24 hours
Other outcomes:
measure: Dynamics of PuO2 during the early postoperative phase
timeFrame: 24 hours
measure: Urine Nephrocheck
timeFrame: 4 hours after CPB
measure: Renal near-infrared spectroscopy (NIRS)
timeFrame: From baseline before surgery until 4 hours after CPB
measure: Creatinine
timeFrame: 7 days
Locations:
Study officials:
affiliation: Institute of Clinical Sciences, Dept of Anesthesia and Intensive Care, Sahlgrenska Academy, Gothenburg University. Gothenburg, Sweden
name: Lukas Lannemyr Lannemyr, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: