Impact of Perfusion Pressure During Extracorporeal Circulation on Postoperative Kidney Function
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Rigshospitalet, Denmark
- Enrollment
- 100
- Locations
- 2
- Primary Endpoint
- Glomerular Filtration Rate measured the day before surgery compared to 4 - 6 days and 4 months (+/- 14 days) postoperative
Study Overview
Brief Summary
In Denmark around 3500 procedures are conducted involving a heart-lung-machine per year. An increase in the prevalence of postoperative kidney insufficiency have been observed following these procedures, during the last years. Kidney related complications are associated with a higher mortality and morbidity.
The reason and mechanisms behind this impaired kidney function is unknown. One possible cause could be that the blood pressure used in the heart-lung-machine is too low, during surgery. In the PPC trial we plan to include 100 patients. One half of the patients are operated with a normal, lower, blood pressure on the heart-lung-machine. The other half receives a blood pressure of > 60 mmHg during surgery.
The primary goal of the trial is to measure the kidney function (GFR) the day before surgery compared to day 4 - 6 and 4 months (+/- 14 days) after surgery. During the surgery a catheter is inserted through the femoral vein into the kidney vein. This makes it possible to measure several biochemical markers and the oxygen consumption of the kidney, during the surgery. Urine samples are also collected and analyzed.
The study hypothesis:
The glomerular filtration rate (GFR) is better preserved after cardiac surgery with extra corporal circulation with an intended increased periprocedural arterial blood pressure compared to current practice.
Detailed Description
- Introduction:
Renal function and cardiac surgery
Impaired kidney function is a well known complication to cardiac surgery and is observed in up to 30% of the patients, depending on the definition of acute kidney injury (AKI). The precise pathophysiological mechanisms are unknown, it is, however, quite obvious that AKI is not initiated by a single harmful factor but seems to be the result of different combined factors. Known risk factors for the development of postoperative AKI are cardiac incompensation, poor ejection fraction, gender, chronic obstructive lung disease, insulin dependent diabetes mellitus (IDDM), previous heart surgery, acute surgery, complexity of surgery, preoperative creatinine levels and prolonged duration of extracorporeal perfusion. These associations are not necessarily causal. It is not surprising that a subacute operation for a severe aortic stenosis in a patient with preoperatively poor circulation and a marginally increased S-creatinine, results in impaired renal function postoperatively. However, to conclude that cardiac surgery is the reason for AKI is not justified.
Several peroperative factors are likely to contribute in the development of AKI. Renal perfusion and oxygen delivery might be reduced (hypotension, lack of pulsatile flow during extracorporeal circulation (ECC), vasoactive pharmacological agents, anaesthesia), risk for emboli, general inflammatory response, direct nephrotoxins (free haemoglobin, free radicals, gentamycin etc.) and haemodilution. Current knowledge is limited and the general insight into regional perfusion during extracorporeal perfusion (heart-lung-machine) is very sparse.
There do, however, exist guidelines regarding flow and blood pressure during ECC, but these are based upon empiric data, which are controversial and vary from centre to centre.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Prevention
- Masking
- None
Eligibility Criteria
- Ages
- 70 Years to — (Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age > 70
- •Combined procedures (heart valve-, bypass- and aortic aneurysm surgery)
Exclusion Criteria
- •Age < 70
- •S-creatinine > 200 µmol/L
- •Acute operation
- •Endocarditis
Outcomes
Primary Outcomes
Glomerular Filtration Rate measured the day before surgery compared to 4 - 6 days and 4 months (+/- 14 days) postoperative
Time Frame: The day before surgery, 4 - 6 days and 4 months (+/- 14 days) postoperative
Measured by means of Cr-EDTA clearance
Secondary Outcomes
- Renal oxygen consumption measured minutes before surgery compared to intraoperative, 6 hours postoperative and 8.00 a.m. the day after surgery(Directly after placement of the renal vein catheter and every 15 minutes during surgery. 6 hours after surgery and 8.00 a.m. the day after surgery.)
- neutrophil gelatinase-associated lipocalin (NGAL) measured just before anaesthesia compared to just after extracorporal perfusion has ended, 6 hours postoperatively, 8.00 a.m. the day after surgery, 2nd and 5th day(Before induction of anaesthesia in the operating room, directly after the extracorporeal perfusion has ended. 6 hours postoperative. 8.00 a.m. the day after surgery. 2nd and 5th day postoperative.)
- Renal renin and proANP excretion measured the day before surgery compared to just after induction of anaesthesia, directly after extracorporeal perfusion has begun, just before extracorporeal perfusion ends, 1st and 5th postoperative day(The day before surgery. Directly after induction of anaesthesia. Directly after extracorporeal perfusion has begun. Just before extra corporeal perfusion is ended.1st and 5th day postoperative)
- Serum Cystatin C measured the day before surgery compared to directly after induction of anaesthesia, directly after extracorporeal perfusion has begun, just before extra corporeal perfusion has ended, 1st and 5th day postoperative(The day before surgery. Directly after induction of anaesthesia. Directly after extracorporeal perfusion has begun. Just before extra corporeal perfusion has ended.1st and 5th day postoperative)
Investigators
Daniel Steinbruchel
DMSc
Rigshospitalet, Denmark