Acute Kidney Injury, Endothelial Dysfunction
Conditions
Keywords
Endothelial function, Acute Kidney Injury, Cardiopulmonary bypass, Cardiac surgery
Brief summary
Cardiopulmonary bypass during cardiac surgery provides blood flow to the body during surgery but has adverse effects on different organs. Blood flow during cardiopulmonary bypass may be pulsatile or non-pulsatile, which may impact normal organ function after surgery. The study will collect data on the type of cardiopulmonary bypass used during surgery and organ function to determine if there is an association between the type of bypass and organ function.
Detailed description
Cardiac surgery is a high-risk elective surgical procedure frequently requiring CPB in which a machine pumps blood while the surgeon operates on the heart. CPB contributes to surgical risk by causing endothelial dysfunction and acute kidney injury (AKI). Endothelial dysfunction and AKI happen because heart lung machines typically generate non-pulsatile blood flow, which is abnormal and results in impaired tissue oxygen delivery. Normal blood flow is pulsatile due intermittent contraction and relaxation of the heart during the cardiac cycle, which produces a mechanical signal that induces endothelial cells to produce nitric oxide. Without nitric oxide, blood flow does not penetrate as deeply into organs such as the kidneys which leads to acute kidney injury. AKI increases mortality 10-fold after cardiac surgery placing many people at risk since over 400,000 people have surgery with CPB each year in the United States. Thus, pulsatile CPB may influence endothelial function and renal blood flow after cardiac surgery. This study will observe patients undergoing cardiac surgery with CPB and compare patients who receive pulsatile or non-pulsatile CPB.
Interventions
None listed
Sponsors
National Heart, Lung, and Blood Institute (NHLBI)
University of Colorado, Denver
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
50 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Age 50 to 70 * Able to provide informed consent * Scheduled for elective cardiac surgery with cardiopulmonary bypass
Exclusion criteria
* Patients undergoing emergency procedures * Diagnosed with sepsis * Experiencing delirium * Experiencing hemodynamic instability (heart rate \> 100 and systolic blood pressure \< 90) * Patients with a mechanical circulatory support device * Requiring vasoactive medications before surgery * Patients with a reduced left ventricular ejection fraction (less than 50%) * Patients with a contraindication to transesophageal echocardiography
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Endothelial function | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Percent change in flow mediated dilation of the brachial artery after cardiac surgery |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Renal blood flow velocity | Intra-operative time point: after cardiopulmonary bypass, up to 12 hours | Renal blood flow velocity measured by pulse wave doppler |
| Acute kidney injury risk | Measured 4 hours after the end of cardiopulmonary bypass, up to 12 hours | Acute kidney injury risk measured by urinary TIMP2\*IGFBP7 |
| Perioperative death | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Death after surgery during the surgical hospital encounter |
| Myocardial infarction | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Myocardial infarction after surgery |
| Stroke | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Stroke after surgery |
| New renal failure requiring renal replacement therapy | From intensive care unit admission after surgery to hospital discharge, up to 30 days | New renal failure requiring renal replacement therapy after surgery |
| Re-exploration for bleeding | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Need for surgical re-exploration to control hemorrhage |
| Post-operative sepsis | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative sepsis determined by positive blood culture |
| New onset atrial fibrillation | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative new onset atrial fibrillation |
| Post-operative blood loss | From intensive care unit admission to 24 hours after intensive care unit admission, up to 24 hours | Post-operative blood loss determined by total surgical drain output |
| Duration of mechanical ventilation | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Duration of mechanical ventilation after surgery |
| Post-operative delirium | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative delirium determined by the Confusion Assessment Method for the Intensive Care Unit score |
| Post-operative hospital length of stay | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Duration of hospital stay after surgery |
| New requirement for mechanical circulatory support | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative initiation of mechanical circulatory support |
| Acute kidney injury | From intensive care unit admission after surgery to intensive care unit discharge, up to 7 days | Acute kidney injury by the KDIGO criteria |
| Post-operative red blood cell transfusion | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative red blood cell transfusion in units |
| Post-operative platelet transfusion | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative platelet transfusion in units |
| Post-operative plasma transfusion | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative plasma transfusion in units |
| Post-operative cryoprecipitate transfusion | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Post-operative cryoprecipitate transfusion in units |
| Intra-operative platelet transfusion | During the intra-operative time period, up to 12 hours | Intra-operative platelet transfusion in units |
| Intra-operative plasma transfusion | During the intra-operative time period, up to 12 hours | Intra-operative plasma transfusion in units |
| Intra-operative cryoprecipitate transfusion | During the intra-operative time period, up to 12 hours | Intra-operative cryoprecipitate transfusion in units |
| Glycocalyx thickness | Start of the intra-operative period to 24 hours after intensive care unit admission | Glycocalyx thickness determined by sublingual microcirculation microscopy |
| Microvascular circulatory function | Start of the intra-operative period to 24 hours after intensive care unit admission | Microvascular circulatory function determined by sublingual microcirculation microscopy |
| New onset of acute lung injury | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Diagnosis of acute lung injury by PaO2 to FiO2 ratio |
| New onset of left ventricular diastolic dysfunction | From intensive care unit admission after surgery to hospital discharge, up to 30 days | Diagnosis new onset diastolic dysfunction by annular e' velocity: septal e' \< 7 cm/sec, lateral e' \<10 cm/sec, average E/e' ratio \> 14, LA volume index \> 34 mL/m2, and peak TR velocity \> 2.8 m/sec. |
| New onset of left ventricular systolic dysfunction | From intensive care unit admission after surgery to hospital discharge, up to 30 days | New onset of left ventricular systolic dysfunction determined by a LV ejection fraction \<50% |
| New onset of right ventricular systolic dysfunction | From intensive care unit admission after surgery to hospital discharge, up to 30 days | New onset of right ventricular systolic dysfunction determined by a tricuspid annular plane systolic excursion less than 16 mm |
| Intra-operative red blood cell transfusion | During the intra-operative time period, up to 12 hours | Intra-operative red blood cell transfusion in units |
Countries
United States
Contacts
Primary ContactNathan J Clendenen, MD, MS
Outcome results
None listed