CURB-AKI
Cardiac Surgery Practices and Concurrent Risks
of AKI, Prolonged Ventilation, and Death
Michael Mathis, MD
Associate Professor of Anesthesiology
Director, Outcomes Research
Michigan Medicine
Karandeep Singh, MD, MMSc
Associator Professor of Int Med -Nephrology
Chief Health AI Officer
UC San Diego Health
Preoperative Risk and the Association between
Hypotension and Postoperative Acute Kidney Injury
Reflections from the MPOG Wood Library Museum…
Time
MAP
65
mmHg
(circa 2019)
… so what were the limitations of that study?
Concurrent Risks
Treatment decisions must
consider key trade-offs
Treatment Effect
Heterogeneity
Individual patients aren’t
population-level averages
Missing
information
Single data sources didn’t
tell the whole picture
A tale of two databases…
Preop
• Structured H&P with
adjudicated
comorbidities
• Surgical Procedure
Details
Postop
• AKI Stage
• Dialysis
Intraop
• Physiologic
• Times/Providers
• Medications
• Fluids
MPOG STS
Integrated MPOG + STS Dataset, 2014-2022
24,726 Adult Cardiac Procedures (CAB, Valve, Aortic)
202 Attending Anesthesiologists, 8 US Hospitals
Concurrent Risks…
• 3 Outcomes:
• Acute Kidney Injury (KDIGO Stage 1 or greater)
• Prolonged postoperative ventilation >24 hours
• Mortality (postoperative 30-day)
• Post-bypass hemodynamic strategies:
Vasopressors
Fluids
Restrictive
Liberal
None
Low-Dose
High-Dose
Individualized Treatment Effects:
Treatment Effect
Kidney
Health
Cardiac
Surgical
Patients
Average
Treatment Effect
Liberal Fluids + Low-Dose Vasopressors
Restrictive Fluids + Low-Dose Vasopressors
Average
Treatment Effect
Individualized Treatment Effect
Liberal Fluids + Low-Dose Vasopressors
Individualized Treatment Effect
Re strictive Fluids + Low-Dose Vasopressors
Patient A
Patient B
Homogenous
Population
Heterogenous
Kidneys
KidneysIndividualized Treatment Effects:
Treatment Effect
Kidney
Health
Cardiac
Surgical
Patients
Kidney Health
Optimal Individualized Treatment Effect
(…versus usual care?)
Lung
Health
Average
Treatment Effect
Average
Treatment Effect
Liberal Fluids + Low-Dose Vasopressors
Restrictive Fluids + Low-Dose Vasopressors
Lung Health
Optimal Individualized Treatment Effect
Population
Heterogenous
Lungs
Clinical / Scientific Implications
Liberal
fluids +
limit
vasopressors
(but not always)
No meaningful increase
to
rates of prolonged ventilation
or mortality
Restrictive
fluids +
limit
vasopressors
(but not always)
No meaningful increase
to
rates of AKI or mortality
Prevailing best
strategy
Tradeoff to
other organ?
CURB-AKI
Thank You
CURB-AKI
** MPOG Member Milestone **
Congratulations to Dr. Nathan Pace!
• 50 years within the University of Utah
Department of Anesthesiology
• >60 million cases contributed to MPOG
as Utah PI
• 12 Cochrane systematic reviews co-
authored
• 42 volumes of ASA’s Summaries of
Emerging Evidence
• Countless MPOG research proposals and
publications impacted
CURB-AKI
Preliminary Data
“Heat Map” of
Vasopressor & Fluid Practices:
Actual Care Received, versus
Estimated Optimal Care
