Faculty Collaboration Database

Association Between Preoperative Proteinuria and Postoperative Acute Kidney Injury and Readmission. JAMA Surg 2018 Sep 01;153(9):e182009

Date

07/05/2018

Pubmed ID

29971429

Pubmed Central ID

PMC6233648

DOI

10.1001/jamasurg.2018.2009

Scopus ID

2-s2.0-85053821401 (requires institutional sign-in at Scopus site)   26 Citations

Abstract

IMPORTANCE: Proteinuria indicates renal dysfunction and is a risk factor for morbidity among medical patients, but less is understood among surgical populations. There is a paucity of studies investigating how preoperative proteinuria is associated with surgical outcomes, including postoperative acute kidney injury (AKI) and readmission.

OBJECTIVE: To assess preoperative urine protein levels as a biomarker for adverse surgical outcomes.

DESIGN, SETTING, AND PARTICIPANTS: A retrospective, population-based study was conducted in a cohort of patients with and without known preoperative renal dysfunction undergoing elective inpatient surgery performed at 119 Veterans Affairs facilities from October 1, 2007, to September 30, 2014. Data analysis was conducted from April 4 to December 1, 2016. Preoperative dialysis, septic, cardiac, ophthalmology, transplantation, and urologic cases were excluded.

EXPOSURES: Preoperative proteinuria as assessed by urinalysis using the closest value within 6 months of surgery: negative (0 mg/dL), trace (15-29 mg/dL), 1+ (30-100 mg/dL), 2+ (101-300 mg/dL), 3+ (301-1000 mg/dL), and 4+ (>1000 mg/dL).

MAIN OUTCOMES AND MEASURES: Primary outcome was postoperative predischarge AKI and 30-day postdischarge unplanned readmission. Secondary outcomes included any 30-day postoperative outcome.

RESULTS: Of 346 676 surgeries, 153 767 met inclusion criteria, with the majority including orthopedic (37%), general (29%), and vascular procedures (14%). Evidence of proteinuria was shown in 43.8% of the population (trace: 20.6%, 1+: 16.0%, 2+: 5.5%, 3+: 1.6%) with 20.4%, 14.9%, 4.3%, and 0.9%, respectively, of the patients having a normal preoperative estimated glomerular filtration rate (eGFR). In unadjusted analysis, preoperative proteinuria was significantly associated with postoperative AKI (negative: 8.6%, trace: 12%, 1+: 14.5%, 2+: 21.2%, 3+: 27.6%; P < .001) and readmission (9.3%, 11.3%, 13.3%, 15.8%, 17.5%, respectively, P < .001). After adjustment, preoperative proteinuria was associated with postoperative AKI in a dose-dependent relationship (trace: odds ratio [OR], 1.2; 95% CI, 1.1-1.3, to 3+: OR, 2.0; 95% CI, 1.8-2.2) and 30-day unplanned readmission (trace: OR, 1.0; 95% CI, 1.0-1.1, to 3+: OR, 1.3; 95% CI, 1.1-1.4). Preoperative proteinuria was associated with AKI independent of eGFR.

CONCLUSIONS AND RELEVANCE: Proteinuria was associated with postoperative AKI and 30-day unplanned readmission independent of preoperative eGFR. Simple urine assessment for proteinuria may identify patients at higher risk of AKI and readmission to guide perioperative management.

Author List

Wahl TS, Graham LA, Morris MS, Richman JS, Hollis RH, Jones CE, Itani KM, Wagner TH, Mull HJ, Whittle JC, Telford GL, Rosen AK, Copeland LA, Burns EA, Hawn MT

Author

Jeffrey Whittle MD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Acute Kidney Injury
Aged
Female
Follow-Up Studies
Glomerular Filtration Rate
Humans
Incidence
Male
Middle Aged
Patient Readmission
Postoperative Complications
Postoperative Period
Preoperative Period
Prognosis
Proteinuria
Retrospective Studies
Risk Assessment
Risk Factors
Surgical Procedures, Operative
United States