Variability in processes of care for acute kidney injury (AKI) is common. Identification of valid process of care indicators is useful to assess the quality of care, so that it can be measured, monitored, and targeted for improvement.

This study identified 40 process of care quality indicators with high perceived validity, including 16 that reached high consensus among all expert panelists, for the prevention, identification, and management of AKI after major surgery. These indicators can be used to design and evaluate initiatives to improve the care of patients with or at risk of AKI after surgery.

AKI is a common problem, with an incidence of 4-7% among all hospital admissions [1-4] and 10-30% after major surgery. AKI is associated with morbidity, increased length of hospital stay, progression to end-stage renal disease (ESRD), high healthcare costs, and death [5-10]. The utilization of dialysis for AKI after major surgery has increased more than 3-fold over the last 10 years in Canada, contributing to longer hospital stays and higher costs of care [11].

While the important outcomes of AKI have been broadly recognized, a lack of consensus remains about high quality processes of care that are important for prevention and management of AKI [12,13]. Variability in processes of care for AKI is reported to be common, despite calls for initiatives to improve the quality of care for patients with or at high risk of AKI [14-16]. Identification of valid process of care indicators for AKI after major surgery would be useful to assess the quality of this care, so that it can be measured, monitored and targeted for improvement [17-20]. Several recently published clinical practice guidelines provide recommendations for AKI prevention, identification and treatment; however, few aspects of AKI prevention and management have been evaluated in rigorously conducted empirical studies in the perioperative setting, and so quality indicators for AKI prevention and care must be selected partly based on the opinions and experience of clinicians with knowledge in this area [21,22].

To inform the development of future initiatives to improve care for AKI after major surgery, we undertook a 3-stage, modified Delphi process with care providers from surgery, critical care, and nephrology in Alberta, Canada. Our aim was to achieve consensus among experts about the most important processes of care for prevention, recognition and management of AKI after major surgery.

This modified process was performed according to a pre-specified protocol and adhered to published recommendations for reporting [23]. Approval of the study was obtained from the Conjoint Health Research Ethics Board of the University of Calgary.

Using a modified Delphi method involving a panel of Alberta physician specialists, we identified 40 process of care quality indicators with high perceived validity for the prevention, identification, and management of AKI after major surgery. Sixteen of these process indicators were identified by panel members with high consensus.

The process of care quality indicators identified as having high validity by our panelists demonstrate the perceived importance of risk stratification and identification of patients at high risk of AKI as well as clinical and laboratory monitoring for early identification of AKI. Our findings illustrate high agreement for monitoring serum creatinine, urine output, and fluid balance after major surgery, with the addition of laboratory testing for, acidosis, and hyperkalemia following AKI onset. Careful monitoring of these measures may aid early recognition of AKI and, provide opportunities to intervene before severe complications develop [6]. This is consistent with recent guidelines for AKI that recommend routine monitoring of patients at risk of AKI in order to ensure timely recognition of AKI [21,24].

With respect to early management of AKI post surgery, indicators including use of intravenous crystalloids for intravascular volume expansion, withholding non-steroidal anti-inflammatory drugs (NSAIDs), aminoglycosides, and withholding or avoiding diuretics in the absence of volume overload, and reviewing current medications to identify those that are nephrotoxic or require dose adjustment also achieved high agreement by panelists. This is consistent with research suggesting that these medications are modifiable risk factors for AKI [6,7,21,24]. There was also general consensus among panel members that several process of care indicators for prevention of contrast-induced AKI were important. These included indicators to avoid NSAIDs and diuretics prior to contrast exposure and to minimize or avoid the use of intravenous contrast when possible.

There was high agreement on four indicators of need for critical care consultation when AKI was accompanied by circulatory or respiratory failure. However, only one of seven final indicators for nephrology consult reached consensus. This may reflect varying perspectives about the role nephrologists play in management of typical cases of AKI due to pre-renal causes or acute tubular necrosis after surgery [25-27].

These process of care quality indicators may be used in future quality improvement or research studies of perioperative AKI. Researchers could use these indicators as targets for interventions designed to improve the quality of care, or to evaluate changes in process of care with knowledge translation interventions including audit and feedback or organizational interventions. These indicators could also be targeted by formal educational interventions or employed as teaching tools for medical trainees.

Our study has a number of strengths. First, the modified Delphi procedure allows for anonymity of responses from panelists, which may provide a more accurate account of their beliefs surrounding best practices by reducing social desirability bias [28]. This approach minimized the risk of a dominant panelist unduly influencing the panel that can be observed in a less structured setting, such as a focus group, and allowed each panelist to present their opinions with equal weighting, regardless of seniority [29,30]. Second, this Delphi process was conducted via the Internet allowing inclusion of panelists from multiple locations across Alberta to participate. Third, the process allowed participants to re-evaluate their beliefs after receiving feedback on responses from other panelists in the third round. Finally, as candidate indicators were based on published and unpublished literature as well as the opinions of panelists, our results incorporated different forms of evidence to develop a broad range of process indicators.

There are also limitations to our study. First, all panelists were from Alberta Canada, thus external validity may be limited in other health care settings where practices differ. However, the challenges of prevention, early identification and management of AKI following major surgery are likely to be similar across different health care settings. Second, we focused on medical care for AKI, and did not include anesthesiologists who may have provided different perspectives on intraoperative processes of care. Third, we focused on processes of care that could be generalized to all patients after major surgery, rather than features of specific types of surgical procedures themselves (e.g. on-pump versus off-pump cardiac surgery) that may alter the risk of AKI. Finally, this modified Delphi process focused on obtaining input on the face validity but not the feasibility of measuring these process indicators for AKI [23]. Future work is required to determine the practicality and accuracy of measuring these variables in clinical settings.

In summary, we used an iterative stepwise approach to obtain expert clinician opinions on indicators of process of care for prevention, identification, and management of perioperative AKI. These indicators can be used to design and evaluate initiatives to improve the care of patients with or at risk of AKI after surgery.