The following section describes the elements of an AKI Follow-up Clinic for adults that are currently utilized at St. Michael’s Hospital and the University Health Network in Toronto, Ontario, Canada. The St. Michael’s clinic has been operating since September 2013, and the University Health Network clinic has been operating since October 2014. These clinics have assessed 150 and 65 new AKI patients since their respective introductions.
Target population
We utilize the following AKI Follow-up Clinic referral criteria.
Inclusion
Exclusion
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Kidney transplant recipients.
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Baseline eGFR under 30 mL/min/1.73 m2.
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Diagnosis of: glomerulonephritis, vasculitis with kidney involvement, hemolytic-uremic syndrome, polycystic kidney disease, multiple myeloma.
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Palliation as primary goal of care.
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Patients with previously established and ongoing nephrology follow-up, including patients discharged with a persistent requirement for renal replacement therapy.
Rationale
AKI severity appears to be the most important risk factor for adverse post-discharge outcomes, [16, 17]. The unanswered question is what threshold of AKI warrants follow-up. Some experts have advocated that nephrology follow-up occur for all patients with KDIGO stage 2–3 AKI [2]. However, the association with CKD, ESRD, and mortality seems to be present even among patients with mild and rapidly reversible AKI who are discharged from hospital with normal or near normal kidney function [18].
Ideally, a simple and practical risk score would identify patients at high risk for CKD progression and mortality post-AKI. These patients could then be selectively targeted for early nephrologist follow-up, as they would be most likely to benefit. Previous studies of patients who survive AKI have reported predictors of kidney disease progression and mortality [19, 20, 16, 21–23]. While there are notable differences in methodology, case-mix, and outcome ascertainment, many of these studies identified similar risk factors. These include: previous nephrology consultation, a history of CKD, pre-existing hypertension or cardiovascular disease, older age, recurrent AKI, and higher serum creatinine one year post-AKI. One study combined several risk factors into a score, but its feasibility is limited by the inclusion of serum albumin, a laboratory parameter that may not be routinely measured in the outpatient setting [16]. Until a post-AKI risk score is developed and tested under real-life conditions, our AKI Follow-up Clinic will target all patients with KDIGO stage 2–3 AKI. The reasons we have chosen to focus on this patient population are twofold: 1) patients with KDIGO stage 2–3 AKI are at greatest risk for adverse events and so most likely to benefit from nephrologist follow-up and 2) concern that including KDIGO stage 1 AKI patients would exceed the current capacity of our outpatient nephrology clinics. This was a local decision based upon our AKI Follow-up Clinic volumes and capacity, and centers with greater or fewer outpatient resources are encouraged to determine their own clinic criteria until more evidence becomes available.
There are some patients with AKI for whom alternate settings of post-discharge follow-up might be more appropriate. Patients with a baseline eGFR under 30 mL/min/1.73 m2 would either have already seen a nephrologist, or would benefit from a multidisciplinary clinic with a focus on dialysis planning given the frequent need for renal replacement therapy in this sub-population [24]. Therefore, we redirect these patients to a CKD clinic rather than an AKI Follow-up Clinic. Some parenchymal kidney diseases (glomerulonephritis, vasculitis with kidney involvement, hemolytic-uremic syndrome, polycystic kidney disease, multiple myeloma) would necessitate monitoring and therapies that are better served by a general nephrology clinic. In our experience, most of these patients already have nephrology follow-up arranged at the time of hospital discharge, but we clarify unclear situations with the inpatient medical team if needed. Lastly, an AKI Follow-up Clinic is redundant for patients with established and ongoing nephrology follow-up (including kidney transplant recipients), and we inform such patients to arrange an appointment with their current nephrologist shortly after hospital discharge.
Referral process and appointment targets
We utilize the following referral process and appointment targets (Fig. 1).
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Referrals accepted from all hospital units through an electronic or paper referral form (Additional file 1: Figure S1)
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Weekly audits by AKI Follow-up Clinic staff to identify patients with AKI who are not referred to clinic at hospital discharge
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Target AKI Follow-up Clinic appointments within 30 days of hospital discharge
Rationale
The first step in designing a referral process is to identify the reasons for low follow-up rates after an episode of AKI. To accomplish this objective, we first created a stakeholder map and engaged leaders of key stakeholder groups (nephrologists, cardiovascular surgeons, general internists, AKI researchers, trainees, nurse practitioners, social workers, and hospital administrators) via electronic mail. Each stakeholder group then nominated a member to join the quality improvement team, which communicated either in-person or electronically at three month intervals. These representatives identified the following as the most important local reasons for low follow-up rates after AKI: 1) lack of appreciation of the importance of AKI follow-up; 2) competing health problems in patients with AKI that are deemed higher priority during both the inpatient and outpatient period; 3) long hospital stays with hospital discharge occurring after AKI has resolved; and 4) multiple healthcare providers per AKI admission and frequent handovers, with lack of perceived responsibility for managing AKI follow-up.
With these challenges in mind, we created an online referral form (Additional file 1: Figure S1) and educational posters (Additional file 2: Figure S2) to facilitate referrals throughout the hospital. The poster is located at nurse and physician work stations on high volume AKI wards (nephrology, cardiovascular surgery, general internal medicine, critical care unit), visible only to healthcare professionals. In addition, we have an administrative or research assistant closely monitor the nephrology consult service patient roster to identify eligible patients and track these patients through their hospital stay even after the nephrology team’s involvement has ceased. This ensures that such patients are referred to the AKI Follow-up Clinic at the time of hospital discharge. This process has been in place since the inception of the AKI Follow-up Clinic. We review its operation on a weekly basis after each clinic, including the staff time required. On average, the screening process requires two hours of staff member time per week, with slight fluctuations based on AKI volumes. Due to the low time commitment, the assistant’s time is funded through clinical programs at the hospital level (~$6500/year).
A major limitation of this approach is the absence of an audit system for patients who are not on the nephrology consult service patient roster. We are currently exploring solutions to this problem, which include electronic AKI surveillance mechanisms and automatic referral prompts to the healthcare team at the time of patient discharge [25–27].
A 30 day appointment target was chosen to align with other medical disciplines and hospital readmission targets set by quality improvement agencies and insurers, including the Centers for Medicare and Medicaid Services [28–30]. Though a first appointment within this time window might not always be feasible to achieve, setting a stretch aim is a well-known quality improvement strategy to drive system change [31], and leaves room for patients to be seen by the 90 day threshold associated with decreased mortality.
AKI Follow-up Clinic medical interventions
We utilize the following standards for each patient encounter (Additional file 3: Figure S3).
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Patient sees a nephrologist at every clinic visit
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Dedicated recommendation section to indicate medications that should be adjusted and/or stopped
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Medical therapy that is in accordance with established hypertension, diabetes, lipid, and CKD practice guidelines
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Low threshold for referral to cardiology and endocrinology for concurrent care of high risk individuals with multiple chronic diseases
Rationale
Studies have demonstrated that nephrologists are more skilled at recognizing and managing CKD complications according to evidence-based guidelines compared with primary care providers [32, 33]. While we await the completion of randomized interventional studies on AKI patients, we cannot be sure that any medical intervention will be effective in mitigating CKD, ESRD, and death in the post-AKI setting. Nonetheless, it seems reasonable to provide simple, low cost interventions that have a plausible clinical rationale.
This list includes medication reconciliation; up to 67 % of patients admitted to the hospital have unintended medication omissions that remain common at discharge [34, 35]. Many vital medications, whose suspension in hospital might have been appropriate in light of the acute clinical circumstances, may not have been restarted by the time of discharge. These discrepancies have been associated with death and hospital readmission, particularly for cessation of chronic disease medications such as statins and anti-platelets agents [36]. In addition, patients may have new medications started in hospital, which we review to ensure proper dosing based on kidney function and clear indications to avoid polypharmacy.
Since patients who survive AKI have worse long-term outcomes than patients with diabetes and coronary artery disease, it seems reasonable to ensure they are meeting established targets recommended by hypertension, diabetes, lipid, and CKD practice guidelines [37–40]. We also mail patients a laboratory requisition prior to clinic that includes measurement of hemoglobin, electrolytes, bicarbonate, serum creatinine, calcium, phosphate, serum albumin, glucose, lipid profile, uric acid, and urine albumin to creatinine ratio.
In addition, increased referrals to specialist colleagues may lead to better management of common coexisting conditions, such as heart failure and diabetes mellitus. The merits of combined care on survival have been demonstrated in multiple disciplines, and improved access to healthcare resources may be an important mediator of downstream outcomes in AKI patients [41, 42]. For patients already followed by multiple specialists, a combined clinic approach where the patient can visit with all of their specialists in a single location may be an effective strategy to enhance follow-up of AKI survivors. Combined clinics are not a new approach to care [43], and may warrant further study for AKI survivors with multiple comorbidities.
Patient, family and healthcare provider education
We employ the following patient, caregiver, and provider education standards.
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Inform patients at first visit that AKI is associated with accelerated CKD, ESRD, and cardiac events
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Provide patients with a “sick-day” medication list (Additional file 4: Figure S4), so that they are aware which medications to stop when feeling ill
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Send referral notes to the patient’s primary care provider and relevant specialists after each visit, educating them on the long-term prognosis of AKI
Rationale
AKI is generally a “silent” component of a patient’s hospitalization, and often patients are not aware that they experienced an episode of AKI. At each clinic visit, we review with patients the natural history of AKI and the potential long-term consequences. This serves as a bridge to discuss medical interventions, especially cardioprotective lifestyle measures. Patients may be more motivated to adhere to lifestyle changes and medication regimens if they are made aware of the long-term consequences of AKI [44]. To promote self-care, we teach patients to hold their diuretics, angiotensin-converting-enzyme inhibitors, and angiotensin receptor blockers during episodes of intravascular volume depletion. This patient population has already declared itself as susceptible to AKI; temporarily stopping these medications is a reasonable strategy to protect against recurrent AKI.
In our opinion and based on our experience, the first AKI Follow-up Clinic visit is the optimal time to educate patients on the long-term effects of AKI, since they have started to recover from their acute illness. We have not attempted to provide patient education during the hospitalization or prior to the clinic visit (using a mailed pamphlet). This is something we are considering in the future, as it may help alleviate patient anxiety prior to the clinic visit and ensure patient engagement with the follow-up process.
The AKI Follow-up Clinic also provides nephrologists with an opportunity to educate primary care providers and specialists on AKI and its downstream complications. Some experts have suggested that an “episode of AKI” should be documented in the medical history portion of the patient’s medical record [2]. Incorporating this recommendation into daily practice will require effective knowledge translation strategies, which an AKI Follow-up Clinic is well-positioned to accomplish. All our patient dictations conclude with the same statement: “Thank you for referring your patient to the Acute Kidney Injury Follow-up Clinic. AKI survivors have a 40 % increased risk of dying in the two years after the initial hospitalization, and AKI is associated with the development of new or accelerated chronic kidney disease. We will see patients in clinic two to three times per year, and follow bloodwork quarterly. The objective of the AKI Follow-up Clinic is to reduce the long-term morbidity and mortality of AKI survivors.”
Follow-up visits and discharge criteria
We utilize the following criteria to monitor patients who survive AKI and determine when patients can be discharged from clinic (Fig. 1).
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Patients are followed by the AKI Follow-up Clinic for a minimum of one year
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Patients complete bloodwork to monitor kidney function, electrolytes, and proteinuria at least every three months
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Patients are eligible to graduate from the AKI Follow-up Clinic provided they have had no further AKI episode over 12 months and appropriate comorbidity follow-up has been arranged
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At clinic discharge, patients are referred for general nephrology follow-up if their eGFR is under 45 mL/min/1.73 m2 (stage 3b CKD) or albumin:creatinine ratio over 30 mg/mmol [39]; otherwise, they are sent back to their family physician for ongoing care along with an educational information letter.
Rationale
The majority of post-AKI adverse events appear to occur in the first three to six months following the AKI episode [18]. Therefore, six months appears to be the minimum period of time during which kidney function should be monitored, with 12 months providing more reassurance new or accelerated CKD will not be missed.
Our approach is to monitor kidney function and albuminuria at regular intervals (minimum three months) during this high-risk time period. In this way, kidney deterioration can be recognized sooner, follow-up arranged, and the necessary steps taken to preserve the remaining kidney function.
An AKI Follow-up Clinic would be unsustainable if it must follow patients for an indefinite period of time. It would also be unable to meet its appointment targets for new patients. We have established pre-specified clinic graduation criteria after one year of follow-up, which consists of no recurrent AKI episodes and appropriate comorbidity follow-up. Patients are transitioned to a general nephrology or CKD clinic according to evidence-based CKD guidelines [39]. The remaining patients return to the care of their family physician, and are provided with an exit pamphlet that outlines their AKI diagnosis, yearly kidney monitoring, and instructions on re-referral for nephrology care (Additional file 5: Figure S5). Long-term patient outcomes are ascertained by linkage to Ontario-wide administrative healthcare databases from ICES, for which patient consent is obtained at the first clinic visit. This creates an AKI survivor database for future research.
Thus far, this discharge criteria has helped the AKI Follow-up Clinic to maintain a mean appointment time of 30 days from hospital discharge. This has been accomplished using a weekly half-day clinic model at a tertiary center with 75 new AKI survivor assessments per year. Until more evidence on follow-up duration after AKI is available, programs are encouraged to modify the discharge criteria to suit local outpatient models, AKI volumes, and care practices.