Step 1. Using the Preop Creatinine (Highest within 60 days) and Postop Creatinine phenotypes, determine if any creatinine values are available.
- If no creatinine are available for both phenotypes, return 'Missing/Unknown' (value_code -999) and Stop.
- If values are found proceed to step 2.
Step 2. Check for values in the Preop Creatinine (Highest within 60 days).
- If no values exist, return ‘No preoperative creatinine‘(value_code -3).
- Otherwise, proceed to step 3.
- If the value has the text <,>,=. <=. >= Use the process in the Table 1 below to determine the value.
Step 3. Use the value obtained from Preop EGFR (Lowest within 60 Days) phenotype to determine if preoperative renal failure is present:
- If BSA-Indexed EGFR < 15 mL/min/1.73 m2, then return 'Preoperative Renal Failure' (value_code -2) and stop.
- Otherwise, proceed to Step 4.
Step 4. Check for postop creatinine values using the Postop Creatinine phenotype
- If no values exist, then return 'No Postoperative Creatinine' (value_code -1).
- Otherwise, proceed to step 5.
- *If Scr value is = 0 mg/dL, then value is ignored (non-valid)
- If the value has the text <,>,=. <=. >= Use the process in the Table 1 below to determine the value.
Step 5. Using Postop Creatinine, determine the highest value from either the 0-2 day creatinine or 2-7 day creatinine AND the values must be before anesthesia start date/time of subsequent surgery*.
- If the 0-2 day creatinine is higher proceed to step 6a.
- If the 2-7 day creatinine is higher, proceed to step 6b.
- *For patients with more than one case in a 7-day period, we do not attribute postop creatinine values to more than 1 case. For example, if there are 3 cases in 3 days, and a creatinine value is obtained only after the 3rd case, that creatinine value will be attributed only to the third case. The first 2 cases will be excluded. There are no changes to the baseline creatinine attribution with multiple cases in a 7-day period.
Step 6a. Using the creatinine from the 0-2 day window,
- If this value is = 200% greater than baseline creatinine (i.e. = 3.0 times baseline), OR Scr > 4.0 mg/dl then return 'AKI Stage 3' (value_code 3)
- Otherwise, if this value is = 100% greater than baseline creatinine (i.e. = 2.0 times baseline), then return 'AKI Stage 2' (value_code 2)
- Otherwise, if this value is = 50% greater than baseline creatinine (i.e. = 1.5 times baseline), then return 'AKI Stage 1' (value_code 1)
- Otherwise if the creatinine value is equal to 0.3 mg/dL or greater than baseline creatinine then return 'AKI Stage 1' (value_code 1)
- Otherwise, return 'No AKI' (value_code 0).
Step 6b. Using the creatinine from the 2-7 day window, determine the following:
- If this value is = 200% greater than baseline creatinine (i.e. = 3.0 times baseline), OR Scr > 4.0 mg/dl then return 'AKI Stage 3' (value_code 3)
- Otherwise, if this value is = 100% greater than baseline creatinine (i.e. = 2.0 times baseline), then return 'AKI Stage 2' (value_code 2)
- Otherwise, if this value is = 50% greater than baseline creatinine (i.e. = 1.5 times baseline), then return 'AKI Stage 1' (value_code 1)
- Otherwise, return 'No AKI' (value_code 0).
| Table 1 |
| Text prior to numaric value |
Logic to Determine Value |
Example |
| < |
Subtract 0.01 from numeric value |
<0.2 would return 0.19 |
| > |
Add 0.01 to numeric value |
>0.2 would return 0.21 |
| = |
Return the numeric value |
=0.2 would return 0.2 |
| <= |
Return the numeric value |
<=0.2 would return 0.2 |
| >= |
Return the numeric value |
>=0.2 would return 0.2 |