docs(lods): note BUN mg/dL cutoffs beside renal CASE

Document Le Gall 17/28/56 mg/dL thresholds next to the renal score so
mmol/L-style arms (e.g. 7.50) are not reintroduced. Mirror in postgres.

Author: acnimma

mimic-iii/concepts/severityscores/lods.sql

@@ -161,6 +161,8 @@ select
   end as cardiovascular
 
   -- renal
+  -- BUN cutoffs are mg/dL (Le Gall et al., JAMA 1996): 0 if <17, 1 if 17-27,
+  -- 3 if 28-55, 5 if >=56. Do not add mmol/L-style thresholds (e.g. 7.50).
   , case
       when bun_max is null
         or urineoutput is null

mimic-iii/concepts_postgres/severityscores/lods.sql

@@ -134,7 +134,7 @@ WITH cpap AS (
       WHEN sysbp_min < 90
       THEN 1
       ELSE 0
-    END AS cardiovascular, /* renal */
+    END AS cardiovascular, /* renal */ /* BUN cutoffs are mg/dL (Le Gall et al., JAMA 1996): 0 if <17, 1 if 17-27, */ /* 3 if 28-55, 5 if >=56. Do not add mmol/L-style thresholds (e.g. 7.50). */
     CASE
       WHEN bun_max IS NULL OR urineoutput IS NULL OR creatinine_max IS NULL
       THEN NULL

mimic-iv/concepts/score/lods.sql

@@ -155,6 +155,8 @@ WITH cpap AS (
         END AS cardiovascular
 
         -- renal
+        -- BUN cutoffs are mg/dL (Le Gall et al., JAMA 1996): 0 if <17, 1 if 17-27,
+        -- 3 if 28-55, 5 if >=56. Do not add mmol/L-style thresholds (e.g. 7.50).
         , CASE
             WHEN bun_max IS NULL
                 OR urineoutput IS NULL

mimic-iv/concepts_postgres/score/lods.sql

@@ -133,7 +133,7 @@ WITH cpap AS (
       WHEN sbp_min < 90
       THEN 1
       ELSE 0
-    END AS cardiovascular, /* renal */
+    END AS cardiovascular, /* renal */ /* BUN cutoffs are mg/dL (Le Gall et al., JAMA 1996): 0 if <17, 1 if 17-27, */ /* 3 if 28-55, 5 if >=56. Do not add mmol/L-style thresholds (e.g. 7.50). */
     CASE
       WHEN bun_max IS NULL OR urineoutput IS NULL OR creatinine_max IS NULL
       THEN NULL