feat: implementation of fluid balance

mimic-iv/concepts_postgres/measurement/daily_fluid_balance.sql

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+DROP TABLE IF EXISTS
+  mimiciv_derived.daily_fluid_balance
+CASCADE;
+
+CREATE TABLE
+  mimiciv_derived.daily_fluid_balance AS
+SELECT
+    i.stay_id,
+    i.infusion_date,
+    (
+    i.total_daily_amount - COALESCE(o.total_output, 0)
+  ) as net_balance
+FROM
+    mimiciv_derived.daily_fluid_in AS i
+    LEFT JOIN mimiciv_derived.daily_fluid_out AS o ON i.stay_id = o.stay_id
+        AND i.infusion_date = o.day;

mimic-iv/concepts_postgres/measurement/daily_fluid_in.sql

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+DROP TABLE IF EXISTS mimiciv_derived.daily_fluid_in
+CASCADE;
+CREATE TABLE mimiciv_derived.daily_fluid_in AS
+WITH RECURSIVE infusion_days AS
+(
+  SELECT stay_id,
+    CAST(starttime AS DATE) AS infusion_date,
+    CASE 
+           WHEN CAST(starttime AS DATE) = CAST(endtime AS DATE) THEN amount
+           ELSE amount / EXTRACT(EPOCH FROM (endtime - starttime)) / 3600 * (24 - EXTRACT(HOUR FROM starttime))
+         END AS daily_amount,
+    endtime
+FROM mimiciv_icu.inputevents
+)
+SELECT stay_id, infusion_date, SUM(daily_amount) AS total_daily_amount
+FROM infusion_days
+GROUP BY stay_id, infusion_date
+ORDER BY stay_id, infusion_date;

mimic-iv/concepts_postgres/measurement/daily_fluid_out.sql

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+DROP TABLE IF EXISTS mimiciv_derived.daily_fluid_out;
+CREATE TABLE mimiciv_derived.daily_fluid_out AS
+SELECT
+    stay_id,
+    DATE(charttime) as day,
+    SUM(value) as total_output
+FROM
+    mimiciv_icu.outputevents
+GROUP BY 
+    stay_id, 
+    day
+ORDER BY 
+    stay_id, 
+    day;