Case of inappropriate ADH syndrome: Hyponatremia due to polyethylene glycol bowel preparation

Table 1 Patient’s serum laboratory data and mental state

Mental state	Reference range	Drowsy to stuporous	Stuporous	Stuporous to verbal response	Complete recovery
		Day 1	Day 2	Day 3	Day 4
Sodium (mEq/L)	136-146	113	117	125	135
Potassium (mEq/L)	3.5-5.1	3.4	3.5	3.1	3.5
Chloride (mEq/L)	98-106	80	84	93	98
Urea nitrogen (mg/dL)	7-20	6.2	9	12.3	6.4
Creatinine (mg/dL)	0.6-1.2	0.51	0.61	0.56	0.45
Glucose (mg/dL)	50-100	125
Osmolality (mOsm/kg)	275-300	233	-	-	278
Free T4 (ng/dL)	0.85-1.86	1.51
TSH (mIU/L)	0.17-4.05	1.77
Cortisol (mg/dL)	9.41-26.06	32.47
ADH (pg/mL)	0.0-6.7	49.87
Spot urinary analysis			-	-
Sodium (mEq/L)		122	-	-	48
Potassium (mEq/L)		28.5	-	-	8
Chloride (mEq/L)		107	-	-	47
Urea nitrogen (mg/dL)		248.2	-	-	222.6
Creatinine (mg/dL)		16	-	-	6.4
Osmolality (mOsm/kg)		344	-	--	249
FENa (%)		3.4			2.5
FEUrea (%)		0.13			0.24

ADH: Antidiuretic hormone; FE_Na: Fractional excretion of sodium; FEU_rea: Fractional excretion of urea.