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.

Table 2 Clinical findings of patients with polyethylene glycol related hyponatremia

	Patient 1[20]	Patient 2[20]	Patient 3[6]	Patient 4[6]	Patient 5[19]	Patient 6[10]
Age, yr	51	62	70	65	59	73
Gender	M	F	F	F	F	F
Past history				Breast Cancer, Total thyroidectomy and RAIT	Hysterectomy withoophrectomy
Underlying disease	Diabetes, ESRD	HTN, Hyperlipidemia	HTN, Osteoporosis,			Hypothyroidism, Depression
Prescription drugs	Amlodipine, Atenolol, Furosemide, Phoslo, Prilosec	Thiazide	Amlodipine, Ibandronic acid, clopidogrel	Levothyroxine	Estradiol, Aspirin	Levothyroxine, citalopram
Preparation methods	N/A	4L PEG	4L PEG + 3 L clear water	4L PEG	3L PEG + 4L weak tea	255g PEG + 64 ounces Gatorade
Sodium (mmol/L)
Baseline	138	138	140	144	N/A	N/A
Lowest	122	116	110	127	120	117
Post-treatment	N/A	130	138	141	138	131
Potassium (mmol/L)	5.1	3.9	3.4	4.3	4.6	3.3
Chloride (mmol/L)	94	79	72	104	N/A	79
Bicarbonate (mmol/L)	20	26	17.3	17.3	17.2	21
Urea Nitrogen (mg/dL)	24.3	2.5	11.8	14.6	N/A	6
Creatinine (mg/dL)	7.7	0.6	0.67	0.71	0.9	0.6
Glucose (mg/dL)	95.5	N/A	148	235	93	N/A
Clinical Presentation	Emesis, IVR, cardiac arrest	Seizure	Seizure	Seizure	Confused mentality	Seizure
Blood pressure (mmHg)	167/78	130/90	190/100	156/85	110/70	Within normal
Pulse (/min)	103	90	84	86	60	Within normal
Brain CT/MRI	Not done	Cerebral edema	No abnormalities	No abnormalities	No abnormalities	Not done
Treatment	None	IV 3% Saline	IV 3% Saline	IV Normal Saline	IV Normal saline	IV 2% Saline, followed by NaCl tablets and water restriction
Outcome	Death	Complete recovery	Complete recovery	Complete recovery	Complete recovery	Complete recovery

ESRD: End stage renal disease; HTN: Hypertension; IVR: Idioventricular rhythm; IV: Intravenous; N/A: Not available; PEG: Polyethylene glycol; RAIT: Radioiodine therapy.