Endoscopy 2013; 45(S 02): E269-E270
DOI: 10.1055/s-0033-1344568
Cases and Techniques Library (CTL)
© Georg Thieme Verlag KG Stuttgart · New York

Seizures due to hyponatremia following polyethylene glycol preparation; a report of two cases

M. K. Baeg
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
J. M. Park
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
S. H. Ko
2  Division of Endocrinology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
G. J. Min
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
K. J. Lee
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
J. H. Yang
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
C. H. Lim
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
S. W. Kim
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
,
M.-G. Choi
1  Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
› Author Affiliations
Further Information

Publication History

Publication Date:
05 September 2013 (online)

Colonoscopic screening and adenoma removal have been reported to reduce deaths from colorectal cancer [1] [2]. Proper bowel preparation is needed for adequate visualization of the colonic mucosa [3]. Issues concerning the safety of oral sodium phosphate have been raised, so guidelines recommend the use of polyethylene glycol (PEG) [3] [4]. It has been reported that using PEG for bowel cleansing prior to colonoscopy does not cause any electrolyte disturbances [5]. However, there have also been reports of serious adverse events related to PEG use [4] [6].

We report here on two women who were admitted with generalized tonic–clonic seizures induced by precolonoscopic PEG preparation. Their pertinent clinical and laboratory data are shown under patients #1 and #2 in [Table 1]. They were treated with intravenous sodium solutions; as their sodium levels recovered, they both showed complete neurologic recovery. Follow-up visits showed normal sodium levels without neurologic deficits.

Table 1

A summary of the clinical findings in our two patients (#1 and #2) and other patients reported in the literature with polyethylene glycol (PEG)-related hyponatremia.

Patient number

1

2

3 [7]

4 [7]

5 [8]

6 [9]

Age

70

65

51

62

59

73

Sex

Female

Female

Male

Female

Female

Female

Past history/underlying disease

Hypertension, osteoporosis, mild stenosis of internal carotid artery

Breast cancer, total thyroidectomy and radioiodine therapy

Diabetes, end-stage renal failure

Hypertension, hyperlipidemia

Hysterectomy with oophorectomy

Hypothyroidism, depression

Prescription drugs

Amlodipine, ibandronic acid, clopidogrel

Levothyroxine

Amlodipine, atenolol, furosemide, calcium acetate, omeprazole

Thiazide

Estradiol, aspirin

Levothyroxine, citalopram

Preparation methods

4 L PEG and 3 L clear water

4 L PEG

N/A

4 L PEG

3 L PEG and 4 L weak tea

255 g PEG and 64 ounces Gatorade

Clinical presentation

Seizure

Seizure

Emesis, idioventricular rhythm, cardiac arrest

Seizure

Confusion

Seizure

Blood pressure, mmHg

190/100

156/85

167/78

130/90

110/70

Within normal range

Pulse, beats per min

84

86

103

90

60

Within normal range

Sodium, mmol/L

 Baseline

140

144

138

138

N/A

N/A

 Lowest

110

127

122

116

120

117

 Post-treatment

138

141

N/A

130

138

131

Potassium, mmol/L

3.4

4.3

5.1

3.9

4.6

3.3

Chloride, mmol/L

72

104

94

79

N/A

79

Bicarbonate, mmol/L

17.3

17.3

20

26

17.2

21

Urea, mg/dL

11.8

14.6

24.3

2.5

N/A

6

Creatinine, mg/dL

0.67

0.71

7.7

0.6

0.9

0.6

Glucose, mg/dL

148

235

95.5

N/A

93

N/A

Brain CT/MRI findings

No abnormalities

No abnormalities

Not done

Cerebral edema

No abnormalities

Not done

Treatment

IV 3 % saline

IV normal saline

None

IV 3 % saline

IV normal saline

IV 2 % saline, then NaCl tablets & water restriction

Outcome

Complete recovery

Complete recovery

Death

Complete recovery

Complete recovery

Complete recovery

N/A, not available; IV, intravenous; NaCl, sodium chloride.

Along with the characteristics of our patients, the clinical findings of the previously reported cases of hyponatremia due to PEG are also shown in [Table 1]. All of the patients were aged over 50, with four being over 60. Patient #3 had pre-existing end-stage renal disease and patient #4 was taking thiazide diuretics, which would have impaired her ability to excrete water [7]. Patient #5 was similar to patient #1 in that she showed normal renal, thyroid, and adrenal function, but had ingested 4 L of fluids in addition to the 3 L of PEG [8]. Nonosmolar antidiuretic hormone stimulation combined with old age and a large volume of fluid most likely caused her hyponatremia. The final patient had been taking serotonin reuptake inhibitors, had inadequate thyroid replacement, and was aged over 70, which would have further aggravated her hyponatremia [9].

Our two patients developed hyponatremia even with the relatively safe laxative PEG, which raises safety issues that should be carefully considered when instituting colonoscopic procedures.

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