Incidence of Hyponatremia in PEG-SD Compared to PEG-ELS

• Development of serum electrolytes levels outside the normal range for [ Time Frame: blood drawn 30 minutes post colonoscopy ] [ Designated as safety issue: Yes ]
  Sodium, chloride, potassium, calcium
• Change from baseline for serum electrolytes [ Time Frame: blood drawn 30 minutes post colonoscopy ] [ Designated as safety issue: Yes ]
  Sodium, chloride, potassium, calcium
• Change in renal function from baseline [ Time Frame: blood drawn pre colonoscopy and 30 minutes post colonoscopy ] [ Designated as safety issue: Yes ]
  Creatinine, calculated GFR
• Changes in the following from baseline a. Serum vasopressin b. Serum osmolality c. Urine electrolytes and osmolality [ Time Frame: blood drawn pre colonoscopy and 30 minutes post colonoscopy ] [ Designated as safety issue: Yes ]
• Serum cortisol and TSH levels for only patients who develop hyponatremia [ Time Frame: blood drawn 30 minutes post colonoscopy ] [ Designated as safety issue: Yes ]
• Hemodynamic/volume changes at baseline and immediately prior to colonoscopy [ Time Frame: hemodynamic measurments taken pre and post colonoscopy ] [ Designated as safety issue: Yes ]
  • Weight
  • Blood pressure supine and upright - systolic, diastolic
  • Pulse supine and upright
  • Development of orthostatic change: yes/no
  • Development of orthostatic symptoms - light-headed, dizzy, diaphoretic, etc.: yes/no
• Adverse Events - Incidence and severity using 10-point Likert scale [ Time Frame: 1 hour post colonoscopy assessment ] [ Designated as safety issue: Yes ]
  • GI - nausea, vomiting, abdominal pain, bloating
  • Light headedness
• Prep Completion: <90% vs. > 90% [ Time Frame: one time assessment pre colonoscopy ] [ Designated as safety issue: No ]
• Indication for colonoscopy: Screen/Surveillance vs. Symptom [ Time Frame: one time assessment pre colonoscopy ] [ Designated as safety issue: No ]
• Assessment of independent risk factors for hyponatremia [ Time Frame: one time assessment pre colonoscopy ] [ Designated as safety issue: No ]
  • Age
  • Sex
  • Race
  • Medications
  • Medical history
  • BMI
  • Anxiety - Beck scale

  • Fluid intake for 24 hours prior to colonoscopy (not including the prep or fluids required to accompany the prep); patients will be shown a liter container to assist with their estimate.

    i. Less than 3 Liters ii. 3-5 liters iii. More than 5 liters

• Efficacy [ Time Frame: endoscopist will evaluate during colonoscopy ] [ Designated as safety issue: No ]
  • Whole colon prep: adequate (excellent/good) vs. inadequate (fair/poor)
  • Cecal or small bowel intubation - Yes/No

Objective: To compare the incidence of peri-colonoscopy hyponatremia associated with PEG 3350 + sports drink (PEG-SD) versus PEG 3350-electrolyte solution + sodium sulfate + sodium ascorbate and ascorbic acid (PEG-ELS).

Hypothesis: As compared to PEG-SD, hyponatremia occurs significantly less often with PEG-ELS.

Looking at the Incidence of Hyponatremia With Two Commonly Prescribed Purgatives for Colonoscopy-Polyethylene Glycol 3350 With a Sports Drink (PEG-SD) Compared to Polyethylene Glycol 3350 With Electrolyte Solution (PEG-ELS)

• Drug: PEG-SD

  PEG-SD

  • Bisacodyl: two 5-mg tablets at 3 pm day prior
  • 1L sports drink* (labeled #1) with PEG-3350 119 gram bottle (labeled #1) at 6 pm night prior

  • 1L SD* (labeled #2) with PEG-3350 119 gram bottle (labeled #2) starting 4 hrs prior to colonoscopy

    • Same flavor, non-red Gatorade® for all patients.
  Other Name: Miralax
• Drug: PEG-ELS
  • 1L + 500 cc clear liquids at 6 pm night prior
  • 1L + 500 cc clear liquids starting 4 hours prior to colonoscopy
  Other Name: MoviPrep

• Active Comparator: PEG-ELS
  Intervention: Drug: PEG-ELS
• Active Comparator: PEG-SD
  Intervention: Drug: PEG-SD

Inclusion Criteria:

• Adults age 18 years or older scheduled for elective outpatient colonoscopy: 8am - noon.

Exclusion Criteria:

• Unable or unwilling to consent
• Pregnant
• Breast feeding

• Significant psychiatric illness

  -> 50% colon resection

• Bowel obstruction
• History of hyponatremia (Serum sodium <135 mmol/L)
• End stage renal disease on dialysis
• History of chronic kidney disease (other than kidney stones)

• Decompensated cirrhosis, including:

  • History of bleeding due to portal hypertension (varices, gastropathy, etc) within 3 months
• Hepatic encephalopathy (not controlled with medications) within 3 months
• Clinical presence of ascites
• Active cardiac disease
• Recent myocardial infarction (<4weeks)
• Unstable angina
• Congestive heart failure NYHA Functional Class Stage III or IV
• Stage III: Marked limitation of activity. Less than ordinary activity (e.g. walking short distances, 20-100 m) causes fatigue, palpitations, dyspnea. Comfortable at rest.
• Stage IV: Severe limitations. Experiences symptoms even while at rest. Mostly bedbound patients.

Exclusion Criteria (post-enrollment), from baseline labs:

• Serum creatinine > 1.5 mg/dL
• Serum potassium < 3.3 or > 5.5 mmol/L
• Serum sodium < 135 mmol/L or >150 mmol/L
• Serum calcium < 8.0 or > 11.0 mg/dL