Fatal Outcome with Sodium Phosphate Enemas

INCIDENT DESCRIPTION

A hospitalized older adult required bowel preparation for a procedure. The hospital’s CPOE system included several standardized order sets for bowel preparation, one of which was selected and modified by the prescriber to reflect the timing of the procedure. An order similar to the following was entered into the health record:

BACKGROUND

Sodium phosphate rectal products are used to treat constipation (at a recommended maximum of 1 enema daily)¹ and as bowel preparation before a colonoscopy or other related procedure. For bowel preparation, up to 2 enemas may be given, spaced 30–60 minutes apart, several hours before the procedure.^2,3 Sodium phosphate products carry significant risks if used incorrectly. Both Health Canada and the US Food and Drug Administration have issued warnings about potential electrolyte abnormalities and have shared reports of serious effects on the heart and kidney.^1,4

CPOE systems with clinical decision support can improve medication safety by guiding users to order medications in a standardized manner consistent with evidence-informed guidelines.⁵ For clinical decision support to be effective, adequate and up-to-date information must provide prescribers with actionable warnings and timely advice (e.g., embedded maximum dose alerts, potential drug–drug interactions).⁵ Advanced clinical decision support in the CPOE could also take into account the patient’s renal function, age, and comorbidities to ensure that dosing guidance and maximum dosing limits offered to the prescriber are appropriate for the particular patient.^5,6

ANALYSIS FINDINGS

Analysis of the incident identified multiple contributing factors, including the following:

• Auto-population of the start date in the selected standardized order set, which resulted in an earlier start date than intended.
• Absence of alerts in the electronic medication systems (CPOE, pharmacy information system, and eMAR) to communicate to health care providers that the dose, as entered, exceeded the maximum recommended daily dose.
• Supply and storage of sodium phosphate products as stock in the patient care area (i.e., outside of the pharmacy and profiled automated dispensing cabinets [ADCs]), which allowed for use of large quantities without system-based checks.
• Automation complacency (i.e., the monitoring of an automated process less frequently or with less vigilance than optimal because of a low degree of suspicion of error and a strong belief in the accuracy of the technology7), which allowed the incorrect dose to persist throughout the medication-use process.
• Possible knowledge deficits related to appropriate administration of sodium phosphate enemas and risk of harm with overuse.

The analysis also included consideration of practices in other Canadian hospitals to identify additional system vulnerabilities that might exist and to inform recommendations. The following are examples of processes that demonstrate these vulnerabilities:

• Auto-verification of orders for sodium phosphate enemas, without a pharmacist check for appropriate indications, dosing, and drug–drug interactions
• Documentation of the administration of these products in the patient care section of the health record (rather than on the eMAR), without safeguards such as bar coding, maximum dose alerts, drug interaction alerts, and other drug information.

RECOMMENDATIONS

Technology-related recommendations are presented below, some of which were identified by the reporting hospital.

• Remove q1h as a frequency option for bowel preparation order set.
  • A bowel preparation order set can incorporate up to 2 doses at specified times to reflect the patient’s needs and timing of the procedure.
  • Usability of the order sets and order parameters can be tested with health care providers.
• Create a forcing function in the electronic medication systems (e.g., CPOE, pharmacy information system, and eMAR) that requires a reason for override, to reduce the risk of more than 2 sodium phosphate enemas being ordered, dispensed, and administered to a particular patient within 24 hours.
• Routinely test maximum dose alerts in electronic medication systems, with consideration for alert fatigue.⁸
• Build easy access to the eMAR from the pharmacy information system to enable a visual check of how the order is displayed in the eMAR, as part of the pharmacist’s order verification process.
• Review the eMAR against the prescriber’s orders to identify discrepancies, as part of the nurse’s order verification process.
• Place sodium phosphate enemas under the control of the pharmacy, requiring clinical verification, bar-coded inventory management, and patient-specific doses (e.g., retrieval from profiled ADCs).

TEST CASE

Test your electronic medication systems using the described incident as a test case to determine whether this error could happen in your organization.

1. Open an electronic health record in the CPOE test environment.
2. Select a test patient.
3. Input “sodium phosphate enema” and review the ordering options.
4. Input the medication details from the problematic test order in the incident description above.
5. Determine whether safeguards exist, as outlined in the chart below.
6. Address any discrepancies identified, and incorporate recommendations from this bulletin.

CONCLUSION

Sodium phosphate administered by enema can cause significant harm when given in excess. Proactive testing of the CPOE, pharmacy information, and eMAR systems for technology-related vulnerabilities can identify gaps and support patient safety. This learning may be applicable to other medications for which several doses may be ordered over a short period of time. Please consider sharing your experience with this test case and related system improvements at info@ismpcanada.ca.