How do I report a case to the college of physicians and surgeons where a patient with diabetes, taking Invokana (canagliflozin), was not informed of the increased risk of diabetic ketoacidosis (DKA) during surgery with NPO (nil per os) status?

Reporting Failure to Disclose SGLT2 Inhibitor-Associated DKA Risk During Surgical Consent

Understanding the Standard of Care Violation

The failure to disclose the increased risk of diabetic ketoacidosis (DKA) with Invokana (canagliflozin) during perioperative NPO status represents a breach of informed consent, as current guidelines explicitly require withholding SGLT2 inhibitors at least 3 days before surgery and educating patients about DKA risk. 1, 2

Established Perioperative Management Standards

The FDA-approved drug label for Invokana explicitly states: "Withhold INVOKANA at least 3 days, if possible, prior to surgery or procedures associated with prolonged fasting" 1. This is not a suggestion—it is a formal dosing recommendation that should be part of standard perioperative care.

Multiple authoritative guidelines reinforce this requirement:

• The American College of Cardiology/American Heart Association 2024 guidelines explicitly recommend SGLT2 inhibitors be withheld 3-4 days before elective noncardiac surgery to reduce perioperative metabolic acidosis risk 3
• The American Diabetes Association recommends discontinuing canagliflozin 3-4 days before scheduled surgery to prevent life-threatening DKA 2
• The 2025 UK multidisciplinary consensus from the Association of Anaesthetists and multiple specialty societies requires that patients be provided written sick-day rules at pre-operative assessment, including information on DKA symptoms and risk-reduction strategies 4

Documented Risk Magnitude

The evidence demonstrates clear perioperative risk:

• Patients taking SGLT2 inhibitors have significantly higher perioperative DKA risk (1.02 vs. 0.69 per 1000 patients, OR 1.48) 4
• Surgery is explicitly listed as a precipitating condition for DKA in the FDA drug label 1
• The FDA label warns that "precipitating conditions for diabetic ketoacidosis include surgery, volume depletion, and reduced caloric intake" 1
• Postmarketing reports document fatal events of ketoacidosis in patients with type 2 diabetes using SGLT2 inhibitors 1

Building Your Complaint Case

Key Elements to Document

Document the specific informed consent failures:

• The surgical consent form should be reviewed to confirm whether SGLT2 inhibitor-associated DKA risk was disclosed 4
• Verify whether the medication history was obtained during pre-operative assessment 4
• Determine if the surgeon or anesthesiologist documented awareness of canagliflozin use 4
• Confirm whether the drug was continued or discontinued, and if discontinued, the timing relative to surgery 1

Establish the standard of care breach:

• The FDA drug label constitutes the legal standard for prescribing information 1
• Multiple specialty society guidelines from 2024-2025 establish the contemporary standard of care 4, 2, 3
• The failure to provide written sick-day rules at pre-operative assessment violates the 2025 consensus recommendations 4

Evidence of Harm or Potential Harm

If DKA occurred:

• Obtain all laboratory values showing metabolic acidosis, ketone levels, and glucose levels 5
• Document the clinical presentation (nausea, vomiting, abdominal pain, shortness of breath) 1
• Note if glucose was relatively normal (euglycemic DKA), as this is characteristic of SGLT2 inhibitor-associated DKA 6, 7
• Document the duration of ketoacidosis and glucosuria, which can persist 3+ days after discontinuation 1, 8

Even if DKA did not occur:

• The failure to disclose a known, serious, potentially fatal risk constitutes inadequate informed consent regardless of outcome 1
• The patient was exposed to unnecessary risk that could have been mitigated 4, 2

Filing the Complaint with the College of Physicians and Surgeons

Jurisdictional Considerations

Contact your provincial/state College of Physicians and Surgeons to obtain their specific complaint forms and procedures. Most colleges have dedicated complaint departments with standardized processes.

Structure Your Written Complaint

Opening statement: Clearly state that you are filing a complaint regarding failure to obtain proper informed consent for surgery in a patient taking canagliflozin (Invokana), specifically the failure to disclose the increased risk of perioperative diabetic ketoacidosis.

Chronological narrative:

• Date of surgical consent
• Patient's medication regimen including canagliflozin
• Surgical procedure performed and NPO duration
• Clinical outcome (whether DKA occurred or not)
• Discovery that the risk was not disclosed

Standard of care violations:

• Quote the FDA drug label requirement to withhold canagliflozin at least 3 days before surgery 1
• Reference the American Diabetes Association and ACC/AHA 2024 guidelines requiring 3-4 day discontinuation 2, 3
• Cite the 2025 UK multidisciplinary consensus requirement for written sick-day rules and DKA education at pre-operative assessment 4
• Note that the FDA label explicitly lists surgery as a precipitating condition for DKA and warns of fatal events 1

Specific failures:

• Failure to identify canagliflozin during pre-operative medication review
• Failure to discontinue the medication appropriately
• Failure to educate the patient about DKA risk and symptoms
• Failure to provide written sick-day rules
• Failure to document informed consent discussion about this specific risk

Supporting Documentation to Include

• Copy of surgical consent form
• Pre-operative assessment documentation
• Medication list or pharmacy records showing canagliflozin prescription
• Operative report
• Laboratory results (if DKA occurred)
• Copies of relevant FDA drug label sections 1
• Copies of guideline recommendations 4, 2, 3

Critical Pitfalls to Avoid

Do not delay filing: Most colleges have time limits for filing complaints (often 1-2 years from the incident or from when you became aware of the issue).

Do not make this about general dissatisfaction: Focus specifically on the informed consent failure regarding a documented, guideline-established risk 4, 1.

Do not overstate the case: Stick to facts and established standards. The FDA label and multiple 2024-2025 guidelines provide unambiguous support 4, 2, 3, 1.

Recognize that euglycemic DKA is particularly dangerous: Blood glucose may be relatively normal (even <250 mg/dL) while severe ketoacidosis develops, making diagnosis more difficult 1, 6, 7. This underscores why prevention through proper discontinuation is critical.

Understand the persistence of risk: Urinary glucose excretion persists for 3 days after discontinuing canagliflozin, with postmarketing reports of ketoacidosis lasting >6 days and up to 2 weeks after discontinuation 1, 8. This prolonged risk period makes pre-operative discontinuation even more important.

Additional Considerations

The 2025 consensus acknowledges uncertainty but still mandates disclosure: While the evidence base has limitations, the consensus statement explicitly requires that "shared decision-making between clinicians and patients" be supported, which cannot occur without disclosure of known risks 4.

Fatal outcomes are documented: The FDA label specifically warns of "postmarketing reports of fatal events of ketoacidosis in patients with type 2 diabetes mellitus using SGLT2 inhibitors, including INVOKANA" 1. This elevates the seriousness of the consent failure.

The standard applies even if surgery was urgent: While emergency surgery poses challenges, the informed consent obligation to disclose known serious risks remains, and documentation of the risk-benefit discussion becomes even more important 4.