Can a patient with diabetes, taking Invokana (canagliflozin), who presented with abdominal pain, nausea, poor oral intake, acid reflux, belching, dizziness, and fatigue, and had lab results showing metabolic acidosis, be considered a victim of medical malpractice in Canada if their appendicitis diagnosis overshadowed their diabetic ketoacidosis (DKA) management, and they underwent surgery after 20+ hours of nil per os (NPO) and were discharged with severe metabolic acidosis?

Medical Malpractice Assessment: Failure to Diagnose and Manage Euglycemic DKA in SGLT2 Inhibitor Patient

This case represents a serious deviation from standard of care with potentially life-threatening consequences—the patient presented with classic euglycemic diabetic ketoacidosis (DKA) secondary to Invokana (canagliflozin) use, which was completely missed despite clear laboratory evidence of severe metabolic acidosis, and the patient was subjected to surgery with prolonged NPO status and discharged with critically dangerous metabolic derangements (bicarbonate 6, anion gap 21). 1, 2

Critical Failures in Clinical Management

Failure to Recognize Euglycemic DKA

The presenting laboratory values were diagnostic of severe metabolic acidosis requiring immediate recognition and treatment:

• pH 7.24 with bicarbonate 17 and anion gap 15 meets criteria for metabolic acidosis requiring urgent investigation 1, 2
• The combination of recent SGLT2 inhibitor use (Invokana discontinued only on presentation day), nausea, poor oral intake, abdominal pain, dizziness, and fatigue are classic presenting symptoms of euglycemic DKA 2, 3, 4
• The FDA explicitly warns that SGLT2 inhibitors cause euglycemic DKA, making this a known and preventable complication 2

Failure to Perform Essential Diagnostic Testing

The absence of ketone testing (serum beta-hydroxybutyrate or urine ketones) in a patient on SGLT2 inhibitors presenting with metabolic acidosis represents a fundamental diagnostic failure. 1, 2

• The American Diabetes Association requires measurement of serum ketones as part of essential laboratory evaluation when DKA is suspected 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA 1
• Emergency physicians must consider euglycemic DKA in any patient on SGLT2 inhibitors presenting with nausea, vomiting, abdominal pain, and clinical dehydration, regardless of blood glucose levels 4

Catastrophic Progression During Hospitalization

The worsening metabolic acidosis from bicarbonate 17 to 13 without ketone testing or appropriate intervention demonstrates ongoing failure to recognize the severity of the patient's condition. 1, 2

• This progressive decline should have triggered immediate reassessment and ketone measurement 1
• The patient required continuous monitoring every 2-4 hours to determine electrolytes, glucose, and venous pH 1

Inappropriate Surgical Decision and NPO Management

Proceeding with surgery after 20+ hours of NPO in a patient with unrecognized euglycemic DKA directly contradicts established guidelines for SGLT2 inhibitor management. 5

• SGLT2 inhibitors should be omitted the day before and day of procedures, with patients adhering to recommended fasting guidelines and avoiding prolonged starvation times 5
• Prolonged fasting in SGLT2 inhibitor patients increases ketone generation and DKA risk 5
• In settings of unavoidable prolonged fasting, glucose-containing intravenous fluids should be considered to mitigate ketone generation 5

Dangerous Discharge with Life-Threatening Laboratory Values

Discharging a patient with bicarbonate 6, anion gap 21, and potassium 5.5 represents an immediate threat to life and gross negligence. 1, 2

• DKA resolution requires ALL of the following: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 1
• Bicarbonate of 6 indicates severe, life-threatening acidosis requiring intensive care unit admission and continuous monitoring 1, 6
• Potassium 5.5 in the setting of severe acidosis suggests total body potassium depletion with risk of life-threatening arrhythmias as acidosis corrects 1

Standard of Care Requirements That Were Violated

Initial Assessment Requirements

When metabolic acidosis is identified, the following are mandatory:

• Diagnostic confirmation requires arterial pH, serum bicarbonate, calculated anion gap, and presence of ketonemia or ketonuria 1
• Essential laboratory evaluation must include serum ketones when DKA is suspected 1
• Identify precipitating factors, particularly SGLT2 inhibitors 1

Treatment Requirements for Confirmed DKA

Had euglycemic DKA been properly diagnosed, treatment should have included:

• Isotonic saline at 15-20 mL/kg/hour during the first hour 1, 2
• Continuous intravenous insulin at 0.1 units/kg/hour for critically ill patients 1
• Potassium monitoring and replacement to maintain 4-5 mEq/L 1
• Blood draws every 2-4 hours to monitor electrolytes, glucose, pH, and anion gap 1
• Surgery should have been postponed until DKA was completely resolved 5, 1

Discharge Criteria Violations

No patient should be discharged until metabolic parameters normalize:

• Serum bicarbonate must be ≥18 mEq/L (patient was 6) 1
• Anion gap must be ≤12 mEq/L (patient was 21) 1
• Venous pH must be >7.3 1

Canadian Medical Malpractice Context

Elements of Malpractice in Canada

For medical malpractice to be established in Canada, four elements must be proven:

1. Duty of care existed - Clearly established in this physician-patient relationship
2. Breach of standard of care - Multiple documented failures to meet established guidelines 5, 1, 2
3. Causation - The failures directly resulted in harm (prolonged acidosis, dangerous discharge state)
4. Damages - The patient suffered harm from the substandard care

Specific Breaches of Standard of Care

This case demonstrates multiple, compounding failures:

• Failure to recognize a known complication of SGLT2 inhibitors despite classic presentation 2, 3, 4
• Failure to perform essential diagnostic testing (ketones) when indicated 1
• Failure to monitor and respond to worsening metabolic acidosis 1
• Inappropriate surgical decision in unstable metabolic state 5
• Dangerous discharge with life-threatening laboratory abnormalities 1

Potential for Serious Harm

The discharge state (bicarbonate 6, AG 21, K+ 5.5) placed the patient at immediate risk for:

• Cardiac arrhythmias and sudden death 1
• Respiratory failure from severe acidosis 6
• Cerebral edema 7
• Multi-organ failure 6

Common Pitfalls That Occurred in This Case

The primary pitfall was anchoring bias—once appendicitis was diagnosed, all symptoms were attributed to it, ignoring the metabolic crisis. 2, 4

• Euglycemic DKA is challenging to identify because of absent marked hyperglycemia, often leading to delayed diagnosis 4
• Emergency physicians must maintain high clinical suspicion for euglycemic DKA in SGLT2 inhibitor patients regardless of glucose levels 2, 4
• The absence of substantial blood glucose abnormalities does not exclude DKA 3, 4

The second critical pitfall was failure to recognize that metabolic acidosis requires explanation—it should never be ignored or attributed to another diagnosis without investigation. 1, 2