Differential Diagnosis for DKA Presenting with Vomiting Only
In a patient with confirmed diabetic ketoacidosis who presents with vomiting as the sole symptom, the key differentials to consider are precipitating causes of the DKA itself, not alternative diagnoses, since DKA is already established. The vomiting is a direct consequence of the metabolic derangement, but identifying what triggered the DKA is critical for proper management 1, 2.
Primary Precipitating Factors to Investigate
Infectious Causes (Most Common)
- Infection is the leading precipitating factor for DKA and must be actively sought 1, 2
- Obtain bacterial cultures from urine, blood, and throat if infection is suspected 1, 2
- Administer appropriate antibiotics if infection is identified 1, 2
- Common sites include urinary tract, respiratory tract, and soft tissue infections 3
Insulin-Related Issues
- Insulin omission or inadequacy is a major precipitating cause, particularly in patients with type 1 diabetes 1, 4
- New diagnosis of diabetes (patient may be unaware of their condition) 3
- Nonadherence to prescribed insulin therapy 3
Medication-Induced DKA
- SGLT2 inhibitors can precipitate euglycemic or typical DKA and must be discontinued immediately 1
- These medications should not be restarted until 3-4 days after metabolic stability is achieved 1
- Glucocorticoid use can precipitate hyperglycemia and DKA 5
Acute Cardiovascular Events
- Myocardial infarction can both precipitate and be masked by DKA 5, 1
- Obtain electrocardiogram as part of initial assessment 1, 2
- Consider cardiac biomarkers if clinically indicated 1
Acute Neurological Events
- Cerebrovascular accident (stroke) can precipitate DKA 5, 1
- Assess for focal neurological deficits during physical examination 1
Gastrointestinal Causes
- Pancreatitis can both cause and be caused by DKA 1, 6
- Acute gastric dilatation may occur in severely obtunded patients 7
- Consider abdominal imaging if acute abdominal signs are present 7
Other Precipitating Factors
Critical Diagnostic Workup
The initial laboratory evaluation must include 1, 2:
- Plasma glucose, blood urea nitrogen/creatinine
- Serum ketones (β-hydroxybutyrate preferred over nitroprusside method) 1, 2
- Electrolytes with calculated anion gap
- Osmolality
- Arterial blood gases or venous pH
- Complete blood count with differential
- Urinalysis and urine ketones
- Electrocardiogram 1, 2
Common Pitfall to Avoid
Do not assume vomiting is simply a symptom of DKA without investigating underlying precipitating causes. Failure to identify and treat the precipitating factor (especially infection or myocardial infarction) can lead to treatment failure and increased mortality 1, 6. The vomiting itself is a consequence of the metabolic acidosis and ketosis, but the trigger must be addressed concurrently with DKA management 5, 1.
Management Priority
While investigating precipitating causes, immediately initiate DKA treatment with isotonic saline at 15-20 mL/kg/hour, continuous IV insulin at 0.1 units/kg/hour (after confirming potassium ≥3.3 mEq/L), and electrolyte replacement 1, 2. Treatment of the underlying cause must occur simultaneously with correction of the metabolic derangement 5, 1.