What is the appropriate evaluation and management for a 19‑year‑old female with type 1 diabetes who has experienced two episodes of vomiting over the past two weeks, with no recent changes in insulin therapy or blood glucose levels?

Evaluation and Management of Recurrent Vomiting in a 19-Year-Old Female with Type 1 Diabetes

This patient requires immediate evaluation for diabetic ketoacidosis (DKA), which is a life-threatening emergency that can present with vomiting even when blood glucose levels appear stable. 1, 2

Immediate Diagnostic Evaluation

Critical First Steps

• Check blood or urine ketones immediately – vomiting accompanied by diabetes may indicate DKA, which requires urgent intervention to prevent complications and death 1, 2
• Obtain venous blood gas to assess pH, pCO2, HCO3, and anion gap 3
• Measure serum electrolytes, particularly potassium, sodium, and chloride 1, 4
• Check blood glucose at time of evaluation (patient's home readings may not reflect current status) 3
• Assess blood urea nitrogen and creatinine to evaluate hydration status and renal function 2

Understanding the Clinical Context

Even though this patient reports "no recent changes in blood sugar levels," vomiting itself is a metabolic stressor that can precipitate DKA through counter-regulatory hormone release 2, 5. The stress of illness frequently aggravates glycemic control and necessitates more frequent monitoring 1. Infections are the most common precipitating factor for DKA (occurring in 73% of cases), and nausea/vomiting are the most common presenting symptoms (63% of cases) 5.

Risk Stratification Based on Ketone Results

If Ketones Are Present (Positive Blood or Urine Ketones)

Admit to hospital immediately for DKA management, even if glucose is not markedly elevated 1, 2:

• Initiate intravenous fluid resuscitation with isotonic saline (never use hypotonic fluids as initial therapy) 1
• Start continuous insulin infusion at 0.1 units/kg/hour intravenously 1, 4
• Monitor hourly vital signs, neurologic status, and capillary glucose 1
• Repeat electrolytes, blood glucose, and blood gases every 2-4 hours 1
• Monitor and replace potassium closely once urine output is established 1, 4
• Maintain a detailed flow sheet documenting all clinical observations, fluids, insulin dosing, and laboratory results 1

If Ketones Are Negative or Trace

Consider alternative diagnoses but maintain high suspicion:

• Evaluate for gastroparesis – affects 30-50% of patients with longstanding type 1 diabetes and presents with nausea, vomiting, early satiety, and postprandial fullness 2
• Rule out gastroenteritis, medication side effects, or other acute gastrointestinal pathology 2
• Check if patient is taking any SGLT2 inhibitors (contraindicated in type 1 diabetes but sometimes used off-label) – these can cause euglycemic DKA 1, 6

Management During Acute Illness

Insulin Management

Patients with type 1 diabetes must continue insulin during acute illness and often require supplemental doses 1:

• Never omit basal insulin, even if unable to eat 1
• Supplemental rapid-acting insulin may be required based on blood glucose and ketone levels 1
• The need for insulin continues and often increases during illness due to counter-regulatory hormones 1

Fluid and Nutrition Management

• Increase fluid intake to prevent dehydration with sodium-containing fluids (broth, tomato juice, sports drinks) 1
• Target 150-200 g carbohydrate daily (45-50 g every 3-4 hours) to prevent starvation ketosis 1
• If regular food is not tolerated, use liquid or soft carbohydrate sources: sugar-sweetened soft drinks, juices, soups, ice cream 1
• If nausea, vomiting, or obtundation prevents fluid and carbohydrate intake, prompt consultation or hospitalization is mandatory 1

Critical Pitfalls to Avoid

Common Errors in Management

• Do not assume stable home glucose readings rule out DKA – acute metabolic decompensation can occur rapidly, and symptoms alone are poor predictors 2, 3
• Do not delay ketone testing – the absence of marked hyperglycemia can delay recognition of DKA, particularly if patient is on SGLT2 inhibitors (which cause euglycemic DKA) 1, 6
• Do not stop insulin therapy during vomiting illness – this is the most dangerous error and can precipitate rapid DKA development 1, 7
• Do not dismiss recurrent vomiting as "just gastroparesis" without ruling out acute metabolic causes first 2

Special Considerations for Gastroparesis

If DKA is ruled out and gastroparesis is suspected 2:

• Optimize blood glucose control (acute hyperglycemia directly impairs GI motility in a dose-dependent manner) 2
• Blood glucose as low as 8 mmol/L (144 mg/dL) can significantly slow gastric emptying 2
• Consider gastric emptying scintigraphy with standardized low-fat egg white meal if symptoms persist 2
• Maintain blood glucose between 4-10 mmol/L (72-180 mg/dL) during any diagnostic testing 2

Patient Education and Follow-Up

Sick Day Management Education

Teach the patient to contact healthcare team immediately when 1:

• Blood glucose levels are persistently elevated
• Ketones are present in blood or urine
• Unable to keep down fluids or food
• Vomiting continues beyond 4-6 hours

Monitoring Requirements

• Test blood glucose and ketones every 2-4 hours during illness 1
• Maintain adequate fluid intake even if unable to eat solid food 1
• Keep glucagon kit available and ensure someone knows how to administer it 1