Management of Elevated RBC/Hematocrit in a Patient with Uncontrolled Diabetes
The elevated RBC and hematocrit are most likely secondary to dehydration from uncontrolled diabetes with osmotic diuresis, and your immediate priority is to ensure the patient receives appropriate fluid resuscitation and glycemic control in the emergency department. 1
Immediate Assessment in the Emergency Department
The ER team should focus on:
Evaluate for hyperglycemic hyperosmolar state (HHS) - Check serum osmolality, electrolytes (particularly sodium and potassium), blood glucose, and assess mental status, as HHS presents with severe hyperglycemia, marked hyperosmolality, and dehydration without significant ketoacidosis 2
Assess hydration status - Look for signs of severe volume depletion including hypotension, tachycardia, poor skin turgor, dry mucous membranes, and altered mental status, as water losses exceed sodium losses in osmotic diuresis 2
Rule out concurrent acute illness - Infection, myocardial infarction, or other precipitating factors that may have triggered the diabetic decompensation 1, 3
Obtain baseline labs - In addition to the CBC you have, ensure HbA1c, comprehensive metabolic panel, urinalysis, and consider cardiac biomarkers if cardiovascular disease is suspected 1
Understanding the Hematocrit Elevation
The elevated RBC (5.65, normal 3.77-5.28) and hematocrit (49.3%, normal 34.0-46.6%) in this clinical context represent:
Hemoconcentration from osmotic diuresis - Uncontrolled diabetes causes glucose-induced osmotic diuresis leading to severe water depletion that exceeds electrolyte losses, resulting in hypertonic dehydration and elevated hematocrit 2
Not true polycythemia - The normal MCV (87), MCH (28.0), and MCHC (32.0) indicate this is concentration rather than a primary bone marrow disorder 2
Expected Emergency Department Management
Fluid Resuscitation
Initial fluid choice: 0.9% normal saline should be administered rapidly (1-2 liters in the first 1-2 hours) until vital signs stabilize and adequate organ perfusion is restored 2
Transition to hypotonic fluids: Once hemodynamically stable, switch to 0.45% saline to correct the free water deficit, as the primary problem is hypertonic dehydration 2
Monitor response: Expect the hematocrit to normalize as intravascular volume is restored and the hemoconcentration resolves 2
Glycemic Control
Insulin therapy: Administer 10-15 units of regular insulin as IV bolus, followed by continuous infusion at approximately 0.1 units/kg/hour 2
Target glucose reduction: Once blood glucose approaches 250-300 mg/dL (13.9-16.7 mmol/L), add 5% dextrose to IV fluids and reduce insulin infusion rate to prevent precipitous drops 2
Avoid hypoglycemia: This is critical as hypoglycemia can trigger arrhythmias and worsen outcomes 1
Electrolyte Management
Potassium replacement: Expect significant total body potassium depletion even if serum levels appear normal initially; replacement will be needed as insulin drives potassium intracellularly 2
Monitor frequently: Check electrolytes every 2-4 hours during acute management 2
Your Role as the Outpatient Provider
Communication with ER
Provide the ER team with:
Recent HbA1c value - This helps determine chronic glycemic control and guides discharge planning 1
Current diabetes medications - What the patient was taking (or not taking) prior to presentation 1
Known complications - Any history of retinopathy, nephropathy, neuropathy, or cardiovascular disease 1
Social factors - Medication adherence issues, access to care, or other barriers to diabetes management 1
Post-Discharge Planning
Once the patient is stabilized and discharged:
Schedule urgent follow-up within 3-7 days to reassess glycemic control and adjust medications 1, 4
Target HbA1c of 7-8% for most patients with diabetes, individualized based on comorbidities, age, and hypoglycemia risk 1
Intensify therapy based on admission HbA1c: If HbA1c was 7-9%, add basal insulin or intensify current regimen; if >9%, consider basal-bolus insulin at 80% of inpatient dose or combination therapy 1, 4
Implement comprehensive diabetes care: Ensure annual screening for microalbuminuria, retinal examination, foot examination, and lipid management 1
Consider SGLT2 inhibitors or GLP-1 receptor agonists if the patient has or is at high risk for cardiovascular disease, as these reduce cardiovascular events and mortality 1
Common Pitfalls to Avoid
Don't attribute elevated hematocrit to primary polycythemia without first correcting dehydration - recheck CBC after adequate hydration 2
Don't delay insulin therapy while waiting for confirmatory tests if clinical presentation suggests hyperglycemic crisis 2, 3
Don't use sliding-scale insulin alone for inpatient or discharge management - this is inadequate for glycemic control 5
Don't fail to identify and treat precipitating causes such as infection, medication non-adherence, or acute coronary syndrome, as these drive the high mortality associated with hyperglycemic crises 1, 2
Don't assume the patient will need lifelong insulin - many patients with type 2 diabetes presenting with HHS can be managed with oral agents or non-insulin injectables after recovery 2