What is the best management approach for an elderly female patient with insulin-dependent diabetes mellitus (IDDM), Alzheimer's disease, Chronic Obstructive Pulmonary Disease (COPD), Heart Failure with Reduced Ejection Fraction (HFrEF), hypertension, and a history of cardiac catheterization, presenting with hyperosmolar hyperglycemic non-ketotic coma (HHS), severe hyperglycemia, and elevated serum osmolality?

Management of Hyperosmolar Hyperglycemic State in an Elderly Patient with Multiple Comorbidities

This elderly patient with HHS requires immediate aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr, followed by intravenous insulin therapy once hypovolemia is corrected and hypokalemia is excluded, with a target glucose of 140-180 mg/dL given her ICU status and high-risk profile. 1, 2

Immediate Priorities (0-60 minutes)

Fluid Resuscitation - First Priority

• Begin with 0.9% normal saline at 15-20 mL/kg/hr to restore circulatory volume and tissue perfusion 1, 3
• This patient likely has a total body water deficit of approximately 9 liters (100-200 mL/kg), which must be corrected within 24 hours 1
• Continue isotonic saline until vital signs stabilize and urine output reaches ≥0.5 mL/kg/h 3
• Exercise extreme caution given her HFrEF—monitor closely for fluid overload with serial lung examinations and consider lower infusion rates if signs of pulmonary edema develop 3, 4

Insulin Therapy - Delayed Until After Initial Fluid Resuscitation

• Do not start insulin immediately—wait until fluid resuscitation has begun and serum potassium is confirmed >3.3 mEq/L 1
• Once hypokalemia is excluded, administer IV bolus of regular insulin 0.15 U/kg, followed by continuous infusion at 0.1 U/kg/hr 1, 5
• Target glucose decline should be gradual—aim for 50-70 mg/dL per hour, not faster 3
• When glucose reaches 250-300 mg/dL, add 5% or 10% dextrose to IV fluids and reduce insulin infusion rate 1, 3

Electrolyte Management

Potassium Replacement - Critical Priority

• Monitor serum potassium every 2-4 hours as insulin therapy will drive potassium intracellularly and can cause life-threatening hypokalemia 1, 6
• Begin potassium replacement when serum levels fall below 5.2 mEq/L, provided adequate urine output is established 1
• This is particularly critical given her HFrEF, as hypokalemia can precipitate ventricular arrhythmias and sudden death 6

Osmolality Monitoring

• Induced change in serum osmolality must not exceed 3 mOsm/kg/hr to prevent cerebral edema 1
• Target osmolality decline of 3.0-8.0 mOsm/kg/h 3
• Current osmolality of 368 mOsm/kg should gradually decrease to <300 mOsm/kg over 24-72 hours 3

Glycemic Targets for This Elderly ICU Patient

ICU-Specific Targets

• Target glucose range of 140-180 mg/dL is appropriate for this intubated ICU patient 2
• Check blood glucose every 1-2 hours until stable 1
• Avoid aggressive glucose lowering below 140 mg/dL given her elderly age, multiple comorbidities (Alzheimer's, HFrEF, COPD), and high risk for hypoglycemia-related mortality 2

Special Considerations for Elderly Patients

• Elderly patients with HHS have twofold increased mortality with hypoglycemia 2
• Her Alzheimer's disease means she cannot perceive or report hypoglycemic symptoms, increasing risk of severe unrecognized hypoglycemia 2
• Renal function must be monitored as elderly patients have decreased renal gluconeogenesis and impaired insulin clearance 2

Addressing Precipitating Factors

Infection Workup

• Elevated WBC of 17.3 suggests possible infection as precipitating factor 1, 3
• Identify and aggressively treat underlying infection—this is the primary determinant of mortality in HHS, not the metabolic derangement itself 2, 3
• Consider pneumonia given her COPD and intubation status, urinary tract infection, or other occult infection 3

Cardiac Evaluation

• Mildly elevated troponin (0.2) and LBBB require monitoring but do not change acute HHS management 2
• Continue her guideline-directed medical therapy for HFrEF during hospitalization unless hemodynamically unstable 2

Monitoring Protocol

Hourly Assessments

• Blood glucose every 1-2 hours 1
• Vital signs and neurological status hourly 3
• Strict intake/output monitoring given HFrEF 3

Every 2-4 Hours

• Serum potassium, sodium, chloride 1
• Calculated serum osmolality 3
• Venous blood gas if acidosis develops 2

Every 4-6 Hours

• Complete metabolic panel including BUN, creatinine 2
• Reassess volume status and adjust fluid rate accordingly 3

Resolution Criteria

HHS is resolved when all of the following are achieved: 3

• Osmolality <300 mOsm/kg
• Hypovolemia corrected with urine output ≥0.5 mL/kg/h
• Cognitive status returned to baseline (accounting for her Alzheimer's disease)
• Blood glucose <15 mmol/L (270 mg/dL)

Transition Planning

Subcutaneous Insulin Transition

• Once HHS resolves and patient is eating, transition to subcutaneous basal-bolus insulin regimen 2
• Start with conservative dosing of 0.3 units/kg total daily dose given her elderly age and multiple comorbidities—divide half as basal insulin once daily and half as rapid-acting before meals 2
• Avoid sliding scale insulin as sole regimen—it results in unacceptable hypoglycemia and hyperglycemia in elderly patients 2

Discharge Planning

• Outpatient follow-up within 1-2 weeks given glycemic medication changes 2
• Many elderly patients with HHS will not require long-term insulin therapy and can be managed with oral agents or diet alone after recovery 5
• Address medication reconciliation, particularly any drugs that may have precipitated HHS (thiazides, steroids) 7

Key Pitfalls to Avoid

• Do not start insulin before adequate fluid resuscitation—this can worsen hypotension and precipitate cardiovascular collapse 1, 5
• Do not correct glucose or osmolality too rapidly—cerebral edema is rare but fatal 1, 3
• Do not overlook potassium replacement—insulin-induced hypokalemia causes respiratory paralysis and ventricular arrhythmias 6
• Do not use hypotonic saline initially in this hypotensive patient—start with 0.9% NaCl until hemodynamically stable 5, 3
• Do not attribute altered mental status solely to HHS—aggressively search for and treat precipitating infection, which determines survival 3, 4