What is the management approach for acute illnesses causing volume depletion?

Management of Acute Illnesses Causing Volume Depletion

The cornerstone of managing acute volume depletion from illness is immediate fluid resuscitation with isotonic saline (0.9% NaCl) while temporarily withholding medications that impair hemodynamic compensation, particularly RAAS inhibitors, diuretics, SGLT2 inhibitors, metformin, and NSAIDs. 1

Immediate Recognition and Triage

Triggers Requiring Sick Day Management

Volume depletion should be suspected when patients develop: 1

• Vomiting or diarrhea resulting in significant fluid losses (100% consensus) 1
• Anorexia or nausea causing significant decrease in fluid intake 1
• New lightheadedness, dizziness, or fainting, particularly orthostatic 1
• Decreased weight (≥3 kg in 2 days) 1
• Decreased urine output 1

Red Flags Requiring Immediate Medical Contact

Patients should contact healthcare providers immediately for: 1

• Reduced level of consciousness or new confusion (100% consensus) 1
• Vomiting >4 times in 12 hours or inability to keep fluids down (96% consensus) 1
• Low blood pressure (SBP <80 mmHg or drop of 20 mmHg systolic/10 mmHg diastolic) 1
• Moderate or high ketones (for patients on SGLT2i or insulin) 1
• Increased heart rate (increase by 30 bpm) 1
• Fever (temperature >38°C on 2 measurements) 1

Medication Management During Acute Illness

Medications to Temporarily Withhold

Immediately stop the following medications when volume depletion is suspected: 1

• SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin) - withhold during prolonged fasting, surgery, or critical medical illness due to ketosis risk 1
• ACE inhibitors/ARBs (perindopril, candesartan, etc.) - 90% consensus to withhold 1
• All diuretics:
  • Loop diuretics (furosemide) - 95% consensus 1
  • Thiazides/thiazide-like diuretics (HCTZ, indapamide) - 90% consensus 1
  • Potassium-sparing diuretics (amiloride, spironolactone) - 95% consensus 1
• NSAIDs - 95% consensus to withhold 1
• Metformin - consensus to withhold 1
• Direct renin inhibitors 1
• ARNI (angiotensin receptor-neprilysin inhibitor) 1

Glucose-Lowering Medication Adjustments

For patients with diabetes: 1

• If blood glucose is low: Hold insulin, sulfonylureas, and meglitinides until blood glucose recovers (96% consensus) 1
• If blood glucose is elevated: Increase basal and bolus insulin by 10-20% empirically 1
• If patient took sulfonylurea before illness onset: Instruct to eat foods to prevent hypoglycemia until medication effect wears off (12-24 hours) 1

Fluid Resuscitation Strategy

Initial Fluid Management

Volume expansion or correction of volume depletion remains the most efficient and evidence-based intervention: 2

• Isotonic saline (0.9% NaCl) is the preferred initial fluid for extracellular fluid volume depletion 3
• Large-volume fluid resuscitation should be initiated immediately in patients with orthostasis, hypotension, or incomplete response to initial treatment 1
• Fluid containing sodium (broth, tomato juice, sports drinks) helps prevent intravascular volume depletion 1

Carbohydrate Replacement

For patients with diabetes during acute illness: 1

• Ingest 150-200g carbohydrate daily (45-50g or 3-4 carbohydrate choices every 3-4 hours) to prevent starvation ketosis 1
• If regular food not tolerated: Use liquid or soft carbohydrate-containing foods (sugar-sweetened soft drinks, juices, soups, ice cream) 1
• Continue insulin during acute illness - do not omit, as counter-regulatory hormones increase insulin requirements 1

Monitoring Requirements

For patients on SGLT2 inhibitors or insulin: 1

• Check blood glucose every 4-6 hours while awake and for duration of symptoms (100% consensus) 1
• Check ketones in patients receiving SGLT2i, insulin, or on ketogenic diets (95% consensus) 1, 4

Duration and Resumption of Therapy

Self-Management Timeline

Sick day protocols are appropriate for temporary self-management: 1

• Maximum duration: 72 hours or until symptoms resolve, whichever comes first 1
• Seek medical assistance if symptoms persist beyond 72 hours (100% consensus) 1
• Contact provider if unable to keep up with fluid intake (100% consensus) 1

Medication Resumption

Resume withheld medications: 1

• Within 24-48 hours of symptom resolution 1
• Only when eating and drinking normally 1
• After confirming adequate volume status 1

Special Considerations for SGLT2 Inhibitors

When restarting SGLT2 inhibitors after acute illness: 1

• Anticipate acute drop in eGFR - this is generally not a reason to discontinue therapy 1
• Reassess volume status and reduce concomitant diuretics if needed 1
• Educate about volume depletion symptoms and low blood pressure 1

Common Pitfalls to Avoid

Critical errors in management include: 1, 3

• Confusing dehydration (intracellular water deficit from hypertonicity) with volume depletion (extracellular sodium and volume loss) - these require different treatments 3, 5
• Continuing RAAS inhibitors during volume depletion - can precipitate acute kidney injury that is usually reversible but requires drug cessation 1
• Administering hypotonic fluids (0.45% saline) indiscriminately - extracellular volume depletion requires isotonic saline 3
• Omitting insulin in diabetic patients during illness - this can lead to diabetic ketoacidosis 1
• Failing to check ketones in SGLT2i users - these patients are at risk for euglycemic diabetic ketoacidosis 1