What are the common causes of fluid overload in the Emergency Department (ED)?

Common Causes of Fluid Overload in the Emergency Department

The most common causes of fluid overload in the Emergency Department include heart failure, renal failure, iatrogenic fluid administration, sepsis, and liver disease, all of which can lead to significant morbidity and mortality if not promptly identified and treated.

Cardiovascular Causes

• Congestive heart failure (CHF) is a primary cause of fluid overload in the ED, characterized by decreased cardiac output leading to venous congestion and edema 1
• Systolic cardiac dysfunction impairs the heart's ability to effectively pump blood, resulting in fluid accumulation in the lungs and peripheral tissues 1
• Hypertensive emergency can precipitate acute heart failure and subsequent fluid overload 1
• Cardiac arrhythmias, particularly atrial fibrillation, can decrease cardiac efficiency and contribute to fluid retention 1

Renal Causes

• Acute kidney injury (AKI) and chronic kidney disease (CKD) impair the kidney's ability to excrete sodium and water, leading to volume expansion 1
• Patients with severe renal insufficiency have diminished response to diuretics, making fluid overload more difficult to manage 2
• Nephrotic syndrome causes hypoalbuminemia, decreasing oncotic pressure and leading to edema formation 3

Iatrogenic Causes

• Excessive intravenous fluid administration, particularly during resuscitation efforts, is a common iatrogenic cause of fluid overload in the ED 1
• Administration of 0.9% saline can cause hyperchloremic acidosis, decreased renal blood flow, and exacerbate sodium retention 1
• Fluid overload of as little as 2.5 L can cause adverse effects including increased postoperative complications and prolonged hospital stays 1
• Patients receiving isotonic fluids at typical maintenance rates are at risk for volume overload, especially those with impaired cardiac, hepatic, or renal function 1

Infectious/Inflammatory Causes

• Sepsis causes increased vascular permeability and third-spacing of fluids, contributing to edema formation 1
• Systemic inflammatory response syndrome (SIRS) leads to capillary leak and fluid sequestration in tissues 1
• Pneumonia is a common infectious trigger for fluid overload, particularly in patients with underlying cardiopulmonary disease 1

Hepatic Causes

• Cirrhotic liver disease causes hypoalbuminemia and portal hypertension, leading to ascites and edema 1
• Patients with cirrhosis have impaired ability to excrete both free water and sodium, putting them at high risk for both volume overload and hyponatremia 1

Special Populations at Risk

• Elderly patients have decreased physiologic reserve and are more susceptible to fluid overload complications 1
• Patients with pre-existing comorbidities (heart failure, renal dysfunction, liver disease) are at higher risk for developing fluid overload even with standard fluid administration 1
• Patients receiving certain medications (steroids, NSAIDs, certain antihypertensives) may have altered fluid homeostasis 1

Clinical Manifestations

• Pulmonary edema with respiratory distress, decreased oxygen saturation, and crackles on auscultation 1
• Peripheral edema, particularly in dependent areas 4
• Jugular venous distension reflecting elevated central venous pressure 4
• Abdominal compartment syndrome in severe cases, leading to decreased mesenteric blood flow and ileus 1
• Decreased tissue oxygenation due to edema impairing gas exchange 1

Diagnostic Approach

• Clinical assessment of volume status through physical examination (edema, jugular venous distension, crackles) 1
• Chest radiography to evaluate for pulmonary edema, pleural effusions 1
• Point-of-care ultrasound to assess for B-lines in lungs, inferior vena cava diameter and collapsibility, and other signs of venous congestion 4
• Laboratory evaluation including BNP/NT-proBNP levels, renal function tests, and electrolytes 1
• Careful monitoring of fluid intake and output, daily weights, and vital signs 1

Management Considerations

• Prompt identification and treatment of the underlying cause is essential 1
• Intravenous loop diuretics are first-line therapy for patients with significant fluid overload 1, 2
• In patients already on chronic diuretic therapy, the initial IV dose should equal or exceed their chronic oral daily dose 1, 2
• For diuretic-resistant cases, combination therapy with a second diuretic (such as metolazone or spironolactone) or continuous infusion of loop diuretics may be necessary 1, 2
• Fluid restriction should be considered, particularly in patients with hyponatremia 1
• Ultrafiltration may be required for refractory fluid overload not responding to medical therapy 2, 5

Pitfalls and Caveats

• Avoid excessive fluid administration in patients with known cardiac, hepatic, or renal dysfunction 1
• Be cautious with 0.9% saline administration as it can cause hyperchloremic acidosis and worsen fluid retention 1
• Monitor for adverse effects of diuretics including electrolyte abnormalities, hypotension, and worsening renal function 6
• Excessive concern about hypotension or azotemia can lead to underuse of diuretics and persistent edema 2
• Fluid overload not only contributes to symptoms but can also impair the effectiveness of other medications 2