• Definition and Prevalence
• Causes and Risk Factors
• Signs and Symptoms
• Diagnostic Evaluation
• Treatment Options
• Prevention

Intravenous (IV) fluid administration is a mainstay of medical therapy across healthcare settings. IV fluids help maintain hydration, replace electrolyte losses, and improve hemodynamic stability in conditions like sepsis or trauma. However, despite their utility, IV fluids can also lead to complications when not carefully managed. One such complication is fluid overload, which occurs when excess fluids accumulate in the body’s tissues and organs. If unaddressed, fluid overload can have serious consequences for patients’ health. This article will provide an overview of fluid overload – its causes, symptoms, diagnosis and treatment – to inform healthcare providers on this common yet preventable complication of IV therapy.

Definition and Prevalence

Fluid overload is defined as the accumulation of excess fluid in the body from intravenous fluid administration. It stems from an imbalance between fluid intake from IV infusions and fluid output from urine, respiration, and perspiration. When more fluids are given than can be effectively eliminated, they are retained in the bloodstream and eventually leak into surrounding tissues. This leads to abnormal, potentially dangerous fluid buildup throughout the body.

Among hospitalized patients receiving IV fluids, the prevalence of fluid overload is estimated to be 15-25%. Critically ill patients, such as those with sepsis, trauma, or respiratory failure, are at highest risk. However, fluid overload can occur in patients receiving IV fluids for any reason if intake exceeds output. Certain conditions like kidney failure can increase susceptibility. Careful monitoring of fluid balance is therefore essential during any IV fluid therapy to minimize complications.

Causes and Risk Factors

There are several factors that can contribute to the development of fluid overload during IV fluid administration:

• Excessive fluid administration – If fluids are given at a higher rate than the body’s normal capacity for elimination, overload can occur. This is more likely with prolonged, high-volume IV fluid therapy.
• Kidney dysfunction – The kidneys play a key role in filtering and excreting excess fluid. Conditions like acute kidney injury and chronic kidney disease impair this function, increasing the risk of fluid accumulation.
• Cardiac dysfunction – Heart failure limits the heart’s pumping ability, leading to backup of fluid in the lungs, liver, and peripheral tissues. Sepsis and myocardial infarction can also depress cardiac function.
• Low serum protein levels – Proteins in the blood help hold fluid within the vasculature. Hypoalbuminemia allows fluid to leak out into the interstitium more readily.
• High sodium content – Most IV fluids contain supraphysiologic sodium levels compared to plasma. This can lead to hypervolemia and fluid retention.

Identifying patients with the above risk factors allows providers to monitor for fluid overload and adjust fluid administration accordingly.

Signs and Symptoms

There are several key signs and symptoms of fluid overload to assess for:

• Edema – Swelling in soft tissues including the extremities, face and abdomen. Pitting edema over the shins or sacrum is an early sign.
• Shortness of breath – Extravascular fluid in the lungs causes crackles/rales and impaired gas exchange. Orthopnea and paroxysmal nocturnal dyspnea can occur.
• Ascites – Fluid accumulation in the abdominal cavity, detectable as abdominal distention or flank dullness.
• Weight gain – A gain of 1-2 lbs per day suggests fluid retention and overload. Sudden increases should prompt evaluation.
• Elevated blood pressure – Excess intravascular volume can substantially increase blood pressure.
• Jugular venous distension – High right atrial pressures produce bulging neck veins.
• Pulmonary rales – Fluid in the alveoli causes crackling sounds audible on auscultation.

Prompt recognition of these signs helps identify fluid overload early so treatment can be initiated. Subtle symptoms typically precede overt volume overload.

Diagnostic Evaluation

The first step in diagnosing fluid overload is a thorough physical exam assessing for edema, increased jugular venous pressure, pulmonary crackles, and other signs as above. Beyond this, diagnostic tests include:

• Chest x-ray – Can reveal pulmonary edema as patchy opacities.
• Blood tests – Check kidney function, electrolytes, and proteins. Elevated BUN and creatinine indicate renal impairment. Low serum albumin increases risk of fluid leaking from vessels.
• Urine output measurement – Oliguria signifies impaired fluid elimination.
• Daily weights – Rising weight over consecutive days indicates accumulating fluid.
• Central venous pressure – Can identify high intravascular volume if significantly elevated.

Once fluid overload is recognized, it is important to differentiate the underlying cause and contributing factors to guide appropriate treatment.

Treatment Options

The key principles for treating fluid overload are 1) reducing/stopping further fluid input and 2) enhancing fluid output:

• Discontinue or reduce IV fluids – Ongoing fluid administration must be curtailed.
• Diuretics – Potent diuretics like furosemide increase urine output to eliminate excess fluid.
• Dialysis – In kidney failure, hemodialysis can filter out large volumes of excess fluid.
• Medications for heart failure – Drugs that improve cardiac contractility may improve circulation and organ perfusion.
• Address underlying conditions – Correcting issues like sepsis, renal failure, or hypoalbuminemia facilitates fluid removal.
• Oxygen therapy – If oxygenation is impaired, oxygen via nasal cannula or face mask can help relieve respiratory distress.
• Reduce sodium intake – Limiting dietary sodium promotes increased fluid excretion.

Monitoring urine output, body weight, respiratory status, and electrolytes is key after implementing above interventions. The rate of fluid removal must be carefully controlled to avoid complications like hypotension or shock.

Prevention

While treatment of established fluid overload is important, prevention is ideal. Strategies to avoid fluid overload include:

• Conservative IV fluid rates and volumes
• Regular assessments of volume status
• Hourly intake/output monitoring
• Daily weight measurements
• Avoiding unnecessary IV fluids
• Adjusting IV fluids for kidney dysfunction
• Judicious use of isotonic, balanced crystalloids over saline

By individualizing fluid plans and vigilantly monitoring patients’ response, providers can minimize risks of fluid overload complications.

Fluid overload is a common yet preventable complication of IV fluid administration. It occurs when fluid input chronically exceeds output, causing abnormal accumulation in the body’s tissues and organs. Careful fluid management, monitoring of volume status, and prompt intervention if overload occurs can help avoid adverse sequelae related to fluid accumulation. With astute assessment and evidence-based fluid stewardship, providers can harness the benefits of IV fluids while mitigating their potential risks