Fluid & Electrolyte Q 14

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Insensible fluid losses include:

  

    A. Urine

    B. Gastric drainage

    C. Bleeding

    D. Perspiration

    

    

Correct Answer: D. Perspiration

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Perspiration and the fluid lost via the lungs are termed insensible losses; normally, insensible losses equal about 1000 cc/day. Insensible fluid loss is the amount of body fluid lost daily that is not easily measured, from the respiratory system, skin, and water in the excreted stool. The exact amount is unmeasurable but is estimated to be between 40 to 800mL/day in the average adult without comorbidities.

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Option A: Expect a minimum of 1.5 mL/kg per hour in children and greater than 1 mL/kg per hour in adults. Special situations such as administering nephrotoxic medications such as acyclovir warrant higher thresholds for urine output to minimize renal toxicity.

Option B: An important distinction in managing fluids is differentiating between maintenance fluids and fluid replacement. Maintenance fluids should address the patient’s basic physiological needs, including both sensible and insensible fluid losses. Sensible fluid losses refer to typical routes of excretion such as urination and defecation.

Option C: One general principle for all patient scenarios is to replace whatever fluid is being lost as accurately as possible. These fluid losses can differ depending on patients’ medical conditions and differ by both volume and composition.

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