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Department: upFront: CLINICAL DO'S & DON'TS

Assessing for dehydration in adults

Rushing, Jill RN, MSN

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doi: 10.1097/01.NURSE.0000348406.04065.6d
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ISOTONIC FLUID VOLUME deficit is a proportionate loss of sodium and water. Characterized by decreased extracellular fluid, including decreased circulating blood volume, isotonic fluid volume deficit results in signs and symptoms of dehydration. Common causes include vomiting, diarrhea, and polyuria.


  • Assess your patient for risk of dehydration. Use a tool to evaluate his risk and implement strategies for ongoing hydration management.
  • Identify causes of fluid volume deficit and implement interventions to restore fluid balance as indicated.
  • Monitor and report abnormal lab results, including serum electrolytes, blood urea nitrogen (BUN), BUN/creatinine ratio, serum osmolality, and urine osmolality.
  • Assess for clinical signs and symptoms of dehydration, including thirst, weight loss, dry mucous membranes, sunken-appearing eyes, decreased skin turgor, increased capillary refill time, hypotension and postural hypotension, tachycardia, weak and thready peripheral pulses, flat neck veins when the patient is in the supine position, and oliguria.

◂Assess capillary refill by applying pressure to a fingernail for 5 seconds. Release the pressure and observe the time (usually 1 to 3 seconds) it takes for the color to return to normal. If it takes longer, the patient may be dehydrated.


◂Assess skin turgor by gently pinching a fold of skin between your thumb and forefinger. The skin you select, such as below the clavicle or on the abdomen, sternum, or forearm, should feel resilient, move easily, and quickly return to its original position when released after a few seconds. If not, the patient may be dehydrated.

  • Some common signs and symptoms of dehydration may be absent or masked in older adults. Look for functional signs of dehydration including a change in mental status or falls, especially in at-risk patients.
  • Carefully measure and record intake and output from all sources.
  • Measure and record weights daily, at the same time each day and using the same scale. Make sure the patient has an empty bladder and is wearing the same amount of clothing.


  • Don't rely on decreased skin turgor to assess dehydration in older adults because skin loses its elasticity with age.
  • Don't test skin turgor on the dorsal hand or anywhere the skin seems loose or thin.
  • Don't rely on older adults' sensation of thirst because this decreases with age.


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        © 2009 Lippincott Williams & Wilkins, Inc.