5.2 Height, Weight, and Intake/Output

Height, Weight, and Intake/Output

Accurate monitoring of height, weight, and fluid balance (Intake and Output) is vital for tracking nutritional status, identifying fluid retention, and determining medication dosages. In residents with chronic conditions such as congestive heart failure (CHF) or end-stage renal disease (ESRD), a sudden change in weight or an imbalance in fluid intake and output can indicate a life-threatening worsening of their disease. Under Oregon Board of Nursing (OSBN) regulations, CNAs must perform these measurements with high precision and document them according to facility protocols, notifying the nurse immediately of any significant changes.

Height and Weight Measurements

Weight measurements are taken upon admission, weekly, or monthly, depending on the care plan. Consistent, accurate weight monitoring is one of the most effective tools for detecting fluid accumulation (edema) or progressive nutritional decline.

• Standing Balance Scale (Stadiometer):
  • Preparation: Before the resident steps on the scale, the CNA must "zero" or balance the scale. For a balance beam scale, this means sliding both weights to zero and ensuring the balance pointer rests in the middle of the trig loop. For digital scales, ensure the display reads "0.0".
  • Safety: Ensure the resident is wearing non-skid footwear to prevent slips. Assist the resident onto the center of the platform. Stand close to the resident to provide support if they lose their balance. Do not touch or hold the resident while the scale is balancing, as this will alter the reading.
  • Recording: Slide the large weight (usually in 50 lb increments) and then the small weight until the beam balances in the center. Read the weight and record it immediately.
  • Oregon TMU Skills Note: During the clinical skills evaluation, you must record the weight within 2 pounds of the observer's reading.
• Wheelchair Scales:
  • Many residents in long-term care cannot stand safely on a platform scale. A wheelchair scale allows the resident to remain seated during weighing.
  • Process: First, determine the tare weight (the weight of the empty wheelchair, including any cushions, footrests, or attachments). Then, push the resident onto the scale, lock the wheelchair brakes, and obtain the total weight. Subtract the tare weight from the total weight to find the resident's actual body weight: Resident Weight = Total Weight - Wheelchair Tare Weight
  • Always verify that the same wheelchair is used for consecutive weighings, or re-measure the tare weight, as different wheelchair models vary significantly in weight.
• Height Measurement:
  • For a standing resident, use the height rod (stadiometer) attached to the scale. Have the resident stand straight, looking forward. Lower the height rod until it rests flat on the crown of the resident's head. Read the measurement in inches or centimeters.
  • For bedbound residents, place the resident in a supine position, flat in bed. Mark the sheet at the top of the head and at the bottom of the heels, then measure the distance between the two marks using a tape measure.

Fluid Intake and Output (I&O)

Fluid balance is the relationship between the fluid taken into the body and the fluid lost. A healthy individual maintains homeostatic balance where intake approximately equals output. CNAs monitor I&O for residents on specific orders, such as those with fluid restrictions or those receiving diuretics.

• Fluid Intake:
  • Fluid intake includes all liquids consumed by mouth, as well as foods that are liquid at room temperature. This includes: water, juice, milk, coffee, tea, soup, gelatin (Jell-O), ice cream, sherbet, and popsicles. It does not include pureed solid foods or pudding.
  • Unit Conversion (Standard Rule): Healthcare facilities and testing agencies use the metric system (milliliters, mL) for documenting fluids. The standard conversion factor is: 1 fluid ounce (oz) = 30 mL (or cc)
  • Intake Calculation: To calculate intake, you must know the capacity of the serving containers used in your facility. If a resident consumes only a portion of a liquid, you must calculate the amount consumed and convert it.
    • Example: A resident is served an 8 oz cup of coffee and a 4 oz carton of juice. They drink all the juice and half of the coffee.
      • Juice consumed: 4 oz * 30 mL/oz = 120 mL
      • Coffee consumed: 4 oz (half of 8 oz) * 30 mL/oz = 120 mL
      • Total Intake: 120 mL + 120 mL = 240 mL
• Fluid Output:
  • Fluid output includes urine, liquid feces (diarrhea), emesis (vomit), and wound drainage. It does not include normal solid stool or perspiration (which is insensible loss).
  • Measuring Graduate: To measure output, pour the fluid into a clear, calibrated measuring container called a graduate.
  • Reading Technique:
    1. Place the graduate on a flat, level surface (do not hold it in the air while reading, as it will tilt and give an inaccurate reading).
    2. Stoop down to read the markings at eye level.
    3. Read the volume at the bottom of the meniscus (the curved line formed by the liquid's surface).
  • Infection Control: Always wear gloves when handling graduates and body fluids. Empty the graduate into the toilet after measuring, rinse it, and store it in the resident's individual bathroom (never in a shared space). Wash hands immediately after removing gloves.