INTAKE & OUTPUT

RECORDING FLUID INTAKE AND OUTPUT

  • Objectives: After this class, students should be able to:
    • State reasons for monitoring fluid intake and output.
    • Interpret fluid balance.
    • Describe signs and symptoms of oedema and dehydration.

IMPORTANCE OF RECORDING INTAKE AND OUTPUT

  • Accurate recording is a lifesaving measure.
  • Monitoring intake and output provides insights into a patient's general health status.
  • Successful recording relies on teamwork involving:
    • Nurses
    • Nurse assistants
    • Physicians
    • Patients
    • Patient relatives

BODY FLUIDS

  • Composition:
    • Body fluids consist of water and electrolytes (dissolved substances in water).
    • Fluids comprise approximately 50%–70% of total body weight.
  • Compartments:
    • Intracellular Fluid (ICF): Fluid within cells.
    • Extracellular Fluid (ECF): Divided into:
    • Interstitial fluid (tissue fluid)
    • Intravascular fluid (within blood vessels)
    • Transcellular Fluid: Found in body cavities (e.g., cerebral spinal fluid, synovial fluid).
INTRACELLULAR FLUID (ICF)
  • Functions:
    • Stabilizes cell structure and shape.
    • Assists in nutrient transport across cell membranes.
  • Water Content in Cells:
    • Skeletal muscle: ~75% water.
    • Fatty tissue: ~10% water.
  • Major ions: Potassium, Magnesium, Phosphate, Proteins.
EXTRACELLULAR FLUID (ECF)
  • Types:
    • Interstitial fluid (IF)
    • Intravascular fluid (IV)
    • Transcellular fluids in joint cavities and various organs (e.g., GI tract, liver, lymphatic vessels).
  • Major Ions: Sodium, Chlorine, Carbonate.

PURPOSES FOR MONITORING FLUID INTAKE AND OUTPUT

  • Confirm some diagnoses.
  • Influence fluid therapy choices.
  • Evaluate fluid balances in patients.
  • Identify significant fluid losses or gains.
  • Assess the patient’s ability to tolerate oral fluids.

FLUID INTAKE

  • Definition: Refers to water and other fluids taken into the body daily.
  • Sources of Water:
    • Liquid intake (oral or via IV)
    • Food metabolism
    • End product of cellular respiration.
  • Average Intake: Approximately 2,000 to 3,000 mL per day.

FLUID OUTPUT

  • Definition: Refers to fluids expelled from the body in a specified period.
  • Types of Fluid Loss:
    • Sensible Fluid Loss: Can be measured (e.g., urine, vomitus, diarrhea, wound drainage).
    • Insensible Fluid Loss: Not easily measured (e.g., fluid through expiration, sweat, salivation, tears).
  • Urine Output: Every individual is expected to pass at least 500 mL of urine in 24 hours; figures below this must be investigated.

SENSIBLE FLUID LOSS

  • Examples include:
    • Urine
    • Vomitus
    • Diarrhea or watery stools
    • Wound drainage.

INSENSIBLE FLUID LOSS

  • Implies fluid loss that cannot be measured with precision, typically involving smaller, continuous losses.
  • Estimation: Add between 300 to 600 mL to outputs for insensible losses.

FACTORS INFLUENCING FLUID LOSS

  • Exercise.
  • Fever.
  • Some medications.
  • Specific diseases (e.g., gastroenteritis, diabetes mellitus).

FLUID BALANCE

  • Calculation: Usually measured over 24 hours. In suspected renal failure cases, the duration can vary.
  • Expected outcome: Fluid lost should equal fluid gained.
  • Formula: Intake - Output = Balance.
INTERPRETING FLUID BALANCE
  • Positive Fluid Balance: Intake exceeds output, leading to potential fluid overload / edema.
  • Negative Fluid Balance: Output exceeds intake, indicating dehydration (causes may include inadequate intake, excessive loss, or both).

DEHYDRATION

  • Definition: Defined as a 1% or greater loss of body mass due to fluid loss, where the body has less water than required for proper functioning.
  • Signs and Symptoms:
    • Poor skin turgor
    • Concentrated or scanty urine
    • Depressed per orbital space
    • Sunken fontanels in infants
    • Dry lips and mucous membranes
    • Weak pulse
    • Decreased salivation
    • Increased capillary refill time
    • Sudden weight loss
    • Hypotension.

CLASSIFICATION OF DEHYDRATION

  • Mild Dehydration: 2-5% fluid loss.
  • Moderate Dehydration: 6-9% fluid loss.
  • Severe Dehydration: 10-14% fluid loss.
  • Risk of Death: Sudden 20% fluid loss can lead to death.
POSITIVE FLUID BALANCE
  • Definition: Intake exceeds output, leading to fluid overload / edema.
  • Conditions causing edema may include:
    • Congestive heart failure
    • Liver cirrhosis
    • Nephrotic syndrome
    • Various other medical conditions.
SIGNS AND SYMPTOMS OF EDEMA
  • Includes:
    • Weight gain
    • Puffy eyelids
    • Blurred vision
    • Distended neck vein
    • Excessive salivation
    • Peripheral swelling
    • Ascites.
    • Moist skin
    • Crackles on auscultation
    • Increased pulse with bounding character
    • Shortness of breath
    • Hypertension.

DOCUMENTING FLUID INTAKE AND OUTPUT

  • Essential for accurately reflecting a patient's fluid status.
  • Documentation should be done in milliliters for uniformity.
  • Charts are used by different hospitals to document intake and output, which is typically monitored over 24 hours.

NURSING SKILLS TO BE ACQUIRED

  • Expected to accurately record fluid intake and output and calculate the balance after learning the necessary skills.

PROCEDURE FOR RECORDING FLUID INTAKE AND OUTPUT

  • Steps include:
    1. Explain the fluid balance chart's importance to the patient for cooperation.
    2. Identify roles of everyone involved.
    3. Gather all necessary equipment (e.g., measuring jugs, fluid charts).
    4. Record all measurements in milliliters.
    5. Record all inputs (infusions, transfusions, etc.) and outputs (urine, watery stools, vomitus).
    6. Sum total intake and output over 24 hours or according to hospital policy.
    7. Compute fluid balance by subtracting output from intake.
    8. Notify nurse in charge or physician of significant discrepancies.