N201 Fluid and Electrolytes

• -       Respiratory

  Acidosis                  Alkalosis 

  o   pH ↓                      pH ↑

  o   CO2 ↑                   CO2 ↓

   
• -                    Metabolic

  Acidosis                   Alkalosis 

  o   pH ↓                          pH ↑

  o   HCO3 ↓                     HCO3 ↑

   
•   Decreased cardiac output and tissue perfusionon:  ↓ circulating blood volumeo   Postural hypotension; syncopeo   Tachycardia, weak and thready pulse
• 2. Compensatory ↑ in ADH:   ↓ UO
•  3. ↑ serum osmolality:  ↑Hct, BUN
•  4. hypoxemia: ↓ perfusion to vital organso   CNS – disorientation, loc o   chest pain, oliguria, anuria
• Albumin


  Made by liver, controls the pressure (ICM)
• Types of osmosis


  • Hypotonic
  • Hypertonic
  • Isotonic
• Oncotic


  Made by proteins
• Causes of edema


  • Increased capillary hydrostatic pressure
  • Loss of plasma proteins
  • Obstruction of lymphatic circulation
  • Increased capillary permeability
  • Third spacing: fluid shifting into a cavity
• Causes of dehydration


  • Vomiting and diarrhea
  • Diaphoresis
  • DKA (diabetic keto-acidosis)
  • Insufficient intake
  • Use of concentrated formula (infants)
• Types of acid-base imbalance

  • Respiratory acidosis
  • Respiratory alkalosis
  • Metabolic acidosis
  • Metabolic alkalosis
• Respiratory acidosis


  Increase in CO2 levels
• Respiratory alkalosis


  Decrease in CO2 levels
• Metabolic acidosis


  Decrease in bicarbonate ions
• Metabolic alkalosis


  Loss of hydrogen ions through kidneys/GI tract
• Compensation mechanisms for acid-base problems

  • Buffers
  • Change in respiration and renal function
• Effects of acidosis


  • Impaired nervous system function
  • Headache
  • Lethargy
  • Weakness
  • Confusion
  • Coma and death
  • Deep rapid breathing
  • Secretion of urine with a low pH
• Effects of alkalosis


  • Increased irritability of the NS causes:
  • Restlessness
  • Muscle twitching
  • Tingling and numbness of the fingers
  • Tetany
  • Seizures
  • Coma
• ABG interpretation: Respiratory acidosis

  pH high, CO2 low
• ABG interpretation: Respiratory alkalosis

  pH low, CO2 high
• ABG interpretation: Metabolic acidosis

  pH low, HCO3 low
• ABG interpretation: Metabolic alkalosis

  pH high, HCO3 high
• Normal ABG values


  • pH 7.35-7.45
  • PaO2 80-100 mmHg
  • Pa CO2 35-45 mm Hg
  • HCO3 22-26 mEq/L
• Hypovolemia in surgical patient

  • Largest loss through the kidneys
  • Lesser amount lost through skin, lungs, GI tract
  • Even when fluids are withheld, the kidneys continue to produce urine – to rid the body of metabolic wastes
• Isotonic FVD


  • Proportionate loss of sodium and water
  • Characterized by a decrease in ECF, including circulating blood volume
  • Typically accompanied by one or more electrolyte imbalances
  • Occurs more rapidly when linked with decrease intake
• Manifestations of FVD


  • Decreased cardiac output and tissue perfusion
  • Compensatory increased in ADH
  • Increase in serum osmolality
  • Hypoxemia
• Goals of treatment for FVD

  • Treat underlying cause
  • Replace the loss: Blood, PRBC, Isotonic IV fluid (physiologic saline; lactated ringer's)
  • Assess the patient, monitor: CV, GI/GU, Integument
• Nursing diagnoses related to FVD

  • Deficient fluid volume
  • Decreased cardiac output
  • Ineffective tissue perfusion
  • Risk for deficient fluid volume
  • Potential complications/problem – hypoxemia, hypovolemic shock
  • Activity intolerance
• Effects of decreased renal perfusion

  • Decreased renal perfusion
  • Increased renin secretion
  • Increased angiotensin 2
  • Increased potassium
  • Decreased serum sodium
  • Increased ACTH then would lead to stress, physical trauma
• Effects of high aldosterone secretion

  Increase sodium reabsorption and increased potassium excretion
• Electrolyte imbalances to differentiate

  • Sodium (135-145 meq/L): Hyper and hypo
  • Potassium imbalance (3.5-5.0meq/L): Hyper and hypo
  • Calcium imbalance (4-5meq/L): Hyper and hypo
• Hypovolemia


  Fluid volume deficit
• Causes of hypovolemia in the surgical patient

  • Largest loss through the kidneys
  • Lesser amount lost through skin, lungs, GI tract
  • Even when fluids are withheld, the kidneys continue to produce urine – to rid the body of metabolic wastes
• Hypovolemia: isotonic fvd


  • Proportionate loss of sodium and water
  • Characterized by a ↓ in ECF; including circulating blood volume
  • Typically accompanied by 1 or more electrolyte imbalances
  • Occurs more rapidly when linked with ↓ intake
• Causes of Fluid Volume deficit in the surgical patient

  • Vascular
  • GI
  • Poor oral intake
• Manifestations of FVD (Hypovolemia)

  • Decreased cardiac output and tissue perfusion
  • Compensatory ↑ in ADH
  • ↑ serum osmolality – ↑ Hct, BUN
  • hypoxemia
• Goals of treatment


  • Treat underlying cause
  • Replace the loss
  • Assess the Patient; Monitor
• Nursing Management of Hypovolemia

  1. Nursing Diagnoses

  2. Potential complication/problem

  3. Activity intolerance
• Sodium imbalance


  Hyper and Hypo