Nursing Care of Clients with Altered Fluid, Electrolyte, and Acid–Base Balance

Fluid and Electrolyte Balance Necessary for life, homeostasis Nursing role: help prevent, treat fluid, electrolyte disturbances

Fluid Approximately 60% of typical adult is fluid Intracellular fluid Varies with age, body size, gender Intracellular fluid Extracellular fluid Intravascular Interstitial Transcellular “Third spacing”: loss of ECF into space that does not contribute to equilibrium

Electrolytes Active chemicals that carry positive (cations), negative (anions) electrical charges Major cations: sodium, potassium, calcium, magnesium, hydrogen ions Major anions: chloride, bicarbonate, phosphate, sulfate, and proteinate ions Electrolyte concentrations differ in fluid compartments

Regulation of Fluid Movement of fluid through capillary walls depends on Hydrostatic pressure: exerted on walls of blood vessels Osmotic pressure: exerted by protein in plasma Direction of fluid movement depends on differences of hydrostatic, osmotic pressure

Regulation of Fluid Osmosis: area of low solute concentration to area of high solute concentration Diffusion: solutes move from area of higher concentration to one of lower concentration Filtration: movement of water, solutes occurs from area of high hydrostatic pressure to area of low hydrostatic pressure Active transport: physiologic pump that moves fluid from area of lower concentration of one of higher concentration

Active Transport Physiologic pump that moves fluid from area of lower concentration to one of higher concentration Movement against concentration gradient Sodium-potassium pump: maintains higher concentration of extracellular sodium, intracellular potassium Requires adenosine (ATP) for energy

Fluids Animation

Fluid Volume or Electrolyte Imbalance Causes of fluid loss Vomiting, diarrhea Gastrointestinal suctioning, intestinal fistulas, and intestinal drainage Diuretic therapy, renal disorders, endocrine disorders Sweating from excessive exercise, increased environmental temperature Hemorrhage Chronic abuse of laxatives

Fluid Volume or Electrolyte Imbalance Cause of Fluid Loss in the Older Adult Self limiting fluids (fear of incontinence) Physical disabilities Cognitive impairments Older adults without air conditioning

Fluid Volume Imbalances Fluid volume deficit (FVD): hypovolemia Fluid volume excess (FVE): hypervolemia

Fluid Volume Deficit Loss of extracellular fluid exceeds intake ratio of water Electrolytes lost in same proportion as they exist in normal body fluids Dehydration: loss of water along with increased serum sodium level May occur in combination with other imbalances

Fluid Volume Deficit (cont’d) Dehydration Causes: fluid loss from vomiting, diarrhea, GI suctioning, sweating, decreased intake, inability to gain access to fluid Risk factors: diabetes insipidus, adrenal insufficiency, osmotic diuresis, hemorrhage, coma, third space shifts

Fluid Volume Deficit (cont’d) Manifestations: rapid weight loss, decreased skin turgor, oliguria, concentrated urine, postural hypotension, rapid weak pulse, increased temperature, cool clammy skin due to vasoconstriction, lassitude, thirst, nausea, muscle weakness, cramps Laboratory data: elevated BUN in relation to serum creatinine, increased hematocrit Serum electrolyte changes may occur

Fluid Volume or Electrolyte Imbalance Treatment for Fluid Volume Deficit (FVD) Oral, intravenous, or enteral routes Manage the effects and prevent further complications by monitoring intake, assessing lab values, and observing vital signs and skin integrity

Fluid Volume Deficit - Nursing Management I&O, VS Monitor for symptoms: skin and tongue turgor, mucosa, UO, mental status Measures to minimize fluid loss Oral care Administration of oral fluids Administration of parenteral fluids

Fluid Volume Excess Due to fluid overload or diminished homeostatic mechanisms Risk factors: heart failure, renal failure, cirrhosis of liver Contributing factors: excessive dietary sodium or sodium-containing IV solutions Manifestations: edema, distended neck veins, abnormal lung sounds (crackles), tachycardia, increased BP, pulse pressure and CVP, increased weight, increased UO, shortness of breath and wheezing Medical management: directed at cause, restriction of fluids and sodium, administration of diuretics

Fluid Volume Excess - Nursing Management I&O and daily weights; assess lung sounds, edema, other symptoms; monitor responses to medications- diuretics Promote adherence to fluid restrictions, patient teaching related to sodium and fluid restrictions Monitor, avoid sources of excessive sodium, including medications Promote rest Semi-Fowler’s position for orthopnea Skin care, positioning/turning

Manifestations of Imbalances Hyponatremia Muscle cramps, weakness, fatigue Dulled sensorium, irritability, personality changes Hypernatremia Most serious effects are seen in the brain Lethargy, weakness, irritability can progress to seizures, coma, and death

Manifestations of Imbalances Hypokalemia EKG changes (flattened or inverted T waves) Skeletal muscle weakness Hyperkalemia Cardiac arrest Paresthesias Abdominal cramping

Manifestations of Imbalances Hypocalcemia Tetany, paresthesias, muscle spasms Hypotension Anxiety, confusion, psychosis Hypercalcemia Muscle weakness, fatigue Personality changes Anorexia, nausea, vomiting

Manifestations of Imbalances Hypomagnesemia Muscle weakness and tremors Dysphasia Tachycardia hypertension Mood and personality changes Hypermagnesemia Depressed deep tendon reflexes Hypotension Respiratory depression

Manifestations of Imbalances Hypophosphatemia Muscle pain and tenderness Muscle weakness and paresthesias Confusion Manifestations of hypophosphatemia Muscle spasms, tetany Soft tissue calcifications

Maintaining Acid-Base Balance Normal plasma pH 7-35-7.45: hydrogen ion concentration Major extracellular fluid buffer system; bicarbonate-carbonic acid buffer system Kidneys regulate bicarbonate in ECF Lungs under control of medulla regulate CO2, carbonic acid in ECF

ACID–BASE DISTURBANCES Plasma pH is an indicator of hydrogen ion (H+) concentration. Normal range pH (7.35–7.45). Buffer systems Kidneys Lungs The H+ concentration is extremely important: Increased concentration H+ Increased acidity Lower the pH. Deceased H+ concentration Increased alkalinity Higher the pH. pH range compatible with life (6.8–7.8)

Acid-Base Disorders Acidosis: hydrogen ion concentration above normal (pH below 7.35) Alkalosis: hydrogen ion concentration below normal (pH above 7.45) Metabolic Acidosis: bicarbonate is decreased in relation to the amount of acid

Acid-Base Disorders Metabolic Alkalosis: excess of bicarbonate in relation to the amount of hydrogen ion Respiratory Acidosis: CO2 is retained, caused by sudden failure of ventilation due to chest trauma, aspiration of foreign body, acute pneumonia, and overdose of narcotics or sedatives Respiratory Alkalosis: CO2 is blown off, caused by mechanical ventilation and anxiety with hyperventilation

Arterial Blood Gases pH 7.35 - (7.4) - 7.45 PaCO2 35 - (40) - 45 mm Hg HCO3ˉ 22 - (24) - 26 mEq/L Assumed average values for ABG interpretation PaO2 80 to 100 mm Hg Oxygen saturation >94% Base excess/deficit ±2 mEq/L

ACID–BASE DISTURBANCES AND COMPENSATION DISORDER INITIAL EVENT COMPENSATION Respiratory acidosis ↑ PaCO2, ↑ or normal Kidneys eliminate H+ and HCO3 −, ↓ pH retain HCO3− Respiratory alkalosis ↓ PaCO2, ↓ or normal Kidneys conserve H+ and HCO3−, ↑ pH excrete HCO3− Metabolic acidosis ↓ or normal PaCO2, Lungs eliminate CO2, ↓ HCO3−, ↓ pH conserve HCO3− Metabolic alkalosis ↑ or normal PaCO2, Lungs ↓ ventilation to↑ ↑ HCO3−, ↑ pH PCO2, kidneys conserve H+ to excrete HCO3−

IV Site Selection

Complications of IV Therapy Fluid overload Air embolism Septicemia, other infections Infiltration, extravasation Phlebitis Thrombophlebitis Hematoma Clotting, obstruction