Acid Base Balance and Fluid Balance disorder Dr

Acid Base Balance and Fluid Balance disorder Dr ; Niazy B Hussam Ph. D candidate

Homeostasis A delicate balance of fluids, electrolytes, and acids and bases is required to maintain good health. This balance is called Homeostasis. n n

Body Fluids Intracellular fluid (ICF) n found within the cells of the body q constitutes 2/3 of total body fluid in adults major cation is potassium q Extracellular fluid (ECF) n found outside the cells q accounts of 1/3 of total body fluid major cation is sodium q q q

Terms Osmosis n movement of water across cell membranes from less concentrated to more concentrated Solutes n substances dissolved in a liquid Osmolality n the concentration within a fluid q q q

More Terms Diffusion n movement of molecules in liquids from an area of higher concentration to lower concentration Filtration n fluid and solutes move together across a membrane q from area of higher pressure to one of lower pressure Active Transport n substance moves across cell membranes from less q concentrated solution to more concentrated - requires a carrier q

Routes of Fluid Loss Urine n Insensible fluid loss Feces n n

Electrolytes Sodium Potassium Chloride Phosphate n n Magnesium Calcium Bicarbonate Electrolytes are important for: . Maintaining fluid balance. Contributing to acid-base regulation. Facilitating enzyme reactions. Transmitting neuromuscular reactions n n n

Acid-Base Balance Acid-Base balance is: n the regulation of HYDROGEN ions. q

p. H The acidity or alkalinity of a solution is n measured as p. H. The more acidic a solution, the lower the p. H. n The more alkaline a solution , the higher the n p. H. Water has a p. H of 7 and is neutral. n The p. H of arterial blood is normally between n 7. 35 and 7. 45

Hydrogen ions The more Hydrogen ions, the more acidic the solution and the LOWER the p. H The lower Hydrogen concentration, the more alkaline the solution and the HIGHER the p. H n n

Buffer Systems Regulate p. H by binding or releasing Hydrogen Most important buffer system: n n Bicarbonate-Carbonic Acid Buffer System q (Blood Buffer systems act instantaneously and thus n constitute the body’s first line of defense against acidbase imbalance)

Respiratory Regulation Lungs n help regulated acid-base balance by eliminating or retaining carbon dioxide p. H may be regulated by altering the rate and q depth of respirations changes in p. H are rapid, q occurring within minutes normal CO 2 level 35 to 45 mm Hg n q § q

Renal Regulation Kidneys n the long-term regulator of acid-base balance slower to respond q may take hours or days to correct p. H n kidneys maintain balance by excreting or q conserving bicarbonate and hydrogen ions normal bicarbonate level 22 to 26 m. Eq/L. n q q

Factors Affecting Balance Age n especially infants and the elderly q Gender and Body Size n Environmental Temperature Lifestyle n Stress q Amount of fat q n

Henderson-Hasselbach Equation Demonstrates interrelationship between Carbonic acid q Bicarbonate q p. H = p. K + log [HCO 3 -] /[H 2 CO 3] n

Acid-Base Imbalances Respiratory Acidosis Respiratory Alkalosis Metabolic Acidosis Metabolic Alkalosis n n

Respiratory Acidosis Mechanism n Hypoventilation or Excess CO 2 Production Etiology n COPD q Neuromuscular Disease q Respiratory Center Depression q Late ARDS q Inadequate mechanical ventilation Sepsis or Burns q Excess carbohydrate intake q q q

Respiratory Acidosis (cont) Symptoms n Dyspnea, Disorientation or coma q Dysrhythmias q p. H < 7. 35, Pa. CO 2 > 45 mm Hg q Hyperkalemia or Hypoxemia Treatment q n Treat underlying cause q Support ventilation q Correct electrolyte imbalance IV Sodium Bicarb q q

Respiratory Alkalosis Risk Factors and etiology Hyperventilation due to n q extreme anxiety, stress, or pain § elevated body temperature § overventilation with ventilator § hypoxia § salicylate overdose § hypoxemia (emphysema or pneumonia) CNS trauma or tumor § §

Respiratory Alkalosis (cont) Symptoms n Tachypnea or Hyperpnea q Complaints of SOB, chest pain q Light-headedness, syncope, coma, seizures q Numbness and tingling of extremities q Difficult concentrating, tremors, blurred vision q Weakness, paresthesias, tetany q Lab findings q p. H above 7. 45 q CO 2 less than 35 q

Respiratory Alkalosis (cont) Treatment n Monitor VS and ABGs n Treat underlying disease n Assist client to breathe more slowly n Help client breathe in a paper bag n or apply re breather mask n Sedation n

Metabolic Acidosis Risk Factors/Etiology n Conditions that increase acids in the blood Renal Failure n DKA n Starvation n Lactic acidosis n Prolonged diarrhea q Toxins (antifreeze or aspirin) q Carbonic anhydrase inhibitors - Diamox q q

Metabolic Acidosis (cont) Symptoms n Kussmaul’s respiration q Lethargy, confusion, headache, weakness Nausea and Vomiting q Lab: q p. H below 7. 35 n Bicarb less than 22 Treatment n n treat underlying cause q monitor, I&O, VS, LOC Sodium Bicarb? ABG q q

Metabolic Alkalosis Risk Factors/Etiology Acid loss due to vomiting n gastric suction q n Loss of potassium due to steroids diuresis n n n Antacids (overuse of) q q

Metabolic Alkalosis (cont) Symptoms n Hypoventilation (compensatory) q Dysrhythmias, dizziness q Paresthesia, numbness, tingling of extremities Hypertonic muscles, tetany q Lab: p. H above 7. 45, Bicarb above 26 q CO 2 normal or increased w/comp Hypokalmia, Hypocalcemia q Treatment n I&O, VS, LOC q give potassium q treat underlying cause q q q

Interpreting ABGs 1. Look at the p. H n is the primary problem acidosis (low) or alkalosis (high) n 2. Check the CO 2 (respiratory indicator) is it less than 35 (alkalosis) or more than 45 (acidosis) n n 3. Check the HCO 3 (metabolic indicator) is it less than 22 (acidosis) or more than 26 (alkalosis) n n 4. Which is primary disorder (Resp. or Metabolic)? If the p. H is low (acidosis), then look to see if CO 2 or HCO 3 is acidosis (which ever is acidosis will be primary). If the p. H is high (alkalosis), then look to see if CO 2 or HCO 3 is alkalosis (which ever is alkalosis is the primary). The one that matches the p. H (acidosis or alkalosis), is the primary disorder. n n

Compensation The Respiratory system and Renal systems n compensate for each other attempt to return the p. H to normal q ABG’s show that compensation is present when n the p. H returns to normal or near normal q If the nonprimary system is in the normal range n (CO 2 35 to 45) (HCO 3 22 -26), then that system is not compensating for the primary. For example: n In respiratory acidosis (p. H<7. 35, CO 2>45), if the HCO 3 is >26, then the kidneys are compensating by retaining bicarbonate. If HCO 3 is normal, then not compensating. q q