ABG's

Lab assessment for pt with metabolic acidosis

pH = low HCO3 = low PaO2 = normal PaCO2 = normal or slightly decreased K+ = often high Check serum potassium level!!

Lab assessment for pt with respiratory acidosis

pH = low HCO3 = variable (normal with rapid onset resp acidosis because kidneys have not had time to compensate. elevated when resp acidosis persists for 24 hrs or longer) PaO2 = low PaCO2 = high K+ = elevated in acute resp acidosis. low in chronic ersp acidosis when renal compensation is present.

S/S of metabolic alkalosis

-Restlessness followed by lethargy -Confusion -Altered LOC -Dysrhythmias -Compensatory hypoventilation -Slow respirations -Diarrhea -Nausea and vomiting -Hypokalemia

Tx and interventions for respiratory acidosis

-raise hob, sit pt up. -get pt to cough -supply o2 to stabilize pt. (but 02 alone may not correct problem) -bronchodilator (for bronchoconstruction) (albuterol, atrovent) -steroids (for inflammation) (inhaled or IV) -mucolytic (guafenisen, or mucinex) -get pt to cough to break up and remove mucus. ***no narcotics, as they will decrease respirations, which will make pt retain CO2 even more**** Address rapidly resolvable causes - pain,pneumothorax, CNS depression r/t medications Monitor for increasing potassium levels.

normal range of bicarbonate (HCO3)

22 - 26mEq/L

normal range of PaCO2

35 - 45 mmHg

normal range of pH

7.35 - 7.45

Causes of respiratory acidosis

Accumulation of CO2 combines with water in body to produce carbonic acid which lowers blood pH. Any condition that can cause HYPOVENTILATION can be responsible: -CNS depression due to head injury, narcotics, sedatives, or anesthesia -Impaired resp muscle function r/t spinal cord injury, neuromuscular diseases, or neuromuscular blocking drugs. -Pulmonary d/o ie, atelectasis, pneumonia, pulmonary edema, bronchial obstruction, COPD -massive pulmonary embolus -Hypoventilation due to pain, chest wall injury/ deformity, abdominal distension.

pH = 7.20 PaCo2 = 60 HCO3 = 19

Combined respiratory & metabolic acidosis

pH = 7.48 PaCo2 = 20 HCO3 = 35

Combined respiratory & metabolic alkalosis

pH = 7.6 PaCo2 = 20 HCO3 = 35

Combined respiratory & metabolic alkalosis

Causes of metabolic acidosis

Deficit of base in bloodstream or excess of acids other than CO2. Base levels may be decreased due to - severe diarrhea and malnutrition Acids may be increased due to - renal failure, diabetic ketoacidosis, anaerobic metabolism, salicylate (aspirin) overdose.

Conditions that increase acid production

Diabetic ketoacidosis Seizures

Condition that overeliminates bases

Diarrhea

Causes of respiratory alkalosis

Excessive loss of CO2 HYPERVENTILATION -psychological responses, ie hysteria, mechanical ventilation, brain trauma/tumor

Primary Disorder

If PaCO2 moves in OPPOSITE direction of the pH, then the primary cause is RESPIRATORY If the PaCO2 moves in the SAME direction as the pH, then the primary cause is METABOLIC

Causes of metabolic alkalosis

Increase of base -excess antacids Decrease of acid -prolonged vomiting -prolonged nasogastric suctioning -hypercortisolism -hyperaldosteronism -thiazide diuretics

Tx and interventions for rmetabolic alkalosis

Interventions to prevent further losses, to restore fluid balance, and to monitor changes (K+ & Cl-). -Drugs are prescribed to resolve the causes of alkalosis and restore normal fluid, electrolyte, and acid-base balance. -Stimulate bicarb excretion of kidneys by using drugs such as acetazolamide (DIamox). -In severe cases IV administration of acids may be used -If cause is patient vomiting, antiemetics may be used.

pH = 7.37 PaCo2 = 32 HCO3 = 19

Metabolic acidosis, fully compensated

pH = 7.20 PaCo2 = 30 HCO3 = 19

Metabolic acidosis, partially compensated

pH = 7.22 PaCo2 = 22 HCO3 = 18

Metabolic acidosis, partially compensated

pH = 7.30 PaCo2 = 36 HCO3 = 18

Metabolic acidosis, uncompensated

pH = 7.43 PaCo2 = 46 HCO3 = 33

Metabolic alkalosis, fully compensated

pH = 7.49 PaCo2 = 48 HCO3 = 30

Metabolic alkalosis, partially compensated

pH = 7.48 PaCo2 = 42 HCO3 = 28

Metabolic alkalosis, uncompensated

S/S of metabolic acidosis

Nervous system s/s - headache, confusion, changes in LOC, disorientation, restlessness, lethargy, then stupor or coma. Cardiac s/s - dysrhythmias Respiratory s/s - Kussmaul respirations -deep, gasping, air-hungry -effort to compensate for pH by blowing off more CO2 -compensatory hyperventilation Additional s/s - warm, flushed skin, nausea/vomiting, muscle twitching, hyperkalemia

S/S of respiratory alkalosis

Nervous system s/s - light-headedness, numbness, tingling, confusion, inability to concentrate, blurred vision Cardiac s/s - dysrythmias and palpitations Respiratory s/s - increased work of breathing, deep, rapid breathing, hyperventilation. Additional s/s - dry mouth, diaphoresis, tetanic spasms of arms and legs, seizures.

Conditions that underproduce bases

Pancreatitis Dehydration

S/S of respiratory acidosis

Pulmonary s/s - dyspnea, rapid, shallow respirations Skin- cyanotic, pallor Nervous system s/s - headache, restlessness, confusion, may progress to drowsiness and unresponsiveness if CO2 levels are too high. Cardio s/s - tachycardia, dysrhythmias, high bp, increased cardiac output Other: headache, muscle weakness, disorientation, hyperkalemia, hypoxia

Tx and interventions for respiratory alkalosis

Resolve underlying problem Monitor pt closely due to their dramatically increased work of breathing may experience respiratory muscle fatigue which can result in acute respiratory failure. -Calm pt down, have them take slow, deep breathes with you. -If pt disoriented or confused, reorient and redirect.

pH = 7.36 PaCo2 = 50 HCO3 = 30

Respiratory acidosis, fully compensated

pH = 7.34 PaCo2 = 48 HCO3 = 27

Respiratory acidosis, partially compensated

pH = 7.34 PaCo2 = 50 HCO3 = 30

Respiratory acidosis, partially compensated

pH = 7.22 PaCo2 = 46 HCO3 = 24

Respiratory acidosis, uncompensated

pH = 7.22 PaCo2 = 55 HCO3 = 25

Respiratory acidosis, uncompensated

pH = 7.43 PaCo2 = 34 HCO3 = 19

Respiratory alkalosis, fully compensated

pH = 7.44 PaCo2 = 30 HCO3 = 19

Respiratory alkalosis, fully compensated

pH = 7.48 PaCo2 = 34 HCO3 = 20

Respiratory alkalosis, partially compensated

pH = 7.52 PaCo2 = 31 HCO3 = 23

Respiratory alkalosis, uncompensated

Conditions that decrease acid elimination

Respiratory impairment Renal impairment

Tx and interventions for metabolic acidosis

Tx dependent on cause. If diabetic hyperglycemia is cause - give insulin to halt production of ketone bodies If due to prolonged diarrhea - give antidiarrheal drugs and rehydrate. IV fluids and Bicarbonate (only adminstered if serum bicarb levels are low.****) Search for hypoxic tissue & restore tissue perfusion. After considering tissue hypoxia consider other causes. Monitor for increasing potassium levels.

States of Compensation

Uncompensated (pH will be outside of normal range) Partial Compensated (pH will be outside of normal range) Fully Compensated (pH will be within normal range)