ABG Values, respiratory vs. metabolic acidosis/alkalosis Flashcards
pH
(acid vs. base based on hydrogen ions)
7.34 - 7.45
PaO2
(partial pressure of oxygen that is dissolved in arterial blood)
80 - 100 mmHg
SaO2
(arterial oxygen saturation)
95 - 100 %
PaCO2
(amount of carbon dioxide dissolved in arterial blood)
35 - 45 mmHg
HCO3
(calculated value of the amount of bicarbonate in the bloodstream, not a blood gas but the anion of carbonic acid)
22 - 26 mEq/L
ROME
compensated vs. uncompensated
Respiratory Opposites
Metabolic Equal
if pH WNL 7.35 - 7.45, compensated
respiratory acidosis
obstructed/depressed airway (not breathing) causes: asthma, atelectasis, COPD, emphysema, bronchitis, hypoventilation
S/S: headache, decreased BP, vent. fib from hyperkalemia, hypoventilation (CO2 is retained which increases H creating acidic state H2CO3 retained, decreased pH)
intervention: O2 as prescribed, semi-Fowler’s position, turn cough and deep breathe, hydration to thin secretions, antibiotics for any respiratory infections constricting bronchioles, suction airway if needed, monitor electrolyte levels
the regulator systems for hydrogen ion concentration or acid-base concentration
- buffer system
- lungs CO2
- kidney HCO3
- potassium exchange
respiratory alkalosis
overstimulation of respiratory system causes: fever, hyperventilation (try to blow off CO2 results in decreased H2CO3), hypoxia (brain demands increase RR to acquire more O2), hysteria, pain, overventilation
S/S: lightheadedness, confusion, tachycardia, dysrhythmias from hypokalemia, numbness and tingling of extremities, hyperventilation, N/V, epigastric pain
intervention: assess cause, encourage breathing patterns, breathing techniques and aids as prescribed such as paper bag, monitor electrolytes
metabolic acidosis
excess loss of base or excess retention of acid causes: diabetes mellitus or diabetic ketoacidosis (insufficient insulin supply causes increased fat metabolism leading to an excess of ketones or other acids), excess intake of acetylsalicylic acid (ASA which increases H+ concentration), high-fat diet (accumulation of fat metabolism waste products leading to build up of ketones and acids), insufficient carb metabolism (O2 supply not sufficient to metabolize carb, lactic acid is produced and lactic acidosis occurs), malnutrition, renal insufficiency (renal injury or disease which causes accumulation of protein metabolism waste products), severe diarrhea (loss of excess intestinal and pancreatic secretions which are normally alkaline leads to excess loss of acid)
S/S: Kussmaul’s respiration (abnormally deep, fast RR), confusion, headache, decreased BP, dysrhythmias from hyperkalemia, warm flushed skin, diarrhea
intervention: assess LOC, monitor IO, IV base solutions, safety and seizure precaution, potassium level (when condition resolves, K+ will move back into cell and may lead to hypokalemia)
metabolic alkalosis
accumulation of base or excess loss of acids causes: diuretics (loss of H+ and Cl causes bicarb to increase), severe vomiting or GI suctioning (loss of HCl acid), hyperaldosteronism (increased reabsorption of Na which results in loss of H+), excess intake of NaBicarb or NaHCO3, massive transfusion of whole blood
intervention: assess, monitor electrolytes, safety precautions, administer meds & IV
Allen’s test
To determine presence of collateral circulation pressure on ulnar, color must return 6-7 seconds, if not choose different site
how to analyze arterial blood gas results?
pH lower than 7.35 = acidosis
pH higher than 7.45 = alkalosis
respiratory function indicator = PCO2
metabolic function indicator = HCO3
- Look at pH, determine if acidosis or alkalosis.
- Look at PCO2. If opposite pH then respiratory imbalance.
- If PCO2 equal pH, then metabolic imbalance.
- Full compensation occurs when pH WNL. If pH not WNL then look at respiratory or metabolic indicators.
