Asynch 5 Acid-Base

Normal Numbers

PCO2

PO2

HCO3-

35-44 mmHG

75-100 mmHG

22-26 mmol/L

3 main systems for deailing with acid/base disruptions

buffers (immediate compensation), respiratory system (rapid), renal (delayed)

Buffer System

Equation

Which system takes care of what side

weak acid + weak base (able to donate/receive proton), carbonic acid + bicarbonate

H2O+CO2 ←> H2CO3 ←> H+ + HCO3-

respiratory function renal function

Respiratory System

lungs compensate (adjust pH in minutes)

acidosis (hyperventilation blows off CO2)

alkalosis (hypoventilation retains CO2), removes volatile acids

Renal system

kidneys compensate (adjust pH in hours to days)

acidosis (retain HCO3, excrete phosphate and ammonium)

alkalosis (excrete HCO3 + reduce HCO3 reabsorption)

Respiratory acid-base disorder=imbalance of?

CO2

hypoventilation: decrease CO2; respiratory acidosis

hyperventilation: increase CO2; respiratory alkalosis

Metabolic acid-base disorder=imbalance of?

HCO3-

increase HCO3=metabolic alkalosis

decrease HCO3= metabolic acidosis

what happens when lungs are hypoventilating

respiratory acidosis etiology

clinical manifestations

not blowing off enough CO2=increase CO2 circulating in blood=increase H+ in blood=decrease pH= respiratory acidosis= kidneys respond by increasing HCO3-

inhibition of resp center in medulla (opiates), respiraotry muscle disorder, disorder of gas exchange, airway obstruction

headache, weakness, tachycardia, dyspnea, tachypnea

what happens when lungs are hyperventilating

respiratory alkalosis etiology

clinical manifestations

exhaling excessive amount of CO2=decrease CO2 in bloodstream=decrease H+=kidney decreases HCO3-=increase pH= respiratory alkalosis

stimulation of medullary respiratory center, hypoxemia

tachy, chest main, numbness of extremities

What happens when decrease HCO3 in blood?

Metabolic Acidosis etiology

Clinical manifestations

Increase H+ in blood=decrease pH=metabolic acidosis=resp system decreases CO2 via hyperventilation

excess production of fixed H+, loss of bicarbonate, inability to excrete fixed H+

hyperkalemia, fruity odor/breath, lethargy/confusion

What happens when blood retains HCO3-?

Metabolic Alkalosis Etiology

Clinical Manifestion

decrease H+ = increase pH = metabolic alkalosis = respiratory system increase CO2 via hypoventilation

high intake of antacids

hypokalemia