Michelle Jocson, MSN/Ed., RN

Identification of the specific acid-base imbalance is important in identifying the underlying cause of the disorder and in determining appropriate treatment

Regulate the bicarbonate level in the ECF

In respiratory acidosis and most metabolic acidosis, kidneys excrete hydrogen and conserve bicarbonate to help restore balance

In respiratory and metabolic alkalosis, kidneys retain hydrogren and

excrete bicarb

Adjusts ventilation in response to the amount of CO2 in the blood

In metabolic acidosis, respirations increase, causing greater elimination of CO2

In metabolic alkalosis, respiratory rate decreases, causing CO2 to be retained

pH 7.35-7.45 PaCO2 35-45 HCO3 22-26

Clinical disturbance characterized by low pH, and low bicarbonate (HCO3) concentration

Low pH Low HCO3

Results from direct loss of bicarbonate- Diarrhea- Diuretics- Early renal insufficiency- TPN without bicarbonate

Headache Confusion Drowsiness Increased respiratory rate and depth Nausea and vomiting Increased BP Cold, clammy skin

Clinical disturbance characterized by a high pH and a high bicarbonate

high pH high HCO3

Vomiting or gastric suction Pyloric stenosis Hypokalemia Hyperaldosteronism Cushing’s syndrome Causes decreased Calcium

Related to hypocalcemia- Tingling of the fingers and toes- Dizziness- Hypertonic muscles- Depressed respirations- Atrial tachycardia

Clinical disorder in which the pH is less than 7.35 and the PaCO2 is greater than 42 mmHg

Always due to the inadequate excretion of CO2 with inadequate ventilation, resulting in elevated CO2 levels

low pH high PaCO2

Pulmonary edema Aspiration of a foreign object Atelectasis Pneumothorax Sedative overdose Sleep apnea Severe pneumonia

Increased pulse and respiratory rate Increased BP Mental cloudiness Feeling of fullness in the head Cerebrovascular vasodilation

Arterial pH is greater than 7.45 and the PaCO2 is less than 38 mm Hg

high pH low PaCO2

Always due to hyperventilation Excessive “blowing off” of CO2- Extreme anxiety- Hypoxemia- Gram negative bacteremia- Inappropriate ventilator settings

Lightheadedness Inability to concentrate Tinnitus Loss of consciousness Tachycardia Ventricular/atrial dysrhythmias