ABG Practice Questions

Has an uncompensated respiratory acidosis with hypoxemia as a result of his pneumonia. This is due to inadequate ventilation and perfusion. The treatment goals would be to improve both ventilation and oxygenation. Ventilation may improve with the use of bronchodilators and pulmonary hygiene. If not, the patient may require CPAP, BiPAP, or intubation and mechanical ventilation. Oxygen therapy should consist of only the minimal amount necessary to increase the oxygen saturation to normal (95%).

Uncompensated metabolic acidosis. This is due to excessive bicarbonate loss from diarrhea. It is interesting to note that there is no compensation. Normally, the respiratory center compensates quickly for metabolic disorders. However, the patient. would have to hyperventilate in order to compensate. This may not be possible in this present condition, and should be evaluated further. Treatment would consist of control of the diarrhea and bowel rest. It should not be necessary to administer bicarbonate in the present condition.

Metabolic and respiratory acidosis with hypoxemia. The metabolic acidosis is caused by sepsis. The respiratory acidosis is secondary to respiratory failure. This presentation of sepsis and associated respiratory failure is consistent with ARDS. Treatment must be aggressive, because acidosis is severe. The respiratory status needs to be stabilized, and would probably require mechanical ventilation. If hypotension exists, aggressive fluid and vasopressor support would be warranted. This patient is at high risk for further complications and should be managed in an ICU. Bicarbonate should not be administered until the underlying sepsis and respiratory failure is treated.

Fully-compensated respiratory acidosis with hypoxemia. Full compensation is evidenced by the normal pH in spite of acid/base disorder. This is the patients baseline and doesn't require treatment.

Uncompensated metabolic alkalosis. This is due to vomiting that results in excessive loss of stomach acid. Treatment consists of fluids, anti-emetics, and management of the electrolyte disorders.

As a result of the neurologic condition, the patient has chronic hyperventilation syndrom. Blood gas shows a fully-compensated respiratory alkalosis. This is a chronic and stable condition and probably requires no treatment.

The patient has overmedicated with TUMS, effectively absorbing too much stomach acid. ABG shows a partially-compensated metabolic alkalosis. Treatment consists of better control of GERD, possibly with H2-blockers (Pepcid) or proton-pump inhibitors (Prilosec).

Severe metabolic and respiratory acidosis with hypoxemia. The metabolic component comes from decreased perfusion, and the respiratory component comes from inadequate ventilation. Treatment would consist of intubation, mechanical ventilation, blood pressure and circulatory support.

Metabolic and respiratory acidosis with hypoxemia. Respiratory acidosis is probably the result of pneumonia (also causing the fever). Pneumonia has altered glucose metabolism, causing hyperglycemia and diabetic ketoacidosis. Treatment should be three-pronged: 1) increase oxygenation with oxygen therapy; CPAP, BiPAP, or mechanical ventilation, 2) treat pneumonia with antibiotics, antipyretics, and good pulmonary hygiene, and 3) administer insulin and IV fluids to decrease blood glucose and treat DKA.

The patient is being overventilated which caused a partially-compensated respiratory alkalosis. Treatment would consist of decreasing ventilatory support, or trying other modes of ventilation to decrease minute volume. Will be difficult to wean from the ventilator in this condition due to the metabolic compensation. Therefore attempts should be made to allow CO2 to increase back to normal before weaning can proceed.