Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBO) is defined as:

Administration of oxygen at pressures greater than 1 atmosphere absolute (ATA)

Most hyperbaric oxygen treatments are conducted at pressures between:

2 and 3 ATA

Which physiologic principle explains the reduction in size of gas bubbles during HBO therapy?

Boyle's Law

HBO therapy is most effective in treating decompression sickness because it:

Compresses nitrogen bubbles trapped in tissues and blood

Which law best explains the increased amount of dissolved oxygen in plasma during HBO therapy?

Henry's Law

At 3 ATA, the dissolved oxygen content of plasma is approximately:

7 mL/dL

A minimum tissue PO₂ required for normal cellular function is:

30 mm Hg

Which physiologic effect of HBO may help reduce edema in burn and crush injury patients?

Vasoconstriction

Formation of new capillary beds stimulated by HBO therapy is called:

Neovascularization

Which chamber type is capable of treating patients at pressures of 6 ATA or greater?

Multiplace chamber

In a multiplace chamber, the chamber is typically filled with:

Air

A major advantage of a multiplace chamber is:

Ability of medical personnel to directly care for patients under pressure

A monoplace hyperbaric chamber typically contains:

100% oxygen atmosphere

The most common acute indication for HBO therapy is:

Air embolism

HBO therapy is considered the primary treatment for:

Decompression sickness

The half-life of carboxyhemoglobin while breathing room air is approximately:

More than 5 hours

The half-life of carboxyhemoglobin during HBO at 3 ATA is approximately:

23 minutes

Which carbon monoxide poisoning patient is most likely to require HBO therapy?

Patient with history of unconsciousness and COHb of 30%

The most common complication of HBO therapy is:

Barotrauma to ears and sinuses

Early signs of central nervous system oxygen toxicity include:

Twitching, sweating, pallor, and restlessness

A late manifestation of CNS oxygen toxicity is:

Seizures and convulsions

Which is an absolute contraindication to HBO therapy?

Untreated pneumothorax

Which is considered a relative contraindication to HBO therapy?

Inner ear infection

During HBO therapy, a ventilated patient's tidal volume may:

Decrease and require correction

Failure to recognize reduced tidal volume and air leaks during HBO therapy can result in:

Hypercapnia and respiratory acidosis