Hyperbaric Medicine Glossary (A–Z)

A

Air break

A scheduled pause breathing normal air during a session to prevent oxygen toxicity.

Angiogenesis

The growth of new blood vessels — a key long-term effect of HBOT.

ATA

Atmospheres Absolute — the unit of pressure used in hyperbaric medicine.

B

Barotrauma

Injury from pressure changes, most commonly to the ears.

Boyle's Law

Gas volume shrinks as pressure rises — why bubbles shrink under recompression.

C

CPT 99183

The billing code for physician supervision of an HBOT session.

D

DAN

Divers Alert Network — the 24/7 emergency resource for diving injuries.

Decompression sickness

Illness from nitrogen bubbles forming after rapid ascent from depth.

F

Fibroblast

The cell that builds collagen and rebuilds wounds — and needs oxygen to work.

H

Henry's Law

The physical law explaining why pressure forces more oxygen into blood plasma.

HIF-1α

A cellular oxygen-sensing protein involved in healing signals.

Hyperoxia

A state of higher-than-normal oxygen levels in tissue.

Hypoxia

A shortage of oxygen in tissue — the problem HBOT aims to correct.

I

Isopression

The steady middle phase of a session at full treatment pressure.

M

Marx protocol

The staged HBOT-and-surgery approach for osteoradionecrosis of the jaw.

Monoplace chamber

A single-patient hyperbaric chamber pressurized with oxygen.

Multiplace chamber

A walk-in chamber holding several patients, pressurized with air.

N

NCD 20.29

The Medicare National Coverage Determination that governs HBOT coverage.

Normobaric

At normal atmospheric pressure (1 ATA).

O

Osteoradionecrosis

Bone death caused by prior radiation therapy.

Oxygen toxicity

The adverse effects of breathing too much oxygen at pressure.

P

Pneumothorax

A collapsed lung — the one absolute contraindication to HBOT.

R

Reperfusion injury

Tissue damage that occurs when blood flow returns after a period of oxygen loss.

S

Stem cell mobilization

HBOT's ability to release stem cells from bone marrow into circulation.

T

TcPO₂

Transcutaneous oxygen measurement used to assess wound healing potential.

U

UHMS

The Undersea and Hyperbaric Medical Society, which sets indication standards.

US Navy Treatment Table 6

The standard recompression protocol for serious decompression sickness.

W

Wagner grade

A classification system for the severity of diabetic foot ulcers.