What are the indications and uses of Hyperbaric Oxygen Therapy (HBOT)?

Indications and Uses of Hyperbaric Oxygen Therapy (HBOT)

Hyperbaric oxygen therapy (HBOT) is indicated for several specific medical conditions, with the strongest evidence supporting its use in necrotizing soft tissue infections, carbon monoxide poisoning, and certain non-healing wounds, though it should not delay standard care when used as an adjunctive treatment.

FDA-Approved and Evidence-Based Indications

Strong Evidence Indications:

• Necrotizing Soft Tissue Infections (NSTI)

  • Recommended as adjunctive therapy after prompt surgical debridement 1
  • Provides significant mortality reduction (RR = 0.47; 95% CI, 0.30-0.74) despite higher costs and longer hospital stays 1
  • Mechanism: Improves leukocyte function, inhibits anaerobic growth, inhibits toxin production, and enhances antibiotic activity 1

• Carbon Monoxide (CO) Poisoning

  • Not routinely recommended for all cases of smoke inhalation but considered on a case-by-case basis 1
  • Factors to consider: patient demographics (children, pregnant women), poisoning severity, patient stability, and availability of specialized HBOT equipment and team 1
  • All patients with suspected CO poisoning should receive immediate oxygen therapy via high concentration mask or 100% FiO2 if mechanically ventilated 1

• Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL)

  • May be offered within 3 months of diagnosis 1
  • Better outcomes in:
    • Younger patients (under 50-60 years)
    • Early treatment (within 2 weeks to 3 months)
    • Moderate to severe hearing loss (usually >60 dB) 1
  • Treatment efficacy: Number needed to treat is 5 patients to improve 1 person's hearing by 25% 1

• Diabetic Foot Ulcers

  • Conditionally recommended for neuro-ischemic or ischemic diabetic foot ulcers when standard care has failed 2
  • Moderate to high strength of evidence supports this indication 2

Other Recognized Indications:

• Radiation-Induced Tissue Injuries 2, 3
• Chronic Refractory Osteomyelitis 3
• Fournier's Gangrene 4
• Arterial Insufficiencies 3

Mechanism of Action

HBOT works through multiple mechanisms:

• Delivers 100% oxygen at pressures between 1.5-3.0 ATA for 60-120 minutes 5
• Increases dissolved oxygen in blood and tissues independent of hemoglobin 6
• Enhances tissue oxygenation 6, 7
• Reduces inflammation 6, 7
• Promotes angiogenesis through endothelial proliferation 4
• Enhances fibroblastic activity 4
• Increases lymphocyte and macrophage activity 4
• Provides bactericidal effects 4
• Modulates oxidative stress 6

Clinical Considerations and Contraindications

Important Considerations:

• Timing is critical:

  • For NSTI: Should not delay standard surgical treatment 1
  • For ISSNHL: Most effective within first 2 weeks to 3 months 1
  • For burn healing: Most beneficial within first 6 hours 1

• Patient Selection:

  • Assess hemodynamic and respiratory stability, especially in burn patients 1
  • Consider age and severity of condition 1
  • Evaluate risk-benefit ratio for patients with vascular closure devices 2

Relative Contraindications:

• Severe hemodynamic or respiratory instability 1
• Recently placed vascular closure devices (<7 days) 2
• Conditions where standard care would be delayed 1

Monitoring and Complications

• Monitor for signs of bleeding or hematoma formation in patients with vascular devices 2
• Assess vital signs for indications of internal bleeding 2
• Evaluate access sites post-procedure 2
• Watch for rare complications such as pseudoaneurysm formation 2

Emerging Applications

Research is ongoing for HBOT in:

• COVID-19 management (targeting hypoxemia, inflammation, and oxidative stress) 6
• Urological conditions (radiation-induced hemorrhagic cystitis, interstitial cystitis, male infertility) 4
• Peripheral tissue injury due to inotropes and vasopressors 7

While HBOT shows promise in these emerging areas, further research including multicenter clinical studies is needed to establish definitive roles in conditions resistant to conventional therapies 4.