Hyperbaric Oxygen Therapy in Critically Ill Patients
Hyperbaric oxygen therapy (HBOT) has extremely limited and specific indications in critically ill patients, with established benefit only for carbon monoxide poisoning post-cardiac arrest (despite poor overall survival) and no proven role in acute stroke, peripheral artery disease wounds, or general critical illness. 1
Established Indications in Critical Care
Carbon Monoxide Poisoning
- HBOT may be considered in critically ill patients with cardiac arrest from carbon monoxide poisoning to reduce persistent or delayed neurological injury, though survival to hospital discharge remains poor regardless of HBOT administration. 1
- The transport risks of moving critically ill post-arrest patients to hyperbaric facilities must be weighed against potential neurological benefits on a case-by-case basis. 1
- Two studies showed improved neurological outcomes in less severe carbon monoxide poisoning (excluding cardiac arrest), but two other studies found no difference in neurologically intact survival. 1
- Systematic reviews concluded that improvement in neurologically intact survival is "possible but unproven." 1
Cyanide Poisoning
- HBOT has theoretical benefit for cyanide poisoning similar to carbon monoxide, though evidence is limited. 1
Conditions Where HBOT is NOT Recommended
Acute Ischemic Stroke
- Data do not support routine use of HBOT in acute ischemic stroke. 1
- Clinical trials have been inconclusive or shown no improvement in outcomes, and a meta-analysis found no evidence that HBOT improves clinical outcomes. 1
- The inherent delay from stroke onset to HBOT initiation (due to need for specialized chamber) is a fundamental problem. 1
Critical Limb Ischemia and Peripheral Artery Disease
- The effectiveness of HBOT for wound healing in critical limb ischemia is unknown. 1
- Literature has focused on patients without severe PAD and has not demonstrated long-term benefit on wound healing or amputation-free survival compared to sham treatment. 1
- One small RCT showed decreased ulcer area at 6 weeks but no significant differences at 6 months or in healing/amputation rates. 1
General ICU Patients
- HBOT should only be included in ICU patient care after careful risk/benefit assessment specific to both the hyperbaric center capabilities and the patient's clinical condition. 2
- HBOT should not delay or interrupt overall patient management. 2
Critical Safety Considerations
Transport Risks
- The risks of transporting critically ill patients to hyperbaric facilities are significant and include: 1, 2, 3
- Interruption of ongoing critical care
- Need for specialized transport teams trained in HBO procedures
- Potential for clinical deterioration during transfer
- Distance from ICU resources
Physiological Effects in Critical Illness
- HBOT causes physiological changes that may further compromise critically ill patients. 2
- Potential complications include barotrauma (middle ear, sinuses), seizures, claustrophobia, hypotension, cardiac arrhythmias, and pneumonia. 1, 4, 5
- Patient monitoring and treatment must continue uninterrupted during HBOT. 2
Facility Requirements
- The hyperbaric chamber should be specifically designed for ICU patients and fully equipped for continued monitoring and treatment. 2
- Ideally located in or immediately adjacent to the ICU. 2
- Requires a large, well-trained team of physicians, nurses, chamber operators, and technicians. 2
- All devices must be tested and safe for hyperbaric environments. 2
Practical Limitations
- High cost and poor availability. 4
- Need for specialized equipment and trained personnel. 4
- Impractical for acute treatment requiring rapid intervention. 4
- 24-hour accessibility often not available, requiring interhospital transfer. 3
Common Pitfall
Do not confuse hyperbaric oxygen therapy (delivered above atmospheric pressure) with normobaric oxygen therapy (standard supplemental oxygen). 1 For cluster headaches, normobaric oxygen is recommended and practical, whereas HBOT is not indicated. 4