Hyperbaric Oxygen for the ICU Patient

OVERVIEW

• Often carried out in a multiplace pressurised chamber, some units have monoplace capabilities
• Consider individual chamber critical care capabilities
• Treatments typically between 2 and 3 ATA (200-300 kPa)
• Typical treatments between 2-2.5 hours, can be >5 hours
• 100% Oxygen provided via hoods/masks/ETT
• Treatment endpoints and staged reviews should be defined prior to commencement

INTENSIVE CARE INDICATIONS

• Fulminant Decompression Illness
• Severe Arterial Gas Embolism (Diving/Iatrogenic)
• Necrotising Soft Tissue Infections / Clostridial Myonecrosis
• Refractory Mucormycosis
• Crush Injuries (Gustilo 3b, compartment syndrome)
• Carbon Monoxide Poisoning *controversial*
• Severe anaemia where transfusion is contraindicated *controversial*

PRACTICAL ISSUES IN CRITICAL CARE

Consideration & Prior to Treatment

• Ensure benefit of indication being treated outweighs risk of transport and time away from ICU
• Patient stability weighed up with chamber critical care capabilities
• All equipment needs to be hyperbaric safe and maintain performance
• Informed consent
• Middle ear venting tympanostomies for intubated patients

In the Chamber

A: ETT cuff to be filled with sterile water or connected to dynamic cuff inflator

B: Titrate ventilation to PaCO2, note that EtCO2 is not linearly proportionate at higher pressures

• Increased air density causes increased work of breathing and can precipitate respiratory failure
• PaO2 may not reach hyperbaric oxygen treatment levels in lung pathology
• Pneumothoraxes need to be treated with chest drains connected to Heimlich valves or pleural vacuum relief devices

C: Haemodynamic shifts related to hyperoxic vasoconstriction

• Critical haemodynamic variations noted particularly during air breaks and decompression phases
• ECMO if considered should have clear safety troubleshooting protocols pre-planned

D: Increased sedation dosing due to reduced sensitivity in hyperbaric environments

E: Warmers generally contraindicated due to ignition (fire) risk

• Unused positive pressure valve ports need to be flushed at pressure to prevent occlusion
• Venting of pressure bags, gas-filled equipment, bottles with fluid-air interface
• All equipment should be able to perform consistently in hyperbaric environments

Post / In Between Treatments

• Slow oxygen wean to prevent hyperoxic related resorption atelectasis
• Minimise supplemental oxygen – reduces risk of oxygen toxicity

REFERRAL CONSIDERATIONS

• Critical care capability of local hyperbaric chamber
• Patient transport capabilities and resourcing
• Certainty of diagnosis to be treated
• Indication and alternative treatment options
• Opportunity cost of being away from ICU

REFERENCES

• Buckley NA, Juurlink DN, Isbister G, Bennett MH, Lavonas EJ. Hyperbaric oxygen for carbon monoxide poisoning. Cochrane database of systematic reviews. 2011(4).
• Devaney B, Frawley G, Frawley L, Pilcher DV. Necrotising soft tissue infections: the effect of hyperbaric oxygen on mortality. Anaesthesia and Intensive Care. 2015 Nov;43(6):685-92.
• Gelsomino M, Tsouras T, Millar I, Fock A. A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment. Diving and Hyperbaric Medicine. 2017 Sep;47(3):191.
• Huang E, editor. UHMS Hyperbaric Medicine Indications Manual. Best Publishing; 2024.
• Millar IL, Lind FG, Jansson KÅ, Hájek M, Smart DR, Fernandes TD, McGinnes RA, Williamson OD, Miller RK, Martin CA, Gabbe BJ. Hyperbaric Oxygen for Lower Limb Trauma (HOLLT): an international multi-centre randomised clinical trial. Diving and Hyperbaric Medicine. 2022 Sep;52(3):164.
• Mitchell SJ, Bennett MH, Moon RE. Decompression sickness and arterial gas embolism. New England Journal of Medicine. 2022 Mar 31;386(13):1254-64.

Critical Care

Compendium

…more CCC

Caleb Lin

MBBS (Hons), MPH, DipDHM, PGDipClinUS, CCPU

Diving & Hyperbaric Medicine Fellow

Fiona Stanley Hospital, Perth.

Dual trainee in Hyperbaric and Emergency Medicine.

Graduated with honours from Monash University. Commenced teaching at Monash University as a bedside tutor then clinical skills tutor whilst training in Emergency. Keen interest in ultrasound to help improve diagnostic efficiency and patient outcomes in the emergency setting. Strong advocate for pre-vocational medical trainees as part of the PMCV accreditation team.