Asia
Hyperbaric
Centre
Who Is
This For?
This supportive protocol is for people recovering from severe limb trauma — crush injuries, compartment syndrome, open fractures with heavy soft-tissue damage — whose surgical team recommends hyperbaric oxygen as an adjunct to their care.
The evidence points to who benefits most:
Severe soft-tissue injury: Gustilo grade II–III open fractures and crush injuries — the population studied in the randomized trials [3] [4].
Established or threatened compartment syndrome: After fasciotomy, or when swelling is threatening the limb's micro-circulation despite surgical management [1] [2].
Older patients with severe injuries: In the randomized trial, the benefit concentrated sharply in patients over 40 with the most severe injuries — 87.5% versus 30% complete healing [3].
Cases heading toward further surgery: When grafts, flaps, vascular revision — or amputation — are being weighed, the trial evidence shows hyperbaric oxygen can change that trajectory [3].
The sequence is non-negotiable: emergency surgery first, hyperbaric oxygen as its partner, ideally within the first day [3] [4]. A doctor's referral is required — here, it will almost always come from your orthopaedic or trauma surgeon, and we coordinate directly with them.
Early. The zone of secondary injury develops over the first 48 to 72 hours after trauma — that is when the tissue's fate is being decided, and when the evidence says intervention counts most [2] [3].
Hyperbaric oxygen should be discussed with the trauma team when:
Emergency surgery is complete and the limb's viability is uncertain — dusky tissue, marginal perfusion, rising compartment pressures, or a flap that looks threatened.
The injury is severe (Gustilo III) and the team wants to protect as much tissue as possible through the critical first days [3] [4].
Further procedures are being scheduled — grafts, flaps, serial debridements — where better tissue condition directly changes what is possible [3].
Swelling is not resolving as expected in the first days after surgery.
One caution, stated plainly: hyperbaric oxygen never substitutes for fasciotomy or vascular repair. If compartment syndrome is suspected and untreated, the answer is the operating theatre — not the chamber. Our role begins alongside surgery, not instead of it [1] [2].
When to Consider HBOT
Breaking the Swelling–Ischemia Cycle
A crushed limb is trapped in a vicious cycle. Injury causes swelling. Swelling raises pressure inside the muscle compartments. Pressure collapses the micro-vessels. Without blood, tissue suffocates — and dying tissue swells more. Round and round, for days after the accident, the injury keeps eating its own margin [1] [2].
Elevating the limb and waiting cannot always break this. Oxygen at normal pressure cannot break this — the red blood cells carrying it cannot pass through the collapsed vessels.
Inside the chamber, we change the physics. At 2.0 to 2.5 ATA, 99.5% medical-grade oxygen dissolves directly into the blood plasma, bypassing red blood cells entirely [1]. This creates a remarkable double action — the reason pressure, not just oxygen, matters here.
First, hyperoxic vasoconstriction. In healthy vessels, high oxygen tension causes a 20% reduction in blood flow — which sounds harmful until you understand what it does to a swollen limb: less inflow means less fluid leaking into tissue, while the plasma still carries abundant oxygen. Swelling falls. The compartment pressure strangling the limb eases [1] [2].
Second, margin perfusion. The oxygen-saturated plasma diffuses into the zone of stasis — the margin of bruised, half-starved tissue between what is clearly alive and what is clearly lost — keeping those cells alive through the critical days while micro-circulation re-establishes [1] [2]. Meanwhile, pressure blunts ischemia-reperfusion injury, the inflammatory second hit that damages tissue when blood flow returns [2].
The goal is specific: shrink the zone of secondary injury, keep the margin alive, and give surgery the best possible tissue to work with.
The Science & Clinical Evidence
We do not make promises. The research does that. Crush injury is an established UHMS indication for adjunctive hyperbaric oxygen [1], and unusually for trauma, it has randomized, sham-controlled evidence.
The landmark trial, published in the Journal of Trauma, randomly assigned 36 people with severe crush injuries — blinded, with sham chamber sessions for the control group — to hyperbaric oxygen twice daily for six days after surgery, or to placebo [3]:
94% vs 56% — complete healing with hyperbaric oxygen versus placebo. Number needed to treat: 3. — Bouachour et al., Journal of Trauma, 1996 [3]
6% vs 33% — the proportion needing further surgery — grafts, flaps, vascular procedures, or amputation — with hyperbaric oxygen versus placebo. No one in the hyperbaric group required amputation. — Bouachour et al., 1996 [3]
The more recent HOLLT randomized trial — 120 open tibial fractures — found significantly less tissue necrosis with hyperbaric oxygen (29% versus 53%), fewer long-term complications, and better functional outcomes at one and two years [4]:
29% vs 53% — tissue necrosis rates with and without hyperbaric oxygen in severe open tibial fractures. — Millar et al., HOLLT trial, 2022 [4]
Where we are honest with you: the HOLLT trial missed its primary composite endpoint (necrosis-or-infection combined, P = .12) — the benefit showed clearly in the individual outcomes, but the trial's headline measure did not reach significance [4]. The randomized evidence here is two trials, not twenty. What supports them is a well-characterised mechanism, decades of surgical series, and consistency of direction: less tissue loss, fewer operations, better function — greatest when sessions begin early and injuries are severe [1] [2] [3] [4]. We present it exactly that way to your surgical team.
Our protocols follow the trial structures and UHMS guidance for acute traumatic ischemia [1] [3]. In this acute phase, the schedule is built around the surgical plan — wound checks, serial procedures, the trauma team's timetable.
Oxygen Purity: 99.5% Medical-Grade Oxygen — pharmaceutical-grade purity certified under the Pharmacy and Poisons Ordinance (Cap. 138) [5].
Chamber Pressure: 2.0 to 2.5 ATA (Atmospheres Absolute) — the range used in the randomized trials [3] [4].
Session Duration: 90 minutes at depth.
Frequency (acute phase): Up to twice daily for the first critical days — the Bouachour protocol ran twice daily for six days — then once daily as the limb stabilises [3].
Total Course: Typically 10 to 14 sessions across the acute phase, guided by wound response and the trauma team's assessment [1] [3].
The Protocol
What To Expect
We understand that entering a hyperbaric chamber can feel unfamiliar. Our team is here to guide you through every step of the process, ensuring you feel comfortable, safe, and supported.
Step 1 — The Briefing & Preparation: Before your first session, our technician will walk you through the safety protocols. You will change into 100% cotton clothing (provided) to eliminate static risk. No electronics, watches, or oil-based cosmetics are allowed inside the chamber.
Step 2 — Pressurisation: As the chamber pressurises over 10-15 minutes, you will feel a sensation in your ears similar to descending in an airplane. Our technician will coach you on simple techniques to clear your ears. Once at depth (2.0-2.4 ATA), you will breathe 99.5% pure oxygen through a comfortable hood or mask. You can read, rest, or watch a screen during the 90-minute session.
Step 3 — Depressurisation & Next Steps: The chamber will slowly depressurise over 10-15 minutes. Once open, you can return to your normal daily activities immediately. Our technician will examine your wound site and coordinate with your primary wound care team to track your progress.
FAQ
How many sessions before I notice a difference?
The acute protocol runs about 10 to 14 sessions over one to two weeks, often starting twice daily [3]. The wound usually shows its answer — colour, swelling, edge viability — within the first several sessions, and your surgical team reads those signs at every dressing change. The randomized evidence is built on this exact early window [3] [4].
Can hyperbaric oxygen replace surgery for compartment syndrome?
Never. Compartment syndrome that needs release needs a scalpel, and every hour of delay costs muscle and nerve. Hyperbaric oxygen is the partner to that surgery — protecting the tissue margin afterwards — not an alternative to it [1] [2]. If anyone offers you a chamber instead of an operating theatre for acute compartment syndrome, that is wrong.
My surgery was several days ago. Is it too late to add hyperbaric oxygen?
The evidence is strongest in the first days — but the decision belongs to your surgical team, and worthwhile benefit has been reported beyond the earliest window [1] [3]. If your wound is struggling, your swelling is not resolving, or further surgery is being planned, ask your surgeon whether adjunctive hyperbaric oxygen fits your case. We will give them the evidence, plainly, including its limits.
UHMS. Crush Injury, Compartment Syndrome, and Other Acute Traumatic Ischemias. UHMS Hyperbaric Oxygen Therapy Indications, 15th Edition. Undersea and Hyperbaric Medical Society. UHMS Official Indications
Strauss MB, et al. Hyperbaric oxygen in crush injuries and acute traumatic ischemias: mechanism and clinical series (zone of stasis, oedema reduction, ischemia-reperfusion). As summarized in UHMS Indications.
Bouachour G, et al. Hyperbaric oxygen therapy in the management of crush injuries: a randomized double-blind placebo-controlled clinical trial. J Trauma. 1996;41(2):333-339. PubMed 8760546
Millar I, et al. HOLLT: Hyperbaric oxygen for lower limb trauma — a randomized controlled trial in open tibial fractures. 2022. [UNVERIFIED — journal/volume to be confirmed before publication]
Hong Kong e-Legislation. Pharmacy and Poisons Ordinance (Cap. 138). Cap. 138 on e-Legislation
