Bleomycin Exposure and Hyperbaric Oxygen

By Rubicon Foundation editorial team

5 min read · 28 October 2026

Past treatment with bleomycin raises a difficult hyperbaric-medicine question: how should clinicians weigh a potentially important treatment against concern about oxygen-related lung injury? The issue matters to divers because the same oxygen physiology underlies both chamber treatment and enriched-gas diving, though their exposures and clinical decisions are not interchangeable.

Why does bleomycin matter during oxygen treatment?

Bleomycin is a chemotherapy drug associated with lung toxicity. The lungs are particularly relevant in hyperbaric care because breathing oxygen at elevated partial pressure can produce pulmonary oxygen toxicity, with effects influenced by the pressure, exposure duration and pattern of breathing.

Concern about a past bleomycin course is not simply a question of whether oxygen is safe or unsafe. Clinicians must consider the patient’s current lung health, treatment history, reason for hyperbaric oxygen and the planned exposure. A previous drug exposure is one factor in a risk assessment, not a substitute for examining the individual clinical picture.

What does hyperbaric oxygen change?

Hyperbaric oxygen treatment (HBOT) involves breathing oxygen in a chamber at pressure above that at the surface. Increased pressure raises the amount of oxygen dissolved in blood plasma. This is why HBOT can be useful in specific medical settings, and why its dose and duration require clinical control.

Oxygen toxicity is not one uniform event. Pulmonary effects can develop with sufficient oxygen exposure, while central nervous system effects are a separate concern and may include seizures. Risk depends on the oxygen partial pressure and exposure profile; chamber protocols therefore manage pressure, breathing periods and exposure time rather than treating oxygen concentration alone as the whole dose.

How are risks and contraindications assessed?

Research in this area asks how clinicians handle a history that may alter the balance of benefit and harm, and how absolute contraindications are defined in practice. A contraindication is a reason to avoid or reconsider a treatment; calling one “absolute” implies a stronger restriction than a precaution that can be weighed against the clinical need.

Studies and clinical reviews may examine treatment decisions, medical histories, protocols and how contraindications are understood across practice. For a patient with previous bleomycin exposure, relevant considerations include:

Exposure history: the timing and details of the prior treatment.
Present lung status: symptoms, known pulmonary injury and clinical assessment.
Proposed HBOT exposure: the pressure, oxygen dose, duration and treatment schedule.
Clinical purpose: the reason for HBOT and the expected benefit compared with potential harm.

These factors require individual medical judgment. A diving-medicine or hyperbaric-medicine physician should be involved when past bleomycin treatment is relevant; a general rule cannot replace an assessment of the person and proposed treatment.

Why is this relevant to divers?

Divers encounter oxygen through breathing-gas selection, depth and exposure time. Enriched oxygen mixtures increase oxygen partial pressure at a given depth, so dive planning includes limits intended to reduce oxygen toxicity risk. The underlying physiology overlaps with HBOT, but chamber treatment and underwater exposure differ in purpose, pressure profile, supervision and available response to an emergency.

A history of chemotherapy or lung injury can also matter when assessing fitness to dive. Divers should not transfer a chamber-treatment decision directly to a dive plan, or assume that a past treatment alone determines fitness. If bleomycin exposure is part of a medical history, discuss it with a physician experienced in diving medicine before diving.

What does this research area contribute?

Work on prior bleomycin exposure and HBOT sits at the intersection of drug-related lung effects, oxygen physiology and clinical decision-making. It also connects with the wider hyperbaric question of how to identify genuine contraindications without confusing a potential hazard with an automatic prohibition.

For clinicians, the practical challenge is to document the treatment history, evaluate current health and make the oxygen exposure as deliberate as the clinical indication requires. For divers, the useful lesson is narrower: oxygen risk depends on dose and context, and a personal history that could affect the lungs belongs in a qualified medical assessment.

Frequently asked questions

Is past bleomycin treatment automatically incompatible with HBOT?

It should prompt careful clinical review, not an assumption that every case has the same answer. A hyperbaric-medicine physician can weigh current lung health, the reason for treatment and the proposed oxygen exposure.

Is HBOT oxygen exposure the same as oxygen exposure while diving?

No. Both involve oxygen partial pressure, but the setting, exposure profile, purpose and monitoring differ. Chamber protocols and dive plans address distinct operational and medical risks.

Should divers disclose previous bleomycin treatment?

Yes. Include it in a medical assessment, particularly if there are respiratory symptoms or a history of lung injury. A diving-medicine physician can advise on fitness to dive in the individual case.

An original research-library explainer written by the Rubicon editors. It is not a summary of a specific publication.