01 / Thinking and memory
More clarity in everyday tasks
Reports describe gains in attention, memory, mental speed, and planning. These are promising areas to discuss when cognitive changes interfere with work or home life.4, 6
Recovery consultations in Scottsdale & Glendale
Hyperbaric oxygen therapy after carbon monoxide poisoning
The emergency may be over, while memory, concentration, movement, or everyday tasks still feel different. RX-O2 regularly treats patients for the delayed neurological consequences of carbon monoxide exposure. Meet with our team to explore whether HBOT could support your next stage of recovery.
Clinical reports describe meaningful improvements in thinking, mobility, and independence after delayed symptoms develop. These findings offer reasons to explore treatment, with goals and expectations tailored to you.1, 2, 3
For medically stable patients after emergency care. HBOT for established delayed symptoms has promising but limited clinical evidence; improvement is not guaranteed.
Your next step starts with a conversation.Attentive care. Meaningful recovery goals.
FDA-cleared chambersHard-shell hyperbaric systems
100% medical oxygenBreathed through a dedicated mask or hood
Physician-led careMedical evaluation before treatment
NHSA-certified techniciansAttentive monitoring during your visit
Focus on what matters in daily life
Explore the potential for meaningful recovery
Recovery goals can be deeply practical: following a conversation, walking with greater confidence, or managing more of your day independently. Published reports suggest that selected patients with delayed CO-related brain injury may improve during a care plan that includes HBOT.
02 / Movement and balance
Working toward greater confidence
Some patients have improved in walking, balance, stiffness, or slowed movement during combined HBOT and rehabilitation care. Medical assessment helps identify the cause and the right recovery plan.1, 3
03 / Function and independence
Reconnecting with your routine
Individual cases include a return to independent activities or employment. These outcomes show what recovery can look like for some people, without predicting how much any one person will improve.1, 4
You do not need all the answers before contacting us. Bring your questions, your current care plan, and what you hope to understand. A consultation can help you weigh potential benefits, uncertainty, practical needs, and costs before making a treatment decision.
Understanding the recovery phase
Why symptoms can appear after you initially feel better
Delayed neurological sequelae, often shortened to DNS, are new neurological or cognitive problems that emerge after an apparent period of recovery from CO poisoning. Some people instead have symptoms that persist from the original injury. The distinction helps guide assessment.2, 5
CO can disrupt oxygen delivery and cellular function. The resulting brain injury may involve inflammation and damage to white matter, the connections that help different parts of the brain communicate. Delayed symptoms can occur after the CO level in the blood has fallen; they are not simply evidence of gas remaining in your body.5, 9
- Memory or concentration changes
- Slower thinking or responses
- Difficulty walking or balancing
- Changes in mood or behavior
- Problems with speech or planning
- Needing more help with daily tasks
HBOT increases oxygen availability under pressure. Researchers are exploring how it may influence injury and recovery processes after CO poisoning. The clinical reports below are encouraging, but they do not establish that HBOT repairs every type of brain injury.
Report new or worsening symptoms promptly to your treating clinician; sudden or severe changes need emergency assessment. Follow your discharge plan. CDC recommends a repeat medical and neurological examination about two weeks after discharge.9
Research after delayed symptoms develop
Encouraging findings for the next stage of recovery
These publications address established delayed neurological effects. The strongest next step is to match the evidence to your history, symptoms, and goals with a hyperbaric specialist.
Literature checked
September 12, 2026
2026 · Individual case report
Recovery of daily function after severe delayed symptoms
HBOT alongside cognitive, speech, and physical rehabilitation
A 29-year-old woman developed marked cognitive and functional decline 38 days after poisoning. Following rehabilitation that included HBOT, her balance, walking, and cognitive function improved. She returned to work six months after rehabilitation discharge, with normal neuropsychological testing before her return.
This is one patient’s combined-care experience. It cannot separate the effect of HBOT from rehabilitation, time, or other treatment, and it is not a promise of the same recovery for others.
Read the 2026 recovery report2021 · Retrospective comparison
An association between post-DNS HBOT and recovery
62 patients with delayed neuropsychiatric sequelae
In a hospital review, receiving HBOT after delayed symptoms developed was associated with recovery at follow-up. Earlier initiation after DNS diagnosis was also associated with a more favorable outcome.
Treatment was not randomized, and only 11 of the 62 patients met the study’s recovery definition. Patient selection, earlier care, and other factors may have influenced the findings. This supports prompt specialist assessment without establishing an RX-O2 response rate or a fixed treatment deadline.
Read the delayed-recovery study2024 · Individual case and literature review
Resolution of disabling movement and cognitive symptoms
Symptoms emerged eight weeks after initial recovery
A 26-year-old woman developed progressive, Parkinsonism-like neurological symptoms after initially recovering from CO poisoning. Following a course of HBOT and intravenous corticosteroids, the authors reported symptom resolution and a return to full-time professional work.
This was a single case using more than one treatment. The authors called for a large randomized trial to establish effectiveness and the best approach for delayed neurological sequelae.
Read the clinical report and review2018: improvement when additional HBOT began 14 months after poisoning
A published case described improvements in movement, mental speed, verbal fluency, and fine motor skills when HBOT was restarted 14 months after CO injury. The patient later regained independence, including employment. This is a reason to ask about persistent symptoms even when considerable time has passed; it does not establish how often late treatment helps or how many sessions another patient needs. Read the late-recovery case.
2022: two patients recovered after combined HBOT and rehabilitation care
Two patients developed severe neurological impairment weeks after CO poisoning. The authors described resolution of clinical and imaging abnormalities after prolonged HBOT, corticosteroids, and rehabilitation. Two cases cannot establish the independent contribution of HBOT, but they add to the reports supporting further investigation of recovery-focused treatment. Read the two-case report and review.
Published online December 2025: attention, memory, and executive function
A case report described progressive cognitive improvements during a program combining medicines, HBOT, and tailored neuropsychological rehabilitation. Some difficulties persisted. It highlights the value of tracking meaningful changes over time and keeping rehabilitation part of the plan. Read the neuropsychological recovery report.
Promising outcomes deserve an informed conversation. Much of the evidence for treating established delayed symptoms comes from case reports and observational studies. People may also improve with rehabilitation and time. A consultation helps you consider the potential contribution of HBOT, the uncertainty, and a practical way to measure progress.
Find newer CO and HBOT research on PubMed. This live search is sorted by publication date; new results have not necessarily been assessed for this page.
A separate clinical question
HBOT during the emergency phase
Emergency teams may consider HBOT for selected cases of acute CO poisoning. Decisions depend on the exposure, examination, neurological or cardiac involvement, pregnancy, and other clinical factors.9
Acute studies ask whether early treatment can reduce later injury. They do not prove that the same result occurs when treating symptoms weeks or months later. Suspected poisoning requires 911 and emergency evaluation.
2002 randomized trial: fewer cognitive sequelae after acute treatment
A trial of 152 patients found cognitive sequelae at six weeks in 25% of the HBOT group and 46.1% of the comparison group. Treatment occurred within a 24-hour protocol after acute poisoning. The trial stopped early and had a baseline imbalance in cerebellar dysfunction. Its findings concern early prevention, not treatment of already established delayed symptoms. Read the randomized trial.
2026 systematic review: why acute decisions remain individualized
A review of six randomized trials found no statistically significant pooled benefit for mortality or neurological outcomes. Evidence certainty was low to very low, and treatment approaches differed. This explains why the overall literature is less conclusive than a single positive trial, while clinical guidance still supports considering HBOT in selected acute cases. Read the systematic review.
After emergency care
Bring your history. Tell us what you hope to regain.
Our facilities regularly care for patients seeking help with the delayed neurological consequences of CO poisoning. A consultation gives you a place to discuss the changes you or your family have noticed and whether HBOT fits your current care.
- Exposure date and hospital records
- Discharge and follow-up instructions
- Symptoms and when they appeared
- Prior oxygen or HBOT treatment
- Current medicines and medical history
- Neurology, imaging, and rehabilitation reports
Your evaluating medical provider can review suitability and coordinate with your neurologist, rehabilitation team, or primary clinician. Together, you can identify realistic goals and discuss how to assess changes in daily function.
Tell us about any ongoing concerns at the exposure location. Emergency responders and qualified professionals must address an unsafe environment; an outpatient treatment plan cannot make continued exposure safe.
The RX-O2 difference
Your facility matters. So does your team.
From your first questions to each treatment visit, our Scottsdale and Glendale clinics focus on medical oversight, patient education, and attentive care.
Care led by a physician
Medical Director Marvin A. Borsand, DO, FACOS, FACCS, HCC, leads clinical oversight. A licensed medical provider evaluates suitability and prescribes treatment when appropriate.
FDA-cleared hard-shell chambers
Our facilities use prescription-level hyperbaric systems, with chamber selection and treatment settings matched to your prescribed plan.
100% medical-grade oxygen
You breathe oxygen through a dedicated mask or hood while the chamber is pressurized with air. Your technicians monitor you throughout treatment.
NHSA-certified hyperbaric technicians
Our technicians are certified through the National Hyperbaric Safety Association and trained in chamber operations, patient monitoring, and emergency procedures.
A clear path forward
Build a plan around your recovery
Share what has changed
Discuss symptoms, your emergency treatment, and the parts of daily life you most want to improve. A family member may help describe changes.
Review treatment suitability
A licensed medical provider considers your history, current function, treatment risks, and how HBOT might fit alongside rehabilitation.
Agree on goals and follow-up
If appropriate, discuss the proposed visits, progress checks, costs, and coordination with your other clinicians before starting.
Start with medical suitability. Our pricing and packages page shows current options. Confirm the recommended plan before purchasing; a published study’s treatment schedule is not a personal prescription.
Local care, two Valley locations
Explore HBOT in Scottsdale or Glendale
Looking for a hyperbaric consultation near Phoenix? RX-O2 offers two locations for patients across the Valley. Call the clinic closest to you for appointment availability and help planning repeat visits.
RX-O2 Scottsdale
9035 E Pima Center Parkway #11Scottsdale, AZ 85258
An East Valley option for patients in Scottsdale, Paradise Valley, Fountain Hills, and nearby communities.
RX-O2 Glendale
5626 N 51st AvenueGlendale, AZ 85301
A West Valley option for patients in Glendale, Peoria, Phoenix, and nearby communities.
Questions about the next step
CO poisoning recovery and HBOT FAQs
Whether symptoms appeared recently or have persisted, your questions are welcome once urgent medical needs have been addressed.
Should I come to RX-O2 if I think I have CO poisoning now?
No. Move outside to fresh air and call 911 for suspected current or recent poisoning. Do not reenter an affected building until emergency responders permit it. RX-O2 consultation booking is for follow-up care after emergency evaluation and stabilization.10
Can symptoms develop after I initially feel better?
Yes. Delayed neurological effects can appear days to weeks after apparent recovery. Some published cases presented several weeks later. New or worsening symptoms require medical reassessment; do not assume they are a routine part of recovery. Sudden confusion, collapse, seizures, chest pain, or weakness warrants emergency care.2, 3
Does RX-O2 treat the delayed neurological effects of CO?
Yes. Our facilities regularly treat patients for delayed neurological consequences of CO exposure after their emergency care. A licensed medical provider determines whether HBOT is appropriate and how it can fit with ongoing neurological and rehabilitation care. We focus on your goals without promising a particular result.
Is it worth asking about treatment months later?
Yes. Persistent symptoms are worth discussing with a specialist. One published case reported improvement when additional HBOT began 14 months after injury. That case supports asking the question; it does not establish a guaranteed benefit or a standard course for late treatment.4
What if I already received HBOT in the hospital?
Bring those records. Delayed symptoms can still occur after acute treatment. Several reports on this page describe additional HBOT during the recovery phase, sometimes with rehabilitation or other treatments. A specialist can review the purpose of your earlier treatment and whether a further course is reasonable.
Does a normal fingertip oxygen reading rule out CO poisoning?
No. An ordinary pulse oximeter can be misleading when carbon monoxide is present. Do not use a reassuring home oxygen reading to dismiss a suspected exposure. Emergency assessment considers the exposure history, symptoms, and appropriate testing.9
What about repeated or lower-level exposure?
The exposure source needs investigation and medical assessment. If exposure may be ongoing or poisoning is suspected, get outside and call 911. After the environment is made safe and urgent needs are addressed, a consultation can explore persistent symptoms. Most studies discussed here involve recognized acute poisoning followed by delayed injury; they do not establish benefit for every nonspecific symptom or suspected low-level exposure.
Will HBOT replace neurological care or rehabilitation?
No. The encouraging reports often involve combined care. Continue your prescribed follow-up and rehabilitation. A consultation can help you consider HBOT as an additional option and choose practical measures of progress.
What chambers, oxygen, and safety measures does RX-O2 use?
RX-O2 uses FDA-cleared hard-shell chambers. You breathe 100% medical oxygen through a dedicated mask or hood while the chamber is pressurized with air. Physician-led care and NHSA-certified technicians support treatment. Risks include ear-pressure injury, usually temporary visual changes, and confinement anxiety; less common serious risks include oxygen-induced seizures and lung pressure injury. Staff review medicines, devices, clothing, and other items for compatibility. Electronics and battery-powered devices are not allowed inside chambers.11, 12
How many sessions will I need, and is treatment covered?
There is no single established HBOT course for delayed neurological sequelae. Recommendations depend on medical suitability, goals, and reassessment. Review pricing and packages with the team before purchasing. Coverage for acute CO poisoning does not automatically mean an outpatient course for delayed symptoms will be covered; confirm your specific benefits.
Where can I book a consultation near Phoenix?
Choose RX-O2 in Scottsdale or Glendale. Call 480-270-6090 for Scottsdale or 623-930-0887 for Glendale, or schedule online. These appointment options are for medically stable patients after emergency care.
Explore what your next stage of recovery could look like.
After emergency care, meet with RX-O2 in Scottsdale or Glendale to discuss your symptoms, your goals, and whether HBOT could help.
Sources & further reading
- Małopolska A et al. (2026). Delayed encephalopathy after carbon monoxide poisoning in a 29-year-old female patient. Postep Psychiatr Neurol.
- Liao SC et al. (2021). Real-world effectiveness of hyperbaric oxygen therapy for delayed neuropsychiatric sequelae after carbon monoxide poisoning. Sci Rep.
- Wong ZK et al. (2024). Hyperbaric oxygen for the treatment of carbon monoxide-induced delayed neurological sequelae: a case report and review of the literature. Diving Hyperb Med.
- Keim L et al. (2018). Hyperbaric oxygen for late sequelae of carbon monoxide poisoning enhances neurological recovery: case report. Undersea Hyperb Med.
- Martani L et al. (2022). Delayed Neurological Sequelae Successfully Treated with Adjuvant, Prolonged Hyperbaric Oxygen Therapy: Review and Case Report. Int J Environ Res Public Health.
- Ingiardi M et al. (2026; online 2025). Delayed-onset parkinsonism after carbon monoxide poisoning: neuropsychological perspectives from a case report. Neurocase.
- Weaver LK et al. (2002). Hyperbaric oxygen for acute carbon monoxide poisoning. N Engl J Med.
- Fujita M et al. (2026). Evaluating the Efficacy of Hyperbaric Oxygen Therapy for Acute Carbon Monoxide Poisoning: A Systematic Review and Meta-Analysis. Acute Med Surg.
- CDC. Clinical Guidance for Carbon Monoxide Poisoning Following Disasters and Severe Weather. Reviewed August 21, 2026.
- U.S. Consumer Product Safety Commission. Carbon Monoxide Fact Sheet.
- Heyboer M III et al. (2017). Hyperbaric Oxygen Therapy: Side Effects Defined and Quantified. Advances in Wound Care, 6(6), 210–224.
- FDA (2025). Follow Instructions for Safe Use of Hyperbaric Oxygen Therapy Devices.
This page highlights six publications on established delayed neurological effects: one retrospective comparison and five case-report publications, one describing two patients. The acute trial and acute systematic review address a separate question. Reviews can include studies also discussed individually; these are not twelve independent treatment trials.
Literature checked September 12, 2026. This is a source-check date, not an independent physician-review attestation or an exhaustive systematic review. New papers require assessment before their findings are added. Educational information does not replace emergency evaluation, diagnosis, or an individual treatment plan.