A Descriptive Study on the Impacts of Hyperbaric Oxygen Therapy on Autistic Individuals Using Parent Testimonies

Introduction Hyperbaric oxygen therapy (HBOT) has been influential in treating many physical and psychological ailments, including the symptoms of autism. This current study aims to evaluate HBOT parents’ goals and exit interviews describing the positive, negative, or no impacts experienced from the HBOT dives, asking the question, “Are your child’s symptoms improving?” Methods Between January 2020 and July 2023, a Class B monoplace hyperbaric chamber (Sechrist 3300H, Sechrist Industries, Inc., Anaheim, California, United States) was used to administer HBOT sessions to patients with autism. Medical-grade oxygen was pressurized to 1.5-2.0 atmospheres absolute at a rate of 1-2 psi/min, with an average oxygen percentage of 100%, for up to five sessions per week. Retrospective descriptive data and patient information through parent testimonials were collected through a chart review of 30 children and one adult with autism who experienced HBOT sessions. Data were presented through exit interviews describing how parents felt about their child’s progress toward goals. Four raters rated parent testimonies on a 5-point Likert scale (1 = Much worse, 2 = Somewhat worse, 3 = Stayed the same, 4 = Somewhat improved, and 5 = Much improved), and an inter-rater reliability estimate using interclass correlation (2) (r = 0.831) was derived, indicating excellent agreement between raters. Results Parents/caregivers provided testimony in an exit interview with a registered nurse after the individual with autism received an entire course of HBOT dives. Descriptive statistics resulted in Rater #1 (M = 4.19, median = 4, SD = 0.654): 87.1% of Rater #1 ratings were Somewhat improved and Much improved; Rater #2 (M = 4.23, median = 4, SD = 0.717): 83.9% of Rater #2 ratings were Somewhat improved and Much improved; Rater #3 (M = 4.23, median = 4, SD = 0.560): 93.5% of Rater #3 ratings were Somewhat improved and Much improved; and Rater #4 (M = 4.26, median = 4, SD = 0.631): 90.3% of Rater #4 ratings were Somewhat improved and Much improved. One-way ANOVA resulted in F (3,123) = 0.052, p = 0.984, which indicated a nonstatistically significant mean difference between rater groups. Conclusions The current study assessed HBOT parents’/caregivers’ goals and exit interviews, describing the effects experienced from the complete course of HBOT dives on their children/individuals. A majority of parents/caregivers declared that their condition had “Much improved” or “Somewhat improved,” based on the 5-point Likert scale. Based on parents’/caregivers’ testimonies, HBOT was demonstrated as a safe and effective intervention, and side effects were primarily mild and did not lead to treatment discontinuation. As a result of this analysis, we recommend continued use of HBOT for treatment.

In a prospective pilot study of autistic children, HBOT at a maximum pressure of 1.5 atmospheres absolute (ATA) with up to 100% oxygen was found to be safe and well tolerated.HBOT did not worsen oxidative stress and significantly decreased inflammation, as measured by CRP levels.Parental observations support improvement in several domains of autism [2].In a double-blind, randomized controlled study, children with autism who received HBOT at 1.3 atm and 24% oxygen for 40 hourly sessions significantly improved overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air [3].
In another study, improvements were found in younger children under study post-therapy for sociability, sensory/cognitive awareness, health/physical/behavior, and sound-sensitive items.In older children, improvements were noted for health/physical/behavior, emotional response, adaptation to change, and total score [5].
There have been multiple literature and systematic reviews concerning the use of HBOT in treating autism, which have reported mixed results ranging from no benefit to some reporting promising results [6][7][8].Lasheen et al. concluded that HBOT improved auditory attention and memory in cases of autism and recommended increasing the sample size in further studies on the effect of HBOT in cases of autism with more HBOT sessions [9].
Meyer noted that numerous studies have demonstrated that HBOT is an effective treatment for children with autism [10].The pressures utilized during treatment with HBOT (1.5 atm/100% oxygen maximum) are proven to improve the common physiological abnormalities in individuals with ASD, such as cerebral hypoperfusion, oxidative stress, inflammation, and mitochondrial dysfunction.Furthermore, studies that targeted the behavioral measurements in ASD also showed positive results, even though most of those studies did not use control groups.The two studies that did utilize control groups, however, had opposing outcomes.Based on the studies performed, overall, the use of HBOT appears to be a promising treatment for children with ASD.
El-baz et al. reported significant improvement in the Autism Evaluation Treatment Checklist (AETC) scale in total score, subscales (sociability, sensory/cognitive awareness, health/physical/behavior, and communication), and the Childhood Autism Rating Scale (CARS) after treatment with at least 20 sessions of HBOT at 1.5 ATA and 100% oxygen [11].The average improvement of the AETC total score in all children was 32.1%, and the average CARS score was 15.1%.Rossignol and Rossignol [12] noted that six children completed 40, one-hour sessions of low-pressure HBOT at 1.3 ATA and 28-30% oxygen and reported an average improvement of the AETC total score in all children of 22.1% and an average improvement of the CARS score in all children of 12.1%.
This current descriptive study aims to evaluate HBOT regarding the goals of the parents/caregivers of children with autism and exit interviews describing the impacts on the children experienced from the HBOT dives.No studies to date have examined parent/caregiver testimonies relative to the impacts of HBOT after 40 dives on their respective children/individuals.

Materials And Methods
Between January 2020 and July 2023, a Class B monoplace hyperbaric chamber (Sechrist 3300H, Sechrist Industries, Inc., Anaheim, California, United States)was used to administer HBOT sessions to patients with autism at The Oxford Center, Brighton, United States.Medical-grade oxygen was pressurized to 1.5-2.0ATA at a rate of 1-2 psi/min, with an average oxygen percentage of 99.803%, for up to five sessions per week.Patients were monitored for adverse events by trained hyperbaric technicians.The hyperbaric chamber was depressurized from 1 to 2 psi/min back to 1.0 ATA.Before entering the hyperbaric chamber, each parent/caregiver was given a pre-treatment screening (consented) by the Certified Hyperbaric Technician (CHT), including goal setting and a review of their child/individual's medical history and what to expect in terms of benefits/risks.The children/individuals were also instructed to equalize the pressure in their ears, like being a passenger on a commercial airliner, which may cause discomfort during the hyperbaric process.
Patients were provided hospital scrubs to wear during the hyperbaric session.They were instructed to remove any metal, i.e., jewelry, glasses, dentures, contact lenses, and other items that may undergo damage due to oxygen hyper-pressurization.Each patient was administered medical-grade pure oxygen in the chamber, lying down.The chamber was sealed and gradually pressurized by the CHT, who communicated with them through the intercom.Patients were treated for between 30 minutes and two hours.After the treatment, the chamber was slowly depressurized, and the patient was released.They were then advised to drink fluids and rest before returning to normal activities.
Parents/caregivers gave feedback, including exit interviews after experiencing the HBOT sessions, describing how their child/individual physically felt and any progress made toward goals.Data was obtained via retrospective chart review from the AdvancedMD database to gather demographic information, discovery

Statistical methods
IBM SPSS Statistics for Windows, Version 29.0.0 (Released 2022; IBM Corp., Armonk, New York, United States) [13] was used for all descriptive analyses.Demographics were summarized for all subjects.Summary statistics (e.g., number of subjects, mean, standard deviation, median, minimum, and maximum) were generated for all continuous variables (i.e., age, HBOT treatment months, dives, and Rater 1-4).Frequencies were reported for gender and rater ratings.Nominal alpha (α) of 0.05 was specified, and statistical significance was declared for p < 0.05.All statistical results were reported via text and table presentation.No conventional power analysis was conducted, as would be the case with studies involving quantitative effect sizes.

Inter-rater reliability
A two-way random effects model was computed where people's effects and measures effects are also random.We used interclass correlation (ICC) (2), which is used when multiple measurements are taken from each averaged rater.The ICC (2) value was 0.831 (95% CI: 0.707-0.911),indicating excellent agreement between the raters [14][15][16].This value was greater than the average Pearson r (0.546), suggesting that the ICC (2) was more sensitive to the variability among raters and measurements.Cronbach's alpha for the four raters was r = 0.827.

Descriptive statistics
For the sample of 31 children, regarding age (M = 6.58,SD = 4.85), the median was 5, the minimum was 2, and the maximum was 26.There were 24 males (77.4%) and seven females (22.6%).Regarding dives (M = 44.61,SD = 12.62), the median was 40, and the mode was 40.The minimum was 38, and the maximum was 86.With months of treatment (M = 2.31, SD = 1.35), the median was two months, the minimum was one month, and the maximum was seven months.For dives (M = 44.61,SD = 12.62), the median was 40, the minimum was 38, and the maximum was 86.For months of HBOT treatments (M = 2.31, SD = 1.35), the median was 2, the minimum was 1, and the maximum was 7.There were no missing values.In order to determine the equality of rater means, a one-way ANOVA was conducted, F (3,123) = 0.052, p = 0.984, indicating a nonstatistically significant difference (p > 0.05) between rater means.See  The data has been represented by the source of variation, the sum of squares, degrees of freedom (df), mean square, F, and p-value.

Discussion
This study found that 87.1% of Rater #1 ratings were Somewhat improved and Much improved, 83.9% of Rater #2 ratings were Somewhat improved and Much improved, 93.5% of Rater #3 ratings were Somewhat improved and Much improved, and 90.3% of Rater #4 ratings were Somewhat improved and Much improved.
This small study may be a positive step in showing the link to multiple improvements for individuals with autism resulting from HBOT.While preliminary and descriptive, these data are consistent with the potential benefits of several known medical pathologies common in autistic patients, including reducing inflammation and enhancing host response gut bacterial colonization.Specifically, three known processes of hyperbaric oxygenation seem to have contributed to these results.

Hyperbaric Oxygenation of Blood and Tissues
Increasing the pressure and percentage of inspired oxygen enhances the partial pressure of oxygen (PaO2), measuring arterial oxygen pressure and indicating efficient lung-to-blood oxygen transfer.It reflects how well oxygen can move from the lungs to the blood.HBOT treatments result in PaO2 ranging from 100 mmHg to 1,483 mmHg.This process causes an increase in the penetration of oxygen into the tissue to 247 µM from 64 µM.This allows tissues experiencing hypoxia due to inflammation to get the needed oxygen [17].

Vasoconstriction
One of the brain's automatic responses to hyperbaric oxygenation is constricting the arteries to reduce blood flow and oxygenation.Reducing blood flow reduces the fluid flowing into edematous tissue and relieves the compartment pressures, allowing stressed and stretched capillaries to relax and open, restoring normal blood flow [18].

Host Response to Bacterial Infection
It is well known that hyperbaric oxygenation helps kill bacteria by oxidative burst, enhancing the process of phagocytosis, which requires oxygen to occur and slows in hypoxic tissue, and synergism with certain antibiotics in enhancing bacterial clearance [19,20].
Oxygen is required for correct bodily function, and this naturally available energy source is used in cellular respiration, metabolism, adenosine triphosphate production, detoxification, immune system support, brain function, and the healing of tissue and bone.Hyperbaric chambers create an environment where the administration of a concentrated form of oxygen is arguably the most vital source of life.Despite the consistent research affirming its safety, the broader mainstream medical community is hesitant to accept the application for conditions such as ASDs [20].

Oxygen quality
For this study, we needed to prove the quality of our treatment gas.We were able to accomplish this with the help of our cryogenic oxygen provider.Liquid oxygen is rigidly controlled and must meet established quality standards.The standards include an oxygen percentage of ≥99.5%, a water vapor content of ≤6 ppm, and no detected odor.Each lot of gas has the results of testing the lot along with an assigned lot number.The vendor provides a copy of their standards compliance.Through this, a running record of each lot at each of our locations is kept.We filed the results, and with an ongoing spreadsheet, we calculated the current average oxygen percentage for the time period of the study.Through this, we were able to, with a strong certainty, know that for the study period, our average oxygen percentage was 99.803% [21].

Table 1
below reports rater ratings and parent testimonies.

number Age Rater #1 Rater #2 Rater #3 Rater #4 Discovery session goal Parent testimony after completion of 40 HBOT dives
Way more eye contact.Caught him singing/sounds of his favorite songs.Now imitating.If you bring a device, he will hold it to your face.Potty training is still ongoing.Sleeps better, listens better, is more vocal, is more aware of his body, and uses hands more.New noises Heard "random words."Learningnew words: said "baby".Still "pretty hyper."Noimprovement in socialization.OT pushed him a lot more, and he made a lot of progress.Made more progress at TOC than in previous therapies.OT started with gross motor and then went to find motor.Mom is very happy with his progress.Mom said, "Speech is most improved."Morebabbling.First two weeks: less hyperactive.Followed instructions.The last two weeks feel like regressed.Since in the US there is no gluten-free, dairy-free, or soy-free diet, feels like this affected progress.Currently and has just started back.He used to be a zombie, but now he reacts like a normal kid.Sleep: CBD oil stopped six weeks ago.Starting again Said a few words since starting HBOT: "Mama" and "Up."Disappointed that Dr. Bogner can't read the results of the NT/genetic test.Good BMs: 2024 Peterson et al.Cureus 16(3): e55648.DOI 10.7759/cureus.556483 of 10 Sleeping better.More aggressive the last few days.brush his teeth on his own Happier.Thankful for the opportunity.Able to handle a lot of situations better.Saw improvement.More expressive language.Sang Jesus Loves the Little Children with Dad.More clear speech.Said bye-bye unprompted and waved.Calmer and can sit and watch TV without running.More social: wants to be with parents and wants to be part of kids playing.Little more interest in toys again.More eye contact.Big School is going very well.Took time to adjust.Was screaming a lot, but has decreased.Increased eye contact, more variety of pretend play, Screaming is still there.Sleeping is better through the night without disturbing everyone else.Out of HBOT can only benefit from there.Has decreased depressive mood.Still has screaming if don't want to be there.BCBA says more verbally.She doesn't think functionally will use words to get what she wants.2024 Peterson et al.Cureus 16(3): e55648.DOI 10.7759/cureus.I want him to heal, be seizure-free, and take care of himself More energy.Constipation is a little better.Seizures are better at night.Don't see/feel them anymore.Sleeps better now.The ABA therapist says he's improving in general.More communication.The speech pathologist hears more sounds.Speech is about the same.He understands and listens more to his father.His speech is still mostly vocalizations.He desperately wants to communicate and sometimes cries when he cannot.From tech's said his friend's name, and said "Papa."Last weekend actively played hide and go seek, taking turns, counting, and hiding.Momentous to hear.All he had said before was "help," "bye," and "set go."Saying "one, two, three, abo" (blast off) with Buzz Lightyear motions.Conversational speaking.He's been more expressive.Less fatigue.More focus.More 2024 Peterson et al.Cureus 16(3): e55648.DOI 10.7759/cureus.phoneto say "Mom, where are you?I'm lost.Can you help me?" impromptu.Advocating for himself.Hearing "Hi."Starting to care.His employer has noticed a change: more conversational.Pleased with what we are seeing.Telling mom about his day.Feeling better; more interested.Spelling better.Wears a mask all day at work.

Table 2
below reports rater means, standard deviations, and medians.

TABLE 2 : Descriptive statistics for raters
Results are reported as n, mean, standard deviation, and median.