Table 2 Summary of included studies

[21]

Multicenter, randomized, double-blind, controlled trial.

62 children with autism, ages 2-7 years old (mean 4.92 +/- 1.21), control group (n = 29) treatment group (n = 33)

40 hourly treatments. treatment group: hyperbaric treatment at 1.3 atmosphere (atm) and 24% oxygen, control group: slightly pressurized room air at 1.03 atm and 21% oxygen

Clinical Global Impression (CGI) scale,

Aberrant Behavior Checklist (ABC)

Autism Treatment Evaluation Checklist (ATEC).

Improvement according to: mean CGI scores (p = 0.0008), receptive language (p < 0.0001), social interaction (p = 0.0473), and eye contact (p = 0.0102);

ABC total score: no improvement except a greater number of children improved in irritability (p = 0.0311).

ATEC: sensory/cognitive awareness improved (p = 0.0367)

HBO: safe and well-tolerated.

[22]

Randomized, double-blind, placebo-controlled design

Children aged 2 to 14 (mean age = 6.18).

46 children enrolled in the study, 12 children withdrew, placebo group(n = 16 treatment group(n = 180

80 hourly sessions for both groups

HBO group: 1.3 atm and supplemental oxygen (approximately 24-28% FiO2) placebo group: free airflow through the chamber at ambient pressure supplements, dietary modifications, and medical interventions were held constant during the intervention [mean number of Applied Behavior Analysis (ABA) treatment hours per month was 109 (HBO 114.7; placebo 103.3)]

Aberrant Behavior Checklist (ABC)

Autism Diagnostic Observation Schedule-Generic (ADOS)

Clinical Global Impression Scale (CGI)

Direct observations

HOT is not more effective than placebo.

1 withdrew after a seizure attack.