Jim -

I've been looking at abstracts for a couple of days, and all I can say is that it's complicated. See, e.g., Analysis of risk factors associated with complications of hyperbaric oxygen therapy, Ambiru S, Furuyama N, Aono M, Otsuka H, Suzuki T, Miyazaki M, J Crit Care 2008 Sep;23(3):295-300. Epub 2007 Dec 11.

Surgical Center and Division of Hyperbaric Medicine, Chiba University Hospital, Chiba 260-8677, Japan.

Abstract
PURPOSE: The aim of this study was to verify independent risk factors of pressure equalization problems associated with hyperbaric oxygen (HBO(2)) therapy.

METHODS: We reviewed a single-institutional study of 1609 patients with 17604 treatments who had HBO(2) therapy in a multiplace chamber, in which the factors examined and their relationship to complications were assessed, using multivariate analyses, to determine the significantly independent risk factors of complications related to HBO(2) therapy.

RESULTS: The compression rate was 0.067 atmospheres absolute/min (6.8 kPa/min). Pressure equalization problems of the middle ear, expressed as pain or discomfort, such as cranial sinus pain, and teeth pain were observed in 156 patients (9.7%). Sixty-six of them could not continue HBO(2) therapy because of these problems. Peripheral circulatory disorders with refractory ulcers or nonhealing wounds and the interval between clinical symptoms and the first day of HBO(2) therapy were independent risk factors of pressure equalization problems. Independent risk factors of cessation due to pressure equalization problems were identified as age more than 61 years, female sex, and interval between symptoms and the first day of HBO(2) therapy.

CONCLUSION: It is suggested that chamber compression must be performed with particular care when patients have peripheral circulatory disorders and have short interval between clinical symptoms and the first day of HBO(2) therapy.[Emphasis added.]

PMID: 18725032 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/pubmed/18725032

Clearly, the highlighted language refers to diabetes, but would the same risks be present in light of the known issues of micro-profusion/endothelial dysfunction associated with CRPS? Dunno.

Mike