published_or_final_version / Biochemistry / Master / Master of Science

Introduction: Hyperbaric oxygen therapy (HBOT) is the administration of 100% oxygen at pressures greater than 1 atmosphere. One recurrent criticism that has been made of this field is that treatment is based on little or no good clinical evidence. Aims: The primary objective of this thesis is to make a useful response to that criticism. I planned to collate all the available randomised evidence in the fields of diving and hyperbaric medicine, supply a critical appraisal of each paper, and synthesise that evidence in a series of systematic reviews with meta-analysis. I also intended to use a cost analysis of hyperbaric practice in our own facility to inform formal cost-effectiveness analysis using the estimates of effect generated by the individual meta-analyses. Methods: A comprehensive search strategy was used to identify all clinical RCTs involving the administration of hyperbaric breathing mixtures. Each trial was appraised using the software developed by the Oxford Centre for Evidence Based Medicine. Each critical appraisal was loaded onto a searchable web site at www.hboevidence.com. Each diagnostic category identified was considered for inclusion in a Cochrane systematic review and meta-analysis. Results: The database includes 130 critical appraisals covering 173 separate reports. The site has received more than 17,000 hits. There are 12 formal meta-analytical reviews and all have been accepted for publication in the Cochrane Database of Systematic Reviews at the time of writing. These form the basis of this thesis and include late radiation tissue injury, chronic wounds, acute hearing loss and tinnitus, multiple sclerosis and decompression illness. The meta-analyses in this thesis suggest there are several areas where HBOT is associated with improved clinical outcomes and that routine use is probably justified in some areas (e.g. radiation proctitis healing with HBOT: NNT 3, 95%CI 2 to 11). On the other hand, these analyses suggest there is most unlikely to be significant clinical benefit from the application of HBOT to patients currently referred for HBOT (e.g. multiple sclerosis). Conclusions: The randomised evidence for the use of HBOT is now significantly easier to access. Recommendations for therapy and future research directions can be made on the basis of these analyses.

Thesis (M. Sc.)--University of Hong Kong, 1970. / Typewritten.

Background: Hyperbaric Oxygen Therapy (HBOT) is used to promote soft and hard tissue repair at sites of injury or disease. It is not known whether it has any effect on uninjured tissues. Objective: To evaluate the effect of HBO on vertebral bones distant from a calvarial surgical site. Materials and Methods: 22 male New Zealand white rabbits were divided into two groups (n=11). All animals underwent surgery to produce bilateral calvarial critical sized defects. Group 1 received HBOT while Group 2 served as controls breathing room air (NBO). The Marx HBO protocol was used (90min, 100% oxygen at 2.4 ATA, 5 days a week for 4 weeks). Subjects were sacrificed at 6 weeks. The vertebrae were analyzed by micro-CT (μCT) and histology. Results: There were no statistical significant differences between the two groups. Conclusion: we concluded that there were no harmful effects of HBOT on non-injured vertebrae at 6 weeks.

The purpose was to examine the acute effects of a HBO 2 treatment on (1) recovery following prolonged exercise and (2) aerobic performance in a trained population. Subjects were 6 male and 6 female, trained runners with mean VO2max values of 64.6 +/- 5.6 and 51.9 +/- 6.6 ml·g-1·min-1 respectively. Subjects were randomly assigned to four exercise-HBO2 conditions: (1) control, (2) exercise - no HBO2. (3) no exercise - HBO2, and (4) exercise - HBO2. Exercise was a 90-minute run at 75--80% of VO2max. HBO2 treatments consisted of breathing 95% O2 at 2.5 atm abs for 90 minutes. At the end of each condition, aerobic performance was assessed with a VO 2max test and by the oxygen cost of running on a treadmill at three submaximal velocities. Recovery was not enhanced following a single HBO 2 treatment at 2.5 atm abs for 90 minutes, nor did it alter submaximal or maximal running performance.

Background: Hyperbaric Oxygen Therapy (HBOT) is used to promote soft and hard tissue repair at sites of injury or disease. It is not known whether it has any effect on uninjured tissues. Objective: To evaluate the effect of HBO on vertebral bones distant from a calvarial surgical site. Materials and Methods: 22 male New Zealand white rabbits were divided into two groups (n=11). All animals underwent surgery to produce bilateral calvarial critical sized defects. Group 1 received HBOT while Group 2 served as controls breathing room air (NBO). The Marx HBO protocol was used (90min, 100% oxygen at 2.4 ATA, 5 days a week for 4 weeks). Subjects were sacrificed at 6 weeks. The vertebrae were analyzed by micro-CT (μCT) and histology. Results: There were no statistical significant differences between the two groups. Conclusion: we concluded that there were no harmful effects of HBOT on non-injured vertebrae at 6 weeks.

No description available.

This study investigated the effects of hyperbaric oxygen (HBO2) therapy following partial arthroscopic meniscectomy surgery on swelling, perceived pain, range of motion at the knee joint, isokinetic strength, and leg function. Subjects were 8 males and 1 female with an acute tear to the meniscus. Subjects were randomly assigned to either a control group (n = 5) or an HBO2 treatment group (n = 5). The HBO 2 group received 5 HBO2 treatments at 2.5 ATA for 90 minutes at 95% O2 beginning 24 hours post-operation. Both groups were tested pre-operation (day 0) and on days 1, 2, 3, 4, 5, 20, 35, and 50 post-surgery. No significant difference was found between groups for any of the dependant variables. The results indicated that the control and HBO2 groups responded in a similar pattern when assessed for swelling, perceived pain, range of motion at the knee joint, leg function and isokinetic strength.

Thesis (M.D.S.) -- University of Adelaide, Dept. of Dentistry, 2000. / Erratum pasted into front end papers. Bibliography: leaves 258-307.

Thesis (M.Sc.)--University of Hong Kong, 1970. / Also available in print.