Double-blind randomized phase II study of hyperbaric oxygen in patients with radiation-induced brachial plexopathy.

BACKGROUND: Radiation-induced brachial plexopathy (RIBP) is an untreatable complication of curative radiotherapy for early breast cancer, characterized by chronic neuropathic pain and limb paralysis. Hyperbaric oxygen (HBO2) therapy is known to promote healing of tissue rendered ischaemic by radiotherapy, but is untested in RIBP. METHODS: Thirty four eligible research volunteers suffering from RIBP were randomized to HBO2 or control group. The HBO2 group breathed 100% oxygen for 100 min in a multiplace hyperbaric chamber on 30 occasions over a period of 6 weeks. The control group accompanied the HBO2 group and breathed a gas mixture equivalent to breathing 100% oxygen at surface pressure. All volunteers and investigators, except the operators of the hyperbaric chamber and the trial statistician, were blind to treatment assignments. The warm sensory threshold, which measures the function of small sensory fibres, was selected as the primary endpoint. FINDINGS: Pre-treatment neurophysiological tests were grossly abnormal in the affected hand compared to the unaffected hand in both HBO2 and control groups, as expected, but no statistically significant differences were noted in either group at any time up to 12 months post-treatment. However, normalization of the warm sensory threshold in two of the HBO2 group was reliably recorded. Two cases with marked chronic arm lymphoedema reported major and persistent improvements in arm volume for at least 12 months after treatment with HBO2. IINTERPRETATION: There is no reliable evidence to support the hypothesis that HBO2 therapy slows or reverses RIBP in a substantial proportion of affected individuals, although improvements in warm sensory threshold offer some suggestion of therapeutic effect. Improvement in long-standing arm lymphoedema was not anticipated, and justifies further investigation.

Outcome after treatment of neurological decompression illness is predicted by a published clinical scoring system.

BACKGROUND: After recompression therapy, some cases of neurological decompression illness (DCI) have a significant residual deficit. Boussuges et al. report a scoring system to predict sequelae using weighted historical and clinical indices at presentation which we applied to the British Hyperbaric Association (BHA) database of UK diving accidents, held at the Institute of Naval Medicine (INM). METHODS: A database search identified 234 cases of neurological DCI from the 2 yr, 1995-6. Of these, 217 case records contained sufficient data to apply the scoring system. Outcome was classified as severe sequelae (i.e., causing a functionally important deficit) or as mild/no sequelae. RESULTS: The median score in UK cases with severe sequelae was 13 (95% C.I. 11.5 to 14.5) and in cases with mild/no sequelae, 6 (95% C.I. 5.5 to 6.5). Significantly more cases with scores > 7 had severe sequelae than cases with scores < or = 7 (chi2, p < 0.0001). The sensitivity of a score > 7 (for severe sequelae) was 94% and the specificity was 65%. The positive predictive value of a score > 7 (for severe sequelae) was 18% and the negative predictive value of a score < or = 7 was 99%. CONCLUSIONS: When applied to the INM/BHA database a score of > 7 by this scoring system has a higher sensitivity and lower specificity for severe sequelae than reported by Boussuges et al. It has a higher predictive accuracy for successful outcome of treatment (99% vs. 89%) but a much lower predictive value for severe sequelae (18% vs. 86%). Convergence between this and other published scoring systems may allow derivation of a generic scoring system that could then be evaluated prospectively in multiple centers.

Defibrillation in hyperbaric chambers: a review.

Defibrillation plays a crucial role in the resuscitation of patients from acute life-threatening cardiac dysrhythmias causing cardiac arrest. Concerns over safety and function of defibrillators under pressure have so far prevented their routine use in clinical hyperbaric chambers. Increasing numbers of unstable and critically ill patients are being treated in such facilities for both diving and non-diving indications. This report reviews the literature relating to hyperbaric defibrillation and examines the indications, contraindications and therapeutic alternatives to this procedure.