Comparison of Australian and New Zealand referral rates for hyperbaric oxygen in oro-facial osteoradionecrosis: evidence-based, funding constraint or clinician whim?

AIM: To compare Australian and New Zealand (NZ) rates of referral to hyperbaric units for patients with, or at risk of developing mandibular or maxillary osteoradionecrosis (ORN) due to a history of radiotherapy for oro-pharyngeal cancer. METHOD: Relevant patient treatment data from all hyperbaric units in Australia and NZ were collated and analysed. RESULTS: The rate of referral to hyperbaric units in Australia for treatment or prophylaxis of patients with, or at risk of oro-facial ORN, was 1.7 times the rate of referral in NZ. Within Australia, there was a greater than three-fold interstate variation. CONCLUSION: There is a significant referral rate difference both within Australia and between Australia and NZ for hyperbaric oxygen therapy for oro-facial ORN. Possible reasons for this difference include access to funding, logistical difficulties, clinician preference for an alternative treatment and clinician attitudes to hyperbaric oxygen.

A systematic review of factitious decompression sickness.

We present a case of factitious decompression sickness (DCS) involving a patient emergently treated at a hyperbaric medicine facility in New Zealand. Patients with factitious disorder feign illnesses such as DCS in order to receive care and attention despite the lack of an underlying illness. Other studies have suggested that 0.6% to as many as 9.3% of hospital admissions are factitious in nature. Therefore we believe that factitious DCS is occurring more often than hyperbaric clinicians suspect. DCS can be life-threatening, and hyperbaric medicine clinicians will almost always "err on the side of caution" when patients are referred with symptoms of DCS. Because DCS can be diagnosed based on subjective symptoms and self-reported history, there are opportunities for factitious patients to receive hyperbaric therapy. The costs associated with factitious DCS include transport, staff resources and preventing patients with treatable conditions from accessing the hyperbaric chamber. We performed a systematic review of the literature and found eight additional reported cases of confirmed or suspected factitious DCS. We report our findings and recommendations for hyperbaric medicine specialists regarding the recognition and management of factitious DCS.

Severe cyclophosphamide-induced haemorrhagic cystitis treated with hyperbaric oxygen.

AIM: Cyclophosphamide-induced haemorrhagic cystitis (CHC) is an uncommon but well-recognised condition caused by a metabolite, acrolein, which is toxic to the urothelium. Based on similarities in the histopathology of radiation- and chemotherapy-induced haemorrhagic cystitis, benefit from hyperbaric oxygen therapy (HBOT) has been proposed. HBOT produces an increased oxygen partial pressure diffusion gradient between the circulation and surrounding tissues, which enhances neutrophil function and fibroblast and macrophage migration into damaged hypoxic soft tissue, promoting collagen formation, fibroblast growth, angiogenesis and white-cell bacterial killing. There are only isolated case reports of HBOT for CHC, in the literature so we reviewed the New Zealand experience with HBOT in CHC. METHOD: The case records of all patients with CHC referred to the three hyperbaric medicine units in New Zealand between 2000 and 2007 were reviewed retrospectively. RESULTS: Six patients, with life-threatening haemorrhage at the time of referral for HBOT weeks or months after initial presentation with CHC, were identified. Cessation of bleeding occurred in all six patients after 14 to 40 HBOT, without complications. All patients remained clear of haematuria at 11 to 36 months follow-up. CONCLUSIONS: We recommend the use of HBOT in the management of intractable cyclophosphamide-induced haemorrhagic cystitis as an effective and low-risk therapy.