Validity of cycle test in air compared to underwater cycling.

According to international guidelines, fitness to dive is generally assessed using a bicycle stress test (BST) in air. To date, there is no study explicitly addressing the question whether the results of a BST in air really predict performance status under water. Therefore, the aim of the present study was twofold: first, to design an experimental setting allowing the examination of physical performance status under water, and second, to examine whether there is an association of response to exercise in air compared to exercise under water using self contained underwater breathing apparatus (SCUBA). We constructed and evaluated a measurement technique for a bicycle ergometry and for gas analysis under water. Part of the work was the development of a new valve system which allowed to collect the exhaled air in total and to transport it to the spirometer next to the pool. Twenty-eight healthy male divers underwent a BST. Compared to a given workload in air, gross capacity decreased significantly by about 50% underwater. High performance in air was associated with a high performance underwater. The examinations were carried out without any complications. In conclusion, our experimental setting allowed the safe and reliable examination of physical performance status under water. First results indicate that the results of a BST in air correlate well with the cardio-circulatory performance status underwater. A subsequent study with a larger sample size will enable us to more precisely model this correlation.

Complications and side effects of hyperbaric oxygen therapy.

BACKGROUND: Despite ongoing controversy, hyperbaric oxygen (HBO) therapy is frequently administered in various clinical situations. Probably because of the unique atmospheric conditions to which the patient is exposed, there are concerns about the safety aspects of this therapy. Possible complications during HBO therapy include barotraumatic lesions (middle ear, nasal sinuses, inner ear, lung, teeth), oxygen toxicity (central nervous system, lung), confinement anxiety, and ocular effects (myopia, cataract growth). METHODS: To analyze the medical safety of HBO therapy, this report reviewed complications and side effects of 782 patients treated for various indications with a total of 11,376 HBO therapy sessions within a multiplace chamber. The absolute treatment pressure was 240 or 250 kPa 114 or 15 msw). The compression was performed in a linear manner with 14 to 15 kPa (1.4 to 1.5 msw) x min(-1). All data were gathered prospectively within a special database. RESULTS: More than 17% of all patients experienced ear pain or discomfort as an expression of problems in equalizing the middle ear pressure. Most episodes were not related to a persistent eustachian tube dysfunction since they only occurred once. Barotraumatic lesions on visual otological examinations (ear microscopy) were verified in 3.8% of all patients. Patients with sensory deficits involving the ear region need special attention, because they seem to be at risk for rupture of the tympanic membrane (three cases documented). A barotrauma of the nasal sinuses occurred rarely and no barotraumatic lesions of the inner ear, lung, or teeth were noted. Oxygen toxicity of the CNS manifested by generalized seizures affected four patients without any recognizable risk factors or prodromes. None of the patients suffered recurrences or sequelae. Regular checks of the blood glucose in diabetics failed to reveal episodes of hypoglycemia as a cause for seizures. Lung function tests of patients undergoing prolonged treatment (average 52.8 sessions) did not deteriorate. CONCLUSION: Patients scheduled for HBO therapy need a careful pre-examination and monitoring. If safety guidelines are strictly followed, HBO therapy is a modality with an acceptable rate of complications. The predominant complication is represented by pressure equalization problems within the middle ear. Serious complications rarely occur.

[Dehydration--a risk factor for the decompression-accident in diving]. / Dehydrierung als Risikofaktor fur den Dekompressionsunfall beim Sporttauchen--ein Fallbericht.

We report on a decompression-accident with neurological manifestation in an experienced recreational diver. As no obvious omission against the prescribed rules of decompression could be observed, dehydration due to intense jogging prior to the dive was identified as a risk-factor. Hyperbaric treatment resulted in a complete restitution. The physiological aspects are discussed and recommendations for the fluid-intake before diving are given.

[Hyperbaric oxygenation (HBO) in the treatment of radiogenic side effects]. / Hyperbare Oxygenierung (HBO) zur Behandlung radiogener Nebenwirkungen.

AIM: Many reports show that late complications of radiotherapy can be successfully treated by hyperbaric oxygen (HBO). This synopsis attempts to review the literature to identify areas of clinical use and further research. PATIENTS AND METHODS: Clinical and experimental data about HBO treatment of radiation late effects are analysed. Mechanisms of hyperbaric oxygen in the treatment of late radiation side effects are discussed. RESULTS: There is evidence in the literature that HBO is beneficial in the treatment of radiation cystitis, osteoradionecrosis of the mandible, hemorrhagic proctitis, soft tissue necrosis and neurologic deficits. The prophylactic use of HBO has shown to prevent the development of osteoradionecrosis after tooth removal and the loss of titanium implants in irradiated facial bones. The physiologic basis of HBO can be referred to induction of neoangiogenesis and revascularisation. CONCLUSIONS: Clinicians can be encouraged to use hyperbaric oxygen for the treatment of radiation cystitis, osteonecrosis of the mandible, hemorrhagic proctitis, soft tissue necrosis and neurologic deficits following radiation therapy.

[Long-term results of treatment of rare aseptic necrosis of the scaphoid bone (Preiser disease) with the Swanson implant]. / Längerfristiges Behandlungsergebnis der seltenen aseptischen Kahnbeinnekrose (M. Preiser) mit Swanson-Implantat.

In 1911 Preiser described the avascular necrosis of the scaphoid bone, which is regarded as a relatively rare clinical and radiological condition. The diagnosis is not established easily, and a small, avascular proximal fragment, e.g. in a scaphoid pseudarthrosis, should not be confused with Preiser's disease. Two histologically diagnosed cases are described: one of thema at operation 42-year old woman received a scaphoid Swanson implant in 1980. At follow-up eight years later, she presented with very satisfying clinical and radiological findings.