Diving and hyperbaric medicine最新文献

Introduction: Effectiveness of delayed hyperbaric oxygen treatment (HBOT) for decompression illness (DCI) and factors affecting treatment delays have not been studied in large groups of patients.

Methods: This retrospective study included 546 DCI patients treated in Finland in the years 1999-2018 and investigated factors associated with recompression delay and outcome. Treatment outcome was defined as fully recovered or presence of residual symptoms on completion of HBOT. The symptoms, use of first aid oxygen, number of recompression treatments needed and characteristics of the study cohort were also addressed.

Results: Delayed HBOT (> 48 h) remained effective with final outcomes similar to those treated within 48 h. Cardio-pulmonary symptoms were associated with a shorter treatment delay (median 15 h vs 28 h without cardiopulmonary symptoms, P < 0.001), whereas mild sensory symptoms were associated with a longer delay (48 vs 24 h, P < 0.001). A shorter delay was also associated with only one required HBOT treatment (median 24 h vs 34 h for those requiring multiple recompressions) ( P = 0.002). Tinnitus and hearing impairment were associated with a higher proportion of incomplete recoveries (78 and 73% respectively, P < 0.001), whereas a smaller proportion of cases with tingling/itching (15%, P = 0.03), nausea (27%, P = 0.03), motor weakness (33%, P = 0.05) and visual disturbances (36%, P = 0.04) exhibited residual symptoms. Patients with severe symptoms had a significantly shorter delay than those with mild symptoms (median 24 h vs 36 h respectively, P < 0.001), and a lower incidence of complete recovery.

Conclusions: Delayed HBOT remains an effective and useful intervention. A shorter delay to recompression is associated with fewer recompressions required to achieve recovery or recovery plateau.

Introduction: The purpose of this study was to investigate the dentin bond strength of composite resins in response to environmental pressure changes.

Methods: Ninety extracted human molar teeth were used. A mould (3 mm x 4 mm) was adapted on dentin, resin composites (conventional [n = 30] and single-shade composites [Ohmnicroma] [n = 30]) were filled in two increments of 2 mm. The bulk-fill composites (n = 30) were filled with one 4 mm increment. The specimens were stored for 30 days in artificial saliva. The specimens were exposed to hyperbaric pressure (283.6 kPa; 2.8 atmospheres absolute [atm abs]) or hypobaric pressure (34.4 kPa; 0.34 atm abs) once daily for 30 days and the control group was stored at atmospheric pressure for 30 days. The bond strength was tested with a universal testing machine and the failures were examined with a stereomicroscope and scanning electron microscope. Statistical analyses were performed using analysis of variance with post hoc tests, and the Weibull analysis.

Results: Regardless of environmental pressure changes, the bulk-fill composites showed the highest bond strength. There was no significant difference in bond strength between the hypobaric and atmospheric pressure (control) groups after 30 days in all resins. The hyperbaric group showed lower bond strength for bulk-fill composites than the control group.

Conclusions: Dentists experienced in diving and aviation medicine should definitely take part in the initial and periodic medical examinations of divers and aircrew to give appropriate treatment. Bulk-fill composite resins can be preferred in divers and aircrew due to high bond strength values.

Respiratory injury during or following hyperbaric oxygen treatment (HBOT) is rare, but associated pressure changes can cause iatrogenic pulmonary barotrauma with potentially severe sequelae such as pneumothoraces. Pulmonary blebs, bullae, and other emphysematous airspace abnormalities increase the risk of respiratory complications and are prevalent in otherwise healthy adults. HBOT providers may elect to use chest X-ray routinely as a pre-treatment screening tool to identify these anomalies, particularly if a history of preceding pulmonary disease is identified, but this approach has a low sensitivity and frequently provides false negative results. Computed tomography scans offer greater sensitivity for airspace lesions, but given the high prevalence of incidental and insignificant pulmonary findings among healthy individuals, would lead to a high false positive rate because most lesions are unlikely to pose a hazard during HBOT. Post-mortem and imaging studies of airspace lesion prevalence show that a significant proportion of patients who undergo HBOT likely have pulmonary abnormalities such as blebs and bullae. Nevertheless, pulmonary barotrauma is rare, and occurs mainly in those with known underlying lung pathology. Consequently, routinely using chest X-ray or computed tomography scans as screening tools prior to HBOT for low-risk patients without a pertinent medical history or lack of clinical symptoms of cardiorespiratory disease is of low value. This review outlines published cases of patients experiencing pulmonary barotrauma while undergoing pressurised treatment/testing in a hyperbaric chamber and analyses the relationship between barotrauma and pulmonary findings on imaging prior to or following exposure. A checklist and clinical decision-making tool based on suggested low-risk and high-risk features are offered to guide the use of targeted baseline thoracic imaging prior to HBOT.

Introduction: Previous studies suggest the effectiveness of hyperbaric oxygen treatment (HBOT) in idiopathic sudden sensorineural hearing loss (ISSNHL) but it is mostly used as an adjuvant and salvage treatment. This study evaluated the effect of primary HBOT according to pretreatment hearing grades and hearing recovery outcomes using modified Siegel's criteria in patients with ISSNHL.

Methods: Fifty-nine ISSNHL patients treated with only HBOT were included. A pure-tone audiogram was recorded before and after a course of HBOT (90 min at 203 kPa daily for 20 days). Using the modified Siegel's criteria, patients were divided into groups according to hearing threshold before and after treatment.

Results: Hearing thresholds were significantly lower after HBOT compared to pre-treatment values across all patients (P < 0.001) with a median value of recovery of 22.5 dB (interquartile range 12.5-33.7 dB). Significantly lower hearing threshold values were recorded at 500, 1,000, 2,000, and 4,000 Hz after treatment (P < 0.001). The greatest recovery was at 1,000 Hz, (change in median threshold = 32 dB) but without a significant difference compared to other frequencies (P = 0.10).

Conclusions: HBOT is a legitimate choice as the primary treatment for ISSNHL, especially if it is readily accessible, and if there are contraindications for corticosteroid therapy.

Background: Hyperbaric oxygen treatment (HBOT) is often used in an attempt to reverse/treat late radiation-induced tissue fibrosis (LRITF). This study aimed to quantify the effects on skin elasticity.

Methods: Skin retraction time was used as a marker of skin elasticity in 13 irradiated breast cancer patients. The measurements were carried out on the affected side as well as the unaffected/healthy side at a mirrored location. Readings were taken at the start and end of HBOT (mean 43 sessions, 80 min at 243 kPa).

Results: Patient age ranged from 39-70 years. All patients underwent surgical lumpectomy and radiotherapy prior to undergoing HBOT. The mean time between radiotherapy and HBOT was 70 months. Seven of the 13 patients underwent chemotherapy. Mean irradiated skin retraction time improved from 417 (SD 158) pre-HBOT to 171 (24) msec post-HBOT (P < 0.001). Mean pre-HBOT retraction time in the non-irradiated skin was 143 (20) msec and did not change.

Conclusions: This promising pilot study that suggests that HBOT may improve skin elasticity in patients with LRITF.

Dysbarism is a medical condition arising from change in ambient pressure which outpace the rate at which the body adapts to it. We report a case of recurrent dysbarism consistent with possible decompression illness presenting with amnesia, hypoaesthesia and other neurological manifestations in a professional breath-hold diver treated successfully with hyperbaric oxygen and fluid resuscitation.

Immersion pulmonary oedema (IPO) can affect sea swimmers, snorkelers, and scuba divers. It can be fatal and cases are often mistaken for drowning. There has been an association between IPO and the development of takotsubo cardiomyopathy. We present a case study of a diver rescued from the water with IPO, who was subsequently found to have takotsubo cardiomyopathy on cardiac magnetic resonance imaging (CMR). This case demonstrates CMR findings as well as follow- up investigation results. The diver's and instructor's perspective during the initial dive incident are also described.