Israel Medical Association Journal

Background: Decompression sickness (DCS) is a clinical syndrome caused by a substantial reduction in barometric pressure. DCS is more common among divers but may also occur during flight or altitude chamber (hypobaric chamber) training. DCS is classified according to symptoms as either Type 1 (musculoskeletal and skin involvement) or Type 2 (neurological and pulmonary involvement). DCS may be life threatening and often necessitates treatment with hyperbaric oxygen therapy (HBOT).

Objectives: To examine the risk for altitude decompression sickness (ADCS) in altitude chamber training and to compare ADCS symptoms and treatment to those of DCS in divers (DDCS).

Methods: We conducted a retrospective cohort study that included all cases of ADCS in the Israeli Air Force between 2015 to 2022. We collected demographic, flight platform, altitude chamber training, clinical manifestations, and treatment data. Data regarding DDCS was obtained via a literature review.

Results: There were 2279 altitude chamber trainees and aviation physiology instructors. Of these, 11 presented ADCS, leading to a calculated ADCS risk of 0.5%. An additional four cases were reported following combat flights. Musculoskeletal involvement was the most common symptom in both DDCS and ADCS. A shorter HBOT protocol was used in 53% of the ADCS cases but only in 30% of the DDCS cases.

Conclusions: Overall, ADCS is a rare event, occurring in less than 1% of altitude chamber trainees. The common manifestation is of musculoskeletal involvement, and the mainstay of treatment remains HBOT.

Background: Blast injuries impair hearing through several mechanisms that are distinct from other causes of acute acoustic trauma (AAT).

Objectives: To compare blast injured patients to those exposed to noise alone in their auditory response to hyperbaric oxygen (HBO) therapy with oral steroids.

Methods: Adult patients with evidence of a previously undocumented ≥ 30 dB pure-tone threshold within 30 days of AAT were treated with a combination of one 2.5 atm HBO therapy session for 90 minutes daily with oral prednisone. Exposure was classified by history as blast (for explosion-induced AAT) or noise. The change in high pure tone average (HPTA) was the primary outcome.

Results: Of 598 ears (387 patients) included in the final analysis, 259 were exposed to blast and 339 to noise. Before treatment, the blast injured patients had significantly more abnormal findings on otoscopy (87% vs. 95%, P = 0.003), higher pure-tone average (18 ± 11 dB vs 12 ± 9 dB; P < 0.001), and higher speech reception thresholds (16 ± 14 dB vs 10 ± 8 dB, P < 0.001). Following treatment, these patients exhibited a significantly smaller improvement in HPTA (6 ± 17 dB vs 10 ± 14 dB P = 0.022) with pure tone thresholds remaining significantly worse across all frequencies in the blast exposed group (mean difference ranging from 3.2 to 6.8 dB, all P < 0.05).

Conclusions: Blast injuries result in unique auditory characteristics and responses to HBO therapy compared to other causes of AAT.

Background: Post-traumatic stress disorder (PTSD) remains a significant and often refractory mental health condition. Hyperbaric oxygen (HBO) therapy has demonstrated promise in alleviating symptoms of PTSD but optimal dosing and treatment duration remain unclear.

Objectives: To evaluate the clinical efficacy and dosing effects of two HBO protocols in patients with PTSD.

Methods: We conducted a randomized controlled trial comparing two HBO protocols: 60 daily sessions of 90 minutes at either 2.0 atmospheres absolute (ATA) or 2.5 ATA (HBO15). Adults with severe PTSD (Clinician Administered PTSD Score [CAPS]-5 ≥ 33) were randomized to treatment arms. CAPS-5 scores were recorded every 2 weeks. Secondary outcomes include measures of depression, sleep, executive function, and safety. Preliminary results are presented for the first nine patients who completed therapy (HBO10: n=5; HBO15: n=4).

Results: Participants in HBO15 were younger (mean age 39 vs. 59 years, P = 0.2). Baseline PTSD severity (CAPS-5) was higher in HBO15 (median 61.5 vs. 48.0, P = 0.4). Other baseline psychological scores were similar between groups. Mean CAPS-5 improvement (ΔCAPS) was greater in HBO15 (-14.0 ± 21.2) vs. HBO10 (-5.3 ± 19.6), although not statistically significant (P = 0.8). Both groups demonstrated the largest symptom reduction by weeks 6–8, with a plateau observed thereafter despite continued treatment through week 12.

Conclusions: Preliminary data suggest both HBO protocols are associated with symptomatic improvement in PTSD, with a trend toward greater effect in the higher-pressure group (2.5 ATA). Improvements appear to peak around 6–8 weeks, potentially indicating a shorter optimal treatment duration.

Cerebral arterial air embolism (CAAE) is a rare, but often fatal, complication of interventional bronchoscopy. Despite its rarity, a high index of suspicion can facilitate early diagnosis and prompt treatment. Standard of care treatment for CAAE is hyperbaric oxygen therapy, despite limited definitive data supporting its efficacy, given the conceptual potential for reversibility of neurological impairment. We describe five cases from our institution, and review the clinical presentation, pathophysiology, diagnosis, and management of suspected CAAE. Based on published case reports involving transbronchial lung biopsies (TBLB), standard of care treatment for CAAE secondary to TBLB is hyperbaric oxygen therapy, although its efficacy in this context has not been unambiguously validated in clinical practice.

Hyperbaric oxygen therapy (HBOT) has been investigated as a primary/adjunctive treatment for a number of injuries and medical conditions including traumatic ischemia, necrotizing soft tissue injuries, non-healing ulcers and osteoradionecrosis, but the results are controversial. There is insufficient evidence to support or reject the use of HBOT to quicken healing or to treat the established non-union of fractures. However, in patients with fibromyalgia, HBOT reduces brain activity in the posterior cortex and increases it in the frontal, cingulate, medial temporal and cerebellar cortices, thus leading to beneficial changes in brain areas that are known to function abnormally. Moreover, the amelioration of pain induced by HBOT significantly decreases the consumption of analgesic medications. In addition, HBOT has anti-inflammatory and oxygenatory effects in patients with primary or secondary vasculitis. 

This review analyzes the efficacy and limitations of HBOT in orthopedic and rheumatologic patients.

 

 Background: Hemorrhagic radiation cystitis (HRC) is a significant clinical problem that occurs after pelvic radiation therapy and is often refractory.

Objectives: To evaluate the efficacy and safety of hyperbaric oxygen therapy (HBO) for HRC.

Methods: Daily 90 minute sessions of HBO at 2 ATM 100% oxygen were given to 32 HRC patients with American Society of Therapeutic Radiology and Oncology (ASTRO) grades 3-4 hematuria.

Results: The median age was 72.5 (48–88 years). The median time interval between radiation therapy and HBO was 4 years (1–26 years). The patients received a median of 30 HBO sessions (3–53). Hematuria resolved in 27 patients (84%) and persisted in 5. Cystectomy was required in two, and ileal-conduit and bilateral percutaneous nephrostomies were performed in one and two patients, respectively. With a median follow-up of 12 months (5–74 months), the hematuria cleared completely in 16 patients (59%) and mild hematuria requiring no further treatment recurred in 10 others. Another patient with ASTRO grade 4 hematuria needed bladder irrigation and blood transfusions. Complications included eardrum perforation in four patients and transient vertigo and mild hemoptysis in one case each. None of them required HBO discontinuation.

Conclusions: HBO controlled bleeding in 84% of the patients. A durable freedom from significant hematuria was achieved in 96% of the patients. HBO seems to be an effective and safe modality in patients with HRC.

Background: Invasive fungal infections by Mucorales or Aspergillus spp. are lethal infections in immune compromised patients. For these infections a multimodal approach is required. One potential tool for treating these infections is hyperbaric oxygen.

Objectives: To evaluate the clinical course and utility of hyperbaric oxygen in patients with invasive fungal infections by Mucorales or Aspergillus spp.

Methods: We conducted a retrospective chart review of 14 patients treated with HBO[1] as part of their multimodal therapy over a 12 year period.

Results: Most patients had significant immune suppression due to either drug treatment or their underlying disorder. Thirteen of the 14 underwent surgery as part of the treatment and all were receiving antifungal therapy while treated with the hyperbaric oxygen. The number of HBO sessions ranged between 1 and 44. Seven of the patients survived the infection. No patient developed complications due to HBO therapy.

Conclusions: HBO is a potentially significant adjunct in the treatment of invasive fungal infections. Evidence on its usefulness as a standard of care in these infections is still lacking. Since it will be difficult to generate conclusive data regarding the importance of HBO in these infections, the value of HBO in these patients should be considered on an individual basis.