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.

Background: The use of oral midazolam as premedication to induce anxiolysis before surgical procedures under local anesthesia is widely accepted in plastic surgery. Rhinoplasty performed under local anesthesia is known to generate high levels of perioperative anxiety, thus the use of appropriate premedication is important. Oral midazolam has been shown to be safe in various procedures. However, the safety of oral midazolam before rhinoplasty has not been evaluated.

Objectives: To evaluate the safety of premedication with oral midazolam prior to rhinoplasty by analyzing the intraoperative blood oxygen saturation levels as predictors of adverse respiratory events.

Methods: We retrospectively reviewed the anesthesia records of 62 patients who underwent rhinoplasty under local anesthesia and received premedication with oral midazolam for anxiolysis between March 2017 and December 2017. The median age of the patients was 25.4 years, and they were all classified as American Society of Anesthesiologists class 1. The patients received 10 mg midazolam hydrochloride orally 1 hour prior to the procedure. Oxygen blood saturation was monitored using a pulse oximeter and recorded every 15 minutes.

Results: All the patients maintained blood oxygen saturation levels above 95% (median peripheral capillary oxygen saturation 99%) on room air, and they did not require supplemental intraoperative oxygen. There were no transient hypoxemic events during and following the procedure.

Conclusions: Our study confirmed the safety of oral midazolam premedication to reduce perioperative anxiety when performing rhinoplasty under local anesthesia.

Background: Accurate pulse oximetry reading at hospital admission is of utmost importance, mainly for patients presenting with hypoxemia. Nevertheless, there is no accepted or evidence-based protocol for such structured measuring.

Objectives: To devise and assess a structured protocol intended to increase the accuracy of pulse oximetry measurement at hospital admission.

Methods: The authors performed a prospective comparison of protocol-based pulse-oximetry measurement with non-protocol based readings in consecutive patients at hospital admission. They also calculated the relative percentage of improvement for each patient (before and after protocol implementation) as a fraction of the change in peripheral capillary oxygen saturation (SpO₂) from 100%.

Results: A total of 460 patients were recruited during a 6 month period. Implementation of a structured measurement protocol significantly changed saturation values. The SpO₂ values of 24.7% of all study participants increased after protocol implementation (ranging from 1% to 21% increase in SpO₂ values). Among hypoxemic patients (initial SpO₂ < 90%), protocol implementation had a greater impact on final SpO₂ measurements, increasing their median SpO₂ readings by 4% (3–8% interquartile range; P < 0.05). Among this study population, 50% of the cohort improved by 17% of their overall potential and 25% improved by 50% of their overall improvement potential. As for patients presenting with hypoxemia, the median improvement was 31% of their overall SpO₂ potential.

Conclusions: Structured, protocol based pulse-oximetry may improve measurement accuracy and reliability. The authors suggest that implementation of such protocols may improve the management of hypoxemic patients.

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: Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation, especially in patients at high risk for extubation failure. In recent years, high flow oxygen system devices have offered an appropriate alternative to standard oxygen therapy devices such as conventional face masks and nasal prongs.

Objectives: To assess the clinical effects of high flow nasal cannula (HFNC) compared with standard oxygen face masks in Intensive Care Unit (ICU) patients after extubation.

Methods: We retrospectively analyzed 67 consecutive ventilated critical care patients in the ICU over a period of 1 year. The patients were allocated to two treatment groups: HFNC (34 patients, group 1) and non-rebreathing oxygen face mask (NRB) (33 patients, group 2). Vital respiratory and hemodynamic parameters were assessed prior to extubation and 6 hours after extubation. The primary clinical outcomes measured were improvement in oxygenation, ventilation-free days, re-intubation, ICU length of stay, and mortality.

Results: The two groups demonstrated similar hemodynamic patterns before and after extubation. The respiratory rate was slightly elevated in both groups after extubation with no differences observed between groups. There were no statistically significant clinical differences in PaCO₂. However, the use of HFNC resulted in improved PaO₂/FiO₂ post-extubation (P < 0.05). There were more ventilator-free days in the HFNC group (P < 0.05) and fewer patients required re-intubation (1 vs. 6). There were no differences in ICU length of stay or mortality.

Conclusion: This study demonstrated better oxygenation for patients treated with HFNC compared with NRB after extubation. HFNC may be more effective than standard oxygen supply devices for oxygenation in the post-extubation period.

 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.