Carbon Monoxide Poisoning (Reprinted from the 2023 Hyperbaric Indications Manual 15 edition).

Despite established exposure limits and safety standards, and the availability of carbon monoxide (CO) alarms, each year an estimated 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. If the CO exposure is sufficiently high, unconsciousness and death occur quickly, and without symptoms.

Gunshot damage to monoplace hyperbaric chamber acrylic.

Introduction: Health care workers are vulnerable to workplace violence, including active shooter incidents. Little is known about how firearms could damage monoplace chamber acrylic and whether a breached pressurized chamber presents additional threat to the patient or bystanders.

Methods: In a remote area where firearm discharge is permitted, we tested the durability of sections of monoplace hyperbaric chamber acrylic under various firearm discharges.

Carbon monoxide poisoning.

Despite established exposure limits and safety standards as well as the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. Common symptoms can include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status.

Structural and Volumetric Brain MRI Findings in Mild Traumatic Brain Injury.

Background And Purpose: Routine MR imaging findings are frequently normal following mild traumatic brain injury and have a limited role in diagnosis and management. Advanced MR imaging can assist in detecting pathology and prognostication but is not readily available outside research settings. However, 3D isotropic sequences with ∼1-mm voxel size are available on community MR imaging scanners.

Carbon monoxide poisonings in hotels and motels: The problem silently continues.

Carbon monoxide poisoning remains common in the United States. One component of effective prevention involves identification of scenarios in which poisoning occurs to guide development of appropriate interventions. This study was conducted to determine the significance of the problem of carbon monoxide poisoning occurring in US hotels, motels and resorts.

Hyperbaric oxygen for mTBI-associated PCS and PTSD: Pooled analysis of results from Department of Defense and other published studies.

Background: Some clinical trials report improvement in persistent post-concussive symptoms (PCS) with hyperbaric oxygen (HBO2) following mild traumatic brain injury (mTBI), but questions remain regarding the utility of HBO2 for PCS, the effects of HBO2 on post-traumatic stress disorder (PTSD), and the influences of sham control exposures.

Methods: A systematic review and pooled analysis was conducted to summarize available evidence for HBO2 in mTBI-associated PCS ± PTSD. Data aggregated from four Department of Defense (DoD) studies with participant-level data (n=254) were grouped into pooled HBO2 and sham intervention groups.

A composite outcome for mild traumatic brain injury in trials of hyperbaric oxygen.

Introduction: Global outcomes can strengthen inferences from clinical trials. We evaluate global outcomes for persistent post-concussive symptoms (PCS) after mild traumatic brain injury (mTBI) in two clinical trials of hyperbaric oxygen (HBO2) in United States service members.

Methods: During study design, outcomes of symptom, cognitive, and functional impairments planned for a trial of HBO2 for PCS (HOPPS) were weighted and grouped into different domains to formulate the composite outcome total score.

Adverse events and blinding in two randomized trials of hyperbaric oxygen for persistent post-concussive symptoms.

Safety monitoring and successful blinding are important features of randomized, blinded clinical trials. We report chamber- and protocol-related adverse events (AEs) for participants enrolled in two randomized, double-blind clinical trials of hyperbaric oxygen (HBO2) for persistent post-concussive symptoms clinicaltrials.gov identifiers NCT01306968, HOPPS, and NCT01611194, BIMA), as well as the success of maintaining the blind with a low-pressure sham control arm.

Extended follow-up in a randomized trial of hyperbaric oxygen for persistent post-concussive symptoms.

To date, several Department of Defense (DoD) and civilian studies have evaluated hyperbaric oxygen for mild forms of traumatic brain injury. Prior to the DoD-sponsored "Brain Injury and Mechanisms of Action of Hyperbaric Oxygen for Persistent Post-Concussive Symptoms after Mild Traumatic Brain Injury (mTBI) (BIMA)" trial, none included post-intervention follow-up beyond three to six months. Post-hoc attempts at long-term follow-up were complicated by low participation and potential self-selection bias.

Eye tracker outcomes in a randomized trial of 40 sessions of hyperbaric oxygen or sham in participants with persistent post concussive symptoms.

Purpose: Eye movements may offer a sensitive method to measure response to intervention in mild traumatic brain injury (mTBI).

Methods: The Brain Injury and Mechanisms of Action of Hyperbaric Oxygen for Persistent Post-Concussive Symptoms after Mild Traumatic Brain Injury Study (BIMA) randomized 71 participants to 40 sessions of hyperbaric oxygen or sham. A companion normative study (Normal) enrolled 75 participants.

Analysis of magnetic resonance spectroscopy relative metabolite ratios in mild traumatic brain injury and normative controls.

Introduction: We evaluated magnetic resonance spectroscopy (MRS) in United States military personnel with persistent symptoms after mild traumatic brain injury (mTBI), comparing over time two groups randomized to receive hyperbaric oxygen or sham chamber sessions and a third group of normative controls.

Methods: Active-duty or veteran military personnel and normative controls underwent MRS outcome measures at baseline, 13 weeks (mTBI group only), and six months. Participants received 3.

Prospective study of anxiety, post-traumatic stress and depression on postural control, gait, otolith and visuospatial function in military service members with persistent post-concussive symptoms.

Purpose: Military service members often report both affective and vestibular complaints after mild traumatic brain injury (mTBI), but associations between symptoms and vestibular deficits can be subtle and inconsistent.

Methods: From two complementary studies, one of military service members with persistent post-concussive symptoms after mTBI (NCT01611194) and the other of adult volunteers with no history of brain injury (NCT01925963), affective symptoms were compared to postural control, gait, otolith and visuospatial function.

Results: The studies enrolled 71 participants with mTBI and 75 normative controls.

Central auditory processing disorders after mild traumatic brain injury.

Auditory processing disorders are common following mild traumatic brain injury (mTBI), but the neurocircuitry involved is not well understood. The present study used functional MRI to examine auditory cortex activation patterns during a passive listening task in a normative population and mTBI patients with and without clinical central auditory processing deficits (APD) as defined by the SCAN-3:A clinical battery. Patients with mTBI had overall patterns of lower auditory cortex activation during the listening tasks as compared to normative controls.

Hidden hearing deficits in military service members with persistent post concussive symptoms.

Introduction: Individuals with persistent symptoms after mild traumatic brain injury (mTBI) often have auditory complaints. In this study, we used the auditory brainstem response (ABR) to determine whether cochlear synaptopathy could explain auditory symptoms.

Methods: 69 adult military service members with mTBI and 25 adults without brain injury (NCT01611194 and NCT01925963) completed pure-tone audiometry, ABR, and central auditory processing tests.

Quantitative analysis tool for clinical functional MRI in mild traumatic brain injury.

Functional magnetic resonance imaging (fMRI) has been available commercially for clinical diagnostic use for many years. However, both clinical interpretation of fMRI by a neuroradiologist and quantitative analysis of fMRI data can require significant personnel resources that exceed reimbursement. In this report, a fully automated computer-based quantification methodology (Enumerated Auditory Response, EAR) has been developed to provide an auditory fMRI assessment of patients who have suffered a mild traumatic brain injury.

Reference ranges and stability of auditory and vestibular measures in a comprehensive assessment battery for traumatic brain injury.

Background: Audiology clinics have many tools available to evaluate auditory and vestibular complaints. However, many tools lack established normative ranges across the life span. We conducted this study to establish reference ranges across the life span for audiology/vestibular measures commonly used to evaluate patients with traumatic brain injury.

Longitudinal study of hyperbaric oxygen intervention on balance and affective symptoms in military service members with persistent post-concussive symptoms.

Background: Dizziness and imbalance are common after mild traumatic brain injury (mTBI). Hyperbaric oxygen (HBO2) has been proposed for persistent post-concussive symptoms after mTBI, but its effect on vestibular function is unknown.

Objective: To describe balance function in military service-members before and after intervention, and to explore the influence of post-traumatic stress disorder (PTSD), anxiety, and depression on vestibular outcomes.

Myositis associated with carbon monoxide poisoning.

Introduction: Carbon monoxide (CO) poisoning causes hypoxia and inflammation, which could adversely affect muscle. We could find no published information about CO poisoning causing myositis.

Case Report: A 53-year-old previously healthy female semi truck driver had CO poisoning from a faulty diesel engine exhaust intermittently over three months, culminating in an episode of acute CO poisoning, with syncope after exiting the truck at the end of the three-month period.

Quantitative EEG Biomarkers for Mild Traumatic Brain Injury.

Purpose: The development of objective biomarkers for mild traumatic brain injury (mTBI) in the chronic period is an important clinical and research goal. Head trauma is known to affect the mechanisms that support the electrophysiological processing of information within and between brain regions, so methods like quantitative EEG may provide viable indices of brain dysfunction associated with even mTBI.

Methods: Resting-state, eyes-closed EEG data were obtained from 71 individuals with military-related mTBI and 82 normal comparison subjects without traumatic brain injury.

Age-Accelerated Reduction in Cortical Surface Area in United States Service Members and Veterans with Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder.

Despite the prevalence of combat-related mild traumatic brain injury (mTBI) and relatively high incidence of concurrent post-traumatic stress disorder (PTSD), the joint effect of these conditions on the brain is not well understood. Further, few studies in the mTBI or PTSD populations focus on cortical surface area measures, despite known disruptions to cytoarchitecture of the cortex. This study examines the effects of comorbid mTBI and PTSD on age-related surface area changes across the cortex, as compared with a group with mTBI only.

Effects of mild traumatic brain injury and post-traumatic stress disorder on resting-state default mode network connectivity.

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are common outcomes for service members. Abnormal connectivity within neural networks has been reported in the resting brain of mTBI and PTSD patients, respectively; however, the potential role of PTSD in changes to neural networks following injury has not been studied in detail. Using a data-driven approach, the present analysis aimed to elucidate resting state functional connectivity in the default mode network (DMN) in those with mTBI only and those with comorbid mTBI and PTSD.

Comprehensive Evaluation of Healthy Volunteers Using Multi-Modality Brain Injury Assessments: An Exploratory, Observational Study.

Even though mild traumatic brain injury is common and can result in persistent symptoms, traditional measurement tools can be insensitive in detecting functional deficits after injury. Some newer assessments do not have well-established norms, and little is known about how these measures perform over time or how cross-domain assessments correlate with one another. We conducted an exploratory study to measure the distribution, stability, and correlation of results from assessments used in mild traumatic brain injury in healthy, community-dwelling adults.