Patient-Reported Outcome Measures Following Hyperbaric Oxygen Therapy for Radiation Cystitis: Early Results From the Multicenter Registry for Hyperbaric Oxygen Therapy

PURPOSE

Our purpose was to determine changes in patient-reported hematuria and urinary symptoms after hyperbaric oxygen (HBO2) treatment for radiation cystitis (RC).

MATERIALS AND METHODS

We analyzed prospectively collected data from the Multicenter Registry for Hyperbaric Oxygen Therapy Consortium accumulated within a week of beginning and ending HBO2. Measures included the modified Radiation Therapy Oncology Group (RTOG) Hematuria Scale, Urinary Distress Inventory Short Form, and EuroQol Five Dimension Five Level instrument. RTOG hematuria and Urinary Distress Inventory Short Form scores were compared using the sign test. Logistic regression was used to evaluate characteristics associated with hematuria improvement.

RESULTS

A total of 470 registry patients had RC. The median age, number of HBO2 sessions, and years after radiation were 73 (IQR 12) years, 39 (IQR 10) sessions, and 5 (IQR 8) years, respectively. Eighty-four percent of patients (393/470) had prostate cancer‒related radiation. EuroQol Five Dimension Five Level scores improved from 0.83 (IQR 0.14) to 0.85 (IQR 0.22; P < .001. Three hundred seventy patients had complete RTOG hematuria scores that improved from 2 (IQR 2) to 0 (IQR 2; P < .001. Two hundred forty-six patients had complete Urinary Distress Inventory Short Form ratings that decreased from 33.3 (IQR 44) to 22.2 (IQR 33; P < .001). Regression analysis of those with visible hematuria before HBO2 showed lower improvement odds associated with higher HBO2 hematuria scores (odds ratio [OR] 0.44, 95% CI 0.26-0.73; P < .01), a smoking history (OR 0.44, 95% CI 0.21-0.92; P = .03), or a nonprostate cancer history (OR 0.32, 95% CI 0.10-0.99; P = .05).

CONCLUSIONS

HBO2 for RC improved reported hematuria, urinary function, and quality of life. Higher baseline hematuria scores, smoking, and nonprostate cancer history were associated with lower odds of hematuria improvement.

Machine learning for predicting cognitive deficits using auditory and demographic factors

IMPORTANCE

Predicting neurocognitive deficits using complex auditory assessments could change how cognitive dysfunction is identified, and monitored over time. Detecting cognitive impairment in people living with HIV (PLWH) is important for early intervention, especially in low- to middle-income countries where most cases exist. Auditory tests relate to neurocognitive test results, but the incremental predictive capability beyond demographic factors is unknown.

OBJECTIVE

Use machine learning to predict neurocognitive deficits, using auditory tests and demographic factors.

SETTING

The Infectious Disease Center in Dar es Salaam, Tanzania.

PARTICIPANTS

Participants were 939 Tanzanian individuals from Dar es Salaam living with and without HIV who were part of a longitudinal study. Patients who had only one visit, a positive history of ear drainage, concussion, significant noise or chemical exposure, neurological disease, mental illness, or exposure to ototoxic antibiotics (e.g., gentamycin), or chemotherapy were excluded. This provided 478 participants (349 PLWH, 129 HIV-negative). Participant data were randomized to training and test sets for machine learning.

MAIN OUTCOME(S) AND MEASURE(S)

The main outcome was whether auditory variables combined with relevant demographic variables could predict neurocognitive dysfunction (defined as a score of <26 on the Kiswahili Montreal Cognitive Assessment) better than demographic factors alone. The performance of predictive machine learning algorithms was primarily evaluated using the area under the receiver operational characteristic curve. Secondary metrics for evaluation included F1 scores, accuracies, and the Youden's indices for the algorithms.

RESULTS

The percentage of individuals with cognitive deficits was 36.2% (139 PLWH and 34 HIV-negative). The Gaussian and kernel naïve Bayes classifiers were the most predictive algorithms for neurocognitive impairment. Algorithms trained with auditory variables had average area under the curve values of 0.91 and 0.87, F1 scores (metric for precision and recall) of 0.81 and 0.76, and average accuracies of 86.3% and 81.9% respectively. Algorithms trained without auditory variables as features were statistically worse (p < .001) in both the primary measure of area under the curve (0.82/0.78) and the secondary measure of accuracy (72.3%/74.5%) for the Gaussian and kernel algorithms respectively.

CONCLUSIONS AND RELEVANCE

Auditory variables improved the prediction of cognitive function. Since auditory tests are easy-to-administer and often naturalistic tasks, they may offer objective measures or predictors of neurocognitive performance suitable for many global settings. Further research and development into using machine learning algorithms for predicting cognitive outcomes should be pursued.

Hyperbaric Oxygen Enabled a Transition to Oral Steroids in an Acute Severe Ulcerative Colitis Flare

Background

Ulcerative colitis (UC) is characterized in part by a dysregulated response to tissue hypoxia. While intravenous (IV) steroids are the mainstay of treatment for acute severe UC (ASUC), up to one-third of patients are refractory to steroids alone and require rescue therapy.

Case Description

A 71-year-old female with extensive UC on infliximab presented with abdominal pain and more than 10 bloody bowel movements per day. Her infliximab concentration was undetectable with a positive antibody level. Flexible sigmoidoscopy on hospital day (HD)1 showed Mayo 3 colitis; biopsies for CMV were negative. She was started on hydrocortisone IV with improvement in her CRP from 56 to 40 mg/L. She also received 1 dose of vedolizumab. Hyperbaric treatments were offered but declined. By HD5, she was clinically improved, with a CRP of 9 mg/L. She was transitioned from IV to oral steroids. After starting oral steroids her symptoms relapsed, her CRP increased from 9 to 48 mg/L, and IV steroids were reinitiated on HD6. Hyperbaric medicine was reconsulted and she completed 5 hyperbaric oxygen (HBO2) treatments (HD 7-11) with prompt reduction in CRP, stool frequency, and bleeding. After 3 HBO2 treatments, she transitioned successfully from IV to oral steroids on HD9.

Conclusions

This case demonstrates the potential of HBO2 therapy to help UC patients transition successfully from IV to oral steroids who were previously refractory to de-escalation. HBO2 therapy may be considered as an adjunctive treatment for patients with ASUC to potentiate the effects of standard therapies and avoid progression to colectomy.

Auditory neural processing in children living with HIV uncovers underlying central nervous system dysfunction

OBJECTIVE

Central nervous system (CNS) damage from HIV infection or treatment can lead to developmental delays and poor educational outcomes in children living with HIV (CLWH). Early markers of central nervous system dysfunction are needed to target interventions and prevent life-long disability. The frequency following response (FFR) is an auditory electrophysiology test that can reflect the health of the central nervous system. In this study, we explore whether the FFR reveals auditory central nervous system dysfunction in CLWH.

STUDY DESIGN

Cross-sectional analysis of an ongoing cohort study. Data were from the child's first visit in the study.

SETTING

The infectious disease center in Dar es Salaam, Tanzania.

METHODS

We collected the FFR from 151 CLWH and 151 HIV-negative children. To evoke the FFR, three speech syllabi (/da/, /ba/, /ga/) were played monaurally to the child's right ear. Response measures included neural timing (peak latencies), strength of frequency encoding (fundamental frequency and first formant amplitude), encoding consistency (inter-response consistency), and encoding precision (stimulus-to-response correlation).

RESULTS

CLWH showed smaller first formant amplitudes ( P  < 0.0001), weaker inter-response consistencies ( P  < 0.0001) and smaller stimulus to response correlations ( P  < 0.0001) than FFRs from HIV-negative children. These findings generalized across the three speech stimuli with moderately strong effect sizes (partial η2 ranged from 0.061 to 0.094).

CONCLUSION

The FFR shows auditory central nervous system dysfunction in CLWH. Neural encoding of auditory stimuli was less robust, more variable, and less accurate. As the FFR is a passive and objective test, it may offer an effective way to assess and detect central nervous system function in CLWH.

A Central Auditory Test reveals differences between drug treatment regimens in adults living with HIV

OBJECTIVE

This exploratory study examined whether central auditory tests show differences between people living with HIV (PLWH) treated with two predominant antiretroviral drug therapy (ART) regimens.

DESIGN

Cross-sectional.

STUDY SAMPLE

253 PLWH (mean age 39.8 years) from the Shanghai Public Health Clinical Centre, China.

METHODS

The Hearing in Noise Test speech reception threshold (SRT) assessed central auditory function and the Montreal Cognitive Assessment (MoCA) assessed cognition. The relationship between ART regimen and SRT was evaluated with multivariable linear regression incorporating age, HIV duration, and peripheral hearing ability. Multivariable logistic regression was used to ascertain if SRT and ART regimen predicted MoCA impairment.

RESULTS

The two predominant ART regimens differed by one drug (zidovudine or tenofovir). Participants taking the zidovudine-containing regimen had poorer SRT performance (p=.012) independent of age and hearing thresholds. MoCA scores did not differ between drug regimens, but a negative relationship was found between SRT and MoCA impairment (p=.048).

CONCLUSIONS

ART regimens differed in their association with central auditory test performance likely reflecting neurocognitive changes in PLWH taking the zidovudine-containing regimen. Central auditory test performance also marginally predicted cognitive impairment, supporting further assessment of central auditory tests to detect neurocognitive deficits in PLWH.

Central auditory test performance predicts future neurocognitive function in children living with and without HIV

Tests of the brain's ability to process complex sounds (central auditory tests) correlate with overall measures of neurocognitive performance. In the low- middle-income countries where resources to conduct detailed cognitive testing is limited, tests that assess the central auditory system may provide a novel and useful way to track neurocognitive performance. This could be particularly useful for children living with HIV (CLWH). To evaluate this, we administered central auditory tests to CLWH and children living without HIV and examined whether central auditory tests given early in a child's life could predict later neurocognitive performance. We used a machine learning technique to incorporate factors known to affect performance on neurocognitive tests, such as education. The results show that central auditory tests are useful predictors of neurocognitive performance and perform as well or in some cases better than factors such as education. Central auditory tests may offer an objective way to track neurocognitive performance in CLWH.

Nationwide survey of medical student interest in and exposure to aerospace medicine

Aerospace Medicine is experiencing a renaissance. Commercial spaceflight is now a reality, meaning that individuals with a variety of medical conditions will be flying in space. NASA has Mars plans, and SpaceX plans to send humans to Mars within the next decade, so today's medical students may be future physicians on these crews. Considering these developments, we evaluated interest in and exposure to Aerospace Medicine among medical students in the United States (US). A 19-question anonymous multiple-choice questionnaire was emailed to current medical students throughout the US. Information about demographics, career and research interests in aerospace medicine, opportunities available at students' respective institutions, and possible avenues for supporting students' interests was collected and analyzed. One thousand two hundred forty-four students (490 men, 751 women, 3 other) with a mean age of 25.8 ± 3.0 years from 60 institutions completed the questionnaire. Most respondents expressed an interest in learning about aerospace medicine during their training. A strong interest in research, as well as career opportunities, exists despite the majority of students reporting minimal access to opportunities to get involved in the field at most of the surveyed institutions. With growing interest and an expected increase in demand for physicians with a background in aerospace medicine, medical schools may be able to support students by increasing access to opportunities.

Pre-flight body weight effects on urinary calcium excretion in space

Microgravity-induced bone loss increases urinary calcium excretion which increases kidney stone formation risk. Not all individuals show the same degree of increase in urinary calcium and some pre-flight characteristics may help identify individuals who may benefit from in-flight monitoring. In weightlessness the bone is unloaded, and the effect of this unloading may be greater for those who weigh more. We studied whether pre-flight body weight was associated with increased in-flight urinary calcium excretion using data from Skylab and the International Space Station (ISS). The study was reviewed and approved by the National Aeronautics and Space Administration (NASA) electronic Institutional Review Board (eIRB) and data were sourced from the Longitudinal Study of Astronaut Health (LSAH) database. The combined Skylab and ISS data included 45 participants (9 Skylab, 36 ISS). Both weight and day in flight were positively related to urinary calcium excretion. There was also an interaction between weight and day in flight with higher weight associated with higher calcium excretion earlier in the mission. This study shows that pre-flight weight is also a factor and could be included in the risk assessments for bone loss and kidney stone formation in space.

Preliteracy assessment in children living with HIV in Tanzania: comparison to results from children living without HIV in Tanzania and the United States

OBJECTIVE

Children with HIV (CWH) are at increased risk for cognitive and developmental delays. Whether HIV affects literacy development, however, remains unknown. Rapid automatized naming (RAN) tasks offer the simplest preliteracy assessment a child can perform that predicts future reading skills across languages.

DESIGN AND METHODS

RAN performance was analyzed cross-sectionally on 473 children (249 children without HIV and 217 CWH; ages 3-9) drawn from a longitudinal study in Tanzania. These data were compared to results from 341 normally developing children without HIV (ages 3-8) from the United States. Participants performed two RAN subtests: colors and objects.

RESULTS

RAN object completion was greater than for the RAN color in Tanzanian children. CWH were less likely to complete either subtest and performed worse on the object subtest compared to Tanzanian children without HIV. Compared to the US cohort, the Tanzanian cohort was less likely to complete both subtests - in particular the colors subtest - and showed more variability in responses at younger ages. After approximately age 6, however, the trajectory of improvement between the United States and Tanzania was similar.

CONCLUSIONS

CWH performed worse on this per-literacy test, indicating literacy skill development in CWH needs further study. The differences between US and Tanzanian results likely reflect variability in when children learn to name colors and objects. The trajectory of improvement between countries became more similar as the children aged. This study motivates further longitudinal analyses aimed at assessing the developmental trajectory of the RAN, its predictive ability for reading skills, and its link with other preliteracy and cognitive skills.

Gap detection responses modelled using the Hill equation in adults with well-controlled HIV

OBJECTIVE

This study's objective was determining whether gap detection deficits are present in a longstanding cohort of people living with HIV (PLWH) compared to those living without HIV (PLWOH) using a new gap detection modelling technique (i.e. fitting gap responses using the Hill equation and analysing the individual gap detection resulting curves with non-linear statistics). This approach provides a measure of both gap threshold and the steepness of the gap length/correct detection relationship.

DESIGN

The relationship between the correct identification rate at each gap length was modelled using the Hill equation. Results were analysed using a nonlinear mixed-effect regression model.

STUDY SAMPLE

45 PLWH (age range 41-78) and 39 PLWOH (age range 38-79) were enrolled and completed gap detection testing.

RESULTS

The likelihood ratio statistic comparing the full regression model with the HIV effects to the null model, assuming one population curve for both groups, was highly significant (p < 0.001), suggesting a less precise relationship between gap length and correct detection in PLWH.

CONCLUSIONS

PLWH showed degraded gap detection ability compared to PLWOH, likely due to central nervous system effects of HIV infection or treatment. The Hill equation provided a new approach for modelling gap detection ability.

Online Interactive Interest-Based Negotiation Training For Managing Conflict In Isolated Environments: Opportunistic Study with E-survey

BACKGROUND

The ability to negotiate effectively while maintaining relationships is critical for successful long-duration space missions. Incidents within the space program have demonstrated the serious consequences from not resolving conflicts optimally. Also, less desirable forms of negotiation, like positional bargaining (e.g., like negotiation over prices) can exacerbate conflicts. Traditional positional bargaining may work for simple, low-stakes transactions but does not prioritize ongoing relationships. Interest-based negotiation, where parties with competing interests and/or goals join to create a mutually beneficial agreement, is crucial in high-stakes situations. This is learnable but needs to be practiced. Refresher training when a conflict arises is important to prevent out-of-practice crewmembers from using less effective negotiation techniques. Ideally, the training should be self-directed and not involve others because, on a space mission, the only other people available may be part of the conflict.

OBJECTIVE

Develop and test an interactive module that teaches the principles and skills of Interest-based negotiation in a way that users find acceptable, valuable for learning, and enjoyable.

METHODS

Using a web-based, interactive-media-approach, we scripted, filmed, and programmed an Interest-based negotiation interactive training module. In the module, the program mentor introduces users to the "The Circle of Value" approach to negotiation and highlights its key concepts through interactive scenarios requiring users to make selections at specific decision points. Each selection prompts feedback designed to reinforce a teaching point or highlight a particular negotiation technique. To evaluate the module, we sought out populations experiencing isolation and confinement (an opportunistic design). This included 9 subjects in isolated and confined environments in the Australian Antarctic Program and the HI-SEAS Mars simulation, as well as a subset of people who self-identified as being isolated and confined during the COVID-19 pandemic. Feedback was collected from participants (n=54) through free-response answers and questionnaires with numerical scaling (0/strongly disagree -> 4/strongly agree) presented at the end of the module.

RESULTS

94% of participants found the activity valuable for learning about conflict management (identified by those who selected either 'somewhat agree' or 'strongly agree'), including 100% of participants in the isolated and confined environments subset (mode=3). 79% of all participants found the module realistic (mode=3), including 67% of isolated and confined environment participants (mode=3). Most participants felt this would be particularly valuable for new team members in an isolated and confined environment (85% of all participants, mode=4; 78% of isolated and confined environment subset, mode=3) as well as veterans.

CONCLUSIONS

This module offers a self-directed, consistent approach to Interest-based negotiation training, which is well received by users. While the data are limited due to the opportunistic study design, results show that the module could be useful for individuals in isolated and confined environments, as well as for anyone involved in high-stakes negotiations where sustaining relationships is essential.

CLINICALTRIAL

Peripheral Auditory Function in Tanzanian Children Living With HIV With Clinically Normal Hearing

IMPORTANCE

Despite normal audiometry, adults living with HIV have lower distortion product otoacoustic emissions (DPOAEs) compared with HIV-negative controls, but the degree of these differences in children living with HIV is unknown. If subclinical auditory deficits are present, results could affect developmental outcomes in children living with HIV (CLWH).

OBJECTIVE

To compare DPOAEs and auditory brainstem responses (ABR) between 2 age- and sex-matched groups of younger children with normal audiometry, 1 infected with HIV and the other uninfected.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study in an infectious disease center in Dar es Salaam, Tanzania. Participants included 340 Tanzanian children aged 3 to 9 years with clinically normal hearing, type A tympanograms bilaterally, and air-conduction thresholds of 20 dB HL or less from 0.5 to 8 kHz. Participants in the cohort repeated testing approximately every 6 months (approximately 2.2 sessions per participant) for a total of 744 total observations. Data were analyzed from March 2020 to January 2022.

MAIN OUTCOMES AND MEASURES

DPOAE amplitudes from 1.5 to 8 kHz using an f2 to f1 ratio of 1.2 and L1/L2 values of 65/55 dB sound pressure level and click-evoked ABR using a slow (21.1/s) and fast (61.1/s) click rate.

RESULTS

A total of 141 CLWH (70 female participants [49.3%]; mean [SD] age, 7.24 [1.67] years) and 199 HIV-negative individuals (99 female participants [49.7%]; mean [SD] age, 7.26 [1.44] years) participated in the study. The groups did not differ significantly in age, static immittance, or air-conduction thresholds. HIV status was independently associated with approximately 1.4 dB (95% CI, -3.28 to 0.30 dB) to 3.8 dB (95% CI, 6.03 to -1.99 dB) lower DPOAE amplitudes at 6 and 8 kHz bilaterally and 0.28 μV (95% CI, 0.01 to 0.33 μV) lower ABR wave V amplitudes in the right ear.

CONCLUSIONS AND RELEVANCE

Consistent with previous findings in young adults, CLWH had slightly, but reliably, lower DPOAEs and ABR wave V amplitudes than HIV-negative controls. The magnitude of these differences was small, but results suggest an early and consistent association between HIV infection or treatment and outer hair cell and auditory brainstem responses in children as young as 3 years. These subclinical changes suggest tracking both auditory function and development outcomes in CLWH is warranted.

Test-Retest repeatability of automated threshold audiometry in Nicaraguan schoolchildren

OBJECTIVE

Automated threshold audiometry (ATA) could increase access to paediatric hearing assessment in low- and middle-income countries, but few studies have evaluated test-retest repeatability of ATA in children. This study aims to analyse test-retest repeatability of ATA and to identify factors that affect the reliability of this method.

DESIGN

ATA was performed twice in a cohort of Nicaraguan schoolchildren. During testing, the proportion of responses occurring in the absence of a stimulus was measured by calculating a stimulus response false positive rate (SRFP). Absolute test-retest repeatability was determined between the two trials, as well as the impact of age, gender, ambient noise, head circumference, and SRFP on these results.

STUDY SAMPLE

807 children were randomly selected from 35 schools in northern Nicaragua.

RESULTS

Across all frequencies, the absolute value of the difference between measurements was 5.5 ± 7.8 dB. 89.6% of test-retest differences were within 10 dB. Intra-class correlation coefficients between the two measurements showed that lower SRFP was associated with improved repeatability. No effect of age, gender, or ambient noise was found.

CONCLUSIONS

ATA produced moderate test-retest repeatability in Nicaraguan schoolchildren. Participant testing behaviours, such as delayed or otherwise inappropriate response patterns, significantly impacts the repeatability of these measurements.

Sensitizing brain metastases to stereotactic radiosurgery using hyperbaric oxygen: A proof-of-principle study

PURPOSE

Increased oxygen levels may enhance the radiosensitivity of brain metastases treated with stereotactic radiosurgery (SRS). This project administered hyperbaric oxygen (HBO) prior to SRS to assess feasibility, safety, and response.

METHODS

38 patients were studied, 19 with 25 brain metastases treated with HBO prior to SRS, and 19 historical controls with 27 metastases, matched for histology, GPA, resection status, and lesion size. Outcomes included time from HBO to SRS, quality-of-life (QOL) measures, local control, distant (brain) metastases, radionecrosis, and overall survival.

RESULTS

The average time from HBO chamber to SRS beam-on was 8.3 ± 1.7 minutes. Solicited adverse events (AEs) were comparable between HBO and control patients; no grade III or IV serious AEs were observed. Radionecrosis-free survival (RNFS), radionecrosis-free survival before whole-brain radiation therapy (WBRT) (RNBWFS), local recurrence-free survival before WBRT (LRBWFS), distant recurrence-free survival before WBRT (DRBWFS), and overall survival (OS) were not significantly different for HBO patients and controls on Kaplan-Meier analysis, though at 1-year estimated survival rates trended in favor of SRS + HBO: RNFS - 83% vs 60%; RNBWFS - 78% vs 60%; LRBWFS - 95% vs 78%; DRBWFS - 61% vs 57%; and OS - 73% vs 56%. Multivariate Cox models indicated no significant association between HBO treatment and hazards of RN, local or distant recurrence, or mortality; however, these did show statistically significant associations (p < 0.05) for: local recurrence with higher volume, radionecrosis with tumor resection, overall survival with resection, and overall survival with higher GPA.

CONCLUSION

Addition of HBO to SRS for brain metastases is feasible without evident decrement in radiation necrosis and other clinical outcomes.

Prospective measurements of hearing threshold during military rifle training with in-ear, protected, noise exposure monitoring

Although a causal relationship exists between military occupational noise exposure and hearing loss, researchers have struggled to identify and/or characterize specific operational noise exposures that produce measurable changes in hearing function shortly following an exposure. Growing evidence suggests that current standards for noise-exposure limits are not good predictors of true hearing damage. In this study, the aim was to capture the dose-response relationship during military rifle training exercises for noise exposure and hearing threshold. To capture exposure, a wearable system capable of measuring impulse noise simultaneously on-body and in-ear, behind hearing protection was used. To characterize hearing threshold changes, portable audiometry was employed within 2 h before and after exposure. The median 8-h time-weighted, protected, free-field equivalent in-ear exposure was 87.5 dBA at one site and 80.7 dBA at a second site. A significant dose-response correlation between in-ear noise exposure and postexposure hearing threshold changes across our population ( R = 0.40 , p = 0.0281) was observed. The results demonstrate an approach for establishing damage risk criteria (DRC) for in-ear, protected measurements based on hearing threshold changes. While an in-ear DRC does not currently exist, it may be critical for predicting the risk of injury for noise environments where protection is mandatory and fit status can vary.

Hyperbaric Oxygen as Successful Monotherapy for a Severe Ulcerative Colitis Flare

This report presents a case of severe ulcerative colitis treated with hyperbaric oxygen as successful monotherapy.

Community health workers and mHealth systems for hearing screening in rural Nicaraguan schoolchildren

Background

We aimed to investigate the effectiveness of using minimally trained community health workers (CHW) to screen schoolchildren in rural Nicaragua for hearing loss using a tablet-based audiometric system integrated with asynchronous telehealth evaluations and mobile health (mHealth) appointment reminders.

Methods

A population-based survey was conducted using community health workers (CHWs) to perform tablet-based audiometry, asynchronous telehealth evaluations, and mHealth reminders to screen 3398 school children (7-9 years of age) in 92 rural Nicaraguan communities. The accuracy of screening, test duration, testing efficiency, telehealth data validity, and compliance with recommended clinic visits were analyzed.

Results

Minimally trained CHWs successfully screened children within remote rural schools with automated audiometry (test duration = 5.8 minutes) followed by manual audiometry if needed (test duration = 4.3 minutes) with an estimated manual audiometry validity of 98.5% based on a review of convergence patterns. For children who were referred based on audiometry, the otoscopy and tympanometry obtained during telehealth evaluations were high quality (as reviewed by 3 experts) in 44.6% and 80.1% of ears, respectively. A combination of automated short message service (SMS) text messages and voice reminders resulted in a follow-up compliance of 75.2%. No families responded to SMS messages alone.

Conclusions

Tablet-based hearing screening administered by minimally trained CHWs is feasible and effective in low- and middle-income countries. Manual audiometry was as efficient as automated audiometry in this setting. The physical exam tasks of otoscopy and tympanometry require additional training. Mobile phone messages improve compliance for confirmatory audiometry, but the utility of SMS messaging alone is unclear in this population.

First Void Urinary Calcium for Tracking Bone Loss and Kidney Stone Risk in Space

INTRODUCTION: Microgravity exposure unloads the skeleton. This increases urinary calcium excretion, which reflects both increased bone loss and kidney stone formation risk. We studied the probability that first morning void (FMV) urinary calcium (Uca) measurements would capture the highest Uca concentration in a day.METHODS: For 8 wk, three men and three women collected void-by-void 24-h urine samples weekly. Uca concentration was analyzed using a calcein-based system. Uca concentrations were ranked among all samples from each person. FMV and non-FMV (nFMV) Uca concentrations were compared with a Mann Whitney U-test. The probability that an FMV would capture the highest Uca concentration in a day was assessed.RESULTS: Among 377 voids collected, 46 were FMV and 331 were nFMV. Among all samples, the Uca concentration for FMV was significantly higher than nFMV (P < 0.0001). Out of the 46 FMVs, 24 were highest in Uca concentration for the corresponding 24-h period, giving a 52.2% probability that any given FMV would capture the highest Uca concentration in a day. The probability of measuring the highest Uca concentration from at least 1 d increased to 77.1%, and 89.1% when two or three FMVs were collected respectively.DISCUSSION: Acquiring 2–3 repeated FMVs provides a high likelihood of capturing the highest Uca from a day. This suggests repeated first morning void Uca concentrations could assess the risk of bone loss and kidney stone formation, which may provide ability for real-time implementation of countermeasure programs to prevent bone and renal complications in prolonged spaceflight.Thamer S, Buckey JC. First void urinary calcium for tracking bone loss and kidney stone risk in space. Aerosp Med Hum Perform. 2022; 93(7):546–550.

The Host-Microbiome Response to Hyperbaric Oxygen Therapy in Ulcerative Colitis Patients

BACKGROUND & AIMS

Hyperbaric oxygen therapy (HBOT) is a promising treatment for moderate-to-severe ulcerative colitis. However, our current understanding of the host and microbial response to HBOT remains unclear. This study examined the molecular mechanisms underpinning HBOT using a multi-omic strategy.

METHODS

Pre- and post-intervention mucosal biopsies, tissue, and fecal samples were collected from HBOT phase 2 clinical trials. Biopsies and fecal samples were subjected to shotgun metaproteomics, metabolomics, 16s rRNA sequencing, and metagenomics. Tissue was subjected to bulk RNA sequencing and digital spatial profiling (DSP) for single-cell RNA and protein analysis, and immunohistochemistry was performed. Fecal samples were also used for colonization experiments in IL10-/- germ-free UC mouse models.

RESULTS

Proteomics identified negative associations between HBOT response and neutrophil azurophilic granule abundance. DSP identified an HBOT-specific reduction of neutrophil STAT3, which was confirmed by immunohistochemistry. HBOT decreased microbial diversity with a proportional increase in Firmicutes and a secondary bile acid lithocholic acid. A major source of the reduction in diversity was the loss of mucus-adherent taxa, resulting in increased MUC2 levels post-HBOT. Targeted database searching revealed strain-level associations between Akkermansia muciniphila and HBOT response status. Colonization of IL10-/- with stool obtained from HBOT responders resulted in lower colitis activity compared with non-responders, with no differences in STAT3 expression, suggesting complementary but independent host and microbial responses.

CONCLUSIONS

HBOT reduces host neutrophil STAT3 and azurophilic granule activity in UC patients and changes in microbial composition and metabolism in ways that improve colitis activity. Intestinal microbiota, especially strain level variations in A muciniphila, may contribute to HBOT non-response.

International Multicenter Registry for Hyperbaric Oxygen Therapy: Results through June 2021

INTRODUCTION

The International Multicenter Registry for Hyperbaric Oxygen Therapy (International Report Registered Identifier DERR1-10.2196/18857) was established in 2011 to capture outcomes and complications data for both Undersea and Hyperbaric Medical Society (UHMS) approved and selected unapproved hyperbaric oxygen (HBO2) therapy indications.

METHODS

A Research Electronic Data Capture (REDCap) template was designed and distributed to all participating centers for prospective data collection. Centers contributed de-identified demographic, treatment, complications, and outcome data. This report provides summary data on sites and enrollment, as well as pre- and post-treatment data on quality of life (EQ-5D-5L questionnaire), head and neck radiationoutcomes, non-healing wounds (Strauss score), and idiopathic sudden sensorineural hearing loss. Data were analyzed mainly using the Wilcoxon signed-rank test.

RESULTS

Twenty-two centers contributed data for 2,880 patients. The most common UHMS-approved indication was delayed radiation injury, followed by enhancement of wound healing, and carbon monoxide poisoning. One hundred and twenty-five patients were treated for non-UHMS approved indications. Quality of life, head and neck radiation symptoms, Strauss wound scores, and hearing were significantly improved after HBO2. Complication rates were low and comparable to previous reports. The registry also offered the ability to analyze factors that affect outcomes, such as smoking and severity of hearing loss.

DISCUSSION

The registry accrues prospective data on defined outcomes from multiple centers and allows for analysis of factors affecting outcomes. This registry does not have a control group, which is a limitation. Nevertheless, the registry provides a unique, comprehensive dataset on HBO2 outcomes from multiple centers internationally.

A Rare Presentation of Intraosseous Sarcoidosis of the Mandible Presenting as Peri-Implantitis: A Case Report and Literature Review

PURPOSE

We describe a rare case of intraosseous sarcoidosis initially presenting as peri-implantitis, perform a review and analysis of 27 cases of intraosseous sarcoidosis, and provide a clinical review of this condition.

METHODS

We searched the literature for patients presenting with intraosseous sarcoidosis of the jaw through June 2020 using key phrases. Additional papers were included via a search of references and citing papers. Data including patient demographic characteristics and diagnostic tests were manually extracted from the cases and then qualitatively coded by the authors. Descriptive statistical analysis was performed to elucidate general themes and characteristics.

RESULTS

A total of 27 cases, dating as early as 1943 and as recent as this case, were identified in the literature, including our case. The average age of these patients was 39 years old, with a range of 16 to 75 years. Eighteen (67%) cases were identified as female and nine (33%) as male. Fourteen cases were reported with localized mandibular involvement. Ten had maxillary disease; 3 cases were generalized to both regions. Nine cases presented anteriorly, 12 posteriorly, and 6 extended across both regions. Eight patients received surgical interventions, such as tooth extractions or lesion removal. Five patients received nonsurgical interventions, such as steroids. Ten patients received combination therapy, often involving surgical intervention and steroid therapy.

CONCLUSION

Our patient had an unusual presentation of intraosseous sarcoidosis mimicking peri-implantitis. To our knowledge, no case in the English literature describes a patient with sarcoidosis presenting with peri-implantitis. Based on the literature review and analysis of our patient's experience, sarcoidosis should be considered on the differential diagnosis for patients with persistent, nonhealing bony lesions in the maxillofacial region, particularly when patients have not been exposed to osteoclast inhibitory therapy or radiation. Pathologic analysis of bone and surrounding tissue in these scenarios is essential.

The Correlation Between Body Weight and Intraocular Pressure

INTRODUCTION: Preflight body weight is a strong predictor of visual changes in spaceflight. To understand the effect of body weight on the eye, we examined the effect of increased body mass index on intraocular pressure on Earth.METHODS: We conducted a systematic review to summarize the relationship between weight parameters (including body mass index (BMI) and obesity indices), and intraocular pressure (IOP). Study selection and data extraction were performed in duplicate using EMBASE, MEDLINE, and CENTRAL, from database inception to the second week of April 2020.RESULTS: A total of 66 individual studies were included for qualitative analysis from the 1364 studies eligible for title and abstract screening. A total of 39 studies were available for quantitative analysis. The average BMI was 25.9 (range, 20.148.8) and the average IOP was 14.9 mmHg (range, 11.627.8). The overall pooled RR between BMI and elevated intraocular pressure (IOP) was 1.06 (95 CI%, 1.041.07), meaning for each unit increase in BMI one is 6 more likely of having higher IOP than baseline. Two studies assessed the effects of bariatric surgery, and both showed significant decreases in IOP postoperatively.CONCLUSION: A higher BMI was associated with increased IOP in ground-based studies. IOP also decreased with weight loss. These data support the idea that alterations in body weight affect intraocular pressures. Further research is needed to understand the relationship between body weight, IOP, and microgravity-induced visual changes. This finding may also be useful clinically.Khan S, Kirubarajan A, Lee M, Pitha I, Buckey JC Jr. The correlation between body weight and intraocular pressure. Aerosp Med Hum Perform. 2021; 92(11):886-897.

The Relationship Between Central Auditory Tests and Neurocognitive Domains in Adults Living With HIV

Objective: Tests requiring central auditory processing, such as speech perception-in-noise, are simple, time efficient, and correlate with cognitive processing. These tests may be useful for tracking brain function. Doing this effectively requires information on which tests correlate with overall cognitive function and specific cognitive domains. This study evaluated the relationship between selected central auditory focused tests and cognitive domains in a cohort of normal hearing adults living with HIV and HIV- controls. The long-term aim is determining the relationships between auditory processing and neurocognitive domains and applying this to analyzing cognitive function in HIV and other neurocognitive disorders longitudinally. Method: Subjects were recruited from an ongoing study in Dar es Salaam, Tanzania. Central auditory measures included the Gap Detection Test (Gap), Hearing in Noise Test (HINT), and Triple Digit Test (TDT). Cognitive measures included variables from the Test of Variables of Attention (TOVA), Cogstate neurocognitive battery, and Kiswahili Montreal Cognitive Assessment (MoCA). The measures represented three cognitive domains: processing speed, learning, and working memory. Bootstrap resampling was used to calculate the mean and standard deviation of the proportion of variance explained by the individual central auditory tests for each cognitive measure. The association of cognitive measures with central auditory variables taking HIV status and age into account was determined using regression models. Results: Hearing in Noise Tests and TDT were significantly associated with Cogstate learning and working memory tests. Gap was not significantly associated with any cognitive measure with age in the model. TDT explained the largest mean proportion of variance and had the strongest relationship to the MoCA and Cogstate tasks. With age in the model, HIV status did not affect the relationship between central auditory tests and cognitive measures. Age was strongly associated with multiple cognitive tests. Conclusion: Central auditory tests were associated with measures of learning and working memory. Compared to the other central auditory tests, TDT was most strongly related to cognitive function. These findings expand on the association between auditory processing and cognitive domains seen in other studies and support evaluating these tests for tracking brain health in HIV and other neurocognitive disorders.

Peripheral Auditory Function in Young HIV-Positive Adults With Clinically Normal Hearing

OBJECTIVE

Little is known about peripheral auditory function in young adults with HIV, who might be expected to show early evidence of hearing loss if HIV infection or treatment does affect peripheral function. The goal of this study was to compare peripheral auditory function in 2 age- and gender-matched groups of young adults with clinically normal hearing with and without HIV.

STUDY DESIGN

Matched cohort study with repeated measures.

SETTING

Infectious disease center in Dar es Salaam, Tanzania.

METHODS

Participants included HIV-positive (n = 38) and HIV-negative (n = 38) adults aged 20 to 30 years who had clinically normal hearing, defined as type A tympanograms, air conduction thresholds ≤25 dB HL bilaterally from 0.5 to 8 kHz, and distortion product otoacoustic emissions (DPOAEs) >6 dB above the noise floor bilaterally from 1.5 to 8 kHz. Participants were tested multiple times over 6-month intervals (average, 2.7 sessions/participant) for a total of 208 observations. Primary outcome measures included tympanograms, air conduction audiograms, DPOAEs, and click-evoked auditory brainstem responses.

RESULTS

HIV groups did not significantly differ in age, static immittance, or air conduction thresholds. HIV-positive status was independently associated with approximately 3.7-dB lower DPOAE amplitudes from 2 to 8 kHz (95% CI, 1.01-6.82) in both ears and 0.04-µV lower (95% CI, 0.003-0.076) auditory brainstem response wave I amplitudes in the right ear.

CONCLUSION

Young adults living with HIV have slightly but reliably smaller DPOAEs and auditory brainstem response wave I amplitudes than matched HIV-negative controls. The magnitude of these differences is small, but these results support measuring peripheral auditory function in HIV-positive individuals as they age.

Renal Effects of Hyperbaric Oxygen Therapy in Patients with Diabetes Mellitus: A Retrospective Study

Hyperbaric oxygen therapy (HBOT) is an adjunctive treatment for patients with diabetic foot ulcers. The prolonged high oxygen level used in HBOT can produce oxidative stress, which may be harmful to the kidney. Animal experiments suggest HBOT does not harm renal function and may have an antiproteinuric effect, but little is known on the effect of HBOT in humans. We performed a retrospective chart review of 94 patients with diabetes mellitus who underwent HBOT at our institution over an eight-year period. Thirty-two patients had serum creatinine levels within 60 days of the start and the end of treatment. Creatinine levels were 1.41 ± 0.89 mg/dl before and 1.52 ± 1.17 mg/dl after hyperbaric treatments with no statistically significant difference (mean (postcreatinine + precreatinine/2) = 0.10 mg/dl, SE = 0.11, t = 0.89). Twenty-three patients had proteinuria measurements before and after HBOT mainly by urine dipstick analysis. A Wilcoxon signed-rank test showed less proteinuria after HBOT than before (N = 23, p=0.002). Proteinuria was absent in 7 of 23 patients (30%) before HBOT and 13 of 23 patients (57%) after HBOT, a reduction by almost 50%. This observation is remarkable because oxidative stress might be expected to increase rather than decrease proteinuria.

Distortion product otoacoustic mapping measured pre- and post-loud sound exposures

OBJECTIVE

Sampling distortion product otoacoustic emissions (DPOAEs) at multiple f₂/f₁ ratios and f₂ frequency values produces a DPOAE "map." This study examined the efficacy of DPOAE mapping compared with pure tone audiometry and standard DPOAEs for detecting noise effects in subjects exposed to loud sound.

DESIGN

A map significance score was developed as a single measure of map change. Significance scores were evaluated before and after exposure to: loud music (LM), controlled noise (CN), and firing range noise (FR) in three separate sets of subjects. Scores were compared to audiometry and standard DPOAE results in the LM study.

STUDY SAMPLE

The LM and CN exposure studies involved 22, and 20 healthy young subjects respectively with normal hearing. Eight Marines were studied before and after FR exposure.

RESULTS

After LM exposure, audiometry showed significant changes at 1, 2, 4, and 6 kHz. Standard DPOAE measures were also significantly different at several frequencies. Map significance scores detected changes more effectively and showed the distribution of DPOAE alterations.

CONCLUSIONS

Map significance scores detected changes after noise exposure more reliably than audiometry and standard DPOAEs. Additionally, maps showed a diffuse response to sound exposure perhaps explaining why individual DP-grams appear less sensitive.

Use of a Self-guided Computerized Cognitive Behavioral Tool During COVID-19: Evaluation Study

BACKGROUND

Internet-based programs can help provide accessible and inexpensive behavioral health care to those in need; however, the evaluation of these interventions has been mostly limited to controlled trials. Data regarding patterns of use and effectiveness of self-referred, open-access online interventions are lacking. We evaluated an online-based treatment designed to address stress, depression, and conflict management, the Dartmouth PATH Program, in a freely available and self-guided format during the COVID-19 pandemic.

OBJECTIVE

The primary aim is to determine users' levels of stress and depression, and the nature of problems and triggers they reported during the COVID-19 pandemic. A secondary objective is to assess the acceptability and usability of the PATH content and determine whether such a program would be useful as a stand-alone open-access resource. The final objective is understanding the high dropout rates associated with online behavioral programs by contrasting the use pattern and program efficacy of individuals who completed session one and did not return to the program with those who came back to complete more sessions.

METHODS

Cumulative anonymous data from 562 individuals were analyzed. Stress triggers, stress responses, and reported problems were analyzed using qualitative analysis techniques. Scores on usability and acceptability questionnaires were evaluated using the sign test and Wilcoxon signed rank test. Mixed-effects linear modeling was used to evaluate changes in stress and depression over time.

RESULTS

A total of 2484 users registered from April through October 2020, most of whom created an account without initiating a module. A total of 562 individuals started the program and were considered in the data analysis. The most common stress triggers individuals reported involved either conflicts with family or spouses and work or workload. The most common problems addressed in the mood module were worry, anxiousness, or stress and difficulty concentrating or procrastination. The attrition rate was high with 13% (21/156) completing the conflict module, 17% (50/289) completing session one of the mood module, and 14% (16/117) completing session one of the stress module. Usability and acceptability scores for the mood and stress modules were significantly better than average. In those who returned to complete sessions, symptoms of stress showed a significant improvement over time (P=.03), and there was a significant decrease in depressive symptoms over all time points (P=.01). Depression severity decreased on average by 20% (SD 35.2%; P=.60) between sessions one and two.

CONCLUSIONS

Conflicts with others, worry, and difficulty concentrating were some of the most common problems people used the programs to address. Individuals who completed the modules indicated improvements in self-reported stress and depression symptoms. Users also found the modules to be effective and rated the program highly for usability and acceptability. Nevertheless, the attrition rate was very high, as has been found with other freely available online-based interventions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02726061; https://clinicaltrials.gov/ct2/show/NCT02726061.

Proposed mechanism for reduced jugular vein flow in microgravity

Internal jugular flow is reduced in space compared with supine values, which can be associated with internal jugular vein (IJV) thrombosis. The mechanism is unknown but important to understand to prevent potentially serious vein thromboses on long duration flights. We used a novel, microgravity‐focused numerical model of the cranial vascular circulation to develop hypotheses for the reduced flow. This model includes the effects of removing hydrostatic gradients and tissue compressive forces – unique effects of weightlessness. The IJV in the model incorporates sensitivity to transmural pressure across the vein, which can dramatically affect resistance and flow in the vein. The model predicts reduced IJV flow in space. Although tissue weight in the neck is reduced in weightlessness, increasing transmural pressure, this is more than offset by the reduction in venous pressure produced by the loss of hydrostatic gradients and tissue pressures throughout the body. This results in a negative transmural pressure and increased IJV resistance. Unlike the IJV, the walls of the vertebral plexus are rigid; transmural pressure does not affect its resistance and so its flow increases in microgravity. This overall result is supported by spaceflight measurements, showing reduced IJV area inflight compared with supine values preflight. Significantly, this hypothesis suggests that interventions that further decrease internal IJV pressure (such as lower body negative pressure), which are not assisted by other drainage mechanisms (e.g. gravity), might lead to stagnant flow or IJV collapse with reduced flow, which could increase rather than decrease the risk of venous thrombosis.

Unexplained multi-sensory neuropathy syndrome in young Tanzanian adults

Background

A unique syndrome affecting young adults of unexplained hearing loss often associated with uncorrectable poor visual acuity and lower extremity numbness is endemic in Dar es Salaam. This study characterized the hearing loss, associated it with other symptoms, and gathered information on potential causes.

Methods

Forty-seven patients (23 men, 24 women) <40 years old with a symptom consistent with the syndrome, negative syphilis test, and no head injury history were recruited from Muhimbili National Hospital. 18 controls (10 men, 8 women) were recruited from the same neighborhoods as patients. Hearing ability and cochlear outer hair cell function (distortion-product otoacoustic emissions (DPOAEs)) were assessed, as were visual acuity and color vision. Peripheral neuropathy was evaluated using the Michigan Neuropathy Screening Instrument (MNSI), and physical examination. Blood C-reactive protein levels and toenail trace metal concentrations were measured. Environmental exposures were elicited using a questionnaire. Patients with at least two of the following signs were defined as having the syndrome: poor hearing with normal DPOAEs, vision not correctable to better than 20/30, or a MNSI score greater than 4.

Results

29 participants met the case definition. CRP levels did not differ between groups but manganese, cobalt and tin levels were each greater in the cases than controls. No other environmental exposure differences were noted.

Conclusions

Toenail manganese, cobalt, and tin levels were higher in those with the syndrome. These metals are potential neurotoxins suggesting a possible environmental origin for this unique and debilitating syndrome.

Physiologic and biochemical rationale for treating COVID-19 patients with hyperbaric oxygen

The SARS-Cov-2 (COVID-19) pandemic remains a major worldwide public health issue. Initially, improved supportive and anti-inflammatory intervention, often employing known drugs or technologies, provided measurable improvement in management. We have recently seen advances in specific therapeutic interventions and in vaccines. Nevertheless, it will be months before most of the world's population can be vaccinated to achieve herd immunity. In the interim, hyperbaric oxygen (HBO2) treatment offers several potentially beneficial therapeutic effects. Three small published series, one with a propensity-score-matched control group, have demonstrated safety and initial efficacy. Additional anecdotal reports are consistent with these publications. HBO2 delivers oxygen in extreme conditions of hypoxemia and tissue hypoxia, even in the presence of lung pathology. It provides anti-inflammatory and anti-proinflammatory effects likely to ameliorate the overexuberant immune response common to COVID-19. Unlike steroids, it exerts these effects without immune suppression. One study suggests HBO2 may reduce the hypercoagulability seen in COVID patients. Also, hyperbaric oxygen offers a likely successful intervention to address the oxygen debt expected to arise from a prolonged period of hypoxemia and tissue hypoxia. To date, 11 studies designed to investigate the impact of HBO2 on patients infected with SARS-Cov-2 have been posted on clinicaltrials.gov. This paper describes the promising physiologic and biochemical effects of hyperbaric oxygen in COVID-19 and potentially in other disorders with similar pathologic mechanisms.

Increased Right Frontal Brain Activity During the Mandarin Hearing-in-Noise Test

Purpose

Previous studies have revealed increased frontal brain activation during speech comprehension in background noise. Few, however, used tonal languages. The normal pattern of brain activation during a challenging speech-in-nose task using a tonal language remains unclear. The Mandarin Hearing-in-Noise Test (HINT) is a well-established test for assessing the ability to interpret speech in background noise. The current study used Mandarin HINT (MHINT) sentences and functional magnetic resonance imaging (fMRI) to assess brain activation with MHINT sentences.

Methods

Thirty native Mandarin-speaking subjects with normal peripheral hearing were recruited. Functional MRI was performed while subjects were presented with either HINT “clear” sentences with low-level background noise [signal-to-noise ratio (SNR) = +3 dB] or “noisy” sentences with high-level background noise (SNR = −5 dB). Subjects were instructed to answer with a button press whether a visually presented target word was included in the sentence. Brain activation between noisy and clear sentences was compared. Activation in each condition was also compared to a resting, no sentence presentation, condition.

Results

Noisy sentence comprehension showed increased activity in areas associated with tone processing and working memory, including the right superior and middle frontal gyri [Brodmann Areas (BAs) 46, 10]. Reduced activity with noisy sentences was seen in auditory, language, memory and somatosensory areas, including the bilateral superior and middle temporal gyri, left Heschl’s gyrus (BAs 21, 22), right temporal pole (BA 38), bilateral amygdala-hippocampus junction, and parahippocampal gyrus (BAs 28, 35), left inferior parietal lobule extending to left postcentral gyrus (BAs 2, 40), and left putamen.

Conclusion

Increased frontal activation in the right hemisphere occurred when comprehending noisy spoken sentences in Mandarin. Compared to studies using non-tonal languages, this activation was strongly right-sided and involved subregions not previously reported. These findings may reflect additional effort in lexical tone perception in this tonal language. Additionally, this continuous fMRI protocol may offer a time-efficient way to assess group differences in brain activation with a challenging speech-in-noise task.

Autonomous Psychological Support for Isolation and Confinement

INTRODUCTION: Isolated and confined environments (ICEs), such as spaceflight, are challenging psychologically. We have been evaluating self-directed tools to sustain and improve psychological well-being in these settings. The Expedition Application for Peak Psychological Performance (Expedition-APPP) is an interactive media-based set of self-directed tools that address conflict resolution, stress management, and depression treatment. Virtual reality (VR) of nature scenes is a tool to improve attention and relieve stress by providing users with an immersive nature experience. We evaluated both Expedition-APPP and VR in an ICE.METHODS: The Expedition-APP was evaluated during three, and nature VR during two, deployments at the HI-SEAS habitat, where crews of six were isolated for 812 mo. Participants used both the Expedition-APPP and VR and shared their feedback and experiences after the deployments in semistructured interviews. These interviews were evaluated using qualitative analysis techniques to gather generalizable insights into implementing autonomous mental health programs for people living and working in ICEs.RESULTS: Expedition-APPP modules provided a shared culture, language, and tools for working through challenges. VR allowed for access to emotions and experiences that were unavailable in the habitat. Suggestions for improvement included making refresher training easily available and providing a wider range of content to address different individuals coping styles.DISCUSSION: Both the Expedition-APPP and VR were appreciated and used, although a wider range of content and experiences was desired by participants.Lyons KD, Slaughenhaupt RM, Mupparaju SH, Lim JS, Anderson AA, Stankovic AS, Cowan DR, Fellows AM, Binsted KA, Buckey JC. Autonomous psychological support for isolation and confinement. Aerosp Med Hum Perform. 2020; 91(11):876885.

Use of custom-moulded earmoulds to improve repeatability of DPOAE map measurements

OBJECTIVE

Distortion product otoacoustic emission (DPOAE) mapping characterises cochlear function, can include both the 2f1-2f2 and 2f2-2f1 DPOAEs, and shows promise for tracking cochlear changes. DPOAE amplitude measurements are not as repeatable longitudinally as pure-tone audiometry, likely due in part to probe placement sensitivity. We hypothesised that DPOAE level map variation over multiple testing sessions could be minimised by replacing traditional rubber tips with custom-moulded probe tips.

DESIGN

Traditional rubber tips (TRT) and custom-moulded probes tips (CMPT) were used to measure DPOAE level maps repeatedly over five sessions. Probe placement was assessed using a frequency sweep in the ear canal. Repeatability of the DPOAE level maps was assessed using a Bland-Altman analysis. Overall map repeatability was assessed by measuring differences in distortion product amplitude over sessions.

STUDY SAMPLE

Crossover study with a convenience sample size of six adults.

RESULTS

The CMPT frequency sweeps showed reduced variability in probe placement. The repeatability coefficient for individual DPOAEs measurements improved from 6.9 dB SPL with the TRT to 5.1 dB SPL with the CMPT. Map repeatability improved for most subjects with the CMPT.

A phase 2B randomised trial of hyperbaric oxygen therapy for ulcerative colitis patients hospitalised for moderate to severe flares

BACKGROUND

Hyperbaric oxygen has been reported to improve disease activity in hospitalised ulcerative colitis (UC) patients.

AIM

To evaluate dosing strategies with hyperbaric oxygen for hospitalised UC patients.

METHODS

We enrolled UC patients hospitalised for acute flares (Mayo score 6-12). Initially, all patients received 3 days of hyperbaric oxygen at 2.4 atmospheres (90 minutes with two air breaks) in addition to intravenous steroids. Day 3 responders (reduction of partial Mayo score ≥ 2 points and rectal bleeding score ≥ 1 point) were randomised to receive a total of 5 days vs 3 days of hyperbaric oxygen.

RESULTS

We treated 20 patients with hyperbaric oxygen (75% prior biologic failure). Day 3 response was achieved in 55% (n = 11/20), with significant reductions in stool frequency, rectal bleeding and CRP (P < 0.01). A more significant reduction in disease activity was observed with 5 days vs 3 days of hyperbaric oxygen (P = 0.03). Infliximab or colectomy was required in only three patients (15%) despite a predicted probability of 80% for second-line therapy. Day 3 hyperbaric oxygen responders were less likely to require re-hospitalisation or colectomy by 3 months vs non-responders (0% vs 66%, P = 0.002). No treatment-related adverse events were observed.

CONCLUSION

Hyperbaric oxygen appears to be effective for optimising response to intravenous steroids in UC patients hospitalised for acute flares, with low rates of re-hospitalisation or colectomy at 3 months. An optimal clinical response is achieved with 5 days of hyperbaric oxygen. Larger phase 3 trials are needed to confirm efficacy and obtain labelled approval.

Urinary Calcium for Tracking Bone Loss and Kidney Stone Risk in Space

INTRODUCTION: Urinary calcium (Uca) levels in space reflect bone loss and kidney stone risk and could be measured using portable devices. This project evaluated the repeatability of Uca measurements to assess how many repeated measurements would be needed to detect significant urinary calcium elevations in space.METHODS: A total of six subjects collected 24-h urine samples weekly for 8 wk and took 500 mg of oral calcium carbonate and 400 IU of vitamin D daily in week 7 and 8. Uca concentration was analyzed using a calcein-based system. The effect of the intake of calcium and vitamin D on Uca levels and the correlation between first void concentration and 24-h mass were assessed with linear mixed effect models. The reproducibility coefficient (RPC) for Uca was determined using Bland-Altman analysis on pairs of measurements at different time points.RESULTS: Oral supplementation did not significantly affect 24-h mass. First void concentration correlated with 24-h mass. The 24-h mass RPCs were 167.0, 116.8, and 108.1 mg for 1-, 2-, and 3-wk average measurements. First void concentration RPCs were 90.6, 76.6, and 72.8 mg L¹. Skylab astronauts 24-h mass increased by 88.9 76.0, 123.5 58.3, 142.2 56.5, and 159.9 83.4 mg after 1, 2, 3, and 4 wk in flight.DISCUSSION: Averaging multiple Uca measurements reduced variability effectively and allowed increases likely to be seen in space to be detected. Consecutive Uca measurements could be tracked over time in space to assess the effectiveness of the countermeasure program. First void concentration could potentially be used rather than 24-h collections.Ren J, Stankovic AS, Knaus DA, Phillips SD, Kynor DB, Buckey JC. Urinary calcium for tracking bone loss and kidney stone risk in space. Aerosp Med Hum Perform. 2020; 91(9):689696.

Development of an International, Multicenter, Hyperbaric Oxygen Treatment Registry and Research Consortium: Protocol for Outcome Data Collection and Analysis

BACKGROUND

Hyperbaric oxygen (HBO₂)-oxygen at pressures higher than atmospheric-is approved for 14 indications by the Undersea and Hyperbaric Medical Society. HBO₂'s main effect is to increase oxygen content in plasma and body tissues, which can counteract hypoxia or ischemia. Laboratory studies show that HBO₂ has effects beyond relieving hypoxia (eg, promoting angiogenesis in irradiated tissue, anti-inflammatory effects, radiosensitization of tumors, hypoxia preconditioning, and fungal growth inhibition) and has potential to treat conditions such as inflammatory bowel disease and pyoderma gangrenosum. Lack of consistently collected outcome data on a large cohort of individuals receiving HBO₂ therapy limits its use for both established and new indications. A course of therapy often involves 30-40 visits to a hyperbaric chamber, so the number of patients seen at any given center is constrained by chamber capacity. As a result, published HBO₂ outcome data tend to be from small case series because few patients with a particular condition are treated at a given center. To solve this problem, a registry that collects and pools data systematically from multiple institutions has been established.

OBJECTIVE

The aim of this study is to collect consistent outcome data across multiple hyperbaric centers to assess treatment effectiveness and establish a research consortium.

METHODS

A consortium of hyperbaric centers who have agreed to collect consistent outcome data on all patients seen has been assembled. Data are collected at each participating center using Research Electronic Data Capture (REDCap), a web-based, data collection system used frequently for research. Standard outcome measures have been defined for each condition, which are programmed into the REDCap data collection templates. Governance is through a consortium agreement that defines data security, data sharing, publications, liability, and other issues. Centers obtain Institutional Review Board (IRB) and ethics approval to participate, either from their own institutions or by relying on the IRB at the coordinating center at Dartmouth College. Dissemination will occur through a yearly report and by publications based on the data in the registry.

RESULTS

Early results from some common indications show significant pretreatment to posttreatment changes. Additional indications and outcome measures are being added using the procedures outlined in the consortium agreement.

CONCLUSIONS

The registry collects consistent outcome information for a therapy that needs further study and a stronger evidence base. It also overcomes the challenge of collecting data from an adequate number of patients for both established and emerging indications by combining data collection from multiple centers. The data entry requirements should be within the capabilities of existing staff at any given hyperbaric center. By using REDCap, the registry can be expanded to include detailed information on particular indications and long-term follow-up on selected patients without significantly increasing the basic data entry requirements. Through the registry, a network of enrolled hyperbaric centers has been established that provides the basis for a clinical trial network.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/18857.

Optic Nerve Length before and after Spaceflight

PURPOSE

The spaceflight-associated neuro-ocular syndrome (SANS) affects astronauts on missions to the International Space Station (ISS). The SANS has blurred vision and ocular changes as typical features. The objective of this study was to investigate if microgravity can create deformations or movements of the eye or optic nerve, and if such changes could be linked to SANS.

DESIGN

Cohort study.

PARTICIPANTS

Twenty-two astronauts (age 48 ± 4 years).

METHODS

The intervention consisted of time in microgravity at the ISS. We co-registered pre- and postspaceflight magnetic resonance imaging (MRI) scans and generated centerline representations of the optic nerve. The coordinates for the optic nerve head (ONH) and optic chiasm (OC) ends of the optic nerve were recorded along with the entire centerline path.

MAIN OUTCOME MEASURES

Optic nerve length, ONH movement, and OC movement after time in microgravity.

RESULTS

Optic nerve length increased (0.80 ± 0.74 mm, P < 0.001), primarily reflecting forward ONH displacement (0.63 ± 0.53 mm, P < 0.001). The forward displacement was positively related to mission duration, preflight body weight, and clinical manifestations of SANS. We also detected upward displacement of the OC (0.39 ± 0.50 mm, P = 0.002), indicative of brain movement, but this observation could not be linked to SANS.

CONCLUSIONS

The spaceflight-induced optic nerve lengthening and anterior movement of the ONH support that SANS is caused by an altered pressure difference between the brain and the eye, leading to a forward push on the posterior of the eye. Body weight is a potential contributing risk factor. Direct assessment of intracranial pressure in space is required to verify the implicated mechanism behind the ocular findings in SANS.

Auditory neurophysiology reveals central nervous system dysfunction in HIV-infected individuals

OBJECTIVE

To test the hypothesis that human immunodeficiency virus (HIV) affects auditory-neurophysiological functions.

METHODS

A convenience sample of 68 HIV+ and 59 HIV- normal-hearing adults was selected from a study set in Dar es Salaam, Tanzania. The speech-evoked frequency-following response (FFR), an objective measure of auditory function, was collected. Outcome measures were FFRs to the fundamental frequency (F0) and to harmonics corresponding to the first formant (F1), two behaviorally relevant cues for understanding speech.

RESULTS

The HIV+ group had weaker responses to the F1 than the HIV- group; this effect generalized across multiple stimuli (d = 0.59). Responses to the F0 were similar between groups.

CONCLUSIONS

Auditory-neurophysiological responses differ between HIV+ and HIV- adults despite normal hearing thresholds.

SIGNIFICANCE

The FFR may reflect HIV-associated central nervous system dysfunction that manifests as disrupted auditory processing of speech harmonics corresponding to the first formant.

Detecting changes in distortion product otoacoustic emission maps using statistical parametric mapping and random field theory

Distortion product otoacoustic emission (DPOAE) maps collect DPOAE emissions over a broad range of frequencies and ratios. One application of DPOAE mapping could be monitoring changes in intracranial pressure (ICP) in space, where non-invasive measures of ICP are an area of interest. Data were collected in two experiments to statistically assess changes in DPOAE maps. A repeatability study where four maps per subject were collected across four weeks to establish "normal" variability in DPOAE data, and a posture study where subjects were measured supine and prone with lower body negative pressure, lower body positive pressure (LBPP), and at atmospheric pressure. DPOAE amplitude maps were analyzed using statistical parametric mapping and random field theory. Postural changes produced regional changes in the maps, specifically in the range of 5-7.5 kHz and between primary tone ratios of 1.13-1.24. These regional changes were most pronounced in the prone LBPP condition, where amplitudes were lower from baseline for the Postural Cohort than the Repeatability Cohort. Statistical parametric mapping provided a sensitive measure of regional DPOAE map changes, which may be useful clinically to monitor ICP noninvasively in individuals or for research to identify differences within in cohorts of people.

Intranasal Scopolamine for Motion Sickness

INTRODUCTION: Rapid onset, noninjection methods are required to provide "as needed" therapy for motion sickness. Intranasal scopolamine (IN SCOP) is attractive because it can be fast acting and work when gastric motility is slowed. Intranasal administration can provide a time to maximal concentration (T_max) of drugs (e.g., naloxone and midazolam) of 30 min or less. We evaluated the efficacy, pharmacodynamics, and pharmacokinetics of IN SCOP in a placebo-controlled, randomized, double-blind, dose-ranging study, and compared pharmacokinetic outcomes against other published results.METHODS: There were 18 healthy adult volunteers (10 M, 8F) who received placebo, low dose (0.2 mg), and high dose (0.4 mg) IN SCOP intranasally using a pump device and a gel formulation. Participants rode in an off-vertical axis rotation (OVAR) chair 1.25 h after dose administration and completed neurocognitive tests to evaluate secondary drug impacts. Pharmacokinetics (PK) and pharmacodynamics (PD) were assessed in eight subjects. PK data were compared to results from previously published studies.RESULTS: Low and high dose IN SCOP increased chair time significantly compared to placebo. No significant sleepiness or cognitive impairment was seen, likely due to the small sample size. T_max was long for both dosages (High dose 75.0 ± 49.4 min, Low dose 61.9 ± 37.1 min), compared to other intranasally administered drugs and some previous studies with IN SCOP. Average T_max was not superior to previously published values for dose-matched (0.4-0.5 mg), orally-delivered SCOP.DISCUSSION: IN SCOP has potential as a rapid administration route for relieving MS symptoms, but more work is needed to identify optimal intranasal formulation and dispensing methods.KEYWORDS: Motion sickness, pharmacokinetics, scopolamine, intranasal administration.Stankovic AS, Alvarenga DL, Daniels VRC, Simmons RG, Buckey JC, Putcha L. Intranasal scopolamine for motion sickness. Aerosp Med Hum Perform. 2019; 90(11):917-924.

Use of Gases to Treat Cochlear Conditions

Although the cochlear vascular supply (stria vascularis) is designed to block to certain compounds and molecules, it must enable gas exchange to survive. The inner ear capillaries must deliver oxygen and remove carbon dioxide for the cochlea to function. These gases diffuse through tissues across a concentration gradient to reach the desired target. Tight junctions or the endothelial basement membrane do not impede them. Therefore, gases that can diffuse into the inner ear are attractive as therapeutic agents. The two gases most often used in this way are oxygen and hydrogen, although carbon dioxide, ozone, and argon have also been investigated. Typically, oxygen is delivered as hyperbaric oxygen (HBO) (oxygen at pressure higher than atmospheric) to provide increased oxygen levels to the inner ear. This not only relieves hypoxia, but also has anti-inflammatory and other biochemical effects. HBO is used clinically to treat idiopathic sudden sensorineural hearing loss, and both animal and human studies suggest it may also assist recovery after acute acoustic trauma. Laboratory studies suggest hydrogen works as a free radical scavenger and reduces the strong oxidants hydroxyl radicals and peroxynitrite. It also has anti-apoptotic effects. Because of its anti-oxidant and anti-inflammatory effects, it has been studied as a treatment for ototoxicity and shows benefit in an animal model of cisplatinum toxicity. Gas diffusion offers an effective way to provide therapy to the inner ear, particularly since some gases (oxygen, hydrogen, carbon dioxide, ozone, argon) have important therapeutic effects for minimizing cochlear damage.

Hyperbaric oxygen therapy is well tolerated and effective for ulcerative colitis patients hospitalized for moderate-severe flares: a phase 2A pilot multi-center, randomized, double-blind, sham-controlled trial

BACKGROUND

Hyperbaric oxygen therapy (HBOT) markedly increases tissue oxygen delivery. Case series suggest it may have a potential therapeutic benefit in ulcerative colitis (UC). We investigated the therapeutic potential of HBOT as an adjunct to steroids for UC flares requiring hospitalization.

METHODS

The study was terminated early due to poor recruitment with 18 of the planned 70 patients enrolled. UC patients hospitalized for moderate-severe flares (Mayo score ≥6, endoscopic sub-score ≥2) were block randomized to steroids + daily HBOT (n = 10) or steroids + daily sham hyperbaric air (n = 8). Patients were blinded to study assignment, and assessments were performed by a blinded gastroenterologist. Primary outcome was the clinical remission rate at study day 5 (partial Mayo score ≤2 with no sub-score >1). Key secondary outcomes were: clinical response (reduction in partial Mayo score ≥2, rectal bleeding sub-score of 0-1) and progression to second-line therapy (colectomy or biologic therapy) during the hospitalization.

RESULTS

A significantly higher proportion of HBOT-treated patients achieved clinical remission at study day 5 and 10 (50 vs. 0%, p = 0.04). HBOT-treated patients less often required progression to second-line therapy during the hospitalization (10 vs. 63%, p = 0.04). The proportion requiring in-hospital colectomy specifically as second-line therapy for medically refractory UC was lower in the HBOT group compared to sham (0 vs. 38%, p = 0.07). There were no serious adverse events.

CONCLUSION

In this small, proof-of-concept, phase 2A trial, the use of HBOT as an adjunctive therapy to steroids for UC patients hospitalized for moderate-severe flares resulted in higher rates of clinical remission, and a reduction in rates of progression to second-line therapy during the hospitalization. Larger well-powered trials are needed, however, to provided definitive evidence of therapeutic benefit.