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Diving and Hyperbaric Medicine Jun 2019Physiological changes are induced by immersion, swimming and using diving equipment. Divers must be fit to dive. Using medication may impact the capacity to adapt to...
BACKGROUND
Physiological changes are induced by immersion, swimming and using diving equipment. Divers must be fit to dive. Using medication may impact the capacity to adapt to hyperbaric conditions. The aim of this systematic review is to assess the interaction of diving/hyperbaric conditions and medication and to provide basic heuristics to support decision making regarding fitness to dive in medicated divers.
METHODS
This was a systematic review of human and animal studies of medications in the hyperbaric environment. Studies were subdivided into those describing a medication/hyperbaric environment interaction and those concerned with prevention of diving disorders. Studies without a relation to diving with compressed air, and those concerning oxygen toxicity, hyperbaric oxygen therapy or the treatment of decompression sickness were excluded.
RESULTS
Forty-four studies matched the inclusion criteria. Animal studies revealed that diazepam and valproate gave limited protection against the onset of the high-pressure neurological syndrome. Lithium had a protective effect against nitrogen-narcosis and losartan reduced cardiac changes in repetitive diving. Human studies showed no beneficial or dangerous pressure-related interactions. In prevention of diving disorders, pseudoephedrine reduced otic barotrauma, vitamins C and E reduced endothelial dysfunction after bounce diving and hepatic oxidative stress in saturation diving.
DISCUSSION AND CONCLUSIONS
Animal studies revealed that psycho-pharmaceuticals can limit the onset of neurologic symptoms and cardiovascular protective drugs might add a potential protective effect against decompression sickness. No evidence of significant risks due to changes in pharmacologic mechanisms were revealed and most medication is not a contraindication to diving. For improving decision making in prescribing medicine for recreational and occupational divers and to enhance safety by increasing our understanding of pharmacology in hyperbaric conditions, future research should focus on controlled human studies.
Topics: Animals; Decompression Sickness; Diving; Humans; Hyperbaric Oxygenation; Inert Gas Narcosis; Swimming
PubMed: 31177519
DOI: 10.28920/dhm49.2.127-136 -
Journal of Critical Care Oct 2021To determine whether higher positive end- expiratory pressure (PEEP) could provide a survival advantage for patients without acute respiratory distress syndrome (ARDS)... (Meta-Analysis)
Meta-Analysis Review
Effect of different levels of PEEP on mortality in ICU patients without acute respiratory distress syndrome: systematic review and meta-analysis with trial sequential analysis.
OBJECTIVE
To determine whether higher positive end- expiratory pressure (PEEP) could provide a survival advantage for patients without acute respiratory distress syndrome (ARDS) compared with lower PEEP.
METHODS
Eligible studies were identified through searches of Embase, Cochrane Library, Web of Science, Medline, and Wanfang database from inception up to 1 June 2021. Trial sequential analysis (TSA) was used in this meta-analysis.
DATA SYNTHESIS
Twenty-seven randomized controlled trials (RCTs) were identified for further evaluation. Higher and lower PEEP arms included 1330 patients and 1650 patients, respectively. A mean level of 9.6±3.4 cmHO was applied in the higher PEEP groups and 1.9±2.6 cmHO was used in the lower PEEP groups. Higher PEEP, compared with lower PEEP, was not associated with reduction of all-cause mortality (RR 1.03; 95% CI 0.91-1.18; P =0.627), and 28-day mortality (RR 1.07 ; 95% CI 0.92-1.24; P =0.365). In terms of risk of ARDS (RR 0.43; 95% CI 0.24-0.78; P =0.005), duration of intensive care unit (MD -1.04; 95%CI-1.36 to -0.73; P < 0.00001), and oxygenation (MD 40.30; 95%CI 0.94 to 79.65; P = 0.045), higher PEEP was superior to lower PEEP. Besides, the pooled analysis showed no significant differences between groups both in the duration of mechanical ventilation (MD 0.00; 95%CI-0.13 to 0.13; P = 0.996) and hospital stay (MD -0.66; 95%CI-1.94 to 0.61; P = 0.309). More importantly, lower PEEP did not increase the risk of pneumonia, atelectasis, barotrauma, hypoxemia, or hypotension among patients compared with higher PEEP. The TSA analysis showed that the results of all-cause mortality and 28-day mortality might be false-negative results.
CONCLUSIONS
Our results suggest that a lower PEEP ventilation strategy was non-inferior to a higher PEEP ventilation strategy in ICU patients without ARDS, with no increased risk of all-cause mortality and 28-day mortality. Further high-quality RCTs should be performed to confirm these findings.
Topics: Humans; Intensive Care Units; Length of Stay; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Distress Syndrome
PubMed: 34274832
DOI: 10.1016/j.jcrc.2021.06.015 -
Annals of the American Thoracic Society Oct 2017Trials investigating use of lower tidal volumes and inspiratory pressures for patients with acute respiratory distress syndrome (ARDS) have shown mixed results. (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Trials investigating use of lower tidal volumes and inspiratory pressures for patients with acute respiratory distress syndrome (ARDS) have shown mixed results.
OBJECTIVES
To compare clinical outcomes of mechanical ventilation strategies that limit tidal volumes and inspiratory pressures (LTV) to strategies with tidal volumes of 10 to 15 ml/kg among patients with ARDS.
METHODS
This is a systematic review and meta-analysis of clinical trials investigating LTV mechanical ventilation strategies. We used random effects models to evaluate the effect of LTV on 28-day mortality, organ failure, ventilator-free days, barotrauma, oxygenation, and ventilation. Our primary analysis excluded trials for which the LTV strategy was combined with the additional strategy of higher positive end-expiratory pressure (PEEP), but these trials were included in a stratified sensitivity analysis. We performed metaregression of tidal volume gradient achieved between intervention and control groups on mortality effect estimates. We used Grading of Recommendations Assessment, Development, and Evaluation methodology to determine the quality of evidence.
RESULTS
Seven randomized trials involving 1,481 patients met eligibility criteria for this review. Mortality was not significantly lower for patients receiving an LTV strategy (33.6%) as compared with control strategies (40.4%) (relative risk [RR], 0.87; 95% confidence interval [CI], 0.70-1.08; heterogeneity statistic I = 46%), nor did an LTV strategy significantly decrease barotrauma or ventilator-free days when compared with a lower PEEP strategy. Quality of evidence for clinical outcomes was downgraded for imprecision. Metaregression showed a significant inverse association between larger tidal volume gradient between LTV and control groups and log odds ratios for mortality (β, -0.1587; P = 0.0022). Sensitivity analysis including trials that protocolized an LTV/high PEEP cointervention showed lower mortality associated with LTV (nine trials and 1,629 patients; RR, 0.80; 95% CI, 0.66-0.98; I = 46%). Compared with trials not using a high PEEP cointervention, trials using a strategy of LTV combined with high PEEP showed a greater mortality benefit (RR, 0.58; 95% CI, 0.41-0.82; P for interaction = 0.05).
CONCLUSIONS
The trend toward lower mortality with LTV ventilation in the primary analysis and the significant relationship between the degree of tidal volume reduction and the mortality effect together suggest, but do not prove, that LTV ventilation improves mortality among critically ill adults with ARDS.
Topics: Adult; Humans; Positive-Pressure Respiration; Randomized Controlled Trials as Topic; Respiratory Distress Syndrome; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 28846440
DOI: 10.1513/AnnalsATS.201704-337OT -
Annals of the American Thoracic Society Oct 2017Higher positive end-expiratory pressure (PEEP) levels may reduce atelectrauma, but increase over-distention lung injury. Whether higher PEEP improves clinical outcomes... (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Higher positive end-expiratory pressure (PEEP) levels may reduce atelectrauma, but increase over-distention lung injury. Whether higher PEEP improves clinical outcomes among patients with acute respiratory distress syndrome (ARDS) is unclear.
OBJECTIVES
To compare clinical outcomes of mechanical ventilation strategies using higher PEEP levels versus lower PEEP strategies in patients with ARDS.
METHODS
We performed a systematic review and meta-analysis of clinical trials investigating mechanical ventilation strategies using higher versus lower PEEP levels. We used random effects models to evaluate the effect of higher PEEP on 28-day mortality, organ failure, ventilator-free days, barotrauma, oxygenation, and ventilation.
RESULTS
We identified eight randomized trials comparing higher versus lower PEEP strategies, enrolling 2,728 patients with ARDS. Patients were 55 (±16) (mean ± SD) years old and 61% were men. Mean PEEP in the higher PEEP groups was 15.1 (±3.6) cm HO as compared with 9.1 (±2.7) cm HO in the lower PEEP groups. Primary analysis excluding two trials that did not use lower Vt ventilation in the lower PEEP control groups did not demonstrate significantly reduced mortality for patients receiving higher PEEP as compared with a lower PEEP (six trials; 2,580 patients; relative risk, 0.91; 95% confidence interval [CI] = 0.80-1.03). A higher PEEP strategy also did not significantly decrease barotrauma, new organ failure, or ventilator-free days when compared with a lower PEEP strategy (moderate-level evidence). Quality of evidence for primary analyses was downgraded for precision, as CIs of outcomes included estimates that would result in divergent recommendations for use of higher PEEP. Secondary analysis, including trials that did not use low Vt in low-PEEP control groups, showed significant mortality reduction for high-PEEP strategies (eight trials; 2,728 patients; relative risk, 0.84; 95% CI = 0.71-0.99), with greater mortality benefit observed for high PEEP in trials that did not use lower Vts in the low-PEEP control group (P = 0.02). Analyses stratifying by use of recruitment maneuvers (P for interaction = 0.69), or use of physiological targets to set PEEP versus PEEP/Fi tables (P for interaction = 0.13), did not show significant effect modification.
CONCLUSIONS
Use of higher PEEP is unlikely to improve clinical outcomes among unselected patients with ARDS.
Topics: Adult; Hospital Mortality; Humans; Positive-Pressure Respiration; Randomized Controlled Trials as Topic; Respiratory Distress Syndrome; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 29043834
DOI: 10.1513/AnnalsATS.201704-338OT -
[Hyperbaric therapy and diving medicine - hyperbaric therapy part 1: evidence-based emergency care].Anasthesiologie, Intensivmedizin,... Oct 2015Hyperbaric oxygen therapy (HBOT), i. e. breathing pure oxygen at elevated ambient pressure, remains the gold standard of care in treating air or gas embolism and... (Meta-Analysis)
Meta-Analysis Review
Hyperbaric oxygen therapy (HBOT), i. e. breathing pure oxygen at elevated ambient pressure, remains the gold standard of care in treating air or gas embolism and decompression illness. Guidelines are less clear on the value of HBOT in acute management of carbon monoxide (CO) poisoning or clostridial necrosis. To evaluate the evidence of clinical efficacy of HBOT we performed a systematic literature review. Part 1 assesses acute indications such as air or gas embolism, decompression sickness, CO-poisoning, clostridialmyonecrosis, necrotizing problem wounds, acute traumatic wounds and arterial retinal occlusion. Part 2 discusses further uses of HBOT as adjuvant treatment and highlights problems in assessing the value of HBOT using evidence-based medicine criteria.
Topics: Decompression Sickness; Diving; Emergency Medical Services; Evidence-Based Medicine; Germany; Humans; Prevalence; Risk Factors; Sports Medicine; Treatment Outcome
PubMed: 26523604
DOI: 10.1055/s-0041-102628 -
Aerospace Medicine and Human Performance Nov 2018A review of decompression sickness (DCS) cases associated with the NASA altitude physiological training (APT) program at the Johnson Space Center (JSC) motivated us to... (Meta-Analysis)
Meta-Analysis
A review of decompression sickness (DCS) cases associated with the NASA altitude physiological training (APT) program at the Johnson Space Center (JSC) motivated us to place our findings into the larger context of DCS prevalence from other APT centers. We reviewed JSC records from 1999 to 2016 and 14 publications from 1968 to 2004 about DCS prevalence in other APT programs. We performed a meta-analysis of 15 APT profiles (488 cases / 385,116 exposures). We used meta-regression to evaluate the relation between estimated exposures and probability of DCS in a test group, accounting for the heterogeneity between studies. Our in-house review identified 6 Type I DCS (1 from an inside observer) and 1 Type II DCS. There were 6 cases in 9560 student hypobaric exposures from 3 NASA training flights; a student pooled prevalence rate of 0.44 cases / 1000 exposures compared to 1.44 cases / 1000 from 12 published APT profiles. The overall pooled DCS prevalence rate was 1.16 cases / 1000 exposures. There was substantial heterogeneity in DCS prevalence across studies. Denitrogenation time, exposure pressure, and exposure time were associated with probability of DCS in the meta-regression model. While the overall DCS prevalence rate is relatively low, there is marked heterogeneity among profiles. The pooled DCS prevalence rate estimate for the NASA profiles was lower than the overall rate. Variability in APT profile DCS prevalence could be further explained given student level and additional test-level covariates.
Topics: Aerospace Medicine; Altitude; Altitude Sickness; Decompression Sickness; Humans; Military Personnel; Physical Conditioning, Human; United States; United States National Aeronautics and Space Administration
PubMed: 30352646
DOI: 10.3357/AMHP.5135.2018 -
Pediatric Pulmonology Jul 2021High-frequency oscillatory ventilation (HFOV) is an alternative mechanical ventilation mode proposed to reduce ventilator-induced lung injuries and improve clinical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
High-frequency oscillatory ventilation (HFOV) is an alternative mechanical ventilation mode proposed to reduce ventilator-induced lung injuries and improve clinical outcomes. The aim of this study was to determine the effects of HFOV compared to conventional mechanical ventilation (CMV) when used in children with hypoxemic respiratory failure.
METHODS
The literature search was conducted to identify all studies published before December 2020. Eligible studies included a population aged between 28 days and 18 years old, presented original data from randomized controlled trials (RCTs) or observational studies, compared the use of HFOV with CMV. Meta-analyses of the pooled data were performed by using random-effects models with inverse-variance weighting.
RESULTS
A total of 11 studies (2605 cases) were included, most of them evaluating patients with acute respiratory distress syndrome. The mean age of participants was 8.2 months and the mean oxygenation index of those included in the RCTs was 24.4. The effect of HFOV on mortality was not significant, and clinically significant harm or benefit could not be excluded (risk ratio [RR], 0.93; 95% confidence interval [CI], 0.72 to 1.20). No significant difference between groups was found in duration of mechanical ventilation (-2.23; 95% CI, -5.07 to 0.61), treatment failure (RR, 0.28; 95% CI, 0.08 to 1.02), and occurrence of barotrauma (RR, 0.88; 95% CI, 0.39 to 1.99).
CONCLUSION
The scarce evidence currently available does not allow us to conclude that HFOV has advantages over CMV and further studies are needed to clarify its role in the treatment of acute hypoxemic respiratory failure in children.
Topics: Adult; Child; Child, Preschool; High-Frequency Ventilation; Humans; Intermittent Positive-Pressure Ventilation; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency
PubMed: 33902159
DOI: 10.1002/ppul.25428 -
Military Medicine Aug 2023Operations Iraqi Freedom and Enduring Freedom saw higher rates of combat ocular trauma (COT) than any past U.S. conflict. The improvised explosive device, the signature...
INTRODUCTION
Operations Iraqi Freedom and Enduring Freedom saw higher rates of combat ocular trauma (COT) than any past U.S. conflict. The improvised explosive device, the signature weapon of the conflicts, as well as improved personal protective equipment and combat medical care all attributed to COT being the fourth most common injury sustained by wounded U.S. service members. This review describes the epidemiology, mechanisms, and treatment patterns and discusses the relationship of traumatic brain injuries (TBIs) to ocular injuries sustained by U.S. service members during the War on Terror.
MATERIALS AND METHODS
A mixed-methods review of the literature was conducted by extracting data from PubMed, Embase, and Cochrane research databases between December 15, 2020, and January 25, 2021, using the COVIDENCE review management software.
RESULTS
Of 827 articles for review, 50 were deemed relevant. Articles were separated using the Birmingham Eye Trauma Terminology into open globe, closed globe, mixed/injury management only, and TBI. Seventeen articles were found to discuss data pertaining to particular databases. Overall, six articles discussed open-globe injuries in the setting of overall COT with a reported rate of 38-64%. Three articles discussed closed-globe injuries in the context of overall COT with a rate of 39-47%. Numerous articles discussed the relationship between COT and TBI. Within the Walter Reed Ocular Trauma Database, 40% of patients with ocular trauma had concomitant TBI. Additionally, the visual sequelae of ocular trauma ranged from 9% to 50% among reporting studies. Other ocular injury patterns receiving attention include neuro-ophthalmic and oculoplastic injuries. By far the most common mechanism of COT was blast injury (64-84%), with improvised explosive devices (IEDs) accounting for 51-69% of ocular injuries. Among the large reporting databases, 41-45% of COT required surgical treatment with an overall enucleation rate of 12-17%.
CONCLUSIONS
The Global War on Terrorism saw an evolution in the types of ocular injuries sustained by U.S. service members compared to previous conflicts. The widespread use of IEDs led to injury patterns not encountered in previous conflicts. Weapons of today utilize blast and shrapnel as the mechanism for destruction. Sequelae such as TBIs and complicated head and neck trauma have pushed innovation in the field of ophthalmology. Improvements in medical technology and personal protective equipment have resulted in not only survival of previously life-threatening injuries, but also a greater chance of severe loss of vision. By analyzing ocular injury data from the trauma literature, improvements in education and training can lead to improvements in point-of-injury care and eye protection for the next generation of warfighters.
Topics: Humans; Visual Acuity; Eye Injuries; Brain Injuries, Traumatic; Iraq War, 2003-2011; Blast Injuries; Disease Progression; Retrospective Studies
PubMed: 35869887
DOI: 10.1093/milmed/usac226 -
European Journal of Orthopaedic Surgery... Feb 2019Gunshot wounds and blast injuries constitute a major public health problem, as the increasing availability of firearms and explosives in conjunction with increasing...
Gunshot wounds and blast injuries constitute a major public health problem, as the increasing availability of firearms and explosives in conjunction with increasing violence in the city setting have brought this reality into civilian life. Extremities are most commonly involved; therefore, orthopedic surgeons should be trained to manage these types of injuries. Complete and accurate assessment of the injury itself is of great importance, as it will determine the severity and the risk of patients. High-risk injuries from missiles and injuries from explosions are associated with moderate or poor outcomes, major complications, and increased need for multiple surgical procedures. On the other hand, low-risk injuries frequently present optimal results and rather low morbidity. The role of microsurgery is essential, especially in the high- and very high-risk injuries, since complex and multiple reconstructions have to be performed, which include the utilization of free flaps, nerve grafts, and tendon transfers.
Topics: Amputation, Surgical; Blast Injuries; Female; Follow-Up Studies; Humans; Lower Extremity; Male; Microsurgery; Reoperation; Replantation; Retrospective Studies; Trauma Severity Indices; Treatment Outcome; Upper Extremity; Wounds, Gunshot
PubMed: 30498906
DOI: 10.1007/s00590-018-2350-4 -
Diving and Hyperbaric Medicine Mar 2023Breath-hold (BH) diving has known risks, for example drowning, pulmonary oedema of immersion and barotrauma. There is also the risk of decompression illness (DCI) from... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Breath-hold (BH) diving has known risks, for example drowning, pulmonary oedema of immersion and barotrauma. There is also the risk of decompression illness (DCI) from decompression sickness (DCS) and/or arterial gas embolism (AGE). The first report on DCS in repetitive freediving was published in 1958 and from then there have been multiple case reports and a few studies but no prior systematic review or meta-analysis.
METHODS
We undertook a systematic literature review to identify articles available from PubMed and Google Scholar concerning breath-hold diving and DCI up to August 2021.
RESULTS
The present study identified 17 articles (14 case reports, three experimental studies) covering 44 incidences of DCI following BH diving.
CONCLUSIONS
This review found that the literature supports both DCS and AGE as potential mechanisms for DCI in BH divers; both should be considered a risk for this cohort of divers, just as for those breathing compressed gas while underwater.
Topics: Humans; Barotrauma; Decompression; Decompression Sickness; Diving; Embolism, Air
PubMed: 36966520
DOI: 10.28920/dhm53.1.31-41