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Journal of Intensive Care Medicine Feb 2023To explore the evidence surrounding the use of Airway Pressure Release Ventilation (APRV) in patients with coronavirus disease 2019 (COVID-19). A Systematic electronic... (Meta-Analysis)
Meta-Analysis Review
To explore the evidence surrounding the use of Airway Pressure Release Ventilation (APRV) in patients with coronavirus disease 2019 (COVID-19). A Systematic electronic search of PUBMED, EMBASE, and the WHO COVID-19 database. We also searched the grey literature via Google and preprint servers (medRxive and research square). Eligible studies included randomised controlled trials and observational studies comparing APRV to conventional mechanical ventilation (CMV) in adults with acute hypoxemic respiratory failure due to COVID-19 and reporting at least one of the following outcomes; in-hospital mortality, ventilator free days (VFDs), ICU length of stay (LOS), changes in gas exchange parameters, and barotrauma. Two authors independently screened and selected articles for inclusion and extracted data in a pre-specified form. Of 181 articles screened, seven studies (one randomised controlled trial, two cohort studies, and four before-after studies) were included comprising 354 patients. APRV was initiated at a mean of 1.2-13 days after intubation. APRV wasn't associated with improved mortality compared to CMV (relative risk [RR], 1.20; 95% CI 0.70-2.05; , 61%) neither better VFDs (ratio of means [RoM], 0.80; 95% CI, 0.52-1.24; , 0%) nor ICU LOS (RoM, 1.10; 95% CI, 0.79-1.51; , 57%). Compared to CMV, APRV was associated with a 33% increase in PaO/FiO ratio (RoM, 1.33; 95% CI, 1.21-1.48; , 29%) and a 9% decrease in PaCO (RoM, 1.09; 95% CI, 1.02-1.15; , 0%). There was no significant increased risk of barotrauma compared to CMV (RR, 1.55; 95% CI, 0.60-4.00; , 0%). In adult patients with COVID-19 requiring mechanical ventilation, APRV is associated with improved gas exchange but not mortality nor VFDs when compared with CMV. The results were limited by high uncertainty given the low quality of the available studies and limited number of patients. Adequately powered and well-designed clinical trials to define the role of APRV in COVID-19 patients are still needed. .
Topics: Humans; Continuous Positive Airway Pressure; COVID-19; Respiratory Insufficiency
PubMed: 35733377
DOI: 10.1177/08850666221109779 -
Journal of the Royal Army Medical Corps Mar 2015Prevention against head wounds from explosively propelled fragments is currently the Mark 7 general service combat helmet, although only limited evidence exists to... (Review)
Review
INTRODUCTION
Prevention against head wounds from explosively propelled fragments is currently the Mark 7 general service combat helmet, although only limited evidence exists to define the coverage required for the helmet to adequately protect against such a threat. The Royal Centre for Defence Medicine was tasked by Defence Equipment and Support to provide a framework for determining the optimum coverage of future combat helmets in order to inform the VIRTUS procurement programme.
METHOD
A systematic review of the literature was undertaken to identify potential solutions to three components felt necessary to define the ideal helmet coverage required for protection against explosively propelled fragments.
RESULTS
The brain and brainstem were identified as the structures requiring coverage by a helmet. No papers were identified that directly defined the margins of these structures to anatomical landmarks, nor how these could be related to helmet coverage.
CONCLUSIONS
We recommend relating the margins of the brain to three identifiable anatomical landmarks (nasion, external auditory meatus and superior nuchal line), which can in turn be related to the coverage provided by the helmet. Early assessments using an anatomical mannequin indicate that the current helmet covers the majority of the brain and brainstem from projectiles with a horizontal trajectory but not from ones that originate from the ground. Protection from projectiles with ground-originating trajectories is reduced by helmets with increased stand-off from the skin. Future helmet coverage assessments should use a finite element numerical modelling approach with representative material properties assigned to intracranial anatomical structures to enable differences in projectile trajectory and helmet coverage to be objectively compared.
Topics: Blast Injuries; Equipment Design; Explosions; Head Injuries, Penetrating; Head Protective Devices; Humans; Military Personnel; Occupational Injuries; United Kingdom
PubMed: 24109105
DOI: 10.1136/jramc-2013-000108 -
Diving and Hyperbaric Medicine Jun 2024Inhalation of high concentrations of carbon dioxide (CO₂) at atmospheric pressure can be toxic with dose-dependent effects on the cardiorespiratory system or the... (Review)
Review
INTRODUCTION
Inhalation of high concentrations of carbon dioxide (CO₂) at atmospheric pressure can be toxic with dose-dependent effects on the cardiorespiratory system or the central nervous system. Exposure to both hyperbaric and hypobaric environments can result in decompression sickness (DCS). The effects of CO₂ on DCS are not well documented with conflicting results. The objective was to review the literature to clarify the effects of CO₂ inhalation on DCS in the context of hypobaric or hyperbaric exposure.
METHODS
The systematic review included experimental animal and human studies in hyper- and hypobaric conditions evaluating the effects of CO₂ on bubble formation, denitrogenation or the occurrence of DCS. The search was based on MEDLINE and PubMed articles with no language or date restrictions and also included articles from the underwater and aviation medicine literature.
RESULTS
Out of 43 articles, only 11 articles were retained and classified according to the criteria of hypo- or hyperbaric exposure, taking into account the duration of CO₂ inhalation in relation to exposure and distinguishing experimental work from studies conducted in humans.
CONCLUSIONS
Before or during a stay in hypobaric conditions, exposure to high concentrations of CO₂ favors bubble formation and the occurrence of DCS. In hyperbaric conditions, high CO₂ concentrations increase the occurrence of DCS when exposure occurs during the bottom phase at maximum pressure, whereas beneficial effects are observed when exposure occurs during decompression. These opposite effects depending on the timing of exposure could be related to 1) the physical properties of CO₂, a highly diffusible gas that can influence bubble formation, 2) vasomotor effects (vasodilation), and 3) anti-inflammatory effects (kinase-nuclear factor and heme oxygenase-1 pathways). The use of O₂-CO₂ breathing mixtures on the surface after diving may be an avenue worth exploring to prevent DCS.
Topics: Animals; Humans; Atmospheric Pressure; Carbon Dioxide; Decompression Sickness; Diving
PubMed: 38870953
DOI: 10.28920/dhm54.2.110-119 -
Minerva Anestesiologica Sep 2022Barotrauma is rare in patients with acute respiratory distress syndrome undergoing mechanical ventilation. Its incidence seems increased among critically ill COVID-19... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Barotrauma is rare in patients with acute respiratory distress syndrome undergoing mechanical ventilation. Its incidence seems increased among critically ill COVID-19 patients. We performed a systematic review and meta-analysis to investigate the incidence, risk factors and clinical outcomes of barotrauma among critically ill COVID-19 patients.
EVIDENCE ACQUISITION
PubMed was searched from March 1, 2020 to August 31, 2021; case series and retrospective cohort studies concerning barotrauma in adult critically ill COVID-19 patients, either hospitalized in the Intensive Care Unit (ICU) or invasively ventilated were included. Primary outcome was the incidence of barotrauma in COVID-19 versus non-COVID-19 patients. Secondary outcomes were clinical characteristics, ventilator parameters, mortality and length of stay between patients with and without barotrauma.
EVIDENCE SYNTHESIS
We identified 21 studies (six case series, 15 retrospective cohorts). The overall incidence of barotrauma was 11 [95% CI: 8-14]% in critically ill COVID-19 patients, vs. 2 [1-3]% in non-COVID-19, P<0.001; the incidence in mechanically ventilated patients was 14 [11-17]% vs. 4 [2-5]% non-COVID-19 patients, P<0.001. There were no differences in demographic, clinical, ventilatory parameters between patients who did and did not develop barotrauma, while, on average, protective ventilation criteria were always respected. Among COVID-19 patients, those with barotrauma had a higher mortality (60 [55-66] vs. 48 [42-54]%, P<0.001) and a longer ICU length of stay (20 [14-26] vs. 13 [10,5-16] days, P=0.03).
CONCLUSIONS
Barotrauma is a frequent complication in critically ill COVID-19 patients and is associated with a poor prognosis. Since lung protective ventilation was delivered, the ventilatory management might not be the sole factor in the development of barotrauma.
Topics: Adult; Barotrauma; COVID-19; Critical Illness; Humans; Incidence; Intensive Care Units; Respiration, Artificial; Retrospective Studies
PubMed: 35416463
DOI: 10.23736/S0375-9393.22.16258-9 -
Intensive Care Medicine Experimental Oct 2020Existing clinical practice guidelines support the use of neuromuscular blocking agents (NMBA) in acute respiratory distress syndrome (ARDS); however, a recent large... (Review)
Review
PURPOSE
Existing clinical practice guidelines support the use of neuromuscular blocking agents (NMBA) in acute respiratory distress syndrome (ARDS); however, a recent large randomized clinical trial (RCT) has questioned this practice. Therefore, we updated a previous systematic review to determine the efficacy and safety of NMBAs in ARDS.
METHODS
We searched MEDLINE, EMBASE (October 2012 to July 2019), the Cochrane (Central) database, and clinical trial registries ( ClinicalTrials.gov , ISRCTN Register, and WHO ICTRP) for RCTs comparing the effects of NMBA as a continuous infusion versus placebo or no NMBA infusion (but allowing intermittent NMBA boluses) on patient-important outcomes for adults with ARDS. Two independent reviewers assessed the methodologic quality of the primary studies and abstracted data.
RESULTS
Seven RCTs, including four new RCTs, met eligibility criteria for this review. These trials enrolled 1598 patients with moderate to severe ARDS at centers in the USA, France, and China. All trials assessed short-term continuous infusions of cisatracurium or vecuronium. The pooled estimate for mortality outcomes showed significant statistical heterogeneity, which was only explained by a subgroup analysis by depth of sedation in the control arm. A continuous NMBA infusion did not improve mortality when compared to a light sedation strategy with no NMBA infusion (relative risk [RR] 0.99; 95% CI 0.86-1.15; moderate certainty; P = 0.93). On the other hand, continuous NMBA infusion reduced mortality when compared to deep sedation with as needed NMBA boluses (RR 0.71; 95% CI 0.57-0.89; low certainty; P = 0.003). Continuous NMBA infusion reduced the rate of barotrauma (RR 0.55; 95% CI 0.35-0.85, moderate certainty; P = 0.008) across eligible trials, but the effect on ventilator-free days, duration of mechanical ventilation, and ICU-acquired weakness was uncertain.
CONCLUSIONS
Inconsistency in study methods and findings precluded the pooling of all trials for mortality. In a pre-planned sensitivity analysis, the impact of NMBA infusion on mortality depends on the strategy used in the control arm, showing reduced mortality when compared to deep sedation, but no effect on mortality when compared to lighter sedation. In both situations, a continuous NMBA infusion may reduce the risk of barotrauma, but the effects on other patient-important outcomes remain unclear. Future research, including an individual patient data meta-analysis, could help clarify some of the observed findings in this updated systematic review.
PubMed: 33095344
DOI: 10.1186/s40635-020-00348-6 -
BMC Anesthesiology Aug 2016Not only arterial hypoxemia but acute lung injury also has become the major concerns of one-lung ventilation (OLV). The use of pressure-controlled ventilation (PCV) for... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Not only arterial hypoxemia but acute lung injury also has become the major concerns of one-lung ventilation (OLV). The use of pressure-controlled ventilation (PCV) for OLV offers the potential advantages of lower airway pressure and intrapulmonary shunt, which result in a reduced risk of barotrauma and improved oxygenation, respectively.
METHODS
We searched Medline, Embase, the Cochrane central register of controlled trials and KoreaMedto find publications comparing the effects of PCV with those of volume-controlled ventilation (VCV) during intraoperative OLV in adults. A meta-analysis of randomized controlled trials was performed using the Cochrane Review Methods.
RESULTS
Six studies (259 participants) were included. The PaO2/FiO2 ratio in PCV was higher than in VCV [weighted mean difference (WMD) = 11.04 mmHg, 95 % confidence interval (CI) = 0.30 to 21.77, P = 0.04, I(2) = 3 %] and peak inspiratory pressure was significantly lower in PCV (WMD = -4.91 cm H2O, 95 % CI = -7.30 to -2.53, P < 0.0001, I (2) = 91 %). No differences in PaCO2, tidal volume, heart rate and blood pressure were observed. There were also no differences incompliance, plateau and mean airway pressure.
CONCLUSIONS
Our meta-analysis provided the evidence of improved oxygenation in PCV. However, it is difficult to draw any definitive conclusions due to the fact that the duration of ventilation in the studies reviewed was insufficient to reveal clinically relevant benefits or disadvantages of PCV. Significantly lower peak inspiratory pressure is the advantage of PCV.
Topics: Humans; One-Lung Ventilation; Positive-Pressure Respiration; Respiration, Artificial
PubMed: 27581657
DOI: 10.1186/s12871-016-0238-6 -
Critical Care (London, England) Jul 2021Drowning is a cause of significant global mortality. The mechanism of injury involves inhalation of water, lung injury and hypoxia. This systematic review addressed the...
BACKGROUND
Drowning is a cause of significant global mortality. The mechanism of injury involves inhalation of water, lung injury and hypoxia. This systematic review addressed the following question: In drowning patients with lung injury, what is the evidence from primary studies regarding treatment strategies and subsequent patient outcomes?
METHODS
The search strategy utilised PRISMA guidelines. Databases searched were MEDLINE, EMBASE, CINAHL, Web of Science and SCOPUS. There were no restrictions on publication date or age of participants. Quality of evidence was evaluated using GRADE methodology.
RESULTS
Forty-one papers were included. The quality of evidence was very low. Seventeen papers addressed the lung injury of drowning in their research question and 24 had less specific research questions, however included relevant outcome data. There were 21 studies regarding extra-corporeal life support, 14 papers covering the theme of ventilation strategies, 14 addressed antibiotic use, seven papers addressed steroid use and five studies investigating diuretic use. There were no clinical trials. One retrospective comparison of therapeutic strategies was found. There was insufficient evidence to make recommendations as to best practice when supplemental oxygen alone is insufficient. Mechanical ventilation is associated with barotrauma in drowning patients, but the evidence predates the practice of lung protective ventilation. There was insufficient evidence to make recommendations regarding adjuvant therapies.
CONCLUSIONS
Treating the lung injury of drowning has a limited evidentiary basis. There is an urgent need for comparative studies of therapeutic strategies in drowning.
Topics: Anti-Bacterial Agents; Barotrauma; Drowning; Extracorporeal Membrane Oxygenation; Humans; Lung Injury; Respiration, Artificial; Treatment Outcome
PubMed: 34281609
DOI: 10.1186/s13054-021-03687-2 -
Medicine May 2019Traumatic vascular injury is caused by explosions and projectiles (bullets and shrapnel); it may affect the arteries and veins of the limbs, and is common in wartime,...
BACKGROUND
Traumatic vascular injury is caused by explosions and projectiles (bullets and shrapnel); it may affect the arteries and veins of the limbs, and is common in wartime, triggering bleeding, and ischemia. The increasing use of high-energy weapons in modern warfare is associated with severe vascular injuries.
METHODS
To summarize the current evidence of diagnosis and treatment for traumatic vascular injury of limbs, for saving limbs and lives, and put forward some new insights, we comprehensively consulted literatures and analyzed progress in injury diagnosis and wound treatment, summarized the advanced treatments now available, especially in wartime, and explored the principal factors in play in an effort to optimize clinical outcomes.
RESULTS
Extremity vascular trauma poses several difficult dilemmas in diagnosis and treatment. The increasing use of high-energy weapons in modern warfare is associated with severe vascular injuries. Any delay in treatment may lead to loss of limbs or death. The development of diagnose and treat vascular injury of extremities are the clinical significance to the tip of military medicine, such as the use of fast, cheap, low invasive diagnostic methods, repairing severe vascular injury as soon as possible, using related technologies actively (fasciotomy, etc).
CONCLUSION
We point out the frontier of the diagnosis and treatment of traumatic vascular injury, also with a new model of wartime injury treatment in American (forward surgical teams and combat support hospitals), French military surgeons regarding management of war-related vascular wounds and Chinese military ("3 districts and 7 grades" model). Many issues remain to be resolved by further experience and investigation.
Topics: Amputation, Surgical; Ankle Brachial Index; Blast Injuries; Blood Vessel Prosthesis; Decompression, Surgical; Emergency Medicine; Extremities; Fasciotomy; Fractures, Bone; Humans; Military Medicine; Military Personnel; Retrospective Studies; Skin Transplantation; Time Factors; Trauma Severity Indices; United States; Vascular Surgical Procedures; Vascular System Injuries
PubMed: 31045795
DOI: 10.1097/MD.0000000000015406 -
British Journal of Anaesthesia Sep 2016Transtracheal jet ventilation (TTJV) is recommended in several airway guidelines as a potentially life-saving procedure during the 'Can't Intubate Can't Oxygenate'... (Review)
Review
BACKGROUND
Transtracheal jet ventilation (TTJV) is recommended in several airway guidelines as a potentially life-saving procedure during the 'Can't Intubate Can't Oxygenate' (CICO) emergency. Some studies have questioned its effectiveness.
METHODS
Our goal was to determine the complication rates of TTJV in the CICO emergency compared with the emergency setting where CICO is not described (non-CICO emergency) or elective surgical setting. Several databases of published and unpublished literature were searched systematically for studies describing TTJV in human subjects. Complications were categorized as device failure, barotrauma (including subcutaneous emphysema), and miscellaneous. Device failure was defined by the inability to place and/or use the TTJV device, not patient survival.
RESULTS
Forty-four studies (428 procedures) met the inclusion criteria. Four studies included both emergency and elective procedures. Thirty studies described 132 emergency TTJV procedures; 90 were CICO emergencies. Eighteen studies described 296 elective TTJV procedures. Device failure occurred in 42% of CICO emergency vs 0% of non-CICO emergency (P<0.001) and 0.3% of elective procedures (P<0.001). Barotrauma occurred in 32% of CICO emergency vs 7% of non-CICO emergency (P<0.001) and 8% of elective procedures (P<0.001). The total number of procedures with any complication was 51% of CICO emergency vs 7% of non-CICO emergency (P<0.001) and 8% of elective procedures (P<0.001). Several reports described TTJV-related subcutaneous emphysema hampering subsequent attempts at surgical airway or tracheal intubation.
CONCLUSIONS
TTJV is associated with a high risk of device failure and barotrauma in the CICO emergency. Guidelines and recommendations supporting the use of TTJV in CICO should be reconsidered.
Topics: Airway Management; Airway Obstruction; Barotrauma; Emergencies; Equipment Failure; High-Frequency Jet Ventilation; Humans; Intubation, Intratracheal
PubMed: 27566790
DOI: 10.1093/bja/aew192 -
Otology & Neurotology : Official... Jun 2018To conduct a systematic review of the published evidence relating to the prevention of otic barotrauma in aviation. In particular, this review sought to identify...
OBJECTIVE
To conduct a systematic review of the published evidence relating to the prevention of otic barotrauma in aviation. In particular, this review sought to identify procedures, techniques, devices, and medications for the prevention of otic barotrauma as well as evaluate the evidence relating to their efficacy.
DATA SOURCES
Ten databases including Embase, MEDLINE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched using the full historical range.
STUDY SELECTION
English language articles including more than or equal to five participants or cases were included. Outcomes of interest were reduced severity or the successful prevention of otic barotrauma in participants undergoing gradual changes in pressure during air travel or its simulation.
DATA EXTRACTION
Articles and data were extracted and analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and other international guidelines.
CONCLUSIONS
This review highlights the lack of published evidence relating to what is a significant and increasingly common problem in otology. There is level 1 evidence that supports the efficacy of oral pseudoephedrine (120 mg) in preventing otic barotrauma in adults. However, oral pseudoephedrine (1 mg/kg) does not appear to be effective in children. There is insufficient evidence to support the efficacy of either nasal balloon inflation or pressure-equalizing ear plugs for the prevention of otic barotrauma. A recently reported, novel technique for insertion of temporary tympanostomy tubes is promising but requires further evaluation.
Topics: Adult; Aerospace Medicine; Air Travel; Barotrauma; Child; Humans
PubMed: 29595579
DOI: 10.1097/MAO.0000000000001779