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The New England Journal of Medicine May 2000Traditional approaches to mechanical ventilation use tidal volumes of 10 to 15 ml per kilogram of body weight and may cause stretch-induced lung injury in patients with... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND
Traditional approaches to mechanical ventilation use tidal volumes of 10 to 15 ml per kilogram of body weight and may cause stretch-induced lung injury in patients with acute lung injury and the acute respiratory distress syndrome. We therefore conducted a trial to determine whether ventilation with lower tidal volumes would improve the clinical outcomes in these patients.
METHODS
Patients with acute lung injury and the acute respiratory distress syndrome were enrolled in a multicenter, randomized trial. The trial compared traditional ventilation treatment, which involved an initial tidal volume of 12 ml per kilogram of predicted body weight and an airway pressure measured after a 0.5-second pause at the end of inspiration (plateau pressure) of 50 cm of water or less, with ventilation with a lower tidal volume, which involved an initial tidal volume of 6 ml per kilogram of predicted body weight and a plateau pressure of 30 cm of water or less. The primary outcomes were death before a patient was discharged home and was breathing without assistance and the number of days without ventilator use from day 1 to day 28.
RESULTS
The trial was stopped after the enrollment of 861 patients because mortality was lower in the group treated with lower tidal volumes than in the group treated with traditional tidal volumes (31.0 percent vs. 39.8 percent, P=0.007), and the number of days without ventilator use during the first 28 days after randomization was greater in this group (mean [+/-SD], 12+/-11 vs. 10+/-11; P=0.007). The mean tidal volumes on days 1 to 3 were 6.2+/-0.8 and 11.8+/-0.8 ml per kilogram of predicted body weight (P<0.001), respectively, and the mean plateau pressures were 25+/-6 and 33+/-8 cm of water (P<0.001), respectively.
CONCLUSIONS
In patients with acute lung injury and the acute respiratory distress syndrome, mechanical ventilation with a lower tidal volume than is traditionally used results in decreased mortality and increases the number of days without ventilator use.
Topics: Barotrauma; Female; Humans; Lung Injury; Male; Middle Aged; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Distress Syndrome; Survival Analysis; Tidal Volume
PubMed: 10793162
DOI: 10.1056/NEJM200005043421801 -
Critical Care (London, England) Jul 2017The adverse effects of mechanical ventilation in acute respiratory distress syndrome (ARDS) arise from two main causes: unphysiological increases of transpulmonary... (Review)
Review
The adverse effects of mechanical ventilation in acute respiratory distress syndrome (ARDS) arise from two main causes: unphysiological increases of transpulmonary pressure and unphysiological increases/decreases of pleural pressure during positive or negative pressure ventilation. The transpulmonary pressure-related side effects primarily account for ventilator-induced lung injury (VILI) while the pleural pressure-related side effects primarily account for hemodynamic alterations. The changes of transpulmonary pressure and pleural pressure resulting from a given applied driving pressure depend on the relative elastances of the lung and chest wall. The term 'volutrauma' should refer to excessive strain, while 'barotrauma' should refer to excessive stress. Strains exceeding 1.5, corresponding to a stress above ~20 cmHO in humans, are severely damaging in experimental animals. Apart from high tidal volumes and high transpulmonary pressures, the respiratory rate and inspiratory flow may also play roles in the genesis of VILI. We do not know which fraction of mortality is attributable to VILI with ventilation comparable to that reported in recent clinical practice surveys (tidal volume ~7.5 ml/kg, positive end-expiratory pressure (PEEP) ~8 cmHO, rate ~20 bpm, associated mortality ~35%). Therefore, a more complete and individually personalized understanding of ARDS lung mechanics and its interaction with the ventilator is needed to improve future care. Knowledge of functional lung size would allow the quantitative estimation of strain. The determination of lung inhomogeneity/stress raisers would help assess local stresses; the measurement of lung recruitability would guide PEEP selection to optimize lung size and homogeneity. Finding a safety threshold for mechanical power, normalized to functional lung volume and tissue heterogeneity, may help precisely define the safety limits of ventilating the individual in question. When a mechanical ventilation set cannot be found to avoid an excessive risk of VILI, alternative methods (such as the artificial lung) should be considered.
Topics: Barotrauma; Extracorporeal Membrane Oxygenation; Forecasting; Humans; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Mechanics; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 28701178
DOI: 10.1186/s13054-017-1750-x -
Jornal Brasileiro de Pneumologia :... Jul 2019
Topics: Adult; Barotrauma; Cocaine-Related Disorders; Humans; Male; Mediastinal Emphysema; Radiography, Thoracic; Tomography, X-Ray Computed
PubMed: 31365685
DOI: 10.1590/1806-3713/e20190169 -
Effect of a protective-ventilation strategy on mortality in the acute respiratory distress syndrome.The New England Journal of Medicine Feb 1998In patients with the acute respiratory distress syndrome, massive alveolar collapse and cyclic lung reopening and overdistention during mechanical ventilation may... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND
In patients with the acute respiratory distress syndrome, massive alveolar collapse and cyclic lung reopening and overdistention during mechanical ventilation may perpetuate alveolar injury. We determined whether a ventilatory strategy designed to minimize such lung injuries could reduce not only pulmonary complications but also mortality at 28 days in patients with the acute respiratory distress syndrome.
METHODS
We randomly assigned 53 patients with early acute respiratory distress syndrome (including 28 described previously), all of whom were receiving identical hemodynamic and general support, to conventional or protective mechanical ventilation. Conventional ventilation was based on the strategy of maintaining the lowest positive end-expiratory pressure (PEEP) for acceptable oxygenation, with a tidal volume of 12 ml per kilogram of body weight and normal arterial carbon dioxide levels (35 to 38 mm Hg). Protective ventilation involved end-expiratory pressures above the lower inflection point on the static pressure-volume curve, a tidal volume of less than 6 ml per kilogram, driving pressures of less than 20 cm of water above the PEEP value, permissive hypercapnia, and preferential use of pressure-limited ventilatory modes.
RESULTS
After 28 days, 11 of 29 patients (38 percent) in the protective-ventilation group had died, as compared with 17 of 24 (71 percent) in the conventional-ventilation group (P<0.001). The rates of weaning from mechanical ventilation were 66 percent in the protective-ventilation group and 29 percent in the conventional-ventilation group (P=0.005): the rates of clinical barotrauma were 7 percent and 42 percent, respectively (P=0.02), despite the use of higher PEEP and mean airway pressures in the protective-ventilation group. The difference in survival to hospital discharge was not significant; 13 of 29 patients (45 percent) in the protective-ventilation group died in the hospital, as compared with 17 of 24 in the conventional-ventilation group (71 percent, P=0.37).
CONCLUSIONS
As compared with conventional ventilation, the protective strategy was associated with improved survival at 28 days, a higher rate of weaning from mechanical ventilation, and a lower rate of barotrauma in patients with the acute respiratory distress syndrome. Protective ventilation was not associated with a higher rate of survival to hospital discharge.
Topics: Adult; Barotrauma; Humans; Lung Injury; Positive-Pressure Respiration; Proportional Hazards Models; Pulmonary Ventilation; Respiratory Distress Syndrome; Risk; Survival Analysis; Tidal Volume
PubMed: 9449727
DOI: 10.1056/NEJM199802053380602 -
Medicina (Kaunas, Lithuania) Jan 2022Dysbarism is a general term which includes the signs and symptoms that can manifest when the body is subject to an increase or a decrease in the atmospheric pressure... (Review)
Review
Dysbarism is a general term which includes the signs and symptoms that can manifest when the body is subject to an increase or a decrease in the atmospheric pressure which occurs either at a rate or duration exceeding the capacity of the body to adapt safely. In the following review, we take dysbarisms into account for our analysis. Starting from the underlying physical laws, we will deal with the pathologies that can develop in the most frequently affected areas of the body, as the atmospheric pressure varies when acclimatization fails. Manifestations of dysbarism range from itching and minor pain to neurological symptoms, cardiac collapse, and death. Overall, four clinical pictures can occur: decompression illness, barotrauma, inert gas narcosis, and oxygen toxicity. We will then review the clinical manifestations and illustrate some hints of therapy. We will first introduce the two forms of decompression sickness. In the next part, we will review the barotrauma, compression, and decompression. The last three parts will be dedicated to gas embolism, inert gas narcosis, and oxygen toxicity. Such an approach is critical for the effective treatment of patients in a hostile environment, or treatment in the emergency room after exposure to extreme physical or environmental factors.
Topics: Barotrauma; Decompression Sickness; Embolism, Air; Humans; Hyperbaric Oxygenation
PubMed: 35056412
DOI: 10.3390/medicina58010104 -
Intensive Care Medicine Mar 2022
Topics: Barotrauma; COVID-19; Humans; Respiration, Artificial; SARS-CoV-2
PubMed: 35089408
DOI: 10.1007/s00134-022-06630-3 -
Heart (British Cardiac Society) Jun 2022As the popularity of scuba diving increases internationally, physicians interacting with divers in the clinical setting must be familiar with the cardiovascular stresses... (Review)
Review
As the popularity of scuba diving increases internationally, physicians interacting with divers in the clinical setting must be familiar with the cardiovascular stresses and risks inherent to this activity. Scuba presents a formidable cardiovascular challenge by combining unique environmental conditions with the physiologic demands of underwater exercise. Haemodynamic stresses encountered at depth include increased hydrostatic pressure leading to central shifts in plasma volume coupled with cold water stimuli leading to simultaneous parasympathetic and sympathetic autonomic responses. Among older divers and those with underlying cardiovascular risk factors, these physiologic changes increase acute cardiac risks while diving. Additional scuba risks, as a consequence of physical gas laws, include arterial gas emboli and decompression sickness. These pathologies are particularly dangerous with altered sensorium in hostile dive conditions. When present, the appropriate management of patent foramen ovale (PFO) is uncertain, but closure of PFO may reduce the risk of paradoxical gas embolism in divers with a prior history of decompression sickness. Finally, similar to other Masters-level athletes, divers with underlying traditional cardiovascular risk should undergo complete cardiac risk stratification to determine 'fitness-to-dive'. The presence of undertreated coronary artery disease, occult cardiomyopathy, channelopathy and arrhythmias must all be investigated and appropriately treated in order to ensure diver safety. A patient-centred approach facilitating shared decision-making between divers and experienced practitioners should be utilised in the management of prospective scuba divers.
Topics: Decompression Sickness; Diving; Embolism, Paradoxical; Foramen Ovale, Patent; Humans; Prospective Studies
PubMed: 34670825
DOI: 10.1136/heartjnl-2021-319601 -
Journal of Applied Physiology... Feb 2010
Topics: Animals; Anostraca; Decompression Sickness; Gases; Humans; Rats; Ultrasonography
PubMed: 20019159
DOI: 10.1152/japplphysiol.01384.2009 -
Pulmonology 2020
Topics: Barotrauma; Cannula; Diving; Humans; Incidence; Male; Mediastinal Emphysema; Mediastinum; Oxygen Inhalation Therapy; Pressure; Radiography, Thoracic; Subcutaneous Emphysema; Treatment Outcome; Young Adult
PubMed: 31735688
DOI: 10.1016/j.pulmoe.2019.09.010 -
Critical Care (London, England) Oct 2018
Topics: Animals; Barotrauma; Disease Models, Animal; Humans; Pulmonary Atelectasis; Ventilator-Induced Lung Injury
PubMed: 30360756
DOI: 10.1186/s13054-018-2199-2