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1.
J Healthc Eng ; 2022: 6436818, 2022.
Article in English | MEDLINE | ID: covidwho-1770041

ABSTRACT

The outbreak of novel COVID-19 has severely and unprecedentedly affected millions of people across the globe. The painful respiratory distress caused during this disease calls for external assistance to the victims in the form of ventilation. The most common types of artificial ventilating units available at the healthcare facilities and hospitals are exorbitantly expensive to manufacture, and their number is fairly inadequate even in the so-called developed countries to cater to the burning needs of an ever-increasing number of ailing human subjects. According to available reports, without the provision of ventilation, the novel COVID-19 patients are succumbing to their ailments in a huge number of cases. This colossal problem of the availability of ventilator units can be addressed to a great extent by readily producible and cost-effective ventilating units that can be used on those suffering patients during an acute emergency and in the absence of conventional expensive ventilators at hospitals and medical care units. This paper has made an attempt to design and simulate a simple, yet effective, mechanized ventilator unit, which can be conveniently assembled without a profuse skillset and operated to resuscitate an ailing human patient. The stepper motor-controlled kinematic linkage is designed to deliver the patient with a necessitated discharge of air at optimum oxygen saturation through the AMBU bag connected in a ventilation circuit. With the associated code on MATLAB, the motor control parameters such as angular displacement and speed are deduced according to the input patient conditions (age group, tidal volume, breathing rate, etc.) and thereafter fed to the controller that drives the stepper motor. With a proposed feedback loop, the real-time static and dynamic compliance, airway resistance values can be approximately determined from the pressure variation cycle and fed to the controller unit to adjust the tidal volume as and when necessary. The simplistic yet robust design not only renders easy manufacturability by conventional and rapid prototyping techniques like 3D printing at different scales but also makes the product easily portable with minimal handling difficulty. Keeping the motto of Health for All as envisioned by the WHO, this low-cost indigenously engineered ventilator will definitely help the poor and afflicted towards their right to health and will help the medical professionals buy some time to manage the patient with acute respiratory distress syndrome (ARDS) towards recovery. Moreover, this instrument mostly includes readily available functional units having standard specifications and can be considered as standard bought-out items.


Subject(s)
COVID-19 , Humans , Pandemics , Respiration, Artificial/methods , Tidal Volume , Ventilators, Mechanical
3.
Crit Care Med ; 50(4): 586-594, 2022 04 01.
Article in English | MEDLINE | ID: covidwho-1764674

ABSTRACT

OBJECTIVES: Airway pressure release ventilation is a ventilatory mode characterized by a mandatory inverse inspiratory:expiratory ratio with a very short expiratory phase, aimed to avoid derecruitment and allow spontaneous breathing. Recent basic and clinical evidence suggests that this mode could be associated with improved outcomes in patients with acute respiratory distress syndrome. The aim of this study was to compare the outcomes between airway pressure release ventilation and traditional ventilation targeting low tidal volume, in patients with severe coronavirus disease 2019. DESIGN: Single-center randomized controlled trial. SETTING: ICU of a Mexican referral center dedicated to care of patients with confirmed diagnosis of coronavirus disease 2019. PATIENTS: Ninety adult intubated patients with acute respiratory distress syndrome associated with severe coronavirus disease 2019. INTERVENTIONS: Within 48 hours after intubation, patients were randomized to either receive ventilatory management with airway pressure release ventilation or continue low tidal volume ventilation. MEASUREMENTS AND MAIN RESULTS: Forty-five patients in airway pressure release ventilation group and 45 in the low tidal volume group were included. Ventilator-free days were 3.7 (0-15) and 5.2 (0-19) in the airway pressure release ventilation and low tidal volume groups, respectively (p = 0.28). During the first 7 days, patients in airway pressure release ventilation had a higher Pao2/Fio2 (mean difference, 26 [95%CI, 13-38]; p < 0.001) and static compliance (mean difference, 3.7 mL/cm H2O [95% CI, 0.2-7.2]; p = 0.03), higher mean airway pressure (mean difference, 3.1 cm H2O [95% CI, 2.1-4.1]; p < 0.001), and higher tidal volume (mean difference, 0.76 mL/kg/predicted body weight [95% CI, 0.5-1.0]; p < 0.001). More patients in airway pressure release ventilation had transient severe hypercapnia, defined as an elevation of Pco2 at greater than or equal to 55 along with a pH less than 7.15 (42% vs 15%; p = 0.009); other outcomes were similar. Overall mortality was 69%, with no difference between the groups (78% in airway pressure release ventilation vs 60% in low tidal volume; p = 0.07). CONCLUSIONS: In conclusion, when compared with low tidal volume, airway pressure release ventilation was not associated with more ventilator-free days or improvement in other relevant outcomes in patients with severe coronavirus disease 2019.


Subject(s)
COVID-19/complications , Continuous Positive Airway Pressure , Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Adult , Aged , COVID-19/mortality , Female , Humans , Male , Mexico , Middle Aged , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/mortality , Tidal Volume
5.
BMC Anesthesiol ; 22(1): 59, 2022 03 04.
Article in English | MEDLINE | ID: covidwho-1724413

ABSTRACT

BACKGROUND: Data on the lung respiratory mechanics and gas exchange in the time course of COVID-19-associated respiratory failure is limited. This study aimed to explore respiratory mechanics and gas exchange, the lung recruitability and risk of overdistension during the time course of mechanical ventilation. METHODS: This was a prospective observational study in critically ill mechanically ventilated patients (n = 116) with COVID-19 admitted into Intensive Care Units of Sechenov University. The primary endpoints were: «optimum¼ positive end-expiratory pressure (PEEP) level balanced between the lowest driving pressure and the highest SpO2 and number of patients with recruitable lung on Days 1 and 7 of mechanical ventilation. We measured driving pressure at different levels of PEEP (14, 12, 10 and 8 cmH2O) with preset tidal volume, and with the increase of tidal volume by 100 ml and 200 ml at preset PEEP level, and calculated static respiratory system compliance (CRS), PaO2/FiO2, alveolar dead space and ventilatory ratio on Days 1, 3, 5, 7, 10, 14 and 21. RESULTS: The «optimum¼ PEEP levels on Day 1 were 11.0 (10.0-12.8) cmH2O and 10.0 (9.0-12.0) cmH2O on Day 7. Positive response to recruitment was observed on Day 1 in 27.6% and on Day 7 in 9.2% of patients. PEEP increase from 10 to 14 cmH2O and VT increase by 100 and 200 ml led to a significant decrease in CRS from Day 1 to Day 14 (p < 0.05). Ventilatory ratio was 2.2 (1.7-2,7) in non-survivors and in 1.9 (1.6-2.6) survivors on Day 1 and decreased on Day 7 in survivors only (p < 0.01). PaO2/FiO2 was 105.5 (76.2-141.7) mmHg in non-survivors on Day 1 and 136.6 (106.7-160.8) in survivors (p = 0.002). In survivors, PaO2/FiO2 rose on Day 3 (p = 0.008) and then between Days 7 and 10 (p = 0.046). CONCLUSION: Lung recruitability was low in COVID-19 and decreased during the course of the disease, but lung overdistension occurred at «intermediate¼ PEEP and VT levels. In survivors gas exchange improvements after Day 7 mismatched CRS. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04445961 . Registered 24 June 2020-Retrospectively registered.


Subject(s)
COVID-19/epidemiology , COVID-19/therapy , Lung/physiopathology , Respiration, Artificial/statistics & numerical data , Respiratory Insufficiency/epidemiology , Aged , COVID-19/physiopathology , Critical Care/methods , Female , Humans , Male , Middle Aged , Noninvasive Ventilation/statistics & numerical data , Positive-Pressure Respiration , Prospective Studies , Respiratory Insufficiency/physiopathology , Respiratory Mechanics , Russia/epidemiology , SARS-CoV-2 , Survival Analysis , Tidal Volume , Treatment Failure
6.
EBioMedicine ; 76: 103868, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1676709

ABSTRACT

BACKGROUND: The manufacturing of any standard mechanical ventilator cannot rapidly be upscaled to several thousand units per week, largely due to supply chain limitations. The aim of this study was to design, verify and perform a pre-clinical evaluation of a mechanical ventilator based on components not required for standard ventilators, and that met the specifications provided by the Medicines and Healthcare Products Regulatory Agency (MHRA) for rapidly-manufactured ventilator systems (RMVS). METHODS: The design utilises closed-loop negative feedback control, with real-time monitoring and alarms. Using a standard test lung, we determined the difference between delivered and target tidal volume (VT) at respiratory rates between 20 and 29 breaths per minute, and the ventilator's ability to deliver consistent VT during continuous operation for >14 days (RMVS specification). Additionally, four anaesthetised domestic pigs (3 male-1 female) were studied before and after lung injury to provide evidence of the ventilator's functionality, and ability to support spontaneous breathing. FINDINGS: Continuous operation lasted 23 days, when the greatest difference between delivered and target VT was 10% at inspiratory flow rates >825 mL/s. In the pre-clinical evaluation, the VT difference was -1 (-90 to 88) mL [mean (LoA)], and positive end-expiratory pressure (PEEP) difference was -2 (-8 to 4) cmH2O. VT delivery being triggered by pressures below PEEP demonstrated spontaneous ventilation support. INTERPRETATION: The mechanical ventilator presented meets the MHRA therapy standards for RMVS and, being based on largely available components, can be manufactured at scale. FUNDING: Work supported by Wellcome/EPSRC Centre for Medical Engineering,King's Together Fund and Oxford University.


Subject(s)
Equipment Design , Respiration, Artificial/instrumentation , Animals , COVID-19/pathology , COVID-19/prevention & control , COVID-19/virology , Female , Male , Respiratory Rate , SARS-CoV-2/isolation & purification , Swine , Tidal Volume
7.
Curr Opin Crit Care ; 28(1): 51-56, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1606528

ABSTRACT

PURPOSE OF REVIEW: To review current evidence on the pathophysiology of COVID-19-related acute respiratory distress syndrome (ARDS) and on the implementation of lung protective ventilation. RECENT FINDINGS: Although multiple observations and physiological studies seem to show a different pathophysiological behaviour in COVID-19-ARDS compared with 'classical' ARDS, numerous studies on thousands of patients do not confirm these findings and COVID-19-ARDS indeed shares similar characteristics and interindividual heterogeneity with ARDS from other causes. Although still scarce, present evidence on the application of lung protective ventilation in COVID-19-ARDS shows that it is indeed consistently applied in ICUs worldwide with a possible signal towards better survival at least in one study. The levels of positive end-expiratory pressure (PEEP) usually applied in these patients are higher than in 'classical' ARDS, proposing once again the issue of PEEP personalization in hypoxemic patients. In the absence of robust evidence, careful evaluation of the patient is needed, and empiric settings should be oriented towards lower levels of PEEP. SUMMARY: According to the present evidence, a lung protective strategy based on low tidal volume and plateau pressures is indicated in COVID-19-ARDS as in ARDS from other causes; however, there are still uncertainties on the appropriate levels of PEEP.


Subject(s)
COVID-19 , Respiratory Distress Syndrome , Humans , Lung , Positive-Pressure Respiration , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , Tidal Volume
8.
Appl Physiol Nutr Metab ; 46(7): 753-762, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1571437

ABSTRACT

We sought to determine the impact of wearing cloth or surgical masks on the cardiopulmonary responses to moderate-intensity exercise. Twelve subjects (n = 5 females) completed three, 8-min cycling trials while breathing through a non-rebreathing valve (laboratory control), cloth, or surgical mask. Heart rate (HR), oxyhemoglobin saturation (SpO2), breathing frequency, mouth pressure, partial pressure of end-tidal carbon dioxide (PetCO2) and oxygen (PetO2), dyspnea were measured throughout exercise. A subset of n = 6 subjects completed an additional exercise bout without a mask (ecological control). There were no differences in breathing frequency, HR or SpO2 across conditions (all p > 0.05). Compared with the laboratory control (4.7 ± 0.9 cmH2O [mean ± SD]), mouth pressure swings were smaller with the surgical mask (0.9 ± 0.7; p < 0.0001), but similar with the cloth mask (3.6 ± 4.8 cmH2O; p = 0.66). Wearing a cloth mask decreased PetO2 (-3.5 ± 3.7 mm Hg) and increased PetCO2 (+2.0 ± 1.3 mm Hg) relative to the ecological control (both p < 0.05). There were no differences in end-tidal gases between mask conditions and laboratory control (both p > 0.05). Dyspnea was similar between the control conditions and the surgical mask (p > 0.05) but was greater with the cloth mask compared with laboratory (+0.9 ± 1.2) and ecological (+1.5 ± 1.3) control conditions (both p < 0.05). Wearing a mask during short-term moderate-intensity exercise may increase dyspnea but has minimal impact on the cardiopulmonary response. Novelty: Wearing surgical or cloth masks during exercise has no impact on breathing frequency, tidal volume, oxygenation, and heart rate However, there are some changes in inspired and expired gas fractions that are physiologically irrelevant. In young healthy individuals, wearing surgical or cloth masks during submaximal exercise has few physiological consequences.


Subject(s)
Exercise/physiology , Heart Rate , Masks , Oxyhemoglobins/metabolism , Respiratory Rate , Adult , COVID-19/prevention & control , Carbon Dioxide/physiology , Dyspnea/physiopathology , Equipment Design , Exercise Test , Face , Female , Humans , Male , Mouth/physiology , Oxygen/physiology , Partial Pressure , Pressure , Skin Temperature , Tidal Volume , Young Adult
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 1557-1561, 2021 11.
Article in English | MEDLINE | ID: covidwho-1566215

ABSTRACT

Three hundred and ten rapid-manufactured mechanical ventilators, named Masi, were produced and validated in Peru, according to applicable standards. From these, a sample of 30 was taken and two ventilation parameters, tidal volume and peak inspiratory pressure, were statically analyzed using control charts and histograms. Results show that several points were outside estimated limits for Shewhart means and ranges charts, which could possibly be due to the quantity of equipment used for data recollection and the fact that the Masi team had over 20 engineers. Nevertheless, Masi ventilators met the tolerance required by their user´s manual and MHRA standard and Peruvian DIGEMID for every parameter.Clinical Relevance-This article shows the performance in the validation stage of the peruvian mechanical ventilator MASI built as an emergency response for the COVID-19 crisis.


Subject(s)
COVID-19 , Humans , Peru , SARS-CoV-2 , Tidal Volume , Ventilators, Mechanical
10.
Respir Care ; 67(2): 216-226, 2022 02.
Article in English | MEDLINE | ID: covidwho-1547585

ABSTRACT

BACKGROUND: The impact of mechanical ventilation parameters and management on outcomes of patients with coronavirus disease 2019 (COVID-19) ARDS is unclear. METHODS: This multi-center observational study enrolled consecutive mechanically ventilated patients with COVID-19 ARDS admitted to one of 7 Korean ICUs between February 1, 2020-February 28, 2021. Patients who were age < 17 y or had missing ventilation parameters for the first 4 d of mechanical ventilation were excluded. Multivariate logistic regression was used to identify which strategies or ventilation parameters that were independently associated with ICU mortality. RESULTS: Overall, 129 subjects (males, 60%) with a median (interquartile range) age of 69 (62-78) y were included. Neuromuscular blocker (NMB) use and prone positioning were applied to 76% and 16% of subjects, respectively. The ICU mortality rate was 37%. In the multivariate analysis, higher dynamic driving pressure (ΔP) values during the first 4 d of mechanical ventilation were associated with increased mortality (adjusted odds ratio 1.16 [95% CI 1.00-1.33], P = .046). NMB use was associated with decreased mortality (adjusted odds ratio 0.27 [95% CI 0.09-0.81], P = .02). The median tidal volume values during the first 4 d of mechanical ventilation and the ICU mortality rate were significantly lower in the NMB group than in the no NMB group. However, subjects who received NMB for ≥ 6 d (vs < 6 d) had higher ICU mortality rate. CONCLUSIONS: In subjects with COVID-19 ARDS receiving mechanical ventilation, ΔP during the first 4 d of mechanical ventilation was independently associated with mortality. The short-term use of NMB facilitated lung-protective ventilation and was independently associated with decreased mortality.


Subject(s)
COVID-19 , Neuromuscular Blocking Agents , Respiratory Distress Syndrome , Humans , Male , Respiration, Artificial , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , Tidal Volume
11.
J Crit Care ; 66: 78-85, 2021 12.
Article in English | MEDLINE | ID: covidwho-1469324

ABSTRACT

PURPOSE: To investigate the possible association between ventilatory settings on the first day of invasive mechanical ventilation (IMV) and mortality in patients admitted to the intensive care unit (ICU) with severe acute respiratory infection (SARI). MATERIALS AND METHODS: In this pre-planned sub-study of a prospective, multicentre observational study, 441 patients with SARI who received controlled IMV during the ICU stay were included in the analysis. RESULTS: ICU and hospital mortality rates were 23.1 and 28.1%, respectively. In multivariable analysis, tidal volume and respiratory rate on the first day of IMV were not associated with an increased risk of death; however, higher driving pressure (DP: odds ratio (OR) 1.05; 95% confidence interval (CI): 1.01-1.1, p = 0.011), plateau pressure (Pplat) (OR 1.08; 95% CI: 1.04-1.13, p < 0.001) and positive end-expiratory pressure (PEEP) (OR 1.13; 95% CI: 1.03-1.24, p = 0.006) were independently associated with in-hospital mortality. In subgroup analysis, in hypoxemic patients and in patients with acute respiratory distress syndrome (ARDS), higher DP, Pplat, and PEEP were associated with increased risk of in-hospital death. CONCLUSIONS: In patients with SARI receiving IMV, higher DP, Pplat and PEEP, and not tidal volume, were associated with a higher risk of in-hospital death, especially in those with hypoxemia or ARDS.


Subject(s)
Positive-Pressure Respiration , Respiration, Artificial , Cohort Studies , Hospital Mortality , Humans , Intensive Care Units , Prospective Studies , Tidal Volume
12.
Eur Rev Med Pharmacol Sci ; 25(18): 5853-5856, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1451043

ABSTRACT

Coronavirus disease 2019-induced acute respiratory distress syndrome (ARDS) is more severe in morbidly obese patients. Mechanical ventilation differs between obese and non-obese patients. We examined these differences in an obese (body mass index = 47 kg/m2) 32-year-old patient followed up in our clinic. The patient was admitted to the intensive care unit due to respiratory failure. Recruitment maneuvers were performed in pressure-controlled ventilation mode. The optimal positive end-expiratory pressure was 25 cm H2O. The inspiratory pressure was adjusted to 45 cm H2O to provide a tidal volume of 6 ml/kg and driving pressure ≤ 15. The patient was discharged with full recovery.


Subject(s)
COVID-19/therapy , Obesity, Morbid , Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Adult , COVID-19/blood , COVID-19/complications , COVID-19/diagnostic imaging , Humans , Intensive Care Units , Male , Obesity, Morbid/complications , Positive-Pressure Respiration/methods , Respiratory Distress Syndrome/complications , Tidal Volume
13.
Crit Care Med ; 50(4): 586-594, 2022 04 01.
Article in English | MEDLINE | ID: covidwho-1447634

ABSTRACT

OBJECTIVES: Airway pressure release ventilation is a ventilatory mode characterized by a mandatory inverse inspiratory:expiratory ratio with a very short expiratory phase, aimed to avoid derecruitment and allow spontaneous breathing. Recent basic and clinical evidence suggests that this mode could be associated with improved outcomes in patients with acute respiratory distress syndrome. The aim of this study was to compare the outcomes between airway pressure release ventilation and traditional ventilation targeting low tidal volume, in patients with severe coronavirus disease 2019. DESIGN: Single-center randomized controlled trial. SETTING: ICU of a Mexican referral center dedicated to care of patients with confirmed diagnosis of coronavirus disease 2019. PATIENTS: Ninety adult intubated patients with acute respiratory distress syndrome associated with severe coronavirus disease 2019. INTERVENTIONS: Within 48 hours after intubation, patients were randomized to either receive ventilatory management with airway pressure release ventilation or continue low tidal volume ventilation. MEASUREMENTS AND MAIN RESULTS: Forty-five patients in airway pressure release ventilation group and 45 in the low tidal volume group were included. Ventilator-free days were 3.7 (0-15) and 5.2 (0-19) in the airway pressure release ventilation and low tidal volume groups, respectively (p = 0.28). During the first 7 days, patients in airway pressure release ventilation had a higher Pao2/Fio2 (mean difference, 26 [95%CI, 13-38]; p < 0.001) and static compliance (mean difference, 3.7 mL/cm H2O [95% CI, 0.2-7.2]; p = 0.03), higher mean airway pressure (mean difference, 3.1 cm H2O [95% CI, 2.1-4.1]; p < 0.001), and higher tidal volume (mean difference, 0.76 mL/kg/predicted body weight [95% CI, 0.5-1.0]; p < 0.001). More patients in airway pressure release ventilation had transient severe hypercapnia, defined as an elevation of Pco2 at greater than or equal to 55 along with a pH less than 7.15 (42% vs 15%; p = 0.009); other outcomes were similar. Overall mortality was 69%, with no difference between the groups (78% in airway pressure release ventilation vs 60% in low tidal volume; p = 0.07). CONCLUSIONS: In conclusion, when compared with low tidal volume, airway pressure release ventilation was not associated with more ventilator-free days or improvement in other relevant outcomes in patients with severe coronavirus disease 2019.


Subject(s)
COVID-19/complications , Continuous Positive Airway Pressure , Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Adult , Aged , COVID-19/mortality , Female , Humans , Male , Mexico , Middle Aged , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/mortality , Tidal Volume
14.
JAMA ; 326(11): 1013-1023, 2021 09 21.
Article in English | MEDLINE | ID: covidwho-1441906

ABSTRACT

Importance: In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes. Objective: To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure. Design, Setting, and Participants: This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020. Interventions: Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210). Main Outcomes and Measures: The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates. Results: Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, -7.6% to 11.5%]; P = .68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, -2.1 [95% CI, -3.8 to -0.3]; P = .02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device. Conclusions and Relevance: Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference. Trial Registration: ClinicalTrials.gov Identifier: NCT02654327.


Subject(s)
Carbon Dioxide/blood , Extracorporeal Circulation , Respiration, Artificial/methods , Respiratory Insufficiency/therapy , Aged , Early Termination of Clinical Trials , Extracorporeal Circulation/adverse effects , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Respiration, Artificial/adverse effects , Respiratory Distress Syndrome/therapy , Respiratory Insufficiency/mortality , Tidal Volume
16.
Crit Care ; 25(1): 283, 2021 08 06.
Article in English | MEDLINE | ID: covidwho-1398871

ABSTRACT

BACKGROUND: The intensity of ventilation, reflected by driving pressure (ΔP) and mechanical power (MP), has an association with outcome in invasively ventilated patients with or without acute respiratory distress syndrome (ARDS). It is uncertain if a similar association exists in coronavirus disease 2019 (COVID-19) patients with acute respiratory failure. METHODS: We aimed to investigate the impact of intensity of ventilation on patient outcome. The PRoVENT-COVID study is a national multicenter observational study in COVID-19 patients receiving invasive ventilation. Ventilator parameters were collected a fixed time points on the first calendar day of invasive ventilation. Mean dynamic ΔP and MP were calculated for individual patients at time points without evidence of spontaneous breathing. A Cox proportional hazard model, and a double stratification analysis adjusted for confounders were used to estimate the independent associations of ΔP and MP with outcome. The primary endpoint was 28-day mortality. RESULTS: In 825 patients included in this analysis, 28-day mortality was 27.5%. ΔP was not independently associated with mortality (HR 1.02 [95% confidence interval 0.88-1.18]; P = 0.750). MP, however, was independently associated with 28-day mortality (HR 1.17 [95% CI 1.01-1.36]; P = 0.031), and increasing quartiles of MP, stratified on comparable levels of ΔP, had higher risks of 28-day mortality (HR 1.15 [95% CI 1.01-1.30]; P = 0.028). CONCLUSIONS: In this cohort of critically ill invasively ventilated COVID-19 patients with acute respiratory failure, we show an independent association of MP, but not ΔP with 28-day mortality. MP could serve as one prognostic biomarker in addition to ΔP in these patients. Efforts aiming at limiting both ΔP and MP could translate in a better outcome. Trial registration Clinicaltrials.gov (study identifier NCT04346342).


Subject(s)
COVID-19/mortality , COVID-19/therapy , Respiration, Artificial/mortality , Respiratory Distress Syndrome/mortality , Respiratory Distress Syndrome/therapy , Aged , Cohort Studies , Critical Illness/mortality , Critical Illness/therapy , Female , Humans , Male , Middle Aged , Mortality/trends , Respiration, Artificial/trends , Retrospective Studies , Tidal Volume/physiology
17.
Lancet Respir Med ; 9(9): 989-998, 2021 09.
Article in English | MEDLINE | ID: covidwho-1392669

ABSTRACT

BACKGROUND: Although COVID-19 has greatly affected many low-income and middle-income countries, detailed information about patients admitted to the intensive care unit (ICU) is still scarce. Our aim was to examine ventilation characteristics and outcomes in invasively ventilated patients with COVID-19 in Argentina, an upper middle-income country. METHODS: In this prospective, multicentre cohort study (SATICOVID), we enrolled patients aged 18 years or older with RT-PCR-confirmed COVID-19 who were on invasive mechanical ventilation and admitted to one of 63 ICUs in Argentina. Patient demographics and clinical, laboratory, and general management variables were collected on day 1 (ICU admission); physiological respiratory and ventilation variables were collected on days 1, 3, and 7. The primary outcome was all-cause in-hospital mortality. All patients were followed until death in hospital or hospital discharge, whichever occurred first. Secondary outcomes were ICU mortality, identification of independent predictors of mortality, duration of invasive mechanical ventilation, and patterns of change in physiological respiratory and mechanical ventilation variables. The study is registered with ClinicalTrials.gov, NCT04611269, and is complete. FINDINGS: Between March 20, 2020, and Oct 31, 2020, we enrolled 1909 invasively ventilated patients with COVID-19, with a median age of 62 years [IQR 52-70]. 1294 (67·8%) were men, hypertension and obesity were the main comorbidities, and 939 (49·2%) patients required vasopressors. Lung-protective ventilation was widely used and median duration of ventilation was 13 days (IQR 7-22). Median tidal volume was 6·1 mL/kg predicted bodyweight (IQR 6·0-7·0) on day 1, and the value increased significantly up to day 7; positive end-expiratory pressure was 10 cm H2O (8-12) on day 1, with a slight but significant decrease to day 7. Ratio of partial pressure of arterial oxygen (PaO2) to fractional inspired oxygen (FiO2) was 160 (IQR 111-218), respiratory system compliance 36 mL/cm H2O (29-44), driving pressure 12 cm H2O (10-14), and FiO2 0·60 (0·45-0·80) on day 1. Acute respiratory distress syndrome developed in 1672 (87·6%) of patients; 1176 (61·6%) received prone positioning. In-hospital mortality was 57·7% (1101/1909 patients) and ICU mortality was 57·0% (1088/1909 patients); 462 (43·8%) patients died of refractory hypoxaemia, frequently overlapping with septic shock (n=174). Cox regression identified age (hazard ratio 1·02 [95% CI 1·01-1·03]), Charlson score (1·16 [1·11-1·23]), endotracheal intubation outside of the ICU (ie, before ICU admission; 1·37 [1·10-1·71]), vasopressor use on day 1 (1·29 [1·07-1·55]), D-dimer concentration (1·02 [1·01-1·03]), PaO2/FiO2 on day 1 (0·998 [0·997-0·999]), arterial pH on day 1 (1·01 [1·00-1·01]), driving pressure on day 1 (1·05 [1·03-1·08]), acute kidney injury (1·66 [1·36-2·03]), and month of admission (1·10 [1·03-1·18]) as independent predictors of mortality. INTERPRETATION: In patients with COVID-19 who required invasive mechanical ventilation, lung-protective ventilation was widely used but mortality was high. Predictors of mortality in our study broadly agreed with those identified in studies of invasively ventilated patients in high-income countries. The sustained burden of COVID-19 on scarce health-care personnel might have contributed to high mortality over the course of our study in Argentina. These data might help to identify points for improvement in the management of patients in middle-income countries and elsewhere. FUNDING: None. TRANSLATION: For the Spanish translation of the Summary see Supplementary Materials section.


Subject(s)
COVID-19/therapy , Respiration, Artificial/statistics & numerical data , Respiratory Insufficiency/therapy , Adult , Aged , Argentina/epidemiology , COVID-19/complications , COVID-19/diagnosis , COVID-19/mortality , COVID-19 Nucleic Acid Testing , Female , Hospital Mortality , Humans , Intensive Care Units/statistics & numerical data , Intubation, Intratracheal/statistics & numerical data , Male , Middle Aged , Prospective Studies , Respiration, Artificial/methods , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/mortality , Respiratory Insufficiency/virology , Risk Factors , SARS-CoV-2/isolation & purification , Tidal Volume , Treatment Outcome , Young Adult
19.
PLoS One ; 16(8): e0256469, 2021.
Article in English | MEDLINE | ID: covidwho-1372013

ABSTRACT

The current COVID-19 pandemic has led the world to an unprecedented global shortage of ventilators, and its sharing has been proposed as an alternative to meet the surge. This study outlines the performance of a preformed novel interface called 'ACRA', designed to split ventilator outflow into two breathing systems. The 'ACRA' interface was built using medical use approved components. It consists of four unidirectional valves, two adjustable flow-restrictor valves placed on the inspiratory limbs of each unit, and one adjustable PEEP valve placed on the expiratory limb of the unit that would require a greater PEEP. The interface was interposed between a ventilator and two lung units (phase I), two breathing simulators (phase II) and two live pigs with heterogeneous lung conditions (phase III). The interface and ventilator adjustments tested the ability to regulate individual pressures and the resulting tidal volumes. Data were analyzed using Friedman and Wilcoxon tests test (p < 0.05). Ventilator outflow splitting, independent pressure adjustments and individual tidal volume monitoring were feasible in all phases. In all experimental measurements, dual ventilation allowed for individual and tight adjustments of the pressure, and thus volume delivered to each paired lung unit without affecting the other unit's ventilation-all the modifications performed on the ventilator equally affected both paired lung units. Although only suggested during a dire crisis, this experiment supports dual ventilation as an alternative worth to be considered.


Subject(s)
Lung/physiopathology , Respiratory Distress Syndrome/physiopathology , Ventilators, Mechanical , Animals , Blood Pressure , Carbon Dioxide/chemistry , Computer Simulation , Disease Models, Animal , Heart Rate , Hydrogen-Ion Concentration , Swine , Tidal Volume
20.
Respir Investig ; 59(5): 628-634, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1364440

ABSTRACT

BACKGROUND: The respiratory dynamics of coronavirus disease 2019 (COVID-19) patients under invasive ventilation are still not well known. In this prospective cohort, we aimed to assess the characteristics of the respiratory system in COVID-19 patients under invasive mechanical ventilation and evaluate their relationship with mortality. METHODS: Fifty-eight COVID-19 patients who underwent invasive mechanical ventilation between March 11, 2020 and September 1, 2020 were enrolled for the present study. Demographics and laboratory values at baseline were recorded. Respiratory variables such as tidal volume, plateau pressure, positive end expiratory pressure, static compliance, and driving pressure were recorded daily under passive conditions. Further, the median values were analyzed. RESULTS: Median age of the patients was 64 years (58-72). Mortality was 60% on day 28. Plateau pressure, driving pressure, and static compliance significantly differ between the survivors and non-survivors. When patients were categorized into two groups based on the median driving pressure (Pdrive) of ≤15 cmH2O or >15 cmH2O during their invasive mechanical ventilation period, there was significantly better survival on day 28 in patients having a Pdrive ≤ 15 cmH2O [28 days (95% CI = 19-28) vs 16 days (95% CI = 6-25), (log-rank p = 0.026). CONCLUSION: COVID-19 related acute respiratory distress syndrome (ARDS) seemed to have similar characteristics as other forms of ARDS. Lung protective ventilation with low plateau and driving pressures might be related to lower mortality.


Subject(s)
COVID-19 , Respiratory Distress Syndrome , Aged , COVID-19/complications , Humans , Middle Aged , Prospective Studies , Respiration, Artificial , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , Tidal Volume
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