Mechanical Power and Ventilatory Ratio in ARDS
Study Details
Study Description
Brief Summary
Mechanical power (MP) and ventilatory ratio (VR) are variables associated with outcomes in patients with acute respiratory distress syndrome (ARDS). In respiratory setting, the optimization of MP should lead to an increase in VR. Therefore, the objectives of this study are: to assess the relationship between MP and VR and to compare the components of MP (ventilatory variables) according to a level of MP (17 J/minute) considered harmful.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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Detailed Description
In patients with acute respiratory distress syndrome (ARDS), mechanical ventilation is a life support therapy; however, its use is associated with ventilator-induced lung injury (VILI). VILI is the final manifestation of changes in lung mechanics that occurs in each ventilatory cycle in a damaged lung parenchyma. In each respiratory cycle, a certain amount of mechanical energy is transferred to the lung, which is used primarily to overcome airway resistance and expand the chest wall.This mechanical energy multiplied by the respiratory rate (RR) is what is known as mechanical power (MP), which reflects the amount of energy applied to the respiratory system per minute during mechanical ventilation (MV). The amount of energy transferred from the ventilator to the patient is measured in joules (J), while MP is defined as the amount of energy transferred per unit of time (J/minute). MP is a summary variable that includes: tidal volume (TV), RR, flow, positive end-expiratory pressure (PEEP) and driving pressure (difference between plateau pressure and PEEP). An experimental study showed that the increase in MP, through the increase in RR, was associated with VILI. There is also evidence that MP can predict the risk of mortality in mechanically ventilated patients with and without ARDS. In addition, a constant increase in the risk of death has been found with MP greater than 17.0 J/min. In turn, since this value could vary according to lung size, it has been proposed that MP normalized to lung size (assessed through lung compliance) may have better performance. One way to optimize the MP would be to limit the RR and TV. However, the decrease in any of these ventilatory variables can lead to inefficient ventilation and an increase in the arterial pressure of carbon dioxide (PaCO2). In recent years, the ventilatory ratio (VR) has been assessed. VR is a unitless ratio that it can be easily calculated using routine bedside variables. Its value reflects the ability of the lungs to excrete CO2 adequately. Higher values of VR were associated with higher pulmonary dead space and with mortality. In the ventilatory setting, the optimization of MP would lead to an increase in VR.In addition, and since the components of MP contribute unequally to its value, it would be important to be able to establish the variables that could be decisive in the ventilatory setting. For this reason, the primary outcome is to assess the relationship between PM and VR. The secondary outcomes are: to estimate the relationship between PM in relation to static compliance (PM/C) and VR, and to assess the differences in respiratory variables considering a MP of 17 J/min as cut-off point.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Patients with MP < 17 j/min Patients with acute respiratory distress syndrome with MP < 17 j/min |
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| Patients with MP ≥ 17 j/min Patients with acute respiratory distress syndrome with MP ≥ 17 j/min |
Other: MP < 17 J/min
assessment of the ventilatory variables according to the MP value (< or >= 17 J/min)
Other Names:
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Outcome Measures
Primary Outcome Measures
- To determine the correlation between mechanical power (MP) and ventilatory rate (VR) [3rd day of mechanical ventilation]
The relationship (correlation) between MP and VR will be assessed, according to the value of both variables on day 3 of mechanical ventilation.
Secondary Outcome Measures
- To determine the correlation between mechanical power (MP) and static compliance (SC) with ventilatory rate (VR). (MP/SC)/VR [3rd day of mechanical ventilation]
The relationship (correlation) between mechanical power (MP) and static compliance (SC) with ventilatory rate (VR) will be assessed, according to the value of both variables on day 3 of mechanical ventilation.
- Assess the behavior of the ventilatory variables according to the MP value (> or < 17 j/min) [3rd day of mechanical ventilation]
The ventilatory variables will be compared according to the MP value (< or >= 17 J/min)
- Assess the hydric balance according to the MP value (> or < 17 j/min) [3rd day of mechanical ventilation]
The hydric balance will be compared according to the MP value (< or >= 17 J/min)
Eligibility Criteria
Criteria
Inclusion Criteria:
- patients who have been receiving mechanical ventilation (MV) and have been defined as with ARDS according to the Berlin definition
Exclusion Criteria:
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patients with chronic pulmonary disease
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patients with an expected duration of MV shorter than 48 h
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patients with a high risk of death within 3 months for reasons other than ARDS
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patients having made the decision to withhold life-sustaining treatment.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Hospital Regional Rio Gallegos | Rio Gallegos | Santa Cruz | Argentina | 9400 |
Sponsors and Collaborators
- Ramos Mejía Hospital
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
- Maj R, Palermo P, Gattarello S, Brusatori S, D'Albo R, Zinnato C, Velati M, Romitti F, Busana M, Wieditz J, Herrmann P, Moerer O, Quintel M, Meissner K, Sanderson B, Chiumello D, Marini JJ, Camporota L, Gattinoni L. Ventilatory ratio, dead space, and venous admixture in acute respiratory distress syndrome. Br J Anaesth. 2022 Dec 2;130(3):360-7. doi: 10.1016/j.bja.2022.10.035. Online ahead of print.
- Marini JJ, Jaber S. Dynamic predictors of VILI risk: beyond the driving pressure. Intensive Care Med. 2016 Oct;42(10):1597-1600. doi: 10.1007/s00134-016-4534-x. Epub 2016 Sep 16. No abstract available.
- Marini JJ. How I optimize power to avoid VILI. Crit Care. 2019 Oct 21;23(1):326. doi: 10.1186/s13054-019-2638-8. No abstract available.
- Serpa Neto A, Deliberato RO, Johnson AEW, Bos LD, Amorim P, Pereira SM, Cazati DC, Cordioli RL, Correa TD, Pollard TJ, Schettino GPP, Timenetsky KT, Celi LA, Pelosi P, Gama de Abreu M, Schultz MJ; PROVE Network Investigators. Mechanical power of ventilation is associated with mortality in critically ill patients: an analysis of patients in two observational cohorts. Intensive Care Med. 2018 Nov;44(11):1914-1922. doi: 10.1007/s00134-018-5375-6. Epub 2018 Oct 5.
- Sinha P, Calfee CS, Beitler JR, Soni N, Ho K, Matthay MA, Kallet RH. Physiologic Analysis and Clinical Performance of the Ventilatory Ratio in Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2019 Feb 1;199(3):333-341. doi: 10.1164/rccm.201804-0692OC.
- Sinha P, Fauvel NJ, Singh S, Soni N. Ventilatory ratio: a simple bedside measure of ventilation. Br J Anaesth. 2009 May;102(5):692-7. doi: 10.1093/bja/aep054. Epub 2009 Apr 3.
- Urner M, Juni P, Hansen B, Wettstein MS, Ferguson ND, Fan E. Time-varying intensity of mechanical ventilation and mortality in patients with acute respiratory failure: a registry-based, prospective cohort study. Lancet Respir Med. 2020 Sep;8(9):905-913. doi: 10.1016/S2213-2600(20)30325-8. Epub 2020 Jul 28.
- Zhang Z, Zheng B, Liu N, Ge H, Hong Y. Mechanical power normalized to predicted body weight as a predictor of mortality in patients with acute respiratory distress syndrome. Intensive Care Med. 2019 Jun;45(6):856-864. doi: 10.1007/s00134-019-05627-9. Epub 2019 May 6.
- Universidad de Magallanes