Clinical trial NCT04435613: Clinical and Physiological Assessment of a Nearly Ultra-protective Lung Ventilation Strategy: A Quasi-experimental Preliminary Study in ARDS Patients
Official title: Clinical and Physiological Assessment of a Nearly Ultra-protective Lung Ventilation Strategy: A Quasi-experimental Preliminary Study in ARDS Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: ARDS
Volumetric Capnography
Keywords: dead space, end-inspiratory pause, respiratory rate, ARDS
Lead sponsor: Clinica las Condes, Chile
Sponsor class: OTHER
First posted: 2020-06-17
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: A quasi-experimental, non-randomized study
Primary purpose: OTHER

Brief summary: This study aims to determine whether a protective mechanical ventilator strategy generates a reduction in the Bohr´s dead space in patients with moderate or severe acute respiratory distress syndrome (ARDS). Commonly used ventilatory strategies in the clinical practice were applied sequentially to assess their impact. Data obtained from volumetric capnography will be recorded after each ventilatory strategy is applied

Detailed description: Protective mechanical ventilation strategies are currently the cornerstone of treatment for patients undergoing mechanical ventilatory support. Among them, we can mention the reduction in tidal volume, the reduction in driving pressure, the PEEP setting, and the respiratory rate reduction. All of these strategies are aimed at preventing ventilator-induced lung injury. Few clinical studies have evaluated the effects of protective mechanical ventilation strategies on dead-space. This study was designed to evaluate dead space and alveolar ventilation with a sequence of protective ventilatory strategies, keeping PEEP levels constant. The ventilatory strategy was developed to reduce tidal volume, set an end-inspiratory pause, and reduce the frequencies of lung tissue impact.

Baseline:

All the patients kept the variables under study constant for 60 minutes. Each of the participants was studied for a period of 150 minutes. PEEP programming was set with transpulmonary end-expiratory pressures to maintain between 0 and 5 cmH2O and was remained constant throughout the study.

Protocol design:

Baseline: Vt 7 ml/kg/PBW Phase I: Vt 6 ml/kg/PBW. Phase II: Vt 5 ml/kg/PBW. Phase III: end-inspiratory pause prolongation until achieving I:E ratio equal to 1, maintaining a constant Vt level (5 ml/kg/PBW) Phase IV: Respiratory rate reduction by 20% of basal conditions, maintaining constant VT level (5 ml/kg/PBW).

After 30 minutes of continuous monitoring, minute ventilation, mechanical power, variables obtained by volumetric capnography, and arterial blood gases were recorded in each study phase.

This study will be performed in the Intensive Care Unit of a University Hospital.

Eligibility criteria: Inclusion Criteria:

* Age older than 18 years
* The requirement of invasive mechanical ventilation for more than 4 hours and less than 72 hours
* Severe hypoxemia (PAFI \< 200) secondary to ARDS

Exclusion Criteria:

* Heart failure stage IV
* Chronic obstructive pulmonary disease (COPD) on home oxygen
* Bronchopulmonary fistula
* Hypovolemic Shock with active hemorrhage
* Gastrointestinal bleeding
* Oesophageal Varices
* Nasopharynx surgery, recent oesophageal or gastric surgery
* Massive Pulmonary Thromboembolism
* Catastrophic respiratory failure requiring urgent extracorporeal life support
* Respiratory acidosis. Hydrogen potential (pH) is less than 7.20 and PaCO2 higher than 60 mmHg at baseline.

Primary outcomes:
measure: To analyse the effects of different protective mechanical ventilator strategies on Bohr's dead space (VDBohr/VT) in patients with acute respiratory distress syndrome
timeFrame: 150 minutes
Secondary outcomes:
Other outcomes:
Locations:
city: Santiago
country: Chile
facility: Clínica Las Condes
state: Metropolitana
Study officials:
affiliation: Critical Care Department, Clínica Las Condes
name: Martín Benites Albanese, Physician
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gattinoni L, Tonetti T, Cressoni M, Cadringher P, Herrmann P, Moerer O, Protti A, Gotti M, Chiurazzi C, Carlesso E, Chiumello D, Quintel M. Ventilator-related causes of lung injury: the mechanical power. Intensive Care Med. 2016 Oct;42(10):1567-1575. doi: 10.1007/s00134-016-4505-2. Epub 2016 Sep 12.
citation: Tusman G, Sipmann FS, Borges JB, Hedenstierna G, Bohm SH. Validation of Bohr dead space measured by volumetric capnography. Intensive Care Med. 2011 May;37(5):870-4. doi: 10.1007/s00134-011-2164-x. Epub 2011 Feb 26.
citation: Tusman G, Gogniat E, Bohm SH, Scandurra A, Suarez-Sipmann F, Torroba A, Casella F, Giannasi S, Roman ES. Reference values for volumetric capnography-derived non-invasive parameters in healthy individuals. J Clin Monit Comput. 2013 Jun;27(3):281-8. doi: 10.1007/s10877-013-9433-x. Epub 2013 Feb 7.
citation: Lellouche F, Delorme M, Brochard L. Impact of Respiratory Rate and Dead Space in the Current Era of Lung Protective Mechanical Ventilation. Chest. 2020 Jul;158(1):45-47. doi: 10.1016/j.chest.2020.02.033. Epub 2020 Jul 2. No abstract available.
citation: Astrom E, Uttman L, Niklason L, Aboab J, Brochard L, Jonson B. Pattern of inspiratory gas delivery affects CO2 elimination in health and after acute lung injury. Intensive Care Med. 2008 Feb;34(2):377-84. doi: 10.1007/s00134-007-0840-7. Epub 2007 Sep 1.
citation: Devaquet J, Jonson B, Niklason L, Si Larbi AG, Uttman L, Aboab J, Brochard L. Effects of inspiratory pause on CO2 elimination and arterial PCO2 in acute lung injury. J Appl Physiol (1985). 2008 Dec;105(6):1944-9. doi: 10.1152/japplphysiol.90682.2008. Epub 2008 Sep 18.
citation: Aguirre-Bermeo H, Moran I, Bottiroli M, Italiano S, Parrilla FJ, Plazolles E, Roche-Campo F, Mancebo J. End-inspiratory pause prolongation in acute respiratory distress syndrome patients: effects on gas exchange and mechanics. Ann Intensive Care. 2016 Dec;6(1):81. doi: 10.1186/s13613-016-0183-z. Epub 2016 Aug 24.