The Role of Morphological Phenotype in ARDS (MPARDS)

Hospital El Cruce

Status: Completed

Conditions: Respiratory Distress Syndrome, Adult

Treatments: Diagnostic Test: CT

Study type: Observational

Funder types: Other

Identifiers

NCT04157946

HElCruce

Details and patient eligibility

About

Although most of the information focuses on understanding how the ventilator produces lung damage, the pulmonary factors that predispose to ventilator-induced lung injury (VILI) have been less studied. Acute respiratory distress syndrome (ARDS) can adopt different morphological phenotypes, with its own clinical and mechanical characteristics. This morphological phenotypes may favor the development of VILI for same ventilatory strategy

Full description

The lung in acute respiratory distress syndrome ARDS) is a heterogeneous viscoelastic system, in which areas with different time constants coexist, causing tidal volume to be distributed unevenly within an anatomically and functionally reduced lung. The administration of a disproportionately high tidal volume for this lung predisposes to the over-distension of the better ventilated alveoli and to the injury by tidal opening and closing of the alveoli more unstable. In this sense, using low tidal volume and homogenizing the lung by means of the prone position have proven beneficial in ARDS.

Tidal volume, driving pressure, inspiratory flow and respiratory rate have been identified as responsible for mechanical ventilation-induced lung injury (VILI). These factors together represent the mechanical power, the insulting energy which is repeatedly applied to a vulnerable lung parenchyma.

Although most of the information focuses on understanding how the ventilator produces lung damage and/or amplifies the existing one, the pulmonary factors that predispose to VILI have been less studied. Acute respiratory distress syndrome can adopt different morphological phenotypes, with its own clinical and mechanical characteristics. Understanding how each subgroup of ARDS responds to the protective ventilatory strategy could help to personalize treatment.

Objectives: To compare the risk of VILI in two groups of ARDS with different morphological phenotypes (focal and non-focal), ventilated with the same protective strategy.

Design: Patients with ARDS were ventilated under the same conditions of both tidal volume (TV) and plateau pressure (PPlat). Positive End Expiratory Pressure (PEEP) was adjusted to reach 30 cmH2O of PPlat. A CT was performed in inspiration and expiration. Transpulmonary pressures (TP) were measured and lung volumes calculated (Volume Analysis Software,Toshiba, Japan). Stress was defined as TP at the end of inspiration (TPinsp) and strain: tidal volume/End Expiratory Lung Volume Patients were classified into focal and non-focal according to the distribution of aeration loss in CT. Mann - Whitney U test was used to compare variables and Pearson correlation coefficient to compare its correlation. Significant: p <0.05

Enrollment: 12 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

Acute respiratory distress syndrome (ARDS).

Exclusion criteria

Emphysema Asthma Pneumothorax Oxygen saturation ≤ 88% Severe shock Ventricular arrhythmia Myocardial ischemia.

Trial design

12 participants in 2 patient groups

Focal

Description:

ARDS was classified according to the pattern that adopted the loss of aeration in the chest CT in the two groups: focal (predominant commitment in the dependant region) and non- focal (patched or diffused involvement of the entire lung)

Treatment:

Diagnostic Test: CT

Non-Focal

Description:

ARDS was classified according to the pattern that adopted the loss of aeration in the chest CT in the two groups: focal (predominant commitment in the dependant region) and non- focal (patched or diffused involvement of the entire lung)

Treatment:

Diagnostic Test: CT