Effect of Prolonged Decubitus on Bronchial Inflammation in COPD Patients Evaluated by Expired NO Concentration Assessment
Bronchial inflammation in COPD represents one of the main causes of not fully reversible
obstruction and airflow limitation. The main inflammatory cells involved are represented by
the neutrophils, while some inflammatory mediators (IL6, IL8, IL1alpha, IL1beta, TNFalfa,
ROS, LTB4, NO) provoke the disruption of the elastic alveolar bonds that support the small
airways, thus invalidating their physical and mechanical characteristics. During decubitus,
in such patients, the more dependent parts of the lung are subjected to gravity force, which
together with chronic inflammation may cause, we suppose, one of the following effects
during tidal breathing:
- a total closure of the smaller bronchioli
- a cyclic opening and closure of the small airways thus provoking friction and an
inflammatory response of mechanical origin.
The Fraction of Exhaled Nitric Oxyde (FeNO) concentration is largely used in clinical
practice as a marker to monitor the lung inflammatory status.
The purpose of the study is to evaluate the possible mechanical origin of the bronchial
inflammation in correlation with prolonged supine decubitus, and so use the NO as an index
of the small airways impairment in COPD patients.
To do this we will measure the exhaled NO concentration in COPD patients with moderate to
severe obstruction, that is a Forced Expiratory Volume less than 70% of predicted value
(FEV1<70%pred). The evaluation will be done in four different moments:
1. before the patient goes to sleep while in supine position
2. immediately after the patient wakes up in the morning, still being in supine position.
3. while sitting on the bed after point 2
4. in the morning after one hour of normal patient's activities, in seated position.
Together with NO concentration, also the Respiratory Frequency and Tidal Volume will be
registered during each evaluation.
All the subjects will be inpatients accessing a respiratory rehabilitation unit. At the
beginning and after 15 days of rehabilitation a functional respiratory assessment will be
made (spirometry, plethysmography, Carbon Monoxide (CO) diffusion lung test), together with
an arterial blood gas analysis and a 6 minutes walking test (WT6').
An initial and a final assessment of dyspnoea will be made by Borg and Modified Medical
Research Council (mMRC) scales. For the study duration all the patients will continue their
inhaled therapy as usual (an ultra long acting anticholinergic once daily plus a long acting
Beta-2 agonist in combination with an inhaled corticosteroid twice daily)
Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Change of Fraction of Exhaled Nitric Oxide related to patient's change of decubitus before and after a rehabilitation cycle
NO concentration will be evaluated in four different sessions at t0 and t1: 1) immediately after the patient goes to bed while he is in supine position; 2) when the patient wakes up, when he's still in the bed in supine position; 3) in sitted position after 5 deep inspirations to total lung capacity 4) after one hour of normal morning activity, again in sitted position. The NO measurements will be collected by a portable NO analyzer at the patient's bed.
The exhaled NO concentration will be assessed in two different moments: the day immediately after the hospitalization (t0) and after 15 days (t1) of rehabilitation activity
Pierachille Santus, Md, PhD
Università degli Studi di Milano-Pneumologia Riabilitativa-Fondazione Salvatore Maugeri-MILANO
Italy: Ethics Committee