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NCT Number: NCT07414108

How Nocturnal Hypoventilation Predicts Long-term Response to Non-invasive Ventilation in Hypercapnic COPD Patients

The study is an observational, single-center, prospective cohort study aiming to evaluate respiratory mechanics data, as well as clinical and functional parameters commonly used in clinical practice in patients with COPD and hypercapnic respiratory failure. The study population consists of patients with COPD and hypercapnia requiring NIV. The primary objective of the study is to evaluate the association between the reduction in partial pressure of carbon dioxide in arterial blood (PaCO₂) levels at 6 and 12 months after initiating non-invasive ventilation (NIV) and the presence of nocturnal hypoventilation detected at baseline in patients with COPD and chronic hypercapnia. Secondary objectives of this study are the evaluation of the following parameters measured at baseline and/or after 6 and 12 months of NIV treatment in patients with COPD and chronic hypercapnia:

* Magnitude of esophageal pressure swing during nocturnal monitoring. * Diaphragm thickness and diaphragmatic thickening fraction assessed by thoracic ultrasound. * Presence of overlap syndrome (COPD + OSA). * Radiological classification of COPD subtypes to assess the association between radiological findings, functional profile, severity of nocturnal hypoventilation, and patterns of chronic hypercapnia. * Respiratory functional parameters, including FEV₁, FVC, FEV₁/FVC ratio, carbon monoxide diffusion capacity (DLCO), and airway resistance (R5 and R20). * Frequency of severe exacerbations and subsequent rehospitalizations during follow-up. * Rate of compliance with respiratory treatment.

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Key information

Conditions

COPD COPD (Chronic Obstructive Pulmonary Disease) Chronic Disease Disease Attributes Hypercapnia Hypercapnic Respiratory Failure, COPD Lung Diseases Lung Diseases, Obstructive Pathologic Processes Pathological Conditions, Signs and Symptoms Pulmonary Disease, Chronic Obstructive Respiration Disorders Respiratory Insufficiency Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

IRCCS Azienda Ospedaliero-Universitaria di Bologna

Bologna, 40138, Italy

Location status: Recruiting

Location contact

Lara Pisani, PhD

CONTACT

[email protected]

0512143253

About this study

To date, the pathophysiological mechanisms underlying the development of persistent hypercapnia in patients with COPD are not completely understood. Likewise, reliable predictive markers capable of identifying both patients at risk of developing this condition and those who may derive the greatest benefit from long-term non-invasive ventilation (NIV) are still lacking. Early identification of a patient phenotype more responsive to this type of intervention could substantially reduce exacerbations, emergency department visits, hospitalizations, and associated healthcare costs, thereby improving the overall efficiency of the local healthcare system. The aim of this study is therefore to identify more accurate and earlier criteria to recognize patients with COPD and hypercapnic respiratory failure who may benefit from long-term non-invasive ventilatory support, through an integrated analysis of respiratory mechanics data and clinical and functional parameters commonly used in routine clinical practice.

The study population consists of patients with COPD and hypercapnic respiratory failure who require NIV and who are evaluated in the outpatient clinic and/or inpatient unit of the Respiratory and Critical Care Unit of the IRCCS AOU of Bologna. For these patients clinical, functional, and respiratory mechanics data will be collected. Data will be collected at the baseline visit-corresponding to the first visit at the OSAS Ventilated outpatient clinic or the first day of hospitalization in the Pneumology and Respiratory Intensive Care Unit-and during follow-up visits, scheduled according to routine clinical practice at 6 and 12 months after initiation of NIV treatment.

The total duration of the study will be 30 months, including 12 months for patient enrollment, 12 months of follow-up, and 6 months for data analysis.

A total of 25 patients will be included.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥ 18 years
  • Patients with COPD and hypercapnia, defined as PaCO₂ > 50 mmHg either chronically or 4 weeks after an acute exacerbation requiring invasive or non-invasive mechanical ventilation
  • Provision of informed consent

Exclusion criteria

  • Progressive neurodegenerative diseases
  • Diaphragmatic disorders
  • Severe hemodynamic instability (>1 vasoactive agent for at least 24 hours)
  • Acute coronary syndrome (unstable angina / myocardial infarction)
  • Severe arrhythmias
  • Presence of contraindications to NIV
  • Cognitive impairment interfering with treatment adherence
  • Active and unstable coronary artery disease
  • Malignancies undergoing active treatment
  • Patients already receiving home non-invasive mechanical ventilation

Treatment and study plan

Primary outcomes

  1. The association between the reduction in PaCO₂ levels and the presence of nocturnal hypoventilation

    Time frame: PaCO₂ (mmHg), measured by ABG - baseline, 3, 6, and 12 months TcCO₂ (mmHg), measured by transcutaneous monitoring - baseline

    The primary outcome is measured through arterial blood gas analysis (ABG) to determine PaCO₂ levels, and through transcutaneous monitoring of oxygen saturation and carbon dioxide (SpO₂ and TcCO₂) to assess the presence of nocturnal hypoventilation.

    Nocturnal hypoventilation is defined as an increase in PaCO₂ during sleep (TcCO₂ >10 mmHg above daytime PaCO₂ with TcCO₂ >50 mmHg for at least 10 minutes, or TcCO₂ >55 mmHg for ≥25% of total sleep time).

Secondary outcomes

  1. Magnitude of esophageal pressure swing during nocturnal monitoring

    Time frame: Baseline

    Placement of a nasogastric respiratory mechanics catheter equipped with an esophageal balloon, and measurement of maximal inspiratory pressure swing (ΔPES).

  2. Diaphragm thickness and diaphragmatic thickening fraction

    Time frame: Baseline

    Assessment of diaphragm thickness variation (TDi-exp, measured from pleural to peritoneal line at end-expiration; normal <1.5 mm suggesting diaphragmatic weakness). Unit of measure: mm

  3. Diaphragmatic thickening fraction

    Time frame: Baseline

    Thickening fraction will be measured with the following formula: TFdi = (inspiratory thickness - expiratory thickness) / expiratory thickness × 100). This outcome will be measure via thoracic ultrasound using a linear probe positioned sagittally along the axillary line at the 8th-9th intercostal space.

  4. Presence of overlap syndrome (COPD + OSA)

    Time frame: Baseline

    Overnight cardiorespiratory monitoring

  5. Radiological classification of COPD subtypes

    Time frame: Baseline

    Data collection from High-resolution computed tomography (HRCT) for morphological evaluation and structural phenotyping (presence or absence of: emphysema, airway-wall thickening, bronchiectasis, air trapping).

  6. Respiratory functional parameters

    Time frame: Baseline, 6 and 12 months

    FEV₁, FVC, FEV₁/FVC ratio measured by spirometry. Unity of measure: L

  7. Respiratory functional parameters

    Time frame: Baseline, 6 and 12 months

    DLCO

  8. Respiratory functional parameters

    Time frame: Baseline, 6 and 12 months

    Resistance at 5 Hz (R5) and Resistance at 20 Hz (R20)

  9. Respiratory functional parameters

    Time frame: Baseline, 6 and 12 months

    6 Minutes Walking Test (6MWT)

  10. Frequency of severe exacerbations

    Time frame: baseline, 6 and 12 months

    number of hospital admissions, ICU admissions, high-dependency unit admissions, and episodes of acute hypercapnic respiratory failure (AHRF) throughout the study period.

  11. Compliance with respiratory treatment

    Time frame: baseline, 6 and 12 months

    number of nights where the respiratory support has been used for at least 4 hours/night divided by the total number of nights during treatment.

Study contacts

Contact information is provided by the study sponsor or research team.

Lara Pisani, PhD

CONTACT

[email protected]

0512143253

Sponsors and collaborators

Lead sponsor

IRCCS Azienda Ospedaliero-Universitaria di Bologna

Other

Registry information

Official study title

Role of Nocturnal Hypoventilation in Predicting the Long-Term Ventilatory Response in Hypercapnic COPD Patients Treated With Non-Invasive Ventilation: A Prospective Observational Study With Clinical, Functional, and Radiological Assessment

Acronym: HYPONIV

Important dates

Study start
2025
Primary completion
2027
Study completion
2028
First posted
Feb 17, 2026
Registry last updated
Feb 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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