Evaluation of Gas Exchange by the Measurement of Lung Diffusion for Carbon Monoxide During General Anaesthesia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01503879
Recruitment Status : Unknown
Verified August 2012 by Prof. Roberto Fumagalli's, San Gerardo Hospital.
Recruitment status was:  Recruiting
First Posted : January 4, 2012
Last Update Posted : August 29, 2012
Information provided by (Responsible Party):
Prof. Roberto Fumagalli's, San Gerardo Hospital

Brief Summary:

Mechanical ventilation is a therapeutic method used in order to keep gas exchange adequate to cell metabolism in patients with acute respiratory failure. It is currently proved that, although on one hand the use of this method keeps gas exchange, on the other hand it promotes and supports pulmonary inflammatory processes (VILI). A recent study about the effect of positive end-expiratory pressure (PEEP) on DLCO (diffusing capacity of the lung for carbon monoxide) in patients undergoing invasive mechanical ventilation has proved that patients without any evident pulmonary disease (negative medical history, negative chest clinical examination, normal chest X-ray radiography and normal arterial oxygen tension [PaO2]) after 24 hours of invasive mechanical ventilation show a significant worsening of pulmonary gas exchange properties. The authors have supposed that this worsening may be caused by an early alteration of alveolar-capillary membrane caused by mechanical ventilation itself. This hypothesis finds support in some studies carried out on animal models which founds that mechanical ventilation, even when low tidal volumes (Vt) are set for a few hours, is able to induce lung injury (as shown by histologic findings). The most sensitive and specific tools the investigators can currently rely on for the study of alveolar-capillary membrane are the measurement of diffusing capacity of the lung for carbon monoxide (DLCO) and the evaluation of plasmatic levels of pulmonary surfactant protein B (SPB). DLCO is a standard, widely diffused technique for the evaluation of functional alterations of alveolar-capillary membrane and it is currently available also for patients undergoing invasive mechanical ventilation. SBP is produced by type II pneumocytes in the alveoli. An increase of its plasmatic levels is correlated to a decay of pulmonary gas exchange; SPB thus can be considered an alveolar-capillary membrane anatomical damage marker.

The primary end-point of this study is to evaluate the changes of anatomical (SPB) and functional (DLCO) features of alveolar-capillary membrane between the spontaneous breathing and mechanical ventilation as well as the progressive changes affecting DLCO and SPB over time during general anaesthesia and mechanical ventilation in patients with otherwise healthy lung undergoing elective surgery. This in order to check the timing of the observed worsening of alveolar-capillary membrane function, and to find out if the process is progressive in time.

The secondary end point is to check if the alterations of functional features of alveolar membrane (DLCO) are proportionate to the increase of alveolar injury marker (SPB), in order to understand if the worsening of alveolar-capillary membrane function is to be attributable to an anatomical damage or to a physiologic change of the ventilation-perfusion matching.

Condition or disease
Lung Diffusion Acute Respiratory Failure

Study Type : Observational
Estimated Enrollment : 20 participants
Time Perspective: Prospective
Official Title: Effects of General Anaesthesia and Invasive Mechanical Ventilation on Alveolo-capillary Membrane: Evaluation of Gas Exchange by the Measurement of Lung Diffusion for Carbon Monoxide (DLCO) and Plasma Dosage of Surfactant Protein-B (SPB).
Study Start Date : October 2011
Estimated Study Completion Date : October 2012

Biospecimen Retention:   Samples Without DNA
surfactant protein B

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Patients undergoing elective surgery lasting more than three hours, requiring general anaesthesia and invasive mechanical ventilation.

Inclusion Criteria:

  • over 18 years of age
  • undergoing a non-thoracic, non-laparoscopic surgery, lasting more than three hours and requiring general anaesthesia and invasive mechanical ventilation

Exclusion Criteria:

  • COPD 3 Gold stage or above
  • ASA physical status classification system 4 or above
  • heart failure NYHA 2 or above
  • chronic kidney disease
  • axillary temperature over 38 °C
  • BMI over 30 kg/m^2
  • pregnancy or breastfeeding

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01503879

Contact: Roberto Fumagalli, MD +390392339269

Ospedale San Gerardo Recruiting
Monza, MB, Italy
Contact: Roberto Fumagalli, MD    +390392339269   
Principal Investigator: Roberto Fumagalli, MD         
Sponsors and Collaborators
San Gerardo Hospital
Principal Investigator: Roberto MD Fumagalli Milano Bicocca University

Responsible Party: Prof. Roberto Fumagalli's, MD, San Gerardo Hospital Identifier: NCT01503879     History of Changes
Other Study ID Numbers: ARHSG 10 2010 DLCO1
First Posted: January 4, 2012    Key Record Dates
Last Update Posted: August 29, 2012
Last Verified: August 2012

Keywords provided by Prof. Roberto Fumagalli's, San Gerardo Hospital:
general anaesthesia
invasive mechanical ventilation

Additional relevant MeSH terms:
Respiratory Insufficiency
Respiratory Distress Syndrome, Adult
Respiration Disorders
Respiratory Tract Diseases
Lung Diseases
Carbon Monoxide
Central Nervous System Depressants
Physiological Effects of Drugs
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents