Patients-ventilator Interaction During Sleep: Effect of Humidification System
Condition: Chronic Hypercapnic Respiratory Failure
MeSH terms: Respiratory Insufficiency; Hypercapnia
Study type: Interventional
Phase: Phase 4

Summary: 
      At present, little data is available in the medical literature regarding the affects of
      humidification on NIMV efficacy, sleep quality and upper airway symptoms in patients
      undergoing nocturnal NIMV.

      The aim of the present pilot study is to assess the impact of two humidification systems on
      sleep quality, NIMV efficacy, patient-ventilator interaction, prevalence of NIMV side
      effects, compliance to treatment, in a group of stable patients already enrolled in a
      long-term nocturnal mechanical ventilation program for chronic hypercapnic respiratory
      failure or sleep hypoventilation.
    

Detailed description: 
      BACKGROUND Non-invasive mechanical ventilation (NIMV), usually delivered during night time,
      is widely used at home in chronic hypercapnic respiratory, both in patients with COPD and
      restrictive thoracic diseases (RTD). The aim of chronic NIMV is to improve daytime arterial
      blood gases, sleep quality decreasing symptoms of hypoventilation (mainly during sleep),
      quality of life and mood.

      Scarce data is available about the NIMV compliance at home; poor compliance may reduce the
      positive effects of mechanical ventilation. Previous data shows that patients enrolled to
      long-term home ventilation program may drop out early, mainly because of skin irritation,
      upper airway problems, and air leaks.

      Studies performed on patients with sleep apnea, receiving CPAP therapy at home, showed that
      the occurrence of leaks during ventilation can cause the development of mucosal inflammation,
      nasal congestion and increased nasal airways resistance. On the other hand, the presence or
      the development of nasal obstruction makes the arise or the worsening of air leaks (the
      vicious cycle) more reliable.

      A lack of humidification may increase nasal resistance and nasal symptoms and, therefore,
      contribute to reduction in compliance. Furthermore, leaks may have significant consequences
      on inspiratory and expiratory trigger functions, inducing poor patient-ventilator
      interactions. Indeed, the presence of ineffective efforts, the most common phenomenon of bad
      patient-ventilation interactions, is very common in patients receiving long term home
      ventilation and usually associated with poorer gas exchange during sleep.

      At present, little data is available in the medical literature regarding the affects of
      humidification on NIMV efficacy, sleep quality and upper airway symptoms in patients
      undergoing nocturnal NIMV.

      The aim of the present pilot study is to assess the impact of two humidification systems on
      sleep quality, NIMV efficacy, patient-ventilator interaction, prevalence of NIMV side
      effects, compliance to treatment, in a group of stable patients already enrolled in a
      long-term nocturnal mechanical ventilation program for chronic hypercapnic respiratory
      failure or sleep hypoventilation.

      PATIENTS We plan to enrol 20 patients with chronic respiratory failure or sleep
      hypoventilation already included in a long-term home non-invasive ventilation program (at
      least 3 months).

      Inclusion criteria Patients in stable conditions (no acute exacerbations in the 4 weeks
      before enrolment), well adapted to ventilation and without problems with the ventilation
      mask.

      Exclusions criteria Patients with acute respiratory failure, recent exacerbations, severe
      co-morbidities (i.e. hearth failure, recent stroke etc.) Recent upper airways surgery.
      Allergic rhinitis, severe nasal stenosis.

      STUDY DESIGN

      Patients will undergo three consecutive nocturnal polysomnographs. Patients will have a
      baseline therapy of NIMV without humidification for 1 week. They will then undergo a
      nocturnal polysomnograph on the last evening of the baseline therapy. Patients will then be
      randomly assigned to use HH or HME for 1 week and undergo a nocturnal polysomnography on the
      last evening . The patients will then be assigned to the second method of humidification for
      1 week and undergo a third nocturnal polysomnograph on the last evening. The whole evaluation
      will be performed with the same ventilator (ideally the patient's device) using the patient's
      mask and with the usual ventilator setting.

      Measures

      At enrolment:

      Lung function test Standard questionnaire about the use and tolerability of NIMV at home
      Measure of NIMV compliance at home Blood gas analysis during wakefulness (during spontaneous
      breathing - SB - and during NIMV) The breathing pattern during wakefulness (during SB and
      NIMV)

      Polysomnographic evaluation

      Full standard assisted polysomnography with simultaneous recordings of Tidal Volume, Leaks,
      pressure in mask, respiratory rate, instantaneous minute ventilation.

      Analysis of sleep data will be performed according to standard criteria (AASM 2007).

      Analysis of breathing pattern and patients-ventilator interaction will be made according to
      previous published methods (Fanfulla, Tuggey, Techsler etc..).

      At the end of the each PSG recording, patients will be asked about their humidification and
      NIMV tolerance as well as the presence of upper airway symptoms (Nava et al).
    

Intervention name(s): heated humidification; heat and moisture exchanger; usual mechanical ventilation without humidification
Intervention type(s): Device; Device; Device
Intervention description(s): temperature 35°; single patient device; mechanical ventilation with usual parameters
Other intervention name(s): HH; HME; control
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: chronic hypercapnic respiratory failure; COPD; RTD; sleep architecture; humidification