Chest
Volume 104, Issue 5, November 1993, Pages 1553-1562
Journal home page for Chest

Clinical Investigations in Critical Care: Comparative Study: Journal Article: Research Support, U.S. Gov't, P.H.S.
Mechanical Insufflation-Exsufflation: Comparison of Peak Expiratory Flows With Manually Assisted and Unassisted Coughing Techniques

https://doi.org/10.1378/chest.104.5.1553Get rights and content

Pulmonary complications are major causes of morbidity and mortality for patients with severe expiratory muscle weakness. The purpose of this study was to compare peak cough expiratory flows (PCEFs) during unassisted and assisted coughing and review the long-term use of mechanical insufflation-exsufflation (MI-E) for 46 neuromuscular ventilator users. These individuals used noninvasive methods of ventilatory support for a mean of 21.1 h/d for 17.3±15.5 years. They relied on manually assisted coughing and/or MI-E during periods of productive airway secretion. They reported a mean of 0.7±1.2 cases of pneumonia and other serious pulmonary complications and 2.8±5.6 hospitalizations during the 16.4-year period and no complications of MI-E. A sample of 21 of these patients with a mean forced vital capacity of 490±370 ml had a mean maximum insufflation capacity (MIC) achieved by a combination of air stacking of ventilator insufflations and glossopharyngeal breathing of 1,670±540 ml. The PCEFs for this sample were: following an unassisted inspiration, 1.81 ± 1.03 L/s; following a MIC maneuver, 3.37±1.07 L/s; with manual assistance by abdominal compression following a MIC maneuver, 4.27±1.29 L/s; and with MI-E, 7.47±1.02 L/s. Each PCEF was significantly greater than the preceding, respectively (p<0.001). We conclude that manually assisted coughing and MI-E are effective and safe methods for facilitating airway secretion clearance for neuromuscular ventilator users who would otherwise be managed by endotracheal suctioning. Severely decreased MIC, but not necessarily vital capacity, is an indication for tracheostomy.

Section snippets

Patients and Methods

Forty-six ventilator-dependent individuals who used noninvasive IPPV techniques and relied on MI-E for airway secretion clearance were surveyed for the frequency of MI-E utilization, difficulties encountered, and intercurrent episodes of pneumonia, and hospitalizations. These 46 patients had the following diagnoses: postpoliomyelitis, 24; pseudohypertrophic muscular dystrophy, 9; spinal cord injury, 5; non-pseudohypertrophic muscular dystrophy myopathies, 5; spinal muscular atrophy,

Results

Of the 46 patients studied, 33 used MI-E as necessary on about 10 to 35 separate occasions, 11 stated that manually assisted coughing was usually adequate so they had used MI-E on several occasions, and two with severely impaired oropharyngeal musculature and a tendency to aspirate used MI-E on a daily basis to clear aspirated food and secretions. None of the patients reported episodes of air collection under the skin of the neck or chest (mediastinal emphysema), lung collapse (pneumothorax),

Discussion

The small physiologic volume of respiratory mucus can normally be easily transported by the mucociliary elevator.40 During RTIs, however, the elevator is overwhelmed and effective PCEF must be generated to avoid mucus plugging and pulmonary complications. Although mucus plugging41, 42 and other difficulties may be associated with long-term tracheostomy,8, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 resorting to strictly noninvasive ventilatory support methods with removal of the tube eliminates

References (67)

  • WilliamsEK et al.

    The use of exsufflation with negative pressure in postoperative patients

    Am J Surg

    (1955)
  • SegalMS et al.

    Alternating positive-negative pressures in mechanical respiration (the cycling valve device employing air pressures)

    Dis Chest

    (1954)
  • CamarataSJ et al.

    The use of enzymes and wetting agents in the treatment of pulmonary atelectasis

    Dis Chest

    (1956)
  • AlexanderMA et al.

    Mechanical ventilation of patients with late stage Duchenne muscular dystrophy: management in the home

    Arch Phys Med Rehabil

    (1979)
  • CurranJF et al.

    Ventilator management in Duchenne muscular dystrophy and postpoliomyelitis syndrome: twelve years' experience

    Arch Phys Med Rehabil

    (1989)
  • ViroslavJ et al.

    Alternatives to tracheostomy ventilation in high level SCI [abstract]

    J Am Paraplegia Soc

    (1991)
  • McDermottI et al.

    Custom-fabricated interfaces for intermittent positive pressure ventilation

    Int J Prosthodont

    (1989)
  • BachJR et al.

    Strapless oral-nasal interfaces for positive pressure ventilation

    Arch Phys Med Rehabil

    (1990)
  • Bach JR. A comparison of long-term ventilatory support from the perspective of the patient and care giver. Chest (in...
  • ForbesJA

    Management of respiratory paralysis using a “mechanical cough” respirator

    Br Med J

    (1958)
  • CherniackRM et al.

    The clinical use of the exsufflator attachment for tank respirators in poliomyelitis

    Ann Intern Med

    (1954)
  • Mier-JedrzejowiczA et al.

    Respiratory muscle weakness during upper respiratory tract infections

    Am Rev Respir Dis

    (1988)
  • EidN et al.

    Chest physiotherapy in review

    Respir Care

    (1991)
  • van der SchansCP et al.

    Effect of manual percussion on tracheobronchial clearance in patients with chronic airflow obstruction and excessive tracheobronchial secretion

    Thorax

    (1986)
  • GrahamWGB et al.

    Efficacy of chest physiotherapy and intermittent positive-pressure breathing in the resolution of pneumonia

    N Engl J Med

    (1978)
  • BatemanJRM et al.

    Is cough as effective as chest physiotherapy in the removal of excessive tracheobronchial secretions?

    Thorax

    (1981)
  • de BoeckC et al.

    Cough versus chest physiotherapy: a comparison of the acute effects on pulmonary function in patients with cystic fibrosis

    Am Rev Respir Dis

    (1984)
  • LeinerGC et al.

    Expiratory peak flow rate: standard values for normal subjects

    Am Rev Respir Dis

    (1963)
  • LeithDE

    Cough

  • KingM et al.

    Clearance of mucus by simulated cough

    J Appl Physiol

    (1985)
  • FeigelsonCI et al.

    Glossopharyngeal breathing as an aid to the coughing mechanism in the patient with chronic poliomyelitis in a respirator

    N Engl J Med

    (1956)
  • KirbyNA et al.

    An evaluation of assisted cough in quadriparetic patients

    Arch Phys Med Rehabil

    (1966)
  • Anonymous. The OEM Cof-flator portable cough machine. St. Louis: Shampaine...
  • Cited by (0)

    This work was funded by the Department of Health and Human Services, Food and Drug Administration, Orphan Products Development grant FD-R-000649-01.

    View full text