Original research
Clinical Implications of Assisted Peak Cough Flow Measured With an External Glottic Control Device for Tracheostomy Decannulation in Patients With Neuromuscular Diseases and Cervical Spinal Cord Injuries: A Pilot Study

https://doi.org/10.1016/j.apmr.2016.02.023Get rights and content

Abstract

Objective

To investigate the clinical usefulness and significance of an external control device substituting for glottic function in determining the feasibility of decannulation in tracheostomized patients with neuromuscular diseases and cervical spinal cord injuries whose assisted peak cough flow (APCF) was unmeasurable or <160L/min.

Design

Before-after trial.

Setting

Inpatient setting in a university hospital.

Participants

Tracheostomized patients (N=16; 11 with neuromuscular diseases and 5 with cervical spinal cord injuries) were recruited.

Interventions

Unassisted peak cough flow (UPCF) and APCF were measured with and without an external glottic control device. Among patients whose APCF without the device was <160L/min, if their APCF with the device was measured as ≥160L/min, they were decannulated. After decannulation, UPCF and APCF were measured again.

Main Outcome Measures

APCF with and without an external glottic control device as well as APCF after decannulation.

Results

After successful decannulation, APCFs were greater than or equal to those measured with the device before decannulation. No patients underwent intubation or retracheostomy, and there were no respiratory complications.

Conclusions

The external glottic control device substituting for innate glottic function is beneficial for determining tracheostomy decannulation. It provides an objective and accurate APCF. It is particularly helpful for patients whose APCF is ≥160L/min while using the device, even if APCF is <160L/min without this device.

Section snippets

Patients

This study included patients with neuromuscular diseases and cervical spinal cord injuries who were tracheostomized and did not satisfy the criterion for decannulation of an APCF of 160L/min, the minimum value necessary for adequate clearance of secretions. They were admitted to the Department of Rehabilitation Medicine at Gangnam Severance Hospital from February 1, 2009 to September 30, 2014. Among patients whose APCF with the tracheostomy tube in place was too low to be measured or <160L/min,

Characteristics and ventilatory status of the patients

During the research period, there were 62 candidates with neuromuscular diseases and cervical spinal cord injuries who met the requirements of decannulation, except APCF. In 26 patients (41.9%), APCF was ≥160L/min without assistance of the device. And in 20 patients (32.3%), APCF could not reach 160L/min even with the use of this device. Therefore, the other 16 patients (25.8%) met the inclusion criteria for this study and were analyzed. The mean age of patients was 43.9 years (range, 19–76y),

Discussion

The process of cough consists of inspiratory, compressive, and expiratory phases.20, 21 The air that is deeply inhaled in the inspiratory phase is trapped in the airway by the closing of the glottis in the compressive phase. With the action of expiratory muscles, intra-thoracic pressure is increased, and by the sudden opening of the glottis, a cough is induced. If any of the 3 phases is impaired, a cough cannot be induced effectively. Inspiratory and expiratory phases of cough can be supported

Conclusions

This study indicates that an external control device substituting for glottic function is beneficial for determining tracheostomy decannulation because it provides an objective and accurate measurement of APCF. Therefore, this device is helpful, particularly in patients whose APCF is ≥160L/min while using the device, even if APCF is <160L/min without this device.

Supplier

  • a.

    Philips Respironics.

References (22)

  • J.R. Bach et al.

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    (2004)
  • Cited by (0)

    Supported by a faculty research grant from the Yonsei University College of Medicine for 2014 (grant no. 6-2014-0015).

    Disclosures: S.-W.K. holds a patent for a device for assisting cough and lung expansion in patients with paralytic bulbar musculature (patent no. 100516324). The other authors have nothing to disclose.

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