Inspiratory Muscle Strength Training in Infants With Congenital Heart Disease and Prolonged Mechanical Ventilation: A Case Report

Barbara K. Smith; Mark S. Bleiweis; Cimaron R. Neel; A. Daniel Martin

doi:10.2522/ptj.20110348

Figures

Figure 1.

Devices used to evaluate and train inspiratory muscle strength: (A) A unidirectional valve and respiratory monitor adapter was attached directly to the end of the endotracheal tube to measure maximal inspiratory pressure. This device also was used to provide inspiratory muscle strength training to infant 1. (B) An inverted positive end-expiratory pressure valve was used to provide a fixed pressure-threshold inspiratory load for infant 2's inspiratory muscle strength training.

Figure 2.

Example of the pressure-time waveform generated during a 15-second inspiratory occlusion maneuver to evaluate maximal inspiratory pressure (MIP) in infant 2. The most negative pressure was the MIP, and rate of inspiratory pressure development was calculated from the time to generate MIP (red arrows).

Figure 3.

Inspiratory muscle performance of the infants: (A) maximal inspiratory pressure and (B) rate of inspiratory pressure development increased in both infants at the time of extubation. The “Pre” measurements reflect the infants' status at rest, prior to the initial evaluation. The “Post” measurements were taken at rest, prior to the last session of inspiratory muscle strength training and extubation.

Tables

Table.

Resting Breathing Pattern and Respiratory Mechanics^{^a}

↵^a Resting breathing pattern and mechanics were measured with the infant in a calm, awake state every morning with a respiratory monitor (Philips-Respironics CO₂SMO). After inspiratory muscle strength training, infants used a slower, deeper breathing pattern with reduced airway resistance in preparation for ventilator weaning. The “Pre” measurements reflect the infants' status at rest, prior to the initial evaluation. The “Post” measurements were taken at rest, prior to the last session of inspiratory muscle strength training and extubation. IMV=intermittent mandatory ventilation; C_dyn=dynamic compliance, R_awi=dynamic inspiratory airway resistance; R_awe=dynamic expiratory airway resistance; PaO₂/FiO₂=partial pressure of oxygen, arterial/fraction of inspired oxygen, N/A=not applicable.

Supplementary Data

eTables

Files in this Data Supplement:

eTables (PDF) (33 KB) - This PDF contains the following eTables:
- eTable 1. Summary of Hospital Course for Infant 1
- eTable 2. Summary of Hospital Course for Infant 2
- eTable 3. Vital Signs Associated With Training Sessions for Infant 1
- eTable 4. Vital Signs Associated With Training Sessions for Infant 2
- eTable 5. Echocardiogram of Infant 1 on Initial Evaluation
- eTable 6. Echocardiogram of Infant 2
- eTable 7. Detailed Ventilator Settings and Pulmonary Mechanics During the Course of Treatment for Infant 1
- eTable 8. Detailed Ventilator Settings and Pulmonary Mechanics During the Course of Treatment for Infant 2