Graduation Year

2007

Document Type

Dissertation

Degree

Ph.D.

Degree Granting Department

Nursing

Major Professor

Audrey Nelson, Ph.D.

Keywords

Posture, Respiration, Breathing, Seating, Postural management

Abstract

Background: In children with cerebral palsy (CP), poor trunk control fosters spinal deformity, pulmonary compromise (Canet, et al., 1998), increased health risks, and costs of long-term care (Braddock, 2001). Evidence links posture and pulmonary function, but influence of wheelchair parameters on pulmonary mechanics is unknown. Objectives: 1) Determine relative contribution of five wheelchair configuration parameters to improvement in pulmonary mechanics--total airway resistance (RAW), tidal volume, minute ventilation (MV), and deadspace to tidal volume ratio; 2) Describe recruitment and retention of school-aged children with CP; and 3) Discuss response of the participants to the protocol. Method: This within-subjects, descriptive study employed a sample of 8 school-aged children with CP and flexible spines who could not sit alone.

In a single session, participants experienced five seating parameters manipulated in a Prairie wheelchair simulator: 1) left and right upper extremity supports; 2) left and right lateral trunk supports; 3) secured, level, derotated pelvis; 4) tilt in space; and 5) all four parameters. The Viasys Jaeger Impulse Oscillometry System and Respironics Non Invasive Cardiac Output monitor (NICO) measured the dependent variable, pulmonary mechanics, via Hans Rudolph facemasks. Spasticity (by Modified Ashworth Scale), patient characteristics, and medications were recorded. A process log captured participant recruitment and retention challenges and response to protocol. Results: Recruitment was challenging; retention was 50%. For this sample, despite lack of power, both RAW and MV improved with upper extremity and lateral trunk supports. Highest RAW was seen with total absence and total presence of the parameters, and secured, level pelvis.

The data collection protocol was feasible for 50% of participants, none of whom could execute conventional measurement. Facemask and seating simulator acceptability were 75 %, improving with participant verbal communication ability. The facemask seal was vulnerable to tilted positioning; 75% of participants became fatigued. RAW measures differed from manufacturer's directions but were reliable. Conclusions: The Prairie seating simulator, Jaeger IOS, Respironics NICO, and Hans Rudolph facemasks effectively measured pulmonary mechanics as a function of wheelchair seating parameters in this sample. Upper extremity and lateral trunk supports most greatly reduced RAW, maintaining MV. Verbal children tolerated the procedure best.

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