• Respiratory movement measuring instrument : reliability, reference values and clinical utility [PhD Thesis]

      María Ragnarsdóttir (University of Iceland, Faculty of Medicine, 2008)
      Methods to evaluae respiratory function such as inspection, palpation, tape measurements, auscultation, chest radiographs and lung volume measurements have been used for a long time. During the last decades several additional evaluation methods have emerged measuring for example respiratory muscle strength and movements. However, few instruments measuring real time bilateral respiratory upper thoracic, lower thoracic and abdominal movements are available and none measuring simultaneously all variables of the respiratory movement pattern. The aims of the studies were to develop an instrument to measure respiratory movements and test its reliability. The instrument, Respiratory Movement Measuring Instrument (RMMI), was developed at the Bioengineering Department at Landspitali University Hospital according to the ideas of the author. Furthermore, to collect reference values for the instrument and investigate its usefulness in clinical practice. The RMMI was used to measure respiratory motion among two groups of healthy individuals in order to obtain reference values and test the reliability of the measurements. To test the clinical usefulness, a group of patients with ankylosing spondylitis (AS) and patients undergoing cardiac surgery (pre- and postoperatively) were studied. Respiratory motion, and lung volumes were measured and abnormal signs on chest radiographs rated among the cardiac surgery patients pre-operatively and one, 12, and 52 weeks postoperatively. Respiratory movements did not decrease significantly with increasing age from 20 to 69 years. The only significant gender difference was that the men had significantly greater abdominal motion during deep breathing. Separate reference values are therefore presented for males and females. Correlations of respiratory movements measured on two consecutive days was strong for both quiet and deep breathing. The AS patients had significantly reduced upper thoracic movements compared with reference values. The cardiac surgery patients had highly significantly reduced average lung volumes, abdominal and lower thoracic movements and showed one or more abnormal sign on a chest radiograph one week post-operatively. Twelve weeks after the operation average abdominal movement was still significantly reduced, but upper thoracic movement had increased. One year after the operation abdominal movement had still not fully recovered but average upper thoracic movement was significantly increased. When the cardiac surgery patients were divided into Mediangroup and IMA-group according to surgical procedure, abdominal motion was significantly more reduced among the IMA-group 12 weeks post-operatively. Both groups had symmetrical abdominal motion pre-operatively, but significantly asymmetrical among the IMA-group 12 week post-operatively. Both groups had symmetrical abdominal movements 52 weeks post-operatively, but the IMA-group had significantly reduced abdominal movements. Abdominal movements were still significantly decreased compared with pre-operative values one year after cardiac surgery. The RMMI is a reliable instrument and is easy to use in clinical practice for measuring respiratory movement and respiratory movement pattern.