European Journal of Cardio-Thoracic Surgery, Vol 10, 312-319, Copyright © 1996 by European Association for Cardio-thoracic Surgery
Value of body plethysmography in preoperative assessment of thoracotomy candidates
S Scholz, J Sticher, C Knothe and G Hempelmann
Department of Anesthesiology and Intensive Care Medicine, Justus-Liebig- University, Giessen, Germany.
The usefulness of body plethysmography in the assessment of thoracotomy
candidates is not well documented. Reported thresholds for operability are
generally expressed in absolute values, which do not take into account a
patient's size, age or gender. Spirometric and plethysmographic data of 103
patients undergoing thoracotomy were examined for their ability to predict
death due to cardiopulmonary insufficiency, pneumonia, and atelectasis
during the first 30 postoperative days. Neither plethysmographic nor
spirometric parameters could predict atelectasis. Patients who underwent
lobectomy were susceptible to the development of atelectasis. A weak
correlation between elevated functional residual capacity (FRC) and
occurrence of postoperative pneumonia was found. Lung function testing was
not able to separate survivors from non-survivors. Patients with pneumonia
were at high risk of death in their postoperative course. Because of the
non- linear relationship, a correlation coefficient between spirometric and
plethysmographic variables was not calculated. The prevalence of cardiac
risk factors was high, so the decision for invasive hemodynamic studies
should rather be based upon a patient's history than restricted to patients
with impaired lung function. Because of methodological differences, and
probably insuitable reference values, body plethysmography cannot
substitute for spirometry. For FRC and FRC to total lung capacity (FRC/
TLC) ratio, further investigations must be undertaken to establish a
correct reference value.
