The Journal of Thoracic and Cardiovascular Surgery, Vol 86, 388-392, Copyright © 1983 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Facilitation of intrathoracic operations by means of high-frequency ventilation
S Seki, Y Fukushima, K Goto, T Kondo, H Konishi and F Kosaka
Gas exchange was measured in eight patients undergoing high-frequency
ventilation (HFV) during intrathoracic operations for lung cancer. HFV
facilitated the operation because the exposed lung moved only slightly to
ventilate and stayed in a less expanded state. Intermittent positive-
pressure breathing (IPPB) (control) was switched to HFV 20 minutes after
the pleural cavity was opened. HFV either was conducted alone (HFV alone)
or was superimposed on a hypoventilation equal to the dead space (HFV on
VD). The driving pressure and frequency of HFV were set at 0.5 kg/cm2 using
3, 6, and 12 Hz with an FI02 of 0.50. The only statistically significant
difference in arterial PO2 between IPPB and HFV occurred when the HFV alone
was used at 12 Hz. Significant differences in arterial PCO2 values existed
between IPPB and HFV alone when the HFV was at 6 and 12 Hz, and between HFV
alone and HFV on VD at 12 Hz. The arterial pH values were lower at 6 and 12
Hz in HFV alone and were significantly different from pH values during
IPPB. Acidosis was due to the respiratory component of HFV only. The
metabolic component remained unchanged. It was concluded that the gas
exchange was adequately maintained at 3 Hz during HFV alone. The
intrathoracic operation was facilitated by less movement as the frequency
increased, although the lung volume tended to expand. The gas exchange,
particularly the elimination of carbon dioxide, worsened during the use of
HFV alone. However, HFV on VD continued to maintain an adequate gas
exchange and facilitate the operation.
