European Journal of Cardio-Thoracic Surgery, Vol 9, 237-241, Copyright © 1995 by European Association for Cardio-thoracic Surgery
Altered regulation of breathing after bilateral lung transplantation
IP Mattila, A Sovijarvi, P Malmberg, L Heikkila, J Sipponen, LA Laitinen and SP Mattila
Department of Thoracic Surgery, Helsinki University Hospital, Finland.
In our previous animal studies on dogs, regulation of breathing was found
to be altered after en bloc transplantation of the heart and both lungs.
During carbon dioxide (CO2) inhalation the minute volume was increased due
to an increase of tidal volume after transplantation whereas before
transplantation both respiratory frequency and tidal volume increased. The
success of the heart-lung transplantation was based on experiments on
baboons as no long-term survivors were obtained in dogs. It was thought
that the regulation of breathing is different in dogs and primates. We
therefore decided to study the regulation of breathing in humans after
bilateral lung transplantation during CO2 stimulation. The regulation of
breathing was tested 2 to 4 months after bilateral lung transplantation in
six patients. Six healthy subjects with intact lungs were tested as
controls. The test persons were allowed to breathe first room air, then 5%
CO2 in air for 4 min and then room air again. The frequency of respiration,
tidal volume and minute ventilation were recorded using a
phneumotachograph. Simultaneously samples of arterial blood were drawn from
a cannulated brachial artery for analysis of pressure of arterial oxygen
(PaO2), pressure of arterial carbon dioxide (PaCO2), base excess (BE) and
pH. During inhalation of CO2 for 4 min the minute volume doubled in both
transplant patients and in controls. The tidal volume of the transplant
patients increased significantly more than that of the controls (P <
0.005) whereas respiratory frequency increased significantly only in the
controls with intact lungs (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
