Intrathoracic and pulmonary blood volume during CO2-pneumoperitoneum in humans.
BACKGROUND
Induction of CO2-pneumoperitoneum may have significant effects on systemic and pulmonary haemodynamics. We hypothesized that intrathoracic (ITBV) and pulmonary blood volume (PBV) are affected during intra-abdominal CO2-insufflation, which may be pronounced by positional changes of the patient.


METHODS
Sixteen anaesthetized patients were studied before, during and after CO2-pneumoperitoneum for laparoscopic cholecystectomy. A dye indicator technique was used to assess ITBV and PBV. In addition, gas exchange and haemodynamics were recorded.


RESULTS
In the supine position, induction of CO2-pneumoperitoneum had no effects on ITBV, PBV and cardiac output. Mean systemic arterial pressure increased from 10.9 +/- 1.5 kPa (82 +/- 11 mmHg) to 12.7 +/- 1.5 kPa (95 +/- 11 mmHg, P < 0.01). In the reverse Trendelenburg position ITBV decreased from 19.8 +/- 5.1 ml.kg-1 to 16.7 +/- 3.7 ml.kg-1 (P < 0.05) during CO2-insufflation, but increased to control values after 20 min. PBV decreased from 4.2 +/- 1.2 ml.kg-1 to 3.4 +/- 1.1 ml.kg (P < 0.05) and remained decreased during CO2-pneumoperitoneum. Calculated venous admixture was unchanged throughout the study. Deflation of CO2-pneumoperitoneum increased ITBV (22.4 +/- 5.2 ml.kg-1, P < 0.05) and cardiac output above control values.


CONCLUSIONS
In anaesthetized-paralyzed patients in the reverse Trendelenburg position intra-abdominal CO2-insufflation is associated with significant alterations of ITBV and PBV. The release of CO2-pneumoperitoneum is associated with a re-distribution of blood into the thorax.
Hachenberg
T
T
Department of Anaesthesiology, Ernst-Moritz-Arndt-Universität, Greifswald, Germany.
Ebel
C
C
Czorny
M
M
Thomas
H
H
Wendt
M
M
D000005:Abdomen; D000768:Anesthesia, General; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D002245:Carbon Dioxide / Q000008:administration & dosage*; D002302:Cardiac Output / Q000502:physiology; D017081:Cholecystectomy, Laparoscopic; D004396:Coloring Agents; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007202:Indicators and Reagents; D007327:Insufflation; D008168:Lung / Q000502:physiology*; D008875:Middle Aged; D019148:Neuromuscular Blockade; D010100:Oxygen / Q000097:blood; D011028:Pneumoperitoneum, Artificial; D011187:Posture / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D016683:Supine Position / Q000502:physiology; D013909:Thorax / Q000502:physiology*
D004396:Coloring Agents; D007202:Indicators and Reagents; D002245:Carbon Dioxide; D010100:Oxygen