Systematic evaluation of different approaches for minimizing hemodynamic changes during pneumoperitoneum.
BACKGROUND
Capnoperitoneum (CP) compromises hemodynamic function during laparoscopy. Three therapeutic concepts were evaluated with an aim to minimize the hemodynamic reaction to CP: First, a controlled increase of intrathoracic blood volume (ITBV) by intravenous fluids; second, partially reduced sympathetic activity by the beta1-blocker esmolol; and third, a decrease in mean arterial pressure (MAP) by the vasodilator sodium nitroprusside.


METHODS
For this study, 43 pigs were assigned to treatment with fluid and sodium nitroprusside (group A) or with esmolol (group B). In both groups, the pigs were assigned to head-up, head-down, or supine position, resulting in three different subgroups. Invasive hemodynamic monitoring was established including left heart catheter and cardiac oxygen lung water determination (COLD) measurements. Measurements were documented before CP with the animals in supine position, after induction of a 14-mmHg CP with the animals in each body position, after a 10% reduction in MAP by vasodilation, and after an increase in ITBV of about 30% by infusion of 6% hydroxyethylstarch solution.


RESULTS
Increasing ITBV improved hemodynamic function in all body positions during CP. Esmolol reduced cardiac output and myocardial contractility. Sodium nitroprusside did not improve hemodynamic function in any body position.


CONCLUSIONS
Optimizing volume load is effective for minimizing hemodynamic changes during CP in the head-up and in head-down positions. In general, beta(1)-blockers cannot be recommended because they might additionally compromise myocardial contractility and suppress compensatory reaction of the sympathetic nerve system. Vasodilation has not improved hemodynamic parameters during CP.
Junghans
T
T
Department of General, Visceral, Vascular, and Thoracic Surgery, Charité Universitary Medicine, Campus Mitte, Schumannstrasse 20/21, Berlin, 10117, Germany. tido.junghans@charite.de
Modersohn
D
D
Dörner
F
F
Neudecker
J
J
Haase
O
O
Schwenk
W
W
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume; D002245:Carbon Dioxide; D005440:Fluid Therapy / Q000379:methods; D006439:Hemodynamics; D007275:Injections, Intravenous; D009599:Nitroprusside / Q000627:therapeutic use; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011315:Preventive Medicine / Q000379:methods*; D011412:Propanolamines / Q000627:therapeutic use; D013552:Swine; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology; D014665:Vasodilator Agents / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D014665:Vasodilator Agents; D002245:Carbon Dioxide; D009599:Nitroprusside; C036604:esmolol