Central haemodynamics and regional blood flows during thoracic epidural analgesia combined with positive pressure ventilation. An experimental study in the pig.
Cardiac output, central haemodynamics and regional blood flows were studied in pigs. The microsphere technique was used for blood flow determinations. Measurements were made during spontaneous breathing (SB) and during intermittent positive pressure ventilation with 0.8 kPa (8 cmH2O) positive end-expiratory pressure (8 PEEP) before and during thoracic epidural analgesia (TEA). TEA in the pig caused reduced cardiac output due to reduced heart rate with maintained stroke volume. During TEA there was also a reduction of mean arterial blood pressure which ran almost parallel to the decrease in cardiac output with maintained systemic vascular resistance during SB and at 8 PEEP. The distribution of cardiac output was basically the same during SB and at 8 PEEP as it was before TEA. However, myocardial blood flow and relative perfusion decreased during TEA, both during SB and at 8 PEEP. TEA also reduced spinal cord blood flow within the thoracic region during SB and at 8 PEEP.
Feuk
U
U
Jakobson
S
S
Norlén
K
K
D000698:Analgesia; D000767:Anesthesia, Epidural; D000818:Animals; D001794:Blood Pressure; D002560:Cerebrovascular Circulation; D003326:Coronary Circulation; D006439:Hemodynamics; D008863:Microspheres; D011175:Positive-Pressure Respiration; D012039:Regional Blood Flow; D013552:Swine