The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.
The pre-ejection period (PEP) has recently been described as a potential parameter for monitoring cardiac preload. This study further investigated the influence of changes in intravascular volume status and the application of positive end-expiratory pressure (PEEP) on the pre-ejection period. In ten pigs, ECG, arterial pressure and stroke volume derived from an aortic flowprobe were registered. Global end-diastolic volume (GEDV) was measured by transcardiopulmonary thermodilution. Total blood volume (TBV) and intrathoracic blood volume (ITBV) were measured by the dye-dilution technique. Measurements were performed during normovolaemic conditions, after volume loading with haemodilution blood (20 ml kg(-1)) and following haemorrhage (30 ml kg(-1)) without PEEP and with PEEP (15 cm H(2)O) applied. Volume loading increased GEDV, ITBV, TBV and SV, whereas PEP remained constant. However, the changes were not significant (P > 0.05). Subsequent haemorrhage significantly decreased GEDV (from 436 to 308 ml), ITBV (from 729 to 452 ml), TBV (from 2,131 to 1,488 ml) (all P-values <0.05), and SV (from 20.7 ml to 14.3 ml, P < 0.001). However, PEP did not change significantly (from 73 to 82 ms, P > 0.05). No correlation between the changes in PEP and changes in any other variable was observed. It is concluded that PEP is not sensitive to the changes in intravascular volume status.
Kubitz
Jens C
JC
Department of Anesthesiology, University of Munich, Grobhadern University Hospital, Marchioninistr. 15, D-81377 Munich, Germany. jens.kubitz@med.uni-muenchen.de
Kemming
Gregor I
GI
Schultheib
Georg
G
Starke
Julia
J
Podtschaske
Armin
A
Goetz
Alwin E
AE
Reuter
Daniel A
DA
D000818:Animals; D001794:Blood Pressure; D001810:Blood Volume; D001811:Blood Volume Determination / Q000379:methods*; D002302:Cardiac Output; D004195:Disease Models, Animal; D020896:Hypovolemia / Q000175:diagnosis* / Q000503:physiopathology*; D011175:Positive-Pressure Respiration / Q000379:methods*; D013223:Statistics as Topic; D013318:Stroke Volume; D013552:Swine; D013815:Thermodilution / Q000379:methods*