title: The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.
abstract: 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.
authors.affiliation: Department of Anesthesiology, University of Munich, Grobhadern University Hospital, Marchioninistr. 15, D-81377 Munich, Germany. jens.kubitz@med.uni-muenchen.de
authors.forename: Jens C
authors.initials: JC
authors.lastname: Kubitz
authors.forename: Gregor I
authors.initials: GI
authors.lastname: Kemming
authors.forename: Georg
authors.initials: G
authors.lastname: Schultheib
authors.forename: Julia
authors.initials: J
authors.lastname: Starke
authors.forename: Armin
authors.initials: A
authors.lastname: Podtschaske
authors.forename: Alwin E
authors.initials: AE
authors.lastname: Goetz
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Reuter
mesh_terms: 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*