Left ventricular hemodynamic effects of rapid, in utero intravascular transfusion in anemic fetal lambs.
We investigated the acute hemodynamic effects of in utero fetal intravascular transfusion in anemic fetuses. A conductance catheter technique of measuring left ventricular (LV) volume and pressure-volume analysis was employed in six anemic ovine fetuses of 131 days gestation (range 131-133 days). The mean fetal weight at necropsy was 3,795 +/- 166g. An intravascular transfusion of 120 ml packed maternal red cells was given over 12 minutes (rate of 2.6 +/- 0.1 ml/kg/min) increasing the hematocrit from 22.5 +/- 1.3% to 41.8 +/- 0.8%. The infusion of packed red cells leads to an approximate increase in blood volume of 30%. Heart rate, left ventricular stroke volume, and contractility, as assessed by end-systolic elastance, did not change significantly with transfusion. Left ventricular afterload, as assessed by effective arterial elastance, increased from 11.4 +/- 1.4 to 18.6 +/- 2.8 (P < 0.01) mmHg/ml with transfusion, returning to baseline levels by 60 minutes posttransfusion. During the transfusion, end-diastolic pressure increased from 4.1 +/- 0.4 to 10.6 +/- 0.8 (P < 0.01) mmHg and end-diastolic volume increased from 2.0 +/- 0.3 to 2.9 +/- 0.5 ml/kg. However, by 60 minutes posttransfusion, end-diastolic pressure had returned to baseline levels, whereas end-diastolic volume remained elevated at 3.2 +/- 0.6 ml/kg. We conclude that the persistent increase in end-diastolic volume implies a possible increase in LV diastolic compliance.
Kilby
M D
MD
Academic Department of Obstetrics and Gynaecology and Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Canada. m.d.kilby@bham.ac.uk
Szwarc
R S
RS
Benson
L N
LN
Morrow
R J
RJ
D000740:Anemia / Q000628:therapy*; D000818:Animals; D001794:Blood Pressure; D001805:Blood Transfusion, Intrauterine; D002302:Cardiac Output; D005260:Female; D005315:Fetal Diseases / Q000503:physiopathology* / Q000628:therapy; D006339:Heart Rate; D006352:Heart Ventricles / Q000196:embryology / Q000503:physiopathology; D006439:Hemodynamics; D009200:Myocardial Contraction; D011247:Pregnancy; D012756:Sheep / Q000196:embryology; D013318:Stroke Volume; D016277:Ventricular Function, Left