Transcript Slide 1

Hematocrit During the Cardiopulmonary Bypass: Impact
on Clinical Outcome During Ascending Aortic Surgery
SF Zhou MD1, AL. Estrera MD2, T Pawelek MD1, C Ignacio MD1, S
Panthayi MD1, MD; K Shebaclo BS1, H Safi MD2, R Sheinbaum MD1
Department of Anesthesia1
Department of Cardiothoracic and Vascular Surgery2
The University of Texas Medical School at Houston
Memorial Hermann Heart & Vascular Institute
Introduction
 Blood transfusions worsen clinical outcomes in
aortic surgery.
 Hemodilutional anemia increases organ
ischemia risk.
 We show the lowest hematocrit (Hct) that
reduces transfusion and prevents hemodilution
associated complications.
Methods
 We reviewed 399 cases of Ascending Aortic
(Aneurysm or Type A dissection) repair with
deep hypothermic circulatory arrest (DHCA).
 Demographics and surgical characteristics
(except age) were similar between groups.
 Patient ages were 17-89 and are grouped by Hct
<16%, <18%, 19%-20%, 21%-22%, > 23% at
temperature < 20C, 20-28C, 28-32C, 3234C, 34-35C during CPB.
Methods
 Databases were established by collecting medical
information through patient medical records and 2010
ICD-9-CM Volume 1 Diagnosis Codes, including
complications of surgical and medical care, not
elsewhere classified 996-999 and diseases of the
specific system or organ.
 The data analysis was by mean ( standard deviation) for
continuous variables and by frequency (percentage) for
qualitative variables. Two-sample t-test or Chi-Square
test was used to compare groups with P-value of less
than 0.05 considered significant.
Results
 Changes in outcome were suggested at Hct <16%
versus >16% at <20C during DHCA and also for
Hct <18% versus>18% at temperature 20-28 C.
 Risk of ARF and postoperative tracheotomy
increased with Hct < 16 (Table 2).
 Chance of discharge home improved with higher
Hct at all temperatures (Table 3). Mortality
decreased at Hct 21-22% at 20-34C and increased
at Hct <16% during DHCA (Table 4).
Results
Results
Conclusion
 Patient temperature affects oxygen demand, blood
viscosity, oxygen carrying capacity and delivery.
 Hct value is a transfusion trigger and should change
with body temperature during aortic surgery.
 Hct 21-22% appears favorable for CPB at 20-34C.
 Hct <16% during DHCA increases mortality.
 Hct <18% during rewarming (20-32C) increases
postoperative ARF risk.