Department of Anesthesiology
GENDER DIFFERENCE IN BLOOD
VOLUME IN PATIENTS
UNDERGOING CABG SURGERY
Mamatha Punjala, Chiedozie
Udeh, Murali Pagala, Changa Tyagaraj, Abdelhamid Elfaham, Ketan Shevde
Presented at the Post
Graduate Assembly in Anesthesiology in New York, Dec. 11-15
Females require more blood transfusion than males
during coronary artery bypass graft (CABG) surgery. Recently we have shown
that this gender difference is due to a combined effect of age, body
surface area (BSA), hematocrit, and duration of surgery (Keshikar et al.,
1999). This ongoing study was undertaken to assess whether differences in
blood volume (BV), R13C volume (RV), and plasma volume (PV) also
contribute to gender difference. Volumes of blood components. were
determined using a BVA-100 blood volume analyzer (DAXOR, Corporation). For
9 males, the mean BV was 4329 ± 197, RV 1506 ± 70, and PV 2670 ± 106.
Whereas for 5 females, the respective values were lower by 12% (P<0.009),
34% (P<0.001), and 11% (P>0.05). When these values, were corrected for BSA,
the RV was lower by 25% (P<0.001) in females than in males. These results
indicate that lower RBC mass in females is a significant factor in
determining their greater requirement for blood transfusion.
Determine whether male and female CABG patients have
different volumes of total blood, RBCs and plasma.
This prospective study involved 34 consenting CABG
patients: 21 males and 13 females. Patients with multiple procedures or
reoperations were excluded.
Each patient received intravenously 1 ml of Albumin
containing 25 µC
of I-131. Five ml blood samples were collected before, and 12, 17, 22, 30,
and 35 min after the injection One ml serum samples were loaded into DAXOR
BVA-100 Blood Volume Analyzer. Based on radioactivity in samples and
standard, the volumes of total blood, RBCs, and plasma were determined for
68.1 ± 1.9
68.9 ± 2.4
80.2 ± 2.5
71.2 ± 3.8*
1.98 ± 0.04
1.76 ± 0.05
Preopt HCT (%)
38.1 ± 1.3
33.4 ± 0.8*
significantly lower volumes of total blood, RBCs, and plasma than males.
Even when the values were
expressed per unit BSA, females still had significantly lower volumes of
total blood and RBCs.
Lower blood and RBC volumes in females may account
for their greater need for transfusion compared to male CABG patients.
Kashikar A., et al. Anethesiology 89:A245, 1998.