Improved coagulation after cardiopulmonary bypass using the Hemobag

1
Improved Coagulation After Cardiopulmonary Bypass
Using the Hemobag Scott R. Beckmann,
B.S.,C.C.P. Thomas Winkler, M.D., William Shely,
M.D., Salem Hospital, Salem, OR, 97301 USA
Introduction
Hemobag and allogeneic blood use
Preserving blood components
Discussion
There are increasing international stresses
within healthcare regarding the allogeneic blood
supply, its use and associated costs and
morbidity (1). The concern is arguably one of
greatest in the cardiac surgery arena today (2).
Improved blood administration practices have
been encouraged by multiple professional
societies whose members provide cardiac surgical
care. (3-4). There are vast differences in
transfusion practices between cardiac surgical
facilities throughout the world (5). As well,
there are numerous blood conservation maneuvers
that are employed during cardiac surgery that
have not been widely adopted as standard of care
(6-8). Patient data from an underutilized
ultrafiltration technique (the Hemobag) to
process residual extracorporeal circuit blood is
presented as an example of a means to reduce
allogeneic blood related risks and costs
(9). This technology allows for the infusion of
shed / residual blood without creating
disturbances in hemodynamic or biochemical
parameters, and avoidance of clinical
complications or any increase in morbity (9-10,
16-17). Further studies indicate that in over
50 of patients, FFP transfusion does not
reliably reduce the PT or INR and exposes
patients to unnecessary risk (18-19).
The Hemobag Blood Salvage Device is a reservoir
system that allows the patients own whole blood
to be salvaged, quickly hemoconcentrated and
safely infused. It efficiently uses the same
convenient reservoir bag while insuring CPB
circuit integrity for reinstituting bypass safely
and securely, if necessary.
Most allogeneic blood products are transfused in
the first few perioperative hours and often based
upon arbitrary clinical observations without
adequate documentation of the need for blood bank
components (3). The results of this case series
strongly suggest that cardiac surgery patients
may be spared donor exposures when the residual
bypass circuit blood is highly concentrated and
quickly reinfused as compared to cell washing
(9-10). Use of the Hemobag for salvaging blood
is associated with significant increases in the
patients protein and cellular concentrations,
that would have normally been discarded (average
of costs of lost proteins /- 4,000USD) (15) thus
lowering coagulation times in the important,
first few hours following CPB (11-14). Use of
multi-pass ultrafiltration (UF) to process the
residual perfusion circuit blood far exceeds the
results of single-pass ultrafiltration methods.
This technique has improved our blood
administration practices and helped avoid many
unnecessary transfusions. The Hemobag patients
obtained significantly improved coagulation
parameters with far fewer blood products than
were required in the non-HB patients. The
Hemobag provides patients with improved quality
of care through the reduction of allogeneic blood
products. Frequently, transfusions are directly
related to costly, negative, patient outcomes and
in many cases can be avoided (20). The Hemobag
now offers perfusionists a new role in optimizing
homeostasis coagulation in the first few
critical hours after the termination of
cardiopulmonary bypass.
Table 1
Figure 1
QUICK VOLUME LINE FOR ANESTHESIA OR TO THE FIELD
(if necessary)
Table 2
Method
Results
Table 1 lists the patient-by-patient allogeneic,
ANH, ATS and Hemobag volumes used in the few
hours immediately post-protamine sulfate
infusion. Figure 2 shows the difference between
CPB and HB blood parameters. Table 2 presents
the results of the statistical analysis of the
differences between groups. Except for PTT, all
parameters changed significantly from the
post-protamine and HB, ATS and ANH blood infusion
to approximately one hour after and arrival in
the ICU. Figure 3 reports the cost savings by
employing the Hemobag. Fibrinogen and Hct
(Figure 4) were significantly higher in the HB
group at the end of the first ICU hour.
Significant reductions in PT and INR were also
observed after HB content infusion however, there
was only a strong trend in decreased average PTT.
NHB patients required significantly more donor
blood products than the HB patients where nine of
the ten patients required no allogeneic blood
during their hospital stay.
A prospective, evenly matched two-cohort case
series design was constructed. Hematocrit,
platelet count, fibrinogen concentration (Fib),
PT, PTT and INR values were compared in 10
Hemobag (HB) and 10 non-HB (NHB) adult cardiac
surgical patients at two times after CPB 1) post
acute normovolemic hemodilution (ANH) infusion
and protamine administration, and 2) after
admission to the ICU approximately one hour after
CPB and HB infusion. An ANH volume (about 4
cc/kg) was withdrawn from each patient after
heparinization, sequestered and returned
immediately after protamine administration in
both the HB and non-HB patients. Cell processing
(Cell Saver 5 Haemonetics Corporation,
Braintree MA) was also employed in both groups of
patients to conserve blood. Immediately
post-bypass, the residual CPB circuit blood was
processed by the Cell Saver 5 in the NHB
patients and the Hemobag technique was utilized
in the HB patients (Figure 1). Residual heparin
in the HB contents was neutralized with an
additional 50mg of protamine sulfate after
infusion. The decision to transfuse allogeneic
blood bank products was made by the same
physicians using the same transfusion criteria
for both groups of patients during the time
periods in this study. Process indicators and
central hospital laboratory results were
statistically compared by independent group
t-test or ANOVA between the NHB and HB patients
before and after the first hours immediately
after protamine administration and the reinfusion
of ATS, ANH and HB blood. Specific factor
comparisons were made employing Bonferroni
adjustments. The alpha level was set at 0.05 or
0.10 depending on the factors. Statistical
analysis was performed using SPSS software (SPSS
14.0, Chicago, IL).
Hct Pre and Post HB Infusion
p 0.010
HB p 0.106
NS
Post-Protamine Post-Infusion
Figure 4
p lt 0.001
INR Changes Pre and Post HB Blood Product
Infusion
Fibrinogen Pre and Post Hemobag Infusion
Savings of Unused Blood Products In the Hemobag
Group
Figure 2
Figure 3
p 0.044
All blood products for the Hemobag patients
charges 1,722 vs. 12,563 for the control
patients. A difference of 10,841
NS

NS
HB p 0.122
7 patients
NS
1 patient
Post-Protamine Post-Infusion
Patient charges ?2(1, N20) 6.11, p lt 0.025
References available on handout copy of
poster.
p lt 0.021
Post-Protamine Post-Infusion
7 NHB pts. received blood products FFP, Plt,
Cryo, RBC 1 HB pt. received blood products FFP,
Plt, Cryo,
p lt 0.001