Transcript Blood Product Ratios in Trauma PowerPoint

Omar Alsuhaibani
Transfusion Medicine
Journal Club
February 2, 2010
Background
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Transfusion therapy is common in trauma
patients.
Massive transfusion is defined as 10 or more
RBC units in a 24 hour period
Massive transfusion occurs in up to 15% of
civilian trauma patients and is associated with a
mortality rate of 20-50%
Most patients requiring massive transfusion die
within 6 hours of admission
May 2005
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international expert conference on massive transfusion
at the US Army's Institute of Surgical Research
concept of “damage control” should be expanded to
include what has subsequently come to be known as
“damage control resuscitation.”
addresses the immediate need for coagulation
components as well as for oxygen delivery in the
severely injured patient
specifies decreasing, to the extent possible, the use of
crystalloids as volume replacement
matching RBC transfusion on a 1:1:1 ratio with plasma
and platelets.
Borgman and coworkers - 2007
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significant reduction in mortality in 246
massively transfused (10 units of RBCs in
24 hr) trauma patients (65% reduced to
19%, p < 0.001), with an optimal plasma
to RBC product ratio of 1.4.
Duchesne and colleagues - 2008
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improved survival in 135 massively
transfused (defined as >10 units of RBCs
during and after initial surgical
intervention) trauma patients who
received less than 2 units of RBCs per unit
of plasma versus 2 or more units of RBCs
per unit of plasma (12% vs. 21% died at
discharge).
Maegele and colleagues - 2008
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retrospectively analyzed their trauma
registry
improved mortality with a RBC:plasma
ratio of less than 0.9 compared to 0.9-1.1
and greater than 1.1
higher amounts of plasma-to-RBC ratio
were associated with increased length of
stay and increased rates of multiorgan
failure.
Sperry and coworkers - 2008
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Multicenter prospective cohort study of 415
blunt-injured adults with hemorrhagic shock who
required 8 or more units of RBCs within the first
12 hours
1:1.50 or more versus less than 1:1.50
plasma:RBC ratio was associated with improved
mortality only after adjusting for confounders,
strongly associated with the development of
acute respiratory distress syndrome (ARDS).
Holcomb and colleagues - 2008
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retrospective study of 466 massively transfused
(10 units of RBCs in 24 hr) civilian patients
the group with a high plasma- and PLT to- RBC
ratio (1 unit of PLTs and plasma to 2 units of
RBCs) had the highest rate of 30-day survival
(73%) compared to patients who received high
plasma and low PLT (54%),low plasma and high
PLT (67%), and low plasma and low PLT (<1
unit of PLTs and plasma to 2 units of RBCs;43%)
ratios (p < 0.001).
the higher 6-hour plasma:RBC and PLT:RBC
ratios were also correlated with survival.(2009)
Teixeira and coworkers - 2009
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retrospective study of 484 trauma patients
who received 10 or more RBCs during 24
hours
plasma:RBC ratio of higher than 1:3 was
associated with survival, but a ratio of
greater than 1:2 was no better than 1:2 or
less to more than 1:3.
Snyder and coworkers - 2009
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the plasma:RBC ratio (1:2 vs.<1:2) was associated with
survival (40% vs. 58% in-hospital mortality rate)
adjusting for multiple variables
Similar to previous studies, an association between
higher FFP:PRBC ratios at 24 hours and improved
survival was observed.
However, after adjustment for survival bias in the
analysis, the association was no longer statistically
significant.
Prospective trials are necessary to evaluate whether
hemostatic resuscitation is clinically beneficial
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Varying definitions were used for massive
transfusion ranging from ≥8 units in 12 h
to >10 units in the first 6 h and varying
ratios of component therapy were
examined
Owing to the nature of severe trauma
requiring high-volume blood product
resuscitation, significant survivor bias is
highly likely.
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Within these limitations, available
literature demonstrates a clear survival
benefit associated with early delivery of
FFP and platelets in exsanguinating
trauma
high ratio therapy may be associated with
a higher incidence of organ failure, ARDS
and infection
This study investigates the improvement in
survival with higher plasma:RBC,
platelet:RBC, and cryoprecipitate:RBC
transfusion ratios in a civilian Level 1
trauma center.
Materials and Methods
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Patient information was derived from a
prospectively entered trauma registry that is
maintained at Grady Health System.
Massive transfusion was defined as transfusion
of 10 or more units of RBC products in the first
24-hour period of the hospital stay.
Non-trauma patients were excluded from this
data set.
This study combines two cohorts of patients:
one after implementation of a massive
transfusion protocol (MTP) and one before
implementation.
Patient inclusion
MTP group
The MTP group was defined as trauma
patients requiring massive transfusion and
who received the MTP at Grady Memorial
Hospital from February 1, 2007, to January
31,2009.
Patient inclusion
Pre-MTP group
The pre-MTP group was created by
querying the prospectively entered trauma
registry and identifying all patients in the
2 years before the institution of the MTP
(February 1, 2005-January 31, 2007) who
received 10 or more units of RBCs in the
first 24 hours of their hospital stay.
MTP design
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derived from military recommendations, with
some modifications.
the protocol is designed to ensure immediate
availability of aggressive and early component
therapy and is activated with a phone call to the
blood bank.
Activation of the protocol is restricted to an
attending or fellow from surgery, anesthesia,
emergency medicine, or critical care
MTP design
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reserved for patients who have massive hemorrhage in
difficult to control anatomic locations, who use
emergency issue RBCs (RBC products are available in the
emergency room and operating room), with ongoing
blood loss of more than 150 mL/minute or with blood
loss of 50% of blood volume in 4 hours or one blood
volume in 24 hours.
The blood bank responds to the call for protocol
activation by immediately placing 6 units of group O
RBCs and 6 units of group AB plasma in a cooler as the
“initiation package.”
The blood bank maintains an adequate inventory of
thawed plasma products for immediate distribution.
MTP design
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The blood bank then continues to prepare predesignated “packages” of components to be
picked up every 30 minutes with a ratio of
plasma:RBC of 1:1 in addition to set amounts of
platelets and cryoprecipitate.
The protocol suggests transfusion of blood
products in the appropriate amounts, but does
not mandate it.
if bleeding is uncontrolled, the trauma service can
request a recombinant factor VIIa (rFVIIa) after
Package 2 with a second dose if needed 30
minutes later.
Data collection
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For the pre-MTP cohort, clinical and blood bank data were
retrospectively collected, and for the MTP patient cohort prospective
data were collected.
Clinical data collected included patient demographics including
- a history of anticoagulant use
- mechanism of injury
- type and severity of anatomic injury
- injury severity score (ISS)
- lengths of stay (hospital length of stay, intensive care unit
length of stay, and ventilator days)
- mortality rate (24 hr, 30 day, and hospital stay)
- time to and length of first operation
- use of a damage control procedure
- presenting vital signs.
Data collection
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Laboratory data were collected including Hb/Hct,
base deficit, and coagulation variables (PT, INR,
aPTT, fibrinogen level, and PLT count) upon
arrival to the emergency department and on
arrival to the intensive care unit.
Blood bank data collected included the number
of units transfused of RBCs, plasma, platelets,
and cryoprecipitate in the first 6 hours, first 24
hours, and entire hospital stay.
Definition of ratios
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plasma:RBC ratio of 1:1 was defined as one plasma product per one
RBC product
PLT:RBC ratio of 1:1 was defined as one apheresis PLT unit per 10
RBC products
cryoprecipitate:RBC ratio of 1:1 was defined as 1 cryoprecipitate unit
per 1 RBC unit (cryoprecipitate was administered in pools of 10 units).
A number value for the ratios was created by
- dividing the number of plasma products by RBC products
(plasma:RBC)
- dividing the number of apheresis platelet products by 10 RBC
products (PLT:RBC)
- dividing the number of cryoprecipitate products by RBC products
(cryoprecipitate:RBC).
Statistical analysis
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Blood product usage at 24 hours was used
for all transfusion variables.
Variables were selected from age, base
deficit, ISS, PT, PTT, RBCs, gender,
plasma:RBC ratio, PLT:RBC ratio, and
cryoprecipitate:RBC ratio by univariate
logistic regression of alive 30 days after
admission, which are significant at an
alpha level of 0.1.
RESULTS
MTP versus pre-MTP cohorts
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Between February 1, 2007, and January 31, 2009, 132 patients met
the inclusion criteria for the MTP cohort.
84 historic controls (pre-MTP) received 10 or more units of RBCs in
the first 24 hours of their hospital stay and were treated between
February 1, 2005, and January 31, 2007.
no difference in any demographic information or injury severity
between the two cohorts:
- age (p = 0.28),
- Gender (p = 0.82),
- trauma mechanism (p = 0.27)
- ISS (p = 0.49)
- initial base deficit (p = 0.51)
RESULTS
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No patient had any documented existing use of anticoagulants.
Blood product usage was similar between the two cohorts, except
increase in plasma with the MTP cohort: 24 hr RBC products (p =
0.85), 24 hr plasma (p < 0.01), 24 hr apheresis PLTs (p = 0.56),
and 24 hr cryoprecipitate units (p = 0.79).
The blood product ratios at 24 hrs were similar except a higher
plasma:RBC ratio in the MTP cohort: plasma:RBC (p 0.001),
PLT:RBC (p = 0.74), cryoprecipitate:RBC (p = 0.46).
rFVIIa usage was similar (p = 0.31).
Patient outcomes were similar: 24-hour and 30-day survival rates
(p = 0.28 and p = 0.47, respectively)
intensive care unit and hospital length of stay
( p = 0.62 and p = 0.23, respectively).
RESULTS
Blood product ratio and survival
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The MTP and pre-MTP cohorts were
combined to investigate the effect of the
plasma, PLT, and cryoprecipitate on RBC
products transfused in the first 24 hours
on patient outcome.
The plasma:RBC ratio, PLT:RBC ratio, and
cryoprecipitate:RBC ratio all had an effect
on survival
RESULTS
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the final model had five explanatory
variables;
plasma:RBC, PLT:RBC, ISS, age, and total
RBCs as independent variables and 30-day
survival as a dependent variable
a total of 202 records over 214 overall
records were used in building the model,
of which 102 survived after 30 days
Limitations
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relatively small sample size
the use of historic controls
Survival Bias
All of the studies regarding plasma:RBC ratios and
massive transfusion outcome have survival bias
in the data because those who survive longer
are more likely to receive more coagulation
factor therapies versus patients who die early
after admission who may receive less
coagulation factors due to delay in coagulation
product transfusion.
Survival Bias
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The strongest survival bias is likely seen in the
plasma:RBC ratio because the 24-hour and 30day mortality were unchanged in the groups
who received the least amount of plasma (i.e.,
these patients died early in their hospital
course).
Correction for survival bias eliminates the
apparent survival benefit of the “high” ratio
group suggesting that death was the cause, not
the effect of the low ratio
Conclusion
“ current data support early and aggressive
coagulation factor replacement through
transfusion of plasma, PLT, and
cryoprecipitate products. Although the
optimal ratio is not precisely defined,
these reports, including this study, support
an aggressive approach to transfusion.”
Conclusion
“ higher ratios of plasma, PLT, and cryoprecipitate
to RBC transfusion were associated with
markedly improved patient survival. Therefore,
MTPs with blood administration ratios that
recapitulate whole blood should be adopted by
centers routinely taking care of trauma patients
in an effort to improve the early resuscitations of
these critically injured patients with a resulting
decrease in mortality.”
PRBC
PLASMA
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