Final Transfusion Talk WAC 11_2007

8/14/2019 Final Transfusion Talk WAC 11_2007

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All Bleeding Eventually Stops:

Are Outcomes Changed by

Transfusion?

Colleen Gorman Koch, MD, MS, FACC

Cardiothoracic Anesthesia and

Outcomes Research

Cleveland Clinic



Objectives

• To better understand risk association

between red blood cell transfusion and

morbid outcomes in cardiac surgical

patients.

• To discuss recent investigations in critically

ill surgical patients and to discuss areas for future investigation.



• Notion that RBC beneficial to

replace lost volume and for

O2 carrying capacity

was unchallenged for years

--as advertised, saves lives

•Concept of risk changed withinfectious transmission and

association between

morbidity and RBC became focus

of research



Limited Resource:

Challenges us to think more conservatively



Risks

Morbidity and MortalityOutcomes



Morbidity and Mortality:

Cohort Investigations

Transfusion

Infection:

Sternal wound

Pneumonia

Pulmonary

dysfunction

Renal

insufficiencyMSOF

Mortality:Short

Long-term

• N, Outcome, RBC binary, heterogeneity, statistics, generalize



Koch, et al., Critical Care Medicine 2006;34:1608-1616

Morbidity and Mortality

in (N=11,963) Isolated CABG

•Increased risk for every morbid outcome•Dose-dependent relationship between each unit and events



Frequency Histogram for RBC Units

Transfused

Koch et al., Critical Care Medicine 2006;34:1608-1616

•48% transfused

•Most commonly

1-2 units transfused



Patient and Procedural Variables

Related to RBC TransfusionKoch et al., Critical Care Medicine 2006;34:1608-1616

•Older, smaller,

lower pre-op HCT,comorbidity,

clinical presentation:

emergency, NYHA,

preop IABP; reoperationlonger clamp times



Infection:End-points: bacteremia, septicemia,

superficial and deep sternal wound infections

Banbury, et al., JACC 2006;202:131

• N=15,592

Independent risk for postoperative infection

•(55%)transfused

•Dose-dependent

relationship



N=1915

N=649

transfused

N=546

Propensitymatched

Engoren, et al. Annals of Thoracic Surgery 2002

Risk factor for 5 year mortality after CTS



N=10,289

Koch et al., Ann Thorac Surg 2006;81:1650-7

•Long-term survival after

controlling for early hazard and

other risk factors

•Risk is biphasic and incremental:

early phase within 6 months

higher than late phase

•Blackstone parametricdecomposition method accounts

for non-proportionality;

simultaneously models time-

varying hazard and risk factors

Transfusion and Long-term

Survival



Koch et al., Annals of Thorac Surg 2006;82:13-20

Quality of life: DASI (N=7,321)

•Reductions in

functional recovery

paralleled RBC

transfused



Annals of Thorac Surg 2006;82:13-20

N=7,321



Other Issues…

• Leukocyte-reduced status

• Age of red cells

• Blood substitutes



Storage Duration:

Hemorrheological Changes

Journal of Surgical Research 2002;102:6-12

•Reversible and irreversible functional and structural changes

•May contribute to decreased microvascular flow,

local hypoxia and post-transfusion complications



Distribution of RBC Units

Exclusively blood stored <14 days (orange, N=2872) and >14 days

(blue, 3130). Distributions between 2 groups are similar.

Mean Storage duration and number of RBC units by storage duration.



Dose-response Relationship Between Max Days

Storage and Probability of Composite Outcome

Increasing linear trend, particularly for those receiving units > 14 days storage duration



Storage Duration and Outcome



Survival and Hazard Curves

N=2872 (yellow, younger), N=3130 (blue, older)

Those receiving older blood had reduced survival particularly

during initial follow-up and more pulmonary, renal and infectious

complications



Predicted Survival and Maximal Age with

Hazard Decomposition Model

1 day = orange; 15 days = red; 30 days = blue; and 42 days = black



PNAS 2007;104



Tissue Oxygenation

• Local microcirculatory control mechanisms areimportant in the restoration of tissue oxygenation.

• Regulatory mechanisms for maintaining adequatetissue oxygen concentration are not wellunderstood.

• Role of oxygen sensor in tissue? Red cell?

• Red cell may play a role as oxygen carrier andoxygen sensor, during hypoxia it may modulateflow by release of vasodilatory nitric oxide.



Tissue Oxygenation

• New findings indicate that red cell function is

more complex than previously assumed.

• Advantage of oxygen sensing by red cells is thatallows an immediate feedback during oxygen off-

loading as hypoxic vasodilator release can directly

alter local vascular tone and hence adapt tissue

perfusion and oxygenation according to local

needs.



Future Investigation

• Clearly we need better data to improve

management decisions related to transfusion

• Prospective cohort investigations provide a‘starting point’ for further investigation;

(understanding limits of statistical methodology)

• Effectiveness needs to be evaluated in RCT for

given levels of anemia in specific population



New Donation Strategy?

Give Blood, Play Hockey

Final Transfusion Talk WAC 11_2007

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