Blood Management Strategies in
Scoliosis Surgery:
Minimizing Blood Loss and
Transfusion Requirements.
Matthew A. Halanski, MD
Pediatric Orthopaedic Surgery
Helen DeVos
Children’s Hospital
Outline
Review our treatment protocol at HDVCH and present our 2 year retrospective data.
Review the literature to understand the multi-modal treatments used to minimize blood loss during scoliosis surgery.
Understand why scoliosis surgery is associated with high blood loss.
We Cut Therefore…
They Bleed.
Blood loss during surgery is a combination of
The question is …
Why SO much during
Scoliosis Surgery?
>50% blood volume losses.
Highly Vascular
Arterial-High Pressure
Venous-Baston’s Plexus
Common Problem Vessels
Anterior surgery – Segmental vessels
Posterior -Sacral foraminal bleeding
Posterior - Vessels just lateral to facet
Scoliosis Surgery- Why all the Blood
loss?
Spinal Deformity Requires Complex Surgery
Osseous Bleeding
Large incisions
Large surface area
Things to Remember #1
Not all
Scoliosis
is the Same
Adolescent
Idiopathic Scoliosis
Neuromuscular
Things to Remember #2
Things to Remember #3
Don’t Lose Sight of the FOREST
When Looking at the TREES!!!
What’s the problem with Blood
Transfusion?
Less Known problems with Increased
Blood Loss and Transfusions.
Difficulty with Surgery.
Difficult to operate where you can’t see!
Neuro-monitoring
Large fluid shifts, changes in BP can cause changes in
spinal cord monitoring.
Post-operative Pulmonary Complications
Increased Post-Operative Infection Rates
Triulzi et al. (Spine) Relative Risk of Infection 5.9*
Murphy et al. (THA) Relative Risk of Infection 10
Known
Patient
Risk Factors for
Increased Blood Loss and Transfusion
Patient weight <30 kg
Patient diagnosis
(Estimated
Blood Loss)
Neuromuscular
(2000-3500mL)
>Idiopathic
(600-1500mL)
Duchenne Muscular
Dystrophy
(930-4000mL)
>SMA/SB>Cerebral Palsy
(1300-2200mL)
.
Known
Surgical
Risk Factors for
Increased Blood Loss
Increasing number of levels = Increase
blood loss
Best predictor – Guay et al 1994.
Average estimate 200cc/level – Murray et al
1997.
Anterior and Posterior Spinal
fusions>Posterior spinal Fusions (600-1500mL)>Anterior Spinal fusions (350-650mL)**.
PSF (65-150mL/level)
ASF (65-135mL/level)
ICBG – increased blood loss (1828 mL vs
1120mL).
Length of procedure
More Time = More Blood loss PSF
(Pouliquen JC. Chirurgie 1990 116:303-311.)
2 hours- EBL 500mL 3 hours- EBL 1500mL 4 hours- EBL 2400mL
How can we minimize blood loss and
Ultimately use of blood products?
Medical (BAS/ND/H)
Surgical Anesthesia
Pre-operative Evaluation:BAS**
Bleeding Disorders and Filling up the Tank
Comprehensive Pre-operative Evaluation
Family Hx/Bleeding History.
Anemia (hematinics and Epo if needed) Coagulopathy (factor replacement) Thrombophilia (avoid Antifibrinolytics) Contraceptives for Menorrhagia
Routine and “special” labs based on apparent risk from history.
CBC w/o diff Retic count PT PTT Fibrinogen CMP
Type & Screen
Von Willebrand Antigen
Von Willebrand Ristocetin Cofactor FactVIII (8) Act
Von Willebrand Multimer
Pre-operative Treatment**
Comprehensive Pre-operative Treatment
Procrit
(Orthobiotech, Bridgewater NJ)
Epoetin alpha, Fe++
Colomina et al.
Alone may increase Hct enough
for procedures with expected blood loss <30%
total volume.
Vitale et al. 2007
Procrit
in NM patients higher
starting and discharge Hct, but no difference in
transfusion rate. (levels fused and time)
Decrease in allogenic blood transfusion up to
Autologous Pre-Operative Blood
Donation
Multiple blood donations for upcoming
surgery
Hematocrit maintained >33%
>50 kg donate normal unit (450+/- 50 mL)
<50 kg donation proportionally smaller
Maximum 1/3 days however standard is 1
week to 10 days.
Shelf life~35 days
Last donation 5-7 days prior to allow
Autologous Pre-Operative Blood
Donation
Benefits
Often meets any transfusion
requirements.
Murray et al 90% PSF
patients requirement met.
Thomson et al. 71% patients
only received autologous
blood while 64% of the blood given to those that required homologous transfusion was auto transfusion.
Primarily indicated for
procedures involving
30-50% patients blood volume.
Risks
Pediatric patients won’t
participate- Murray et al 70% patients for
PSF donated.
Adverse reaction rate
similar to that for
homologous transfusions,
1.5-5%.
30-50% autologous blood
not transfused-discarded.
Risks of bacterial
contamination and
identification errors.
Preventing Blood Loss: Patient Positioning
Un-Kinking the Hose!!**
Anesthesia:
Saving the Blood
Normovolemic Hemodilution
Removal of blood day of surgery after
anesthesia.
From estimated blood volume and
pre-operative Hct; volume to be remove calculated roughly 20% blood volume.
Average 644 mL (Copely et al 1999) Desired Hct of 30%
Replaced with crystalloid – (Lactated
Ringers)
Ratio of replacement 3:1 (3 LR:1 blood). Thus when patient bleeds – they bleed
dilute blood.
Held at room temperature- until end of
procedure.
Given back in reverse – RBC plus clotting
factors Saved To be Given After Patient’s Circulating Blood to Bleed
Anesthesia: “Controlled Hypotension”
Turning Down the Faucet**
Hypotensive Anethesia “Controlled Hypotension”
Systolic BP 80-90 mmHg
MAP 50-70 mmHg or 30% decrease in baseline MAP
End organ perfusion is maintained via the
auto-regulatory function in the end organ arteriolar beds.
Spinal cord autoregulates (between mean pressures
of 50-150mmHg, Fahmy et al ) to maintain perfusion.
Risk
Posterior Ischemic Optic Neuropathy (PION)– increased
intra-ocular pressure (prone positioning), hypotension, anemia, prolonged prone surgery >6 hours.
Benefits- Significant Blood Loss Reduction
Patel et al. PSF with hypotensive anesthsia
-EBL decreased by 40% and transfusion requirements by 45%. Also decreased operative times by 10%
(Fentanyl and Enflurane). Malcom-Smith and McMaster
Minimizing Blood Loss:
Anti-Fibrinolytics**
Increased fibrinolysis can cause increased
bleeding
Inhibit fibrinolysis by preventing
plamisminogen
plasmin.
Anti-fibrinolytics prevent this.
Pharmacologic- Anti-Fibrinolytics- All Off label
use in Orthopaedic Procedures PSF.
Aprotinin
Tranexamic Acid (
TXA
, Cyklokapron, Pfizer, NY, NY)
Epsilon amino-caproic acid (
Amicar
) (Xanodyne
Minimizing Blood Loss:
Anti-Fibrinolytics
Aprotinin
Protease inhibitor isolated from bovine
lung (1930).
Two effects on coagulation:
Inhibits enzymatic formations of plasma kallikrein. This in turn inhibits conversion on plamsinogenplasmin. Protects vWF receptors on platelets
which preserves platelet adhesion.
Scoliosis (High Risk)
15,000 KIU/kg LD/20 minutes 7,500 KIU/kg/hr during procedure
Majority of benefit demonstrated in
cardiac patients to decrease blood loss and transfusion requirements.
Similar in Orthopaedic literature
Kohshhal et al 2003 Scoliosis (N=43) decreased EBL, transfusion rate but
no significant.
Urban et al. Adult spine surgery (N=60 total)
Compared with Placebo, Amicar, and Aprotinin
showed a lower blood loss and transfusion requirement in Aprotinin <Amicar <Control.
Minimizing Blood Loss:
Anti-Fibrinolytics
Aprotinin
Problems
Anaphylactoid reactions – increase with repeated exposures:
No exposure incidence 0.1%
Exposure within last 6 months 5% Exposure >6 months 1%
Contra-indicated in those exposed within 12 months.
(BART Study) Blood Conservation Using Antifibrinolytics
in a Randomized Trial – increased 30 day mortality with
Aprotinin lead to worldwide suspension of use in 2007.
Conflicting data on Renal Failure and MI.
Increased risk of renal dysfunction in those with DM.
Shown Safe in pediatric patients (cardiac surgery)
Backer et al 2007 (N=1230 without, N=1251 with) no difference in mortality, kidney failure, dialysis, neurologic complications.
Minimizing Blood Loss:
Anti-Fibrinolytics**
TXA 7-10X as potent as Amicar. Loading dose 10mg/kg Infusion 1mg/kg/hr Amicar Loading dose 100-150mg/kg Infusion 10-15mg/kg/hr Both are Lysine analogs- Excreted in urine
Saturate the Lysine binding sites of plasminogen to prevent binding to fibrin.
Amicar Transexamic Acid
Minimizing
Blood Loss:
Prospective Comparisons
Anti-Fibrinolytics**
Transexamic Acid (TXA)
Neilipovitz, AIS (N=40)
1253+/-884mL vs 1784+/-733 (cell
saver plus transfusion) significant.
Sethna, PSF (N=44)
EBL decreased 41% vs placebo.
(1230+/-535 vs 2085 +/-1188) Shapiro, DMD (N=56) EBL decreased 42% (1944+/-789 vs 3382+/-1795) Homologous transfusion decreased 41%
Cell Saver Autologous transfusion
decreased 42% 100 mg/kg LD then 10 mg/kg/hr Amicar 4 separate studies Florentino-Pineda 2001, 2004 Thompson 2005, 2007 (N=36)
Total Peri-operative blood loss
decreased was significant 1391+/-212 vs 1716+/- 284 mL)
EBL not significant (893+/-166 mL vs
952+/-303 mL)
Post-operative drainage – significant.
(498+/-179 mL vs 764+/-284 mL)
Decreased Autologous units
transfused 1.1+/-1U vs 2.1+/-1.3.
Increasing fibrinogen levels throughout
post operative period
Meta-Analysis
Anti-Fibrinolytics**
Cochrane Collaboration – Tzortopoulou 2007
1950-2007 studies looking at the effect of anti-fibrinolytics on peri-operative blood loss in patients <18 years old undergoing scoliosis surgery.
Included Aprotinin, TXA, Amicar.
6 studies, 127 controls, 127 given anti-fibrinolytics.
Anti-fibrinolytic use decreased amount of blood loss by 427 mL. Risk of transfusion was similar in placebo or treatment groups. Amount of blood transfused was less in the treatment group then
control group by 327 mL.
All three drugs appeared similarly effective.
Minimizing
Blood Loss:
Other Agents
DDAVP- Desamino-8-d-arginine-Vasopressin
Diabetes insipidus
Interacts with factor VIII and vWF by increasing their release from endothelial
storgae sites.
VIII works with IX to activate X vWF stabilizes VIII
transports throughout circulation
Mediates platelet adhesion to subendothelium
Recommended dose 0.15-0.3 ug/kg
IV administration 15-20 minutes before the case – prevents hypotension. Increases baseline levels 3-5X’s.
Intra-nasal and subcutaneous administration also works
Mixed Results in the literature – no difference in randomized double blinded trials.
Theroux et al 1997 –
EBL and Transfusion rates the same DDAVP/Control Factor VIIIC and VWF increased*
Minimizing
Blood Loss:
Other Agents
Recombinant factor VIIa
Used in hemophiliacs patients with factor VIII inhibitors.
Recent use in non-hemophiliac patients – who have failed to clot – and has
controlled otherwise life threatening hemmorage
Dosed 40-100 g/kg repeating doses at 2-6 hour intervals. Sachs et al 2007 –
decreased adjusted blood loss and adjusted transfusion levels No ill effects (one ischemic stroke and death!)
Premarin (Wyeth-Ayerst Laboratories, Philidelphia,PA)
Conjugated estrogen- action unknown –
they induce polymerization of acid mucopolysaccharides in the walls of capillaries
and change them into a gel state-thus the vessel becomes less permeable.
Alter factor V levels
Alter vessel wall –platelet interactions
McCall and Bilderback
1997- 1mg/kg IV post-operatively
37% decrease in post-operative drainage over 48 hours in pediatric scoliosis
Help Stop The Bleeding:
Preventing Hypothermia**
Mild hypothermia,
defined as
temperatures less than 36°C,may cause:
Coagulopathy due to decreased platelet
function
Decreased resistance to surgical Infection
May affect spinal cord monitoring (SSPE
latencies)
Maintain at 37°C
forced-air warming devices
fluid warmers
increased ambient temperature in the
Minimizing Blood Loss:
Surgical Technique
Exposure.
Epinepherine injection or electrocautery
Sub-periosteal dissection
Electrocautery vs blunt cobb exposure
“Meticulous hemostasis”
Visualize bleeding
Adequate lighting +/-headlamps
Magnification if needed – (Loupes 3.2X magnification)
Hemostasis saves time in allowing
better visualization and allows surgery
to proceed easier and faster.
Minimizing Blood Loss:
Cautery
Mono-polar– Bovie
high temperature irreversibly shrinks
collagen in vesslescompletely occluding vessel lumen.
High surrounding thermal injury to tissue. Bi-polar –current is between tips of forceps
More localized
Less collateral damage
Aquamantys (TissueLink Medical, Dover NH) Bipolar radiofrequency
Continuous saline to prevent charring Decreases burning
Minimizing Blood Loss:
Topical Hemostasis
Surgical Techniques- topical hemostasis used.
Bone Wax= Dutch boy but inhibits bone healing
Gel Foam Floseal Surgiflo
Minimizing Blood Loss:
Topical Hemostasis
Minimizing Blood Loss:
Instrumentation
Type and Amount
Minimizing Blood Loss:
Surgical Technique – Cutting the Bone
Save to the End of the Procedure
Osteotomies
Facetectomies
Bone Graft
Decortication
Salvaging Lost Blood**
Surgical Technique-Blood Salvage Systems
Blood rich Coagulation poor may precipitate DIC – some
give post-operatively only.
Recycles blood lost on the field-relatively safe at volumes
<3000mL
Flynn et al - 50% decrease in homologous blood
requirements mean of 1.5 Units salvaged. (spine and orthopaedic)
Lennon et al 1987- 50% decrease in the amount of
homologous blood used.
Copley et al 1999- question routine use – only 5% spared
transfusion from its use.
Simpson 1994 found only 12% patients benefited from the
salvage (total joints).
Expensive and Must lose enough to have enough to
get back.
Cell Saver (Haemonetics, Braintree MA)
Minimum EBL ~500mL
Orthopat (Haemonetics, Braintree MA)
Smaller Volume blood losses intra-operative Post-Operative Blood Captured and Re-infused.
Turning off the Faucet:
Post-Operative Care
Blood Avoidance – Management.
Continuation of Anti-fibrinolytics, Hematinics
Lab Values
Standard Protocol –
No transfusion<7
others individual basis
Surgeon–To drain or not to drain.
Anesthesia –
Eyes OK
No missing teeth
Cost Analysis
From Thoms et al JAAOS 2009
Decrease Allogenic Transfusion Priceless?? $300-$2300+ Pre-operative BAS Evaluation Hematinics /Procrit Referral $2100 Autologous Donations 3X$700 $800 Blood Salvage $$ Surgical Technique Two Surgeon Approach Topical Hemostasis Hypotensive Anesthesia BAS Transfusion Practices Post op Hemantics $1-1200 Anti-Fibrinolytics TXA- $300 Amicar-$3 Aprotinin-$1200 NormoVolemic Hemodilution Bone Graft $2600 Implants $10-40,000 Surgeon/Anesthesia fees $10,000’s Spinal Cord Monitoring $3000
HDVCH Standard Approach
Decrease Allogenic Transfusion Pre-operative BAS Evaluation Hematinics Procrit Referral Autologous Donations Blood Sallvage Surgical Technique Two Surgeon Approach Hypotensive Anesthesia BAS Transfusion Practices Post op Hematinics Anti-Fibrinolytics TXA Amicar Aprotinin NormoVolemic HemodilutionSeptember 2007 - September 2009*
Number of surgeries 110
Neuromuscular 28
Idiopathic 60
Others (Congenital & Secondary) 22
Pre-operative Screening 104 (94%)
Pre-operative Hematinics 37 (34%)
Pre-operative Epo 13 (12%)
Contceptives 2x for Menorrhagia + Antifibrinolytics 1 for month prior to surgery. No Antifibrinolytics developed venous
thrombosis
HDVCH 2 Year Experience
Type of Scoliosis and
Demographics
0 2 4 6 8 10 12 14 16 # of Segments # of Osteotomies Idiopathic Neuromuscular Idiopathic n=60 Neuromuscular n=28 P Value (Mann Whitney) Sex (F) % 45 (75%) 14 (50%) .02* Weight 58 + 18 46 + 18 .004 Age (months) 162 + 39 157 + 51 .869 Comorbidities 18 (30%) 27 (96%) .001* Cobb Angle 61 + 18 66 + 21 .188 No of segments fused 10 + 3 15 + 2 .001 No of osteotomies 6 + 3 8 + 5 .27* Chi Square test
Type of Scoliosis and
Outcome
0 10 20 30 40 50 60Total Blood Loss ml/kg *
Hb drop gm/dL * % Transfused ** Idiopathic Neuromuscular
P .001
P .002 P .001
Cobb Angle, Blood Loss and
Transfusions
0 10 20 30 40 50 60 0-40 41-50 51-60 61-70 71-80 81-140Blood Loss ml/kg % Transfused
n=6 n=20 n=25 n=18 n=15 n=10 Cobb Angle
Anti-Fibrinolytics Effect
Amicar (67) Tranexamic (17) Non (12) P Value Initial Hb 13.6 + 1.2 14.1 + 1.1 14.1 + 1 0.16 KW Post-Op Hb 8.8 + 1.5 10 + 1.1 a 8.9 + 1.2 b 0.12 KW Total blood loss /kg 30 + 32 17 + 15 18 + 10 .33 KW
Hypotension in PACU 31 (46%) 5 (39%) 0 .007 * Transfused 11 (16%) 1 (6%) 1 (8.3%) -Pre Op Fibrinogen 244 + 84 232 + 50 267 + 84 -Highest Post Op Fibrinogen 488 + 235 670 + 248 561 + 238
-* Fishers Exact test
Markers of
Transfused
Scoliosis Patients
0 10 20 30 40 50 60 70 80 90Weight * Idiopathic % ** # Levels Fused * Total Blood loss/kg * Non Transfused Transfused
P .006 P .001
P .003 P .0001
* Mann Whitney test **Fisher Exact test
Predictors of Transfusion
Requirement
P .001
P .009
P .007
* Logistic regression of individual variables:
•Logistic regression of all variables:
Older age OR .973 (.951-.996) P 0.025 Higher blood loss OR 1.129 (1.06-1.2) P .001
more
higher
higher
Incidence of Von Willebrand
Disease
12 out of 110 (10.9% ) diagnosed with Von Willebrand disease
4 of 24 (14.3%) Neuromuscular 6 of 60 (10%) Idiopathic
2 of 22 (9.1%) In other scoliosis types
Overall P 0.074 Fisher Exact test
Out of groups AIS & NM Von Willebrand patients (n=10)
5 had (+) personal or family history of bleeding 4 received Humate-P intra-operatively
One patient out of 10 required a transfusion (10%) (AIS).
One patient (in AIS group) had Von Willebrand activity level of <
30, received Humate-P & was not transfused.
Von Willebrand in Scoliosis
Patients
VW Activity
AIS NM (+) History Received
Humate P
Total blood loss a Transfused
< 50% 2 4 2 2 1133 ± 19 1 50-70% 3 0 2 1 725 ± 56 0 > 70% 1 0 1 1 400 0 Mean Activity b 53 ± 19 36 ± 8
a. P .188 (Kruskall Wallis) b P .171 (Mann Whitney) Only one patient below 30%
There was a trend toward higher blood loss with
Summary
■
Blood management in Scoliosis Surgery requires a
Multi-Disciplinary Multi-modal Approach.
■
Here at HDVCH – we have found our data to compare well
with that in the literature:
■ Posterior spinal fusion is associated with significant blood loss & risks of needing transfusions – particularly in neuromuscular scoliosis.
■ High blood losses were associated with higher Cobb Angles
■ Transfusion needs were associated with Neuromuscular curves,
smaller weight, larger number of segments fused and higher blood losses.
■ Unexpected high incidence of mild Von Willebrand disease was
noticed (more in neuromuscular scoliosis) and tended to be associated with higher blood loss.
