Thrombocytopenia-Associated Multiple Organ Failure and Pediatric Septic Shock: Is Plasma Exchange a...
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Transcript of Thrombocytopenia-Associated Multiple Organ Failure and Pediatric Septic Shock: Is Plasma Exchange a...
Thrombocytopenia-Associated Multiple Organ Failure and Pediatric Septic Shock: Is Plasma
Exchange a Promising Therapy?
James D Fortenberry MD, FCCM, FAAPPediatrician in Chief
Children’s Healthcare of AtlantaProfessor, Pediatric Critical Care
Emory University School of MedicineAtlanta, Georgia
2
Disclosures
No financial disclosures I am an intensivist
• Dumber than smartest nephrologist
• Able to intubate dumbest kidney
3
Respiratory Failure
Cardiovascular Failure
Renal FailureHematologic Failure
Immunologic Failure
The MODS Patient
HIGH MORTALITY
50-90%
-Courtesy of Matt Paden
4
Thrombotic Thrombocytopenic Purpura (TTP)
A thrombotic microangiopathy syndrome Critical defect: deficiency of ADAMTS-13
(< 10%):
A disintegrin and metalloprotease with thrombospondin motifs-13 (formerly vWf cleaving protease)
Ultra-large vWf multimer-platelet thrombi Microthrombotic multi-organ vascular injury:
MOF and autopsy findings
5
Thrombotic Microangiopathy: TTP/TAMOF
IL- 8TNF-IL- 6+R
ADAMTS13 AbIL-6
X
ADAMTS13(vWF-CP)
Endothelium
Endothelium PAI-1
PAI-1
PAI-1
PAI-1
PAI-1 PAI-1
vWF
vWF
PAI-1
TFPI TFPI
PlasminPlasminogen
PAI-1
X
Platelet
Platelet
Platelet
Platelet
Platelet
Platelet
TF TF
Shear stress
Platelet
Platelet
Platelet
ADAMTS13 AbIL-6
ADAMTS13(vWF-CP)
x
IL- 8TNF-
IL- 6+R
6
Thrombocytopenia-Associated Multiple Organ Failure (TAMOF)
A thrombotic microangiopathy described in children (Nguyen, Carcillo 2001)
Similarities to TTP• Deficient ADAMTS-13• Increased ADAMTS-13 inhibitors• Increased vWF antigen• Increased ULvWF multimers• Thrombocytopenia
Primarily secondary to sepsis 3 or greater organ failure High mortality in children
7
ADAMTS-13 Deficiency in Adult Sepsis
-Martin et al., Crit Care Med 2007
8
Adult Sepsis-Survival by ADAMTS-13 Level
ADAMTS-13 above median
Below median
-Martin et al., Crit Care Med 2007
9
ADAMTS-13 Deficiency in Pediatric Sepsis
-Nguyen, Hematologica 2006
10
Refractory Sepsis/MOSF: Desperate Times…
Diseases desperate grownBy desperate appliance are relieved, Or not at all.
-Claudius, King of Denmark,Hamlet Act IV Scene 3W. Shakespeare
11
Rationale for Plasma Exchange: TTP
80-90% mortality Plasma Exchange
10% mortality:• Replenishes ADAMTS-
13
• Removes ADAMTS-13 inhibitors
• Removes thrombogenic ULvWf multimers
-Rock, NEJM 1991
12
Plasma Exchange: Rationale In Sepsis
Subset of patients who demonstrate thrombotic microangiopathy similar to TTP
Similar clinical and coagulation factor profile• Deficiency of vWf cleaving protease (ADAMTS-
13)• Platelet/vWf microthrombi• Thrombocytopenia
13
14
CRRT/Plasma Exchange
CRRT/Plasma Exchange
Time
Time
SIRS/CARS
SIRS CARS SIRS CARS
I mmunohomeostasis
I mmunohomeostasis
Pro-inflammatoryMediators
Anti-inflammatoryMediators
IL-1TNF PAF
IL-10
Adapted f rom Ronco et al. Artificial Organs 27(9) 792-801, 2003
Peak Concentration Model of Sepsis
15
Plasmapheresis in Severe Sepsis and Septic Shock
PRCT, Russian adult ICU
106 sepsis patients randomized to:• Standard therapy• Addition of
plasmapheresis (1/2 FFP, 1/2 albumin)
Decreased mortality with plasmapheresis
- Busund et al., Intensive Care Medicine 2002;28:1410
53.8
33.3
0
10
20
30
40
50
60
Standard Plasma
*
*P< .05
16
TAMOF/Plasma Exchange in Children: CHP Trial
28 children with TAMOF• Decreased ADAMTS-13 vs. non-TAMOF• Correlated with outcome
Small RCT (10 patients) 28-day survival
• No PEx: 1/5• PEx: 5/5 (p < .05)
-Nguyen et al., CCM 2008
17
CHP Trial: PELOD Improved with PEx
Pediatric Logistic Organ Dysfunction Score
DAY
0 5 10 15 20 25 30
PE
LOD
0
20
40
60
80
100
Plasma ExchangeNo Plasma Exchange
Figure 3. Pediatric Logistic Organ Dysfunction Score, Mean with standarderror for patients who received plasma exchange therapy (N = 5) and who did not receive plasma exchange therapy (N = 5) for each day x 28 days.
17-Nguyen et al., CCM 2008
PEx
18
Plasma Exchange Replenishes ADAMTS-13
-Nguyen et al., CCM 2008
19
Children’s TAMOF Network
Broader group of Pediatric ICUs Goals:
• Create a study group to perform prospective, observational studies
• Identify TAMOF and evaluate: Clinical and biochemical course Use of specific therapies Associated outcomes
• Inform development of future prospective trials
20
Children’s TAMOF Network
Enrolling centers (site co-I):• Children’s of Atlanta at Egleston: coordinating center
(Fortenberry)• Children’s of Pittsburgh (Raj Aneja/Joe Carcillo)• Cincinnati Children’s (Derek Wheeler)• Nationwide Children’s-Columbus OH (Mark Hall)• Phoenix Children’s Hospital (Sandra Buttram/Heidi
Dalton)• Texas Childrens’ Hospital (Laura Loftis/Trung
Nguyen)• Michigan-Mott Children’s (Yong Han)• Minnesota (Rod Tarrago)• Vanderbilt-Carrell Children’s (Rick Barr/Geoffrey
Fleming)
21
Hypotheses
Children with TAMOF demonstrate decreased ADAMTS-13 levels and increased vWf antigen levels.
Children with TAMOF receiving PEx demonstrate associated improvement of organ dysfunction and survival vs. those receiving standard therapy alone.
22
Methods
Prospective, observational, nonrandomized cohort study
Enrolled patients 1 month-21 years of age meeting TAMOF criteria:• Sepsis, transplant, chemotherapy• Platelet count < 100,000/mm3
• Organ failure index (OFI) > 2 Data collected via web-based registry
23
Methods
Blood obtained for:• ADAMTS-13• vWf antigen levels• Studies performed at Baylor College of Medicine
(Trung Nguyen MD) Therapy, and use of PEx at attending/center
discretion• Typical: centrifugation approach• Suggested protocol:
FFP: 1.5x plasma volume day 1 1x plasma volume daily exchanges x 4 days
• Duration at MD discretion
24
Results: Demographics
Overall No PEx (21) PEx (60)
Mean age (yr) 8.6 + 6.2 6.7 + 6.3 9.2 + 6.4
Mean weight (kg)
35.2 + 27.9 29.8 + 27.6 37.2 + 28.5
Race: White (%) 65.4 63.6 66.1
Race: A-A 19.8 22.7 18.6
Diagnosis-Sepsis
79/81 20/21 59/60
Ever on ECMO 30/81 (37%) 4/21 (13) 26/60 (43.3)
Ever on CRRT 46/81 (56.8%) 8/21 (41.1) 38/60 (63.3)
-No differences between groups
- 81 patients enrolled and met criteria
25
Results: Severity of Ilness
Overall No PEx (21) PEx (60) P value
Baseline PELOD
20.2 + 12.1 15.8 + 10.1 21.9 + 12.4 .04
Baseline PRISM 18.2 + 6.8 16.9 + 5.5 18.7 + 7.2 0.28
Baseline OFI 4.5 + 1.2 4.2 + 1.0 4.6 + 1.2 0.21
Baseline Platelet Count (x 1000)
62.2 + 42.1 55.9 + 35 64.6 + 44.7 0.42
Baseline ADAMTS-13 (%)
52.9 + 27.8 63.7 + 26 49.9 + 28 0.22
Baseline vWF Ag (%)
161 + 66.3 217 + 73 146 + 56.4 0.005
26
Results: Therapies
Treatment:• No PEx: 21 patients• PEx: 60 patients
Use of CVVH: 46 patients (57%)• No PEx 8 (41%)• PEx 38 (63%) p = 0.07
Use of ECMO: 30 patients (37%)• No PEx: 4 (13%)• PEx: 26 (44%) p = 0.07
27
TAMOF Network Results: 28 Day Survival
No PEx: 61.9%
PEx: 68.3%
P = 0.5
-PELOD scores decreased more rapidly in patients receiving PEx (p < .05)
*
- PEx associated with increase in ADAMTS-13 in first 4 days
30
Multivariable Risk Factors for Death: PELOD and Plasma Exchange
Variable
Descriptive StatisticsNo. (%) / Mean (SD)
Estimate Standard Error
Odds Ratio
95% CI P-value
ECMO 30/81 (37.0%)0.4676
0.6167 1.596 0.48-5.4 0.45
CVVH 45/81 (55.6%)0.7484
0.6215 2.114 0.63-7.2 0.23
Baseline PELOD(per 5 pt increase)
21.2 (11.4)0.1100
0.0321 1.734
1.27-2.4
0.0006
MRSA Infection
12/81 (14.8%)0.8618
1.2200 2.367
0.51-10.9
0.27
Plasma Exchange
60/81 (74.1%) -1.3213 0.6801 0.267 0.07-1.01
0.05
31
Risk Factors
For every 5 unit increase in PELOD score at baseline (day 1 on study) mortality risk increases 1.73 times (p=0.0006)
PEx reduced risk of death by 73.3% = odds of survival 3.75 times higher with PEx (p = 0.05)
32
Conclusions
TAMOF patients demonstrated:• Decreased ADAMTS-13, increased vWf
antigen, consistent with TTP profile Use of PEx vs. standard therapy was
associated with: Greater improvement in organ dysfunction Better survival (adjusted for severity, risk
factors) Cannot conclude outcome benefit
33
Next Steps
These results could inform a randomized trial to determine contribution of PEx to TAMOF outcome
Need to better define subgroups; use biomarkers• ADAMTS-13 real-time
Submitted a U34 Planning Grant: Rare Thrombotic and Hemostatic Disorders
34
Alexis- A Success Story
35
Why Not Plasma Infusion Alone?
Plasma Infusion• Restores procoagulant
factors• Restores anticoagulant
factors (protein C, AT III, TFP-I)
• Restores prostacyclin• Restores tPA• Restores ADAMTS-13
Plasma Exchange• Restores factor
homeostasis like plasma infusion
In addition:• Removes ADAMTS-13
inhibitors• Removes ultra-large
vWF multimers• Removes tissue factor• Removes excess PAI-1• Maintains fluid balance
during procedure vs. infusion
36
Course of Organ Dysfunction and TMA: Plasma Infusion vs. Plasma Exchange
36 adult TMA patients Decreased mortality with
plasma exchange Plasma infusion group
• received larger volumes
• had larger weight gain
- Darmon et al., Crit Care Med, 2006
31.8
0
0
5
10
15
20
25
30
35
Plasma
Infusion
Plasma
Exchange
*
37
Days of Plasma Exchange
Non-survivors(n = 19)
Survivors(n = 40)
No. / Total (%)
Total Days on PEx Therapy 1 6/19 (31.6%) 0/40 (0%)
2 4/19 (21.1%) 1/40 (2.5%)
3 1/19 (5.3%) 7/40 (17.5%)
4 1/19 (5.3%) 1/40 (2.5%)
5 2/19 (10.5%) 14/40 (35.0%)
6 1/19 (5.3%) 6/40 (15.0%)
7 1/19 (5.3%) 9/40 (22.5%)
8 2/19 (10.5%) 0/40 (0%)
10 0/19 (0%) 2/40 (5.0%)
14 1/19 (5.3%) 0/40 (0%)
38
Results: Site Enrollment
Non-Plasma Exchange Group(n = 21)
Plasma Exchange Group(n = 60)
Deaths by Site
CHOA-Egleston 0/1 (0%) 10/22 (45.5%)
Pittsburgh - 0/6 (0%)
Columbus 3/5 (60.0%) -
Cincinnati 0/2 (0%) -
Texas Children’s 3/5 (60.0%) 1/2 (50.0%)
Minnesota 0/1 (0%) 3/13 (23.1%)
Vanderbilt 1/6 (16.7%) 2/4 (50.0%)
Michigan - 1/9 (11.1%)
Phoenix 1/2 (50.0%) 2/3 (66.7%)
All sites 8/21 (36.4%) 19/60 (32.2%)
39
Results: TAMOF Patients
Overall survival 54/81 (67%) • No PEx: 13/21 (61.9%)• PEx: 41/60 (68.3%) NS
Survival: PELOD > 21 (47)• No PEx 50 %• PEx 56.4 %
Survival: PELOD < 21 (34)• No PEx 77.8 %• PEx 90.5 %
40
Everything will be all right in the end. So if it is not all right, then it is not yet the end.
41
Desperate but Reasonable?
42
Plasma Therapies in Sepsis-Why Use Them?
General: exchange “transfer factors” Specific: control thrombotic microangiopathy
(TMA) Slow progression of TMA-induced organ
failure Treat coagulation abnormalities