Transcript Document

Acute Respiratory Distress Syndrome
(ARDS)
The Extreme
Sue A. Ravenscraft, MD
Pulmonary, Sleep, and Critical Care
Park Nicollet/Methodist Hospital
Clinical Professor of Medicine
University of Minnesota Medical School
The Case
ECMO
Management of ARDS
• Mechanical Ventilation strategies
• Prone Ventilation
• Novel/Adjunctive Therapy
Case
19 year old female college student
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Lives in the dormitory
Healthy, non-smoker
No recent travel, trauma, exposures
Influenza vaccine current
Emergency Department
1 day of dry cough/emesis
T = 99.3, Sat 97%
Lungs:  left base
• Influenza negative
• Azithromycin
Urgent Care (Day 2)
Fever with persistent cough,  appetite
Physical exam:
Temp: 39.2, RR 32, HR 144, BP 108/82, 93% on RA
Moderately dehydrated and febrile
wbc 5.8
2 L IV Saline
IM Ceftriaxone
Δ oral Levofloxacin
ED/Admission (Day 3)
Continued cough and emesis with diarrhea,
fever and chest pain
Temp 100.8, 169/87, HR 128, RR 18
O2 96 % (3 L/min)
Creat 2.3
Given fluids, Ceftriaxone, azithromycin
Admitted to Medicine floor
Admission CXR
RET
Tachypneic (rr=60) and O2 sats 40%.
Patient complaining of dyspnea, chest
pain with coughing and deep
inspiration
2130
0000
0434
BP
127/72
126/79
158/87
HR
118
108
137
Temp
98.6
99.1
99.7
Resp
48
40
69
O2
94%
93%
60%
0445
138
79%
RET
Temp 99.7, HR 137, BP 158/87, RR 68, O2 60%
Alert in severe distress, speaking in 1 word phrases
Lungs: coarse BS,  breath sounds
• Moved to ICU
• Non-invasive
ventilation
(BiPAP)
7.38/36/45/20
ICU
• Increased work of breathing continues on high
flow oxygen
• Intubated
A/P:
Respiratory failure with ARDS and bilateral
pneumonia
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Low tidal volume: VT 380, RR 24, PEEP 10, FiO2 90%
Nebulized Epoprostenol (Flolan™)
Bronchoscopy when stable
Consult Nephrology and ID
Berlin Definition of ARDS 2012
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(JAMA 2012; 307:2526)
Symptoms within 1 week of clinical insult, or new or worsening
symptoms during week
Bilateral opacities consistent with pulmonary edema on CXR/CT
Opacities not be explained by pleural effusions, lobar collapse,
or pulmonary nodules
No underlying cardiac failure or fluid overload
Measured PaO2/FiO2 on PEEP ≥ 5 cm H20
Mild: > 200 mmHg ≤ 300 mmHg
Moderate: > 100 mmHg ≤ 200 mmHg
Severe: ≤ 100 mmHg
pH: 7.38/36.2/ 45.5/20.8
Oxymizer 15L (delivers between 65-75% FiO2)
Pa02/Fi02: 65 mmHg
Incidence: ARDS inpatient
15-19 years of
age: 16 per 10,000 persons-years
ARDS: Etiology
Common causes: (> 60 identified)
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Sepsis *
Aspiration *
Pneumonia *
Severe trauma
Massive Transfusion
Transfusion related acute lung injury (TRALI)
Lung and hematopoietic stem cell transplant
Drug and alcohol
Risk factors: Genetic determinants, cigarette smoking,
cardiopulmonary bypass, pneumonectomy, acute pancreatitis,
obesity, and near drowning
ARDS: Definition
Disease of the lung parenchyma that leads to
impaired gas exchange. It is associated with
pulmonary cytokine release, impaired endothelial
barriers, loss of surfactant, fluid accumulation
in the alveoli and, later, fibrotic changes.
ICU Day 5
Nephrology: likely acute kidney injury in setting of
critical illness with subsequent transition to ATN
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Creat 4.5
Oliguric
5 kg in 24 hours
Multiple labs sent
Infectious Disease: Bilateral pneumonia/pneumonitis
in immunocometent host
• Serologies, cultures and bronchoscopy non-diagnostic
• Vancomycin, Pipracillin-Tazobactam/Levofloxacin
ICU Day 6
7.23/40/69/16
Sat 93.9
VT 380 ml, FIO2 60%, PEEP 10
PaO2/FiO2: 116
(Moderate ARDS)
• Continues nebulized high-dose
Epoprostenol (Flolan)
• Patient drops saturations with
movement recovers quickly
• Anuric and started CRRT today
• Prone ventilation deferred due
to CRRT
ICU Day 8
7.21/69/66/27
Sats 91.8%
RR 24, FIO2 80%, PEEP 12, PC +25
PaO2/FiO2: 83 (severe ARDS)
• Sats marginal with permissive
hypercapnia.
• Bronchoscopy done with removal
of thick secretions
• Proned
ICU Day 9
pH 7.30/50/122/24
RR 24, VT 430 ml, FiO2
100%, PEEP 12, PC 33
Marginal improvement after
proning; continues to be very
difficult to ventilate and
oxygenate
CRRT tolerated while prone
It Didn’t Work!
ICU Day 10
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Worsened overnight
Intolerant of supine position
Sats in 70s with any movement
Unable to transfer
U of MN contacted
and arranged for
transport on ECMO
The Transport:
One Chance
The Team:
U of MN
Cardiac surgeon, Fellow
2 prefusionists
Transport paramedics
Methodist
ICU nurses, OR nurses, RT, Intensivist, Critical
Care Fellow, Nephrologist, Cardiologist, Echo Tech
Catheters Placed
UMN: Day 3
• ECMO continues
• Lung transplant
Considered
• No improvement
Lung Transplant Consult: (Day 4)
Renal failure a significant contraindication
Neurologic status is not known
Discussed poor prognosis and the general survival
data of lung transplant with patient’s family.
Agreeable with lung transplant as a last option.
Median survival for single-lung recipients is 4.6 years.
Median survival for double-lung recipients is 6.6 years
Lung Transplant evaluation
Decision made by transplant surgeon
and pulmonologist on service to
proceed with emergent listing for
bilateral lung transplant
LAS score (Lung allocation score)
May 2005
Reducing the number of deaths on lung transplant waiting list
Ensuring the efficient and equitable allocation of lungs to
active transplant candidates
Assigns a score ranging from 0 to 100 to all candidates older
than age 12. It is a weighted combination of the predicted
risk of death during the following year on the waiting list
and the predicted likelihood of survival during the first
year following transplantation.
Higher lung allocation scores indicate the patient is more
likely to benefit from a lung transplant.
UMN: Day 10
• Bilateral sequential lung
transplantation with
cardiopulmonary bypass
support
• Chest closure (4 days
afterwards)
• Tracheostomy (11 days
afterwards)
ED
Day 0
UC
Admission
Day Day 3
2
ICU
Day 4
RET
Dialysis
ECMO
(Day 10)
Prone position
UMN
Transplant
evaluation
Lung Transplantation
(Day 20)
Native Lung
Pathology: Diffuse alveolar damage
Follow-up: Present day
19 year-old, healthy, female with ARDS of unknown etiology
despite extensive infectious, rheumatologic, and pulmonary workup.
ECMO as bridge to BSLTx
Slow recovery requiring tracheostomy and rehab
Home 3 months after transplant
Kidney function did not return.
Successful living related donor
kidney transplant 5 months later
Now home and off dialysis
ECMO
(Extracorporeal Membrane Oxygenation)
Mechanical devices to temporarily
support the failing heart or lungs
• Cardiopulmonary bypass used in OR for
short term support
• VA ECMO drains from RA or IJ
through membrane lung returned to
femoral or subclavian artery (cardiac)
• VV ECMO drains from IVC through
membrane lung returned to IJ (lung)
VV ECMO
VV ECMO
Cannulas are large (31 Fr)
• Double lumen available
• Flow 4-5 L/min
Minimal lung ventilation
• Plateau pressure 20 cmH2O
• FIO2 50%
Anticoagulated
ECMO: Does it work?
75 matched pairs with H1N1 induced ARDS found that
referral and transfer to an ECMO center was associated
with lower hospital mortality (23.7 versus 52.5 percent)
(JAMA. 2011;306(15):1659)
Efficacy and economic assessment of conventional ventilatory
support versus extracorporeal membrane oxygenation for
severe adult respiratory failure (CESAR): a multicentre
randomised controlled trial.
(Lancet 2009;374(9698):1351)
n=90 each group
ECMO group 68 (75%) received ECMO
63% no disability at 6 months
Conventional group
47% no disability at 6 months
Mechanical Ventilation in ARDS
• High ventilating pressures cause
ventilator induced lung injury
• Lung Protective Ventilation
• Low VT improves mortality
• Meta-analysis 6 trails (n=1297)
• 6 ml/kg vs 12 ml/kg
• 28 day mortality 27% vs 37%
(Ann Intern Med 2009;157:566)
Mechanical Ventilation: ARDS
Low Tidal Volume Ventilation
Slowly drop VT to 6 ml/kg IBW and
maintain Pplat ≤ 30 cmH2O
(Plateau)
Mechanical Ventilation: ARDS
Low Tidal Volume Ventilation
Permissive Hypercapnia
• PaCO2 increases to keep pH ≥ 7.25
• PEEP to keep lung open and minimize
cyclic atelectasis (8-16 cmH20)
• Goal to drop FIO2 ≤ 60% before
decreasing PEEP and increasing VT
• Consider recruitment maneuvers
ARDS: Prone Positioning
Improves ventilation/perfusion
matching
Oxygenation and Proning
ARDS: Prone Positioning
Multicenter randomized trial
• Prone > 16 hours/day vs supine
(n=230/group)
Severe ARDS PaO2/FIO2 <150 mmHg
• Lung protective ventilation
– VT 6 ml/kg, Pplat < 30 cmH2O, pH > 7.2
– Ventilated < 36 hours
• Primary endpoint 28 day mortality
N Engl J Med. 2013;368(23):2159
16%
(p < 0.001)
38%
28 Day mortality
N Engl J Med. 2013;368(23):2159
ARDS: Adjunctive/Novel Therapy
Inhaled Vasodilators
Selectively dilate vessels in well ventilated lung zones
and improve oxygenation by improved V/Q matching.
Also improve pulmonary hypertension
ARDS: Inhaled Vasodilators
Inhaled Prostacyclin (Epoprostenol,Flolan™)
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Nebulized in inspiratory line
Vary strength
No sophisticated equipment
Improves oxygenation, not mortality
ARDS: Inhaled Vasodilators
Nitric Oxide
• Requires specialized system
• Byproduct nitrogen dioxide highly toxic
• oxygenation
ARDS: Adjunctive/Novel Therapy
Surfactant
• Rationale: prevent atelectasis
• No conclusive data in adults
• Some positive data infants and children
Antioxidants (dietary oils)
• Rationale: reactive oxygen species and
partial depletion of antioxidant defense
appear important in propagation of ARDS
• A few early trial promising
• Recent trials negative, more ongoing
ARDS: Adjunctive/Novel Therapy
High Frequency Ventilation
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Rationale: benefit of low VT ventilation known
f > 60 and VT smaller than dead space
Used after 3 days of hypoxemia
Clinical expertise critical
Used in infants
ARDS: Adjunctive/Novel Therapy
Glucocorticoids (steroids)
• Ongoing controversy: trials both
positive and neutral
• Likely most helpful early and should
not be initiated after 14 days (after
fibroproliferative phase of disease)
ARDS: Patient Outcome
Mortality ≅ 25-30%
Psychiatric: PTSD, depression,
anxiety 30-60% at one year
Physical: abnormal exercise test
66% at 1 and 3 years
Pulmonary: most patients 80%
predicted by 6 months
And to think we complained about hand hygiene!
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