venovenous

Question 1

severe mortality associated with ARDS with conventional ventilation

Answer 1

• severe respiratory failure and acute respiratory distress syndrome (ARDS) ranges from 40% to 50% with conventional medical management.

Question 2

GENERAL goals of lung-protective ventilation

Answer 2

lung-protective ventilation seeks to:

1. avoid barotrauma (by monitoring transpulmonary pressure and avoiding high airway pressures),
2. avoid volutrauma (by avoiding excessive tidal volumes, thereby allowing the lung to rest),
3. avoid atelectotrauma (by maintaining adequate positive end-expiratory pressure (PEEP)]
4. avoid oxygen toxicity (by decreasing ventilator oxygen levels when PEEP is adequate)

Question 3

typical initial circuit settings for VV-ECMO

Answer 3

1. FIO2 (fraction of inspired oxygen) is set at 1.0
2. sweep gas-flow rate of 2–5 L/min (sweep up to 15 L/min for PACo2 < 40)
3. evolutions per minute (RPM) set to achieve 50–80 mL/kg IBW /min of flow.
4. Maintain SaO2 80-85 (as long as pt doing OK - SVO2, lactate nl )

Question 4

Typical initial flow of VV-ECMO

Answer 4

revolutions per minute (RPM) set to achieve 50–80 mL/kg/min of flow.

Question 5

Currently recommended ventilator settings for initiation of VV ECMO

Answer 5

• tidal volume to 4–6 mL/kg of predicted body weight
• plateau pressure of ≤25 cmH2O,
• with a PEEP of 10 cmH2O

Question 6

Initial tidal volume for patients on VV

Answer 6

tidal volume to 4–6 mL/kg of predicted body weight

Question 7

Goal Plateau pressure for patients on VV

Answer 7

plateau pressure of ≤25 cmH2O,

Question 8

Goal PEEP for patients on VV

Answer 8

with a PEEP of 10 cmH2O

Question 9

in VV-ECMO what are the key determinants of peripheral oxygen saturation?

Answer 9

1. the oxygen fraction of the circuit
2. the ratio of ECMO flow to native cardiac output
3. metabolic demand
4. native lung function
5. Recirculation

Question 10

Initial sweep for patients on VV-ECMO

Answer 10

sweep gas-flow rate of 2–5 L/min (sweep up to 15 L/min for PACo2 < 40)

Question 11

Goal initial SaO2 for patients on VV ECMO

Answer 11

Maintain SaO2 80-85 (as long as pt doing OK - SVO2, lactate nl )

Question 12

Levy protocol - for SaO2 < 88%

initial things to check

Answer 12

Check CXR - cannula malposition/ Recirculation

Circuit for filter dysfunction

Lung complications?

Low pre-filter SaO2?

Question 13

Levy protocol - for SaO2 < 88%

• cannula OK, no recirc
• No lung issues
• Prefilter SAO2 Ok

what next?

Answer 13

increase the ECMO flow to 6-7 L

Question 14

Levy protocol persistent SAO2

Flow at 7 L.min

CIrcuit OK

No lung complications

what next?

Answer 14

Check Hgb, transfuse to HgB > 10

Question 15

Persistent hypoxemia, flow, circuit, HgB already corrected what to check for ?

Answer 15

QECMO / QCO < 60%

if present, consider:

Hypoxemia or Esmolol

Question 16

The classic signs of recirculation

Answer 16

The classic signs of recirculation are low SaO2 and high SpreO2 (preoxygenator saturation).

Question 17

The formula for recirculation:

Answer 17

Recirculation (%) = (SpreO2 – SvO2) / (SpostO2 – SvO2) × 100

Question 18

“30-30-10-10” approach

Answer 18

“30-30-10-10” approach Goal ventilator settings

• FIO2 : 30
• PPlat < 30 cmH20
• PEEP: 10
• RR: 10

Question 19

Labs used to evaluate the amount of hemolysis in ECMO circuit.

Answer 19

• Lactate dehydrogenase
  
  • can indicate circuit-induced hemolysis (only if sepsis is not present)
• Routine testing for free plasma hemoglobin:
  
  • more accurately determines if hemolysis is occurring in the circuit.

Question 20

From what material is the oxygenator membrane constructed ?

Answer 20

polymethylpentene

• less hemolysis
• less pressure drop
• less plasma leakage
• has a longer lifespan than materials used in earlier oxygenators

Question 21

Normal-pressure drop across the Oxygenator membrane?

At what level pressure drop is changing the oxygenator strongly suggested ?

Answer 21

A normal pressure drop across a membrane is <50 mmHg;

a change in pressure >100 mmHg strongly suggests an obstruction within the oxygenator

Question 22

Incidence of RV failure with ARDS ?

Answer 22

The incidence of RV failure related to ARDS has been reported to be 10–25%.

Question 23

Treatment of RV failure on VV-ECMO

Answer 23

• Treat Pulmonary Hypertension
  
  • hypoxemia
  • hypercarbia
  • acidemia cause
• pulmonary vasodilators
• inotropes
• diuretics.

Question 24

initial treatments of Pulmonary Hypertension

Answer 24

Treat Pulmonary Hypertension

1. hypoxemia
2. hypercarbia
3. acidemia cause

Question 25

Mortality associated with severe ARDS

Answer 25

up to 45%

Question 26

Does the patient fulfill oxygenation and/or ventilation criteria?

Answer 26

Does the patient fulfill oxygenation and/or ventilation criteria?

1. • On FiO2 ≥ 80%, PEEP ≥ 10 cmH2O, VT ≤ 6ml/kg (PBW)
2. • PaO2/FiO2 < 50 mmHg for > 3 hours
3. • PaO2/FiO2 < 80 mmHg for > 6 hours
4. • pH < 7.25, PaCO2 ≥ 60 mmHg with RR 35/min for > 6 H

Question 27

ELSO specific criteria for VV-ECMO

Answer 27

1. Mortality > 80%;
2. PaO2/FIO2 < 80 mm Hg with FIO2 > 90%,
3. Murray score 3-4;
4. CO2 retention on mechanical ventilation despite high Pplat (>30 cm H20);
5. Severe air leak syndromes;
6. Need for intubation in a patient on the lung transplant list;
7. Cardiac or respiratory collapse

Question 28

ELSO Mortality Rule

Answer 28

ELSO Mortality Rule:

ECMO should be considered when the expected mortality rate surpasses 50%,

ECMO is indicated when it exceeds 80%.

Question 29

ARDS severity and Expected mortality with P/F ratio >200-300?

Answer 29

>200-300

Mild ARDS

27%- expected mortality

Question 30

ARDS severity and expected mortality with P/F ratio of >100-200?

Answer 30

P/F Ratio >100-200

Moderate ARDS

32% expected mortality

Question 31

ARDS severity and predicted mortality with P/F Ratio of ≤100

Answer 31

Severe ARDS

45% predicted mortality.

Question 32

Impact of CRRT on mortality

Answer 32

3.7 fold increase