Critical Care

Question 1

How to calculate driving pressure

Answer 1

Tidal Volume / compliance

DP= Plateau pressure - PEEP

Goal <15

Question 2

How to reduce driving pressure

Answer 2

Lower Tidal Volume
improve compliance (change peep)

Question 3

POCUS: lung slide absent with B lines means…

Answer 3

Pneumonia

Question 4

POCUS findings of pneumothorax

Answer 4

Absent lung slide
A lines
NO b lines
Lung point to confirm

Question 5

What is set on APRV

Answer 5

Glorified CPAP with quick breaks to release CO2

• P high - 30-35
• P low (PEEP) - 0-5
• T high (inspiratory time) - usually 4- 8 sec
• T low (exp time) - usually 0.3-0.8sec
• FiO2

RR= # releases (ie 60sec/Thigh - Tlow)

Question 6

What do you adjust on VV ECMO to change CO2 clearance

Answer 6

Sweep gas flow

Question 7

What do you adjust on VV ECMO to change Oxygenation

Answer 7

oxygenator blood flow

Question 8

Overall goal with vent when pt on VV ECMO?

Answer 8

Reduce FiO2 and vent pressures to achieve the most protective vent settings

Question 9

Causes of low compliance on vent (ie increased PIP and plateau pressure)

Answer 9

Pulmonary:
- atelectasis
- Pulm edema
- Pneumothorax
- Hyperinflation
- Pulmonary fibrosis

Extra pulm:
- Abdominal distention
- Chest wall rigidity
- Main stem ETT

Question 10

What causes high lung resistance on vent?

Answer 10

Increased PIP with normal Pplat

-Secretions
-Bronchospasm (asthma, COPD)
-Trouble with tube (biting, kinked, too small)
-Circuit filled with water

Question 11

calculating Compliance

Answer 11

Compliance = TV/ (plateau pressure - PEEP)

Question 12

How to assess for abdominal compartment syndrome

Answer 12

Bladder pressure

> 12 abnormal
Severe is >25

Question 13

How to classify ARDS severity?

Answer 13

P/F

Severe <100
Moderate 100-200
mild 200-300

(ALI no longer a category with new criteria)

Question 13

How to fix delayed cycle termination dyssynchrony?

Answer 13

Problem with pt exhaling while machine still giving insp support

Fix: Shorten set I time on vent
or switch to PS
or adjust sedation

Question 14

What causes double triggering?

Answer 14

pt insp time > vent insp time
2 breath given w/o expiration b/c pt still inhaling and vent changes to exhalation

Leads to large TV (although might not appear so on monitor)

Question 15

How to fix double triggering?

Answer 15

Fix with increasing I time or decreasing flow

Question 16

What causes flow asynchronies?

Answer 16

Flow startvation
Pt trying to start another breath during vent supported inspiration because pt trying to get more flow

Question 17

How to improve flow asynchronies?

Answer 17

increase flow
Switch to PS

Question 18

What causes missed trigger asynchrony?

Answer 18

pt tries to take breath but effort does not trigger mechanical breath.

Causes:
- air trapping / intrinsic PEEP
- Triggering threshold too high
- Weak resp muscles

Question 19

How to fix missed triggering asynchrony?

Answer 19

Increase sedation
decrease triggering threshold
change insp pressure/flow and cycling criteria

Question 20

How to fix auto PEEP?

Answer 20

increase expiratory time
bronchodilators
increase intrinsic PEEP

Question 21

What causes auto trigger asynchrony?

Answer 21

Air leak

breath initiated from external trigger before vol returns to zero
air leak –> decrease exhalation pressure

Question 22

How to fix auto trigger asynchrony?

Answer 22

Fix leak
If cant (ie bronchopleural fistula) reduce the PEEP to zero so you dont get the auto trigger

Question 23

How to use pulse pressure variation to assess volume responsiveness?

Answer 23

PPV proportional to stroke volume. greater variability in SV (increased PPV) more likely to be fluid responsive.

PPV>12% means if give fluids likely will have increased SV

Question 24

3 conditions for using pulse pressure variation as assessment for volume responsiveness?

Answer 24

1. Pt in sinus rhythm
2. on MV w/o spontaneous resp and TV=8cc/kg
3. NO open chest

also abd pressure <12
HR/RR ratio >3.6

Question 25

What is pulsus pardoxus?

Answer 25

decrease in SBP >10 with respiration

suggests tamponade, severe asthma, COPD

Question 26

Appearance of pulsus alternans on a-line?

Answer 26

alternating strong and weak pulses
iso low cardiac output shock states

Question 27

Appearance of pulsus bisfirens on a-line?

Answer 27

double peaked pulses
Severe AR +/- AS

Question 28

Appearance of pulsus tardus on a-line?

Answer 28

Late peaking pulse
Seen in severe AS

Question 29

Criteria for decannulating pt with trach?

Answer 29

• Pt not requiring suctioning more than 2 times every 8h during 24h period

Superior to using capping trial

Question 30

Management of submassive hemoptysis?

Answer 30

Observation
CXR
labs for coagulation etc
CT with contrast

Consider inhaled TXA 3 times daily for up to 5 days

(Study: reduced expectorated blood and increase chance resolution, decrease need for invasive tests, reduced recurrent bleed at 1 yr)

Question 31

Causes of rapid decreased TV in pressure targeted vent modes?

Answer 31

obstructive changes (mucous plugging, tube kink, foreign body, blood clot, bronchospasm) – will see reduced inspiratory flow and prolonged expiratory time

Compliance reduction (flash edema, pneumothorax, pleural bleeding, mainstem ett) – reduced insp flow, exp and insp times short