Critical Care

Question 1

How can PEEP and Pplat differ in patients receiving APRV?

Answer 1

Pplat should be the same as the set inspiratory pressure, but PEEP may be higher if the patient is auto-PEEPing, may need to perform expiratory pause to see.

Question 2

How can a circuit leak affect the patient’s ventilation?

Answer 2

Can falsely trigger more breaths as the drops in pressure are interpreted as patient effort. Can be due to partial circuit disconnect, ruptures cuff, or large BP fistula

Question 3

What conditions need to be met for IVC/SVC variation or pulse pressure variation to have adequate predictive value for volume responsiveness?

Answer 3

Patient must be passive, in sinus rhythm, VT 8ml/kg IBW, abdominal pressure less than 12, HR/RR ratio >3.6.

Question 4

When is Pplat measured?

Answer 4

During an inspiratory pause, and a no-flow state

Question 5

How is right ventricular pressure overload distinguished from volume overload on POCUS?

Answer 5

The timing of septal flattening. If during systole and diastole, then pressure overload. If only on diastole, then volume overload.

Question 6

What is one measure seen to reduce delerium in intubated patients?

Answer 6

PT/OT started at the time of intubation for patients that can tolerate it. No data to support day-night time routines.

Question 7

What would you see on ultrasound for a pneumothorax?

Answer 7

Absence of lung sliding, sometimes a lung point, A lines

Presence of B lines rules out PTX

Question 8

What are the features of EVALI?

Answer 8

Features: diffuse lung injury, can see tetrahydrocannabinol and vit E acetate in BAL, vaping in the last 90 days
Imaging: diffuse GGO, organizing PNA
Dx: rule out other causes, eosinophilia in BAL/peripheral blood rare
Tx: steroids, supportive treatment

Question 9

What causes autocycling?

Answer 9

Sawtooth pattern on vent on expiration, which signals pressure fluctuation in the airway to alter flow but not trigger the vent.

Can be due to cardiac contraction, mechanical ventricular assist devices, bubbling of a chest tube suction device, oscillations of water in ventilator tubing.

Question 10

What are the benefits to APRV vent settings?

Answer 10

Generally less sedation/paralysis as patients are encouraged to breathe on top of the settings. But end point such as vent free days and survival have not been seen, and in some cases may worsen barotrauma in ARDS patients.

Question 11

What is the estimated RAP on TTE evaluation of the IVC?

Answer 11

0-5cm: IVC collapses entirely and is <1.5cm
5-10cm: IVC collapses >50% and is 1.5-2.5cm
11-15cm: IVC collapses <50% and is 1.5-2.5cm
16-20cm: IVC collapses <50% and is >2.5cm

Question 12

How does one determine candidacy for decannulation from tracheostomy?

Answer 12

Spontaneous breathing with continuous flow oxygen for 12+hrs on two consecutive days, not requiring suctioning more than 2x in 8 hr period over 24hrs (better criteria than 24hr capping and with less PNA and short LOS)

Question 13

What vent changes can be made for ARDS patients who are then cannulated?

Answer 13

Decrease FiO2, decrease TV. Maintain PEEP to prevent collapse-reopening injury.

Question 14

What risk factors are there for developing methemoglobinemia?

Answer 14

Change from oxygen binding ferrous state to non-binding ferric state in Hgb.

Meds: chloroquine, dapsone, bactrim, lido, nitrates, reglan

Treat with methylene blue

Question 15

How does a difference in arterial line transducer level correlate with the difference in pressure?

Answer 15

10cm- 7.6mmHg
When the transducer is above the level of the heart, the tracing is a falsely low BP

Question 16

How long would one treat amiodarone toxicity with steroids?

Answer 16

40-60mg/day with a slow taper over 4-12 months

Question 17

What change in VTI predicts volume responsiveness?

Answer 17

10% or more

Question 18

Describe the differences between serotonin syndrome, NMS, and malignant hypertension

Answer 18

SS- mental status change, hyperactive GI disturbance, neuromuscular abnormalities, and autonomic dysfunction (pupillary dilation/mydriasis with BP changes and diaphoresis). 2hrs-24hrs after ingestion of culprit.

NMS- often rapid increase in antipsychotic meds. AMS, rigidity, pyrexia, elevated CK, autonomic dysfunction. Don’t see the shivering/hyperreflexia/myoclonus/ataxia/GI symptoms of SS

MH- usually anesthesia related. Abrupt elevation in end-tidal CO2. hyperthermia, rigidity, dysautonomia like NMS, but is more abrupt.

Question 19

What is electrical impedance tomography?

Answer 19

Uses analysis of electrical impedance signals across the chest to depict regional lung ventilation, may be helpful in avoiding overdistention

Question 20

When does one start to worry about self-induced lung injury on the ventilator?

Answer 20

VT More than 15mL/kg despite low pressure support

Question 21

Recall the regions affected by their corresponding coronary artery on short axis POCUS

Answer 21

Question 22

What are some causes of sudden volume loss on pressure control ventilation?

Answer 22

Obstruction- will see reduction in inspiratory flow, expiratory flow and expiratory time is prolonged. Caused by plugging, kinking of tubes, foreign body, blood clot in ETT, bronchospasm

Abrupt compliance reduction- inspiratory/expiratory flow reduced but also times are short. Caused by flash edema, PTX, pleural bleeding, mainstem bronchus intubation

Circuit leak- discrepancy between inspired volume and expired volume (expired much less)

Question 23

What causes increases in peak and/or plateau pressures in volume control?

Answer 23

Both increased- compliance worsening

Peak increased but not plateau- resistance worsening

Question 24

How do you calculate stroke volume from VTI?

Answer 24

SV= cross-sectional area X VTI
VTI need LVOT diameter to the square the radius X pi

Question 25

What ultrasound sign can you see in infiltrative cardiomyopathy?

Answer 25

“starry night” appearance of myocardium, such as in amyloidosis

Question 26

What factors place patients at risk for developing CAUTI?

Answer 26

Duration of catheterization, bacterial colonization of the drainage bag, older age, female gender, DM, breach of sterile technique, disruption of closed system

Question 27

How can one determine the intrinsic PEEP on the vent?

Answer 27

Expiratory hold

Question 29

How can pulsus paradoxus be seen on ultrasound?

Answer 29

During inspiration when intrathoracic pressure is increased, LV preload increased and LV afterload decreases resulting in increased LVOT velocities. Opposite on exhalation.

Question 30

What strategy can be used to eliminate double triggering on the ventilator?

Answer 30

Adding 1s inspiratory hold is it will cut off the circuit from registering any inspiratory effort during that time

Question 31

What is a lung pulse seen on ultrasound?

Answer 31

A still but inflated lung is in contact with pleural space and pulsating from heart movement, no PTX present at that spot

Question 32

What are POCUS findings for PTX?

Answer 32

Absent lung sliding with A lines, lung point (specific but not sensitive)

Question 33

What is abdominal rounding consistent with?

Answer 33

During expiration, the lateral walls of the abdomen go inward, and the periumbilical region moves outward. Sign of volume overload as the body is trying to create intrinsic PEEP to reduce afterload on the left ventricle

Question 34

How do you manage drug coagulopathies for ICH?

Answer 34

Those receiving vit K- prothrombin complex over fresh frozen plasma

Antiplatelet- don’t give platelets unless going in to surgery

Question 35

Review a chart for vasopressors

Answer 35

Question 36

How does albumin+diuretic affect ARDS patients with hypoproteinemia?

Answer 36

Better oxygenation, more effective fluid removal, better hemodynamic tolerance

Question 37

Solutions to ventilator asynchronies

Answer 37

Ineffective trigger: decrease trigger threshold on vent
Double trigger: increase inspiratory time
Flow asynchrony: increase flow
Delayed termination: decrease inspiratory time
Premature termination: increase inspiratory time
Intrinsic PEEP: measure with expiratory hold, decrease rate/TV, deep sedation

Question 38

What are some things you’ll need to watch for in cooling and rewarming of TTM management?

Answer 38

Cooling: cold diuresis, coagulopathy, insulin resistance (hyperglycemia), bradycardia, increased lactate, reduced drug clearance

Rewarming: hyperkalemia (shift to extracellular), seizures
Rewarm at 0.25C/hr

Question 39

After TTM (72hrs out), what factors are associated with poor neuro outcomes?

Answer 39

2+ of the following:
No pupillary/corneal reflexes
Bilaterally absent N20 SSEP wave
Highly malignant EEG after 24hr
NSE >60ug/L at 48h and/or 72h
Status myoclonus
Diffuse and extensive anoxic injury on CT/MRI

Question 40

How do you calculate brain perfusion pressure?

Answer 40

MAP-ICP
Normal 60-80