Critical Care Flashcards
How to calculate driving pressure
Tidal Volume / compliance
DP= Plateau pressure - PEEP
Goal <15
How to reduce driving pressure
Lower Tidal Volume
improve compliance (change peep)
POCUS: lung slide absent with B lines means…
Pneumonia
POCUS findings of pneumothorax
Absent lung slide
A lines
NO b lines
Lung point to confirm
What is set on APRV
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)
What do you adjust on VV ECMO to change CO2 clearance
Sweep gas flow
What do you adjust on VV ECMO to change Oxygenation
oxygenator blood flow
Overall goal with vent when pt on VV ECMO?
Reduce FiO2 and vent pressures to achieve the most protective vent settings
Causes of low compliance on vent (ie increased PIP and plateau pressure)
Pulmonary:
- atelectasis
- Pulm edema
- Pneumothorax
- Hyperinflation
- Pulmonary fibrosis
Extra pulm:
- Abdominal distention
- Chest wall rigidity
- Main stem ETT
What causes high lung resistance on vent?
Increased PIP with normal Pplat
-Secretions
-Bronchospasm (asthma, COPD)
-Trouble with tube (biting, kinked, too small)
-Circuit filled with water
calculating Compliance
Compliance = TV/ (plateau pressure - PEEP)
How to assess for abdominal compartment syndrome
Bladder pressure
> 12 abnormal
Severe is >25
How to classify ARDS severity?
P/F
Severe <100
Moderate 100-200
mild 200-300
(ALI no longer a category with new criteria)
How to fix delayed cycle termination dyssynchrony?
Problem with pt exhaling while machine still giving insp support
Fix: Shorten set I time on vent
or switch to PS
or adjust sedation
What causes double triggering?
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)
How to fix double triggering?
Fix with increasing I time or decreasing flow
What causes flow asynchronies?
Flow startvation
Pt trying to start another breath during vent supported inspiration because pt trying to get more flow
How to improve flow asynchronies?
increase flow
Switch to PS
What causes missed trigger asynchrony?
pt tries to take breath but effort does not trigger mechanical breath.
Causes:
- air trapping / intrinsic PEEP
- Triggering threshold too high
- Weak resp muscles
How to fix missed triggering asynchrony?
Increase sedation
Address autopeep
Decrease TV
decrease triggering threshold
change insp pressure/flow and cycling criteria
How to fix auto PEEP?
increase expiratory time (decrease rr, increase flow)
bronchodilators
increase intrinsic PEEP
What causes auto trigger asynchrony?
Air leak
breath initiated from external trigger before vol returns to zero
air leak –> decrease exhalation pressure
How to fix auto trigger asynchrony?
Fix leak
If cant (ie bronchopleural fistula) reduce the PEEP to zero so you dont get the auto trigger
How to use pulse pressure variation to assess volume responsiveness?
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
3 conditions for using pulse pressure variation as assessment for volume responsiveness?
- Pt in sinus rhythm
- on MV w/o spontaneous resp and TV=8cc/kg
- NO open chest
also abd pressure <12
HR/RR ratio >3.6
What is pulsus pardoxus?
decrease in SBP >10 with respiration
suggests tamponade, severe asthma, COPD
Appearance of pulsus alternans on a-line?
alternating strong and weak pulses
iso low cardiac output shock states
Appearance of pulsus bisfirens on a-line?
double peaked pulses
Severe AR +/- AS
Appearance of pulsus tardus on a-line?
Late peaking pulse
Seen in severe AS
Criteria for decannulating pt with trach?
- Pt not requiring suctioning more than 2 times every 8h during 24h period
Superior to using capping trial
Management of submassive hemoptysis?
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)
Causes of rapid decreased TV in pressure targeted vent modes?
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
Calculating stroke volume using POCUS
SV= cross-sectional area x velocity time integral (VTI)
SV= (LVOT/2)^2 x pi x VTI
Assessing right atrial pressure using IVC POCUS- expected measures for high pressure
RAP 16-20- IVC collapses <50% on inspiration and is >2.5cm in diameter
How to estimate RAP 5-10cm on POCUS
IVC collapses >50% on inspiration and is 1.5-2.5cm diameter
How to fix diff in a line BP and cuff?
Pressure transducer should be at level of heart
If higher than heart then BP will be lower
10cm water height = 7.4 mmHg bp
Changing height of arm does not matter as long as transducer is level with heart
Which bacteria can raise CK
Streptococcus (including S pneumoniae)
Staphylococcus aureus
Legionella species
Klebsiella species
Pseudomonas species
Escherichia coli.
Which viruses can raise CK in sepsis
SARS-CoV-2, influenza virus, coxsackievirus, and HIV
Symptoms of serotonin syndrome
mental status changes, GI disturbances (diarrhea), neuromuscular abnormalities (hyperreflexia, shivering, myoclonus, rigidity), and autonomic dysfunction (fever, shock, flushing)
<12 h after exposure
Neuroleptic malignant syndrome (NMS) clinical presentation
changes in mental status (mainly delirium)
generalized rigidity (Parkinson-like)
hyperpyrexia
abnormal metabolic changes (elevation of CK levels)
autonomic nervous system imbalance (HTN)
14-72 h after exposure
Treatment of amiodarone toxicity
Prednisone 50mg daily
Risk factors for amiodarone pulm tox
dose of ≥400 mg/day and is highest in those on it for >2 months
Can occur at any dose
Histology of amiodarone tox
lipid-laden foamy macrophages in alveolar spaces
meaning of tetrahydrocannabinol and vitamin E acetate in BAL fluid
Likely EVALI
What causes dilution of end-expiratory CO2
Air leak
- cuff underinflation
- displacement of the tube high up in the trachea
- high mean airway pressure
What does a obstruction in the airway look like on end exp CO2 capnogram?
less steep upstroke without an alveolar plateau (shark fin) - reflects the inhomogeneity of gas distribution and alveolar ventilation
Treatment for myasthenia crisis
Plasma exchange to remove Ab (works faster than IVIG)
IVIG
Coronary Sinus
Babesia on Histology
trophozoites- pleomorphic ring forms and have been known to cluster as Maltese crosses
ring-like parasites inside erythrocytes on Giemsa- or Wright-stained blood smears
Treatment of hemothorax iso DIC
Likely will need surgery because embolization likely to be unsuccessful so need to find bleeding vessel
How to fix double triggering
Extend inspiratory time
If severe lung injury and need to add 1 second inspiratory pause so pt cant initiate another breath.
Change to PS
What is this?
Moderator band (contains right bundle branch)
Initial treatment of spontaneous intracerebral hemorrhage in pt on warfarin
Reversal of AC with 4-factor prothrombin complex (faster than FFP)
No need to control BP
Brain death testing
Confirm Coma with exam
Apena test - elevation PaCO2 to 60 or 20mmHg higher than baseline
(10 min!)
2 exams 24hr apart
Breathing pattern of during expiration, the lateral walls of the abdomen go inward, and the periumbilical region moves outward is characteristic of?
Abdominal rounding
Volume overload and heart failure
What pressor to add if need second pressor in septic shock
Vasopressin
What pressor to add if refractory afib on high dose norepi
Phenylephrine
Pressors for cardiogenic shock
Dobutamine or milrinone
AND
norepi
Pressor for anaphylaxis
epinephrine
When to use dopamine
NEVER
More mortality
more arrhythmias
Length of empiric abx in ICU
3-5d
Duration of abx therapy in septic shock
7-10d
When to prolong use of abx in septic shock in ICU
- Slow clinical response
- Undrained focus of infection
- S aureus bacteremia
- certain viral/fungal infections
- severe immune impairment
