ARDS evidence based treatment ppt (18/24)

evidence based management of ARDS

1. treat underlying cause

2. low VT and use PEEP

3. monitor pressures

4. conserve fluids

5. reduce complications

Low VT ventilation benefits. Why did higher TVs not work?

6mL/kg decreases mortality, quickly liberates from the vent and decreases extra pulmonary organ failure. Higher VTs were only used to fix the ABG; however, this killed the pt in doing so. Mortality was proven to decrease despite having worse O2, increased CO2 and a lower pH.

does ARDS affect the lungs heterogeneous vs. homogeneous?

Heterogeneous. Air goes to path w/ least Raw, which targets good alveoli, which can eventually lead to over distending those alveoli and making them bad. This means there are normal, injured (partially able to participate in gas exchange) and completely damaged (filled w/ fluid, cannot participate) alveoli

How does low VT prevent heterogeneous affects?

1. protects over distention by breaking cycle of inflammation

2. minimizes ALL airway pressures (Static + dynamic)

3. uses ENOUGH PEEP instead (not too much. it combats atelectasis)

what can too high of PEEP do?

1. increases airway pressure

2. increases DS

3. decreases venous return due to hypertension as over distended alveoli constricts BF

4. barotrauma

goal of PEEP

maximize alveolar recruitment and prevent cycles of recruitment/derecruitment

what pressure is the most predictive of lung injury? is this a diagnostic feature of ARDS?

pplat <30 w/ the lower the better as it decreases alveolar over distention and reduces risk of lung strain through decreasing VT. must adjust VT to ensure pplat goal.

NO! pplat is not specific o the alveoli.

what pathology/health issues can high pplats represent? is PEEP only for the lungs?

1. stiff, noncompliant lungs (ARDS, ILD, heart failure)

2. pneumos

3. auto-peeping

4. mucus plug

5. right main stem intubation

6. compartment syndrome

7. chest wall fat, obesity (not always lungs that needs PEEP, can be done for chest wall!)

football graph analogy

top and bottom of the football has decreased compliance due to over distention or under distention, and the center is when compensation is ideal. to prevent the bottom from happening, you increase PEEP. to prevent the top from happening, you decrease VT.

what is the main pressure that helps ARDS survival??

maintaining driving pressure (aka “open lung” approach), which is the ratio of VT to static compliance, reduces VT and pplats and an APPROPRIATE higher PEEP.

decreased DP → gentler ventilation (<15)mnbu8mnmn → increased compliance

can we piss out ARDS?

not really but a little bit as it could get rid of pulmonary edema but would decrease BP. first want to correct shock, then diuresis should be attempted as increased lung water is underlying cause for many clinical abnormalities of ARDS. CVP is used as guide as it represents fluid status (measures RA).

does proning help ARDS?

only if done early and not for long.

does ICS help ARDS?

only if caused by pneumonitis, anaphylactic response to chemo, COVID ARDS.

does paralytics help ARDS? which paralytic is preferred?

can decrease VO2, asynchrony and inflammatory response and promote homogenous distribution. But works like ironing: do it early and not for long.

cisatracurium as it does not have adverse effects but is long.

applications for paralytics? what is it not used for?

1. urgent intubation

2. status asthmaticus

3. increased ICP

4. therapeutic hypothermia protocol

NOT SEPSIS

can you do SBT on LPV patients? what happens while they are spontaneously breathing?

YES! unless they’re still on sedatives or proned. can produce higher trans pulmonary pressure in diaphragm, preventing collapse + reducing atelectasis.

supportive therapies (8)

1. treat underlying infection

2. DVT prophylaxis

3. HOB 30deg

4. hand washing

5. sedation/analgesia

6. avoid steroid use

7. pressure ulcer prevention

8. feeding protocol

refractory hypoxia

1. mechanical trouble (tubing, vent, plugging)

2. NMBAs

3. recruitment maneuvers (positioning, PEEP)

4. inhaled epo

5. HFV

steps for vent setup and adjustments for ARDS

1. calculate IBW

2. select ANY mode

3. achieve initial 6mlL/kg

4. set RR to baseline Ve (MUST do together as decreasing VT will increase RR to increase Ve)

5. adjust VT + RR to achieve pH and pplat goals (pH <7.20 = increase RR to correct pH).

6. set FiO2 + PEEP for SaO2 goal

7. diureses after resolving shock

what does acidosis affect?

vasopressors + stresses out organs.

PEEP ladder

PaO2 goal is >60mmHg as long as pt is not SHIFTED on curve. start @0.6FiO2 +10, as you only need to change the FiO2 if needing to change things.

what are you juggling w/ LPV w/ ladder?

1. protection (lower VT, pressures and pplat)

2. prop open alveoli (PEEP, not about O2)

3. ventilate + O2 (pH!)

what does Jen always tell u about CO2 + LPV

THERE ARE NO CO2 GOALS IN LPV!!!!

calculations

alveolar DS = ((VT - VTDS) * RR) / 1000

cstat = VT/(pplat-PEEP)

anatomic DS = IBW x 2

accurate RR = old aVe / (VT - VTDS) = new RR