Pulmonary Physiology Volume Control Pressure Control Pressure Support

Respiratory Therapy Measure of static lung compliance. If in AC-VC, perform

a.k.a.
“AC” Assist Control; AC-VC, ~CMV (controlled mandatory
a.k.a. AC-PC; Assist Control Pressure Control; ~CMV-PC a.k.a PS (~BiPAP). Spontaneous: Pressure-present
inspiratory pause (when there is no flow, there is no effect ventilation = all modes with RR and fixed Ti)
Pocket Reference PPlateau of Resistance; Pplat@Palv); or set Pause Time ~0.5s;
Target: < 30, Optimal: ~ 25
Settings
RR, Vt, PEEP, FiO2, Flow Trigger, Flow pattern, I:E (either Settings
RR, Pinsp, PEEP, FiO2, Flow Trigger, rise time, I:E (set
directly or by inspiratory time Ti)
Settings Pinsp, PEEP, FiO2, Flow Trigger, Rise time
directly or via peak flow, Ti settings)
PIP: Total inspiratory work by vent; Reflects resistance & Decreasing Ramp (potentially more physiologic)
- Decreasing Ramp (potentially more physiologic)
Card design by Respiratory care providers from: PPeak inspiratory compliance; Normal ~20 cmH20 (@8cc/kg and adult ETT); Square wave/constant vs Decreasing Ramp (potentially Flow Determined by: 1) PS level, 2) R, Rise Time (­ rise time ®
Resp failure 30-40 (low VT use); Concern if >40.
Flow more physiologic) Flow
- Peak Flow determined by 1) Pinsp level, 2) R, 3)Ti (shorter ¯ peak flow and 3.) pt effort
= more flow), 4) pressure rise time (¯ Rise Time ® ­ Peak
v 0.9 Flow), 5) pt effort (­ effort ® ­ peak flow)
Pplat-PEEP: tidal stress (lung injury & mortality risk). Target Determined by set RR, Vt, & Flow Pattern (i.e. for any set Determined by patient effort & flow termination (“Esens” –
PDriving peak flow, Square (¯ Ti) & Ramp (­ Ti); Normal Ti: 1-1.5s;
I:E see below “Breath Termination”)
< 15 cmH2O. Signif mort risk > 20 cmH2O. Determined by set Ti & RR (Volume & flow variable)
0.7-0.9sec to ¯ airtrapping & asynchrony I:E Time cycled = Ti or I:E set, then flow adjusts to deliver Vt
I:E At rest ~1:2, exertion ~1:1; Obstructive pulmonary dz ~1:3 I:E -Increase flow rate will decrease inspiratory time (Ti) Pros ­Synchrony: allows pt to determine peak flow, VT and Ti
-Example: Vt 500/RR20/Flow 60
-Avoids high PIPs
--Cycle time = 3s; Ti = 0.5s = (0.5L/60LPM)(60s per minute) No guaranteed MV; Vt determined by pt (big or small); high
Normal 4-6 LPM; may be lower if drug OD, hypothermic, -Variable flow – ­ pt effort causes ­ flow to maintain
--Texp = 3-0.5 = 2.5s à I:E = 0.5:2.5 = 1:5 PS and/or low Esens in COPD can incr air-trapping à
Oxygen & Delivery Devices Minute Vent deep sedation; may be higher 8-14 LPM if OPD or ARDS. constant airway pressure = Potentially better synchrony: ­ Cons asynchrony. Muscle Weakness/Fatigue: ¯ effort or ability to
Target 6-8 LPM OPD, 10-15 ARDS Pros pt effort ® ­ flow & ­ Vt
Guaranteed MV regardless of changing respiratory system sustain effort)® hypoventilation, ­ fatigue
Pros mechanics; Precise control of Vt to limit lung injury
-“Automated/active expiratory valves” - transiently opens
Pros: Ubiquitous, easy; Range 1-8LPM Clinical range: 50-80 LPM. With exertion or distress 100- expiratory valve to vent off pressure w/ coughing,
NC Cons: Cold and dry if >4LPM, epistaxis Peak Flow 150; ventilator default ~60LPM asynchrony. ­comfort & ¯ barotrauma risk Breath
FiO2: 2-4% /LPM; variable (mouth breathing, high minute ventilation) Delivers Vt at all cost = PIPs vary with C & R; breath Pt flow or pressure triggered
Cons stacking; fixed flow and Ti can increase asynchrony when pt Initiation
∆ v / ∆ p = VT/Plateau-PEEP VT and MV not guaranteed; Vt determined by C and R
-Static compliance: (Normal ~100 mL/cmH2O) = lung (50) +
Vt and flow demand > vent settings Cons (might be bigger or smaller than is optimal)
If no pt
Pros: Higher FiO2; Can be more comfortable than NC Compliance chest wall (50); measured at end inspiratory pause; Normal Control: Time trigger (60s/set RR): fixed VE trigger
Apnea; (Most vents will have backup rate; all have alarm)
NRB/ Cons: Bad if high MV; difficult to estimate severity of hypoxemia intubated recumbent 60-80; ARDS < 40) Breath Assist: Pt effort triggers full breath at set Ti and fixed VT and Breath Control: Time trigger – (60s/set RR)
FM FiO2: Simple 5-10LPM (~FiO2 35-50%); NRB 10-15 LPM (~ FiO2 -Dynamic compliance: includes system resistance & inertia Initiation flowrate Initiation Assist: Pt trigger delivers Pinsp for inspiratory time cycle
Flow cycled: Delivers Pinsp until flow drops to
60-80% if MV not too high) Breath predetermined % of initial peak flow ~Esens (Standard
R= PIP-Pplat/ inspir flow (square pattern, 60LPM) If no pt If no pt Termination setting ~25%; ~40-50% if OPD to prevent air trapping)
Resistance Normal< 10cmH2O/L/sec, Concern: > 15cmH2O/L/sec Delivers full set Vt at set rate Delivers Pinsp at set rate and Ti
Pros: Able to achieve high FiO2 even w/ high MV; washout CO2 trigger trigger
(less rebreathing); heated/humidified; Possible improved outcomes Higher Pinsp, short rise time, low trigger sensitivity = less
Notes work or air hunger; PS does not = SBT
HFNC in acute hypox resp failure 80 Time cycled = breath ends at Ti limit; Alarms if VT not Breath
Volume* (ml/kg) *adult male
Frat et al, NEJM, 2015 achieved; flow is set, breath ends once Vt delivered Time cycled = I:E or Ti set, breath ends at set time
Cons: Requires special device Breath Pressure cycled = (safety mechanism); breath termination termination
FiO2: >90% FiO2 (variability with MV, mouth breathing)
termination by clinician set high pressure limit; “pop-off” breath ends;
IRV Default set to 50 cmH2O - When changing from AC-VC, set Pinsp as Pplat-PEEP
IC

Flow
Pros: Possibly decrease density = better ventilation from AC-VC or consider half of PIP from AC-VC
Notes - Can ­Ti to allow pause or ¯Ti to ­peak flow at the end
Cons: Requires special device; Caution w/ 80/20 mix in severe Inspiratory pause (~0.3s) can be built into each breath, will
Heliox 37 Notes increase mean airway pressure inspiration ~decr asynchrony when VE demand is high
hypercarbic failure; not all NIPPV or IPPV can use VC
FiO2: 20% or 30% mixes available; $$$ TV TLC
30 Decelerating Flow Constant Flow Decelerating Flow

Pressure
Pros: May avoid intubation (COPD, cardiogenic pulm edema, mild
ARDS, upper airway obstruction) by decr work of breathing & adding
ERV

Flow
Flow

Flow
PEEP FRC
15
Cons: Gastric insufflation (if PIP>20-25); Cannot use if aspiration
risk or unable to protect airway (or if can’t remove mask themselves);
RV RV
uncomfortable/skin breakdown; may worsen lung injury due to Ti too short Ti Appropriate Ti too long
increased transpulmonary pressure gradient; caution if RHF (flow to zero) Dual Mode
Confusing terminology: IPAP (=driving pressure + PEEP) and EPAP

Pressure
Pressure

Pressure
NIPPV (=PEEP). PS of “5 over 5” is the same as PS delta 5 over 5, is the Hypoxia Pressure regulated volume control (PRVC); VC+, AutoFlow
same as IPAP 10/EPAP 5 a.k.a. ~PC with a target Vt & variable Pinsp (∆1-3cmH2O per
FiO2: 1.0 Alveolar Gas Equation (A-a) breath) to meet goal Vt despite chagning C and R;
[(FiO2%/100) * (Patm - 47 mmHg) - (PaCO2/0.8)] - PaO2
Initial Settings: PS (∆P) 5 / PEEP (EPAP) 5-10; Titrate ∆P up to 15 ¯ Likelihood of hypo/hyperventilation associated with PC
to reduce inspr work Brochard et al, NEJM 1995 -Always small gradient = (age/4) +4; Patm sea level ~760mmHg SIMV Misc Vent Settings when R or C changes. As C ­ or R ¯ ® Pinsp ¯. As C ¯ or
Winck et al, Crit Care 2006 *PAO2 = function of oxygen in air (Patm-Pwater)FiO2 and ventilation (PaCO2/0.8) Pros R ­®­Pinsp.
Hilbert et al, NEJM 2001 *Remember, Patm not FiO2 changes with altitude (top of Everest, FiO2 = 0.21) a.k.a. Synchronized intermittent mandatory ventilation; mixed mode Insp Time If Time-cycled, set I:E or Ti; If Volume cycled, flow is set; ~0.9s -Active expiratory valve present
*Healthy subject on FiO2 1.0, ABG PaO2 ~660
Guaranteed MV (control breaths by PC, VC, Dual); Spont Aka slope or flow attack; Speed of rise of flow (VC) or pressure - C & R can change significantly without notification
Causes of Hypoxemia (PaO2)
Disclaimer: This card is intended to be educational in nature and is not a substitute for clinical decision
*Normal A-a: Not enough 02 (low Patm, or low FiO2), too much CO2 (hypercarbia),
Pros breath (CPAP or PSV) = better synchrony; avoids breath Rise Time (PC); how quick PIP reached; too short = uncomfortable; too - Vent can’t discern if VT>target is due to ­ Pt effort or ­C;
making based on the medical condition presented. It is intended to serve as an introduction to terminology. stacking; sometimes useful if vent triggering inappropriately long = low Vt (PCV) or higher P (VCV); ~0.2s fastest
It is the responsibility of the user to ensure all information contained herein is current and accurate by using hypoventilation Cons vent response to both = ¯ Pinsp; Can lead to closed-loop
published references. This card is a collaborative effort by representatives of multiple academic medical Esteban et al, N Engl J Med 1995
”runaway” (¯Pinsp® ­ Pt Effort® ¯ Pinsp); ­ Pt work
*Elevated A-a: Diffusion defect, V/Q mismatch, shunt
centers. Cons Less ‘control’ over Vt and MV; May prolong weaning Insp Trigger Flow (3-5LPM) more sensitive than pressure trigger (-2cmH20) Note: If PIP<20; evaluate for “VT starvation” (VT>set VT)
 High Pressures Setting PEEP Obstructive Lung Disease ARDS Management ARDS Management
*PEEP doesn’t recruit, it prevents de-recruitment, generally PIPs/Plts recruit - Similar to ARDSnet – permissive hypercapnea and avoid Berlin 1. Acute (<1 week)
High PIP barotrauma; Increase expiratory time (avoid breath stacking); 2. Bilateral opacities on CXR or Chest CT Ideal Body Weight:
Ensure pt is sedated + paralyzed, check plateau (insp hold): ARDSnet PEEP Tables
Definition
shorten inspiratory phase, lower RR, trend pressures closely; 3. P:F ratio< 300mmHg w/ >5cmH20 PEEP
-In ARDS pts, use PEEP table; consider low PEEP if tenuous hemodynamics or Goals Plat<40, pH>7.15, PaO2>60 (2012) 4. Must not be fully explained by cardiac failure or fluid overload Males = 50 + 2.3 [height
Incr Pplat nl Pplat other concerns for hemodynamic consequences of higher PEEPs - Avoid ‘divots’ (premature drop in exp flow to zero) = uncaptured on clinical exam ARDS Task Force, JAMA, 2012 (inches) -60]
△Pplat-PIP <10 △Pplat-PIP >10 breaths that hinder exhalation; titrate sedation prn
Dx = low compliance Dx = high resistance Gestalt Method - Be patient, severe exacerbations (esp asthma) can take time
Incr Pplat ARDS Mild = P/F 200 – 300 = ~27% mortality Females = 45.5 + 2.3
△Pplat-PIP >10 - Despite existence of numerous techniques (below), mean PEEP to maintain Moderate = P/F 100 – 200 = ~32% mortality [height (inches) – 60]
oxygenation in most major ARDS trials spans a narrow and moderate range (9-13) Severity
Dx = low compliance + Mode: VCV preferred as rapid changes in obstruction affect MV; Severe = P/F < 100 = ~45% mortality
high resistance - Many nuances and imprecisions to below methods make clinical utility limited consider PRVC if PIPs > 50
- Titrating PEEP to oxygenation is easy and reasonable, though pulmonary RR: ~10-14; Consider RR 6-9 if PEEPi still >5 despite E time 5s Ventilator 1. Calculate ideal body weight (IBW) to set VT – See box right
Troubleshooting Resistance: work mechanics must be utilized, especially if poor oxygenation response TV: 6-9ml/kg 2. Select vent mode (Usually start w/AC-VC , can use PC)
Set-Up per
outside (machine) to inside (alveoli); - Default 5, cardiogenic pulmonary edema 10, OPD 0-3, ARDS (use table) Settings Insp Time/Flow: 0.7-0.9s / 60-80Lpm
ARDSNet
3. Set initial Vt = 8cc/kg IBW Selective Pulmonary Vasodilator Therapy
circuit problem, ETT kink/occlusion/biting, PEEP: start @0; may need 3-8 to ¯ work of breathing in recovery 4. Reduce Vt by 1 cc/kg as able until Vt = 6cc/kg IBW
ETT obstructed/mainstem, large airway P Static compliance Method Exp time: goal 4-5s Protocol 5. Adjust Vt and RR to achieve Pplat <30; pay attention to Inhaled Prostacyclin (aka: PGI2)*
obstruction (mucous plug), small/medium - Assess effect of PEEP changes in compliance Heliox: only works w/select vents; limited data; consider if severe preintubation minute ventilation as initial guide Dose: start at 50 ng/kg/min PBW (range: 10-50); should be weaned (10ng/kg/min
airway obstruction (bronchospasm); • If Crs (respiratory system) improves, then attributable to alveolar hyperinflation and/or acidosis; $$$ 6. PEEP >5; FiO2/PEEP as below (see PEEP Box) increments q30min) to avoid hemodynamic compromise
auscultation & passing a suction catheter recruitment; if Crs decreases, then overdistending; 7. Oxygenation goal: PaO2 55-80; SpO2 88-95% Notes: Possibly more beneficial in secondary ARDS and pts with baseline RV
can quickly eliminate many of these. t • Crs during PEEP titration largely determined by Vt chosen - Gas trapping: expiratory flow not returning to baseline 8. Ventilation goal: pH>7.15, permissive hypercapnea dysfunction; incr surfactant production via cAMP pathway; antiplatelet activity only
- Goal is to set PEEP to match or exceed auto-PEEP (see auto-PEEP box) PEEPi - (Quantified with expiratory pause; pt must remain apneic for demonstrated thus far for IV route; half-life = minutes;
Intrinsic ~5sec or more; assesses iatrogenic gas trapping best)
Tidal - Goal 6 cc/kg (range 4-6)
PEEP According to P-V Curves (“Open Lung Ventilation Strategy) - PEEPi trends with Vd/Vt (can be used to titrate PEEP) - Consider decreasing below 6cc/kg if not meeting plateau goals iNO*
End Expiratory Inspiratory Flow Inspiratory hold to - Reduced inflammation & improved outcomes (NEED SOURCE) Peep Volumes
- Pplat might be best method to assess dynamic gas trapping - EVERY CC/KG counts! Dose: 20ppm (range 2-80ppm); should be weaned (5ppm increments q30min) to
phase prior to

(S1-3)
opens alveoli; measure Pplateau - Results in higher PEEP needed than when using Crs technique - Consider liberalization if/when: Oxygenation, C, Vd/Vt
Quantifies intrinsic peep Suggests intrinsic peep avoid hemodynamic compromise
breath Determine PIPs (force back against - Lower inflection point (LIP) = zone of recruitment improving (PEEP<10; FiO2<60) and dysynch/uncomfortable Notes: $, requires $ delivery equipment; no direct SVR effect; met-Hgb; half-life =
closed circuit) • Set PEEP ~2 above LIP seconds; free radicals; can cause acute LVEDP overload (caution if reduced LV
- Upper inflection point = decreased Crs from overdistension - ”birds beak” FACTT Trial of conservative vs. liberal fluid strategy showed function); caution of pulm hemorrhage, plts<50 or anticoagulated
Fluid
• Limit Vt so Pplat is below upper inflection point conservative fluid strategy à improved oxygenation, more
Management
- Limitations: accurate curves difficult to obtain unless patient paralyzed; LIP may ventilator-free & ICU-free days, no increased shock, no mortality *No survival data; Caution: pulm vasodilators can cause incr LVEDP; do not use if
represent Ccw (chest wall); may represent overcoming intrinsic PEEP f/lung with effect ARDSnet, NEJM, 2006 pulmonary hemorrhage
prolonged time constants; may represent only beginning of opening rather than -concentrate drips, consider diuresis early if appropriate
Normal optimal pressure for opening
Normal
Normal PIP Pplt
Pplt Dead Space Method Vent Liberation
Pplateau & Plateau Pressure: check at least q4h Recruitment Maneuvers
Compliance PIP Pdriving --if>30cmH20, consider decrease Vt by 1cc/kg steps
alveoli problem Normal -Vd/Vt sensitive to detecting recruitment/derecruitment and overdistension --If <30cmH20 and dysynchrony and unable to address with - Caution: can kill a pt. Check with attending and RT - many contraindications
Resistance PIP Pplt SBT ~Criteria Goals sedation (and can’t paralyze), consider increase by 1cc/kg - Must have arterial line; adequately sedated and/or paralyzed patient
Esophageal Balloon Palv insp = Pplat 1) FiO2 < 0.50 and PEEP <8, 2) No ­ in PEEP/FiO2 requirements over past 24hrs
problem Driving Pressure: deltaP=Vt/CRS = Pplat-PEEP - Consider if (approximately): FiO2 >70%, 16 PEEP and P:F<150
- May be useful if high BMI, abd pressure 3) pH > 7.30. VE < 15 L/min, 4) ~MAP > 60 mmHg (minimal pressors), 5) ICP: non- - Threshold opening pressure <35 in most ARDS pts; AC-PC more stable and
- Transpulmonary pressure (Ptp) ~stress Palv exp = PEEPtot labile and < 20 mmHg w/ CPP > 60 mmHg, 6) No MI in previous ~48hr
--Uses Vt normalized to functional aerated lung
across lung - Allows PEEP and Vt titration Pes ~ Ppleural --Goal <15 (***each ∆7cmH2O =1.4 RR increase***) effective than sustained inflation RM Iannuzzi et al, Min Anes, 2010
Deadspace Calculation Pes Weaning strategies Esteban et al, N Engl J Med 1995 Amato et al, NEJM, 2015 Borges et al, Am J R CCM, 2006
accounting for Ccw (chest wall) and lung P = P
tp alv - Ppl Example Protocol:
Gestalt Method compliance - Once daily SBT PS ∆ 7/PEEP 5-8 cmH2O x 2hr (2nd daily trial permissible if - AC-PC Pdr 15-20, PEEP 20; RR 20; I:E 1:1 (Ti 1.5s)
- Ppl = -2 resting; -5 nl Vt; -35 TLC failure was sedation-related or caused by some other transient issue) Paralysis ACURASYS Trial: Paralysis w/in 48h, x48h, severe ARDS, 24%
- Of 500mL VT, ~150mL = anatomic deadspace = normal (anatomic+alveolar = Palv vs 33% @30d mortality benefit; placebo got more BDZs; some
- Increase PEEP q2min by 5cmH20 to max 50/35 (if tolerated hemodynamically)
physiologic deadspace) - Contraindications: varices, esoph - SBT x 30min ~probably as good as SBT x 2hr if <48h intubated - Return to 40/25 5-15min
trauma/surgery - SBT x 2hr better predictor if intubated >48h Esteban et al, Am J Respir CCM. 1999 caveats w/data analysis Papazian et al, NEJM, 2010
- During exhalation, at the alveolus, Palveolar CO2 ~ PaCO2; however, during - Then decremental PEEP trial
- If cardiogenic pulmonary edema risk: Consider 15min T-piece (ie d/c PS & PEEP) ROSE Trial: Similar to ACURASYS, larger (1006 pts), no
expiration Palveolar CO2 is mixed with gas from anatomic and physiologic -Titrate to end exp pressure (PEEP – Pes) = (If hypoTN or TBI, consider PEEP 16 and Pdr 20; Increase Pdr q2min by 5cmH20
0 -10 (higher pressure for higher FiO2 - RSBI (rapid Shallow Breathing Index) = f/Vt is unreliable; <80 goal for extubation; mortality difference PETAL NEJM, 2019
deadspace = diluted. Thus end tidal CO2 is always lower than PaCO2 to max 50/16 then back to 15-20/16)
requirement; if EIP negative ~ alv collapse) sensitive, not specific (if > 105, good predictor of failure) --Cisatracurium ($): Loading: 0.2 mg/kg; gtt: 0.5-10 mg/hr
- This difference (usually less than 5) can be used to estimate deadspace
-Titrate Vt to maintain end-inspiratory Pabd - Daily sedation interruption = faster extubation, shorter LOS Kress JP et al. NEJM --Vecuronium: Loading: 0.08-0.1 mg/kg; gtt dose: 1-10 mg/kg Post RM Stabilization:
transpulmonary pressure <25cmH20 Wean by decremental PEEP trial: f/25cmH20 by 2-3cmH20 q5-10min until desats
Extubation ‘criteria’ Vd/Vt Measure Vd/Vt w/ vent changes; can be used to predict mortality (target SpO2 90% throughout in order to be able to assess real-time effects)
Volume Capnography Method PetCO2 - Have you fixed the original problem? (>60% = sig incr mortality), assess volume status, assess
- PEco2 (Mixed expired CO2) Increased compliance - Adequate oxygenation? (PaO2 > ~60 on PEEP< 8 cmH2O, FiO2 <.50) optimal PEEP
‘Bird’s beak’ - Adequate ventilation w/o excessive work of breathing? (∆PaCO2 ­ of < 10
measured by integrating exhaled
CO2 concentration and exhaled gas
(abnormal) mmHg with remaining pH > 7.30 during SBT)
PROSEVA – most recent RCT, mortality benefit of proning (16%
Vent Associated Pneumonia
n - Secretions? (assess cough strength, suction frequency & secretion volume) Proning
flow rate (NICO Monitor) tio vs 33% @28d)
la
Upper inflection point - Airway protection? (assess gag, spont cough and GCS) - Dx: PNA in pt intubated/ventilated x 48h prior to onset; new infiltrate plus >1 of (new
--Alveolar deadspace impacted by: ha • Assess risk of airway obstruction: intubation >6d, trauma or multiple --Patient selection: stabilized 12-24h severe ARDS
Ex (UIP) fever, WBCs, >70yo w/AMS) AND >2 of (sputum, cough, SOB, worse P:F or exam
hypovolemia (ie increased west reintubations, large ETT, prolonged prone, flat, volume overload, --Duration: ~17h prone at a time, x4+4Guerin
sessions; until 2013
et al, NEJM,
findings); For additional/alternate PNA criteria see – CDC VAP Definitions
zone I), pulmonary hypotension, PE, Volume head/necktrauma, among others P:F>150 w/PEEP<10 supine x>4h Order trach asp (non quantitative Cx), though not required for Dx
n

Decreased compliance
tio

non-vascular deadspace, Xp, Phase III • Cuff Leak Test: pt must be sedated (interaction with vent = incr PIP = incr leak --Equipment: Don’t necessarily need special bed
ira

Zq, Phase I Phase II - Prevention measures: HOB>30, mouthcare, adequate ETT cuff pressure +
sp

overdistension of alveoli (e.g. too anatomic Transition to

Alveolar ventilation = false reassurance); Mode: CMV-VC (VT: 8-10 mL/kg, RR: 12-15, TI: 1.5sec.
In

Y, alveolar dead Deflate cuff: Wait 6 breaths: expired VT should ¯ by > 110mL. subglottic suctioning*, decrease # of transports f/ICU.
much PEEP) deadspace alveolar deadspace ECMO - Ongoing trials to determine if benefit of ECMO in ARDS
space • *Extubation criteria/goals for neuro patients may be different (e.g. visual - Tx: MSSA + pseudomonal coverage; MRSA tx if risk factors; double cover
Lower inflection point (LIP) - Some centers use ECMO over proning for all severe ARDS pseudomonas if MDR risk factors; de-escalate abx at 48-72h pnd cultures +
tracking, swallowing, GCS>10, <40yo) Asehnoune et al, Anesthesiology, 2017
VD/VT = (PACO2 –PECO2)/PACO2 - No upcoming procedures
- Existing data (CESAR Trial) support transfer to an ECMO
Noah etc/s
center (not necessarily receiving ECMO) Consider al, for
JAMA 2011
ECMO
procalciitonin trend; <7d course or if pseudomonas consider 14d course
Bohr’s equation uses A = alveolar; Enghoff uses PaCO2; E = mixed expired (not end tidal) - Hemodynamics - reintubation of an unstable patient can be lethal Kallil et al, IDSA Guidelines, Clin Infect Dis. 2016
Pressure for pt’s not meeting ARDSnet goals CESAR Trial, Lancet 2009