Link to the by Nick Mark MD onepagericu.com VASOPRESSORS DEMYSTIFIED ONE most current @nickmmark version → Does this person need vasopressors? EPINEPHRINE • Consider all etiologies of (cardiogenic, obstructive, α > β1 = β2 hypovolemic, and distributive); are other treatments (fluids, 0.5 – 30 mcg/min blood transfusions, , etc.) indicated? NOREPINEPHRINE (a.k.a. Levophed, ‘levo’, noradrenaline) Good general purpose pressor with • Is there evidence of hypoperfusion? Is BP accurate? MIXED α/β α > β1 β1 < α combined vasoconstriction and inotropy Often used first line for . What is my blood pressure goal? Use mean arterial pressure (MAP) as your goal; target MAP >65 DOBUTAMINE EPINEPHRINE 1 – 10 mcg/min MAP > 60 mmHg may be equivalent to MAP > 65 mmHg in (a.k.a. ) patients over 65 years old β1 < < α Ideal for anaphylactic shock (also Although higher MAP goals are generally not beneficial, some (inotropes not PURE β PURE α has bronchodilator activity) patients (neurological issues, stenosed coronaries, etc) may vasopressors) Increases lactic acid production benefit from higher individualized MAP goals ISOPROTERENOL VASOPRESSIN 0.01 – 0.06 units/min Β1/ Β2 only α only Which vasopressor to start? Long half-life; hard to titrate, often used at Treat the underlying physiology (is a mixed vasoconstriction and a fixed dose. Non-catecholamine pressor; Good adjunct for septic shock inotropy desirable?, High PA pressures ! VASO, Anaphylaxis ! EPI (+) Inotropy Vasoconstriction Unlike other pressors it does not ↑ PA Vasodilation pressures but higher risk for gut ischemia Push-dose versus continuous infusion Central versus peripheral administration? 20 – 80 mcg/min Push-dose good for transient (e.g. post intubation) or PHENYLEPHRINE Do not wait for central access to begin pressors if needed! (a.k.a. Neosynephrine ‘neo’) when pressor infusion is not immediately available. Two options: It is safe and effective to give vasopressors peripherally if: Pure α effects; good for pure • PHENYLEPHRINE syringe (pre-mixed); administer 50-100 mcg • The IV is newly placed, in a larger vein (4mm or larger) and vasodilatory states or in patients who EPINEPHRINE: combine 1 cc of a 10 cc Epi syringe (1:10,000 not in the hand, wrist, or antecubital fossa cannot tolerate inotropy ( or ACLS dose) with 9 cc of saline (makes 100 mcg epi in 10 cc); • Afib w/ RVR) administer 10-20 mcg at a time (repeat q1 minute) You have a protocol to monitor for extravasation • You know what to do if there is extravasation (protocol) If a patient requires push dose, expect a need for an ongoing PHENYLEPHRINE, NOREPINEPHRINE, EPINEPHRINE can be infusion. DOPAMINE 1 – 20 mcg/kg/min given peripherally. (Avoid VASOSPRESSIN peripherally) In the Mixed effects; May be vasodilatory case of high dose pressors, multiple pressors, or prolonged at low doses (hard to ‘wean’ off) infusion central venous access is recommended. Add additional pressors if needed In patients with , Again consider the physiology. Does this person need inotropy? DA is more arrythmogenic than NE. Do they need blood products/fluid? Steroids? Are they acidemic? (requiring > 2 pressors) For , no benefit to starting in a particular sequence, though NE ! VASO ! EPI ! PHENYL ! DA is common. Vasopressor refractory shock STEROIDS METHYLENE BLUE Am I treating the cause of shock? Stress Dose Steroids Nitric oxide scavenger that can • Consider differential d/dx of shock (e.g. • Hydrocortisone 50 mg q6 hrs IV be used if pressor refractory Weaning vasopressors don’t treat blood loss w/ pressors!) • Wean over days as pressor • 1 – 2 mg/kg SLOW IV push • Good for refractory Wean one pressor at a time; may be advantage to weaning VASO • Acidosis decreases efficacy of pressors! requirement decreases 05)

hypotension or hypotension - before NE. Some patients may benefit from adding Increase dose of pressors: EPI, NE, DA, • Reduces pressor 04

due to vasoplegia (e.g. after - 10 mg 8 hr PO to facilitate weaning from pressors/liberating from PHENYL do not have a true max dose. requirement/duration cardiopulmonary bypass) ICU. Consider contraindications and renal dosing. Consider stress dose steroids and alternative agents (such as methylene blue, angiotensin II) or interventions (VA ECMO) v1.0 (2020 v1.0 Link to the by Nick Mark MD onepagericu.com VOLUME RESUSCITATION ONE most current @nickmmark version → Link to the by Nick Mark MD onepagericu.com HYPOXIA ONE most current @nickmmark version → HYPOXIA = insufficient oxygen in the tissues, several types exist: • ISCHEMIC – not enough blood flow to deliver oxygen • ANEMIC - blood unable to carry enough oxygen • TOXIC - cells unable to use oxygen (e.g. cyanide poisoning) • HYPOXEMIC - low oxygen levels in the blood

There are SIX CAUSES of HYPOXEMIC HYPOXIA PAO2 = 100 PAO2 = 100

1. Low Inspired FIO2

VBG ABG PvO2 = 40 PaO2 = 100 CVO2 = 15 CAO2 = 20 2. Alveolar Hypoventilation SpO2 = 100%

3. V/Q Mismatch

Shunt! PAO2 = 100 PAO2 = 0 4. Shunt

VBG ABG VBG PvO2 = 40 PaO2 = 60 PvO2 = 40 5. Impaired diffusion CVO2 = 15 CAO2 = 17.5 CVO2 = 15

SpO2 ~80%

6. Low SvO2 Increase FiO2 from 21% to 100%

Still shunting deoxygenated blood PAO2 = 700 PAO2 = 0

VBG ABG VBG PvO2 = 40 PaO2 = 60 PvO2 = 40 CVO2 = 15 CAO2 = 18.5 CVO2 = 15

SpO2 ~88%

Still hypoxemic! Effective Hypoxic Pulmonary P O = 700 P O = 0 A 2 A 2 Vasoconstriction (HPV)

VBG ABG VBG PvO2 = 40 PaO2 = 60 PvO2 = 40 CVO2 = 15 CAO2 = 19.5 CVO2 = 15

SpO2 ~98% People with more People with less effective HPV effective HPV

People with Short of breath but near Very uncomfortable Stronger Hypoxic normal SpO2 with very low SpO2 Ventilatory Drive “Uncomfortable normal” Respiratory distress

People with Well feeling with near Minimal distress with weaker Hypoxic normal SpO2 very low SpO2 Effective Hypoxic Ventilatory Drive Normal appearing “Happy hypoxemic” Pulmonary Vasoconstriction (HPV) Link to the by Nick Mark MD onepagericu.com OVERVIEW OF VENTILATOR MODES ONE most current @nickmmark Goals for mechanical ventilation: version → Define treatment goals 1. Oxygenation – support PaO2/SpO2 Measurement and optimization: 2. Ventilation – maintain pH 3. Patient comfort – vent synchrony, ↓ sedation ABG Pulse Ox Choose a ventilator mode & initial 4. Facilitate weaning – minimize muscle loss, Measure settings promote readiness to wean from support ABG/SpO2 pH / PCO2 / PaO2 / HCO3 SpO2

Ventilator Modes: Measure ABG/VBG/Spo2

If unable to achieve, can redefine achieve, Ifcan to unable Fall into two broad categories: pressure and goals (e.g. permissive hypercapnia) permissive (e.g. goals VENTILATION OXYGENATION

Ask am I achieving my goals? Adjust 03) volume modes. Each mode has three features: If you want to increase If you want to change the PaO2 -

Settings 04 • Trigger (T) – what initiates a breath? the pH ! increase the or SpO2 adjust oxygenation - Try a • Cycle (C) – what ends a breath? ventilation parameters parameters (FiO2 and PEEP) Adjust Try adjunct • Limit (L) – what stops a breath early? different (sedation, NMB, Settings Each mode has Pro’s and Con’s to consider. mode bronchodilator, etc) (2020 v1.0 Mode Description Pro’s Con’s Major settings / example Monitor

Every breath delivered (mandatory and patient Good general-purpose mode; Requires you to Pressures VC triggered) are all the same set volume Ensures a minimum MV is monitor pressures to RR, TV, PEEP, FIO2 (Ppeak, Volume Control achieved. Good mode for lung avoid barotrauma. Pplat) (a.k.a. assist control T – time/pressure/flow, C – volume, L – volume protective ventilation (LPV) (See my OnePager on 12 bpm, 450cc, +8, 60% volume) ARDS for details.) (RR – respiratory rate, TV – tidal volume) Every breath delivered (time & patient) are a set Good for limiting pressure; may Requires you to Volumes RR, IP, TI, Risetime, PEEP, FIO2 PC pressure for a set time be more comfortable for select monitor volumes to (TV, MV) Pressure Control patients. Also can be used for LPV avoid volutrauma or 12 bpm, 25 cmH2O, 0.9 sec, 0.15 sec, +8, 60% (a.k.a. assist control T - time/pressure/flow, C – time, L - pressure (no difference in mortality) hypoventilation pressure) (IP – inspiratory pressure, TI – inspiratory time) Hybrid PC mode that dynamically changes Guarantees TV but delivers In patients who are Pressures PRVC inspiratory pressure to deliver a desired volume pressure-controlled breaths; (e.g. struggling to breath RR, TV, TI, Risetime, Pmax, PEEP, FIO2 & Pressure Regulated low risk of causing VILI), which the machine will volumes Volume Control T - time/pressure/flow, C – volume, L - volume potentially may be more provide less support 12 bpm, 450cc, 0.9 sec, 0.15 sec, 30 cmH2O, +8,60% (a.k.a. VC+) comfortable for patients (Pmax – maximum pressure) Delivers mandatory breaths with a fixed volume May be useful for patients with Seldom used; not Pressure SIMV but patient can’t trigger (patient breaths are not hiccups to avoid alkalemia effective for RR, TV, PEEP, FIO2 (Ppeak Synchronous the same as mandatory breaths); can use PS weaning; often found Pplat) Intermittent to be uncomfortable Mandatory Ventilation T – time , C – volume, L - volume 12 bpm, 450 cc, +8, 60%

All breaths are patient initiated; ventilation Ideal weaning mode (used in SBTs Does not guarantee a Volumes PS, PEEP, FiO2 Note that PS is PS determined solely by patient (no backup rate). and for prolonged periods); most rate; need to monitor above PEEP so (TV, MV) Pressure Support comfortable because it allows to ensure adequate “Ten over Five” T – pressure/flow, C – flow, L - pressure patient to control ventilation ventilation +10, +5, 40% PIP = 15cmH2O Inverse ratio ventilation (e.g. I time > E time) Great for ARDS patients who are Complex T , T , P , P , FIO2 Volumes APRV that allows patient to breath spontaneously; can spontaneously breathing (e.g. not mode/settings; Risk High Low high low & gas Airway Pressure combine w/ PS on NMB); may improve comfort & of VILI if settings are 5.5 sec, 0.5 sec, 25 cmH O, 0 cmH O, 60% exchange oxygenation (but no mortality done improperly; 2 2 PCO2 / Release Ventilation T – time, C – time, L - pressure (a.k.a. Bi-Vent) benefit) doesn’t make sense if (Thigh/low – time high/low, Phigh/low – pressure EtCO2 on NMB high/lowNote that Plow is analogous to PEEP) Link to the by Nick Mark MD onepagericu.com VOLUME ASSIST/CONTROL VENTILATION ONE most current @nickmmark version → How does this mode work? • Delivers a set volume of air with each breath; patient triggered breaths are identical to machine triggered breaths • Time and patient triggered, volume cycled, volume limited mode

What are the variables I set? Pressure • RR – respiratory rate • TV – tidal volume (better to express in terms of cc/kg PWB than ccs) • PEEP – positive end expiratory pressure (typically at least +5) • FiO2 – fraction of inhaled oxygen (typically at least 30%) Decerating • V – (“v dot) inspiratory flow rate (typically 30-60 lpm) Flow pattern breaths • Flow pattern – is the flow constant (e.g. takes longer square wave) or decelerating (‘decel’) Decel may be more comfortable but Patient it prolongs the inspiratory phase triggered breath Volume When should I use this mode? • Ensures that a patient receives a minimum MV • This is a good general-purpose mode; good for providing Inhalation Exhalation I E Lung Protective Ventilation (LPV) • PRVC may have lower peak pressures; pressure modes may be more comfortable for select patients ABG: pH / PCO2 / PaO2 / HCO3 What do I need to monitor? Advanced settings • Need to make sure the peak pressure and plateau VENTILATION OXYGENATION I:E RATIO TRIGGER pressure do not exceed safe limits. → If Pplat is too high decrease the Tv • You will also need to monitor MV. If the patient is SETTINGS: ̇ Flow Pattern triggering excessively (or auto-triggering), they can RR Tv PEEP FiO2 � become alkalemic. Flow Choosing Initial settings EXAMPLE: 12bpm 6cc/kg +5 50% 40lpm Square wave • RR - Try to match the persons initial minute ventilation by Decelerating Pressure selecting a rate to match their pre-intubation MV needs. If you want to increase If you want to increase If you want to decrease Flow trigger is • TV - Use 8cc/kg PBW and adjust as needed. For patients the pH ! increase the the PaO2 or SpO2 Inhalation time (increase may be more 09) with ARDS (or at high risk) consider starting at 6cc/kg PBW. minute ventilation increase the FiO2 and the I:E ration) ! increase sensitive that - 04 • Start with low PEEP and high FiO2 and wean to maintain (MV) by changing the PEEP the inspiratory flow rate pressure; adjust - RR and TV (V) and use square wave to limit SpO2 goal (typically > 90%). flow pattern autotriggering 2020 v1.0 ( v1.0 Link to the by Nick Mark MD onepagericu.com PRESSURE CONTROL VENTILATION ONE most current @nickmmark version → PRESSURE CONTROL How does this mode work? All breaths deliver a set • Patient triggered, flow cycled mode pressure for a set duration • Delivers a set pressure for a set duration with each breath

• There is no ‘backup rate’ Pressure • The size and frequency of breaths is completely determined by the patient.

When should I use this mode? Flow

What do I need to monitor? • If you have selected the proper IP (IP = Pplat) then the flow should be Patient triggered breath zero by the end of each breath. (looks like time triggered) Volume

Inhalation Exhalation I E

ABG: pH / PCO2 / PaO2 / HCO3 Advanced settings VENTILATION OXYGENATION I:E RATIO TRIGGER

SETTINGS: RR IP Itime PEEP FiO2 Rise time

Flow EXAMPLE: 12bpm 25cmH2O 0.9sec +5 50% 5% Pressure

If you want to change If you want to change A faster rise time (e.g. a Flow trigger is the pH ! increase the IP the PaO2 or SpO2 smaller percent) is generally more and Itime to increase the adjust FiO2 and PEEP associated with a slight sensitive that volume delivered or decrease in I:E pressure increase the RR Link to the by Nick Mark MD onepagericu.com BASIC VENTILATOR MODES ONE most current @nickmmark version → PRESSURE SUPPORT How does this mode work? • Time and patient triggered, time cycled mode • Delivers a set pressure for a set duration with each breath

• Patient triggered breaths are identical to machine triggered breaths Pressure

When should I use this mode?

What do I need to monitor? • If you have selected the proper IP (IP = Pplat) then the flow should be Flow zero by the end of each breath.

All breaths are Each breath varies in patient triggered duration/volume Volume

Inhalation Exhalation I E Normal I:E is 1:2

ABG: pH / PCO2 / PaO2 / HCO3 Advanced settings VENTILATION OXYGENATION I:E RATIO TRIGGER

SETTINGS: RR IP Itime PEEP FiO2 Rise time

EXAMPLE: 12bpm 20 6cc/kg +5 50% 5% Flow Pressure

If you want to change If you want to change A faster rise time (e.g. a Flow trigger is the pH ! increase the IP the PaO2 or SpO2 smaller percent) is generally more and Itime to increase the adjust FiO2 and PEEP associated with a slight sensitive that volume delivered or decrease in I:E pressure increase the RR Link to the by Nick Mark MD onepagericu.com BASIC VENTILATOR MODES ONE most current @nickmmark version → T AIRWAY PRESSURE RELEASE VENTILATION Thigh low How does this mode work? • Delivers a set pressure for a set duration with each machine breath • Patient breaths are not the same as machine breaths but can occur at Phigh Pressure any point in the respiratory cycle Plow Patient breaths are • This is used for Inverse Ratio ventilation (e.g. more time in I than E in possible at any point contrast to normal physiology) • Time and patient triggered, time cycled, pressure limited mode

When should I use this mode? Flow • Theoretical benefits include less need for sedation or NMB by permitting spontaneous respiration, improved oxygenation, and improved hemodynamics. Spontaneous respiration may preserve diaphragm strength and improve lower lobe atelectasis. Volume What do I need to monitor? • If you have selected the proper IP (IP = Pplat) then the flow should be Inhalation Exhalation I E zero by the end of each breath. • There are risks of causing lung injury if the Thigh is too long and Normal I:E is 1:2 derecruitment occurs. There are also risks of derecruitment if compliance or resistance change and Tlow is not changed. ABG: pH / PCO2 / PaO2 / HCO3 Choosing Initial settings Advanced settings • Set Phigh = the plateau pressure (as VENTILATION OXYGENATION measured on VC) • Set Plow = 0 (to maximize) • Set the Thigh (minimum of 4 sec) and SETTINGS: PEEP Tlow to adjust the ventilation; Tlow Phigh Plow FiO2 PS

EXAMPLE: 20 6cc/kg +5 50% 5% Flow Pressure

If you want to change If you want to change A faster rise time (e.g. a Flow trigger is the pH ! increase the IP the PaO2 or SpO2 smaller percent) is generally more and Itime to increase the adjust FiO2 and PEEP associated with a slight sensitive that volume delivered or decrease in I:E pressure increase the RR