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 shock (cardiogenic, obstructive, α > β1 = β2 hypovolemic, and distributive); are other treatments (fluids, NOREPINEPHRINE 0.5 – 30 mcg/min blood transfusions, inotropes, etc.) indicated? NOREPINEPHRINE (a.k.a. Levophed, ‘levo’, noradrenaline) DOPAMINE 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 septic shock. 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. adrenaline) 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 PHENYLEPHRINE 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 hypotension (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 (tachycardia 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 cardiogenic shock, 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 sepsis, 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 MIDODRINE 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 redefineachieve, 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.