Transcript Fluids and vasopressors/inotropes in resuscitation.

Vasopressors and
Inotropes
Critical Care Lecture Series
Objectives
ICU
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What are the different classes of shock and
give examples of each.
Discuss how to investigate and the
management principles behind each of the
causes of shock.
What are the different crystalloids and colloids
available for resuscitation?
Have knowledge of the mechanism of action of
commonly used vasopressors and inotropes,
including dopamine, dobutamine, milnerone,
levophed, phenylephrine, epinephrine,
vasopressin
Discuss adverse events associated with the
above agents.
Is My Patient in Shock?
ICU
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Definition of shock
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Inadequate end organ perfusion leading
to inadequate oxygen delivery
N.B. a patient in shock does not have
to be hypotensive
ICU
Treatment of Shock
ICU
 Basic
Resuscitation:
ABCDE’s
A: Airway establishment
 B: Breathing: control WOB
 C(a): Circulation Optimization
 C(b): Control O2 consumption
 D: Delivery of O2 adequately
 E Extraction of O2
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Fluid resuscitation
ICU
Very important….
 Therapy with least detrimental effects
 Fluid therapy may be beneficial in any
type of shock
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Even cardiogenic shock/pulmonary
edema
Fluid Resusitation
ICU
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Must “test the patient”
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Must always look for the effect of
treatment
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Give volume and look for
response/improvement
Always start with NS of RL
? Need blood
Re-evaluate patient after fluid
If no improvement, and no adverse effects,
repeat
If adverse effect, needs inotropes/vasopressor
if still in shock
Too much: pulmonary edema (O2 sats)
ICU
A: Airway establishment
Indications for intubation:
1. Failure of oxygenation or ventilation
2. Failure to protect airway
3. Condition present or procedure needed
that will require intubation
“shock” is an indication for intubation
Hypotension common after intubation
B: Breathing: control WOB
ICU
Respiratory muscles are significant
consumers of oxygen
 Control will allow better O2 delivery
to other tissues
 Sedation after intubation
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C(a): Circulation
Optimization
ICU
Most causes of shock require some
volume re-expansion – even
cardiogenic shock
- Starling curve
 Crystalloid as good as colloid
 Vasopressors ineffective if
hypovolemic
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“double edged sword”
C(b): Control O2
consumption
ICU
Reduce hyper-adrenergic state
 Analgesia/sedation/muscle relaxation
 temperature
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ICU
D: Delivery of O2 adequately
Follow sats (keep > 92%)
 ? Transfusion (Hbg >80-100)
 Lactate
 SmvO2
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E: Extraction of O2
ICU
O2 must get from lungs to Hbg to
tissues
 O2 extraction important in some
types of shock
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Cyanide, MetHbg, SEPSIS
ICU
ABCDE’s: Summary
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A: Airway establishment: 02,biPap, ETT
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B: Breathing: control WOB: Sedation, analgesia
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C(a): Circulation Optimization: fluids, inotropes,
pressors
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C(b): Control O2 consumption: sedation, temp
control, seizure control
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D: Delivery of O2 adequately: Hbg, fluid, pressor,
inotropes
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E: Extraction of O2: R/O cyanide, metHbg, sepsis
Vasopressors
ICU
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Many different pressors/inotropes
Need to understand how they work to use
effectively
If choose wrong one, or use
inappropriately, can harm the patient
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Adrenergic precipitation of arrhythmias
Drive the heart too fast resulting in decreased
filling time and decreased stroke volume
Vasoconstriction of splachnic circulation and
coronary arteries
Inotropes may make certain patients
hypotensive
Vasopressors
ICU
β1 agonist/stimulation: chronitropic,
inotropic
 β2 agonist/stimulation: vasodilation,
bronchodilation
 α: vasoconstriction
 D: increases renal blood flow
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ICU
Vasopressors and inotropes:
the chart (everything you need to know)
Normal
Need CO
Need nothing
Blood
pressure
Low Need
BP and
CO
Low
Need BP
Normal
Cardiac Output
Dopamine
ICU
Dopaminergic, Beta, Alpha: ranges ?
 Dopa: 1-5 ug/kg/min
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Beta: 5-10 ug/kg/min
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Inoptropy/chronotropy
Alpha: >10 ug/kg/min
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? Renal flow
Vasoconstriction
Major use: increasing HR, ? bp
Dobutamine
ICU
Beta (little alpha)
 Inotropic/chronotropic
 2-20 ug/kg/min
 Major use: Systolic dysfunction
 Caveat: can/will decrease MAP
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Milrinone
ICU
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Used as an inotrope
Mechanism of Action
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Side Effects
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5-15 minutes
Duration
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can also cause vasodilatation but tends to have less chronotropy than
dobutamine
Onset of action
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Phosphodiesterase inhibitor
decrease the rate of cyclic AMP degradation
increase in cyclic AMP concentration leads to enhanced calcium influx
into the cell, a rise in cell calcium concentration, and increased
contractility
Half life of approximately 2 hours (so its gonna last a while
Dose
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Loading dose: 50 mcg/kg administered over 10 minutes followed by
0.375 mcg/kg/minute
Phenylepherine
ICU
Pure alpha agonist
 Vasoconstrictor with no effect on
inotropy/chronotropy
 0.2-3.0 ug/kg/min
 Major use: non-cardiogenic
hypotension
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Norepinepherine
ICU
Alpha and Beta
 0.02-3.0 ug/kg/min
 Major Use: when you need A&B
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? Drug of choice for septic shock
Epinepherine
ICU
Alpha and Beta
 0.01 – 1.0 ug/kg/min
 Major Use: when you need A&B
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resuscitation
Vasopressors and inotropes
ICU
Normal
Blood
pressure
Low
Dobutamine
Milrinone
nothing
Dopamine
Levophed
Epinepherine
Or
Dobutamine/phenyl
Phenylepherine
Levophed
(dopamine)
Low
Normal
Cardiac Output
ICU
ICU
Overview of the
Management of Shock
Case Study
ICU
65 yo male presents to ED
 Complaining of cough and feeling
very unwell
 HR 120, BP 100/60, RR 30, temp 39
 Is this patient in shock?
 What investigations
 What treatment would you start?
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Case Study
ICU
The patient’s BP drops to 90/50, what
would you do now?
 Would you start pressors? Which one?
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Case Study
ICU
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The patient is on 0.8ug/kg/min of
levophed through a femoral line. Why
might the patient not be responding
to the vasopressors? What
measurement would be helpful in
improving this man’s MAP?
Case Study
ICU
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The patient has been resuscitated,
now has a BP of 110/90. HR 65. His
JVP is 12. His lactate continues to rise
however. He is also anuric. Is this
patient in shock? What is your
management now?
Summary
ICU
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Shock can be the consequence of
decreased SVR, decreased CO or both.
Management of shock should be tailored to
the physiologic state of the patient of the
patient.
Drugs are available to augment SVR, HR,
afterload and contractility.
Remember to optimize preload and
consider the oxygen carrying capacity of
the blood.