Inotropes
&
Vasopressors
Dr.M.Elakiya

Definitions
Inotropes:
Agents administered to increase myocardial
contractility and therefore cardiac index
Vasopressor
Agents are administered to increase vascular
tone and thereby elevate mean arterial
pressure (MAP).

Inotropes Vs. Vasopressors

Inotropes
• Drugs that affect the
force of contraction of
myocardial muscle
• Positive or negative
• Term “inotrope”
generally used to
describe positive
effect

Vasopressor
• Drugs that stimulates
smooth muscle
contraction of the
capillaries & arteries
• Cause
vasoconstriction & a
consequent rise in
blood pressure

Main Goal
Tissue
perfusion &
oxygenation

Physiological Principles
MAP = CO x SVR
CO = HR x SV
Preload Contractility Afterload
~ 1
r4

Basic principles - Vasopressors
MAP = CO x SVR
CO = HR x SV
Preload Contractility Afterload
~ 1
r4

Basic principles - Inotropes
MAP = CO x SVR
CO = HR x SV
Preload Contractility Afterload

Use of inotropes & vasopressors

Drug Classification
• Catecholamines : Dopamine, Dobutamine,
Adrenaline, Noradrenaline
• Phosphodiesterase Inhibitors : Milrinone,
Amrinone
• Vasopressors : Vasopressin, Phenylephrine
• Vasodilators : Nitroglycerine,Sodium
Nitroprusside

?????
A 10yrs old child presented to the ER with complaints of
nausea,bilious vomiting,abdominal pain with altered
sensorium
He has history of recurrent bowel obstructions
VITALS
HR- 162/min
RR-32/min
T- 101 F
BP-70/42 mmHg
SPO2-95% in RA
The child is in hypotensive shock.
crystalloids had to be given at 20ml/kg
But iv line couldn’t be secured,so INTRAOSSEOUS line
inserted

 After securing intraosseous line and after receiving 3
boluses of crystalloids at 20ml/kg the child remained
hypotensive
 WHAT IS THE NEXT STEP?
 WHAT MEDICATION TO START?
 WHAT DOSAGE?
 The examination findings important in guiding the therapy
are
- Capillary refill time
- tactile temperature of extremities
- mental status
- peripheral and central pulses

Choice of inotropes
 Cold shock with narrow pulse pressure with low MAP for age
- Dopamine is started at 10mics/kg/min
- if hypotension is profound and pt is unstable start
adrenaline 0.3-0.5 mics/kg/min
- if BP is still low Noradrenaline is preferred
 cold normotensive shock (MAP normal/high)
- Start dobutamine at 7.5-10 mics/kg/min
-consider PDE Inhibitors for myocardial dysfunction or
pulmonary hypertension

 Warm shock with hypotension
- first choice is Nor adrenaline 0.05-
0.5mics/kg/min
- if refractory vasopressin or
terlipressin can be used
 Warm shock with normal BP
- aggressive fluid therapy.usually
inotropes not required
- noradrenaline if diastolic BP
excessively low
- dobutamine in cases of metabolic
acidosis and low ScVo2

Dopamine
Hemodynamic effects
 Dose dependent - At low doses (0.5-3.0 μg/kg/min),
dopamine acts predominantly on D1 receptors in the renal,
mesenteric, cerebral and coronary beds resulting in selective
vasodilation.
 At intermediate doses (3-10 μg/kg/min), also stimulates β1
receptor and increases cardiac output (CO), predominantly by
increasing stroke volume with variable effect on heart rate.
 At higher dose (10-20 μg/kg/min), the predominant effect is
to stimulate α1-adrenergic receptors and produce
vasoconstriction with an increased systemic vascular
resistance (SVR),and the sum of these effects is an increase in
mean arterial pressure (MAP).

DOPAMINE
 Indication :
Fluid refractory septic shock
Cardiogenic shock with vasodilation(warm septic shock)
 Side effects
• tachycardia
• Arryhthmias
• Extravasation
• Tachyphyllaxis
 Reconstitution
1ml=40mg
6 X body weight in 50ml NS
5ml/hr will deliver 10 mics/kg/min
7.5ml/hr will deliver 15 mics/kg/min

DOBUTAMINE
 Hemodynamic effects:
Improves cardiac output by improving stroke volume &
decreasing afterload with minimal tachycardia.
 Predominantly 1
 Small effect at 2
It is a potent inotrope with weaker chronotropic
activity
 DOSE
1 ampule = 250mg/5ml
6 X BODY WT in 50ml NS

Indications
 Normotensive cardiogenic shock due to primary
myocardial pathology
Fluid refractory septic shock when the blood pressure is
normal /high
Cardiogenic shock due to severe hypoxia ischemia of any
etiology

Adrenaline
 Adrenaline is a potent agonist for β1, β2 and α1 receptors
present in cardiac and vascular smooth muscle.
Hemodynamic effects:
 0.05 – 0.3 mics/kg/min – inotropy, chronotropy
 0.3- 1 mics/kg/min – pressor
Low dose of adrenaline increases cardiac output because of
β1 receptor mediated inotropic and chronotropic effects
At higher doses α-receptor mediated vasoconstriction
predominates which results increased SVR in addition to
increased CO.

indications
 Cardiogenic shock with decompensated shock { Improves
diastolic BP, resulting in better coronary perfusion & improved
myocardial function }
 Myocardial dysfunction after cardiac arrest
 Anaphylactic shock
 Fluid unresponsive dopamine refractory hypotensive septic
shock
 Severe shock of any etiology

ADRENALINE INFUSION Preparation
1 ampoule 1ml (1:1000 = 1mg / ml)
Rate: 1ml/hr = 1mcg/min (Document rate on Syringe Pump
& in Patient’s Notes) Dose: 0.05 – 0.5mcg/kg/min (starting
infusion rate 0.1 mcg/kg/min) Titrate accordingly to desired
BP
Calculations : 0.3 x body weight;dilute the required dose in
NS(Eg: 10kg - 3ml in 47ml NS)
Use single strength in ED, especially if infusion is through a
peripheral line.
Make sure BP cuff is not on the Arm of the peripheral line.
Regularly inspect the site of insertion of the peripheral line.

How to start and titrate
• Start infusion @0.1-0.3 mcg/kg/min.
• If BP improves but perfusion worsens add inodilators
• Doses > 0.6 mics/kg/min are rarely useful as ensuing organ
ischemia may lead to MODS
Anaphylaxis
a) IV Adrenaline 1:10 000 -Dilute 1mg (1ml) to 10 cc N/S -Dose: Give
titrating bolus 1 ml up to 0.1ml/kg
b) or if IV line not available, give deep IM Adrenaline 1:1000 -Dose:
0.01mg/kg (i.e: Body wt 50kg= 0.5mg = 0.5ml) Max 0.5mg
c) IV Infusion if patient not response with boluses.

Norepinephrine
 Predominantly stimulates 1 receptors increases SBP &DBP
 It has minimal chronotropic effects because of which it is a drug of choice
in settings where heart rate stimulation is undesirable.
 High doses of noradrenaline can be safely used to maintain cerebral
perfusion pressure without significantly compromising the circulatory
flow.
Uses
 Hypotension due to
vasodilatation
 Warm septic shock refractory to fluid and dopamine

Side effects
↑ Afterload { not appropriate in cardiogenic shock}
Worsens perfusion leading to multi organ failure
DOSE
0.1-1 mics/kg/min (titrate based on assessment)
PREPARATION
0.3 x body weight;dilute the required dose in
5%dextrose
Rate: 1ml/hr = 1mcg/min

conclusion
 Early recognition and management in initial
stages is very critical in treating shock
 Ultimate treatment of underlying cause
forms the cornerstone of management

That’s All
Thank You