SHK 1 ®

Diagnosis and Management

of Shock

SHK 1 ®

SHK 2 ®

Objectives

• Identify the major types of shock and principles

of management

• Review fluid resuscitation and use of

vasopressor and inotropic agents

• Understand concepts of O2 supply and demand

• Discuss the differential diagnosis of oliguria

SHK 2 ®

SHK 3 ®

Shock

• Always a symptom of primary cause

• Inadequate blood flow to meet tissue

oxygen demand

• May be associated with hypotension

• Associated with signs of hypoperfusion:

mental status change, oliguria, acidosis

SHK 3 ®

SHK 4 ®

Shock Categories

SHK 4

• Cardiogenic

• Hypovolemic

• Distributive

• Obstructive

®

SHK 5 ®

Cardiogenic Shock

• Decreased contractility

• Increased filling pressures,

decreased LV stroke work,

decreased cardiac output

• Increased systemic

vascular resistance –

compensatory

SHK 6 ®

Hypovolemic Shock

• Decreased cardiac output

• Decreased filling pressures

• Compensatory increase in

systemic vascular resistance

SHK 6 ®

SHK 7 ®

Distributive Shock

• Normal or increased cardiac output

• Low systemic vascular resistance

• Low to normal filling pressures

• Sepsis, anaphylaxis, neurogenic,

and acute adrenal insufficiency

SHK 7 ®

SHK 8 ®

Obstructive Shock

• Decreased cardiac output

• Increased systemic vascular

resistance

• Variable filling pressures

dependent on etiology

• Cardiac tamponade, tension

pneumothorax, massive

pulmonary embolus

SHK 9 ®

Cardiogenic Shock Management

• Treat arrhythmias

• Diastolic dysfunction may

require increased filling

pressures

• Vasodilators if not hypotensive

• Inotrope administration

SHK 10 ®

Cardiogenic Shock Management

• Vasopressor agent needed if

hypotension present to raise

aortic diastolic pressure

• Consultation for mechanical

assist device

• Preload and afterload reduction

to improve hypoxemia if blood

pressure adequate

SHK 11 ®

Hypovolemic Shock

Management

• Volume resuscitation – crystalloid,

colloid

• Initial crystalloid choices

– Lactated Ringer’s solution

– Normal saline (high chloride may

produce hyperchloremic acidosis)

• Match fluid given to fluid lost

– Blood, crystalloid, colloid

SHK 11

®

SHK 12 ®

Distributive Shock Therapy

• Restore intravascular volume

• Hypotension despite volume therapy

– Inotropes and/or vasopressors

• Vasopressors for MAP < 60 mm Hg

• Adjunctive interventions dependent

on etiology

SHK 12 ®

SHK 13 ®

Obstructive Shock Treatment

• Relieve obstruction

– Pericardiocentesis

– Tube thoracostomy

– Treat pulmonary embolus

• Temporary benefit from fluid

or inotrope administration

SHK 14 ®

Fluid Therapy

• Crystalloids

– Lactated Ringer’s solution

– Normal saline

• Colloids

– Hetastarch

– Albumin

– Gelatins

• Packed red blood cells

• Infuse to physiologic endpoints

SHK 14

®

SHK 15 ®

Fluid Therapy

• Correct hypotension first

• Decrease heart rate

• Correct hypoperfusion abnormalities

• Monitor for deterioration of

oxygenation

SHK 15 ®

SHK 16 ®

Inotropic / Vasopressor Agents

• Dopamine

– Low dose (2-3 g/kg/min) – mild inotrope

plus renal effect (?)

– Intermediate dose (4-10 g/kg/min) –

inotropic effect

– High dose ( >10 g/kg/min) – vasoconstriction

– Chronotropic effect

SHK 16 ®

SHK 17 ®

Inotropic Agents

• Dobutamine

–5-20 g/kg/min

– Inotropic and variable chronotropic effects

–Decrease in systemic vascular resistance

SHK 17 ®

SHK 18 ®

Inotropic / Vasopressor

Agents

• Norepinephrine

–0.05 g/kg/min and titrate to effect

– Inotropic and vasopressor effects

–Potent vasopressor at high doses

SHK 18 ®

SHK 19 ®

Inotropic / Vasopressor Agents

• Epinephrine

–Both and actions for inotropic and

vasopressor effects

–0.1 g/kg/min and titrate

– Increases myocardial O2 consumption

SHK 19 ®

SHK 20 ®

Therapeutic Goals in Shock

• Increase O2 delivery

• Optimize O2 content of blood

• Improve cardiac output and

blood pressure

• Match systemic O2 needs with O2 delivery

• Reverse/prevent organ hypoperfusion

SHK 21 ®

Oliguria

• Marker of hypoperfusion

• Urine output in adults

<0.5 mL/kg/hr for >2 hrs

• Etiologies

–Prerenal

–Renal

–Postrenal

SHK 21 ®

SHK 22 ®

Evaluation of Oliguria

• History and physical examination

• Laboratory evaluation

–Urine sodium

–Urine osmolality or specific gravity

–BUN, creatinine

SHK 22 ®

SHK 23 ®

Evaluation of Oliguria

Laboratory Test Prerenal ATN

Blood Urea Nitrogen/ >20 10–20

Creatinine Ratio

Urine Specific Gravity >1.020 <1.010

Urine Osmolality (mOsm/L) >500 <350

Urinary Sodium (mEq/L) <20 >40

Fractional Excretion of Sodium (%) <1 >2

SHK 24 ®

Therapy in Acute Renal Insufficiency

• Correct underlying cause

• Monitor urine output

• Assure euvolemia

• Diuretics not therapeutic

• Low-dose dopamine may urine flow

• Adjust dosages of other drugs

• Monitor electrolytes, BUN, creatinine

• Consider dialysis or hemofiltration

SHK 24 ®

SHK 25 ®

Pediatric Considerations

• BP not good indication of hypoperfusion

• Capillary refill, extremity temperature better

signs of poor systemic perfusion

• Epinephrine preferable to norepinephrine due to

more chronotropic benefit

• Fluid boluses of 20 mL/kg titrated to BP or total

60 mL/kg, before inotropes or vasopressors

SHK 25 ®

SHK 26 ®

Pediatric Considerations

• Neonates – consider congenital

obstructive left heart syndrome (hypoplastic

left heart syndrome, AS, bicuspid aortic

valve, coartio aorta) as cause of obstructive

shock

• Oliguria

– <2 yrs old, urine volume <2 mL/kg/hr

– Older children, urine volume

<1 mL/kg/hr

SHK 26 ®

SHK 27 ®

Key Points