Syok Pada Anak

Haryson Tondy Winoto,dr.,Msi.Med.,Sp.A

Bag. Anak UWKS

Definition

• Failure of delivery oxygen and substrates to

meet the metabolic demands of the tissue beds

SUPPLY < DEMAND

Oxygen delivery < Oxygen Consumption

DO2 < VO2

• Failure to remove metabolic end-products

• Result of inadequate blood flow and/or oxygen

delivery

2

Definition • Common pathway

– Failure to deliver substrates conversion to anaerobic metabolism

• Reversible if recognized early

• Irreversible organ damage at the late stage

– Progressive acidosis and eventually cell death

• Early recognition is key

3

Types of Shock

Type Pathophysiology Signs & Symptoms

Hypovolemic ↓ PRELOAD: ↓CO, ↑ SVR,

intravascular volume loss

↑HR, ↓ pulses, delayed cap

refill, dry skin, sunken eyes,

oliguria

Distributive ↓ AFTERLOAD (SVR)

Anaphylactic ↑ CO, ↓ SVR Angioedema, low BP,

wheezing, resp. distress

Spinal Normal CO, ↓ SVR Low BP without tachycardia;

paralysis, h/o trauma

Cardiogenic ↓ CO, variable SVR Normal to ↑ HR, ↓ pulses,

delayed CR, JVD, murmur or

gallop, hepatomegaly

Septic Variable More to come

Pathophysiology

• Children

– Higher % body water

– Higher resting metabolic rate

– Higher insensible losses

– Lower renal concentrating ability

– Subtle signs/symptoms

• Higher risk for organ hypo-perfusion

6

Pathophysiology

O2 supply < O2 demand

O2 delivery < O2 consumption

DO2 < VO2

7

Hemodynamic response to hemorrhage model for cardiovascular response to hypovolemia from hemorrhage (based on normal data). Adapted from Schwaitzberg SD, Bergman KS, Harris BH. A pediatric trauma model of continuous hemorrhage. J Pediatr Surg. Jul 1988;23(7):605-9.

Blood Pressure and Volume

% blood loss % BP

25% Normal

50% 60% o

9

•BP drops quickly after

reaching 50% blood loss

•CO follows BP closely

Oxygen delivery (DO2)

• DO2 = CO x CaO2

– DO2 : oxygen delivery

– CO : Cardiac output

– CaO2: arterial oxygen content

• CO = HR x SV

– HR: heart rate

– SV: stroke volume

• CaO2 = HgB x SaO2 x 1.34 + (0.003 x PaO2)

– Oxygen content = oxygen carried by HgB + dissolved

oxygen

10

Oxygen delivery (DO2)

DO2 = CO x CaO2

11

Critical DO2: consumption

depends on delivery

Oxygen delivery

DO2 = CO x CaO2

12

Cardiac Output

Heart Rate Stroke volume

Preload Afterload Contractility

Oxygen delivery

DO2 = CO x CaO2

• CO = HR x SV

• HR is independent

– Neonates depend on HR (can’t increase SV)

• SV depends on

– Pre-load: volume of blood

– After-load: resistance to contraction

– Contractility: force

Oxygen delivery

DO2 = CO x CaO2

• CaO2 = HgB x SaO2 x 1.34 + (0.003 x PaO2)

• Normal circumstance: CaO2 is closely associated

with SaO2

• Severe anemia or in the presence of abnormal HgB

(i.e. CO poisoning) - CaO2 is strongly affected by

PaO2

Hypo-perfusion

• Poor perfusion of a vital organs leads to organ dysfunction

– Decreased urine output

– Altered mental status

– Elevated LFTs, bilirubin

• Switches to anaerobic metabolism Lactate

• Activates inflammatory cascade

– Activates neutrophils, releases cytokines

• Increases adrenergic stress response

– Increases lipolysis/glycogenolysis (also increases lactate)

– Releases catecholamine and corticosteroid

Evaluation & Treatment

17

Initial Assessment

• Goals

–Immediate identification of life-

threatening conditions

–Rapid recognition of circulatory

compromise

–Early classification of the type and

cause of shock 18

Initial Assessment

• Airway

– Mental status: can the patient maintain the

airway

• Breathing

– ?impending respiratory failure

• Circulation

– Heart rate, pulses, blood pressure

– Capillary refills - perfusion

• Dextrose 19

Treatment

20

Increase O2 delivery

Decrease O2 demands

Increase O2 contents

Increase cardiac output

Increase blood pressure

Early intubation

Sedation

Analgesia

Treatment: Inotropes

25

Agent Site of Action Dose

Mcg/kg/min

Effects

Dopamine Dopaminergic

Beta

Alpha > Beta

1-3

5-10

11-20

Renal vasodilation

Inotrope/vasoconstriction

Increase perip. Vasc. resistance

Dobutamine Beta 1 & 2 1-20 Inotrope

Vasodilation

Epineprhine Beta > alpha 0.05 – 1.0 Inotrope, vasoconstriction

Tachycardia

Norepinephrine Alpha > beta 0.05 – 1.0 Profound vasoconstriction

inotrope

Milranone Phosphodiesterase

inhibitor

0.5 – 0.75 Inotrope

vasodilation

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