SHOCK 2007SHOCK 2007

SHOCKSHOCK20072007

Ariel G. Bentancur, MDAriel G. Bentancur, MDEmergency Department, Sheba Medical Center, Emergency Department, Sheba Medical Center,

IsraelIsrael

““Dry” Definition of ShockDry” Definition of Shock

A circulatory situation where A circulatory situation where

inadequate tissue/end organ inadequate tissue/end organ oxygenation and perfusionoxygenation and perfusion is is

present.present.

End OrganEnd Organ??

BrainBrain HeartHeart KidneysKidneys GutGut

Expanded definition:Expanded definition:

A generalized circulatory derangement A generalized circulatory derangement causing multiple organ hypoperfusion causing multiple organ hypoperfusion and strong sympathetic activation, and and strong sympathetic activation, and

when intense or sustained enough when intense or sustained enough ( minutes to hours) irreversible ( minutes to hours) irreversible

metabolic, inflammatory, and clotting metabolic, inflammatory, and clotting disorders leading to the patient’s disorders leading to the patient’s

permanent function deficit or death. permanent function deficit or death.

So how we recognize So how we recognize shock?shock?

Grossly byGrossly by::Signs of strong sympathetic activation:Signs of strong sympathetic activation: TachycardiaTachycardia PallorPallor Extremity coldnessExtremity coldness SweatingSweating TachypneaTachypnea

Signs of hemodynamic instability:Signs of hemodynamic instability: Inappropriate low blood pressure valuesInappropriate low blood pressure values

Signs of organ dysfunction:Signs of organ dysfunction: Altered consciousnessAltered consciousness OliguriaOliguria

BUTBUT……

Depends on:Depends on:

CATEGORY of shockCATEGORY of shock

DEGREE of shock severityDEGREE of shock severity

SHOCK CATEGORIESSHOCK CATEGORIES

1.1. HYPOVOLEMICHYPOVOLEMIC

2.2. CARDIOGENICCARDIOGENIC

3.3. NEUROGENICNEUROGENIC

4.4. SEPTICSEPTIC

5.5. ANAPHILACTICANAPHILACTIC

6.6. OBSTRUCTIVEOBSTRUCTIVE

7.7. OVERDOSE/TOXIN RELATEDOVERDOSE/TOXIN RELATED

HYPOVOLEMIC SHOCKHYPOVOLEMIC SHOCK

The initial insult is a loss of circulatory fluid The initial insult is a loss of circulatory fluid volume, by:volume, by:

BleedingBleeding BurnsBurns VomitingVomiting DiarrheaDiarrhea SweatingSweating ““Stomas”Stomas” Third space fluid sequestrationThird space fluid sequestration

CARDIOGENIC SHOCKCARDIOGENIC SHOCK

Severe myocardial pump failure due Severe myocardial pump failure due to:to:

Extensive anterior wall myocardial Extensive anterior wall myocardial infarctioninfarction

Right ventricular infarctionRight ventricular infarction ArrhythmiaArrhythmia Commotio cordisCommotio cordis

CARDIOGENIC SHOCKCARDIOGENIC SHOCK

Defined by:Defined by:

Systolic blood pressure <90 mmHg Systolic blood pressure <90 mmHg andand Wedge pressure of >20 mmHgWedge pressure of >20 mmHg

OrOr

Cardiac index <1.8 L/minCardiac index <1.8 L/min

OrOr

Inotropics or intra-aortic balloon couterpulsation Inotropics or intra-aortic balloon couterpulsation used to achieve Systolic blood pressure >90 used to achieve Systolic blood pressure >90 mmHg.mmHg.

CARDIOGENIC SHOCKCARDIOGENIC SHOCK

Recognized by:Recognized by:

History: Acute Cardiac Syndrome or History: Acute Cardiac Syndrome or chest trauma.chest trauma.

ECG changes: arrhythmia or ST segment ECG changes: arrhythmia or ST segment changes.changes.

Echocardiographic demonstration of Echocardiographic demonstration of ventricular hypokinesia.ventricular hypokinesia.

NEUROGENIC SHOCKNEUROGENIC SHOCK

Caused byCaused by severe injury to the CNS severe injury to the CNS

MechanismMechanism: A distribution Shock: A distribution Shock loss of nervous control of the vascular tone and loss of nervous control of the vascular tone and

subsequent fall of peripheral vascular resistance.subsequent fall of peripheral vascular resistance. loss of vascular regulation.loss of vascular regulation. pooling of blood in the splanchnic bed pooling of blood in the splanchnic bed

Clinical characteristicsClinical characteristics: : Despite of shock presence the skin is warm and Despite of shock presence the skin is warm and

pink. pink. Pulse is normal or slow due to unmatched Pulse is normal or slow due to unmatched

parasympathetic tone. parasympathetic tone.

SEPTIC SHOCKSEPTIC SHOCK

It is also a distribution shock caused by It is also a distribution shock caused by severe systemic infection.severe systemic infection.

Mechanism:Mechanism: Increased circulatory demand.Increased circulatory demand. A loss of the vascular tone with a A loss of the vascular tone with a

subsequent decrease of the peripheral subsequent decrease of the peripheral vascular resistance.vascular resistance.

Circulatory volume unchanged but Circulatory volume unchanged but splachnic bed volume sequestration is splachnic bed volume sequestration is present. present.

SEPTIC SHOCKSEPTIC SHOCK

Recognized by:Recognized by: History: present or recent febrile History: present or recent febrile

disease.disease.

Physical examination:Physical examination: Hypotension Hypotension Warm, dry skin.Warm, dry skin. Tachycardia.Tachycardia.

ANAPHYLACTIC SHOCKANAPHYLACTIC SHOCK

Caused by exposure to allergen.Caused by exposure to allergen.

Mechanism: Mechanism: Distribution shockDistribution shock IgE/Mastocyte mediated acute IgE/Mastocyte mediated acute

reaction.reaction. Histamine/bradichinine/Histamine/bradichinine/

cytokine(ILC4)/PAF/PGD2 mediated cytokine(ILC4)/PAF/PGD2 mediated vasodilatation and blood volume vasodilatation and blood volume sequestration in the splanchnic bed.sequestration in the splanchnic bed.

ANAPHYLACTIC SHOCKANAPHYLACTIC SHOCK

Recognized by:Recognized by:

History of exposure.History of exposure. History of past anaphylactic History of past anaphylactic

reaction.reaction. Coexistence of: skin rush, Coexistence of: skin rush,

angioedema, bronchospasm.angioedema, bronchospasm.

OBSTRUCTIVE SHOCKOBSTRUCTIVE SHOCK

A restriction to blood flow or diastolic A restriction to blood flow or diastolic heart filling like in:heart filling like in:

Pericardiac TamponadePericardiac Tamponade

Tension PneumothoraxTension Pneumothorax

Stacked cardiac prosthetic valveStacked cardiac prosthetic valve

Massive Pulmonary EmboliMassive Pulmonary Emboli

OBSTRUCTIVE SHOCKOBSTRUCTIVE SHOCK

MechanismMechanism::

Blood Volume is normalBlood Volume is normal

Cardiac pump function is normalCardiac pump function is normal

Vascular tone is normalVascular tone is normal

Increased resistance to blood flow Increased resistance to blood flow or ventricular diastolic function or ventricular diastolic function cause a low cardiac outputcause a low cardiac output!!

OVERDOSE/TOXIN OVERDOSE/TOXIN RELATED SHOCKRELATED SHOCK

Caused by: Caused by: Medications:Medications:Drugs used for the treatment of hypertension:Drugs used for the treatment of hypertension:Ca++ channel blockersCa++ channel blockersββ-blockers-blockersororDigoxinDigoxinTryciclic antidepressantsTryciclic antidepressants ToxinsToxinsDigested- scombroid fish poisoningDigested- scombroid fish poisoningSnake biteSnake bite

OVERDOSE/TOXIN OVERDOSE/TOXIN RELATED SHOCKRELATED SHOCK

May develop through mixed May develop through mixed mechanisms:mechanisms:

Vasodilatation and a decrease of Vasodilatation and a decrease of peripheral vascular resistance.peripheral vascular resistance.

Decreased ventricular systolic Decreased ventricular systolic function.function.

SHOCK SEVERITY SHOCK SEVERITY DEGREEDEGREE Best understood by the severity classification of hemorrhagic shock:Best understood by the severity classification of hemorrhagic shock:

Degree of Degree of HemorrhageHemorrhage

Class 1Class 1

Very MildVery MildClass 2Class 2

MildMildClass 3Class 3

ModerateModerateClass 4Class 4

SevereSevere

Estimated Estimated volume of volume of blood lossblood loss

<<15%15%

<<750750 mlml

15-25%15-25%

750-1500750-1500 mlml

26-39%26-39%

1500-20001500-2000 mlml

40%40%≤≤

>>20002000 mlml

CardiovasculaCardiovascular signsr signs

HR <100HR <100

Normal b.pNormal b.p..

HR >100HR >100

Normal b.pNormal b.p..

HR >120HR >120

HypotensionHypotensionHR >140HR >140

Deep Deep hypotensionhypotension

Respiratory Respiratory signssigns

Normal RRNormal RR

14-2014-20

Mild tachypneaMild tachypnea

20-3020-30

Moderate Moderate tachypneatachypnea

30-3530-35

Severe Severe tachypneatachypnea

>>3535

CNS signsCNS signsAnxiousAnxiousIrritable/Irritable/confused/confused/combativecombative

Lethargic/low Lethargic/low pain responsepain response

Lethargic/Lethargic/comacoma

Skin signsSkin signsWarm/pink/Warm/pink/normal capillary normal capillary refillrefill

Cool Cool extremitiesextremities//

Delayed Delayed capillary fillcapillary fill

Cool Cool extremitiesextremities//

Delayed Delayed capillary fillcapillary fill

Cool Cool extremitiesextremities//

Delayed Delayed capillary fillcapillary fill

Kidney/Kidney/metabolicmetabolic

signssigns

Normal urine Normal urine outputoutput

Normal serum Normal serum PHPH

Oliguria 20-Oliguria 20-30ml/m30ml/m

Normal serum Normal serum PHPH

Oliguria<15ml/Oliguria<15ml/m/↑urea/m/↑urea/Metabolic Metabolic acidosisacidosis

AnuriaAnuria

Severe Severe acidosisacidosis

Shock SignsShock SignsTachycardia-ageTachycardia-age

Infant > 160 bpmInfant > 160 bpm

Pre-school >140 bpmPre-school >140 bpm

School-puberty >120 bpmSchool-puberty >120 bpm

Puberty-adult >100 bpmPuberty-adult >100 bpm

Shock SignsShock SignsTachycardia-ageTachycardia-age

Influenced by:Influenced by:

AgeAge PacemakerPacemaker MedicationsMedications

SHOCKSHOCK

Summary:Summary: Should be early recognized.Should be early recognized. Sole reliance on SBP results in delayed Sole reliance on SBP results in delayed

recognition.recognition. Treat shock and the causes early.Treat shock and the causes early. Hypovolemic versus cardiogenic versus Hypovolemic versus cardiogenic versus

distribution versus obstructive versus mixed distribution versus obstructive versus mixed shock.shock.

The clinical picture depends on type and severity.The clinical picture depends on type and severity. If treated partially or late it becomes almost If treated partially or late it becomes almost

irreversible resulting in MOF and death.irreversible resulting in MOF and death.

DISCUSSIONDISCUSSION

COMMON SENSE-COMMON SENSE-MECHANISMMECHANISM

YES, SHOCK PRESENTYES, SHOCK PRESENT

NO SHOCK PRESENTNO SHOCK PRESENT