Presented by: Dr. Mashfiqul Presented by: Dr. Mashfiqul Hasan Hasan

EmOC (anaesthesia) traineeEmOC (anaesthesia) trainee

ICMHICMH

Shock is a state of wide spread tissue Shock is a state of wide spread tissue hypo perfusion caused by hypo perfusion caused by an inadequate cardiac output oran inadequate cardiac output orineffective circulatory blood volume, ineffective circulatory blood volume,

leading to inadequate supply of leading to inadequate supply of oxygen and nutrients to the tissues oxygen and nutrients to the tissues and removal of metabolic wastes and removal of metabolic wastes from there to the organs of from there to the organs of excretion.excretion.

What isWhat is shock ?shock ?What isWhat is shock ?shock ?

Shock caused by inadequate Shock caused by inadequate cardiac outputcardiac output

CO = SV x HRCO = SV x HR

Stroke Volume

Stroke VolumeStroke Volume

Volume of Blood pumped by each Volume of Blood pumped by each ventricle during 1 cardiac cycle.ventricle during 1 cardiac cycle.

What affects Stroke volume?

Heart Muscle Damag

e

Blood Volume

MechanicalObstruction

Mechanical Obstruction

Rhythm Problems

Heart rateHeart rate

Sever bradycardia due to any cause.Sever bradycardia due to any cause.

Shock due to ineffective Shock due to ineffective circulatory blood volumecirculatory blood volume

BP = CO x SVRBP = CO x SVR

Stages of shockStages of shock

Non progressive stageNon progressive stage

Progressive stageProgressive stage

Irreversible stageIrreversible stage

Classification of shockClassification of shock

Hypovolemic shockHypovolemic shock

Cardiogenic shockCardiogenic shock

Distributive shockDistributive shock

Obstructive shockObstructive shock

Hypovolemic shockHypovolemic shock Loss of blood:Loss of blood:

External hemorrhage: trauma(accidental, External hemorrhage: trauma(accidental, surgical), GI bleeding, PV bleedingsurgical), GI bleeding, PV bleeding

Internal hemorrhage: hemothorax, Internal hemorrhage: hemothorax, hemoperitoneum, hematoma, haemorrhage due hemoperitoneum, hematoma, haemorrhage due to pelvic bone fracture, femur fracture, etc.to pelvic bone fracture, femur fracture, etc.

Loss of plasma: burn, exfoliative dermatitisLoss of plasma: burn, exfoliative dermatitis Loss of fluid & electrolytes: Loss of fluid & electrolytes:

External: diarrhoea, vomiting, excessive External: diarrhoea, vomiting, excessive sweating, hyperosmolar state (DKA, HONKDC)sweating, hyperosmolar state (DKA, HONKDC)

Internal: pancreatitis, ascites, bowel obstructionInternal: pancreatitis, ascites, bowel obstruction

Effect of hemorrhage on cardiac Effect of hemorrhage on cardiac output & blood pressureoutput & blood pressure

100%100%

50%50%

00 1010 2020 3030 4040 5050

ArterialArterial pressurepressure

Cardiac outputCardiac output

Percentage of total blood removedPercentage of total blood removed

What prevented fall of blood What prevented fall of blood pressure?pressure?

Reflex sympathetic compensation:Reflex sympathetic compensation: Arterioles constrict, increasing peripheral Arterioles constrict, increasing peripheral

resistanceresistance Vein & venous reservoirs constrict (esp. skin & Vein & venous reservoirs constrict (esp. skin &

splanchnic), thereby increasing the venous splanchnic), thereby increasing the venous returnreturn

Stimulation of the cardiac activityStimulation of the cardiac activity Activation of Renin-Angiotensin-Activation of Renin-Angiotensin-

Aldosterone systemAldosterone system Formation and release of vasopressinFormation and release of vasopressin

Decreased cardiac outputDecreased cardiac output

Decreased arterial pressureDecreased arterial pressure

Decreased systemic blood flowDecreased systemic blood flow

Decreased nutrition of tissuesDecreased nutrition of tissues Intravascular clottingIntravascular clottingDecreased cardiac nutritionDecreased cardiac nutrition

Decreased nutritionDecreased nutrition of vascular systemof vascular system

Decreased nutritionDecreased nutrition of the brainof the brain Tissue ischemiaTissue ischemia

Decreased vasomotorDecreased vasomotor activityactivity

Vascular dilatationVascular dilatation

Venous poolingVenous poolingOf bloodOf blood

Cardiac depressionCardiac depression Decreased venous returnDecreased venous return

Increased Increased CapillaryCapillary

permeabilitypermeability

Decreased Decreased blood volumeblood volume

Release of Release of Toxins/lactic acidosisToxins/lactic acidosis

Progression of shockProgression of shock

Progressive shockProgressive shock

Classification of HaemorrhageClassification of Haemorrhage Class-I: Blood loss 15%Class-I: Blood loss 15%

Normal pulse rate and blood pressureNormal pulse rate and blood pressure Tilt test + Tilt test +

Class-II: Blood loss 20-25%Class-II: Blood loss 20-25% Tachycardia, TachypnoeaTachycardia, Tachypnoea Low systolic blood pressureLow systolic blood pressure Pulse pressure less than 30mmHgPulse pressure less than 30mmHg Delayed capillary fillingDelayed capillary filling

Class-III: Blood loss 30-35%Class-III: Blood loss 30-35% Skin-cold, clammy and paleSkin-cold, clammy and pale Severe drop in blood pressureSevere drop in blood pressure Restlessness, oliguria, metabolic acidosisRestlessness, oliguria, metabolic acidosis

Class-IV Blood loss 40-50%Class-IV Blood loss 40-50% Profound hypotensionProfound hypotension Carotid pulse may only be palpableCarotid pulse may only be palpable Irreversible shockIrreversible shock

DiagnosisDiagnosis

HistoryHistoryPhysical signs of haemodynamic Physical signs of haemodynamic

instabilityinstabilityThe diagnosis is more difficult when The diagnosis is more difficult when

the source of blood loss is occult, as the source of blood loss is occult, as into the gastrointestinal tract, into the gastrointestinal tract, fracture of femur, pelvic fracture or fracture of femur, pelvic fracture or when plasma volume alone is when plasma volume alone is depleted. depleted.

MonitoringMonitoring

Patients in shock require care in an Patients in shock require care in an intensive care unit. intensive care unit.

Arterial pressure through an indwelling Arterial pressure through an indwelling line, pulse, and respiratory rate should be line, pulse, and respiratory rate should be monitored continuously;monitored continuously;

A Foley catheter should be inserted to A Foley catheter should be inserted to follow urine flow; follow urine flow;

Mental status should be assessed Mental status should be assessed frequently.frequently.

Invasive monitoring: Pulmonary artery Invasive monitoring: Pulmonary artery catheter (PAC, Swan-Ganz catheter). catheter (PAC, Swan-Ganz catheter).

Hemodynamic ParametersHemodynamic Parameters

CVP & PCWP CO SVR

Cardiogenic High Low High

Extra-cardiac

obstructive (Low) Low High

Hypovolemic Low Low High

Sepsis Variable Variable Low

Toxic Shock (Low) (High) Low

Anaphylaxis Low High Low

Management of hypovoloemic Management of hypovoloemic shockshock

Irrespective of etiology the first treatment of Irrespective of etiology the first treatment of shock is 100%Oshock is 100%O2 2 inhalation.inhalation.

Initial resuscitation requires rapid re-Initial resuscitation requires rapid re-expansion of the circulating intravascular expansion of the circulating intravascular volume and interventions to control ongoing volume and interventions to control ongoing losses.losses.

Volume resuscitation is initiated with the Volume resuscitation is initiated with the rapid infusion of a balanced salt solution rapid infusion of a balanced salt solution such as Ringer's lactate or Normal saline such as Ringer's lactate or Normal saline through large-bore intravenous lines. through large-bore intravenous lines.

No distinct benefit from the use of colloid No distinct benefit from the use of colloid has been demonstrated & in some studies has been demonstrated & in some studies they seem to be even harmful.they seem to be even harmful.

Hypovolemic Shock - Fluid Hypovolemic Shock - Fluid SelectionSelection

Distribution % Intravascular

Normal saline Extracellular space 25-30%

Lactated Ringer’s Extracellular space 25-30%

5% DA Total body water space 8-10%

Blood/ Colloids Intravascular space 100%

Distribution of fluidDistribution of fluid

Aims of therapyAims of therapy

To achieve and maintain To achieve and maintain

MAP of 70-80 mm of HgMAP of 70-80 mm of HgUrine output >0.5 ml/kg/hourUrine output >0.5 ml/kg/hourTreatment of the cause.Treatment of the cause.

Further managementFurther management Continuing blood loss, with hemoglobin Continuing blood loss, with hemoglobin

concentrations declining to 10 g/dL should concentrations declining to 10 g/dL should initiate blood transfusion, cross-matched initiate blood transfusion, cross-matched whole blood. whole blood.

In the presence of severe and/or prolonged In the presence of severe and/or prolonged hypotension, inotropic support with dopamine, hypotension, inotropic support with dopamine, vasopressin, or dobutamine vasopressin, or dobutamine may bemay be required required to maintain adequate ventricular performance to maintain adequate ventricular performance afterafter blood volume has been restored. blood volume has been restored.

Once hemorrhage is controlled and the patient Once hemorrhage is controlled and the patient has been stabilized, blood transfusions may has been stabilized, blood transfusions may not be continued unless the hemoglobin is not be continued unless the hemoglobin is <~7g/dL <~7g/dL

Cardiogenic shockCardiogenic shock

Myocardial ischemia or infarction Myocardial ischemia or infarction (pump failure)(pump failure)

Myocarditis, cardiomyopathyMyocarditis, cardiomyopathyArrhythmiaArrhythmiaAcute valvular dysfunctionAcute valvular dysfunction

Cardiogenic Shock

Hemodynamic ParametersHemodynamic Parameters

CVP & PCWP CO SVR

Cardiogenic High Low High

Extra-cardiac

obstructive (Low) Low High

Hypovolemic Low Low High

Sepsis Variable Variable Low

Toxic Shock (Low) (High) Low

Anaphylaxis Low High Low

Management Management

Adjusting volume status to a level Adjusting volume status to a level that ensures optimum LV filling that ensures optimum LV filling pressure.pressure.

Use of ionotropic drugs.Use of ionotropic drugs.

Hemodynamic effects of Hemodynamic effects of adrenoceptor subtypesadrenoceptor subtypes

Type Type Tissue Tissue Actions Actions

Alpha Alpha Most vascular Most vascular smooth musclesmooth muscle

Contraction Contraction

Beta 1Beta 1 Heart Heart Increases force & rate of Increases force & rate of contractioncontraction

Beta 2Beta 2 Vascular smooth Vascular smooth musclemuscle

RelaxationRelaxation

D 1D 1 Smooth muscle Smooth muscle Dilates renal blood vesselsDilates renal blood vessels

AdrenalineAdrenaline NoradrenalineNoradrenaline Dobutamine Dobutamine Dopamine Dopamine

Effects of Inotropic Agents Effects of Inotropic Agents

EpinephrineEpinephrine 0.02 – 0.50.02 – 0.5

NorepinephrinNorepinephrinee

0.05 – 0.50.05 – 0.5

DopamineDopamine DD 2 -202 -20

DobutaminDobutaminee

2 - 202 - 20

Drug Receptor CO SVR Dose Range

(g/kg/min)

1

Dopamine Dopamine An endogenous precursor of norepinephrine withAn endogenous precursor of norepinephrine with

multiple dose-related effectsmultiple dose-related effects

Low Dose (0.5 - 5 mcg/kg/min)Low Dose (0.5 - 5 mcg/kg/min)22 and dopaminergic (DR) effects and dopaminergic (DR) effectsEnhanced blood flow to renal and Enhanced blood flow to renal and

splanchnic bedssplanchnic bedsModerate Dose (5 -10 mcg/kg/min)Moderate Dose (5 -10 mcg/kg/min)

Positive inotropic effectsPositive inotropic effectsHigh Dose (>10 mcg/kg/min)High Dose (>10 mcg/kg/min)

-actions (vasoconstriction)-actions (vasoconstriction)

Distributive shockDistributive shock

Septic shockSeptic shockAnaphylactic shockAnaphylactic shockNeurogenic shockNeurogenic shockVasodilator drugsVasodilator drugsAcute adrenal insufficiencyAcute adrenal insufficiency

Septic shockSeptic shock

Sepsis with hypotension (arterial blood pressure Sepsis with hypotension (arterial blood pressure <90 mmHg systolic, or 40 mmHg less than <90 mmHg systolic, or 40 mmHg less than patient's normal blood pressure) for at least 1 h patient's normal blood pressure) for at least 1 h despite adequate fluid resuscitation;despite adequate fluid resuscitation;

oror

Need for vasopressors to maintain systolic blood Need for vasopressors to maintain systolic blood pressure 90 mmHg pressure 90 mmHg oror mean arterial pressure 70 mean arterial pressure 70 mmHgmmHg

Features of Septic Shock

High Cardiac OutputHigh Cardiac OutputLow Systemic Vascular ResistanceLow Systemic Vascular ResistanceMyocardial DysfunctionMyocardial DysfunctionHypovolemia as Ongoing Circulating Hypovolemia as Ongoing Circulating

Volume Lost To Interstitial SpaceVolume Lost To Interstitial Space

General managementGeneral management

Measure CVPMeasure CVP If CVP is <8 mm of Hg – fluid is infusedIf CVP is <8 mm of Hg – fluid is infused to raise it to 8-12 mm of Hgto raise it to 8-12 mm of Hg

Measure MAPMeasure MAP If MAP is still <65 mm of HgIf MAP is still <65 mm of Hg- use vasoactive agent - use vasoactive agent

Maintain MAP >65 mm of HgMaintain MAP >65 mm of Hg

Management of septic shockManagement of septic shock

Neurogenic ShockNeurogenic Shock

Neurogenic shock is caused by- Neurogenic shock is caused by- traumatic spinal cord injury or traumatic spinal cord injury or effects of an epidural or spinal anesthetic. effects of an epidural or spinal anesthetic.

This results in loss of sympathetic tone with a This results in loss of sympathetic tone with a reduction in systemic vascular resistance and reduction in systemic vascular resistance and hypotension without a compensatory tachycardia.hypotension without a compensatory tachycardia.

The extremities are often warm, in contrast to the The extremities are often warm, in contrast to the usual vasoconstriction-induced coolness in usual vasoconstriction-induced coolness in hypovolemic or cardiogenic shock. hypovolemic or cardiogenic shock.

Reflex vagal parasympathetic stimulation evoked Reflex vagal parasympathetic stimulation evoked by pain, gastric dilation, or fright may simulate by pain, gastric dilation, or fright may simulate neurogenic shock, producing hypotension, neurogenic shock, producing hypotension, bradycardia, and syncope. bradycardia, and syncope.

Management of neurogenic Management of neurogenic shockshock

Treatment involves a simultaneous Treatment involves a simultaneous approach to the relative hypovolemia and approach to the relative hypovolemia and to the loss of vasomotor tone. to the loss of vasomotor tone.

Excessive volumes of fluid may be required Excessive volumes of fluid may be required to restore normal hemodynamics if given to restore normal hemodynamics if given alone. alone.

A pure alpha-adrenergic agent A pure alpha-adrenergic agent (Ephedrine/phenylephrine) may be (Ephedrine/phenylephrine) may be necessary to augment vascular resistance necessary to augment vascular resistance and maintain an adequate mean arterial and maintain an adequate mean arterial pressure. pressure.

In severe cases noradrenaline/adrenaline In severe cases noradrenaline/adrenaline may be used.may be used.

Anaphylactic shockAnaphylactic shock

Anaphylaxis is a potentially life-Anaphylaxis is a potentially life-threatening, systemic allergic threatening, systemic allergic reaction caused by the release of reaction caused by the release of histamine and other vasoactive histamine and other vasoactive mediators.mediators.

The most common allergens are The most common allergens are foods, latex, insect venom and drugs.foods, latex, insect venom and drugs.

Anaphylaxis: IgE-mediated Anaphylaxis: IgE-mediated mast cell degranulationmast cell degranulation

FoodsFoods Peanuts Peanuts Tree nuts Tree nuts Fish and shellfish Fish and shellfish Milk Milk Eggs Eggs Soy products Soy products

Insect stingsInsect stings Bee venom Bee venom Wasp venom Wasp venom

Chemicals, drugs and other foreign proteinsChemicals, drugs and other foreign proteins Penicillin and other antibiotics Penicillin and other antibiotics Intravenous anaesthetic agents, e.g. suxamethonium, Intravenous anaesthetic agents, e.g. suxamethonium,

propofol propofol Latex Latex

Anaphylactoid, non-IgE-Anaphylactoid, non-IgE-mediated mast cell mediated mast cell

degranulationdegranulation DrugsDrugs

Opiates Opiates Aspirin Aspirin Radiocontrast media Radiocontrast media

PhysicalPhysical Exercise Exercise Cold Cold

IdiopathicIdiopathic No cause can be identified in 30% of patients No cause can be identified in 30% of patients

with anaphylaxis with anaphylaxis

Management of anaphylaxisManagement of anaphylaxis

Anaphylaxis is an acute medical emergency. The Anaphylaxis is an acute medical emergency. The immediate management includes: immediate management includes: preventing further contact with the allergen (e.g. preventing further contact with the allergen (e.g.

removal of bee sting) removal of bee sting) ensuring airway patency ensuring airway patency administration of oxygen administration of oxygen restoration of blood pressure (laying the patient flat, restoration of blood pressure (laying the patient flat,

intravenous fluids) intravenous fluids) prompt administration of adrenaline (epinephrine).prompt administration of adrenaline (epinephrine). Intravenous antihistamines (chlorphenamine 10-20 mg Intravenous antihistamines (chlorphenamine 10-20 mg

i.m. or slow i.v. injection), which limit ongoing i.m. or slow i.v. injection), which limit ongoing inflammation.inflammation.

Corticosteroids (hydrocortisone 100-300 mg) prevent Corticosteroids (hydrocortisone 100-300 mg) prevent late-phase symptoms in severely affected patients. late-phase symptoms in severely affected patients.

Obstructive shockObstructive shock Tension pneumothoraxTension pneumothorax Pericardial disease (temponade, constrictive Pericardial disease (temponade, constrictive

pericarditis)pericarditis) Disease of pulmonary vasculature (massive Disease of pulmonary vasculature (massive

pulmonary emboli, pulmonary pulmonary emboli, pulmonary hypertension)hypertension)

Cardiac tumor (atrial myxoma)Cardiac tumor (atrial myxoma) Left atrial mural thrombusLeft atrial mural thrombus Obstuctive valvular disease (aortic or mitral Obstuctive valvular disease (aortic or mitral

stenosis)stenosis)These are medical emergencies requiring prompt diagnosis & treatment These are medical emergencies requiring prompt diagnosis & treatment

THANKS TO EVERYBODYTHANKS TO EVERYBODY