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ShockShock

Loring W. Rue, III, MD, FACSLoring W. Rue, III, MD, FACSProfessor and Vice ChairmanProfessor and Vice Chairman

Department of SurgeryDepartment of SurgeryUniversity of Alabama at BirminghamUniversity of Alabama at Birmingham

ShockShock

•What is it?What is it?

•How to deal How to deal with itwith it

Shock- Surgical LegacyShock- Surgical Legacy

• G.J. Guthrie was the G.J. Guthrie was the first to use the term first to use the term shock in the context shock in the context of physiologic of physiologic instabilityinstability

• Surgeon for Duke of Surgeon for Duke of Wellington in Wellington in Peninsula campaign Peninsula campaign against Napoleonagainst Napoleon


• George CrileGeorge Crile– Developed experimental Developed experimental

models of hemorrhagic shockmodels of hemorrhagic shock– First to describe the decrease First to describe the decrease

in CVP and cardiac output in CVP and cardiac output associated with hemorrhageassociated with hemorrhage

•An Experimental Research into An Experimental Research into Surgical ShockSurgical Shock (1899) (1899)


• Alfred BlalockAlfred Blalock– Demonstrated the Demonstrated the

hypovolemia associated hypovolemia associated with hemorrhage resulted with hemorrhage resulted in:in:•HYPOTENSIONHYPOTENSION•METABOLIC ACIDOSISMETABOLIC ACIDOSIS• IMPAIRED OXYGEN DELIVERY IMPAIRED OXYGEN DELIVERY

TO TISSUESTO TISSUES

– Physiologic derangements Physiologic derangements corrected by volume corrected by volume resuscitationresuscitation

What is Shock?What is Shock?

• Inadequate provision of oxygen to Inadequate provision of oxygen to peripheral tissues resulting from peripheral tissues resulting from either insufficient perfusion or either insufficient perfusion or abnormal extraction of oxygenabnormal extraction of oxygen

• Results in anaerobic metabolic Results in anaerobic metabolic pathwayspathways

Shock- PathophysiologyShock- Pathophysiology

• In the setting of adequate In the setting of adequate oxygen:oxygen:– Glucose metabolized via Glucose metabolized via

citric acid cycle yielding a citric acid cycle yielding a net of 36 ATPnet of 36 ATP

• In the setting of In the setting of inadequate oxygen:inadequate oxygen:– No citric acid cycle-lactate No citric acid cycle-lactate

generated yielding 2 ATPgenerated yielding 2 ATP

Shock- Anaerobic Shock- Anaerobic MetabolismMetabolism• Results in significant Results in significant

intracellular energy deficits:intracellular energy deficits:– Cell membrane repair Cell membrane repair

mechanisms alteredmechanisms altered– Electrolyte disturbances occurElectrolyte disturbances occur– Rupture of endoplasmic Rupture of endoplasmic

reticulumreticulum– Mitochondrial dysfunction Mitochondrial dysfunction

occursoccurs– Rupture of lysosomesRupture of lysosomes

Shock and Reperfusion Shock and Reperfusion InjuryInjury• Resuscitation and tissue reperfusion in this Resuscitation and tissue reperfusion in this

setting results in free radical generationsetting results in free radical generation

• Can lead to cell death and organ dysfunctionCan lead to cell death and organ dysfunction

Shock and Metabolic Acidosis:Shock and Metabolic Acidosis:Not A Good ThingNot A Good Thing

• Cardiac Effects:Cardiac Effects:– Blood flow is redistributed from Blood flow is redistributed from

endocardium to epicardium with endocardium to epicardium with potential myocardial dysfunctionpotential myocardial dysfunction

– Poor response to systemic Poor response to systemic catecholaminescatecholamines


• Pulmonary EffectsPulmonary Effects– Impairment of central Impairment of central

respiratory driverespiratory drive

• CNS EffectsCNS Effects– Autoregulatory Autoregulatory

mechanisms of cerebral mechanisms of cerebral blood flow overridden blood flow overridden with MAP < 60with MAP < 60


• Renal EffectsRenal Effects– Afferent arteriolar Afferent arteriolar

vasoconstriction with RBF vasoconstriction with RBF redistributed from cortex redistributed from cortex to medullato medulla

– GFR decreases: oliguria / GFR decreases: oliguria / anuriaanuria

• Gastrointestinal EffectsGastrointestinal Effects– Gut ischemia > mucosal Gut ischemia > mucosal

necrosis > bacterial necrosis > bacterial translocationtranslocation

Shock- Shock- Systemic Compensatory Systemic Compensatory MechanismsMechanisms Intravascular volume

Baroreceptor activity Mechanoreceptor activity

CNS Response

Pituitary releases-ADH-ACTH

Na/Water retentionCortisol released

Sympathetic nervous

stimulation Epinepherine Norepinepherine Renin/Angio/Aldo

Enhanced cardiac functionPeripheral vasoconstriction

Na/Water retentionPeripheral vasoconstriction

Shock- Clinical FeaturesShock- Clinical Features

• HypotensionHypotension• TachypneaTachypnea• Oliguria / AnuriaOliguria / Anuria• Impaired Mental StatusImpaired Mental Status

Depending upon cause, may also demonstrateDepending upon cause, may also demonstrate

• Narrowing of pulse pressureNarrowing of pulse pressure• TachycardiaTachycardia

Shock- Management Shock- Management PrioritiesPriorities

• Airway adequacyAirway adequacy

• Breathing restorationBreathing restoration

• Circulatory support-Circulatory support- method method dependent upon cause of shockdependent upon cause of shock

Shock - Resuscitation Shock - Resuscitation EndpointsEndpoints• ClassicClassic

– Restoration of blood pressureRestoration of blood pressure– Normalization of heart rate and urine Normalization of heart rate and urine

outputoutput– Appropriate mental statusAppropriate mental status

• ImprovedImproved– All of the above plusAll of the above plus– Normalization of serum lactate levelsNormalization of serum lactate levels– Resolution of base deficitResolution of base deficit

Shock- Judging the Adequacy Shock- Judging the Adequacy of Resuscitationof Resuscitation

• Monitor resuscitation with serial Monitor resuscitation with serial ABGs (attention to base deficit) and ABGs (attention to base deficit) and serum lactate levels.serum lactate levels.

Shock CausalityShock Causality

• HypovolemicHypovolemic• Cardiac Cardiac

TamponadeTamponade• Tension Tension

PneumothoraxPneumothorax• CardiogenicCardiogenic• NeurogenicNeurogenic• SepticSeptic

Approach to the Trauma Patient -Approach to the Trauma Patient -Appropriate for Any Patient in ShockAppropriate for Any Patient in Shock

• TriageTriage

• Primary SurveyPrimary Survey

• ResuscitationResuscitation

• Secondary SurveySecondary Survey

• Monitoring and Re-evaluationMonitoring and Re-evaluation

• Definitive CareDefinitive Care

Initial Assessment of the Trauma Initial Assessment of the Trauma Patient– Primary SurveyPatient– Primary Survey

A – AIRWAY with C-SPINE CONTROLA – AIRWAY with C-SPINE CONTROL

B – BREATHINGB – BREATHING

C – CIRCULATION with BLEEDING CONTROLC – CIRCULATION with BLEEDING CONTROL

D – DISABILITY, NEUROLOGIC STATUSD – DISABILITY, NEUROLOGIC STATUS

E – EXPOSURE and ENVIRONMENTE – EXPOSURE and ENVIRONMENT

Life threatening problems identified and managed Life threatening problems identified and managed simultaneouslysimultaneously

Hypovolemic ShockHypovolemic Shock

• Must treat the source of hypovolemia and Must treat the source of hypovolemia and arrest ongoing fluid lossesarrest ongoing fluid losses

• The usual suspects:The usual suspects:– Thorax (CXR or CT)Thorax (CXR or CT)– Abdomen (CT or Ultrasound)Abdomen (CT or Ultrasound)– Pelvis (CT or plain film)Pelvis (CT or plain film)– Retroperitoneal (CT)Retroperitoneal (CT)– Extremities – fractures or open wounds (plain Extremities – fractures or open wounds (plain

films)films)

• All can be evaluated by operative All can be evaluated by operative interventionintervention

Initial Assessment – Initial Assessment – RadiographsRadiographs

• Cervical spineCervical spine

• ChestChest

• PelvisPelvis


• Categorized by severity as Class I-IVCategorized by severity as Class I-IV


• Mainstay of therapy- Volume Mainstay of therapy- Volume restorationrestoration– CrystalloidsCrystalloids– ColloidsColloids

•BloodBlood

•PlasmaPlasma

•Blood SubstitutesBlood Substitutes

Hypovolemic Shock – Hypovolemic Shock – Basic Management Principles-1Basic Management Principles-1

• Immediate and rapid Immediate and rapid administration of 2 liters warm administration of 2 liters warm Lactated Ringers through Lactated Ringers through large bore peripheral IVslarge bore peripheral IVs

• Check for response to therapyCheck for response to therapy• If no response, either:If no response, either:

– Not enough “treatment given”Not enough “treatment given”– Incorrect treatmentIncorrect treatment

Hypovolemic Shock – Hypovolemic Shock – Basic Management Principles-2Basic Management Principles-2

• Consequently, repeat Consequently, repeat fluid bolusfluid bolus

• Re-assessRe-assess

• If no response, either:If no response, either:– Massive exsanguinating Massive exsanguinating

hemorrhagehemorrhage– Other causes: think Other causes: think

Cardiogenic or Neurogenic Cardiogenic or Neurogenic in the trauma patientin the trauma patient

Tension PneumothoraxTension Pneumothorax


• Progressive entry of air Progressive entry of air into pleural spaceinto pleural space

• Collapse of ipsilateral Collapse of ipsilateral lunglung

• Mediastinal shiftMediastinal shift• Compromised venous Compromised venous

return to heartreturn to heart• Hypotension / decreased Hypotension / decreased

cardiac outputcardiac output• Cardiovascular collapseCardiovascular collapse• Needle decompression / Needle decompression /

chest tubechest tube


• HypotensionHypotension• Absent breath soundsAbsent breath sounds• Neck vein distensionNeck vein distension• Hyperresonant thoracic percussion noteHyperresonant thoracic percussion note• Contralateral tracheal shiftContralateral tracheal shift• Subcutaneous emphysemaSubcutaneous emphysema• Mechanism of injuryMechanism of injury• Clinical diagnosisClinical diagnosis

Cardiogenic ShockCardiogenic Shock

• The heart fails to deliver The heart fails to deliver an adequate amount of an adequate amount of blood to the body blood to the body resulting in resulting in hypoperfusion of hypoperfusion of peripheral tissuesperipheral tissues

• The heart cannot The heart cannot generate a sufficient generate a sufficient stroke volume and stroke volume and cardiac outputcardiac output

• Can be the result of Can be the result of impaired diastolic or impaired diastolic or systolic function or a systolic function or a combination of the twocombination of the two

Cardiogenic ShockCardiogenic Shock

• Most often due to Most often due to myocardial ischemia or myocardial ischemia or infarction or resultant infarction or resultant complications of papillary complications of papillary muscle rupture or muscle rupture or ventricular septal ruptureventricular septal rupture

• In trauma setting, think In trauma setting, think cardiac contusion in blunt cardiac contusion in blunt force trauma and cardiac force trauma and cardiac tamponade in penetrating tamponade in penetrating trauma.trauma.

Cardiogenic Shock-Cardiogenic Shock-Basic Management PrinciplesBasic Management Principles

• For pure “pump” failure, For pure “pump” failure, options include:options include:– Pharmacologic agentsPharmacologic agents– Re-perfusion strategiesRe-perfusion strategies

• Lytic agentsLytic agents• StentsStents• Coronary bypassCoronary bypass

– Mechanical assists (Intra-aortic Mechanical assists (Intra-aortic balloon)balloon)

• For tamponade physiology- For tamponade physiology- surgerysurgery

Cardiac TamponadeCardiac Tamponade

Penetrating Cardiac InjuryPenetrating Cardiac Injury

Penetrating Cardiac InjuriesPenetrating Cardiac Injuries

•Etiology usually Etiology usually knives or knives or bullets on the bullets on the streets, butstreets, but

• In the hospital In the hospital lines, catheterslines, catheters


• Relative role of tamponade Relative role of tamponade vs. severe hemorrhage vs. severe hemorrhage determined by :determined by :– Size of pericardial rentSize of pericardial rent– Rate of bleeding from Rate of bleeding from

cardiac woundcardiac wound– Chamber of heart involvedChamber of heart involved

STAB WOUNDS – TAMPONADESTAB WOUNDS – TAMPONADEGSW - BLEEDGSW - BLEED


• Tamponade Physiology:Tamponade Physiology:– Blood accumulates in pericardiumBlood accumulates in pericardium– Stroke volume decreasesStroke volume decreases– Right atrial pressure increasesRight atrial pressure increases– Right ventricle distendsRight ventricle distends– Ventricular septum shifts to leftVentricular septum shifts to left– Left ventricle filling compromisedLeft ventricle filling compromised– Cardiac output decreases, hypotension Cardiac output decreases, hypotension

ensuesensues


• Pre-hospital :Pre-hospital :– Get patient to hospital ASAPGet patient to hospital ASAP– Mattox / Feliciano study of 100 consecutive Mattox / Feliciano study of 100 consecutive

patients – if external CPR > 3 minutes- patients – if external CPR > 3 minutes- 100% mortality100% mortality

• Emergency department :Emergency department :– Hemodynamics stable- ECHO +/- Hemodynamics stable- ECHO +/-

subxyphoid windowsubxyphoid window– Hemodynamics unstable – ED Hemodynamics unstable – ED

thoracotomy / OR *thoracotomy / OR *

Neurogenic ShockNeurogenic Shock

• A form of distributive shock A form of distributive shock caused by the sudden loss of caused by the sudden loss of CNS signals to vascular smooth CNS signals to vascular smooth muscle following spinal cord muscle following spinal cord injuryinjury

• Results in an immediate Results in an immediate decrease in peripheral vascular decrease in peripheral vascular resistance and hypotensionresistance and hypotension

• May be associated with normal May be associated with normal heart rate or even bradycardiaheart rate or even bradycardia

Neurogenic ShockNeurogenic ShockBasic Management PrinciplesBasic Management Principles

• Adequate oxygenationAdequate oxygenation• Spine immobilizationSpine immobilization• Restore vasomotor tone after Restore vasomotor tone after

insuring adequate volume insuring adequate volume statusstatus– Alpha agonist pharmacologic Alpha agonist pharmacologic

agentsagents

• Often a role for early use of Often a role for early use of flow directed pulmonary flow directed pulmonary artery catheterartery catheter

Septic ShockSeptic Shock

• A type of distributive A type of distributive shock related to loss of shock related to loss of vasomotor tone in vasomotor tone in response to severe response to severe systemic infection or systemic infection or inflammatory responseinflammatory response

• Results from release of Results from release of multiple cellular mediators multiple cellular mediators which stimulate a which stimulate a neurohormonal systemic neurohormonal systemic response and influence response and influence vascular resistancevascular resistance

Septic ShockSeptic Shock

• Inadequate Inadequate treatment can treatment can lead to ARDS and lead to ARDS and multiple organ multiple organ failurefailure

• Mortality Mortality approaches 50%approaches 50%

Septic ShockSeptic ShockBasic Management PrinciplesBasic Management Principles

• Remove the source of infection Remove the source of infection or nidus for unlimited or nidus for unlimited inflammatory responseinflammatory response

• Antimicrobial therapy directed Antimicrobial therapy directed against offending organismsagainst offending organisms

• Support organ functionSupport organ function• Alpha agonists to maintain Alpha agonists to maintain

vasomotor tonevasomotor tone• Aggressive use of flow directed Aggressive use of flow directed

pulmonary artery catheterspulmonary artery catheters

ShockShockA Guide to ResuscitationA Guide to ResuscitationFlow Directed Pulmonary Artery Flow Directed Pulmonary Artery CatheterCatheter

• AKA the Swan- Ganz AKA the Swan- Ganz catheter, introduced into catheter, introduced into clinical practice in 1970clinical practice in 1970

• Integrates cardiopulmonary Integrates cardiopulmonary physiologic data of the physiologic data of the patientpatient

• Aides in determining Aides in determining appropriate theraputic appropriate theraputic interventions when cause of interventions when cause of shock unknownshock unknown

• Allows resuscitation to Allows resuscitation to physiologic endpointsphysiologic endpoints

ShockShockFlow Directed PA CathetersFlow Directed PA Catheters

ShockShockThe Role of the PA CatheterThe Role of the PA Catheter

• Most often used in conjunction with Most often used in conjunction with standard intravascular monitoring standard intravascular monitoring devices (central venous line, arterial devices (central venous line, arterial line) , EKG and pulse oximetryline) , EKG and pulse oximetry

• Provide both measured and Provide both measured and calculated physiologic indicescalculated physiologic indices

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• Measured physiologic indices:Measured physiologic indices:

– Mean arterial pressure (a-line)Mean arterial pressure (a-line)– Heart rate (EKG, a-line)Heart rate (EKG, a-line)– Central venous pressure (CVL, PA Central venous pressure (CVL, PA

catheter)catheter)– Pulmonary artery occlusion pressure, Pulmonary artery occlusion pressure,

AKA the “wedge pressure” (PA catheter)AKA the “wedge pressure” (PA catheter)– Oxygen saturation (pulse oximetry, ABG)Oxygen saturation (pulse oximetry, ABG)

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• The measured indices enable The measured indices enable

calculation of other parameters:calculation of other parameters:– Systemic Vascular ResistanceSystemic Vascular Resistance

•[(MAP-CVP) x 80] / CO[(MAP-CVP) x 80] / CO

– Stroke Volume Stroke Volume •CO / HRCO / HR

•Usually “indexed” by patient BSA (SV / BSA)Usually “indexed” by patient BSA (SV / BSA)

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• Invasive hemodynamic monitoring Invasive hemodynamic monitoring

can provide insight into the principal can provide insight into the principal determinants of CO and hence tissue determinants of CO and hence tissue perfusion:perfusion:– PreloadPreload: (CVP, better yet PAOP): (CVP, better yet PAOP)– AfterloadAfterload: (SVR and MAP): (SVR and MAP)– ContractilityContractility: (SI): (SI)

Shock-Shock-How Can the PA catheter help?How Can the PA catheter help?

• Hypovolemic shock-Hypovolemic shock-– Low CO, low PAOP and CVP, high SVRLow CO, low PAOP and CVP, high SVR

• Cardiogenic shock-Cardiogenic shock-– Low CO, high PAOP and CVP, low SILow CO, high PAOP and CVP, low SI

• Septic shock-Septic shock-– High CO, low PAOP and CVP, low SVRHigh CO, low PAOP and CVP, low SVR

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• Therapy can be directed where Therapy can be directed where

intervention needed:intervention needed:

Inadequate PreloadInadequate Preload = Hypovolemia = Hypovolemia•Volume- either crystalloids or colloids depending Volume- either crystalloids or colloids depending

upon patient Hb and coagulation parametersupon patient Hb and coagulation parameters

Excess PreloadExcess Preload = Congestive Heart Failure = Congestive Heart Failure•Diuretics +/- InotropesDiuretics +/- Inotropes

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• Therapy can be directed where intervention Therapy can be directed where intervention

needed:needed:

Inadequate afterloadInadequate afterload = neurogenic or = neurogenic or septic shockseptic shock•Alpha agonists AKA Pressors (Norepinephrine Alpha agonists AKA Pressors (Norepinephrine

or Neosynephreine)or Neosynephreine)

Excessive afterloadExcessive afterload = Hypertensive CVD = Hypertensive CVD•Vasodilators ( Sodium Nitroprusside, Vasodilators ( Sodium Nitroprusside,

Nitroglycerine)Nitroglycerine)

ShockShockThe Role of the PA Catheter, The Role of the PA Catheter, etcetc• Therapy can be directed where Therapy can be directed where

intervention needed:intervention needed:

Inadequate contractilityInadequate contractility = cardiogenic = cardiogenic shockshock•Beta agonists AKA InotropesBeta agonists AKA Inotropes

– EpinepherineEpinepherine– Dobutamine (good if increased afterload Dobutamine (good if increased afterload

as well)as well)

Shock- Pitfalls in Shock- Pitfalls in ManagementManagement

• Assuming blood pressure equates to Assuming blood pressure equates to cardiac outputcardiac output

• Extremes of ageExtremes of age

• HypothermiaHypothermia

• AthletesAthletes

• PregnancyPregnancy

• Medications / PacemakersMedications / Pacemakers

Points for the StudentPoints for the Student

• Understand the rationale for the pitfalls in Understand the rationale for the pitfalls in shock management as listed on slideshock management as listed on slide

• What is the optimal and most efficient What is the optimal and most efficient diagnostic modalities for the patient with diagnostic modalities for the patient with presumed hypovolemic shock?presumed hypovolemic shock?

• Understand the clinical features of the 6 Understand the clinical features of the 6 major causes of shock.major causes of shock.

• Trivia question: Who is depicted on the Trivia question: Who is depicted on the slide “Penetrating Cardiac Injury” ?slide “Penetrating Cardiac Injury” ?

Patient Scenario - 1Patient Scenario - 1

• 42 yo woman ejected from car following 42 yo woman ejected from car following collision with a tree. Pre-hospital data:collision with a tree. Pre-hospital data:– HR 110 BP 88/46 RR 26HR 110 BP 88/46 RR 26– Confused, skin cold and clammyConfused, skin cold and clammy

• Is she in shock? If so what are potential Is she in shock? If so what are potential etiologies? How do we assess and treat?etiologies? How do we assess and treat?


• 42 yo woman involved in MVC arrives 42 yo woman involved in MVC arrives in ED with full spine protection and in ED with full spine protection and supplement oxygensupplement oxygen– HR 120 BP 80 /46 RR 32HR 120 BP 80 /46 RR 32

• Is she in shock? If so what are Is she in shock? If so what are potential etiologies? How do we potential etiologies? How do we assess and treat?assess and treat?


• After 2000cc warm lactated Ringers:After 2000cc warm lactated Ringers:– HR 90 BP 110 / 80 RR 22HR 90 BP 110 / 80 RR 22

• How has the patient responded? How has the patient responded? What are the diagnostic implications?What are the diagnostic implications?


• What if the same patient, after What if the same patient, after 2000cc warm lactated Ringers:2000cc warm lactated Ringers:– HR 130 BP 80 / 60 RR 40HR 130 BP 80 / 60 RR 40

• Clinical interpretation?Clinical interpretation?


• 18 yo man stabbed in the left chest 18 yo man stabbed in the left chest with large kitchen knifewith large kitchen knife– BP 80 / 60 HR 130 RR 30BP 80 / 60 HR 130 RR 30

• Is he in shock ? Diagnostic Is he in shock ? Diagnostic possibilities ? How do you quickly possibilities ? How do you quickly evaluate and treat ?evaluate and treat ?


• 56 yo man now 6 days after undergoing a 56 yo man now 6 days after undergoing a left hemicolectomy for cancer. Develops left hemicolectomy for cancer. Develops oliguria and altered sensorium. oliguria and altered sensorium. Transferred to the ICU- PA catheter placedTransferred to the ICU- PA catheter placed

• Several hours later, patient is hypotensive Several hours later, patient is hypotensive BP 80 / 60 HR 140BP 80 / 60 HR 140

• What are the diagnostic possibilities ? What are the diagnostic possibilities ? What would the PA catheter data look like What would the PA catheter data look like for the various diagnostic possibilities?for the various diagnostic possibilities?

documents

Health & Medicine

serum lactate

oliguria anuria

penetrating

cardiac output

cardiac tamponade

potential

diagnostic

metabolic