lesson 06

Copyright © 2007, 2003 by Mosby, Inc., an affiliate of Elsevier Inc.

Lesson 6Lesson 6

ShockShock

Copyright © 2007, 2003 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 2

ObjectivesObjectives

As a result of active participation in this As a result of active participation in this lesson you should be able tolesson you should be able to Explain the pathophysiology of shock to include Explain the pathophysiology of shock to include

the role of shock in immediate and delayed the role of shock in immediate and delayed trauma morbidity and mortalitytrauma morbidity and mortality

Relate mechanism of injury and assessment Relate mechanism of injury and assessment findings to identify patients in shock and patients findings to identify patients in shock and patients with the potential to develop shockwith the potential to develop shock

Describe the assessment and management Describe the assessment and management of the patient in shock or with the potentialof the patient in shock or with the potentialfor shock, including the limitations offor shock, including the limitations ofprehospital careprehospital care


ScenarioScenario

It is just past noon on a Sunday. It is sunny and It is just past noon on a Sunday. It is sunny and 6464° ° Fahrenheit (18Fahrenheit (18°° Celsius). As you get out of Celsius). As you get out of your vehicle in a shopping center parking lot your vehicle in a shopping center parking lot you hear a loud “boom.” Turning toward the you hear a loud “boom.” Turning toward the sound, you see an airborne motorcyclist land in sound, you see an airborne motorcyclist land in front of the stopped car he has just rear-ended. front of the stopped car he has just rear-ended.


ScenarioScenario

It appears that the car was stopped to turn into the It appears that the car was stopped to turn into the parking lot when the motorcycle hit it from behind parking lot when the motorcycle hit it from behind at about 45 miles (72 kilometers) per hour. The at about 45 miles (72 kilometers) per hour. The rider was ejected from the motorcycle and landed rider was ejected from the motorcycle and landed in front of the stopped vehicle. in front of the stopped vehicle.


Scenario: Scene Size-UpScenario: Scene Size-Up

What are the What are the considerations for considerations for scene safety?scene safety?

What are the potential What are the potential injuries associated injuries associated with this mechanism?with this mechanism?


ScenarioScenario

Noting that another bystander is calling 911, Noting that another bystander is calling 911, you jog the short distance to the scene, where you jog the short distance to the scene, where the patient is lying on his back. You note that he the patient is lying on his back. You note that he is wearing a helmet. Although the day is mild is wearing a helmet. Although the day is mild and he is wearing a leather jacket, the patient is and he is wearing a leather jacket, the patient is shivering uncontrollably. shivering uncontrollably.


Scenario: Primary SurveyScenario: Primary Survey

Is there evidence of shock?Is there evidence of shock?

Classification of Hemorrhagic Shock


Scenario: Primary SurveyScenario: Primary Survey

Awake, agitated, slow to process questionsAwake, agitated, slow to process questions Shivering, paleShivering, pale Breathing is slightly faster than normalBreathing is slightly faster than normal Skin is cool; radial pulse is over 100Skin is cool; radial pulse is over 100


Scenario: Critical ThinkingScenario: Critical Thinking

What do these findings suggest?What do these findings suggest? Is the patient in shock?Is the patient in shock?



What is happening to this patient?What is happening to this patient?


ShockShock

A state of generalized cellular hypoperfusion A state of generalized cellular hypoperfusion leading to inadequate cellular oxygenation to leading to inadequate cellular oxygenation to meet metabolic needsmeet metabolic needs

Organ Tolerance to Ischemia


HypoperfusionHypoperfusion

The patient is losing blood volumeThe patient is losing blood volume Loss of circulating volume means fewer RBCs Loss of circulating volume means fewer RBCs

circulating through the capillary beds to deliver circulating through the capillary beds to deliver oxygen to the cellsoxygen to the cells

Lack of oxygen impairs metabolismLack of oxygen impairs metabolism

Every RBC counts!Every RBC counts!


MetabolismMetabolism

All cells require energy to functionAll cells require energy to function Aerobic metabolismAerobic metabolism

Oxygen is required for efficient production of the Oxygen is required for efficient production of the energy molecule ATP and converting pyruvate to energy molecule ATP and converting pyruvate to carbon dioxide and water through the Kreb’s cyclecarbon dioxide and water through the Kreb’s cycle

Anaerobic metabolismAnaerobic metabolism Inadequate oxygen results in decreased ATP Inadequate oxygen results in decreased ATP

(energy molecule) production and accumulation(energy molecule) production and accumulationof lactic acidof lactic acid


ConsequencesConsequences

Decreased ATP (energy) for cell membrane Decreased ATP (energy) for cell membrane functionfunction Potassium and lactic acid enter the blood Potassium and lactic acid enter the blood

• Low pH results in release of cellular enzymes that autodigest Low pH results in release of cellular enzymes that autodigest cellscells

• Cellular death, organ failure resultCellular death, organ failure result Sodium and water enter the cellSodium and water enter the cell

• Cellular edemaCellular edema• Further loss of intravascular (blood) volumeFurther loss of intravascular (blood) volume



What is happening to this patient?What is happening to this patient? The use of ATP (energy) produces heatThe use of ATP (energy) produces heat With inadequate ATP (energy), the patient is not With inadequate ATP (energy), the patient is not

producing heatproducing heat Even with relatively mild temperatures, the patient is Even with relatively mild temperatures, the patient is

losing heat to the environment and cannot balance losing heat to the environment and cannot balance heat loss with heat productionheat loss with heat production

He is using what little ATP (energy) he is producingHe is using what little ATP (energy) he is producingto shiver and is producing lactic acid through to shiver and is producing lactic acid through anaerobic metabolismanaerobic metabolism

Hypothermia impairs blood clottingHypothermia impairs blood clotting


Scenario: Critical ThinkingScenario: Critical Thinking What is happening to this patient?What is happening to this patient?

He is entering a downward spiralHe is entering a downward spiral He needs your helpHe needs your help

What can you do for this patient before What can you do for this patient before additional help arrives?additional help arrives?

Organ Tolerance to Ischemia


ShockShock ClassificationsClassifications

HypovolemicHypovolemic• Hypovolemic shock due to hemorrhage is the most common cause of Hypovolemic shock due to hemorrhage is the most common cause of

shock in the trauma patientshock in the trauma patient

• Assume hemorrhagic shock until proven otherwiseAssume hemorrhagic shock until proven otherwise

DistributiveDistributive CardiogenicCardiogenic

Classification of Hemorrhagic Shock


Pathophysiology of Pathophysiology of Hemorrhagic ShockHemorrhagic Shock

Shock is progressiveShock is progressive Compensatory mechanisms are short-termCompensatory mechanisms are short-term Events in hypovolemic shockEvents in hypovolemic shock

Hemodynamic changesHemodynamic changes Cellular (metabolic) changesCellular (metabolic) changes Microvascular changesMicrovascular changes


Pathophysiology of ShockPathophysiology of Shock

HemodynamicsHemodynamics Perfusion of the body tissues requiresPerfusion of the body tissues requires

• An effective pumpAn effective pump

• An adequate volume of bloodAn adequate volume of blood

• Vascular resistanceVascular resistance



The heart must be an effective pumpThe heart must be an effective pump

CO = SV CO = SV ×× HR HR

Stroke volume depends on adequate return of Stroke volume depends on adequate return of blood to the heartblood to the heart

If blood volume decreases, cardiac output will If blood volume decreases, cardiac output will decrease unless the body alters the heart ratedecrease unless the body alters the heart rate



Adequate blood pressure is required for Adequate blood pressure is required for perfusionperfusion

Cardiac output is one factor in maintaining blood Cardiac output is one factor in maintaining blood pressurepressure

BP = CO BP = CO ×× SVR SVR

Vasoconstriction occurs to increase systemic Vasoconstriction occurs to increase systemic vascular resistance if cardiac output fallsvascular resistance if cardiac output falls



Microvascular changesMicrovascular changes Early: precapillary and postcapillary sphincters Early: precapillary and postcapillary sphincters

constrict causing constrict causing ischemiaischemia As acidosis increases: precapillary sphincters As acidosis increases: precapillary sphincters

relax but postcapillary sphincters remain relax but postcapillary sphincters remain constricted causing constricted causing stagnationstagnation

Finally: postcapillary sphincters relax causing Finally: postcapillary sphincters relax causing washoutwashout, releasing microemboli and aggravating , releasing microemboli and aggravating acidosisacidosis



VasoconstrictionVasoconstriction Ischemic phase of shockIschemic phase of shock

Ischemic sensitivityIschemic sensitivity Brain: 4 to 6 minutesBrain: 4 to 6 minutes

• Altered LOC occurs earlyAltered LOC occurs early

Organs: 45 to 90 minutesOrgans: 45 to 90 minutes• Acute renal failure, ARDSAcute renal failure, ARDS

Skin and skeletal muscle: hoursSkin and skeletal muscle: hours


Classifications of ShockClassifications of Shock

Distributive shockDistributive shock NeurogenicNeurogenic——decreased systemic vascular decreased systemic vascular

resistance resistance Cardiogenic shock (in the trauma patient)Cardiogenic shock (in the trauma patient)

IntrinsicIntrinsic• Blunt cardiac trauma leading to muscle damage and/or Blunt cardiac trauma leading to muscle damage and/or

dysrhythmiadysrhythmia

• Valvular disruptionValvular disruption

ExtrinsicExtrinsic• Pericardial tamponadePericardial tamponade

• Tension pneumothoraxTension pneumothorax


ScenarioScenario

How does the How does the pathophysiology of shock pathophysiology of shock explain the patient’s explain the patient’s presentation?presentation?


Signs of ShockSigns of Shock

TachypneaTachypnea Hypoxia and acidosis stimulate the respiratory Hypoxia and acidosis stimulate the respiratory

centercenter 20 to 30 breaths per minute20 to 30 breaths per minute More than 30 breaths per minuteMore than 30 breaths per minute Intolerance of oxygen face maskIntolerance of oxygen face mask



CirculationCirculation Assessment for hemorrhageAssessment for hemorrhage Level of consciousnessLevel of consciousness Heart rateHeart rate PulsePulse Skin color and temperatureSkin color and temperature Capillary refillCapillary refill Blood pressureBlood pressure



DisabilityDisability Decreased cerebral perfusion results in altered Decreased cerebral perfusion results in altered

LOCLOC Other causes of altered LOC will not kill the patient Other causes of altered LOC will not kill the patient

as rapidly as shockas rapidly as shock Assume altered LOC is due to shock and treatAssume altered LOC is due to shock and treat


Signs of ShockSigns of Shock Musculoskeletal injuriesMusculoskeletal injuries

Major or multiple fractures can lead to Major or multiple fractures can lead to significant blood losssignificant blood loss

Of particular concern are femur and pelvic Of particular concern are femur and pelvic fracturesfractures

Don’t underestimate blood loss due to Don’t underestimate blood loss due to multiple fractures excluding the femurs multiple fractures excluding the femurs and pelvisand pelvis



FractureFracture Blood Loss (mL)Blood Loss (mL)

Single ribSingle rib 125125

Radius or ulnaRadius or ulna 250250––500500

HumerusHumerus 750750

Tibia or fibulaTibia or fibula 500500––10001000

FemurFemur 10001000––20002000

PelvisPelvis MassiveMassive



Internal organ injuryInternal organ injury Shock is assumed to be Shock is assumed to be

hypovolemic in the absence of hypovolemic in the absence of other explanationsother explanations

Abdominal trauma is a cause of Abdominal trauma is a cause of significant hidden hemorrhagesignificant hidden hemorrhage

Assume abdominal trauma if Assume abdominal trauma if hypovolemic shock is not hypovolemic shock is not otherwise explainableotherwise explainable


Scenario: Secondary SurveyScenario: Secondary Survey

A BLS engine has A BLS engine has arrivedarrived

FindingsFindings HR 124HR 124 RR 28RR 28 BP 124/86BP 124/86 DeformitiesDeformities

• Bilateral femursBilateral femurs

• Right humerusRight humerus


Classifications of HemorrhageClassifications of Hemorrhage

Class IClass I Less than 15% blood lossLess than 15% blood loss Few signsFew signs

Class IIClass II 15%-30% blood loss15%-30% blood loss Increased HR, RRIncreased HR, RR Decreased pulse pressureDecreased pulse pressure

Class IIIClass III 30%-40% blood loss30%-40% blood loss HR greater than 120HR greater than 120 RR 30-40RR 30-40 Decompensation (systolic BP less thanDecompensation (systolic BP less than

90 mm Hg)90 mm Hg)

Class IVClass IV More than 40% blood lossMore than 40% blood loss HR greater than 140HR greater than 140 Marked decrease in systolic BP Marked decrease in systolic BP Profound lethargyProfound lethargy



What class of hemorrhage do you suspect What class of hemorrhage do you suspect this patient is experiencing?this patient is experiencing?

How do you know?How do you know? What is the likely source of the patient’s What is the likely source of the patient’s

hemorrhage?hemorrhage?


Assessment: Critical ThinkingAssessment: Critical Thinking

What factors may affect a patient’s What factors may affect a patient’s presentation in shock?presentation in shock? PregnancyPregnancy MedicationsMedications AgeAge Preexisting medical conditionsPreexisting medical conditions


Shock ManagementShock Management

Four questions guide Four questions guide resuscitationresuscitation What is the cause of shock in this What is the cause of shock in this

patient?patient? What is the care of this type of What is the care of this type of

shock?shock? Where can the patient get this care?Where can the patient get this care? What can be done between now and What can be done between now and

the time the patient reaches the time the patient reaches definitive care?definitive care?

A fisherman who run over by a motorboat suffered severe damange to his lower extremities. His life was saved by first responders who applied tourniquets to both thighs.


Shock ManagementShock Management

Reduced cardiac output and impaired tissue Reduced cardiac output and impaired tissue oxygenation are occurring before the blood oxygenation are occurring before the blood pressure drops.pressure drops.

Proper shock management improves the Proper shock management improves the oxygenation of RBCs and improves the oxygenation of RBCs and improves the delivery of RBCs to the tissues.delivery of RBCs to the tissues. AirwayAirway VentilationVentilation OxygenationOxygenation CirculationCirculation


Scenario: AirwayScenario: Airway

What are the patient’s airway needs?What are the patient’s airway needs?


Scenario: OxygenationScenario: Oxygenation

What guides the What guides the

administration ofadministration of

oxygenation for this oxygenation for this

patient?patient?


Scenario: BreathingScenario: Breathing

Does the patient require assisted Does the patient require assisted ventilations?ventilations?


Scenario: CirculationScenario: Circulation

What can be done to improve the patient’s What can be done to improve the patient’s circulation?circulation?


Hemorrhage ControlHemorrhage Control

Hemorrhage control is critical to perfusionHemorrhage control is critical to perfusion TechniquesTechniques

Direct pressure will control most external Direct pressure will control most external hemorrhagehemorrhage

TourniquetTourniquet ImmobilizationImmobilization Consider elevationConsider elevation Consider use of arterial pressure pointsConsider use of arterial pressure points Topical hemostatic agents may be Topical hemostatic agents may be

recommended for prolonged transport recommended for prolonged transport situationssituations


Circulation: Fluid TherapyCirculation: Fluid Therapy

Why fluid therapy?Why fluid therapy? Controversies and disadvantagesControversies and disadvantages Areas of investigationAreas of investigation


Circulation: Fluid TherapyCirculation: Fluid Therapy

Current recommended practiceCurrent recommended practice Classes II, III, and IV shockClasses II, III, and IV shock Initial rapid bolus of 1000 to 2000 mL of warmed Initial rapid bolus of 1000 to 2000 mL of warmed

lactated Ringer’s solutionlactated Ringer’s solution Pediatric patients: 20 mL/kgPediatric patients: 20 mL/kg Maintain systolic BP at 85 to 90 mm HgMaintain systolic BP at 85 to 90 mm Hg


Circulation: Patient PositioningCirculation: Patient Positioning

SupineSupine Not TrendelenburgNot Trendelenburg No need to elevate lower extremitiesNo need to elevate lower extremities


Circulation: PASGCirculation: PASG

IndicationsIndications ContraindicationsContraindications Not effective for control of external Not effective for control of external

hemorrhagehemorrhage


Transport ConsiderationsTransport Considerations

Transport without Transport without delay does not delay does not mean “scoop and mean “scoop and run”run”

Patient compartment Patient compartment temperature should temperature should be 85be 85°° F (29 F (29°° C) C)

Considerations in Considerations in prolonged transportprolonged transport


Complications of ShockComplications of Shock

Untreated, shock progressesUntreated, shock progresses Prehospital care can make a difference in the Prehospital care can make a difference in the

patient’s eventual outcomepatient’s eventual outcome Acute renal failureAcute renal failure Acute respiratory distress syndromeAcute respiratory distress syndrome Hematologic failureHematologic failure Multiple organ dysfunction syndromeMultiple organ dysfunction syndrome


Minimizing ComplicationsMinimizing Complications

Assess for shockAssess for shock Assume hemorrhagic shock until proven Assume hemorrhagic shock until proven

otherwiseotherwise Remember: cardiac output and tissue Remember: cardiac output and tissue

oxygenation are impaired earlyoxygenation are impaired early Restore/maintain: airway, ventilation, Restore/maintain: airway, ventilation,

oxygenation, circulationoxygenation, circulation Hypothermia creates a cycle of worsening Hypothermia creates a cycle of worsening

shock and hypothermiashock and hypothermia Transport without delayTransport without delay


Scenario: On-going AssessmentScenario: On-going Assessment

En route to the ED, paramedics have started En route to the ED, paramedics have started an IV on the patient. His blood pressure an IV on the patient. His blood pressure increased with a bolus of fluid, but decreased increased with a bolus of fluid, but decreased shortly after receiving the bolus.shortly after receiving the bolus. What does this tell you about the patient’s What does this tell you about the patient’s

condition?condition?


On-going AssessmentOn-going Assessment

There are three responses to fluid therapy:There are three responses to fluid therapy: Rapid responseRapid response Transient responseTransient response Minimal or no responseMinimal or no response


Scenario: OutcomeScenario: Outcome

ED evaluationED evaluation Orthopedic traumaOrthopedic trauma Nonoperative injuries Nonoperative injuries

to kidney and spleento kidney and spleen Orthopedic surgeryOrthopedic surgery Uncomplicated Uncomplicated

recoveryrecovery


SummarySummary

Shock is a state of cellular hypoperfusion Shock is a state of cellular hypoperfusion leading to inadequate energy production to leading to inadequate energy production to meet metabolic needsmeet metabolic needs

The most common cause of shock in the The most common cause of shock in the trauma patient is hemorrhagetrauma patient is hemorrhage

Shock is hemorrhagic until proven otherwiseShock is hemorrhagic until proven otherwise


SummarySummary

The management of shock is aimed at The management of shock is aimed at improving oxygenation of RBCs and improving oxygenation of RBCs and improving delivery of RBCs to the improving delivery of RBCs to the microcirculationmicrocirculation How do we do this?How do we do this?


QUESTIONS?QUESTIONS?

lesson 06

Education

role of shock

evidence of shock

common cause of shock

trauma patient

inadequate atp energy

blood volume decreases

energy molecule atp

blood clotting