SHOCKSHOCKJames Taclin C. Banez, M.D.James Taclin C. Banez, M.D.

Definition:Definition: Conditions that lowers tissue perfusionConditions that lowers tissue perfusion

1.1.decrease tonicity of blood vessel walldecrease tonicity of blood vessel wall neurogenic shockneurogenic shock early septic shockearly septic shock anaphylactic shockanaphylactic shock

2.2.decrease blood volumedecrease blood volume hypovolemic shock (hemorrhagic shock)hypovolemic shock (hemorrhagic shock)

3.3.decrease cardiac output due to myocardial decrease cardiac output due to myocardial failure.failure.

– myocardial ischemiamyocardial ischemia– cardiac compressive shock (pericardial cardiac compressive shock (pericardial

tamponade)tamponade)

TYPE:TYPE:1.1. Hypovolemic Shock:Hypovolemic Shock:

low pre-loadlow pre-load low systemic arterial pressurelow systemic arterial pressure tachycardiatachycardia increase vascular resistanceincrease vascular resistance

2.2. Traumatic Shock:Traumatic Shock: hypovolemiahypovolemia toxic factors (cytokines) from injured toxic factors (cytokines) from injured

tissues enters to the blood ----> activates tissues enters to the blood ----> activates intravascular inflammation & intravascular intravascular inflammation & intravascular coagulation. (increase vascular coagulation. (increase vascular permeability ---> multiple organ failure).permeability ---> multiple organ failure).

3.3. Cardiogenic Shock:Cardiogenic Shock: heart failureheart failure blood clogged behind the heartblood clogged behind the heart increase filling pressureincrease filling pressure

4.4. Cardiac Compressive Shock:Cardiac Compressive Shock: has a normal hearthas a normal heart low cardiac return due to extrinsic low cardiac return due to extrinsic

compressioncompression pericardial tamponadepericardial tamponade

5.5. Septic ShockSeptic Shock systemic changes brought by bacterial toxinssystemic changes brought by bacterial toxins

6.6. Neurogenic ShockNeurogenic Shock loss of arterial and venous toneloss of arterial and venous tone pool of blood in dilated peripheral venous pool of blood in dilated peripheral venous

systemsystem

Cellular Changes:Cellular Changes: decrease tissue perfusion ----> decrease decrease tissue perfusion ----> decrease

oxygen delivery ----> decrease ATP -----> oxygen delivery ----> decrease ATP -----> Na/K membrane pump fails ----> Na & Cl Na/K membrane pump fails ----> Na & Cl enters the cell ---> isotonic cellular enters the cell ---> isotonic cellular swelling ----> cell death.swelling ----> cell death.

Renal Response:Renal Response: Normal kidneys can tolerate renal ischemia Normal kidneys can tolerate renal ischemia

from 15 mins to a maximum of 90 mins. Can from 15 mins to a maximum of 90 mins. Can be prolonged w/ hypothermia and/or steroid)be prolonged w/ hypothermia and/or steroid)

Prolonged hypoperfusion leads to functional Prolonged hypoperfusion leads to functional and anatomic changes presenting as and anatomic changes presenting as azotemia.azotemia.

Renal failure indexRenal failure index::

((Urine Na x Plasma creatinineUrine Na x Plasma creatinine) )

Urine creatinineUrine creatinine

< 1 usually indicates pre-renal oliguria< 1 usually indicates pre-renal oliguria

> 1 indicates acute renal failure> 1 indicates acute renal failure

Pulmonary Response:Pulmonary Response: Damage Alveolar – Capillary Damage Alveolar – Capillary

interfaceinterface in case of shock ----> in case of shock ----> acute diffuse lung injury.acute diffuse lung injury.

Leakage of proteinaceous fluid Leakage of proteinaceous fluid into the interstitium and alveolar into the interstitium and alveolar space.space.

Leads to Leads to ARDSARDS: : Hypoxemia unresponsive to Hypoxemia unresponsive to

elevation of FiO2elevation of FiO2 Decreased pulmonary complianceDecreased pulmonary compliance Needs high airway pressure to Needs high airway pressure to

attain adequate tidal volumeattain adequate tidal volume

PathophysiologyPathophysiology

Hypovolemic Shock:Hypovolemic Shock: most commonmost common Most of the blood is lost from systemic and Most of the blood is lost from systemic and

small veins (50%) ----> decrease cardiac small veins (50%) ----> decrease cardiac return ----> low cardiac output ----> decrease return ----> low cardiac output ----> decrease blood pressureblood pressure

Degree of Hemorrhagic Degree of Hemorrhagic ShockShock

Mild Hemorrhagic Shock:Mild Hemorrhagic Shock: < 20% blood lost< 20% blood lost adrenergic constriction of blood vessels in adrenergic constriction of blood vessels in

the skinthe skin thirsty, feels coldthirsty, feels cold normal BP, PR and urine outputnormal BP, PR and urine output

Degree of Hemorrhagic Degree of Hemorrhagic ShockShock

Moderate Hemorrhagic Shock:Moderate Hemorrhagic Shock: 20 – 40% blood loss20 – 40% blood loss (+) above signs and symptoms(+) above signs and symptoms low urine outputlow urine output

Due to aldosteron and ADHDue to aldosteron and ADH

Degree of Hemorrhagic Degree of Hemorrhagic ShockShock

Severe Hemorrhagic Shock:Severe Hemorrhagic Shock: 40% blood lost40% blood lost In addition to above s/sx pt has low BP and In addition to above s/sx pt has low BP and

rapid pulse raterapid pulse rate signs of M.I. ---> Q waves and depressed signs of M.I. ---> Q waves and depressed

St-T segmentsSt-T segments

Compensatory Compensatory MechanismMechanism

1.1. Adrenergic dischargeAdrenergic discharge

2.2. Hyperventilation:Hyperventilation: with spontaneous deep breathing there is a with spontaneous deep breathing there is a

decreased intra-thoracic ----> increase decreased intra-thoracic ----> increase ventricular end diastolic volume ----> ventricular end diastolic volume ----> increase cardiac output.increase cardiac output.

3.3. Collapse:Collapse: Displaced blood from extremity to the heart Displaced blood from extremity to the heart

and the brain and the brain

Compensatory Compensatory MechanismMechanism4.4. Release of fluid from Release of fluid from

the interstitium into the interstitium into the vascular space:the vascular space:

Epinephrine causes Epinephrine causes constriction of the constriction of the arterioles and precapillary arterioles and precapillary sphincter ----> decrease sphincter ----> decrease intracapillary hydrostatic intracapillary hydrostatic pressure ----> influx of pressure ----> influx of H2O, Na & ClH2O, Na & Cl

Compensatory Compensatory MechanismMechanism

5.5. Release of vasoactive hormones:Release of vasoactive hormones:

6.6. Resorption of fluid from intracellular Resorption of fluid from intracellular to extracellular space:to extracellular space:

Epinephrine, cortisol and glucagon Epinephrine, cortisol and glucagon increases concentration of interstitial increases concentration of interstitial glucose glucose ---->----> extracellular hyperosmolality extracellular hyperosmolality ---->----> draws H2O from cell draws H2O from cell ---->----> hydrostatic hydrostatic pressure in the interstitium pressure in the interstitium ---->----> forced forced H2O and CHON into the lymphatics H2O and CHON into the lymphatics -------------> -------------> oncotic pressure oncotic pressure intravascular intravascular ----> ----> attracts H2O attracts H2O intravascularly furtherintravascularly further

Compensatory Compensatory MechanismMechanism

7.7. Renal conservation of body H2O and Renal conservation of body H2O and electrolyteelectrolyte

aldosteronealdosterone anti-diuretic hormone (vasopressin)anti-diuretic hormone (vasopressin)

Decompensation in Decompensation in Hypovolemic ShockHypovolemic Shock

1.1. Relaxation of arteriolar and Relaxation of arteriolar and precapillary spasmprecapillary spasm

forced H20 and electrolyte from vascular forced H20 and electrolyte from vascular space into the interstitiumspace into the interstitium

2.2. Deterioration of cell membrane Deterioration of cell membrane functionfunction

Two Most Sensitive Signs of Two Most Sensitive Signs of Hypovolemia are:Hypovolemia are:

1.1. Cutaneous vasoconstrictionCutaneous vasoconstriction

2.2. OliguriaOliguria

AlcoholAlcohol can cause vasodilation and can cause vasodilation and inhibits secretion of ADHinhibits secretion of ADH

Monitoring:Monitoring:

Management:Management: resuscitate patient and control blood lost resuscitate patient and control blood lost

and correct dehydrationand correct dehydration give balance salt solution (crytalloid)give balance salt solution (crytalloid) disadvantage of giving colloid disadvantage of giving colloid

resuscitation.resuscitation.1.1. Post-resuscitation HPNPost-resuscitation HPN

2.2. Increase intravascular volume at the expense Increase intravascular volume at the expense of necessary interstitial fluidof necessary interstitial fluid

3.3. Depression of albumin synthesisDepression of albumin synthesis

4.4. Depression of circulating immunoglobulinDepression of circulating immunoglobulin

5.5. More expensive and less easier to titrateMore expensive and less easier to titrate

Management:Management: Supine position w/ elevated both lowerSupine position w/ elevated both lower

extremitiesextremities: : preferred position for patient preferred position for patient in shockin shock

Elderly patient ---> check condition of the Elderly patient ---> check condition of the heart (digitalis) ability to compensate.heart (digitalis) ability to compensate.

Steroid is not indicatedSteroid is not indicated O2 inhalation is of little value if vascular O2 inhalation is of little value if vascular

volume is not correctedvolume is not corrected

Causes of Refractory Shock:Causes of Refractory Shock:1.1. Continuing blood loss from primary Continuing blood loss from primary

injury or another sourceinjury or another source

2.2. Inadequate replacement of fluidsInadequate replacement of fluids

3.3. Massive trauma or other Massive trauma or other derangementderangement

4.4. Myocardial infarctionMyocardial infarction

5.5. Concomitant septic shockConcomitant septic shock

Traumatic ShockTraumatic Shock Traumatized tissue activates Traumatized tissue activates

coagulation system forming:coagulation system forming:1.1. Microthrombi:Microthrombi:

Occludes pulmonary vasculature ---> increase Occludes pulmonary vasculature ---> increase pulmonary vascular resistance ----> increase pulmonary vascular resistance ----> increase right arterial pressureright arterial pressure

2.2. Humoral products of microthrombiHumoral products of microthrombi:: cytoxinescytoxines Increases vascular permeability ---> loss of Increases vascular permeability ---> loss of

plasmaplasma

Traumatic ShockTraumatic Shock

Treatment:Treatment: Primary treatment is correct hypovolemiaPrimary treatment is correct hypovolemia Debridement of ischemic or dead tissueDebridement of ischemic or dead tissue If necessary connect to a mechanical If necessary connect to a mechanical

ventilatory supportventilatory support

Cardiogenic ShockCardiogenic Shock s/sx of myocardial ischemias/sx of myocardial ischemia Increase CVP and pulmonary artery Increase CVP and pulmonary artery

wedge pressure w/ decrease C.O. and wedge pressure w/ decrease C.O. and fails to respond with fluid solution.fails to respond with fluid solution.

Treatment:Treatment: Bed rest, O2 inhalation, narcotic analgesicBed rest, O2 inhalation, narcotic analgesic Monitoring of cardiac functionMonitoring of cardiac function Medications: digitalis / dopamine / ganglionic Medications: digitalis / dopamine / ganglionic

blocking agents / lidocaineblocking agents / lidocaine Low cardiac output secondary to low heart Low cardiac output secondary to low heart

rate ---> cardiac pacemakerrate ---> cardiac pacemaker

Cardiac Compressive Cardiac Compressive ShockShock

Pericardial tamponade:Pericardial tamponade: there is decrease pericardial compliance on there is decrease pericardial compliance on

right atrium, right ventricle and left atrium right atrium, right ventricle and left atrium --------> decrease cardiac output associated --------> decrease cardiac output associated with high filling pressure and small chamber with high filling pressure and small chamber volumes.volumes.

Cardiac Compressive Cardiac Compressive ShockShock

Sign/Symptoms:Sign/Symptoms: Distended neck veinsDistended neck veins Muffled heart soundMuffled heart sound HypotensionHypotension TachycardiaTachycardia Pulsus paradoxicusPulsus paradoxicus OliguriaOliguria Cold clammy skinCold clammy skin

Cardiac Compressive Cardiac Compressive ShockShock

Chest X-ray:Chest X-ray: Water bottle shape (erect film)Water bottle shape (erect film)

Management:Management: in in unstable ptunstable pt.. – do anterolateral – do anterolateral

thoracotomy w/ decompression of the thoracotomy w/ decompression of the tamponade and surgical control of the tamponade and surgical control of the abnormalityabnormality

In In stable pt.stable pt. – do pericardiocentesis, – do pericardiocentesis, withdrawal of 50cc. Blood shd. Return withdrawal of 50cc. Blood shd. Return cardiovascular dynamics to normalcardiovascular dynamics to normal

Septic ShockSeptic Shock

Causes:Causes:1.1. Gram positive sepsis (exotoxin)Gram positive sepsis (exotoxin)

2.2. Gram negative sepsis (endotoxin)Gram negative sepsis (endotoxin) More commonMore common Source of infection:Source of infection:

a.a. genito-urinarygenito-urinary

b.b. respiratoryrespiratory

c.c. alimentaryalimentary

d.d. integumentaryintegumentary

Septic ShockSeptic ShockEarly septic shock:Early septic shock:

warm extremity, pt is still normovolemicwarm extremity, pt is still normovolemic toxin increases core body temperaturetoxin increases core body temperature BP decreases due to vasodilatation BP decreases due to vasodilatation

(decrease peripheral resistance)(decrease peripheral resistance) increase cardiac output due to minimal increase cardiac output due to minimal

resistanceresistance increase heart rate and increase cardiac increase heart rate and increase cardiac

contractilitycontractility hyperventilationhyperventilation ----> ----> respiratory respiratory

alkalosisalkalosis

Septic ShockSeptic ShockLate septic shock:Late septic shock:

cold extremity, patient is hypovolemiccold extremity, patient is hypovolemic hypovolemia due to --> increase hypovolemia due to --> increase

vascular permeability and decrease vascular permeability and decrease cardiac outputcardiac output1.1. Increase vascular permeability (endotoxin)Increase vascular permeability (endotoxin)2.2. Decrease cardiac output Decrease cardiac output due to increased due to increased

pulmonary vascular resistance (endotoxin)pulmonary vascular resistance (endotoxin)3.3. Increase right ventricular pressure --> due to Increase right ventricular pressure --> due to

impairment of emptying.impairment of emptying. Increase peripheral resistance Increase peripheral resistance (cold (cold

cyanotic extremities)cyanotic extremities) Decrease CVPDecrease CVP

Septic ShockSeptic Shock

Treatment:Treatment: volume replacementvolume replacement look for the source of infection to give the look for the source of infection to give the

proper antibiotic (culture and sensitivity)proper antibiotic (culture and sensitivity) Earliest sign of gm(-) infection:Earliest sign of gm(-) infection:

1.1. hyperventilationhyperventilation

2.2. respiratory alkalosisrespiratory alkalosis

3.3. altered sensoriumaltered sensorium

Neurogenic ShockNeurogenic Shock

Seen in spinal cord injuries and spinal Seen in spinal cord injuries and spinal anesthesia.anesthesia.

normovolemic / hypovolemic pt.:normovolemic / hypovolemic pt.:− Blood pool in the systemic venules and Blood pool in the systemic venules and

small veins resulting to decrease right heart small veins resulting to decrease right heart filling ----> decrease stroke volume ----> filling ----> decrease stroke volume ----> decrease cardiac output ----> (+) angiotensin decrease cardiac output ----> (+) angiotensin and ADHand ADH

Neurogenic ShockNeurogenic Shock hypervolemic pt.:hypervolemic pt.:

− cardiac output increase due to expanded cardiac output increase due to expanded blood volume and decrease vascular blood volume and decrease vascular resistance.resistance.

− hypotension due to decrease vascular hypotension due to decrease vascular resistanceresistance

Treatment:Treatment: Give IVF, if BP does not respond ----> give Give IVF, if BP does not respond ----> give

vasoconstrictor to restore venous tone ----> vasoconstrictor to restore venous tone ----> restore right cardiac filling ----> increase restore right cardiac filling ----> increase cardiac output.cardiac output.

Elevate the lower extremitiesElevate the lower extremities

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