SHOCK IN CHILDRENSanju Susan SamuelFellow-Pediatric Critical Care Medicine

OBJECTIVES Definition Physiology Classification of Shock Common Etiologies Recognition and Assessment Management

DEFINITION An acute, complex state of circulatory

dysfunction that results in failure to deliver sufficient amount of oxygen and nutrients to meet tissue metabolic demands.

Therefore, basically DO2 < VO2.

If prolonged and left untreated- Can lead to multiple organ failure and eventually death.

Figure 1. FACTORS AFFECTING OXYGEN DELIVERY

DO2

CaO2

CO

SV

HR

Oxygenation

Hgb

A-a gradient DPG

Acid-Base Balance Blockers

Competitors Temperature

Drugs Conduction System

Ventricular Compliance

EDV

ESV Contractility

CVP Venous Volume

Venous Tone

Afterload Blockers Temperature Competitors Drugs Autonomic Tone

Metabolic Milieu Ions

Acid Base Temperature

Drugs Toxins

Influenced By

Influenced By

Influenced By

Influenced By

What is needed to maintain Perfusion?? PUMP- Heart PIPES- Vessels FLUID- Blood

Pump Failure Pipe Failure Loss of Volume

How can Perfusion fail??

Causes of Inadequate Perfusion Inadequate Pump Inadequate preload Poor contractility Excessive Afterload Inadequate HR

Inadequate Fluid Volume Hypovolemia

Inadequate Container Excessive Dilatation Inadequate systemic vascular resistance

So-what happens??

Anaerobic MetabolismAnaerobic MetabolismAnaerobic Metabolism

GLUCOSE METABOLISM

2 LACTIC ACID

2 ATP

HEAT (32 kcal)

Aerobic MetabolismAerobic MetabolismAerobic Metabolism

6 O2

GLUCOSE

METABOLISM

6 CO2

6 H2O

36 ATP

HEAT (417 kcal)

PHASES OF SHOCK Compensated Shock- Intrinsic regulatory mechanisms- Vital organ function is maintained

Uncompensated Shock- Compromise of microvascular perfusion- Deterioration of organ function- Hypotension develops

Irreversible Shock- Damage to key organs.

RECOGNITION & ASSESSMENT Respiratory- Quality of Respirations- Auscultatory Findings Cardiovascular- Pulse- Blood Pressure, Pulse pressure Skin-Color-Capillary Refill-Temperature-Moist/ Dry

Recognition & Assessment.. Neurological-Full/ flat/ sunken fontanelle-Calm/ anxious/ irritable-Alert/ lethargic-Responsive to parents-level of consciousness-Muscle tone-pupillary size Renal- Urinary output

SIGNS OF SHOCK Early Signs1. Tachycardia2. Normal blood pressure3. Mildly delayed capillary refill4. Fussy child

Signs of Shock.. Late Signs1. Persisting tachycardia or bradycardia2. Hypotension- LATE sign!!3. Poor capillary refill4. Altered mental status5. Irregular breathing pattern6. Poor muscle tone7. Lower limit of SBP=70 + (2 x age in years)

FUNCTIONAL CLASSIFICATION OF SHOCK

Hypovolemic Distributive Cardiogenic Obstructive Septic

Whole blood loss

Plasma loss

Fluid/ electrolyte losses

Septic

Anaphylaxis

Spinal anesthesia

Infectious

CMP

Carditis

Metabolic

Arrythmia

Pericardial tamponade

Tension Pneumothorax

Pulmonary HTN

HYPOVOLEMIC SHOCK MCC of shock in children Decrease in the intravascular blood volume to

such an extent that effective tissue perfusion cannot be maintained.

Preload decrease

Decreased Stroke Volume

Decreased C.O.

Management of Hypovolemic Shock Establishment of adequate oxygenation and

ventilation O2- ALWAYS the first drug administered. Adequate IV or IO Early correction of hypovolemia-Crystalloids: Readily available, safe, least expensive-First bolus 20cc/kg- ASAP-Continuous monitoring of vitals-Monitoring of CVP: Maintain > 10mmHg-Identify causes of ongoing losses- Blood available: if hemorrhagic shock.

Solution makeup Osmol Glucose Na+ Cl- K+ Ca+ Lactate

5% D/W 278 50g/l 0 0 0 0 0 10%D/W 556 100g/l 0 0 0 0 0 .45% NS 154 0 77 77 0 0 0 .9% NS 308 0 154 154 0 0 0 LR 274 0 130 109 4 1.5 28

Na, Cl, K, Ca, and lactate are measured in mmol/liter.

The Stages of Shock

Normal Eucardia, normal BP and CR

Tachycardia alone, normal BP and CR HR is maintaining CO despite reduced stroke volume (CO = HR x SV)

Hypotension with normal CR = Warm shock Vascular tone cannot maintain blood pressure but HR maintains CO

Prolonged CR with normal BP = Cold shock HR does not maintain CO but vascular tone maintains BP

Prolonged CR + hypotension = Decompensated Cold Shock HR does not maintain CO and vascular tone does not maintain BP

(Carcillo et al., Pediatrics 2009)(Slides are courtesy of Dr. Carcillo)

CARDIOGENIC SHOCK1. a. Toxic substances released during

course of shock. b. Myocardial Edema c. Adrenergic receptor dysfunction d. Impaired sarcolemmic Calcium flux e. Reduced coronary blood flow

2. Diastolic Dysfunction

PathophysiologyLV able to eject less volume of bld/ beat

Dec. Stroke Volume

Increased Venous Return

Increased EDV

Increased LV diastolic filling pressure

Backflow from LV to lungs

Dec.C.O

Increased O2 extraction by tissues

Arterial O2 desaturation

Etiology of Cardiogenic Shock Dysrrhythmias Cardiomyopathies

Congenital Heart Disease

Trauma

Hypoxic-Ischemic eventInfectiousMetabolicConnective Tissue DisorderNM disordersToxinsOthers

Recognizing Cardiogenic ShockHistory Physical Examination CXR

Excessive Resp

effort Prolonged

feeding time Poor weight

gain Excessive

sweating Frequent

resp. tract infections

Inc HR, Inc RR Gallop Cold extremites, weak peripheral

pulses Rales Dyspnea, cyanosis Hepatomegaly Neck V dsitension Peripheral edema Hypotension

Cardiomegaly Pulm venous congestionHyperinflation

Managing Cardiogenic Shock…

Minimize Myocardial O2 demands

Maximize Myocardial Performance

Exclude & Explore

Intubation

Maintain normothermia

Provide sedation

Correct anemia

Correct Dysrhythmias

Optimize Preload

Improve Contractility

Reduce Afterload

Exclude traumatic or CHD

Explore surgical options

OBSTRUCTIVE SHOCK Normal Preload Normal myocardial function Inadequate C.O. Etiology

Recognize and treat underlying cause!!

Tension PneumothoraxPulmonary/ Systemic HTNCongenital/ Acquired outflow obstructions

Ac. Pericardial Tamponade

DISTRIBUTIVE SHOCK PathoPhysiology:a. Maldistribution of blood flow to tissue due to abnormal

vasomotor tone.b. Profound inadequate tissue oxygenation.c. Normal or High C.O.

Etiology

Management: Recognize and treat underlying cause

AnaphylaxisSpinal or Epidural anesthesiaDisruption of spinal cordIatrogenic

SIRS/Sepsis/Septic shock

Mediator release:exogenous & endogenous

Maldistribution

of blood flow

Cardiacdysfunction

Imbalance of oxygensupply and

demand

Alterations in

metabolism

SEPTIC SHOCK

ACUTE ORGAN DYSFUNCTION(Severe Sepsis)

DEATH

SEPSIS

SIRS Sepsis Severe Sepsis

Septic Shock

Systemic inflammatory response to variety of severe clinical insults indicated by 2 or more of the following:Temp > 38 or < 36HR > 90bpm (adults)/ >2SD(ped)RR > 20/min (adults)/>2SD(ped) OR PACO2 <32mmhgWBC>12000, <4000 or > 10% bands

Systemic response to infection manifested by 2 or more of the following as a result of infection: Temp > 38 or < 36HR>90RR>20 or PaCO2 < 32WBC>12000. <4000 or >10% bands

Sepsis associated with:Organ dysfunctionHypoperfusion (Lactic acidosis, oliguria, altered mental status)Hypotension

Warm Shock Cold Shock Fluid-Refractory/Dopamine resistant

Catecholamine Resistant

Refractory Shock

Early, compensated

Clinical Signs-Inc.HR-Warm extremities, bounding pulses

Physiologic Parameters-Wide PP-Inc. C.O.-Inc. MvO2-Dec.SVR

Lab Data-Hypocardia-Inc. Lactate-Inc.Glucose

Late, UncompensatedClinical Signs-Cold, clammy extremities-Rapid, thready pulses-Shallow breathing

Physiologic Parameters-Narrow PP-Dec.CVP, C.O-Dec. MvO2 sat-Inc. SVR-Oliguria-Capillary Leak

Lab Data-Metab. Acidosis-Hypoxia-Coagulopathy-Hypoglycemia

Persistance of shock despite > 60cc/kg fluid resuscitation

Persistance of shock despite Dopamine at >10mcg/kg/mn

Persistance of shock despite administration of direct acting catecholaminesEpinephrine/ Nor-Epinephrine

Persistance of shock despite:-Goal direct inotropic/ pressor therapy-Use of vasodilators-Maintenance of metabolic and hormonal homeostasis

Early Goal directed therapy in treatment of sepsis and septic shock- Rivers et al., NEJM, Nov 2001

Community-Acquired Sepsis Pneumonia-Quinolone PLUS B-lactam Abdominal-Carbapenem OR Pip-Tazo Skin/Soft Tissue-Vanco PLUS Carbapenem or Pip-Tazo Urinary Tract-Quinolone PLUS Amp/Vanco Unknown-Vanco PLUS B-lactam

Health-Care Associated Sepsis Lung-B-lactam PLUS Vanco Bloodstream -B-lactam PLUS Vanco +/- Antifungal Surgical Site -B-lactam PLUS Vanco +/- Anaerobic coverage Suspected Candida-Caspofungin Unknown-B-lactam PLUS Vanco

Antibiotic Guidelines in Sepsis by Suspected SiteAntibiotic Guidelines in Sepsis by Suspected Site

HEMODYNAMIC VARIABLES IN SHOCK STATES

or Septic: Late

Or Septic: Early

Or Or Or Distributive

Or Obstructive

Or Cardiogenic

Or Hypovolemic

CVPWedgeMAPSVRCO

B.P or Systemic Vascular Resistance

Therapies for Hemodynamic Patterns in Shock State

Therefore, the Basics…. Stabilize respiration

Assess perfusion

Fluid administration

IV Access

Vasopressors

Inotropic therapy

Red blood cell transfusions if needed

References Pediatric Critical Care: Fuhrman, Zimmerman Surviving Sepsis Guidelines E-medicine Uptodate online SCCM website