July 2019
Modulators: Dr.Dereje
Dr.Anteneh
Presenter:
Million Negasa( B
pharm)
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2
Out lines
Definition
Review of basic physiologic aspects
Epidemiology of shock
Pathophysiology
Classification by type & severity
Approach & Management
References
SHOCK: Definition
•Shock is an acute process characterized by
the body’s inability to deliver adequate
oxygen to meet the metabolic demands of
vital organs and tissues.
–Significant reduction of systemic tissue perfusion,
resulting in decreased tissue oxygen delivery
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Physiology
Preload
Contractilit
y
Afterload
Cardiac
Output
Stroke
Volume
X
Heart rate
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•Arterial Oxygen Content
=> Oxygen content of the RBC + the oxygen
dissolved in plasma
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Epidemiology
•Shock occurs in approx. 2% of all hospitalized
infants, children, & adults in developed countries
•The mortality rate varies based on the
etiology and clinical circumstances.
•Mortality from shock is less among children than
adults. For children with severe sepsis, mortality is
about 10 %, in comparison to 35 to 40 % within
one month of the onset of septic shock for adults.
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Epidem....
•Nevertheless, outcomes for children with
shock (in terms of morbidity & cost) are
significant.
•Hypovolemic shock, the most
common cause of shock in children
world wide
–Which is most frequently caused by
Diarrhoea, Vomiting, or Haemorrhage
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Pathophysiology of Shock
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The combination of a continued presence of an inciting trigger and
the body’s exaggerated and potentially harmful neurohumoral,
inflammatory, and cellular responses leads to the progression of
shock.
Types of Shock
Type of
Shock
Pathophysiology Signs & Symptoms
Hypovolem
ic
↓PRELOAD: ↓CO,
↑SVR,
intravascular
volume loss
↑HR, ↓ pulses, delayed RF,
dry skin, sunken eyes, oliguria
Distributive ↓ AFTERLOAD
(SVR)
Anaphylacti
c
↑ CO, ↓SVR
Angioedema, low BP,
wheezing, respiratory distress
Spinal Normal CO, ↓SVRLow BP without tachycardia;
paralysis,
Septic Variable More to come
Cardiogenic ↓CO, Variable SVRNormal to ↑HR, ↓pulses,
DCR, JVD, Murmur or
Gallop, Hepatomegaly
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Cardiogenic Shock
Cardiac output falls due to the pathology in the
heart itself & is defined as CI < 2.2 L/min/m2.
•Cardiac Pump Failure 2
0
to poor myocardial function
•Manifested physiologically as systolic function & CO.
•Cardiogenic shock is uncommon among children than
adults
•Diverse mechanisms can be divided into 3 general categories:
1.Cardiomyopathies
2.Arrhythmias : Structural Heart Disease,
Drug Intoxications, and Hypothermia are
leading causes of arrhythmia in children
3.Obstructive disorders
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Distributive Shock: causes
•Is a state of abnormal vasodilatation & decreased SVR.
Abnormal Vessel Tone (decreased after load)
Sepsis: gram-negative sepsis, other infections
Anaphylaxis
Neurogenesis (Spinal)
Spinal cord transection
Anesthesia
Drug overdose
Drug intoxication (Diuretics), hypoxia, poisoning
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Septic
Shock
Decrease
d Volume
Decreased
Pump
Function
Abnormal
Vessel
Tone
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Septic Shock =Severe sepsis plusplus the persistence of
hypoperfusion or hypotension despite adequate fluid
resuscitation or a requirement for vasoactive agents
Sepsis is the most common aetiology of distributive
shock among children
Hemorrhagic Shock classification by
Severity
•Four classes based upon % loss of blood volume.
•As with nonhemorrhagic losses, clinical features
are typically used to estimate BV deficit.
•Many children with class II hemorrhage, and
•All of those with classes III & IV are in shock.
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Hemorrhage Severity Classification
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Classe
s
% of fluid
Loss
Symptomss/Signs Treatment
I Up to 15% Minimal physiologic changes are evidentCrstalloid fluid
II 15-30%
Mild tachycardia & tachypnea with a
narrow PP, slightly DCR, decreased
UOP, & mild anxiety.
Crstalloid fluid
May require Blood
products
III 30-40%
Tachycardia, Tachypnea,
Hypotension, DCR, Altered
Mentation, Oliguria
Crstalloid solution &
Most Pt Need Blood
IV >40% Usually cold & pale with profoundly
depressed mentation, marked tachypnea
& tachycardia, and anuria.
Quick Blood products
Operative Intervention
often necessary to
control haemorrhage
Hypovolemic Shock
Clinical symptoms
•Often manifests initially as orthostatic
hypotension and is associated with
Dry mucous membrane, dry axillae
Sunken fontanel/eyes
Poor skin turgor
DCR, Cool extremities
Low or no urine output
•Tachycardia => compensated shock!
•Normal BP until volume loss >30-40%
•Further volume loss and exacerbation of shock by
pre-existing low plasma oncotic pressure
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•Hypotension is typically a late finding among
children in shock.
•For children, hypotension is defined as a
systolic blood pressure < 5
t h
percentile of
normal for age:
–< 60 mmHg in term neonates
–< 70 mmHg in infants
–< 70 mmHg + 2x age in years in 1 to 10
years
–< 90 mmHg in children >10 years of age
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C/M ... General
•Regardless of etiology, in uncompensated shock,
late in the progression of disease:
–Hypotension
–High SVR
–Decreased cardiac output
–Respiratory failure
–Obtundation, and
–Oliguria
–Elevated blood lactate levels
•Reflect poor tissue oxygen delivery in all forms of
shock.
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•Additional clinical findings in shock include:
–Cutaneous lesions such as
•Petechiae
•Diffuse erythema
•Ecchymoses
•Ecthyma gangrenosum and
•Peripheral gangrene
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Shock – Effects on Organ
Heart – CO / hypotension / myocardial depressants
↓
Lung - gas exchange / tachypnoea/ pulmonary edema
↓
Endocrine – ADH reabsorption of water
→↑
CNS – perfusion – drowsy
↓
Blood - Coagulation abnormalities – DIC
Renal - GFR - urine output
↓ ↓
GIT – mucosal ischaemia – bleeding & hepatic enzyme
↑
levels
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Compensatory Mechanism
Baroreceptors and Chemoreceptors- Disinhibits
vasomotor centers which increases adrenergic
output.
Renin-Angiotension system- Angiotensin I and
Angiotensin II
Antidiuretic Hormone/Vasopressin
Adrenal Cortex- Aldosterone
ACTH from pituitary- Cortisol
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Stages of Shock
Compensated Shock
Decompensated Shock
Irreversible Shock
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1. Compensated (Nonprogressive) Shock
•Compensatory mechanisms attempts to
maintain BP: NORMAL BP
•Unexplained tachycardia
•Mild tachypnea
•Delayed capillary refill
•Orthostatic changes in pressure or pulse
•Irritability
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2. Decompensated (Progressive) Shock
It is a state of inadequate end-organ perfusion
Compensatory mechanisms fails & HYPOTENSION
occurs.
Increased tachycardia, increased tachypnea
Altered mental state, low urine output,
Poor peripheral pulses.
Capillary refill markedly delayed
Cool extremities
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3. Irreversible (Refractory) shock
•It occurs as a consequence of decompensated
shock not managed properly and at right time.
•Permanent cellular damage & MODS.
•Recovery does not occur even with adequate
restoration of circulatory volume
•Death occurs due to:
–Refractory Acidosis, Myocardial & Brain
Ischemia.
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Complications of Shock
The main complications of severe shock
are:
1.Shock Lung (ARDS)
2.Acute Renal Failure
3.Gastrointestinal Ulceration
4.Disseminated Intravascular Coagulation
5.Multisystem Organ Failure
6.Death
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Approaches to Shock
Patient
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Goals of the initial Evaluation of
Shock
Immediate identification of life-threatening
conditions.
(eg, tension pneumothorax, hemothorax, cardiac
tamponade, or pulmonary embolism).
Rapid recognition of circulatory compromise.
Early classification of the type and cause of shock.
Rapid Assessment
Appearance
Significant changes in appearance
like:
poor tone
unfocused gaze indicators of decreased cerebral
perfusion.
weak cry
Subtle differences in appearance
decreased responsiveness to caretakers & painful
procedures.
Breathing
A child with depressed mental status as the result
of shock may not be able to maintain a patent
airway.
Tachypnea without respiratory distress can
develop in response to metabolic acidosis.
Children with cardiogenic shock typically have
some increased work of breathing in addition to
tachypnea.
Circulation
Quality of central and peripheral pulses
Decreased intensity of distal pulses in comparison to
central pulses suggests peripheral vasoconstriction and
compensated shock.
Bounding pulses may be present in patients with
distributive (“warm”) shock.
Skin temperature
Skin may be mottled or cool in children with
compensated shock.
This finding can also be influenced by environmental
temperature.
Con…
Capillary refill
>2seconds .
Flash capillary refill (<1 second)
The usefulness of capillary refill is limited by:
•inter-observer variability.
•environmental temperature.
Heart rate
Tachycardia ( compensated shock )
Bradycardia (Hypoxia, spinal cord injury and some
drugs).
History
1.Hx of injurey
2.A history of fluid loss
3.Fever and/or immunocompromised
4.A history of exposure to an allergen
5.Hx of exposure to toxins
6.Patients with chronic heart disease
7.risk for adrenal insufficiency
Approach to the classification of undifferentiated
shock in children, Does a child has…?
Physical Examination
V/S
•Abnormal V/S provide essential information regarding :
–Severity, classification & cause of shock.
A.RR –usually tachypneic.
B.HR
osinus tachycardia (except cardiogenic shock from a
brady arrhythmia or spinal cord injury).
oIn compensated shock, it may be the only abnormal
vital sign.
oOther causes of tachycardia with poor perfusion in
children include: (SVT & VT)
Con…
C. BP : normal / low BP.
D. T° : Fever (hypothermia in young infants)
E. Others: Stridor, wheezing (anaphylaxis).
C.Crackles (pneumonia, septic shock / HF, cardiogenic
shock).
D.Distended neck veins (HF, or cardiac tamponade or
tension pneumonia- or hemothorax).
E.Abnormal heart sounds ( murmurs or a gallop rhythm
/ muffled heart tones
F.Pulse differential
G.Hepatomegaly
Con..
Con…
DX
A.clinically (hx & p/e ).
E.g
Con…
B. Laboratory findings
i. comprehensive metabolic panel (CMP)
RBS ?
arterial or venous blood gas analysis
blood lactate
serum electrolytes ( Na+, K+, Ca++...)
BUN and SCr
ionized blood calcium
STB & ALT
Con…
II. Complete Blood Count
Hb
WBC differential (Neutropenia & leukopenia are
ominous sign of overwhelming sepsis).
III. Coagulation studies
thrombocytopenia may herald a bleeding disorder.
Disordered coagulation cascade activation
(Prolonged PT & aPTT , INR, Low Fibrinogen
and D-dimer)
IV. Culture body fluids( blood, urine, CSE..)
Con…
VI. Others
U/A ,Diagnostic serologic testing .
Inflammatory biomarkers (eg, C-reactive
protein).
B. Imaging
I.Chest x-ray.
II.Echocardiography
III.Catheterization and angiography
RX SHOCK
Shock Management Principles
1.Supportive Care
–ABC of Life
–Intubation, mechanical ventilation, Oxygen as
needed
1.Fluid Management
2.Treatment of underlying causes
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Initial Management
•Early recognition and prompt intervention are
extremely important in the management of all
forms of shock.
•Regardless of the cause: ABC Don’t Ever Forget
Glucose
•Baseline mortality is much lower in pediatric
shock than in adult shock i.e due to early
interventions.
key steps to manage shock
1. Give oxygen (for infants 0.5 -1 l/min, older children 1-
2 l/min).
2. Give 10% Glucose 5 ml/kg by IV.
3.Keep the child warm.
4.Direct manual pressure to control
bleeding.
5. Take blood samples for emergency laboratory tests
6. Give IV fluids
7. First assess the child for severe malnutrition before
selecting treatment.
Intravenous Fluids
A. Shock With NO SAM
Fluid bolus of 20ml/kg isotonic fluid (maximum of 3X)
If there is still NO improvement:
Consider Blood Transfusion unless there is profuse
watery diarrhea.
In this case, repeat Ringer's lactate.
If shock remains refractory following 60-80 mL/kg of
volume resuscitation, vasopressor therapy (norepinephrine,
or epinephrine) .
B. Child With SAM
•Theseverely malnourished child is considered to have
shock if he/she is lethargic or unconscious and has
cold hands plus either:
–slow capillary refill (>3seconds),or
–weak, fast or absent radial or femoral pulses and
–absence of signs of heart failure in an edematous child.
Con…
Weight a child.
IV Fluid (15ml/kg over 1hr).
Give normal saline or Ringer lactate with 5% glucose.
check PR and RR every 5-10 minutes.
If improved, change the IV fluid with oral intake/
Resomal after 2 hr.
If there is improvement: Repeat 15ml/kg over 1 hr.
Con…
If there is NO improvement:
Call senior health worker.
Give maintenance IV fluid 4ml/kg/hr while
waiting for blood.
Transfuse fresh whole blood at 10ml/kg slowly
over 3 hrs.
use packed cells, if in cardiac failure.
Con…
Monitor with the Multi-chart and shock follow up chart.
Use one of the following solutions, listed in order of
preference:
Ringer’s lactate solution with 5% glucose*
0.9 per cent normal saline with 5% glucose*
(add 125 ml of 40 % or 100 ml of 50% glucose to 1
liter of 0.9% saline to make this fluid)
*If either of these are used, add sterile potassium chloride
(20 Mmol/l) if possible.
Observe the child and check RR and PR every 10 minutes.
Con…
•If the RR (by 5 BPM) and PR (by 25 PPM) increase and child is
gaining weight.
–stop the IV rehydration & assume septic or cardiogenic
shock.
•If RR & PR are slower after 1hour, the child is improving.
–Repeat the same amount of IV fluids for another hour.
–Continue to check RR & PR every 10 minutes.
•After two hours of IV fluids, switch to oral or NG rehydration with
ReSoMal.
•Give 5-10 ml/kg ReSoMal in alternate hrs. with F-75 for up to 10
hrs or until fully rehydrated.
A- HYPOVOLEMIC SHOCK
TREATMENT
GOAL – restore circulating volume and tissue
perfusion & correct the cause
1. Assess airway.
2. Administer oxygen.
3. Give IV Fluid bolus of 20ml/kg isotonic fluid
(maximum of 3) .
In case of shock refractory to fluids, start inotrope
(dopamine).
B- septic shock
Provide broad-spectrum antimicrobial agents.
Neonates (ampicillin plus cefotaxime and/or
gentamicin).
intraabdominal process is suspected, anaerobic
coverage ,such as metronidazole, clindamycin, or
piperacillin-tazobactam.
Nosocomial sepsis ( 3rd- or 4th-generation
cephalosporin or a penicillin with an extended
Gramnegative spectrum). e.g., piperacillin-tazobactam.
Con…
community-acquired infections with Neisseria
meningitidis (3rd-generation cephalosporin,
(ceftriaxone or cefotaxime)).
resistant Streptococcus pneumoniae & MRSA require
the addition of vancomycin.
immunocompromised patients (Empirical coverage for
fungal infections).
C- Distributive shock
primary abnormality in vascular tone.
may benefit temporarily from volume
resuscitation.
early initiation of a vasoconstrictive agent to
increase SVR .
con…
1.ANAPHYLACTIC SHOCK
Airway, Withdrawal of Ag, Cautious fluid
administration
IV epinephrine
Antihistamine
Corticosteroids
Vasopressors or Inotropes
Con…
2. NEUROGENIC SHOCK
Cautious fluid administration
Vasopressors & Inotropes
Correct hypothermia
Treat bradycardia with atropine
Observe and prevent DVT.
•May benefit from :phenylephrine or vasopressin
to increase SVR.
D- cardiogenic shock RX
GOAL :
increase CO, treat reversible causes& decrease myocardial
workload
1. Assess airway , administer oxygen /mechanical ventilation
2. Inotropic agents, vasoactive drugs.
3. IV fluids (5-10ml/kg boluses over longer time)
4. Morphine to decrease preload and anxiety
5. Short acting beta blockers for refractory tachycardia
E- obstructive shock
• fluid resuscitation may be briefly temporizing in
maintaining cardiac output.
•primary insult must be immediately addressed.
Such as…
–pericardiocentesis for pericardial effusion,
–pleurocentesis for pneumothorax
–thrombectomy/thrombolysis for PE.
–prostaglandin infusion for ductus-dependent
cardiac lesions.
Dopamine
Low-dose: 1 to 5 mcg/kg/minute, results in increased renal blood
flow and urine output
Intermediate-dose: 5 to 10 mcg/kg/minute, results in increased
renal blood flow, heart rate, cardiac contractility, and cardiac output
High-dose: >10 mcg/kg/minute, alpha-adrenergic effects begin to
predominate, resulting in vasoconstriction, increased blood pressure
in addition to increased heart rate, cardiac contractility, and cardiac
output due to beta-adrenergic effects.
Physiologic indicators and target goals
After the initial fluid bolus, evaluate for:
1) Quality of central and peripheral pulses (strong,
distal pulses equal to central pulses)
2) Skin perfusion (warm, with capillary refill <2
seconds)
3) Mental status (normal mental status)
4) Urine output (≥1 mL/kg per hr)
5) BP (systolic pressure at least fifth percentile for
age)
PROGNOSIS
In septic shock, mortality rates are as low as 3% in
previously healthy children and 6-9% in children with
chronic illness (compared with 25-30% in adults).
This is due to early recognition and therapy.
But still shock and MODS remain one of the leading
causes of death in infants and children.
The risk of death depends on:
underlying etiology.
presence of chronic illness.
host immune response.
timing of recognition and therapy.
References
1.NELSON TEXTBOOK OF PEDIATRICS 20
TH
&
21th EDITION.
2.UPTODATE 2018.
3.PEDIATRIC HOSPITAL CARE: ETHIOPIA
(SECOND EDITION, 2016).
4.GUIDELINES FOR THE MANAGEMENT OF
ACUTE MALNUTRITION, FMOH, 2016.
73Shock Seminar: By Firomsa D &
G/Tsadik E