Download Circulatory Shock

Pediatric Circulatory Shock
Christa Jefferis Kirk, PharmD
[email protected]
Seattle Children’s Hospital
Seattle, Washington
Objectives
•
Understand the physiology behind circulation and shock
•
Gain a basic understanding of how shock initially develops and
potential consequences
•
Recognize the various types of shock
•
Know the basic treatment of pediatric shock including fluid
replacement and pharmacologic intervention
•
Briefly discuss PALS and how the pharmacists can help
1
Definition and Basic physiology
What is it and how does it happen?
What is circulatory shock?
• “When systemic oxygen and nutrient supply
become acutely inadequate to meet the
metabolic demands of the body’s organ
systems.”
2
Other ways to think about it…
• Demand > Supply
• “The O (2) won’t go where
the blood don’t flow”
• Oxygen delivery man
Physiology of Blood Pressure Maintenance
Myocardial
Contractility
Force applied
Stroke Volume
(volume of blood
ejected from left
ventricle)
Preload
Volume of blood
in ventricle
Cardiac Output
Heart Rate
Blood Pressure
Systemic
Vascular
Resistance
Afterload
Resistance to
contraction
3
Physiology Goal
(maintain blood pressure)
BP
CO x SVR
HR x SV
Preload, Afterload,
Contractility
Four Essential Components of Oxygen
and Nutrient Delivery
• Fluid
•
preload
• Pump
• contractility
• Vessels
• create afterload with
alteration in vascular tone
• Flow
• affected by structure and
systemic vascular
resistance
4
Classification and physiology of Shock
How do we tell them apart?
Types of Shock
• Hypovolemic (fluid)
• Hemorrhagic
• Nonhemorrhagic
• Cardiogenic (pump)
• Distributive (vessels)
• Septic (fluid/vessels/pump)
• Obstructive (flow)
5
Classification of Shock
Compensated
• Blood flow is normal/increased but mal-distributed, vital organs
perfused
• Signs: elevated heart rate, “flash” or delayed capillary refill,
fussy/irritable
Uncompensated
• Reduction in circulating volume due to compromised
microvascular perfusion, diminished perfusion to vital organs
• Signs: decreased heart rate, decreased capillary refill, altered
mental status (lethargy, coma), hypotonia, hypotension
Irreversible
• Little or no perfusion vital organs
• Irreparable damage
• Signs: hemodynamics unresponsive to all treatment, death
6
Hypovolemic Shock
•
Decreased preload
•
Primary cause of shock in
pediatrics worldwide (6-20 million
deaths annually)
Loss of volume:
• Water loss
• Blood loss
• Internal/external
Common Causes?
•
•
•
i.e. Not enough fluid for the pump
Physiology of Hypovolemic Shock
• Hemorrhage
• Dehydration
Low
intravascular
volume
Decreased
Stroke
Volume
• Decreased preload
• Decreased
ventricular filling
• Decreased cardiac
output
• Increased heart
rate
Inadequate
supply of O2
and nutrients
to body
7
Cardiogenic Shock
•
•
•
•
•
Decreased contractility
• Pump is not working effectively
Underlying cardiac dysfunction
Electrical – arrhythmia
Mechanical
• Cardiomyopathy
• Metabolic acidosis
• Anatomic malformations
• Hypoxia
Common causes:
• congenital heart disease
• recent cardiac surgery
• recent viral illness
• late septic shock
Physiology of Cardiogenic Shock
• Arrhythmia
• Myocarditis
• Congenital heart
defect
Decreased
contractility and LV
function
Decreased stroke
volume
• Pump is defective
• Decreased
volume of blood
ejected
• Decreased
cardiac output
Inadequate supply
of O2 and nutrients
to body
8
Distributive Shock
•
•
•
•
Decreased vascular tone – weak
and/or leaky pipes
Neurological damage leads to
inhibition of sympathetic nerve
system
Anaphylaxis leads to
compromised vessel integrity and
capillary leak
Causes:
•
•
•
•
allergic reaction (bee stings,
medication reactions)
trauma
infections (early sepsis)
drug intoxication – which ones??
Physiology of Distributive Shock
• *Anaphylaxis =
antibody/antigen →
vasoactive mediators
• Neurogenic =
decreased sympathetic
response
Venous and
arterial dilation
Decreased
Stroke Volume
• *Capillary leak
• Decreased venous
return
• Decreased vascular
resistance
• *Peripheral edema
• Decreased cardiac
output
• Hypotension
Inadequate
supply of O2 and
nutrients to body
9
Obstructive Shock
•
Decreased stroke volume due
to obstruction on or around the
heart
•
•
•
Something is blocking the heart or
the pipes around the heart
Causes:
• tamponade
• tension pneumothorax
• pulmonary embolism
Must then treat the underlying
problem with a procedure or
medication in order to resolve
Physiology of Obstructive Shock
• Tamponade
• Congenital heart
disease
• Pulmonary
embolism
Decreased
contractility
Decreased stroke
volume
• Reduced
ventricular filling
during diastole
• Increased
afterload
• Decreased cardiac
output
• Increased heart
rate
Inadequate supply
of O2 and nutrients
to body
10
Stages of Septic Shock
Early “warm”
Late “cold”
General idea
Decreased peripheral
vascular resistance;
increased cardiac output
Increased peripheral
vascular resistance;
decreased cardiac
output
Cardiac function
Heart rate is elevated
BP is normal
Heart rate is
elevated/diminished
BP is lower
Peripheral Perfusion
Extremities are warm
and with increased
pulses
“Flash” capillary refill
Extremities are cold with
decreased pulses
Significantly prolonged
capillary refill
Brain
Agitated, irritable
Lethargic, unresponsive
Kidneys
Diminished urine output
Little to no urine output
End Organ Function:
Physiology of Early Septic Shock
• Infection releases
cytokines, vasoactive
mediators
• Vessels and tissues
harmed
Peripheral
vasodilation
Decreased stroke
volume
• Increased edema
and capillary leak
• Increased heart
rate and
contractility
• Decreased cardiac
output
• Increased heart rate
Inadequate supply
of O2 and nutrients
to body
11
Physiology of Late Septic Shock
• Increased heart rate
• Endotoxins affect
heart function
• Heart unable to keep
up with demand
Decreased
contractility and LV
function
Decreased stroke
volume
• Increased preload
• Increased
afterload
• Heart begins to fail
• Decreased heart rate
• Bradycardia
• Hypotension
Multi-organ System
Failure
Identifying patients in shock
12
History and Physical Exam
 Eating/drinking
 Nausea/vomiting/diarrhea
 Trauma/injury
 Fever
 Edema/”tenting”/rash
 Liver – enlarged/normal/”down”
Clinical Assessment
• History
• Heart rate/Blood pressure
• Peripheral circulation
• Capillary refill
• Pulses
• Extremity temperature
• Respiratory status
• End Organ Perfusion
13
History and Physical Exam
 Eating/drinking
 Nausea/vomiting/diarrhea
 Trauma/injury
 Fever
 Edema/”tenting”/rash
 Liver – enlarged/normal/”down”
Cardiovascular
• Heart Rate
• Generally rate is elevated if:
• ≥180 bpm for infants
• ≥160 bpm for children greater than 1 year old
• Blood Pressure
• General rule of thumb for lower limit of systolic blood pressure:
• SBP= 70 + (2 x age in years)
• DBP is age related but usually between 50-80
14
Cardiovascular and Respiratory Rates
Age
Heart Rate
(beats per
min)
Neonates
(full term,
<28 days)
Infants
(1-12
months)
Children
(1-7 years)
120-180
Systolic
Blood
Pressure
(mmHg)
60-90
Mean
Arterial
Pressure
(mmHg)
55
Respiratory
Rate
(breaths per
min)
40-60
120-180
70-95
60
25-50
120-160
80-110
65
15-30
Children
(7-18
years)
90-140
90-140
65
12-20
Hypotension
•
Ominous sign in pediatric patients (vs. adults)
•
Children are able to maintain normal cardiac output and
blood pressure even after significant loss of volume by
increasing heart rate and vascular tone (co=hr x sv).
•
Hypotension does not become evident until the body
has worn out its own compensating responses.
•
Important to recognize and treat shock in a timely
manner
• BEFORE hypotension occurs
15
Peripheral Circulation
• Skin Perfusion
• Capillary Refill Time
• normal is ≤2 seconds
• Temperature
• Color/mottling
• Peripheral Pulses
• Present or absent?
• Strength: diminished,
normal, bounding
Respiratory
• Respiratory Status
Pulse Oximetry
(oxygen saturation
levels)
Normal
95-100%
Mild hypoxia
91-94%
Moderate hypoxia
86-90%
Severe hypoxia
≤85%
• Rate and pattern
• Work of breathing
• Oxygenation: color of
skin/lips, pulse
oximetry
16
End Organ Perfusion
• CNS Perfusion
•
•
•
•
Mental status
Response to pain
Muscle tone
Pupil size/response
• Renal Perfusion
• Urine output > 1mL/kg/hr
Treatment
We know what it is…now
what do we do?
17
Treatment
(simplified)








PALS
Replace fluid losses
Correct electrolytes
Blood products for blood loss
Cultures/antibiotics (when appropriate)
Unresponsive to fluids = vasopressors
Steroids only if indicated
ECLS
Goal Directed Therapy
•
Recognize shock FAST
•
•
Replete intravascular volume quickly
•
•
Han, Carcillo, et al noted early recognition based on capillary refill and blood
pressure (i.e. no labs needed) and treatment within the first hour reduced
mortality by 40%.
Carcillo et al revealed data that administration of fluids ≥ 60ml/kg within the first
hour of presentation significantly reduced mortality in pediatric patients – some
patients required up to 200ml/kg.
Improve capillary refill time (CR ≤ 2 seconds)
•
Han et al demonstrated that each hour delayed in improving BP and CR created
a 2-fold increase in odds ratio for mortality.
Normal BP and HR for age
•
Han et al noted that aggressive, early treatment in the ED improved survival by
9-fold in neonatal and pediatric septic shock patients.
18
Pediatric Advanced Life
Support
•
•
•
•
•
CAB – compressions, airway,
breathing
CPR
Intubate – increases oxygen –
less demand on the heart
Establish venous access
• Peripheral within 90
seconds
• Intraosseous (tibia or
sternum)
• Central venous catheter
Consider hypothermia
Fluid Management
• Crystalloid vs. Colloid
• Crystalloid
• normal saline or lactated ringer’s
• first choice
• Colloid
• Dextran, albumin, blood products, hydroxyethyl starch
• Large molecules that draw fluid into intravascular
space
• Good for volume concerns (heart patients) and thirdspacing
19
Vasoactive Medications
Inotropes
Phosphodiesterase
inhibitors
Dopamine
Epinephrine
Dobutamine
Milrinone
↑ contractility
↑ heart rate
↓ SVR
↑ contractility
↑coronary perfusion
Vasoconstrictors
Epinephrine
(>0.3mcg/kg/min)
Norepinephrine
Dopamine
(>10mcg/kg/min)
Vasopressin
↑ SVR
↑ contractility
(except
vasopressin)
Improving Stroke Volume
Increase preload
Increase contractility
(↑ heart rate)
Increase SVR
(↑ vasoconstriction)
Reduce afterload
• Volume
• crystalloid or colloid
• blood products
• Vasoactive medications
• lower dose dopamine or epinephrine
• dobutamine
• Good for distributive shock and “cold” shock
• Vasoactive medications
• higher dose dopamine and epinephrine
• norepinephrine
• Good for cardiogenic shock and “warm” shock
• Vasodilators
• Milrinone
20
Recognize
Shock
Initial
Therapy
Establish access
Establish IV access
Maintain airway
Oxygenate
Volume
10mL/kg (neonate)
20mL/kg (pediatric)
Initially up to
60mL/kg
Correct electrolyte
abnormalities
(glucose, calcium,
potassium)
Get cultures
Start antibiotics
(if indicated)
Fluid
Resistant
Shock
More volume
(consider blood
products)
Treat underlying
causes
(tamponade,
pneumothorax, etc)
Secure airway
(intubate)
Dopamine (peripheral
if necessary)
Titrate up to
10mcg/kg/min
Refractory
Shock
COLD SHOCK
ADD low dose
epinephrine via
central line
Consider milrinone
WARM SHOCK
ADD high dose
epinephrine or
norepinephrine via
central line
Steroids??
ECMO??
When to Add Steroids
• Continued
hypotension after
extensive
vasopressor
administration
• History of adrenal
insufficiency
• Patient has been on
steroids
• CNS abnormality
• Purpura fulminans
• Anaphylaxis
21
Extracorporeal Life Support (ECLS)
• Provides a means of
oxygenating the blood
outside the body
• Many studies have shown it
increases survival rates and
improves post-resuscitation
outcomes
Image from: www.nlm.nih.gov
Case presentation
What does the real thing look like?
22
History
• LKS is a 2 year old little girl s/p tonsillectomy 2 days prior
to admission.
• She was sent home on post-op day 0 and was initially
doing well.
• Later that evening she became tired and fussy in
addition to refusing to eat. She had a fever and vomited
once.
• The next morning she appeared lethargic and pale.
Physical Exam
• Clinical presentation
• Lethargic, glossy eyes
• Unresponsive to pain
• Pale
• Exam notable for:
•
•
•
•
•
•
Cool, clammy extremities
Capillary refill = 6 seconds
HR=166
BP=78/34
Temp=39.8
Mom stated she had only required a few diaper changes in the
last 12 hours.
23
Goal: Recognize Shock FAST
• Do you think this patient
is in shock?
• Why or why not?
• If yes, what type of shock
do you suspect?
Goal: Replete Intravascular Volume
QUICKLY
• INITIAL THERAPY
• Maintain airway, provide oxygen if necessary
• Establish access
• Unable to get a peripheral IV – what is the next step?
• What would be the first medication you would
recommend?
• Based on her elevated temp and appearance what
other medication(s) might be appropriate?
• Obtain labs
• Intubate
24
Labs
• Finally you get some access and the following labs are
ordered and reported to you:
• HCT = 24% (normal = 35-45%)
• Hgb=8.2 (normal = 11.5-14.5)
• WBC=25.8 (normal = 6.0-15.5)
• CRP=16.3 (normal < 0.8)
• Abnormal coagulation labs (elevated INR)
• pH=7.20; base deficit = -5
• Glucose=45 (normal=80-120)
Goal: Address Potential Causes
• INITIAL THERAPY
• Heart rate improves to the 150’s – periphery remains cool
• Team would like to give more fluid, based on the labs what
fluid would you recommend?
• How much of this fluid would you recommend?
• What other labs would we want to correct?
25
Goal: Improve Capillary Refill Time and
Maintain Normal Blood Pressure
• TREAT RESISTANT SHOCK
• After our initial therapy, BP drops from 100/52 to 53/17,
what can we add?
• After starting and titrating this medication, periphery
remains cool and BP is only 75/35 – what would you add
now?
• If patient doesn’t respond after titration of infusions, what
are other options?
Pharmacist to the rescue
Why should I know this…and how can I help?
26
Harness the Power of Pharmacy
“By day, Bob Benton is a seemingly normal
— and incredibly brilliant — pharmacist
who runs his own small drug store.
However, whenever evil or danger appears,
he becomes the costumed crime-fighter
known as the Black Terror. Thanks to
“formic ethers” he invented, he has gained
heightened strength, speed, agility, and
endurance. But even more than that, he
has the power of pharmacy.”
From: www.politedissent.com
“In this story, Ben
Benton and his
assistant Tim were
attending an estate
auction when a group
of thugs “forcibly”
persuaded an elderly
antique buff from
bidding on a certain old
chair. The chair had
been used to hide
some priceless jewelry,
which the gang stole,
fought off the Black
Terror, and then
escaped.”
27
Role of the Pharmacist
•
Medication preparation/verification
•
Drug information
•
Record information - history/background of patient
•
Recognize signs and symptoms of adverse drug reactions
•
Toxicology resource
•
Act as a liaison for pharmacy services or products unvailable in the
code cart or the code team.
Why Pharmacists are Great!
• Studies are emerging in adult and pediatric
medicine that show that pharmacist participation
in code/trauma situations is key to decreasing
morbidity and mortality
• More studies are needed but that means that
more pharmacists must be more involved!
28
Questions?
References
•
•
•
•
•
•
•
Yager P and Noviski N. Shock. Pediatrics in Review. 2010;31: 311-319
Brierly J, Carcillo JA, Choong K et al. Clinical Practice Parameters for
Hemodynamic Support of Pediatric and Neonatal Septic Shock: 2007
Update from the American College of Critical Care Medicine. Critical
Care Medicine 2009;37(2): 666-688.
McKiernan C, Lieberman S. Circulatory Shock in Children: An
Overview. Pediatrics in Review 2005 Dec;26(12): 451-460.
Altermann D, Daley B, Kennedy, A, et. al. “Considerations in Pediatric
Trauma.” 31 Aug. 2006. eMedicine. 25 Jan. 2007.
<www.emedicine.com/med/topic3223.htm>
Kelly S, Hays D, O’Brien T, et. al. (2005): Pharmacists Enhancing Patient
Safety During Trauma Resucitations. ASHP Midyear, Las Vegas, Nevada.
Carcillo JA, Davis AL, Zaritsky A. Role of Early Fluid Resuscitation in
Pediatric Septic Shock. JAMA 1991; 266(9): 1242-5.
Carcillo JA, Han, K, Lin J, and Orr R. Goal Directed Management of
Pediatric Shock in the Emergency Department. Clin Ped Emer Med
2007; 8: 165-175.
29
References
•
•
•
•
Han YY, Carcillo JA, Dragotta MA, et. al. Early Reversal of PediatricNeonatal Septic Shock by Community Physicians is Associated with
Improved Outcomes. Pediatrics 2003; 112: 793-9.
Rivers E, Nguyen B, Havstad, et. al. Early Goal Directed Therapy in the
Treatment of Severe Sepsis and septic shock. N Engl J Med 2001; 346:
1368-77.
Vernon DD, Furnival RA, Hansen KW et al. Effect of a pediatric trauma
team response team on emergency department treatment time and
mortality of pediatric trauma victims. Pediatrics 1999;103(1):20-4.
Klabunde, Richard. “Cardiovascular Physiology.” Cardiovascular Physiology
Concepts. 01 Jan 2007. Lippincott Williams 05 Feb. 2007.
www.cvphysiology.com
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