Post on 10-Jul-2015
Shock
1Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Is This Patient in Shock?• Patient looks ill
• Altered mental status
• Skin cool and mottled or hot
and flushed
• Weak or absent peripheral
pulses
• SBP <90
• Tachycardia
Yes! These are all signs and symptoms of shock
2Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
• A 68 yo M with presents to the ED with abrupt onset of
diffuse abdominal pain with radiation to his low back. The pt
is hypotensive, tachycardic, afebrile (no fever), with cool but
dry skin.
• An 81 yo F ED with altered mental status. She is febrile to
39.4, hypotensive with a widened pulse pressure, tachycardic,
with warm extremities
Case
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 4
• A 41 yo M presents to the ED after an MVC complaining of
decreased sensation below his waist and is now hypotensive,
bradycardic, with warm extremities
Case
• A 55 yo M DM presents with “crushing” substernal chest
pain, diaphoresis, hypotension, tachycardia and cool,
clammy extremities
Objectives
Definition Approach to the hypotensive patient Types Specific treatments
5Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Definition of Shock• A complex clinical syndrome caused by an acute
failure of circulatory function and characterized by inadequate tissue and organ perfusion.
• Inadequate oxygen delivery to meet metabolic demands
• Results in global tissue hypoperfusion and metabolic acidosis
• Shock can occur with a normal blood pressure and hypotension can occur without shock
6Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
DEFINATION Shock give rise to systemic hypoperfusion caused by reduction either in
cardiac output or in effective circulatory blood volume. End results are : Hypotension
Tissue hypoperfusion
Cellular hypoxia
Reversible injury
Irreversible injury with persistent of shock
End organ dysfunction
Death
Determinants of Oxygen Delivery
OxygenDelivery = Content (CaO2) x Cardiac output (CO)
CaO2 = 1.34 (Hgb x SaO2) + (PaO2 x 0.003) SaO2: Oxygen saturation Hgb: Hemoglobin concentration PaO2: partial pressure Oxygen in plasma
↳ To improve Oxygen content Increase Hemoglobin concentration Increase saturation
8Dr Mai Duc Thao. ED. Friendship Hospital.Ha noi 2013
CaO2 is arterial oxygen content (in milliliters per deciliter), Hb is hemoglobin concentration (in grams per deciliter), SaO2 is hemoglobin saturation of arterial blood (in percent), and PaO2 is partial pressure of dissolved oxygen in arterial blood (in millimeters of mercury).
Determinants of Oxygen Delivery Cardiac output
C.O = Heart rate x stroke volume
↳ To improve Cardiac output
Increase Heart rate
Increase Stroke Volume
Preload – volume of blood in the ventricle
Afterload – resistance to contraction
Contractility – force applied
9Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Understanding Shock autonomic responses ?
• Inadequate systemic oxygen delivery activates autonomic
responses to maintain systemic oxygen delivery
Sympathetic nervous system:
• Epinephrine, dopamine, and cortisol release
• Causes vasoconstriction, increase in HR, and
increase of cardiac contractility (cardiac output)
Renin-angiotensin axis
• Water and sodium conservation and vasoconstriction
• Increase in blood volume and blood pressure10Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Myocardial Contractility Stroke Volume Preload Cardiac Output Afterload
Blood Pressure Heart Rate Systemic Vascular Resistance
Textbook of Pediatric Advanced Life Support, 1988Textbook of Pediatric Advanced Life Support, 1988
11Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Understanding Shock
Understanding Shock• Cellular responses to decreased systemic oxygen delivery
• ATP depletion → ion pump dysfunction (Na+, K+ATPase)
• Cellular edema
• Hydrolysis of cellular membranes and cellular death
• Goal is to maintain cerebral and cardiac perfusion
• Vasoconstriction of splanchnic, musculoskeletal, and renal
blood flow
Leads to systemic metabolic lactic acidosis that
overcomes the body’s compensatory mechanisms 12Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Global Tissue Hypoxia
• Endothelial inflammation and disruption
• Inability of O2 delivery to meet demand, Anaerobic
respiration
Result:
• Lactic acidosis
• Cardiovascular insufficiency
• Increased metabolic demands13Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Multiorgan DysfunctionSyndrome (MODS)
• Progression of physiologic effects as shock ensues
• Cardiac depression
• Respiratory distress
• Renal failure
• DIC
• Result is end organ failure
14Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
• ABCs
• Cardiorespiratory monitor
• Pulse oximetry
• Supplemental oxygen
• IV access
• ABG, labs
• Foley catheter
• Vital signs including rectal temperature
Approach to the Patient in Shock
15Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Approach to the Patient in Shock
• History• Recent illness• Fever• Chest pain, SOB• Abdominal pain• Comorbidities• Medications• Toxins/Ingestions• Recent hospitalization or
surgery• Baseline mental status
• Physical examination• Vital Signs• CNS – mental status• Skin – color, temp, rashes,
sores• Heart sounds• Resp – lung sounds, RR,
oxygen sat, ABG• GI – abd pain…• Renal – urine output
16Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Diagnosis
• Physical exam (VS, mental status, skin color, temperature, pulses, etc)
• Infectious source• Labs:
• CBC• Chemistries• Lactate• Coagulation studies• Cultures• ABG
17Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Further Evaluation• CT of head/sinuses
• Lumbar puncture
• Wound cultures
• Acute abdominal series
• Abdominal/pelvic CT or US
• Cortisol level
• Fibrinogen, FDPs, D-dimer
18Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Treatment
• ABCDE
• Airway
• control work of Breathing
• optimize Circulation
• assure adequate oxygen Delivery
• achieve End points of resuscitation
19Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Airway• Determine need for intubation but remember: intubation
can worsen hypotension
• Sedatives can lower blood pressure
• Positive pressure ventilation decreases preload
May need volume resuscitation prior to intubation to
avoid hemodynamic collapse
20Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Control Work of Breathing
• Respiratory muscles consume a significant amount of
oxygen
• Tachypnea can contribute to lactic acidosis
• Mechanical ventilation and sedation decrease WOB and
improves survival
21Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Optimizing Circulation• Isotonic crystalloids
• Titrated to:
• CVP 8-12 mm Hg
• Urine output 0.5 ml/kg/hr (30 ml/hr)
• Improving heart rate
• May require 4-6 L of fluids
• No outcome benefit from colloids
22Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Maintaining Oxygen Delivery• Decrease oxygen demands
• Provide analgesia and anxiolytics to relax muscles and
avoid shivering
• Maintain arterial oxygen saturation/content
• Give supplemental oxygen
• Maintain Hemoglobin > 10 g/dL
• Serial lactate levels or central venous oxygen saturations to
assess tissue oxygen extraction
23Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
End Points of Resuscitation• Goal of resuscitation is to maximize survival and minimize
morbidity
• Use objective hemodynamic and physiologic values to guide
therapy
• Goal directed approach
• Urine output > 0.5 mL/kg/hr
• CVP 8-12 mmHg
• MAP 65 to 90 mmHg
• Central venous oxygen concentration > 70%24Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Persistent Hypotension• Inadequate volume resuscitation
• Pneumothorax
• Cardiac tamponade
• Hidden bleeding
• Adrenal insufficiency
• Medication allergy
25Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Practically Speaking….
• Keep one eye on these patients
• Frequent vitals signs:
• Monitor success of therapies
• Watch for decompensated shock
• Let your nurses know that these patients are sick!
26Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
27Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
First aid
28Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
First aid
Types of Shock • Hypovolemic
• Septic
• Cardiogenic
• Anaphylactic
• Neurogenic, trauma
• Obstructive
• poison
29Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Classification of Shock
Hypovolemic Shock (#1 cause world wide)Dehydration, hemorrhagic (Hemorrhagic, nonhemorrhagic) Cardiogenic Shock
Pump failure, obstructive, L-R shunt Ischemic, Myopathic, Mechanical, Arrhythmia
Distributive Shock Neurogenic (spinal shock), Anaphylaxis, septic
Obstructive Massive Pulmonary embolism, Tension pneumothorax Cardiac tamponade, Constrictive pericarditis Septic Shock – All of the above
30Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 31
Classification of Shock
An Introduction to
ClinicalEmergencyMedicineSwaminatha V. Mahadevan, MD , FACEP, FAAEM
Associate Chief, Division of Emer gency MedicineAssistant Professor of Surgery (Emergency Medicine)Stanford University School of MedicineEmergency Department Medical DirectorMedical Student Clerkship Dir ector Stanford University Medical Center, Stanford, CA
G us M. G armel, MD , FACEP, FAAEM
Co-Program Director, Stanford/Kaiser Emergency Medicine ResidencyClinical Associate Professor of Surgery (Emergency Medicine)Stanford University School of MedicineSenior Staff Emergency Physician, The Permanente Medical Gr oupClerkship Director for Medical Students and Rotating InternsKaiser Permanente Medical Center , Santa Clara, CA
Cambridge University Press 2005
Physiologic parameters in shock states
32Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
What Type of Shock is This?
• 68 yo M with presents to the ED with abrupt onset of diffuse
abdominal pain with radiation to his low back. The pt is
hypotensive, tachycardic, afebrile (no fever), with cool but
dry skin.
Hypovolemic Shock
33Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
34
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
35
• Tachycardia and hypotension.
• Cool and frequently cyanotic extremities.
• Collapsed neck veins.
• Oliguria or anuria.
• Rapid correction of signs with volume infusio
ESSENTIALS OF DIAGNOSIS
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 36
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 37
Mild (<20%) Moderate(20-40%) Severe(>40%)
Cold extremitiesDiaphoresisAnxiety
Same +TachycardiaTachypnoeaOliguriaPostural -hypotension
Same +HypotensionMental status deterioration
Hypovolemic Shock
What Type of Shock is This?
• An 81 yo F ED with altered mental status. She is febrile to
39.4, hypotensive with a widened pulse pressure, tachycardic,
with warm extremities
Septic
38Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 39
Manifestation of excessive & inflammatory response of
endogenous immune mechanism two or more of the following:– T >38 or <36 C– HR >90 bpm – RR >20/min or PaCO2 <32 mmHg– WBC >12,000 or <4,000 cells/ or >10% bands
Sepsis is SIRS with established focus of infection
Septic shock - severe sepsis unresponsive to continuous fluid
infusion and inotropes
Septic shock
Definition by American College of Chest Physicians/Society of Critical Care Medicine
SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference, Levy MM et al., Crit. Care Med. 2003, 31(4): 1250-1256)
A clinician, armed with the sepsis bundles, attacks the three heads of severe sepsis: hypotension, hypoperfusion, and organ dysfunction.
Crit Care Med. 2004;320(Suppl):S595-S597
What Type of Shock is This?• A 55 yo M DM presents with “crushing” substernal chest
pain, diaphoresis, hypotension, tachycardia and cool,
clammy extremities
Cardiogenic shock
42Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 43
• Decreased urine output.
• Impaired mental function.
• Cool extremities.
• Distended neck veins.
• Hypotension with evidence of peripheral and pulmonary
venous congestion.
• Acute myocardial infarction most common cause
ESSENTIALS OF DIAGNOSIS
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 44
Circulatory pump failure in setting of adequate
vascular volume
Sustained hypotension SBP < 90 mm Hg for at least
30 minutes
CI < 2.2 L/min/m2
PAWP >15mmHg
Surgical importance in patients with chest trauma for
Tamponade
Tension pneumothorax
Cardiogenic shock
45Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
What Type of Shock is This?• A 34 yo F presents to the ED after dining at a restaurant where
shortly after eating the first few bites of her meal, became anxious,
diaphoretic, began wheezing, noted diffuse pruritic rash, nausea,
and a sensation of her “throat closing off”. She is currently
hypotensive, tachycardic and ill appearing.
Anaphalactic46Dr Mai Duc Thao. ED. Friendship Hospital.
Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 47
ESSENTIALS OF DIAGNOSIS
•Cutaneous flushing, pruritus.
•Abdominal distention, nausea, vomiting, diarrhea.
•Airway obstruction owing to laryngeal edema.
•Bronchospasm, bronchorrhea, pulmonary edema.
•Tachycardia, syncope, hypotension.
•Cardiovascular collapse.
Management of anaphylaxis Anaphylaxis is an acute medical emergency. The
immediate management includes: preventing further contact with the allergen (e.g. removal of
bee sting) ensuring airway patency administration of oxygen restoration of blood pressure (laying the patient flat,
intravenous fluids) prompt administration of adrenaline (epinephrine). Intravenous antihistamines (chlorphenamine 10-20 mg i.m.
or slow i.v. injection), which limit ongoing inflammation. Corticosteroids (hydrocortisone 100-300 mg) prevent late-
phase symptoms in severely affected patients.
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
What Type of Shock is This?• A 41 yo M presents to the ED after an MVC complaining of
decreased sensation below his waist and is now hypotensive,
bradycardic, with warm extremities
Neurogenic shock
49Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 50
• Preceded by trauma or spinal anesthesia.
• Hypotension with tachycardia.
• Cutaneous warmth and flushing in the
denervated area.
• Venous pooling.
ESSENTIALS OF DIAGNOSIS
Neurogenic Shock
51Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
What Type of Shock is This?
• A 24 yo M presents to the ED after an MVC c/o chest pain and
difficulty breathing. On PE, you note the pt to be tachycardic,
hypotensive, hypoxic, and with decreased breath sounds on left
Obstructive
52Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Obstructive Shock
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 54
HypothermiaHypothermia BradycardiaBradycardia HypotensionHypotension Respiratory depressionRespiratory depression Constricted pupilsConstricted pupils CNS depressionCNS depression
Narcotic - toxicNarcotic - toxic
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 55
ABCABC Consider thiamine, dextrose, naloxone if depressed GCSConsider thiamine, dextrose, naloxone if depressed GCS Prevent further absorptionPrevent further absorption
Decontaminate eyes, clothes, skin, hair if appropriate eyes, clothes, skin, hair if appropriate Activated charcoal + sorbitol (if < 1 hour from ingestion)+ sorbitol (if < 1 hour from ingestion) Gastric lavage (if < 1 hour from ingestion and life-threatening drug or dose) (if < 1 hour from ingestion and life-threatening drug or dose)
In general not usedIn general not used Whole bowel irrigation for for ““body packingbody packing”” illicit drugs illicit drugs
In general not usedIn general not used
Enhance eliminationEnhance elimination Forced diuresis and urinary alkalinisation (salicylates and barbiturates)(salicylates and barbiturates) Multiple dose activated charcoal 0.5 g/kg every 2-4 hours0.5 g/kg every 2-4 hours
binds toxin and interrupts enterohepatic recirculationbinds toxin and interrupts enterohepatic recirculation mainly life-threatening ingestion of carbamazepine, dapsone, phenobarbital, quinine or theophyllinemainly life-threatening ingestion of carbamazepine, dapsone, phenobarbital, quinine or theophylline
Extracorporeal removal (for active metabolites, delayed toxicity or poor organ clearance)(for active metabolites, delayed toxicity or poor organ clearance) HaemodialysisHaemodialysis - low MW (<500 d), soluble, low Vd (< 1L/kg) e.g. methanol, ethylene glycol, - low MW (<500 d), soluble, low Vd (< 1L/kg) e.g. methanol, ethylene glycol,
salicylates, lithiumsalicylates, lithium HaemoperfusionHaemoperfusion - e.g theophylline, phenobarbital, phenytoin, carbamazepine, paraquat - e.g theophylline, phenobarbital, phenytoin, carbamazepine, paraquat Haemofil t rat ionHaemofi l t rat ion for large Vd and extensive tissue bound toxins but removes virtually all drugs for large Vd and extensive tissue bound toxins but removes virtually all drugs
AntidotesAntidotes
General ManagementGeneral Management
56Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 57
Dr Mai Duc Thao. ED. Friendship Hospital. Ha noi 2013 58
References Tintinalli. Emergency Medicine. 6th
edition Rivers et al. Early Goal-Directed
Therapy in the Treatment of Severe Sepsis and Septic Shock. NEJM 2001; 345(19):1368.
59Dr Mai Duc Thao. ED. Friendship
Hospital. Ha noi 2013