Microsoft PowerPoint - 0905 [] Shock is the “physiologic state characterized by significant reduction of systemic tissue perfusion, resulting in decreased tissue oxygen delivery.”
Imbalance between oxygen delivery and oxygen consumption which leads to cell death, end organ damage, multi-system organ failure, and death
How to evaluate ?
Level of consciousness
Initially may show few symptoms Continuum starts with Anxiety Agitation Confusion and Delirium Obtundation and Coma
In infants Poor tone Unfocused gaze Weak cry Lethargy/Coma (Sunken or bulging fontanelle)
Pulse Tachycardia HR > 100 - What are a few exceptions? Rapid, weak, thready distal pulses
Respirations Tachypnea Shallow, irregular, labored
Blood Pressure May be normal! Definition of hypotension Systolic < 90 mmHg MAP < 65 mmHg 40 mmHg drop systolic BP from from baseline
Children Systolic BP < 1 month = < 60 mmHg Systolic BP 1 month - 10 years = < 70 mmHg + (2 x age in years)
In children hypotension develops late, late, late A pre-terminal event
Symptoms and Signs of Shock
Skin Cold, clammy (Cardiogenic, Obstructive,
Hemorrhagic) Warm (Distributive shock) Mottled appearance in children Look for petechia
Dry Mucous membranes Low urine output <0.5 ml/kg/hr
4 out of 6 criteria have to be met
Ill appearance or altered mental status Heart rate >100 Respiratory rate > 22 (or PaCO2 < 32 mmHg) Urine output < 0.5 ml/kg/hr Arterial hypotension > 20 minutes duration Lactate > 4 mmol/L (36 mg/dL)
Lactate SCV O2
Acidosis
Emergency case of epigastric pain for 1 day DVT history, on warfarin BT 37.5; HR 130; RR 25; SpO2 93% After Abd CT s/c contrast.
What are your thoughts?
Hypovolemic Cardiogenic Distributive/Vasogenic Obstructive
Systemic Vascular Resistance (SVR) Cardiac Output (CO) = HR x Stroke volume Mixed Venous Oxygen Saturation (SvO2) Central Venous Pressure (CVP) Mean Arterial pressure (MAP) Shock Index: HR/BP
MAP= [SBP + (2 x DBP)]/3 MAP = (CO x SVR) + CVP
1500 ml 3000 ml
3000 ml
Heart pumps well, but not enough blood volume to pump
MAP = CO x SVR
HR x Stroke volume
Normal MAP = CO x SVR
Hypovolemic MAP = ↓CO x SVR MAP = ↓CO x ↑ SVR ↓MAP = ↓↓CO x ↑ SVR
Myocardial Infarction Arrythmias (Atrial fibrillation, ventricular
tachycardias, bradycardias, etc) Mechanical abnormalities (valvular defects)
Heart fails to pump blood out
MAP = CO x SVR
Normal MAP = CO x SVR
Cardiogenic MAP = ↓CO x SVR MAP = ↓CO x ↑ SVR ↓MAP = ↓↓CO x ↑ SVR
↓MAP = ↓ CO (HR x Stroke Volume) x ↑SVR
Decreased Contractility (Myocardial Infarction, myocarditis, cardiomypothy, Post resuscitation syndrome following cardiac arrest)
Mechanical Dysfunction – (Papillary muscle rupture post-MI, Severe Aortic Stenosis, rupture of ventricular aneurysms etc)
Arrhythmia – (Heart block, ventricular tachycardia, SVT, atrial fibrillation etc.)
Cardiotoxicity (B blocker and Calcium Channel Blocker Overdose)
Heart pumps well, but there is peripheral vasodilation due to loss of vessel tone
MAP = CO x SVR
HR x Stroke volume
MAP = ↑co x ↓ SVR
↓MAP = ↑co x ↓↓ SVR
↓MAP = ↑CO (HR x SV) x ↓ SVR
Loss of Vessel tone Inflammatory cascade Sepsis and Toxic Shock Syndrome Anaphylaxis
Decreased sympathetic nervous system function Neurogenic - C spine or upper thoracic cord injuries
Heart pumps well, but the output is decreased due to an obstruction (in or out of the heart)
MAP = CO x SVR
HR x Stroke volume
Normal MAP = CO x SVR
Obstructive MAP = ↓CO x SVR MAP = ↓CO x ↑ SVR ↓MAP = ↓↓CO x ↑ SVR
↓MAP = ↓ CO (HR x Stroke Volume) x ↑SVR
Heart is working but there is a block to the outflow Massive pulmonary embolism Cardiac tamponade Tension pneumothorax
Obstruction of venous return to heart Vena cava syndrome - eg. neoplasms
Type of Shock
Insult Physiologic Effect
↓CO ↑SVR
↓CO ↑SVR
Hemorrhagic Heart pumps well, but not enough blood volume to pump
↓CO ↑SVR
↓SVR ↑CO
CAB O2 / IV / Monitor / Fluids BT / BP / HR / RR Tank (Volume) / Tank (Resistance) / Pump /
Rate
Resistance Rate Volume Pump
There are only a few causes of low SVR. They ALL cause vasodilation: • Sepsis • Acute spinal cord injury (Neurogenic shock) • Vasodilators (NTG, anesthetics) • Anaphylaxis
Look at and feel the patient!
Low SVR has the features: warm !!! pink (maybe also a rash) hyperdynamic heart (fast and
pounding) Sign of hypovolemic
patient will have cool or cold arms/legs patient will NOT look pink
Cause of shock or low BP is then:
low CO (Rate/Volume/Pump)
• BP = CO x SVR • CO = SV x HR
Easy to access, Shown in vital signs and EKG monitor for rhythm Bradycardia or tachycardia As ACLS algorithm
SVR, cold extremities left heart failure: SOB+lung
edema right heart failure: no SOBfull
JVP + leg edema
VolumeJVP tension pneumothorax pericardial tamponade
RV infarction pulmonary embolism
Rapid Ultrasound in SHock
BP = CO x SVR
contractility valves
Peripheral (pale/cold;
(eg. RV infarction) Inotropic or Vasopressor support: Dobutamine Milrinone Norepinephrine Dopamine Epinephrine
Oxygenation If MI – ASA, Heparin, and Revascularization If arrthymia – correct arrthymia If extracardiac abnormality – reverse or treat cause
Maximize oxygen delivery Control further blood loss Tourniquets Surgical intervention
Fluid resuscitation NS fluid boluses Blood product administration
Remove offending agent Establish an airway and return circulation Pharmacologic support: Epinephrine – reverses peripheral vasodilation,
dilates bronchial airways, increases myocardial contractility, and suppresses histamine/ leukotriene release Antihistamine (benadryl) – may help counter
histamine-mediated vasodilation and bronchoconstriction Corticosteroids (hydrocortisone) – may help
shorten reaction Bronchodilators
Soar, J et al. 2013 (Online Accessed on 22 August 2013) URL:  http://www.resus.org.uk/pages/reaction.pdf
Establish an airway to maintain adequate oxygenation and ventilation
Fluid resuscitation for MAP>65mmHg Inotropic support Dobutamine Dopamine
Atropine for severe bradycardia High dose methylprednisolone therapy
Emergency Medicine. 2009 (Online Accessed on 22 August 2013)  URL: http://emergencymed.wordpress.com/2009/03/11/neurogenicshock/
What kind of case ? How to treat the patient ?
Emergency case of abd pain for 1 day DVT history, on warfarin BT 38.5; HR 130; RR 20; SpO2 95% After Abd CT s/c contrast.
low SVR ?
CT, warm PR 140 IRHB, Af v RVR JVP flat No abd peritoneal sign.
Contrast-related anaphylaxis Early sepsis/ warm shock
SVR,
1. warm, JVP flat sepsis : volume resuscitation ± inotropic
agents 2. cold, JVP full sepsis cardiogenic control rate
DVT history with coumadin control Peritonitis, increasing pain with movement Look pale, JVP flat, Extremities cold PR 130 NSR
Volume depletion: severe sepsis or other ? CT: retroperitoneal hematoma The patient was in shock because of acute
bleeding and not because of sepsis
Patient felt SOB, deteriorated SpO2 90% Cold Extremities JVP full CxR: clear lung CT: negative finding, but engorge IVC
DVT history pul embolism Less for RVMI
Patient with discomfort ! Extremities cold. JVP not flap BP 240/140, PR 160, RR 30, SpO2 93% Lab: lactate 32, pH 7.2, HCO3 10,
? ? ?
What is the SVR in this patient? High (cold arms and legs)
Is tachycardia related to the shock ? No !
What is the preload in this patient ? Adequate and possible overload
Is the CO adequate ? Possible low if relatively high in SVR
Shock due to Hypoperfusion in capillary bed Need Vasodilators to decreased SVR !!
Hypovolemic (bleeding)
Others Cardiac tamponade Tension