Shock
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Transcript of Shock
Shock
Daniel Eshetu
Objectives Understand the pathogenesis of shock Classify different categories of shock Be able to assess different categories
of shock Will understand management principles
of shock
Why do we learn shock repeatedly?
Shock one of the commonest EM problems in all disciplines(Imed,surgery,Oby-GY,Pediatrics,etc)
If Not promptly handled it is a killer(Prompt diagnoses, management and monitoring is vital)
Frequently delay in diagnoses, delay in decision, inappropriate management and referral kills patients.
Case scenerio A 32 years old woman presented with
profuse watery diarrhea and becomes agitated(resless/anxious).
BP is 60/40 Pulse weak/120/min RR 30/min.
What is your approach/How do you manage?
What is your order in the order sheet?
EM Evaluation of Pts(ABCD/VS)
A –Air way opening B-Breathing or function of respiration C-circulation D-Disability-neurologic functions(AVPU
or Glasow coma scale-alert,respond to verbal stimuli,respond to noxious stimuli,unresponsive)
V/S-BP,PR,RR,Temp
Approach/Management1. The ABCD/ primaryassessement and
stabilization of the patient is priority.2. Frequent monitoring and
reassessment and adjustment of management .
3. Detailed HX,P/E,and workup for identification of the cause and manage accordingly.
Order sheet=in the first 20min then revise after 20’
1. N/S 1000CC fast to go in 20/min(bolus or 1000/20=50ml/min=not count in drops,2 veins may be neeed)
2. Oxygen with face mask with flow of 10l/min3. Keep warm in shock position4. Reassure5. Monitor BP,PR,RR,SaO2 every 15min6. Catheterize and monitor urine output every
hour
DefinitionSHOCK: inadequate organ perfusion to meet
the tissue’s oxygenation demand. Organ perfusion depends on blood flow which depends on arterial blood pressure(ABP).
(Pressure is low )
Cardiac arrest :Sudden stoppage of the heart to pump blood and as a result no circulation to the brain.
(Pressure is 0)
Physiology of ABP ABP cardiac out put(CO) and peripheral vascular resistance
CO= Stroke volume(SV) * heart rate(HR)
SV EDV(depends on venous return) , myocardial contractility and the after load.
Systemic Vascular Resistance (SVR) Vessel length, Blood viscosity, Vessel diameter
Hypotension
• In Adults:– systolic BP ≤ 90 mm Hg– mean arterial pressure ≤ 60 mm Hg– Reduction of systolic BP > 40 mm Hg from the patient’s
baseline pressure– Hypotension causes inadequate transport and delivery of
oxygen and Glucose.– Hypotension(shock) affects the biochemistry of
cells(Aerobic to anaerobic) and cellular dysfunction occurs.
Cellular Requirements Oxygen Glucose
C6H12O6 (s) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l) + heat
Glycolysis-first pathway in glucose metabolism and Krebs Cycle
1
Pathophysiology Shock affects mitochondria first Oxidative Phosphorylation impaired & anaerobic
metabolism begins leading to lactic acid production. Without oxygen mitochondria convert pyruvate/fuels
to lactate → lactic acid(LDH) Failure of the Krebs cycle
Oxygen is the final electron accepter to form water
Pathophysiology-cellular dysfunction ATP production falls, the Na+/K+ pump fails resulting in
the inability to correct the cell electronic potential.
-Cell swelling occurs leading to rupture and death.
ATP + H2O ⇒ ADP + Pi + H+ + Energy Acidosis results from the accumulation of acid during
anaerobic metabolism.
H+ shift extracellularly and a metabolic acidosis develops
Effects of shock on the body/systems serum pH is lowered(acidoses) lead to tachypnea. endothelial dysfunction-endothelial leak and coagulation
cascade stimulated(DIC). Kidney-tubular necrosis and acute renal failure. stimulation of inflammatory and anti-inflammatory cascades Heart-hypoxia causes reduced contractility and interstitial
edema causes poor diastolic compliance. compensatory catecholamine release causing tachycardia Lung-capillary leak with acute respiratory distress
syndrome may occur.
Compensation in shock baroreceptor reflexesbaroreceptor reflexes → sympathetic
stimulation → constrict arteriols in most parts of the body and venous reservoirs → protection of coronary and protection of coronary and
cerebral blood flowcerebral blood flowangiotensinangiotensin aldosteron, ADH aldosteron, ADH → vasoconstriction,water and salt retention by the kidneys
Stages Pre-shock Shock End-organ dysfunction
Stages: Pre-shock(compensated) Warm or compensated shock Compensatory mechanisms are able to
compensate for diminished perfusion. Tachycardia, peripheral vasoconstriction,
and either a modest increase or decrease in BP may be the only sign.
Stages: shock• Compensatory mechanisms become
overwhelmed, resulting in:– Tachycardia– Tachypnea ,Metabolic acidosis– Oilguria– Cool, clammy skin
• Usually occur with Loss of 20-25% of effective blood volume
• Eventually irreversible shock or multiple end organ damage happens.
Etiologic classification(HDCO)
HYPOVOLEMIC
DISTRIBUTIVE
CARDIOGENIC
OBSTRUCTIVE
Hypovolemic Shock Causes
hemorrhage vomiting diarrhea dehydration third-space loss burns
Signs cardiac
output PAOP SVR
Classes of Hypovolemic Shock
Distributive Shock• Types
– Sepsis– Anaphylactic– Acute adrenal insufficiency– Neurogenic
• Signs– ± cardiac output– SVR
Case scenerio 60 years old type 2 DM patient presented to ED with
new onset of cough,shortness of breath ,fever and left sided pleuritic chest pain of 3 days duration.The patient was taking predinisolone for rheumatoid arthritis but discontinued a month before.
On P/E 60/30 RR 36/min Temp 390c PR 120/min He is confused. Analyze this case and how do you manage?
Order sheet=in the first 20min then revise after 20’1. N/S 1000CC fast to go in 20/min(bolus or
1000/20=50ml/min=not count in drops,2 veins may be needed)
2. Oxygen with face mask with flow of 10l/min3. Immediate broad-spectrum antibiotics4. Keep warm in shock position5. Reassure6. Monitor BP,PR,RR,SaO2 every 15min7. Catheterize and monitor urine output every hour8. If no response with fluid-innotropes
Case scenerio A 32 years old woman presented with
sudden collapse after TAT was administered. Intern in ED immediately evaluated a patient who had labored breathing and weak and fast pulse.
What is your approach/How do you manage?
Case A 40 years old man after spinal
developed hypotension and confusion and BP=6/40 and PR=120/min.What is your diagnoses?
Cardiogenic shock Results from pump failure and decreased
cardiac output Main categories:
Myopathies Arrythimia Mechanical Extracardiac/obstructive small amount of Fluids first, then cautious
pressers
Obstructive Shock Causes
Cardiac Tamponade Tension Pneumothorax Massive Pulmonary Embolus
Signs cardiac output SVR
General Assessment and V/S BP is decreased PR increase due to compensatory sympathetic
discharge RR increase: as a result of inadequate perfusion of
the organs including the brain.Hypoxia is a drive to stimulate respiratory center and respiratory compensation metabolic acidosis also can occur due to tissue hypoxia
General AssessmentCirculation: The patient may have mottled or pale,
diaphoretic skin due to increased peripheral vascular resistance secondary to increased sympathetic discharge.
In severe cases cyanosis may be seen
Assessment-CirculationConduct a thorough evaluation of the
circulation, including both: Cardiovascular function assessment –
heart rate, blood pressure, pulse pressure, and capillary refill time
End-organ function assessment- skin, brain, and renal perfusion
Assessment-PR and Pulse pressure Tachycardia is an important early sign of shock because
of compensatory mechanisms that help to maintain cardiac output during shock
The pulse should be carefully palpated for volume and pressure.
The palpable pulse volume(strength of the pulse) is normally relate to stroke volume and pulse pressure (the difference between systolic and diastolic pressures)
Assessment-Pulse volume/pressure
Narrowing pulse pressure with “thready “ pulses in shock with low cardiac output
Wide pulse pressure with bounding pulses(due to normal or increased stroke volume and low systemic vascular resistance) are seen in septic shock
Discrepancy in volume between peripheral and central pulses is an important sign of decreased cardiac output
Loss of peripheral and central pulses indicates cardiac arrest
Assessment-Circulation(BP) At first compensatory mechanisms may maintain BP
by increasing systemic vascular resistance Hypotension is a late and often sudden sign of
cardiovascular decompensation, therefore even mild hypotension should be treated quickly and aggressively
25% of blood volume must be lost before a drop in blood pressure occurs.
Hypotension may occur early in septic shock
Assessment- Capillary Refill Time Sluggish, delayed, or
prolonged capillary refill time of > 2-3 seconds can be a sign of shock, fever, or cold temperature
Brisk capillary refill may be present in septic shock
End organ function assessment
Skin Perfusion Cool extremities and pale, diaphoretic skin are early
signs of shock.Brain Perfusion Altered mental status is one of the most important
clinical indicators of deteriorating shock.Renal Perfusion Urine output of < 1ml/kg per hour in an infant or young
child, and < 30ml/hr in adolescents can be an important sign of decreased systemic cardiovascular perfusion
Management of ShockThe fundamentals of shock management are : Optimizing oxygen content of the blood Improving volume and distribution of cardiac output Reducing oxygen demand Correcting metabolic derangements: hypoglycemia,
hypocalcemia, hyperkalemia, metabolic acidosis
Management of ShockTherapeutic end points of shock
management are: Normal pulses (central & peripheral) Capillary refill < 2 seconds Warm extremities Normal mental status Normal BP Urine output >0.5-1ml/kg/hr Decreased serum lactate
General Management of Shock Positioning Oxygen administration Obtain vascular access Fluid resuscitation Monitoring Frequent Assessment Pharmacologic support consultation
Fluid Administration
crystalloids are cheaper and main choice(NS or RL) 2-3litres in 20-30minutes or in children start fluid
resuscitation for hypovolemic and distributive shock with 20ml/kg isotonic crystalloid (NS or RL) administered as a bolus over 5-20 minutes
Fluid is given more slowly in cardiogenic shock. Repeat dose if no improvement with in 10-20’ blood must supplement in hemorrhage. One big vein, or two smaller veins with large canulla. Pressors?
Blood Products Therapy Blood and blood products are not the first
choice for immediate volume expansion in shock
Blood is recommended for volume loss in trauma patients with inadequate perfusion despite administration of 2-3 boluses of isotonic crystalloid
Packed red blood cells 10ml/kg is recommended.
Monitoring
continuous assessment of the physiologic status is necessary.
Blood pressure, pulse, and respiratory rate should be monitored continuously
a Foley catheter should be inserted to follow urine flow
and mental status should be assessed frequently.
Oxygen saturation
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SHOCK
THE END.