Shock Flashcards
Definition of Shock:
- state of cellular and tissue hypoxia
- due to reduced oxygen delivery
- or increased consumption
- resulting in tissue hypoperfusion and metabolic acidosis
- initially reversible
another definition of shock:
- inadequate tissue perfusion resulting in impaired cellular metabolism
- cells deprived of oxygen and nutrients resulting in anaerobic metabolism
- lactic acid causes tissue acidosis and organ dysfunction
shock is caused by 3 major problems:
- Problems with the heart
- Circulating blood is low
- Overwhelming infection
early signs of shock:
- MAP decrease of 10 BP from baseline
- effective compensation
- O2 to vital organs
- increased HR
compensatory signs:
- MAP decreased 10-15 BP from baseline
- increased renin
- increased ADH
- Vasoconstriction
- decreased pulse pressure
- increased HR
- decreased pH
- restless
- Apprehensive
progressive signs:
- MAP decreased 20 BP from baseline
- tissue hypoxia
- decreased urine
- weak rapid pulse
- sensory neural changes
refractory signs:
- excessive cell
- organ damage
- multi system organ failure
- decreased pH
MAP=
(SABP+2DABP)/3
Bodys reaction to shock:
- Arteriolar Vasoconstriction
- shunting blood from skin, muscle, kidneys, and spleen - Increase in HR and contractility
- increase cardiac output - Constriction of venous vessels
- increasing venous return - release of vasoactive hormones
- Release of ADH to conserve intravascular volume
What happens during global tissue hypoxia?
- endothelial inflammation and disruption
- lactic acidosis
- cardiovascular insufficiency
- increased metabolic demands
- vicious cycle!
MODS= multi organ dysfunction syndrome:
- cardiac depression
- respiratory distress
- renal failure
- DIC
- End organ failure
4 types of shock:
- distributive (septic most common)
- cardiogenic
- hypovolemic
- obstructive
most types of shock are caused by the disruption of:
- pump
- pipes
- volume
hypovolemic shock:
- lack of blood or fluid
- hemorrhagic most common
obstructive shock:
-some type of obstruction
distributive shock:
- inadequate distribution of blood
- neuro/vasogenic
- anaphylactic
- spetic
cardiogenic shock:
-hearts inability to supply adequate blood supply
clinical manifestations of shock:
- hypotension
- tachycardia
- oliguria
- mental status changes
- cool, clammy, cyanotic skin, mottled skin
- metabolic acidosis- high anion gap with elevated lactate
initial stabilization:
- ABCs
- stop underlying condition
- assess perfusion:
- hypotension (shock can occur without this)
- cool skin, tacky, obtundation, restless, anuria
- 2 large bore IVs, IO, or central line placement
Goals of TX:
ABCDE Airway control work of Breathing optimize Circulation assure adequate oxygen Delivery achieve End points of resuscitation
68 yo M with hx of HTN and DM presents to the ED c/o severe N/V. Wife says he isn’t “acting right.” Hasn’t been able to tolerate PO for 2 days.
The pt is hypotensive, tachycardic, afebrile, with cool but dry skin, poor turgor.
Hypovolemic Shock
non-hemorrhagic hypovolemic shock:
Vomiting (DKA) Diarrhea Bowel obstruction, pancreatitis Burns Neglect, environmental (dehydration)
hemorrhagic hypovolemic shock:
GI bleed Trauma Massive hemoptysis AAA rupture Ectopic pregnancy, postpartum bleeding
An 81 yo with altered mental status. She is febrile to 39.4, hypotensive, coughing, hypoxic to 88%, tachycardic to 133.
Disruptive
Prob 2/2 Sepsis
clinical signs of septic shock:
Hyperthermia or hypothermia Tachycardia Wide pulse pressure Low blood pressure (SBP<90) Mental status changes Beware of compensated shock! Blood pressure may be “normal”
A 55 yo M with hx of HTN, DM presents with “crushing” substernal CP, diaphoresis, hypotension, tachycardia and cool, clammy extremities.
cardiogenic
cardiogenic shock
heart fails to pump
-decreased contractility causes decreased cardiac output and impaired perfusion
Leading cause of death in MI:
cardiogenic shock
causes of cardiogenic shock:
- AMI
- Sepsis
- Myocarditis
- myocardial contusion
- aortic or mitral stenosis, HCM
- Acute aortic insufficiency
24 yo mowing the lawn and stung by something. 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.
Disruptive
2/2 Anaphylaxis
Distributive shock:
Excessive dilation of blood vessels or decreased vascular resistance
Fluids pool in dependent areas of the body and is not returned to the arterial circulation
Complicated by increased capillary permeability causing plasma into interstitial compartment
symptoms of anaphylactic shock:
First- Pruritus, flushing, urticaria appear
Next- Throat fullness, anxiety, chest tightness, shortness of breath and lightheadedness
Finally- Altered mental status, respiratory distress and circulatory collapse
anaphylactic shock tx:
ABC’s Angioedema and respiratory compromise require immediate intubation IV, cardiac monitor, pulse oximetry IVFs, oxygen Epinephrine Second line Corticosteriods H1 and H2 blockers
Epi is most important step:
0.3 mg IM of 1:1000 (epi-pen) Repeat every 5-10 min as needed Caution with patients taking beta blockers- can cause severe hypertension due to unopposed alpha stimulation For CV collapse, 1 mg IV of 1:10,000 If refractory, start IV drip
how long do you observe its who’ve received epi?
All patients who receive epinephrine should be observed for 4-6 hours
If symptom-free, discharge home
If on beta blockers or h/o severe reaction in past, consider admission
A 41 yo M presents to the ER after an MVC complaining of decreased sensation below his waist and is now hypotensive, bradycardic, with warm extremities
Disruptive
Neurogenic
Neurogenic shock:
Occurs after acute spinal cord injury
Sympathetic outflow is disrupted leaving unopposed vagal tone
Results in hypotension and bradycardia
Spinal shock- temporary loss of spinal reflex activity below a total or near total spinal cord injury (not the same as neurogenic shock, the terms are not interchangeable)
Neurogenic shock tx:
A,B,Cs Remember C-spine precautions Fluid resuscitation Keep MAP at 85-90 mm Hg for first 7 days Thought to minimize secondary cord injury If crystalloid is insufficient, use vasopressors Search for other causes of hypotension For bradycardia Atropine Pacemaker
Methylprednisolone tx:
Used only for blunt spinal cord injury
High dose therapy for 23 hours
Must be started within 8 hours
Controversial- Risk for infection, GI bleed
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
causes of obstructive shock:
Tension PTX, pericardial tamponade, PE, aortic dissection, abdominal distention
