Chapter 41 Key Objectives Flashcards
List examples of peri-arrest conditions that critical patients can present with in the field. (p 2275)
Peri-Arrest period - the time either just before or just after cardiac arrest, when the pt is critical, and care must be given in order to prevent progression or regression into Cardiac Arrest.
Examples: unstable dysrhythmias (bradycardia, SVT, V-tach, complete AV block) shock, syncope, heart failure, myocardial ischemia.
Describe the process of determining a differential diagnosis in the field assessment of a critical patient. (pp 2275–2277)
1.) Identify & manage life threats
2.) Rule out other various conditions using your AEIOU-TIPS (MT-SHIP)
3.) Hx & physical exam
Discuss the rapid decision making involved in the assessment and management of a critical patient. (pp 2277–2280)
Intuitions & gut feelings on a pt with poor general impression
1.) Here is what I think we are dealing with.
2.) Here is what I think we should do.
3.) Here is why.
4.) Here is what we should keep our eyes on.
5.) Is there anything else we should be concerned about?
List examples of bias that can affect your critical decision making. (p 2278)
Overconfidence - assuming you know what’s going on. Always search for info that would refute the differential dx.
Look at all possible angles.
Pt may be intoxicated, but pt may have also fallen and have a subdural hematoma.
Did that pt with cardiac hx c/o chest pain, dig a garden the previous day? Is the pain intermittent and reproducible, or is it constant?
What results from inadequate cardiac output, decreased Stroke volume ratio, or the inability of RBC’s to deliver O2 to tissues.
Shock
Discuss the pathophysiology of shock and peri-arrest situations. (pp 2284–2286)
When there is a state of failure & ultimate collapse of the CV system, in order to protect vital organs, the body compensates by shunting blood to the important organs.
Blood clots
Hormonal mechanisms - baroreceptors - chemoreceptors
Describe the effects of decreased perfusion at the capillary level. (pp 2289–2290)
A.) As perfusion decreases, cellular ischemia occurs. Minimal blood flow passes through the capillaries cells switch to anaerobic metabolism, which leads to acidosis.
B.) During anaerobic metabolism, incomplete glucose breakdown leads to an accumulation of pyruvic acid.
C.) Ischemia stimulates incomplete glucose breakdown increased CO2 production by the tissues. The higher the body’s metabolic rate, the higher the CO2 level will be.
D.) Cellular flooding explodes cell membranes & releases lymosomal enzymes, which then autodigests the tissues.
E.) Accumulating acids & waste products acts as potent vasodilators, further decreasing venous return & diminishing blood flow to the vital organs & tissues. The arterial pressure falls to the point at which even the heart & lungs are no longer perfused.
F.) The bloods sluggish flow, coupled with its acidity, leads to platelet agglutination & formation of microthrombi. Because the capillary walls are stretched, they lose their ability to retain large molecules, allowing them to leak into interstitial spaces.
G.) In conjunction with this ongoing injury, the WBC’s & clotting system are impaired, decreasing resistance to infection & increasing development of DIC.
Define shock in relation to aerobic and anaerobic metabolism. (p 2288)
A.) As the pt decompensates, perfusion to brain & coronary arteries decreases, cells switch from aerobic to anaerobic metabolism.
B.) This transition is a critical point, & lactic acidosis begins to develop from the more inefficient anaerobic metabolism.
C.) This new shift decreases cardiac function & makes the heart more susceptible to the circulating catecholamines, causing dysrhythmias.
S/S of what type of shock?
Weak pulse
Clammy skin
SOB
N/V
Normal BP
Narrowing pulse pressure
15-30% blood loss
Compensated Shock
S/S of which type of shock?
Abnormally low BP
40% or greater blood loss
Blood is shunted away from liver, kidneys, and lungs to continue to perfuse heart & brain
Irreversible shock
Pathophysiology of Poor Perfusion
A.) Sympathetic response stimulates heart, blood vessels, & adrenal glands.
B.) Alpha 1 receptors cause vasoconstriction when stimulated by epinephrine.
C.) In the heart, Adrenalin binds to Beta-1 receptors, increases inotropy (contraction), chronotropy (rate), & dromotropy (speed of conduction).
D.) Cells near glomeruli in kidneys, secrete renin. Angiotensin is converted into angiotensin 1 by renin.
E.) In the lungs, Angiotensin 1 is converted to Angiotensin 2, which increases SVR & BP.
F.) Aldosterone is a hormone that influences reabsorption of sodium, & therefore water, increasing plasma volume.
Orthostatic hypotension is an indication of what?
How is orthostatic BP obtained?
What constitutes a positive orthostatic BP?
Hypovolemia.
Obtain BP while lying, then seated, then again while standing.
A drop of 20mm hg of SBP, & increase of 10mm hg of DBP, increase in HR by 20.
What type of shock is due to the heart being unable to circulate sufficient blood to maintain peripheral O2 delivery?
Cardiogenic
What is normal ejection fraction?
55-70%
Populations of older adults with hx of DM & hx of AMI w/ejection fraction of less than 35%, are at higher risk of developing what?
Cardiogenic Shock
Treatment for pts w/cardiogenic shock?
Position of comfort
Secure airway
Adm O2 if O2 SAT drops below 94% (consider CPAP)
Cardiac Monitor
IV
Auscultate lungs, if clear, fluid challenge of 200ml to increase preload
Evaluate effects on BP & breath sounds
Some EMS systems advocate Dopamine at low dosages (5mg/kg per min) if the pt has MAP of less than 60.
This occurs when blood flow is blocked in the heart or great vessels, most common cause is trauma, tension pneumo or cardiac Tamponade….
Obstructive Shock
What occurs when blood leaks into the pericardium, causing an accumulation of blood within the pericardial sac?
Cardiac Tamponade - Supportive Care & rapid transport
Only defininitive treatment is pericardiocentesis, rarely allowed to be performed pre-hospital.
The pericardium has minimal ability to stretch, so as blood continues to pool & obstruct blood flow to the heart, resulting in decreased blood flow from the heart. What S/S would you expect to see?
Muffled heart sounds
Merging SBP & DBP (SBP drops, DBP rises)
Electrical Alternans & small QRS complex on EKG
Shock caused from spinal cord injury, or less often, from brain conditions, tumors, or pressure on spinal cord.
Neurogenic shock
In neurogenic shock, the nervous system is not stimulated, so there would be no release of catecholamines, epinephrine, or norepinephrine, which would typically cause what?
Pale, cool, diaphoretic skin. In NS, there will be an absence below the level of injury. Swelling & edema of the cord begins 30 mins after insult to spinal cord. Increased level of pain above level of injury, absence of pain, temp, & touch below injury level.
What type of shock occurs when there is widespread dilation of vessels, causing pooling of blood in vascular beds & decreased tissue perfusion?
And what are the 4 types of this type shock?
Distributive
Septic
Neurogenic
Anaphylactic
Psychogenic (less common)
What type of shock activates the inflammatory-immune response, causing leaky capillaries, vasodilation, & third-space fluid shifts (into lungs, causing ventilatory problems)?
Septic shock
S/S of Sepic shock & how to treat
AMS
Weak, thready pulse
Shallow/Rapid respirations
Warm/Hot skin
O2
Fluid therapy
Blankets to conserve body heat
Dopamine to maintain BP, if fluid didn’t help
The development of a heightened reaction to a substance
Sensitization
In this type of shock, immune system chemicals are released when the person is exposed to an allergen, causing bronchoconstriction, and widespread vasodilation that causes vessels to leak, resulting in Hypovolemia.
Anaphylactic Shock
the time either just before or just after cardiac arrest, when the pt is critical, and care must be given in order to prevent progression or regression into CA.
Peri-Arrest Period
Examples of Peri-Arrest Conditions
Unstable dysrhythmias (bradycardia, SVT, V-tach, complete AV block) shock, syncope, heart failure, myocardial ischemia.
Conditions that precede the onset of a disease
Pre morbid Conditions
In emergency medicine, the “disease” is life-threatening trauma or medical conditions that need to be rapidly identified & treated.
AEIOU-TIPS
Acidosis (hypoxia), Alcohol
Epilepsy, Encephalopathy
Infection
Overdose
UTI
Trauma, tumor, toxins
Insulin
Psych
Sepsis, Seizures
A type of cognitive basis in which a person settles on a finding too early in the diagnostic process & fails to adjust their thought process or diagnosis as new information is acquired.
Anchoring bias
A tendency to gather & rely on info that confirms the person’s existing views & to avoid or downplay info that does not confirm their pre-existing hypothesis or differential diagnosis.
Confirmation bias
H & T’s & treatment for each
Hypovolemia - Fluid resuscitation
Hypoxia - O2
Hydrogen Ions - O2
Hypo/Hyperkalemia - (Hypo-inverted T wave) dehydration, fluids; supportive care (Hyper-peaked T wave)
Hypothermia - warm them
Tension Pneumothorax - needle decompression
Cardiac Tamponade - supportive care
Toxins - Narcan for opioid OD
Thrombosis (PE) - O2, airway, supportive care
Thrombosis (coronary) - Treat cardiac signs/symptoms (MONA/FONA)
The hearts contractility that allows it to increase or decrease the volume of blood it pumps with each contraction
Stroke Volume
The heart’s ability to contract (or inability, if it’s sick)
Myocardial contractility
As preload increases, the volume of blood within the ventricles increases, causing the heart muscle to stretch. When stretched, myocardial contractility increases, leading to greater force of contraction & increased cardiac output. This concept is known as….
Frank-Starling mechanism
The force or resistance against which the heart pumps is…
Afterload
What is dependent on cardiac output, systemic vascular resistance, & blood volume and is considered a rough measure of perfusion…
BP
What is ultimately the BP required to sustain organ perfusion?
MAP
Multiple Severe Fx’s
Abd/Chest Injury
Spinal Injury
Severe Infxn’s
Massive MI
Anaphylaxis
These conditions should give you a high index of suspicion for…..
Shock
The 3 basic causes of shock:
1.) Pump Failure: from disease, injury, obstructive causes.
2.) Low fluid volume: from bleeding that causes hypoperfusion.
3.) Poor vessel function: causes inefficient perfusion.
S/S of which type of shock?
AMS
Hypotension
Labored breathing
Thready or absent peripheral pulses
Dilated Pupils
Approx 30% blood loss
Decompensated Shock
In neurogenic shock, all vessels below injury site increase in size & capacity, resulting in what?
Blood pooling. When the vessels become enlarged, the 5-6L of blood volume can no longer fill the vascular system, resulting in relative Hypovolemia and hypotension.
Treatment for neurogenic shock.
Spinal immobilization.
Keep pt warm (thermoregulation comprised, subject to hypothermia)
IV fluids based on hemodynamic status
IV bolus’ in 20mg/kg increments to maintain BP (up to 2L)
Atropine 0.5mg IVP or Dopamine drip at 10 mcg/kg/min (if needed)
Recurrent large areas of subcutaneous edema, sudden onset, frequently as a result of allergy to food or drugs, usually resolved within 24hrs.
Angioedema
Shock caused by a sudden reaction of the nervous system, producing a temporary, generalized, vascular dilation. Blood pools in vessels, causing temporary reduced blood flow to brain, resulting in syncope.
Psychogenic Shock
