Shock
critical condition that results in adequate perfusion of cells, tissue, organs. also referred to as hypoperfusion
-other info: in a shock state the body attempts to restore homeostasis through a response of the nervous system and release of hormones.
how to restore perfusion
Oxygen and glucose delivery, the restore production of a larger amounts of energy required reverse the lactic acid buildup and reestablish the function of sodium potassium pump.
Etiologies of shock
- Inadequate volume: of blood (caused by burns, bleeding, diarrhea, excessive urination)
- Inadequate pump (heart) function: not able to pump blood throughout the body effectively (heart attack)
- Inadequate vessel tone: size of the vessel and the resista
ways to increase the blood pressure and perfusion
decrease the size of the vessel through vasoconstriction, or fill the vessel with more volume to increase the internal vessel pressure
categories of shock
Hypovolemic
Cardiogenic
Metabolic/Respiratory
Obstructive
Distributive
Hypovolemic shock
Shocked that is caused from a low blood volume. It can be due to blood loss or loss of some other fluid. most common form of this is the loss of whole blood.
Distributive shock
Associated with the decrease in intravascular volume caused by vasodilation and an in increasing capillary permeability. when the vessel is bigger and it is not filled all the way causing a reduction in blood volume
Cardiogenic Shock
Caused by an effective pump function of the heart. On the left ventricle fails to generate enough force to reject sufficient blood from the chamber into the systemic circulation this results in poor tissue perfusion
Obstructive Shock
obstruction, that does not allow blood to move forward. An example of this would be a blood clot.
-two other conditons: tension pneumothorax and pericardial Tamponade. both
tension pneumothorax
an injury to the lung resulting in air getting into the pleural space
pericardial tamponade
fluid in the pericardium(sacs around the heart) builds up and results in compression of the heart
Metabolic or respiratory shock
Described as a dysfunction in the ability of oxygen to defuse into the blood be carried by hemoglobin and use effectively for the cell for metabolism.
-example: carbon monoxide interferes with the ability of hemoglobin to carry oxygen. creating a hypoxic
hemorrhagic hyperemic shock
the loss of whole blood. Medical causes may include gastrointestinal bleeding, uterine bleeding, aortic disease, esophagel disease
nonhemorrhagic hyperemic shock
loss of fluid from the intravascular space. (no loss of blood) primarily water, plasma, proteins, and electrolytes.
examples: severe diarrhea, vomiting, excessive sweating, excessive urination.
Burn Shock
Burns disrupt capillaries and vessels allowing them to leak plasma and plasma proteins. this collection of fluid causes edema.
Anaphylactic Shock
Is a type of distributed shock. the patient could have an allergic reaction causing massive vasodilation. hydrostatic pressure pushes fluid into the interstitial space. dilated vessels cause a reduction in systemic vascular resistance. epinephrine is the
septic shock
type of distributive shock. Results from an infection that releases bacteria or toxins in the blood causing vasodilation. Fluid leaks out and into the interstitial space.
-you will focus on managing an airway but consider contacting advanced life support.
Neurogenic shock
Is the type of distributive shock. Spinal cord is injured damaging the sympathetic nerve fibers that control vessel tone causing the vessels to dilate.
cariogenic shock
Is most often due to an acute myocardial infarction (heart attack), congestive heart failure, abnormal cardiac rhythm, or overdose on drugs that depressed the pumping function of the heart such as beta blockers o calcium channel blockers.
Baroreceptors response to shock
baroreceptors regulate pressure inside the aorta and carotid arteries, so when so when there is a reduction in blood volume our pump function or vasodilation the baroreceptors sends the reduction in the arterial wall and trigger direct sympathetic nerve s
the effects of sympathetic stimulation
-increase in heart rate
-increase stroke volume
-vasoconstriction
-stimulation to release epinephrine and norepinephrine from the adrenal gland
Alpha 1 effects
- Contraction of the muscles controlling the iris(dilated pupils)
- Contraction of vascular muscle (narrow pulse pressure)
- Stimulation of Sweat Glands
results in vasoconstriction
Beta 1 effects
- Increased heart rate
- Increased speed of impulse through donuction system (tachycardia)
- Increased force of contraction (pounding heart)
Beta 2 effects
- Bronchial muscle dilation
- Skeletal muscle contractility
epinephrine effects on the body
- Increased heart rate
- Increasted contractility
- Vasoconstriction
- Sweat gland stimulation
- Decreased insulin secretion
- Conversion of store glucose in liver to blood glucose
- Conversion of noncarbohydrates into sugar
- Iris muscle contraction
norepinephrine effects on the body
- Vasoconstriction
- Sweat gland stimulation
Antidiuretic Hormone (Vasopressin) effects on body
- Increased sodium reabsorption in the kidneys
Angiotensin II effects on body
- Vasoconstriction
- Increased Heart Rate
- Sodium reabsorption in the kidney
Aldosterone effects on the body
- Sodium reabsorption in the kidney
Glucagon effects on the body
- Conversion of stored glucose in liver to blood glucose
- Increased heart rate and contractility
cycle of hemorrhagic shock
pg. 420
Stages of shock
Compensatory, Decompensatory, irreversible
decompensatory shock (progressive)
Advanced stage of shock in which the body's compensatory mechanisms are no longer able to maintain a blood pressure and perfuse the vital organs. decrease in brain perfusion leads to cerebral ischemia.
irreversible shock
Final stage of shock in which organs and cells are so damaged that recovery is impossible. micro emboli begin to block capillaries leading to multiple system organ failure
Signs and symptoms of compensated shock
Anxiety, normal blood pressure (possible narrowing of pulse pressure), tachycardia, thready or weak pulse in extremities, pale/cool/moist skin
Signs and symptoms of decompensated's shock
AMS, Hypotension, Tachycardia, Weak-absent pulse, 'air hunger', White/waxy/cold skin
signs of poor perfusion
- AMS
- Pale, cool, clammy skin
- Delayed capillary refill
- Decreased urine output
- Weak or absent peripheral pulses
resuscitation
bringing the patient back from the dead
sudden death
when the patient dies within 1 hour of onset of the signs and symptoms
chance of resuscitation
decreases by 10 percent for every minute the patient is in ventricular fibrillation (v-fib)
most sensitive organ to cardiac arrest
Brain after 4-6 minutes the brain loses brain cells and it becomes irreversible
Three phases following cardiac arrest that lead to death
electrical phase
circulatory
metabolic
electrical phase
Phase which begins immediately upon cardiac arrest and ends 4 minutes later. Aerobic metabolism is still maintained with continued energy production for cell function. Heart is prepared for defibrillation and restoration of cardiac rhythm.
circulatory phase
Begins at 4 minutes after the onset of cardiac arrest and ends 10 minutes after the onset of cardiac arrest. During this phase oxygen stores have been exhausted and the myocardial cells shift from aerobic metabolism to anaerobic. During this phase, due to
metabolic phase
Begins 10 minutes after the onset of cardiac arrest. Heart is starved of oxygen and glucose and has a large amount of acid build up. Due to lack of glucose and ATP the K/Na pumps fail allowing Na to enter and stay within the cell, attracting water and rup
downtime
From the time the patient goes into cardiac arrest until CPR is effectively being performed
total downtime
Total time from when the patient went into cardiac arrest until you deliver the patient to the emergency department
return of spontaneous circulation (rosc)
Is when the patient remains a spontaneous poles during the resuscitation effort the patient must breathe on his own
survival
patient who survives to be discharged from the hospital if the patient later dies it is not considered survival.
witnessed cardiac arrest
eat witnesses the patient become unresponsive
unwitnessed cardiac arrest
arrives on scene and the patient is already unresponsive
chain of survival
1. immediate recognition and activation
2. immediate high-quality CPR
3. rapid defibrillation
4. basic and advanced medical services
5. advanced life-support and post arrest care
pediatric chain of survival
-Prevention of arrest
-early high-quality CPR performed by bystanders
-rapid activation of EMS or other emergency responders
-effective advanced life support and rapid
-transport too appropriate medical facility
-integrated post cardiac arrest care
chest compression rate
100/minute but no more than 120/min
compression to ventilation RATIO
-30:2 other than two-rescuer crew
-ventilation should be given every 6 seconds (10 ventilation/min)
types of AEDs
fully automated & semiautomated
-fully automated: EMT attaches pads to patient, and the machine does the rest, you only have to turn it on you do not have to click an analysis button
- semiautomated : one we used in class
ventricular fibrillation (VF OR V-FIB)
when the cardiac rhythm produces no pulse or cardiac output
ventricular tachycardia (VT OR V-TACH)
-is a very fast heart rhythm, this is generated by the ventricle not the SA node
-reduces cardiac output
-AED will respond if the heart rate exceeds 180 bpm, since they are not pulseless you would not defibrillate
Asystole
absence of electrical activity and pumping of the heart. registers on the monitor as a flatline.
defibrillation is not appropriate
Pulseless electrical activity
The heart has an organize rhythm, but either of the heart muscle is so weekend that it fails to pump where the heart muscle does not respond to electrical activity for the circulatory system has lost so much blood that there's nothing to pump.
Defibrillat
qualifications to use AED
unresponsive, with no breathing, or agonal breathing, no signs of life, no pulse. NOT INTENDED FOR TRAUMA PATIENTS
AED maintenance
-AED failure is the most common attribution to improper care (battery failure).