Ch 12 Shock Flashcards
Cyanosis
Blue skin discoloration that is caused by a reduced level of oxygen in the blood
Decompensated Shock
The late stage of shock when blood pressure is falling
Dehydration
Loss of water from the tissues of the body, may cause or aggravate shock
Very young or old patients are particularly susceptible
Distributive Shock
A condition that occurs when there is widespread dilation of the small arterioles, small veins, or both
Edema
The presence of abnormally large amounts of fluid between cells in the body tissues, causing swelling of the affected area
Homeostasis
A balance of all systems of the body
Hypothermia
A condition in which the internal body temperature falls below 95 degrees F (35 C)
Hypovolemic Shock
Shock caused by fluid or blood loss
Injuries involving bleeding may result in hemorrhagic shock, while vomiting and diarrhea may result in non-hemorrhagic shock
Also occurs with severe thermal burns (loss of intravascular plasma), and crushing injuries
Myocardial Contractility
The ability of the heart muscle to contract
As volume of blood increases, precontraction pressure builds and muscles stretch, as the muscles stretch, contractility increases
Neurogenic Shock
Circulatory failure caused by paralysis of the nerves that control the size of the blood vessels, leading to widespread dilation; seen in patients with spinal cord (especially upper cervical levels) injuries
The muscles of the walls of blood vessels are cut off from the sympathetic nervous system, allowing them to dilate widely and causing blood to pool
Obstructive Shock
Shock that occurs when there is a block to blood flow in the heart or great vessels causing an insufficient blood supply to the body’s tissues
Perfusion
The flow of blood through body tissues and vessels
Pericardial Effusion
A collection of fluid between the pericardial sac and the myocardium; may lead to cardiac tamponade
Preload
The precontraction pressure in the heart as the volume of blood builds up
As preload increases, the volume of blood coming into the heart increases, which causes the muscles to stretch
Psychogenic Shock
Shock caused by a sudden, temporary reduction in blood supply to the brain that causes fainting (syncope)
Pulmonary Embolism
A blood clot that breaks off from a large vein and travels to the blood vessels of the lung, causing obstruction of blood flow
Backup of blood in the left ventricle leads to catastrophic obstructive shock and complete pump failure
Pulse pressure
the difference between the systolic and the diastolic pressures
Signifies the amount of force the hear generates with each contraction; a pulse pressure of < 25 mm Hg may be seen in patients with shock
Sensitization
Developing a sensitivity to a substance that initially caused no allergic reaction
Septic Shock
A complex type of shock caused by severe infection, usually a bacterial infection
Vessel walls leak and are unable to contract well; widespread dilation and plasma loss result in shock
Insufficient volume + leaked fluid often collects in the respiratory system + vasodilation
Shock
A condition in which the circulatory system fails to provide sufficient circulation to enable every body part to perform its function; also called hypoperfusion
Sphincters
Circular muscles that encircle and, by contacting, constrict a duct, tube or opening
Syncope
Fainting or transient loss of consciousness that occurs when blood pools in dilated vessels, reducing the blood supply to the brain, resulting in the brain ceasing to function normally and the patient faints
In the early stages of shock the body will
Attempt to compensate by maintaining homeostasis
Systemic circulation
Carries oxygen-rich blood from the left ventricle through the body and back to the right atrium
Blood passes through the tissues and organs, delivering oxygen and nutrients
Oxygen diffuses through ______ into the bloodstream
The walls of the alveoli
If Oxygenated blood is not properly circulated
Cell death may occur
Diffusion
A passive process in which molecules move from an area of higher concentration to an area with a lower concentration
Carbon Dioxide can be transported in the blood from tissues back to the lungs in three ways
- dissolved in the plasma
- combined with water in the form of bicarbonate
- attached to hemoglobin
Bicarbonate
Concentrations become higher as as more carbon dioxide is produced and blood moves toward the lungs
Breaks back down to carbon dioxide and water and carbon dioxide is exhaled
The transportation of carbon dioxide out of the tissues will become impaired in cases of
Shock
To compensate for shock
The body directs blood flow away from organs that are more tolerant to low flow (ex: Skin and intestines) to organs that cannot tolerate low flow (ex: heart, brain, lungs)
Perfusion triangle
Heart (pump) Blood vessels (container function) Blood (content function) - vehicle for oxygen, fight infection, clotting,
Clotting
Clots forms for retention of blood due to blockage in circulation (blood stasis), changes in the vessel walls (such as a wound) and the bloods ability to clot (as a result of disease process or medication)
Important to control blood loss, HOWEVER, clots are unstable and prone to rupture because blood keeps moving as a result of pressure generated by the contractions of the heart and actions of vessels
Blood pressure
Is a rough measure of perfusion; carefully controlled by the body so that there is always sufficient circulation or perfusion
Capillary hydrostatic pressure
Tents to force fluids through capillary walls
Interstitial fluid hydrostatic pressure
Pushes fluid back into the cells
Blood flow through capillary beds is regulated by
Capillary sphincters
Capillary sphincters
Controlled by the autonomic nervous system and respond to stimuli such as heat, cold, need for oxygen, need for waste removal
Regulation of blood flow is determined by
Cellular need and is accomplished by vessel constriction/dilation
Perfusion requires
A working cardiovascular system
Adequate oxygen exchange in the lungs
Adequate nutrients in the form of glucose in the blood
Adequate waste removal
Adequate ventilation and oxygenation are primary concerns because
Carbon dioxide is one of the primary waste products of cellular metabolism (work) and is removed through the lungs
Causes of pump failure
Heart attack, trauma to the heart, obstructive causes (large pulmonary embolus)
Causes of low fluid volume
Trauma to the vessels or tissues, fluid loss from the GI tract (vomiting/diarrhea can also lower the fluid component of blood)
Causes of poor vessel function
Infection, drug overdose (narcotic), spinal cord injury, anaphylaxis
The ____ side of the autonomic nervous system, which is responsible for the fight-or-flight response, will assume more control of bodily functions during shock
Sympathetic
The response of the autonomic nervous system releases
Epinephrine and norepinephrine, which cause changes in certain body functions (increase HR, strength of cardiac contractions), vasoconstriction in nonessential areas (skin and GI tract), which maintains pressure in the system and sustain perfusion of vital organs
The parasympathetic nervous system
Sends signals to the cardiac, smooth and glandular muscles
It is important to understand the underlying processes of shock and its causes because
Shock is a complex physiologic process that gives subtle signs of its presence before it becomes severe
Cariogenic Shock
A state in which not enough oxygen is delivered to the tissues of the body, caused by low output of blood from the heart. It can be a severe complication of a large MI as well as other conditions
A major effect is blood backup into the lungs - pulmonary edema
Afterload
The force or resistance against which the heart pumps
As afterload increases, cardiac output decreases
Increased afterload may cause the heart to overwork and is often a reason heart failure develops in patients with hypertension
Anaphylactic Shock
An extreme, life-threatening, systemic allergic reaction that may include shock and respiratory failure; Widespread vascular dilation, increased permeability and bronchoconstriction
May occur quickly or as a second phase reaction 1-8 hours after the initial reaction
Aneurysm
A swelling or enlargement of a part of an artery, resulting from weakening of the arterial wall
Autonomic nervous system
The part of the nervous system that regulates involuntary activities of the body, such as heart rate, blood pressure and digestion
Cardiac tamponade
Compression of the heart as the result of buildup of blood or other fluid in the pericardial sac, leading to decreased cardiac output
May be caused by blunt or penetrative trauma that causes hemorrhage around the heart
May also be seen in patients with cancer and autoimmune diseases
Compensated Shock
the early stage of shock, in which the body can still compensate for blood loss
Cardiac output is dependent on
Adequate strength to contract
Adequate blood to pump
Three most common examples of obstructive shock
Cardiac tamponade
Tension pneumothorax
Pulmonary embolism
Signs and symptoms of cardiac tamponade
Beck’s triad: the presence of JVD, muffled heart sounds, and narrowing pulse pressure
Tension pneumothorax
Damage to the lung tissue allows air into the chest cavity and begins to shift the chest organs toward the uninjured side; the lung collapses if left untreated and accumulated air will begin to apply pressure to the structures in the mediastinum (heart and great vessels)
Vena Cava loses its ability to stay fully expanded, leading to reduced blood return to the right side of the heart
Signs and symptoms of tension pneumothroax
Dropping blood pressure
Patient becomes anxious and short of breath
HR and RR increases and becomes shallow
Difficulty when attempting to ventilate with a BVM
Affected side will have decreased or absent lung sounds
Cyanosis
Tracheal deviation (Late sign)
Four most common types of distributive shock
Septic shock
Neurogenic shock
Anaphylactic shock
Psychogenic shock
Signs and symptoms of neurogenic shock
Absence of sweating below the level of injury
Normal and low heart rate in the presence of hypotension
Normal warm skin
Microcirculation
True capillaries branch off the arterioles and allow for exchange between cells and circulation
Main function is the regulation of blood flow and tissue perfusion, blood pressure, tissue fluid, delivery of oxygen, removal of carbon dioxide and the regulation of body temperature
Signs and symptoms of anaphylactic shock
Upper airway constriction Tightness in chest, persistent dry cough Wheezing, dyspnea, cessation of breathing Weak pulse Drop in blood pressure Cyanosis (late sign) Edema (especially face, tongue, neck) Hives Abdominal cramping Altered mental status Nausea And more...
Anemia
Abnormally low Red blood cell numbers
May be the result of chronic or acute bleeding, deficiency in vitamins/minerals, or part of an underlying disease process
Tissues may become hypoxic because blood is unable to deliver adequate amounts of oxygen to tissues even if the hemoglobin is fully saturated
When shock has progressed too far
It is irreversible and there is no way to assess if a patient has reached that point
Blood pressure and shock:
The last measurable change in shock and at this point, shock may be well developed, particularly for infants
Expect shock in patines with any one of the following conditions
Multiple severe fractures Abdominal or chest injury Spinal injury A severe infection A major heart attack Anaphylaxis
_____ will alert you to the presence of evolving shock and allow you to expedite transport and begin immediate treatment
Monitoring vital signs evert 5 minutes
Signs and symptoms of compensated shock
Agitation Anxiety Restlessness Feeling of impending doom Altered mental status Weak, rapid (thready), absent pulse Clammy skin Pallor, with cyanosis about the lips Shallow, rapid breathing Air hunger Nausea/vomiting Capillary refill > 2 seconds in infants/children Marked thirst Narrowing pulse pressure
Signs and symptoms of decompensated shock
Falling blood pressure (systolic 90 mm Hg or lower in adults) Labored or irregular breathing Ashen, mottled or cyanotic skin Thready or absent peripheral pulses Dull eyes, dilated pupils Poor urinary output
Treatment for cardiogenic shock
Position of comfort (typically semi-sitting)
High-flow oxygen
Assist ventilations
Transport promptly and consider ALS
Patients should NOT receive nitroglycerin because by definition they are hypotensive
Treatment for obstructive shock
ALS to assist and/or rapidly transport
High-flow oxygen
Dependent on cause:
Cardiac tamponade - the only definitive care is surgery
Tension pneumothorax - non-rebreather mask, cautious application of positive pressure ventilation, Chest decompression (ALS)
Treatment for septic shock
Prompt transport High-flow oxygen Assist ventilations to maintain tidal volume Keep patient warn Consider ALS
Treatment for neurogenic shock
Patients will often require a long hospitalization Secure/maintain airway Spinal immobilization Assist ventilations High-flow oxygen Preserve body heat Prompt transport Consider ALS
Treatment for anaphylactic shock
Manage the airway Assist ventilations High-flow oxygen Determine cause Assist administration of Epi Prompt transport Consider ALS
Treatment for psychogenic shock
Determine duration of unconsciousness Position patient supine Record initial vital signs/mental status Suspect head injury if the patient is confused, slow to regain consciousness, or unable to walk Prompt transport
Treatment for hypovolemic shock
Secure airway Assist ventilations High-flow oxygen Control external bleeding Recognize internal bleeding and provide aggressive general support Keep warm Prompt Transport Consider ALS
Treatment for respiratory insufficiency
Secure/maintain airway Clear mouth and throat of any obstructions, including mucus, vomit, FB Assist ventilations High-flow oxygen Prompt Transport
Treatment for shock in older patients
May have more serious complications than younger patients; Medications may mask or mimic signs of shock
Be alert for higher resting HR and irregular pulse
Be alert for higher RR, lower tidal volume, decreased gag reflex
Remember dentures may cause airway obstruction
Remember thinner, drier, less elastic, fragile skin – need for thermal regulation
Renal system decreased function
Slower gastric emptying
