Chapter 13 Shock Flashcards
perfusion
Perfusion is the means by which blood provides nutrients and removes cellular waste.
Adequate perfusion is required to provide cells oxygen and nutrients and remove waste products.
- Any compromise in perfusion can lead to cellular injury or death.
Poor perfusion (shock)
In cases of poor perfusion (shock), the transportation of carbon dioxide out of the tissues will become impaired, resulting in a dangerous buildup of waste products that may cause cellular damage.
Shock
Shock is a state of collapse and failure of the cardiovascular system that leads to inadequate circulation.
1. To protect vital organs, the body directs blood flow from organs that are more tolerant of low flow (such as the skin and intestines) to organs that cannot tolerate low blood flow (such as the heart, brain, and lungs).
2. Early recognition of the signs and symptoms of shock can save lives.
3. Shock is life threatening and requires immediate recognition and rapid treatment.
perfusion triangle
The heart (pump), blood vessels (container), and blood (content)
The cardiovascular system consists of three parts
The heart (pump), blood vessels (container), and blood (content)
Shock - The cardiovascular system consists of three parts
- The heart (pump), blood vessels (container), and blood (content).
a. These three parts can be referred to as the “perfusion triangle.”
b. When a patient is in shock, one or more of the three parts is not working properly.
Systolic pressure
Systolic pressure is the peak arterial pressure, or pressure generated every time the heart contracts.
Diastolic pressure
Diastolic pressure is the pressure maintained within the arteries while the heart rests between heartbeats.
Pulse
Pulse pressure is the difference between the systolic and diastolic pressures (systolic – diastolic = pulse pressure).
for example 120/80 (Systolic is 120 - Diastolic is 80) Pulse is 120 - 80 = 40
a. It signifies the amount of force the heart generates with each contraction.
b. A pulse pressure of less than 25 mm Hg may be seen in patients with shock.
Blood flow through the capillary beds is regulated by
the capillary sphincters, circular muscular walls that constrict and dilate
capillary sphincters
- These sphincters are under the control of the autonomic nervous system.
- Capillary sphincters also respond to other stimuli such as:
a. Heat
b. Cold
c. The need for oxygen
d. The need for waste removal - Regulation of blood flow is determined by cellular needs.
Perfusion also requires adequate:
- Oxygen exchange in the lungs
- Nutrients in the form of glucose in the blood
- Waste removal, primarily through the lungs
Oxygen, Nutrients, Waste removal
Mechanisms are in place to help support the respiratory and cardiovascular systems when the need for perfusion of vital organs is increase
- Includes the autonomic nervous system and hormones.
a. The sympathetic side of the autonomic nervous system, which is responsible for the fight-or-flight response, will assume more control of the body’s functions during a state of shock.
b. This response by the autonomic nervous system causes the release of hormones such as epinephrine and norepinephrine.
c. Hormones cause an increase in heart rate and in the strength of cardiac contractions, as well as vasoconstriction in nonessential areas, primarily in the skin and gastrointestinal tract (peripheral vasoconstriction).
d. This response causes all the signs and symptoms of shock in a patient.
The autonomic nervous is comprised of two parts
the sympathetic nervous system and the parasympathetic nervous system
sympathetic nervous system (fight-or-flight)
parasympathetic nervous system (coming effect - opposite of the sympathetic)
There are many different types of shock that result from three basic causes – what are the three Causes of Shock
pump failure, poor vessel function, and low fluid volume
What are the four types of Shock
A. Cardiogenic shock
B. Obstructive shock
C. Distributive shock
D. Hypovolemic shock
Cardiogenic shock
- Caused by inadequate function of the heart, or pump failure
- A major effect is the backup of blood into the pulmonary vessels.
- The resulting buildup of pulmonary fluid is called pulmonary edema.
- Cardiogenic shock develops when the heart cannot maintain sufficient output to meet the demands of the body.
a. Cardiac output is the volume of blood that the heart can pump per minute, and it is dependent upon several factors.
i. The heart must have adequate strength for the heart muscle to contract (myocardial contractility).
ii. The heart must receive adequate blood to pump (preload).
iii. The resistance to flow in the peripheral circulation must be appropriate (afterload).
Ventricular contraction
Ventricular contraction, also known as ventricular systole, is a phase of the cardiac cycle where the ventricles of the heart contract and eject blood into the aorta and pulmonary arteries. The process begins with the closure of the mitral and tricuspid valves to prevent backflow of blood into the atria, a phase known as isovolumic contraction. As the ventricles contract, pressure rises rapidly inside them, surpassing the pressure in the aorta and pulmonary arteries, which leads to the opening of the aortic and pulmonary valves, allowing the ejection of blood from the heart
What is Hypovolemic shock
An amount of fluid issue
The result of an inadequate amount of fluid or volume in the circulatory system
What is Distributive shock
A distribution of fluids from the heart issue
What is Obstructive shock
An Obstruction of fluids to the heart issue
What is Cardiogenic shock
A Issue of fluid circulation within the heart
When do infants and children expirince a drop in blood pressure
maintain their blood pressure until they have blood loss that is more than half their blood volume
What does it mean when the time blood pressure drops in infants and children who are in shock
they are close to death
When a drop in blood pressure is evident in a shock victim it means that
shock is well developed
Expect shock if a patient has any one of the following conditions (name 6)
a. Multiple severe fractures
b. Abdominal or chest injury
c. Spinal injury
d. A severe infection
e. A major heart attack
f. Anaphylaxis (A severe, potentially life-threatening allergic reaction)
What is the AVPU scale
Alert
Voice Responsive
Pain Responsive
Unconscious
What is mechanism of injury
Mechanism of injury (MOI) specifically refers to the method by which trauma and its associated forces directly or indirectly impacts the human body
Begin immediate treatment for shock as soon as you realize that the condition may exist – do the following 12 steps
- Follow standard precautions.
- Control all obvious external bleeding.
- Make sure the patient has an open airway.
- Maintain manual in-line stabilization, if necessary, and check breathing and pulse.
- Comfort, calm, and reassure the patient, while maintaining the patient in the supine position.
- Never allow patients to eat or drink anything prior to being evaluated by a physician.
- If spinal immobilization is indicated, splint the patient on a backboard.
- Remember that inadequate ventilation may be a major factor in the development of shock. Always provide oxygen, assist with ventilations, and use airway control adjuncts as needed.
- To prevent the loss of body heat, place blankets under and over the patient.
- Transport the patient and treat additional injuries en route.
- Consider rendezvous with ALS if possible, and consider aeromedical transport.
- Accurately record the patient’s vital signs approximately every 5 minutes throughout treatment and transport.
Signs and symptoms of Treating cardiogenic shock - list 4
a. Weak, irregular pulse
b. Cyanosis about the lips and underneath the fingernails
c. Anxiety
d. Nausea
Treating obstructive shock
- Cardiac tamponade
a. Increasing cardiac output should be the priority.
b. Apply high-flow oxygen.
c. Surgery is the only definitive treatment. - Tension pneumothorax
a. Administer high-flow oxygen via nonrebreathing mask early to prevent hypoxia.
b. Chest decompression is required to relieve the pressure in the chest.
c. Chest decompression is an ALS skill. Ask for ALS assistance early in the call if available; however, do not delay transport waiting for the arrival of ALS.
What is the brachial artery
The brachial artery is the major blood vessel supplying blood to your upper arm, elbow, forearm and hand
In the event of a large laceration to the wrist with rapid bleeding, what should you do
A. administering high-flow supplemental oxygen
B. apply pressure to the brachial artery
C. wrapping the towel with pressure bandages
D. Apply a tourniquet
B. apply pressure to the brachial artery.
In the event of a large laceration to the wrist with rapid bleeding, direct pressure is the first line of treatment. If direct pressure over the wound itself is not sufficient to stop the bleeding, applying pressure to the brachial artery, which is the major blood vessel of the upper arm, can help control bleeding. This is because the brachial artery is the main arterial supply to the arm and hand, and pressure here can reduce blood flow to the wound. However, this is usually a temporary measure until more definitive care can be provided.
It’s important to note that, in general, a tourniquet (option D) is used when direct pressure is not effective or possible, and it is applied proximal to (meaning closer to the body than) the wound. The use of a tourniquet is a more advanced technique and should only be applied by someone trained in its use, as incorrect application can lead to further injury.
The options A (administering high-flow supplemental oxygen) and C (wrapping the towel with pressure bandages) are not the most immediately appropriate responses for rapid bleeding, though they may be used as part of the overall management after the bleeding is controlled.
what is tachycardia
Tachycardia is an increased heart rate for any reason
What is septic shock
it is part of the distribution shock
Septic shock is a life-threatening condition caused by a severe localized or system-wide infection that requires immediate medical attention.
Symptoms include low blood pressure, pale and cool arms and legs, chills, difficulty breathing, and decreased urine output. Mental confusion and disorientation may also develop quickly.
Emergency treatment may include supplemental oxygen, intravenous fluids, antibiotics, and other medications.
what is anaphylaxis
A severe, potentially life-threatening allergic reaction.
The reaction can occur within seconds or minutes of exposure to an allergen.
Symptoms include a skin rash, nausea, vomiting, difficulty breathing, and shock.
If not treated right away, usually with epinephrine, it can result in unconsciousness or death.
what is ischemic stroke
An ischemic stroke occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes
what is compensated shock
Pre-shock or compensated shock - As the name suggests, this stage is characterized by compensatory mechanisms to counter the decrease in tissue perfusion, including tachycardia, peripheral vasoconstriction, and changes in systemic blood pressure.
Signs of compensated shock
Cool extremities
Weak thready peripheral pulse
Delayed capillary refill
Tachycardia in the absence of fever
Narrowing pulse pressure (PP)
what does vasodilation mean
The dilatation of blood vessels, which decreases blood pressure
Hypovolemic shock caused by severe burns is the result of a loss of:
plasma.
in an acute injury setting neurogenic shock is commonly accompanied by
hypothermia
What is Pulmonary edema
A condition caused by excess fluid in the lungs.
Pulmonary edema is usually caused by a heart condition. Other causes include pneumonia, exposure to certain toxins and drugs, and being at high elevations.
Depending on the cause, pulmonary edema symptoms may appear suddenly or develop over time. Mild to extreme breathing difficulty can occur. Cough, chest pain, and fatigue are other symptoms.
Treatment generally includes supplemental oxygen and medications.
What is simple pneumothorax
A spontaneous pneumothorax is the sudden onset of a collapsed lung without any apparent cause, such as a traumatic injury to the chest or a known lung disease.
What is Tension pneumothorax
Tension pneumothorax develops when a lung or chest wall injury is such that it allows air into the pleural space but not out of it (a one-way valve)
what is decompensated shock
Decompensated shock is defined as “the late phase of shock in which the body’s compensatory mechanisms (such as increased heart rate, vasoconstriction, increased respiratory rate) are unable to maintain adequate perfusion to the brain and vital organs.” It occurs when the blood volume decreases by more than 30%
