Shock Flashcards
What is shock?
Shock is a physiologic state characterized by a significant reduction of system tissue perfusion, resulting in decreased oxygen delivery to the tissues.
Shock created and imbalance between _______ and _______
oxygen delivery, oxygen consumption
What two broad things can prolonged oxygen deprivation lead to?
- Cellular hypoxia
- Derangement of critical biochemical processes
These both can progress to the systemic level
What are the cellular effects from shock? (4 things)
- cell membrane ion pump dysfunction
- intracellular edema
- leakage of intracellular content into the extracellular space
- inadequate regulation of intracellular pH
What are the systemic effect from shock? (4)
- alterations in serum pH
- endothelial dysfunction
- redox state
- further stimulation of inflammatory and anti-inflammatory cascades
True or False: The effects of oxygen deprivation are initially reversible, but rapidly become irreversible.
True
The result of oxygen deprivation include which sequential consequences? (4)
- cell death
- end-organ damage
- multi-system organ failure
- death
Individual cellular disruption from oxygen deprivation can soon lead to ________ _______.
Tissue disruption
True or False: The clinical presentation of shock is always the same severity.
False: The clinical presentation of shock is variable ranging from:
- being asymptomatic
- having minimal symptoms
- circulatory collapse
- subsequent cardiac arrest
What are the three general signs for all types of shock that may or ay not be present?
- Low blood pressure
- Decreased urine output
- Altered mental status
Although tachycardia is common, patients taking _______ , patients that have cardiac _________, or patient with shock due to an ________ ____________ may have normal or slow heart rates.
- beta-blockers
- pacemakers
- intra-abdominal bleeding
What are the 4 main types of shock?
- Hypovolemic
- Cardiogenic
- Distributive
- Obstructive
Name two example of an inciting event of shock?
- a focus of infection (ie. abscess)
2. an injury (i.e. gunshot)
What are the three stages of shock?
- pre-shock
- shock
- end-organ dysfunctions that can culminate in irreversible end-organ damage and death
What is pre-shock also known as? (2 names)
- Warm shock
2. Compensated shock
What is pre-shock characterized by?
Rapid compensation of diminished tissue perfusion by various homeostatic mechanisms.
Will a healthy individual in pre-shock show symptoms?
No, compensatory mechanisms during pre-shock may allow an otherwise healthy adult to be symptomatic despite a 10 percent reduction in total effective arterial blood volume.
Patients maintain relatively normal vital signs in pre-shock
What are possible clinical signs of pre-shock, if any exist? (3)
- Tachycardia
- peripheral vasoconstriction,
- modest increase or decrease in systemic blood pressure
As a patient passes through pre-shock into shock, which signs and symptoms may show? (8)
- hypotension
- tachycardia
- dyspnea
- mental confusion
- restlessness
- diaphoresis
- cool,clammy skin
- thirst, with dry mouth
Is low B/P is early sign or a late and serious sign of shock?
Last and serious
What are the later signs and symptoms of shock? (7)
- Dropping or unobtainable blood pressure
- Rapid, thready pulse
- Dusky discoloration of skin
- Skin is cool or cold to the touch
- irregular, gasping respirations
- Decreased LOC with eventual unresponsiveness
- Dilated pupils, dull lusterless eyes
What is hypovolemic shock?
Hypovolemic shock, also known as hemorrhagic shock, is a life-threatening condition that results when you lose more than 20 percent (one-fifth) of your body’s blood or fluid supply.
What are the three categories of causes for hypovolemic shock?
- Loss of blood (hemorrhagic):
- Loss of plasma (or loss of other fluids)
- Internal loss of fluids (third spacing)
Give examples of causes of hypovolemic shock due to loss of blood. (6)
- external hemorrhage
- internal hemorrhage (esophageal varices, peptic ulcer perforation, burst abdominal aorta)
- trauma
- GI bleed
- hematoma
- hemothorax or hemoperitoneum
Give example of causes of hypovolemic shock due to loss of fluids other than blood. (7)
- Burns - can lead to extremely low blood pressure
- vomiting
- diarrhea
- excessive sweating
- loss of fluids and electrolytes
- hyperosmolar states (diabetic ketoacidosis)
- exfoliative dermatisis
True or false: Hypovolemic shock due to load of fluids in worse in infants and the elderly and may progress more quickly.
True
Give examples of causes of hypovolemic shock from internal loss of fluids. (4)
- Pancreatitis
- Ascites - severe malnutrition
- Bowel obstruction
- Sever liver disease
What is “third spacing”
Third-spacing occurs when too much fluid moves from the intravascular space (blood vessels) into the interstitial or “third” space-the nonfunctional area between cells. This can cause potentially serious problems such as edema, reduced cardiac output, and hypotension.
What key signs or symptoms may you see in hypovolemic shock? (3-6)
- Rapid, weak, thready pulse
- Tachycardia
- Tachypnea due to sympathetic nervous system stimulation and acidosis.
also. ..
4. hypothermia due to decreased perfusion and evaporation of sweat
5. Thirst and dry mouth, due to fluid depletion
6. Cold and mottles skin, due to insufficient perfusion (lived reticular)
When bleeding in a person appears excessive it may be due to multiple risk factors such as: (4)
- Disorders involving vascular integrity
- Disorders of platelet number and/or function
- Disorders of coagulation factors
- Medications
Which of the following condition bleed spontaneously and which one has a longer bleeding time??
Von Willebrand’s dz
Heamonphila
Von Willebrand’s dz - no spontaneous bleeding, but can bleed for a much longer time
Heamophilia - bleed spontaneously
Which drugs can cause an increase in bleeding time? (3)
- NSAIDs
- Aspirin
- Warfarin (Coumadin)
How do NSAIDs increase bleeding time?
They inhibit the aggregation of platelets, thereby increasing the risk of bleeding
Which drug has a reversible effect on platelet aggregation and which has an irreversible effect?
NSAIDs - reversible
aspirin - irreversible; therefore, the inhibitory effect of aspirin is present until the affected platelets have been replaces
What is the mechanism of Ibuprofen (Motrin, Advil) to reduce inflammation?
Is it reversible or irreversible?
Inhibits Cox 1 and 2 enzymes
reversible
How many hours does it take for the platelets exposed to Ibuprofen to resume their pre-medication level of aggravation.
48 - 72 hours (2-3 days) of discontinuing the drug
How long does a patient need to be taken off of aspirin before a surgery?
AT LEAST 7 days, preferably 14 days.
What is Warfarin’s (Coumadin’s) mechanism of action?
Inhibits the production of Vitamin K in the gut
Warfarin (Coumadin) and Heparin must be closely monitored as the bleeding risk can be markedly increased by interaction with other medications.
What blood test is checked in a pt taking Warfarin and what is check in a pt taking Heparin?
PT is checked in Coumadin
PTT is checked in Heparin
What is the antidote for elevated INR due to too much Coumarin?
Vitamin K
Vitamin K is required for the production of which clotting factors?
II, VII, IX, and X
Concurrent use of Warfarin with _______ can cause Warfarin related bleeding.
Explain why.
Antibiotics
The number of Vitamin K producing guts bacteria can be significantly reduced.
Prothrombin time (PT) measures which pathway of coagulation.
Extrinsic: Factors I, II, V, VII, X
What is the world-wide standardization of PT?
INR
What is Shock Index?
The shock index is the patient’s heart rate divided by the pt’s systolic blood pressure. - a stronger predictor of the impact of blood loss than vital signs alone.
heart rate/ blood pressure
What is the scale of hemorrhagic shock?
Class 1 - involves 1-15% of patient’s blood volume. There is typically no change int he patient’s vital signs. Fluid resuscitation is not usually necessary TREATMENT: stop bleeding and make sure normal BP maintains
What does Class 1 hemorrhage involve?
Class 1 - involves 1-15% of patient’s blood volume.
There is typically no change in the patient’s vital signs.
Fluid resuscitation is not usually necessary
TREATMENT: stop bleeding and make sure normal BP maintains
What does Class 2 hemorrhage involve? (4 key points)
Class II hemorrhage involves approximately 15 to 30% of the patient’s total blood volume.
- Tachycardia
- Narrowing of the difference between the systolic and diastolic blood pressures. (pulse pressure decreases)
- Peripheral vasoconstriction.
- Skin, pale and cool to touch
Volume resuscitation with crystalloids such as hypertonic saline solution or lactated Ringer’s solution is generally required.
If the source of blood loss has been adequately treated than a blood transfusion is generally not required.
What is the name of the common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin
Livedo reticularis
What does Class III hemorrhage involve? (4 key things)
Loss of approximately 30 to 40% of the patient’s circulating blood volume
1) Blood pressure drops
2) heart rate increases
3) peripheral hypo perfusion increases
4) mental status worsen with altering LOC
Fluid resuscitation with crystalloid fluids and blood transfusion is usually necessary.
What does class IV hemorrhage involve?
Class IV hemorrhage involves the loss of >40% of the patient’s circulating blood volume.
The limit of the body’s compensation is reached and aggressive resuscitation is required in order to prevent death.
What locations do you palpate on the body to estimate B/P?
If radial pulse is palp - B/P is ≈ 80 syst
If a brachial pulse is palp. - B/P ≈ 70 syst.
If a femoral pulse is palp. - B/P ≈ 60 syst.
If a carotid pulse is palp. - B/P ≈ 50 syst.
What are mast trousers used for?
Used on multiple injured persons or suspected abdominal aneurysm to maintain B/P until they get to ER.
What are important steps to take with a patient in hemorrhagic shock due to trauma. (8 main points)
- Establish a patent and protected airway while protecting the cervical spine
- Maximize oxygenation
- Gain intravenous access and initiate fluid resuscitation
- Control hemorrhage - must maintain pressure to bleeding site especially if dealing with an arterial bleed.
- Elevate lower extremities and maintain a head-low position unless contraindication (facial or scalp injuries)
- Immobilize fractures as this lessens damage to soft tissues from splintered bone ends
- Monitor level of consciousness and reassess V/S at least every 3 - 5 minutes.
- NO FOOD OR DRINK!!!
What is cariogenic shock?
Cardiogenic shock results from an inadequate circulation of blood due to primary failure of the ventricles of the heart, resulting in insufficient perfusion of tissues to meet the demands for oxygen and nutrients.
Is cardiogenic shock reversible?
Cardiogenic shock is largely irreversible and is more often fatal than not.
What are some causes of cariogenic shock? (name 5, and which is the most common?
- Pump failure secondary to MI
- Rupture of ventricular septum, free ventricular wall or papillary muscle
- Dysrythmias (number 1 cause)
- Tamponade
- Acute valvular dysfunction (particularly the aortic valve)
What do the symptoms of cardiogenic shock include? (3)
Similar symptoms to hypovolemic shock PLUS!
- distended jugular veins due to increased jugular venous pressure
- Arrhythmias, often tachycardias
- Pulsus paradoxus in case of tamponade (plus faint heart sounds)
What does the treatment of cariogenic shock include? (5)
How about in the special cases listed below? (3 of the 5)
- shock refractory to fluids
- shock with abnormal heart beat
- shock due to MI
Depeneding on the type of cariogenic shock, treatment involves:
- infusion of intravenous fluids
- In shock refractory to fluids, add inotropic medication in addition
- In case of an abnormal heart rhythm, several anti-arrhythmic agents may be administered
- If cariogenic shock is due to an MI, attempts to open the heart’s arteries may help.
- Intra-aortic ballon pump
What is the purpose of an intra-aortic balloon pump? (2)
- Increases myocardial oxygen perfusion
2. Increases cardiac output
What is distributive shock?
distributive shock is different from the other three categories in that it occurs even though the output of the heart is at above normal level.
What are some causes of distributive shock. Include the most common cause (7)
- Most common cause is sepsis
- Systemic inflammation response syndrome (SIRS) - due to conditions other than infection such as
a. pancreatitis
b. burns
c. trauma - TSS
- Anaphalaxis
- Adrenal insufficiency
- Reactions of drugs or toxins
- Heavy Metal poisoning
What 5 types of shock are encompassed in the term “distributive shock?”
- Septic shock
- Anaphylactic shock
- Neurogenic shock
- Vasodilator srugs
- Endocrine related shock: Thyroid - significant hyperthyroid
What are the main goals of treatment in distributive shock? (2)
- Reverse the underlying cause
2. Achieve hemodynamic stabilization
What does immediate treatment of distributive shock involve? (3)
- Fluid resuscitation
- Vasoactive drugs: both vasopressors and inotropes
- Corticosteroids are often used with patients whose hypotension does not respond to fluid resuscitation and vasopressors
What are some important adjunct goals in the treatment of distributive shock? (3)
- control inflammation
- control vascular function
- control coagulation
These three things correct pathological difference in blood flow and microvascular shunting.
What medications are used to treat septic shock?
Antimicrobial drugs
Which sources of septic shock infection will require surgical treatment? (5)
- Necrotizing fasciitis
- Cholangitis
- Abscess
- Intestinal ischemia
- Infected medical devices
What is anaphylactic shock treated with?
epinephrine
What is the leading non-cardiac cause of death in intensive care units?
Septic shock
Which infection sites are most likely to lead to septic shock? (3)
- Chest
- Abdomen
- Genitourinary tract
What are the key points of the pathophysiology of septic shock? (4)
- Blood flow in microvasculature is abnormal
a. some capillaries are under perfused
b. some capillaries have normal to high blood flow - The endothelial cells lining the blood vessels become less responsive to vasoconstrictive agents
- Endothelial cell lose their glycocalyx normal coating and negative ionic charge, become leaky and cause extensive over-expressions of nitric oxide (NO)
- Coagulation cascade is disrupted
What three findings are present in septic shock?
- Activation of the coagulation pathways resulting in DIC (disseminated intravascular coagulation)
- Increased neutrophils
- Reduced contractility of the heart
What causes the hypotension in anaphylactic shock? (2)
- A massive release of histamine by mast cells (activated by antigen bound IgE)
- increased production and release of prostaglandins.
What causes neurogenic shock?
Caused by the loss of vascular tone normally supported by the sympathetic nervous system due to injury to the central nervous system especially spinal chord.
What is another cause of neurogenic shock that is not a CNS injury?
Rupture of a hollow organ in the abdomen with subsequent evacuation of its content into the peritoneal cavity.
Widespread peritoneal irritation by the ruptured viscous contents (ex. peptic ulcer perforation), which then leads to a strong vagal activation and generalized extensive peripheral vasodilation and bradycardia.
What is obstructive shock?
A form of shock associated with physical obstruction of the great vessels or the heart itself.
What are some causes of obstructive shock?
- Pulmonary embolism
- Emboli to the cardiac vessels
- Severe aortic stenosis
- Cardiac tamponade
