Shock is a medical emergency in which the organs and tissues of the body are not receiving an adequate flow of blood. This deprives the organs and tissues of oxygen (carried in the blood) and allows the buildup of waste products. Shock can result in serious damage or even death
There are three stages of shock: Stage I (also called compensated, or nonprogressive), Stage II (also called decompensated or progressive), and Stage III (also called irreversible).
In Stage I of shock, when low blood flow (perfusion) is first detected, a number of systems are activated in order to maintain/restore perfusion. The result is that the heart beats faster, the blood vessels throughout the body become slightly smaller in diameter, and the kidney works to retain fluid in the circulatory system. All this serves to maximize blood flow to the most important organs and systems in the body. The patient in this stage of shock has very few symptoms, and treatment can completely halt any progression.
In Stage II of shock, these methods of compensation begin to fail. The systems of the body are unable to improve perfusion any longer, and the patient's symptoms reflect that fact. Oxygen deprivation in the brain causes the patient to become confused and disoriented, while oxygen deprivation in the heart may cause chest pain
. With quick and appropriate treatment, this stage of shock can be reversed.
In Stage III of shock, the length of time that poor perfusion has existed begins to take a permanent toll on the body's organs and tissues. The heart's functioning continues to spiral downward, and the kidneys usually shut down completely. Cells in organs and tissues throughout the body are injured and dying. The endpoint of Stage III shock is the patient's death.
Causes and symptoms
Shock is caused by three major categories of problems: cardiogenic (meaning problems associated with the heart's functioning); hypovolemic (meaning that the total volume of blood available to circulate is low); and septic shock
(caused by overwhelming infection, usually by bacteria).
Cardiogenic shock can be caused by any disease, or event, which prevents the heart muscle from pumping strongly and consistently enough to circulate the blood normally. Heart attack
, conditions which cause inflammation of the heart muscle (myocarditis), disturbances of the electrical rhythm of the heart, any kind of mass or fluid accumulation and/or blood clot which interferes with flow out of the heart can all significantly affect the heart's ability to adequately pump a normal quantity of blood.
Hypovolemic shock occurs when the total volume of blood in the body falls well below normal. This can occur when there is excess fluid loss, as in dehydration
due to severe vomiting or diarrhea, diseases which cause excess urination (diabetes insipidus, diabetes mellitus, and kidney failure), extensive burns
, blockage in the intestine, inflammation of the pancreas (pancreatitis
), or severe bleeding of any kind.
Septic shock can occur when an untreated or inadequately treated infection (usually bacterial) is allowed to progress. Bacteria often produce poisonous chemicals (toxins) which can cause injury throughout the body. When large quantities of these bacteria, and their toxins, begin circulating in the bloodstream, every organ and tissue in the body is at risk of their damaging effects. The most damaging consequences of these bacteria and toxins include poor functioning of the heart muscle; widening of the diameter of the blood vessels; a drop in blood pressure; activation of the blood clotting system, causing blood clots
, followed by a risk of uncontrollable bleeding; damage to the lungs, causing acute respiratory distress syndrome; liver failure; kidney failure; and coma
Initial symptoms of shock include cold, clammy hands and feet; pale or blue-tinged skin tone; weak, fast pulse rate; fast rate of breathing; low blood pressure. A variety of other symptoms may be present, but they are dependent on the underlying cause of shock.
Diagnosis of shock is based on the patient's symptoms, as well as criteria including a significant drop in blood pressure, extremely low urine output, and blood tests that reveal overly acidic blood with a low circulating concentration of carbon dioxide. Other tests are performed, as appropriate, to try to determine the underlying condition responsible for the patient's state of shock.
The most important goals in the treatment of shock include: quickly diagnosing the patient's state of shock; quickly intervening to halt the underlying condition (stopping bleeding, re-starting the heart, giving antibiotics
to combat an infection, etc.); treating the effects of shock (low oxygen, increased acid in the blood, activation of the blood clotting system); and supporting vital functions (blood pressure, urine flow, heart function).
Treatment includes keeping the patient warm, with legs raised and head down to improve blood flow to the brain, putting a needle in a vein in order to give fluids or blood transfusions, as necessary; giving the patient extra oxygen to breathe and medications to improve the heart's functioning; and treating the underlying condition which led to shock.
The prognosis of an individual patient in shock depends on the stage of shock when treatment was begun, the underlying condition causing shock, and the general medical state of the patient.
The most preventable type of shock is caused by dehydration during illnesses with severe vomiting or diarrhea
. Shock can be avoided by recognizing that a patient who is unable to drink in order to replace lost fluids needs to be given fluids intravenously (through a needle in a vein). Other types of shock are only preventable insofar as one can prevent their underlying conditions, or can monitor and manage those conditions well enough so that they never progress to the point of shock.
Kerasote, Ted. "After Shock: Recognizing and Treating Shock." Sports Afield 217 (May 1997): 60+.
— A condition of having too little of something.
— Blood flow through an organ or tissue.
— An overwhelming infection throughout the body, usually caused by bacteria in the bloodstream.
1. a sudden disturbance of mental equilibrium.
a condition of acute peripheral circulatory failure due to derangement of circulatory control or loss of circulating fluid. It is marked by hypotension and coldness of the skin, and often by tachycardia and anxiety. Untreated shock can be fatal. Called also circulatory collapse
Mechanisms of Circulatory Shock. The essentials of shock are easier to understand if the circulatory system is thought of as a four-part mechanical device made up of a pump (the heart), a complex system of flexible tubes (the blood vessels), a circulating fluid (the blood), and a fine regulating system or “computer” (the nervous system) designed to control fluid flow and pressure. The diameter of the blood vessels is controlled by impulses from the nervous system which cause the muscular walls to contract. The nervous system also affects the rapidity and strength of the heartbeat, and thereby the blood pressure as well.
Shock, which is associated with a dangerously low blood pressure, can be produced by factors that attack the strength of the heart as a pump, decrease the volume of the blood in the system, or permit the blood vessels to increase in diameter.
Types of Circulatory Shock
. There are five main types: Hypovolemic (low-volume) shock
occurs whenever there is insufficient blood to fill the circulatory system. Neurogenic shock
is due to disorders of the nervous system. Anaphylactic (allergic) shock
and septic shock
are both due to reactions that impair the muscular functioning of the blood vessels. And cardiogenic shock
is caused by impaired function of the heart.
Hypovolemic (Low-Volume) Shock. This is a common type that happens when blood or plasma is lost in such quantities that the remaining blood cannot fill the circulatory system despite constriction of the blood vessels. The blood loss may be external, as when a vessel is severed by an injury, or the blood may be “lost” into spaces inside the body where it is no longer accessible to the circulatory system, as in severe gastrointestinal bleeding from ulcers, fractures of large bones with hemorrhage into surrounding tissues, or major burns that attract large quantities of blood fluids to the burn site outside blood vessels and capillaries. The treatment of hypovolemic shock requires replacement of the lost volume.
Neurogenic Shock. This type, often accompanied by fainting, may be brought on by severe pain, fright, unpleasant sights, or other strong stimuli that overwhelm the usual regulatory capacity of the nervous system. The diameter of the blood vessels increases, the heart slows, and the blood pressure falls to the point where the supply of oxygen carried by the blood to the brain is insufficient, which can bring on fainting. Placing the head lower than the body is usually sufficient to relieve this form of shock.
Anaphylactic (Allergic) Shock.
This type (see also anaphylaxis
) is a rare phenomenon that occurs when a person receives an injection of a foreign protein but is highly sensitive to it. The blood vessels and other tissues are affected directly by the allergic reaction. Within a few minutes, the blood pressure falls and severe dyspnea develops. The sudden deaths that in rare cases follow bee stings or injection of certain medicines are due to anaphylactic reactions.
Septic Shock. This type, resulting from bacterial infection, is being recognized with increasing frequency. Certain organisms contain a toxin that seems to act on the blood vessels when it is released into the bloodstream. The blood eventually pools within parts of the circulatory system that expand easily, causing the blood pressure to drop sharply. Gram-negative shock is a form of septic shock due to infection with gram-negative bacteria.
Cardiogenic Shock. This type may be caused by conditions that interfere with the function of the heart as a pump, such as severe myocardial infarction, severe heart failure, and certain disorders of rate and rhythm.
Pathogenesis of shock. (ARDS = adult respiratory distress syndrome, GI = gastrointestinal, IL = interleukin, TNF = tumor necrosis factor.) From Damjanov, 2000.
cardiogenic shock shock resulting from primary failure of the heart in its pumping function, as in myocardial infarction, severe cardiomyopathy, or mechanical obstruction or compression of the heart; clinical characteristics are similar to those of hypovolemic shock.
colloidoclastic shock colloidoclasia.
cultural shock feelings of helplessness and discomfort experienced by an outsider attempting to comprehend or effectively adapt to a different cultural group or unfamiliar cultural context.
hypovolemic shock shock resulting from insufficient blood volume for the maintenance of adequate cardiac output, blood pressure, and tissue perfusion. Without modification the term refers to absolute hypovolemic shock caused by acute hemorrhage or excessive fluid loss. Relative hypovolemic shock refers to a situation in which the blood volume is normal but insufficient because of widespread vasodilation as in neurogenic shock or septic shock. Clinical characteristics include hypotension; hyperventilation; cold, clammy, cyanotic skin; a weak and rapid pulse; oliguria; and mental confusion, combativeness, or anxiety.
insulin shock a hypoglycemic reaction to overdosage of insulin, a skipped meal, or strenuous exercise in an insulin-dependent diabetic, with tremor, dizziness, cool moist skin, hunger, and tachycardia; if untreated it may progress to coma and convulsions.
respirator shock circulatory shock due to interference with the flow of blood through the great vessels and chambers of the heart, causing pooling of blood in the veins and the abdominal organs and a resultant vascular collapse. The condition sometimes occurs as a result of increased intrathoracic pressure in patients who are being maintained on a mechanical ventilator.
septic shock shock associated with overwhelming infection, usually by gram-negative bacteria, although it may be produced by other bacteria, viruses, fungi, and protozoa. It is thought to result from the action of endotoxins or other products of the infectious agent on the vascular system causing large volumes of blood to be sequestered in the capillaries and veins; activation of the complement and kinin systems and the release of histamine, cytokines, prostaglandins, and other mediators may be involved. Clinical characteristics include initial chills and fever, warm flushed skin, increased cardiac output, and a lesser degree of hypotension than with hypovolemic shock; if therapy is ineffective, it may progress to the clinical picture associated with hypovolemic shock.
spinal shock the loss of spinal reflexes after injury of the spinal cord that appears in the muscles innervated by the cord segments situated below the site of the lesion.
1. The condition in which the cells of the body receive inadequate amounts of oxygen secondary to changes in perfusion; most commonly secondary to blood loss or sepsis.
2. A sudden physical or biochemical disturbance that results in inadequate blood flow and oxygenation of an animal's vital organs.
3. A state of profound mental and physical depression consequent to severe physical injury or to emotional disturbance.
4. A state characterized by inadequacy of blood flow throughout the body to the extent that damage occurs to the cells of the tissues; if the shock is prolonged, the cardiovascular system itself becomes damaged and begins to deteriorate, resulting in a vicious cycle that leads to death.
[Fr. choc, fr. Germanic]
1. a sudden disturbance of mental equilibrium.
2. a profound hemodynamic and metabolic disturbance due to failure of the circulatory system to maintain adequate perfusion of vital organs.
cardiogenic shock shock resulting from inadequate cardiac function, as from myocardial infarction or mechanical obstruction; characteristics include hypovolemia, hypotension, cold skin, weak pulse, and confusion.
endotoxin shock septic shock due to release of endotoxins by gram-negative bacteria.
hypovolemic shock shock due to insufficient blood volume, either from hemorrhage or other loss of fluid or from widespread vasodilation so that normal blood volume cannot maintain tissue perfusion; symptoms are like those of cardiogenic shock.
insulin shock a hypoglycemic reaction to overdosage of insulin, a skipped meal, or strenuous exercise in an insulin-dependent diabetic, with tremor, dizziness, cool moist skin, hunger, and tachycardia, sometimes progressing to coma and convulsions.
septic shock shock associated with overwhelming infection, most commonly infection with gram-negative bacteria, thought to result from the actions of endotoxins and other products of the infectious agent that cause sequestration of blood in the capillaries and veins.
1. A massive, acute physiological reaction usually to physical trauma, infection, or allergy, characterized by a marked loss of blood pressure, resulting in a diminished blood flow to body tissues and a rapid heart rate.
2. The sensation and muscular spasm caused by an electric current passing through the body or a body part.
v. shocked, shocking, shocks
1. To induce a state of physical shock in (an animal or person).
a. To subject (an animal or person) to an electric shock.
b. To administer electric current to (a patient) to treat cardiac arrest or life-threatening arrhythmias.
c. To administer electroconvulsive therapy to (a patient).
an abnormal condition of inadequate blood flow to the body's tissues, with life-threatening cellular dysfunction. The condition is usually associated with inadequate cardiac output, hypotension, oliguria, changes in peripheral blood flow resistance and distribution, and tissue damage. Causal factors include hemorrhage, vomiting, diarrhea, inadequate fluid intake, or excessive fluid loss, resulting in hypovolemia. Kinds of shock include anaphylactic shock
, cardiogenic shock
, hypovolemic shock
, neurogenic shock,
and septic shock
observations Hypovolemic shock is the most common kind of shock. There is decreased blood flow with a resulting reduction in the delivery of oxygen, nutrients, hormones, and electrolytes to the body's tissues and a concomitant decreased removal of metabolic wastes. Pulse and respirations are increased. Blood pressure may decline after an initial slight increase. The patient often shows signs of restlessness and anxiety, an effect related to decreased blood flow to the brain. There also may be weakness, lethargy, pallor, and a cool, moist skin. As shock progresses, the body temperature falls, respirations become rapid and shallow, and the pulse pressure (the difference between systolic and diastolic blood pressures) narrows as compensatory vasoconstriction causes the diastolic pressure to be elevated or maintained in the face of a falling systolic blood pressure. Urinary output is reduced. Hemorrhage may be apparent or concealed, although other factors, such as vomiting or diarrhea, may account for the deficiency of body fluids.
interventions Fluid volume must be restored quickly so that there can be a rapid return of oxygenated blood to the perfusion-deprived tissues. Supplemental oxygen should be administered. Blood volume is expanded with IV fluids, such as a lactated Ringer's solution or a 5% dextrose in normal saline solution. Packed red blood cells, plasma, and plasma substitutes are also given for shock of hemorrhagic origin. Metabolic acidosis may result from anaerobic metabolism.
nursing considerations After vital functions are restored and diagnosis has been made, the patient in shock must be monitored continuously until recovery is assured. The patient should remain flat in bed, but the lower extremities can be raised to improve venous return (modified Trendelenburg's position). The Trendelenburg position should be avoided because it tends to push the abdominal organs against the diaphragm and increases the work of breathing. Position changes should be made slowly. Vasoactive drugs may be ordered when the blood volume is adequate. The patient's skin color, temperature, vital signs, intake and output, pulse oximetry, and level of consciousness should be monitored closely.
SHOCK Cardiology A clinical trial–Should We Emergently Revascularize Occluded Coronaries for Cardiogenic shock comparing the efficacy of emergency revascularization and initial medical stabilization in managing Pts with MI complicated by cardiogenic shock. See Cardiogenic shock.
shock A condition characterized by signs and Sx due to a cardiac output below that required to fill the arteries with blood of sufficient pressure to adequately perfuse organs and tissue Clinical Hypotension, poor peripheral perfusion, hyperventilation, tachycardia, oliguria, cyanosis, mental clouding, a sense of great anxiety and foreboding, confusion and, sometimes, combativeness Causes Trauma with major multiorgan system injury, septicemia, fluid loss–blood or intractible diarrhea, burns, high voltage electric current, abrupt loss of myocardial activity Classification Based on related mechanisms of cardiac dysfunction–pump failure, ↓ volume–loss of blood or extracellular fluid or changes in arterial resistance or venous capacity Pathogenesis Shock activates sympathetic nervous system via the carotic and aortic baroreceptors, ↑ catecholamines, vasoconstriction of 'non-essential' organs–intestine, kidneys, skin to maintain blood flow to vital organs–heart and brain; with time, hypotension becomes irreversible. See Anaphylactic shock, Bacteremic shock, Calcium shock, Cardiogenic shock, Cardiopulmonary obstructive shock, Culture shock, Heat shock, Hypotension, Hypovolemic shock, Insulin shock, Psychologic shock, Refractory septic shock, Septic shock, Spinal shock.
1. A sudden physical or mental disturbance.
2. A state of profound mental and physical depression consequent upon severe physical injury or an emotional disturbance.
3. A severe disturbance of hemodynamics in which the circulatory system fails to maintain adequate perfusion of vital organs; may be due to reduction of blood volume (hemorrhage, dehydration), cardiac failure, or dilation of the vascular system in toxemia or septicemia.
4. The abnormally palpable impact, appreciated by a hand on the chest wall, of an accentuated heart sound.
[Fr. choc, fr. Germanic]
A syndrome featuring low blood pressure, a prejudiced blood supply to important organs such as the brain and heart, and low kidney output. Causes of shock include severe blood loss, burns, severe infection, allergy, heart damage from CORONARY THROMBOSIS
and head injury. Untreated shock may be rapidly fatal. The main element in treatment is the rapid restoration of the circulating blood volume by transfusion and the use of the drug VASOPRESSIN
to help to maintain the blood pressure.
2. A temporary state of psychological overburdening from severe mental distress, often associate with stupefaction.
shock profound physical depression characterized by low blood pressure, circulatory collapse and coma
anaphylactic shock due to hypersensitivity; see anaphylaxis
cardiogenic shock due to decline in cardiac output secondary to serious heart disease, e.g. myocardial infarction
haemorrhagic shock due to acute haemorrhage, characterized by marked hypotension, hypovolaemia, tachycardia, pallor, cold and clammy skin and oliguria
hypovolaemic shock due to sudden reduction in circulating blood volume (e.g. severe haemorrhage, dehydration, faint [vasovagal attack] or anaphylaxis)
insulin shock due to relative overdose of insulin/relatively low levels of blood glucose (i.e. a ‘hypo’), characterized by sweating, tremor, anxiety, vertigo, double vision, which if left untreated can progress to delirium, convulsions, coma and collapse, but can be readily reversed by ingestion of sugar (e.g. sweet drink or biscuit) in conscious patient, or injection of glucagon (if the patient is unconscious)
1. State in which cells of body receive inadequate amounts of oxygen secondary to changes in perfusion; most commonly due to blood loss or sepsis.
2. Sudden physical or biochemical disturbance that results in inadequate blood flow and oxygenation of an animal's vital organs.
3. State of profound mental and physical depression consequent to severe physical injury or to emotional disturbance.
[Fr. choc, fr. Germanic]
n 1. a state of collapse of the body after injury or trauma. Shock may be either primary or secondary. The principal effects of shock are slowing of the peripheral blood flow and reduction in cardiac output.
2. a circulatory insufficiency caused by a disparity between circulating blood volume and vascular capacity.
n pain produced as a result of galvanic currents caused by similar or dissimilar metallic restorations.
n an ineffectual circulating volume of blood resulting from loss of whole blood.
a coma resulting from too much insulin or an inadequate intake of food. Symptoms include wet or moist skin, hypersalivation or drooling, normal blood pressure, tremors, dilated pupils, normal or bounding pulse, and firm eyeballs. Sugar and acetoacetic acid may be present in bladder urine but are absent in the second specimen. The blood sugar is low (hypoglycemia). See also coma, diabetic.
n shock caused by loss of nervous control of peripheral vessels, resulting in an increase in the vascular capacity. Onset is usually sudden but is quickly reversible if the cause is removed and treatment is instituted immediately.
n shock that has a neurogenic basis in which pain and psychic factors affect the vascular system. Occurs immediately after an injury.
n shock that occurs some time after the injury (6 to 24 hours later). It is associated with changes in capillary permeability and subsequent loss of plasma into the tissue spaces. Changes in capillary permeability are probably related to histamine release associated with tissue injury.
n a shock produced by trauma, whether psychic or physical. In general usage, this term refers to shock following physical trauma, with hemorrhage, peripheral blood vessel dilation, and changes in capillary permeability.
a condition of acute peripheral circulatory failure due to derangement of circulatory control or loss of circulating fluid. It is marked by hypotension, coldness of the skin and tachycardia.
hyaline globules composed of fibrin degradation products which act as microthrombi and cause hemorrhage and necrosis.
the loss and redistribution of fluid, electrolytes and plasma protein, increased blood viscosity and increased peripheral resistance that follow a severe burn contribute to shock.
classically associated with acute myocardial infarction in humans; in animals may be caused by intrinsic congestive heart failure, cardiac depression caused by anesthetic overdosage or other drugs with negative inotropism, rarely, thromboembolism.
shock due to breakdown of the physical equilibrium of the body colloids. Thought to cause anaphylactic shock due to the absorption of the colloids into the bloodstream.
see vasogenic shock (below).
see electrical injuries.
electric shock. See also electrical stunning.
caused by endotoxins, especially Escherichia coli.
See also toxemic
animals in shock develop changes in the gut including congestion and hemorrhage into the lumen.
shock due to reduced blood volume as a result of water deprivation, fluid loss due to diarrhea, vomiting, extensive burns, intestinal obstruction, whole blood loss.
a condition of circulatory insufficiency resulting from overdosage with insulin, which causes too sudden reduction of blood sugar. It is marked by tremor, weakness, convulsions and collapse.
shock which has reached the stage where irreparable damage has been done to tissues, e.g. liver, kidneys and treatment will not salvage the patient although it might prolong life for a long time.
animals in shock due to massive burns, septicemia, disseminated intravascular coagulation (DIC), acute viral or bacterial pneumonias or trauma develop an acute respiratory distress syndrome. The pulmonary lesion is a nonspecific acute or subacute interstitial pneumonia.
a temporary cessation of function in nervous tissue caused by an acute insult such as trauma without the part having been directly or detectably damaged. The loss of function is only temporary, usually for a few minutes but it may last for several hours. There may be residual signs due to direct damage when the shock passes. Stunning by a lightning stroke is an example.
those organs, specific to each animal species, which respond to allergens circulating in the blood.
flaccid paralysis up and down the body from the site of the spinal cord lesion. Accompanied by a fall in skin temperature, vasodilatation and sweating. Signs disappear within an hour or two. There may be residual signs due to physical injury to tissue.
vasogenic shock, vasculogenic shock
shock exists because of the severe reduction in effective circulating blood volume caused by sequestration of blood and other fluids in the vascular system and their withdrawal from the circulating blood. Is the classical shock of traumatic injury, burns, uterine prolapse, extensive surgery.
Patient discussion about shock
Q. SHOCK-WHAT IS IT? clinical anaphylactic shock
A. shock is when the fluid volume in the blood decreases to a dangerous amount. then the body "panics" because most of the organs don't get oxygen and don't remove carbon dioxide and die. so the body start to shut down "unnecessary" organ's blood flow. like skin and such.
this is death closing in on you in minutes.
Q. I was shocked to note that vaccination in the children could cause autism too. Is that true? Very recently I have delivered a cute male baby and I could see a change in me after my delivery in the sense that I always think about him. My sister’s son who is 5 years old is diagnosed with Autism and I just can’t see the sufferings of my sister with him. She experiences difficulty in almost all dealings with him right from brushing, giving bah and making him to study….etc. Now I fear that my son should not get in to autism although I know that this is too early to think about disorder in my son. But as my sister’s son got in to this disorder, this has affected me a lot. Hope you can understand my feelings towards my baby. When I browsed through the net, I was shocked to note that vaccination in the children could cause autism too. Is that true? Can I get some idea…..
A. Hey! I appreciate your care for the new born. But to be honest, fearing at this stage will only trouble you and your baby in the sense that your emotions could catch your baby especially when you breast feed. I want you to be cheerful so as to bring up a healthy child. The signs of autism in the new born are something which should not be thought about at this stage. All you may have to think is to bring up him nicely without any disease. As regards vaccinations that could create autism in children, there is no proof that a vaccine causes Autism. It is only a belief and all the children are vaccinated and not all get autism. It is not a fair idea to suspect vaccination as vaccinations are administered in a new born child after carrying out the necessary tests.
Q. Is electric shock efficient for ocd? Is it dangerous? My husband has OCD for 15 years now. He was also diagnosed with mania-depressia. He takes so many medications and nothing really helps. We were offered to try electric shock and I'm scared. Is it dangerous? What are the chances of this method to work for him?
A. Electroconvulsive therapy (ECT) is indeed considered effective for OCD, although it's not the first line of treatment. It does have its risks, including memory loss, disorientation and sort of confusion. There is also a change in the activity of the heart but it's rarely significant.More discussions about shock
Generally it can be said that it's not an absolutely safe treatment, but it may help, especially if other drugs don't help.
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