-Anything that causes hypoperfusion of the vital organs
-will progress to death unless there is compensation for the abnormalities
Clincial Symptoms of Shock
below 90mm Hg systolic pressure, pale, cool clammy skin, disorientation, decrease cardiac output, weak pulse, no urine production, decrease pH
General Symptoms of Shock
-short of breath
type of shock in which the left ventricle fails to pump enough blood for the body to function
-ischemia, MI, myocardial or pericardial infections, dysrhythmias are all causes
-insufficient intravascular fluid volume from loss of whole blood, blood plasma, interstitial fluid or of whole blood, blood plasma, interstitial fluid or fluid sequestriation outstide the arterial vasculature.
-extent of burn shock is directly related to body surface area burned.
-extent of burn shock directly related to body surface area burned
-20-40% in adults / 8-25% in children requires cardiovascular support (IV fluids)
-within minutes after a major burn, the systemic capillary system permeability increases causing hypovolemic shock and massive edema
-treatment is to infuse more fluid than is being lost.
Neurogenic Shock (Vasogenic Shock)
caused by nerve condition that dilates blood vessels and thus reduces blood flow; loss of sympathetic impulses sent to smooth muscles of blood vessels
-widespread vasodilation from imbalance between parasympathetic and sympathetic stimulation
-persistent vasodilation causing relative hypovolemia
a severe, widespread acute hypersensitivity that occurs when an allergen is introduced to the bloodstream of an allergic individual. characterized by bronchoconstriction, labored breathing, widespread vasodilation, circulatory shock, and sometimes sudden death. antihistamines are inadequate to counter this type of hypersensitivity, but epinephrine relieves the symptoms by dilating the bronchioles, increasing cardiac output, and restoring blood pressure.
Shock syndrome that is frequently fatal, caused by the systemic release of the cytokine TNF-α after bacterial infection of the bloodstream, usually with Gram-negative bacteria.
-also causing relative hypovolemia
Toxic substances made of lipids and carbohydrates associated with the outer membrane of Gram-negative bacteria.
-cause the host to initiate a sever inflammatory process leading to widespread vasodilation and vascular collapse
-seriousness of the burn is determined by the DEPTH and extent of the AREA involved
-Age and health are contributing factors
Major Burn Definition (American Burn Association)
-3rd degree burns on 10% of the body or any burns on face, hands, feet or perineum
-2nd degree burns on >25% body
Rule of 9's
head and neck: 9% ,
Anterior trunk: 18% ,
Posterior trunk: 18% ,
Arms ( 9% each ): 18% ,
Legs (18% each): 36% ,
First Degree Burns
Only the epidermis is damaged. Skin turns red and swollen. Heals after two to three days
-erythema and delayed blistering
-skin function and sensory function maintained
-no treatment necessary unless it is an infant or elderly patient
-the ill effects are usually due to dehydration
Second Degree Burns
deep burns that damage both the epidermis and part of the dermis and may be caused by contact with flames, hot liquids, or chemicals; and form fluid filled blisters and heal with little to no scarring
-superficial partial-thickness and deep partial-thickness
-Erythema, edema, rapid blistering (epidermal/dermal separation), pain (exposed to nerve endings)
-skin buds and hair will reappear
-the amount of scarring is genetic
Third Degree Burns
destruction of cutaneous and subcutaneous tissues; seared, charred, or roasted tissue
-skin function is lost
-involves epidermis, dermis and possibly some subcutaneous tissue
-loss of skin function and sensory function
-white, cherry red or black skin
Metabolic and Inflammatory (cellular) response to Burn Injury
-disruption of membrane potential
-burns initiate a hypermetabolic state (resetting of the hypothalamic thermostat)
-high core temperature and evaporative water loss
-initiates a hypercoagulative response
Discuss the three essential elements of survival of major burn injury.
Ans: The three essential elements of survival of major burn injury are meticulous wound management, adequate fluids and nutrition, and early surgical excision and grafting. All these elements help prevent of treat infection that may result after severe burns. Meticulous wound management is necessary to promote healing and create a wound environment that will successfully support skin grafting. Adequate fluids are needed to counteract burn shock initially and then to replace the fluid loss through the burn site. Increased caloric intake is necessary to provide energy for wound healing. Early surgical excision and grafting aid in wound healing and decrease the risk of subsequent infection at the injury site.
Differentiate among first-degree, second-degree and third-degree burns. Give an example of each.
Ans: A first-degree burn is an epidermal injury in which skin functions and barrier protections are maintained. It is characterized by redness, pain, and tenderness to touch. In large first-degree burns, localized edema, chills, headache and nausea or vomiting may occur. Blisters do not occur immediately, although they may be present after 24 hours. The skin will usually peel in 24 to 48 hours and heal within 5 days. Sunburn is an example of a first-degree burn...A second-degree or partial-thickness burn is an epidermal and dermal injury in which skin functions and barrier protections are absent but skin appendages are maintained. Second-degree burns can be either superficial or deep depending on the depth of dermal injury. They are very painful. An example of a second-degree burn is a thermal burn from a hot liquid. Superficial second-degree burns are characterized by the immediate development of fluid-filled blisters. The skin is red to pale ivory and moist because of the lost of vapor barrier. The injury heals in 21 to 28 days with the possibility of scarring depending on genetic predisposition and the amount of time the injury takes to heal...A third-degree or full-thinkness burn is an injury that affects all layers of skin including epidermis, dermis, and subcutaneous tissue. It may even involve bone and underlying tissues. All skin appendages, skin functions, and barrier protections are lost. Blisters are rare. There is no associated pain. The skin color is cherry red, white, or black. It looks dry, think, and papery or dry and leathery. It will heal only with skin grafting. Scarring usually occurs.
What is cardiogenic shock and what causes it?
Ans: Cardiogenic shock is caused by the heart's inability to pump blood to the tissues and end organs adequately such as from a myocardial infarction or a massive episode of myocardial ischemia. In this type of shock, here is constant hypotension and hypoperfusion of the tissues because of cardiac dysfunction. Conditions that lead to cardiogenic shock include contractility reduction, diastolic filling impairment or an obstruction.
Explain the progression of septic shock.
Ans: Septic shock beings with an infection that is either recognized or may be hard to locate. Afterward the bacteria gets into the bloodstream, which causes bacteremia by either being induced directly from the infection site or from toxic substances secreted by the bacteria.
What are the clinical manifestations of respiratory failure in MODS?
Ans: The clinical manifestations are caused by damage to the inflammatory mediators, tissue hypoxia, and hypermetabolism. Respiratory failure is indicated by tachypnea, pulmonary edema with crackles, diminished breath sounds, use of accessory muscles, and hypoxemia.
Why is fluid resuscitation so important in burn injuries?
Ans: With severe burn injury, an enormous amount of fluid is lost from the body's circulating volume. The only way to correct it is by replacement, such as Ringer solution, which allows the circulating blood volume to be restored by increasing the permeability of the capillaries.
Billy, 42, suffered third-degree burns over 70% of his body when his charcoal grill exploded in front him after he accidentally dropped a can of lighter fluid in the grill. What is considered the most reliable indication that his condition is improving?
Ans: Urine output is considered the most reliable indicator. Because Billy receives sufficient IV fluids, he should be excreting 30 to 50 ml/hr or urine.
The final common pathway in all shock is:
Ans: Impairment of cellular metabolism
Exp: A final outcome of impaired cellular metabolism is the buildup of metabolic end products in the cell and interstitial spaces.
How does any type of shock cause oliguria?
Ans: By decreasing the perfusion to the kidneys
Exp: Low urine output is a classic sign of shock
The renin-angiotensin-aldosterone system compensates for hypovolemic shock by stimulating:
Ans: Aldosterone release, which retains sodium and hence water to increase the blood volume
Exp: In the kidneys, renin (through several intermediaries) stimulates aldosterone release and the retention of sodium (and hence water), whereas antidiuretic hormone (ADH, or vasopressin) from the posterior pituitary gland increases water retention.
Hypovolemic shock begins to develop when intravascular volume has decreased by ______
Exp: Hypovolemic shock begins to develop when intravascular volume has decreased by about 15%.
_____ shock is often more severe than other forms because of its sudden, rapid systemic vasodilation.
Exp: Anaphylactic shock is often more severe than other types of normovolemic shock because the hypersensitivity reaction that triggers vasodilation has other pathophysiologic effects that rapidly involve the entire body.
What type of shock results from the decreased systemic vascular resistance (SVR)?
Exp: Clinical manifestations of septic shock are persistent low arterial pressure, low SVR from vasodilation and an alteration in oxygen extraction by all cells.
For which type of shock would antihistamines and corticosteroids be prescribed?
Exp: Epinephrine is administered to decrease mast cell and basophil degranulation, cause vasoconstriction, and reverse airway constriction. Volume expanders (e.g., lactated Ringer solution) are given intravenously to reverse the relative hypovolemia, and antihistamines and steroids are given to stop the inflammatory reaction.
A clinical syndrome involving a systemic response to infection, which is manifested by two or more of the systemic inflammatory response syndrome (SIRS) criteria is the definition of:
Exp: Sepsis is a systemic response to infection that is manifested by two or more of the SIRS criteria.
What mechanism causes organ injury in primary MODS?
Ans: Impaired perfusion
Exp: In primary MODs the organ injury is directly associated with a specific insult, most often ischemia or impaired perfusion from an episode of shock or trauma, thermal injury, soft tissue necrosis, or invasive infection.
Blistering of the skin occurs in _____ burns.
Ans: Superficial second-degree
Exp: The hallmark of superficial partial-thickness injury is the appearance of thin-walled, fluid-filled blisters that develop within just a few minutes after injury.
Acute burn injury results in _____ shock.
Exp: Burn shock consists of a hypovolemic cardiovascular component and a cellular component. Hypovolemia associated with burn shock results from massive fluid losses from the circulating blood volume.
The fluid most often used in fluid resuscitation following a major burn injury is:
Ans: Lactated Ringer
Exp: Lactated Ringer solution is used because it closely approximates extracellular fluid, the repository of fluid leaving the circulatory system during this phase of extensive edema formation.
The most reliable criterion of adequate fluid resuscitation following a major burn injury is:
Ans: Urine output
Exp: The most reliable criterion for adequate resuscitation of burn shock is urine output
The endpoint of burn shock is defined as the time when the individual is able to:
Ans: Maintain adequate urine output for 2 hours
Exp: The endpoint of burn shock is defined as the state in which the individual is able to maintain urine output for 2 hours with the intravenous fluid administration rate equal to the individuals calculated maintenance rate.
Burn injury induces almost immediate:
Exp: Burn injury induces a hypermetabolic state that persists until wound closure.
The shock is the outcome of a widespread hypersensitivity reaction known as anaphylaxis.
Results from the inability of the heart to pump adequate blood to tissues and end organs from any cause, the most common being within hours of an acute myocardial infarction or severe episode of myocardial ischemia.