Perfusion 3 - Types of Shock

True or false? More than one type of shark can be present at the same time

True. For example, trauma caused by a car crash may trigger hemorrhage, leading to hypovolemic shock, in a myocardial infarction leading to cardiogenic shock

Shock is classified by the type of impairment causing it:

- hypovolemic shock - cardiogenic shock - distributive shock (septic shock, neurogenic shock, anaphylactic shock) - obstructive shock

Nonprogressive (compensatory) stage of hypovolemic shock

Occurs when MAP decreases by 10 to 15 mmHg from baseline

Progressive stage of hypovolemic shock

Occurs when there is a sustained decrease in MAP of more than 20 mmHg from baseline. Vital organs develop hypoxia, and less vital organs become anoxic and ischemic. As a result of poor perfusion and a build up of metabolites, some tissues die

Refractory stage of shock and multiple organ dysfunction syndrome

Occurs when too much cell death and tissue damage result from too little oxygen reaching the tissues. Vital organs have extensive damage and cannot respond effectively to interventions, and shop continues. So much damage has occurred with release of metabolites in the enzymes that damage to vital organs continues despite interventions. The sequence of cell damage caused by massive release of toxic metabolites and enzymes is termed MODS. Once damage has started the sequence cycles and more dead and dying sells open and release metabolites. Small clots microphone by or triggered to form, which block tissue perfusion and damage more cells. Liver, heart, brain, and kidney function are lost first. Most profound change is damage to the heart muscle.

Health promotion and maintenance of hypovolemic shock

Prevent dehydration with adequate fluid intake. Prevent trauma and hemorrhage by using proper safety equipment and seatbelts and being aware of hazards in home or work place. Assess all patients with invasive procedures or trauma for obvious or occult impaired clotting with bleeding. Compare pulse quality and rate with baseline. Compare urine output with fluid intake. Check vital signs of patients who have persistent thirst. Assess for shock in any patient who develops a change in mental status, an increase in pain, or an increase in anxiety. Teach patients outside the hospital the manifestations of shock. Stress the importance of seeking immediate help for obvious heavy bleeding, persistent thirst, decreased urine output, lightheadedness, or a sense of impending doom.

Manifestations of refractory stage of shock and MODS

Rapid loss of consciousness, non-palpable pulse, cold and dusky extremities, slow and shallow respirations, unmeasurable measurable oxygen saturation. Therapy is not effective in saving patient's life, even if calls of shock is corrected and M AP temporarily returns to normal

Manifestations of the non-progressive stage of hypovolemic shock

Subjective: thirst and anxiety. Objective: restlessness, tachycardia, increased respiratory rate, decreased urine output, falling systolic blood pressure, rising diastolic blood pressure, narrowing pulse pressure, cool extremities, and a 2 to 5% decrease in oxygen saturation

Although the causes and initial manifestations associated with the different types of shock very, eventually the effects of hypotension and anaerobic cellular metabolism (metabolism without oxygen) result in

The common key features of shock

Cardiogenic shock occurs when

The heart muscle is unhealthy and pumping is impaired. Myocardial infarction is the most common cause of direct pump failure. Any type of pump failure decreases cardiac output and MAP

Capillary leak syndrome

The response of capillaries to the presence of body chemicals that in large capillary pores and allow fluid to shift from the capillaries into the interstitial tissue, these fluids are stagnant and cannot deliver oxygen or remove tissue waste products. Problems causing fluid shifts include severe burns, liver disorders, ascites, peritonitis, large wounds, kidney disease, hypoproteinemia, and trauma.

Hypovolemic shock occurs when

Too little circulating blood volume decreases MAP, resulting in inadequate total body perfusion and oxygenation. Common problems leading to hypovolemic shock our poor clotting with hemmorhage and dehydration

Manifestations of progressive stage of hypovolemic shock

Worsening of changes resulting from decreased tissue perfusion. Subjective: Impending doom, confusion, increased thirst. Objective: rapid, weak pulse, low blood pressure, pallor to cyanosis of oral mucosa and nail beds, cool and moist skin, anuria, and a 5 to 20% decrease in oxygen saturation. Laboratory data at the stage may show low blood pH along with rising lactic acid and potassium levels

Shock is often a result of?

Cardiovascular problems

Shock

Widespread abnormal cellular metabolism that occurs when gas exchange with oxygenation and tissue perfusion needs are not met sufficiently to maintain cell function. It is a condition rather than a disease and is the whole body response that occurs when two little oxygen is delivered to the tissues. All body organs are affected

Chemical-induced distributive shock

3 common origins: anaphylaxis, sepsis, and capillary leak syndrome. It occurs when certain body chemicals or foreign substances in the blood and vessel start widespread changes in blood vessel walls. The chemicals are usually exogenous, but this type of shock can be induced by substances normally found in the body, such as excessive amounts of histamine.

Sepsis

A widespread infection that triggers whole body inflammation. It leads to distributive shock when the infectious microorganisms are present in the blood and is most commonly called septic shock.

Anaphylaxis

An extreme type I allergic reaction. It begins within seconds to minutes after exposure to a specific allergen in a susceptible person. The result is widespread loss of blood vessel tone, with decreased blood pressure and decreased cardiac output

Distributive shock occurs when

Blood volume is not lost from the body but is distributed to the interstitialbtissues where it cannot oerfuse orgabs. It can be caused by blood vvesselbdilation, pooling of blood in. Cenous and capillary beds and increased capillary leak. All these factors derease MAP and may be started either by nerve changes (neural induced) or by the presence of some chemicals (chemical induced)

Physical assessment/clinical manifestations of hypovolemic shock:

Cardiovascular changes: decreased mean arterial pressure leading to compensatory responses. Assessed central and peripheral pulses for rate and quality. Increased heart rate is the first manifestation of shock. Because stroke volume is decreased the peripheral pulses are difficult to palpate and are blocked with light pressure. As shock progresses peripheral pulses may be absent. Compare blood pressure with patient's normal baseline. Nearer pulse pressure. Oxygen saturation: pulse oximetry values between 90 and 95% occur with nonprogressive stage of shock, values between 75 and 80% occur with progressive stage of shock. Any value below 70% is considered life-threatening emergency and may signal refractory stage of shock. Respiratory changes: assess rate and depth of respiration. Respiratory rate increases during shock to ensure that oxygen intake is increased so it can be delivered to critical tissues. When shock progresses to stage which lactic acidosis is present the respiratory depth also increases.

Obstructive shock

Caused by problems that impair the ability of the normal heart to pump effectively. The heart itself remains normal, but conditions outside the heart prevent either adequate filling of the heart or adequate contraction of the healthy heart muscle. The most common cause of obstructive shock is cardiac tamponade

Assessment of shock

History: ask about risk factors related to hypovolemic shock. Ask about recent illness, trauma, procedures, or chronic health problems that may lead to shock (ex. G.I. ulcers, general surgery, hemophilia, liver disorders, prolonged vomiting or diarrhea). Record age (shock from trauma is more common in young adults and other types of shock are more common in older adults). Ask about aspirin use, other NSAIDs. Ask last 24 hour fluid intake and output. Areas to examine for poor Claudine and hemorrhage include the Gumm's, Williams, and sides of dressings, drains, and vascular accesses. Also check under patient for blood. Observe for any swelling or skin discoloration that may indicate internal hemorrhage.

Neural-induced distributive shock

Loss of MAP that occurs when sympathetic nerve impulses are decreased and blood vessel smooth muscles relax, causing vasodilation and poor perfusion. Shock results when vasodilation is widespread (loss of sympathetic tone)