Chapter 19- Shock

What is the most common cause of cariogenic shock? 1.) Pancreatitis 2.) Anaphylactic Shock 3.) Acute Myocardial Infarction 4.) Gastrointestinal bleed

ACUTE MYOCARDIAL INFARCTION RATIONALE: Acute myocardial infarction is the most common cause of cardiogenic shock due to the problem of cardiac pump failure occurring. Shock related to pancreatitis and gastrointestinal bleed is generally hypovolemic shock. Shock related to anaphylaxis, or anaphylactic shock, is a type of distributive shock.

Progressive Stage

systemic circulation continues to constrict in the attempt to maintain blood flow to vital organs -Decrease of peripheral blood flow = weak, absent pulses -blood becomes thicker (viscous) because blood volume decreases

A pt. in anaphylactic shock has massive edema. What would explain this condition? 1.) Increased capillary permeability 2.) Pooling of blood in dependent parts of the body 3.) Retention of excess water by the kidneys 4.) Overproduction of antidiuretic hormone

Increased capillary permeability RATIONALE: Massive edema with anaphylactic shock is related to increased capillary permeability resulting from the release of chemicals that dilate vessels in response to a severe allergic reaction. Pooling of blood occurs in all peripheral tissues and not just in dependent parts of the body, leading to decreased venous return and a decrease in cardiac output. The kidneys do not retain excess water, but kidney output is decreased due to the decrease in cardiac output. There is not overproduction of antidiuretic hormone.

Which acid-base disturbance should the nurse anticipate with the intermediate or progressive stage of shock? 1.) Metabolic Alkalosis 2.) Respiratory Acidosis 3.) Metabolic Acidosis 4.) Respiratory Acidosis

METABOLIC ACIDOSIS Rationale: As shock progresses, cells are deprived of oxygen and resort to anaerobic metabolism, with production of lactic acid resulting in metabolic acidosis. Metabolic alkalosis results from an increase in bicarbonate levels or a loss of hydrogen ions caused by prolonged nasogastric suctioning, excessive vomiting, diuretics, and electrolyte disturbances. Respiratory alkalosis is generally caused by hyperventilation and is marked by a low PaCO2 with a resultant rise in pH. Respiratory acidosis occurs when the respiratory system doesn't eliminate enough carbon dioxide to keep the normal acid-base balance, leading to a buildup in carbonic acid and a decrease in pH.

Hypovolemic Shock

Occurs when the circulating blood volume is inadequate to maintain the supply of O2 & Nutrients. - excessive loss of blood, plasma -Rapid blood loss = hypovolemic shock -Associated with diarrhea, vomiting, excessive perspiration, burns, pancreatitis, intestinal obstruction -S/S: Rapid HR, Low BP, shallow breathing, little, no urine output

Multiple Organ Dysfunction Syndrome (MODS)

When one or more organs begin to fail

Cardiogenic Shock

When the heart fails as a pump - decreased myocardial contractility = decreased cardiac output and impaired tissue perfusion. -70-90% mortality rates -Other causes; dysrhythmias, cardiomyopathy, myocarditis, valvular disease

Septic Shock

a systemic inflammatory response to a documented or suspected infection. -tissue perfusion = metabolic acidosis -develops when pathogenic organisms release toxic substances that cause blood vessels to DILATE, decreasing vascular resistance & Increasing permeability

A pt. is admitted to the emergency department in distributive shock. Which of the following factors can lead to distributive shock? (Select all that apply) 1.) Bacterial Infection 2.) Blood or Fluid Loss 3.) Dilation of blood vessels 4.) An antigen-antibody reaction 5.) Failure of the heart as a pump

Bacterial Infection, Dilation of blood vessels, An antigen-antibody reaction RATIONALE: Distributive shock refers to widespread vasodilation. This type of shock causes the blood to be improperly distributed. Distributive shock is not related to blood or fluid loss. Antigen-antibody reaction is related to anaphylactic shock, which is a type of distributive shock. Cardiogenic shock is when the heart fails as a pump.

What are the four types of shock?

-Hypovolemic (inadequate circulation volume) - Cariogenic (decreased myocardial contractility) -Obstructive (inadequate circulatory blood flow) -Distributive (widespread vasodilation)

4 stages of shock:

1- initiation 2- Compensatory 3- Proressive 4- Refractory

Definition of SHOCK

A syndrome characterized by inadequate tissue perfusion resulting in impaired cellular metabolism

To replace water and electrolytes, what fluid is administered?

Crystalloids

Refractory stage

Irreversible; shock and total body failure

3 Types of Distributive Shock

-Anaphylactic -Septic -Neurogenic Problem is NOT LOSS of blood, but excessive dilation of blood vessels or decreased vascular resistance, causing blood to be improperly distributed

Obstructive Shock

Blood flow is reduced and prevented to enter or leave the heart by a mechanical obstruction -lack of blood flow = circulatory arrest -heart stops pumping blood through body Causes: -tension pneumothorax (collapse of lung, increase of intrathoracic pressure) -Pericardial tamponade: fluid collects in pericardial sac -Pulmonary embolus ( blockage of pulmonary artery or 1 or more brances, resulting in SOB)

A pt. in shock has been given blood, crystalloids, and osmotic fluids. The nurse's assessment reveals: PR 80bpm, bounding, regular; RR 30 breaths/min; BP 140/86' dyspnea and crackles throughout lung fields. Which complication should the nurse suspect? 1.) Sepsis 2.) Multiple Organ Failure 3.)Pneumonia 4.) Circulatory Overload

CIRCULATORY OVERLOAD RATIONALE: Signs of circulatory overload include full, bounding pulse; dilute urine; increased respiratory rate; abnormal lung sounds; dyspnea; and edema. Signs of sepsis leading to septic shock include documented or suspected infection; inadequate tissue perfusion related to metabolic acidosis; hypotension; acute encephalopathy; oliguria; or coagulation disorders. Signs of multiple organ failure occur when the tissues of major organs are not perfused and lactic acid builds up, leading to organ dysfunction such as systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Pneumonia can lead to septic shock, hypotension unresponsive to fluid resuscitation, and signs of inadequate tissue perfusion with a decrease in lung sounds.

When pts. have lost LARGE amounts of plasma proteins, which fluid is most appropriate for restoring blood volume? 1.) Packed red blood cells 2.) Crystalloid fluids 3.) Normal Saline 4.) Colloids

COLLOIDS RATIONALE: Blood, crystalloids, and osmotic agents all serve to increase the blood volume. Increased pulse volume, increased blood pressure, and rales and crackles in the lungs in the shock patient suggest circulatory overload. With sepsis, blood pressure normally falls and heart rate increases. Changes in lung sounds occur with pneumonia, but the change in blood pressure (BP) is not expected; heart rate would probably be increased more than 80 bpm. MODS is characterized by tachycardia, and hypotension is more likely than normal to elevated BP.

A patient has developed peritonitis after a traumatic injury to the abdomen. The nurse knows that this pt. is at greatest risk for which type of shock?

HYPOVOLEMIC Rationale: It is the most common type of shock and most often occurs as a result of rapid blood loss. Cardiogenic shock occurs when the heart fails as a pump. Other conditions to ineffective myocardial cell function include dysrhythmias, cardiomyopathy, myocarditis, valvular disease, and structural disorders. Anaphylactic shock occurs as a result of a severe allergic reaction leading to the release of chemicals that dilate blood vessels and increase capillary permeability. Neurogenic shock occurs when a nervous system disruption affects the vasomotor center in the medulla.

The nurse is concerned about cerebral perfusion in a pt. who is in shock. Which assessment provides the best indicator of cerebral perfusion? 1.) Presence of reflexes 2.) LOC (level of consciousness) 3.) Emotional state 4.) Mean arterial pressure

LOC RATIONALE: With shock, a decrease in cerebral perfusion leads to ischemia and a decrease in cerebral blood flow. Therefore, assessing the patient's level of consciousness is the best, first action. Assessment of reflexes may be done after the level of consciousness is determined. The patient's emotional state would be included in the level of consciousness assessment. Determining a patient's mean arterial pressure is included in hemodynamic monitoring and is not as easy or adequate an assessment as determining a patient's level of consciousness.

Which interventions REDUCE the risk of SIRS and MOD in a pt. with pancreatitis? (SAP) 1.) Maintain strict asepsis with invasive procedures 2.) Provide frequent oral care with chlorhexideine gluconate 3.) Position the pt. in High Fowler Position 4.) Practice scrupulous hand washing 5.) Administer enteral feedings as ordered

Maintain strict asepsis, Provide oral care, Practice scrupulous hand washing, administer enteral feedings RATIONALE: Interventions that reduce the risk of systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) in a patient with pancreatitis include maintaining strict asepsis with invasive procedures, providing frequent oral care with chlorhexidine gluconate, practicing scrupulous hand washing, and administering enteral feedings as ordered. The patient should be in a semi-Fowler or semirecumbent position and not a high Fowler position. This position helps to reduce the risk of ventilator-associated pneumonia.

What do anaphylactic shock, septic shock, and neurogenic shock have in COMMON? 1.) Infection 2.) Allergic reaction 3.) Vasodilation 4.) Heart Failure

VASODILATION Rationale: Anaphylactic, septic, and neurogenic shocks are all types of distributive shock and all are related to vasodilation. Infection is related to septic shock but not to anaphylactic or neurogenic shock. Allergic reactions are related to anaphylactic shock but not to neurogenic or septic shock. Heart failure is related to cardiogenic shock.

Compensatory Stage

continued reduction in cardiac output triggers a set of neural, endocrine, & chemical mechanism.

Systemic Inflammatory Response Syndrome (SIRS)

damaged to the endothelium of blood vessels and a hyper metabolic state. -conditions that lead to SIRS - multiple transfusions, massive tissue injury, burns, pancreatitis

Initiation stage

decrease in the delivery of O2, inadequate extraction of oxygen & decreased cardiac output

Anaphylactic Shock

occurs when a person has severe allergic reaction that results in release of chemicals that DIALTE blood vessels & increase capillary permeability -causes constriction of bronchi and airway obstruction -can result with cardiac, renal, pulmonary, and multisystem organ failure

Neurogenic Shock

occurs when disruption in the nervous system affects vasomotor center in the medulla -cause the smooth muscles of blood vessels to CONSTRICT -s/s: bradycardia, warm, dry, pink