Introduction

• Definition of Shock • Types and Etiology of Shock • Signs and Symptoms of Shock • Case Study – Body’s Response to Shock – Treatment of Shock – Prevention • How to treat someone in anaphylactic shock • Management of anaphylaxis in a hospital setting.

Shock, what is it?

• Shock is a critical condition caused by a sudden drop in blood flowing through the body secondary to circulatory system failure (an inadequate blood flow causing insufficient delivery of oxygen & nutrients to meet the metabolic needs of tissue).

• This can damage multiple organs

Types of Shock:

• Cardiogenic Shock • Hypovolemic Shock • Vascular/Distributive Shock – Septic Shock – Neurogenic - caused by damage to the nervous system – Anaphylactic - caused by allergic reactions

Cardiogenic Shock

• This type of shock is associated with heart problems. It is due to a reduction in cardiac output caused by a primary cardiac disorder.

•

Example

: severe myocardial infarction/ Cardiac failure!

Hypovolemic Shock

• This type of shock is caused by deficiency of intravascular blood volume and the inability to meet the metabolic needs of tissues.

•

Example

: Hemorrhage and dehydration

Vascular/Distributive Shock

• This type of shock is characterized by the loss of blood vessel tone, enlargement of the vascular compartment, and displacement of the vascular volume from the systemic circulation.

• Venous return is decreased in distributive shock, which leads to a diminished cardiac output but not a decrease in total volume; this type of shock is also referred to normovolemic shock.

• This type of shock is a systemic response to a severe infection.

Neurogenic Shock

• This type of shock is caused by decreased sympathetic control of blood vessel tone. This is due to a defect in the vasomotor center located in the brain stem.

• Example: Output from the vasomotor center can be interrupted by brain injury, the depressant actions of drugs, general anesthesia, hypoxia, or lack of glucose.

Anaphylactic Shock

• This type of shock is considered the most severe systemic allergic reaction. It results from an immunologically mediated reaction in which vasodilator substances such as histamine are released into the blood. • This causes vasodilation or arterioles and venules along with a marked increase in capillary permeability.

Causes of anaphylaxis

• Drugs – Penicillin • Foods – Nuts – Shellfish • Environmental – Insect venoms – Latex

Early signs/symptoms of Anaphylatic shock:

• Hypotension • High pulse rate: weak and rapid • Dyspnea, coughing, choking, wheezing, and chest tightness • Tachypnea/ hyperventilation • Dry mucous membranes • Burning & warming sensation of the skin, itching, and urticaria (hives) • Restlessness • Anxiety or agitation • Nausea, abdominal cramps • Thirst • Weakness • WBC - elevated eosinophil count due to allergic reaction

Late symptoms of Anaphylactic shock:

• Decreased urinary output • Severe fluid and electrolyte imbalance • Confusion • Hypothermia • Drowsiness • Diaphoresis, moist skin • Lethargy, that can lead to coma

Case Study

C.L. is a 35-year-old male who is admitted to your floor with a c/c of right flank pain.

9:00 am The M.D. leaves the following orders:

R/O right renal calculi V/S q 4 h BR with BRP Strain all urine Strict I & O CBC, SMAC 20, Chest x-ray, EKG Intravenous Pylogram (I.V.P.) this AM D5 2 N/S 300 cc/hr.

Demerol 100 mg IM q 4 h prn for pain

At 9:05 am the nurse clarifies the M.D. orders:

R/O right renal calculi V/S q 4 h BR with BRP Strain all urine Strict I & O CBC, SMAC 20, Chest x-ray, EKG Intravenous Pylogram (I.V.P.) this AM D5 2 N/S 300 cc/hr.

Demerol 100 mg IM q 4 h prn for pain

10:00 a.m

• •

You accompany C.L. for his I.V.P. The tech administers the contrast medium I.V.

10:05 a.m.

Within minutes C.L. c/o his lips feeling tingly, his tongue swollen and that he has difficulty swallowing and breathing. He states, "I feel like I'm dying." You place him in semi-fowlers and take his v/s.

R 30 with progressive difficulty and stridor Wheezes heard on auscultation.

B/P 80/60 P 120 thready Skin flushed, dry

10:10 a.m.

Epinephrine (1:1000) 1.0 ml S/C is given STAT - IV #1 is changed to 0.9% N/S 1000 cc - A second I.V. is initiated with 0.9% N.S. Both IV's are rapidly infusing.

- Arterial Blood Gases (ABGs) are drawn and sent stat.

- Oxygen at 100% via mask is applied.

10:20 a.m.

Vital Signs: B/P: 84/68 PR: 124 bounding RR: 26 S.O.B. noted; decreased stridor, decreased wheezes noted.

Dopamine gtt. is hung - to be titrated to maintain systolic > 80 to 110 mmHg.

10:30 a.m.

Vital Signs: BP:92/68 HR:120 Reg.

RR:24 •lungs clear throughout without wheezing or stridor.

•Patient c/o that he "feels itchy all over.“ You note urticaria diffusely over his body. • Benadryl 75 mg IM is given STAT with some relief.

10:45 a.m.

Vital Signs • BP: 108/170 • PR: 100 Reg • RR: 22 • Patient A & 0 x3. Skin cool, flushed and dry. • Minimal S.O.B. noted without diaphoresis, wheezes or stridor. • Patient states that he is breathing easier and has decreased itching. • Cardiac monitor ---> Normal Sinus Rhythm (NSR).

• IV #1 0.9% N/S rapidly infusing in the right antecubital space.

• I.V.#2 0.9% N/S rapidly infusing in the left antecubital space. • Dopamine gtt @ 4 mcq/kg/min infusing.

• ABG results: pH 7.31

PO 2 95 CO 2 35 HCO 2 19 O 2 Sat 99

• Transferred to M.I.C.U. • Dr. Jones in attendance.

• M.Smith, R.N.

Question 1:

As the primary nurse in charge of C.L’s care, you check his chart for allergies. You note that he is only allergic to “shellfish”. What, if any, is the connection between an allergy to shellfish and contrast medium?

Differences between a CM allergy and a Shellfish allergy

Contrast Medium (CM) Allergy CM is an iodine based substance used in radiology. CM can cause allergic reaction r/t to either Iodine itself or the dye component of CM.

Allergy to the IV dye is not a true allergy • The dye causes the direct release of histamine and other chemicals from mast cells without the help of allergic antibodies Shellfish Allergy Shellfish contains iodine, but allergy to shellfish is caused by the protein tropomyosin and NOT the iodine component.

Relation between a Contrast Medium and Shellfish Allergy

No Correlation btw Allergy to shellfish and CM !

Allergy to Iodine should be tested independently whether allergy to fish is present or not.

Contrast Medium

It is generally used to improve the visibility of internal bodily structures in an x-ray image.

Question 2 & 3:

What is the pathophysiology behind Anaphylactic Shock?

What chemical mediators are responsible for vasodilation and increased capillary permeability?

Pathophysiology of Shock

Immunologic Disorders

There are three levels of immunologic disorders: •Hypersensitivity – allergy response • Autoimmune Disease – body’s response against self-antigens • Immunodeficiency – the immune response is below normal

Hypersensitivity

Hypersensitivity is an immune response that is beyond normal and is damaging rather than beneficial

Hypersensitivity

There are 4 classes of hypersensitivity: • Type I (anaphylactic) reaction • Type II (cytotoxic) reaction • Type III (immune complex) reaction • Type IV (delayed cell-mediated) reaction

Hypersensitivity – Type I (anaphylactic) reaction

Type I (anaphylactic) reaction can be: • Localized • Systemic

Hypersensitivity – Type I (anaphylactic) reaction

Localized anaphylactic reaction:

• Usually ingested or inhaled allergens • Symptoms include: – Hives – Asthma – Hay fever

Hypersensitivity – Type I (anaphylactic) reaction

Systemic anaphylactic reaction

• Usually injected allergens, but can be ingested • Very quick response • Symptoms include: – coughing – edema – drop in blood pressure – possibly death

Hypersensitivity

• Upon the first exposure to an allergen a person will not necessarily develop a response.

• Antibodies (Immunoglobins (Ig) will be formed after the first exposure to fight off the same allergen upon a second exposure.

Mechanism of Type I (anaphylactic) Hypersensitivity

• Specifically Immunoglobin E (IgE) is found floating around the cell and also bound to basophils and mast cells • When an allergen enters the body the allergen will bind with IgE on the basophils and mast cells

Mechanism of Type I (anaphylactic) Hypersensitivity

• A signal transduction pathway will tell the cell to degranulate and release chemical mediators such as histamines, leukotrines, and prostaglandins

Mechanism of Type I (anaphylactic) Hypersensitivity

• Chemical mediators cause dilation and leakage of plasma from capillaries, airway constriction, and increased mucus production • This, in turn, can cause itching, swelling, and pain

Chemical Mediators

• Many chemical mediators of inflammation are released by Human Mast Cells and Basophils including:

Mediator

Histamine Prostaglandin Platelet-activating factor (PAF) Leukotrienes Neutral Proteases Acid Hydrolases Heparin Superoxide dismutase

Chemical Characteristics

Simple Amine Simple Amine Phospholipid Acid lipid Small protein enzymes Fairly large proteins Peptide chain bearing long chain sulfated amino sugars Enzymatic protein

The three most responsible for vasodilation and increased capillary permeability are:

1) Histamine 2) Prostaglandin 3) Leukotrienes

Histamine

 Once histamines are released into the tissues, they exert a variety of effects:  Contracts visceral smooth muscle  Causes inflammation  Increases permeability of capillaries  Increases respiratory mucous gland activity  Produces sensation of itching  Dilate Blood Vessels  Stimulate gland secretion  Prompt the release of proteins from cells  These effects, in turn, help the body rid itself of foreign invaders  Dilation of blood vessels increases circulation to the injured area, washing away harmful bacteria  Proteins also attract other immune cells to the area, such as macrophages.

Leukotrienes

• Leukotrienes are inflammatory mediators that cause vasodilation and mucosal swelling, which results in inflammation and congestion.

• Leukotrienes are also responsible for: – Prolonged visceral smooth muscle spasm – Increased permeability of venules

Prostalglandin

• Prostalglandins are mediators that have strong physiological effects: – Vasodilation – Bronchodilation – GI tract smooth muscle contraction – stimulates constriction and clotting of platelets – Increases mediator release by basophils

Chemical Mediators

Inflammation

• Caused by the release of histamine from basophil or mast cells • Directly effects epithelial cells of vessel wall – Pulls the epithelial cells apart from each other – Installs cell adhesion molecules (CAM) on the surface of the vessel wall • Causes leukocytes to stick to the CAM on the sides of the vessel wall • Leukocytes then squeeze through the gaps created by the epithelial cells

Inflammation

• When leukocytes reach their target, they secrete more cytokines, which recruit more neutrophils and macrophages • Leukocytes secrete colony stimulating factor, which causes the bone marrow to create more leukocytes

07/31/08

Inflammation

Inflammation

Inflammation

Question 4:

How is the Cardiovascular System affected by anaphylaxis?

In anaphylaxis, the cardiovascular symptoms are:

-Hypotension -Vasodilation occurs when the muscular walls of the arteries dilates and relaxes causing the cardiac output to decrease and peripheral vascular resistance.

-Increased capillary permeability leads to the leakage of fluid through the epithelium from the blood to the interstitial fluid.

-Vasodilation and increased capillary permeability causes hypovolemia -Tachycardia - is a result to compensate for the low blood volume circulating through the body

Question 5:

How is the Pulmonary System affected by anaphylaxis?

The Effects of Shock on the Pulmonary System

The Effects of Shock on the Pulmonary System

Question 6:

What are some complications that can result from Anaphylactic Shock?

Complications of Anaphylactic Shock

• Airway Blockage • Cardiac or respiratory arrest • Arrhythmias • Laryngeal edema • Myocardial ischemia • Hypoxia -Prolonged hypoxia [possibly leading to brain injury • Death

Multiple Organ Failure

• Brain: - Ischemia encephalopathy: Decrease of tissue perfusion in the brain.

• Heart: -Coagulation necrosis: Decrease of tissue perfusion in the brain.

-Subendocardial hemorrhage: large amount of blood loss in inner layer of myocardium.

-Contraction band necrosis: inability of myocardial cells to contract.

• Kidneys: -Tubular ischemia injury causing oliguria: decreased urine output.

-Anuria: absence of urine -Electrolyte disturbances

Multiple Organ Failure Continued

• Lungs: -Shock lung: edema, impaired perfusion, reduction in alveolar space causing atelectasis and impaired breathing.

• Adrenals : -Cell lipid depletion • GI: -hemorrhagic enteropathy: hemorrhage and necrosis of intestinal lining • Liver: -fatty deposits or central hemorrhagic necrosis

Widespread Tissue Hypoxia

Oxygen deficit from decreased respiration rate This lowers the pH of tissues and organs and causes vasodilatation Vasodilatation debilitates cardiac output Causes intracellular aerobic respiration to cease Anaerobic respiration takes over Lactic acid is produced and causes the pH of the blood to decrease Anaerobic respiration produces lactic acid With decreased cardiac output the tissues are at risk for hypoxic injury If not corrected immediately, irreversible damage can take place and death can ensue .

Question 7:

How do the following affect hemodynamic stabilization?

A- Rapid Infusion of IV fluids. (2-3 L in 20-30 min) B- Epinephrine C- Dopamine

Hemodynamic Stabilization: Restoring the Rate and Rhythm of the Heart • Rapid Infusion:  2-3 Liters of fluid in 20-30 minutes. -This increases blood volume.

-Isotonic solution is used (e.g. 0.9% saline)

Hemodynamic Profile: Characteristic of Shock State

• Systolic arterial pressure less than 90 mm Hg or 30 to 60 mm Hg below the previous baseline level.

• Evidence of decreased blood flow to major organ systems: - Urine output less than 20 ml/hour, usually with decreased sodium content - Peripheral vasoconstriction associated with cold, clammy skin - Impaired mental function • Cardiac index less than 2.1 L/min/m 2 • Evidence of left-sided heart failure with LVEDP/pulmonary capillary wedge pressure (PCWP) greater than 18 to 21 mm Hg.

Hemodynamic Stabilization: Epinephrine and Dopamine

• Vasopressor agents -Stimulate alpha receptors to vasoconstrict, which increases arterial blood pressure and resistance to ventricular ejection.

-Stimulate beta receptors to increase contractility.

• Both effects are beneficial to the stabilizing of circulation.

-Possibility of danger because both effects increase need for oxygen increasing myocardium infarction.

• Use of Vasopressor usually limited to extreme hypotension that no other therapy will have an effect.

Epinephrine

• Vasopressor • Antagonizes the effects of Histamine • Relaxes smooth muscle of bronchi • Positive chronotropic and inotropic effects on heart • Raises blood sugar • Rapid IV infusion: direct stimulation of heart and increases systolic blood pressure • Slow IV infusion: increase in systolic pressure and decrease in diastolic

Dopamine

• Vasopressor • Increases pumping strength and function of heart and kidney blood supply.

• Selective vasodilator by redirecting blood flow to critical organs.

• Increases cardiac output • Causes vasoconstriction which increases the systemic vascular resistance.

• Dopamine is typically used in septic shock or cardiogenic shock.

Question 8:

What is the rationale for giving Benadryl 75 mg IM stat to C.L.?

Why Benadryl?

 Benadryl has “antihistamine and antipruritic effects” Benadryl is given to "competitively block the effects of histamine at H1 receptor sites." Benadryl therefore works to combat the increase of histamines that his body produced in response to the allergy.

So is the dosage correct?

 75mg IM of Benadryl is an appropriate dose to administer to CL because Benadryl can be administered “10-50mg IV or deep IM up to 100mg if required”

Question 9:

Interpret C.L.’s ABGs?

What is normal?

pH 7.35-7.45

HCO2 22-26 pO2 80-100 SaO2 95-100% CO2 35-45

pH pO2 CO2 HCO2 SaO2

Clients ABG Results

7.31

95 35 19 99 low Normal Normal low Normal

ABG Interpretation

Question 10:

List, in priority order, three nursing diagnoses

Prioritized Nursing Diagnosis 1 2 3 • Ineffective Airway Clearance R/T constricted airways • Decreased cardiac output R/T insufficient blood volume • Decreased peripheral tissue perfusion R/T vascular dilation

Question 11:

Before C.L. is discharge from the hospital, what needs to be taught to him in terms of patient education, re: his allergic reaction?

Education

 Foods that may cause an allergic response  When dining out, ask the chef if foods may contain minor traces of shellfish  Environmental allergies  How to react to anaphylactic shock  When diagnostic testing make sure patient has not prior allergies to contrast medium

Education

 Educate about the use and importance of EpiPens and Epinephrine pumps  Medical I.D. bracelets or watches could be purchased for ease of allergy recognition. These bracelets states the person’s name, medical condition, specific allergens that cause anaphylatic shock.

Epinephrine

• EpiPen is a prescribed medication by a physician who will educate the proper technique of using this device.

• Patients are encourage to use the medication before the device’s expiration date.

• However, it has no adverse affects if used after the expiration date

EpiPen

Adult: one adult auto-injector (0.3 mg) Infant and child: one infant/child auto-injector (0.15 mg)

Question 12:

How might this incident have been avoided?

Prevention

• Learn about situations that can trigger a response or increase risk of exposure • Participate in precautionary measures such as skin tests and use of antihistamines or corticosteroids prior to exposure of possible triggers • Wear a tag that identifies any allergies • Always look at labels and be aware of ingredients

Emergency Plan

• Despite using all possible preventative measures, it is not always possible to avoid an allergic reaction. • Have a written emergency plan and make it available to places frequently visited such as school and work • If at high risk, carry an EpiPen

What to do if you find someone is in anaphylatic shock?

• Call 911 • Check ABC • Ask bystanders the events leading up to anaphylatic reaction • Continuously check the rate of breathing • Place the patient in shock position if conscious and without injuries.

[ Lie flat, elevate legs/ high-flow oxygen, support airway and assist ventilation as required.]

What to do if you find someone in anaphylatic shock?

• Continuously check the rate of breathing • Place the patient in shock position if conscious and without injuries.

• Keep the patient warm and comfortable

Management of Anaphylaxis in a hospital setting:

• http://video.aol.com/video-detail/anaphylactic shock-when-allergies-are-deadly/2165467462