Shock and Anaphylaxis Chapter 37 Written by: Melissa Dearing – LSC-Kingwood

Shock- Definition Syndrome associated with an imbalance between the supply of essential nutrients, oxygen and substrate to the tissues of an organ and the metabolic demand of that organ.

Shock – Physiological Changes Organism level Must maintain adequate cardiac output in order to supply cells and tissues with an oxygen-rich environment. Cellular level The cells have to have oxygen to produce energy Without oxygen the cells shift to anaerobic metabolism and begin to produce lactic acid.

Cardiac Output Shock state can be classified based on whether the inadequate cardiac output is related to a problem with: Heart rate Preload Inotropy Afterload

Nutrients and O 2 Cardiac output responsible for delivery of O2 and nutrients to tissue 2 Methods 1: Some nutrients and O2 is dissolved n the blood 2: Most nutrients and O2 are bound to blood cells and carried to the tissues.

Blood Delivery to Tissues Cardiac output carries O2 to the tissue Tissue and cells uptake the oxygen Organ byproducts such as Co2 is then released into the blood stream to be carried back to the lungs

3 Kinds of Shock Hypovolemic Shock Cardiogenic Shock Distributive Shock

Hypovolemic Shock Inadequate amount of preload to be pumped out of the R heart Not enough blood to supply the entire body with nutrients and oxygen Most common type of shock in children Called hemorrhagic shock when RBC are lost from the vascular space Can be due to extracellular fluid loss from: diarrhea, vomiting or inadequate fluid intake

Cardiogenic Shock Directly related to inotropy and afterload Decreased cardiac output due to a problem with the HR, contractility of the heart and afterload HR may slow due to: hypoxia or heart block leading to ↓perfusion and shock. Cardiac arrythmias that produce a HR that is too fast will also ↓perfusion.

Distributive Shock Results from vasodilatation of the vascular bed Loss of afterload and diastolic pressure Can be caused by: Sepsis Neurological insult Anaphylaxis Adrenal insufficiency

Assessment ABC’s of resuscitation Rapid assessment of the airway Breathing Circulation Assessment of Vital Signs Patient Hx

Assessment Examination Fever Skin turgor (rigidity) Bleeding Bruising Trauma Capillary Refill Hemodynamic measurements

Assessment Examination Skin Pale? Cyanotic? Mottled? Cool?

Assessment Examination Brain LOC Response to commands Stuporous? Comatose? Anxiety? Use Glasgow Coma Score

Assessment Examination Visceral organs Monitor urine output Adequate urine production is 1 ml/kg/hr Ensures adequate renal blood flow Assumption can be made that other organs are receiving adequate flow

Monitoring Continuous assessment leads to and follows therapeutic intervention Methods to detect physiological changes: Arterial catheter CVP monitor Pulmonary artery catheter

Treatment Respiratory Vascular Myocardial Function PVR Nutritional Status

Anaphylaxis A type of shock that occurs from peripheral vasodilation. Caused by body’s hypersensitivity to a particular antigen. Examples: Latex Food Drugs Snake venom Bee stings

Anaphylaxis Pathology Chemical mediators are released in response to antigen causing an inflammatory response.

Anaphylaxis Presentation Varies with severity Skin eruption Respiratory compromise Cardiovascular collapse Similar to distributive shock Vasodilation effects of histamine create a decrease in the preload and afterload

Anaphylaxis Treatment 2 Phases 1 st Phase: Vital Functions Airway Oxygen Ventilation Circulatory Function 2 nd Phase: Combating Antigen Exposure Limit antigen exposure Give antihistamine and corticosteroids