400 likes | 416 Views
Resuscitation and Shock. LSU Medical Student Clerkship, New Orleans, LA. Goals Provide an introduction to the ABC’s of resuscitation in the ED Review available oxygen delivery devices and airway adjuncts Describe the pathophysiology of shock and its major subtypes
E N D
Resuscitation and Shock LSU Medical Student Clerkship, New Orleans, LA
Goals • Provide an introduction to the ABC’s of resuscitation in the ED • Review available oxygen delivery devices and airway adjuncts • Describe the pathophysiology of shock and its major subtypes • Provide an introduction to the basics of treatment of shock in the ED
Shock • Shock is defined as circulatory insufficiency that creates an imbalance between tissue oxygen supply and oxygen demand. The result of shock is global tissue hypoperfusion and is associated with a decreased venous oxygen content and metabolic acidosis (lactic acidosis).
Pathophysiology of Shock • Imbalance between tissue supply and demand Anaerobic Metabolism Lactic Acid Production
Emergency Medicine Always Starts with the ABC’s • Compressions • A – Airway • B - Breathing • C - Circulation
Airway • Remove any obstructions • Head tilt, chin lift • Jaw Thrust • Oropharyngeal and nasopharyngeal airways • Orotracheal and nasotracheal intubation • Cricothyroidotomy and Tracheotomy
Rapid Sequence Intubation • Assume every ED patient has a full stomach • Combination of sedation and paralysis to facilitate procedure • Evidence based to increase chance of success and decrease incidence of aspiration • Not without its dangers: paralyzing a patient who cannot be ventilated
Rapid Sequence Intubation • Assume every ED patient has a full stomach • Combination of sedation and paralysis to facilitate procedure • Evidence based to increase chance of success and decrease incidence of aspiration • Not without its dangers: paralyzing a patient who cannot be ventilated
RSI Indications • Airway Protection • Respiratory Failure • Expected Clinical Course
Breathing • Hypoxic Respiratory Failure • Hypercapnic Respiratory Failure • Mechanical Respiratory Failure
Oxygen Delivery Devices • Nasal Cannula - up to 40% FiO2 • Venturi mask - fixed 25% to 50% FiO2 • Nonrebreather mask - theoretical 100% FiO2 • Bag Valve Mask – 100%FiO2 • Noninvasive Positive Pressure Ventilation (BiPAP or CPAP) FiO2 up to 100% based on setting
Circulation • Restoration of a pulse is the first goal • ACLS • However having a pulse is not the end of the story • Adequate circulation requires correction of original mismatch
Types of Shock • Hypovolemic • Cardiogenic • Distributive • Obstructive
Hypovolemic Shock • Caused by inadequate circulating volume (decreased preload) • Hemorrhage (trauma, ruptured AAA, GI bleeding) • Fluid loss (diarrhea, vomiting, poor intake, burns, third spacing)
Cardiogenic Shock • Caused by pump failure (decreased cardiac output) • Myopathic – systolic dysfunction, diastolic dysfunction • Dysrrythmic – disorganized cardiac activity
Distributive Shock • Caused by maldistribution of bloodflow from peripheral vasodilatation and decrease in SVR (decreased afterload) • Sepsis • Neurogenic • Anaphylaxis • Toxic shock syndrome
Obstructive shock • Caused by extracardiac obstruction to blood flow • Cardiac tamponade, tension pneumothorax, pulmonary embolus
Clinical Presentation of Shock • Clinical presentation varies with type of shock • History and physical are key for determining underlying cause • Hypotension is very common • Altered mental status may be most sensitive sign of illness • Lethargy, cool clammy skin, tachypnea, tachycardia, and cyanosis are common as well DIAGNOSE THE UNDERLYING CAUSE!!!!
Treating Shock • Early intervention is vital to reducing morbidity and mortality • All efforts are aimed at balancing maximizing tissue oxygen supply decreasing tissue oxygen demand
Systemic inflammatory response syndrome • Early phase • 1) temperature greater than 38°C (100.4°F) or less than 36°C (96.8°F); • (2) heart rate faster than 90 beats/min; • (3) respiratory rate faster than 20 breaths/min; • (4) white blood cell count greater than 12.0 less than 4.0 , or with greater than 10 percent bands
Multi organ disease • myocardial depression • adult respiratory distress syndrome, • disseminated intravascular coagulation, • hepatic failure • renal failure.
Treating Shock - Breathing • Maximize oxygenation (Keep Sa02 > 93%) • Control the work of breathing. Respiratory muscles are highly metabolic and can greatly increase oxygen demand.
Treating Shock – Fluid Resuscitation • Most patients in shock have either an absolute or relative volume deficit, except the patient in cardiogenic shock with pulmonary edema • Central venous catheterization can guide help guide via central venous pressure monitoring and SVCO2 monitoring • A good bolus is a bold bolus!! • Massive trauma transfusion- more blood products/ crystalloids
Treating Shock – Vasopressors • Vasopressor agents are used when there has been an inadequate response to volume resuscitation or when a patient has contraindications to volume infusion • Vasopressors are most effective after fluid resuscitation but may be necessary to avoid prolonged hypotension • Goal is generally a MAP of 65
Treating Shock – Endpoints • No therapeutic end point is universally effective, and only a few have been tested in prospective trials, with mixed results.
Take Home Points • The goal of resuscitation is to maximize survival and minimize morbidity using objective hemodynamic and physiologic values to guide therapy. • The first few hours are vital. • Diagnose and treat the underlying cause!!! • Stay ahead of shock!!!!!!!