Resuscitation and Shock

LSU Medical Student Clerkship, New Orleans, LA

Resuscitation

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

Resuscitation

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).

Resuscitation

Pathophysiology of Shock

Imbalance between tissue supply and demand Anaerobic Metabolism Lactic Acid Production

Resuscitation

Emergency Medicine Always Starts with the ABC’s

Compressions

A – Airway

B - Breathing

C - Circulation

Resuscitation

Airway

Remove any obstructions Head tilt, chin lift Jaw Thrust Oropharyngeal and nasopharyngeal airways Orotracheal and nasotracheal intubation Cricothyroidotomy and Tracheotomy

ResuscitationJaw Thrust

ResuscitationHead Tilt

ResuscitationNasopharygeal airway

ResuscitationOrotracheal airway

ResuscitationSupraglottic devices

ResuscitationOrotracheal

ResuscitationNeck airways

Resuscitationchallenges…

Resuscitation

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

Resuscitation

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

ResuscitationRSI Indications

Airway Protection

Respiratory Failure

Expected Clinical Course

Resuscitation

Breathing

Hypoxic Respiratory Failure

Hypercapnic Respiratory Failure

Mechanical Respiratory Failure

Resuscitation

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

ResuscitationNasal cannula/ Venturi mask

Resuscitation

ResuscitationPositive pressure ventilation

Resuscitation

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

Resuscitation

Types of Shock

Hypovolemic Cardiogenic Distributive Obstructive

Resuscitation

Hypovolemic Shock

Caused by inadequate circulating volume (decreased preload)

Hemorrhage (trauma, ruptured AAA, GI bleeding) Fluid loss (diarrhea, vomiting, poor intake, burns,

third spacing)

Resuscitation

Cardiogenic Shock

Caused by pump failure (decreased cardiac output) Myopathic – systolic dysfunction, diastolic

dysfunction Dysrrythmic – disorganized cardiac activity

Resuscitation

Distributive Shock

Caused by maldistribution of bloodflow from peripheral vasodilatation and decrease in SVR (decreased afterload)

Sepsis Neurogenic Anaphylaxis Toxic shock syndrome

ResuscitationObstructive shock

Caused by extracardiac obstruction to blood flow

Cardiac tamponade, tension pneumothorax, pulmonary embolus

ResuscitationClinical 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!!!!

Resuscitation

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

ResuscitationSystemic 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

ResuscitationMulti organ disease

myocardial depression adult respiratory distress syndrome, disseminated intravascular coagulation, hepatic failure renal failure.

ResuscitationEarly Goal Directed Shock Therapy

Resuscitation

Treating Shock - Breathing

Maximize oxygenation (Keep Sa02 > 93%) Control the work of breathing. Respiratory muscles

are highly metabolic and can greatly increase oxygen demand.

ResuscitationTreating 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

Resuscitation

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

Resuscitation

Treating Shock – Vasopressors

Resuscitation

Treating Shock – Endpoints

No therapeutic end point is universally effective, and only a few have been tested in prospective trials, with mixed results.

Resuscitation

Treating Shock – EndpointsTable 30-8 Hemodynamic Resuscitation End Points Modality Goals

CVP 10–12 mm Hg Preload

PAOP 12–18 mm Hg

MAP 90–100 mm Hg Afterload

SVR = (MAP – CVP/CO)(80)

800–1400 dyne s/cm5

CO 5.0 L/min

CI 2.5–4.5 L per min m2

Contractility

SV = CO/heart rate 50–60 mL per min

Heart rate 60–100 bpm Avoid >100 bpm; this will decrease SV and increase myocardial oxygen consumption

Coronary perfusion pressure

CPP = DBP – CVP (or PAOP)

>60 mm Hg

ScvO2 or SmvO2

>70% Tissue oxygenation

Serum lactate <2mM/L

Resuscitation

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!!!!!!!