shock

Objective 1: Interpret the pathophysiology of shock, identify the manifestations of shock, and classify the four categories of shock (hypovolemic, distributive, and obstructive, and cardiogenic). (CO 1, 3) Objective 2: Differentiate the stages of shock, and be able to identify characteristics of the overlapping stages on the shock continuum. (CO 1, 3) Objective 3: Discuss the etiology, signs and symptoms, treatment, prognosis, and evidence-based nursing management related to care of individuals experiencing sensory overload/deprivation and altered communication patterns. (CO 1, 2, 3, 4, 5, 6, 7, 8)

what is shock

inadequate tissue perfusion

the tissues are not receiving enough oxygen and nutrients

3 components that keeps circulation adequate

1. heart

2. vascular tone

3. blood volume

hypovolemic shock

main problem: insufficient circulating fluid

think: tank is empty

initial stage

this stage occurs primarily at the cellular level and is generally not clinically apparent

aerobic met →anaerobic met → lactic acid build up

compensatory stage

REVERSIBLE

atp, compensatory mechanisms are still effective enough that most metabolic needs continue to be met

compensatory stage symptoms

• dec SV

• dec CO

• inc RR

• inc HR

• dec BP

• MAP <65

• pale extremities

pulmonary response in compensatory stage

anaerobic metabolism contributes to acid-base disturbance so:

tachypnea → helps maintain A/B balance + inc O2 supply

progressive stage

compensation is failing

dec cellular perfusion → inc capillary permeability

fluid and proteins leak:

vascular space → interstitial space

refractory stage

irreversible

• cellular necrosis

• MODS

• acidosis

• inc cap permeability

preload

the force that stretches the cardiac muscle prior to contraction. often thought of as the amount of blood that returns to the right atrium

afterload

this is the “load” against which the heart ejects blood. the pressure the heart must work against when pumping blood from the left ventricle during systole

stroke vol

the amount of blood the LV pumps out with each systolic contraction (heartbeat)

cardiac output

SV X HR measured in L/min

systemic vascular resistance

resistance in the circulatory system that is used to create BP, the flow of blood and is also a component of cardiac fxn

pulmonary vascular resistance

resistance against blood flow from the pulmonary artery to the LA

MAP

avg arterial pressure throughout one cardiac cycle of systole and diastole

baroreceptors

are receptors throughout the vascular system to relay info to the ANS

ischemia

condition in which inadequate bf supply and therefore O2 to an organ