Pathophysiology of Shock

Early Shock S/S

-Tachycardia

-Increased contractile force

-Peripheral vasoconstriction

-An attempted in crease in cardiac output

BP normal or only slightly decreased

Patient: fatigue, weakness, thirst, or feeling unwell

Compensatory Shock

BP and tissue perfusion maintained

Fluid shifted to vascular space

Tachycardia

Tachypnea

Cool, pale moist skin

Progressive/Decompensated Shock

comp mechs don’t work

metabolic acidosis

hypoxia

tachycardia

tachypnea

hypotension

cold, mottleed skin

confusion, lethargy

oliguria

GI ileus

liver impairment

DIC

Refractory Shock

IRREVERSIBLE

Multiple organ failures

Arrythmias

Systemic Effects of Shock: Respiratory

respiratory acidosis as alveoli collapse and gas can’t exchange

intervention: mechanical ventilation

CVP

right-sided filling pressure & fluid status

high = fluid overload

PA

Elevated when blood is backing up bc of pump failure and pulmonary congestion

Hypovolemic Shock s/s

Hypotension

Tachycardia

Weak pulses

Cool, pale moist skin

Delayed capillary refill

Decreased urine output

Lethargy

Low CVP

Low Hgb/Hct when blood loss is established

Hemodynamic Shock Interventions

ABCs

Keep pt flat

Avoid unnecessary oral fluids

Esophageal varices: avoid NG unless specified

Fluids: 0.9 NS, lactated ringers, albumin

Treat underlying cause

Cardiogenic Shock Cause

Heart pump can’t function effectively

Decreased cardiac output causes [3]

Decreased MAP

MI

Less contractilityC

Cardiogenic shock causes

MI

Cardiac arrest

Severe dysrhytmias

Cardiac tamponade

Drugs that impair cardiac contracitlity

Cardiomyopahty

Cardiogenic Shock S/S

Hypotension

Tachypnea

Tachycardia

Peripheral perfusion

Weak pulses

Crackles

Pulmonary edema from left-sided heart failure

Systemic edema from right-sided heart failure

Elevated CVP

HIGH PRELOAD

Dysrhythmias

Cardiogenic Shock Interventions

ABCs

oxygenation and ventilation

Avoid giving fluid bolus

Cardiogenic Shock Treatment

Dobutamine

Dopamine

Digoxin

Calcium

Dobutamine Use & Mechanism

Use: cardiogenic shock
Mechanism: increasing contractility and cardiac output

SE: Tachycardia, PVCs, afib, other dysrhythmias, chest pain, or MI

Dopamine Use and Mechanism

Use: cardiogenic shock
Mechanism: Support blood pressure and perfusion, increases afterload

Monitor: dysrhythmias and excessive vasoconstriction

Digoxin

Use: Slow heart race & increase contractility
Mechanism: Slows heart rate by making heart beat more strongly

SE: hypokalemia

Calcium

Use: HR maintenance and myocardial contractility

Morphine

reduces anxiety, preload, and cardiac workload

monitor: resp depression & hypotension

Nitroglycerin

Use: reduce preload and myocardial ischemic pain

SE: hypotension

Mechanical support for cardiogenic shock

Intra-aortic balloon pump

Intraaortic balloon pump

Position: descending aorta

Use: improve systemic perfusion and reduce heart workload

Mechanism: inflates when heart at rest; deflates when heart pumping

Cardiogenic Hemodynamic Pattern

CVP: 2-6

PA: 40/20

Cardiogenic Shock Interventions

Establish/maintain patent airway

Use mechanical ventilation if necessary

MAINTAIN PA02 > 80 during first 4-6 hrs of care

Cardiogenic Shock Monitoring Vitals

Every 15 min

Urine output every HR in ICU

Arterial Line Safety

NEVER ADMINISTER MEDS THROUGH AN ARTERIAL LINE

High Alert Infusions

DO NOT PUSH another medication through a port containing a high-alert infusion, such as heparin, dopamine, or another vasoactive drug

Lifespan Considerations

Children: hypovolemic shock risk bc of dehydration, poor intake, etc

Pregnancy: hypovolemic shock risk due to volume shift sensitivity

Older adults: cardiogenic shock risk due to increased cardiac issuesV

Continuous vasoactive infusions must be administered through an

infusion pump

Titration goals [4]

1. Target MAP

2. Minimum systolic BP

3. Desired HR

4. Cardiac output or perfusion goal

Vasoconstrictors

Levophed/norepinephrine

Epinephrine

Phenylephrine

Levophed Use/Mechanism

Use: Increase BP, vascular tone
Mechanism: constricting blood vessels

SE: peripheral ischemia, decreased urine outputE

Epinephrine Use/Mechanism

Use: Anaphylaxis, increased myocardial contractility, HR, BP, RELAXATION of bronchial smooth muscles
Mechanism: stimulates alpha and beta adrenergic receptors

SE:

-tachycardia

-atrial or supraventricular tachyarrhythmias

-ventricular tachycardia

-increased myocardial oxygen demand

-ischemic chest pain

Chest pain during epinephrine or another vasoactive infusion MUST

BE REPORTED IMMEDIATELY

Phenylephrine Use/Mechanisms

Phenylephrine use: shock-like states; drug-induced hypotension; bp maintenance

Mechanism: alpha adrenergic vasopressor that increased vascular tone and supports bp

SE: excessive vasoconstriction, hypertension, decreased peripheral perfusion, and ischemic symptoms

Phenylephrine NOTE

Doesn’t directly increase HR —> can be used when patient is tachycardic

Combination Therapy

Dobutamine + dopamine

Norepinephrine + dobutamine

Inotropes: Meds

Dobutamine

Dopamine

Inotropes Mechanism [2]

Increase myocardial contractility & strength of cardiac contractionsInot

Inotrope Usage

Increase cardiac output