HHS CPO Shock Syndromes and Vasoactive Medications

Shock

Acute, widespread process of impaired tissue perfusion, imbalance between oxygen supply and demand → cellular, metabolic, hemodynamic alteration

Stages of Shock

1. initial

2. compensatory

3. progressive

4. refractory

Initial Stage

• Decreased cardiac output

• Tissue perfusion threatened

• VS can be normal

Compensatory Stage

Mediated by SNS

Neural → stimulate SA, AV, myocardium → Increased HR, contractility → increased CO

Hormonal → RAAS activation → vasoconstriction, vol retention, glucocorticoid release

Chemical → epi and norepi

Progressive Stage

Compensation fails to meet tissue demands → ineffective perfusion

• Switch to anaerobic metabolism → lactic acid

• Vasodilation, increased tissue permeability

Refractory Stage

Irreversible, individual organs can die

• MODS → 2+ organs dysfunctional

Categories of Shock

1. Hypovolemic

2. Cardiogenic

3. Obstructive

4. Distributive (Anaphylaxis, neurogenic, septic)

Signs of Shock

Cold, clammy skin

Hypotension

Oliguria

Rapid, shallow breaths

Drowsiness, confusion

Irritability

Tachycardia

Elevated/reduced CVP

Multi-organ damage

Bloodwork to Send

• Serum lactate

• Serum bicarbonate

• ABG

• Mixed venous

Absolute Hypovolemia

Loss of fluid from intravascular space

• External loss of fluid or internal shifting of fluid from intravascular → extravascular

Relative Hypovolemia

Vasodilation resulting in inc vascular capacity relative to circulating volume

Hypovolemic Shock Treatment

• Correct cause

• Fluid, blood to restore volume

• Meds to stabilize hemorrhage (TXA, vit K, Calcium Chloride)

• Restore tissue perfusion

• Prevent complications

Fluid Management

750 ml blood loss → Crystalloid

750-1500 ml blood loss → Crystalloid

1500-2000 ml blood loss → Crystalloid and blood

>2000 ml blood loss → Crystalloid and blood

Cardiogenic Shock

Impaired ability to contract and pump blood (primary pump failure)

• Loss of 40% of ability to pump

Cardiogenic Shock Causes

• MI

• Dysrhythmias

• Mitral or aortic stenosis

Cardiogenic Shock Characteristics

• Hypotension (SBP<90)

• Evidence of poor tissue perfusion

• Cardiac → tachy, CP, dysrhythmias

• Pulmonary → crackles, SOB, edema

• Persistence of shock after correction of non myocardial factors

Cardiogenic Shock Management

• ABC

• Underlying cause

• Administer meds (ino/vaso, diuretics, antiarrhythmics)

• Intubation/mech vent

• Emergency revascularization

• Mechanical circulatory assist devices

Obstructive Shock

Obstruction of blood flow (external to heart) limiting blood from leaving or returning to heart

Obstructive Shock Presentation

• Decreased tissue perfusion

• Respiratory distress

• Tachycardia

• Hypotension

Obstructive Shock Management

TREAT THE CAUSE

• Tension pneumo → needle decompression, chest tube

• Pulmonary embolism → thrombolytic TNK, embolectomy

• Cardiac tamponade → pericardiocentesis, thoracotomy

Distributive Shock

Systemic vasodilation resulting in decreased blood flow to vital organs

• Anaphylaxis

• Neurogenic

• Sepsis/Septic shock

Anaphylaxis

Immediate hypersensitivity reaction → severe systemic response

• Activation of mast cells, basophils

Anaphylaxis Characteristics

CNS → HA, restlessness, anxiety

CVS → dizziness, hypotension, angina, arrhythmia, tachycardia

Resp → cough, dyspnea, stridor, wheeze

GI → vomiting, diarrhea, abdo pain

Skin → flushing, itching, hives, angioedema

Anaphylaxis Medications

• Rapid volume replacement

• Epi 0.5mg IM

• H1 antihistamine (benadryl) 50 mg IVP

• H2 antihistamine (famotidine) 20 mg IVP

• Bronchodilators (ventolin) 4-8 puffs

• Glucocorticoids (hydrocortisone) 50 mg IVP

Neurogenic Shock

Loss/suppression of sympathetic tone → massive vasodilation, bradycardia, reduced contractility

• Caused by anything disrupting SNS

Neurogenic Shock Manifestations

Hypotension → secondary to vasodilation of vascular beds below level of injury

BRADYcardia → suppression of cardiac accelerator reflex

Warm, dry skin

Neurogenic Shock Management

• ABC

• Symptom management

• Promote optimal tissue perfusion

• Prevent cardiac instability (fluids, vasopressors, atropine)

Sepsis

Life threatening clinical syndrome caused by an infection and dysrefulated physiological systematic reponse

• Perfusion abnormalities → multi organ dysfunction

Septic Shock

Severe sepsis with extreme circulatory, cellular, metabolic effects

• Mortality >40%

Septic Shock Manifestations

• aLOC

• Hypotension

• Tachycardia

• Tachypnea

• Chills and fever

• Warm flushed skin

• Decreased urine output

• Fatigue and weakness

Septic Shock Management

1. Lactate level

2. Cultures

3. Broad spectrum abx

4. Fluid resuscitation (30 ml/kg crystalloid for hypotension, lactate >4)

5. Vasopressors to maintain MAP >65

Alpha 1 Receptor Effects

Stimulation → vasoconstriction, smooth muscle contraction

Inhibition → vasodilation, smooth muscle relaxation

Beta 1 Receptor Effects

Stimulation → inc HR, contractility, kidneys release renin

Inhibition → (selective) dec HR, BP

Beta 2 Receptor Effects

Stimulation → smooth muscle relaxation, vasodilation, bronchodilation

Inhibition → (non-selective) dec HR, BP. bronchoconstriction

Medications Used in Shock

1. Vasoconstrictors

2. Vasodilators

3. Inotropes

4. Antiarrhythmatic

Vasoconstrictors

• Epinephrine

• Norepinephrine

• Alpha-range dopamine

• Phenylephrine

• Vasopressin

Vasodilators

• Nitroprusside

• Nitroglycerine

• Hydralazine

• Labetalol

Inotropes

• Beta-range dopamine

• Dobutamine

• Epinephrine

• Norepinephrine

• Milrinone

Antiarrhythmics

• Amiodarone

• Adenosine

• Labetalol

• Metoprolol

• Diltiazem

• Lidocaine

Epinephrine

Dose → start at 0.02 mcg/kg/min, maintain at 0.05-0.5 mcg/kg/min

Titration → based on MAP

Reconstitution → 4/8/16 in 250 ml NS or D5W

Norepinephrine (Levophed)

Dose → 0.01-3 mcg/kg/min

Titration → Yes

Reconstitution → Premade in D5W (8mg in 250 ml D5W/NS)

Phenylephrine (Neocynephrine)

Dose → Bolus 100-200 mcg, infusion 0.05-4mcg/kg/min

Titration → Yes (infusion)

Reconstitution → 10 mg/100 ml NS (bolus), 50 mg/250 ml NS (infusion)

Vasopressin

Dose → 2-2.4 unit/hr

Titration → No, set dose ordered

Reconstitution → Nurse makes first dose, 20 u/50 ml NS

Nitroglycerin

Dose → 10-200 mcg/min

Titration → Yes

Reconstitution → 50mg/250ml (200mcg/ml) in glass bottle

Nitroprusside (Nipride)

Dose → start at 0.5 mcg/kg/min (titrate by 0.2 mcg/kg/min q5min, max 8-10)

Titration → Yes

Reconstitution → by RNs, 50mg/250ml D5W (protected from light)

Dopamine

Dose → 0.05-20 mcg/kg/min

Titration → Yes

Reconstitution → Premade, 400mg/250ml D5W

Dobutamine

Dose → Initial 2.5 mcg/kg/min, up to 20 mcg/kg/min

Titration → No, set ordered dose

Reconstitution → Premade, 250mg/250ml or 500mg/250ml

Milrinone

Dose → 0.25-0.75 mcg/kg/min

Titration → No, set ordered dose

Reconstitution → Made by pharmacy, 1st made by nurse. 20mg/100ml NS

Amiodarone

Dose →

Bolus: 150mg/100ml D5W or NS

Infusion:

• CVL → 900mg/250ml non PVC bag

• PIV → 450mg/250ml non PVC bag

Metoprolol

IVP or bolus 5-15 mg

Labetalol

IVP 10-25 mg, or infusion 100mg/50ml, 200mg/100ml