Unit 1: Neurogenic Shock Flashcards
Neurogenic Shock
- distributive shock
- a disruption in sympathetic nervous system stimulation
- vasodilation and hypovolemia; hypoperfusion
- loss of vasomotor tone
- vessel walls relaxing and dilating
- bradycardia
- hypotension
Sympathetic Nervous System Disruption
a disruption in SNS stimulation = a inability of vascular smooth muscle to constrict = decreased blood return to the heart and decreased cardiac output
-bradycardia, hypoperfusion
Causes of Neurogenic Shock
- spinal cord injury (above T6 level)
- stroke in the brain stem
- high doses of barbiturates and anesthesia techniques (both general and regional)
Clinical Manifestations of Neurogenic Shcok
- decreased vascular tone; vulnerable to hypoperfusion
- warm and dry skin d/t vasodilation
- hypovolemia b/c the size of the systemic vasculature has expanded w/o current increase in volume to fill that expanded space
- bradycardia
- hypotension
- changes in LOC
- metabolic acidosis
Medical Management of Neurogenic Shock
- Correcting primary etiology
- Correcting the Cardiovascular effects (hypotension, bradycardia)
- Fluid resuscitation (boluses of crystalloids to increase stretch of the myocardial fibers in the atria = an increase in strength of ventricular contractions and increased cardiac output)
- Vasoactive infusions (e.g. norepinephrine (Levophed), epinephrine (adrenaline), phenylephrine (Neo-Synephrine)
- Atropine to block vagal (parasympathetic) stimulation
- Transcutaneous or transvenous pacing capabilities to treat sustained symptomatic bradycardia
Vasoactive Tx for Loss of Vascular Tone
- phenylephrine
- norepinephrine
- epinephrine
- dopamine
Fluid resuscitation
to restore vascular volume and improved systemic perfusion
How to treat Episodic Bradycardia
- parasympatholytic medications (Atropine)
- transcutaneous and then transvenous pacing ay be used to treat repeated episodes of bradycardia
Serum Lactate (lactic acid) Levels and ABGs
to monitor acidosis and judge effectiveness of resuscitation strategies
Ongoing Tx of decreased vascular tone
-oral sympathomimetics, causing constriction of the peripheral vasculature
Complications of Neurogenic Shock
- Continued systemic hypoperfusion leading to multisystem organ failure
- Hypoperfusion occurs as a result of massive systemic vasodilation causing a reduction in cardiac output and blood pressure
- Bradycardia can occur, further compromising blood flow to vital tissues and organs b/c of disruption of sympathetic outflow; contributes to decreased cardiac output and BP
Nursing Management: Assessment and Analysis
w/ neurogenic shock, require cardiovascular monitoring in order to detect bradycardia, dysrhythmias, and hypotension that result from a disruption in sympathetic innervations
> Rapid Medical Interventions:
- atropine
- transcutaneous or transvenous pacing
- fluid resuscitation
- vasoactive medications
- ongoing assessments: monitoring cardiac output, intravascular volume, and other hemodynamic parameters
- mechanical ventilation depending on underlying cause
- management of complications: DVT, PE, and skin breakdown
Rapid Medical Interventions
- Atropine
- Transcutaneous or Transvenous Pacing
- Fluid resuscitation
- Vasoactive medications
- Ongoing Assessments: monitoring cardiac output, intravascular volume, and other hemodynamic parameters
- Mechanical ventilation depending on underlying cause
- Management of complications: DVT, PE, Skin breakdown
Nursing Diagnoses
- Impaired tissue perfusion r/t hypotension, bradycardia, and peripheral vasodilation
- Risk for fluid volume deficit d/t hypovolemia that occurs w/ loss of vasomotor tone and maldistribution of volume in vascular space
- Anticipatory grieving r/t sudden loss of function and accompanying critical illness
Nursing Assessments for Neurogenic Shock
- Vital signs q 1-2 hours for vasoactive infusions
- Hemodynamic Parameters q 2 to 4 hours or after tx of bolus or fluid
- Intake + Output q 1-2 hours
- Physical Assessment at q 4 hours
Assessments: Vital Signs q 1-2 hours for vasoactive infusions
> norepinephrine (Levophed); phenylephrine (Neo-Synephrine)
- allows identification of cardiovascular deterioration (hypotension, bradycardia)
- may require further intervention: titration of vasoactive meds; use of pacemaker; atropine (increases HR)
Assessments: Hemodynamic Parameters q 2 to 4 hours or after tx of bolus or fluid
> Central venous pressure (CVP), Pulmonary artery occlusion pressure (PAOP), cardiac output/ cardiac index (CO/CI), stroke volume (SV), systemic vascular resistance (SVR)
- measure q 2 to 4 hours or after tx of bolus of IV infusions
- to evaluate response of therapies
- CVP or PAOP to determine adequate vascular volume or preload is established
- CO or CI to determine overall condition of vascular system
- SVR to quantify the degree of vasoconstriction or vasodilation in the vascular system (afterload)
Assessments: Intake and Output q 1-2 hours
determines if fluid balance is in excess or if patient requires additional fluid
Assessment: Physical Assessment at least q 4 hours
-helps in detecting multisystem complications that may arise
>ARDs, pneumonia, paralytic ileus, skin breakdown
Nursing Actions
- Raise HOB slowly (10-15 degrees/hour) in a systematic matter
- Assist w/ insertion of an arterial line for continuous BP monitoring
- Assist w/ insertion of a pulmonary artery catheter in situations where cardiovascular function is severe
- IV fluids and IV sympathomimetic agents
- Atropine
- Prepare for Transcutaneous pacing if patient does not have transvenous pacing wires in place
- Implement VTE prophylaxis
Nursing Actions: Raise HOB slowly (10-15 degrees/hour) in a systematic matter
- b/c of loss of systemic vascular tone, raising HOB may cause orthostatic hypotension b/c of an inability of the peripheral blood vessels to constrict upon position change
- orthostatic hypotension may cause hemodynamic instability (lowered BP and cardiac output)
Nursing Actions: Assist w/ insertion of an arterial line for continuous BP monitoring
- enables continuous monitoring of BP and the ability to set alarm parameters so that hypotension is immediately identified
- frequent blood sampling for ABGS and lab tests is facilitated by presence of arterial line
Nursing Actions: Assist w/ insertion of a pulmonary artery catheter in situation where cardiovascular function is severe
-allows for frequent monitoring of preload (CVP and PAOP), afterload (SVR), and contractility
Nursing Actions: IV fluids and IV Sympathomimetic agents (phenylephrine, norepinephrine)
- fluid resuscitation to increase vascular volume; which is inadequate compared to the increased in the size of vascular space d/t vasodilation
- sympathomimetics increase vasomotor tone; reflected as an increase in systemic vascular resistance (SVR)
- raise cardiac output; restore adequate tissue perfusion
Nursing Actions: Atropine
- inhibit vagal nerve action (parasympathetic)
- increases HR
Nursing Actions: Prepare for transcutaneous pacing if pt does not have transvenous pacing wires in place
- temporary pacemaker to manage bradycardia in neurogenic shock b/c of sympathetic nervous system dysfunction
- if dysfunction of sympathetic nervous system is irreversible, a permanent pacemaker may be required
Nursing Actions: VTE prophylaxis
- high risk for VTE; especially if etiology is spinal cord injury
- sequential compression devices
- pneumatic foot pumps
- pharmacological methods
Nursing Teaching
- Explain specific cause of neurogenic shock and anticipated impact on immediate and future hospital care
- explain reason for medical therapy
- explain supportive therapies
Evaluating Care Outcomes
- monitoring of patients response to interventions is necessary to establish and maintain adequate tissue perfusion
- tissue perfusion compromised b/c of systemic hypoperfusion
- evaluation of BP, HR, RR, hemodynamic parameters (preload [CVP; PAOP]) provides info on therapy effectiveness
- evaluation of mentation
- vascular tone managed w/ sympathomimetics
- bradycardia may be managed w/ pacemaker
