Shock Notes Flashcards
Shock
Syndrome characterized by decreased tissue perfusion and impaired cellular metabolism.
4 Categories for Shock
Cardiogenic
Hypovolemic
Distributive
Obstructive
Cardiogenic Shock
systolic or diastolic dysfunction of the heart’s pumping action results in reduced CO , SV & BP.
Most common cause is MI
Cardiogenic Shock c/m:
Tachycardia & hypotension - early manifestations
Decreased Cap refill, SV, CO, SVR, PAWP, CVP
Tachypneic & crackles
Decreased urine output, and increase Na+ and H2O retention
Pallor, cool and clammy skin
Anxiety, agitation & confusion
n/v, hypoactive bowel sounds
Hypovolemic Shock
Inadequate volume in the intravascular space to support adequate perfusion.
Can be absolute or relative
Pts can compensate a loss of up to 15% of total volume.
Hypovolemic Shock c/m:
Tachycardia, decreased preload, CO, CVP, PAWP, and Cap refill and Increased SVR. Tachypnea to bradypnea (late) Decreased urine output Pallor, cool and clammy skin Anxiety, agitation & confusion Absent Bowel Sounds Decreased Hct, Hgb & increased lactate, urine specific gravity changes in electrolytes
Distributive Shock
Neurogenic
Anaphylaxis
Septic
Neurogenic
Hemodynamic phenomenon that can occur within 30 min of a spinal cord injury and lasts up to 6 wks.
Gen. associated with cervical or spinal cord injuries.
Neurogenic c/m:
Bradycardia, decreased BP, CO, CVP, SVR, change in temperature
Dysfunction r/t level of injury
Bladder dysfunction
Decreased skin perfusion, cool or warm dry skin
Flaccid paralysis below the level of lesion, loss of reflex activity
Bowel dysfunction
Anaphylactic shock
acute life-threatening hypersensitivity reaction to a sensitizing substance
Leads to respiratory distress due to laryngeal edema, severe bronchospasm, and circulatory failure
Anaphylactic shock c/m:
Tachycardia, increased CO, decreased CVP, PAWP, CP, Third spacing of fluid
SOB, Edema of larynx & epiglottis, wheezing, stridor, and rhinitis
incontinence
flushing, pruritus, uticaria, angioedema
anxiety, feeling of impending doom, confusion, decreased LOC, metallic taste
cramping, abd pain, n/v, diarrhea
sudden onset, hx of allergies, exposure to contrast media.
Sepsis and septic shock
Sepsis: life-threatening syndrome in response to an infection.
Septic shock: subset of species characterized by persistent hypotension despite fluid resuscitation and inadequate and inadequate tissue perfusion
Sepsis and septic shock c/m:
tachycardia, temperature changes, myocardial dysfunction, biventricular dilation, decreased EF
hyperventilation, crackles, respiratory alkalosis or acidosis, hypoxemia, respiratory failure, ARDS, pulmonary HTN
decreased urine output
warm and flushed skin to cool and mottled skin (late)
change in mental status, agitation , coma
GI bleeding, paralytic ileus
WBC changes, decreased platelets, urine na+, increased lactate, blood glucose, procalcitonin, urine specific gravity, and positive blood cultures.
Obstructive shock
develops when a physical obstruction to blood flow occurs with decreased CO.
Obstructive shock c/m
Tachycardia, decreased BP, preload, CO and increased SVR, CVP, JVD and pulsus paradoxus Tachypnea to bradypnea (late), SOB decreased urine output Pallor, cool and clammy skin anxiety, agitation, confusion Decreased to absent bowel sounds Specific to cause of obstruction
Stages of shock
Initial
Compensatory
Progressive
Refractory
Neurologic Compensatory Stage
Oriented to person, place, time
Restless, apprehensive, confused
Change in level of consciousness
Cardiovascular Compensatory Stage
Sympathetic nervous system response: • Release of epinephrine/norepinephrine (vasoconstriction) • ↑ MVO2 • ↑ Contractility • ↑ HR Coronary artery dilation Narrowed pulse pressure ↓ BP
Respiratory Compensatory Stage
Blood flow to the lungs: • ↑ Physiologic dead space • ↑ Ventilation-perfusion mismatch • Hyperventilation • ↑ Minute ventilation (VE) • Tachypnea
GI Compensatory Stage
↓ Blood supply
↓ GI motility
Hypoactive bowel sounds
↑ Risk for paralytic ileus
Renal Compensatory Stage
↓ Renal blood flow
↑ Renin resulting in release of angiotensin (vasoconstrictor)
↑ Aldosterone resulting in Na+ and H2O reabsorption
↑ Antidiuretic hormone resulting in H2O reabsorption
Temperature and Skin Compensatory Stage
Normal or abnormal
Pale and cool
Warm and flushed
Neurologic Progressive Stage
↓ Cerebral perfusion pressure
↓ Cerebral blood flow
↓ Responsiveness to stimuli
Delirium
Cardiovascular Progressive Stage
↑ Capillary permeability → systemic interstitial edema
↓ CO → ↓ BP and ↑ HR
MAP <60 mm Hg (or 40 mm Hg drop in BP from baseline)
↓ Coronary perfusion → dysrhythmias, myocardial ischemia, MI
↓ Peripheral perfusion → ischemia of distal extremities, ↓ pulses, ↓ capillary refill
Respiratory Progressive Stage
ARDS: • ↑ Capillary permeability • Pulmonary vasoconstriction • Pulmonary interstitial edema • Alveolar edema • Diffuse infiltrates • Tachypnea • ↓ Compliance • Moist crackles
GI Progressive Stage
Vasoconstriction and ↓ perfusion → ischemic gut (e.g., stomach, small and large intestines, gallbladder, pancreas): • Erosive ulcers • GI bleeding • Translocation of GI bacteria • Impaired absorption of nutrients
Renal Progressive Stage
Renal tubules become ischemic → acute tubular necrosis ↓ Urine output ↑ BUN-to-creatinine ratio ↑ Urine sodium ↓ Urine osmolality and specific gravity ↓ Urine potassium Metabolic acidosis
Hepatic Progressive Stage
Failure to metabolize drugs and waste products
Cell death (↑ liver enzymes)
Jaundice (↓ clearance of bilirubin)
↑ NH3 (ammonia) and lactate
Hematologic Progressive Stage
DIC:
• Thrombin clots in microcirculation
• Consumption of platelets and clotting factors
Temperature and Skin Progressive
Hypothermia or hyperthermia
Cold and clammy
Neurologic Refractory Stage
Unresponsive
Areflexia (loss of reflexes)
Pupils nonreactive and dilated
Cardiovascular Refractory Stage
Profound hypotension
↓ CO
Bradycardia, irregular rhythm
↓ BP inadequate to perfuse vital organs
Respiratory Refractory Stage
Severe refractory hypoxemia
Respiratory failure
GI Refractory Stage
Ischemic gut
Renal Refractory Stage
Anuria
Hepatic Refractory Stage
Metabolic changes from accumulation of waste products (e.g., NH3, lactate, CO2)
Hematologic Refractory Stage
DIC progresses
Emergency Management of Shock
Initial:
• If unresponsive, assess circulation, airway, and breathing (CAB).
• If responsive, monitor airway, breathing, and circulation (ABC).
• Stabilize cervical spine as appropriate.
• Control any external bleeding with direct pressure or pressure dressing.
• Give high-flow O2 (100%) by nonrebreather mask or bag-valve-mask.
• Anticipate need for intubation and mechanical ventilation.
• Establish IV access with 2 large-bore catheters (14- to 16-gauge) or an intraosseous access device; aid with central line insertion.
• Begin fluid resuscitation with crystalloids (e.g., 30 mL/kg repeated until hemodynamic improvement is seen).
• Draw blood for laboratory studies (e.g., blood cultures, lactate, WBC).
• Assess for life-threatening injuries (e.g., cardiac tamponade, liver laceration, tension pneumothorax).
• Consider vasopressor therapy if hypotension persists after fluid resuscitation.
• Insert an indwelling urinary catheter and nasogastric tube.
• Start antibiotic therapy after blood cultures if sepsis is suspected.
• Obtain 12-lead ECG and treat dysrhythmias.
Ongoing Monitoring:
• ABCs
• Level of consciousness
• Vital signs, including pulse oximetry; peripheral pulses, capillary refill, skin color and temperature
• Respiratory status
• Heart rate and rhythm
• Urine output
Fluid Therapy
Isotonic Crystalloids
Hypertonic Crystalloids
Blood Products
Colloids
Isotonic Crystalloids: Mechanism of Action & Indication
0.9% NaCl, normal saline solution (NSS) or Lactated Ringer’s (LR) solution
Fluid primarily stays in the intravascular space, ↑ intravascular volume.
Used for initial volume replacement in most types of shock.
Isotonic Crystalloids: Nursing Implications
Monitor patient closely for circulatory overload. Do not use LR in patients with liver failure.LR may be used if hyperchloremic acidosis develops from use of NSS in fluid resuscitation.
Hypertonic Crystalloids: Mechanism of Action & Indication
1.8%, 3%, 5% NaCl
Fluid stays in the intravascular space, increases serum osmolarity, shifts fluid volume from intracellular space to extracellular space to intravascular space.
May be used for initial volume expansion in hypovolemic shock.
Hypertonic Crystalloids: Nursing Implications
Monitor patient closely for signs of hypernatremia (e.g., disorientation, seizures).
Central line preferred for infusing saline solutions ≥3%, since these may damage veins.
Blood Products: Mechanism of Action & Indication
Packed red blood cells
Fresh frozen plasma
Platelets
Replaces blood loss, increases O2-carrying capability.
Replaces coagulation factors.
Helps control bleeding caused by thrombocytopenia
All types.
Blood Products: Nursing Implications
Same precautions as any blood administration
Human serum albumin (5% or 25%): Mechanism of Action & Indication
Colloids
Can increase plasma colloid osmotic pressure.
Rapid volume expansion.
All types except cardiogenic and neurogenic shock
Human serum albumin (5% or 25%): Nursing Implications
Use 5% solution in hypovolemic patients. Use 25% solution in patients with fluid and sodium restrictions.
Monitor for circulatory overload. Mild side effects of chills, fever, and urticaria may develop.
More expensive than crystalloids.
dextran (dextran 40): Mechanism of Action & Indication
Colloids
Hyperosmotic glucose polymer.
Limited use because of side effects, including reducing platelet adhesion, diluting clotting factors.
dextran (dextran 40): Nursing Implications
Increases risk for bleeding.
Monitor patient for allergic reactions and AKI. Has maximum volume recommendations per manufacturer.
Cardiogenic Shock & Septic Shock: Oxygenation Interprofessional Care
Provide supplemental O2 (e.g., nasal cannula, nonrebreather mask)
Intubation and mechanical ventilation, if needed
Monitor ScvO2 or SvO2
Hypovolemic Shock:
Oxygenation Interprofessional Care
- Provide supplemental O2
* Monitor ScvO2 or ScvO2
Neurogenic, Anaphylactic & Obstructive Shock: Oxygenation Interprofessional Care
- Maintain patent airway
- Provide supplemental O2
- Intubation and mechanical ventilation (if needed)
Cardiogenic Shock: Circulation Interprofessional Care
Restore blood flow with angioplasty with stenting, emergent coronary revascularization
• Reduce workload of heart with circulatory assist devices: IABP, VAD
Hypovolemic Shock: Circulation Interprofessional Care
- Rapid fluid replacement using 2 large-bore (14–16 gauge) peripheral IV lines, an intraosseous access device, or central venous catheter
- Restore fluid volume (e.g., blood or blood products, crystalloids)
- End points of fluid resuscitation:
- CVP 15 mm Hg
- PAWP 10–12 mm Hg
Septic Shock: Circulation Interprofessional Care
- Aggressive fluid resuscitation (e.g., 30 mL/kg of crystalloids repeated if hemodynamic improvement is noted)
- End points of fluid resuscitation are based on:
- Focused physical examination including vital signs, cardiopulmonary assessment, capillary refill, peripheral pulses, and skin or any 2 of the following:
- ScvO2 >70 or SvO2 >65
- CVP 8–12 mm Hg
- Cardiovascular ultrasound
- Assessment of fluid responsiveness with passive leg raise or fluid challenge
Neurogenic Shock: Circulation Interprofessional Care
Cautious administration of fluids
Anaphylactic Shock: Circulation Interprofessional Care
Aggressive fluid resuscitation with colloids
Obstructive Shock: Circulation Interprofessional Care
- Restore circulation by treating cause of obstruction
* Fluid resuscitation may provide temporary improvement in CO and BP
Cardiogenic Shock: Drug Therapy
- Nitrates (e.g., nitroglycerin)
- Inotropes (e.g., dobutamine)
- Diuretics (e.g., furosemide)
- β-Adrenergic blockers (contraindicated with ↓ ejection fraction)
Septic Shock: Drug Therapy
- Antibiotics as ordered
- Vasopressors (e.g., norepinephrine)
- Inotropes (e.g., dobutamine)
- Anticoagulants (e.g., low-molecular-weight heparin)
Neurogenic Shock: Drug Therapy
- Vasopressors (e.g., phenylephrine)
* Atropine (for bradycardia)
Anaphylactic Shock: Drug Therapy
- Epinephrine (IM or IV)
- Antihistamines (e.g., diphenhydramine)
- Histamine (H2)-receptor blockers (e.g., ranitidine [Zantac])
- Bronchodilators: nebulized (e.g., albuterol)
- Corticosteroids (if hypotension persists
Cardiogenic Shock: Supportive Therapy
Treat dysrhythmias
Hypovolemic Shock: Supportive Therapy
- Correct the cause (e.g., stop bleeding, GI losses)
* Use warmed IV fluids, including blood products (if appropriate)
Septic Shock: Supportive Therapy
- Obtain cultures (e.g., blood, wound) before beginning antibiotics
- Monitor temperature
- Control blood glucose
- Stress ulcer prophylaxis
Neurogenic Shock: Supportive Therapy
- Minimize spinal cord trauma with stabilization
* Monitor temperature
Anaphylactic Shock: Supportive Therapy
- Identify and remove offending cause
- Prevent via avoidance of known allergens
- Premedicate with history of prior sensitivity (e.g., contrast media)
Obstructive Shock: Supportive Therapy
• Treat cause of obstruction (e.g., pericardiocentesis for cardiac tamponade, needle decompression or chest tube insertion for tension pneumothorax, embolectomy for pulmonary embolism)
Phenylephrine: Mechanism of Action and Indications
α-Adrenergic agonist (peripheral vasoconstriction)
Renal, mesenteric, splanchnic, cutaneous, and pulmonary blood vessel constriction
↑ HR, BP, SVR
↑/↓ CO
Neurogenic shock
Phenylephrine: Nursing Implication
Monitor for reflex bradycardia, headache, restlessness.
Monitor for renal failure from ↓ renal blood flow.
Give via central line (infiltration leads to tissue sloughing).
