Shock

Monica Patel 1076

Outline

DefinitionTypes of ShocksRisk FactorsSigns and SymptomsDiagnosisTreatment and ManagementCase Study References

Pathophysiology ofShock

Systemic hypoperfusion (decreased blood flow) due to reduction in either cardiac output or the effective circulating blood volume

Impaired tissue perfusion occurs when an imbalance develops between cellular oxygen supply and cellular oxygen demand

Often accompanies severe injury or illness Can lead to other conditions such as lack of

oxygen in the body’s tissues (hypoxia), heart attack (cardiac arrest), or organ damage.

Clinical Features of Shock

Hypotension (Hypovolemic and Cardiogenic) With a weak, rapid pulse

Oliguria (decreased kidney perfusion) Altered mental status (decreased brain

perfusion) Tachypnea Tachycardia Cool, clammy, cyanotic skin

Vasoconstrictive mechanisms to redirect blood from periphery to vital organs

Stages of Shock

Nonprogressive phase: compensated stage, normal mechanisms will cause recovery. (baroreceptor reflexes, angiotensin secretion by the kidneys, vasopressin-constriction of peripheral arteries and veins).

Progressive phase: the phase characterized by tissue hypoperfusion and worsening circulatory and metabolic abnormalities including lactic acidosis leading to metabolic acidosis.

Irreversible phase: the phase during which damage is so severe that, even if perfusion is restored, survival is not possible.

Types of ShocksCardiogenic shock

Blood pump problem

Hypovolemic Shock Blood volume problem

Distributive shockSeptic Shock

Blood vessel problem

Other Type of Shock:

Neurogenic ShockDistributive type of shock

resulting in hypotension with bradycardia

Anaphylactic ShockSerious allergic reaction

Cardiogenic Shock Low cardiac output due to outflow

obstruction or myocardial pump failure

Inability of the heart to maintain adequate tissue perfusion secondary to impaired pump function or failure

Most commonly the result of a heart attack Other causes: valve disease, arrhythmias,

tamponade, cardiomyopathies

Risk Factors

Previous history of myocardial infarction

Plaque buildup in the coronary arteries

Long-term valvular disease

Clinical Presentation

Cool skin Tachypnea Hypotension Fatigue Altered mental status Narrowed pulse pressure Rales, murmur

Diagnosis

Physical examination (pulse and blood pressure)

Confirm the following tests: Blood pressure measurement Blood tests Electrocardiogram Echocardiography: heart activity and blood

flow Swan-Ganz Catheter: pulmonary catheter to

observe pumping activity of the heart

Treatment and Management Correct hypotension:

Fluid resuscitation to correct hypovolemia Vasoactive agents:

Dopamine-will increase heart rate and cardiac work

Dobutamine-may drop blood pressure Norepinephrine Epinephrine

Treatment Continued:

Oxygenation Optimizing pump function:

Morphine as needed (decreases preload, anxiety)

If Myocardial infarction: Heparin and revascularization

If arrhythmia-correct arrhythmia If extracardiac abnormality:

Reverse or treat cause

Hypovolemic Shock Most common type of shock Life threatening condition that results when you

lose more than 20% of your body’s blood or fluid supply. The severe fluid loss makes it impossible for the heart to pump sufficient blood to your body.

Resulting in decreased cardiac output Causes:

Vomiting, diarrhea, bowel obstruction, burns GI bleeding, trauma,

Can cause organ failure This condition requires immediate emergency

medical attention for survival

Risk Factors Losing about 1/5 or more of the normal

amount of blood in your body causes hypovolemic shock.

Excessive blood loss due to: Bleeding from cuts

Bleeding from other injuries

Internal bleeding, such as in the GI tract

Clinical Presentation

Tachycardia and tachypnea Weak, thready pulses Hypotension Cool and clammy skin Mental status changes Decreased urine output (dark and

concentrated)

Diagnosis

In addition to physical symptoms the following testing methods can be done to confirm: Blood testing to check for electrolyte imbalances

and kidney function CT scan or an ultrasound to visualize body organs Echocardiogram to measure heart rhythm Endoscopy to examine esophagus and other GI

organs Right heart catherization to check how blood is

circulating Urinary catherization to measure the amount of

urine in the bladder

Treatment and Management

Pre-hospital care: External bleeding should be controlled by direct

pressure Immobilization patient (if trauma is involved) Securing adequate airway Ensuring ventilation Maximizing circulation Medications to increase the heart’s pumping

abilities (dobutamine, epinephrine, norepinephrine)

**delay in any of the above can be harmful to the patient and can lead to death

Septic Shock Systemic inflammation response

syndrome (SIRS) secondary to a documented infection.

Response is a state of acute circulatory failure involving persistent arterial hypotension despite adequate fluid resuscitation or by tissue hypoperfusion unexplained by other causes.

Risk Factors

Risk factors: certain groups of people are more at risk. Why? They have weaker immune systems. Newborn babie, elderly people, pregnant

women, people with long-term health conditions (diabetes, cirrhosis, or kidney failure), people with lowered immune systems (people with HIV or AIDS or receiving chemotherapy)

Traumatic wounds Use of invasive catheters Drug therapy

Signs and Symptoms

Hyperthermia (Early state) Hypothermia (late stage) Tachycardia Wide pule pressure Decreased blood pressure

Diagnosis Important points for diagnosis:

Identify subtle presentations Screen patient for evidence of tissue

hypoperfusion, such as cool or clammy skin, and elevated shock index (heart rate to systolic blood pressure > 0.9)

A lactic acid level higher than 4 mm/dL has been used as an entry criterion for early goal-directed therapy (EGDT) and an indicator of severe tissue hypoperfusion

Treatment Hospitalization is required

Adequate antibiotic therapy is required (as early as possible)

Resuscitate the patient using supportive measures to correct hypoxia, hypotension, and impaired tissue oxygenation (hypoperfusion)

Identify the source of infection, and treat with antimicrobial therapy, surgery, or both.

Antibiotics

Treatment Continued

• Antibiotics- Survival correlates with how quickly the correct drug was given

• Cover gram positive and gram negative bacteria• Zosyn 3.375 grams IV and ceftriaxone 1 gram IV or• Imipenem 1 gram IV

• Add additional coverage as indicated• Pseudomonas- Gentamicin or Cefepime• MRSA- Vancomycin • Intra-abdominal or head/neck anaerobic infections-

Clindamycin or Metronidazole • Asplenic- Ceftriaxone for N. meningitidis, H.

infuenzae• Neutropenic – Cefepime or Imipenem

Case Study

Mrs. S is a 65 year old obese female who presents to ED complaining “crushing” substernal chest pain, tachycardia, cool, clammy extremities. History of myocardial infarction is present. Husband also states she has become slightly confused.

Vitals: HR 46, BP 68/32, RR 23, SpO2 95% on RA, Afebrile.Labs: WBC 8.1, Hgb 12.1, BUN 12, Creat 1.0, Troponin 3.1, BG 121.

EKG shows ST elevation in II, III, aVF

What kind of shock does the patient have?????

A. Cardiogenic

B. Hypovolemic

C. Septic

Cardiogenic Shock!!!!

References Robbins, Stanley L., Vinay Kumar, and Ramzi S. Cotran. “Shock.” Robbins and

Cotran Pathologic Basis of Disease. 8th ed. Philadelphia, PA: Saunders/Elsevier, 2010. 129-33. Print.

Medscape Reference. 1994 (Online accessed 20 June 2014) URL: http://emedicine.medscape.com/article/152191-treatment#showall.

Medscape LLC. 2014 (Online access on 20 June 2014) URL: http://emedicine.medscape.com/article/760145-treatment.