S2: Ch1 Cv 3-3

Front 1

595. Tx of Shock?

Back 1

a. ABCs should be addressed for all pts in shock!!!
b. With the exception of cardiogenic (and sometimes neurogenic), a generous amount f IV fluid is usually required to resuscitate the pt.
c. The more advanced the stage of shock, the greater the fluid (and blood requirement).

Front 2

596. Cardiac Output, SVR, and PCWP in Cardiogenic shock?

Back 2

1. Cardiac output:↓
2. SVR:↑
3. PCWP:↑

Front 3

597. Cardiac Output, SVR, and PCWP in Hypovolemic shock?

Back 3

1. Cardiac output:↓
2. SVR:↑
3. PCWP:↓

Front 4

598. Cardiac Output, SVR, and PCWP in Neurogenic shock?

Back 4

1. Cardiac output: ↓
2. SVR:↓
3. PCWP: ↓

Front 5

599. Cardiac Output, SVR, and PCWP in Septic shock?

Back 5

1. Cardiac output: ↑
2. SVR: ↓
3. PCWP: ↓

Front 6

600. General characteristics of Cardiogenic shock?

Back 6

a. Occurs when a heart is unable to generate a cardiac output sufficient to maintain tissue perfusion.

Front 7

601. Definition of cardiogenic shock?

Back 7

a. Can be defined as a systolic BP <90 w/urine output < 20mL/hr and adequate left ventricular filling pressure

Front 8

602. Causes of cardiogenic shock?

Back 8

1. After acute MI- most common cause.
2. Cardiac tamponade (compression of heart
3. Tension pneumothorax (compression of heart)
4. Arrhythmias
5. Massive PE leading to RVF
6. Myocardial disease (cardiomyopathies, myocarditis).

Front 9

603. Clinical features of cardiogenic shock?

Back 9

a. Typical findings seen in shock (altered sensorium, pale cool skin, hypotension, tachycardia, etc0.
b. Engorged neck veins!!!- Venous pressure is usually elevated
c. Pulmonary congestion.

Front 10

604. In which types of shock is JVP and PCWP elevated?

Back 10

a. Only cardiogenic shock!!!!

Front 11

605. Diagnosis of Cardiogenic Shock?

Back 11

a. ECG- ST segment elevation suggesting acute MI or arrhythmia are the most common findings.
b. Echo-can diagnose a variety of mechanical complications of MI, identify valve disease, estimate EF, look for pericardial effusion, etc.
c. Hemodynamic monitoring w/Swan-Ganz catheter may be indicated: pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure, CO, cardiac index,
d. SVR-keep cardiac output >4L/min, cardiac index >2.2, PCWP <18.

Front 12

606. Tx of Cardiogenic shock?

Back 12

a. ABCs
b. Identify and treat underlying cause
c. Vasopressors: Dopamine is often initial drug used.
d. Afterload-reducing agents such as nitroglycerin or nitroprusside are typically not used initially because they aggravate hypotension. They may be used later w/vasopressors.
e. IV fluids are likely to be harmful if L. ventricular pressures are elevated!!!

Front 13

607. Tx of underlying causes of cardiogenic shock?

Back 13

i. Acute MI: standard tx w/aspirin, heparin.
1. Aggressive management, i.e., emergent revascularization w/PTCA or CABG).
ii. If cardiac tamponade: Pericardiocentesis/surgery.
iii. Surgical correction of valvular abnormalities.
iv. Tx of arrhythmias.
b. Recent studies indicate IABP improves survival.

Front 14

608. What vasopressors should be used in cardiogenic shock?

Back 14

a. Dopamine is often the initial drug used.
b. Dobutamine may be used in combination w/dopamine to further increase cardiac output.
c. NE and Phenylephrine may be used in severe or resistant cases.

Front 15

609. Intra-aortic Balloon Pump (AIBP)?

Back 15

a. A device that gives “mechanical support” to failing heart-It works opposite to the normal pumping action of the heart, i.e., it serves to “pump” during diastole and “relax” during systole.
b. A balloon catheter is positioned in the descending thoracic aorta just distal to subclavian artery.
c. ***It facilitates ventricular empting by deflating at the onset of diastole (increasing diastolic pressure). The net effect is enhanced myocardial oxygenation and increased cardiac output.

Front 16

610. Is Intra-Aortic Balloon Pump useful in cardiogenic shock?

Back 16

a. Yes, recent studies have shown that use of an IABP improves survival in pts w/cardiogenic shock.
b. Effects include:
1. Decreased afterload
2. Increased Cardiac Output
3. Decreased myocardial oxygen demand.

Front 17

611. Indications for Intra-Aortic Balloon Pump IABP?

Back 17

1. Angina refractory to medical therapy
2. Mechanical complications of MI
3. Cardiogenic Shock
4. Low cardiac output states
5. Bridge to surgery in severe aortic stenosis.

Front 18

612. Hypovolemic shock?

Back 18

a. Decreased circulatory blood volume leads to decreased preload and cardiac output.
b. The rate of volume loss is very important. The slower the loss, the greater the effectiveness of compensatory mechanisms. Acute loss is associated w/higher morbidity and mortality
c. Pts w/significant medical comorbidities (especially cardiac) may be unable to compensate physiologically in the early stages of hypovolemic shock.

Front 19

613. How many classes of hypovolemic shock are there and what are they based on?

Back 19

613. How many classes of hypovolemic shock are there and what are they based on?

Front 20

614. What % blood loss is associated w/each class of volume loss in Hypovolemic shock?

Back 20

1. Class I 10-15%
2. Class II 20-30%
3. Class III 30-40%
4. Class IV >40%.

Front 21

615. Cause of hypovolemic shock?

Back 21

a. Haemorrhage (Trauma, GI bleeding, Retroperitoneal)
b. Non-haemorrhage (voluminous vomiting, Severe diarrhea, Severe dehydration for any reason, Burns, 3rd-space losses in bowl obstruction.

Front 22

616. At what volume of blood loss do compensatory mechanisms begin to fail?

Back 22

a. When >20-25% of blood volume is lost.
b. If CVP is low, hypovolemic shock is most likely present.

Front 23

617. Most useful indicator of the effectiveness of treatment for hypovolemic shock?

Back 23

a. Monitoring urine output.
b. A pulmonary artery catheter and/or central venous line, if available, are very helpful in monitoring as well.

Front 24

618. Diagnosis of hypovolemic shock?

Back 24

a. If the diagnosis is unclear from the pt’s vital signs and clinical picture, a central venous line or a pulmonary artery catheter can give invaluable information for hemodynamic monitoring: decreased central venous pressure (CVP)/PCWP, decreased CO, increased SVR.

Front 25

619. Tx of Hypovolemic shock?

Back 25

a. Airway and breathing- pts in SEVERE shock and circulatory collapse generally require intubation and mechanical ventilation.
b. Circulation: If haemorrhage is the cause, apply direct pressure.
c. IV hydration.
d. For non-haemorrhagic shock, blood is not necessary. Crystalloid solution w/appropriate electrolyte replacement is adequate.

Front 26

620. IV hydration for each class of hypovolemic shock?

Back 26

a. Pts w/class I shock usually do not require fluid resuscitation.
b. Pts w/class II shock benefit from fluids
c. Pts w/class III and IV shock require fluid resuscitation.

Front 27

621. Septic Shock?

Back 27

a. Septic shock is defined as hypotension induced by sepsis that persists despite adequate fluid resuscitation. This results in hypoperfusion and ultimately to multiple organ system failure.

Front 28

622. Common causes of Septic shock?

Back 28

a. Include (but not limited to):
1. Pneumonia
2. Pyelonephritis
3. Meningitis
4. Abscess formation
5. Cholangitis
6. Cellulitis
7. Peritonitis.

Front 29

623. Clinical progression of septic shock?

Back 29

a. Progression from systemic inflammatory response syndrome (SIRS) to sepsis, to septic shock, to multiorgan dysfunction syndrome.