1. Shock
Overview
Salah Abusin, MD, MRCP
Cardiology Fellow
Chicago, IL
Secretary General
Sudanese American Medical Association

2. Shock
• Shock is the clinical syndrome that results
from inadequate tissue perfusion resulting in
reduced oxygen delivery
• Usually accompanied with hypotension
– Mean BP < 65
– Mean BP = DBP + 1/3 Pulse pressure
– Pulse Pressure= SBP - DBP

3. Cardinal Signs
• Hypotension
– Absolute hypotension (systolic blood pressure <90
mmHg) or
– Relative hypotension (ea drop in systolic blood
pressure >40 mmHg from baseline).
• Oliguria
– < 0.5 ml/kg/hr
• Altered Mental Status
• Cold Clammy Skin
• Lactic Acidosis

4. Types of Shock
• Hypovolemic
• Cardiogenic
• Septic
• Other
– Traumatic
– Neurogenic
– Hypoadrenal

5. Hemodynamic Parameters
• Blood Pressure = Cardiac Output x Peripheral Resistance
• Cardiac Output (COP)
– is the volume of blood being pumped by the heart in one
minute
– Measured in liters/min
– 4-8 l/min
• Cardiac Index (CI)
– Relates Cardiac Output to body surface area
– Measures in liters/min/m2
– 2.6-4.2 l/min/m2

6. Hemodynamic Parameters
• Central Venous Pressure (CVP)
– The pressure of blood in the thoracic vena cava
– Equivalent to the pressure in the right atrium
– 5-10 mmHg

7. Hemodynamic Parameters
• Pulmonary Capillary
Wedge Pressure
– pressure measured by
wedging a pulmonary
catheter with an inflated
balloon into a small
pulmonary arterial branch
– Reflects Left ventricle End
Diastolic Pressure (aka
Filling Pressure) in the
absence of mitral stenosis
– 6-12 mmHg

8. Hypovolemic Shock
• Reduced Preload due to loss of intravascular
volume
• Symptoms
– hematemesis, hematochezia, melena,
– vomiting, diarrhea, or abdominal pain.
• Suggestive Signs
– decreased skin turgor (in younger patients),
– dry skin, dry axillae, dry tongue, or dry oral mucosa
– postural hypotension,
– decreased jugular venous pressure
– Decreased CVP

9. Causes

10. Mild Moderate Severe
<20% Blood loss 20-40% Blood >40% Blood Loss
Loss
Cool extremities Same plus: Same, plus:
Increased capillary Tachycardia Hemodynamic
refill time Tachypnea instability
Diaphoresis Oliguria Marked tachycardia
Collapsed veins Postural Hypotension
Anxiety changes Mental status
deterioration (coma

11. Cardiogenic Shock
• Due to Pump Failure
• Symptoms
– Dyspnea
– Chest Pain
– Palpitations
– History of Cardiac Disease
• Signs
– Diffuse Lung crackles
– New murmur, gallops, or soft heart sounds
– Increased JVP
– Increased CVP
– Diminished Distal Pulses

12. Cardiogenic Shock
• Suggestive Findings on Investigations
– Pulmonary Congestion on CXR
– Recent or Current Ischemia on ECG
– Elevated Cardiac Enzymes
– Echocardiogram may demonstrate etiology

13. Cardiogenic Shock - Causes
• Acute myocardial infarction
– Pump failure due to Large MI
– Mechanical complications
• Acute MR due to papillary muscle rupture or severe
dysfunction
• Ventricular septal defect
• Left ventricular free wall rupture
• Right ventricular infarction

14. Cardiogenic Shock - Causes
• End-stage cardiomyopathy
• Myocarditis
• Left ventricular outflow tract obstruction
– Aortic stenosis
– Hypertrophic obstructive cardiomyopathy
• Obstruction to left ventricular filling
– Mitral stenosis
– Left atrial myxoma
• Acute mitral regurgitation (chordal rupture)
• Acute aortic insufficiency
• Myocardial contusion
• Prolonged cardiopulmonary bypass

15. Septic/Distributive Shock
• Symptoms
– dyspnea, productive cough,
– dysuria, hematuria,
– chills, myalgias, rashes, fatigue, malaise,
– headache, photophobia
• Signs
– fever,
– tachypnea, tachycardia,
– Altered mental status,
– flushing

16. Hypovolemic Shock
• Cardiac Output
• Decreased
• PCWP
• Low
• CVP/RAP
• Low
• Blood Pressure
• Low
• Systemic Vascular
Resistance
• Increases

17. Cardiogenic Shock
• Cardiac Output
• reduced
• PCWP
• Increased
• CVP/RAP
• increased
• Blood Pressure
• Low
• Systemic Vascular
Resistance
• Increased

18. Septic/Distributive Shock
• Cardiac Output
• Normal or
increased
• PCWP
• normal
• CVP/RAP
• Increased or
reduced
• Blood Pressure
• Low
• Systemic Vascular
Resistance
• Reduced

19. Physiologic Preload Pump Afterload Tissue
variable function perfusion
Clinical Pulmonary Cardiac output Systemic Mixed venous
measurement capillary vascular oxygen
wedge resistance saturation
pressure
Hypovolemic ↓ ↓ ↑ ↓
Cardiogenic ↑ ↓ ↑ ↓
Distributive ↓ or ↔ ↑ ↓ ↑

20. Monitoring
• Admission to ICU with 1:1 Nursing
• Hourly Vital Signs (as a minimum)
– HR, BP, RR
• Foley Catheter
– Hourly measurement of urine output
• Monitoring of Mental Status
• Central Venous Access
• Invasive BP Monitoring

21. Central Venous Access
• Use
– Large Volume Resuscitation if inadequate
peripheral access (i.e. >18G in a proximal vein)
– Administration of Vasopressors
– Measurement of CVP & Central Venous Oxygen
saturation
• Sites
– Internal Jugular Vein
– Subclavian Vein

24. Invasive BP Monitoring
via Peripheral Arterial Line
• Uses
– Accurate measurement of BP
• Sphygmomanometer less accurate in shock, and when
vasopressors are being used
– Frequent Arterial Blood Gas Sampling
• In patients on mechanical ventilators &/or Respiratory
Failure
– Alternative to venipuncture if central venous
access is not in place

26. Pulmonary Artery Catheterization
• Diagnosis of Type of Shock
• Direct Measurement of
– Cardiac Output
– Pulmonary Capillary Wedge Pressure
– Mixed Venous Oxygen Saturation
• Calculate the Systemic Vascular Resistance

28. Thank You