Introduction: Shock Definition: circulatory failure resulting in - - PowerPoint PPT Presentation

Definition: circulatory failure resulting in reduced oxygen delivery to the tissues

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Introduction: Shock

Shock Examples

Hypovolaemic Haemorrhagic Non-haemorrhagic Obstructive Pulmonary Mechanical Cardiogenic Cardiomyopathic Arrhythmic Mechanical Distributive Septic Anaphylactic Neurogenic

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Pathophysiology: Shock

• Cardiogenic
• Obstructive
• Distributive
• Hypovolaemic

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Compensated: BP maintained

• Baroreceptor reflex
• RAAS
• Catecholamine
• ADH release

Decompensated shock: hypotensive

• Failure of neurohormonal mechanisms

Irreversible

• Multi-organ failure

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Clinical features

Type of shock Clinical features Hypovolaemic

• Hypotension and tachycardia
• Weak, thready pulse with cool, pale, moist skin
• Symptoms of source, e.g. diarrhoea

Obstructive

• Cardiovascular collapse
• Pleuritic chest pain, dyspnoea: pulmonary embolism
• Beck triad: cardiac tamponade
• Pleuritic chest pain, tracheal deviation, dyspnoea: tension pneumothorax

Cardiogenic

• Hypotension and tachycardia, may be bradycardic (e.g. bradyarrhythmia)
• Weak, thready pulse with cool, pale, moist skin

Distributive Septic

• Hypotension and tachycardia
• Warm peripheries with bounding pulse
• Symptoms of infective source, e.g. productive cough

Anaphylactic

• Hypotension and tachycardia
• Cough, dyspnea, stridor, urticaria

Neurogenic

• Hypotension and bradycardia
• Warm and dry skin

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Clinical features

System Signs

Circulation Hypotension and tachycardia

• Cold peripheries
• Capillary refill time > 2 seconds

Cardiac Acute coronary syndrome CNS Confusion Respiratory Respiratory failure Kidneys AKI

• Reduced urine output

Liver Acute liver failure GI tract Bowel ischaemia Skin Necrosis and gangrene

Bedside

• Blood pressure monitoring: may require arterial line for continuous monitoring
• f the mean arterial pressure
• SBP < 90mmHg
• MAP < 65mmHg

Bloods

• Blood gas: venous or arterial
• Lactate > 2mmol/L

Management

• ABCDE
• IV fluids
• Vasopressors and inotropes

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General principles: Assessment of Shock

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Case-based discussion: 1

(1)

History

A 45-year-old gentleman presents with profuse coffee ground vomiting over the last two days. He is a heavy smoker.

Observations

HR 120, BP 90/60, RR 31, SpO2 95%, Temp 37.6

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Question: 1

(1)

Definition: reduced intravascular vascular volume resulting in circulatory failure and reduced

• xygen delivery to the tissues

Aetiology

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Introduction: Hypovolaemic Shock

Haemorrhagic Non-haemorrhagic

Trauma

• Blood on the floor plus four

Burns GI bleed Diarrhoea Aneurysm Vomiting Intracranial Third-space loss

• Pancreatitis
• Bowel ischaemia

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Pathophysiology: Hypovolaemic Shock

MAP = CO x TPR

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Question: 2

(1)

History

A 45-year-old gentleman presents with profuse coffee ground vomiting over the last two days. He is a heavy smoker.

Observations

HR 120, BP 90/60, RR 31, SpO2 95%, Temp 37.6

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Question: 3

(1)

History

A 45-year-old gentleman presents with profuse coffee ground vomiting over the last two days. He is a heavy smoker.

Observations

HR 120, BP 90/60, RR 31, SpO2 95%, Temp 37.6

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Classification: Haemorrhagic Shock

Symptoms Signs

1 2 3 4 Blood loss < 750ml < 15% 750-1500ml 15-30% 1500-2000ml 30-40% > 2000ml > 40% Heart rate <100 >100 120-140 >140 Systolic BP ↓ ↓ Pulse pressure Normal Narrow Narrow Narrow Respiratory rate 14-20 20-30 >30 >35 Urine output (ml/h) > 30 20-30 5-20 Negligible Mental function Normal Anxious Anxious Anxious Confused Confused Unresponsive

First-line

• IV fluids: boluses of crystalloid
• Avoid excessive hydration in haemorrhagic

shock (permissive hypotension)

• Blood products: indicated in haemorrhagic

shock

• Major haemorrhage protocol
• Red cells
• FFP
• Platelets
• Cryoprecipitate
• Treat the underlying cause

Second-line

• Vasopressors

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Management: Hypovolaemic Shock

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Major haemorrhage protocol

Blood product Components

Packed red cells Red cells FFP All clotting factors Platelets Platelets Cryoprecipitate Fibrinogen, vWF, factor VIII, factor XIII Prothrombin complex Factors II, VII, IX, X

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Case-based discussion: 2

(1)

History

A 45-year-old gentleman presents with shortness

• f breath and chest pain, worse on breathing in. He

has reported coughing up blood earlier in the day. He is a long-term smoker.

Observations

HR 120, BP 90/50, RR 25, SpO2 95%, Temp 37.6

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Question: 4

(1)

Definition: extracardiac causes of pump failure resulting in circulatory failure and

reduced oxygen delivery to the tissues

Aetiology

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Introduction: Obstructive Shock

Pulmonary vasculature Mechanical

PE Cardiac tamponade Tension pneumothorax

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Pathophysiology: Obstructive Shock

MAP = CO x TPR

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(1)

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(2) (3)

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(4)

• PE
• Thrombolysis: alteplase
• Cardiac tamponade
• Pericardiocentesis
• Tension pneumothorax
• Needle decompression: large bore

cannula in the 2nd intercostal space, mid-clavicular line

• Chest drain

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Management: Obstructive Shock

(5)

History

You are working in the emergency department within the resuscitation room. You are looking after a patient who had a STEMI 5 days ago. When auscultating their heart, you can hear an audible pansystolic murmur at the apex.

Observations

BP 90/60, HR 120, RR 30, SpO2 88%, Temp 36.5

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Case-based discussion: 3

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Question: 5

Definition: cardiac causes of pump failure resulting in circulatory failure and reduced

• xygen delivery to the tissues

Aetiology

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Introduction: Cardiogenic shock

Cardiomyopathic Arrhythmic Mechanical

Myocardial infarction Tachyarrhythmia Valvular insufficiency Bradyarrhythmia Septal rupture Ventricular wall rupture

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Pathophysiology: Cardiogenic Shock

MAP = CO x TPR

• IV fluids: be cautious with rehydration
• Vasopressors and inotropes
• Treat the underlying cause

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Management: Cardiogenic Shock

History

A 56-year-old lady is found collapsed by the side of her pond by her husband. She was last seen 30 minutes ago fixing her garden fence. She is brought in by ambulance and found to be acutely confused.

Observations

HR 48, BP 80/60, RR 14, SpO2 90%, Temp 35.1

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Case-based discussion: 4

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Question: 6

Definition: severe vasodilation resulting in circulatory failure and reduced oxygen delivery

to the tissues

Aetiology

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Introduction: Distributive Shock

Septic Anaphylactic Neurogenic

Bacterial Food Traumatic CNS injury Viral Drugs Fungal Insect bites

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Pathophysiology: Distributive Shock

MAP = CO x TPR

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Pathophysiology: Anaphylactic Shock

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Pathophysiology: Septic Shock

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Pathophysiology: Neurogenic Shock

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(6)

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Management: Distributive Shock

General principles

• Fluids: crystalloid boluses
• Vasopressors and inotropes
• Noradrenaline
• Dobutamine

Specific treatment

• Septic shock: broad spectrum antibiotics
• Anaphylactic

shock: adrenaline, anti-histamine, corticosteroids

• Neurogenic shock: atropine

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Top-decile question

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Top-decile question

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Recap

• Shock
• Cardiogenic
• Distributive
• Hypovolemic
• Obstructive
• Hypotension and raised lactate are the hallmarks
• ABCDE management
• IV fluids and vasopressors
• Treat the underlying cause

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References

1. James Heilman, MD / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0) 2. James Heilman, MD / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0) 3. BruceBlaus / CC BY (https://creativecommons.org/licenses/by/3.0) 4. Photographed by User Clinical Cases 00:42, 7 November 2006 / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.5) 5. Wiki public domain 6. Андрей Королев 86 / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

All other images were made by BiteMedicine and not suitable for redistribution

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