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

Introduction: Shock Definition: circulatory failure resulting in reduced oxygen delivery to the tissues Shock Examples Haemorrhagic Hypovolaemic Non-haemorrhagic Pulmonary Obstructive Mechanical Cardiogenic Cardiomyopathic Arrhythmic Mechanical Distributive Septic Anaphylactic Neurogenic 2

Pathophysiology: Shock • Cardiogenic • Obstructive • Hypovolaemic • Distributive 3

Compensated: BP maintained Baroreceptor reflex • RAAS • Catecholamine • ADH release • Decompensated shock: hypotensive Failure of neurohormonal mechanisms • Irreversible Multi-organ failure • 4

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 5

Clinical features System Signs Circulation Hypotension and tachycardia • Cold peripheries • Capillary refill time > 2 seconds Cardiac Acute coronary syndrome CNS Confusion Respiratory failure Respiratory AKI Kidneys Reduced urine output • Acute liver failure Liver Bowel ischaemia GI tract Necrosis and gangrene Skin 6

General principles: Assessment of Shock Bedside • Blood pressure monitoring: may require arterial line for continuous monitoring of the mean arterial pressure • SBP < 90mmHg • MAP < 65mmHg Bloods • Blood gas: venous or arterial • Lactate > 2mmol/L Management • ABCDE • IV fluids • Vasopressors and inotropes 7

Case-based discussion: 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 (1) 8

Question: 1 (1) 9

Introduction: Hypovolaemic Shock Definition: reduced intravascular vascular volume resulting in circulatory failure and reduced oxygen delivery to the tissues Aetiology Haemorrhagic Non-haemorrhagic Trauma Burns • Blood on the floor plus four GI bleed Diarrhoea Vomiting Aneurysm Third-space loss Intracranial Pancreatitis • Bowel ischaemia • 10

Pathophysiology: Hypovolaemic Shock MAP = CO x TPR 11

Question: 2 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 (1) 12

Question: 3 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 (1) 13

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

Management: Hypovolaemic Shock 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 15 • Vasopressors

Major haemorrhage protocol Blood product Components Packed red cells Red cells FFP All clotting factors Platelets Platelets Fibrinogen, vWF, factor VIII, factor Cryoprecipitate XIII Factors II, VII, IX, X Prothrombin complex 16

Case-based discussion: 2 History A 45-year-old gentleman presents with shortness of 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 (1) 17

Question: 4 (1) 18

Introduction: Obstructive Shock Definition: extracardiac causes of pump failure resulting in circulatory failure and reduced oxygen delivery to the tissues Aetiology Pulmonary vasculature Mechanical PE Cardiac tamponade Tension pneumothorax 19

Pathophysiology: Obstructive Shock MAP = CO x TPR 20

(1) 21

(2) (3) 22

(4) 23

Management: Obstructive Shock • PE • Thrombolysis: alteplase • Cardiac tamponade • Pericardiocentesis • Tension pneumothorax • Needle decompression: large bore cannula in the 2 nd intercostal space, mid-clavicular line • Chest drain (5) 24

Case-based discussion: 3 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 25

Question: 5 26

Introduction: Cardiogenic shock Definition: cardiac causes of pump failure resulting in circulatory failure and reduced oxygen delivery to the tissues Aetiology Cardiomyopathic Arrhythmic Mechanical Myocardial infarction Tachyarrhythmia Valvular insufficiency Bradyarrhythmia Septal rupture Ventricular wall rupture 27

Pathophysiology: Cardiogenic Shock MAP = CO x TPR 28

Management: Cardiogenic Shock • IV fluids: be cautious with rehydration • Vasopressors and inotropes • Treat the underlying cause 29

Case-based discussion: 4 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 30

Question: 6 31

Introduction: Distributive Shock Definition: severe vasodilation resulting in circulatory failure and reduced oxygen delivery to the tissues Aetiology Septic Anaphylactic Neurogenic Bacterial Food Traumatic CNS injury Viral Drugs Fungal Insect bites 32

Pathophysiology: Distributive Shock MAP = CO x TPR 33

Pathophysiology: Anaphylactic Shock 34

Pathophysiology: Septic Shock 35

Pathophysiology: Neurogenic Shock 36

(6) 37

Management: Distributive Shock General principles • Fluids: crystalloid boluses • Vasopressors and inotropes • Noradrenaline • Dobutamine Specific treatment • Septic shock: broad spectrum antibiotics • adrenaline, anti-histamine, Anaphylactic shock: corticosteroids • Neurogenic shock: atropine 38

Top-decile question 39

Top-decile question 40

Recap Shock • Cardiogenic • Distributive • Hypovolemic • Obstructive • Hypotension and raised lactate are the hallmarks • ABCDE management • IV fluids and vasopressors • Treat the underlying cause • 41

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 42

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