SHOCK

Objectives Understand what shock is Understand what shock is Define types of shock Define types of shock Understand Pathophysiology of shock Understand Pathophysiology of shock Understand how to treat shock Understand how to treat shock

WHAT IS SHOCK? Inadequate Tissue Perfusion

Symptoms of Shock Anxiety /Nervousness Anxiety /Nervousness Dizziness Dizziness Weakness Weakness Faintness Faintness Nausea & Vomiting Nausea & Vomiting Thirst Thirst Confusion Confusion Decreased UO Decreased UO Hx of Trauma / other illness Hx of Trauma / other illness Vomiting & Diarrhoea Vomiting & Diarrhoea Chest Pain Chest Pain Fevers / Rigors Fevers / Rigors SOB SOB General SymptomsSpecific Symptoms

Signs of Shock Pale Cold & Clammy Sweating Cyanosis Tachycardia Tachypnoea Confused / Aggiatated Unconscious Hypotensive Stridor / SOB

Circulatory Homeostasis BP = CO X PVR CO – Cardiac Output PVR – Peripheral Vascular resistance Tissue perfusion is driven by blood pressure

Cardiac Output CO = SV X HR This means that BP= SV X HR X PVR Blood Pressure = Stroke Volume X Heart Rate X Peripheral Vascular Resistance

Stroke Volume Volume of Blood pumped by the heart during 1 cycle Volume of Blood pumped by the heart during 1 cycle What affects Stroke volume? Heart Muscle Damage Blood Volume Mechanical Obstruction Rhythm Problems

What makes up blood volume Plasma RBCs WBCs Platelets

What Alters Blood Volume? Haemorrhage Haemorrhage Plasma Loss Plasma Loss Redistribution of Extracellular Volume Redistribution of Extracellular Volume

Heart Rate Heart rate increases as a compensatory response to Shock Heart rate increases as a compensatory response to Shock Rarely you get Rarely you get High Output failure Heart rate too fast to allow adequate refilling of heart between beats

Peripheral Vascular Resistance PVR regulated by ARTERIOLAR tone. Dilatation opens Arteriovenous beds & increases volume of circulatory system

What Alters PVR? Circulation cytokines & Inflammatory mediators (e.g. Histamine) Circulation cytokines & Inflammatory mediators (e.g. Histamine) Endotoxins Endotoxins Drugs (e.g. Nitrates) Drugs (e.g. Nitrates)

Types of Shock HypovolaemicCardiogenicRedistributive

Hypovolaemic Volume Loss Volume Loss Blood loss -Haemorrhage Blood loss -Haemorrhage Plasma Loss-Burns / Pancreatitis

Cardiogenic Pump Failure Pump Failure May be due to inability of heart to Contact inability of heart to Contact Inability of heart to pump blood Inability of heart to pump blood

Redistributive Decreased Peripheral Vascular Resistance Decreased Peripheral Vascular Resistance Septic Shock Septic Shock Spinal / Neurogenic Shock Spinal / Neurogenic Shock ANAPHYLACTIC shock ANAPHYLACTIC shock

Pathophysiological Response “Flight or fight response” “Flight or fight response” Increased Catecholamine release Increased Catecholamine release Activation of Renin-Angiotensin system Activation of Renin-Angiotensin system Increase glucocorticoid and mineralcorticoid release Increase glucocorticoid and mineralcorticoid release Activation of Sympathetic nervous system Activation of Sympathetic nervous system

Treatment of Shock ABCABC

Ensure Adequate Intravascular Volume Ensure Adequate Intravascular Volume Support Pump Support Pump

Anaphylactic Shock Caused by a hypersensitivity reaction to an allergen in a previously sensitised patient Caused by a hypersensitivity reaction to an allergen in a previously sensitised patient

Common Allergens Nuts Bee / Wasp Stings DRUGS

Common Features Angio-oedema Angio-oedema Bronchoconstriction Bronchoconstriction Vasodilatation and hypotension Vasodilatation and hypotension Urticareal rash Urticareal rash

Angio-oedema

Treatment RECOGNISE THE PROBLEM GET HELP ABC

Treatment Ensure Airway is adequate Ensure Airway is adequate Oxygen Oxygen IV access early IV access early IV fluids IV fluids ADRENALINE 0.5ml 1 in 1000 IM ADRENALINE 0.5ml 1 in 1000 IM Bronchodilators Bronchodilators Steroids Steroids

SHOCK Clinical Scenarios

1) A 26 year old man with a comminuted closed fracture of the femur shaft undergoes intramedullary nail fixation. Two days post operatively, he develops a pyrexia, shortness of breath and tachycardia. 1) A 26 year old man with a comminuted closed fracture of the femur shaft undergoes intramedullary nail fixation. Two days post operatively, he develops a pyrexia, shortness of breath and tachycardia. Discuss the emergency management? Discuss the emergency management?

2) A 72 year old man develops sudden back pain and is brought to the emergency department with a swollen,tense abdomen. He is tachycardic,with a low volume pulse and low BP. 2) A 72 year old man develops sudden back pain and is brought to the emergency department with a swollen,tense abdomen. He is tachycardic,with a low volume pulse and low BP. Discuss the emergency management? Discuss the emergency management?

3) A 72 year old man with an underlying prostate carcinoma sustains a femoral shaft fracture.He undergoes intramedullary nail fixation. At post operative day 7 he develops a shortness of breath,hypotension and a tachycardia 3) A 72 year old man with an underlying prostate carcinoma sustains a femoral shaft fracture.He undergoes intramedullary nail fixation. At post operative day 7 he develops a shortness of breath,hypotension and a tachycardia Discuss the emergency management? Discuss the emergency management?