Shock Year 4 Tutorials A B C D E

Objectives: What is shock? What is shock? Types of shock Types of shock Management principles Management principles

Shock Definition: State of inadequate tissue perfusion and tissue oxygenation as a result of a deficiency in the circulation

Types of Shock: Distributive – Septic Distributive – SepticAnaphylacticNeurogenic Cardiogenic Cardiogenic Obstructive –Tension pneumothorax Cardiac tamponade Obstructive –Tension pneumothorax Cardiac tamponade Hypovolaemic Hypovolaemic

BP = CO x SVR HR x SV Normal vascular tone determined by sympathetic innervation Contractility Preload (ventricle stretch) Afterload CARDIAC PHYSIOLOGY

Distributive - Sepsis SIRS = 2 of SIRS = 2 of RR > 20 breaths per minute RR > 20 breaths per minute WCC 12 WCC 12 Heart rate > 90 beats per minute Heart rate > 90 beats per minute Temperature: Fever > 38.0 °C or 38.0 °C or < 36.0 °C Sepsis = SIRS + Evidence of infection Sepsis = SIRS + Evidence of infection

Distributive - Septic Massive vasodilation Massive vasodilation BP = CO x SVR ( ) BP = CO x SVR ( ) Often dehydrated Often dehydrated Fluids & antibiotics, Fluids & antibiotics, Vasoconstrictors. Vasoconstrictors.

Distributive - Anaphylaxis Massive vasodilation Massive vasodilation Type 1 hypersensitivity Type 1 hypersensitivity Treatment: Treatment: Fluids, adrenaline, chlorphenamine, steroids Fluids, adrenaline, chlorphenamine, steroids ?Anaesthetist ?Anaesthetist

Distributive - Neurogenic Massive vasodilation Massive vasodilation Loss of sympathetic vascular tone. Loss of sympathetic vascular tone. Fluids and vasoconstrictors. Fluids and vasoconstrictors.

Cardiogenic shock PUMP failure! PUMP failure! Cannot empty pump Cannot empty pump BP = CO x SVR CO = HR x SV ( contractility) ( contractility) Causes: Causes: Acute MI Acute MI Large Infarction Large Infarction Papillary muscle rupture Papillary muscle rupture Other Conditions Other Conditions Septic shock Septic shock Myocarditis Myocarditis Arrhythmias Arrhythmias Drugs – eg beta-blocker overdose Drugs – eg beta-blocker overdose Myocardial contusion Myocardial contusion

Cardiogenic shock Treat underlying cause if possible Treat underlying cause if possible Inotropes. Inotropes. Balloon pump Balloon pump

Obstructive –Tension Pneumothorax Accumulation of air under pressure in the pleural space. Accumulation of air under pressure in the pleural space. 1-way valve 1-way valve Mediastinal shift: preload & afterload = SV Mediastinal shift: preload & afterload = SV

Obstructive –Tension Pneumothorax Treatment: Treatment: Needle decompression Needle decompression Chest drain Chest drain

Obstructive – Cardiac Tamponade Accumulation of fluid in the pericardial space, resulting in reduced ventricular filling Accumulation of fluid in the pericardial space, resulting in reduced ventricular filling Rapid filling of only 150ml causes compromise Rapid filling of only 150ml causes compromise

Obstructive – Cardiac Tamponade Becks triad: Becks triad: increased jugular venous pressure, increased jugular venous pressure, hypotension hypotension diminished heart sounds. diminished heart sounds. Treatment: needle pericardiocentesis Treatment: needle pericardiocentesis

Hypovolaemic Shock The system is DRY. The system is DRY. Causes: Causes: Haemorrhage Haemorrhage Sepsis Sepsis D&V D&V BP = CO x SVR BP = CO x SVR CO = HR x SV CO = HR x SV

Hypovolaemic / Haemorrhagic Where is the Blood? Where is the Blood? Revealed Revealed On the floor, at the scene On the floor, at the scene Concealed Concealed Chest Chest Peritoneal/Pelvis Peritoneal/Pelvis Long bones Long bones Retroperitoneum Retroperitoneum

Hypvolaemic shock management: Treat underlying cause Treat underlying cause haemorrhage control – 1 st aid, angio, theatre haemorrhage control – 1 st aid, angio, theatre Venous access / fluids Venous access / fluids Fluid replacement Fluid replacement

Vascular access: TWO large venflons TWO large venflons Where? Where? Anticubital fossa Anticubital fossa Consider IO Consider IO Take samples – X-match Take samples – X-match

Initial fluid therapy: Crystalloid Crystalloid Colloid Colloid Consider warming Consider warming Cross matched Cross matched Type specific Type specific ‘O’ negative ‘O’ negative Massive transfusion protocol Massive transfusion protocol

Response to fluid treatment: General General Urine - 30ml / hour (0.5mg/kg) Urine - 30ml / hour (0.5mg/kg) Acid / Base balance (lactic acidosis) Acid / Base balance (lactic acidosis)

Shock summary Distributive – Distributive – vasodilation - reduced SVR vasodilation - reduced SVR Cardiogenic – Cardiogenic – reduced heart rate / stroke volume - pump failure reduced heart rate / stroke volume - pump failure Obstructive – Obstructive – reduced stroke volume – blood can’t get in or out reduced stroke volume – blood can’t get in or out Hypovolaemic – Hypovolaemic – reduced stroke volume - lack of blood volume reduced stroke volume - lack of blood volume May be a combination

Shock summary ABCs ABCs Assess degree and cause Assess degree and cause Intervene: Intervene: Treat underlying cause Treat underlying cause Maintain CO and SVR - fluids, vasocostictors, inotropes Maintain CO and SVR - fluids, vasocostictors, inotropes Reassess Reassess Get HELP Get HELP

Questions ? A&E Department, Aberdeen Royal Infirmary 24