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Acute Care Workshop. Dr Stephanie Sim Dr Sharon Christie Dr James Shaw Dr Lysa Owen. Plan for today. Learning Objectives Powerpoint presentation (on Blackboard) Demonstration of ABCDE Split into 2 groups Simulation Break at half time then swap.
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Acute Care Workshop Dr Stephanie Sim Dr Sharon Christie Dr James Shaw Dr Lysa Owen
Plan for today • Learning Objectives • Powerpoint presentation (on Blackboard) • Demonstration of ABCDE Split into 2 groups • Simulation • Break at half time then swap
Describe the pathophysiology of hypoxia and hypotension Identify when a patient is acutely unwell Demonstrate ability to assess an acutely unwell patient using ABCDE Initiate appropriate management Demonstrate awareness of specific treatment regimens Outcomes Acute care Workshop
Oxygen cascade • Series of steps: atmospheric air mitochondria • pO2 at any stage in subsequent steps
Remember Context is really important…. • A patient with ‘normal values’ when breathing at a rate of 40 bpm, is not as well as someone breathing at a rate of 12bpm • A patient with Sats of 96% on 60% O2 is not as well as someone breathing air with the same O2 sats! • A patient with PaO2 of 9kPa is getting better if it was 8 before and he is on the same concentration of O2,but getting worse if it was previously 10kPa!
Blood pressure Related to Arterial & venous system with organ autoregulation Blood Pressure Cardiac Output (CO) X Systemic vascular resistance (SVR) Heart Rate X Stroke Volume
Blood pressure Related to • Arterial & venous system with organ autoregulation Blood Pressure Cardiac Output (CO) X Systemic vascular resistance (SVR) Heart Rate X Stroke Volume Afterload ↓↓ SEPSIS/ ANAPHYLAXIS/ NEUROGENIC Myocardial contractility ↓↓ CARDIOGENIC SHOCK Preload ↓↓HYPOVOLAEMIA/ HAEMORRHAGE
Blood pressure THEREFORE Blood Pressure depends on Circulating blood volume ↓ in hypovalaemia/ haemorrhage Pump function ↓ in cardiogenic shock Systemic vascular resistance ↓ in sepsis ↓ in anaphylaxis
Response to shock • Tachycardia, Tachypnoea • Progressive peripheral vasoconstriction (if possible) • Shift to anaerobic metabolism for hypoxic cells, then lose the ability to generate ATP, loss of electrical gradient and cell death
Causes of Shock • Haemorrhagic (70Kg man)
Signs of shock Tachycardia, tachypnoea and vasoconstriction => Diagnosis of shock until proven otherwise (relying on BP drop delays diagnosis) Relative to normal (kids, young adults, elderly) Varying ability to mount response (B blocker, Ca channel blocker, paced, etc) Urine output – indicator of renal blood flow Should be >0.5ml/Kg/hour Acid Base Abnormality Respiratory alkalosis initially> Metabolic Acidosis
Assessment of shock • Airway • Breathing – give O2, RR, SpO2, Breath Sounds • Circulation – stem bleeding/obtain adequateiv access/assess tissue perfusion (P,BP,CRT) ?Fluids required (likely to be) • Disability – AVPU, BM, Pupils • Exposure – Complete examination re possible cause, temp, TPAR • ?Catheterisation
Fluid Homeostasis Normal 70 Kg male = 42litre (60%) Water Extracellular Fluid (ECF) Intracellular Fluid (ICF) 9.4 litres 4.6 litres 28 litres Interstitial Plasma
Normal Physiology Compartment volume maintained by • Oncotic pressure (retains fluid) • Hydrostatic pressure (forces fluid out of vessel) • Osmotic gradients • Electrolyte pumps
Types of fluid replacement • Crystalloids • Colloids • Blood
Crystalloids Eg. Dextrose, Saline, Hartmans True solutions - substances which will diffuse through a semi-permeable membrane Pros/Cons: • Easily available • Cheap • Variable volume of distribution (can end up in undesirable spaces!)
Colloids Eg. Gelofusine, “glue” – Greek Substance which does not diffuse through a semipermeable membrane. Large particles (protein or carbohydrate) that are suspended in water Pros/Cons : • Stays in intravascular space • Relatively expensive • Risk of anaphylaxis • No proven benefit over saline in hypovolaemia
Blood Pros/Cons : Well recognised • Replaces ‘like with like’ • Carries oxygen well! • Expensive • Risk of transfusion reactions • Infection risk etc
Distribution of Fluids ECF ICF Interstitial Fluid Circulation 5%Dextrose (essentially WATER) 0.9% Saline Blood Colloid (expands plasma volume due to oncotic pressure)
Main points • Recognise patient is unwell • Treat early (ideally before hypoxic, hypotensive) • Optimise what you can (ABCDE) *Remember Oxygen* • General measures to improve blood pressure • *Fluids* ( in almost all cases) • Inotropes • Specific measures to treat cause • Monitor response • Urine output, ABGs • Blood pressure/ cardiac monitor • Central lines etc • Etc
Outcomes Acute care Workshop Describe the pathophysiology of hypoxia and hypotension Identify when a patient is acutely unwell Demonstrate ability to assess an acutely unwell patient using ABCDE Initiate appropriate management Demonstrate awareness of specific treatment regimens