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

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

Hypoxia

Oxygen cascade

Dry atmospheric gas, (~21)

Humidified tracheal gas, (~19.8)

Alveolar gas, (~14)

Arterial blood, (~13.3)

Capillary blood, (~7)

Mitochondria, (~4)

0

5

10

15

20

25

pO2

(kPa)

• 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 pressureRelated 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

Preload ↓↓HYPOVOLAEMIA/ HAEMORRHAGE

Myocardial contractility ↓↓ CARDIOGENIC SHOCK

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)

Class I Class II Class III Class IV

Blood loss (ml) Up to 750 750-1500 1500-2000 >2000

Blood loss

(% volume)Up to 15% 15-30% 30-40% >40%

Pulse rate <100 >100 >120 >140

Blood pressure Normal Normal Decreased Decreased

Pulse pressureNormal or increased

Decreased Decreased Decreased

Respiratory Rate 14-20 20-30 30-40 >35

Urine Output ml/hr >30 20-30 5-15 Negligible

CNS/Mental statusSlightly anxious

Mildly anxious

Anxious, confused

Confused, lethargic

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 adequate iv

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

Intracellular Fluid (ICF)Extracellular

Fluid (ECF)

Interstitial Plasma

9.4 litres

4.6 litres

28 litres

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

ColloidsBlood

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!)

ColloidsEg. Gelofusine,“glue” – GreekSubstance which does not diffuse through a semipermeable membrane.Large particles (protein or carbohydrate) that aresuspended 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

5%Dextrose(essentially WATER)

0.9% Saline

Blood

Colloid (expands plasma

volume due to oncotic pressure)

ICFECFIn

terstitial Flu

id

Circu

lation

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

Any Questions?

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