1. Melanie Tan C is for Circulation Locum Consultant in Anaesthesia, UCLH

2. Contents CVS physiology CVS changes Step by step during Anaesthesia + Surgery Managing changes CVS assessment Hypertension and Ischaemic Heart Disease Function All slides downloadable from website!! www.ucl.ac.uk/anaesthesia

3. CVS physiology: 0 2 delivery Heart –Double circulation to lungs / tissues –Work = 0 2 requirement –  rate, pre / afterload, contractility Oxygen content of blood  Hb, Sa0 2 Oxygen delivery = Amount of oxygen to tissues for cells to do ‘work’ = ATP generation / oxidative phosphorylation = Oxygen content x Cardiac Output

4. CVS physiology MAP = CO x SVR HR x SV Vaso-? constricted ? dilated

5. What happens to the CVS with Anaesthesia Surgery Illness Heart Vessels Blood Tissues

6. CVS effects.. Anxiety, walking to theatre, pain Induction of anaesthesia Onset of spinal anaesthesia Intubation Surgical stimulation /knife to skin Haemorrhage Extubation ?Recovery or complication

7. Autonomic Nervous System

8. Induction of anaesthesia Blood Pressure = CO x SVR HR x ↓SV ie vasodilated ↓ ↓ GA: negative inotrope + vasodilates Spinal/Epidural: vasodilates

9. Induction of anaesthesia Preoperative

10. Cardiovascular changes ‘artists impression’ version often filled in!

11. Intubation Blood Pressure = CO x SVR ↑HR x ↑SV ie vasocontricted ↑ ↑ positive inotrope + positive chronotrope vasocontricts

12. Intubation

13. ECHO of heart going fast

14. Surgical Incision

15. Knife 2 Skin

16. Hypovolaemia Diagnosis Classification – stages 1 to 4 Consequences: Organ hypoperfusion The ‘modern’ approach: monitoring HR x SV Vaso-? constricted ? dilated MAP = CO x SVR

17. Extubation Pain

18. Postoperative Recovery or complication? Systemic inflammatory response to surgery CVS tries to supply oxygen Increased sympathetic tone Tachycardia, increased inotropy- all need oxygen

19. CVS Changes: management Prevention of tachycardia/hypertension –Reduce anxiety –Good analgesia –Deepen anaesthesia –Nerve blocks / epidural –Specific drugs eg B Blockers & vasodilators Prevent hypotension ?cause –Fluid resuscitation vs targets –Vasoconstrictors + chronotopic drugs Blood Pressure = CO x SVR HR x SV

20. Preoperative CVS Evaluation Hx ‘How far can you walk? Up 2 flights?‘ ‘Short of breath’? exercise tolerance/SOB / chest pain drugs, interventions?, anticoagulants etc Examination HR / BP / Cardiac failure / Valves / Fluid status Investigations Bloods, ECG, +/- other Mx

21. Preoperative CVS Evaluation Emergency operations  get on + do it Unstable Angina, CCF, uncontrolled rhythm Discuss with cardiology Stable angina / valves / BP  / poor exercise Discuss with senior anaesthetist Rx depends on surgery Preop investigations, intraop monitors + manipulation Postop to ICU/HDU

22. Summary CVS changes at each stage The Good, The Bad & The Ugly Identify patients at risk Aim: minimise changes Aim: maximise oxygen delivery Manipulate CVS with specific techniques