Anaesthesia/Periop Revision Dr Rob Stephens Consultant in Anaesthesia UCLH Hon Senior Lecturer UCL Thanks to Dr Roger Cordery

Google UCL Stephens Google UCL Anaesthesia Student

Only 50 minutes!! Search..‘department of anaesthesia’

Contents Physiology Anaesthesia Basics Analgesia Fluid Basics Airway /kit Basics Drugs / Perioperative Medicine

Physiology CO = SV x Hr MAP = CO x SVR O 2 delivery = CO x O 2 content (= Hb x SaO 2 ) Hypoxaemia = low O 2 in blood Deadspace = ventilation with no gas exchange = ventilation with no perfusion eg PE, Hemorrhage Shunt = perfusion with no ventilation eg Pneumonia, collapsed lung

Anaesthesia Basics Check out podcast Introduction to AnaesthesiaIntroduction to Anaesthesia At ees/students

Anaesthesia Triad of Anaesthesia – Hypnosis – Analgesia – +/-Neuromuscular paralysis

Anaesthesia Triad of Anaesthesia – Hypnosis – Analgesia – +/-Neuromuscular paralysis

Anaesthesia- Hypnosis Hypnosis= reducing consciouness Either I/v or volatile I/V Thiopentone Propofol CVS RS NS Depressants Volatiles- gasses- Sevoflurane, Isoflurane Breathe in, then out CVS RS NS Depressants I/V Ketamine Different side effects

Anaesthesia Triad of Anaesthesia – Hypnosis – Analgesia – +/-Neuromuscular paralysis

Anaesthesia: Analgesia Other, psychology, local, regional, systemic Local/regional – Na + channel Lignocaine, Bupivicaine Systemic – ‘ladder’ plus adjvants (extras) – Simple –Paracetamol – NSAID – oral, I/v s/e GI/platelets/ asthma/renal – Opioids = any drug acting on opioid receptors s/e N+Vomit / constipation / RS /NS Dihydrocoedine, Morphine, Fentanyl I/m, PCA (cautious i/v) Oral,transdermal – Gabapentin, Amitriptyline, Nitrous oxide etc

Analgesia Other, psychology, local, regional, systemic Postop pain – depends on expected needs ?Intraop block/epidural + systemic Everyone gets Paracetamol regularly 1G QDS ?add NSAID regularly eg Ibuprofen 200mg-400mg TDS ?add Dihydrocoedine regular ?need stronger – oral PRN Oral Morphine ? need stronger – PCA – i/v

Analgesia- PCA Patient Controlled Analgesia Morphine IV 1mg/ml PCA Pictur1mg bolus No background 5 min lockout Nursing Obs

Anaesthesia Triad of Anaesthesia – Hypnosis – Analgesia – +/-Neuromuscular paralysis

Anaesthesia: Neuromuscular To allow intubation and easy ventilation No movement for surgery NMJ Nicotinic Cholinergic antagonists – Non-competitive/depolarising = Suxamethonium= 2 acetylcholine molecules – Competitive/non- depolarising = Others – Atracurium, Rocuronium, Vecuronium.. Reversal- inhibit the enzyme that breaks down Ach (Cholinesterase) with Neostigmine used in Myaesthenia Gravis

Anaesthesia: 3 classical phases Preoperative – v important Induction- going to sleep – Dangerous – Mostly Analgesia, Iv hypnosis, paralysis – O 2, Air, ABCD Maintenance –during surgery Emergence – once surgery has ended ?postop? and recovery

‘Preoperative’ CVS SOBOE < 2 flights stairs? = Heart Failure Angina? = IHD Can’t assess exercise tolerance? Many other issues…. risk vs benefit of surgery ?postpone elective surgery to ’optimise’ ?

Fluid Therapy Everyone gets confused! Think about why you’re called to see patient Hx, Exam, Ix, Management Ward Guidelines- NICE vs others How can you monitor fluid status? Colloids / Crystalloids / Blood products Colloids vs Crystalloids – no real evidence

Fluid: Crystalloids / Colloids CSL = Hartmann’s Saline 0.9% Gelofusin / Geloplamsa Picture of Fluids

NICE ward fluid Assess - usual ways Resuscitate – Hartmanns/ Saline 500ml 15ml Routine Maintenance Oral ideally, if i/v Glucose g /day 25-30ml / kg / day Na K Cl 1mmol/kg/day Replace + Redistribution

Fluid Therapy Crystalloid – Saline / Glucose / Hartmann’s – Saline – Na Cl, acidosis, renal dysfunction – Glucose = water, no electrolytes, hyponatraemia – Hartmann’s-less Na K+, Ca+ less Cl, has lactate, no acidosis Colloids – smaller volumes / artificial- allergy – Gelatin in saline/Hartmann’s-like ‘Gelofusin’ ‘geloplasma’

Blood PRC FFPPlateletsCryoprecipitateOther PRC Transfusion – Immune / Infection /Over-Underload PRC Massive transfusion – Blood = cold,  K,  Ca, Coagulopathy Usually aim for 70-80g/L Unless CVS/RS disease

Fluid Intravenous Cannulae / ‘Venflons’ 22 g 20 g18 g 16 g 14 g Awake Asleep / local

Fluid Preparation Chat / Gloves / Sterilize skin Correct dressing + documentation

Arterial blood gas Essentially like venous – apart from 0xygen. pH pCO 2 sBEx (sHCO 3 ) Oxygen- what’s the Fi0 2 Other stuff UCLH happen to have bought – Eg Na, K, lactate, CO, Hb, MetHb New way of thinking- ‘Stewart’ (gold medal)

Airway Airways obstruct Under Anaesthesia If consciousness reduced Likely if GCS <8

Oxygen Nasal Cannuale1-3L/min Variable Flow ‘Hudson Mask’ 1-15L/min ‘Venturi’ Masks:Coloured for different % Tight fitting mask or hood for CPAP / NiV Oxygen via Airway ie anaesthetised / sedated

Airway 0 Give Oxygen – different ways 1 Airway Manouvers – caution in head trauma Jaw thrust / Head tilt / chin lift / 2 Airway Adjuncts Guedel 3 Airway kit eg Laryngeal Mask Airway 4 ‘Definitive’ Airway Intubate- Cuffed Oral EndoTracheal Tube / Tracheostomy 5 Surgical Airway – Cricothyroid /Tracheostomy

Airway Equipment

Airway Use adjuncts Adult male Adult female

Airway Equipment

Equipment

Video of LMA

Airway Equipment Cuffed Oral (nasal) Endotracheal Tube ‘ET Tube’ Internal Diameter sized Need to be paralyzed Inserted under Laryngoscopy

Airway Equipment

Drugs before surgery Don’t stop CVS drugs except ACE ie continue B Blockers, Ca ++ antagonists, Nitrates etc Don’t stop Asprin/Clopidegril with Coronary Stents Type 2 DM: no food, no hypoglycaemics ‘NBM’ –sips of water ok for drugs

Fasting Food, milk, 6 hours Clear fluids 2 hours Water -30 ml hour until surgery

Summary Anaesthesia- triad Hypnosis – IV Gas Analgesia – local, regional systemic Preoperative / 3 phases / Postoperative Fluids Equipment Welcome in theatre anytime Google UCL Stephens Google UCL Anaesthesia Student