DR G SIYAKA Obstetric anaesthesia

OUTLINE Physiological changes of pregnancy Anaesthesia for caesarean delivery Analgesia for labour Complications and contraindications to neuraxial anaesthesia Medical conditions in pregnancy Obstetric emergencies

Physiological changes of pregnancy Cardiovascular Changes in CO, SV,HR Changes in BP,SVR Aorta-caval compression Respiratory Lung mechanics Gas exchange Oxygen consumption

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Physiological changes of pregnancy Airway Haematological Blood volume Anaemia, thrombocytopaenia Clotting factors Gastrointestinal Delayed stomach emptying LOS tone

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Evaluating the pregnant patient History Examination Special investigations Informed consent and premed

Anaesthesia for caesarean delivery Anaesthetic technique Pre-operative evaluation Theatre preparation Regional anaesthesia(spinal) Fluid co-load Baseline monitoring Aseptic technique

Anaesthesia for caesarean delivery Needle Drugs Testing your block Managing hypotension Uterotonic therapy

Anaesthesia for caesarean delivery General anaesthesia Only if contra-indication to spinal anaesthesia Pre-op evaluation,check aspiration prophylaxis been given Monitoring Pre-oxygenation, RSI with cricoid pressure Confirm intubation and allow surgeon to start

Maintenance of anaesthesia with volatile MAC 0.75,oxygen 50% and nitrous oxide/air Oxytocin Analgesia – opioids, NSAID, paracetamol,+/_ block(TAP) Reverse NMBs Extubate awake

Analgesia for labour Physiology of labour 1 st stage 2 nd stage

Analgesia for labour Pre-operative evaluation Check emergency equipment Epidural analgesia Preparation Needle Drugs including test dose Infusion regimens

Analgesia for labour Combined spinal epidural(CSE) Rationale for doing CSE Needles Drugs Infusion regimens

Complications of neuraxial anaesthesia Hypotension High spinal blockade PDPH ( classic description) Infection ( meningitis, arachnoiditis, epidural abscess) Spinal haematoma Failed spinal

Contraindications to neuraxial blockade Absolute Pt refusal, uncooperative Severe hypovolaemia Infection at injection site Coagulopathy ( platelets, INR, urea) Fixed output states (AS, constrictive pericarditis,HOCM) Raised intracranial pressure Patient refusal

Contraindications to neuraxial blockade Relative Systemic sepsis Active neurological disease Previous back surgery Complex surgery

Medical conditions in pregnancy Hypertension Classification-chronic hypertension -pre-eclampsia -eclampsia -gestational hypertension Problems related to pre eclampsia

Medical conditions in pregnancy Pre eclampsia Treatment goals Seizure prophylaxis Blood pressure control : methyldopa, CCB, labetalol Fluid management ULTIMATELY DELIVERY OF PLACENTA

Obstetric emergencies Major obstetric haemorrhage i.e. blood loss> 500ml post vaginal delivery, 1000ml post c/section delivery Causes APH (placenta praevia, placental abruption, uterine rupture) PPH( atony, retained tissue, trauma, coagulopathy)

Management Assess History medical and obstetric Exam,may even need an EUA Monitor ECG,NIBP,oxygen saturation Consider invasive monitoring IABP, CVP

Resuscitate Oxygen L/min If pre-delivery keep in L lateral Two large bore cannulae Take blood for FBC, clotting profile, X match Fluids : crystalloid, colloid,blood Transfuse if Hb 1.5, fibrinogen < 1.0 g/L

Stop the bleeding Bimanual compression Oxytocin Carboprost Misoprostol

Stop the bleeding Uterine balloon tamponade B Lynch compression sutures Devascularisation Hysterectomy as last resort

Adjuncts Cell salvage Interventional radiology Methotrexate Tranexamic acid Recombinant factor VIIa

Obstetric emergencies Amniotic fluid embolism