Obstetrics Nuala Lucas OAA

What we knew before NAP6 Had received very limited prospective examination available knowledge case reports/series & reviews Scottish Confidential Audit of Severe Maternal Morbidity 3/100,000 births Retrospective US review 2.7 / 100,000 deliveries UK Obstetric Surveillance System 1.6 / 100,000 maternities

Specific concerns for obstetrics Two ‘patients’ Broad differential diagnosis Latex allergy?

Obstetric cases 8 cases identified NAP6 Activity Survey estimated 233,886 obstetric anaesthetics are administered PA in UK Incidence of severe obstetric perioperative anaphylaxis of 3.4 per 100,000 (95% CI 1.48-6.74 per 100,000) 6 cases associated with neuraxial anaesthesia, 2 cases associated with general anaesthesia

Numerical analysis Operative procedure Category 1 CS Category 3 CS EUA/PPH Unknown 2 4 1

Mon-Fri ‘daytime hours’ Numerical analysis Operative procedure Category 1 CS Category 3 CS EUA/PPH Unknown 2 4 1 Timing Mon-Fri ‘daytime hours’ Out of hours 3 5

Mon-Fri ‘daytime hours’ Numerical analysis Operative procedure Category 1 CS Category 3 CS EUA/PPH Unknown 2 4 1 Timing Mon-Fri ‘daytime hours’ Out of hours 3 5 Anaesthetist Consultant NCCG Trainee 3 2

Mon-Fri ‘daytime hours’ Anaesthetist for resus Numerical analysis Operative procedure Category 1 CS Category 3 CS EUA/PPH Unknown 2 4 1 Timing Mon-Fri ‘daytime hours’ Out of hours 3 5 Anaesthetist for resus Consultant Unknown 7 1

Presentation 4/6 patients who developed anaphylaxis assoc with neuraxial anaesthesia complained of feeling unwell prior to the onset of hypotension or other clinical signs ‘New’hypotension In 4 cases (both GA and 2/6 neuraxial cases) there was prompt recognition of the clinical event Only one case (neuraxial anaesthesia) was the event promptly recognised as anaphylaxis

‘New’ hypotension

Management Chlorphenamine 5/8 Hydrocortisone 6/8 Fluid mx appropriate ? Anaphylaxis pack 2/8

Management Chlorphenamine 5/8 Hydrocortisone 6/8 Fluid mx appropriate ? Anaphylaxis pack 2/8

Outcomes Post event Aftercare Baby 5/6 caesarean section cases No cardiac arrests Aftercare ITU/Recovery/Operating theatre/Observation bay on LW – 2/2/2/2 3/5 delayed hospital discharge One woman reported anxiety re future anaesthetics Baby 5/6 caesarean section cases – onset after delivery of baby 1/6 onset immediately before delivery of baby

Culprits

Recommendations Individual Institutional An allergy history should be taken even when there is extreme urgency to deliver the baby Anaesthetists should be vigilant to non-obstetric causes of hypotension in obstetric patients Anaphylaxis should be actively considered where the cause of maternal hypotension or collapse is unclear, and mast cell tryptase levels should be measured Anaphylaxis in obstetric patients should be managed following the same principles as in non-obstetric patients. Anaesthetists should be aware that hypotension due to anaphylaxis can be exacerbated by neuraxial blockade and or aortocaval compression Institutional Obstetric units should ensure immediate availability of anaesthetic anaphylaxis treatment and investigation packs wherever general or regional anaesthesia is administered

Other findings - choice of induction agent

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