16.10 Airway + Obstetrics

Question 1

a) What factors may contribute to
difficulties encountered when securing the airway
under general anaesthesia in the pregnant patient?
(9 marks)

Answer 1

1. Patient:
   » Increased fatty tissue.
   » Increased breast size.
   » Increased tongue size.
   » Pharyngeal or laryngeal oedema.
   » Obesity (an increasing problem in the obstetric population generally).
   » Active labour may make cooperation with pre-induction positioning
   difficult.
2. Circumstantial:
   » Site of obstetric theatre often isolated,
   away from main theatres, without
   the second line airway equipment held in main theatres.

> > Urgency resulting in failure to:
• Assess airway.
• Starve patient.
• Premedicate the patient with antacid.
• Position correctly.
• Assess alternative modes of anaesthesia.

> > Intraoperative conversion of regional to general anaesthesia may be challenging.

Staffing:
» Anaesthetist: commonly out-of-hours,
therefore a trainee, low experience
of general anaesthesia for obstetrics.

> > Team:
poor planning, poor communication,
lack of awareness of other
health care professionals about the
potential difficulty with airway.
Failure to warn, failure to assist.

Question 2

b) What measures can be taken to reduce airway-related morbidity and mortality associated with general
anaesthesia in a pregnant woman? (8 marks)

Answer 2

Organisational:
» Locate labour ward theatre close
to main theatres and delivery suite.

> > Establish the personnel bleep
list to be contacted in the event of need
for general anaesthesia for pregnant woman – to include a second anaesthetist

> > Ensure adequate airway equipment,
including immediate availability of difficult airway trolley.

> > Staff training, skills and drills,
implementation of DAS/OAA guidelines.

> > Multidisciplinary protocols for
antenatal assessment of high-risk
parturients, and pathways for
ensuring communication of a written
management plan to staff on duty
when parturient presents in labour.

> > Guidance for handover between staff
involved in obstetric care to include those at
risk of airway issues such as those at risk of needing general anaesthesia and those known to have difficult or predicted difficult airway.

Prior to general anaesthesia:
» Outpatient antenatal assessment of high-risk women (obese, known previous difficult airway, regional likely to be difficult/unacceptable/
contraindicated).

> > Inpatient intrapartum assessment by
anaesthetist of high-risk women.

> > Junior anaesthetist to discuss
likely problem patients with senior to assist
in development of management plan.

> > Regular ranitidine in labour for
selected women according to protocol,
oral or intravenous.

> > Plans for likely difficult patients
to be discussed with other staff,
equipment readied.

> > Anaesthetist to remain aware of
efficacy of epidurals in situ on labour
ward in order to increase chances of
successful regional anaesthesia in
an emergency, thus reducing need
for general anaesthesia.

At the time of general anaesthesia:

> > Planned, daytime delivery with senior staff
for patients deemed very challenging.

> > Team briefing of airway plan,
second anaesthetist present.

> > Suitable equipment ready,
including full difficult airway kit.

> > Confirmation of premedication
with ranitidine and sodium citrate.

> > Optimum patient positioning: ramping.

> > Awareness of impact of left
lateral tilt on anatomy.
Adequate preoxygenation,
cricoid pressure and auscultation of chest and
check of capnography before cricoid pressure released.

After general anaesthesia:
» Same care with extubation as intubation:
consider stomach emptying with orogastric tube,
ensure the patient is wide awake,
sitting up, fully
reversed (use nerve stimulator).

> > Awareness of impact of opioids on
conscious level postoperatively (and
use of opioid sparing techniques if suitable).

> > Trained recovery staff, properly equipped recovery.

Question 3

c) What are the recommendations in the 4th National Audit Project (Major Complications of Airway
Management in the UK, NAP 4) regarding airway management in the pregnant woman? (3 marks)

Answer 3

> > Difficult airway management and CICO
skills must be kept up to date.

> > Obstetric anaesthetists should be
familiar with using second-generation
SADs for airway rescue.

> > Awake fibreoptic intubation
should be available (skills and equipment)
anywhere in the hospital.

> > All recovery staff
(including midwives working in recovery)
should be properly trained
and skills regularly updated.