2. Obstetrics Flashcards
Q1 — Pre-eclampsia
A 25-year-old woman who is 37 weeks pregnant and known to have preeclampsia
is admitted to the labour ward with a blood pressure of
160/110mmHg on several readings.
a) What is the definition of pre-eclampsia?
Pre-eclampsia is a multisystem disorder with:
● Hypertension (BP >140/90mmHg) presenting after 20 weeks’
gestation.
● Significant proteinuria, i.e,
spot urinary protein: creatinine ratio
>30mg/mmol or a
24-hour urine collection with >300mg protein.
b) Define gestational hypertension.
Hypertension presenting after 20 weeks’ gestation without significant
proteinuria.
c) How can you define severe pre-eclampsia?
Proteinuria with severe hypertension (BP >160/110mmHg).
OR
Mild to moderate hypertension (140/90 to 159/109mmHg) with any of the
following features:
● Severe headache.
● Visual disturbance such as flashing lights or blurring.
● Vomiting.
● Subcostal pain.
● Papilloedema.
● Clonus (³3 beats).
● Liver tenderness.
● Thrombocytopenia (<100 × 109/L).
● Abnormal liver enzymes.
● HELLP syndrome
d) Explain the pathogenesis of pre-eclampsia.
**
● Impaired trophoblastic cell invasion.
● Failure of spiral artery dilatation.
● Placental hypoperfusion and hypoxia.
● Releases cytokines and inflammatory factors into the maternal
circulation triggering endothelial dysfunction.
● Increase in vascular reactivity, permeability, and coagulation cascade
activation.
● Organ damage.
e) Which related symptoms should pregnant women be told to
report immediately?
● Severe headache.
● Problems with vision, such as blurring or flashing before the eyes
● Severe pain just below the ribs or abdominal pain.
● Vomiting.
● Sudden swelling of the face, hands or feet.
● Reduced foetal movement.
f) How should this patient be monitored following admission to
the labour ward?
● Obstetric consultant-led care with input from anaesthetic and
neonatology teams.
● Monitor for signs and symptoms of severe pre-eclampsia.
● Monitor with the following — ECG, NIBP/IABP, pulse oximetry, RR,
fluid input/output, hourly reflexes.
● Six-hourly blood tests to monitor the platelet count, renal function
and liver enzymes.
● Foetal monitoring — US scan and CTG.
g) How would you control BP in this patient?
Maintain systolic pressure <150mmHg and diastolic pressure 80-
100mmHg.
● Reduce BP at the rate of 1-2mmHg per minute.
● First-line — oral labetalol.
● Oral methyldopa and nifedipine if labetalol is contraindicated
(bronchial asthma).
● Refractory hypertension — administer IV labetalol or IV hydralazine.
● Intra-arterial BP monitoring and HDU care may be considered.
h) What changes would you make to your airway management for
a pregnant woman, if this woman needed a general anaesthetic
for a caesarean section?
Anticipate a difficult airway.
● Manage the hypertensive response to laryngoscopy with alfentanil,
remifentanil, esmolol, atenolol.
● Manage hypertension at emergence with the same drugs.
● Smaller size ETT due to upper airway oedema.
● Gentle airway instrumentation to avoid trauma
i) What are the other considerations for GA?
● Non-depolarising muscle relaxants are potentiated by magnesium
sulphate; hence, smaller doses should be used with neuromuscular
monitoring.
● Appropriate neonatal resuscitation facilities.
● A higher risk of PPH but avoid ergometrine.
● Good postoperative analgesia/regional techniques like TAP blocks.
● Avoid NSAIDs.
● The likelihood of postoperative airway oedema
and pulmonary
oedema.
● Postoperative HDU/ITU care.
j) What are the complications of pre-eclampsia?
Maternal complications:
● Eclampsia.
● Intracerebral haemorrhage.
● Pulmonary oedema.
● Acute renal failure.
● Liver dysfunction.
● Coagulation abnormalities
Foetal complications:
● Abruptio placentae.
● Intrauterine growth restriction.
● Premature delivery.
● Intrauterine foetal death.
Q2 — Postdural puncture headache
The obstetric team tell you about a patient who is 2 days postpartum with
a suspicion of a postdural puncture headache (PDPH).
a) What is the differential diagnosis for this patient with a
suspected postpartum headache?
● Non-specific — dehydration, caffeine withdrawal, sleep deprivation.
● Tension headache.
● Lactation headache.
● Migraine.
● Sinusitis.
● Pre-eclampsia/eclampsia.
● Cortical vein thrombosis.
● Subarachnoid haemorrhage.
● Posterior reversible leukoencephalopathy syndrome.
● Space-occupying lesion — brain tumour, subdural haematoma.
● Cerebral infarction/ischaemia.
● Meningitis, encephalitis.
b) What features, in this patient, would lead you to consider a
serious underlying cause?
● Focal neurological deficit.
● Seizures.
● Altered conscious level.
● Absence of postural component.
● Presence of infectious markers.
● Hypertension and proteinuria — pre-eclampsia/eclampsia.
c) What is the mechanism/pathogenesis of headache in PDPH?
CSF leakage and a decrease in intracranial pressure causes:
● Traction on unsupported intracranial pain-sensitive structures such as
the tentorium and blood vessels.
● Compensatory vasodilatation of intracranial blood vessels.**
d) List the clinical features of PDPH.
● 90% of headaches develop within 3 days of the procedure.
● Headache is often frontal-occipital.
● Aggravated in the upright position, and when coughing or straining.
● Relieved on lying down.
● Associated symptoms include neck stiffness, nausea and vomiting,
visual disturbance, photophobia, auditory symptoms, cranial nerve
palsies.
e) List the management strategies for this patient who is suffering
with a PDPH.
f) You diagnose a PDPH and arrange treatment by an epidural
blood patch (EBP). How is an epidural blood patch performed?
● Obtain consent.
● IV access.
● Complete asepsis by both anaesthetists.
● Position the patient — usually laterally for patient comfort.
● Performed at or one space below the original site of dural puncture.
● The epidural space is identified.
● The assistant should aseptically withdraw 20ml of blood from a
peripheral vein.
● 10-20ml should be injected into the epidural space.
● Should radicular pain occur, slow or stop injecting.
g) What advice would you give to the patient after an EBP?
● Post-procedure, the patient should lie flat for 1-2 hours.
● Refrain from vigorous activity or lifting for a few days.
● Consider prescribing stool softeners to avoid constipation.
● Before leaving hospital, patients should be counselled to report fever,
severe back pain, or radicular pain immediately
h) Describe the mechanism of action of EBP.
● Tamponade effect of blood in the epidural space.
● Increased intracranial pressure and relief from headache.
● Formation of a clot seals the puncture site preventing further CSF
leak
i) What are the described risks of an EBP?
Risk of an epidural:
● Dural puncture.
● Permanent and temporary nerve damage.
● Meningitis.
● Risk of haematoma.
Risk of an EBP:
● Early complications:
- backache during injection;
- fever;
- bradycardia;
- seizures.
● Late complications include:
- meningitis;
- subdural haematoma;
- arachnoiditis;
- radicular pain;
- recurrence of headache.
a) Which methods of testing may be used to confirm the
adequacy of a spinal (intrathecal) block for an elective
caesarean section?
Sensory block:
● Temperature — ethyl chloride spray/cold sensation.
● Pin prick.
● Pressure.
● Touch.
● Proprioception, vibration.
A block to cold sensation at T2-4 and pin prick at T4-T5 confirms the
adequacy of the block for a caesarean section.
Motor block using the Bromage scale:
● 0 = no motor block.
● 1 = inability to straight leg raise but able to move knee and feet.
● 2 = inability to straight leg raise or move knee, able to move feet.
● 3 = complete motor block.
A score of 3 indicates a higher lumbar block.
Autonomic block:
● Hypotension.
● Bradycardia.
● Temperature changes
b) Describe the actions you could take if your spinal block proves
inadequate on testing prior to starting surgery for an elective
(category 4) caesarean section.
● Tilting the patient head down.
● If there is no evidence of block after 20 minutes, repeat the same
dose of spinal or do a combined spinal epidural.
● If the block is inadequate, consider an epidural catheter and gradual
top-ups. Repeating the spinal in this case may lead to a high/total
spinal.
● Consider GA.
● Discussion with the mother, surgeon and senior colleague, and foetal
monitoring to influence decision-making.
c) What are the early symptoms and signs of a spinal block that is
ascending too high?
T1-T4 block:
● Weak cough, shortness of breath (paralysis of intercoastal muscles).
● Hypotension and bradycardia (cardiac sympathetic block).
● Nausea and vomiting.
● Foetal compromise.
C6-C8 block:
● Paraesthesia of hands and arms.
C3-C5 block:
● Desaturation and respiratory arrest (diaphragmatic paralysis).
● Brainstem involvement and intracranial spread:
- a difficulty in phonation and swallowing;
- loss of consciousness.
d) How should you manage a patient who complains of pain
during an elective caesarean section under spinal anaesthesia?
● Stop surgery if required.
● Reassure.
● Communication with the mother and surgeon.
● Offer analgesia.
● Entonox®.
● Intravenous opioid:
- 25-50mg fentanyl, repeat as necessary;
- inform the neonatologist if this is given before delivery of the baby.
● Surgical infiltration of local anaesthetic.
● Epidural opioid/LA.
● General anaesthesia.
Categories of section
Category 1.
Immediate threat to the life of the woman or fetus
(for example, suspected uterine rupture,
major placental abruption,
cord prolapse, fetal hypoxia or
persistent fetal bradycardia).
Perform category 1 caesarean birth as soon as possible, and in most situations within 30 minutes of making the decision
Category 2. Maternal or fetal compromise which is not immediately life-threatening.
Perform category 2 caesarean birth as soon as possible, and in most situations within 75 minutes of making the decision.
Category 3. No maternal or fetal compromise but needs early birth.
Category 4. Birth timed to suit woman or healthcare provider.
