Obstetrics Flashcards
What is the mortality of an amniotic fluid embolism?
20%
What is the incidence of AFE?
1/8,000 to 1/80,000
When does a presentation of AFE typically occur?
During labour or within 30 minutes of delivery
What are the core features of AFE? (4)
Bronchospasm
Pulmonary hypertension
Left ventricular failure
Coagulopathy
What are the most common presenting features of AFE?
Aura (restlessness, agitation, numbness) - 30%
Dyspnoea - 20%
Acute foetal compromise - 20%
Hypoxaemia
Hypotension
What are the most common features of AFE?
Maternal haemorrhage - 65%
Hypotension - 63%
Shortness of breath - 62%
Coagulopathy - 62%
Aura - 47%
Foetal compromise - 43%
Cardiac arrest - 40%
Cardiac dysrhythmias - 27%
Seizures - 20%
How is a diagnosis of AFE confirmed?
It is a clinical diagnosis, however it can only be confirmed on post mortem examination of the pulmonary vessels containing foetal squames and hair
What are the likely biochemical results of AFE?
↓ fibrinogen
↓ platelets
↑ fibrin degradation products
↑ APTT
↑ PT
Why is cryoprecipitate of particular use in AFE?
Cryoprecipitate containsfibronectinwhich activates thereticuloendothelialsystem and helps to filter antigenic material, and contains fibrinogen which is low in AFE
Which sensory nerve roots are responsible for transmitting the pain of the 1st stage of labour?
T10-L1
Which sensory nerve roots are responsible for transmitting the pain of the 2nd stage of labour?
S2-S4
What are the advantages of a PCEA bolus regimen
Improved satisfaction
Reduced staff resources
Potentially lower motor block
What is a standard regimen for a remifentanil PCA for labour analgesia?
0.3-0.5 mcg/kg 2-3 min lockout
Usually 40 mcg bolus
Define pre-eclampsia
Disorder of pregnancy:
- New-onset hypertension (systolic blood pressure ≥140 mmHg and/or a diastolic blood pressure ≥90 mmHg)
- After 20 weeks’ gestation
Although often accompanied by new-onset proteinuria, it may present in the absence of proteinuria in some women
Define severe pre-eclampsia
Pre-eclampsia with severe hypertension and/or
with symptoms,
and/or
biochemical,
and/or
haematological impairment
Mild hypertension
SBP 140-149mmHg
DBP 90-99mmHg
Moderate hypertension
SBP 150-159mmHg
DBP 100–109mmHg
Severe hypertension
SBP > 160mmHg
DBP > 110mmHg
Symptoms of pre-eclampsia?
Severe headache
Problems with vision, such as blurring
Severe pain just below the ribs
Vomiting
Sudden swelling of the face, hands or feet
Which patients are at increased risk of pre-eclampsia?
Hypertensive disease during a previous pregnancy
Chronic hypertension
Type 1 or 2 diabetes
Chronic kidney disease
Autoimmune disease such as SLE or antiphospholipid syndrome
What is the proposed therapy for those at increased risk of pre-eclampsia?
Aspirin daily 75 mg
What is the success rate of epidural blood patch?
50-80%
Differential diagnosis for PDPH
Simple tension headache
Migraine
Venous sinus thrombosis
Intracranial haemorrhage
Intracranial mass
Pre-eclampsia
Meningitis
What is the procedure for epidural blood patch?
Most senior anaesthetist
Strict asepsis
20 mL blood - stop if pressure/pain
Lie supine for 2 hours
Gradually mobilise
Follow up 2 hour, 24 hours, 1 week, 1 month
Management of seizures in LA toxicity
Benzodiazepine, thiopental or propofol in small incremental doses
What should you do to follow up LA toxicity?
Transfer to appropriate clinical area (ITU)
Exclude pancreatitis by clinical review, daily amylase/lipase for 2 days
Report cases to the NPSA
Document lipid use at lipidregistry.org
What are the doses of intralipid during LA toxicity
1.5 ml/kg over 1 min of 20% lipid emulsion
Start infusion of 15 ml/kg/hr
Give up to 2 rpt boluses
Double infusion to 30 ml/kg/hr
Maximum cumulative dose of 12 ml/kg
When is the peak time for teratogenicity of anaesthetic agents?
Week 3-8 gestation
21-56 days
What are the treatment options for severe PET?
Labetalol (Oral/Infusion)
Hydralazine IV
Oral Nifedipine
Magnesium
Fluid Restrict
Expedite Delivery
What are the features of an epidural haematoma?
Back pain: often severe and local, and can radiate to the arms or legs
Weakness: progressive weakness in the lower extremities, often bilateral
Paraesthesias: numbness or other sensory deficits in the lower extremities
Bowel and bladder dysfunction
Pain when pressure is applied: can be aggravated by direct pressure on the spine, coughing, sneezing, or straining
Phase 1 of AFE
Phase 1 (~30 mins)
Amniotic fluid + foetal cells enter maternal circulation
Release of biochemical mediators
Pulmonary artery vasospasm → pulmonary hypertension
Elevated right ventricular pressures + right ventricular dysfunction
Hypoxaemia + hypotension
Myocardial and capillary damage
Phase 2 of AFE
Phase 2 (if phase 1 survived)
Left ventricular failure
Pulmonary oedema
Biochemical mediators trigger DIC → massive haemorrhage + atony
