Obs Gynae

Question 1

causes of maternal cardiac arrest

Answer 1

similar to general adult population — 6Hs and 5 Ts

hypovolaemia
bleeding – obs related (APH, PPH, eclampsia causing intracranial haemorrhage & spenic A/hepatic rupture) vs non-obs related
relative hypovolaemia — sec to dense spinal block
shock — septic, neurogenic, cardiogenic

hypoxia
(HbF preferentially takes up O2 — hypoxia more easily & quickly)

hydrogen ions (acidosis)

hyper/hypoK

hypothermia

hypoglycaemia

toxicity
drugs – MgSO4, LA, illicit drugs

tamponade (cardiac)

tension pneumothorax

thrombosis
increased risk of clot formation — DVT, PE
AFE amniotic fluid embolism

trauma

Question 2

management of maternal cardiac arrest

Answer 2

check for response

no response = call for help — crash cart, AED, call for obs resuscitation team, if >22 wks gestation = call for neonatal team

place a wedge beneath the patient or tilt the patient
if not possible = manual left displacement of uterus
left lateral not possible coz cant CPR in that position

commence CPR — compressions higher on sternum

once help arrives
Connect the AED machine to patient
Give 100% supplementary O2 consider airway adjuncts if needed (intubate early)
Insert 2 wide bore IV cannulas

if shockable rhythm (Vfib or pulseless VT) = provide shock
ensure foetal monitoring detached prior to shocking

after 4 mins of effective attempt to resus + mother still unresponsive = emergency delivery or perimortem caesarean section

Question 3

what is an ectopic pregnancy

Answer 3

implantation of foetus outside of the uterus

Question 4

where do ectopic pregnancies implant

Answer 4

majority (>95%) fallopian tubes

others: ovaries, cervix, abdominal

Question 5

causes of ectopic pregnancy

Answer 5

PID pelvic inflammatory disease
tubal surgery or peritubal adhesions
prev ectopic
IUD intra-uterine device
ART assisted reproductive technology

Question 6

presentation of ectopic pregnancy

Answer 6

symptoms (Hx)
lower abdominal or pelvic pain
amenorrhoea
PV bleeding

signs (exam)
pelvic tenderness
adnexal tenderness
abdominal tenderness

Question 7

Ix for suspected ectopic pregnancy

Answer 7

urine pregnancy test
serum hCG — since expected rise in beta hCG in ectopic pregnancy is blunted
US

Question 8

management of ectopic pregnancy

Answer 8

conservative Tx
indication: v.v.safe — live within safe distance, low serum hCG, pregnancy small
monitor until hCG <15

medical Tx = single IM dose methotrexate 50 g/m2
indication: minimal symptoms, stable, not ruptured, no blood dyscrasia, no infection, etc
measure beta hCG day 4 & 7
monitor until hCG <15

surgical Tx = laparoscopic salpingectomy or salpingostomy

+/- anti-D if required (ie mum rhesus -ve dad rhesus +ve)

Question 9

what is a massive obstetric haemorrhage

Answer 9

loss of >1.5L of blood

Question 10

causes of massive obstetric haemorrhage

Answer 10

antepartum haemorrhage
placental abruption
placenta praevia
severe chorioamnionitis
severe septicaemia
severe pre-eclampsia – hepatic rupture, splenic A rupture, ICH

intrapartum haemorrhage
intrapartum abruption
uterine rupture
AFE amniotic fluid embolism
complications of CS
placenta accreta spectrum

postpartum haemorrhage — 4Ts
tone: atonic uterus
tissue: retained products of conception
trauma: genital tract trauma
thrombus: coagulopathy

Question 11

complications of major obstetric haemorrhage

Answer 11

CVS
acute hypovolaemia — shock
sudden + rapid CVS decompensation

Respi
pulmonary oedema
ARDS acute respiratory distress syndrome

renal
metabolic acidosis — hypoxia causing anaerobic metabolism

haem
loss of clotting factors — washout phenomenon
DIC disseminated intravascular coagulation

endo
sheehan’s syndrome — chronic hypopituitarism sec to pituitary infarction

multiorgan dysfunction/failure

iatrogenic complications — sec to fluid replacement & blood transfusion

Question 12

what is antepartum haemorrhage

Answer 12

bleeding from the genital tract in pregnancy >24 wks gestation + before 2nd stage of labour

Question 13

classification of APH

Answer 13

non-substantial APH: <50ml blood loss
minor APH: <50ml blood loss + has settled

substantial APH: >50ml blood loss
major APH: estimated loss 50-1000ml + no signs clinical shock
massive APH: >1000ml loss + signs of clinical shock

Question 14

causes of APH antepartum haemorrhage

Answer 14

majority are indeterminate — assumed to be due to marginal haemorrhage (bleeding from the edge of the placenta)

serious causes include
placental abruption 1%
placenta praevia 1%

other causes incl
cervical ectropion
local infection of vaginal
varicosities in vulva region

Question 15

management of massive obstetric haemorrhage

Answer 15

emergency – call for senior help

ABCDEs
tilt to left lateral if >20 wks gestation
supplementary O2
2 wide bore 14G IV cannulas — start IV infusion

Ix
bloods
FBC
U&E
coag profile
GXM 4 units
Kleihauer-Betke stain

US — localise placenta + check foetal HR
CTG — assess foetal wellbeing

analgesia
consider delivery – anticipate PPH (atonic uterus)
consult haematology
call NICU if foetus still alive

Question 16

complications of APH

Answer 16

maternal
anaemia
infection
shock
multiorgan dysfunction — renal tubular necrosis
consumptive coagulopathy — risk of DIC
PPH — atonic uterus sec to major bleed
prolonged hospital stay
complications of blood transfusion

foetal
hypoxia
SGA small for gestational age or FGR foetal growth restriction
prematurity — iatrogenic vs spontaneous
foetal demise

Question 17

what is placenta praevia

Answer 17

when the placenta is inserted (wholly or in part) into the lower segment of the uterus

Question 18

presentation of placenta praevia vs placental abruption

Answer 18

placenta praevia = PAINLESS bleeding vs placental abruption = PAINFUL

signs
praevia = high presenting part (ie not engaged) or transverse/oblique lie
abruption = woody hard/firm uterus (persistently hard)

Question 19

classification of placenta praevia

Answer 19

grade I: placenta extends into lower uterine segment
grade II: placenta extends to edge of internal os
grade III: placenta covers internal os BUT isnt centrally placed
grade IV: placenta covers internal os + is centrally placed

Question 20

Ix for APH

Answer 20

Hx & Exam

Hx
nature of bleeding
any show
any pain
any precipitant
is it settling
happened before

exam
IMEWS
signs of anaemia
fundus < dates
uterine tenderness, woody hard, high presenting part

DONT DO VAGINAL EXAM — until US r/o placenta praevia

bloods
FBC
etc etc

Question 21

management of placenta praevia

Answer 21

if low lying placenta noted on 20 wk anatomy scan = arrange for placental localisation scan at 32-34 wks

1 bleed = discharge
2 bleeds = admit until delivery
major placenta praevia = admit from 34 wks until delivery

if grade I & II (>2cm from internal os) = can vaginal
if Grade II (<2cm from internal os), III or IV = caesarean section

elective delivery — aim for 37 wks

Question 22

what is placental abruption

Answer 22

it is the separation of the placenta from the uterus prior to delivery of foetus

Question 23

risk factors for placental abruption

Answer 23

HTN — esp if acute or fulminating pre-eclampsia or eclampsia
trauma
smoking, alcohol, cocaine use
Hx abruption
chorioamnionitis
extremes of maternal age
low SES