Revision - Obs 6 Flashcards
What is secreted by the posterior pituitary?
1) ADH
2) Oxytocin
What class of drug is Atosiban?
Oxytocin receptor ANTagonist
Can be used as an alternative to nifedipine for tocolysis in premature labour.
Side effects of ergometrine?
1) HTN
2) Coronary artery spasm
3) D&V
Who should ergometrine be avoided in?
1) Pre-eclampsia
2) HTN
What is Syntometrine?
Syntometrine is a combination drug containing oxytocin (Syntocinon) and ergometrine.
What is one key prostaglandin to be aware of in labour?
Dinoprostone (E2)
What class of drugs inhibit prostaglandins?
NSAIDs e.g. ibuprofen
Impact of prostaglandins on BP?
Act as vasodilators and lower BP
(hence NSAIDs increase BP)
Indication of misoprostol in labour?
1) It is used as medical management in miscarriage, to help complete the miscarriage.
2) Used alongside mifepristone for abortions
3) Induction of labour after intrauterine fetal death
Indication of Mifepristone in pregnancy?
1) abortions (used alongside misoprostol for abortions)
2) induction of labour of labour after intrauterine fetal death
What class of drug is carboprost?
Synthetic prostaglandin analogue
Indication of carboprost?
Given as deep IM injection in postpartum haemorrhage where ergometrine and oxytocin have been inadequate
Contraindication of carboprost?
Asthma
Mechanism of tranexamic acid
1) Binds to plasminogen and activates it to plasmin (plasminogen activator)
2) Plasmin works by dissolve the fibrin within blood clots
3) Therefore, by decreasing the activity of the enzyme plasmin, TXA acid helps prevent the breakdown of blood clots –> reduces bleeding
When is delay in the first stage of labour is considered?
1) less than 2cm cervical dilatation in 4 hours
or
2) slowing of progress in multiparous women
There are two lines on the partogram that indicate when labour may not be progressing adequately.
What are these labelled?
‘Alert’ and ‘action’
The dilation of the cervix is plotted against the duration of labour (time). When it takes too long for the cervix to dilate, the readings will cross to the right of the alert and action lines.
What is crossing the ‘alert’ line on a partogram an indication for?
Amniotomy (artificially rupturing the membranes) and repeat examination in 2 hours.
What does crossing the ‘action’ line on a partogram indicate?
Care needs to be escalated to obstetric-led care and senior decision-makers for appropriate action.
When does delay in the 2nd stage of labour occur?
When the active 2nd stage (pushing) lasts over:
1) 2 hours in nulliparous women
2) 1 hour in multiparous women
When there are weak uterine contractions, what can be given to stimulate the uterus?
Oxytocin infusion
What does ‘attitude’ of the fetus refer to?
The posture of the fetus e.g. how rounded the back is, how the head and limbs are flexed.
What does the ‘lie’ of the fetus refer to?
The position of the fetus in relation to the mother’s body:
- transverse
- longitudinal
- oblique
What does the ‘presentation’ of the fetus refer to?
The part of the fetus closest to the cervix:
- cephalic
- shoulder
- breech
When does delay in the 3rd stage of labour occur?
1) >30 minutes with active management
2) >60 minutes with physiological management
What does active management of the 3rd stage of labour involve?
1) IV oxytocin
2) Controlled cord traction
During labour, patients may be offered the option of patient-controlled analgesia.
What drug is offered?
IV remifentanil (short acting opiate)
What 2 medications must be accessible if giving a patient patient-controlled remifentanil?
1) naloxone: for respiratory depression
2) atropine: for bradycardia
What are the 2 anaesthetic options for an epidural?
1) levobupivacaine
2) bupivacaine
These are usually mixed with fentanyl
What is the most significant risk factor for cord prolapse?
When the fetus is in an abnormal lie after 37 weeks gestation (i.e. unstable, transverse or oblique).
Why can retrofilling the bladder with 500-700ml of saline be helpful in cord prolapse?
As it gently elevates the presenting part (reduces compression on cord)
What is the biggest maternal risk factor for shoulder dystocia?
Diabetes: the risk is significantly higher, even with a similar-sized baby.
Often offered c-section.
Should the mother keep pushing or stop pushing in shoulder dystocia?
Stop pushing - worsens the impaction
Risk of fetal and maternal complicatiosn when using forceps vs ventouse in birth?
Forceps –> lower risk of fetal complications but a higher risk of maternal complications.
Ventouse –> higher risk of fetal complications but a lower risk of maternal complications.
What is recommended after instrumental delivery to reduce the risk of maternal infection?
A single dose of co-amoxiclav
To use the ventouse, where is the cup applied?
The cup is applied with its centre over the flexion point on the fetal skull (in the midline, 3cm anterior to the posterior fontanelle).
Where is the flexion point on the foetal head?
In the midline, 6 cm posterior to the anterior fontanelle or 3 cm anterior to the posterior fontanelle.
What is the main foetal complication of using a ventouse?
Cephalohaematoma
What is the main foetal complication of using forceps in delivery?
Facial nerve palsy, with facial paralysis on one side.