Instrumental delivery Flashcards
Discuss instrumental delivery
-Incidence (2)
-Fetal indications (1)
-Maternal indications (5)
-Indications due to labour (1)
-Chance of subsequent vaginal birth (1)
- Incidence
-10% of vaginal births are instrumental deliveries
-30% of nullips (UK data) - Fetal indications
-Fetal distress in second stage - Maternal
-Cardiac disease with contra-indication to push
-Hypertensive crisis
-Proliferative retinopathy
-Cerebral aneurysm
-Maternal exhaustion - Labour
-Prolonged second stage - Chance of subsequent vaginal birth - 78-91%
What are the contra-indications to instrumental delivery?
-All instrumentals (5)
-Ventouse delivery (4)
- All instrumentals
-Risk of fetal bleeding - haemophilia or plt disorder
-Risk of fetal skull fracture - osteogenesis imperfecta
-Mother refusal
-Not fully dilated
-Fetal head above spines - Ventouse delivery
-Face presentation
-<34 weeks. Caution from 34-36 weeks (Relative contra-indication)
-Multiple FBS (relative contra-indication)
-Maternal condition where valsalva is contraindicated
Discuss factors that reduce the need for instrumental delivery (6)
-One to one continuous care (RR 0.9)
-Upright or lateral position in second stage of labour (RR 0.75) unless has epidural and then left lateral is better.
-Avoidance of epidural (Old data and now epidurals are less dense)
-Appropriate use of oxytocin - in nulips with malposition or inadequate contractions or second stage in nulips with an epidural
-Passive decent for up to 2 hrs or until urge to push
-Manual rotation of malpresentation
What factors increase the risk of failed instrumental delivery (6)
-BMI >30
-Macrosomia
-OP position
-Mid-cavity delivery
-Short maternal stature
-Head circumference >95%
Discuss the classifications of instrumental delivery
-Outlet (4)
-Low cavity (2)
-Mid cavity (3)
-High (3)
- Outlet
Fetal scalp seen without separating the labia
Fetal skull on pelvic floor
Fetal head at perineum
Position is direct OA or within 45 degrees L or R of these - Low cavity
Fetal skull is at +2 or more but not at level of pelvic floor
Position is either <45 degrees from DOA or > 45 degrees from DOA - Mid cavity
Fetal Head is no more than 1/5th palpable above the brim
Fetal skull is between +2 and spines
Position is either <45 degrees from DOA or > 45 degrees from DOA - High
Fetal head is 2 or more 5ths above pelvic brim
Fetal skull is above the ischial spines
High instrumentals are not recommended
What are the prerequisites for instrumental delivery (9)
-1/5th head abdominally or less
-Fully dilated
-At or below spines
-Vertex presentation
-Exact position known (Use USS)
-Adequate pelvis
-Ruptured membranes
-Consent from mother
-Caput and moulding <2+
Discuss choice of instrument for instrumental delivery
-What should be considered (7)
-When should forceps be chosen (6)
-When should ventouse be chosen (1)
- What should be considered
-Position and station of baby
-Amount of caput and moulding
-Effectiveness of analgesia
-Parity
-Urgency
-Maternal choice
-Skill of operator - When should forceps be used
-Ineffective maternal effort
-Valsalva is contra-indicated
-If needed for the after coming head in breech
-<34 weeks
-Too much caput and moulding
-Requirement of rapid delivery - When should ventouse be used
-Use in absence of clear indication for forceps delivery
Discuss the findings of forceps vs ventouse
-Outcomes more common with forceps (5)
-Outcomes less common with forceps (3)
-No difference between forceps or ventous (3)
- Outcomes more common with forceps
-Achieve vaginal birth RR 0.65
-3&4th degree tears RR 1.89
-Perineal injury RR 2.48
-Incontinence/ altered continence RR 1.77. No diff at 5yrs.
-Facial injury RR 5.1 - Outcomes less likely with forceps
-Failed instrumental RR 0.65
-Cephalohaematoma RR 2.4
-Retinal haemorrhage RR 2.0 - No difference
-Any neonatal injury
-Low apgar score at 5 mins
-Fetal acidosis
What are the maternal risks of instrumental delivery (8)
- Perineal trauma
- Anal sphincter trauma - ventouse 4% forceps 12%
- PPH
- Urinary difficulties
- Pelvic floor injury
- Prolapse
- Dyspareunia
- PTSD and psychological conditions
What are the fetal risks of instrumental delivery (9)
- Shoulder dystocia
- Brachial plexus injury
- Cervical spine injury 07:1000
- Skull fracture - rare
- Cranial bleeding
-Cephalohaematoma - worse with ventouse but not NS
-Subgaleal haemorrhage 1:300 ventouse deliveries
-Intracranial haemorrhage 1:600 forceps 1:800 ventouse, 1:900 EMCS - Facial nerve palsy and corneal abrasion (forceps)
- Minor scalp and soft tissue damage
- Retinal haemorrhage - ventouse
- NICU admission
Discuss failed instrumental
-Considerations for next action
-Impact to mother if sequential use of instruments
-Impact to fetus if sequential use of instruments
- Consideration for next action
-Review indication for instrumental
-Options are switch instruments, maternal effort, CS
-Individualise care with maternal input - Impact to mother
-Increased PPH
-Increased blood transfusion
-Increased lower segment tear
-Increased bladder damage
-Increased Hysterectomy
-Increased ICU admission - Impact to baby
-Increased need for resus
-Increased neonatal acidosis
-Increased intracranial haemorrhage
Discuss postpartum care for women with instrumental delivery
- IV Augmentin with 3hrs (ANODE trial - 58% reduction in infection)
- Take cord gases
- Delayed cord clamping if safe
- Active third stage
- Examine and repair perineum
- Analgesia
- Debrief
- Perineal cares
- Bladder cares - IDC for 12hrs if epidural/spinal
- Laxatives
- Physiotherapy
- Consider thromboprophylaxis
-Instrumental unless mid cavity is not itself a risk factor
Discuss types of ventouse cup and uses
-Silicone cup (3)
-Metal cup (3)
-Kiwi cup (2)
- Silicone cup
-Handle on tubing
-Easy to insert
-Use for uncomplicated deliveries with <45 degrees rotation - Metal cup
-OA or OP cups types. Use OP cup if deflexed OT position
-Use for difficult delivery, oblique, mid cavity, moderate amount of caput, large fetus or deflexed head
-More likely to result in successful VB (OR 1.6) - Kiwi cup
-Use for any delivery
-Less successful but similar safety profile
-Less scalp injuries (13% cf 24%)
Discuss placement of ventouse cup and delivery steps (10)
- Place cup so force is directly through flexion point and evenly across sagital suture.
- Flexion point is 3cm from posterior fontanell and 6 cm from anterior fontanelle
- Place rim of cup at edge of posterior fontanelle
- Apply 20g/cm of pressure and check for suction and whether maternal tissue is caught
- Increase pressure to 80g/cm
- Provide traction at right angles of cup with contractions with contractions and maternal effort. Keep thumb on cup and finger on vertex
- Between pulls maintain gentle traction to avoid loss of station
- Avoid rocking or twisting of the cup - increases subgaleal haemorrhage
- As head descends past symphysis pubis start to apply traction from horizontal to vertical
- Consider episiotomy
What are the reasons ventouse delivery should be abandoned
- Time
Upper limit until delivery is 20mins from first pull
Consider different approach if birth not looking imminent by 15mins - Number of pulls
3 pulls at a maximum with no decent
If decent can do more pulls if at pelvic floor - Cup detachments
-Up to 3 pop offs if decent
-Rapid decompression leads to vessel damage and increases risk of sub-galeal haemorrhage
Discuss the types of forceps
-Straight forceps (3)
-Rotational forceps (1)
-Short forceps (2)
- Straight forceps
-Neville Barnes
-Andersons
-Simpsons - Rotational forceps
-Keillands - Short
-Pipers
-Wrigleys
What are the checks that should be done to make sure the forceps are placed correctly (4)
- Posterior fontanelle should be midway between the shanks and 1cm above the plane of the shanks. If > 1cm then can cause head extension and difficult delivery
- Fenestrations should be barely palpable - only a finger tip. If palpable the blades are not cupping the fetal face but digging into the cheeks
- Lamboid sutures should be above the eqi-distant from the superior surface of the blades
- Apply the blades the same way for DOA and DOP
Discuss manual rotation
-Success rate (3)
- Success rate
-Up to 89%
-Reduces rate of CS
-Low chance of success if nulliparous, performed before full dilitation or first stage complicated by FTP
Discuss manual rotation - techniques (2)
Two type of technique
1. First technique
-Place whole hand in vagina with palm up
-Flex and slightly dislogde head
-Supernate or pronate hand in between contractions
-Hold fetal head in place for few contractions or until instrument applied to maintain position
2. Second technique
-Place fingers on lamboid sutures and use dialing motion to rotate fetal head
-Hold fetal head for few contractions or until instrument applied to maintain position
Discuss rotational forceps
-Type of forceps used
-Risk compared to CS (4)
-Risks compared to rotational ventouse (2)
- Type of forceps - Keillands
- Risk compared to CS
-Increased traumatic intracranial injury
-Increased cervical spine injury
-No evidence of increased maternal morbidity
-No evidence of long term morbidity for baby - Risk compared to rotational ventouse
-Less failure
-Less intracranial and supaponeuritic/ Subgaleal haemorrhage
When is rotational delivery considered
When occiput is more than 45 degrees from OA and in mid cavity
Discuss considerations for rotational forceps delivery
- The fetal head must be engaged (by abdo and vaginal assessment
- Analgesia should be adequate - epidural or spinal
- Only do if experienced or under supervision
- Rotate with a relaxed uterus. Consider tocolysis - GTN
- Do not rotate and apply traction at the same time. Rotate first traction second
- Abandon the procedure if:
-Application is difficult
-Handles don’t easily approximate
-Rotation is not easily achieved
-Lack of decent with moderate pressure
Discuss the key factors in rotational forceps (11 steps) (RANZCOG)
- Aim to prevent fetal malposition
-Judicious use of oxytocin
-Manual rotation - Assess to determine if suitable
-Check analgesia
-If position difficult to assess = red flag
-Empty woman’s bladder - Communicate with woman and gain consent
-Maternal complications - cervical and perineal trauma
-Fetal complications - cervical spine and ICH
-Episiotomy recommended - Prepare staff and birthing room
- Reconfirm fetal position
- Apply forceps
-Use wandering technique
-Apply between contractions
-Correct asyniclitism between contractions
-If difficult = Red flag - Rotate
-Between contractions
-Use force with one hand. Other hand on maternal abdo
-Ensure OA position after rotation
-Red flag difficult rotation - Apply traction
-Traction during a contraction
-Cut Episiotomy
-Too much force required = Red flag - Birth of head
-Remove blades
-Prepare for shoulder dystocia - Check and repair perineum
- Debrief and document
Discuss episiotomy use with instrumental delivery
-Reduction in OASIS tears with forceps
-Reduction in OASIS tears with ventouse
-NNT to avoid OASIS tears overall
-Recommendations
- Reduction for forceps - 24%
- Reduction for ventouse - 16%
- NNT 19 to avoid 1 OASIS injury
- Recommendations
-Consider for all women having their first vaginal birth requiring instruments
Discuss the ANODE trial
-Aim
-Method
-Outcomes
- To see if a stat dose of augmentin prevented maternal infection for operative VB
- Method
-Multi center RCT blinded - Outcomes
-Confirmed or suspected infection within 6 weeks of birth
Discuss the ANODE trial
-Numbers included
-Findings
- Numbers included
-3500 - Results
-Suspected or confirmed infection 11% in Augmentin group 19% in placebo (SS)
-Less perineal pain and breakdown in augmentin group (SS)
