Caesarean sections Flashcards
1
Q
Discuss caesarean sections in NZ and Australia
-Rates in Australia
-Rates in NZ
-Elective repeat CS rate
A
- Aus rates - 33% 2015
- NZ rates 25% 2015
- Elective rates = 14% of all CS
2
Q
What are the success rates for VBAC for the following
-VBAC following single previous CS
-VBAC after 2 previous CS
-VBAC with previous VB
-VBAC if no previous VB, Previous CS for FTP, Requiring IOL, BMI >30
-VBAC if BMI >40
-Preterm VBAC
-Twin VBAC
A
- VBAC following single previous CS - 75% (varied in the literature)
- VBAC after 2 previous CS - 65-75%
(No difference in success rates for 1 or 2 CS) - VBAC with previous VB - 85-95%
- VBAC if no previous VB, BMI >30, Previous CS for FTP, Requiring IOL = 40%
- VBAC if BMI > 40 = 39% (> double risk of uterine rupture)
- Preterm VBAC - same success rate as term VBAC (Less rupture)
- Twin VBAC - same as success rate as singleton VBAC
3
Q
What are the factors which favour a successful VBAC (4)
A
-Previous safe VB
-Previous successful VBAC
-Spontaneous onset of labour
-Uncomplicated pregnancy without other risk factors
4
Q
What are the factors which reduce success of a VBAC (11)
A
-Previous CS for dystocia
-IOL
-Co-existing fetal, placental or maternal conditions
-Maternal BMI >30
-Fetal macrosomia >4kg
-Advance maternal age
-Short stature
-More than one previous CS
-Risk factors associated with increase risk of scar rupture
-Gestation >41 weeks
-Fetal malpresentation
5
Q
What are the contraindications to VBAC (5)
A
- Previous classical section
- Previous T or J extension
- Congenital uterine anomalies
- Inability to perform an EMCS
- Contraindications to VB
6
Q
What are the risk and benefits of VBAC
-Neonate risks (5)
-Neonate benefits (2)
A
- Neonate risks
-Increased uterine rupture 1:200 with 1:7 chance of death or brain injury
-Increased perinatal mortality 0.4-0.7:1000 (Low and comparable to nullips)
-Fetal acidosis <7.0pH 1.5:1000
-Increased HIE 0.4: 1000
-Increased Intracranial injury 1:1900
-Increased birth injury - Neonatal benefits
-Reduced neonatal distress 2-3%
-Higher breastfeeding rates
7
Q
What are the maternal risks and benefits of VBAC
-Risks (6)
-Benefits (4)
A
- Maternal risks
-Increased risk of emergency CS 1:4
-Increased serious CS complication rate compared with ELCS 13% vs 7%
-Increased risk uterine rupture 1:200
-Increased womb infection 29:1000
-Increased need for blood transfusion 2:1000
-Hysterectomy 0.8:1000
-Pelvic floor trauma - 5% 3rd and 4th
-Instrumental delivery 39% - Benefits
-Avoid major surgery
-Earlier mobilisation and DC from hospital
-Reduce future pregnancy complication
-Increase chance of future successful VBAC
8
Q
- What are the neonatal risks and benefits for ELCS
-Risks (3)
-Benefits (4)
A
- Risks
-Chance of EMCS prior to ELCS 118:1000
-Increased neonatal respiratory distress 4-5% (No difference after 40/40)
-Lower rates of breast feeding - Benefits
-Decreased uterine rupture <0.2:1000
-Reduced perinatal mortality 1:100,000
-Reduced HIE 0:1000
-Reduced intracranial injury 1:2750
9
Q
What are the maternal risks and benefits of ELCS
-Risks (2)
-Benefits (5)
A
- Risks
-Increased surgical complications
-Increased risk of complications in future pregnancies - Benefits
-Decreased womb infection 15:1000
-Decreased need for blood transfusion 10:1000
-Decreased uterine rupture <0.2:1000
-Avoid pelvic floor trauma
-Can plan time for birth
-Avoid EMCS with increased complications (13 vs 7%)
10
Q
What are the risk factors for uterine scar rupture (8)
A
-Very rare if unscarred uterus 0.5-2:10 000
-Multiparity
-Previous classical 90:1000
-Inverted T or J incision 19:1000
-Low vertical incision 20:1000
-IOL and augmentation esp with prostaglandins
-Pregnancy interval <18 months 2-3x risk
-Risk of recurrent rupture = >5%
-Previous uterine surgery with breech of cavity
11
Q
What are the signs of uterine rupture (9)
A
-Abnormal CTG (65-75%)
-Haematuria 25%
-Loss of station
-Concave abdomen
-Shoulder tip pain or diaphragm irritation
-Constant pain persists between contraction 8%
-Blood stained liquor 4%
-Cessation of effective uterine activity
-Maternal tachycardia or hypotension
12
Q
Discuss VBAC and induction of labour
-Risk of repeat CS
-Chance of successful VBAC
-Risk of rupture (5)
A
- Risk of repeat CS - 33% with IOL cf 18% if Spont labour
- Chance of successful VBAC = 65%
- Risk of rupture
-2-3 times higher with IOL
-Risk 10:1000 (Double spontaneous labour)
-Risk increased 4 times with use of oxytocin (2:100)
-Combined PG with oxy has highest risk
13
Q
Discuss augmentation and VBAC
-Chance of VBAC success
-Risk of uterine rupture
A
- Chance of VBAC success 75%
- Chance of uterine rupture 8-9:1000
14
Q
Discuss VBAC after >1 previous CS
-Success rate of VBAC
-Rupture rate
-Advice for VBAC after 3 CS
A
- Success rate for VBAC 70%
- Rate of rupture 1.6% (Note less than with oxy IOL)
- Advice for VBAC after 3 CS - don’t!!
15
Q
Discuss evidence based CS technique
-Which techniques have high level evidence (5)
-Which techniques are not supported by the evidence (3)
A
- -Pre-skin incision antibiotics reduce maternal infection RR0.5
-Blunt extension of the uterotomy in cephalad-caudad direction reduces blood loss and lateral extensions
-Spontaneous removal of the placenta reduces infection and blood loss cf MROP.
-Single layer closure in women who have completed their families
-Suture closure of adipose tissue if more than 2cm RR 052 for haematoma / seroma formation - Techniques not supported
-Manual cervical dilation
-Subcut drains
-Supplemental oxygen
16
Q
Discuss pre-operative steps for evidence based CS
-Antibiotics (3)
-IDC (3)
-Skin prep (1)
-Vaginal cleansing (2)
A
- Antibiotics
-15-60 mins before skin incision.
-First generation cephalosporin
-Reduction in infection RR 0.5 compared to after skin incision
-Avoid augmentin - Indwelling catheter
-Evidence is poor
-NICE recommend
-Catheterisation associated with increased UTI and no increase in bladder injury. Poor evidence - Skin preparation
-Chlorhexidine associated with reduced surgical site infection cf iodine (RR 0.7) - Vaginal cleansing
-Perform with providine iodine
-Reduces post-CS endometritis esp. if in labour (RR 0.41) 7.1% vs 3.1%
17
Q
Discuss incision type
-Pfannenstiel
-Joel-Cohen
A
- Pfannenstiel incision
-2-3cm above superior aspect of SP slightly curved - Joel-Cohen
-Straight incision 3cm below the line that transects the ASIS. Blunt entry through into the peritoneum.
-Joel-Cohen associated with less blood loss, faster operation time, less analgesia requirement, shorted post-op hospital stay cf pfannenstiel
18
Q
Discuss evidence based CS
-Management of the fascial layer (3)
-Management of the bladder flap
-Hysterotomy method
A
- Management of the fascial layer
-Insufficient evidence to dissect off rectus muscles
-Low level evidence suggests not to dissect the lower rectus fascia
-Sharp entry to fascia with blunt extension recommended - Management of the bladder flap
-Omission of a bladder flap reduces time to delivery 1.27 mins
-No difference in bladder injury, blood loss.
-Consider in repeat CS, CS at fully, Prelabour CS - Hysterotomy method
-J incision preferable to inverted T if extension required
-Blunt extension of hysterotomy cephalo-caudal recommended - less blood loss, less angle extension cf sharp
19
Q
Discuss evidence base CS
-PPH prophylaxis (4)
-Placental delivery (3)
-Uterine exteriorisation (3)
-Hysterotomy closure (4)
A
- PPH prophylaxis
-5IU oxy with delivery of anterior shoulder
-Routine oxy infusion
-Misoprostol confers no advantage over oxy
-TXA associated with reduced EBL >1000 and further use of uterotonics - Placental delivery
-Delivery spontaneously with CCT
-Avoid manual removal - increased blood loss, endometritis, Rh sensitisation
-Only do intra-uterine wiping if placental membranes seen - 1 x small RCT - Uterine exteriorisation
-New evidence suggests exteriorisation reduces blood loss
-Surgeon’s preference
-May be associated with increased discomfort. - Hysterotomy closure
-No difference in single or double layer closure for scar rupture / dehiscence / accreta / praevia
-Single layer faster operation time and maybe less blood loss
-Continuous and unlocked
-No evidence for suture type
20
Q
Discuss evidence based CS
-Management of peritoneum (3)
-Intraperitoneal drain use (2)
-Sheath closure (1)
-Subcut closure (3)
-Skin closure (2)
A
- Management of peritoneum
-Closure associated with increased post op pain
-May be associated with reduced adhesions
-Insufficient evidence to support closure - Intraperitoneal drains
-Consider if anticoagulated
-Use large bore non suction - Sheath closure
-Continuous closure with absorbable suture - Sub cut closure
-Perform subcut irrigation - 1 x RCT
-Close if >2cm of adipose
-Reduction in haematoma/seroma formation RR 0.52
-No difference for wound infection - Skin closure
-Subcut stitches
-Stables associated with increased wound separation and no difference in wound infection
-Use absorbable monofilament
21
Q
Discuss RANZCOG categories for CS urgency classification (4 categories)
A
- Category one: urgent threat to the life or health of mother or baby
- Category two: Fetal or maternal compromise but not immediately life threatening
- Category three: Requiring earlier than planned delivery but without current evidence of fetal compromise
- Category four: CS at a time that is acceptable to the woman and team
22
Q
Discuss the RANZCOG recommendations for classifying CS urgency (5)
A
-Supports a nuanced approach to determine urgency
-Recommends no specific time interval attached to categories
-Urgency must be re-evaluated and this communicated with team
-Centers with >4000 should have own obstetric OT
-Clear communication important to reduce decision to delivery interval
23
Q
Discuss classical caesarean section
-Indications (8)
-Technique (2)
-Risks (2)
A
- Indications
-Poorly formed lower segment
-Large uterine fibroids in lower segment
-Transverse lie and PPROM esp if back down
-Placenta praevia with large vessels in LUS
-Severe adhesions limiting access to LUS
-Planned CS hysterectomy
-Morbidly adherent placenta
-Perimortem CS - Technique
-Close in 3 layers
-Use monfilament for third layer to reduce adhesions - Risks
-PPH
-Increased risk of uterine rupture 9:1000
24
Q
What are the risks associated with CS at fully / impacted fetal head
-Risks to baby (2)
-Risks to mother (6)
A
- Risks to baby
-Skull fracture
-Intracranial haemorrhage - Risks to mother
-Angle extensions into lower segment / vagina
-Bladder injury
-Ureteric injury
-Haemorrhage
-Blood transfusion
-Need for ICU
25
Discuss delivery principles for impacted fetal head / CS at fully
-Pre-operative considerations (4)
-Intra-operative considerations
-Post delivery considerations
1. Pre-operative considerations
-Assess whether Vaginal or CS safest
-Apply upward pressure to assist disimpaction
-Consider fetal pillow (RR 0.23 for angle extension
2. Intra-operative considerations
-Perform hysterotomy higher to avoid going through vagina
-Stand on step
-Trendelenburg tilt
-Relax uterus - between contraction/tocolysis
-Turn to OT position
-Try to disimpact head with opposite hand
-Consider experienced assistant for vaginal disimpaction
-Extend incision
-Deliver breech
3. Post delivery considerations
-PPH prophylaxis
-Examine bladder carefully
-Examine carefully for hysterotomy extensions
26
Discuss CS delivery of breech baby
-Risks to fetus (6)
-Delivery method (8)
1. Risk to baby
-Overall risk lower cf vaginal delivery
-Dislocation of hip, shoulder
-Cervical spine injury
-Spinal cord injury
-Vertebral artery injury
-Brachial plexus injury
2. Delivery method
-Extend uterotomy cephalo-caudal
-Elevate breech to hysterotomy
-Delivery legs with Pinards manoeuvres
-Delivery Shoulders with Lovsett's manouevres
-Delivery Head maintaining fundal pressure to keep head flexed.
-If head not spontaneously delivered perform MSV manouvre
-If head still not delivered use obstetric forceps
-If head still not delivered consider tocolysis and inverted T incision
27
Discuss emergency peripartum hysterectomy
-Definition (1)
-Incidence (2)
-Causative factors (4)
-Risk factors (6)
1. Definition
Hysterectomy performed immediately following or within 24hrs of delivery
2. Incidence
-0.2-5:1000
-95% follow CS delivery
3. Causative factors
-Morbidly adherent placenta (55%)
-Placenta praevia (20%)
-Uterine atony
-Uterine scar rupture
4. Risk factors
-Previous CS (9% risk if >6)
-Previous uterine surgery
-Advance maternal age
-Placenta praevia
-Multiparity
-Multiple pregnancy
28
Discuss emergency peripartum hysterectomy
-Considerations pre-hysterectomy(3)
-Surgical difficulties (5)
-Surgical considerations (3)
1. Considerations
-If Hysterectomy is inevitable then don't delay
-Should be decided on by senior clinician. Better if 2 SMO's
-Can do aortic compression to buy time for decision and senior help
2. Difficulties
-Distended cervix - hard to identify external os
-Engorged and dilated pelvic blood vessels
-Friable and oedematous tissue
-Large bulky uterus
-Unstable patient
3. Surgical considerations
-Reflect bladder to minimise injury and displace ureters distally
-Use extra clamps on vessels to ensure haemostasis
-Consider subtotal hysterectomy as faster, safer.
29
Discuss PPH at CS
-Incidence (2)
-Maternal risk factors (6)
-Fetal risk factors (1)
-Situational risk factors (2)
1. Incidence
-7% of EMCS
-5% of ELCS
2. Maternal risk factors
-Obstructed labour
-APH
-Placenta praevia/ morbidly adherent placenta
-Prolonged labour
-Obesity
-Uterine fibroids
3. Fetal risk factors
-Macrosomia
4. Situational risk factors
-EMCS
-GA
30
Discuss PPH at CS
-Causes (4 categories)
-Prevention (4)
1. Causes
Uterine atony
Tissue trauma
-Angle extensions
-Cervicovaginal injury
-Bladder injury
-Muscle and adhesion bleeding
Placental
-Placenta praevia
-Morbidly adherent placenta
Coagulopathy
2. Prevention
-Meticulous surgical technique (JCM best)
-Correction of dextrose-rotation
-Correct placement of hysterotomy incision
-Delivery of placenta by CCT
31
Discuss management of PPH in CS (6)
1.Direct treatment at cause
2.Consider TXA for all causes
3.Manage atony with ecbolics, B-Lynch
4.Manage trauma with prompt surgical repair
-Secure angles
-Haemostatic sutures or uterine artery ligation
5. Bleeding from placental bed
-Figure of 8 sutures into placental bed
-Bakri balloon
32
Discuss rates of CS
-Incidence in NZ and Australia
-Reasons for increased CS rates (9)
-Evidence based ways to reduce CS rates (6)
1. Incidence
-31% Australia
-27% NZ
2. Reasons for increased CS rates
-Increasing maternal BMI
-Increasing maternal advanced age
-Increasing multiple pregnancy
-Reduction in rotational instrumental deliveries
-Increase in CS for breech
-Increase in placenta praevia and morbidly adherent placenta
-Increase rates of neonatal survival at earlier gestation
-Increased maternal co-morbidities
-Increased anxiety regarding litigation
3. Means to reduce CS rates
-One to on continuous care
-IOL after 41/40
-Partogram with 4 hr action line
-Consultant obstetrician to make decision
-Fetal blood sampling
-Increase VBAC and ECV
33
Discuss vaginal seeding
-Definition (1)
-Reasons for doing (4)
-Benefits
-Risks
-What to do if mother is requesting
1. Definition
-Innoculating a cotton swab with vaginal flora and exposing mouth, nose and skin of neonate
2. Reasons for doing
-Microbiome determined by mode of delivery.
-CS delivered infant have microbiome of maternal skin not vaginal mucosa
-Thought these differences may influence atopy and autoimmune diseases
-Children born by CS have increased rates of obesity, diabetes asthma and autoimmune disease.
3. Benefits
-AS yet unproven
4. Risks
-GBS, Chlamydia, HSV, Gonorrhoea
5. What to do if requested
-Risk of harm not justified without evidence of benefit
-If women wants to perform herself then consider testing for vaginal pathogens
-Make sure woman is well informed
-Ensure paeds and MW are aware
34
Discuss elective caesarean sections
-Indications for CS (9)
-When should a CS not be offered
-What are the increased risks of ELCS cf planned VB (7)
1. Indications for CS
-Malpresentation: Breech / transverse
-Twins: MCMA or leading twin breech
-Placenta praevia
-Previous CS: declining VBAC, previous classical, J or T incision
-High HIV viral load >400 copies/mL
-Primary genital herpes
-HIV with concurrent Hep C
-Maternal diabetes with EFW >4.5kg
-EFW >5kg without maternal diabetes
2. When should ELCS not be offered
-Preterm birth - effect of ELCS unknown
-SGA - Effect of ELCS unknown
-Hep B or Hep C - unnecessary
3. Increase in ELCS risks cf planned VB
-Maternal death 5 times risk
-Peripartum hysterectomy 2 x risk
-Wound infection 3 x risk
-Endometritis 12% increase
-Less urinary and prolapse issues with ELCS
-Pain same between groups at 4 months
-Increased Neonatal mortality, asthma, GI infections, respiratory infections
35
Discuss approach of ELCS for maternal request (5 points)
1. No RCT to help guide evidence
2. Explore reasons why requested
3. Discuss risks and benefits of VB vs CS
4. Offer support / intervention depending on reason for request
5. As per RANZCOG can either:
-Agree to provide once satisfied woman is well informed of choice
-If declines to provide must refer to another obstetrician for second opinion
36
Discuss timing of ELCS
-When should it be performed (5)
-Risk of pre-CS labour
-Should steroids be given for ELCS (4)
1. Timing
-39 weeks of after to avoid: increase in neonatal respiratory disorders, behavioural and neurodevelopmental issues associated with birth before 39/40
Increased metabolic disorders, increased adult mental illness
-Small increase risk in still birth related to increase of SB with increasing gestation
2. Risk of labour pre-CS
-10% if booked at 39 weeks
3. Should steroids be given for ELCS
-RCOG recommend steroids until 38+6 for ELCS
-C Steroid study aimed to answer this question
-ASTECS non-blinded RCT found Babies who had steroids from 37 weeks for ELCS had less SCBU admissions but very high NNT as admissions were rare
-RANZCOG say consider giving if you can't defer CS until after 39/40
37
Discuss complications of CS
-Incidence of complications at EMCS and ELCS (2)
-Factors that increase risk of complications (6)
1. Incidence of complications
-ELCS - 7%
-EMCS 16%
2. Factors that increase complication risk
-Obesity
-Cat 1 CS
-Previous surgery
-Pre-existing medical conditions
-Dilation 9-10cm 33:100
-EMCS
38
Discuss risks of CS complications
-Maternal (11)
-Fetal (3)
1. Maternal risks
-ICU admission 9:1000
-Emergency hysterectomy 8:1000
-Return to OT 5:1000
-Bladder injury 1:1000
-Ureteric injury 3:10 000
-Bowel injury - Rare
-Death 1: 12 000
-Repeat CS 1:4
-Wound infection 10:100
-Endometritis 18:100
-Ileus 10%
2. Fetal Risks
-IVH 1:900
-Fetal laceration 2:100
-Increased TTN, Pulmonary HTN, surfactant def (2-7 times increase)
-Still birth in future pregnancies 1-4:1000
39
How do CS impact future pregnancies (10)
-Delayed conception
-Increased ectopic pregnancy
-Uterine rupture
-Placenta praevia
-Placenta accreta
-Adhesions complicating future pregnancies
-Unexplained still birth >34 weeks
-IUGR
-PTB
-Unexplained still birth
40
Discuss Ogilvie syndrome
-Definition
-Pathophysiology
-Management
1. Definition
-Acute large bowel obstruction without mechanical cause
2. Pathophysiology
-Imbalance in the autonomic innervation of the colon leading to atony and proximal dilation
-May occur due to PNS during CS
-Caecum becomes dilated leading to ischemia, perforation and peritonitis
3. Management
-If Caecum <10cm consider conservative management. Avoid lactulose and opiates
If Caecum >10-12cm
-Consider neostigmine
-Urgent colonic decompression with rectal flatus tube
-If perforation urgent laparotomy
41
Discuss RANZCOG recommendations for managing VBAC in labour (6)
1. In a site with neonatal and OT access
2. Continuous fetal monitoring
3. IV access
4. Clear fluids only
5. VE at least every 4 hrs until 7cm then every 2 hours
6. Epidural is not contra-indicated
42
In what circumstances is the risk of fetal injury at CS increased (3)
-Deep impaction of fetal head in pelvis - skull fracture, ICH
-Fetal macrosomia -brachial plexus injury
-Breech presentation - cervical spine, spinal cord and vertebral injury
43
Discuss recommendations (RANZCOG) for delivery of an impacted fetal head in second stage
-Pre-operative delivery (4)
-Intra-operative (3)
-Post-operative (1)
1. Pre-operative
-A vaginal examination should be done by a senior doctor prior to CS commencing to exclude whether a VB is safer and easier
-Steady pressure to the fetal head to assist disimpaction should be applied (Hand or fetal pillow)
-Have experiences OB and paeds in the room
-Alter anaesthetics about need for acute tocolysis and PPH
2. Intra-operative
-Elevate the head into the abdomen by either - upward pressure from below or elevation of the fetal fetal by the accoucheur by passing the hand over the head and elevating
-Consider a tocolytic GTN
-Delivery by breech extraction
3. Post-operative
-Prepare for PPH secondary to atony, trauma, infection
44
How should shoulder dystocia in a CS be managed (3)
1. Anticipate macrosomia and make a larger incision. Extend as required
2. Consider delivery of the posterior arm
3. Consider a J or T incision
45
Discuss the ASTECS trial
-Aim (1)
-Study methodology
-Primary outcomes
-Secondary outcomes
1. Aim
-To see if steroids reduce respiratory distress in babies born by ELCS
2. Study design
-Pragmatic RCT
-10 maternity units
-2 x IM doses of 12mg betamethasone 48hrs before delivery
-Included women >37/40
-Not blinded
3. Primary outcome
-NICU admission for respiratory distress
4. Secondary outcomes
-Level of respiratory distress
-Level of care required
46
Discuss ASTECS trial
-Number included in the study (1)
-Results of the primary outcome (2)
-Results of the secondary outcome (3)
-Recommendations
1. Number included in the study
n = 950
2. Primary outcome results
RR of respiratory distress if treated with steroids 0.46 (SS)
-Reduction in respiratory distress in ELCS from 1.1 to 0.2%
3. Secondary outcome results
-Severity of respiratory distress was similar in both groups
-Babies in the control group required higher level of care
-Increased need for NICU associated with earlier gestation in both groups but more pronounced in control group in all categories
4. Recommendations
-Give steroids for ELCS
-Try to avoid ELCS before 39/40
