13. Operative Obstetrics Flashcards
1
Q
Define: Operative Vaginal Delivery (1)
A
forceps or vacuum extraction
2
Q
Name fetal indications: Operative Vaginal Delivery (2)
A
- atypical or abnormal fetal heart rate tracing, evidence of fetal compromise
- consider if second stage is prolonged, as this may be due to poor contractions or failure of fetal head to rotate
3
Q
Name maternal indications: Operative Vaginal Delivery (2)
A
- need to avoid voluntary expulsive effort (e.g. cardiac/cerebrovascular disease)
- exhaustion, lack of cooperation, and excessive analgesia may impair pushing effort
4
Q
Name: Prerequisites for Operative Vaginal Delivery (11)
A
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- Anesthesia (adequate)
- Bladder empty
- Cervix fully dilated and effaced with ROM
- Determine position of fetal head
- Equipment ready (including facilities for emergent C/S)
- Fontanelle (posterior fontanelle midway between thighs)
- Gentle traction
- Handle elevated
- Incision (episiotomy)
- Once jaw visible remove forceps
- Knowledgeable operator
5
Q
Name contraindicaitons: Operative Vaginal Delivery (4)
A
- unknown fetal head presentation
- unengaged head
- fetal bone demineralization disorder (e.g. osteogenesis imperfecta)
- fetal bleeding disorder (e.g. hemophilia or vWD)
6
Q
Describe: Outlet Forceps Position (3)
A
- head visible between labia in between contractions
- sagittal suture in or close to AP diameter
- rotation cannot exceed 45°
7
Q
Describe: Low Forceps Position (2)
A
- presenting part at station +2 or greater
- subdivided based on whether rotation less than or greater than 45º
8
Q
Describe: Mid Forceps Position (1)
A
9
Q
Name: Types of Forceps (4)
A
- Simpson or Tucker-McLane forceps for OA presentations
- Kielland (rotational) forceps when rotation of head or correction of asynclitism is required
- Piper forceps for after-coming head in breech delivery
- Wrigley’s for preterm babies
10
Q
Describe: Vacuum Extraction (1)
A
- traction instrument used as alternative to forceps delivery; aids maternal pushing
11
Q
Name contraindications: Vacuum Extraction (4)
A
- <34 wk GA (<2500 g)
- fetal head deflexed
- fetus requires rotation
- fetal condition (e.g. bleeding disorder)
12
Q
Name advantages and disadvantages: Forceps (3)
A
- Advantages:
- Higher overall success rate for vaginal delivery
- Decreased incidence of fetal morbidity
- Disadvantages: Greater incidence of maternal injury
13
Q
Name advantages and disadvantages: Vacuum Extraction (6)
A
- Advantages:
- Easier to apply
- Less anesthesia required
- Less maternal soft-tissue injury compared to forceps
- Disadvantages:
- Suitable only for vertex presentations
- Maternal pushing required
- Contraindicated in preterm delivery
14
Q
Name maternal complications: Forceps (6)
A
- anesthesia risk
- lacerations
- injury to bladder
- uterus, or bone, pelvic nerve damage
- postpartum hemorrhage (PPH)
- infections
15
Q
Name fetal complications: Forceps (6)
A
- fractures
- facial nerve palsy
- trauma to face/scalp
- intracerebral hemorrhage
- cephalohematoma
- cord compression
16
Q
Name complications: Vacuum Extraction (4)
A
- Increased incidence of cephalohematoma and retinal hemorrhages, and jaundice compared to forceps
- Subgaleal hemorrhage
- Subaponeurotic hemorrhage
- Soft tissue trauma
17
Q
Name: Limits for Trial of Vacuum (3)
A
- After 3 pulls over 3 contractions with no progress
- After 3 pop-offs with no obvious cause
- 20 min and delivery is not imminent
18
Q
Classify: Lacerations
A
- first degree: involves skin and vaginal mucosa but not underlying fascia and muscle
- second degree: involves fascia and muscles of the perineal body but not the anal sphincter
- third degree: involves the anal sphincter (partial IIIa or complete IIIb)
- fourth degree: extends through the anal sphincter into the rectal mucosa
19
Q
What should be done for third and fourth degree tears? (2)
A
- a single prophylactic dose of IV antibiotics (2nd generation cephalosporin, e.g. cefoxitin or cefotetan) should be administered to reduce perineal wound complications
- laxatives should also be prescribed and constipation should be avoided
20
Q
Define: Episiotomy (4)
A
- incision in the perineal body at the time of delivery
- essentially a controlled second degree laceration
- midline: incision through central tendinous portion of perineal body and insertions of superficial transverse perineal and bulbocavernosus muscles
- heals better, but increases risk of 3rd/4th degree tears
- mediolateral: incision through bulbocavernosus, superficial transverse perineal muscle, and levator ani
- reduced risk of extensive tear but more painful
21
Q
Name indications: Episiotomy (5)
A
- to relieve obstruction of the unyielding perineum
- to expedite delivery (e.g. abnormal FHR pattern)
- instrumental delivery
- controversial between practitioners as to whether it is preferable to make a cut or let the perineum tear as needed
- current evidence suggests letting perineum tear and then repair as needed (restricted use)
22
Q
Name complications: Episiotomy (5)
A
- infection
- hematoma
- extension into anal musculature or rectal mucosa
- fistula formation
- incontinence
23
Q
Describe epidemiology: Cesarean Delivery (1)
A
- overall 28% rate in Canada (range 18.5-35.3% by province/territory)
24
Q
Name indications: Cesarean Delivery (3)
A
- maternal: obstruction, active herpetic lesion on vulva, invasive cervical cancer, previous uterine surgery (past C/S is most common), and underlying maternal illness (eclampsia, HELLP syndrome, heart disease)
- maternal-fetal: failure to progress, placental abruption or previa, and vasa previa
- fetal: abnormal fetal heart tracing, malpresentation, cord prolapse, and certain congenital anomalies
25
Q
Name types of SKIN Cesarean Incisions in Cesarean Delivery (6)
A
- transverse (Pfannenstiel)
- decreased exposure and slower entry
- improved strength and cosmesis
- vertical midline
- rapid peritoneal entry and increased exposure
- increased dehiscence
26
Q
Name types of UTERINE Cesarean Incisions in Cesarean Delivery (1)
A
- low transverse (most common): in non-contractile lower segment
27
Q
Name types Cesarean Incisions that decrease chance for rupture in subsequent pregnancies (4)
A
- low vertical
- used for very preterm infants or poorly developed maternal lower uterine segment
- classical (rare): in thick, contractile segment
- used for transverse lie, preterm breech, fetal anomaly, >2 fetuses, lower segment adhesions, obstructing fibroid, and inaccessible lower uterine segment (e.g. morbid obesity)
28
Q
Name layers to dissect in cesarean (7)
A
- Skin
- fatty layer
- fascia
- muscle separation (rectus abdominis)
- peritoneum
- bladder flap
- uterus
29
Q
Name Layers of the Rectus Sheath in cesarean (10)
A
- Above the arcuate line:
- external oblique
- external internal oblique
- internal oblique
- rectus abdominis
- internal internal oblique
- transversus abdominis
- Below the arcuate line:
- external oblique
- internal oblique
- transversus abdominis
- rectus abdominis
30
Q
Name of the Obliterated Umbilical Ligament
A
Urachus
31
Q
Name risks/complications (7)
A
- anaesthetic complications (e.g. aspiration)
- hemorrhage (average blood loss ~1000 cc)
- infection (UTI, wound, and endometritis)
- single dose prophylactic antibiotic should be used (e.g. cefazolin 1-2 g)
- injury to surrounding structures (bowel, bladder, ureter, and uterus)
- thromboembolism (deep vein thrombosis DVT, pulmonary embolism PE)
- increased recovery time/hospital stay
- maternal mortality (<0.1%)
32
Q
Describe: Trial of Labour after Cesarean Section (TOLAC) (3)
A
- should be recommended if no contraindications after previous low transverse incision
- success rate varies with indication for previous C/S (generally 60-80%)
- risk of uterine rupture (<1% with low transverse incision), increased by interval <18 mo and one layer closure
33
Q
Name contraindications: Trial of Labour after Cesarean Section (TOLAC) (5)
A
- previous classical, inverted T, or unknown uterine incision, or complete transection of uterus (6% risk of rupture)
- history of uterine surgery (e.g. myomectomy) or previous uterine rupture
- multiple gestation
- non-vertex presentation or placenta previa
- inadequate facilities or personnel for emergency C/S
34
Q
Describe: Safety of vaginal birth after Cesarean (VBAC) (4)
A
- Rate of successful VBAC ranges from 60-82%
- No significant difference in maternal deaths or hysterectomies between VBAC or C/S
- Uterine rupture more common in VBAC group
- Evidence regarding fetal outcome is lacking
