8- Complicated pregnancy (Operative delivery and pain relief) Flashcards
Instrumental delivery refers to
a vagina delivery assisted by either a
- ventouse suction cup
- forceps
indications for instrumental delivery
- Failure to progress
- Fetal distress
- Maternal exhaustion
- Control of the head in various fetal positions
RF for requiring instruemntal delivery
- epidural for analgesia
- high fetal weight
- older mothers
- high BMI mothers
Having an instrumental delivery increases the risk to the mother of:
- Postpartum haemorrhage
- Episiotomy
- Perineal tears
- Injury to the anal sphincter
- Incontinence of the bladder or bowel
- Nerve injury (obturator or femoral nerve)
The key risks for baby when having an instrumental delivery
- Cephalohaematoma with ventouse
- Facial nerve palsy with forceps
Rarely there can be serious risks to the baby:
- Subgaleal haemorrhage (most dangerous)
- Intracranial haemorrhage
- Skull fracture
- Spinal cord injury
forceps safer for…..
ventouse safer for….
forceps safer for baby
ventouse safer for mother
ventous
The suction cup goes on the baby’s head, and the doctor or midwife applies careful traction to the cord to help pull the baby out of the vagina.
- The main complication for the baby is cephalohaematoma. This involves a collection of blood between the skull and the periosteum.
forceps
They come as two pieces of curved metal that attach together, go either side of the baby’s head and grip the head in a way that allows the doctor or midwife to apply careful traction and pull the head from the vagina.
Complications to baby
- bruises on babys face
- facial nerve palsy, with facial paralysis on one side.
- Rarely the baby can develop fat necrosis, leading to hardened lumps of fat on their cheeks.
forcep delivery complications to mother
Nerve Injuries
Rarely an instrumental delivery may result in nerve injury for the mother. This usually resolves over 6 – 8 weeks. The affected nerves may be:
- Femoral nerve- weakness of knee extension, loss of patella reflex and numbness of anteiror thigh and medial lower leg
- Obturator nerve- weakness of hip adduction and rotation and numbness of the medial thigh
caesareans can be
elective or emergency
Elective caesarean indication
- Previous caesarean
- Symptomatic after a previous significant perineal tear
- Placenta praevia
- Vasa praevia
- Breech presentation
- Multiple pregnancy
- Uncontrolled HIV infection
- Cervical cancer
elective caesarean performed under which sort of anaesthetic
a spinal anaesthetic
elective caesarean performed after ….. weeks gest
39
types of emergency caesarean categories
- Category 1: There is an immediate threat to the life of the mother or baby. Decision to delivery time is 30 minutes.
- Category 2: There is not an imminent threat to life, but caesarean is required urgently due to compromise of the mother or baby. Decision to delivery time is 75 minutes.
- Category 3: Delivery is required, but mother and baby are stable.
- Category 4: This is an elective caesarean, as described above.
which incisions are used for caesareans
Most common (transverse lower uterine segment incision)
- Pfannestiel incision (curved)
- Joel-cohen incisions (straight incision slightly higher) - **recommended
Less common
- Vertical incision- rarely used**
vertical incision may be used if
- very premature deliveries
- anterior placenta praevia
what sort of dissection is used in C-section
blunt dissection after initial incision with a scalpel. Involves using fingers, blunt instrumetns and traction to tear the tissues apart. Baby is then delivered by hand with assitance of pressur eon the fundus.
- less bleeding, shorter operating times and less risk to baby
The layers of the abdomen that need to be dissected during a caesarean are:
- Skin
- Subcutaneous tissue
- Fascia / rectus sheath (the aponeurosis of the transversus abdominis and external and internal oblique muscles)
- Rectus abdominis muscles (separated vertically)
- Peritoneum
- Vesicouterine peritoneum (and bladder) – the bladder is separated from the uterus with a bladder flap
- Uterus (perimetrium, myometrium and endometrium)
- Amniotic sac
closing the uterus
Uterus is closed inside the abdomen using two layers of sutures.
*
Exteriorisation (taking the uterus out of the abdomen) is avoided if possible. The abdomen and skin are then closed.*
anaesthetic for c-section
Most common: Spinal anaesthetic (involves injecting local anaesthetic into the CSF)
Less common: general anaesthetic
Risks associated with having an anaesthetic:
- Allergic reactions or anaphylaxis
- Hypotension
- Headache
- Urinary retention
- Nerve damage (spinal anaesthetic)
- Haematoma (spinal anaesthetic)
- Sore throat (general anaesthetic)
- Damage to the teeth or mouth (general anaesthetic)
measures to reduce risks during caesarean section
- H2 receptor antagonists (e.g. ranitidine) or proton pump inhibitors (e.g. omeprazole) before the procedure
- Prophylactic antibiotics during the procedure to reduce the risk of infection
- Oxytocin during the procedure to reduce the risk of postpartum haemorrhage
- Venous thromboembolism (VTE) prophylaxis with low molecular weight heparin
why are H2 receptor antagonists or proton pump inhibitors given before c-section
reduce risk of aspiration pneumonitis during caesarean section, caused by acid reflux and aspiration during the prolonged period lying flat.
surgical risks of c-section for mother
General
* Bleeding
* Infection
* Pain
* Venous thromboembolism
Damage to local structures
- ureter
- bladder
- bowel
- blood vessels
Effect on abdominal organs
- ileus
- adhesions
- hernias
Effect on furutre pregnancies
- increased risk of repeat caesarean
- increased risk of uterin rupture
- increased risk of placenta praevia
- increased risk of stillbirth
complications after c-section
Postpartum haemorrhage
Wound infection
Wound dehiscence
Endometritis
Venous thromboemolism
surgical risks of c-section baby
- Risk of lacerations (about 2%)
- Increased incidence of transient tachypnoea of the newborn
VBAC
vaginal birth after caesarean
success rate of VBAC
75%
risks of VBAC
uterine rupture due to friable scar tissue from c-section
VBAC contraindications
- Previous uterine rupture
- Classical caesarean scar (a vertical incision)
- Other usual contraindications to vaginal delivery (e.g. placenta praevia)
prophylaxis for VTE involves
- Early mobilisation
- Anti-embolism stockings or intermittent pneumatic compression of the legs
- Low molecular weight heparin (e.g. enoxaparin)
simple advice which can improve symptoms of labour
- Understanding what to expect
- Having good support
- Being in a relaxed environment
- Changing position to stay comfortable
- Controlled breathing
- Water births may help some women
- TENS machines may be useful in the early stages of labour
pain relief avallable for labour
- simple analgesia
- gas and air (entonox)
- intramuscular pethidine or diamorphine
- patient controlled analgesia
- epidural
Simple Analgesia
- Paracetamol is frequently used in early labour. Codeine may be added for additional effect.
- NSAIDs are avoided (anti-prostaglandin which wont help pregnancy)
Gas and Air (Entonox)
.
Gas and air contains a mixture of 50% nitrous oxide and 50% oxygen.
- This is used during contractions for short term pain relief.
- The woman takes deep breaths using a mouthpiece at the start of a contraction, then stops using it as the contraction eases.
- It can cause lightheadedness, nausea or sleepiness
Intramuscular Pethidine or Diamorphine
Pethidine and diamorphine are opioid medications, usually given by intramuscular injection. They may help with anxiety and distress
risks of using opiods in labour
- They may cause drowsiness or nausea in the mother, and can cause respiratory depression in the neonate if given too close to birth.
- The effect on the baby may make the first feed more difficult.
Patient Controlled Analgesia
Patients may be offered the option of patient-controlled intravenous remifentanil. This involves the patient pressing a button at the start of a contraction to administer a bolus of this short-acting opiate medication.
risk of patient controlled analgesia
Patient-controlled analgesia requires careful monitoring. There needs to be input from an anaesthetist, and facilities in place if adverse events occur. This includes access to naloxone for respiratory depression, and atropine for bradycardia.
how does an epidural work
An epidural involves inserting a small tube (catheter) into the epidural space in the lower back. This is outside the dura mater, separate from the spinal cord and CSF. Local anaesthetic medications are infused through the catheter into the epidural space, where they diffuse to the surrounding tissues and through to the spinal cord, where they have an analgesic effect. This offers good pain relief during labour. Anaesthetic options are levobupivacaine or bupivacaine, usually mixed with fentanyl.
adverse effect of epidural
- Headache after insertion
- Hypotension (reduces acitvity of sympathetic chain)
- Motor weakness in the legs
- Nerve damage
- Prolonged second stage
- Increased probability of instrumental delivery
when would a patient need urgent anaesthetic review after an epidural
if they develop significant motor weakness - unable to straight leg raise
- may have catheter in subarachnoid space- within the spinal cord
perineal trauma occurs when
A perineal tear occurs where the external vaginal opening is too narrow to accommodate the baby. This leads to the skin and tissues in that area tearing as the baby’s head passes.
Perineal tears can range from a graze, to a large tear involving the anal sphincter (third-degree) and rectal mucosa (fourth-degree).
when are perineal tears most common
- First births (nulliparity)
- Large babies (over 4kg)
- Shoulder dystocia
- Asian ethnicity
- Occipito-posterior position
- Instrumental deliveries
Classification of perineal tears
There are four degrees of perineal tear, each involving injury to tissue beyond the previous:
- First-degree – injury limited to the frenulum of the labia minora (where they meet posteriorly) and superficial skin
- Second-degree – including the perineal muscles, but not affecting the anal sphincter
- Third-degree – including the anal sphincter, but not affecting the rectal mucosa
- Fourth-degree – including the rectal mucosa
hird-degree tears can be subcategorised as:
- 3A – less than 50% of the external anal sphincter affected
- 3B – more than 50% of the external anal sphincter affected
- 3C – external and internal anal sphincter affected
management of first degree tears
no sutures
management of second degree tears
sutures
management of third and fourth degree tears
repaired in theatre
Additional measures are taken to reduce the risk of complications of perineal tears
- Broad-spectrum antibiotics to reduce the risk of infection
- Laxatives to reduce the risk of constipation and wound dehiscence
- Physiotherapy to reduce the risk and severity of incontinence
- Followup to monitor for longstanding complications
Women that are symptomatic after third or fourth-degree tears are offered an
elective caesarean section in subsequent pregnancies.
complications of perineal tear
- Pain
- Infection
- Bleeding
- Wound dehiscence or wound breakdown
Perineal tears can lead to several lasting complications:
- Urinary incontinence
- Anal incontinence and altered bowel habit (third and fourth-degree tears)
- Fistula between the vagina and bowel (rare)
- Sexual dysfunction and dyspareunia (painful sex)
- Psychological and mental health consequences
Perineal tears can lead to several lasting complications:
- Urinary incontinence
- Anal incontinence and altered bowel habit (third and fourth-degree tears)
- Fistula between the vagina and bowel (rare)
- Sexual dysfunction and dyspareunia (painful sex)
- Psychological and mental health consequences
what methods can be used to reduce risk of perineal tear
- episiotomy
- perineal massage
what methods can be used to reduce risk of perineal tear
- episiotomy
- perineal massage
episiotomy
An episiotomy is where the obstetrician or midwife cuts the perineum before the baby is delivered. This is done in anticipation of needing additional room for delivery of the baby (e.g. before forceps delivery). It is performed under local anaesthetic. A cut is made at around 45 degrees diagonally, from the opening of the vagina downwards and laterally, to avoid damaging the anal sphincter. This is called a mediolateral episiotomy. The cut is sutured after delivery.
episiotomy
An episiotomy is where the obstetrician or midwife cuts the perineum before the baby is delivered. This is done in anticipation of needing additional room for delivery of the baby (e.g. before forceps delivery). It is performed under local anaesthetic. A cut is made at around 45 degrees diagonally, from the opening of the vagina downwards and laterally, to avoid damaging the anal sphincter. This is called a mediolateral episiotomy. The cut is sutured after delivery.
