By Dr. SAFINA MUFTI TMO GCU

Obstetric analgesia and anesthesia

DEFINITION OF PAIN

It is an UNPLEASANT SENSORY and EMOTINAL EXPERIECE associated with ACTUAL

POTENTIAL TISSUE DAMAGE or DESCRIBED IN

TERMS OF SUCH DAMAGE.

NATURE OF LABOUR PAINS

1st stageVisceral pain Diffuse abdominal cramping Uterine contractions Dilatation of cervix T10-L12nd stageSomatic pain Perineum- sharper and more continuous Pressure or nerve entrapment-caused by

fetal head, may cause severe leg or back pain S2-S4

EEE EENDORPHINS

Natural pain killer produced from pituitary gland released during stressful events or in moment of grate pain it is responsible for euphoric feelings known as “runner’s high” and “adrenaline rush

Natural pain killer produced from pitutary gland released during stressful events or in moment of great pain it is responsible for euphoric feelings known as “runner’s high and adrenaline rush”Its secretion triggered by consumption of certain food “chocolate , chilli peppers” also triggered by massage therapy or accupuncture.

METHODS OF LABOUR PAIN RELIEF

PHARMACOLOGICAL NON PHARMACOLOGICAL1)SYSTEMIC PSYCHOPROPHYLAXIS+ BREATHING EXERCISES PARENTRAL HYPNOSIS NARCOTICS TENS TRANQUILISERS ACCUPUNCTURE INHALATIONAL HYDROTHERPY N2O ACCUPRESSURE METHOXYFLURANE AUDIO ANALGESIA ENFLURANE HOT &COLD APPLICATION ISOFLURANE AROMATHERAPY2)REGIONAL DOUBLE HIP SQUEEZ EPIDURAL STERILE WATER INJECTIONS SPINAL PUDENDAL BLOCK PARACERVICAL BLOCK3) GA4) LA or PERINEAL INFILTERATION

NON-PHARMACOLOGICAL stretagies:

• Support from a coach(experienced in childbirth) or any companion

• Hydrotherapy (water therapy)

Standing under warm shower or soaking in tube of warm water , the temperature of water used should be between 35-37c .

• TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION(TENS)

Two paired of electrodes attached to women back T10-L1 .

Low- intensity electrical stimulation is given continuously or applied by women herself as a contraction begin .

Block afferent fibers and preventing pain to travel from uterus to spinal cord synapses and facilitate release of endorphin

Carries no harm to fetus and mother.

AcupunctureBased on concept that illness result from an imbalance of energy , to correct the imbalance needles are inserted into the skin at specific body points , activation of these point lead to release of endorphins .

Helpful in first stage of labor

Acupressure

Application of pressure or massage to heel of the hand ,fist or pads of the

thumb and fingers

Application of Heat and ColdHeat Application •To increase blood flow and relieves muscle ischemia. •increases relaxationCold application

• slowing transmission of pain.

Aromatherapy

A study revealed that aromatherapy decreased the labour pain, but did not affect the duration of labour phases.

HypnosisIn this the focus of attention is to reduce awareness of the external environment.For childbirth, hypnosis is often used to focus attention on feelings of comfort or numbness as well as to enhance women's feelings of relaxation and sense

Sterile water injections (SWI) •Sterile water injections (SWI) are an effective method for the relief of back pain in labour. •The procedure involves a small amount of sterile water (0.1 ml to 0.2 ml) injected under the skin at four locations on the lower back (sacrum).•It causes brief stinging sensation-distracting from labour pains-3hrs

Double Hip SqueezeThe double hip squeeze changes the shape of the pelvis and releases tension on the sacroiliac joints.

PHARMACOLOGICAL STRETAGIES

OBSTETRIC ANALGESIA

OBSTETRIC ANESTHESIA

PHARMACOLOGICAL STRETAGIESNarcotic analgesic (opioid analgesic) Narcotic analgesic includes: pethidine

(meperidin) , fentanyl remifentanil, morphine, tramadol

Pethedin-most commonly used analgesic in labor has sedative and antispasmodic actions makes it effective not only for relieving pain & relaxing cervix providing feeling of euphoria and well-being

Narcotic antagonist : naloxon (Narcan)

Advantages increased ability to cope with labor Its nurse-administeredNo amnesic effect but create a felling of well-being or euphoria

Disadvantages Uncomfortable side effects, such as nausea and vomiting, pruritus, drowsiness and neonatal depressionPain is not eliminated completely

OBSTETRIC ANESTHESIA

The inhalation lasted for 53 minutes. The chloroform was given on handkerchief in 15 minim doses : The Queen expressed herself as greatly relived .

SIR JAMES YOUNG SIMPSON (1847 ) FIRST USED ANAESTHESIA IN OBSTETRICS

JOHN SNOW (1853) USED ANAESTHESIA ON QUEEN VICTORIA FOR THE BIRTH OF PRINCE LEOPOLD.

. AnesthesiaThe use of medication to partially or totally block

all sensation to an area of the bodyLocal anesthesiaReduce ability of local nerve fiber to conduct pain Numbs the perineum just before birth to allow for episiotomy and repairRegional anesthesia

injection of local anesthetic agent -tetracaine or bupivacine to block specific nerve pathways that supply a particular organ or area of the body

spinal analgesia epidural analgesia combined spinal epidural

•General anesthesia Intra Venous AnalgesiaInhalational Analgesia

LOCAL ANESTHESIA

PUDENDAL BLOCK

Spinal Anaesthesia(subarachnoid)

A fine gauge atraumatic spinal needle is inserted in to the subarachnoid space

Small volume of local anaesthetic (bupivocain/ropivocain) is injected in 3rd ,4th or 5th lumber space, after

which the spinal needle is withdrawnNot used for routine

analgesia in labour• Anesthesia normally raise to

level of T10 , up to umbilicus and including both legs.

Complication hypotension from sympathetic

blockage lead to impaired placental perfusion and ineffective breathing

pattern may occur during spinal anesthesia

Turn the women to her left side I.V fluid administration to increase blood

volume Vasopressin to increase BPO2 may be used Check V/S every 5-10min

pharmacological strategiesComplication spinal headacheOccur because continuous leakage of CSF from

the needle insertion site or by instillation of air into CSF , shift in pressure of CSF cause strain in vertebral meanings.

Incidence reduced by using of : small-gauge needle (25G) Increase fluid intake to replace spinal fluid

Epidural analgesiaEpidural catheter inserted at the level of L2-L3 L3-L4 or L4-L5 interspace & to the epidural

space.Catheter is aspirated to check the positionTest dose given to confirm the catheter position small volume of diluted local anaesthetic (10-15ml)After 5mins loading dose of mixture of 0.1% Bupivacaine with fentanyl 12mcg/ml is givenPrepare ephedrine for IV injection(30mg diluted

in 9mg of saline or water)Infusion of epidural solution 6-12ml/hr

EPIDURAL ANESTHESIA

Important…Secure IV access

Establishment/after each bolus measure BP every 5min for 15min,provide continuous EFM for 30 min

Every hour; check level of sensory block.

Continue until completion of the 3rd stage & any perineal repair.

Birth should take place within 4hours.

ContraindicationsCoagulation disordersLocal or systemic sepsisHypovolemiaInsufficient no.of trained staff

ComplicationsAccidental dural puncture-leak of CSF

causing spinal headacheAccidental total spinal anaesthesia -severe

hypotension, respiratory failure, unconsciousness & death

Drug toxicity occur with accidental placement of catheter within a blood vesselBladder dysfunctionShort term respiratory distress in baby

3. Combined spinal-epidural anesthesia CSECombination of opioid and local anesthesia injected

inside epidura and in subarachnoid space , used to block pain transmission without compromising motor ability

It is associated with greater incident with FHR abnormalities than epidural analgesia alone

Patient control epidural analgesia The newest method is the using PCA that  will be

programmed specially for the patient by anesthesiologist indwelling catheter and programmed pump that allow women to control the dose of analgesic , this method provide optimal analgesia with higher maternal satisfaction and enhance sense of control during labor. (saito et al,2005)

Inhalational analgesiaduring labour involves the self-

administered inhalation of sub-anaesthetic concentrations of agents while the mother remains awake and her protective laryngeal reflexes remain intact

Inhalational analgesiaN2O does not interfere

with uterine contractions.

No effect on fetus too.

Premixed nitrous oxide &oxygen.

N2O 50% and O2 50%

ENTONOX-cylinders with a capacity of 500 L are available.

Inhalation should begin 45 seconds before the onset of pain.

Systemic/General anesthesia

Indication for cesarean section delivery when

regional techniques cannot be used: Coagulopathy, infection (spinal),

hypovolemia , moderate to severe vulvular stenosis, progressive neurologic disease

Mother : unconscious, no pain, unpleasant memories

Fetus: should not be injured with minimal depression and intact reflex irritability so deliver baby as soon as possible.

Anesthesia apparatus

Sevoflurane: isoflurane:

Procedure:1. Be prepared with antacid 2. Give 100% oxygen with a close-fitting

mask for 3’3. Patient’s abdomen is surgical

scrubbed (disinfection) and draped for surgery (anesthetics act on the fetus ↓)

4. Thiopental, 2-5mg/kg iv succinylcholinE, 120~140mg iv5. Endotracheal intubation6.50% Nitrous oxide, 50% oxygen,

(0.5%)halothane or isofluran

Special side effects of general anesthesia in obstetrics

1.Aspiration of gastric contents into the lung Before endotracheal intubation ,

apply cricoid pressure to prevent aspiration.2.narcotics and barbiturates may cause

neonatal depress after delivery. The use of a narcotic antogonist (naloxone)

may reverse the effects

Type Drug Usual dosage

Effect on mother

Effect on labor progress

Effect on fetus or newborn

Narcotic analgesi

c

Meperidine (demerol)

25 mg IV, 50-100

mg IM q3-4 hr: also epidurally

Effective of

analgesic: feeling of well-being

Relaxation, possibly aiding

progress during

cervical relaxation. Slows labor

contractions if given early

Should be given 3 hr

before birth to avoid

respiratory depression

and decrease heart rate

Nalbuphine(nubain)

10-20 mg IM q3-6 hr, 0.3-3 mg/kg

over 10-15 min IV

Slowing of respirator

y rate; effective analgesic

Mild maternal sedation

Results in some

respiratory depression

Butorphinol (stadol)

1-2 mg IM or IV q3-

4hr

Withdrawal

symptoms if woman is opiate

dependent

Possible slowing of

labor if given early

Results in some

respiratory depression

Morphine sulfate

Intrathecally 0.2-1mg: 5

mg epidurally

Pruritus; effective analgesia

Possible slowing of

labor contractions

some respiratory depression

Fentanyl (subilimaz

e)

50-100µg IM or 25-50 µg IV ; epidurally

Hypotension;

respiratory

depression

slowing of labor if given

early

respiratory depression

Type Drug Usual dosage Effect on mother

Effect on labor progress

Effect on fetus or newborn

Lumbar epidural block

Marcaine or Naropin

Administered for first stage of labor; with continuous block, anesthesia will last through birth; injected at L3-4;

Rapid onset, in minutes; lasting 60-90 min; loss of pain perception of labor contractions and birth; possible maternal hypotension

slowing of labor if given early; pushing feeling obliterated resulting in possible prolonged second stage

May result in respiratory depression. May be some differences in response in first few days of life.

Pudendal block

Local anesthetic lidocaine (Xylocaine)

Administered just before birth for perineal anesthesia; injected through vagina

Rapid anesthesia of perineum

None apparent

None apparent

Local infiltration of perinem

Local anesthetic lidocaine (Xylocaine

Injected just before episiotomy incision

anesthesia of perineumAlmost immediately

None apparent

None apparent

General intravenous anesthetic

thiopental

Administered IV by anesthesiologist or nurse-anesthetist

Rapid anesthesia; also rapid recovery

Forceps required because abdominal pushing is no longer possible

Results in infant being born with CNS deperssion

Analgesia and anesthesia for abnormal obstetrics

The trapped head in breech delivery

If an epidural block is in place, no further analgesia will be required (forceps?)

General anesthesia is acceptable

Fetal distressFetus development of

bradycardia and appearance of meconium

Uterine perfusion is correlated with BP. Hypotension will aggravate fetal distress

The probable choice are no analgesia, minimal systemic analgesia (small dose), or segmental epidural block

Neonatal resuscitation is needed

Preeclmpsia-Eclampsia

Composed of hypertension, generalized edema, and proteinuria.

The primary pathologic characteristics is generalized arterial spasm

Regional and general anesthesia are used

Contraindications to regional anesthesia include coagulopathy, urgency for fetal distress

Hemorrhage and shock Placenta previa and aruptio

placenta are accompanied by serious maternal hemorrhage.

Treatment of shock must be formulated.

Ketamine can support BP for induction

Regional block is contraindicated in the presence of hypovolemia