PAINLESS LABOUR

DR. ANKITA GUPTA

DEBATE

When the anesthetic effects of ether and chloroform were discovered in the mid 1800's, many members of the British clergy argued that this human intervention in the miracle of birth was sin against the will of God.

If God had wished labor to be painless, he would have created it so. 

According to Scripture, childbirth pain originated when God punished Eve and her descendants for Eve's disobedience in the Garden of Eden. 

They believed that it was wrong to avoid the pain of divine punishment.

DEBATE

James Young Simpson used diethyl ether to anesthetize a woman with a deformed pelvis for childbirth.

Queen Victoria undaunted by the clergy chose one day to use an anesthetic during labor and the clergy's position crumpled like the great wall of 'Berlin'.

The first woman anesthetized for childbirth in the United States was Fanny Longfellow, wife of the American poet Henry Wadsworth Longfellow.

DEBATE

Labor results in severe pain for many women. There is no other circumstance where it is considered acceptable for a person to experience untreated severe pain, amenable to safe intervention, while under a physician’s care… Maternal request is a sufficient medical indication for pain relief during labor.”

ACOG & ASA

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

JOHN SNOW (1853) USED ANAESTHESIA ON QUEEN VICTORIA FOR THE BIRTH OF PRINCE LEOPOLD.The inhalation lasted for 53 minutes. The chloroform was given on handkerchief in 15 minim doses : The Queen expressed herself as greatly relived .

NATURE OF LABOUR PAINS

1st stageVisceral pain Diffuse abdominal cramping Uterine contractions 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

WHAT DETERMINES MATERNAL SATISFACTION

Pain relief Quality of relationship with caregiver Participation in decision making Home-like birth environment Caregivers with whom they are acquainted

personally

The goals of labor analgesia

"The delivery of the infant into the arms of a conscious and pain-free mother is one of the most exciting and rewarding moments in medicine.“

THE IDEAL LABOUR ANALGESIC

Good pain relief No autonomic block (hypotension) No adverse maternal or fetal side effects No motor block No effect on labour or delivery no increase in caessarean or instrumental deliveries Patient can ambulate Economical

Sensory innervation of upper genital tract Pain during the first stage of labor is generated

largely from the uterus cervix & upper vagina. Visceral sensory fibers traverse through the

Frankenhäuser ganglion, and enter into the pelvic plexus and then into the middle and superior internal iliac plexuses.

From there, the fibers travel in the lumbar and lower thoracic sympathetic chains to enter the spinal cord through the white rami communicantes associated with the T10 through T12 and L1 nerves.

Early in labor, the pain of uterine contractions is transmitted predominantly through the T11 and T12 nerves.

Sensory innervation of lower genital tract Pain in second stage of vaginal delivery arises

from stimuli from the lower genital tract. These are transmitted primarily through the

Pudendal nerve, the peripheral branches of which provide sensory innervation to the perineum, anus, and the more medial and inferior parts of the vulva and clitoris.

sensory nerve fibers of the pudendal Nerve are derived from ventral branches of the S2 through S4 nerves.

Note:The motor pathways to the uterus leave the spinal cord at the level of T7 and T8 vertebrae. Theoretically, any method of sensory block that does not also block motor pathways to the uterus can be used for analgesia during labor.

PAIN PATHWAY IN LABOUR

METHODS OF LABOUR PAIN RELIEF

PHARMACOLOGICAL NON PHARMACOLOGICAL

1)SYSTEMIC PSYCHOPROPHYLAXIS+ BREETHING EXERCISES

PARENTRAL HYPNOSIS

NARCOTICS TENS

TRANQUILISERS ACCUPUNCTURE

INHALATIONAL HYDROTHERPY

N2O ELECTRO ANALGESIA

METHOXYFLURANE AUDIO ANALGESIA

ENFLURANE

ISOFLURANE

2)REGIONAL

EPIDURAL

SPINAL

PUDENDAL BLOCK

PARACERVICAL BLOCK

3) GA

4) LA or PERINEAL INFILTERATION

NON PHARMACOLOGICAL METHODS:Psych prophylaxis & breathing exercise: Lamaze technique. Principal concept is to have natural child

birth. Antenatal education of patient about

physiology of child birth. Relaxation exercises to overcome fear and

anxiety -reduces oxygen demand and reduces CO2 production.

Breathing exercises during different stages of labour

in early labour – deep breathing towards the end of 1st stage – more rapid breathing During bearing down – breath holding Constant human support during labour. Delivery in semi darkness.

Hypnotherapy

Mongan method also known as Hypno Birthing , Hypnobabies, Natal Hypnotherapy and the GentleBirth program

can significantly shorten labor, reduce pain and reduce the need for intervention, produced higher apgar scores, reduce the incidence of postpartum depression and increase the incidence of spontaneous deliveries.

No studies abort its efficacy.

TENS

TENS (transcutaneous electrical nerve stimulation).

A maternity TENS machine consists of a hand-held controller connected by two sets of fine leads to four sticky pads. These are placed on your back. 

The machine gives out little pulses of electrical energy that reach your skin via the leads and pads.

The pulses may give you a tingling or buzzing sensation, depending on the setting 

stimulates the release of endorphins. Controls pain via Gate control. Most useful in labour before the pain becomes too intense. drug dose requirements may be less.

WATER BIRTHING Soviet researcher Igor Charkovsky and

French obstetrician Frederick Leboyer developed in 1960s

Practices in United States, Canada, Australia, and New Zealand, as well as many European countries, including the United Kingdom and Germany

By 2005, over 9000 hospitals in the US and more than three-quarters of all NHS hospitals (UK) provided this option.

Provides pain relief and a less traumatic birth experience for the baby

Redistribution of blood volume, which stimulates the release of oxytocin and vasopressin (Katz 1990)

Aid stretching of the perineum, slows crowning of the infant's head, reduces the use of episiotomy

a decrease in perinatal mortality (1.2 per 1,000 for waterbirth vs. 4 per 1,000 for conventional birth) during 1994-1996 in the UK.

The buoyance of water provides supports and relaxes the ligaments and tissues of mother which helps mother in taking comfortable position during labour.

Risks to the infant such as infection and water inhalation?

"there are no valid reports of infants deaths due to water aspiration or inhalation" (Harper 2000)

Slowed labor? A decrease in the intensity of contractions.

Maternal blood loss? - Difficult to assess. The amount of blood loss reduced due to lowering

BP and heart rate.

MUSIC:

Ancient Greeks played soothing instrumental music to women in labor.

Alters mood, reduces stress and promotes positive thoughts.

A trigger for a breathing response or as a cue for relaxation.

used as a distraction.

MASSAGE

Touch has been associated with the power of healing since the beginning of civilization

a source of counter-stimulation Examples; Therapeutic massage (eg: shiatsu),

perineal massage

METHOD OF TOUCH AND MASSGAE

lightly stroking the abdomen. vigorously firm stroking where it hurts most. firm circular massage using the palm of the hand

over the center of the back or sacrum. rhythmical squeezing and letting go of the

shoulder muscles . a long stroke down the length of the back,

buttocks and down the back of the legs. stroking across the forehead, down the neck and

down the arms . simply holding hands!!!

SHIATSUJapanese form of therapeutic massage. Shiatsu

means ‘finger pressure’. Similar to acupuncture. Pain-relieving pressure points (‘tsubo’) are stimulated without the use of needles

ACCUPUNCTURE: Traditional form of Chinese medicine. Involves insertion of needles at selected points

to get desired results. Mechanism is via endorphin release and Gate

control theory. Produces hypo analgesia but complete relief is

never achieved . Pain relief without the support of narcotics is

very poor. Advantages –no harmful effect no effect on uterine contractions Disadvantages- time consuming limits patient's movement sterile aseptic techniques

PHARMACOLOGIC METHODS:PARENTRAL AGENTS When uterine contractions and cervical

dilatation cause discomfort, pain relief with a narcotic such as meperidine, plus one of the tranquilizer drugs such as promethazine, is usually appropriate.

the mother should rest quietly between contractions.

discomfort usually is felt at the acme of an effective uterine contraction, but the pain is generally not unbearable.

Meperidine and Promethazine Meperidine, 50 to 100 mg, with

promethazine, 25 mg, may be administered intramuscularly at intervals of 2 to 4 hours.

Rapid effect is achieved by giving meperidine intravenously in doses of 25 to 50 mg every 1 to 2 hours. *

Meperidine readily crosses the placenta, and its half-life in the newborn is approximately 13 hours or longer (American College of Obstetricians and Gynecologists, 2002).

Its depressant effect in the fetus follows closely behind the peak maternal analgesic effect.

According to Bricker and Lavender (2002), meperidine is the most common opioid used worldwide for pain relief from labor.

Women randomized to self-administered analgesia were given 50-mg meperidine with 25-mg promethazine intravenously as an initial bolus. Thereafter, an infusion pump was set to deliver 15 mg of meperidine every 10 minutes as needed until delivery. Neonatal sedation, as measured by need for naloxone treatment in the delivery room, was identified in 3 percent of newborns.

Butorphanol (Stadol) This synthetic narcotic, given in 1- to 2-mg

doses The major side effects are somnolence,

dizziness, and dysphoria. Neonatal respiratory depression is reported to

be less than with meperidine, but care must be taken that the two drugs are not given contiguously because butorphanol antagonizes the narcotic effects of meperidine.

Angel and colleagues (1984) and Hatjis and Meis (1986) described a sinusoidal fetal heart rate pattern following butorphanol administration.

Fentanyl This short-acting and potent synthetic opioid

may be given in doses of 50 to 100 g intravenously every hour.

Its main disadvantage is a short duration of action, which requires frequent dosing or the use of a patient-controlled intravenous pump.

Atkinson and associates (1994) reported that butorphanol provided better initial analgesia than fentanyl and was associated with fewer requests for more medication or for epidural analgesia.

NOTE :Parenteral sedation is not without risks. Hawkins and colleagues (1997b) reported that 4 of 129 maternal anesthetic-related deaths were from such sedation—one from aspiration, two from inadequate ventilation, and one from overdosage.

Narcotics used during labor may cause newborn respiratory depression

INHALATIONAL AGENTS:N20: A self-administered mixture of 50-percent nitrous oxide (N2O) and oxygen provides satisfactory analgesia during labor.* The use of intermittent nitrous oxide for labor pain has been reviewed by Rosen (2002a) and the following technique suggested: Instruct the woman to take slow deep breaths and to begin

inhaling 30 seconds before the next anticipated contraction and to cease when the contraction starts to recede

Remove the mask between contractions and encourage her to breathe normally. No one but the patient or knowledgeable personnel should hold the mask

Instruct a caregiver to remain in verbal contact with the patient

Provide the expectation that the pain will likely not be eliminated, but that the gas should provide some relief

Ensure intravenous access, pulse oximetry, and adequate scavenging of exhaled gases

REGIONAL BLOCK Various nerve blocks have been developed over the years to provide

pain relief during labor and delivery. They are correctly referred to as

regional blocks.

Pudendal Block This block is a relatively safe and simple method of

providing analgesia for spontaneous delivery. The end of the introducer is placed against the vaginal

mucosa just beneath the tip of the ischial spine. The needle is pushed beyond the tip of the director into the mucosa and a mucosal wheal is made with 1 mL of 1-percent lidocaine solution or an equivalent dose of another local anesthetic.

The needle is then advanced until it touches the sacrospinous ligament, which is infiltrated with 3 mL of lidocaine.

The needle is advanced farther through the ligament* Another 3 mL of solution is injected into this region.

Next, the needle is withdrawn into the introducer, which is moved to just above the ischial spine. The needle is inserted through the mucosa and 3 more mL is deposited.

The procedure is then repeated on the other side.

Paracervical Block This block usually provides satisfactory pain

relief during the first stage of labor. Not use it routinely because the pudendal

nerves are not blocked, Additional analgesia is required for delivery. For paracervical blockade, usually lidocaine or

chloroprocaine, 5 to 10 mL of a 1-percent solution, is injected into the cervix laterally at 3 and 9 o'clock.

Bupivacaine is contraindicated because of an increased risk of cardiotoxicity (American Academy of Pediatrics and American College of Obstetricians and Gynecologists, 2007; Rosen, 2002b).

Relatively short acting, paracervical block may have to be repeated during labor.

Spinal (Subarachnoid) Block Introduction of a local anesthetic into the

subarachnoid space to effect analgesia . Advantages include a short procedure time,

rapid onset of blockade, and high success rate.

Smaller subarachnoid space during pregnancy, (engorgement of the internal vertebral venous plexus) the same amount of anesthetic agent in the same volume of solution produces a much higher blockade in parturients than in nonpregnant women.

Low spinal block can be used for forceps or vacuum delivery.

The level of analgesia should extend to the T10 dermatome(umbilicus).

Several local anesthetic agents have been used for spinal analgesia. Addition of glucose to any of these agents creates a hyperbaric solution, which is heavier and denser than cerebrospinal fluid.

A sitting position causes a hyperbaric solution to settle caudally, whereas a lateral position will have a greater effect on the dependent side.

Lidocaine given in a hyperbaric solution produces excellent analgesia and has the advantage of a rapid onset and relatively short duration. Bupivacaine in an 8.25-percent dextrose solution provides satisfactory anesthesia to the lower vagina and the perineum for more than 1 hour..

COMPLICATIONS: Hypotension Postdural puncture headache Failed regional blockade High spinal blockade Chemical meningitis or epidural abscess or

hematoma

CONTRAINDICATIONS Refractory maternal hypotension Maternal coagulopathy Maternal use of once-daily dose of low-

molecular-weight heparin within 12 hours Untreated maternal bacteremia Skin infection over site of needle placement Increased intracranial pressure caused by a

mass lesion

LOCAL INFILTRATION Local infiltration refers to the injection of an

anesthetic medicine (such as Lidocaine/Xylocaine) into a specific area of the body.

For use during labor, the anesthetic is injected just under the skin surrounding the opening of the vagina.

This method is used mainly during normal vaginal delivery, episiotomy (cutting of the perineum), and repair of episiotomy or tears.

While simple to administer, local infiltration with anesthetic is not risk-free and rarely may be associated with poisoning and inadvertent administration of the drug to the baby.

It works only at the site of injection and does not alleviate pain caused by contractions or pelvic floor stretching.

General Anesthesia The increased safety of regional analgesia

has increased the relative risk of general anesthesia.

The case-fatality rate of general anesthesia for cesarean delivery is estimated to be approximately 32 per million live births compared with 1.9 per million for regional analgesia (Hawkins and associates, 1997b).

Patient PreparationPrior to anesthesia induction, several steps should be taken to help minimize the risk of complications for the mother and fetus. These include the use of Antacids Uterine Displacement- The uterus may compress the

inferior vena cava and aorta when the mother is supine. With lateral uterine displacement, the duration of general anesthesia has less effect on neonatal condition than when the woman remains supine (Crawford and colleagues, 1972).

Preoxygenation- Because functional reserve lung capacity is reduced, pregnant women become hypoxemic more rapidly during periods of apnea than do non pregnant patients.

To minimize hypoxia between the time of muscle relaxant injection and intubation, it is important first to replace nitrogen in the lungs with oxygen.

This is accomplished by administering 100-percent oxygen via face mask for 2 to 3 minutes prior to anesthesia induction.

Induction of Anesthesia Thiopental- This thiobarbiturate given intravenously

is widely used and offers easy and rapid induction, prompt recovery, and minimal risk of vomiting..

Ketamine- This agent also may be used to render a patient unconscious. Doses of 1 mg/kg induce general anesthesia.

Or, intravenously in low doses of 0.2 to 0.3 mg/kg, ketamine may be used to produce analgesia and sedation just prior to vaginal delivery.

It usually causes a rise in blood pressure, and thus it generally should be avoided in women who are already hypertensive.

Unpleasant delirium and hallucinations are commonly induced by this agent.

Intubation Immediately after a patient is rendered

unconscious, a muscle relaxant is given to aid intubation.

Succinylcholine, a rapid-onset and short-acting agent, commonly is used.

Cricoid pressure—the Sellick maneuver—is used by a trained assistant to occlude the esophagus from the onset of induction until intubation is completed.

Before the operation begins, proper placement of the endotracheal tube must be confirmed.

Gas Anesthetics- Once the endotracheal tube is secured, a 50:50 mixture of nitrous oxide and oxygen is administered to provide analgesia.

A volatile halogenated agent is added to provide amnesia and additional analgesia.

Volatile Anesthetics- The most commonly used volatile anesthetics in the United States include isoflurane and two of its derivatives, desflurane and sevoflurane.

They are usually added in low concentrations to the nitrous oxide-oxygen mixture to provide amnesia.

They are potent, nonexplosive agents that produce remarkable uterine relaxation when given in high concentrations.

THANK YOU