1-Introduction about anesthesia in pregnancy 2-Uterine innervations and Pain pathway 3- list the different types,uses,complications,contraindications.

Analgesia and Anesthesia in

ObstetricsSUPER VISED BY;

ASIS.PROF.MOHAMMED AL-KHATIM

Done by :Eman Abdullah AL- otibi

Objective:

1-Introduction about anesthesia in pregnancy 2-Uterine innervations and Pain pathway3- list the different types ,uses ,complications ,contraindications and Factors determining the choice of anesthesia. 4-special considerations while using anesthesia in labor including cardiovascular diseases and uterine inversion

Introduction

Labor and delivery is a time of intense pain, which is often influenced by the psychological ,emotional , social, cultural ,

and physiological state of the parturient. multiple methods of alleviating pain are currently available during the birthing process.

Definition: Anesthesia: is the absence of all

sensation ,including pain,touch,temperature,and pressure.

Analgesia: is the absence of nociceptive stimuli ,with the preservation of motor &touch sensation.

Ideal :allow the patient to participant in her labor and delivery .

Pain pathway:1-During first stage of labor(visceral pain): *Visceral pain produced by distention of

the uterous &cervix and ischemia of the uterine and cervical Tissue

* Pain signal traverse T10 to L12-During second stage of labor(visceral+

somatic)* Distention of the vagina ,perineum and

pelvic floor* Pain signals traverse the pudendal

nerve ( S2 to S4)* more somatic pain

Type of anesthesia &analgesia:

1-non pharmacological 2-pharmacological

-#Non pharmacological :use In a highly motivated patients this may be all that they require 

1-relaxation and concentration on breathing2-Massage - including aromatherapy

3-Acupuncture and acupressure4 -audioanalgesia.

5-maternal movement and positioning.#Pharmacological:

1-local injection2-periphral nerve block

3-regional (epidural, spinal)4-systemic(IV, IM ,inhalation)

•5-general anesthesia

A)Local injection: (field bloke)

*indication: Used before episiotomies &for repair of episiotomies or tears that occur during and after

delivery  

* Advantage : no systemic complication if administered correctly

* Complication: (rare) systemic complication - toxicity may cause hypotension, arrhythmia and

seizures.

(The maximum dose of lidocaine should be 4.5mg\kg per dose)

Commonly used agent include lidocaine (1% to 2%) or 2-chloroprocaine (1% to 3%) which provide anthesia

20 -40 mint...

B)Peripheral nerve block (pudendal, paracervical)

*indication:

- Paracervical block used in →-first stage of labor in patient in which the

epidural or spinal contraindicated - rarely used today duo to fetal adverse effect.

- pudendal block used as →-supplemental during second stage of labor if

epidural has not provide adequate analgesia to the sacral nerves.

-Also use in lower forceps .

Advantages: highly effective and provide an alternative method of pain control .

*Complication: IV injection→ hematoma ,infection.

Para cervical block→ fetal bradycardia is a common side effect (15%).

Pudendal block→♠fetal compromise (rarely occur)

♠maternal toxicity from rapid absorption of the drug

C)regional(epidural, spinal)

Epidural:

1 -introduce a catheter into epidural space through a needle usually into the mid-lumber region.

2 -The catheter is then secured to the patient's back with adhesive tape.

3 -Medication is administered via the epidural route using continuous infusion pumps.

4 -A test dose may be given to ensure the correct position of catheter.

Application

(CSE )Combined spinal epidural The needle-through-needle approach.

A single bolus of opiod,perhaps with local anesthetic into subarachanoid space, in addition to an epidural catheter placement in the lumbar epidural space.

This method combine a rapid onset of action of spinal with epidural to provide long-lasting

throughout the labor and delivery process .

loss of pain sensation occurs below the T8 to T10 levels, with varying degrees of motor blockage.

 Indications:1-1st stage of labor.(preferred method of birth control)

2 -difficulty with intubation.3 -a history of malignant hyperthermia.

4 -CVS or respiratory disorders.5 -preeclampsia.

Advantage :

provide effective anesthesia &yet allows patient to participates in her labor &delivery.

*Complication:

1-Infection:meningitis ,epidural abscess

2-Neurological complication :

♦ Spinal headache: -may result in up to 70% of patient .

- ttt include analgesics, supine positioning, hydration

♦ Obstetric nerve palsies:

the commonly injured nerves include lumbosacral trunk ,lateral Coetaneous nerve ,femoral nerve, and common peroneal.

♦back pain

.

3-drug-related complication:

♦Systemic toxicity: tinnitus, disorientation, and seizures.

CV symptoms include hypotension,

Cardiac arrest.

♦ High spinal: result in a more cranial progression of anesthesia.

♦ Motor bloc

4-Hypotension: (because dilatation of vascular beds decrease in venous (return☻become significant if clinical sign are shown in the mother

)light-headedness (Or fetus(bradycardia).☻ttt with IV fluids or small dose of ephedrine (5mg)

5-Fetal complication:♦ Malpresentation

) not clearly known increase risk of shoulder dystocia(

6-complication in labor;♦ Instrumentation

♦ prolongation of second stage of labor.

*contraindication: 1-patient's refusal

2-Uncorrected/untreated coagulopathy→ hematoma

3-Skin infection of the lower back→ meningitis.4-Bacteremia →meningitis.

5-Hypotension/hypovolemia6-↑intracranial pressure →herniation of

cerebral content through foramen magnum

D)Systemic (IV, IM, inhalation)

-Use opiods (morphine, mepridine),or mixed opiod agonist –antagonist(butorphanole).

- Have very limited efficacy for the relief of labor pain.- They work best in the first stage of labor.

*Indication based on maternal request*Complication:

- Mother &fetus respiratory depression(cross placenta barrier)

- If there is continuous sign of respiratory depression→ repeated dose of naloxone are indicated.

-Fentanyl &nalbuphine have the shortest neonatal half-lives of the commonly used.

E)-General anesthesia

Indication: ☻In urgent situation (shoulder dystocia,

head entrapment)☻ If there is contraindication to regional

anesthesia.

Advantage:♦Rapid onset of uterine relaxation occurs, which

is desirable with management of uterine inversion, internal/external cephalic version, or

fetal entrapment..

**Complication:1-Fetal side effect (respiratory

depression)→oxygenation, naloxone, intubation after delivery.

2-Uterine bleeding →managed by pitocin.3-Risk with intubation increase risk of aspiration

and hypoxia. 4 -Drug related complications: Potential side

effects of the intrathecal opioids include maternal respiratory depression and hypoxemia.

During the first stage of labor : visceral pain is mollified by the preferred use of regional anesthesia

♠During vaginal delivery the goal is block nociceptive pathway while preserve motor function

By☺ local anesthesia or peripheral nerve blocks . After delivery (post partum ) by oral analgesics.

♠During C.S:1 -better use regional anesthesia (safe, effective, and allows the mother to

interact with the baby soon after the delivery )2 -general anesthesia renders the patient unconscious and unable to

experience the moment of birth and is used in urgent situation..3 -local anesthesia can be used by the obstetrician who is familiar with

maximal doses.

Postoperative pain managementSystemic administration or continuation of the epidural Eventually tranitioned to oral pain medication..

#Special consideration: Cardiovascular diseases:

Regurgitant lesions : Regional anesthesia is better compared to general anesthesia, because It will Improve the blood supply.Stenotic lesions:The general anesthesia will be better compared to the regional one ,

because the regional anesthesia will further augments the hypotension. -Hypertension:

We have to balance Regional anesthesia will lead to more hypotension

Uterine inversion :Usually halothane is used to do relaxation, then we will evert the uterus .

Factors determining the choice of anesthesia1-fittness and condition of the mother2-type and duration of the condition .

3-condition of the fetus.4 -presence of contraindications.5 -opinion of the anesthesiologist

Summary :

Definition:Analgesia ,Anesthesia

Type of anesthesia &analgesia 1-non pharmacological

2-pharmacological

Reference