Mod VII: Anesthesia for Vaginal Delivery

Question 1

_{Anesthesia for Vaginal Delivery}

What’s the goal of Anesthesia for Vaginal Delivery

Answer 1

The Control of Labor Pain

Question 2

_{Anesthesia for Vaginal Delivery}

In the 1st Stage of labor, what causes pain? which dermatomal level should be blocked?

Answer 2

Contraction of the uterus causes pain

Block T10 - L1 level to control this pain

Question 3

_{Anesthesia for Vaginal Delivery}

In the Second Stage of labor, what causes pain? which dermatomal level should be blocked?

Answer 3

Contraction of the uterus

Block T10 - L1

Question 4

_{Anesthesia for Vaginal Delivery}

In the Second Stage of labor, where does the pain from Birth originate? which dermatomal level should be blocked?

Answer 4

From birth canal

Block S2 - S4

Question 5

_{Anesthesia for Vaginal Delivery - Control of Labor Pain}

What are the Labor effects on mother?

Answer 5

Increased sympathetic nervous system activity

^{Increased plasma catecholamine levels}

^{Increase in cardiac output}

^{Increase in peripheral vascular resistance}

^{Reduction in uteroplacental perfusion - As much as 50% in animal studies.}

^{Analgesia may result in 50% decrease in catecholamine concentrations}

Periods of hyperventilation versus hypoventilation

^{Leads to maternal and/or fetal hypoxemia}

^{Analgesia abolished increases in oxygen consumption.}

Psychological effects…

^{Vary bu cultures - stoic vs screaming during the differents stages of labor}

Question 6

_{Anesthesia for Vaginal Delivery - Control of Labor Pain}

Increased sympathetic nervous system activity on the mother during labor manifest as:

Answer 6

Increased plasma catecholamine levels

^{Analgesia may result in 50% decrease in catecholamine concentrations​}

Increase in cardiac output

Increase in peripheral vascular resistance

Reduction in uteroplacental perfusion

^{As much as 50% in animal studies}

Question 7

_{Anesthesia for Vaginal Delivery - Control of Labor Pain}

How does labor affect uteroplacental perfusion?

Answer 7

Reduction in uteroplacental perfusion

As much as 50% in animal studies

Question 8

_{Regional Anesthesia - Effect on Labor and Delivery}

The use of Regional Anesthesia during the First stage of labor is a/w Conflicting studies, including:

Answer 8

Prolongation of labor by 1-2 hours

Greater oxytocin administration

Question 9

_{Regional Anesthesia - Effect on Labor and Delivery}

The use of Regional Anesthesia during the First stage of labor is may be a/w Prolongation of labor by 1-2 hours and Greater oxytocin administration - Is this Enough to withhold pain relief?

Answer 9

Many OBs would like to hold off until active phase

Which doesn’t occur until the uterus is dilated to 5cm

However, it’s Unlikely the pt will wait that long due to discomfort of the mother

Question 10

_{Regional Anesthesia - Effect on Labor and Delivery}

How does the use of Regional Anesthesia during the Second stage of labor affect the pelvis?

Answer 10

Relaxation of the pelvic floor

Interferes with the internal rotation of the fetal head as they engage during birth

Some providers Dilute local preferably with opioid to reduce this phenomenon

High doses may increase the risk of instrumentation during the actual birth process

It’s up to you to find that appropriate balance of local to opioid mix

Question 11

_{Regional Anesthesia - Effect on Labor and Delivery}

The use of Regional Anesthesia during the Second stage of labor causes Relaxation of the pelvic floor, which interferes with the internal rotation of the fetal head as they engage during birth. How do some providers deal w/ this phenomenon?

Answer 11

Dilute local anesthetics preferably with opioids to reduce this phenomenon

Question 12

_{Regional Anesthesia - Effect on Labor and Delivery}

The use of Regional Anesthesia during the Second stage of labor causes Relaxation of the pelvic floor, which interferes with the internal rotation of the fetal head as they engage during birth. Some providers Dilute local preferably with opioid to reduce this phenomenon. What’s a risk of high dose opioids?

Answer 12

May increase the risk of instrumentation during the actual birth process

It’s up to you to find that appropriate balance of local to opioid mix

Question 13

_{Epidural Preparation}

Preanesthetic evaluation for Epidural anesthesia include:

Answer 13

Informed consent

Review of medical history

Physical exam with vital signs

^{G-Gravida=number of pregnancies}

^{P-Para=number of pregnancies over 20 weeks}

Question 14

_{Epidural Preparation}

A Preanesthetic evaluation for Epidural anesthesia reveals the following “2-0-0-2” - What does that mean?

Answer 14

2 pregnancies

0 premature births

0 abortions/miscarriages

2 living children

Question 15

_{Epidural Preparation}

Which Equipments must be readied for Epidural Preparation?

Answer 15

Resuscitation equipment

Always check emergency airway equipment

• Supplemental oxygen

Question 16

_{Epidural Preparation}

Monitors for Epidural Preparation:

Answer 16

BP

Pulse oximeter

FHR—pre and post but not mandatory during

_{[FHR monitoring is not mandatory during Epidural placement but is ideal]}

Question 17

_{Epidural Preparation}

IV access and Fluids for Epidural Preparation:

Answer 17

18g IV catheter

^{Access is very important in case of need for resuscitation}

AT LEAST 500cc fluids prior to placement

^{To combat potential hypotension usually a/w epidural placement}

Question 18

_{Epidural Preparation}

Position for Epidural Preparation:

Answer 18

Sitting

^{(preferred!!!)}

Lateral

^{(left lateral preferred)}

Question 19

_{Epidural Preparation}

What’s the puprose of performing a test dose after epidural placement?

Answer 19

Allows recognition of intravenous or subarachnoid placement

Uses a mixture Lidocaine with epinephrine as test dose

Look for s/s of intravenous or subarachnoid placement

Question 20

_{Epidural Preparation}

What do you do when you are uncertain as to the result of the test dose?

Answer 20

Try another test dose, or

“Replace the catheter”; this is the safest thing to do

Question 21

_{Epidural Preparation}

The four Local Anesthetics commonly used for Epidural Preparation include:

Answer 21

Bupivacaine

Ropivicaine

Lidocaine

2% or 3% -Chloroprocaine

Question 22

_{Epidural Preparation}

Why is Bupivacaine the most often used Epidural LA?

Answer 22

B/c it has limited placental transfer

d/t being Highly protein bound

Question 23

_{Epidural Preparation}

What are Bupivacaine’s onset and peak times? How how long does it provide analgesia?

Answer 23

Onset 5-10 minutes, Peak 20 minutes

8-10 mls provides 2 hours of analgesia (DOA)

Question 24

_{Epidural Preparation}

Which is Less cardiodepressant and arrhythmogenic

A. Ropivicaine

B. Bupivacaine

Answer 24

A. Ropivicaine

B. Bupivacaine

Question 25

_{Epidural Preparation}

Which is LA is more potent?

A. Ropivicaine

B. Bupivacaine

Answer 25

A. Ropivicaine

B. Bupivacaine

Ropivicaine 40% less potent than Bupivacaine

Question 26

_{Epidural Preparation}

Which is LA is a/w a Higher cost?

A. Ropivicaine

B. Bupivacaine

Answer 26

A. Ropivicaine

B. Bupivacaine

Question 27

_{Epidural Preparation}

What’s the DOA of Lidocaine? How does lidocaine’s DOA compares to Bupivacaine’s?

Answer 27

Lidocaine => 1-1.5 hours (DOA)

Question 28

_{Epidural Preparation}

How does Lidocaine’s analegesic effect compares to Bupivacaine’s?

Answer 28

Lidocaine may not equal analgesia provided by bupivacaine

Question 29

_{Epidural Preparation}

2% or 3% Chloroprocaine is an Ester LA with rapid onset of action - What’s its DOA?

Answer 29

2% or 3% -Chloroprocaine => 40 minutes block duration

Question 30

_{Epidural Preparation}

How does 2% or 3% Chloroprocaine affect epidural bupivacaine and opioids?

Answer 30

Diminishes the effect of epidural bupivacaine and opioids

Question 31

_{Epidural Preparation}

What are the two different classes of LA?

Answer 31

Amides

All amide local anesthetics contain an “i” in the name. For example, lidocaine,mepivacaine, prilocaine, bupivacaine, ropivacaine, and levo-bupivacaine all contain an “i” before the “-caine”

Esters

Esters such as procaine, chloroprocaine, and tetracaine do not contain an “i” before the “-caine”.

Question 32

_{Epidural Preparation}

What’s the drug of choice if you need immediate onset of epidural?

Answer 32

2% or 3% -Chloroprocaine

Indicated for a pt where the epidural was put in late, and you anticipate that labor will start w/in minutes, or

Pt w/ multiple gestations

If you have more time, use Bupivacaine!!!

Question 33

_{Maintenance of Epidural Analgesia}

Intermittent Bolus - are these typically necessary?

Answer 33

Yes

Administer PRN

Question 34

_{Maintenance of Epidural Analgesia - Intermittent Bolus}

What must you always complete prior to administration of an Intermittent Bolus of epidural LA?

Answer 34

Patient assessment

Document it!!!!

Question 35

_{Maintenance of Epidural Analgesia - Intermittent Bolus}

Why is it important to Aspirate first and titrate slowly prior to Intermittent Bolus for Maintenance of Epidural Analgesia?

Answer 35

To ensure that the catheter hasn’t migrated to a different level or to a vein

Question 36

_{Maintenance of Epidural Analgesia}

What are the Benefits of Maintenance of Epidural Analgesia w/ a Continuous Infusion over intermittent boluses?

Answer 36

Maintenance of a stable level of analgesia

More stable maternal heart rate and blood pressure

Decreased risk of hypotension (b/c no labile drug infusions)

Less frequent need for bolus

Question 37

_{Maintenance of Epidural Analgesia}

During Maintenance of Epidural Analgesia via Continuous Infusion you must continue to look for Signs of migration into which spaces?

Answer 37

Vascular space & Subarachnoid space

Question 38

_{Maintenance of Epidural Analgesia}

During Maintenance of Epidural Analgesia via Continuous Infusion which assessments must you still complete every 1-2 hours?

Answer 38

Catheter position

Quality of block and labor progression

Sensory level/Intensity of motor block

Maternal BP/Fetal heart rate tracing

Document these on the record

Question 39

_{Maintenance of Epidural Analgesia}

During Maintenance of Epidural Analgesia via Continuous Infusion which Equipment will you need?

Answer 39

Pump specific for epidural infusion

Tubing specific for epidural infusion

Be sure epidural tag on tubing to prevent accidental “IV” injection into epidural space

Sterile preparation of local anesthetic—remember preservative free solutions

Question 40

_{Epidural Techniques}

A popular epidural techinique uses a combination of which two drugs?

Answer 40

Bupivacaine + Narcotic (Fentanyl)

^{Loading dose of Bupivacaine => 0.25% 5-10 ml +}

^{Fentanyl 5-10 mcg/ml}

Begin infusion

^{0.125% bupivacaine}

^{1-2 mcg/ml fentanyl}

^{Rate of 8-15 ml/hr}

Adjust rate according to maternal response

^{Intermittent dosing may be required}

Question 41

_{Labor Analgesia Second Stage}

Pain in Second Stage of labor is a/w Pain Impulses from which dermatomes?

Answer 41

S2-S4

Pain Impulses from dermatomes may not be covered by epidural

Could be source of breakthrough pain impulses

Usually happens during the very late stages of labor when the fetus is engaged to be delivered

The pt at this point need more analgesia than motor blockade

Question 42

_{Labor Analgesia Second Stage}

How is Pain in Second Stage of labor d/t Pain Impulses from dermatomes S2-S4 managed?

Answer 42

Epidural dosing may need alteration at this point

More analgesia, less motor block

Bolus dosing may be necessary

May need to inject a “delivery dose”

Be cautious with combination LA and blood loss r/t hypotension.

Question 43

_{Anesthesia for Vaginal Delivery}

What are potential Complications of Epidural anesthesia?

Answer 43

Hypotension

Inadequate analgesia

Dural Puncture

Pruritis

Respiratory Depression

Question 44

_{Epidural Complications}

The primary Epidural Complication is Hypotension - How do we combat it?

Answer 44

Crystalloids

Position to left-lateral position

Supplemental oxygen

5-10mg ephedrine

Phenylephrine when maternal HR elevated

Question 45

_{Epidural Complications}

What are possible causes of Inadequate analgesia from epidural?

Answer 45

Type of catheter

Depth of placement

Epidural failure rate is 1.5-5%

Question 46

_{Epidural Complications}

What’s the % risk of Dural Puncture?

Answer 46

1 - 8%

Skill dependent

Question 47

_{Epidural Complications}

What are your options if you experience a Dural Puncture?

Answer 47

Move to another space

Consider Continuous spinal

Question 48

_{Epidural Complications}

What question should you anwer first if you encouter Pruritis (itching) during epidural?

Answer 48

Is it Histamine mediated?

Epidural Complications

Question 49

_{Epidural Complications}

What’s the Treatment for pruritis?

Answer 49

Small doses of naloxone (usual treatment)

If severe then 0.4 naloxone in 100 cc NS infused over an hour

Nalbuphine (Partial opioid agonist) 2.5 to 5 mg

Question 50

_{Epidural Complications}

Respiratory Depression a/w Epidural is dose related - As a result, how should you dose intrathecal fentanyl or sufentanil?

Answer 50

No more than 25 mcg fentanyl intrathecally

Or 10 mcg sufentanil

Question 51

_{Epidural Complications}

What’s the Rule of thumb for presentation of Respiratory Depression w/ epidural opioid administration - How does solubility of opioids affect order of presentation of respiratory depression?

Answer 51

Lipid soluble

Lipid soluble will present early depression (fentanyl, sufentanil) within 1-2 hours

Hydrophilic

Hydrophilic—will present late depression (morphine)

Rostral spread due to delayed absorption

6-12 hours

Post op orders important!!

Question 52

_{Epidural Complications}

Opioids with which solubility present early respiratory depression?

Answer 52

Lipid soluble​

Lipid soluble will present early depression (fentanyl, sufentanil) within 1-2 hours

Question 53

_{Epidural Complications}

Why do Hydrophilic opioids (morphine) present late respiratory depression?

Answer 53

Rostral spread due to delayed absorption

Can take 6-12 hours

Take this into account when Considering Post op orders after epidural!!!

Question 54

_{Epidural Take Home Points}

Regional anesthesia may slightly increase length of labor - so why do we still use it?

Answer 54

Benefits outweigh this phenomenon

Question 55

_{Epidural Take Home Points}

There should not be an arbitrary set point for epidural placement - Why not?

Answer 55

Epidural should be individualized based on how the pt is feeling and how she is able to tolerate the labor process

Question 56

_{Epidural Take Home Points}

Which drug concentrations should be utilized for epidural?

Answer 56

Diluted concentrations of epidural or neuraxial drugs should be utilized

Question 57

_{Epidural Take Home Points}

Why is important to EDUCATE parturients about pain control?

Answer 57

Some think they’re not supposed to feel a thing or not to move

Educate them on what to expect