Labor Analgesia, Pharmacology, & Complications - Quiz 2 Flashcards Preview

Summer 2020 - APA Foundations 2 - OB > Labor Analgesia, Pharmacology, & Complications - Quiz 2 > Flashcards

Flashcards in Labor Analgesia, Pharmacology, & Complications - Quiz 2 Deck (89)
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1

Where is the pain in the 1st stage of labor?

Lower Uterine - T10 - L1

2

Where is the pain during the 2nd stage of labor?

Perineal structures via Pudendal Nerves - S2 - S4

3

What are some Non-Pharmacological Analgesics for Labor?

  • Hypnosis
  • Psychoprophylaxis (Lamaze) - behavior & breathing techniques
  • Accupunture - Energy flow patterns

4

What is the problem w/ using Opioids on Parturients?

Crosses Placenta & Depresses Fetus

5

What is the advantage of using PCA's for pain for parturients?

Better Satisfaction

Less Fetus Depression

Less Nausea

Less Respiratory Risk for mom

6

Why is morphine not normally given to the mom for pain?

Baby's immature blood brain barrier increases risk for respiratory depression

7

Which pain med given for labor is contraindicated in patients with seizures or renal failure?

Meperidine

Can cause frequent N/V

Active Metabolites

Fetal Resp. Depression unlikely if given < 1 hr before delivery

8

What are some considerations when giving Fentanyl to a parturient?

100x more potent than morphine

Rapid transfer across Placenta

Respiratory depression lasts longer than pain control

9

What is Nalbuphine (Nubain)?

Opioid Antagonist, Kappa Agonist

Treats Opioid Pruritis

Causes Dysphoria

Resp. Depression Ceiling

10

Why is Butorphanol (Stadol) sometimes used instead of Fentanyl?

Better pain control & less itching

Sedation

Resp. Depression Ceiling

11

Why are gases rarely used to control paturient pain?

Aspiration

Decreases Uterine Tone

 

12

When is a Paracervical Block placed?

1st stage of Labor

Inject 5cc of LA submucosally @ 3 & 9oclock beside cervix

13

What are the risks involved w/ ParaCervical Blocks?

Injection into Uterine Artery

Fetal LA Toxicity

Nerve Injury

Hematoma

14

When are Pudendal Blocks used?

2nd Labor Stage

&

When Neuraxial Blocks are Contraindicated

Transvaginal Approach under Ischial Spines w/ Bilateral Needle Placement

15

What are the risks associated with Pudendal Blocks?

Fetal Injury, Infection, and Hematoma

16

Which Local Anesthetics are derivatives of Para-Aminobenzoic Acid (PABA)?

Amino Esters

PABA = Allergen

Metabolized by Cholinesterase

17

Which class of Local Anesthetics are more often used in OB?

Amino Amides

No PABA = No Allergic Reactions

Liver Metabolism

18

What is the Local Anesthetic relationship b/t its Lipid Solubility & Potency?

More Lipid Soluble = More Potent & Enchances Placental Diffusion

19

How does Protein Binding affect Local Anesthetics?

More Protein Binding = Longer Duration & Decreases Placental Transfer

20

Protein binding Local Anesthetics have a ____ affinity & ____ capacity to A1-acid Glycoprotein

Protein binding Local Anesthetics have a High Affinity & Low Capacity to A1-acid Glycoprotein

21

Protein binding Local Anesthetics have a ____ affinity & ____ capacity to Albumin

Protein binding Local Anesthetics have a Low Affinity & High Capacity to Albumin

22

Which property of Local Anesthetics determines Speed of Onset?

pKa

The closer the pKa is to physiological pH, the faster onset

Bicarb is used to artifically raise physiological pH

23

What would be the results of increasing Local Anesthetic Volume & Dose?

Faster Onset & Longer Duration

24

What can be given to prevent Systemic Absorption of Local Anesthetic?

Vasoconstrictors - Epi, Norepi, Neo

25

How does Temperature affect Local Anesthetics?

Warmed LA = faster onset

26

 How does Pregnancy affect Local Anesthetics?

Preggos need less LA & has faster onset

27

Which type of nerves are more susceptible to blocks?

C- Fibers - small & unmyelinated

Larger fibers need more LA

28

What are the most commonly used Epidural Analgesics for Labor?

Bupivacaine

Ropivacaine

Lidocaine

29

What Local Anesthetics are used for Operative Epidural Analgesia?

Lidocaine & 2-Chloroprocaine

30

Which Local Anesthetics are used for Spinal Anesthesia?

Tetracaine & Bupivacaine

31

Which Local Anesthetic can be used to test and activate the Epidural Catheter, has a short duration, and causes a lot of Motor Block?

Lidocaine

32

Which Ester LA is the only one used in the Epidural Space?

2-Chloroprocaine

Rapid Onset, Short Duration

Lots of Motor Bock

Low Toxicity Risk

33

When in particular would you NOT use 2-Chloroprocaine?

In patients w/ Atypical Pseudocholinesterase

34

What happens when you give Epidural Fentanyl after the patient had 2-Chloroprocaine?

Fentanyl would be less effective

35

What makes Bupivacaine a good Local to use during labor?

Long Duration & Less Motor Block

BIG dose = V-Tach/V-Fib

36

Which of the following LA's is the most Cardiotoxic: Levobupivacaine, Ropivacaine, Bupivacaine?

Bupivicane > Levobupivacaine > Ropivacaine (25% less potent)

Only Bupivacaine is approved for Spinals

37

How should Epidural Drugs be given in OB?

Small Doses incrementally as test doses

38

What is the next course of action if the patient experiences paresthesia while a spinal is being dosed?

Remove Needle

39

Where should Spinals be placed in Obstetrics?

As low as possible, Below L3

40

Where is Tuffier's Line?

Transverse line passing thru lumbar spine b/t posterior iliac crests - L4

41

Which dermatomes should be covered for Obstetrics

Lumbar Level - T10 - S4

42

What are contraindications to Neuraxial Blocks?

Patient Refuse

Site Infection

Coagulopathy

Intracranial Mass

Aortic Stenosis

Existing Spinal/Neuro Disease

Hemodynamic Instability

43

What are the steps in placing an Epidural?

  1. Position Patient
  2. Prep Skin
  3. Numb Skin
  4. Identify Space w/ Midline or Paramedian Approach
  5. Use Tuohy Needle & LOR Technique

44

How far should the Catheter tip be advanced once the Epidural Space is identified?

Until 5 cm of the tip lie in the space

45

How should the Epidural Catheter be handled?

Dont pull catheter back thru needle - may shear

Aspirate to R/O CSF or Blood

Give Test Dose

Secure Catheter

46

What are the difference b/t Epidurals & Spinals?

Drugs thru Spinals are 10x more potent & smaller needle used (22-27ga)

Epidural uses 17-18ga needles

47

When are Subarachnoid Blocks used for Labor?

C-Sections

When delivery is soon & no time for Epidural

Opioid only or LA Combo

48

What are the Pros and Cons of Combined Spinal Epidural?

Instant Relief, but difficult to test epidural catheter

49

What are signs of LA Toxicity?

Tinnitus

Light-Headedness

Loss of Consciousness

Convulsions

Metallic Taste

Numbness

Respiratory Arrest

 

 

50

How does Acidosis & High PaCO2 affect Local Anesthetics?

Lowers Seizure Threshold

&

Decreases Protein Binding = More Free LA

51

How does Local Anesthetic Toxicity affect the CV System?

Inhibits Sodium Channels

↓Rate of Depolarization

↓Action Potential Duration

↓Effective Refractory Period

 

52

What should be done for a patient with LA Toxicity that started convulsing?

  • Clear Airway
  • Position Patient - Avoid Aortocaval Compression
  • Bag Mask Ventilation
  • Benzos
  • Manage arrythmias
  • Immediate Delivery if Possible

53

What can be given for Refractory Local Anesthetic Toxicity

20% Intralipid

54

What are symptoms of Subdural Block?

(Catheter is b/t Dura & Arachnoid Mater)

Apnea

Loss of Consciousness

Horner's Syndrome

55

What should be done if a Subdural Block is detected?

Dont dose & Replace catheter into Epidural Space

56

What is Term Labor?

37 - 42 Completed Weeks

57

What is considered Preterm Labor?

Regular contractions every 10 minutes causing cervical change before 37 weeks

58

What infant weight is considered low?

Low Birth Weight < 2500g

Very Low Birth Weight < 1500g
(usual wt. @ 29 wks)

59

Mortality is 90% if infants born _____ and Survival rate is > 90% if they're born ______

Mortality is90% if infants born < 24wks and Survival rate is > 90% if they're born > 30 wks

@ 34 wks = 98% survival

60

What are the Prematurity Comorbidities?

  • Respiratory Distress Syndrome
  • Sepsis
  • Necrotizing Enterocolitis
  • Intracranial Hemorrhage
  • Ischemic Cerebral Damage
  • Immature Matabolism
  • Hypoglycemia
  • Hyperbilirubinemia

61

What bacteria is associated with Preterm Labor?

Group B Strep,  Neisseria Gonorrhoeae, and Bacterial Vaginosis in Genital Tract

62

When is a C-Section safer than delivery in regards to Preterm Labor?

Breech Presentation

63

How does Ethanol work as Tocolytic Therapy?

Inhibits ADH & Oxytocin Release

Risk for Intoxication, Loss of Consciousness, and Aspiration

64

How does Aminophylline work as Tocolytic Therapy?

Phosphodiesterase that relaxes Uterus by increasing cAMP 

Narrow Therapeutic Margin & Toxic

65

How does Nifedipine work for Tocolytic Therapy?

Decreases free calcium to decrease Myometrium Contractility

66

What are the side effects of using Nifedipine as a Tocolytic?

Hypotension

Tachycardia

Peripheral Edema

Myocardial Depression

Postpartum Hemorrhage

Decreased UBF & Fetal Hypoxemia/Acidosis

67

Which type of Tocolytic Therapy makes the patient more prone to Cardiac Depression from Volatile Agents?

Calcium Channel Blockers

68

What are some Prostaglandin Inhibitors that are used for Tocolytic Therapy?

Indomethacin & Sulindac

Decreases CycloOxygenase to decrease Prostaglandin

69

What are the Maternal side effects of Prostaglandin Inhibitors?

Nausea

Heartburn

Decreased platelets & bleeding

Pulm. HTN

70

What are the Fetal side effects of Prostaglandin Inhibitors?

Premature closure of ductus

Persistent Circulation

Renal Impairment

71

Which medication is the most commonly used for Tocolytic Therapy?

Magnesium

Prevents Calcium Increase

Increases cAMP

72

How does Magnesium affect MAC & NMBs?

Decreases MAC

Patient more sensitive to all NMBs

73

What would you see with a Magnesium level of 8 - 10?

Loss of Deep Tendon Reflexes

74

What would you see with a Magnesium level of 10 - 15?

Resp. Depression & Wide QRS & P-R Interval

75

How should Magnesium toxicity be treated?

Calcium Gluconate or Calcium Chloride

76

What are the Beta Adrenergic Agonists used for Tocolytic Therapy?

Terbutaline & Ritodrine

Directly increases cAMP to Relax Uterus

77

What are the side effects of using Terbutaline or Ritodrine?

N/V

Anxiety

Hyperglycemia

Hyperinsulinemia

Hypokalemia

Acidosis

Pulmonary Edema

78

How much does the risk of Fetal Death increase w/ having twins vs singleton?

5-6x d/t increased risk of prematurity

Second twin has greater risk d/t placental abruption, cord prolapse, & malpresentation

79

What are the Maternal complications of having Mutliple Gestations?

Increased CO earlier

Anemia

↓TLC & FRC

↑O2 Consumption

Bigger Uterus = Aortocaval Compression & Aspiration

80

What can be expected with Multiple Gestations?

Preterm Labor - 50%

Placental Abruption

Pregnancy Induced HTN

Malpresentation

Placenta Previa

C-Section for triplets or more

81

What are the Anesthetic considerations for Multiple Gestations?

Early Epidural Placement

Hemorrhage

Treat as C-Section

Dense Block

2-Chloroprocaine for Rapid Onset

Nitroglycerine to Relax Uteus for Rotating Baby

82

What are the signs and symptoms of a Uterine Rupture?

Sudden & Severe Abdominal Pain

Vaginal Bleed

Hypotension

Labor Stops

Fetal Distress - Most Reliable Sign

83

What is the best presentation for delivery?

Faced down, Flexed C-Spine w/ chin to chest

84

What is a Breech Presentation?

Both feet down

Frank: Both Legs Up Near Head

Incomplete: One leg up one leg down

90% of Breech = C-Section

85

Why is there an Increased Risk for Fetal Death associated w/ Breech Presentation?

Asphyxia

Birth Trauma

Cord Prolapse

Maternal infection d/t Manipulation

86

Which presentation is an Absolute Indication for C-Section?

Transverse Lie Presentation

87

What are problems with Postmaturity (Gestation > 42 wks)?

↓UBF

Cord Compression

Meconium Staining of Amniotic Fluid

Big Baby w/ Big Shoulders

88

What are the causes of Intrauterine Fetal Demise (IUFD)?

  • Abnormal Chromosomes
  • Congenital Malformations
  • Infections
  • Cord Accidents
  • Multiple Gestations
  • Placental Factors
  • Isoimmunization
  • Maternal Trauma
  • Maternal Immune/Thyroid Disease

89

What can happen to the cord that results in Intrauteral Fetal Demise?

Prolapse

Entanglement

Torsion

< 30 cm Length = compression, constriction, rupture

> 72 cm Length = Entanglement