Complex OB Flashcards

Question 1

Q

Effects of pregnancy on:

plasma volume?

total blood volume?

hemoglobin?

fibrinogen?

serum cholinesterase activity?

Answer

A

plasma volume- increase 40-50%
total blood volume- increase 25-40%
hemoglobin- dilutional decrease. 11-12 g/dL normal in pregnancy
fibrinogen- increase 100%
serum cholinesterase activity- decrease 20-30%

Question 2

Q

Effect of pregnancy on:

SVR?

CO?

systemic blood pressure?

Answer

A

SVR- decrease 50%
CO- increase 30-50%
Systemic blood pressure- decrease (slight)

Question 3

Q

Respriatory effects of pregnancy on

Functional residual capacity?

Minute ventilation?

Alveolar ventilation

Oxygen consumption

Carbon dioxide production

arterial carbon dioxide tension

minimum alveolar concentration

Answer

A

Functional residual capacity- decrease 20-30%
Minute ventilation- increase 50%
Alveolar ventilation- increase 70%
Oxygen consumption- increase 20%
Carbon dioxide production- increase 35%
arterial carbon dioxide tension- decrease 10 mmHg
arterial oxygen tension- increase 10 mmHg
minimum alveolar concentration- decrease 30-40%

Question 4

Q

CV changes in pregnancy?

Answer

A

Normal findings
- S1 and S3 toward end pregnant
- Left axis deviation
- Left ventricular hypertrophy
Abnormal:
- chest pain,
- syncope,
- high grade murmur, arrythmias,
- HR symptoms,
- clinical sig SOB → further assessment

Question 5

Q

Effect of pregnancy on blood volume/composition?

Answer

A

Increase intravascular fluid volume in 1^st trimester

Rising progesterone levels → increased RAAS
- more Na reabsorption → H2O retention

Albumin – 25 % dec

Total protein- 10% dec

decrease colloidal osmotic pressure
- 50% increase in plasma volume → prepare for BL during delivery
- Blood volume normalize 6-9 Postpartum

Question 6

Q

GI effects in pregnant women?

Answer

A

increase GI displacement

full stomach @ 12 week

Question 7

Q

Hemodynamic changes in pregnancy?

Answer

A

CO highest right after delivery
- Increase 80-100% to prelabor values
  - d/t autotransfusion of empty uterus that now contracts and release of aorta-caval compression (baby not on IVC now)
    - RISKY time for CV hx pts (ex: fixed valvular stenosis/pHTN) → huge sudden increase in CO
SVR sig decrease but CO INCREASE
- Change in BP not very sig, but slight change
  - S/D/MAP decrease 5-10% by 20 wks
    - More drop in diastolic d/t SVR drop
  - Grad increases while closer to term preg
CVP/Pulm capillary wedge pressure – no change
- Increase plasma volume + drop venous capacity → offsets change

Question 8

Q

What is the impact of aortocaval compression during pregnancy?

Answer

A

Uterus sitting on IVC → decrease BP
- Supine hypoTN syndrome – decrease MAP > 15 mmHg w/ increase HR > 20bpm
  - CV sig changes: diaphoresis, N/V, mental status change
- Tx: LUD position (elevate R hip 10-15 cm w/ wedge/tilt)
  - Prevent hypoTN and increase fetal BF

Question 9

Q

Airway changes during pregnancy?

Answer

A

Capillary engorgement
DAW
- Avoid instruments
- Most expert
- Small ETT
- Position optimal
- Decrease FRC… → reserve dec

Question 10

Q

Coagulation changes during pregnancy?

Answer

A

Hypercoagulable state → increase fibrinogen, factor 7
Factor 11 & 13 decreased
ATIII, Protein S- decreased
Protein C- unchanged
Plt normal- but dec 10% d/t dilutional effect
- Gestational thrombocytopenia -d/t hemodilution and rapid plt turnover
  - r/o: ITP, hemolysis, elevated liver enzymes, HELLP → do TEG on at risk pt
  - PLT usually not < 70k unless problem
- Normal pregnancy: PT and aPTT decreased by 20%

Question 11

Q

Effect of pregnnacy on MAC?

Answer

A

unknown mech

Progesterone ??
MAC Reduced up to 40%

Question 12

Q

Effect of LA during pregnancy?

Answer

A

more sensitive

Neuraxial req reduced by 40% at term
- Epidural veins distended
- Volume of epidural fat increases
  - → increases size of epidural space/volume of CSF in SA space → more spread
DOSE: DECREASED

Question 13

Q

What are the stages of labor?

Answer

A

First
- Start: regular painful contractions
- End: complete cervical dilation
  - Length: ~ 2 - 20 hours
Second
- Start: complete cervical dilation
- End: birth
Third
- Start: Birth
- End: Placenta delivery
Fourth (New)
- Placenta to hemostatic stabilization
  - (1 -4 hours after delivery)

Question 14

Q

Labor pain in 1st versus 2nd stage

Answer

A

1^st Stage - visceral
- Cervical distention and stretching of lower uterine segment
  - Latent phase: T10 – T12
  - Active Phase: T10 – L1
- Non-specific nociceptor – unmyelinated C fibers
  - Visceral afferent fibers travel with sympathetic nerve fibers to uterine & cervical plexus and then through hypogastric & aortic plexus
2^nd Stage – somatic
- Mediation:
  - Pudendal nerve (S2-4)
  - Somatic afferent fibers – myelinated A delta

Question 15

Q

Meperidine use in labor?

Answer

A

Dose 25 mg IV
Onset 5-10 min
DUration 2-4 hours
Active metabolite normeperidine can affect neonate if delivery occurs between 1-3 hours after administration
F/M ratio >1 @ 2 hours, ,1 @ 4 hours

Question 16

Q

Morphine use in labor?

Answer

A

Dose 2-5 mg
Onset 5 min IV
Duration 3-4 hours
Infrequently used- greater respiratory depression than with meperidine
F./M ratio 0.92

Question 17

Q

Fentanyl use in labor?

Answer

A

Dose 25-50 mcg IV
Onset 2-3 minutes
Duration 30-60 min
Short acting, accumulates over time
highly protein bound
F/M ratio 0.57

Question 18

Q

Sufentanil use in labor?

Answer

A

5-10 mcg IV
Onset 2-3 min
Duration 2-3 hours
Potent respiratory depressant- use with caution

Question 19

Q

Remifentanil use in labor?

Answer

A

0.25- 1 mcg/kg
Onset 1-2 min
Duration 3-5 min
Sedation, respiratory depression
crosses placenta- rapidly metabolized by fetus
- esterases are fully develops @ birth

Question 20

Q

Nubain use in labor?

Answer

A

Dose 5-10 mg IV
Onset 2-3 min
Duration 3-4 hours
Opioid agonist/antagonist
sedating, ceiling on respiratory depression
F/M ratio 0.97

Question 21

Q

Ketamine use in labor?

Answer

A

10-15 mg IV
Onset 1-3 min
Duration 10-15 min
Possiblity of delirium and hallucination

Question 22

Q

Nitrous oxide use in labor?

Answer

A

<50%
Onset immediate
duration minutes
minimal effect on mother/fetus, may only be partially effective
- Impact on B12 synthesis

Question 23

Q

Regional anesthesia options for labor pain?

Answer

A

Spinal opioids alone
- Single vs intermittent injection
- Good in high-risk patients – cardiac patients
Local anesthetic +/- opioids
- **Epidural
  - Local only vs. local + opioids**
- Dural puncture epidural can inadvertently do CSE and do wet tap and do this technique unintentionally
  - Place epidural – puncture dura with spinal needle
  - Bolus epidural
    - Risks: typically these are result of wet-tap (unintentional tech)
- Combined spinal epidural (CSE)frequent technique for quick analgesia and follow up with epidural for continued labor
  - Walking epidural – low dose local +/- opioid intrathecal
  - Thread epidural catheter – initiate epidural at later moment
    - Uses: quick analgesia and need bolus epidurals after
- Saddle block – pudendal nerve (somatic pain)
  - Bupivacaine 2.5 mg and fentanyl 25 mcg

Question 24

Q

Considerations for fetal heart rate monitoring? tachycardia? Bradycardia?

Answer

A

Follow:
- Baseline HR (120-160 bpm)
- beat to beat variability
- FHR pattern
Baseline
- Normal varies between 120 -160 BPM
Fetal Tachycardia- fetal distress
- > 160 BPM
  - Fetal hypoxia
  - maternal fever
  - sympathomimetic drugs
  - fetal anemia
  - fetal cardiac anomalies
Fetal Bradycardia (more ominous)
- < 100 BPM
  - Fetal head compression
  - umbilical cord compression
  - sympatholytic drugs
  - prolonged hypoxia
  - fetal cardiac anomalies

Question 25

Q

What are some various fetal heart rate patterns?

Answer

A

A. Early Decelerations
- Fetal head compression → baroreceptor activation
  - Uniform in nature – mirrors contraction
  - ~ 10 – 40 beat/min –NOT associated w/ fetal distress
B. Late Decelerations
- Uteroplacental insufficiency
  - Decrease FHR at or following peak of uterine contraction
  - Decrease varies b/t 10 – 20 beats/min
  - Gradual and smooth return to baseline
  - can be concerning
C. Variable Decelerations
- Most common fetal pattern
  - Variable in onset, duration, and magnitude
    - > 30 BPM
  - R/t cord compression
  - Associated with: FETAL HYPOXIA
    - FHR declines < 60 BPM
    - lasts > 60 seconds
    - persists > 30 minutes

Late decels and ominous variable decels → emergent c/s

Question 26

Q

Category I FHR intepretation system?

Answer

A

All of the following:

Baseline rate 110-160 bpm
Baseline FHR variability moderate
Late or variable decels- absent
early decel present or absent
accelerations: present or absent

Question 27

Q

Category II FHR Interpretation?

Answer

A

Categroy II FHR tracings include all FHR tracings not categorized as category I or Category III
Category II tracings may represent an appreciable fraction of those encountered in clinical care
Examples include any of the following:
- baseline rate
  - bradycardia not accompanied by absent baseline variability
  - tachycardia
- baseline FHR variability
  - minimal baseline variability
  - absent baseline variability not accompanied by recurrent decelerations
  - marked baseline variaiblity
- accelerations
  - absence of induced accelerations after fetal stimulation
- periodic or episodic decels
  - recurrent varaibile decels- accompanied by minimal or moderate baseline variability
  - prolonged decelerations >2 minutes but <10 minutes
  - recurrent late decelerations with moderate baseline variaiblity
  - variable decelerations with other characteristics such as slow return to baseline “overshot” or “shoulders”

Question 28

Q

Category III FHR interpretations systme?

Answer

A

Absent baseline FHR varaibility and any of the following:
- recurrent late decels
- recurrent varaibile decels
- bradycardia
- sinusoidal pattern
concerning and need to go to OR

Question 29

Q

Preop considerations for elective c-section (from coexist)

Answer

A

Preoperatively
1. History /Physical
  - Airway evaluation
2. Informed Consent
3. LUD (left uterine displacement)
  - > 20 weeks – Aortic Caval Syndrome
4. IV access (free flowing 18-16 gauge)
5. Hydration (minimal 500 mL)
6. Aspiration prophylaxis (bicitra, metoclopramide, ranitidine)
7. Supplemental O2
8. Anesthetic plan/ postoperative analgesia plan
Choice of anesthetic depends on
1. Indications for surgery
2. Degree of urgency
3. Maternal status
4. Condition of fetus
5. Desires of the patient
  - Sometimes too emergent → put to sleep

Question 30

Q

What is first line for bleeding postpartum?

Answer

A

Rule of 3’s

Oxytocin 3 units (prepack syringe in 5 ml)
3 min evaluation intervals
3 total doses
Oxytocin infusion 3 units/hr maintenance
- 3 units are given as a slow bolus
- Uterine tone reassessed at 3 and 6 minutes
- If inadequate, additional 3 doses are given after each reassessment
- If uterine atony persists after 3 dosesà switch to another drug
- After establishment of uterine tone, infuse 3 units/hr X 5 hours
Oxytocin as a rapid IV bolus:
- Direct SM relaxant à SVR, hypotension, and tachycardia (going in too fast)
  - Hypotension may result in CV collapse
  - Chest pain, myocardial ischemia may develop (can give op)
  - Water intoxication and hyponatremia (Structural similarities b/t oxytocin and vasopressin)

Question 31

Q

2nd line for bleeding postpartum? (coexist)

Answer

A

Methylergonovine (Methergine-ergot alkaloid)
- Dosage: 0.2 mg IM
- Onset: 10 min
- Duration: 2-4 hours
- Can it be given IV: NOT RECOMMENDED
  - Intense vasoconstriction, acute HTN, seizures, retinal detachment, coronary artery spasms, CVA
- May be repeated x1 after 30 min
- Contraindications: HTN, preeclampsia, CAD

Question 32

Q

3rd line for bleeding postpartum (coexist)

Answer

A

15-Methylprostaglandin F_2a(carboprost - Hemobate)
- Dose: 250 mcg IM
- May repeat every 15 min x 8 doses (2 mg)
  - SE: fever, chills, n/v, diarrhea, and bronchoconstriction

***Who should not receive this drug? Asthmatics

Question 33

Q

Indications for emergenct c-section?

Answer

A

Immediate danger to life of mother or fetus
- OB Code/Crash with failed intubation
  - Why more difficult- can’t wake up patient
  - What options are available to you?- emergency airway management. OB uses local/infiltration technique

Question 34

Q

Anesthetic plan for preop/induction emergent c-section? (coexist)

Answer

A

Preop assessment of airway
Large bore IV
Aspiration prophylaxis (Non-particulate antacid, H2-blocker, Reglan)
Monitors/suction/ emergency airway cart
Optimal airway positioning/ LUD
Preoxygenate! (3 min or longer)
Prep + drape –surgeon ready
RSI w/cricoid (10 N while awake; inc to 30 N after LOC) → start putting force before even asleep
- Agents available
  - Ketamine (used with maternal hypotensive crisis) 1 mg/kg
  - Etomidate 0.3 mg/kg
  - Propofol 2-2.5 mg/kg
  - Succinylcholine 1-1.5 mg/kg
    - Preferred muscle relaxant

Question 35

Q

Intubation considerations for emergent c-section? What happens immediately following intubation?

Answer

A

Intubate
- Expect difficult intubation
- Proper positioning
- Short handled laryngoscope (Datta) recommended
- Use minimal amount of time; first attempt best attempt
- Smaller ETT 6.0 or 6.5
- Use caution…friable tissues and decreased airway size
Verify placement of ETT → tell surgeon!
- Then…Surgeon makes skin incision (after tube placement verified)
Ventilate with 50% O2/50% N2O & VA (~1 MAC) → overpressure!
- Don’t forget to turn on gas! Tremendous recall
Secure ETT, tape eyes, OGT
****Critical interval of 3 minutes between uterine incision and delivery of fetus
- Tremendous recall risk → medications waring down and youre busy (mom remembers)
Delivery of baby
- PCA pump (bc didn’t do spinal)
- As soon as baby is delivered→ can give Versed, Fent, etc.

Question 36

Q

What happens after delivery in emergent c-section (coexist)

Answer

A

AFTER DELIVERY:
- Reduce VA (.75 MAC) → may increase N2O to 70%, and give opioids and benzodiazepine
  - Reduce MAC → don’t want to vasodilate & bleed out
Possible NDMR
Delivery of placenta
Then can add oxytocin to IV → start contracting of uterus so that mom doesn’t hemorrhage
At end:
- Suction OGT
- Reverse NDMR if necessary
- Extubate AWAKE
  - Emergence and recovery is a critical period for anesthesia-related deaths from airway factors!

Question 37

Q

Maternal mortality statistics?

Answer

A

Profound decrease b/t 1991- 2002
- Decreased morbidity/mortality from GA and increased from neuraxial (preg = DAW)
  - move from always GA to neuraxial, esp good with increased risk DAW in pregnancy
Most often related to cesarean delivery
- Failed intubations = 23%
- Respiratory failure = 20%
- High spinal/epidural = 16%
- Others:
  - LAST
  - PDPHa
  - Nerve injury

Question 38

Q

What is gestational HTN?

Answer

A

Most frequent cause of HTN during pregnancy
Incidence:
- ~ 7% parturients
Characterizations:
- Elevated BP after 20 weeks gestation (bp >140/90)
  - Without proteinuria
- Most cases develop > 37 weeks’ gestation
- Self-limiting: Resolves by 12 weeks postpartum
- ~ ¼ will develop preeclampsia
  - True diagnosis only made after delivery when chronic hypertension can be ruled out

Question 39

Q

What is chronic hypertension of pregnancy?

Answer

A

Systolic BP > 140 and/or diastolic BP > 90
- Starts before pregnancy or PRIOR to 20 weeks
Elevated blood pressure that fails to resolve after delivery
Consequences:
- Develops into preeclampsia ~ 1/5- ¼ affected patients
- Still an important risk factor for unfavorable maternal and fetal pregnancy outcomes

Question 40

Q

What is chronic hypertension with preeclampsia?

Answer

A

Occurs when preeclampsia develops in a woman with chronic HTN
- Dx: proteinuria onset
- Or sudden increase in proteinuria, blood pressure, or both
Morbidity increased for both the mother and fetus compared to preeclampsia

Question 41

Q

What is preeclampsia?

Answer

A

Preeclampsia is a multisystem disease unique to human pregnancy
Occurs in 3 - 8% of all pregnancies
Accounts for 15 – 19% of maternal deaths in the US and UK
Doubled in the last decade

Question 42

Q

What is mild pre-eclampsia?

Answer

A

BP > 140/90 after 20 wks gestation
Proteinuria
- 300 mg/24 hours
- 1+ on dipstick
- protein/creatine ratio > 0.3

Question 43

Q

What is severe pre-eclampsia?

Answer

A

BP > 160/110
Proteinuria
- > 5g/24 hours
- >3+ on dipstick)
Thrombocytopenia
- platelet < 100,000
Serum creatinine
- > 1.1 mg/dl (or 2x’s baseline)
Pulmonary edema
New onset cerebral or visual disturbances
Impaired liver function
Epigastric pain
Intrauterine growth restriction

Question 44

Q

What are some coexisting and obstetric factors that increase risk for pre-eclampsia?

Answer

A

Coexisting
- Chronic renal disease
- Lupus
- Protein S deficiency
- Increased pulse pressure during 1st trimester
Obstetric Factors
- African American
- Nulliparity
- Advanced age (> 40)
- Smoking
- Obesity
- Diabetes
- Multiple gestation
- History of pre-eclampsia

Question 45

Q

Pathogenesis of preeclampstia?

Answer

A

Unknown Exact pathogenic mechanism
- Hypothesis: Immune maladaptation → leads to inflammation
Focus on the placenta
- Delivery of placenta resolves preeclampsia
- Can occur in absence of a fetus (molar pregnancy)
2 stage disorder
- 1^st stage = asymptomatic
- 2^nd stage = symptomatic

Question 46

Q

What occurs during the first stage of preeclampsia?

Answer

A

Impaired remodeling of spiral arteries
- End branch of the uterine artery that supplies placenta
Normally
- Cytotrophoblasts invade the spiral arteries changing them to low resistance and high flow vessels
  - Adrenergic denervation
Preeclampsia
- Invasion is incomplete leaving small and constricted vessels that are responsive to adrenergic stimuli
- basically vessels to uterus do not undergo necessary remodeling, so it leaves a high pressure system. still have response to adrenergic stimuli

Question 47

Q

What occurs during the second stage of pre-eclampsia?

Answer

A

Widespread endothelial dysfunction that is organ specific develops
Insufficient placental BF → leads to placental hypoxia
- → IUGR
Increased production of free radicals and lipid peroxides
Imbalances
- Vasoconstrictors: (thromboxane A2 = ⇧)
- Vasodilators (prostacyclin’s = ⇩)
Hypoxia →
- increase antiangiogenic factors (sFlt-1 and soluble endoglin) factors → decrease vascular endothelial growth factors and placental growth factors.

Question 48

Q

Pathophys of preeclampsia?

Answer

A

unknown cause
leads to endothelial damage
Cascade of events
- Plt aggregation
- Dec production of vasodilatory substances
- Increase vascular sensitivity to vasoconstrictive sub (Angiotension, NE) → vasospasms
Consequences:
- Increase capillary permeability
  - → proteinuria
- Hemolytic anemia
- Increase Liver enzymes
  - HELLP
    - Increase SVR
    - Decrease aldosterone escapre
    - Increase Na/H2O retention →
      - HTN
      - Edema → preeclampsia/eclampsia

Question 49

Q

Neurolgoic and CV pathologic alterations in preeclampsia?

Answer

A

Neurological

Headache
Visual disturbances
Hyperreflexia
Seizures (*eclampsia)
Cerebral edema
- Increased risk

Cardiovascular

Increased BP
Decreased intravascular volume (d/t contraction of vascular space)
Increased arteriolar resistance
Heart failure

Question 50

Q

Respiratory changes in preeclampsia

Answer

A

Respiratory changes
- Pharyngeal and laryngeal edema → airway management difficult
  - Potentially WORSE d/t Na/H2O retention
- Pulmonary edema

Question 51

Q

Hepatic and renal changes in preeclampsia?

Answer

A

Hepatic
- Impaired function
- Elevated enzymes
- Hematomas
- Ruptures
Renal
- Proteinuria
- Na retention
- Decreased GFR
- Oliguria
- Increased serum uric acid – decreased urate clearance

Question 52

Q

Hemetalogic alterations in preeclampsia?

Answer

A

Coagulopathy
- Thrombocytopenia (both)
  - Quantitative: number
  - Qualitative: function
- Platelet dysfunction
- Prolonged PTT
  - *risk of cerebral hemorrhage → so need to tx HTN
    - Tx: (SBP >160) w/ labetolol, Hydralazine, nifedipine

Question 53

Q

General managmenet of preeclampsia?

Answer

A

Lots of overlap between obstetricians and anesthesia

General Overview

Timing of delivery
- R/o regional technique d/t coagulopathy?
Fetal and maternal surveillance
Treatment of hypertension
Seizure prophylaxis

Question 54

Q

Timing of delivery in preeclampsia?

Answer

A

Delivery only cure
- > 37 weeks
  - Induction of labor
- > 34 weeks with severe symptoms
- < 34 weeks
  - Expectant management
  - Delay delivery for 24 – 48 hours
  - Administer steroids to facilitate fetal lung function
    - Ex: betamethasone- mature fetal lungs
  - Should be undertaken at facilities with neonatal and maternal intensive care resources

Question 55

Q

What is involved in surveillance of preeclampsia?

Answer

A

S/S of end organ damage
- Ex: renal, liver
Laboratory
- CBC
  - PLT count (most important)
  - > 100,000
  - <100,000 – additional tests
    - PT/PTT/INR
- Chemistry
- Urine protein/creatinine
- LFTs
- Uric acid testing – conflicting evidence

Question 56

Q

What are some guidelines for treatment of HTN in preeclampsia?

Answer

A

Control BP- important
- Considerations:
  - Rapid maternal perfusion pressure changes can adversely affect uteroplacental perfusion pressure
    - → uteroplacental perfusion pressure form arteries are already maximally dilated
    - *If drop BP rapidly → negatively affect perfusion to placenta
Targets:
- 15 – 25% reduction BP
  - Initial BP > 160 (labetalol, Hydralazine, nifedipine)
- Systolic: 120 – 160 mmHg
- Diastolic: 80 – 105 mmHg

Question 57

Q

What are some first line agents for treating HTN in preeclampsia?

Answer

A

Labetalol
- Crosses placenta but does NOT cause fetal bradycardia
- B:A of 7:1
- Dose:
  - 1^st: 20 mg IV
  - 2^nd: 40 mg q10min
    - Max: 220 mg
Hydralazine
- MOA: Potent direct vasodilator
  - decreases MAP and SVR
  - increasing HR and CO
- Dose: 5 mg IV q20 minutes
  - Max: 20 mg

Question 58

Q

What are second line anti-HTN to treat HTN in preeclampsia?

Answer

A

Nifedipine
- Dose: 10 mg PO q20 min
  - Max: 50 mg
Nicardipine
- Dose: 1– 6 mg/hr
- CAUTION:
  - Combo Ca+ blockers + Mg+ è
    - profound hypoTN
    - myocardial depression
Others: sodium nitroprusside and nitroglycerine

Question 59

Q

What meds should you use with caution in patients with preeclampsia?

Answer

A

Methergine- any form of HTN in peripartum period
- Lead to HTN crisis
Sensitive to exogenous and endogenous catecholamines (adrenergic agents)
Magnesium- utilized for preeclampsia
- Leads to uterine atony → increased PP bleeding

Question 60

Q

Seizure prophylaxis in preeclampsia?

Answer

A

Magnesium Sulfate
- Bolus: 4 – 6 grams over 10 - 30 minutes
- Maintenance of 1 -2 gm’s/hour
  - Continued for 24 hours following delivery
- Maternal Side-effects:
  - flushing, HA, dizziness
  - skeletal muscle weakness, decreased deep tendon reflex
  - respiratory depression
  - hypotension
  - pulmonary edema
  - uterine atony (pp) → increase bleeding risk
- Fetal side effects:
  - neonatal hypotonia
  - respiratory depression

Question 61

Q

What is normal serum magenisum?

Therapeutic level for preeclampsia?

When are EKG changes seen?

Loss of DTR with Mg level?

Respiratoyr arrest?

Cardiac arrest?

Treatment for mg toxicity?

Answer

A

Normal: 1.7 – 2.4 mg/dl
Therapeutic: 5 – 9 mg/dl (prevent szs)
EKG changes: 6 – 12 mg/dl
Loss of DTR: 11 – 12 mg/dl
Respiratory arrest: 15 – 20 mg/dl
Cardiac arrest: > 25 mg/dl

Treatment- Mag toxicity

Calcium gluconate: 1 gm over 10 minutes
Calcium chloride: 300 mg over 10 minutes
- Ex: stop mag → admin Ca → monitor for EKG changes

Question 62

Q

Airway managmenet in patietn with preeclampsia?

Answer

A

Generalized edema → obscure anatomical landmarks
Be prepared for a difficult airway, even more so than normal pregnant pt due to edema
Increased vascularity of Nasopharynx
- Tissue swollen/friable → tendency to bleed

Question 63

Q

Hemodynamic monitoring in patient with preeclampsia?

Answer

A

Noninvasive blood
- Mild and uncomplicated severe
A-line- for sick/uncontrolled HTN
- Need for frequent ABG measurement
- Continuous monitoring during induction/emergence in poorly controlled hypertension
- Calculated systolic pressure variation
Central- severe
- Careful considerations and placement
TEE- severe
Useful technique for assessing cardiopulmonary status
AW swollen/vascular as is → CAREFUL w/ probe

Question 64

Q

Labor management of preeclampsia?

Answer

A

neuraxial (CLE or CSE)

Preferred method of pain control
- Recommendation → EARLY placement
  - Ex: analgesia → dec level catecholamines/stress hormones circulating → increase uterine BF, less CV effects
Advantages:
- Provision of high quality analgesia
- Decreased levels of catecholamines and stress hormones
- Conversion of analgesia to anesthesia - avoids general anesthesia
- Increase uterine blood flow
Considerations:
- Coagulation status (Plt**)
- Intravascular volume status
  - Contracted intravascular space → need volume prior to placement
- HypoTN tx
  - Change in autoreg curve
- Use of epinephrine containing solutions (ex: 2% Lido w/ 1:200,000 epi for loading dose)
  - Impact on BP?

Answer 65

A

Coagulation: Plts
- > 100,000 = traditional level
- > 80,000 = currently acceptable w/o other risk factors
- < 50,000 = unacceptable risk
- 50,000 – 80,000
  - risk vs benefits of regional vs. general anesthesia
Considerations
- Platelet count trends over last 24 – 48 hours
  - If platelet count is decreasing – may want to place epidural catheter early
- Coexisting coagulopathies
  - Evaluate
    - Coagulation studies
    - LFTs
    - TEG and platelet function analysis
      - unproved technology in thrombocytopenia in pregnant patients
      - d/t multifactorial issues in preg

Answer 66

A

1. Most skilled provider
1. Single shot technique
1. Use of a flexible, wire-embedded epidural catheter
  * Less trauma
1. Monitor S/S of neurological complication (ex: epidural hematoma)
1. Check plt count before removal
  * NEED: > 75 – 80,000 BEFORE REMOVING
1. Imaging studies should be obtained immediately if question to neuro fx
  * CT
  * MRI

Answer 67

A

Preloading vs co-loading = equivocal outcomes
- *Do not delay initiation of neuraxial techniques simply to administer a fixed volume of fluids
Considerations:
- Restrictive fluid management: small 250 ml fluid boluses
  - Do not want to fluid overload → pulm edema

Answer 68

A

Exaggerated response to endo/exogenous catecholamines (in preeclamptic pts)
- Small doses!!
  - Ephedrine (5 – 10 mg)
  - Phenylephrine (25 – 50 mcg)
Careful titration – severe preeclamptics may have exaggerated response
Epinephrine in labor epidural = equivocal
- Absence of malignant HTN (>160/110)
  - → epinephrine unlikely pose sig HTN crisis risk
  - But AVOID:
    - Reduction of uterine BF in animals
    - Preeclamptics exaggerated vasoactive response
- Used for decades in obstetric anesthesia
Prudent to avoid epinephrine containing solutions
- Reduced chronotropic response during pregnancy
- Maternal heart rate variability during contractions
- Reduction of uterine blood flow in animal models
Patients with preeclampsia may have increased vasoactive response

Answer 69

A

Preferred Anesthesia → Neuraxial
Spinal vs epidural
- Initially – spinal anesthetics were avoided in patients with severe preeclampsia
- Now, not supported by the evidence
  - Hypotension did occur – only 1 minute longer and easily treated ephedrine/phenylephrine
  - No significant difference in neonatal outcomes
- Epidural
  - Initiated with 2% lidocaine or 3% 2-chloroprocaine

Answer 70

A

Airway considerations
- Edema
Hypertensive response to laryngoscopy
- *Laryngoscopy most sympathetic response!
- < 160/110 before induction and extubation
- Maintain:
  - 140 - 160/90-100 throughout
- Tx: HTN
  - Labetalol
  - Remifentanil (0.5 mcg/kg)
    - Good drug: esterases fetus already mature → able to metabolize at same rate as mom
Muscle relaxants
- Continue muscle relaxants throughout surgery
- Considerations:
  - Very small doses
  - Monitor with nerve stimulator
    - Esp w/ Mag admin → decrease muscle tone/delay NMF
  - NM & Mag
    - Steriodal: DOA and potency increased d/t magnesium
      - Ex: rocuronium, vecuronium, and mivacurium
    - Succinylcholine: DOA NOT affected by magnesium
- Reversal agents – including sugammadex is acceptable once baby out

Answer 71

A

Place radial arterial line if BP severe
Verify difficult airway equipment & smaller sized tubes available (6.0, 6.5)
Administration of H2 blocker or reglan 30 – 60 minutes before
Sodium citrate 30 ml’s prior to induction
De-nitrogenate
Labetalol 10 mg iv boluses to get BP to <160/110
Monitor FHR- s/s fetal distress
Consider remifentanil 0.5 mcg/kg or other adjuncts to help blunt
RSI with Propofol/succinylcholine or etomidate/succinylcholine
Maintain with ½ MAC volatile and 50% N2O
1. After delivery →
  1. Decrease VA
  2. Admin:
    1. Benzo- Versed
    2. Opioid
    3. Propofol
Small doses of opioids and avoid muscle relaxants if possible (bc Mag)
Reverse muscle relaxants and administer more labetalol/hydralazine to prevent hypertension on extubation

Answer 72

A

Life threatening emergency
- 0.1 – 5.9 per 10,000 pregnancies
Most often occurs 2^nd half of pregnancy
- > 20 wks gestation
Risk factors:
- young maternal age
- nulliparity
- multiple gestation
- pre-existing HTN
- preeclampsia
80% develop premonitory signs:
- Headache
- visual disturbances
- photophobia
- altered mental status
- epigastric pain

Answer 73

A

Eclampsia (Seizure) onset:
- Abrupt onset of facial twitching → then tonic phase → followed by clonic phase (often with apnea)
  - ~ lasts about 1 minute
Complications:
- Aspiration
- cerebral hemorrhage
- kidney failure
- cardiac arrest
- placental abruption
- extreme prematurity

Answer 74

A

Stop the convulsions
- Benzodiazepine
- Propofol
- Magnesium
Establish an airway
Turn patient to left side
Administer 100% oxygen
Apply VS monitors - frequent assessment
Check BP frequently – control hypertension (DBP < 110 mmHg)
- Labetolol
- Hydralazine
- Nifedipine
Ensure adequate IV access
Ensure adequate ventilation/oxygenation
Maintain circulation
Deliver the baby expeditiously

Answer 75

A

Stable
- Epidural and spinal acceptable
Unstable
- GA preferred
- Techniques for patients with increased intracranial pressure
  - Propofol- positive effects on cerebral BF
  - Maintain cerebral perfusion pressure
    - MAP – ICP (MAP up, ICP down)
  - Avoid anything decreasing CPP
    - Hypoxemia
    - Hypoventilation
    - hyperglycemia
- Persistent neurological evaluations

Answer 76

A

Defined:
- Hemolysis
- Elevated levels of liver enzyme
- Low platelets
  - Maybe a variant of severe preeclampsia
Associated with: DIC, abruption, pulmonary edema, acute renal failure, liver failure, sepsis, & death
- 70% deliver pre-term

Answer 77

A

Hemolysis
- Microangiopathic hemolytic anemia
- Abnormal peripheral blood smear
  - Schistocytes
  - burr cells
  - echinocytes
- Bilirubin > 1.2 mg/dl
Elevated Liver Enzymes
- AST > 70 IU/L
- LDH > 600 IU/L
Low Platelets
- < 100,000
- Platelet transfusion
  - < 20,000 or significant bleeding in all paturients
< 40,00 scheduled for cesarean section

Answer 78

A

Rupture of subcapsular hematoma of liver (possibility)
- Life threatening complication of HELLP syndrome
- S/S:
  - abdominal pain
  - N/V
  - Headache
  - enlarged liver
  - hypotension
- Dx - Ultrasound or CT scan
- Tx – emergency surgery- delivery of fetus
  - volume resuscitation
  - coagulation management

Answer 79

A

Thrombocytopenia- 10% pregnancies
Etologies:
- > 20 wks → can be sign of HELLP
- Typically benign → Gestational Thrombocytopenia
Plts
- Normal: Plts # decrease 10%
- Threshold
  - ~100,000 safe (varies)
  - 70-100,000
  - NO < 50,000
- Coexisting bleeding disorders → increased risk
  - Ex: VWF Deficiency → risk of peripartum hemorrhage
Increased risk of clotting
- DVT/PE → d/t hormone changes
  - Preexisting factor 5 leiden, Protein S/C/AT/Antiphospholipid deficiencies → increase risk clotting
    - Tx: anticoag therapy → impacts delivery plan

Answer 80

A

Antepartum hemorrhage- Leading cause maternal mortality
# /Need of blood transfusions → morbidity indicator
blood loss
- typically underestimated
- delay to treat– since magnitude of loss is underapprecieated

Answer 81

A

Present if placenta implants in advance of fetal presenting part of fetus
- Dx: (Miller)
  - Placenta low in uterus
  - in front of presenting fetus
  - Either covering or encroaching on cervical os
Occurs in 0.4 -1% of pregnancies (0.5%)

Answer 82

A

Marginal
- Lies close to, but does not cover the cervical os
Partial
- Partially covers the cervical os
Complete
- Placenta completely covers the cervical os

Answer 83

A

Previous cesarean section (prior scar tissue)
Prior placental previa
Multiparity
advanced maternal age
assisted pregnancy
smoking

Answer 84

A

Diagnosis:
- Painless vaginal bleeding during the 2^nd or 3^rd semester
  - Self-limited
- Transvaginal ultrasound
- Digital or speculum exam requires “double set-up”
OB Management
- Bed rest
- Between 24 and 34 weeks – betamethasone
  - → accelerate fetal lung maturity/surfactant development
- C-Section delivery

Answer 85

A

All patients admitted with vaginal bleeding should be evaluated by anesthesia on arrival to the labor deck
Increased risk for intraoperative BL
- Placenta maybe injured during incision
- Lower uterine segment may not contract as well
- Increased risk for placenta accreta
Prepare for massive BL
- 2 large bore IV’s, fluid warmer, blood tubing, rapid infuser, invasive monitoring equipment, a-line

Answer 86

A

Choice of anesthetic technique depends on:
- urgency of delivery
- maternal vital signs
- pregnancy history
Without active bleeding & normal vital signs
- Epidural or CSE acceptable (one RCT showed epidural superior to GA)
Active bleeding or altered vital signs (d/t prolonged bleeding)
- RSI- CV instability
- Induction agent based on hemodynamic status
  - Low dose Propofol or etomidate & ketamine all have been used
- Maintenance
  - Depends on hemodynamic status
  - Benzodiazepine/ketamine vs nitrous/volatile
- Bleeding management (Uterotonics)
  - Oxytocin
  - Hemabate
  - Methergine
  - D/C VA if bleeding continues
    - → Increase N2O [] + midaz or low dose Propofol/ketamine infusion
  - Activate massive transfusion protocol

Answer 87

A

Defined:
- Complete or partial separation of placenta from the uterine wall (decidua basalis) > 20 wks gestation but before delivery of fetus
S/S:
- Vaginal bleeding
  - Significant BL trapped behind placenta (remain in uterus)
    - → Coagulopathy!!
- PAINFUL/tenderness w/ examination
  - placenta previa is painless
Fetal compromise occurs
- Loss of placental surface area
  - → Oxygen tissue exchanging surfaces area reduced → fetal distress

Answer 88

A

advanced maternal age
Chorioamnionitis
PROM
Hx of abruption
multiparity
preeclampsia
hypertension
substance abuse- cocaine *
ETOH/tobacco use
direct/indirect trauma *

Answer 89

A

Vaginal bleeding (clotted dark blood)
Coagulopathies
uterine tenderness
hypotension
increased uterine activity
- Bleeding may be concealed and gross underestimation of hemorrhage can occur
Fetus:
- Non-reassuring FHR
- Bradycardia
- loss of variability
Ultrasound examination

Answer 90

A

Delivery of infant and placenta
Degree of compromise determines timing and route
- Expectant
- Vaginal
- Emergent cesarean section

Answer 91

A

Labor
- Epidural
Cesarean delivery
- Stable – adequate volume resuscitation and normal coagulation
  - Epidural, Spinal, CSE
- Severe ( >50% placenta detached) – fetal death rate approaches 50%
  - Crash GA
    - ketamine/etomidate and succinylcholine
  - Multiple large bore IV’s – place a-line/CVP
  - Volume resuscitation – 1:1:1 ratio
  - Monitor for DIC
  - Monitor for uterine atony (uterotonics*)

Answer 92

A

Uterine wall defect with maternal hemorrhage and/or fetal compromise
- require emergency C-section or postpartum laparotomy(after delivery)
  - Disastrous for mother and fetus

Answer 93

A

Obstetric:
- Prior uterine surgery
- induction of labor
- high dose oxytocin
- Trial of labor after cesarean (TOLAC)
  - Scar dehiscence
Trauma:
- OB:
  - Forceps application
  - internal podalic version
  - excessive fundal pressure
- Non-OB: Blunt or penetrating trauma

Answer 94

A

Abnormal FHR and fetal distress – most common sign
Abdominal pain (sudden & severe), abnormal FHR, and vaginal bleeding (<9%)
Hypotension, vaginal bleeding, change in uterine contour, and changes in contraction pattern – cessation of labor
Breakthrough pain and need for frequent redosing of neuraxial labor

Answer 95

A

Antepartum – emergent laparotomy with delivery
Uterine repair
Arterial ligation – may not control bleeding and delay definitive treatment
Hysterectomy

Answer 96

A

Stable
- May proceeded with preexisting epidural for labor analgesia
Unstable
- Emergency cesarean section and laparotomy
- Aggressive volume resuscitation

Answer 97

A

When placenta abnormally adheres to uterus
Types: (3)
- Placenta accreta vera
  - Adherence of the basal plate directly to the uterine myometrium without an intervening decidual layer
  - Miller: Abnormal adherence to myometrium w. absent decidual line of separation (w/o entering decidual layer)
- Placenta increta
  - When the chronic villi invade the myometrium
  - Miller: Abnormal implantation and growth of placenta into myometrium
- Placenta percreta
  - Invasion through the myometrium into the serosa and adjacent organs
  - Miller: Growth of placenta through uterine wall (myometrium) with placental implantation onto surrounding tissue (bladder, bowel, ovaries, etc)

Answer 98

A

Mirrors the cesarean section rate
Previous cesarean delivery or other uterine surgery increase the risk
# C/S deliveries → Increase risk!!
- 0 = 3%
- 1 = 11%
- 2 = 40%
- 3 = 61%
- 4 or > = 67%

Answer 99

A

Plan:
- Planned preterm c/s and hysterectomy with placenta left in situ
  - → removing likely to initiate massive hemorrhage
- Goal: Gestation > 34 weeks
- Most often at institutions that manage complex OB patients
However must be prepared for emergency delivery and hysterectomy at any institution the care for parturients
- Crash GA
  - RSI
- Blood loss can be massive
- Prepare for massive transfusion
- Efforts to stop bleeding:
  - Internal iliac artery balloon catheters
  - resuscitative endovascular balloon occlusion of aorta

Answer 100

A

Placenta that has not undergone expulsion w/in 30 min of birth
- whole placenta
- placenta parts
Consequences: post-partum hemorrhage
Therapy:
- Epidural = top up +/- conscious sedation
- Intravenous = nitroglycerine 1 mcg/kg
  - May also try sublingual spray 400 mcg
- GA with high dose volatiles
All the risks that go with general anesthesia

Answer 101

A

The uterus inverts through the cervix into the vagina
- Rare – 1: 2,000 – 10,000 deliveries
Risk factors:
- Pulling on the umbilical cord
- uterine atony
- placenta previa
- connective tissue disorders
S/S:
- postpartum hemorrhage
- hypotension
- *Bradycardia – traction on uterine ligament

Answer 102

A

Immediate uterine relaxation followed by uterine contraction
- Nitroglycerine
  - 50 – 200 mcg IV
  - 400 mcg sublingual
- GETA with high dose VA
- Monitor fluid volume status
  - Uterine contraction
    - Oxytocin
    - Hemabate
    - methergine

Answer 103

A

Normal Blood Loss
- Vaginal delivery = 500 ml
- Cesarean section = 800 – 1000 ml’s
  - Well tolerated d/t physiological increase plasma volume (compensates)
Post-partum hemorrhage
- American College of Obstetrician and Gynecologists
  - > 1,000 ml’s
  - Signs and symptoms of hypovolemia
  - Within 24 hours of birth
  - US rate = 3%
    - Most common cause of maternal mortality world wide

Answer 104

A

Uterine Atony

Most common cause of severe post-partum hemorrhage
- 80% of cases
Patho:
- Uterine atony results from inability of uterus to contract and constrict uterine vessels

Answer 105

A

OB:
- Multiple gestation
- Polyhydramnios
- high parity
- prolonged labor
- choriamnionitis
- induced/augmented labor
- c-section
Maternal:
- advanced maternal age
- hypertension
- diabetes
Other:
- tocolytic drugs – slows down labor
  - ex: Magnesium
- high VA []

Answer 106

A

Oxytocin

First line drug therapy for uterine atony prophylaxis
Synthetic preparation with 6 minute half life
Rapidly metabolized by the liver and cleared in the urine and bile
Dosage:
- 20 units/L crystalloid @ 200 – 500 ml/hour – (uncomplicated c/s)
  - can double if ineffective 40 Units
- Some newer protocols:
  - Ex: 3 unit boluses of oxytocin, rest on infusion pump
Side Effects:
- Vasodilation
- Hypotension
- Tachycardia
- coronary vasoconstriction (don’t push large doses)
- hyponatremia (with large dosages)

Answer 107

A

Ergot alkaloids

Methylergonovine or ergonovine (methergine)
- Dose: 0.2 mg IM Q 30 minutes x’s 1
- Relative contraindications:
  - Hypertensive
  - CAD
  - preeclampsia
- Side effects: Nausea/vomiting, increased blood pressure, chest pain, blurred vision and headache, seizure,

Answer 108

A

Prostaglandins

15-Methylprostaglandin (carboprost) – Hemabate
- Dose: 0.25 mg IM Q 15 min to 2 mg
- Relative contraindications:
  - Reactive airway disease (asthma)
  - pulmonary hypertension
  - hypoxemia
- Side effects: Bronchoconstriction, nausea, vomiting, diarrhea,
Misoprostol
- Dose: 600 – 1000 mcg PR
- Relative contraindications: None
- Side effects: fever, chills, nausea, vomiting, & diarrhea

Answer 109

A

Manual message
Intrauterine balloon tamponade
Uterine compression sutures
Embolization of arteries supplying the uterus
Cesarean hysterectomy

Answer 110

A

BL:
- > 500 ml vaginal
- > 1000 ml cesarean
VS: Normal
Labs: Normal
Treatment:
- Place 100% oxygen
- Start large bore IV
- increase IV fluids
- T/C 2 units

Answer 111

A

BL:
- > 1500 ml’s or
- > 2 uterotonics
VS: Normal
Labs: Normal
Treatment:
- Call for help
- Start 2^nd large bore IV
- Draw stat labs (CBC, coags, fibrinogen)
- Obtain 2 units RBC’s and FFP (1:1) → anticipate OR if not there already
  - Type specific better than O-negative
- Provide analgesia
- Prepare OR

Answer 112

A

BL:
- > 1500 ml’s EBL
- > 2 units PRBC’s admin
VS/labs: abnormal
- oliguria

Treatment:

Move to OR – mobilize additional resources
Initiate massive transfusion protocol
- Fixed ratio transfusion (1:1:1)
- Add cryoprecipitate, TXA, and calcium
  - TXA: crosses placenta
    - Recommendation: wait until cord clamped to admin
  - Cell salvage- possible
Factor VIIa - not recommended for routine use
Admin per TEG studies

Answer 113

A

CV collapse

Answer 114

A

Lactate- Decrease
Base excess- Normalize
Hemoglobin: > 7 g/dl
Platelets: > 50,000/mm3
Fibrinogen: > 200 mg/dl
INR: < 1.5 times normal

Answer 115

A

Breech

Transverse or Shoulder

Shoulder Dystocia
- Emergency
- Occurs after delivery of head, the shoulders cannot be delivered secondary to impaction on maternal pelvis
- A/w:
  - Prolonged gestation
  - Labor induction
  - Obesity
  - High fetal wt
  - Prolonged dilation from 8-10 cm
  - Epidural analgesia

Answer 116

A

Approximately 1:150 births
Physiological changes
- Accelerate and exaggerate physiological changes of pregnancy
- Increased uterine size
- Pulmonary
  - Reduced TLC and FRC
  - Aspiration risk - Increased
  - Tracheal intubation (Difficult)- Increased
- CV
  - Additional 750 ml plasma volume increase
  - 20% greater increase in CO
    - SV 15%
    - HR 3%
  - Greater aortocaval compression

Answer 117

A

Epidural – great flexibility and optimal analgesia
- Low threshold to replace equivocal epidural
Move to OR for delivery
- Establish 2^nd large bore IV → increased risk for uterine atony and bleeding
Be ready to convert epidural from analgesia to anesthesia- supplement
In case of uterine inversion:
- Nitroglycerin
  - 400 mcg sublingual or
  - 150 – 250 mcg IV

Answer 118

A

Vaginal Twin A/Operative Twin B
- Epidural = same as vaginal devliery
- May require rapid conversion to general anesthesia with high concentration of volatile anesthetic

Answer 119

A

Spinal vs CSE
Mean umbilical venous/arterial lidocaine [] were 35 – 53% higher in twin newborns compared to singletons (increased sensitivity to LA)
- Increased plasma volume combined with a decreased plasma protein volume
- Clinical relevance of these findings remain unclear (Chestnut – Chapter 34)

Answer 120

A

Regular contractions occurring b/t 20 – 37 wks gestation
- Result: dilation or effacement of cervix
  - Approximately 8% - 10% of births in US
  - Indicated in 50 -80% of perinatal deaths
Survivability depends on:
- gestational age
- maturity of organ systems
- weight

Answer 121

A

History of preterm delivery,
preterm rupture of membranes,
age (< 18 or >35),
trauma
, infection, s
moking,
drug history,
multiple gestation,
low socioeconomic status,
acute illness,
abdominal surgery during pregnancy &
abnormal uterine or cervical anatomy.

Answer 122

A

Bedrest with FHR monitoring
Corticosteroids for fetal lung development (Betamethasone)
Tocolytics (suppression of uterine activity)

Answer 123

A

Magnesium
- Same as before
Calcium channel blockers
- Inhibit influx of calcium
  - Nifedipine PO
SE: Hypotension, flushing, dizziness, nausea

Tocolytics

Cyclooxygenase inhibitors
- Blocks arachidonic conversion
- Ex: Indomethacin
  - Maternal SE: Nausea/vomiting
  - Fetal SE:
    - constriction of ductus arteriosus
    - pulmonary HTN
    - renal dysfunction
    - intraventricular hemorrhage
Beta-agonists
- Ex: Terbutaline
- Smooth muscle relaxation (increase CAMP – activates protein kinase – inactivating myosin light chain kinase – decreasing contraction)
  - SE: Tachycardia, cerebral vasospasm, chest pain, arrhythmias, palpitations, hyperglycemia, hypokalemia, pulmonary edema
  - Fetal SE: tachycardia, hypoglycemia, hypocalcemia & hypotension

Answer 124

A

Goal is a slow controlled delivery with minimal pushing
Large episiotomy and low forceps are often used
Spinal/general
- Complete pelvic relaxation
- Better Apgar scores than with general
- Minimize fluids with beta agonists – pulmonary edema
General
Fetus is more vulnerable to sedative effects of opioids and anesthetics

Answer 125

A

Rare but often fatal complication that can occur during labor
Pathophysiology remains poorly understood
Epidemiology
- No universally accepted definition for identifying cases
- Differing ascertainment methods yield different rates
- Ultimately a diagnosis of exclusion
Society for Maternal-Fetal Medicine and Amniotic Fluid Foundation
- Sudden onset of cardiovascular arrest or both hypotension and respiratory arrest
- Documentation of overt DIC, after the appearance of initial signs or symptoms.
  - The coagulopathy must be detected before sufficient blood loss is lost to account for dilutional or shock related to consumptive coagulopathy.
- Clinical onset during labor or within 30 minutes of delivery of the placenta
- No fever during labor

Answer 126

A

Acute Hypotension or cardiac arrest
Acute hypoxia (dyspnea, cyanosis, or respiratory arrest)
Onset during labor, cesarean delivery, dilation & evacuation, or within 30 minutes post partum
Absence of an alternative explanation of the observed signs and symptoms

Answer 127

A

Older age
Obstetric factors
1. Abnormal placenta
2. Placental abruption
3. Eclampsia
4. Multiple gestation
5. Induction of labor
6. Operative delivery

Answer 128

A

Appears to be a systemic inflammatory response associated with inappropriate release of endogenous inflammatory mediators and platelet activation
Exact trigger is unknown
A rare pathologic fetal antigen
Usual antigen presented in an unusual way – amount, timing, or frequency of entry into circulation
Fetal cells, lanugo hair, and mucin into the maternal pelvic vasculature is a common event
- However, pulmonary artery aspirates of patients without AFE have shown fetal material in it
Systemic inflammatory response:
- arachidonic acid metabolites like thromboxane, prostaglandins, leukotrienes, and endothelins.
- Fetal squamous cells release tissue factor which activates platelets to release thromboxane and serotonin

Answer 129

A

Presentation
- Initial – Prior to delivery
- Seizure, loss of consciousness, and profound dyspnea
- Maternal symptoms appear BEFORE abrupt onset of variable decelerations and fetal bradycardia
Presentation Around Delivery
- Acute cardiovascular collapse
- Pulmonary hypertension
  - Right ventricular dilation, decreased CO & profound V/Q mismatch
  - ABG’s 30 minutes on 100% FiO2 = < 30 mmHg
- Cardiovascular
  - Vary = ST segment/T wave abnormalities to arrhythmias or asystole
  - ECHO = dilated, akinetic RV with progressive dilation
  - Right ventricle dilation leads to decreased LV function and decreased CO
- Massive hemorrhage & DIC
  - Thrombocytopenia and significant hypofibrinogenemia

Answer 130

A

1. Maintain Oxygenation
  * Intubate and administer 100% oxygen
1. Hemodynamic Support
  * Place a-line and central line as necessary
  * Administer fluids and vasopressors as necessary
  - Ensure left uterine displacement
    * TEE to guide fluid replacement therapy
    * Chest compressions as needed
1. Correction of coagulation
  * Activate massive transfusion protocol
  * Serial laboratory assessments
  * Coagulopathy support: TXA, recombinant Factor VIIa, prothrombin complex concentrates, or fibrinogen concentrate

Answer 131

A

Cardiopulmonary bypass
Extracorporeal membrane oxygenation
Continuous hemofiltration
Medication regime (A-OK)
- Atropine 1 mg
  - Blocks vagal reflex → blocks systemic hypoTN
- Ondansetron 8 mg
  - Blocks serotonin pathway → ultimately decrease pulm vasoconstriction
- Ketorlac 30 mg
  - Blocks thromboxane → typically releases inflam mediators

Answer 132

A

Incidence of surgery → estimated at 0.75 – 2.2%
Indications: cervical incompetence, ovarian cysts, appendicitis, cholecystitis, malignancies, and trauma
Timing of surgery – Swiss Study
- First trimester: 42%
- Second: 35% (preferred- but not elective. Less risk)
- Third: 23%
Practical considerations
- Surgery should not be denied because of trimester considerations
- Second trimester is preferred because of lowest risk of spontaneous abortion and preterm labor
- Emergency surgery – primary goal is to preserve the life of the mother

Answer 133

A

Teratogenicity
- Most structural abnormalities result from exposure during organogenesis
  - 31 – 71 days after first day of last menstrual period
- Physiological derangements
- Diagnostic procedures
- Drugs
  - No anesthetic agents is proven teratogenic in humans
  - Most anesthesia providers AVOID:
    - Nitrous oxide (inhibits methionine synthase)
    - Benzodiazepines – cleft lip/palate risk

Answer 134

A

Preoperative
- Multi-disciplinary team available
- Good airway exam (multiple different plans)
- Pharmacological prophylaxis against acid aspiration (H2 blocker, reglan, bicitria)
  - > 12 weeks
Choice of Anesthesia
- Local
- Regional
- Neuraxial
- General – only if necessary (avoid if can)

Answer 135

A

Monitoring
- When fetus is viable (20 -24 weeks) and technically feasible
- OB provider available for diagnosis and intervention
Prevention of compression
- Beginning at 18 -20 weeks
- Good left uterus displacement
  - When mom supine → significant hypoTN

Answer 136

A

De-nitrogenation
- d/t dec FRC
RSI with cricoid pressure
Volatile, muscle relaxants, opioids, and reversals acceptable
No difference in maternal/fetal outcomes based on anesthetic agents
Maintain PaCO2 in normal pregnancy range
- 28 – 32 mmHg
Avoid hypoxemia, hypotension, acidosis and hyperventilation
Use low pneumoperitoneum pressure and Trendelenburg position
Avoid NSAIDS – close PDA

Answer 137

A

Mothers > 35 years of age
- > 35 = 20%
- > 40 = 4 %
Higher morbidity and mortality for both mother and fetus
Increased risk for miscarriage, congenital anomalies, preterm delivery, placental abruption & c-section (2x’s more likely to request)
Focus patients co-morbid conditions
- 38% had pre-existing condition

Answer 138

A

Trial of Labor After Cesarean Section
C-section rate was 32% in 2016
Trial
- Based on c-section type (classic vs low transverse)
- 60 – 80% successful
Contraindications
- Multiple gestations, two previous sections, severe preeclampsia, obesity, previous stalled labor
Risk
- Uterine rupture
- Uterine atony
- Blood transfusions

Answer 139

A

Failure of labor to progress normally
- < 0.5 cm dilation during 1st stage of labor after active labor is established
- > 2 hours pushing after full dilation and no change of station
Due to:
- Ineffective uterine contraction
- Arrest of cervical dilation
Treatment
- Oxytocin
- C-section

Answer 140

A

Intra-amniotic infection
S/S
- Maternal leukocytosis
- Maternal tachycardia
- Fetal tachycardia
- Uterine tenderness
- Foul smelling odor
Tx
- Antibiotics
- Delivery

Answer 141

A

Affects up to 1.6% of all pregnancies
Leading non-obstetric cause of maternal mortality
Optimal management begins at conception
- Consult cardiology early
  - Most already know about
- Tailor anesthetic plan to exact lesion
  - severe AS, not good candidate neuraxial anesthetic
Regional anesthesia is good
- Analgesia = decrease pain and lowers catecholamine release
  - Epidural = slow onset – easier to maintain hemodynamic parameters
    - better choice
- Careful fluid administration
Always provide supplemental oxygen
SBE prophylaxis = consult with OB

Answer 142

A

Occurs in about 3% of pregnancies
Blood sugar goal: 60 -120 mg/dl
Problems:
- placental insufficiency
- preeclampsia
- hypertension
No evidence that one anesthetic technique is superior to another
Consequences:
- Maternal: DKA, HHNC, hypoglycemia, macro/microvascular disease, stiff joint syndrome, diabetic nephropathy,
- Fetal: large for gestational age (shoulder dystocia/birth trauma) and structural malformations

Answer 143

A

Higher rates of chronic hypertension, gestational diabetes, preeclampsia and UTI
Increased risk of
- premature labor,
- low birth weight,
- fetal/neonatal demise
Increased cesarean section rates, post partum hemorrhage, and hospital stays
Good preanesthetic evaluation
- Particular to airway evaluation
- Have multiple airway adjunct available
Establish IV access early
Apply supplemental O2
Establish epidural early – high failure rate
- LA → lower dose req (smaller epidural space)
- Ensure LUD

Answer 144

A

Most common abused substance in pregnancy = 18%
Nicotine causes vasoconstriction and may decrease placental blood flow and oxygenation
Associated with
- miscarriages,
- IUGR,
- placental previa,
- abruptio placentae,
- preterm delivery &
- SIDS.

Answer 145

A

9% of pregnant women between 15 - 44 report drinking in the past month
Associated with liver disease, coagulopathy, cardiomyopathy, and esophageal varices
- Fetal alcohol syndrome – 33% of heavy drinkers
Acute intoxication:
- GETA w/ RSI and aspiration prophylaxis
May also undergo acute alcohol withdrawal during the intrapartum or postpartum period = 6 to 48 hours after cessation
- Nausea, vomiting, tachycardia, tremors, agitation, hallucinations and seizures

Answer 146

A

Multiple effects on mother and fetus
Increased risk for preeclampsia and bleeding
Continue opioids through peripartum course
May have increased opioid requirements
Monitor neonates for abstinence syndrome

Answer 147

A

Consequences:
- 1st trimester = congenital anomalies
- 2^nd/ 3^rd = premature labor, IUGR, placental insufficiency, or placental abruption
Direct vasodilators to avoid CV and CNS complications
- Tx hypoTN with direct acting agents
  - Ex: phenylephrine
General anesthesia may be associated with uncontrolled hypertension/tachycardia and dysrhythmias
Chronic a/w thrombocytopenia
Abuse Requirement
- Chronic = decrease MAC
- Acute use = increase MAC

Answer 148

A

Frequently used = 4.7%
Readily crosses the placenta – however, no know effects
Preterm labor and IUGR can occur
Long term users = increased secretions, impaired cough & potentially increased airway reactivity

Answer 149

A

Leads to indirect sympathetic stimulation (serotonin, norepi & dopamine)
- Vasoconstriction with labile blood pressure and tachycardia
Both neuraxial and general anesthesia have been used
Acute use may increase risk for urgent cesarean section under general anesthesia
- Treat like acute cocaine use

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