Obstetrics: Anesthesia for Complicated Pregnancy Flashcards
1
Q
What is labor that occurs between 20 & 37 weeks?
A
Premature labor
2
Q
What percentage of deliveries are premature?
A
8%
3
Q
What are contributing factors to premature labor?
A
- Extremes of age
- Inadequate prenatal care
- Infections
- Prior preterm labor
- Multiple gestations
4
Q
T OR F:
Preterm infants under 30 weeks and weighing less than 1500 G have more complications than term infants
A
TRUE
5
Q
What is the most common complication in premature babies?
A
Inadequate surfactant levels and low lung maturity
6
Q
At what age does surfactant become adequate?
A
35 weeks
7
Q
What is PROM?
A
Premature rupture of membranes
8
Q
What happens during PROM?
A
Leakage of amniotic fluid that occurs before the onset of labor
9
Q
What is incidence of PROM?
A
- 10% of all pregnancies
- - 35% of all premature deliveries
10
Q
What are contributing factors to PROM?
A
- History of PROM or premature labor
- Multiple gestations
- Smoking
- Infections
11
Q
T or F:
Spontaneous labor starts within 24 hours of PROM in 90% of patients
A
TRUE
12
Q
If PROM occurs before 34 weeks gestation, what is course of action?
A
Stop the pregnancy if you can
Start antibiotics
Start tocolytics for 5-7 days
13
Q
If PROM occurs after 34 weeks gestation, what is course of action?
A
Deliver the baby
14
Q
Chorioamnionitis is what?
A
Infection of the chorionic and amnionic membranes that may or may not involve the placenta, uterus, and umbilical cord
15
Q
What is chorioamnionitis usually associated with?
A
PROM
16
Q
What are some maternal complications of chorioamnionitis?
A
- Dysfunctional labor
- Septicemia (infection)
- Postpartum hemorrhage
17
Q
What are some fetal complications of chorioamnionitis?
A
- Premature labor
- Acidosis
- Septicemia (infection)
18
Q
What are clinical signs of chorioamnionitis?
A
- Fever >38* C
- Maternal and fetal tachycardia
- Foul smelling or purulent amniotic fluid
19
Q
Is regional anesthesia safe for patients that have chorioamnionitis?
A
Is safe as long as no signs of septicemia at placement site
20
Q
What has happened when an onset of sudden fetal bradycardia and profound decelerations is noted?
A
Umbilical cord prolapse
when umbilical cord is wedged between baby and canal possibly kinking off cord
21
Q
What are predisposing factors of umbilical cord prolapse?
A
- Excessive cord length
- Malpresentation ( baby not head down)
- Grand parity >5 ( history of more than 5 pregnancies)
- Multiple gestations
22
Q
What is treatment for umbilical cord prolapse?
A
- Immediate steep trendelendburg
- - Pushing of fetus back into pelvis until stat C-section can be performed
23
Q
What is an entry of amniotic fluid into the maternal circulation that occurs through any break in uteroplacental membranes?
A
Amniotic fluid embolism
24
Q
What is the mortality rate of an amniotic fluid embolism?
A
86%
25
What does amniotic fluid contain?
- - Fetal debris
- - Prostaglandin
- - Leukotrienes
26
What is incidence of Amniotic fluid embolism?
Very rare, but accounts for 10% of all maternal deaths with 50% mortality rate in 1st hour
27
What is the classic triad of symptoms to present during an amniotic fluid embolism?
- - Acute hypoxemia
- - Hemodynamic collapse w/ severe hypotension
- - Coagulopathy without obvious cause
28
What are the 3 main pathophysiological manifestations with amniotic fluid embolism?
1) Acute pulmonary embolism
2) DIC
3) Uterine atony
29
What is the treatment for an amniotic fluid embolism?
- - Resuscitation and supportive care
- - CPR
- - Immediate delivery of baby improves maternal and fetal outcome
30
What are 3 types of partum hemorrhages?
- - Antepartum
- - Peripartum (intrapartum)
- - Postpartum
31
What is antepartum?
Placenta previa
| Placental abruption
32
What is peripartum?
Uterine rupture
33
What is postpartum?
```
Placenta accreta (placenta grows through endometrium)
Uterine atony
```
34
What is placenta previa?
Complication in which placenta is wedged into uterine segment
35
What are 3 types of placenta previa?
- - Central or complete previa (37% of time)
- - Incomplete or partial previa ( 27% of time)
- - Low lying or marginal previa (46 % of time)
36
What is complete placenta previa?
Placenta completely covers internal cervical OS
37
What is partial placenta previa?
Placenta partially covers internal cervical OS
38
What is marginal placenta previa?
-- Placenta is close to the internal cervica OS without extending beyond its edge
(The anterior lying placenta previa increases risk of excessive bleeding during C/S)
39
What is incidence of placenta previa?
0.5%
| Goes up to 5% for subsequent pregnancies
40
What risk factors are associated with placenta previa?
- - Scarring of uterine wall
- - Many previous pregnancies
- - Abnormally developed uterus
41
What is most common symptom of placenta previa?
Painless vaginal bleeding
42
What is the management of placenta previa for a women less than 37 weeks gestation?
Bedrest and observation
43
What is the management of placenta previa for a women after 37 weeks gestation?
C/S
44
When can you deliver vaginally with placenta previa?
When marginal placenta previa exist and bleeding is only mild
45
T or F:
| All patients with vaginal bleeding are assumed to have placenta previa until proven otherwise
TRUE
46
What type of anesthetics can you use for placenta previa?
-- Regional if patient is hemodynamically stable and no active bleeding
-- General with stat C/S if active bleeding or patient is unstable
47
For most OB procedures, how much blood needs to be crossmatched and available for transfusion?
2 units
48
What is a premature separation of normal placenta after 20 weeks of gestation?
Placenta abruption
49
How does placenta abruption cause fetal distress?
The separation of placenta equates for a loss of area for maternal-fetal gas exchange causing fetal distress
50
What is the most common cause of intrapartum fetal death?
Placental abruption
51
What are some risk factors for placental abruption?
- - HTN
- - Trauma
- - Prolonged PROM
- - Tobacco, alcohol, cocaine usage
- - Short umbilical cord
52
What are some symptoms of placental abruption?
- - Painful vaginal bleeding
- - HTN
- - Uterine tenderness
53
What is the unique diagnosis for placental abruption?
Amniotic fluid is port wine colored
54
Minimal placental abruption is characterized by what?
- - Preterm with no fetal distress
| - - Patient is hospitalized and pregnancy allowed to continue until fetal lung maturation
55
Mild to moderate placental abruption is characterized by what?
-- If >37 weeks and no fetal distress, then vaginal delivery is allowed
-- If fetal distress is apparent, then immediate C/S
-- Fibrinogen levels are mildly reduced and patient starting to get to DIC
56
Severe placental abruption is characterized by what?
-- Fibrinogen, Factor 5 and 7, and platelet counts all low
-- Is life threatening emergency and requires STAT C-section
57
What is IFD?
Intrauterine fetal demise
58
What type of anesthetic is preferred for placental abruptions?
General b/c of high blood loss and required treatment of hyprovolemia
59
What is a uterine rupture?
When the integrity of the myometrial wall is breached that typically occurs during active labor
60
What are the signs and symptoms of uterine rupture?
- - Frank hemorrhage that causes hypotension
- - Fetal distress (most reliable sign)
- - Abdominal pain that breaks through epidural
- - Constant pain that has no relief between contractions
61
What is the treatment for a uterine rupture?
Volume resuscitation & immediate laparotomy
62
What is a retained placenta?
Placenta fragments that are still attached to uterus after delivery
63
What is the detrimental effect of a retained placenta?
When fragments are still attached, causes the uterus to not be able to contract properly and cause open blood vessels and sinuses to continue to bleed profusely
64
What is treatment for retained placenta?
Manual exploration of uterus
| --- Nitroglycerin may be useful in relaxing the uterus
65
What is an abnormally adherent placenta?
Placenta accreta
66
What are 3 types of plenta accreta?
- - Placenta accreta vera
- - Placenta increta
- - Placenta percreta
67
Which placenta accreta is an invasion of the myometrium and occurs around 17% of time?
Placenta increta
68
Which placenta accreta is only an adherence to the myometrium without invasion or passage through uterine muscle?
Placenta accreta vera
| occurs majority of time ~78%
69
Which placenta accreta is an invasion of the uterine serosa or other pelvic structures (like a through and through of myometrium) and only occurs around 5% of time?
Placenta percreta
70
When is diagnosis made for placenta accreta?
Usually during separation of placenta at delivery and is confirmed by laparotomy
71
What is the treatment for placenta accreta?
-- Uterine curretage and oversewing can be tried but rarely works
-- Most require C/S and a postpartum hysterectomy/laparotomy to repair
72
What is uterine atony?
Condition in which uterus is not contracting down
73
What is uterine atony usually accompanied with?
Retained placenta
74
What is treatment for uterine atony?
Oxytocin
| if really severe then mertherigine and then if more contraction needed then hemabate
75
What is the 1st line drug treatment that all patients receive to help with uterine contraction?
Oxytocin
76
What is the major side effect of oxytocin and what must be done to ensure this doesn't occur?
Hypotension
Give drug slowly as hypotension usually only comes on when drug given too quickly
77
T or F:
| Oxytocin stimulates both the frequency and force of contractile activity
TRUE
78
What is normal postpartum dose given of oxytocin?
20 units diluted in 1000 mL
Titrate infusion to around 30 mU/min
79
What is onset and half life of oxytocin?
Onset : 1 min
Half life: 1-5 min
80
What is 2nd line drug therapy used to aid uterine contraction?
Methylergonovine maleate or METHERGINE
81
How does methergine work?
Works directly on smooth muscle of uterus via alpha receptors
82
What side effect do you usually see with methergine?
Increased CVP and BP
83
What is the dose of methergine?
IM : 0.2 mg
IV : 0.02 mg
Onsets: IM = 2-5 min
IV= immediate
84
What patient population must you use caution with if giving methergine?
- - Preeclampsia (because already HTN)
- - HTN
- - Asthmatics
- - Cardiac disease (because increase in CVP)
85
What is the last line drug therapy used for uterine contractions?
Prostaglandin f2alpha or HEMABATE or carboprost
86
What is dose of hemabate and what is maximum dose?
IM : 250 mcg
Repeated every 15 min intervals
Max dose : 2 mg
87
T OR F:
| You can give hemabate to asthmatics freely
FALSE
| be very cautious with asthmatics
88
For a uterine inversion, what can your blood loss be and what is effect of this?
EBL can be 700 mL/min
| Cause patient to become hypotensive
89
What can you give to help OB treat uterine inversion?
NTG and Sevo to relax uterus
90
Which condition presents with NO pain, NO fetal distress, and lots of bleeding
Placenta previa
91
Which condition presents with pain, fetal distress, and lots of bleeding (some of which can be concealed/hidden from us)
Placenta abruption
92
Which condition presents with pain, LOSS of fetal heart rate, and lots of bleeding
Uterine rupture
93
Which condition presents postpartum with NO pain with some bleeding
Retained placenta
94
Which condition presents postpartum with NO pain with lots of bleeding
Placenta accreta
95
Which condition presents postpartum with NO pain with some bleeding
Uterine atony
96
Uterine atony and retained placenta both present the same
But remember uterine atony is usually accompanied by a retained placenta so to diagnose rule out atony, not retained placenta
97
What are most common causes of HTN in pregnancy?
- - Pt chronic HTN
- - PIH (pregnancy induced HTN)
- - Preeclampsia / Eclampsia
- - HELLP syndrome
98
What is defined as a chronic HTN?
Systolic BP > 140 mmHg or Diastolic > 90 mmHg before 20 weeks gestation
99
What is the safe beta blocker that can be given to chronic HTN patients that are pregnant?
Labetolol
100
How is PIH defined?
Same as chronic ( S >140 and D > 90) but brought on by pregnancy
-- Can also be defined as consistent increase in S or D pressures by 30 mmHg & 15 mmHg above patients normal baseline BP
101
What is triad of symptoms of preeclampsia?
1) HTN
2) Proteinuria
3) Edema after 20 weeks that resolves 48 hours after delivery
102
What are some of the risk factors for preeclampsia?
- - Primigravidas (1st baby)
- - Obesity
- - Chronic HTN
- - Previous history
103
What is the pathophysiology of preeclampsia?
COMPLICATED AND NOT UNDERSTOOD so no one knows
104
Severe preeclampsia is defined as what?
```
S > 160 mmHg or D > 110 mmHg
OR
Proteinuria > 5 G / 24 hours
OR
*Cerebral edema causing headache
* Pulmonary edema
* Oliguria (< 400 mL / 24 hours)
* Platelets < 100000
```
105
T or F:
| Severe preeclampsia contributes to 20-40% of maternal deaths and 20% of perinatal deaths
TRUE
106
What is HELLP syndrome?
PIH associated with:
hemolysis
elevated liver enzymes
low platelet counts
107
Which type of anesthetic is needed for HELLP syndrome?
GA
| regional is contraindicated because actively falling platelet count
108
When does preeclampsia turn into eclampsia?
When seizures occurs
109
What is treatment for preeclampsia?
- -Bedrest
- - Antihypertensives
- - Magnesium sulfate
110
What antihypertensives are safe for pregnancy?
- - Labetolol 5-10 mg
- - Hydralazine 5 mg
- - Methyldopa 250-500 mg PO
- - Mag sulfate
- - Nitroprusside
111
What is mag sulfate used for ?
Treat hyperreflexia and prevention of seizures because it reduces CNS irritability
112
What is the goal therapeutic level of mag sulfate?
4-6 mEq / L
113
What are normal levels of mag sulfate?
1.5-2 mEq / L
114
What are detrimental effects of increased levels of mag sulfate?
Start to have detrimental effects on heart
115
What are ranges for excess mag sulfate and what does each cause?
: 5-10 eEq / L causes ECG changes
: 10 mEq causes respiratory depression and weakness
: 15 mEq causes SA and AV blocks
: 25 mEq causes cardiac arrest
116
Which drug poses a risk of cyanide toxicity to the fetus in large doses?
Nitroprusside
117
What is only definitive treatment to preeclampsia?
Delivery of fetus and placenta
118
Does mild preeclampsia require a C/S?
NO
| patients just pose higher risk so just be careful and cautious
119
For severe preeclampsia patients, what is anesthetic plan.
- - A line always
- - On antihypertensives
- - Monitor urine output closely
- - Hypovolemia corrected slowly ( no more than 500 mL crystalloid)
- - Check platelet counts frequently (no regional if counts < 80000)
- - EPIDURAL OR SPINAL 1st CHOICE
120
Why are epidurals preferred in preeclamptic patients?
- - Avoids risk of failed intubation
- - Avoids hypotension
- - Improves uteroplacental perfusion by 75% in PIH patients
121
When treating patients with hypotension, what must you do to doses of drugs given?
REDUCE them
ephedrine 5mg at at time
phenylephrine 50 mcg at a time
122
What does mag sulfate do to non-depolarizing muscle relaxants?
Potentiates them so require much less of drug
123
What is true of regurgitant valves during pregnancy?
- - Pregnancy tolerated well
- - Regional anesthesia well tolerated
- - Avoid pain, increased CO2, decreased O2, avoid myocardial depression
124
What is 2nd most common valve defect in pregnant patients?
Mitral regurg
125
How should you handle patients with regurg?
- - Avoid bradycardia
- - Avoid HTN
- - Consider afterload reduction
126
Which valve defect may develop after an attack of rheumatic fever?
Aortic regurg
127
What is true of stenotic valves during pregnancy?
- - Pregnancy poorly tolerated
- - Consider invasive monitoring
- - Maintain normal HR
128
With mitral stenosis, what do you have to watch out for?
- - Avoid sinus tachycardia
- - Avoid A fib
- - Avoid increases in blood volume
129
How should you handle patients with aortic stenosis?
- - Avoid decreased SVR
- - Avoid bradycardia
- - Avoid hypovolemia
130
Just for review, what are left to right shunts?
- VSD
- ASD
- PDA
131
Just for review, what is the right to left shunt?
- ToF (tetrology of fallot)
1) RV hypertrophy / RV outflow obstruction
2) Overriding aorta
3) VSD
132
How can cardiomyopathies present in pregnancy?
Fatigue or URI/ congestion
133
What are the risk factors for cardiomyopathy in pregnancy?
- - Multiple gestations
- - Preeclampsia
- - Obesity
- - Advanced maternal age
134
What is incidence and risk factors of gestational diabetes?
4% of pregnancies
- - Advanced maternal age (AMA)
- - Obesity
- - DM or family history of DM
- - H/O of stillbirth or neonate death
135
What are effects on mother of gestational diabetes?
- - PIH increased likelihood
- - C-section likelihood
- - Preterm labor likelihood
- - Polyhydramnios (increased amount of amniotic fluid)
136
What are effects on fetus of gestational diabetes?
- - Larger birth weight
- - Structural malformations
- - Neonatal hypoglycemia
- - Neonatal respiratory distress syndrome
137
What is macrosomia?
Large birth weight or baby large for gestational age
| Increases likelihood of injury/trauma to mother and fetus during delivery
138
T or F:
Hyperglycemia during period of critical organogenesis before 7th week postconception in single strongest factor in DM pregnant women
TRUE
139
From question above, known this
Basically blood sugar during 1st trimester must be tightly controlled to lower risk of any harm done by DM to mother and fetus
140
T or F:
| CNS structural malformations are the most common malformation caused by DM to fetus?
FALSE
is 2nd most common
CARDIAC is most common
141
What is target glucose concentration for pregnancy?
=< 100 mg/dL
142
T or F:
| Asthma has a variable course of action in pregnancy (may improve may worsen may remain the same)
TRUE
143
What is normal pregnancy ABG?
Respiratory alkalosis
pH 7.44
pCO2 30
pO2 105
144
What is normal non pregnant ABG?
pH 7.35
pCO2 30-40
pO2 85
145
What are the goals for asthmatics during labor?
- - Regional anesthetic is preferred
- - Avoid pain
- - Avoid hypo and hyper carbia
- - Provide minimal sedation
146
For a stable asthmatic, what is management goal?
- - Regional preferred
| - - Avoid endotracheal intubation
147
For an unstable asthmatic, what is management goal?
- - Regional REALLY PREFERRED
- - If GA, pretreat with albuterol
- - RSI
- - High MAC (1.5)
- - Albuterol before extubation
148
For C/S in obese patients, what 2 detrimental risks are increased?
- - Incidence of fetal distress
| - - Abnormal labor (arrest of descent)
149
For morbidly obese patients, what detrimental outcomes are increased?
- - Incidence of shoulder distocia
| - - RIsk of maternal death
