OB Flashcards
1
Q
What anticholinergic should you use in pregnant ladies to prevent fetal bradycardia from neostigmine?
A
Atropine
2
Q
What is the therapeutic range for magnesium in treating eclampsia?
A
5-9 mg/dl
3
Q
What do high levels of magnesium cause?
A
They prevent presynaptic release of acetylcholine thereby decreasing the amount of acetylcholine in the NMJ
Inhibits calcium influx
4
Q
At what levels of magnesium are deep tendon reflexes reduced?
A
5 mg/dl
5
Q
At what levels of magnesium is muscle weakness and respiratory depression produced?
A
7 mg/dl
6
Q
When does hypotension occur in hypermagnesemia?
A
7-12 mg/dl
7
Q
When are DTRs lost and cardiac conduction abnormalities seen in hypermagnesemia
A
12 mg/dl
8
Q
When does asystole occur in hypermagnesemia?
A
25 mg/dl
9
Q
What is the best immediate treatment for hypermagnesemia
A
Calcium Gluconeogenesis
10
Q
What is transient neurological syndrome?
A
Pain or sensory abnormalities in the low back, butt, and LE within 24 hours of postoperatively period that disappear in 4-5 days caused by intrathecal lidocaine
11
Q
In what position does TNS most commonly occur?
A
In the lithotomy position
12
Q
What other local anesthetic has a similar risk of causing TNS to lidocaine?
A
Mepivacaine
13
Q
What is the most desired sensory level block for a c-section?
A
T4 because of manipulation and traction on the abdominal organs and peritoneum
14
Q
What is the new definition for preeclampsia?
A
Past 20 weeks: Hypertension (severe = 160/110) \+ Severe symptoms: Headache TCP < 100K Elevated Liver Enzymes Persistent RUQ pain Persistent headache/cerebral symptoms Renal insufficiency (serum Cr twice normal) Pulmonary edema
15
Q
What is chronic hypertension in pregnancy?
A
BP > 140/90 before 20 weeks
16
Q
What is gestational hypertension?
A
High BP after 20 weeks with no other associated symptoms
17
Q
What are the first line treatments for severe HTN (160/105) in preeclampsia?
A
Hydralazine and Labetalol
2nd line: oral nifedipine
18
Q
What are you trying to prevent by treating severe HTN?
A
Maternal stroke and CHF
Fetal growtch retardation
19
Q
What are the treatments for refractory BP?
A
Esmolol
NIcardipine drip
Nitroprusside drip
20
Q
What can esmolol cause in the fetus?
A
Bradycardia
21
Q
Which antihypertensives cross the placenta?
A
All of them
There are only trials on animals
22
Q
What should you do if a neonate’s heart rate drops below 100?
A
Start positive pressure ventilation
23
Q
What should you do if a neonate’s heart rate drops below 60 for > 30 seconds?
A
Start chest compressions at 3:1 ratio with ventilation.
Giving a rate of 120 per minute (90 compressions + 30 breaths per minute)
24
Q
What is the most common cause of fetal bradycardia?
A
Hypoxia
25
Why should FiO2 be lowered ASAP when resuscitating a neonate?
Due to free radicals and hypoxic-reoxygenation effects: pulmonary toxicity, retinopathy of premature
26
What should you do if the fetal heart rate remains below 60 despite chest compression for more than 30 seconds?
10-30 mcg/kg of epinephrine q 3-5 minutes
27
How much volume resuscitation should be given to a neonate?
10 ml/kg of crystalloid
28
What is the definition of postpartum hemorrhage?
Greater than 500 ml blood loss in vaginal delivery
| Greater than 1L blood loss in ceserean
29
What is the most common cause of postpartum hemorrhage?
Uterine atony due to bleeding intrauterine vessels which are normally constricted with uterine contraction
30
What are the risk factors for uterine atony?
```
Multiparity
Polyhydramnios
Oxytocin-induced labor
Chorioamnionitis
Prolonged labor
```
31
What is the first line treatment for uterine atony?
Uterine massage
32
What is the first line medical treatment for uterine atony?
Oxytocin - stimulates uterine myosin
33
What are the side effects of oxytocin?
```
Hypotension with bolus
Headache
Nausea
Arrythmias
Diuresis
Hypertonic uterine contractions
```
34
What is methylergonovine?
An ergot alkaloid that causes uterine contraction by increasing intracellular calcium.
Note: also causes vasoconstriction elsewhere - increase pulmonary vascular resistance, systemic vascular resistance
35
What are the side effects of methylergononvine?
Coronary vasospasm
Bradycardia
Cardiogenic Pulmonary edema
Severe hypertension
36
In what conditions is the use of methergine contraindicated?
Pregnancy induced hypertension
Preeclampsia
Chronic HTN
CAD
37
What is carboprost tromethamine?
prostaglandin F2a which causes uterine contraction
38
What are the side effects of carboprost tromethamine?
Bronchospasm
Nausea
Diarrhea
Labile BP
39
What conditions is carboprost contraindicated in?
Reactive airway disease
| HTN
40
When would you use vasopressin for uterine contraction?
As a rescue measure because it is very short acting and has to inject directly into the uterus
41
What is the first line treatment for uterine relaxation in the setting of uterine inversion?
Nitroglycerin - IV or sublingual
42
What is uterine inversion?
A surgical emergency - must get uterus reversed before the cervix closes on the fundus
43
What is misoprostol?
Synthetic prostaglandin E1 used for uterine contraction or ripening the cervix.
Given po or pr
44
What is hPL?
Human placental lactogen - it is an insulin antagonist which increases lipolysis and glycosis for glucose for baby
45
What happens to renal blood flow in pregnancy?
It increases by 20-25%, which increases GFR and therefore decreases BUN/Cr ratio
46
What happens to renal bicarb excretion in pregnancy?
It is increased due to compensation for respiratory alkalosis
47
Why are pregnant patients more prone to UTIs?
Because progesterone causes dilation and therefore stasis of the ureters
48
What are the CV effects of pregnancy?
Increased blood volume --> increased HR, SV, CO
Increase in venous capacitance (so normal CVP)
Decrease in peripheral vascular resistance
BP decreases by 10% until 34 weeks and then returns to normal prepregnancy values
***There is an increase in myocardial O2 demand)
49
What are the pulmonary effects of pregnancy?
Decreased FRC (from decreased ERV and RV)
Increase in minute ventilation -->respiratory alkalosis - due to dec. alveolar ventilation ( inc. PaCO2 compensation)
Increased TV by 40%
Vital capacity = unchanged
Total oxygen consumption increases by 20%
50
What CV parameter does not change in pregnancy?
CVP due to increased venous capacitance
51
What pulmonary parameter does not change in pregnancy?
Vital capacity
52
Why is there increased minute ventilation in pregnancy?
Decreased FRC
| Progesterone increases RR
53
What happens to hematocrit in pregnancy?
Decreased slightly due to increased plasma volume in relation to overall increase in BV
54
How much does Hgb change in pregnancy?
<11 g/dl in 1st and 3rd trimester
| < 10.5 g/dl in 2nd trimester
55
What happens to fibrinogen in pregnancy?
It increases --> hypercoagulability due to induction of liver enzymes
56
What causes hypercoagulability in pregnancy?
Increased Factor II, VII, VIII, X, fibrinogen due to induction of liver enzymes
Resistance to protein C and S
Venous stasis
57
What can be used in pregnancy to treat DVT?
```
Lovenox
Dalteparin (Thrombin inhibitor)
Heparin drip
Heparin
Continue lovenox for 6 weeks after delivery!
```
58
What happens to gastric emptying time in pregnancy?
It increases, more gastric motility, more salivation, relaxation of sphincters (higher parasympathetic tone)
59
What happens to cortisol levels in pregnancy?
They increase
60
What happens to thyroid-binding globulin and total T4?
It increases due to liver induction
61
What happens to TSH?
It decreases due negative feedback
62
What happens to free T3/T4 in pregnancy?
It remains normal
63
What is the latent first stage of labor?
Onset of labor to 3-4 cm dilation
64
What is the active first stage of labor?
4 cm to complete cervical dilation
65
What is the second stage of labor?
Complete cervical dilation to delivery of the baby
66
What is the third stage of labor?
Delivery of baby to delivery of placenta
67
What is a normal fetal heart rate?
110-160 bpm
68
What are the causes of fetal bradycardia?
1. Hypoxia - due to uterine hyperstimulation, rapid fetal descent, cord prolapse
69
What are the causes of fetal tachycardia?
Hypoxia, maternal fever, fetal anemia
70
What is normal variability in the FHR?
6-25 bpm
71
What is marked variability and what does it indicate?
>25 bpm, hypoxia
72
What does sinusoidal variability mean?
Severe fetal anemia
73
What drug causes pseudovariability?
Meperidine
74
What are FHR accelerations and what do they indicate?
Increase in HR by 15 bpm in less than 30 seconds
| Indicate appropriate response to environment
75
What is minimal variability and what does it indicate?
HR less than 6 bpm indicative of fetal hypoxia, opioid use, magnesium or sleep cycle
76
What are variable decelerations and what do they indicate?
They are decels with nadir < 30 seconds, > 15 seconds but less than 2 minutes that can happen at any time
77
What are the causes of variable decels?
Oligohydramnios
Nuchal cord
Cord prolapse
78
What will you see if the umbilical vein gets compressed first?
Reflex tachycardia due to decreased venous return and therefore decreased CO
79
What will you see if the umbilical artery gets compressed first?
Reflex brady due to increased SVR and BP
80
What are late decels?
Gradual onset of decrease in FHR after uterine contraction indicative of uteroplacental insufficiency and fetal hypoxia
81
What are early decels?
Gradual onset mirroring uterine contraction indicative of head compression
82
What nerves are being stimulates with uterine contraction and cervical dilation?
T10-L1 (visceral)
83
What nerves are being stimulated during fetal descent and delivery?
S2-S4 (somatic)
84
What are the absolute contraindications to regional anesthesia?
```
Refractory maternal hypotension
Maternal coagulopathy
Maternal use of lovenox
Untreated maternal bacteremia
Skin infection of site
Increased ICP
```
85
What is placenta previa?
Abnormal placental implantation covering cervical os
- need c-section because baby will compress vessels and compromise blood supply
86
What are the symptoms of placenta previa?
Painless bright red bleeding
87
What are the complications of placenta previa?
Increased risk of placenta accreta
Vasa previa --> fetal exsanguination
Premature delivery, PROM, IUGR
Recurrence risk = 4-8%
88
What are the complications of placental abruption?
Hemorrhagic shock
DIC
Fetal hypoxa/death
Recurrence rate = 5-16%, 2nd offense > 25%
89
What are the risk factors of placental abruption?
HTN, cocaine, trauma, smoking, excessive stimulation, prior!!!
90
What are the risk factors of placenta previa?
```
Prior C sections
Grand multiparity
Advnaced maternal age
Multiple gestation
Prior
Smoking, cocaine
Fibroids
```
91
What is placenta accreta?
Placental implantation in myometrium --> massive blood loss --> hysterectomy
92
What are the normal rates of progression in stage 1 of labor?
>1.2 cm/hr nulliparous
| >1.5 cm/hr multiparous
93
What is prolonged second stage of labor?
Arrest of fetal descent
94
What is PROM?
Ruptures of membranes >1 Hour before the onset of labor
95
What is PPROM?
Premature (<37 weeks)
| ***associated with oligohydramnios
96
What is prolonged ROM?
ROM occurring > 18 hours prior to delivery
97
When should betamethasone and tocolytics be given?
Premature labor < 34 weeks.
98
What is the first line tocolytic for less than 32 weeks?
Indomethacin
99
Which tocolytics are contraindicated in diabetics?
B2 agonism (ritodrine and terbutaline) due to hyperglycemia
100
What are the indications for a c-section?
```
Transverse position
Fibroids
Maternal death
Hysterectomy to be performed afterward
Cervical cancer
Active herpes
HIV
Abruption
Cord compression/prolapse
Erythroblastosis fetalis
```
101
What artery does the uterine artery come from?
Internal iliac
102
What is Sheehan's syndrome?
Pituitary ischemia and necrosis that leads to anterior pituitary insufficiency
***Associated with postpartum hemorrhage.
103
What is the presenting symptom of Sheehan's?
Inability to lactate due to decrease prolactin levels
104
What are the symptoms of Sheehan's?
Cold insensitivity, Weakness, lethargy (dec. TSH/ACTH)
Genital atrophy (dec. FSH/LH, estrogen, testosterone)
Menstrual disorder
105
What is a risk of IUFD?
DIC due to tissue factor released from placenta
106
What is an early sign of DIC after IUFD?
Low fibrinogen levels (<100) because these should be higher in pregnancy
107
What causes shivering in epidural anesthesia?
Peripheral vasodilation thereby decreased core temperature and vasoconstriction above the level of the block
108
What causes shivering in labor and delivery?
Progesterone increases body temperature
There is more norepinephrine release which can augment core temperature
Immunologic reaction from maternofetal transfusion
109
What are the components of Apgar scoring?
1. Skin color
2. Heart rate
3. Muscle tone
4. Reflex irritability
5. Respiratory effort
Highest score = 10
Lowest score = 0
110
Is Apgar scoring a predictor of long term outcome?
NO
111
Which local anesthetic is most likely to cause ion trapping and accumulating in the fetus in fetal acidosis?
Lidocaine
112
What is ion trapping?
Happens with decreased fetal ph which will favor the ionized form of local anesthetics (NH3+) because it is basic. Since ionized form cannot pass the placental barrier, it gets trapped in the acidotic fetus
113
Why is lidocaine more likely to cause ion trapping than ropivacaine or bupivacaine?
It is less protein bound than ropiv or bupiv
114
Why is chlorprocaine the preferred anesthetic for bolusing in a parturient?
It is quickly metabolized by plasma esterases so it will not accumulate in an acidotic fetus
115
How does magnesium cause lower blood pressure?
1. By competing with calcium in vascular smooth muscle cells thereby decreasing actin-myosin crosslinking
2. By increasing endothelial intracellular NO and prostaglandin I2 which have vasodilatory properties
116
At what level of magnesium does AV block and myocardial depression occur?
> 10 g/dl
117
What other receptors does magnesium inhibit?
NMDA
118
What does a time sensitive operation mean when talking about doing an operation during pregnancy?
It needs to be done within 1-6 weeks.
119
What is the best option for decreasing risk of miscarriage for an operation?
Delaying surgery until the second trimester
120
What causes higher risk of abortion and preterm labor in the perioperative period?
Manipulation of the uterus
Surgery
The condition necessitating surgery
NOT anesthesia
121
Which surgeries have the lowest risk of preterm labor?
Extremity surgery
| Surgery that does not mess with the uterus
122
Why should regional anesthesia be used in pregnancy?
Decreased aspiration risk
Decreased use of opioids
Does not decrease risk of preterm labor
123
When is the risk of preterm labor the highest?
3rd trimester
124
When is variability in FHR seen?
25-27 weeks
125
Is there evidence for preoperative use of tocolytics to prevent preterm labor?
No
126
What anesthetic techniques have been shown to decrease the risk of preterm labor?
None
127
What happens to MAC in pregnancy?
It decreases by 25-40%
128
What happens to alveolar ventilation in pregnancy?
Increases by 70% due to the effects of progesterone
129
What happens to PaCO2?
Decreases by 10 mmHg due to hyperventilation
130
What happens to arterial oxygen tension?
Increase by 10 mm Hg
131
What happens to plasma volume?
Increase by 40%
132
What happens to maternal P50 in pregnancy?
It increases from 27 to 30 (decrease in hemoglobin affinity for oxygen)
133
What is the fetal P50?
19-21 mm Hg, so the gradient is larger faciliating offloading of maternal oxygen to fetal hemoglobin
134
What is the side effect of CSE compared to epidural anesthesia?
Worse opioid induced pruritis
135
What are the advantages of CSE?
More rapid onset of pain control (2-5 minutes)
| Provides good analagesia for c-section and delivery
136
Who is CSE contraindicated in?
Patients who need a safely functioning epidural
- difficult airway
- high likelihood of C-section
- fetal distress
137
What works better for somatic pain/.
Local anesthetic
138
What should be tried as second line for uterine atony?
Carboprost
| Given IM at intervals of 15-90 minutes, max of 8 times
139
What is ex utero intrapartum treatment?
performed when the fetus needs life-saving measures like bronchoscopy, echo, trach, ECMO
Hysterotomy is performed and just the head is delivered to do whatever needs to be done
140
What is required for ex utero intrapartum treatment?
Uterine relaxation to faciliate procedure and maintain uteroplacental sufficiency and fetal gas exchange
Techniques: High volatile
NTG
CSE + NTG boluses of infusion
Side effects: maternal hypotension and hemorrhage
141
What is the first line for uteral relaxation for retained placenta ?
IV NTG
142
What is the preferred technique for uterine relaxation in a bleeding patient?
Regional anesthesia rather than high volatile and other vasodilatory agents that may make this worse
143
What is the leading cause of maternal death in the US?
CV complications: cardiomyopathy,
144
What is responsible for the increased risk of aspiration and GERD in pregnant patients?
Progesterone - causes smooth muscle relaxation, LES tone relaxation, decreased intestinal motility
145
What does relaxin do?
Causes remodelling of collagen in the pelvis causing separation of pubic symphysis and widening of the pelvic inlet
146
What does oxytocin do?
Causes uterine contraction
| Milk production
147
What is the anesthetic of choice for cervical cerclage when the cervix is dilated and there are bulging membranes?
General since volatile relaxes uterine muscle to facilitate replacement of the membranes.
Take great caution to avoid increases in intraabdominal and intrauterine pressure (coughing, retching)
148
How quickly does NTG provide uterine relaxation?
40-90 seconds
149
What is the half-life of NTG?
1-3 minutes
150
What are the indications for uterine relaxation?
```
Twin in weird position needing delivery
Breech position for delivery of head
C section of fetus with abnormality
Oxytocin overdose
Retained placenta/products
Inverted uterus
```
151
What is not a reason for uterus relaxation?
Placental abruption
152
What is atosiban?
Antagonist of oxytocin and vasopressin - tocolytic
not FDA approved because showed to have higher rate of neonatal mortality
153
When does indomethacin cause PDA closure in gestation?
after 32 weeks
154
Why is magnesium contraindicated as a tocolytic in patients with myasthenia gravis?
It antagonizes calcium (reduces influx) thereby decreasing the release of acetylcholine from alpha motor neurons
It decreases the sensitivity of acetylcholine receptors to acetylcholine
155
What is the mechanism of action of nifedipine?
Blocks voltage gated calcium channels - not in myocardium
156
What are the potential side effects of nifedipine?
Pulmonary edema
Flushing
AV block
Nausea
157
What is in high circulating levels in pre-eclampsia?
Thromboxane A2
158
What is low in pre-eclampsia?
Prostagland I2
159
What is the pathophysiology of pre-eclampsia?
Vascular hyperreactivity --> uterine constriction, uteroplacental insufficiency
Intravascular volume depletion
Decreased renal blood flow from increased vascular resistance
Pulmonary edema due to capillary leakage and increased inflammation
Platelet activation and coagulopathy with prolonged PTT
160
What are the risk factors for maternal death?
African american or hispanic
BMI > 29
Multigestation
Advanced maternal age
161
What can ritodrine stimulate to happen in the fetus?
Hypoglycemia due to hyperinsulinemia from maternal hyperglycemia
162
What are the maternal side effects of ritodrine and terbutaline?
Pulmonary edema, SVT, myocardial ischemia, hyperglycemia, hypokalemia, tremor, ileus, N/V, hallucinations
163
What happens to dead space in the parturient?
Decreases due to increased cardiac output
164
What is the most common and reliable sign of uterine rupture?
Nonreassuring fetal heart tones
165
What are the fetal side effects of ritodrine and terbutaline?
Myocardial ischemia and hypertrophy
Tachy
Hyperglycemia
Hyperinsulinemia
166
What are the neonatal effects of ritodrine and terbutaline?
```
Hypoglycemia
IVH
Hyperbilirubinemia
Hypocalcemia
Hypotension
```
167
What electrolyte abnormality does oxytocin cause?
Hyponatremia because resembles ADH so causes natriuresis and water retention
168
What is placenta accreta is associated with the most EBL?
Placenta percreta - may invade through uterine serosa to other pelvic structures
169
What is placenta increta?
When chorionic villi invade the myometrium
170
What is the highest risk factor for placenta accreta?
Prior c section with placenta overlying the scar
171
What should you avoid in general anesthesia for pregnant people?
Hypocapnia (hyperventilation)
Hypoxia
Hypotension
172
Which 2 factors are unchanged in pregnancy?
II and V (thrombin)
173
Which factors are decreased in pregnancy?
Factor XI and Factor
| XIII
174
What happens to platelets in pregnancy?
Decreased by 10%
175
What happens to factor VIII in pregnancy?
increases
176
What are the signs/symptoms of AFE?
1st phase: Pulmonary vasospasm --> RHF
| 2nd phase: LHF --> pulmonary edema, coagulopathy, shock, utetotonicity, fetal bradycardia
177
What is the pathophys of AFE?
Leukotrienes spilled into maternal circulation casuing massive mast cell degranulation and immune response
178
What is the incidence of PDPH after spinal?
1-11%
179
What is the incidence of PDPH after epidural needle puncture of dura?
52%
180
What are the characteristics of a PDPH?
Fronto-occipital radiating to neck, worse with upright position, occurring with 24-48 hours after puncture, associated with cranial nerve deficits
181
How long do symptoms usually last?
1 week but can persist for months to years
182
What are the risk factors for PDPH?
```
Female gender
Lower BMI
Previous PDPH
Age under 40
Pregnancy
Larger needle
Provider inexperience
Air used for loss of resistance
```
183
What are the other analgesia options for labor?
```
Remifentanil infusion
Nitrous
Saddle block (intrathecal injection and leave patient sitting for awhile)
Perineal infiltration
Pudendal nerve block
Cervical block
Lumbar paravertebral
```
184
What are lumbar paravertebral blocks associated with?
Lower risk of bleeding
185
What happens to d-dimer in pregnancy?
It increases due to more fibrin split products from elevated fibrinogen
186
What is the cause for increased blood volume in pregnancy?
Sodium retention via the RAAS because of increased metabolic demands
187
When is maternal CO the highest?
Immediate following delivery due to uterine autotransfusion
188
What accounts for the increase in CO in the first trimester?
Heart rate
189
What accounts for the increase in CO in the second trimester?
Increased SV
190
What are the effects of adding epinephrine to bupivacaine epidural?
Increases duration and intensity of block through alpha 1 agonism
Decreases the minimum local anesthetic concentration (the amount needed to create a good block) likely through alpha 2
191
What are the risk factors for placental abruption?
```
Paternal and maternal tobacco abuse
Cocaine
HTN
advanced maternal age
increase parity
trauma
PROM
chorio
bleeding in early pregnancyhistory of abruption
```
192
What population has a higher incidence of abruption?
AA with respiratory disease
193
Why is nasal instrumentation contraindicated in pregnancy?
Engorgement of tissues and risk of epistaxis
194
What is the PO2 of the umbilical artery?
16
195
What is th PCO2of the umbilical artery?
55
196
What is the pO2 of the umbilical veins?
28
197
What is the PCO2 of the umbilical veins?
40
198
How much does MAC decrease in pregnancy by full term?
40%
199
What plays a role in decreasing MAC in pregnancy?
Progesterone
| B-endorphins released during labor and delivery
200
What is MLAC?
Minimum local anesthetic toxicity - the local analgesic concentration leading to satisfactory analgesia in 50% of patients
201
What happens to MLAC in pregnancy?
Reduced by 30 % (due to hormones)
202
What are the effects of the enlarged uterus?
Obstruction of IVC
Engorgement of epidural venous plexus (higher risk for intravascular injections)
Decreased CSF
Decreased potential volume of epidural space
Increased epidural space pressure
203
What happens to oxygen consumption and minute ventilation ?
They both increase
204
What is PaCO2 in pregnancy?
28-32 mmHg
205
What happens to P50 for hemoglobin?
It increases from 27 to 30
206
What happens to closing capacity and vital capacity in pregnancy?
Nothing
207
When does FRC return to normal after delivery?
48 hours
208
When do MAC levels return to normal?
The third day after delivery
209
What might you see on chest film of a pregnant lady?
Prominent vascular markings due to higher pulmonary blood volume and an elevated diaphragm
210
What happens to dead space?
Decreased
211
What happens to shunting?
Increases
212
What happens to induction time?
Decreased due to pulmonary vascular engorgement and higher minute ventilation
213
Why should smaller ETT be used in pregnant women?
Engorgement of respiratory mucosa have higher risk of bleeding/trauma
214
What is the average blood loss of a vaginal delivery?
400-500 ml
215
What is the average blood loss of a c-section?
1L
216
What is the blood volume pregnant woman?
90 ml/kg
217
How much is cardiac output increased in pregnancy?
40 % - 20% heart rate and 20% stroke volume
218
When dos cardiac output return to normal?
2 weeks after delivery
