EXAM 3 Review Flashcards
1
Q
In the liver, blood flow through the
A
DUCTUS VENOSUS
2
Q
When Ductus Venosus closes remnant is
A
LIGAMENTUM VENOSUS
3
Q
Foramen Ovale closes and becomes the
A
FOSSA OVALIS
4
Q
When Ductus Arteriosus closes it becomes
A
LIGAMENTUM ARTERIOSUM
5
Q
DUCTUS venosus shunt is
A
LIVER
6
Q
Foramen ovale shunt is
A
Right atrium to left atrium
7
Q
Ducturs arteriosus shunt is CONNECTION between
A
Pulmonary artery to AORTA
8
Q
Fetal blood Oxyhemoglobin dissociation curve
A
↓ 2,3 DPG, shift to the left (Left for LOVE of oxygen) increased affinity for oxygen (hold on to oxygen)
9
Q
Womb approx hgb
A
15g/dL
10
Q
Fetal PO2 max is
A
50-60mmhg
11
Q
Fetal blood and CO2 relationship
A
less affinity for CO2
12
Q
Highest possible baby SPO2 is
A
90%
13
Q
For a PaO2 of 60 what is the SPO2 approx?
A
90%
14
Q
For a PaO2 of 50, what is the SPO2 approx?
A
80%
15
Q
In the fetal circulation, Hgb binding is (increased/decreased)
A
Increased
16
Q
Parallel circuit in the fetal circulation
A
Both right and left venticles provide systemic blood flow
17
Q
In fetal circulation, PVR is
A
High
18
Q
In fetal Circulation, SVR is
A
Low
19
Q
What is the ratio of R to left contribution in fetal circulation
A
2:1 Right to left ration
Right is 2x LV output because of R to L shunt
20
Q
The ductus venosus receives blood
A
Inferior vena cava coming from lower extremities
21
Q
Where does the first admixture occur
A
in the Ductus venous in the liver
22
Q
The presence of which structure makes the SVR low in the fetal circulation?
A
Placenta
23
Q
Immediately after delivery, the removal of the placenta leads to what changes?
A
ELEVATED SVR
24
Q
Most of the oxygenated blood in fetal circulation comes from ?
A
UMBILICAL VEIN from PLACENTA
25
Where does blood/ nutrients exchange occur?
In the INTERVILLOUS SPACE
26
Explain blood flow in fetal circulation
| Path of oxygenated blood from placenta
1. OXYGENATED: From placenta, blood flow through umbilical vein which separates into 2 branches (one is portal vein, the other is DUCTUS VENOSUS, which join the IVC
2. The blood bypasses the liver, goes through the Ductus venosus into the IVC
3. Blood enters RA
4. Goes from RA through FORAMEN OVALE to LA
5. From LA to LV
6. From LV to proximal aorta then supplied to the coronaries and Head vessels and upper torso
27
Fetal blood in the
Chorionic villi
28
What are the 4 shunts
Ductus Venosus :
Foramen Ovale : right atrium to Left atrium
Ductus Arteriosus: pulmonary artery to Aorta
29
What are the 4 shunts
Ductus Venosus : Joins IVC blood, blood bypasses liver
Foramen Ovale : right atrium to Left atrium
Ductus Arteriosus: pulmonary artery to Aorta
Placenta
30
Path of UNOXYGENATED blood in fetal circulation
1. flow directly from Superior vena cava to tricuspid to Right ventricle
2. From RV to Pulmonary artery
31
Path of UNOXYGENATED blood in fetal circulation( blood from body)
1. flow directly from Superior vena cava to tricuspid to Right ventricle
2. From RV to Pulmonary artery
3. Because lungs not inflated , and PVR is high, most of the DEOXYGENATED blood return to AORTA via the DUCTUS ARTERIOSUS
4. Then from the aorta FLOW to UMBILICAL ARTERIES
5. FROM UMBILICAL ARTERIES back to PLACENTA
32
What maintains DA potency ?
Prostaglandings
33
How can hypoxemia leads to PDA?
Hypoxemia will release endothelial nitric oxide which will results in vasoilation, may OPEN PDA after closure
34
What medication is given to attempt to close PDA?
Indomethacin (blocks PGE1, prostaglandins)
35
Functional closure of shunt happens
Immediately after birth
36
What causes the dramatic increase in SVR in postnatal circulation ?
Removal of placenta
37
What causes the dramatic decrease in PVR in postnatal circulation?
INFLATION of the lungs with the first breath
38
What pressure must be generated to fully expand lungs
40-60 cm H2O
39
In maternal circulation what is the direction of the Oxyhemoglobin curve?
↑ 2,3 DPG, Shift to the Right ( R- for RELEASE O2) lower O2 affinity)
40
Foramen ovale in fetal circulation closes due to
Increase in LVEDP (Left ventricle End diatole Pressure)
41
Functional closure of shunt happens
immediately
42
Does mother and Baby blood ever mix?
No
43
90 % of placental blood flow through which structures
Intervillous space
44
Properties that facilitate placental transfer
High lipid solubility
Low molecular weight
Lipophillic
45
CO2 is present in the form of ? Give percentage
62% of CO2 is in the form of BICARBONATE (HCO3-)
46
Placental O2 consumption rate
8ml/min/kg of FETAL WEIGHT
47
Efficiency of placenta compared to lungs
1/5th the efficiency of adult lung
48
The Placenta is supplied by 2 arteries which are
UTERINE and OVARIAN arteries
49
Uterine blood flow is
Directly proportional to the fetal umbilical venous partial pressure of O2
50
These arteries may bleed after placental removal
Spiral arteries
51
What can worsen spiral arteries bleeding after removal of placenta?
Nitrous oxide
52
Connect placenta to uterus
Spiral arteries
53
Uterine blood flow formula
Uterine arterial- venous pressure / Uterine Vascular resistance
54
Perfusion pressure relationship with Uterine Blood flow
Direct relationship (as one increases, the other increases)
55
Vascular resistance and Uterine Blood flow
INVERSE PROPORTIONAL relationship (as VR increases, UBF decreases vice versa)
56
2 main determinants of UBF
Perfusion pressure and vascular resistance
57
UBF at term is
>700-900 ml/min
58
Uterine blood vessels are _________to vasopressors than systemic blood vessels
More sensitive
59
Vasodilators that may dilate uterine vessels
Nitrous oxide
| PGE (prostanglandins)
60
What is altered in pregnancy as vasoconstriction?
Hypertensive response to IV epinephrine, phenylephrine and Angiotensin II is diminished
61
This receptor altered in pregnancy
Altered receptor mediated G-protein coupling
62
Placental transfer requiring ATP (2)
Active transport
| Pinocytosis
63
Placental transfer NOT REQUIRING ATP
Passive transport
| Facilitated transport
64
Placental transfer is LIMITED To
FLOW
65
Placental transfer is not limited to
diffusion
66
Placental transfer : passive transport driven by (COMLDM)
```
Concentration gradient
Occurs via membrane or protein
Molecular weight
Lipid solubilty
Degree of ionization
Membrane surface area
```
67
Passive process requiring carrier protein
Facilitated transport
68
Determinants of ACUTE changes in UBF are
Systemic Blood pressure
Uterine venous pressure
Uterine Vascular resistance
69
The 3 Determinants of ACUTE changes in UBF are
Systemic Blood pressure
Uterine venous pressure
Uterine Vascular resistance
70
Best positions for UBF
Prone- best (i.e on all four extremities)
| Left LATERAL TILT
71
Worst position for UBF
SUPINE
72
Why is supine position worse for the pregnant female?
AORTAL CAVAL Compression: Gravid uterus sitting on top of major vessels, decreases preload and venous return which decreases CO and lead to hypotension
73
HYPOTENSION in pregnant ladies associated with
VOMITING
74
Which medication can be given IM to prevent vomiting
EPHEDRINE IM 50mg
75
These 2 hormones increases vascular resistance leading to decrease perfusion
Vasopressin
| Angiotensin II
76
Factors that decrease UTERINE arterial presure
Supine position
Hemorrhage/ hypotension
Drug induced hypotension
Hypotension during sympathetic Blockade
77
Factors that increase UTERINE PRESSURE
Venal caval compression
UTERINE CONTRACTION
Drug induced uterine hypertonus (oxytocin, cocaine)
Skeletal muscle hypertonous
78
Most common cause of UTERINE PRESSURE increase is
Uterine contractions
79
2 major thing in summary decreasing perfusion pressure
Decrease Arterial pressure
| Increase uterine venous pressure
80
Causes of Decrease uterine Blood flow
1. Endogenous vasoconstrictors (catecholamines, vasopressin)
| 2. Exogenous Vasoconstrictors ( Phenylephrine> ephedrine) high concentrations of local anesthetics
81
Uterine blood flow if often reduce clinically (P-DUE) 4 factors
Position
Drug induced HYPOTENSION
UTERINE CONTRACTIONS and PUSHING EFFORTS
Endogenous and Exogenous vasoconstrictors
82
PaO2 of 60 gives SPO2 of
90
83
Diffusion rate of O2 vs CO2
CO2 has a high diffusion capacity, 20x greater than O2
84
Progesterone in pregnancy direct effect
Dilation of airways
85
***Progesterone on CO2
Increased sensitivity of CENTRAL CHEMORECEPTORS to CO2
86
Progesterone in pregancy indirect effect
Enhances B2 agonist activity
87
**Progesterone and MAC
It decreases MAC requirement by 30 %
88
If progesterone decreases MAC by 30%, if the MAC is 1.4 what would be the new MAC?
1.4 (0.30) = 0.42 so 1.4-0.42 = 0.98
89
Hormonal changes due to 4 main hormones (PECR)
Progesterone
Estrogen
Cortison
Relaxin
90
Action of Cortison and Relaxin
Dilates airways
91
Pregnancy and Estrogen
High local ESTROGEN leads to a DIMINISHED in activity of KEY intracellular enzymes that mediate vasconstriction
92
Plasma volume changes secondary to hormones
Increases due Progesterone and Estrogen
93
Progesterone and GI
Esophageal peristalsis/intestinal transit are slowed
| due to Progesterone
94
_____And _______ are minimally affected if at all?
Gastric acid content and plasma gastrin levels
95
Progesterone on Kidneys and ureters
Kidneys enlarge and the ureters/renal pelvis dilate
96
Kidneys enlarged due to
Progesterone
97
Ureter and renal pelvis dilate due to
Progesterone
98
Estrogen increases ____% which leads to ______
| What other thing causes renin release beside Estrogen?
100%; renin releases from juxtaglomerular cells of nephron cleave angiotensinogen
Sympathetic input
99
Pregnancy induced ↑ forgetfulness due to
Progesterone
100
Alveolar anesthetic concentrations rise fastersecondary to
* ↑ MV
| * ↓ FRC
101
Progesterone increases by _____% which leads to _________
Increase aldosterone levels
102
2 Actions of aldosterone
Increase sodium and water reabsorption by nephron collecting duct →Increase effective blood volume to correct initial stimulus to the system
103
Vicious cycle of persistent Fetal circulation (HPIR)
1. hypoxia/hypercabnia/acidosis/ cold
2. Pulmonary vasoconstriction
3. Increased pulmonary vasoconstriction
4. RIGHT TO LEFT SHUNTING of BLOOD
Back to number 1.. vicious cycle
104
What is the danger of persistent fetal circulation
Can pop open foramen ovale and return circulation to fetal circulation
105
Estrogen and endocrine
Increase plasma cortisol during 1st trimester by 100%
| by 200% by term
106
Joint mobility and pregnancy
RELAXIN increase joint mobility
107
Blood glucose and pregnancy
LACTOGEN; reduces tissue sensitivity to insulin
108
Which hormone reduces tissue sensitivity to insulin during pregnancy ?
Lactogen
109
What changes in occur in MV in pregnancy ?
MV increase by 50%
110
The MV ventilation is because of _____not _____
TV increase by 45%, NOT RR
111
RR with pregnancy
remains the same
112
Pregnancy O2 consumption and Co2 production
O2 consumption and CO2 production increases by 60%
primary due to fetus, uterus and placenta
secondary due to cardiac/resp work
113
Diaphram changes during pregnancy
FLATTER and Higher
114
Inspiration at term is TOTALLY
Diaphragmatic
115
Respiration at term dependent of PHRENIC NERVE which is
C3, C4, C5
116
FRC and pregnancy
Decreases by 20%
117
FRC is reduced TO
80%
118
Why does FRC decreases? What is the meaning of a decreased FRC?
because Diaphragm is higher
| Less O2 reserve , less time to intubate, desaturation occurs quicker. MUST PRE-OXYGENATE
119
When does FRC changes start?
by the 5th month
120
These 2 respiratory paramaters remains the same during pregnancy
Vital capacity
| RR
121
FRC is combination of ___ and _____
| % decrease of each ?
ERV 25%
| RV 15%
122
Critical FRC point any further you loose ability to ventilate
* Pneumonia
* Pulmonary edema
* ARDS
123
PaCO2 decreases due to
• ↑ TV/MV
124
PaCO2 in pregnancy _____ by when?
Decrease PaCO2 to 30 mmHg by 12 weeks
125
What compensate for the decrease of PaCO2 ?
Bicarbonate decreases to ~ 20 mEq/L to compensate for the reduced PaCO2
126
pH in pregnancy
Slightly alkalotic
127
PaO2 level during pregnancy 1st, 2nd, 3rd respectively
107 - 105- 103
128
pH blood gas level 1st, 2nd,3rd
7.44
129
Bicarb pre-pregnant levels
24
130
Bicarb during pregnancy, 1st, 2nd,3rd respectively
21-20-20
131
PaCO2 pre-pregnant
40
132
PaCO2 gas level 1st, 2nd,3rd
30
133
Which hormones may account for back pain and carpal tunnel syndrome during pregnancy ?
Relaxin
134
Thoracic age and pregnancy
Increases in size
135
This hormone is a respiratory stimulant
Progesterone
136
Hormone responsible for the decreased PaCO2
Progesterone (stimulate respiration)
137
Pregnancy and Local anesthetics changes
increase sensitivity to local anesthetics due to progesterone increase
138
Progesterone causes
Capillary engorgement and nasal passageway swelling
139
Recommended ETT tube size
6.5mm
140
Avoid in pregnant patient as far as UPPER airways
Any nasal NG, nasal airway or oral airway due to AIRWAY SWELLING
141
Highest maternal mortality associated with
Difficult intubations
142
Mallampati scores and pregnancy
Increases
143
Denitrogenation is more
rapid due to increase MV and decrease FRC
144
In pregnancy • PaCO2 of 40mmHg leads to
acute respiratory acidosis
145
• FRC ↑ but below normal up until
1-2wks postpartum
146
How long does it take for TV, MV and O2 consumption remain elevated
up to 6 weeks
147
CV: issues Murmur associated with pregnancy
Grade I-II systolic murmur is typically heard; usually TR or MR
148
Regurgitation with pregnancy
Tricuspid regurgitation 94% and Mitral
149
Pulmonary compliance and pregnancy
Pulmonary compliance DECREASES
150
Thoracic compliance during pregnancy
Thoracic compliance INCREASES
151
NO effect on this respiratory parameters
FEV, FEV1/FRC, Flow volume loop or CLOsing capacity
152
NO effect on this respiratory parameters
FEV, FEV1/FRC, Flow volume loop or closing capacity
153
Obese and pregnant patient will show
RESTRICTIVE pattern
154
Supine position decrease PaO2 by
Reducing FRC
Closing small airways
Increase shunt
Reducing CO via Aortacaval compression
155
Types of hypertrophy normal in pregnancy
LVH
156
Pulmonary pressure and pregnancy
Elevated
157
EKG changes and pregnancy
Sinus tachycardia with short PR
158
When is the CO the highest in pregnancy
Immediately after delivery 75%
159
When is the SV the highest in pregnancy
Immediately after delivery 75%
160
IS the pregnant female at risk for AORTIC DYSFUNCTION?
No
161
CO and pregnancy and distribution of change
CO increases by 50%
HR increase by 25%
SV increase by 25%
162
EF and pregancy
LVEDP increases , EF increases
163
Pulse pressure and pregnancy
Widening pulse pressure
164
ORGANS with increase perfusion are (KUE)? any other organs affected?
Kidneys
Uterus
Extremities
NO
165
What happens during Aorto Caval Compression
Aorta is partially obstructed
166
In supine position aorta is (IPCR)
Increased femoral venous pressure
Partially obstructed
Collaterals cannot maintain venous return
Right side pressure Fall
167
In Lateral Decubitus Position (PCA)
Partial caval obstruction
Collateral MAINTAIN venous return
AORTA is unaffected
168
BEST POSITION if can't do prone
LATERAL DECUBITUS POSITION
169
Collateral veins that maintain venous return when patient in lateral decubitus position (IPE)
Intraosseous vertebral vein
Paravertebral vein
Epidural venous plexus
170
Aortocaval compression preload is
Decreases 10-20%
171
Uterine blood flow and aortocaval compression
Decreases by 20%
172
Lower extremities flow and aortocaval compression
falls by 50%
173
SUPINE HYPOTENSIVE SYNDROME is
From the profound drop in VENOUS RETURN from which the CV system CANNOT COMPENSATE
174
There is rising pulse pressure because
Diastolic pressure lower due to low resistance vascular intervillous space and homone induced vasodilation
175
Supine position associated with
Hypotension → vomiting
| Bradycardia
176
SV increased in pregnancy is mostly due to
Preload
177
Spinal anesthesia CSF volume and pregnancy
↓ spinal CSF volume
178
Spinal Anesthetic Requirements and pregnancy
•Reduced by 25%
179
High spinal and epidural catastrophic
* Check hands
| * C6
180
Fasting gastric volume and pH are normalized by
18hrs postpartum
181
IF patient start to have contractions
STOP all neuraxial anesthesia process (can cause wet tap - hit spinal --> headaches)
182
Renal plasma flow, GFR, and creatinine clearance all
↑
183
Renal plasma flow, GFR, and creatinine clearance all normalize by
8-12 wks PP)
184
Returns toward pre-pregnant sympathetic tone by
24-48 hrs
185
Epidural vein and pregnancy
•Distension of Epidural Veins
186
Regional and Pregnancy
LOCAL Anesthetics requirement lowered
187
Do Left lateral
before spinal anesthesia
188
Do Left lateral position
before spinal anesthesia
189
This medication is unaffected by pregnancy
Propofol
190
Epidural pressure and pregnancy
↑ EPIDURAL PRESSURE
191
Pneumatic space and ↓ spinal CSF volume and pregnancy
• ↓ SPINAL CSF and pneumatic space
192
Preoxygenation for pregnant can lead to PaO2 500mmHg which allows
3 mins of apnea
193
First stage of labor
onset of true labor until cervix is completely dilated (10 cm)
194
Subdivision of first stage of labor
Early labor phase: time of onset until cervix dilated
3cm
Active labor phase: cervix dilates from 3cm to 7cm
Transition phase: cervix dilates from 7cm to 10 cm
195
Second stage of Labor
period after cervix dilated to 10cm until the baby is delivered.
196
Third stage of Labor
Delivery of the placenta.
197
1st stage of labor what type of pain
Visceral
198
1st stage Dull pain transmitters are the
| Cervical dilation mediated by
unmyelinated C fibers
199
1st stage pain comes from
T10-L1(L2) DERMATOMES
200
Second stage
Cervical dilatation progresses
Fetal head descends into pelvis
Stretches and compresses pelvic structures
201
In second stage pain is mediated by
THE SACRAL PLEXUS
| T12-L1, S2-S4
202
This nerve block provides sensory to perineum
PUDENTAL BLOCK
203
Not always completely anesthetized with epidural
The Pudental NERVE
204
Third Stage of Labor
Placental EXPULSION
205
Which anesthetic block is better during SECOND stage of labor?
Pudental Block (rarely done, high risk)
206
MAC return to normal when?
72 hours (3 days) postpartum
207
Patient return had baby 3 days ago, do you need to alter MAC?
no
208
Dull, diffuse midline define
Visceral
209
Sharp, pricking, throbbing,and/or burning sensation
Somatic
210
Increase sensitivity to
YOU NEED LESS
-curonium
Ester Benzoisoquilines
Despite increase clearance
211
Onset of perineal pain is associated with which stage of labor?
2nd stage
212
Appropriate analgesia for FIRST stage labor
Neuraxial, Paravertebral and Paracervical
213
Associated with the most FETAL BRADYCARDIA
PARACERVICAL (especially with bupivacaine)
214
Less spinal due requirement due to
thoracic Kyphosis apex is higher (stopping use from apnea)
215
Decreased normal dose of LOCAL Anesthetics start during
2nd trimester
216
Regional more difficult due to
Lombar lordosis
217
When does requirement of LOCAL anesthetics return to normal ?
40 hours postpartum
218
Obstetric History
```
Gravity = # of conceptions
Parity = # of live births
Abortus = # of preterm dead birth
```
219
G1 P2 means
TWINS
220
Any regional will decrease
FRC
221
ASSESS NEURO C6 gives you the ability to do
put 2 fingers together with hands
| Watch for signs of respiratory depression
222
_____________ has a poor predictive value for abnormal outcome
Abnormal FHR
223
Historical RISK FACTOR For abnormal outcome
| SUWAN
```
Smoking
Unmarried
Weight < 50 kg
Age <18 or >39 years
No education beyond primary
```
224
Past OB risk factor for Abnormal outcome
| PIP
Hx of perinatal loss
Hx of infant < 2500gms
Hx of preterm birth (<28 weeks gestation)
225
Past MEDICAL hx risk factor for abnormal outcome
| RRP TC
```
Rh negative with antibodies
Renal disease
Previous cone biopsy
Thyroid disease
Cardiac disease
```
226
During Pregnancy; RISK FACTOR FOR negative outcome
| MAH 4Ps GBD
```
Multiple gestation
Anemia
HTN
Pyelonephritis
Proteinuria
Placental abruption
Placenta previa
Gestational or Established Diabetes
Bleeding before 28 weeks gestation
Delivery before 37 or after 42 weeks gestation
```
227
PROM
PREMATURE RUPTURE OF MEMBRANES
228
PPROM
PROM + PREMATURITY
229
• > 34 WEEKS =
INDUCE AND DELIVER
230
• < 31 WEEKS: EXPECTANT MANAGEMENT
EXPECTANT MANAGEMENT with prophylatics ABTs, tocolytics, and glucocorticoids (to accelerate lung maturity)]
Can lead to Chorioamnionitis
231
ACOG RECOMMENDATIONS for PROM• IN BETWEEN
= EVALUATE FETAL LUNG MATURITY
| • ANTIBIOTIC PROPHYLAXIS
232
VBAC
ONLY CALLED VBAC ONCE YOU DELIVER
233
VBAC is TECHNICALLY TOLAC:
TRIAL OF LABOR AFTER CESAREAN
234
VBAC precluding Factors (UNMI)
```
FACTORS:
• UNSUCCESSFUL TOLAC
• NO PREVIOUS VAGINAL BIRTHS
• MULTIPLE CS
• INDUCED/AUGMENTED LABOR
```
235
VBAC successful with patient with a
LOW transverse INCISION
236
Risks with VBAC
Uterine Rupture less than 1% with low transverse
237
RIsk VBAC compared to elective CS and Failed TOLAC
Risk (better to worse)
| VBAC> Elective repeat CS > Failed TOLAC
238
Interpreting causes of Fetal HR changes
```
VEAL CHOP
Variable Decels - Cord Compression
Early decels - Head Compression
Accelerations -- Ok or give Oxygen
Late decels --- Placental Insufficiency
```
239
2 predictor of POOR fetal status
Sinusoidal pattern
| Absent baseline variability
240
Who needs preop regardless epidural or not
Above 24 weeks
241
Variability of FHR means
Reassuring pattern
| Normal neurologic function of fetus parasympathetic and sympathetic functions
242
Best position is
occiput anterior (baby kissing mom)
243
Loss of resistance with needle indicates
Epidural space
244
Can cause transient neurological symptoms
LIDOCAINE
245
General assssment
maternal health history
Obstetric history
Anesthesia related to obstetric hx
246
NPO and obstetric
All patients are considered full stomach and at risk for pulmonary aspiration
247
Supine position should be avoided unless a
LEFT UTERINE DISPlACEMENT device (>`15deg) wedge is placed UNDER THE RIGHT HIP
248
Most common cause of Neonatal depression
Intrauterine asphyxia
249
Preferred anesthesia
Spinal or EPIDURAL (less hemodynamic fluctuation, gradual resolution and lower maternal mortality
250
Sings of fetal compromiss
Absence of baseline variability and accelerations
251
More prolonged and Painful labor
OCCIPUT POSTERIOR (manuel or forceps rotation for delivery)
252
Epidural activation for first stage of labor
3ml test dose with local anesthetic 1:200000 epi
less toxicity in case of UNINTENTIONAL INTRAVASCULAR INJECTION
Administer between contraction
Wait 5 minutes, with patient supine and Left uterine displacement
253
Dosing for initial boulus
10ml in 5ml increments
0. 1% to 0.2% ropivacaine
0. 0652% to 0.125% Bupivacaine combined with 50-100mcg fentany or 10-20mcg of sufentanyl
254
DA Functional Closure –
12 hours
255
DA Physiologically Closed
48 hours
256
DA Permanent Anatomic Closure
2 wks
257
Sensitive to DA
Oxygen, pH, & prostaglandins
• ↑ PaO2
• Less acidic pH
• Loss of placental prostaglandins
258
Ductus Venosus Ligamentum Venosum
• Shunts blood from liver to IVC - 50% or less
259
• Closes within 7 day
DV
