EXAM 3 REVIEW Flashcards
1
Q
Surfactant production : what types of cells?
A
Type II pneumocytes are responsible for the production and secretion of surfactant
2
Q
When does surfactant production starts? when does concentration peak?
A
begins between 22 and 26 weeks, and concentrations peak between 35 and 36 weeks’ gestation.
3
Q
Surfactant role is to ? what law describes how surfactant decreases surface tension?
A
decreases surface tension within the alveoli to decrease alveolar collapse. This relationship can be explained by the Law of Laplace
4
Q
Can enhance surfactant maturation>?
A
Administration of Glucocorticoids in women in preterm labor can enhance the maturation process.
5
Q
Surfactant production is sufficient in most cases by what week of gestation?
A
By 35 weeks gestation,
6
Q
What is the major phospholipid of surfactant?
A
Dipalmitoyl lecithin
7
Q
How do we test a pregnant mother to see if her baby’s lungs have reached maturity?
A
Look at the Lecithin:Sphingomyelin ratio in the amniotic fluid.
8
Q
The incidence of PDPH and age
A
inversely related to age and seen infrequently in those older than 70 and younger than 10 years old.
9
Q
Incidence of PDPH and GENDER
A
Women appear to be slightly more susceptible than men, and pregnancy may increase the incidence.
10
Q
Incidence of PDPH needle diameter?
A
In general, large diameter needles are more likely to be associated with PDPH when compared with small-diameter needles.
11
Q
A dural puncture with a 17-gauge epidural needle has a
A
70% PDPH rate compared with less than 1% with a pencil-point spinal needle.
12
Q
With respect to spinal needles, the incidence of PDPH is significantly
A
reduced with the use of pencil-point needles (e.g., Pencan, Sprotte, Whitacre) compared with beveled cutting needles (e.g., Quincke).
13
Q
PDPH air vs saline
A
occurred in 67% of the patients in the air group as opposed to 10% in the saline group
14
Q
The angle at which the needle approaches the dura
may also
A
modify the amount of CSF leakage and therefore the
incidence of PDPH;
15
Q
3 major risks for PDPH
A
Younger age (20-30 at higher risk)
Female Sex
Use of a CUTTING-TYPE needle
16
Q
_______are not considered a first-line technique for neuraxial anesthesia due to the increased risk for PDPH
A
Continuous spinal anesthetics
17
Q
Studies have shown that leaving the catheter in place for at least ________ reduces the incidence of headache after removal.
A
least 12 hours reduces the incidence of headache after removal.
18
Q
Autonomic innervation of the neonatal heart
A
Autonomic innervation of the neonatal heart is predominantly controlled by the parasympathetic nervous system;
19
Q
SNS and neonate
A
the sympathetic nervous system is immature at birth.
20
Q
ANS dominance in neonate
A
Parasympathetic dominance produces bradycardia with minor clinical interventions such as pharyngeal suctioning and laryngoscopy
21
Q
Marked variation in the newborn heart rate and rhythm occur secondary to
A
changes in autonomic tone.
22
Q
At birth, vagal myelination occurs
A
more rapidly than sympathetic innervation. At birth, parasympathetic is more developed
23
Q
AT birth When aortic arch and carotid baroreceptors are stimulated, there is a resulting
A
decrease in BP and slowing of the heart rate.
24
Q
The autonomic nervous system activates
A
non-shivering thermogenesis in infants.
25
By what week of gestation is surfactant production sufficient enough to prevent respiratory distress syndrome in most infants?
By 35 weeks gestation, surfactant production is sufficient in most cases.
26
Compared to adults, the narrowest portion of the pediatric airway is at the
cricoid,
27
The level of the the relative vertical location of the larynx is
C2-C4 (C3-C6 in adults),
28
Epiglottis in the neonate
epiglottis is longer, more narrow, and stiff.
29
Neonate larynx is proportionately
smaller
30
When does the foramen ovale typically close?
Within one hour of life
31
In the normal, full-term infant, you would expect the glottis to be at the level of
C4
32
Select two reasons for low renal blood flow and glomerular filtration rate in utero.
Low glomerular capillary permeability
| Small number of glomeruli
33
At birth the neonatal larynx is ______ compared with the mouth and pharynx
small compared with the mouth and pharynx.
34
The epiglottis is, and the
short and small
35
Neonate vallecula is
shallow so that the tongue approximates the epiglottis.
36
Mouth breathing vs nasal breathing
The larynx is pointed toward the nasopharynx, facilitating nasal breathing.
37
The arytenoids are
large in proportion to the lumen of the larynx.
38
The subglottic region is
smaller than the glottic opening with the cartilages telescoping into one another, forming a conical shape
39
Neonate: The narrowest portion of the airway, and the
| cricoid lumen is not a
The cricoid cartilage
| not round but mostly an ellipsoid structure
40
The newborn tongue is I
large and difficult to manipulate because of the position of the hyoid.
41
Neonatal submental
smaller potential submental space is present, in which it is possible to displace the tongue during laryngoscopy.
42
Larynx position and tongue of the neonate
The anterior position of the larynx and the large tongue increase the potential difficulty of mask
ventilation
43
Larynx is located more (caudad vs cephalad) and at what level of the Cspine?
cephalad and anterior, extending from the second to the fourth cervical vertebrae (C2 to C4)
44
The anesthetic implication of the more cephalad location is that
placing a neonate in the “sniffing position” for laryngoscopy and intubation will only move the larynx in an anterior direction.
45
The occiput of the newborn’s head is
large and prominent.
46
Neonate: what aids in the visual alignment of the oral, pharyngeal, and laryngeal axes during laryngoscopy
The placement of a rolled towel under the shoulders
47
Neonate laryngeal location
C2-C4
48
Neonate Right Mainstem bronchus
Less vertical
49
Full term infant GLOTTIS is at
C4
50
Preterm infant GLOTTIS is at
C3
51
Neonates and NDNMB
Increased sensitivity to the effects of NMBDs.
52
Why neonate have increased sensitivity to the NMBD? What happens to clearance and duration?
The increased volume of distribution means that a single NMBD dose for the neonate is the same as for the older child, but reduced clearance and increased sensitivity prolong duration.
53
Neuromuscular blocking drugs: ionization and lipophyilicity, implication.
highly ionized and have a low lipophilicity, which limits their ability to cross the bloodbrain barrier.
54
Because of NDNMB are highly ionized and have low liphophilicity These pharmacologic properties restrict the
distribution of neuromuscular blockers to the ECF compartment, which is larger in the neonate and infant than in the child and adult
55
Affect the pharmacokinetics and pharmacodynamics of neuromuscular blockers
Increases in ECF volume and the ongoing maturation of neonatal skeletal muscle and acetylcholine receptors
56
NMJ in neonate
The neuromuscular junction is incompletely developed
57
Infants requires ____doses of Succinylcholine why?
LARGER DOSE OF succinylcholine (2-3mg/kg) because of the LARGER VOLUME OF DISTRIBUTION
58
MR and onset of action for neonates
Faster onset of muscle relaxants because of a shorter circulation times than adults
59
Must be ALWAYS administered before succinylcholine if used.
ATROPINE 0.1 mg minimum
60
Response to NDNMB is variable due to
IMMATURITY OF THE NMJ tending to increase sensitivity , and a disproportionately LARGER extracellular compartment reducing drug concentration
61
Immaturity of the neonatal hepatic function
PROLONGS the duration of action for drugs that depend PRIMARILY on HEPATIC METABOLISM.
62
The acetylcholine receptors of the newborn are
anatomically different from the adult receptors, which may explain the sensitivity of the neonate to the nondepolarizing class of neuromuscular blocker
63
The increase in dose requirement for succinylcholine is in part a
result of the increased volume of distribution within the large extracellular compartment.
64
Neonates are more __________to the effects of succinylcholine than children and adults.
resistant
65
Plasma cholinesterase activity is __________in neonates
reduced
66
The duration of action after a single dose is of expected duration_________ A much prolonged duration of action after a single bolus
dose would suggest the y.
(6 to 10 minutes).presence of an inherited deficiency of plasma cholinesterase activity
67
Succinylcholine is only used for
emergency airway control in children under 12 years of age due to the risk of severe hyperkalemia in patients with undiagnosed myopathies
68
NDNMB reversal Adequacy: The rule of thumb is to observe
flexion of the elbows and hips,
| knee to chest movements, return of abdominal muscle tone, andpresence of facial grimacing.
69
Neonates are capable of generating an .
MIF of −70 cm H2O with the first few
| breaths after birth
70
An MIF of at least −32 cm H2O has been found to correspond with
leg lift, which is indicative of the adequacy
| of ventilatory reserve required before tracheal extubation
71
When a child experience cardiac arrest after succinylcholine administration, immediate treatment for
HYPERKALEMIA should be instituted
72
Owing to the immaturity of the contractile elements of the
| neonatal myocardium, the belief is that pediatric cardiac output
is solely dependent on heart rate
73
______is frequently administered for the treatment of decreased cardiac output.
Atropine
74
Marked increases in heart rate fail to a large extent to produce
further increases in cardiac output.
75
Produce dramatic decreases in cardiac output that threaten organ perfusion in neonates
The combination of hypovolemia and bradycardia
76
Epinephrine vs atropine in neonates
Epinephrine rather than atropine increases contractility and heart rate and is now advocated for the treatment of bradycardia and
decreased cardiac output in pediatric patients.
77
3 things that can cause increases in afterload ____, ____, ____ will produce further reductions in cardiac output (HAP)
(e.g., acidosis, hypothermia, pain)
78
SV and CO in neonates
Strove VOLUME is FIXED
| CO is very sensitive to changes in HR
79
The neonate may develop congestive heart failure because the stiff
left ventricle will not stretch to accommodate large fluid loads
80
Left ventricular distention from volume overload compresses
the adjacent right ventricle, producing additional embarrassment to cardiac output.
81
The fetal circulatory system relies on the
placenta for delivery of oxygen and transport of carbon dioxide (CO2).
82
What is the functional unit of the placenta?
The chorionic villus is the functional unit of the placenta.
83
Normally, fetal blood is separated from the maternal blood in the placenta by a thin layer of cells known as
syncytial trophocytes.
84
Substances able to pass through placenta
Oxygen, CO2, and small nonionized particles readily pass through this layer, whereas substances with a larger molecular weight are prevented from diffusing across the syncytial
trophocytes.
85
Fetal circulation is characterized by
high pulmonary vascular resistance (uninflated atelectatic lungs and hypoxic vasoconstriction) and low systemic circulatory resistance (high flow and low impedance of the placental vessels)
86
Fetal deoxygenated blood travels
down the aorta and through the internal iliac arteries, arriving in the placenta via paired umbilical arteries.
87
The umbilical arteries divide, forming the
forming the arterioles, capillaries, and venules of the intervillous placental space.
88
Oxygenated blood is delivered to the fetus from the
placenta via a single umbilical vein.
89
Fetal circulation: This oxygenated blood bypasses the lungs by flowing through
extracardiac (ductus arteriosus, ductus venosus) and intracardiac (foramen ovale) shunts, forming a parallel circulation
90
The ductus venosus routes oxygenated
blood away from the sinusoids of the liver
91
The oxygenated blood in the inferior vena cava is directed by the
eustachian valve toward the atrial septum and passes through the foramen ovale to enter the left side of the circulation.
92
Oxygenated blood passes into the
left ventricle and exits the aorta, supplying the coronary arteries.
93
Blood entering the pulmonary artery from the right ventricle flows to the
aorta via the ductus arteriosus.
94
Only ____to ___%of the combined ventricular output flows through the pulmonary circulation.
5% to 10%
95
The pathologic mechanism factors is
increased pulmonary vascular resistance (PVR) and right-to-left shunting
96
Normal PaO2 from umbilical artery is
20-30 mmHg
97
Normal O2 saturation is about (in umbilical artery)
40%
98
Fetal hgb and 2,3 DPG
Does not bind to 2,3 DPG
99
The ductus arteriosus is a fetal connection between the
pulmonary artery and the descending aorta
100
When does the foramen ovale typically close?
Within 1 hour of life as LA pressure exceed RA pressure
101
Fetal Hgb replaced by adult Hgb by
3-4 mths
102
While in utero, what keep the ductus arteriosus open.?
prostaglandins
103
Resting cardiac output in the newborn is approximately_____This means faster
200 mL/kg/ min. Means faster circulation times that are capable of delivering and removing drugs from their sites of action at a higher rate.
104
The minimum alveolar concentration (MAC) of the inhalation anesthetics is
less in neonates than in infants.
105
Neonates have a somewhat_____when does it peak?
lower MAC, which peaks at around 30 days of age and decreases thereafter
106
MAC is greater in infants than in
neonates and adults
107
MAC is the HIGHEST at
6 months of age
108
Airway resistance is greater in
neonates and declines markedly with growth from 19 to 28 cm H2O/L/sec to less than 2 cm H2O/L/ sec in adults.
109
Airway resistance and law
According to Poiseuille’s law, airway resistance
| is inversely proportional to the fourth power of the radius of the airway during laminar flow.
110
A neonate must overcome the
resistance to airflow, as well as the elastic recoil of the lungs and chest wall.
111
The rate of ventilation that uses the least amount of muscular
energy and generates a satisfactory tidal volume has been found to be
37 breaths per minute in the healthy newborn.
112
The metabolic cost of breathing in the neonate is similar to
| an adult, approximately
0.5 mL per 0.5 L of ventilation.
113
Airway resistance changes with
age.
114
Although the larger airway resistance remains constant, airway resistance in the smaller airways is
increased.
115
The increase in airway resistance and neonate
increases the work of breathing in the neonate.
116
Small airway disease (e.g., pneumonia) produces
additional increases in the work of breathing.
117
Myocardial contractility/ compliance in Neonate
↓ Myocardial contractility/↓ myocardial
| compliance
118
Myocardial depression may be exaggerated when
inhalation anesthetics are administered to pediatric patients
119
Not recommended during resuscitation of the depressed neonate is
naloxone
120
Higher doses of epinephrine can lead to decreased myocardial function at doses in the range of
0.1 mg/kg IV with EPINEPHRINE
121
2 patients who have a greater risk of central apnea.
patients who were born before 36 weeks’ gestation and whose postconceptual age is less than 60 weeks
122
For this reason, these patients should bes.
kept overnight
| for observation after any surgical procedure
123
The risk of apnea if the patient has
received regional anesthesia versus receiving general anesthesia is less; however, these patients should be admitted and monitored postoperatively as well
124
Administration of what 2 to a less than 60 weeks PCA, MOST DECREASE the RISK of POSTOPERATIVE APNEA →
CAFFEINE and CPAP
125
Neonate should be hospitalized and monitored for
24 hours after surgery as a single dose of caffeine may not provide sufficient protection against apnea
126
What put a less than 60 weeks PCA more at risk for apnea →
PREOPERATIVE ANEMIA such as hematocrit less than 30%, hx of apnea, or hx of apnea at home
127
ALL infants younger than 60 weeks PCA should be
monitored for at least 24 hours after surgery.
128
The HIGHEST RISK for POSTOPERATIVE apnea and BRADYCARDIA is within
6 hours of surgery and can be seen up to 12 hours after surgery.
129
PCA babies, ALL elective surgery should be
delayed until they are older than 60 weeks PCA
| Apnea is strongly and inversely related to both gestation and PCA
130
During what period following general anesthesia are premature neonates most likely to exhibit apnea and bradycardia?
4-6 hours
131
Most STRONGLY associated with an increased RISK OF CENTRAL POSTOP APNEA is →
ANEMIA, SEPSIS, hypothermia
132
Premature EBV
90-100
133
Newborn EBV (less than 1 mo of age)
80-90
134
Infants 3 mo to 3 yr EBV
75-80
135
Preterm neonate ETT size
2.0-3.0
136
Full-term neonate ETT size
3.0-3.5
137
3 months to 1 year of age ETT size
4.0
138
Neonate intubation preferable blade
straight blade preferable.
139
Intubating neonates steps
blade is placed along the right side of the mouth sweeping the tongue to the left. The epiglottis is picked up with the tip of the blade and the tracheal inlet exposed. The tube is inserted with the convex side to the left. When the tip approaches the glottic opening, rotate the tube 90 degrees counterclockwise. The advantage of one over another is the characteristic that allows the large tongue of the neonate to be manipulated out of the visual field.
140
There are also modifications of straight blades that allow
insufflation of oxygen into the pharynx during intubation
141
Cleft lip, with or without cleft palate, may
complicate intubation.
142
If there is concern for difficult airway,
awake intubation should be considered.
143
can obstruct the airway during mask ventilation.
The small mouth and large tongue
144
Neonates have very
small nares, and when obstructed by an anesthesia facemask, they do not convert
to mouth breathing, particularly if the mouth is being held closed.
145
May make direct laryngoscopy and visualization of the glottis impossible, requiring other types of airway management
small and/or receding chin, as seen in Pierre
| Robin and Treacher Collins syndromes,
146
____can obstruct half of the neonate’s airway and should be placed_____
A nasogastric tube ; orally
147
Anomalies such as _______or _______
| of the neck can produce upper airway obstruction
cystic hygroma or hemangioma
148
Neonate head: can make airway management difficult.
The shape and size of the head, with
| or without the presence of pathology,
149
Two types of muscle fibers are present in muscle tissue—specifically,
the diaphragm and intercostals.
150
Type 1 muscle fibers are
slow twitch muscle fibers and are resistant to fatigue.
151
These fibers are essential for sustained ventilatory activity.
Type 1
152
Type 2 muscle fibers, also known as
fast twitch muscle fibers, are fast twitch but fatigue rapidly.
153
A newborn infant’s diaphragm is composed of
25% type 1 muscle fibers as compared to 55% type 1 muscle fibers in the adult diaphragm.
154
Neonates: Also, type 2 muscle fibers are predominant within
the intercostals.
155
A newborn infant’s diaphragm is composed of 25% type 1
muscle fibers as compared to 55% type 1 muscle fibers in the adult diaphragm. Also, type 2 muscle fibers are predominant within the intercostals. Therefore, newborns and young infants are at
risk of muscle fatigue, respiratory distress, and respiratory arrest
156
Allow for expansion of the thoracic cavity and the associated
increase in negative intrathoracic pressure in neonates
Primarily the diaphragm and to a lesser extent the intercostal muscles
157
The boxlike configuration of an infant's thorax permits
less elastic recoil than the dorsoventrally flattened thoracic cage of the adult does
158
The oxyhemoglobin curve of a newborn is shifted to the
left compared to that of an adult because of the PRESENCE of FETAL HEMOGLOBIN which has a HIGHER AFFINITY FOR OXYGEN
159
During the first 3-6 months of life, the oxyhemoglobin curve begins to shift to the
right, which helps compensate for the anemia of infancy.
160
Careful monitoring of what may be needed to maintain
| oxygenation during surgery?
the acid-base status, the use of increased peak inspiratory pressure, and positive end-expiratory pressure
161
Will attenuate the increase in pulmonary vascular resistance
Oxygenation
Avoidance of acidosis
Maintenance of normothermia
162
A _____level is sufficient for performing a cesarean section under epidural anesthesia.
A T4 level
163
A dermatomal level required to provide effective anesthesia for cesarean section.
T4
164
After a negative test dose and careful aspiration for blood and CSF Lidocaine dose and epinephrine concentration?
lidocaine 2% with epinephrine 1:200,000 can be used when dosed in 3- to 5-mL increments.
165
Volume required for a T4 Level?
A total volume of approximately 20 to 25 mL is required to obtain a T4 level.
166
Bupivacaine is generally
avoided due to the increased maternal mortality associated with it when toxicity occurs
167
Pain pathway during labor: Uterus and cervix innervation is
T10 to L1-L2, pain impulses
168
First stage of labor pain carried by
carried by visceral afferent type C fibers
169
Pain impulses carried by somatic nerve fibers , pudental nerves.
Perineum pain S2 - S4
170
Preterm labor is defined as
Delivery before 37 weeks of gestation
171
Preterm labor diagnosis is facilitated by measuring
Fetal fibronectin and maternal cervical ultrasonography
172
As a general rule, if tocolytics are given, they should be given
concomitantly with corticosteroids.
173
A patient is receiving tocolytic therapy or preterm labor. Which of the following is most concerning or this patient?
PULMONARY EDEMA
174
Drugs administered to treat preterm labor and STOP uterine contractions that interfere with fetal oxygen
Terbutaline
175
Procedures that are associated with the greatest incidence of preterm labor.
Abdominal and pelvic procedures
176
Most likely to be associated with preterm labor
Intra-abdominal procedures during the third trimester
177
Preterm labor parturients consider
preterm labor may allow time for the onset of the therapeutic effect of corticosteroids.
178
The cause of preterm labor is not well understood; however, four pathways are:
Myometrial and fetal membrane overdistention
Decidual hemorrhage
precocious fetal endocrine activation, and
intrauterine infection or inflammation
179
Lipid Emulsion Therapy initial dose and maintenance
IV bolus of 1.5 ml/kg of 20% lipid emulsion is given OVER 1 minute, FOLLOWED BY an infusion of 0.25 ml/kg/min until AT LEAST 10 MINUTES AFTER SUCCESSFUL ACHIEVEMENT of CIRCULATORY STABILITY.
180
A major component of resuscitation, because cardiac arrest from LAST is different than typical out of the hospital cardiac arrest
20% lipid emulsion
181
```
Parturient Changes in airway begin at
There are NO PREDICTORS of increasing airway class and no association between amount of WEIGHT gain
```
12 weeks of gestation
182
Airway changes in parturient in caused by
CAPILLARY ENGORGEMENT of the mucosa causes AIRWAY EDEMA and INCREASED FRIABILITY
183
ET tube for the parturient
SMALLER Endotracheal tube (6.0 - 6.5) necessary
184
What is contraindicated to do in the parturient airway and why?
INCREASED Friability makes the NASAL mucosa MORE FRIABLE making NASAL INTUBATION relatively CONTRAINDICATED
185
Number of patients with mallampati class III or IV airways increases dramatically between
12 and 38 weeks of gestation
186
WHILE further worsening of MALLAMPATI class occurring during
active labor
187
PREDICTORS of increasing airway class
There are NONE and no association between amount of WEIGHT gain
188
Placenta accreta is the
abnormal implantation of the placenta into the uterine wall
189
Placenta accreta is associated with
Increasing cause for MATERNAL HEMORRHAGE and requirement for PERIPARTUM HYSTERECTOMY
190
Parturient at risk for Placenta Accreta
OVERALL risk as high as 60% in women with a NUMBER OF PREVIOUS C-SECTION (3 or more)
HX of PLACENTA PREVIA
191
Which is true of pain associated with the second stage of labor? Think SS
IT IS SOMATIC (Second-Somatic)
192
The second stage of labor starts when the
cervix is fully dilated to 10 cm and ends when the fetus is delivered.
193
Pudental nerve distribution
Pudental nerve distribution of the pelvic floor S2-S4
194
Pain from the second stage of labor is somatic, includes the
S2-S4 spinal cord segments,
195
2nd stage labor pain is caused by
by stretching of the perineum, fascia, skin, and subcutaneous tissue.
196
2nd stage labor pain mediated by
Affarent nerve conducted along the pudental nerves S2-S4
197
Volatile anesthetics agents are advantageous for maintenance of anesthesia because of
uterine relaxation and prevent premature labor
198
Gas that has no effect on uterine relaxation
Nitrous oxide
199
VA and uterine relaxation
All volatile anesthetics promote uterine relaxation in a dose-dependent manner.
200
MAC and uterine relaxation
1.5 MAC of volatile agent, uterine contractility is Decreased by 50%
201
Which of the following interventions would be an alternative to administering an inhalation agent to facilitating uterine relaxation in a parturient?
NITROGLYCERIN
202
Which of the following would be considered an average blood loss from an uncomplicated cesarean section?
1000 ml (1L)
203
The average blood loss for a vaginal delivery is and for
500 mL
204
Average blood loss for an an uncomplicated cesarean section, the blood loss is
800 to 1000 mL.
205
Normal blood losses at delivery are generally well tolerated in the healthy parturient as a result of
compensatory mechanisms
206
Pain experience during the first stage of labor, mostly caused by
UTERINE CONTRACTION and DILATION of the CERVIX
207
First stage labor Pain is PRIMARILY transmitted via
SYMPATHETIC FIBERS ORIGINATING from T10 - L1
208
Pain from the first stage of labor is visceral, involves spinal cord segments T10-L1, and is caused by
traction on the round ligament, cervical dilation, and uterine contractions.
209
First stage of labor pain begins with
Onset of regular painful contractions and ends at complete dilation of the cervix.
210
First stage of labor pain is what type of pain
VISCERAL.
211
Increase in CO during pregnancy is due to
SVR decreases by as much as 21% by term. Much of this change is due to the decreased resistance in the vasculature of the uterus, placenta, kidneys, and lungs.
increase in STROKE VOLUME
212
Pregnancy and CO
CO increases by 40%
213
Cardiovascular changes begin as early as the
fourth week of pregnancy; then continue into the postpartum period
214
The heart rate is increased by______ at term.
When a woman
is in labor, cardiac output increases during uterine contractions
as a result of autotransfusion from the contracting uterus to the
central circulation.10
20% to 30%
215
HR: This increase in HR begins in the ______and peaks by
first trimester ;32 weeks of gestation.
216
Normal heart rate (HR) variability does not appear to be changed until late in pregnancy, when
tachyarrhythmias are more common
217
Cardiac output increases by approximately
40% over nonpregnant values.
218
This increase in cardiac output begins in the
fifth week of pregnancy and results from an increase in stroke volume (SV) 20%-50%) and, to a lesser extent, heart rate.
219
Some studies previously indicated cardiac output decreased in the third trimester, but these results were likely due to
aortocaval compression from studying subjects in the supine position
220
At term, approximately __% of the CO perfuses the gravid uterus.
10-15 % of the cardiac output perfuses the gravid uterus.
221
When a woman is in labor, cardiac output increases during uterine contractions as a result of
autotransfusion from the contracting uterus to the
| central circulation.
222
When a woman is in labor, CO
Increases during uterine contractions.
223
Immediately after delivery, What happens to the cardiac cardiac output?
increases as much by as 80% above predator values as a result of an increase in central volume from the now contracted uterus and relief of aortocaval compression.
224
Immediately after delivery, CO increases by as much as 80% , what are the implications ?
As a result, patients with preexisting cardiac anomalies
| are at an increased risk for decompensation in the immediate postpartum period.
225
Cardiac output gradually returns to baseline within
14 days as HR and SV normalize
226
During pregnancy the diaphragm what happens to the heart.?.
rises, shifting the heart up and to the left, making the cardiac silhouette appear enlarged on x-ray examination
227
Ventricular walls and EDV in pregnant women
The ventricular walls thicken and end-diastolic
| volume increases
228
PE of pregnant patients: Heart
A benign grade 1 or 2 systolic murmur or a third heart sound may be heard on auscultation
229
When is a murmur in a parturient requires further evaluation?
If the systolic murmur is greater than grade 3 or accompanied by chest pain or syncope, further evaluation is necessary
230
2 things that are pathologic and not normal in the parturient heart?
Diastolic murmurs and cardiac enlargement are considered pathologic.
231
Normal pregnancy also may result in signs of cardiac abnormality such as
exercise intolerance, shortness of breath, and edema.
232
Pregnant women and BARORECEPTOR reflexes
baroreflex-mediated changes. in HR at term than at 6 to 8 weeks postpartum
233
In the presence of adequate neuraxial analgesia and little sympathetic stimulation, there is often a corresponding decrease in
maternal heart rate during uterine contractions due to the transiently increased preload
234
Systemic vascular resistance (SVR) and parturient
decreases as much as 21% by the end of a term pregnancy, owing in large part to decreased resistance in the uteroplacental, pulmonary, renal, and cutaneous
vascular beds.
235
At term gestation of _____% of the cardiac output
| perfuses the low resistance intervillous space of the uterus
10%
236
Venous capacitance and Pregnant women
The venous capacitance system loses tone, allowing pooling of the larger blood volume.
237
This decrease in SVR results in little
overall systolic blood pressure change during normal pregnancy, despite the increased blood volume.
238
DBP and pregnant women
A decrease in diastolic blood pressure of up to 15 mmHg may occur, resulting in a decrease in mean pressure.
239
Supine hypotensive syndrome in a parturient is most likely to occur at
36-38 weeks
240
Select two physiologic characteristics that you would expect to be decreased in the obstetric patient at term →
Hgb, SBP
241
The platelet count and pregnancy
decreases during pregnancy due to dilution and an increase in platelet consumption. Between 10 and 15% of term parturients will have a platelet count less than 150,000.
242
By term, plasma volume________by _____%
ncreases by about 40 percent,
243
Term and Hemoglobin
decreases to 11-12 g/dL
244
Term and fibrinogen
Doubles
245
2 changes in term pregnancy that maximize oxygen delivery?
The increased cardiac output and a shift to the right in the oxyhemoglobin dissociation curve help to maximize oxygen delivery.
246
-During labor , CO further increases _____% over the pre-labor values in the first stage and up to _____% in the 2nd stage, and as high as _____% immediately after delivery.
10-25% over pre-labor values in the first stage and up to 40% in the 2nd stage, and as high as 80% immediately after delivery
247
BV is increased by up to
45% over Pre-pregnancy values (range in 30-50%)
248
BV increases by what leads to dilutional anemia?
Red cell volume increases by only 30% leading to PHYSIOLOGIC ANEMIA of pregnancy
249
TOTAL BLOOD VOLUME and pregnancy
increase by 25-40%
250
BV increased is due to
HIGH aldosterone secondary to RAAS upregulation.
251
Blood volume is markedly
MARKEDLY INCREASED AND PREPARES THE PARTURIENT FOR THE BLOOD LOSS associated with delivery
252
Plasma volume and pregnancy
increases by 40%
253
Plasma volume is increased to a greater extent than
Red Blood cell volume resulting in a delusional anemia.
254
Erythrocyte mass change
increases by about 20%
255
Decreased HEMATOCRIT referred to as physiologic anemia Because the
red blood cell mass only increases by about 20%, there is a relative anemia present.
256
Plasma volume increases by ___%during pregnancy while erythrocyte mass increases by about ___%. The relatively smaller increase in red blood cell mass leads to a
40% ; 20%; decreased hematocrit, referred to as the physiologic anemia of pregnancy.
257
The increased plasma volume is likely the result of
greater circulating levels of progesterone and estrogen resulting in enhanced renin-angiotensin-aldosterone activity
258
Systolic Blood pressure and pregnancy
decreases by 5%
259
Pregnancy: Increase in SVR results in little overall
systolic blood pressure change during normal pregnancy, despite the increased blood volume
260
Maternal stroke volume index, heart rate,
| and systolic blood pressure were
higher in the lateral positions compared with the sitting and supine-tilt positions
261
All pregnant women are at increased risk of aspiration and should be considered to
because of the anatomic and physiologic changes to the gastrointestinal system
262
All pregnant women should be considered to ____starting after ______weeks of gestation
have a full stomach after week 12 of gestation.
263
Maternal intubation
Rapid sequence induction with a rapid acting muscle relaxant (succinylcholine). Pre-oxygenate but do hand ventilated, maintain cricoid pressure until intubation is achieve and the cuff is inflated.
264
High doses of oxytocin can produce
diastolic hypotension (and some degree of systolic hypotension), flushing, and tachycardia.
265
By what week of gestation is surfactant production sufficient enough to prevent respiratory distress syndrome in most infants?
35 weeks
266
What is the most reliable test for detecting an inadvertent intrathecal or intravascular epidural catheter placement in a laboring parturient?
Negative aspiration for CSF or blood
267
During the third trimester of pregnancy, the cardiac output
increases primarily due to an increase in stroke volume
268
Plt count considered too low to perform a neuraxial anesthetic.
A platelet count less than 75,000-80,000 is
269
The drug of choice for treating hypertension during anesthesia in a parturient with preeclampsia is
Labetalol
270
What sensory level block would be appropriate for performing a cesarean section under epidural anesthesia?
T4
271
Which of the following parameters increases with pregnancy?
PaO2
272
How long after delivery does the cardiac output of the mother remain elevated?
14 days
273
Which of the following is associated with a higher risk of placenta accreta in parturients already presenting with placenta previa?
History of multiple cesarean sections
274
Which is the most common epidural test dose of local anesthetic (LA) containing epinephrine?
3 mL of LA containing 5 mcg/mL (1:200,000) of epinephrine
275
The epinephrine in an epidural test dose is less reliable in which patient class?
Patients in active labor
276
Recommended for pregnant women receiving general anesthesia from In such a case, an alternative method, such as
awake intubation, may be necessary
Rapid sequence induction, cricoid pressure, and a cuffed endotracheal tube are
277
RSI starting ___Weeks of gestation
20 WEEKS on even if no symptoms of reflux are present.
278
Although rapid-sequence induction is the technique most commonly used to minimize the risk of gastric aspiration during induction of general anesthesia, it is not indicated if
Laryngoscopist has doubts about his or her ability to
| intubate the patient.
279
If questioning ability to intubate
In such a case, an alternative method, such as
| awake intubation, may be necessary
280
Intravenous rapid sequence induction:
* Cricoid pressure
* Propofol, ketamine, or etomidate
* Succinylcholine (rocuronium or vecuronium if succinylcholine is contraindicated)
281
Pregnant Intubation with a______ to ______ETT
6.0- to 7.0-mm cuffed endotracheal tube
282
The muscle relaxant of choice during the rapid-sequence induction of an obstetric patient.
Succinylcholine
283
In pregnant patients on magnesium therapy, how do you modify the intubation?
defasciculation with a small dose of a nondepolarizing neuromuscular blocking agent is not recommended because significant paralysis may result, increasing the risk of aspiration of gastric contents.
284
Magnesium potentiates
depolarizing and, especially, nondepolarizing relaxants.
285
For TEST dose, Administer
3ml and observe for maternal heart for 60 seconds and level of block for 3-5 minutes. If no sign for subarachnoid or intravascular injection, administer 3-5 ml and observe for 3-5 minutes.
286
When administered intravascularly , lidocaine 45 mg will often results in early signs and symptoms of modest systemic toxicity such as
CIRCUMORAL NUMBNESS
LIGHTHEADEDNESS
AUDITORY CHANGES
287
Commonly administered test dose is 3ml of lidocaine 1.5% with epinephrine 1:200,000. Lidocaine ____mg and ____mcg of epinephrine
This is 45 mg dose of lidocaine, 15mcg of epinephrine
288
Test dose is done to identify epidural catheters that are
inadvertently inserted into either the subarachnoid space or an epidural vein
289
Test dose
Reveal inadvertent subarachnoid or intravascular injection
290
In laboring patients, test dose
increases in HR are less specific indicators of intravascular injection because of the changes in HR that normally occur with uterine contractions.
291
Epinephrine may cause significant
uterine artery constriction in a small number of patients, resulting in a decrease in fetal O2 delivery.
292
Without administration of a test dose, may be effective in revealing intrathecal or intravascular catheter.
Careful aspiration for blood or CSF alone,
293
Test dose required when administering
LARGER and MORE CONCENTRATED DOSES, such as giving an epidural for cesarean delivery.
294
Reliability impaired in the face of B-Blockade,
advanced age and active labor.
295
Use an alternative to patients with B-Blockade
Fentanyl
296
Use minimum ED, careful aspiration,
incremental injection, coupled with the use of intravascular markers when large doses are used.
297
For neonate Administration of _________prior to the administration of the TEST dose may increase the sensitivity of the test dose.
ATROPINE 10mcg/kg
298
You are preparing to place an epidural catheter in an obstetric patient who is taking metoprolol. Which of the following would be the best formulation for an epidural test dose?
Although epinephrine reliably increases the heart rate in pregnant patients, it is less specific in laboring patients because the heart rate varies widely during and between labor contractions. Also, in patients taking beta-blockers, it may not be very effective. In those instances, the use of fentanyl to see if sedation is produced is an alternative.
299
After IV, exposing an infant to 0.5mc/kg of epinephrine during sevoflurane anesthesia, the most likely changes that mark an intravascular injection are
1) Elevated in T-wave amplitude by 25% (MOST SENSITIVE)
2) an increase in HR by 10bpm
3) increase in systolic blood pressure by 15mmHg.
300
Most appropriate test dose of epinephrine for a 5 kg 3 month old is
2.5 mcg (0.75mcg/kg)
301
The epinephrine in an epidural test dose is less reliable in which patient class?
less specific in laboring patients because the heart rate varies widely during and between labor contractions.
302
Postdural puncture headache is generally relieved by assuming a
Lying position
303
P50 in the mother
Increases and go to the RIGHT
304
P50 in the fetus
Decreases and go to the LEFT>
305
MAC peak at the highest
2-3 months.
306
Vd in neonate
Large
307
Protein binding in neonate
Decreased (INCREASE FREE DRUG LEVELS)
308
Body fat % in neonate
Decreased
309
Renal and hepatic function in the neonate
immature
