ITE CA-2 OB anesthesia

Question 1

4 classes of tocolytic drugs

Answer 1

β-adrenergic agonists,
calcium channel blockers,
cyclooxygenase inhibitors (e.g., NSAIDs), and
magnesium sulfate

Question 2

B-agonists used to treat preterm labor

Answer 2

ritodrine and terbutaline

Question 3

maternal effects of b-agonists to treat pre-term labor

Answer 3

cardiopulm: pulmonary edema, MI, tachycardia, vasocilation, hypotension, dysrhythmias

Endocrine: hyperglycemia, hyperinsulinemia, hypokalemia (from increased insulin), altered thyroid fxn, antidiuresis

Misc: tremor, palpitations, hallucinations, ileus (N/V), fever, nervousness

Question 4

Fetal effects of b-agonists to treat pre-term labor

Answer 4

tachycardia, MI, myocardial hypertrophy, hyperglycemia, hyperinsulinemia

Question 5

Neonatal effects of b-agonists to treat pre-term labor

Answer 5

tachycardia, hypotension, intraventricular hemorrhage, hyperbilirubinemia, hypocalcemia, hyperglycemia -> hypoglycemia

Question 6

Pregnant women with cord injury above ___ may have an increased risk of preterm labor

Answer 6

Pregnant women with cord injury above T11 may have an increased risk of preterm labor

Question 7

Pregnant women with cord injury above T11 may have an increased risk of ________

Answer 7

Pregnant women with cord injury above T11 may have an increased risk of preterm labor

Question 8

For chronic lesions above ___, autonomic hyperreflexia occurs in > 85% of pregnancies

Answer 8

For chronic lesions above T6, autonomic hyperreflexia occurs in > 85% of pregnancies

Question 9

How treat labor pain in patient with chronic lesion above T6

Answer 9

For chronic lesions above T6, autonomic hyperreflexia occurs in > 85% of pregnancies. Neuraxial anesthesia is often effective and placement of an intrathecal catheter may allow for continuous titration of the block. Most obstetric anesthesiologists choose epidural anesthesia in this situation. Lateral position is preferred for the procedure as the sitting position results in pooling of blood in the lower extremities.

Question 10

Medical complications of spinal cord injury aggravated by pregnancy

Answer 10

Medical complications of spinal cord injury aggravated by pregnancy include decreased respiratory reserve, atelectasis, impaired cough, anemia, deep vein thrombosis, thromboembolic phenomena, chronic urinary tract infections, urinary tract calculi, proteinuria, renal insufficiency, decubitus ulcers, hypertension, and autonomic hyperreflexia.

Question 11

Aspiration of meconium stained amniotic fluid treatment

Answer 11

Aspiration of meconium stained amniotic fluid can lead to meconium aspiration syndrome in newborns. Suctioning the oropharynx or intubating and suctioning the trachea of apparently vigorous infants has NOT been shown to be beneficial. If the infant born through meconium-stained amniotic fluid has poor muscle tone and inadequate breathing efforts, resuscitate under a radiant warmer. Positive pressure ventilation should be initiated if the infant is not breathing or the heart rate is less than 100/min after the initial steps are completed.

Question 12

Can diagnose preeclampsia in absence of proteinuria with any of what

Answer 12

thrombocytopenia, renal insufficiency, pulmonary edema, cerebral disturbances, or hepatic dysfunction.

Question 13

Chronic hypertension in pregnancy

Answer 13

Chronic hypertension involves pre-pregnancy blood pressures greater than 140/90 mmHg or elevated blood pressure that fails to resolve after the post-partum period.

Question 14

Gestational hypertension

Answer 14

Gestational hypertension manifests as elevated blood pressure after 20 weeks gestation, without any systemic manifestations, and resolves 12 weeks postpartum.

Question 15

Preeclampsia is

Answer 15

Preeclampsia is new onset hypertension and proteinuria after 20 weeks gestation. If hypertension exists without proteinuria, preeclampsia is also defined as thrombocytopenia, impaired liver function, new development of renal insufficiency, pulmonary edema, or new-onset cerebral or visual disturbances.

Question 16

The most common cause of early postpartum hemorrhage and risk factors

Answer 16

The most common cause of early postpartum hemorrhage is uterine atony which results in continued bleeding from intrauterine vessels that are torn with placenta delivery. Risk factors for uterine atony include multiparity, multiple gestations, polyhydramnios, chorioamnionitis, prolonged labor, oxytocin-induced labor, and mechanical factors.

Question 17

Primary pulmonary hypertension in pregnancy

Answer 17

Primary pulmonary hypertension (PPH) in pregnant patients has a high mortality rate usually from right heart failure. The anesthetic technique is aimed at minimizing increases in peripheral vascular resistance. PPH is most commonly seen in younger women and is poorly tolerated in pregnancy; pregnancy is discouraged in these patients and termination is advised should pregnancy occur.

The normal physiological changes of pregnancy are poorly tolerated by women with pulmonary hypertension. Pregnancy is associated with increased plasma volume and decreased systemic vascular resistance, both resulting in an increase in cardiac output. In healthy women, a decrease in pulmonary vascular resistance accommodates the requirements for increased cardiac output. In women with pulmonary hypertension, pulmonary vascular disease prevents the fall in pulmonary vascular resistance, leading to a rise in pulmonary artery pressure with increased cardiac output. Ultimately, the necessary increase in cardiac output cannot be achieved resulting in right heart failure.

Question 18

Anesthetic considerations for pregnant patient with primary pulmonary hypertension.

Answer 18

The biggest difficulty in planning for an anesthetic in the pregnant patient with PPH is minimizing increases in PVR (pulmonary vascular resistance). Pain during labor and vaginal delivery is especially detrimental because it may further increase pulmonary vascular resistance and decrease venous return. Neuraxial analgesia is useful for preventing pain-induced increases in pulmonary vascular resistance. Dilute local anesthetic solutions with the addition of opioids will minimize the decrease in systemic vascular resistance (SVR). General and epidural anesthesia have been used for cesarean delivery. Spinal anesthesia may result in a sudden decrease in SVR and is thus not recommended for cesarean delivery. Risks of general anesthesia include increased pulmonary artery pressures during laryngoscopy and tracheal intubation, the adverse effects of PPV on venous return, and the negative inotropic effects of volatile anesthetics. In addition to oxygen, the administration of isoproterenol, inhaled nitric oxide, calcium channel blockers, or sildenafil may be useful for decreasing pulmonary vascular resistance. Hemodynamic monitoring, including systemic and pulmonary arterial pressures, remains controversial in these patients with no evidence to support the use of pulmonary artery catheters. Pulmonary artery rupture and thrombosis are risks of pulmonary artery catheters in the presence of pulmonary hypertension, but some argue that the benefits in these critically ill patients appear to offset these potential hazards.

Question 19

First line for uterine atony

Answer 19

IV oxytocin

Question 20

Treatment for uterine atony that is contraindicated in the setting of pregnancy-induced hypertension or preeclampsia and why

Answer 20

Methylergonovine maleate is contraindicated in the setting of pregnancy-induced hypertension or preeclampsia since it is an ergot derivative that may lead to hypertensive emergency.

Question 21

Treatment for uterine atony contraindicated in asthma

Answer 21

Carboprost tromethamine is contraindicated in patients with significant reactive airway disease since it has prostaglandin-like effects and can cause bronchospasm.

Question 22

Most effective way to reduce risk of aspiration in OB patients

Answer 22

avoid a general

Question 23

Why OB patient greater risk of aspiration?

Answer 23

If general anesthesia cannot be avoided, know that the patient will be at increased risk of aspiration compared to a non-pregnant patient, primarily because the increased incidence of difficult airway and the decreased competency of the lower esophageal sphincter.

Question 24

Main factor for development of pneumonitis in aspiration?

Prophylaxis?

Answer 24

If aspiration occurs, the main factor for the development of pneumonitis appears to be the pH of the aspirate. For prophylaxis, the ASA guidelines recommend avoiding solid food in laboring patients and considering non-particulate antacids, H2-receptor antagonists, and/or metoclopramide before cesarean section.

Question 25

labor stage 1

Answer 25

Stage I: A) Latent phase Variable duration Starts at onset of labor Complete when the rate of cervical dilation increases (~ 3 cm) B) Active phase (contractions every 2-3 mins, last 1 min, up to 70 mm Hg) acceleration phase phase of maximal slope deceleration phase Normal active labor should progress 1 cm/hr Most common measure of uterine activity is the Montevideo unit (avg intensity frequency per 10 minutes)

Question 26

labor stage II

Answer 26

Stage II: interval between maximal dilation and delivery (20-120 mins)

Question 27

labor stage III

Answer 27

Stage III: starts after delivery of the baby and ends with placental delivery (5-20 mins)

Question 28

seizure threshold in pregnancy

Answer 28

Higher estrogen levels during pregnancy lower the seizure threshold. Pregnancy can cause variable effects on the frequency of seizures. A variety of etiologies may increase seizure frequency in pregnant women. Greater sodium retention and water retention are suggested methods of increased seizure activity. Also, anticonvulsant drug levels can be decreased during pregnancy secondary to decreased plasma protein binding and greater drug clearance. Estrogen is a proconvulsant, whereas, progesterone is an anticonvulsant.

Question 29

labor stage one spinal segments

Answer 29

The first stage of labor is defined as the beginning of labor to maximal cervical dilation. Pain impulses arise primarily from the uterus during this stage of labor. These stimuli enter the spinal cord at the T10, T11, T12, and L1 spinal segments

Question 30

labor stage II spinal segments

Answer 30

The second stage of labor is defined as the interval between full cervical dilation and delivery of the infant. Pain impulses primarily arise from stretching of the perineum. These stimuli arise from nerve fibers through the pudendal nerve to the spinal cord at S2, S3, and S4 levels.

Question 31

lumbar sympathetic block would cover what stages of labor

Answer 31

stage I

Question 32

caudal epidural would cover what stages of labor

Answer 32

stage I and II (not sure about III but it probably would)

Question 33

paracervical block

Answer 33

A paracervical block is an alternative block technique in pregnant women. It adequately can provide analgesia for the first stage of labor. The block is performed by injecting local anesthetic in the fornix of the vagina around the cervix to block nerve transmission through the paracervical ganglion. This block provides no pain relief for the second stage of labor.

Question 34

pudendal nerve block

Answer 34

A pudendal nerve block covers the lower sacral nerve roots (S2-S4) and provides sensory innervation to the lower part of the vagina, vulva, and perineum. The block is completed by depositing local anesthetic behind each sacrospinous ligament. This nerve block is not useful for labor analgesia, however, it provides satisfactory analgesia for outlet forceps delivery.

Question 35

med to give in case of shoulder dystocia

Answer 35

Shoulder dystocia is a fetal life-threatening emergency. Nitroglycerin provides fast-onset uterine relaxation to assist with obstetric manipulation and delivery. Nitroglycerin is a faster and more potent uterine relaxant as compared to beta-agonist terbutaline although its duration of action is much shorter.

Question 36

How do clotting factors change in pregnancy

Answer 36

Pregnancy is a prothrombotic state with increased levels of many clotting factors. Factors VII, VIII, IX, X, and XII levels are all increased. In addition there is a decrease in factor C & S levels. This causes shorter PT and PTT times. However, not all factors are increased during pregnancy with factors XI and XIII levels decreasing slightly. Platelets stable or slight decrease

Question 37

The risk of deep venous thrombosis (DVT) is increased during pregnancy mainly because of an increase in circulating levels of fibrinogen.

Answer 37

The risk of deep venous thrombosis (DVT) is increased during pregnancy mainly because of an increase in circulating levels of fibrinogen.

Question 38

Fibrinogen is factor __

Answer 38

1

Question 39

Risk factors for fetal drug toxicity

Answer 39

Drug characteristics that facilitate placental transfer include: small size (< 500 Dalton's), nonionized/lipid soluble, poorly protein bound, and high maternal concentration. Drugs that undergo ion trapping (most importantly local anesthetics) can accumulate more quickly in the setting of fetal acidosis.

Question 40

Some important drugs that do not cross the placenta:

Answer 40

Some important drugs that do not cross the placenta: | He Is Going Nowhere Soon = Heparin, Insulin, Glycopyrrolate, Non-depolarizing muscle relaxants, Succinylcholine.

Question 41

How reverse in OB without sugammadex

Answer 41

The inability of glycopyrrolate to cross the placenta is important to consider when reversing a pregnant woman from neuromuscular blockade. Neostigmine is also a quaternary structure but does cross the placenta to a small degree. If glycopyrrolate is administrated with neostigmine, the fetus will accordingly be exposed to more neostigmine than glycopyrrolate and can become bradycardic. For this reason, atropine may be preferred in combination with neostigmine to antagonize non-depolarizing neuromuscular blockade in pregnant patients.

Question 42

Platelets in pregnant woman

Answer 42

Platelets may lead to Rh sensitization and consideration should be given to administering Rh immunoglobulin (often referred to by its commercial name RhoGAM) to women of child-bearing age or younger.

Question 43

Double Bohr effect

Answer 43

The double Bohr effect describes a condition in the placenta where the maternal Bohr effect and the fetal Bohr effect occur in opposite binding conditions. From the maternal side the hemoglobin is in an acidic environment, which promotes oxygen offloading. The fetal hemoglobin on the placental side is in an alkalotic state, which promotes oxygen uptake or binding. The double Bohr effect accounts for somewhere between 2-8% of oxygen transfer across the placenta.

Question 44

Fetal hemoglobin level

Answer 44

The normal fetal hemoglobin concentration is approximately 17mg/dL. The normal maternal hemoglobin concentration is 12mg/dL

Question 45

How much does maternal blood vol increase in pregnancy? | By what mechanism?

Answer 45

An increase of up to 45% of maternal blood volume is seen during pregnancy. This effect occurs early within pregnancy and is due to sodium retention via the renin-angiotensin system.

Question 46

Oxy-hgb dissoc curve shift in pregnancy

Answer 46

Right

Question 47

Maternal CO trend in pregnancy and what is the peak. When is HR vs stroke volume

Answer 47

Maternal cardiac output progressively increases during pregnancy and throughout labor, reaching its peak immediately following delivery (2.5x prepregnancy values). Cardiac output then quickly declines postpartum and begins to approach prepregnant values by two weeks postpartum. Maternal cardiac output increases significantly throughout pregnancy, please see figure below. In the first trimester, maternal heart rate increases and accounts for the 35-40% rise in cardiac output seen by the end of the first trimester. During the second and third trimester, stroke volume increases. At the end of the second trimester, cardiac output is 50% greater than the prepregnant state and will remain at this level during the third trimester, just prior to the onset of labor. The onset of labor induces further progressive increases in cardiac output which amounts to an increase of as much as 110% above the prepregnant state.

Question 48

Neonatal resuscitation

Answer 48

During neonatal resuscitation, positive pressure ventilation is indicated if the neonate’s heart rate drops below 100 bpm. If the heart rate falls below 60 bpm for more than 30 seconds despite adequate ventilation, chest compressions should be started. If the heart rate remains below 60 bpm despite adequate ventilation and chest compressions, epinephrine should be administered.

Question 49

Block for stage 1 of labor and risk

Answer 49

Pudendal block provides analgesia for the 2nd stage of labor. By blocking the pudendal nerve vaginal and perineal distention pain is blocked. A paracervical block provides analgesia for the 1st stage of labor especially cervical dilation. However, paracervical blocks are associated with a high rate of fetal bradycardia. The rate of fetal bradycardia is increased if fetal acidosis is present.

Question 50

Block for stage 2 of labor

Answer 50

Pudendal block provides analgesia for the 2nd stage of labor. By blocking the pudendal nerve vaginal and perineal distention pain is blocked. A paracervical block provides analgesia for the 1st stage of labor especially cervical dilation. However, paracervical blocks are associated with a high rate of fetal bradycardia. The rate of fetal bradycardia is increased if fetal acidosis is present.

Question 51

Labor stage one dermatome levels

Answer 51

T10-L1

Question 52

Stage 2 of labor dermatomes

Answer 52

T12-L1, S2 - S4

Question 53

Preeclampsia - endocrine - SVR - uterine blood flow - placental blood flow

Answer 53

In preeclampsia, there is an elevation in thromboxane A2 levels and a decrease in prostacyclin levels leading to a primarily vasoconstricted state. Preeclampsia is characterized by global vascular hyperreactivity leading to intravascular volume depletion, high systemic vascular resistance, uterine vasoconstriction of the myometrium, and decreased uterine and placental blood flow.

Question 54

Preeclampsia - more or less nitric oxide - platelets? - renal blood flow - why pulm edema

Answer 54

Endothelial cell activation leads to reduced nitric oxide production and platelet activation. Renal blood flow is decreased leading to decreased urine output. Pulmonary edema occurs secondary to capillary leakage and increased inflammatory response. The hypercoagulable state and platelet activation is juxtaposed with a coagulopathy secondary to decreased platelet counts and prolonged PTT.

Question 55

``` Drug characteristics affecting maternal to fetal placental transfer Characteristics Increased transfer Decreased transfer Size (molecular weight) Charge Lipid solubility Ionization Protein binding Free drug fraction ```

Answer 55

Drug characteristics affecting maternal to fetal placental transfer Characteristics Increased transfer Decreased transfer Size (molecular weight) < 500 Daltons Charge Uncharged Charged Lipid solubility Lipophilic Hydrophilic Ionization Unionized Ionized Protein binding Low (albumin) High (α-1-acid glycoprotein) Free drug fraction High Low

Question 56

serum albumin concentration high or low in pregnancy

Answer 56

decreases because of plasma expansion

Question 57

serum alpha and beta globulins in pregnancy

Answer 57

increase

Question 58

transferrin level in pregnancy

Answer 58

increase

Question 59

TIBC in pregnancy

Answer 59

increases

Question 60

serum iron in pregnancy

Answer 60

decreases

Question 61

Amniotic fluid embolism is characterized by | When emergent c section?

Answer 61

Amniotic fluid embolism is characterized by an early stage with pulmonary vasospasm and right heart dysfunction or failure leading to a second stage with pulmonary edema and left heart dysfunction or failure. Maternal coagulopathy (consumptive) occurs in the majority of cases. Emergency cesarean section is required if uterine hypertonus leads to fetal bradycardia and distress.

Question 62

Significant risk factors for preterm labor include a history of previous preterm delivery, non-Hispanic black race, and multiple gestations.

Answer 62

Significant risk factors for preterm labor include a history of previous preterm delivery, non-Hispanic black race, and multiple gestations. Other factors associated with preterm labor include extremes of age, low socioeconomic status, low prepregnancy body mass index, abnormal uterine anatomy, abnormal cervical anatomy, trauma, abdominal surgery during pregnancy, tobacco use, and substance abuse. An interpregnancy interval of less than six months is a factor associated with preterm labor.

Question 63

``` how do following affect risk of PDPH after accidental dural puncture with epidural needle: gender obesity needle gauge age pregnancy previous history ```

Answer 63

``` females more likely to get PDPH obesity decrease smaller gauge (higher number) decrease older age decrease (under 40 years most common; over 60 rare) pregnancy decrease previous history increase ```

Question 64

options other than nitroglycerin for uterine relaxation

Answer 64

Other options include inhaled amyl nitrite and beta-adrenergic agonists (IV ritodrine, IV salbutamol, IV terbutaline).

Question 65

Cervix covered by which dermatomes

Answer 65

T10-L1

Question 66

Vagina and perineal covered by which dermatomes

Answer 66

S2-S4

Question 67

Risk factors for uterine rupture in the parturient

Answer 67

``` Risk factors for uterine rupture in the parturient include ***prior uterine surgery*** (upper segment scar >> lower segment scar), uterine hypercontractility, oxytocin use, prostaglandin use, prolonged labor, dystocia, multiparity, multiple gestations, congenital uterine anomalies, polyhydramnios, and trauma. ```

Question 68

Preeclampsia diagnostic criteria

Answer 68

Preeclampsia is diagnosed with the presence of hypertension (> 140/90 mm Hg) after 20 weeks with proteinuria or the presence of one of the 6 features listed below (these are used in the diagnosis of preeclampsia with severe features): 1) BP ≥ 160/110 on two occasions at least four hours apart 2) Thrombocytopenia < 100,000 3) Impaired liver function 4) Progressive renal insufficiency 5) Pulmonary edema 6) New-onset cerebral or visual disturbances

Question 69

How much protein for proteinuria in preeclampsia

Answer 69

Proteinuria: • Greater than or equal to 300 mg per 24-hour urine collection (or this amount extrapolated from a timed collection) OR • Protein/creatinine ratio greater than or equal to 0.3 mg/dL • Dipstick reading of 1+ (used only if other quantitative methods not available)

Question 70

Severe Features of Preeclampsia

Answer 70

Severe Features of Preeclampsia 1) Systolic blood pressure of 160 mm Hg or higher, or diastolic blood pressure of 110 mm Hg or higher on two occasions at least 4 hours apart while the patient is on bed rest (unless antihypertensive therapy is initiated before this time) 2) Thrombocytopenia (platelet count less than 100,000/microliter) 3) Impaired liver function as indicated by abnormally elevated blood concentrations of liver enzymes (to twice normal concentration), severe persistent right upper quadrant or epigastric pain unresponsive to medication and not accounted for by alternative diagnoses, or both 4) Progressive renal insufficiency (serum creatinine concentration greater than 1.1 mg/dL or a doubling of the serum creatinine concentration in the absence of other renal disease) 5) Pulmonary edema 6) New-onset cerebral or visual disturbances

Question 71

Effects at what ranges for magnesium

Answer 71

Therapeutic range: 5-9 >5-10 depressed cardiac conduction, widened QRS, and prolonged PR intervals on ECG >7 Hypotension, bradycardia, vasodilation Deep tendon reflexes are reduced at magnesium levels >5 mg/dL and are lost at >12 mg/dL. Muscle weakness (can cause blurred vision), and hypoventilation (reflecting diaphragm weakness) occur at magnesium levels of 7-12 mg/dL. 15-20 Resp arrest >25 asystole

Question 72

How is magnesium cleared

Answer 72

Patients with renal failure are more prone to hypermagnesemia, as excretion of magnesium is directly correlated to glomerular filtration rate.

Question 73

Terbutaline

Answer 73

Terbutaline is a tocolytic used to produce uterine muscle relaxation, thus facilitating intrauterine version procedures.

Question 74

Carboprost

Answer 74

Carboprost tromethamine (15-methyl prostaglandin F2α) is a uterotonic used to increase uterine muscle tone following delivery.

Question 75

What is hemabate called

Answer 75

Carboprost

Question 76

Carboprost contraindications

Answer 76

pulm hypertension | reactive airway disease (bronchospasm, increased intrapulm shunt, hypoxemia)

Question 77

Carboprost mechanism

Answer 77

increase in myometrial free calcium concentration

Question 78

Terbutaline side effects

Answer 78

A side effect of terbutaline is tachycardia and pulmonary edema (beta1-agonist effects)

Question 79

Resp changes in the parturient

Answer 79

Expiratory reserve volume, functional residual capacity, and total lung capacity all see a decrease as the fetus nears the term. The vital capacity, which includes inspiratory reserve volume, tidal volume, and expiratory reserve volume, remains unchanged as there is a concomitant increase in the inspiratory reserve volume and tidal volume that occur to accommodate an increased minute ventilation for the increase in oxygen demands. Respiratory changes in the parturient include a cephalad movement of the diaphragm with a concomitant increase in the anteroposterior and transverse diameter of the thoracic rib cage. There is a decrease in the functional residual capacity and its components as well as an increase in the inspiratory reserve volume. Airway resistance remains relatively unchanged.

Question 80

Uterine rupture vs dehiscence

Answer 80

Dehiscence is a wall defect that does not result in hemorrhage or fetal distress. This condition, therefore, does not warrant emergency surgical intervention. Uterine rupture can be a catastrophic event in which the integrity of the entire thickness of the myometrial wall is compromised. This condition can result in hemorrhage and fetal distress, therefore mandating emergency surgical intervention. Rupture of a uterine scar carries increased morbidity and mortality to both mother and fetus. This is largely because of the vascularity of and placental implantation within the anterior uterine wall.

Question 81

Alveolar dead space increase or decrease in active labor and why

Answer 81

Reduced secondary to increase in cardiac output

Question 82

renal insufficiency labs in pregnant women

Answer 82

A serum creatinine concentration greater than 0.8 mg/dL and a blood urea nitrogen concentration greater than 13 mg/dL (which are normal values for the nonpregnant patient) suggest renal insufficiency in the pregnant woman.

Question 83

Normal fibrinogen levels

Answer 83

Normal fibrinogen levels are about 225-500 mg/dL

Question 84

Risk factors for failed neuraxial anesthesia during cesarean delivery include

Answer 84

Risk factors for failed neuraxial anesthesia during cesarean delivery include increasing maternal size, late labor epidural placement, and a rapid decision-to-incision interval.

Question 85

Initial treatment for hypermagnesemia

Answer 85

Initial treatment for hypermagnesemia in the face of hemodynamic compromise or extreme muscle weakness is calcium chloride or gluconate. Dialysis is the definitive treatment but may take a long time to institute.

Question 86

APGAR score

Answer 86

skin color - blue; blue extrem, pink chest; pink heart rate - absent; <100; >100 reflex irritability - no response; feeble cry w stim; strong response w stim muscle tone - none; some flexion; active respiratory effort - absent; weak or irregular; strong and regular

Question 87

amniotic fluid embolism 2 phases result of

Answer 87

AFE is divided into two phases: cardiovascular collapse followed by consumptive coagulopathy immune response to amniotic fluid in maternal pulm vasculature

Question 88

Polyhydramnios | associated with

Answer 88

Polyhydramnios is increased amniotic fluid volume. It occurs in 1% of pregnancies and is associated with increased fetal urine production or fetal structural abnormalities preventing fetal swallowing. Polyhydramnios is associated with preterm labor and premature rupture of membranes as well as postpartum uterine atony. Other causes include neuromuscular disease inhibiting fetal swallowing, maternal diabetes, congenital infections, fetal anencephaly, fetal trisomies, and twin gestation with twin-to-twin transfusion syndrome.

Question 89

maternal ACE-i use ass'd with ____hydramnios

Answer 89

oligo

Question 90

The treatment of choice for polyhydramnios is

Answer 90

The treatment of choice for polyhydramnios is indomethacin

Question 91

Factors that increase spread of epidural

Answer 91

``` Increased volume of the injectate, positive airway pressure, lateral/Trendelenburg position, and increased age all generally increase the epidural spread of local anesthetics. Of these, the volume of injection has the most significant impact. ```

Question 92

Speed of injection effect on epidural

Answer 92

Speed of injection appears to impact the onset rather than the spread of local anesthetic.

Question 93

``` Changes in pregnancy Cardiac Output Heart Rate Stroke Volume Intravascular Volume Central Venous Pressure Plasma Volume Red Blood Cell Mass Systemic Vascular Resistance ```

Answer 93

Cardiac Output Increased 40-50% Heart Rate Increased 15-25% Stroke Volume Increased 30% Intravascular Volume Increased 35% Central Venous Pressure No Change Plasma Volume Increase 45% Red Blood Cell Mass Increased 20% Systemic Vascular Resistance Decreased 15-20%

Question 94

The major disadvantage of a paracervical nerve block during labor is

Answer 94

The major disadvantage of a paracervical nerve block during labor is a high frequency of fetal bradycardia associated with decreased fetal oxygenation and fetal acidosis.

Question 95

Run a code on OB

Answer 95

American Heart Association guidelines recommend beginning perimortem cesarean (resuscitative hysterotomy) at four minutes and completing delivery of the fetus by five minutes following cardiac arrest. Manual left uterine displacement should be performed during resuscitation, including during the performance of perimortem cesarean until the fetus is delivered.

Question 96

Risk factors for placenta accreta

Answer 96

``` Advanced maternal age multiparity prior uterine surgery placenta previa smoking multiparity previous myometrial tissue (previous myomectomy or Asherman syndrome) ``` However, the number one risk factor is previous cesarean section with the placenta overlying the surgical scar.

Question 97

placenta accreta management

Answer 97

Management is planned preterm cesarean section with the placenta left in situ.

Question 98

Fetal heart rate variability is primarily determined by the

Answer 98

Fetal heart rate variability is primarily determined by the parasympathetic tone of a fetus and is decreased during periods of CNS depression.

Question 99

Variable decelerations characterized by:

Answer 99

Characteristics of variable deceleration: 1) Visually apparent abrupt decrease in FHR occurs 2) Abrupt FHR decrease is defined as from the onset of the deceleration to the beginning of the FHR nadir of less than 30 seconds 3) The decrease in FHR of 15 bpm or greater occurs, lasting 15 seconds or longer and less than 2 minutes in duration 4) When the variable decelerations are associated with uterine contractions, their onset, depth, and duration commonly vary with successive uterine contractions

Question 100

Significance of decelerations: early late variable

Answer 100

Early decelerations are unrelated to fetal oxygenation while late and variable decelerations are related to interrupted fetal oxygenation.

Question 101

Things that cause uterine distention make breech presentation more or less likely

Answer 101

more

Question 102

most common causes for delay in latent phase of labor

Answer 102

An unripe cervix and false labor are two of the most common causes for a delay in the latent phase of labor.

Question 103

Regional anesthesia and delay of labor

Answer 103

The controversy of whether regional anesthesia delays the latent phase of cervical dilation continues. Most controlled studies have not shown a significant prolongation of labor in the latent phase or active phase with regional anesthesia

Question 104

High-dose oxytocin metabilic derrangement

Answer 104

High-dose oxytocin has antidiuretic and natriuretic effects which can cause hyponatremia. (similar structure to vasopressin)

Question 105

oxytocin structurally similar to

Answer 105

Due to structural similarities between oxytocin and vasopressin, high-dose vasopressin administration can cause uterine contractions.

Question 106

Fetal acidosis and local anesthetics

Answer 106

Local anesthetics are basic drugs that cross placental membranes via simple diffusion. Fetal acidosis promotes conversion of the nonionized form of local anesthetic into the ionized form. As ionized drugs do not easily cross the placental membrane, this leads to accumulation of local anesthetic within the fetus, a phenomenon called “ion trapping.”

Question 107

ABG in pregnancy

Answer 107

Increased minute ventilation in pregnancy causes a respiratory alkalosis as PaCO2 falls to approximately 30 mmHg. An incomplete compensatory metabolic acidosis (bicarbonate falls to 20-21 mEq/L) means pH will rise slightly (around 7.44). Increased alveolar ventilation also leads to an increase in PaO2 (to 105-107 mmHg) early in pregnancy although this will slowly decline back towards normal as pregnancy progresses.

Question 108

Volatiles effect on uterus in pregnancy | N2O

Answer 108

All volatile halogenated agents cause a dose-related relaxation of uterine smooth muscle. Nitrous oxide has no effect on uterine muscle tone. The concentration of sevoflurane and desflurane required to decrease myometrial contractility by 50% varies from 0.8 MAC to 1.7 MAC. In comparison, the same decrease is seen with isoflurane with MAC values of approximately 2.4.

Question 109

d-dimer in pregnancy

Answer 109

increased

Question 110

INR peak after donor hepatectomy

Answer 110

INR increases following donor hepatectomy, peaking on POD 1-3, which should be considered prior to epidural administration.

Question 111

Cause of shivering during labor

Answer 111

Shivering during labor occurs irrespective of whether neuraxial anesthesia is employed. It is more likely to occur in patients who have had neuraxial anesthesia and it may be secondary to changes in body temperature, although the pathophysiology is not completely understood and non-thermoregulatory factors may contribute.

Question 112

The supine position for pregnant patients near term may result in

Answer 112

The supine position for pregnant patients near term may result in aortocaval compression. Supine hypotensive syndrome results from partial or complete occlusion of the inferior vena cava, causing decreased venous return to the right ventricle. Partial compression of the aorta may also occur, causing increased blood pressure in the maternal upper extremities and hypotension in the lower extremities.

Question 113

Oligohydramnios what % of pregnancies what abnormalities what med can cause it

Answer 113

Oligohydramnios occurs in 4% of pregnancies and is associated with fetal lung hypoplasia and musculoskeletal abnormalities. ACE inhibitor use has been linked to developing oligohydramnios and should be avoided in pregnancy.

Question 114

Maternal administration of magnesium

Answer 114

Maternal administration of magnesium can have profound effects on the neonate, such as hypotonia, depressed respiratory drive, and poor feeding (secondary to poor sucking capabilities related to generalized weakness). Care is largely supportive.

Question 115

The following methods can be used for pain relief in the first stage:

Answer 115

The following methods can be used for pain relief in the first stage: epidural, spinal, paracervical block, CSE, and remifentanil infusion if regional or nerve block is contraindicated. However, it should be noted that spinal local anesthetics may wear off before delivery thus opioid spinal injections may be beneficial.

Question 116

The following methods can be used for pain relief in the second stage of labor:

Answer 116

The following methods can be used for pain relief in the second stage of labor: spinal, epidural, CSE, and pudendal block.

Question 117

Drugs that don't cross the placenta

Answer 117

``` tHINGS Heparin Insulin NDNMB Glycopyrolate Sux ...also phenylephrine ```

Question 118

what dermatomes need to be blocked for c section stage 1 labor stage 2 labor

Answer 118

Adequate neuraxial anesthesia for a cesarean section is best achieved through sensory blockade of the T4-S4 dermatomes. For adequate analgesia for stage I labor, the T10-L1 dermatomes should be covered. The second stage of labor requires additional coverage at S2-4.

Question 119

The risk factors for bradycardia with spinal

Answer 119

The risk for, and severity of, bradycardia increases with higher block height and occurs via several different mechanisms. First, blockade of the sympathetic cardiac accelerator fibers at T1-T4 can decrease baseline heart rate. Second, decreases in preload triggers several downstream effects including vagally-mediated reflexes which slow the heart rate in response to central volume depletion, or the Bezold-Jarisch reflex, which causes bradycardia in response to decreased cardiac filling pressures. Additional risk factors for bradycardia include age < 50, ASA 1 physical status, baseline heart rate < 60, and concurrent β-blocker use. Again, it should be noted that the risk factors for cardiac arrest include ASA physical status 1 patients who are young.

Question 120

Meralgia paresthetica in pregnancy

Answer 120

Meralgia paresthetica (MP) is entrapment of the LFCN, associated with burning pain over the distribution. Pregnant women often present with MP following prolonged labor. The LCFN may be impinged against the inguinal ligament while their legs are in stirrups.

Question 121

fibrinogen in pregnancy

Answer 121

Pregnancy is a state of hypercoagulability with a most notable increase in the levels of fibrinogen, up to double the concentration, in order to limit postpartum hemorrhage.

Question 122

what coag factors increase in pregnancy

Answer 122

Factors that increase include I (fibrinogen), VII, VIII, IX, X, XII, and von Willebrand factor which peak at the time of parturition.

Question 123

what coag factors decrease in pregnancy

Answer 123

Factors that decrease include XI, XIII, antithrombin III, and tPa Also, resistance to activated protein C occurs as well as a decline in the level of protein S.

Question 124

what happens to PLTS, red cell mass, plasma volume in pregnancy

Answer 124

A dilutional and consumptive thrombocytopenia occurs which usually results in a decrease of 10% in platelet count. About 6-15% of pregnant patients have a platelet count of less than 150 * 10^9/L. Other hematologic changes that occur include an increase in red blood cell mass of 20-30% and an increase in plasma volume of 40-50% resulting in dilutional anemia

Question 125

contraindications to the 2 common second line uterotonics

Answer 125

Several second-line therapies exist to help control postpartum hemorrhage due to uterine atony. Being aware of these contraindications - methylergonovine in coronary artery disease and preeclampsia/eclampsia ( it can cause coronary artery spasm and systemic vasoconstriction that increases systemic hypertension.), and carboprost in asthma ( because it increases pulmonary vascular resistance that can cause pulmonary hypertension and induces bronchoconstriction) - is essential to providing appropriate anesthetic care.

Question 126

define fetal tachycardia

Answer 126

160+

Question 127

magnesium levels at which loss of deep tendon reflexes

Answer 127

10-12

Question 128

name 3 things ass'd with PDPH

Answer 128

tinnitus, diplopia, CN VII palsy

Question 129

what stage of labor corresponds to greatest increase in cardiac output

Answer 129

stage 3

Question 130

fibrinogen in pregnancy

Answer 130

this card said decreased but i think that is wrong

Question 131

5 minute apgar score ass'd with

Answer 131

neurologic outcome

Question 132

3 risk factors for uterine atony

Answer 132

long labor, macrosomia, polyhydramnios

Question 133

Which of the following maternal treatments will MOST LIKELY benefit a fetus when given for preterm labor without rupture of membranes?

Answer 133

Corticosteroid therapy has been shown to improve neonatal outcome and magnesium therapy has been shown to provide some fetal neuroprotection when used in the setting of preterm labor. Tocolytic therapy is not advocated for routine use except to prolong pregnancy long enough to allow for corticosteroid administration.

Question 134

Treatment of hypermagnesemia includes

Answer 134

Treatment of hypermagnesemia includes 1) stopping the source of magnesium, 2) antagonizing the effects of magnesium with calcium, and if moderate or severe 3) increasing elimination of magnesium with loop diuretics or possibly hemodialysis.

Question 135

Fetal acidemia

Answer 135

Fetal acidosis may be assessed through fetal scalp blood gas analysis. Lactate or pH levels that fall in the range for fetal acidemia may prompt obstetricians to consider transitioning to emergent operative delivery, especially in the setting of non-reassuring fetal heart monitoring. Fetal acidemia is defined as pH < 7.21 or lactate > 4.8 mmol/L.