Final Review Flashcards
Pregnancy is a normal physiologic state, and physiological parameters in pregnancy are altered—T/F
True
MAC is ___ (increased/decreased) in pregnancy
Decreased
Pregnancy causes ___ (increased/decreased) sensitivity to local anesthetics
Increased
Ventilation in pregnancy is ___ (increased/decreased)
Increased
Tidal volume is increased ___% at term
40%
Respiratory rate ___ (increases/decreases) during pregnancy
Increases—15%
Minute ventilation is ___ (increased/decreased) during pregnancy
Increased—50%
PaCO2 ___ (increases/decreases) during pregnancy to ___-___ mm Hg
Decreases to 28-32 mm Hg
PaCO2 decreases during pregnancy d/t ___ventilation, respiratory ___osis,
Hyperventilation, respiratory alkalosis
Body compensates to respiratory alkalosis during pregnancy by excreting ___ ions to maintain a normal pH…this leads to ___ (what acid-base balance?)
Bicarbonate ions; leads to metabolic acidosis
Expanding uterus pushes the diaphragm ___
Cephalad (up towards head)
FRC decreases by ___% in pregnancy
20%
There are no changes in vital capacity or total lung capacity during pregnancy—T/F?
True
FRC ___ (increases/decreases) during pregnancy
Decreases
Maternal oxygen consumption ___ (increases/decreases) during pregnancy
Increases
Decrease in FRC and increase in maternal O2 consumption makes it more likely for mom to develop maternal ___ during induction of general anesthesia
Maternal hypoxia
Need to ___ prior to induction because there is such a high risk of maternal hypoxia
Pre-oxygenate/denitrogenate
P50 of hemoglobin ___ (increases/decreases) from ___ to ___ mm Hg
Increases from 27 to 30 mm Hg
Increase in P50 of hemoglobin during pregnancy allows for ___
Oxygen delivery to the fetus
Dead space in pregnancy is ___ (increased/decreased)
Decreased
Airway resistance in pregnancy is ___ (increased/decreased)
Decreased
Congestion of respiratory mucosa occurs during pregnancy secondary to vasodilation—T/F?
True
Lots of soft tissue in the neck, chest, and breasts may cause obstruction and difficulty placing laryngoscope properly; a shorter laryngoscope handle should be available for use—T/F?
True
Mucosal venous engorgement/edema creates risk for bleeding in airway with intubation—T/F?
True
Nasal instrumentation should be avoided in pregnant patients—T/F?
True
Larger ETTs should be used for pregnant women—T/F?
False…want to use SMALLER ETT—6.5, 7.0, or 7.5 ETT
What induction technique should be used to prevent maternal hypoxia?
Rapid sequence induction with cricoid pressure
Goal is to maintain ___carbia during general anesthesia
Normocarbia
Avoid ___ventilation because decreased PaCO2 will cause uterine vaso___; ___ (increased/decreased) placental blood flow; and metabolic ___ in the mother
Avoid hyperventilation; cause uterine vasoconstriction; decreased placental blood flow; metabolic alkalosis in the mother
Metabolic alkalosis in the mother will shift the oxyhemoglobin curve to the ___, so maternal hemoglobin will ___
To the left, so maternal hemoglobin will hold onto oxygen and not release it to the fetus
Plasma volume ___ (increases/decreases) during pregnancy by ___%
Increases by 45%
RBC volume ___ (increases/decreases) by ___%
Increases by 20%
Sodium/water retention occurs in pregnant patients—T/F?
True
Pregnant patients are hypervolemic—T/F?
True
Cardiac output ___ (increases/decreases) in pregnancy by ___%
Increases by 40%
HR ___ (increases/decreases) by ___%
Increases by 15-30%
Stroke volume ___ (increases/decreases) by ___%
Increases by 30%
In pregnancy, the oxyhemoglobin dissociation curve shifts to the ___
Right—so maternal hemoglobin releases O2 to be delivered to the fetus
Peripheral vascular resistance ___ (increases/decreases) in pregnancy by ___%
Decreases by 15%
Why does PVR drop in pregnancy?
Increased progesterone relaxes venous smooth muscle
Cardiac output change in latent (inactive) phase of labor = ___% increase
15% increase
Cardiac output change in active phase of labor = ___% increase
30% increase
Cardiac output change in second stage of labor = ___% increase
45% increase
Cardiac output change postpartum = ___% increase
80% increase
Pregnant women’s response to adrenergic drugs is increased—T/F?
False—response to adrenergic drugs is blunted in pregnancy
CXR will show cardiac hypertrophy during pregnancy—T/F?
True
Heart murmurs auscultated during pregnancy are a cause of concern—T/F?
False—heart murmurs are common on auscultation in pregnant women
Systolic murmurs are ___
Normal
Diastolic murmurs are ___ if heard
Pathologic
S3 heart sound may be heard during pregnancy—T/F?
True
There is a ___ (increase/decrease) in plasma colloid osmotic pressure d/t relative hypervolemia that occurs during pregnancy
Decrease
Supine hypotension syndrome is aka ___
Aortocaval compression
Aortocaval compression syndrome occurs in ___% of term parturients when they lie flat
20%
Symptoms of aortocaval compression = ___tension, ___, ___, ___, ___
Hypotension, pallor, nausea, vomiting, diaphoresis
Can see symptoms of aortocaval compression as early as ___ weeks gestation
20 weeks
Treatment for aortocaval compression = place patient in ___ position
Left lateral uterine tilt position
Cell mediated immunity is ___ (increased/decreased) during pregnancy
Decreased
Pregnancy creates a hypercoaguable state, putting parturients at higher risk for PE—T/F?
True
Fibrinogen is ___ (increased/decreased) during pregnancy
Increased
PT and PTT ___ (increased/decrease) by ___%
Decrease by 20%
Renal blood flow/glomerular filtration are both ___ (increased/decreased) by 50% by the 16th week of pregnancy; remains ___ until delivery
Increased; remains elevated
Serum BUN and creatinine are mildly ___
Reduced—may see BUN 8, creatinine 0.5
Mild glycosuria/proteinuria is common in pregnancy—T/F?
True
Increased progesterone ___ (increases/decreases) gastroesophageal sphincter tone; displacement of the stomach by the uterus also ___ competence of the gastroesophageal sphincter
Decreases; reduces
___ (increased/decreased) risk of symptomatic aspiration during pregnancy
Increased
There is a 20% decrease in pseudocholinesterase levels in pregnancy, so the amt of succs administered should be reduced—T/F?
True
Gallbladder becomes sluggish during pregnancy, can result in gallstones—T/F?
True
Albumin levels are increased in pregnancy—T/F?
False—decreased albumin levels, affects protein-bound drugs
Insulin resistance occurs during pregnancy d/t higher plasma glucose levels in the parturient—T/F?
True
Oxygen transfer between mom and baby depends on mom’s ___ blood flow and fetal ___ blood flow
Mom’s uterine blood flow and fetal umbilical blood flow
O2 has the smallest storage to utilization ratio in the fetus—fetus can store ___ ml of O2 and O2 consumption is ___ ml/min
Store 42 ml of O2 and O2 consumption is 21 ml/min
Placental blood PaO2 = ___ mm Hg
40 mm Hg
Mom has a ___ (left/right) shift in oxyhemoglobin curve
Right shift—releases O2 to fetus
Fetus has a ___ (left/right) shift in oxyhemoglobin curve
Left shift—accepts O2 from mom
Fetal hemoglobin is ___ (lower/higher) than maternal hemoglobin
Higher
Fetal hemoglobin has a ___ (lower/higher) affinity for CO2 than does maternal hemoglobin
Lower
Uterine blood flow is ___% of cardiac output— ___ ccs per min
10%—700 ccs per min
Under normal conditions, uterine blood flow is only ___ ccs per min
50 ccs per min
___% of uterine blood flow goes to the placenta; the rest goes to the myometrium (uterine muscle)
80%
What are (3) factors that influence uterine blood flow?—systemic ___, uterine ___, uterine ___
- Systemic BP
- Uterine vasoconstriction
- Uterine contractions
Propofol and thiopental mildly reduce UBF via maternal hypotension—T/F?
True
Induction agent dosages can be cut by 1/3-1/2 of the usual doses to minimize maternal hypotension—T/F?
True
Volatile agents ___ (increase/decrease) UBF secondary to hypotension
Decrease UBF
At < 1 MAC, hypotensive effects of volatile agents are minor—T/F?
True
Can keep volatile agents ___ MAC because pregnancy ___ (increases/decreases) MAC
< 1 MAC because pregnancy decreases MAC
Ketamine, nitrous oxide, and opioids have ___ effect on UBF
Little to no effect
High serum local anesthetic levels can result in uterine vaso___
Vasoconstriction
Goal is to maintain ___tension in pregnant mom so baby continues to get adequate blood flow via placenta
Normotension
Neuraxial analgesia ___ (increases/decreases) maternal catecholamine levels and reduces vasoconstriction, thus improving uterine blood flow
Decreases
Once baby is born, pulmonary vascular resistance [in the baby] ___ (increases/decreases) as oxygen enters the lungs
Decreases
If baby isn’t crying when born and still isn’t crying after stimulation, you need to initiate ___
Positive pressure ventilation
Hypoxia or acidosis will increase ___ shunting through the ductus in the newborn, creating a ___
Increase R to L shunting; creates a “downward spiral”
Downward spiral = ___ of the newborn
Persistent pulmonary hypertension of the newborn (occurs when baby is hypoxic/acidotic, blood backs up into R side of heart, causing pulmonary hypertension)
Stages of labor:
Stages 1, 2, and 3
Stage 1 of labor is divided into two phases—___ phase and ___ phase
Latent phase and active phase
Latent phase of labor = minor dilation of cervix ___-___ cm, ___ (frequent/infrequent) contractions
Minor dilation of cervix 2-4 cm, infrequent contractions
Active phase of labor = progressive dilation to ___ cm and ___ (regular/irregular) contractions every ___ to ___ minutes
Progressive dilation to 10 cm and regular contractions every 3 to 5 minutes
Stage 2 of labor = time from ___ until ___
Complete dilation until infant delivered
Stage 3 of labor = time from ___ until ___
Delivery of infant until placenta delivered
Ptocin (oxytocin) can ___ (increase/decrease) rate of contractions to every ___ to ___ minutes
Increase rate of contractions to every 1-1.5 mins
Uterine atony = uterus does ___ contract; risk for ___
Does not contract; risk for massive bleeding
Uterine atony can be caused by too much ___
Oxytocin (ptocin)
What is the most common complication of neuraxial blocks?
Nerve injury
Insertion and removal of epidural catheter should only occur when ___ is normal
Coagulation function
Always make sure that the tip of the catheter is ___ upon removal
Intact
In pregnant women with no history of bleeding problems, no signs/symptoms of PIH, not on anticoagulation, it is safe to proceed with neuraxial block—T/F?
True
Patients with PIH and neuraxial blocks—platelet count > ___ is required before proceeding with block; normal ___, ___ are also required
> 100k; normal PT, PTT are also required
If patient is on low molecular weight heparin, consider ___ instead of neuraxial block
IV analgesia
Avoid block for ___ hours if therapeutic on anticoagulation
24 hours
Avoid block for ___ hours if prophylactic anticoagulation
12 hours
Remove catheter at least ___ hours after last dose
At least 12 hours
Do not administer LMWH until ___-___ hours after block is placed or catheter is removed
2-4 hours
Avoid concurrent ___ or ___ with neuraxial blocks
NSAIDs or anticoagulants with neuraxial blocks
What are two main signs of epidural hematoma?—bilateral ___ weakness and ___ pain
- Bilateral leg weakness
- Back pain
What are two other signs of epidural hematoma? (think bowel/bladder)
- Incontinence
- Absent rectal sphincter tone
If epidural hematoma is suspected, patient must get a stat ___
CT/MRI
Surgical decompression of epidural hematoma must occur within ___ hours for full neurological recovery to occur
6 hours
If an epidural abscess is present, can take ___-___ days for signs to occur
4-10 days
Treatment of epidural abscess = ___ and ___
Antibiotics and laminectomy
Treatment of epidural abscess—have ___-___ hour window before permanent damage ensues
6-12 hour
Epidural abscess s&s—severe ___ pain that is worse with ___
Severe back pain that is worse with flexion
Epidural abscess s&s—exquisite ___ tenderness
Local
Epidural abscess s&s—___, ___, meningitis-like ___ with ___ stiffness
Fever, malaise, meningitis-like headache with neck stiffness
Lab changes with epidural abscess—___ WBC, ___ ESR, ___ blood culture
Increased WBC, increased ESR, positive blood culture
Transient neurological symptoms (TNS) = pain and dysthesia in ___, ___, or ___ that can follow a subarachnoid block, resolves within ___ hours
Pain and dysthesia in buttocks, legs, or calves that can follow a SAB, resolves within 72 hours
Dysthesia = abnormal ___
Sensation—can be aching, burning, prickling feeling
TNS is most commonly caused by ___ spinals
Lidocaine—more common with high doses of concentrated lidocaine 5%
Compression injuries are very common d/t ___ position
Lithotomy
Post-dural puncture headache = ___ headache
Spinal headache
Spinal headache is throbbing, postural***, with variable distribution—T/F?
True
Onset of spinal headache is typically ___-___ hours after dura puncture
12-48 hours
Duration of spinal headache
Few days to weeks
___ gauge and ___ needles increase PDPH incidence
Larger gauge and cutting edge needles
___ point needles are significantly better than ___ tip needles because dura fibers are not cut but just pushed apart
Pencil point needles are better than cutting tip needles
Hallmark sign of PDPH =
Continuous headache when in upright position (i.e.: sitting or standing)
Relief from PDPH only comes when ___
Laying completely flat
Non-invasive treatment of PDPH =
Bed rest
Most PDPH resolve within ___ week
1
Other non-invasive treatment modalities for PDPH include PO, IV, epidural analgesics—i.e.: NSAIDs, acetaminophen, opioids; cerebral vasoconstrictors—i.e.: PO/IV caffeine, theophylline, sumatriptan—T/F
True
Definitive treatment of PDPH = ___
Epidural blood patch
What is this describing?—epidural space is identified and 15-20 ccs of patient’s own blood is injected into the epidural space; clotting factors in the blood help seal the hole in the dura; try to inject at the same level as the initial dural puncture
Epidural blood patch
Epidural blood patch—start slow and stop either when patient says headache is gone or they have a pressure sensation in the ears—T/F?
True
What is the most common cause of perioperative headache?
Caffeine withdrawal
Total spinal anesthesia = ___tension, ___nea, ___nia
Hypotension, dyspnea, aphonia
Management of total spinal—place patient in ___ position
Left uterine displacement/trendelenburg position
Treatment of total spinal—early resuscitation, ventilation, and circulatory support are essential; epi may be needed; intensive maternal/fetal monitoring are crucial—T/F?
True
Management of total spinal—can give naloxone for intraspinal opioid—T/F?
True
Urgent C-section is mandatory for treatment of total spinal—T/F?
False—NOT mandatory—decision is based on fetal assessment after maternal stabilization
OB population is at increased risk for ___
Aspiration
Aspiration is high risk in parturients because they have more ___ which causes smooth muscle ___; gastric sphincter is ___
Progrestrone; smooth muscle relaxation; gastric sphincter is relaxed
Moms have ___ (slower/faster) gastric emptying
Slower
Moms have ___ (higher/lower) gastric pH
Lower
Suspect ___ with hypoxia, pulmonary edema, bronchospasm
Aspiration
Aspiration prevention in parturients = ___ pressure
Cricoid pressure (Sellick’s maneuver)
Aspiration prevention—elective C-section patients should fast for at least ___ hours, even if regional is planned
6 hours
Always assume a ___ stomach in parturients
Full
Sodium citrate can be given to ___ gastric pH; works within ___; lasts ~___ mins
Raise gastric pH; works within minutes; lasts ~30 mins
H2 blockers take at least ___ minutes to work
30 minutes
Reglan facilitates ___, requires ___-___ minutes
Gastric emptying, requires 40-60 mins
Pain pathways—1st stage of labor—pain source is primarily ___
Lower uterine segment from contractions (T10-L1)
Pain pathways—2nd stage of labor—pain source is ___ structures via ___ nerve
Perineal structures via pudendal nerve (S2-S4)
All opioids cross the placenta and depress the fetus—T/F?
True
___ provides great satisfaction scores, less neonatal depression, less nausea, less risk of maternal respiratory depression
PCA
This medication causes increased risk of respiratory depression for neonate d/t immature BBB and is not often used
Morphine
This medication onset is 5 minutes; has a very long half-life of 18-23 hours; respiratory depression can be avoided if this medication is given less than 1 hour before delivery; has active metabolites; causes frequent nausea, vomiting; do NOT give to patients with seizure history or renal failure
Meperidine (Demerol)
This medication is 100x more potent than morphine; onset is 3-5 minutes; rapid transfer across the placenta; respiratory depression may outlast analgesia; you can give a loading dose of this medication through PCA
Fentanyl
This medication is a mu opioid antagonist, kappa agonist; there is a ceiling effect on respiratory depression from this medication but there is no difference in side effects; great for helping mom get through the worst of her contractions; only lasts 45 mins-1 hour
Nalbuphine (Nubain)
Nalbuphine (Nubain)—___ is common with this medication
Dysphoria
Nalbuphine (Nubain) can be used to treat ___
Opioid pruritis
Some reports suggest that this medication offers better analgesia than fentanyl; sedation is common; there is a ceiling effect on respiratory depression
Butorphanol (Stadol)
Meperidine (demerol) has a very long half life of ___-___ hours
18-23 hours
Meperidine (demerol)—respiratory depression can be avoided if this medication is given ___ hour before delivery
1
Meperidine (demerol) has ___
Active metabolites
Meperidine (demerol) should NOT be given to patients with ___ history or ___ failure
Seizure history or renal failure
___ block can be used during the 1st stage of labor; risks include accidental injection into uterine artery, fetal local anesthetic toxicity, nerve injury, or hematoma
Paracervical block
___ block can be used during the 2nd stage of labor; good for patients with contraindications to neuraxial block; needle is placed transvaginally under ischial spines; risks include injury, infection, hematoma
Pudendal block
Local anesthetics—amino ___ are derivatives of PABA (known allergen); metabolized by plasma cholinesterase; examples include cocaine, procaine, chlorpromazine, tetracaine
Esters
Local anesthetics—amino ___ are metabolized by the liver; no PABA; true allergies are rare; examples include lidocaine, bupivacaine, prilocaine, ropivacaine, etidocaine
Amides
Local anesthetics—lipid solubility = ___
Potency
Local anesthetics—the more lipid soluble, the more ___ diffusion
Placental
Local anesthetics—protein binding influences ___…increased protein binding = ___ (shorter/longer) duration
Duration of action…increased protein binding = longer duration
Local anesthetics—high protein binding ___ (increases/decreases) placental transfer
Decreases
Local anesthetics are weak ___
Bases
Local anesthetics work on the ___ channel
Sodium
PKA =
50% ionized, 50% nonionized
PKA determines the ___
Speed of onset
The closer the pKa to the physiologic pH, the ___ the onset
Faster
Can add ___ to artificially raise the pH and speed the onset of action
Sodium bicarbonate
Increasing dose of local anesthetic given = ___ onset, ___ duration
Faster onset, longer duration
Vasoconstrictors given with local anesthetics prevents ___ absorption
Vascular absorption
Increasing temperature of LA ___ onset time
Reduces
In pregnancy, should use ___ (more/less) local anesthetic; there will be a ___ onset of blockade, possibly due to progesterone
Less local anesthetic; there will be a faster onset of blockade
Bupivacaine, ropivacaine, and lidocaine should be used for ___ epidural anesthesia
Labor
Lidocaine and 2-chloroprocaine should be used for ___ epidural anesthesia
Operative
Tetracaine and bupivacaine should be used for ___ anesthesia
Spinal
This LA is used for labor epidural anesthesia; not used as a continuous infusion; can be useful as a top off and to test the function of an epidural catheter; used to activate epidural catheter for c-section; results in a lot of motor block; 45 min DOA
Lidocaine
This LA is used for epidural c/s; this is the only ester local used in epidural space; rapid onset, very short duration; results in lots of motor block; low risk of toxicity; very rapidly metabolized in the blood by pseudocholinesterase; do not use for spinals
2-chloroprocaine
2-chloroprocaine is contraindicated in patients with ___
Atypical pseudocholinesterase
This LA is used for epidural labor; long duration; less motor block than most other agents; produces refractory Vtach/VF if large IV dose is given accidentally
Bupivacaine
This LA is the L isomer of bupivacaine; less cardiotoxic; new drug; NOT approved for spinal
Levobupivacaine
This LA is less cardiotoxic than levobupivacaine; 25% less potent than bupivacaine; NOT approved for spinal
Ropivacaine
Epidurals should be dosed ___
Incrementally—every dose is a test dose!
___ is sometimes used as test dose for epidural
Epi
For OB epidural analgesia, it is best to cover ___-___ dermatomes
T10-S4
