Term
| Who performed the first OB anesthetic? |
|
Definition
James Young Simpson using ether on Jan 19th 1847.
He also loved to use chloroform |
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Term
| This man was opposed to anesthesia for OB because abolishment of pain would hinder the efforts of the woman to effectively push during contractions. |
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Definition
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Term
| Who was the first physician anesthetist? |
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Definition
| John Snow. He used chloroform on Queen Victoria during the birth of prince Leopold and princess Beatrice |
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Term
| Who performed the first OB anesthetic in the U.S.? |
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Definition
| Nathan C. Keep. He used Ether 4/7/1847 |
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Term
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Definition
| He used ether in 1847 on his wife for labor |
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Term
| How much blood flow does the uterus receive toward term? |
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Definition
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Term
| What is the significance of capillary engorgement (d/t inc. blood volume) on the airway? |
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Definition
| Makes the airway smaller. Use smaller ETT |
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Term
| T/F. Progesterone causes tracheal and bronchial constriction. |
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Definition
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Term
How does pregnancy affect the following:
a. minute ventilation
b. alveolar ventilation
c. tidal volume
d. respiratory rate |
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Definition
a. inc. 50%
b. inc. 70%
c. inc. 40%
d. inc. 15% |
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Term
how does pregnancy affect the following:
a. PaO2
b. inspiratory lung capacity
c. O2 consumption
d. anatomic dead space
e. PaCO2 |
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Definition
a. inc. 10%
b. inc. 5-15%
c. inc. 20%
d. No change
e. dec. 10 mmHg |
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Term
How does pregnancy affect the following:
a. lung compliance
b. arterial pH
c. vital capacity
d. FEV1
e. Peak expiratory flow |
|
Definition
a. no change
b. no change
c. no change
d. no change
e. no change |
|
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Term
how does pregnancy affect the following:
a. maximum breathing capacity
b. closing volume
c. alveolar dead space
d. airway resistance
e. total pulmonary resistance
f. chest wall compliance
g. total compliance |
|
Definition
a. no change
b. no change
c. no change maybe a SLIGHT decrease
d. dec. 36%
e. dec. 50%
f. dec. 45%
g. dec. 30% |
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Term
How does pregnancy affect the following:
a. serum bicarb
b. total lung capacity
c. FRC
d. ERV
e. residual volume |
|
Definition
a. dec. 4 mEq/L
b. dec. up to 5%
c. dec. 15-20%
d. dec. 20%
e. dec. 20% |
|
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Term
| What happens to inspiratory capacity during pregnancy? What is its effect on FRC? |
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Definition
| IC increases by ~15% during third trimester d/t inc. Vt and inc. IRV. This causes FRC to decrease by ~20% |
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Term
| T/F. Progesterone is a resp. stimulant. |
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Definition
| TRUE. so pregnant women sensitive to CO2 |
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Term
A) How does pregnancy affect oxyhemoglobin dissociation curve?
B) would ABG of preg. woman reflect hyperventilation or hypoventilation? |
|
Definition
causes shift to right (releases O2 to tissues) this is GOOD.
B) Hyperventilation |
|
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Term
| How does CO2 affect uteroplacental circulation? |
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Definition
| hypocapnia will cause vasocontriction which will decrease perfusion to fetus |
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Term
| How does pregnancy affect ABG? |
|
Definition
| PaCO2 drops to 30 (resp alk) and HCO3 drops to 20 (met. acidosis) to compensate. Net effect is a slight inc. in pH from 7.4 to 7.44 |
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Term
| What are the fetal effects of maternal hyperventilation? |
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Definition
| hypocapnia, Constriction of uterine arteries, fetal acidosis, and a shift in OHD curve to LEFT (d/t alkalosis) |
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Term
| What is the bodies protective mechanism to resp. alkalosis that prevents OHD curve shift to left? |
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Definition
| Decreased plasma bicarb. and increased 2,3 DPG levels. |
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Term
| How does pregnancy affect CO? Why? |
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Definition
| CO is increased (+50%) d/t increased SV (+25%) during first half of preg. and BOTH increased SV and HR (+25%) during second half. |
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Term
| Why does stroke volume increase during pregnancy? |
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Definition
| Blood volume is increased (RBC +20% and plasma +45%). The higher inc. in plasma volume causes a dilutional anemia called "physiologic anemia of pregnancy." |
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Term
| **When is CO at its highest?** |
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Definition
| First hour after delivery |
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Term
| How well is blood loss tolerated in the pregnant woman? |
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Definition
| It is physiologically tolerated d/t increased blood volume |
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Term
| What is the average blood loss for vaginal and cesarean deliveries? |
|
Definition
vaginal: 300-500 mL
cesarean: 500-1000 mL |
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Term
| elevated diaphragm causes displacement of heart to ____ with ______ axis deviation. |
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Definition
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Term
| What are the most common dysrhythmias assoc. with pregnancy? |
|
Definition
| PAC's, PVC's, and sinus tach. |
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Term
|
Definition
Two components:
1. IVC compression which occurs after 24 wks gestation. Venous return occurs by diversion thru azygos vein/paravertebral system. There is also compensatory increase in sympathetic tone and HR
2. Aortoiliac obstruction- no maternal symptoms, however placental blood flow decreases. Femoral BP will be much lower than brachial BP |
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Term
| What is a common thing done in obstetric anesthesia that exaggerates supine hypotensive syndrome? |
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Definition
| regional anesthesia (sympathectomy) |
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Term
A) What happens to plasma protein concentration during pregnancy?
B) What happens to WBC count?
C) What happens to clotting factor concentration? |
|
Definition
A) decreases which decreases plasma oncotic pressure-- pulm edema
B) Increases
C) All factors inc. except XI and XIII which leads to hypercoagulability.
Fibrinolysis also is enhanced |
|
|
Term
| Why does the pregnant woman become hypercoagulable? |
|
Definition
| It is a mechanism to prevent excessive blood loss during placental separation. However it increases risk of VTE |
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Term
| What are the changes in GI physiology during pregnancy? |
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Definition
| 1. stomach is displaced upward toward left side of diaphragm and axis is rotated 45 degrees. 2. Leads to decreased tone of lower esophageal high pressure zone + progestins= GI reflux 3. Gastric contents are more acidic (especially during labor) |
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Term
| T/F. ALL pregnant patients, regardless of wks. gestation should be treated as FULL STOMACH. |
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Definition
| FALSE. Should be considered full stomach from 8 wks gestation to 6 wks post partum |
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Term
| What agents can be used for aspiration prophylaxis? |
|
Definition
| H2 blocker (pepcid, zantac), reglan, sodium citrate (Bicitra) 0.3M every 3 hours |
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Term
| How should the airway be managed in the pregnant patient for surgery? |
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Definition
| Rapid sequence induction (with cricoid), avoid nasal intubation, awake extubation, smaller ETT. |
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Term
| How does pregnancy affect the renal system? |
|
Definition
1. ureters & pelvis dilate starting at week 12 which causes a state of hydronephrosis
2. RBF & GFR increase 50%
3. protein/albumin excretion increases
4. glucose (glycosuria) & bicarb. excretion increases
5. high aldosterone levels cause an increase in total body Na and H2O
5. |
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Term
| Pregnancy does not normally cause renal problems, but if there are renal problems it is usually encountered with _________. |
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Definition
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Term
| How does pregnancy affect the hepatic system? |
|
Definition
1. minor increase in SGOT (AST) and LDH
2. decrease in plasma cholinesterase (clinically insignif.)
3. inc. in production of coag. factors |
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Term
| How does pregnancy affect the CNS? |
|
Definition
1. At term, there is enhanced sensitivity to local anesthetics during regional anesthesia d/t progesterone.
2. MAC is decreased (25% to 40%)
3. obstruction of IVC causes engorgement of epidural venous plexus which decreases potential volume of epidural space and dec. spinal CSF volume |
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Term
| What is the cause of decreased MAC during pregnancy? |
|
Definition
| increased progesterone and beta endorphins |
|
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Term
| How does pregnancy affect the endocrine system? |
|
Definition
1. pregnancy is diabetogenic: insulin resistance d/t increased human placental lactogen (aka human chorionic somatomamotropin)
2. HCG and estrogen responsible for thyroid hyperplasia (clinically insignificant) |
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Term
| T/F. Uterine vasculature is auto-regulated. |
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Definition
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Term
| When is the best time to give an IV medication during labor? |
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Definition
| During a contraction it causes less uteroplacental blood flow and less will get to fetus. |
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Term
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Definition
1. weighs about 500g 2. produces hormones to sustain pregnancy (progesterone) 3. protects fetus from the maternal immune system 4. allows for active and passive transport of nutrients & metabolites
5. respiratory gas exchange |
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Term
How do the following affect the fetus during pregnancy:
a. inhalational agents
b. induction agents
c. opioids
d. muscle relaxants
e. anticholinergics |
|
Definition
a. rapid transfer, no effect on fetus (<1 MAC)
b. no effect on fetus (except for benzos)
c. they readily cross placenta and can cause resp. depression of fetus. Morphine mostly, then meperidine. Fentanyl has little effect.
d. do not cross placenta (they are quats)
e. atropine and scopolamine easily cross placenta. Use Robinul instead |
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Term
How do the following affect the fetus:
a. anticholinesterase agents
b. antihypertensive agents and vasopressors
c. anticoagulants |
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Definition
a. neostigmine safe
b. ephedrine, beta blockers, and vasodilators are transferred to fetus
c. DO NOT give warfarin. Heparin is anticoagulant of choice |
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Term
|
Definition
relationship of long axis of fetus to long axis of mother
1. transverse: fetal axis is perpendicular (horizontal) to mother's axis. Vaginal delivery impossible
2. Longitudinal: fetal axis with mothers axis |
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Term
|
Definition
| portion of fetus overlying pelvic inlet. Either cephalic, breech, or shoulder |
|
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Term
|
Definition
relationship of fetal bony point to maternal pelvis.
vertex- occiput
breech- sacrum
face- mentum
shoulder- acromion |
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Term
|
Definition
1. from start of contractions until fully dilated
2. pain impulse: visceral afferent C fibers
3. Pain dermatomes: T11-T12 during early (latent) phase and T10-L1/L2 during active phase |
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Term
|
Definition
1. from full dilation to delivery of baby
2. distention of vaginal vault and perineum
3. Crowning of head to complete cervical dilation and delivery
4. Pain impulse: pudendal nerves thru posterior roots of parasymp. chain. Possible A-delta fibers (SOMATIC- sharp, more constant pain than visceral)
5. pain dermatomes: S2-S4 |
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Term
| T/F. Neonatology team must be present for delivery if the patient has received fentanyl? |
|
Definition
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|
Term
| Which opioid is associated with a lower incidence of N/V? |
|
Definition
|
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Term
| When would inhalational anesthesia for a vaginal delivery be indicated? |
|
Definition
1. Fetal distress
2. Uterine inversion- to relax uterus
3. breech manual removal of placenta
4. tetanic contractions |
|
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Term
| When would inhalational anesthesia for a vaginal delivery be indicated? |
|
Definition
1. Fetal distress
2. Uterine inversion- to relax uterus
3. breech manual removal of placenta
4. tetanic contractions |
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Term
|
Definition
1. used for analgesia during first stage of labor
2. technique: needle introduced into left or right lateral vaginal fornix (2-3mm into mucosa)then into other side
3. complications: fetal bradycardia is most common. There is also possible drug-induced uterine artery vasospasm causing decreased perfusion to fetus |
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Term
|
Definition
1. Used for analgesia during first stage of labor
2. bilateral block at level of L2 interrupts pain impulses to cervix, uterus, and upper 1/3 of vagina
3. landmarks: transverse process of L2 and psoas muscle
4. low risk of complications |
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Term
|
Definition
1. Analgesia during SECOND stage of labor.
2. 10ml of LA injected behind each sacrospinous ligament (thru vagina)
3. pudendal nerve arises from S2-S4 between the sacrospinous ligament and sacrotuberous ligament.
4. complications: vaginal and ischiorectal hematoma or abcess |
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Term
| T/F. Maternal request alone is sufficient indication for epidural anesthesia/analgesia. |
|
Definition
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Term
| What are the indications for epidural anesthesia in obstetrics? |
|
Definition
1. maternal request
2. anticipation of operative delivery (malpresentation, multiple gestation, etc.)
3. obstetric disease (preeclampsia, non-reassuring FHR tracing)
4. maternal conditions that complicate or contraindicate GA (morbid obesity, MH susceptible, difficult airway, etc.)
5. maternal coexisting disease (severe cardiac or resp disease) |
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Term
| What are the advantages of epidural anesthesia? |
|
Definition
1. reduces maternal catecholamine levels
2. blunts hyperventilation-hypoventilation syndrome
3. facilitates delivery of twins, breech, and preterm infants
4. effective control of BP in pre-eclamptics.
5. blunts hemodynamic effects of uterine contractions
6. Conversion from vaginal delivery to cesarean
7. **excellent analgesia without sedation** |
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Term
| What are the disadvantages of epidural anesthesia? |
|
Definition
1. hypotension (aortocaval syndrome)
2. systemic toxicity
3. high block
4. PDPH
5. motor block
6. ??prolongation of labor stages and increase in cesarean deliveries?? |
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Term
| What are the contraindications to epidural anesthesia? |
|
Definition
Absolute: patient refusal, uncooperative patient, uncorrected severe coagulopathy, uncontrolled hemorrhage/hypovolemia, epidural site infection, sepsis, unskilled anesthesia provider
Relative: Increased ICP, untreated systemic infection, severe pre-existing neuro deficit |
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Term
|
Definition
1. Walking epidural: fentanyl only, no LA. Pt not confined to bed b/c there is no motor block. Good for early labor
2. Regular epidural: low dose vs. high dose LA. Occasional bolus vs. continuous infusion
3. Combined spinal-epidural: patient in late stages of labor. Good for replacing an epidural that didn't work well during labor and need quick analgesia |
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Term
| What is Tuffier's or Jacoby's line? |
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Definition
| imaginary line passing b/w the iliac crests (typically at L4 spinous process or L4-L5 interspace). Not always at this level. Depends on other issues such as weight |
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Term
| What things must the patient do in order to be allowed to walk with a "walking epidural"? |
|
Definition
1. get out of bed without assistance, stand and do a deep knee bend with good motor control
2. Must have IV pole and support person |
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Term
| Should you test dose with a fentanyl walking epidural? |
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Definition
| No, because you want the patient to be able to walk |
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Term
| Should you test dose with a fentanyl walking epidural? |
|
Definition
| No, because you want the patient to be able to walk |
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Term
| What are the physiologic responses/complications to epidural anesthesia? |
|
Definition
| Hypotension, bradycardia, N/V (d/t HoTN and dec. perfusion to n/v centers in brain), inadequate block, intravascular injection, dural puncture, high block, prolonged motor block, back pain |
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Term
|
Definition
| inhibition of uterine contractions |
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Term
| How does labor analgesia cause fetal bradycardia? |
|
Definition
1. Pain relief causes a decrease in sympathetic output, most importantly epinephrine. Since epinephrine is a tocolytic (causes uterine relaxation), low levels of epinephrine will cause uterine tone to increase, which causes decrease uteroplacental perfusion. If low enough it will cause fetal bradycardia.
2. Pain relief can also cause dec. BP which will increase norepi levels and cause uterine artery vasoconstriction, which decreases placental blood flow as well. |
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Term
| What is the treatment for fetal bradycardia? |
|
Definition
1. **uterine displacement**
2. Turn off Pitocin
3. Treat maternal hypotension
4. Oxygen
5. Fetal scalp stimulation
If uterine hypertonus is persistent, tocolytics should be instituted such as terbutaline 0.25mg SubQ or Nitro spray (2-3 sprays) or IV 200-400 mcg |
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|
Term
| chloroprocaine (Nesacaine) |
|
Definition
1. Max dose 12 mg/kg OR 800-1000 mg
2. Ester with VERY RAPID onset (3-5 mins)
3. Duration ~30 mins.
4. Good for stat Cesarean |
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Term
|
Definition
1. Max dose 4 mg/kg or 7 mg/kg with epi
2. onset: 10-15 mins.
3. Duration: 90-180 mins. |
|
|
Term
|
Definition
1. Max dose 2-3 mg/kg
2. onset: 10-20 mins
3. duration: up to 180 mins.
4. continuous epidural infusion for labor: 0.1% ropivacaine with fentanyl 2 mcg/mL
5. GREATER SENSORY BLOCK THAN MOTOR BLOCK |
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Term
|
Definition
1. max dose 1.5-3 mg/kg
2. onset: 15-20 mins.
3. duration: 180-300 mins.
4. used to raise a C-section level in pt with severe BP issues
5. Used for continuous labor epidurals with fentanyl 0.075% with 10mcg/mL |
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Term
| What are the signs/symptoms/ and treatment of local anesthetic toxicity? |
|
Definition
1. earliest sign is personality change
2. tinnitus, circumoral numbness, lightheadedness, confusion, muscle twitching, convulsions, respiratory arrest, and CV collapse
3. Treatment: stop LA administration, 100% O2 via FM, maintain LUD, pressors, fluids, barbiturate/benzo/propofol, intralipids |
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