Flashcards in Exam 1A: OB Changes in Pregnancy; C/S Deck (97):
Mean weight increase in pregnancy
17% of prepregnant weight (12kg or 26lbs)
Metabolism parameters which are elevated during pregnancy (3)
O2 consumption, Co2 production and minute ventilation
Thoracic cage increases in circumference by 5-7cm during pregnancy due to
increase in AP and transverse diameters
Flaring of the ribs begins at the end of ____ trimester resulting in increase in the SUBCOSTAL angle.
This hormone plays a role in all of the shifting of the ribs.
Voice changes frequently result from involvement of the __(2)
false vocal cords and arytenoid region of the larynx
Airway edema due to engorgement is most evident during which trimester?
What accounts for the faster uptake of gases in pregnancy? (2)
decreased FRC and increased min ventilation
Airway conductance increases indicating
dilation of the larger airways below the larynx
Hormones which increase airway conductance (3)
progesterone (enhanced beta-adrenergic activity) , relaxin, cortisone
The diaphragmatic excursion in pregnant women are caused by (2)
1. greater descent of the diaphragm from its elevated resting position
2. Limitations of thoracic cage expansion
The elevation of diaphragm is compensated by the _____ therefore diaphragmatic motion is not restricted.
increase in AP diameter of the chest
Dilation of large airways compensates for expected increase in airway resistance. Increase in airway resistance is results from (2)
2. Decreased resting lung volume
Note: this will lead to increased dead space by 45%
Progesterone and PaCo2 blood levels are closely related.
1. This hormone increases the sensitivity of central respiratory stimulant.
2. This hormone also may contribute to increased ventilation.
With epidural anesthesia, the first stage of labor values remain pre-labor. During the 2nd stage (expulsion), result ___ (4)
increased MV, O2 consumption, lactate. decreased PaCO2
FRC increases after delivery but remains below pre pregnancy value for ____ weeks
1- 2 weeks
Diaphragm shifts the heart anteriorly and left and may look enlarged on CXR. Where is the apical impulse located in pregnant patients?
4th ICS MCL
Due to increased blood flow in pregnancy, what heart sound may be heard?
benign grade 1 - 2 systolic murmur
Blood volume: (trimester)
1. Increased BV
2. Maximum rate
3. Slower change
1. 1st trimester
2. 2nd trimester
3. 3rd trimester
Due to high blood volume and elevated diaphragm, pregnancy can cause what cardiac alteration?
Which valve regurgitation is present in 94% of term pregnant patients? (2)
tricuspid and pulmonic regurgitation
1. At term, blood volume is increased as much as ____.
2. Total blood volume reaches ___
1. 1 - 1.5L
2. 90 ml/kg
Why is there dilution anemia in pregnancy?
Hgb is slower than plasma volume increase
1. Biggest change in cardiac output occurs ______.
2. When does cardiac output return to normal?
1. immediately after delivery
2. 2 weeks postpartum
Why is BP not increased in pregnancy?
due to decreased SVR and PVR, and increased aortic compliance
1. Parameters to consider maternal anemia secondary to Fe deficiency.
2. Hgb level which indicates low-volume state.
1. Hct < 33, Hgb < 11
2. Hgb > 14
Low volume state in pregnancy is caused by (3)
3. Inapproproate diuretics
Uterine blood flow:
1. Before conception
2. At term
3. 90% of uterine flow perfuses the
1. 50 - 190ml/min
2. 700 - 900 ml/min
3. Intervillous space + myometrium
1. Aortocaval compression is the degree of compression of the ________ depends on the position of the pregnant woman.
2. It occurs as early as
1. aorta and IVC
2. 13 - 16 weeks
Treatment for aortocaval compression (4)
1. This vasopressor causes less lactic acidosis in baby; decreases uterine blood flow
2. This vasopressor increases CO without uterine artery constriction
This results from relief of cabal compression, reduced lower extremity venous pressure and reduction of maternal vascular capacitance.
Relative hypovolemia and Increased venous return (follow vaginal delivery)
This is the state of a woman during childbirth or immediately thereafter.
This hormone rises by 8 weeks gestation increases RBC production
1. This hormone increases plasma renin activity.
2. This hormone enhances aldosterone production.
1. Pregnant patients are hyper coagulable as evidenced by what labs?
2. Normal parturients Platelet count
3. Other parturients platelet count
1. decreased PT and PTT
2. < 150 K
3. < 100 K
1. Amount of blood loss during vaginal delivery
2. Amount of blood loss during CS
3. H/H falls during ___ post partum then rapidly rise the next ___
1. 600 ml
2. 500 - 1000 ml
3. 3 days postpartum then rise the next 3 days
1. This is a prothrombotic disorder resulting in both arterial and venous thrombosis.
2. It is characterized by presence of 2 auto antibodies, namely:
3. Diagnosis (4)
1. Antiphospholipid or Hughes' Syndrome
2. Lupus anticoagulant and anticardiolipin Ab
3. (+) Arterial and venous thromboses, pregnancy loss, (+) anticardiolipin Ab or Lupus anticoagulant, Elevated aPTT
Pathophysiology of Antiphospholipid syndrome
B2 glycoprotein-1 binds to glycoprotein 1B alpha on platelets causing PLATELET adhesion.
1. This is the apparent mechanism of mortality in Antiphospholipid syndrome.
2. This treatment can reduce pregnancy loss associated with antiphospholipid syndrome.
3. Treatment for women (+) antiphospholipid syndrome and (+) hx of thrombosis
1. Placental infarction
2. Unfractionated heparin and ASA
3. Full anticoagulation
1. Rare syndrome that consists of multi system organ thrombosis and failure.
2. Management for number 1
1. Asherson's Syndrome
2. Full anticoagulation, steroids, plasma exchanges, IV Ig
This may be done to document clearance of heparin
1. Coagulation factor deficiencies
2. Prolonged PTT
3. On ASA
4. Low dose LMWH
5. High dose LMWH
1. relative contraindications
2. Not a contraindication
3. Not a contraindication
4. Wait at least 12 hours since last dose
5. Wait at least 24 hours since last dose
Management of Asherson's syndrome going for general anesthetics
compression stockings and warm fluid (to prevent venous thrombosis)
1. Gravid uterus changes angle of the GE junction causing reduction in tone of the ____
2. This hormone reduces the tone of the GE sphincter.
1. Lower esophageal high-pressure zone (LEHZ)
Mendelson's syndrome criteria
1. pH 30cc
At what week that pregnant patient is already a high risk for aspiration due to delayed gastric emptying?
Ureters and renal pelves dilate by end of 1st trimester due to which hormone?
Decrease of _____ results in incomplete gallbladder emptying.
cholecystokinin (This can lead to cholesterol gallstones.)
Thyroid level changes in pregnancy
1. Increased T3 and T4
2. Normal Free T3 and Free T4
Pregnants are insulin resistant due to which hormone?
This may contribute to high incidence of back pain during pregnancy.
Ligamentous laxity (relaxin)
As the uterus enlarges during pregnancy, ___ is enhanced, maintaining center of gravity over lower extremities.
1. Lumbar lordosis stretches which nerve and can result in mild sensory loss over antero-lateral thigh.
2. Anterior flexion of the neck and slumping of shoulder accompany this lumbar lordosis and can result in ______.
1. Lateral femoral cutaneous nerve
2. Brachial plexus neuropathy
1. This is regarded as a rigid tube that contains 2 fluid-filled distensible tubes
2. What are these 2 distensible tubes? When one volume within one tube increases, a compensatory loss of fluid from the other occurs.
1. Epidural space
2. Dural sac and epidural veins
During pregnancy, compression of the IVC increases venous pressure below the obstruction. This diverts venous blood through the ______ within the epidural space, distending the epidural veins and reducing the _____
vertebral plexus...... spinal CSF volume.
MAC is decreased in pregnancy up to _____. Return to normal 3 - 5 days after delivery.
Internal diameter of trachea is reduced during pregnancy because of capillary engorgement of the mucosa. What ETT size should you use?
6 - 6.5 ETT
1. Ventilation should be adjusted so that the PaCo2 of the parturient is maintained at ____.
2. Allowing the PaCo2 to increase to normal for non pregnant women results in _____.
1. 30 mmHg
2. acute respiratory acidosis
During CS, a PaCo2 of 30 mmHg can be achieved by maintaing MV at ___.
121 ml/kg/min (greater than 77 compared to nonpreggy)
Why is thiopental not used in the US?
Manufacturer pulled out because it was used for lethal injection
Volume distribution of preggies? Inc or Dec?
When is the highest decrease in PlasmaChE noted???
3rd day postpartum
1. Enhanced sensitivity to ___
2. ED50 is reduced by more than 50%
3. Not altered in pregnancy
1. Aminosteroid: Vec and Roc
Pharmacodynamic of Local anesthetics:
1. Pregnant women exhibit a more ________ of spinal anesthesia than non preys who receive the same dose of local anesthetic.
2. Number 1 is due to (3)
1. rapid onset and longer duration
2. Increased neural sensitivity, reduction in CSF protein, increased CSF pH
Marcaine (bupivacaine) is the drug of choice for spinal
1. Stock on hand
1. 7.5 mg/ ml, 15 mg/2ml
2. Dose: 10 - 12 mg (1.4 ml)
T/F: Epidural dose requirements
Large doses of LA have the same result of spread in preggy and non preggy. Smaller doses have greater spread in preggy women than nonpreggy.
This is a term referred to when a mom had previous CS and now wants to try vaginal delivery.
Types of CS incisions (3)
1. Midline vertical: for emergency, preterm, malpresentation
2. Pfannenstiel: horizontal suprapubic
3. Low transverse
This facilitates visualization and repair of the uterus.
Which neonatal morbidity is increased with CS?
1. This neuraxial anesthetic is faster, superior block and more cost effective.
2. What drug is commonly used in number 1?
1. Single-shot spinal
2. Hyperbaric (with Dextrose) bupivacaine 12 mg
Avoid spinal in patients with active herpes
Aspiration prophylaxis (3). Give these drugs even if patient is to get spinal. In case you have failed spinal.
1. Reglan: increases gastric emptying
2. Bacitra: Increases pH
3. H2 antagonist: decreases secretion of acids
Dose of NS or LR bolus for neuroaxial block.
1000ml (or 15 - 20 ml/kg)
How many mg of Versed will cause 30 mins of amnesia?
5 mg IV
This is more prevalent in infant whose mother received large glucose infusion.
This lab test is normal protocol for OB admitted patients.
Type and screen
General anesthetic using ___% MAC results in greater blood loss than use of N20-opioid or regional technique
Drugs which need to be available when doing CS (2)
methergine and pitocin
If patient is complaining of N/V even after LUD, what do you do?
give ephedrine 10, 20, or 30 mg!!!
Quality of the SAB has been reported to be improved by the addition of which medications? (4)
epi, morphine, fentanyl, sufenta
What is the action of epi when added in spinal anesthesia?
prolongs and increases the density of block
Drugs used for epidural (3)
1. 2-chlorprocaine 3%
2. Lidocaine 2%
3. Bupivacaine 0.5%
For redo sing epidural, what do you need to check? (2)
1. check level of pain (pinch)
2. Check BP
What is the action of bicarb when added to local anesthetics?
Increases pH of the solution and increasing the proportion of nonionized local anesthetic --> shortening time to onset of blockade.
1. This position is associated with increased CS rates and fetal/maternal morbidity
2. This uses manual external pressure on the maternal abdomen to alter fetal presentation
3. Tocolytics used with number 2.
2. External cephalic version (should be done > 36 weeks)
3. terbutaline or NTG --> acts on smooth muscles to relax uterus
These conditions reduce ECV success (3)
1. Increase in gestational age
2. fetal growth
3. decrease in amniotic fluid
Intrauterine resuscitation drug (for hypertonus and tachysystole)
NTG 50 - 100 mcg IV (perform spinal or epidural)
Name 2 contraindications to regional anesthesia
heart valve on heparin, low platelet
This allows lower doses of local anesthetic. For CS, lowest dose of spinal bupivacaine doses are used, supplementation done through the epidural catheter
This type of fluid is more effective in treating hypotension but is not normally used due to increased potential for allergic reactions.
Animal studies demonstrate increased analgesia duration and reduced incidence of hypotension when given spinal.
Neostigmine 100 mcg
This is a preservative-free morphine probably most popular adjuvant due to duration of 17 - 27 hours post CS. Pruritus dose-related. Could do CSE.
duramorph 0.1 mg - 3.75 mg
These are the 4 issues that complicate postop recovery and decrease maternal satisfaction.
1. pain: give toradol
2. pruritus: give benadryl, nubain
4. post op shivering: Demerol 25 mg IV