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89 Cards in this Set
- Front
- Back
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During Pregnancy mean body weight increases by what %?
(how many kg) |
17%
12-14kg ~30lbs |
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How much of the 12-14kg gained during pregnancy is from:
1) uterus & contents 2)blood volume & interstitial fluid 3) new fat & protein |
1)6kg
2)2-4kg 3)4kg |
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When does the largest amount of weight gain occur during pregnancy?
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The last two trimesters 5-6kg each.
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How much does the average neonate weight?
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3kg (6.6lbs)
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When during pregnancy does the physiologic changes of the CV system occur?
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as early as the 4th week
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What does the effect of increased maternal hormone (estrogen/progesterone) production have on maternal blood volume?
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estrogen increases plasma renin activity, which enhances Na+ reabsorption and water retention.
Progesterone enhances aldosterone production Renin & Aldosterone cause retention of about 900 meq Na and 7000ml TBW |
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How much does total body volume increase at term? When does it return to normal?
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80-100 ml/kg
1000-1500 ml 7--14 days |
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True or False
BP increases in normal pregnancy. |
False, BP does not increase in normal pregnancy. There is a decreased SVR and pulmonary vascular resistance
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Why is it normal for pregancy to cause a low H&H?
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Red cell volume only increases 15-20% compared to plasma increase by 50%.
Normal H&H is 12 & 35 Usually from an iron deficiency - PNV very important |
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What does a elevated HGB mean during pregnancy?
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low volume status
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What is a normal WBC level during the third trimester? why is it important to know their WBC level?
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22,000 normal
May not want to do a spinal/epidural if WBC elevated and suspect septicemia - meningitis |
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What happens to Coagulation factors during pregnancy?
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most increase, except platelet count may decrease or increase.
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Why do plasma protein levels drop during pregnancy?
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due to dilution. total amount of protein will actually increase, just not enough compared to the dilution factor.
This causes a decrease in plasma colloid oncotic pressure which leads to edema |
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What occurs with plasma cholinesterase levels? why is this important?
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decrease by 25%, Chlorprocaine (an ester) is metabolized this way
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What are the clinical implications of increased blood volume?
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Meets needs of uterus and feto-placental unit
Fills increasing venous reservoir Protects against blood loss at delivery Increases risk of bloody tap |
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What is the average blood loss for uncomplicated vaginal delivery?
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500ml
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What is the average blood loss for C-section or vaginal delivery of twins?
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800-1000ml
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What factors occur to help compensate for the blood loss that occurs with birth?
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Uterus contracts at time of delivers - autotransfusion 500ml blood
Hypercoagulability occurs during pregnancy to help prevent blood loss |
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True of False:
Pregnant patients who are chronically hypertensive are less likely to need a transfusion? |
False, they are more likely to need a transfusion sooner becuase of their decreased blood volume from chronic vasoconstriction
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What occurs to the Cardiac output during:
1) 1st trimester 2) contractions 3) post delivery |
1) increases by 30-40% (hr ^ 15% SV ^ 30%)
2) progressivly increase (15% latent, 30% active, 45%expulsive) 3) greatest increase occurs after delivery 80% above prelabor values. may reach 10-12 L/min |
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When does Cardiac Output return to normal after prengancy?
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10 days - 2 weeks
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What occurs to the CVP and PAP during pregnancy and labor?
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CVP & PAP same during pregnancy
CVP increases 4-6 cm during labor |
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What occurs to the heart with pregnancy?
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- displaces upward/leftward
- appears enlarged on xray - increased LV wall (LVH by 12 weeks) - may develop innocent I-II grade systolic murmur, which is caused by increased blood flow and vasodilation - 3rd & 4th heart sounds may be heard during late pregnancy - EKG changes |
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True or False:
It is normal for a pregnant patient to have a grade II diastolic murmur |
false, it is pathologic if it is diastolic
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What EKG changes are normal during pregnancy?
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benign dysrhythmia
reversible ST,T, Q wave changes left axis deviation |
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What symptoms are seen with Aortocaval Compression Syndrome?
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Maternal tachycardia, diaphoresis, nausea, vomiting, faiting, pallor, hypotension, and mental changes.
Fenal Distress/bradycardia |
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What is the cause of aortocaval compression syndrome?
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compression of the IVC and Aorta by gravid uterus in the supine position.
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Compression of the IVC causes maternal or fetal symptoms?
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Maternal:
- decreased venous return to Right heart - decreased CO - decreased BP |
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Compression of the aorta causes maternal or fetal symptoms?
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Fetal:
- hypotension in lower extremities and uterine arteries - decreased uterine blood flow - fetal distress |
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True or False:
Perfusion of the uterus decreases in the supine position only when maternal BP is low. |
False,
Perfusion decreases in the supine position even with normal maternal BP. |
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What mechanisms try to compensate for aortocaval compression syndrome?
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- Increased flow to the azygous vein
- Increased SNS activity in response to decreased BP - Increased venous pressure below IVC obstruction, which causes diversion of venous blood to paravertebral (epidural) veins and then to azygous vein to SVC to Right heart |
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What is the role of the Azygous vein in aortocaval compression syndrome.
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When the IVC is obstructed the azygous vein is the principal vein by which blood can return to the heart.
- the azygous vein is a single vein that is a branch of the ascending lumbar vein - it arrises in the abdomen - passes through diaphragm along right side of vertebral column to T4 - enters the SVC |
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What is the treatment of aortocaval compression syndrome?
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LUD 15-30%
- right uterine displacement more effective in ~10% IVF (nonglucose containing) IV Ephedrine or low dose Neo Trendelenburg if severe (must also maintain LUD) |
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What changes occur to the maternal upper-airway and what are the implications?
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Capillary engorgement of mucosa causing swelling of nasal and oral pharynx, larynx, and trachea. These symptoms are worsened in pressence of URI or pre-eclampsia
The implications: smaller ETT gentle manipulation to avoid more edema/bleeding nasal intubations = nose bleed upper AW obstruction may occur early with induction |
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True or False:
Minute volume increases 45-50% during pregnancy, this change is mostly due to the large increase in tidal volume. |
True
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What is the normal PaCO2 by 12 weeks gestation?
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30-32 due to chronic hyperventilation, but there is no net change in pH. Renal excretion of bicarb increases to compensate.
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What respiratory changes occur during labor?
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minute volume may increase by 300% when painful contractions leading to hyperventilation
Marked hypocarbia |
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True or False:
Functional reserve capacity (FRC) increases by 15-20% during pregnancy. |
False,
Decreases by 15-20% |
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What are the effects of pregnancy on the anesthetics we will give?
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Decreased MAC of Volatiles by 40%
Wider Dermatomal spread of sensory anesthesia - reduce dose by 25-50% Reduced anesthetic requirement from: engorged epidural veins, increased CSF pressure, Increased sensitivity to locals |
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What renal changes occur with pregnancy?
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Increased renal blood flow and GFR (50% by 4th mo. and return to normal ~3rd trimester)
Reduced BUN/Cr is normal Ureters, renal calyces, and pelvis dilate = urinary stasis, frequent UTIs and Stones |
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What Hepatic changes occur with pregnancy?
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Liver displaced posteriorly, to the right and upward
Dilutional decrease in plasma protein levels SGOT, alk phos, cholesterol, normally increase Plasma Cholinesterase decreased 24% before delivery and by 33% 3days PP |
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What clinical implications will be seen with the changes of plasma cholinesterase during pregnancy?
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plasma cholinesterase decreases 24% before delivery and by 33% 3days PP. It returns to normal after 2-6 weeks.
Will rarely see prolonged resp. depression after normal sux dosing. Other drugs metabolized by plasma cholinesterase may be prolonged. |
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What GI changes occur with pregnancy?
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Increased reflux, esophagitis, heart burn
Prolonged gastric emptying, increased gastric volume Increased intragastric pressure Increased risk for aspiration |
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When do you consider the pregnant patient to have a full stomach? When does this resolve?
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Begining at 15-20 weeks gestation.
Ends 6weeks postpartum |
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What musculoskeletal changes are seen with pregnancy?
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Relaxin is secreted by ovaries causing relaxation of ligaments.
Increase in lumbar lordosis making regional anesthesia more difficult Pelvic widening causes head down tilt when in lateral position (cephalad spread of spinal/epidural) |
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What position do you place a pregnant patient in for spinal/epidural administration if unable to tolerate sitting?
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Right side down
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The usual blood loss with a normal delivery is?
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400-500ml
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The usual blood loss with a vaginal delivery of twins or uncomplicated C-section is?
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800-1000ml
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Which local anesthetic for epidural anesthesia results in the lowest fetal blood concentration?
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Chlorprocaine
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Lower doses of local anesthetics for epidural or spinal anesthesia are required in the OB patient because why?
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The epidural and subarachnoid spaces are decreased in size.
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True or False:
In the pregnant patient at term you would expect to see an increase in functional reserve capacity. |
False
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True or False:
In the pregnant patient at term you would expect to see an increase in inspiratory capacity. |
True
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Why is induction and emergence from anesthesia with inhalation agents in the pregnant patient more rapid?
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because of increased alveolar ventilation and decreased FRC
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True or False:
Aortocaval compression results in fetal tachycardia. |
False Fetal bradycardia
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Why should dextrose containing solutions for fluid preloading in the pregnant patient no be used?
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they may cause neonatal hypoglycemia
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What is uterine blood flow at term pregnancy?
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700-900ml/min
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When is cardiac output greatest?
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immediately after delivery of the newborn
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A 19yr old is brought to the OR for a emergency C-section. She has a functioning epidural in place what local do you want to use for surgical anesthesia?
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3% 2-Chloroprocaine
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True or False:
Passive diffusion of substances across the placenta is enhanced by decreased maternal protein binding. |
True
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True or False:
Passive diffusion of substances across the placenta is enhanced by the high degree of ionization of the substance |
False
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During the first and second stages of labor, pain is transmitted through which pathways:
T10-L1; S2-S4 or T8-T10; L3-L4 |
T10-L1; S2-S4
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What is the maximum recommended dose of ketamine in obstetrics?
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1mg/kg
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The placenta is impermeable to substances with a molecular weight greater than ________.
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1000
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Substances with a molecular weight of less than ____ can easily cross the placenta.
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600
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In OB, hypotension during regional anesthesia should be treated if SBP is less than ____.
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100mmHg
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Pregnant surgical patients are more prone to aspiration as early as _________.
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15-20weeks
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You are called to place an epidural on a patient in active labor. Current lab work shows:
WBC 17 HGB 10.6 WCT 32 PLT 243 What should you do? |
place the epidural using standard technique
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Why does the pregnant patient rapidly desaturate during induction of GA?
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closing volumes that approach or exceed FRC
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True or False:
It is appropriate to proceed with an epidural if the laboring woman is 4cm dilated and +1Station |
True.
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What is a typical test dose to check epidural placement?
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45mg Lidocaine plus 15mcg epinephrine
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True or False:
physiological changes associated with pregnancy include increased BUN and Cr. |
False, they are decreased
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True or False:
Platelets are produced at a higher rate and consumed at a higher rate leading to enhanced platelet turnover. |
True
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You are called to place an epidural and upon exam you note a grade I-II systolic murmur, what should you do?
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continue, these are normal findings in some patients at term.
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Hyperventilation _____ the seizure threshold and potentially _____ uterine blood flow.
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Increases, Decreases
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True or False:
Changes in respiratory parameters that occur during pregnancy include increased tidal volume. |
True.
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True or False:
The pregnant patient at term is at increased risk for aspiration due to reflux caused by displacement of the GE junction. |
False
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True or False:
As uterine vascular resistance goes down, uterine perfusion pressure goes up. |
True
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True or False:
As the pregnant persons venous pressure goes down, uterine perfusion pressure goes down. |
False
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The most common initial effects seen in patients with a high spinal blockade are?
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nausea and hypotension
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In order to virtually eliminate risk of spinal cord injury, what is the highest level at which lumbar puncture should be performed in an adult.
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L2
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Upon administration of 20ml bolus injection of 0.5% bupivacaine into a continuous epidural catheter, you note the patient complains of light-headedness and numbness of the legs and tongue. This patient has most likely experienced?
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an intervenous injection from migration of the catheter.
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What are the four key chemical properties of local anesthetics?
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lipid solubility
degree of ionization capacity to produce vasodilation protein binding |
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What are three absolute contraindications to spinal anesthesia?
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localized infection at puncture site
patient refusal uncorrected coagulation defects |
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True or False:
Ephedrine is a mixed beta-, alpha-antagonist. |
False, its a mixed beta-, alpha-agonist
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True or False:
Phenylephrine is an alpha-agonist. |
True
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True or False:
Local anesthetics block sodium channels in the inactivated state to prevent propagation of action potential |
True
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What is the drug of choice for the treatment of dysrhythmias associated with bupivacaine toxicity.
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Amioderone
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True or False:
Meperidine produces greater respiratory depression in neonates than morphine. |
False
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Which symptom of intravascular injection of a large volume of LA would likely occur first?
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Tingling of the lips
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