Basic Ultrasound Flashcards

Question

Femur Length Landmarks/Measurement

Answer 1

Landmarks * Longitudinal view Measure * Diaphysis to diaphysis * Omit “HOOK”or femoral epiphysis * 90° angle

Answer 2

* Complete * Over/up to IO * Low Lying * ≤ 2.0 cm IO * Rescan at 32 wks; +36 wks

Answer 3

Any maternal or fetal condition that would affect utero-placental functioning **_Maternal_** * Hypertension * Diabetes * Preterm Labor * Sickle Cell Disease, Thalassemias * Elevated Maternal Serum Alpha Feto protein **_Fetal_** * IUGR * Abnormal fetal ultrasound * Multiple gestations * Decreased fetal activity * Isoimmunizations * Previous stillborn * Post-dates

Answer 4

* Fetal movement counts * Non-stress tests * Biophysical profile scoring * Contraction stress tests

Answer 5

* Monitors fetal heart rate and uterine activity * Note for the presence or absence of 2 accelerations in 20 minutes (or up to 40 minutes or longer) * _Reactive (Reassuring)_: 2 or more accelerations * 15 beats by 15 seconds (over 32 weeks gestation) * 10 beats by 10 beats (under 31 and 6/7 weeks gestation) * Detects 99% well-oxygenated and non-acidemic fetuses * _Non Reactive (Non-reassuring)_: 0 – 1 acceleration only * Repeat testing within 24 hours * BPP or CST * 50% of fetuses with non-reassuring FHR are OK * _Vibroacoustic stimulation_: 1 – 2 seconds using specially designed artificial larynx placed on maternal abdomen * May repeat 3x at max 2 seconds to elicit fetal heart rate accelerations

Answer 6

* Assess fetal intrauterine adaptation * Ultrasound evaluation for 30 minutes * 5 Assessment Parameters (2 points each, all or none) * NST (reactive) * Fluid (2 cm pocket) * Breathing (30 seconds) * Tone (1 episode) * Movement (3 gross body movements) * Reassuring = 8 or 10 → no further testing * Nonreassuring = \< 6 → further testing or delivery * Equivocal → retest in 12 - 24 hours * 6 * Abnormal - consider delivery * 4 - high probability of asphixia * 2 - asphixia almost certain * 0 asphixia certain

Answer 7

Modified BPP = NST and AFI * NST - short term indicator of fetal hypoxic status * AFI - indication of long-term placental function

Answer 8

1. Subjective - sonographer compares the overall amount of fluid [free of cord and body parts] to the area that the baby and placenta are occupying 2. Single deepest vertical pocket - measure the single deepest vertical fluid pocket of fluid [free of cord and body parts] 3. Amniotic fluid index (AFI): * ***_Must hold transducer perpendicular to the floor_*** * Divide uterus into 4 quadrants with 2 perpendicular lines * Measure largest vertical fluid pocket [free of cord and body parts] in centimeters * AFI is the sum = total of the four quadrants

Answer 9

**_Oligohydramnios_** * AFI \< 5 cm * \< 2 cm single deepest vertical pocket of fluid **_Normal_** * AFI \> 5 – 23 cm * A normal single-pocket measurement is between 2 – 7 cm **_Polyhydramnios_** * AFI \> 24 cm * \> 8 cm single deepest vertical pocket of fluid

Answer 10

* aka Oxytocin challenge test * Contraindications * PTL * High risk for preterm delivery * PPROM * Placenta previa * Classical uterine scar * Observe baseline FHR and uterine activity for 10-20 min * If \< 3 contractions lasting at least 40 sec in 10 min → nipple stim or oxytocin to produce 3 contractions in 10 min * Negative test = no late or significant variable decels * Positive = late decels in at least 50% of contractions (consider further testing or delivery)

Answer 11

**_False Negative Test_** - normal result with resultant fetal death within 1 week of testing * Very low rates * NST= 1.9/1000 women CST= 0.3/1000 women BPP & modified BPP = 0.8/1000 women **_False Positive Test_** - abnormal test result that prompts delivery for an uncomprised fetus

Basic Ultrasound Flashcards

(36 cards)