Antepartum: Diagnostic Testing Wks 14-24 Flashcards
Non stress test (NST)Purpose: (4)NST is based on?When is it performed?
Purpose: 1) To assess placental function and oxygenation2) Fetal well-being3) Evaluate fetal heart rate response to fetal movement (L 283) (Saunders 321)Performed during third trimester
Contraction stress test (CST)Purpose: (3)When is this test performed?
Purpose: 1) To evaluate the respiratory function (exchange) of the placenta. 2) Determines fetal ability to tolerate labor and fetal well-being3) Fetus is exposed to the stress of contractions to assess the adequacy of placental perfusion under simulated labor conditionsTest is performed if non stress test is abnormal(Saunders 321)
Biophysical Profile (BPP)Generalized descriptionUltrasound used for fetal breathing, movement of body or limbs, fetal tone, amniotic fluid volume.Reactive Fetal Heart Rate (FHR) with NST
Use of real-time ultrasound to visualize physical and physiological characteristics of the fetus and observe for fetal biophysical responses to stimuli
Test for fetal lung maturity (L/S ratio, PG)1) What does L/S stand for?2) When is is performed?3) How is it performed?
1) Lecithin and sphingomyelinThis test measures the amount of two substances, lecithin and sphingomyelin, that are found in the amniotic fluid during pregnancy. The two substances are surfactants, chemicals made by the lungs that allow them to work properly. Without surfactants, the small air sacs in your lungs, called alveoli, would collapse, preventing oxygen from entering the bloodstream.2) In the last three months of pregnancy, your fetus’ lung surfactants can freely pass into the amniotic fluid. Once the surfactant becomes part of the amniotic fluid, your doctor can measure it.3) via amoniocentesis(URMC Web)
Percutaneous umbilical blood sampling (PUBS)1) What is it?2) What type of blood studies can be done via this test? (6)
1) Technique used for obtaining blood that allows for 2a) rapid chromosome dx karyotyping (visualize chromosomes)b) Kleihauer-Betke test- ensures its fetal blood obtainedc) Indirect Coomb’s test: transfusion for Rh isoimmunizationd) Hydrops fetalise) CBC with differentialf) Blood gases(London 154)
Fetal Kick CountDetermine:Purpose:
Determine:Purpose:
Nonstress TestNursing Interventions: (6)
1) External ultrasound transducer and tocodynamometer applied to client2) 20 tracing obtained to observe FHR and uterine activity3) Baseline BP obtained and monitored frequently4) Client in side lying position to avoid vena cava compression5) Client presses button every time she feels fetal movement6) The monitor records a mark at each point of fetal movement which is used as reference point to assess the FHR response(Saunders 321)
Nonstress Test ResultsReactive Nonstress Test (Normal, Negative) (4)
Reactive-indicates healthy fetus1) The result requires 2 or more FHR accelerations of at least 15 beats/minute2) Lasting at lease 15 seconds from the beginning of the acceleration to the end3) In association with fetal movement4) During a 20 minute period(Saunders 321)
Nonstress Test ResultsNonreactive Nonstress Test (Abnormal) (2)
1) No accelerations or accelerations of less than 15 beats/min2) 0r lasting less than 15 seconds duration occurs during a 40 minute observation(Saunders 321)
Nonstress Test ResultsUnsatisfactory
The result cannot be interpreted because of the poor quality of the FHR tracing
Contraction Stress TestInterventions
1) External fetal monitor is applied to pt2) 20 to 30 minute baseline strip is recorded3) Uterus is stimulated to contract via oxytocin (Pitocin) or by nipple stimulation until 3 palpable contractions with duration of 40 seconds or more in 10 minute period have been achieved4) Monitor maternal BP frequently
Contraction Stress Test ResultsNegative Contraction Stress Test (Normal)
A negative result is represented by no late decelerations of the fetal heart rate
Contraction Stress Test ResultsPositive Contraction Stress Test (Abnormal)
A positive result is represented by late decelerations of FHR, with 50% or more of the contractions in the absence of hyper stimulation of the uterus.
Contraction Stress Test ResultsEquivocal
An equivocal result contains decelerations, but with less than 50% of the constructions or uterine activity shows a hyperstimulated uterus
Contraction Stress Test ResultsUnsatisfactory
An unsatisfactory result means that adequate uterine contractions cannot be achieved or the FHR tracing is of insufficient quality for adequate interpretation