Fetal Heart Monitoring PDF

Fetal Heart Monitoring Fetal / Contraction Monitoring Methods: Ultrasound: measures FHR ○ It is a belt like device placed externally on the maternal abdomen to assess FHR ○ FHR is heard most clearly on the fetal back! ○ In the...

Fetal Heart Monitoring Fetal / Contraction Monitoring Methods: Ultrasound: measures FHR ○ It is a belt like device placed externally on the maternal abdomen to assess FHR ○ FHR is heard most clearly on the fetal back! ○ In the Cephalic presentation, FHR is best assessed in the lower quadrant of the maternal abdomen. In the breech presentation, FHR will be best assessed at the umbilicus. Tocotransducer: measures the contraction frequency and duration but NOT intensity ○ It is an external belt placed on the fundus of the uterus. Intrauterine pressure catheter (IUPC): device used to measure contraction intensity in mm Hg! ○ There are only 2 ways to assess contraction intensity: palpation & IUPC device ○ 50-70 mm Hg are considered effective contractions Fetal Spiral Electrode (FSE): considered the most accurate method of detecting fetal heart characteristics ○ Device placed internally for a direct assessment of the fetal heart. The electrode will be placed on the fetal head. ○ It is only used when external devices are inadequate in monitoring fetal heart rate. Montevideo units (MVU): measurement of effective labor based on subtracting the baseline uterine pressure from the peak uterine pressure of each contraction in a 10-minute window of time and then taking the sum of these pressures. ○ 250 is considered effective labor Uterine Activity Normal: 5 contractions in 10 minutes!!!!!! ○ 1 contraction every 2-3 minutes & duration (60-90 seconds) Tachysystole: greater than 5 contractions in 10 minutes ○ INTERVENTIONS: STOP pitocin, hydration (IV bolus), repositioning, and terbutaline Fetal Heart Rate: NORMALS Baseline fetal heart rate: refers to the average FHR that occurs during a 10 minute segment Normal HR: 110-160 bpm ○ Approximate the mean FHR by rounding to increments of 5 bpm during a 10 minute segment. How to read a strip? The segment between the dead lines above represents 1 minute! 10 boxes = 10 minutes. The top strip represents FHR measure from the ultrasound. The bottom strip represents uterine contraction measured via the toco. Need to know vocabulary: contractions & FHR Acme The highest point of a contraction Nadir the lowest point in a deceleration  Fetal Heart Rate Interpretations Tachycardia: fetal heart rate exceeds 160 > bpm in a 10 minute strip Maternal causes: Infection, illicit drug use, hypoxia, dehydration, anxiety, or anemia Fetal causes: hypoxia, anemia, infection, prolonged fetal activity, or cardiac abnormalities Bradycardia: fetal heart rate declines < 110 bpm in a 10 minute strip Maternal causes: analgesics, cord compression, hypothermia, prolonged hypoglycemia, Fetal causes: prolonged cord compression, hypoxia, acidosis, hypothermia, and fetal congenital heart block Variability: Irregular fluctuation in the baseline FHR Pathophysiology: It represents the interplay between the parasympathetic and sympathetic nervous system. The constant push-and-pull effect on the FHR from the parasympathetic and sympathetic systems produce a moment-to-moment change in FHR. ○ In other words, presence of variability indicates that both branches of the CNS are working and the fetus is receiving adequate O2! Types of variabilities: ○ Absent: variability of the FHR is undetectable from the baseline or there is no variability present at all! (flat line) ○ Minimal: variability is undetectable from the baseline or < 5 pm ○ Moderate: variability is 6-25 bpm ○ Marked: variability is greater than 25 bpm. Accelerations Visually apparent abrupt increase in FHR above baseline. An acceleration is described as the “15 by 15 window”: heart rate will increase by at least 15 bpm and last for at least 15 seconds. ○ Before 32 weeks gestation: accelerations are described as a “10 by 10 window” where the heart rate will increase by at least 10 bpm and last for 10 seconds. Decelerations Visually apparent decrease in FHR and return to baseline associated with uterine contractions. The onset, nadir, and recovery of the deceleration, in most cases, coincide with the beginning, peak, and ending of a contraction. Late decelerations: ○ Visually apparent, symmetrical, transistor decrease in FHR that occurs AFTER the peak (acme) of the contraction! The FHR may not return to baseline levels until well-after the contraction has ended. ○ To simply put it, the deceleration is delayed in timing, with the nadir of the deceleration occurring after the peak of the contraction ○ Cause: #1 - Uteroplacental insufficiency Pathophysiology: Placental insufficiency is exacerbated by contractions and its effects on the fetus are worsened. Planeta is unable to deliver adequate oxygen and nutrients. It has decreased to the extent of causing fetal hypoxia. As a result, the fetus is not affected by a contraction until AFTER because of slow / inadequate delivery. ○ Nursing considerations: Goal - improve placental blood flow via interventions that will work to increase blood flow and reduce contractions ○ Nursing Interventions: (1) Change position (left lateral - increases placental blood flow) (2) Stop Pitocin (3) Fluid Bolus (4) O2 if needed (5) Notify provider Early deceleration: ○ Gradual decrease and return of FHR associated with a uterine contraction. The nadir and recovery of the deceleration are coincident with the beginning, peak and ending of the contraction. In other words, it is a symmetrical deceleration that will occur WITH a contraction. ○ Causes: head compression! Pathophysiology: as the labor progresses and the fetal head engages, the cervix will compress on the head. The vagus nerve is stimulated and there is a decline in heart rate. It is benign and expected response! ○ Nursing considerations: BENIGN and expected response! ○ Nursing Interventions: continue monitoring FHR No Interventions!  Variable decelerations: ○ Visually abrupt decrease in FHR below the baseline. The abrupt decrease is calculated from the onset to the nadir. It may or may not demonstrate no consistent relationship to uterine contractions.The deceleration is transient & correctable. The most common deceleration pattern in laboring women. ○ Cause: #1 - Cord Compression Pathophysiology: Variable decelerations are caused by umbilical cord compression. As the cord is compressed, there will be a decrease in blood flow to the fetus. As a result, decreased oxygen perfusion. ○ Nursing considerations: #1 Goal in treatment: decompression of the umbilical cord = FHR return to baseline ○ Nursing Interventions: Vaginal exam to exam for prolapsed cord Position changes (ex. Knee chest) to alleviate pressure off the cord Turn of pitocin if used Amnioinfusion - increase intrauterine fluid to promote decrease cord compression Notify provider Kneed to know the pattern terminology: The decelerations can sometimes occur in specific patterns. It is important to know the terminology to identify how / pattern in which they are occurring. Also, to identify what category FHR is occur VEAL CHOP POOS (FHR Mnemonic) Interpreting Fetal Heart Rate Patterns (Table 14.1) Category I: Normal The FHR indicates a favorable physiological response! Normal fetal acid-base status and does not require intervention. -Baseline: normal range (110-160 bpm) -Variability: moderate -Accelerations: present or absent -Decelerations: present or absent early decelerations BUT no late or variable decelerations Category II: The FHR indicates that further evaluation is needed and continued Indeterminate surveillance. Not predictive of abnormal acid-base balance. -Baseline rate: tachycardia or bradycardia -Variability: absent, minimal, or marked -Accelerations: absent after fetal stimulation -Decelerations: -Recurrent late decelerations with moderate variability -Recurrent variable decelerations accompanied by minimal or moderate variability -Variable decelerations with slow return to baseline (overshoots or shoulders) -Prolonged decelerations >2 minutes but less than 10 Category III: The FHR indicates an unfavorable physiological response. Predictive of Abnormal abnormal acid-base balance and requires intervention. C-section is likely. -Baseline: bradycardia -Variability: absent -Decelerations: EMERGENCY! -Recurrent late decelerations -Recurrent variable decelerations What do you need to know for the exam? Different types of decelerations: early, late, and variable ○ Causes & Nursing interventions Know how to identify the type of deceleration occuring in a scenario. ○ Need to identify it based on a sentence / explanation NOT an image or strip ○ Know acme v. nadir Know the different category strips Know what is tachysystole & interventions for it (turn off pitocin & reposition)