Electronic Fetal Monitoring

Electronic Fetal Monitoring Ultrasound fetal monitor - Picks up the movement of the heart valves Tocodynamometer (toco) - Measures pressure/strain of the top of the fundus Fetal scalp electrode - Picks up the electrical activity spikes of the QRS complex (R-R) Intrauterine Pressure Catheter (IUPC) - Measures pressure inside uterus in mmHg What does the nurse look for in a systemic assessment of fetal heart rate? - -Pattern evolution -Accompanying clinical characteristics -Normalcy vs. urgency -Baseline rate -Variability -Periodic/episodic changes -Uterine activity Baseline fetal heart rate - The approximate mean fetal heart rate rounded to increments of 5bpm during a 10 minute period -Excludes accelerations, decelerations, and periods of marked variability -Must be 2 minutes of identifiable baseline segments (not necessarily continuous) in a 10 minute window What is the length in time of each box on the fetal heart monitor? - 10 seconds What is a normal baseline FHR? - 110-160 bpm Fetal bradycardia - <110 bpm Fetal tachycardia - >160 bpm Fetal heart rate variability - Fluctuations in the baseline fetal heart rate that are irregular in amplitude and frequency -Variability is good Absent FHR variability - Amplitude range undetectable Minimal FHR variability - Less than 5bpm Moderate FHR variability - Between 6 and 25bpm Marked FHR variability - Greater than 25 bpm When does the nurse typically see marked variability? - When the fetus had a deceleration and is trying to compensate to fix oxygenation What is the most important thing to look at in fetal heart rate? - Variability What does variability in fetal heart rate tell the nurse? - It indicates baroreceptors and chemoreceptors are doing well and that the baby is well oxygenated What does decreased variability tell the nurse? - Baby is stressed and oxygenation is decreased -Could also just be because baby is asleep Sinusoidal pattern - Smooth wavelike appearance with no variability What does a sinusoidal pattern tell the nurse? - The baby is highly distressed and is often past the point of being okay What are some possible causes of sinusoidal patterns in fetal heart monitoring? - -Anemia -Drugs -Hypoxia -Fetal infection -Cardiac abnormalities Accelerations in FHR - Visually apparent abrupt increases in FHR above the baseline -Onset to peak in less than 30 seconds In a fetus greater than or equal to 32 weeks, the peak of accelerations are greater than or equal to ___bpm and last for ___ seconds from onset to return to baseline - 15; 15 In a fetus less than 32 weeks, the peak of accelerations are greater than or equal to ___bpm and last for ___ seconds from onset to return to baseline - 10; 10 Prolonged accelerations - Acceleration that lasts for >2 minutes but <10 minutes What do accelerations in FHR indicate? - Normal fetal acid-base status Decelerations - Periodic decrease in the baseline fetal heart rate Early decelerations - Begin prior to peak of the contraction and end by the end of it -Gradual onset: greater than or equal to 30 seconds from onset to nadir -Nadir simultaneous with peak of contraction What causes early decelerations? - Head compression -Getting closer to delivery What nerve is being compressed in early decelerations? - Vasovagal nerve Nadir - Lowest point of the deceleration Late decelerations - Nadir after the peak of contraction -Gradual onset: greater than or equal to 30 seconds from the onset of nadir -Can be causes by fetal distress and hypoxia How are late decelerations managed? - -Position changes -Oxygen -Fluids Variable decelerations - Decelerations lasting from 15 seconds to 2 minutes that do not occur in any pattern What causes variable decelerations? - Cord compression What is the worst type of deceleration to see on the FHR? - Late decelerations Prolonged decelerations - Decrease of greater than or equal to 15bpm lasting at least 2 minutes, but less than 10 minutes Periodic decelerations - Decelerations of fetal heart rate associated with uterine contractions Episodic decelerations - Decelerations of fetal heart rate that are associated with fetal movement Recurrent decelrations - Decelerations that occur with at least 50% of uterine contractions within a 20-minute period Intermittent decelerations - Decelerations that occur with less than 50% of uterine contractions within a 20-minute period Normal uterine activity - < 5 contractions in 10 minutes averaged over 30 minutes Tachysystole - More than five uterine contractions in 10 minutes, averaged over a 30-minute window Category 1 FHR - -Normal fetal heart rate tracing -Baseline 110-160 -Moderate variability no late or variable -Early decells or accels ok Category 2 FHR - Characterized by intermediate FHR patterns -Tachy or bradycardia -Minimal or absent baseline variability not accompanied by recurrent decelerations -Marked baseline variability -No accelerations -Periodic or episodic decelerations. Category 3 FHR - Abnormal FHR predictive of abnormal fetal acid-base status -Recucrent late and variable decelerations -Bradycardia -Sinusoidal pattern Baroreceptors - Cells that are sensitive to blood pressure changes and can decrease fetal heart rate Chemoreceptors - Chemical sensors in the brain and blood vessels that identify changing levels of oxygen and carbon dioxide -Increase FHR initially to compensate, but prolonged hypoxia can decrease FHR Initial response to decreased oxygen causes fetal heart rate to ________________, and prolonged oxygen deprivation causes heart rate to ________________ - Increase; decrease VEAL CHOP - V: Variable decels --> C: cord compression Reposition, O2, notify dr E: early decels --> H: head compression Normal A: accels O: okay L: late decels P: placental deficiency Turn, O2, d/c Pitocin, notify dr