Fetal monitoring in critical care setting

Fetal monitoring in critical care

1. TOPIC: FETAL MONITORING IN CRITICAL CARE. Moderator: Dr. Swarna Deepak k sir. Speaker: Dr. J.Rohith

2. Modalities for fetal monitoring in FGR: For the unseen patient, Evaluation of fetal heart rate indicates primary method of fetal well being. Characteristics of fetal heart rate provide valuable information such as tolerating the effect of maternal condition. Fetal movement count . Fetal heart rate monitoring. Computerised CTG ( cCTG ). Fetal biophysical profile (BPP). Fetal Doppler.

3. Non-stress test (NST): It is a continuous electronic monitoring of the fetal heart rate along with recording of fetal movements ( cardiotocography ) There is an observed association of FHR acceleration with fetal movements, which when present, indicates a healthy fetus. It can reliably be used as a screening test NST works on hypothesis of intact neurologic coupling between fetal CNS and fetal heart the test is valuable to identify the fetal wellness rather than illness.

4. NST is performed taking into consideration the following variables: Baseline FHR Variability of the FHR Presence or absence of accelerations Presence or absence of decelerations Interpretation Reactive (reassuring)— When two or more accelerations of more than 15 beats per minute above the baseline and longer than 15 seconds in duration are present in a 20 minute observation Non-reactive (Non-reassuring)— Absence of any fetal reactivity in a 40 min observation

5. METHODS OF FETAL MONITORING : 1. Ultrasound. 2. Continuous Electronic Fetal Monitoring. 3.Biochemical- Fetal Scalp Blood Sampling. 4.Fetal electrocardiogram Umbilical arterial cord blood samples.

6. CONTINUOUS ELECTRONIC FETAL MONITORING MATERNAL CONDITIONS: Hypertension/preeclampsia Diabetes APH Maternal medical disease cardiac disease , Severe anemia H yperthyroidism V ascular disease R enal disease Previous stillbirth or neonatal disease FETAL CONDITIONS: Prematurity Oligihydramnios Abnormal umbilical artery Doppler velocimetry . Rhesus isoimmunisation Multiple pregnancy Breech presentation

7. Baseline FHR: Normal baseline FHR is 110-160 bpm. Moderate bradycardia- 100-109 bpm. Moderate tachycardia- 161-180 bpm. Abnormal bradycardia- 180 bpm. Causes of Fetal Bradycardia (FHR < 110 bpm).

8. Causes of Fetal Bradycardia (FHR < 110 bpm) Fetal hypoxia, acidosis Fetal sepsis, anomalies Use of local anesthetic drugs, epidural analgesia. Drugs to mother, e.g. pethidine , antihypertensives (methyldopa, propranolol) , MgSO4. Fetal heart conduction defect. Causes of Fetal Tachycardia(FHR>160bpm) Drugs to mother: β-sympathomimetic agents used to inhibit preterm labor ( isoxsuprine , ritodrine ); Vagolytic : atropine Infection—both maternal and fetal Anemia —both maternal and fetal Fetal hypoxia Maternal- hypothyroidsm , metabolic acide

9. Baseline variability: Minor fluctuations in baseline FHR occurring at 3–5 cycles/minute (It is the oscillation of baseline FHR excluding the accelerations and decelerations. Normal base line variability -Greater or equal to 5 bpm – 25 bpm between contractions. Non-reassuring baseline variability Less than 5 bpm for 40 mins or more but less than 90 minutes Abnormal baseline variability Less than 5 bpm for 90 minutes or more. CAUSES OF DECREASED VARIABILITY: Maternal medications Pethidine Tranquilisers, Corticosteroids ,Atropine ,General anaesthesia . Fetal conditions Prematurity ,Sleep cycle ,Anaemia, Metabolic academia, Congenital malformations .

10. Acceleration: Transient increase in FHR by 15 bpm or more lasting for at least 15 seconds. Prolonged acceleration lasts > 2 min but < 10 min and when it is > 10 min it is a baseline change. Acceleration denotes an intact neurohormonal and cardiovascular activity and therefore a healthy fetus .

11. Deceleration: Transient decrease in FHR below the baseline by 15 bpm or more and lasting ≥ 15 seconds. Three basic types of deceleration are observed and are called early, late and variable. Early deceleration : uniform, repetitive, periodic slowing of FHR with onset early in the contraction and return to baseline at the end of contraction. It is due to head compression.

12. Late deceleration: Causes of late deceleration: Placental pathology ( postmaturity , hypertension, diabetes, placental abruption) Excessive uterine contractions Injudicious use of oxytocin Regional anesthesia (spinal or epidural).

13. Variable deceleration: It is the intermittent periodic slowing (variable) of FHR with rapid onset and recovery (V shaped). When it is U shaped with reduced variability and/or duration >3min it is suggestive of fetal hypoxia /acidosis. Decelerations are variable in all respect of size, shape, depth, duration and timing to the uterine contractions It is thought to indicate cord compression and may disappear with the change in position of the patient.

14. Sinusoidal pattern: A regular oscillation of the baseline resembling a sine wave with little baseline variability . This smooth, undulating pattern, lasting at least 10 mins , has a relatively fixed period of 3–5 cycles per minute and an amplitude of 5–15 bpm above and below the baseline Associated with- fetal anemia, fetomaternal hemorrhage , fetal hypoxia , narcotics are given to mother

15. PRETERMINAL CTG: CTGs that has the characteristics of absent baseline variability and shallow late decelerations in a CTG trace that had no reactive segment. Such a trace suggests a blunted response of the nervous system due to contraction-induced hypoxia. It may suggest a fetus that may be already hypoxic

16. REFERENCES : Jhons Hopkins fetal heart monitoring. University of Rochester medical center manual. FOGSI GCPR on Fetal growth Restriction.

17. THANK YOU !