Lates. Variables. Bradycardia A Common Language. Earlys. Fetal Heart Rate Monitoring The Things That Trip Us Up

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1 Fetal Heart Rate Monitoring The Things That Trip Us Up Michael Fox RN, BSN, Director perinatal resource group for Obstetric and neonatal care Fetal Heart Rate Monitoring The Things That Trip Us Up Diagnostic Terminology Lack of Interpretive Consensus Under Appreciation of Importance of FHR Variability Over Emphasis on Significance the Decelerations Misinterpretation of the literature - Need for Accelerations During labor A Common Language. we had to first agree on what we saw and what we were going to call it. Committee established neutrality of nomenclature. Emphasized FHR terminology was purely descriptive not diagnostic No assumptions are made of the etiology of the patterns or their relationship to hypoxemia or metabolic acidemia. Hierarchy of Goodness and Badness Earlys Variables Invisible baggage-the background conversation that s resisting change Lates Bradycardia 1

2 End result Weight of the evidence suggest Variability Decelerations Decelerations Variability Why Is Ranking Information So Important?????? We are simply not skillful at considering multiple factors. We give some variables too much weight and ignore others. We ultimately make each decision using one principle predictor at a time. First cue used to evaluate tracing disproportionately impacts our evaluation of everything else that follows Effective System FHR Interpretation should help direct providers to give each feature tracing it s appropriate weight NICHD 2008 Three - Tier Fetal Heart Rate Interpretation System I Normal II Indeterminate Abnormal 2

3 NICHD 2008 NICHD 2008 Category 1 FHR bpm Moderate Variability No late or variable decelerations ± earlys ± accelerations I Normal Category Absent variability with: Recurrent Late decelerations Variable decelerations Bradycardia Sinusoidal pattern Abnormal NICHD 2008 Category II Tracings Everything else The Mess In the Middle II Indeterminate NICHD: Category II Tracings? Not a homogenous group. Include FHR patterns with the full spectrum of variability Patterns with the full range of association or lack thereof with significant acidemia. 3

4 Categories aren t useful for verbal communication without clearly describing the tracing. Simplify and make clear the framework for how we interpret and manage FHR tracings. I Normal II Indeterminate Abnormal Interpretive Framework Should Reduce Variation Clearly identify the relationship between FHR patterns and significant acidemia Clarify how our presumptive diagnosis informs the choice and timing of our interventions I Normal II Indeterminate Abnormal Fetal acidemia and electronic fetal heart rate patterns: Is there evidence of an association? J. T. Parer a; T. King a; S. Flanders a; M. Fox a; S. J. Kilpatrick b The Journal of Maternal-Fetal & Neonatal Medicine, Volume 19, Issue 5 May Simple Guidelines FHR Monitoring 1. FHR decelerations as an independent finding are poorly predictive of complicated outcomes. 2. The degree of variability is the most sensitive indicator of the adequacy of oxygen delivery to the fetus at any given moment in time. 3. A metabolic acidosis typically develops slowly in association with recurrent decelerations and an evolutionary reduction of FHR variability over time. 4. The deeper the decelerations the > likelihood for developing a significant acidosis. 4

5 NICHD 2008: On Moderate FHR Variability Moderate FHR Variability reliably predicts the absence of fetal metabolic acidemia at the time it is observed. ACOG Practice Bulletin #116 November 2010 Moderate Variability Given the diverse spectrum of abnormal FHR patterns in Category II The presence of FHR accelerations or moderate FHR variability or both are highly predictive of normal fetal acid-base status and thus may help guide clinical management NICHD 2010: On Minimal FHR Variability Minimal FHR Variability (in the absence of accelerations that cannot be explained resolved with resuscitation) should be considered as potentially indicative of fetal acidemia and managed accordingly NICHD 2010 On Absent FHR Variability Category tracing with Absent FHR Variability is abnormal and conveys an increased risk of fetal acidemia at the time it is observed 5

6 Core Interpretive Principles Moderate FHR variability reliably predicts the absence of fetal metabolic acidemia at the time it is observed. Minimal variability should be considered as potentially indicative of fetal acidemia and should be managed accordingly Absent variability with decelerations is abnormal and conveys an increased risk of fetal acidemia at the time it is observed I Normal II Indeterminate Abnormal The opportunity then and now. We have to make the obvious EXPLICIT Interpretive Principles Moderate FHR variability reliably predicts the absence of fetal metabolic acidemia at the time it is observed. Minimal variability (with decelerations) should be considered as potentially indicative of fetal acidemia and should be managed accordingly Absent variability with decelerations is abnormal and conveys an increased risk of fetal acidemia at the time it is observed Significant Acidemia? NO Maybe Presumed Evolution of Significant Acidemia? Clearly identify what the typical and observable changes in the FHR tracing associated with a increased likelihood for birth in the presence of a significant fetal acidemia? 1. Evolutionary loss of FHR variability 2. In association with recurrent decelerations and/or bradycardia 3. That get deeper over time 6

7 Jagged Pattern and Evolution Unpredictable Based On the Degree of Variability Accompanies the Decelerations Moderate Moderate Minimal No No Maybe Minimal Absent Absent Smooth, Round, Blunted, Flat Maybe Presumed Presumed Identify Patterns Relationship to Significant Acidemia Category I II X Significant Acidemia Yes NO X Maybe Fetal acidemia and electronic fetal heart rate patterns: Is there evidence of an association? J. T. Parer a; T. King a; S. Flanders a; M. Fox a; S. J. Kilpatrick b The Journal of Maternal-Fetal & Neonatal Medicine, Volume 19, Issue 5 May % of the fetuses with moderate FHR variability, with or without decelerations or second stage bradycardia will be born in the absence of a significant metabolic acidosis, and/or in the presence of neonatal vigor. When moderate FHR variability is present at the time of birth < 1% of neonates will be born with an Apgar score <7 at 5 minutes. 7

8 Category 1. I 2. II 3. 53% 45% Significant Acidemia 1. Yes 2. No 3. Maybe 35% 59% 2% 6% 2 nd stage prolonged deceleration/bradycardia 2 nd stage prolonged deceleration/bradycardia Category I X II Category I X II nd stage prolonged deceleration/bradycardia Acute Hypoxia Significant Acidemia Yes NO X Maybe Significant Acidemia Yes NO X Maybe 8

9 Category I X II X Significant Acidemia Yes X NO Maybe X ACOG Practice Bulletin #116 November 2010 Minimal FHR Variability Category II tracings with continued minimal variability (in the absence of accelerations or normal scalp ph) that cannot be explained or resolved with resuscitation should be considered as potentially indicative of fetal acidemia and should be managed accordingly Category I X II Significant Acidemia Yes NO X Maybe 9

10 Category 1. I 2. X II 3. 91% Significant Acidemia 1. YES 2. X NO 3. X MAYBE 48% 47% 0% 9% 5% ACOG Practice Bulletin #116 November 2010 Depth & Duration of FHR Decelerations Evaluation of recurrent variable decelerations includes their frequency, depth and duration, uterine contraction pattern, FHR variability. Recurrent variable decelerations that progress to greater depth and longer duration are more indicative of impending fetal acidemia. Category I II X 70% 16% 14% 10

11 Significant Acidemia Yes X No Maybe Negative OCT 100% 0% 0% NICHD 2008: On FHR Accelerations The presence of FHR accelerations (either spontaneous or stimulated) reliably predicts the absence of fetal metabolic acidemia. The absence of accelerations does not, however, reliably predict fetal acidemia. Scalp Stimulation Test-No Periodic Changes Indications Sampling # fetuses # Scalp ph < 7.20 No periodic changes - Good Variability Normal baseline 0 0 Tachycardia 4 0 No periodic changes - Diminished Variability Nl. baseline rate 26 1 Tachycardia 15 1 Total 45 2 S. Clark-Scalp Stimulation Test: A Clinical Alternative to Fetal Blood Sampling. Am. J. Obstet. Gynecol. 148: Category I II X Significant Acidemia Yes X NO Maybe 11

12 ACOG Practice Bulletin #116 November 2010 Category : Absent FHR Variability A Category tracing (absent variability with either late or variable decelerations, bradycardia and sinusoidal pattern) is abnormal and conveys an increased risk of fetal acidemia at the time it is observed Category I X II Significant Acidemia Yes X NO Maybe Making Care Safer - A Consistent Approach to FHR Tracing Evaluation Communication and Management What Do We Need To Do Reduce Risk In Labor and Delivery Develop consistent, reliable processes for the things we can anticipate. Focus on improving our ability to respond to and manage the unexpected. Michael Leonard 12

13 Use NICHD Terminology Don t Default to Diagnostic Non Standardized Terminology A Common Goal Accomplish delivery in the absence of significant acidemia defined as cord umbilical artery blood gas at the time of birth, Delivery in the a CUA gas meq L-1 and/or Apgar score 7 at 5 minutes NICHD 2008 Three- Tier Fetal Heart Rate Interpretation System I Normal II Indeterminate Abnormal 4 Key Interpretive Guidelines 1. FHR Decelerations as an independent finding are poorly predictive of complicated outcomes. 2. The degree of variability is the most sensitive indicator of the adequacy of oxygen delivery to the fetus at any given moment in time. 3. A metabolic acidosis typically develops slowly in association with recurrent decelerations and an evolutionary reduction of FHR variability over time. 4. The deeper the decelerations the > likelihood for developing a significant acidosis. 13

14 Variability Decelerations Evaluate Tracing Ranked Order Uterine activity Baseline FHR Evolution tracing over time Evidence Based Indications For Action Based on the degree of variability that accompanies the decelerations Make a presumptive Diagnosis Significant Acidosis? YES? NO? MAYBE? Evidence Based Indications For Action Based on your presumptive Diagnosis Significant Acidosis? YES? NO? MAYBE? 7 Key Collaborative Interventions 1. Observation 2. Notification 3. Bedside Evaluation 4. Preparation for Delivery 5. Delivery 6. Resuscitation 7. Transfer/Transport 7 Key Collaborative Practice Guidelines 7 key Collaborative Interventions Linked Collaborative Practice Guidelines 14

15 The Bottom Line We must have a system of fetal heart rate monitoring that makes it easy to do things right and hard to do them wrong." Adapted Modified from IOM report