Fetal Heart Rate Monitoring: The Category II Conundrum Tekoa L. - PowerPoint PPT Presentation

6/16/2017 Disclosure � I have no financial disclosures related to this presentation Fetal Heart Rate Monitoring: The Category II Conundrum Tekoa L. King CNM, MPH October 26, 2016 3 Interpreting Fetal Heart Rate Patterns is a Classic Objectives “Blind Men and Elephant” Problem � A quick history � The Category II chasm ー Current recommended management algorithms � Research findings: The relationship between FHR patterns and newborn acidemia The relationship between FHR patterns and fetal � Proposed solution for Category II interpretation oxygenation status is indirect and only one variable in a and management complex interplay of physiologic variables 1

6/16/2017 Category I, “ Normal ” NICHD 2008 FHR Categories ー FHR patterns that are “ normal ” : Associated with fetal well-being � Category I (normal) � Includes all of the following: ー Baseline rate:110-160 bpm ー Present in 99.5% of tracings ー FHR variability: moderate ー FHR patterns that are “ indeterminate ” : Inconsistently associated with � Category II (indeterminate) ー No late or variable decelerations ー Early decelerations: present or absent fetal acidemia ー Present in 84.1% of tracings ー Accelerations: present or absent ー FHR patterns that are “ abnormal ” : Consistently associated with fetal � Category III (abnormal) acidemia ー Present in 0.1% of tracings Macones et al 2008, Jackson MJ 2011 Macones et al 2008 Macones et al 2008, Jackson M 2011 Category III “ Abnormal ” Category II � Absent baseline FHR variability and : ー Recurrent late decelerations or, ー Recurrent variable decelerations or, ー Bradycardia � Sinusoidal pattern Includes all FHR patterns not categorized as normal or abnormal Parer et al 2006, Macones et al 2008 2

6/16/2017 What is the Problem? What is the Problem? 3. The FHR patterns in Category II are heterogeneous in 1. There are more than 40 different FHR patterns in that they reflect varying risks for fetal acidemia Category II 2. These are also the FHR patterns seen most frequently in 4. Any clinical setting that uses the NICHD 3-tier system clinical practice has to grapple with how to manage Category II tracings ー 22% of time in first stage ー 40-75% of time in second stage Sheiner E 2001, Jackson MJ 2011 Jackson M 2011 Jackson M 2011 2010: ACOG Practice Bulletin: How Did The NICHD Guidelines Start Being Implemented? 4 Categories � Reliance on accelerations is misleading: Spontaneous accelerations are not a necessary sign of fetal well-being during labor � To be successful, the algorithm needs to include all members of the team. This means including information the nurse at the bedside needs which is when to notify a clinician � Category II does not include absent variability Linda Troutfetter RN Petaluma Valley Hospital 3

6/16/2017 2010: ACOG Practice Bulletin: Miller and Miller 2011: 5 Categories 4 Categories � This algorithm incorporates thinking about FHR patterns physiologically but it is a complex � Reliance on accelerations is misleading: version of standard practice and as such, it Spontaneous accelerations are not a necessary sign layers a complex set of mental steps over what of fetal well-being during labor we already do. � To be successful, the algorithm needs to include all members of the team. This means including information the nurse at the bedside needs which is when to notify a clinician � Category II does not include absent variability Clark et al 2013 Miller and Miller 2011: 5 Categories � This algorithm incorporates thinking about FHR patterns physiologically but it is a complex version of standard practice and as such, it layers a complex set of mental steps over what we already do. 4

6/16/2017 Clark et al 2013 Clark et al 2013 FHR pattern Recommended Management 1. Mod variability without recurrent decels Observe 2. Mod variability with recurrent Cesarean section decelerations for 1 hr in latent phase 3. Mod variability with recurrent Observe decelerations for 1 hr in active phase and normal labor progress 4. Mod variability with recurrent Cesarean section decelerations for 1 hr in active phase and abnormal labor progress 5. Mod variability with recurrent Observe decelerations for 1 hr hr in second stage and normal progress 6. Mod variability with recurrent Cesarean section or OVD decelerations for 1 hr hr in second stage with abnormal progress 7. Minimal or absent variability without Observe for one hour, if recurrent decelerations for 30 minutes persistent Cesarean or OVD 8. Minimal or absent variability with Cesarean section or OVD recurrent decelerations for 30 minutes 21 Parer-Ikeda 5-tier System Number of non- � It does provide the relationship reassuring FHR between every FHR pattern possible and the categories in corresponding risk of acidemia professional guidelines � Very complicated! � Does not account for pattern evolution over time Julian T Parer MD PhD 1934-2016 5

6/16/2017 23 FHR Management Algorithms: Objectives Summary � A quick history � All split Category II into 2 or 3 subcategories � The Category II chasm ー Current recommended management algorithms � They all base the subdivisions on the degree of variability and presence or absence of accelerations � Research findings: The relationship between FHR � This is a good start (!) but these algorithms do not take into patterns and newborn acidemia account two critical factors � 1. Change over time � 2. Role of depth and duration of decelerations � Proposed solution for Category II interpretation and management Current Research on FHR Categories and The Relationship Between FHR Patterns and Management Newborn Acidemia � Category I and Category III are well correlated with 1. Newborn acidemia with decreasing FHR variability and acid/base status at birth ー Category I: Normal acid-base status recurrent decelerations develops over a period of time approximating one hour: (PATTERN EVOLUTION) ー Category III: Significant risk of metabolic acidemia that is associated with adverse neurologic outcomes 2. There is a positive relationship between the depth and severity of deceleration or bradycardia and the degree � 5-tier system that has 3 intermediate categories correlates of acidemia: (AREA UNDER THE CURVE) better with acid-base status at birth than does the 3-tier system or 2-tier systems Coletta J 2011, Bannerman C 2011, Blackwell SC 2011, Holtzmann M 2014, Di Tommasso 2013, Soncini E Parer JT et al 2010 Parer JT et al 2006 2014, Penfield C 2016, Katsuragi S 2015, Elliot C 2010, 6

6/16/2017 2. Pattern of Developing Acidemia over Time Recurrent variable or late decelerations Decelerations get deeper and spontaneous accelerations no longer present Compensatory tachycardia +/- Variability diminishes Ultimately a terminal bradycardia Dalton KJ et al 1983, Parer et al 2006, Ugwumadu A 2014, Vintzileos A 2016 Vintzleos A 2016 3. Role of Depth and Duration 3. Role of Depth and Duration � The best predictor of newborn acidosis is: Fetal or newborn acidemia is the result after: ー “the area under the curve” which integrates depth and FHR 80 bpm 25 min duration of bradycardic rate ー Calculated area under the curve is translated into minutes FHR 70 bpm 13 min per bpm FHR 60 bpm 8 min FHR 40 bpm 5 min Tortosa MN 1990, Giannubilo SR 2007, Tranquilli AL 2013, Cahill A 2013, Triebewasser et al 2016 Giannubilo SR 2007, Tranquilli AL 2013, Cahill A 2013 7

6/16/2017 4. Example: Problem of Minimal vs Absent 4. The Problem of Minimal vs Absent Variability Variability � The NICHD arbitrarily defined absent variability as the key � Williams et al 2002 ー N=488 term births component of Category III ー FHR pattern 1 hour before birth correlated to UA cord � However, the studies that identified the FHR patterns pH and BD subsequently placed in Category III analyzed FHR tracings � Minimal/absent variability with recurrent late with: decelerations for 1 hr before birth: ー “minimal/absent” variability (Williams KP 2003) ー 32% had BD <-12 ー “decreased variability” (Paul 1995) ー 24% had pH <7.0 ー “Less than 5 bpm change in rate” (Beard 1974) ー “Loss of short term variability” (Gull 1992, Dellinger 2000, Larma 2007) � Similar findings for minimal/absent variability with recurrent variable decelerations Williams KP 2003 32 33 Summary: Lingering Problems Objectives � Current FHR management algorithms: � A quick history ー Static without accounting for duration (pattern evolution � The Category II chasm over time) or depth of decelerations ー Current recommended management algorithms ー Artificial distinction between minimal and absent variability when the focus should be on diminishing variability ー Algorithms that use “accelerations or moderate variability” � Research findings: The relationship between FHR patterns and newborn acidemia may artificially elevate the role of accelerations in labor � Proposed solution for Category II interpretation and management 8