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The Category II Conundrum

Tekoa L. King CNM, MPH

June 6, 2014

Disclosure

• I have no financial disclosures related to this talk

What Most of us Think of as a Category 2 Conundrum

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But what I hope to do today..

Category II Controversy

Category II is a Continuum

Category II Complications

Category II Collaboration

Category II Common sense

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Objectives

• NICHD Category II– What is the problem?

• Relationship between FHR characteristics and newborn acidemia

• Proposed algorithms for managing category II

• Where do you go from here?

What’s the Problem?

1. There are more than 40 different FHR

patterns in Category II

2. Category II is a heterogeneous group of

FHR patterns that reflect varying risks for

fetal acidemia

Jackson M 2011

What’s the Problem?

1. These are also the FHR patterns seen

most frequently in clinical practice

– 22% of time in first stage

– 40% of time in second stage

2. Any clinical setting that wants to use the

NICHD 3-tier system has to grapple with

how to manage category II tracings

Jackson M 2011

4 Facts Summarize the Relationship Between FHR Patterns and Newborn Acidemia1. Moderate variability is strongly

predictive of neonatal vigor independent of the presence of variant patterns. This pattern has a negative predictive value of 98%-99% for a term fetus

2. Pattern evolution: newborn acidemia with decreasing FHR variability in combination with decelerations develops over a period of time approximating one hour

Parer JT et al 2006

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3. There is a positive relationship between the depth and severity of deceleration or bradycardia and the degree of acidemia

4. Minimal and absent variability with late or severe variable decelerations are the FHR patterns most likely to be associated with fetal acidemia although the positive predictive value for newborn acidosis is 10-30%

Parer JT et al 2006

4 Facts Summarize the Relationship Between FHR Patterns and Newborn Acidemia

1. The Role of Pattern Evolution

• Acute acidemia does not occur unless recurrent decelerations are present

• Decelerations get deeper as acidemia increases

• Variability decreases as acidemia increases

• Watching for components of pattern evolution is the clinical key

Parer et al 2006

Pattern of Developing Acidemia

Parer JT, Ikeda T 2007

Ultimately a terminal bradycardia

Recurrent variable or late decelerations

Variability declines: moderate to minimal to absent

Decelerations get deeper

Compensatory tachycardia +/-

2. Role of Depth and Duration

• The best predictor of newborn acidosis is:– “the area under the curve” which

integrates depth and duration– Calculated area under the curve is

translated into minutes per bpm

Tranquilli AL 2013, Cahill A 2013

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3. The Problem of Minimal vs Absent Variability

• Although the NICHD arbitrarily used absent variability as the key component of Category III FHR patterns,

• The studies that identified these patterns used “minimal or absent” variability

Parer JT et al 2006, Williams KP 2003, Krebs HB 1979, Beard RW 1971, Paul RH 1975

3. The Problem of Minimal vs Absent Variability• 8 small FHR studies available that

correlated outcomes of minimal/absent variability with decelerations to newborn outcome

– N = 588 patients with minimal or absent variability and recurrent decelerations

– 23% (n=137) were born with neonatal depression, BD > 12 mEq/L, 5 min Apgar < 7

Parer JT et al 2006, Williams KP 2003, Krebs HB 1979, Beard RW 1971, Paul RH 1975

3. Problem of Minimal vs Absent Variability• Williams et al 2002

– N=488 term births, 41 w minimal/absent variability and recurrent decels

– FHR pattern 1 hour before birth correlated to UA cord pH and BD

– Minimal/absent variability w recurrent late decelerations for 1 hr before birth:

• 32% had BD <-12• 24% had pH <7.0

– Similar findings for minimal/absent variability w recurrent variable decelerations

Williams KP 2003

UCSF 5-tier system

• Very complicated! • But it does give us the background PhD

thesis version of the relationship between every FHR pattern possible and the corresponding risk of acidemia

• Good for background source material

Parer JT Ikeda T 2007

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*Macones et al AJOG 2008:112:661**Position change, increasing IV fluid, reducing uterine activity, modified pushing, etc.

Parer JT Ikeda T 2007

FHR 5-tier app 2012www.obapps.org

Linda Troutfetter RN Petaluma Valley Hospital

How Did The NICHD Guidelines Start Being Used in Practice?

2010: ACOG Practice Bulletin: Now we Have 4 Categories• This algorithm addresses FHR

monitoring from the perspective of the physician BUT…the physician is not usually the first person on the scene….and therefore, this algorithm does not start at the beginning with recommendations for the first responder….the bedside provider

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Miller and Miller 2011

• 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.

• May be a good teaching tool for clinicians new to obstetrics

Clark et al 2013

Clark et al 2013 Summary of Category II Algorithms Proposed or In Use• Split Category II into 2 or 3 subcategories

• They base this split on the degree of variability and presence or absence of accelerations

Each of them take into account some of the 3 FHR characteristics that reflect the

development of fetal acidemia that were not addressed by the NICHD 3-tier system

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Current Research on FHR Management Categories

Coletta J 2011, Bannerman C 2011, DiTommasso M 2010, Katsuragi S 2013

• Category I and Category III are well correlated with acid/base status at birth

• 5-tier system intermediate categories are well correlated with acid-base status at birth

• 5-tier system predicts acidemia better than 3-tier system

Current Research on FHR Management Categories

27Coletta J 2011

Integrating These Findings into Protocols for Category II FHR Patterns• FHR patterns are ever-changing during

the course of labor. An algorithm that tries to encompass everything will be necessarily complex

• Management will always depend on clinical factors and institutional resources

– Therefore, one national algorithm is not clinically valuable

Integrating These Findings into Protocols for Category II FHR Patterns• Best choice is to categorize FHR pattern

interpretation into sub-categories that are consistent with their known risk for fetal acidemia

• FHR management protocols need to:

– Start with the bedside provider and,

– They need to be based on institutional resources

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How do Skilled Clinicians Think?

• Observe

• Evaluate and Get More Information

• Emergent Delivery

Interpretation of Risk Management

5 Categories Based On Clinical Interpretation and Management• 1: No acidemia (Category I)

• 2A: No central fetal acidemia (adequate oxygen) (Category I and II)

• 2B: No central fetal acidemia, but FHR pattern suggests intermittent reductions in O2 which may result in fetal O2 debt (Category II)

• 2C: Fetus potentially on verge of decompensation (Category II)

• III: Evidence of actual or impending damaging fetal asphyxia (Category III)

Parer JT et al 2007, Parer JT & King Tl 2010

Tools for Creating Category II Guidelines

Fox M et al 2000

Tools for Creating Category II Guidelines

MODERATE VARIABILITY

INTERPRETATION MANAGEMENT

Moderate variability Normal baseline Recurrent

decelerations

Moderate variability

Tachycardia No decelerations

Moderate variability Tachycardia Recurrent

decelerations

Centrally oxygenated At risk for Pattern

Evolution

Conservative measures

Notify clinician in X minutes if unresolved

Centrally oxygenated At risk for Pattern

Evolution

Pattern of developing acidemia

Conservative measures

Bedside evaluation by clinician in X minutes

Conservative measures

Notify clinician to create plan

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Category II Management Based on Pattern Evolution

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Recurrent decelerations

Variability diminishing

Decelerations getting deeper and/or tachycardia

Conservative measures

Conservative measuresConsult and make a plan for reevaluation in short period of time

Consider delivery in short period of time

Summary

• Current NICHD Category II is not clinically useful

• Algorithms promoted to solve this problem all split Category II into 2 or 3 subcategories for interpretation/management

– Interpretation can be based on the known relationships between FHR patterns and newborn acidemia

– Management has to be based on institutional resources

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Summary

• Proposed solutions to Category II:

– Consistent in the FHR patterns placed in each subcategories

– Consistent with research on the relationship between FHR patterns and newborn acidemia

– 2 or 3 subcategories

• Acknowledge pattern evolution

• Integrates depth and duration of decelerations

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Thank YouTekoa L. King CNM, MPH

tking@acnm.org

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Appendix

FHR patterns in 3 subcategories of Category II

by risk of developing acidemia

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Category IIA: No Risk Present at This Time

• Category IIA: Centrally oxygenated, no acidemia

– Moderate variability, decelerations present with or without accelerations

– Tachycardia without decelerations

– Minimal variability without decelerations

Parer JT et al 2007, Parer JT & King Tl 2010

Category IIB: Possible Risk or Risk Likely to Develop

• Category IIB: No central acidemia but FHR pattern indicates recurrent reductions in fetal oxygenation

– Decelerations are getting deeper

– Moderate variability and severe decelerations

– Minimal variability with variable or late decelerations

– Tachycardia with decelerations

Parer JT et al 2007, Parer JT & King Tl 2010

Category IIC: Yes, Risk is Present

• Category IIC: Fetus on the verge of decompensation

– Minimal variability and recurrent severe decelerations in classic pattern evolution trajectory

– Bradycardia with decreasing variability

Parer JT et al 2007, Parer JT & King Tl 2010

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References

Studies that have evaluated suggested algorithms for

Category IIand

Publications of collaborative FHR protocol development

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References

• AmericanCollegeofObstetriciansandGynecologists.ManagementofIntrapartumFetalHeartRateTracingsPracticeBulletinNumber116November2010. Obstet Gynecol 2010;116:1232–40

• BannermanCG,etal.Assessmentoftheconcordanceamong2‐tier,3‐tier,and5‐tierfetalheartrateclassificationsystems.AmJObstet Gynecol.2011Sep;205(3):288.e1‐4.Epub 2011

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References• CahillAG,etal.Terminalfetalheartdecelerationsandneonataloutcomes.ObstetGynecol.2013Nov;122(5):1070‐6.

• Coletta J,etal.The5‐tiersystemofassessingfetalheartratetracingsissuperiortothe3‐tiersysteminidentifyingfetalacidemia.AmJObstet Gynecol.2011;206:Dec22.

• DiTommaso M,et al.Comparisonoffiveclassificationsystemsforinterpretingelectronicfetalmonitoringinpredictingneonatalstatusatbirth.JMatern FetalNeonatalMed.2013Mar;26(5):487‐90.

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References

• ElliottC,etal.Gradedclassificationoffetalheartratetracings:associationwithneonatalmetabolicacidosisandneurologicmorbidity.AmJObstetGynecol.2010Mar;202(3):258.e1‐8.

• FoxM,etal.FetalHeartRateMonitoring:Interpretationandcollaborativemanagement.JMidwiferyWomens Health2000;45:498‐507.

• JacksonM,etal.Frequencyoffetalheartratecategoriesandshort‐termneonataloutcome.Obstet Gynecol 2011;118:803‐8

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References

• Katsuragi S,etal.Immediatenewbornoutcomeandmodeofdelivery:useofstandardizedfetalheartratepatternmanagement.JMatern FetalNeonatalMed.2013Jan;26(1):71‐4

• MacEachin SR,etal.Thefetalheartratecollaborativepracticeproject.Situationalawarenessinelectronicfetalheartratemonitoring;AKaiserPermanenteperinatalpatientsafetyprograminitiative.JPerinat Neonat Nurs 2009;23:314‐23

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References• Macones GA,etal.NationalInstituteofChildHealthandHumanDevelopmentResearchWorkshopReportonElectronicfetalheartratemonitoring.Obsetet Gyneocl2008;112:661‐6,JOGNN2008;37:510‐15

• MillerDA,MillerLA.Electronicfetalheartratemonitoring:applyingprinciplesofpatientsafety.AmJObstet Gynecol.2012Apr;206(4):278‐83.

• Okai T,et al;PerinatologyCommitteeoftheJapanSocietyofObstetricsandGynecology.Intrapartummanagementguidelinesbasedonfetalheartratepatternclassification.JObstetGynaecol Res.2010Oct;36(5):925‐8

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References• ParerJT,KingTL.Fetalheartratemonitoring:thenextstep.AmJObstetGynecol 2010;203:520‐1

• ParerJT,IkedaT.Aframeworkforstandardizedmanagementofintrapartumfetalheartratepatterns.AmJObstetGynecol 2007;197:26e.1‐26.e6.

• Schnettler WT,etal.Amodifiedfetalheartratetracinginterpretationsystemforpredictionofcesareansection.JMaternFetalNeonatalMed.2012Jul;25(7):1055‐8

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References• Soncini E,etal.Intrapartumfetalheartratemonitoring:evaluationofastandardizedsystemofinterpretationforpredictionofmetabolicacidosisatdeliveryandneonatalneurologicalmorbidity.JMatern FetalNeonatalMed.2013Dec9

• Tranquilli AL,etal.Thecorrelationbetweenfetalbradycardiaareainthesecondstageoflaborandacidemiaatbirth.JMatern FetalNeonatalMed.2013Sep;26(14):1425‐9

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References

• WilliamsKP,Galerneau F.Intrapartumfetalheartratepatternsinthepredictionofneonatalacidemia.AmJObstet Gynecol2003;188:820‐3.

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