Tiziana Frusca Università di Parma Direttore UO Ostetricia e Ginecologia Azienda Ospedaliera Universitaria di Parma

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1 Tiziana Frusca Università di Parma Direttore UO Ostetricia e Ginecologia Azienda Ospedaliera Universitaria di Parma tiziana.frusca@unipr.it

2 BASELINE RATE - Bradycardia not accompanied by absent baseline variability - Tachycardia BASELINE FHR VARIABILITY - Minimal baseline variability - Absent baseline variability with no recurrent decelerations -Marked baseline variability ACCELERATIONS - Absence of included accelerations after fetal stimulation PERIODIC OR EPISODIC DECELERATIONS - Recurrent variable decelerations accompanied by minimal or moderate baseline variability -Prolonged deceleration more than 2minutes but less than 10 minutes -Recurrent late decelerations with moderate baseline variability -Variable decelerations with other characteristics such as slow return to 2 baseline, overshoots or shoulders

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5 Classificazione ACOG e severità della acidemia 5

6 BJOG 2014;121: tracking the evolution of fetal defensive and compensatory responses to hypoxic ischaemic insults, then it should be possible, at least theoretically,to discriminate from a pool of pathological CTGs those etuses at genuine risk of acidosis and acidaemia (increased H+ in the bloodstream) or impaired neonatal adaptation from the subset that are no guidelines are silent on scenarios associated with fetal damage, such as fever, chorioamnionitis, fetal systemic inflammatory response syndrome (FSIRS) and its noxious synergistic interaction with hypoxia, fetal strokes, lack of fetal cycling behaviour, maternal disease, and the recognition of maternal heart rate (MHR) monitoring, to name a few. 6

7 Intrapartum FHR interpretation a step-wise physiologic approach Step 1 the normal and the abnormal initial CTG Step 2 recognition of the compensated and the decompensating fetus Slowly evolving hypoxia Subacute hypoxia Acute hypoxia (prolonged FHR deceleration and bradycardia) The continuing focus on the morphological appearances of FHR decelerations by current guidelines and training modules denies the clinician an understanding of how the fetus defends itself, compensates for intrapartum hypoxic ischaemic insults, and the ability to recognise the patterns that suggest loss of compensation. 7

8 from pattern recognition to a physiological interpretation labor as a stress test oxytocin and prostaglandin : useful but potentially dangerous the most important question: is the fetus able to cope? baroreceptor response and chemoreceptor response understanding what is happening and being able to predict next fetal adaptation the response is almost always not to rush for a cesarean section intrauterine resuscitation 8

9 REGOLAZIONE DEI BAROCETTORI STIRAMENTO AUMENTO DELLA PRESSIONE ARTERIOSA ENDOLUMINALE RIDUZIONE DELLA FREQUENZA CARDIACA VASODILATAZIONE PERIFERICA

10 REGOLAZIONE DEI CHEMOCETTORI GLOMI AORTICI E GLOMI CAROTIDEI CHEMO- CETTORI RISPOSTA CRONICA (IPOSSIA CRONICA): FREQUENZA CARDIACA O2 CO2 ph

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12 Monitoring..means to monitor fetal hearth AND CONTRACTIONS

13 WHY TO MONITOR

14 WHY TO MONITOR

15 The oxigen and CO2 exchange from fetus to mother is interrupted during a contractions (when the uterine pressure is 30 mmhg or more), because an interruption of the ematic placental flow occurs After a contraction, the fetus needs seconds to get again to a normal oxygenation The fetal ability to manage the labour overall depends on his ability to rapidly get a normal oxygenation after the contractions Uterine contractions and placental flow

16 Uterine contractions and placental flow - Oxygen extraction from other tissues increased - Reduction of non-essential activities Intact - The fetus is able to react to the acute hypoxia of the labour - Optimal reaction to hypoxia - Total compensation - Fetal distress markers - Low risk of asphyxial damage Mechanism of fetal defence - Sympathetic activities increased - Ematic flow redistribution Reduced - Decrease in reserves for a fetus who was healthy but was exposed to a lot of hypoxial stimuli. Postterm fetus - Reduced reaction to hypoxia - Reduced compensation - Variable markers of fetal distress - Present risk of asphyxial damage - Anaerobic metabolism Absent - Antenatal problems with chronic distress. Mechanisms of defence already used. IUGR fetus. - Minimal or absent reaction to hypoxia - Decompensation - Typical signs of fetal distress missed High risk of asphyxial damage

17 pro e contro CTG in travaglio di parto indicazioni nel basso rischio (cosa é il basso rischio?) come eseguire la cardiotocografia analisi del tracciato dalla valutazione gestaltica (pattern recognition) alla interpretazione fisiopatologica classificazione del tracciato compiti e responsabilità della ostetrica/ compiti e responsabilità del medico decisioni cliniche il periodo espulsivo 17

18 Admission test

19 tracing acquisition: maternal position paper scales and speed external vs internal monitoring simultaneous maternal hearth rate monitoring twins storage of tracing 19

20 speed velocity The horizontal scale for CTG registration and viewing is commonly called paper speed and available options are usually 1, 2, or 3 cm/min. 20

21 monitoring twins Continuous external FHR monitoring of twin gestations during labor should preferably be performed with dual channel monitors that allow simultaneous monitoring of both FHRs, as duplicate monitoring of the same twin may occur and this can be picked up by observing almost identical tracings.. During the second stage of labor, external FHR monitoring of twins is particularly affected by signal loss, and for this reason some experts believe that the presenting twin should preferably be monitored internally for better signal quality. Other experts believe that external monitoring of both twins is acceptable, provided that distinct and good quality FHR signals can be obtained. 21

22 external versus internal external monitoring External FHRmonitoring is more prone to signal loss, to inadvertent monitoring of the maternal heart rate (Fig. 1) and to signal artifacts such as double-counting (Fig. 2) and half-counting, particularly during the second stage of labor.

23 storage of tracing patient name, place of recording, paper speed, and date and time when acquisition started and ended. digital CTG archives Noi aggiungiamo nel timbro CTG: nome dell ostetrica PA e FC della donna, nome del medico che valuta il tracciato 23

24 analysis of tracing baseline normal baseline tachycardia > minutes epidural analgesia, maternal pyrexia, betaagonist, parasympathetica blockers, initial phase of non acute fetal hypoxemia bradycardia < 110 >10 min maternal hypothermia, betablockers,fetal arythmia, postdate pregnancies Variability 24

25 analysis of tracing accelerations increase of more 15 bpm more than 15 sec after w establishment of fetal behavioural states : absence of accelerations during deep sleep for 50 minutes (cycling!!!) accelerations coincident with contractions especially in the second stage of labor suggest possible erroneous recording of the maternal hearth rate

26 analysis of tracing The expulsive effort of women during the second stage of labour is associated with a maternal tachycardia and hence accelerations of the fetal heart rate observed with contractions or maternal pushing during second stage must be viewed with caution 26

27 analysis of tracing decelerations early variable : baroreceptor mediated responce to increased arterial pressure seldom correlated to acidosis but if Ushaped component, reduced variability, duration >3 min 27

28 analysis of tracing late decelerations chemoreceptor mediated response to fetal hypoxemia when contraction are adequately monitored dec start more than 20 sec after the onset of contraction 28

29 Acute hypoxia prolonged decelerations lasting more than 3 min chemoreceptor mediated component indicating acute hypoxia and acidosis and require emergent intervention -association with hypoxia /acidosis ph drops 0.01 every 1 min 29

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32 CTG classification ctg classification every 30 minutes 32

33 actions in situations of suspected fetal hypoxia/acidosis excessive uterine activity stop oxytocine tocolysis stop pushing aortocaval compression change maternal position fluid administration during the second stage of labor acidosis may develo more rapidly 33

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35 Second stage- periodo espulsivo Il fatto di percepire l espletamento del parto come temporalmente vicino, determina nel II stadio una maggior tendenza all accelerazione sistematica dei tempi di fronte a tracciati CTG non rassicuranti o indeterminati. Questo si traduce in una sottovalutazione degli effetti deleteri della tachisistole, che non solo non viene corretta se presente, ma talvolta deliberatamente provocata mediante un utilizzo spesso indiscriminato dell infusione di ossitocina, con un controllo meno rigoroso dei dosaggi rispetto al periodo dilatante. L incitamento ad esercitare sforzi espulsivi vigorosi, su comando, a glottide chiusa e di durata prefissata, con l intento di accelerare l espletamento del parto si inserisce negativamente in questo contesto. (LG SLOG) Antonella Cromi nessuna delle principali classificazioni della cardiotocografia proposte da società scientifiche internazionali distingue il periodo dilatante dall espulsivo la classificazione proposta da Melchior & Bernard nel 1972, rivista da Piquard nel 1988 dimostrato un valore prognostico 35

36 Misure correttive in presenza di CTG anomala in periodo espulsivo Cosa viene fatto: Si mette la donna in posizione litotomica Si aumentano le contrazioni Si incoraggia la donna a spingere ad ogni contrazione, Si comincia a fare l appoggino Spesso si crea panico Cosa bisognerebbe fare: Rallentare le contrazioni (ridurre la ossitocina!) Far spingere la donna a spinte alternate Far spingere in posizione laterale Stimolare lo scalpo fetale O2?? Liquidi?? Calma e sangue freddo

37 Take home messages La demonizzazione della cardiotocografia ha origini nel suo scorretto utilizzo, scorretta interpretazione e scorretta risposta L outcome su cui valutare la sensibilità della cardiotococografia in travaglio non può essere la mortalità o la paralisi cerebrale L analisi dei tracciati secondo la pattern recognition determina errori nella valutazione prognostica La classificazione del tracciato deve esser ripetuta periodicamente analizzando tutte le sue componenti e confrontando con il primo tracciato Il tracciato va contestualizzato nella situazione clinica della madre e del feto Un tracciato classe 2 ACOG o sopetto FIGO non significa necessariamente un taglio cesareo o un parto operativo 37

38 St.George s management Testo 38