الفهرس 
الملخص العربى
Physiology of Oxygen Delivery to the FoetusOnly 14 pages are availabe for public view
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Abstract
Update In Intrapartum Fetal Monitoring
Since the introduction of EFM into the practice of obstetrics, clinicians have been deluged with conflicting information concerning its usefulness in reducing foetal morbidity and mortality. Despite criticism, EFM is currently used for evaluation of most labouring patients in the United States; therefore, it is imperative that physicians and nurses using this technology understand basic foetal physiology and principles of EFM. Clinicans must use standardized and unambiguou; definitions for FHR tracings and must be able to differentiate normal FHR tracings from abnormal tracing.
The American College of Obstetricians and Gynecologists (ACOG) after considerable debate in 1988 reported that EFM offered no benefit over intermittent ausculation in labour management, thus removing EFM as required for even a high- risk pregnant patients ACOG, (1995).
However, only few practitioners or hospitals in the United States removed EFM units from their labour and delivery floors . As a matter of fact, EFM steadily increased. By the late 1980s, nuirses and physicians had found EFM helpful in obstetric, wards, with large number of anecdotal cases associating EFM with saving the life of a foetus or significantly alerting the health care team of an impending problem.
In 1993, five years after the ACOG’s decision to no longer support EFM over intermittent auscultation, Vintzeleos, (1993), reported the results of a randomized study that revealed a reduction in perinatal mortality attributed to foetal hypoxia. In a follow-up study in 1995 in which a meta- analysis of nine randomized trials comprising 18,561 patients was performed, it was concluded that the use of EFM in labour was associated with a reduction in death caused by foetal hypoxia by approximately 60% (Vintzelios et al., 1995). The meta-analysis also concluded that approximately 1 perinatal death per 1000 birth may be prevented by use of EFM during labour. The meta-analysis revealed an increase in operative deliveries in the EFM group, in particular, an increased cesarean section and forceps rate for suspected foetal distress of 2.55- and 2.50 fold, respectively.
In that same year, Tacker et al ., (1995) published a review article on the efficacy and safety of intrapartum EFM. Based on a review of 12 published randomized clinical trials including 58,855 pregnant women and their newborns from 10 clinical centers in the United States, Europe, Australia, and Africa, it was concluded that the only clinically significant benefit from the use of routine EFM in Jow-or high-risk pregnancies was a reduction of neonatai seizures (Tlmcker et al., 1995). They suggested that much is still to be learned about labour and its effects on the foetus. Despite the support for intermittent auscultation by the ACOG, its use is limited in the United States. Studies on intermittent ausculation versus EFM have revealed interesting findings. In large randomized study comparing intermittent ausculation with EFM, Ellison and co - workers noted that only one pattern (late decelerations) correlated significantly with neonatal neurologic examinations in the first week of life. They concluded th’at a technology {EFM} that defines more than 40% of heart rate patterns as deviant cannot possibly be accurate in predicting a very low frequency outcome such as neurolgical abnormalities (ElIison etal., 1991). In a study of 862 labouring patients undergoing intermittent auscultation as outlined by the ACOG, Morrison et al., (1993) found that in 420 patients, intermittent auscultation was not begun because of the inability of nurses to meet a i:l staffing requirement; in 12 patients, ausculation could not be performed because of maternal obesity. Of the 423 patients undergoing intermittent ausculation, 392 were unable to complete appropriate monitoring because of frequency of requirements or recording criteria. Only 31 partients in the entire group were successfully monitored with intermittent auscultation, and these patients all had 1:1 nursing care. Clearly, many busy obstetric units are unable to meet the requirements of intermittent ausculation to avoid criticism in the event of an unsuspected poor outcome.
Because of the difficulties mentioned previously, nurses and physicians use EFM in most labouring patients; there continues to be need for appropriate education on the use of EFM interpretation. The best method to educate physicians and nurses on the use EFM is an important question to ask and answer. Because of the lack of agreement on EFM terminology, definitions, or treatment guidelines, considerable variations exists in the mariner in which clinicians approach the use of” EFM.
Despite numerous attempts to formalize the subject of EFM, no recommendations have been agreed on by the large number of health care professionals providing care for labouring patients. The National Institute of Child Health and Human Development (NICHD) convened a research planning workshop oetween May 1995 and November 1996 to develop standarlized and unambiguous definitions of FHR tracings, , which it was hoped would be used by all clinicians in teaching, practice, and research. The NICHD’s effort published in December 1997, has paved the way for an ”improved dialogue between physicians and nurses as well as helping to implement more meaningful research.(NICHD wokshop 1997).
The purpose of the workshop was to develop standardized and unambiguous definitions for FHR tracings and to publish research recommendations. The following assumptions and factors common to
FHR interpretation in North America were included intheNICHD report:
1- The definitions are primarily developed for visual interpretation of the FHR pattern.
2- The definitions apply to the interpretation of patterns produced from either a direct foetal electrode detecting the foetal electrocardiogram or an external Doppler device detecting the FKR events with use of the autocorrelation technique.
3-The prime emphasis is on intrapartum patterns; however, the definitions are also applicable to antepartum observations.
4- The characteristics to be defined are those commonly used in clinical practice, and no prior assumptions are made regarding the putative cause of the pattern or its relationship to hypoxemia or metabolic acidemia.
5-The patterns to be defined are characterized as baseline foteal heart rate activity or periodic foetal haert rate patterns. Periodic patterns are associated with uterine contractions, whereas baseline patterns are not associated with uterine contractions.
6-The periodic patterns are distinguished on the basis of waveform currently accepted as abrupt versus gradual onset of the deceleration.
7-No distinction is made between short- term variability (or beat- to- beat variability or R-R wave peroid differences in the electrocardiogram) and long- term variability because in actual practice they are visually determined as a unit. The definition for variability is based visually on the amplitude of the complexes with exclusion of the regular sinusoidal pattern. The sinusoidal pattern differs from variability in that it has a smooth sine wavelike pattern of regular frequency and amplitude. It is therefore excluded in the definition of FHR variability.
8- The individual components of the FHR patterns that are defined usually evolve over time; therefore, a full description of FHR tracing requires both qualitative and quantitative description of baseline rate, baseline FHR variability, the presence of accelerations, periodic or episodic decelerations, and changes or trends of FHR patterns over time.foetal heart rate patterns of deceleration and variability were also defined.
The Royal college of obst and Gyn.,(200I) on the other hand dida
remarkable MYort as regards to the lntrapartum assessment of foetal well
being. The following algorithm offers a brief and a very clear guideline presented by the Royal college; According to the reviews of the Cochrane library, 2000, the Following has to be noted:
The Cochrane Review compared the effect on newborn and maternal outcomes of routine electronic monitoring of fetal heart rate (EFM) and of the use of intermittent auscltai ion during labour. Data from nine trials involving more than 18000 women indicated that except for helping to reduce neonatal seizures there are no other short or long term benefits of EFM. The use of EFM was associated with significant increases in the use of caesarean section and assisted vaginal delivery.
Moreover the following was documented in the Cochrane review, 2000:
”Electronic fetal monitoring was introduced into widespread clinical practice before evidence from Randomised control trials (RCTs) demonstrated either efficacy or safety. Some have argued that the RCTs were conducted before the technology was sufficiently developed, and that its true benefit may be undervalued. Technologies such as EFM need to be developed carefully and tested in limited settings, usually academic centers, before widespread diffusion. Their efficacy and safety need to be clearly demonstrated before they become in robtine practice. As evident from the experience with EFM/, Widespread diffusion of a technology bef jre efficacy and safety are detenrined can lead to misuse, misunderstanding, and unnecessary concerns with malpractice. The benefits once claimed for EFM are clearly more modest than once believed and appear to be primarily in the prevention of neonatal seizures. However, the long-term implications of this outcome appear less serious than once believed. Abno-mal neurologic consequences were not consistently higher amon; children monitored by auscultation relative to those monitored electronically. At the same time, the risks associated with the.use of EFM, especially the risk of cesarean delivery, appear to have been reduced but not eliminated. Therefore, the current American College of Obstetricians and Gynecologists position, which leaves the decision to the woman and her clinician, seems prudent.”
As regards to the world Health Organization Reproductive Health Library (WHO RHL), the following was also documented in the Cochrane review, 2000: ”Routine EFM must be abandoned in low-risk pregnancies. High-risk pregnancies must be referred with the choice between the use of EFM or intermittent auscultation being left to the judgement of the attending physician. This seems to be a reasonable approach until some questions related to the real value of EFM in preventing adverse neonatal outcomes are answered.
Finally After literature reviews cited in this essay & taking into consideration cost benefit analysis, the recommendations offered by the royal college of obstetrics &. Gynaecology seem to be most appropriatt in our Egyptian hospitals. However, further investigations in the form of randomized control studies should be performed so as to justify this trend.