Extreme Prematurity - Practices, Bioethics, And The Law Part 2 potx

P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 4 INFLUENCE OF OBSTETRIC MANAGEMENT H ow physicians, in particular obstetricians, view and assess viability can affect perinatal survival figures. In an American study(44) that examined the relationship between obstetric care during labor and delivery and the survival of EPTIs, the authors compared the outcomes of those who were considered viable ante- natally and those who were not. The factors evaluated in the judg- ment of viability were estimated age (> 26 weeks) and estimated weight (> 650g), lethal anomalies, and parental requests. In the total population studied, some were misclassified (usually weight estimation), or parents had requested aggressive management or the opposite. This “allowed” the authors to study the survival of infants who, by their standards, would have been considered non- viable but who received antenatal and perinatal care as if they were viable. Although in some groups the numbers were small, the chances of survival were strongly associated with the ante- natal assessment of viability. The odds of survival for all fetuses treated as viable were 17 times the odds for those considered non- viable. Birth weight alone did not explain wholly the relationship between antepartum viability assessment and outcome. Thus, in 16 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 INFLUENCE OF OBSTETRIC MANAGEMENT this study, survival of the EPTI was related to judgments of viabil- ity that determined their care. Silver et al. also published similar findings.(45) These studies, which had relatively small numbers, do not suggest that there is no limit to fetal viability, but they do caution the reader to take into account obstetric management strategies when examining figures concerning the outcome of the EPTI. Obstetricians evaluate antenatal data to make decisions concerning the management of an anticipated extremely preterm delivery. Bottoms et al.(46,47) evaluated whether antenatal infor- mation could accurately predict the survival of ELBW infants with and without major morbidity, using data collected in 1992–1993. The reported findings were that the willingness of an obstetrician to perform a cesarean section at 24 weeks’ gestation was associ- ated with an improvement in survival from 33% to 57%, but the risk of serious morbidity doubled from 20% to 40%. Survivals, and survival without disability, were significantly better when birth resulted from active medical management, compared to a passive approach, with or without cesarean section. The use of prepartum ultrasonographic data could not reliably distinguish who would survive without serious morbidity, although there was a threshold below which no survivors were found. 17 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 5 EFFECT OF RESUSCITATION IN THE DELIVERY ROOM I n 1996, Rennie wrote that outcome after full cardiopulmonary resuscitation (CPR) following delivery of a very preterm infant was “appalling.”(48) Her justifications for this conclusion were reports published in the early 1990s. In one, from Manchester, England, three of five babies born less than 28 weeks’ gestation, who received full CPR, including adrenaline, died and the sur- vivors were handicapped.(49)Inareport from Oklahoma, there were no survivors of very low birth weight (VLBW) infants who required more than one resuscitative attempt.(50)Insimilar cir- cumstances there were only two normal survivors, during the years 1989–1993, reported in a study from Cambridge, England, and all six infants given full CPR in Ottawa, Canada, with birth weights less than 750g, during 1989–1992, died.(51)Insharp contrast to these reports are later ones that suggest that condition at birth of an EPTI may not be a good indicator of viability or later out- come.(52) Jankov, Asztalos, and Skidmore evaluated whether vig- orous resuscitation of ELBW infants at birth improved survival or increased the chances of major neurodevelopmental disability. They reported the outcome of a group of infants born weighing 18 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 EFFECT OF RESUSCITATION IN THE DELIVERY ROOM 750g or less who received CPR (positive pressure ventilation, car- diac compression, +/− adrenaline) in the delivery room. About 57% survived, and 88% were free of major neurodevelopmental disability at follow-up.(53) Similar findings have been published by several other authors(54–56) and it does appear that CPR in the delivery room for the EPTI does not necessarily lead to a large decrease in survival or an increase in major neurologic sequelae compared to those who survived following only intubation and positive pressure ventilation. 19 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 6 NATIONAL COMPARISONS O utcomes for the EPTI may differ from country to coun- try; the reasons include economic resources and access to sophisticated technological care in developing countries and vary- ing attitudes and perceptions in the more developed countries. The latter will be discussed later in this chapter, but here I briefly document findings concerning the Netherlands and survival in some developing countries. Lorenz et al.(22) reported on the out- come of EPTIs born less than 26 weeks in two population-based cohorts, New Jersey (NJ), United States and the Netherlands, who received systematically different approaches to their care during the mid-1980s. In the NJ cohort, almost all babies received inten- sive care, whereas the policy was more selective in the Nether- lands. Assisted ventilation was more commonly used in NJ, 95% versus 64%, and almost all the difference resulted from the use of assisted ventilation in infants who subsequently died. Mortality at 28 days was about 46% in NJ and 73% in the Netherlands. No infant less than 25 weeks’ gestation survived to 28 days in the Netherlands. Survival to 2 years in NJ was twice that in the 20 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 NATIONAL COMPARISONS Netherlands. The prevalence of disabling cerebral palsy was 17.2% among survivors in NJ and 3.4% in the Netherlands. In the NJ cohort, 1,820 ventilator days were expended per 100 live births compared to 448 days in the Netherlands, but the difference in nonventilator days was not statistically different. In summary, the management approach in NJ resulted in 24 additional survivors per 100 live births, 7 additional cases of disabling cerebral palsy per 100 live births, and at a cost of 1,372 additional ventilator days per 100 live births.(22) That there is a significant difference in approach to the management of the EPTI in the Netherlands compared to NJ that is of great consequence is clear. How this is accomplished can be found in an article by Van der Heide and associates published in 1997.(57) Theyreportedonendoflife deci- sions for neonates in the Netherlands, and although only some of the babies were EPTIs, it does reflect attitude and practice. In the report, they stated that 57% of all infant and neonatal deaths had been preceded by a decision to forego life-sustaining treatment, and was accompanied by the administration of potentially life- shortening drugs to relieve pain or other symptoms in 23% and by the administration of drugs with the explicit aim of hastening death in 8%. Parents were involved in 79% of decisions.The most common reason for not involving parents was stated as “it was so obviously the only correct decision.”(57) The rates for neonatal mortality differ betweendeveloping and developed countries, as does the practice of neonatal care. Most worldwide neonatal deaths occur in the developing world, and at least one-third of these are in preterm infants.(58,59)Inastudy published in 2003,(58) the mortality rate for infants born at 28– 29 weeks was 478 per 1,000 live births in a geographically diverse group of developing countries (Brazil, Colombia, Thailand, India, and the Philippines) compared to 83 in two developed countries 21 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 THEEXTREMELY PRETERM INFANT (United States, Ireland). In the developing countries, interven- tions such as surfactant, ventilators, blood gases, and oximetry were variable, and several physicians considered pregnancies less than 28 weeks nonviable. How physicians judge viability affects perinatal interventions and mortality not only in developed coun- tries but also in developing ones. 22 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 7 PREDICTION OF OUTCOME T here can be substantial error rate when physicians estimate outcome for the EPTI.(60–63)Tyson and associates(30) reported error rates of 52% and 21% in the prediction of death and survival for infants weighing 501–800g at birth. Despite the requirement that physicians practice according to the best avail- able evidence, this may not always be the case, and in such circum- stances they may incorrectly estimate the chances of death and disability,(64) which affects their decisions as well as the counsel- ing of parents.(44,60) In 2001, it was reported that at the University Medical Center in Leiden, a leading center for the the treatment of preterm infants in the Netherlands, a decision, in principle, was taken to stop active intensive treatment of babies born less than 25 weeks’ ges- tation.(65) However, the head of neonatology at the center stated that, “infants born before 25 weeks would still be given ‘vigorous support’ if the parents wished and the medical team considered the infant viable at birth.”(65) The decision was made because, in their study of premature births from 1996 through 1997, 66% of those born at 23 and 24 weeks died, and half the survivors had severe physical or mental handicaps.(65) 23 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 8 LIMIT OF VIABILITY A lthough there is no sharp demarcation point, over time the limit of viability has become progressively lower, from a birth weight of 1,500g before 1940, to 1,000g and 28 weeks’ gestation by the 1970s.(20) Survival is now common for infants of less than 750g and for those of 25 weeks’ gestation. The lower limit of viability appears, at present, to be approximately 22–23 com- pleted weeks of gestation, with survival and morbidity improving markedly with each later week of gestation. It is now governed by technological capacity, medical intervention, and the attitudes of the medical profession.(63,66) 24 P1: KNR 0521862213sec1 CUFX052/Miller 0 521 86221 3 printer:cupusbw August 21, 2006 13:27 9 MORBIDITY E xtremely preterm birth is associated with several morbidi- ties ranging from the very severe to the relatively mild, and the risk increases as gestational age decreases.(67) The morbidi- ties include cerebral palsy, mental retardation, learning and lan- guage disability, disorders of attention and behavior, visual and hearing impairment, chronic lung disease, gastrointestinal dys- function, and poor growth.(68–74) Furthermore, survivors may require prolonged hospital stays, in-home nursing and technolog- ical services, and societal and state support, all of which add to emotional and financial family burdens.(75,76) Although there is some relationship between disorders of higher brain func- tion and psychosocial, socioeconomic, and environmental fac- tors,(77,78) there is now substantial evidence that neurodevelop- mental disability arises from poor brain development apart from frank parenchymal brain injury. Former EPTIs have been reported to show decreased regional brain volumes, compared to term con- trols, including reduced volumes of cortical gray matter, the hip- pocampi, and corpus callosum, in addition to an increase in the 25 [...]... more than 3 standard deviations below the mean were recorded as 22 %, 27 %, and 25 % respectively The prevalence in the Dutch population was 11% The cerebral palsy rates were 19% for New Jersey, 13% for Ontario, 16% for Bavaria, and 8% for Holland Although a significant number of children, who were ELBW, have serious neurodevelopmental disabilities, the majority do not, and the rate is least in the Dutch population... N T examined when and how a neonatologist would counsel parents expecting the delivery of an EPTI Counseling included the survival prognosis and almost always morbidity The most important factor was the gestational age of the infant At 22 weeks’ gestation only 24 % always or often counseled, and this rose to 77% at 25 weeks Otherwise it was the obstetrician who did the counseling Of the neonatologists... where there is variability and disagreement They also noted that the personal characteristics and views of the 34 PERCEPTIONS AND PR ACTICES physicians strongly influence their decision making, and that they may impose their own values on the family But the situation is one in which there is often uncertainty Because of this, many neonatologists, Rhoden wrote,(1 32) follow a “least-worst” strategy, that... nontreatment of extremely preterm, critically ill, or malformed infants in the NICU at the University of California San Francisco between 1989 and 19 92 There were 108 infant deaths, the majority of whom were ELBW, following the withdrawal of life support, and 13 deaths followed the withholding of treatment These deaths represented 73% of the total deaths, the others occurring while the infants continued... withdraw treatment, the majority of parents saw this as part of parental responsibility.” At the second interview, 13 months after the event, 98% felt the decision had been right, although there was some concern over the validity of the prognosis and the distressing dying process The authors determined that the role of the physicians is strongly influential as they “are not only the purveyors of fact... after the expected date of delivery The mean Bayley Mental Developmental Index was 84 +/− 12, and the mean Psychomotor Developmental Index was 87 +/− 13 Nineteen percent of the children had scores more than 3 standard 27 T H E E X T R E M E LY P R E T E R M I N FA N T deviations below the mean and were classified as severely disabled There were 11% who scored between 2 and 3 standard deviations below the. .. results, and those from Bavaria the lowest, relative to their peers and the other populations It should be noted that for New Jersey the ascertainment rate for psychometric testing was only 60% compared to 87% and 90% for the Bavarian and Ontario research subjects It has been reported that similar nonparticipants in other studies are more likely to have intellectual and behavioral difficulties.(115) Furthermore,... life.(133,1 42 144) 38 PERCEPTIONS AND PR ACTICES In Scotland, McHaffie, Laing, Parker, and McMillan(145) examined the practices of 176 neonatologists and nurses, in addition to the perceptions of 108 parents of 62 babies for whom there was discussion about withholding invasive treatment All the infants had a prognosis of either early death or a serious disabling impairment All of them died, and the parents... Britain( 120 ) and the United States.( 121 , 122 ) However, although adolescents who were born extremely preterm are more likely to have to cope with more health and educational challenges, studies on quality of life seem to demonstrate that most of this group do not feel that their quality of life is very different from others.( 123 , 124 ) Despite some variability in the reported rates of impairment and disability,... infants 22 27 weeks’ gestation or less than 1,000g The British services were more centralized and specialist based, but they had higher rates of prematurity and sicker babies with worse outcomes, despite the delivery of more intensive care The authors rejected the notion that this was the result of systematically worse care and suggested it was “a reflection of innate reproductive health in the two . Colombia, Thailand, India, and the Philippines) compared to 83 in two developed countries 21 P1: KNR 0 521 8 622 13sec1 CUFX0 52/ Miller 0 521 8 622 1 3 printer:cupusbw August 21 , 20 06 13 :27 THEEXTREMELY. was 87 +/− 13. Nine- teen percent of the children had scores more than 3 standard 27 P1: KNR 0 521 8 622 13sec1 CUFX0 52/ Miller 0 521 8 622 1 3 printer:cupusbw August 21 , 20 06 13 :27 THEEXTREMELY PRETERM. KNR 0 521 8 622 13sec1 CUFX0 52/ Miller 0 521 8 622 1 3 printer:cupusbw August 21 , 20 06 13 :27 NATIONAL COMPARISONS Netherlands. The prevalence of disabling cerebral palsy was 17 .2% among survivors in NJ and