Recomendaciones para el empleo de técnicas neurofisiológicas en el diagnóstico de muerte encefálica de la Sociedad de Neurofisiología Clínica de las Comunidades de Valencia y Murcia / Recommendations for the use of neurophysiological techniques in the diagnosis of brain death from the Clinical Neurophysiology Society of the Communities of Valencia and Murcia

En España, el trasplante de órganos constituye uno de los mayores retos y trabajo en equipo de los centros hospitalarios. Se estima que en 2020 España aportó a la Unión Europea el 19% de la totalidad de los donantes. El diagnóstico de apoyo confirmatorio recomienda por ley algunas técnicas complementarias en determinados casos, entre ellas las técnicas neurofisiológicas, en especial el uso del electroencefalograma y los potenciales evocados. Estos casos plantean al neurofisiólogo clínico la toma acertada de decisiones tanto clínicas como técnicas para su correcta realización e interpretación. Hasta ahora no existe a nivel nacional un consenso de realización de estas técnicas. Es una revisión bibliográfica actualizada sobre las técnicas neurofisiológicas (electroencefalograma y potenciales evocados), con análisis mediante método Delphi y juicio de expertos del grupo de trabajo de la Sociedad de Neurofisiología Clínica de las Comunidades de Valencia y Murcia. Las técnicas neurofisiológicas permiten ser un apoyo en el diagnóstico de muerte encefálica, tanto de forma confirmatoria como para acortar tiempos de observación. Para su realización se precisan unos mínimos estándares técnicos que permitan realizar de forma óptima los estudios. Especialmente hay que tener en cuenta la medicación, la situación hemodinámica, la ausencia de hipotermia y el grupo de edad. Presentamos la primera guía en castellano elaborada por la Sociedad de Neurofisiología de las Comunidades de Valencia y Murcia para la realización en nuestros hospitales de las técnicas neurofisiológicas en el diagnóstico de muerte encefálica.(AU)

In Spain organ transplantation constitutes one of the greatest challenges and teamwork of hospital centres. It is estimated that in the year 2020 Spain contributed 19% of all donors to the European Union. The confirmatory support diagnosis recommends by law some complementary techniques in certain cases, including neurophysiological techniques, especially the use of electroencephalogram and evoked potentials. These cases require the clinical neurophysiologist to make the right clinical and technical decisions for the correct performance and interpretation of the same. To date, there is no national consensus on the performance of these techniques. Updated bibliographic review on neurophysiological techniques (electroencephalogram and evoked potentials). Analysis by Delphi method and expert judgment of the working group of the Clinical Neurophysiology Society of the Communities of Valencia and Murcia. Neurophysiological techniques can be a support in the diagnosis of encephalic death, both confirmatory and to shorten observation times. In order to perform them, minimum technical standards are required to allow optimal performance of the studies, especially taking into account medication, hemodynamic situation, absence of hypothermia, and age group. We present the first guide in Spanish elaborated by the Society of Neurophysiology of the Communities of Valencia and Murcia for the performance in our hospitals of neurophysiological techniques in the diagnosis of brain death.(AU)

[Recommendations for the use of neurophysiological techniques in the diagnosis of brain death from the Clinical Neurophysiology Society of the Communities of Valencia and Murcia]. / Recomendaciones para el empleo de técnicas neurofisiológicas en el diagnóstico de muerte encefálica de la Sociedad de Neurofisiología Clínica de las Comunidades de Valencia y Murcia.

In Spain organ transplantation constitutes one of the greatest challenges and teamwork of hospital centres. It is estimated that in the year 2020 Spain contributed 19% of all donors to the European Union. The confirmatory support diagnosis recommends by law some complementary techniques in certain cases, including neurophysiological techniques, especially the use of electroencephalogram and evoked potentials. These cases require the clinical neurophysiologist to make the right clinical and technical decisions for the correct performance and interpretation of the same. To date, there is no national consensus on the performance of these techniques. Updated bibliographic review on neurophysiological techniques (electroencephalogram and evoked potentials). Analysis by Delphi method and expert judgment of the working group of the Clinical Neurophysiology Society of the Communities of Valencia and Murcia. Neurophysiological techniques can be a support in the diagnosis of encephalic death, both confirmatory and to shorten observation times. In order to perform them, minimum technical standards are required to allow optimal performance of the studies, especially taking into account medication, hemodynamic situation, absence of hypothermia, and age group. We present the first guide in Spanish elaborated by the Society of Neurophysiology of the Communities of Valencia and Murcia for the performance in our hospitals of neurophysiological techniques in the diagnosis of brain death.

TITLE: Recomendaciones para el empleo de técnicas neurofisiológicas en el diagnóstico de muerte encefálica de la Sociedad de Neurofisiología Clínica de las Comunidades de Valencia y Murcia.En España, el trasplante de órganos constituye uno de los mayores retos y trabajo en equipo de los centros hospitalarios. Se estima que en 2020 España aportó a la Unión Europea el 19% de la totalidad de los donantes. El diagnóstico de apoyo confirmatorio recomienda por ley algunas técnicas complementarias en determinados casos, entre ellas las técnicas neurofisiológicas, en especial el uso del electroencefalograma y los potenciales evocados. Estos casos plantean al neurofisiólogo clínico la toma acertada de decisiones tanto clínicas como técnicas para su correcta realización e interpretación. Hasta ahora no existe a nivel nacional un consenso de realización de estas técnicas. Es una revisión bibliográfica actualizada sobre las técnicas neurofisiológicas (electroencefalograma y potenciales evocados), con análisis mediante método Delphi y juicio de expertos del grupo de trabajo de la Sociedad de Neurofisiología Clínica de las Comunidades de Valencia y Murcia. Las técnicas neurofisiológicas permiten ser un apoyo en el diagnóstico de muerte encefálica, tanto de forma confirmatoria como para acortar tiempos de observación. Para su realización se precisan unos mínimos estándares técnicos que permitan realizar de forma óptima los estudios. Especialmente hay que tener en cuenta la medicación, la situación hemodinámica, la ausencia de hipotermia y el grupo de edad. Presentamos la primera guía en castellano elaborada por la Sociedad de Neurofisiología de las Comunidades de Valencia y Murcia para la realización en nuestros hospitales de las técnicas neurofisiológicas en el diagnóstico de muerte encefálica.

Hormone-sensitive lipase deficiency disturbs the fatty acid composition of mouse testis.

Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from intracellular stores. In mice, HSL deficiency results in male sterility caused by a major defect in spermatogenesis. The testes contain high concentrations of PUFA and specific PUFA are essential for spermatogenesis. We investigated the fatty acid composition and the mRNA levels of key enzymes involved in fatty acid metabolism in testis of HSL-knockout mice. HSL deficiency altered fatty acid composition in the testis but not in plasma. The most important changes were decreases in the essential n-6 PUFA LNA and the n-3 PUFA ALA, and an increase in the corresponding synthesis intermediates C22:4n-6 and C22:5n-3 without changes in DPAn-6 or DHA acids. Mead acid, which has been associated with an essential fatty acid deficit leading to male infertility, was increased in the testis from HSL-knockout mice. Moreover, the expression of SCD-1, FADS1, and FADS2 was increased while expression of ELOVL2, an essential enzyme for the formation of very-long PUFA in testis, was decreased. Given the indispensability of these fatty acids for spermatogenesis, the changes in fatty acid metabolism observed in testes from HSL-knockout male mice may underlie the infertility of these animals.

Preregistration study on the safety and contraceptive efficacy of a progesterone-releasing vaginal ring in Chilean nursing women.

The contraceptive efficacy and safety of a progesterone-releasing vaginal ring (PVR) manufactured in Chile were compared to that of the Copper T 380A IUD (T-Cu) in nursing women enrolled at three Chilean clinics. A total of 285 volunteers chose to use the PVR and 262 the T-Cu. Plasma progesterone levels attained with the ring decreased from 25 to 14 nmol/L from month 1 to month 3 of use. Ring replacement was scheduled every 3 months. Volunteers continued in the study until weaning or completing the continuous use of four PVRs. No pregnancies occurred in 2320 and 2183 woman-months of exposure with the PVR and the T-Cu, respectively. Lower continuation rates in the first 6 months because of problems with use and a longer lactational amenorrhea were observed in the PVR than in the T-Cu group. Breast-feeding performance and infant growth were similar in both groups. These results confirm the high efficacy and safety of the PVR for nursing women and have led to the registration of the PVR by Chilean health authorities.

PIP: This study compares the contraceptive efficacy and safety of a progesterone-releasing vaginal ring (PVR) manufactured in Chile and a Copper T 380A IUD (T-Cu) in nursing women enrolled at three Chilean clinics. A total of 285 volunteers used the PVR and 262 used T-Cu. Plasma progesterone levels attained with the ring decreased from 25 to 14 nmol/l from month 1 to month 3 of use. Ring replacement was scheduled every 3 months. Volunteers continued in the study until weaning or completing the continuous use of 4 PVRs. There were no pregnancies in 2320 and 2183 woman-months of exposure with the PVR and the T-Cu, respectively. Lower continuation rates in the first 6 months because of problems with use and a longer lactational amenorrhea were seen in the PVR group. Breast-feeding performance and infant growth were similar in both groups. These results prove the high efficacy and safety of the PVR for nursing women. This has led to the registration of the PVR by Chilean health authorities.

Fertility regulation in nursing women. IX. Contraceptive performance, duration of lactation, infant growth, and bleeding patterns during use of progesterone vaginal rings, progestin-only pills, Norplant implants, and Copper T 380-A intrauterine devices.

This study evaluated the performance of progesterone vaginal rings (n = 187), progestin-only pills (n = 117), Norplant implants (n = 120), and Copper T 380-A intrauterine devices (n = 122) in lactating women. Contraceptive efficacy, bleeding pattern, and influence of the method upon breastfeeding duration and infant growth were compared with those of untreated women (n = 236) who relied on lactational infertility. Participants were healthy, 18 to 38 years, had had a normal delivery, and were intending to breastfeed for as long as possible. Contraceptives were initiated at day 57 +/- 3 postpartum. Results are reported for the first year of use. All methods were highly effective, with pregnancy rates below 1%. None affected breastfeeding performance or the rate of infant growth. Users of the progestin-only methods experienced a period of lactational amenorrhea 4 to 5 months longer than did users of Copper T or untreated women. More than half of the women in each contraceptive group reported a bleeding in the first month after treatment initiation, which was not considered in the calculation of the duration of amenorrhea. Prolonged or frequent bleedings were infrequent. The proportion of bleedings lasting more than 10 days ranged from 0 in the progestin-only pills group to 7% in the Norplant implants group. The four methods, initiated around the eighth postpartum week, provided effective contraception with no negative effects upon lactation or infant growth and without the bleeding problems associated with their use in nonlactating women.

Breast-feeding duration and growth of fully breast-fed infants in a poor urban Chilean population.

The duration of breast-feeding and the growth of fully breast-fed infants during the first year of life were analyzed according to sex, birth weight, characteristics of the mother, and breast-feeding pattern. All infants (n = 1217) were healthy and fully breast-fed at 30 d postpartum and 63% and 24% were still fully breast-fed at 6 and 12 mo, respectively. The median ages at introduction of nondairy food and of milk supplements were 6.0 and 7.4 mo, respectively. The probability of remaining fully breast-fed for 12 mo was significantly higher in infants with higher birth weight and higher maternal weight, and in infants who breast-fed seven times a day or more in the first 6 mo. The comparison of the monthly weight and length of fully breast-fed infants with the World Health Organization/National Center for Health Statistics reference data showed the adequacy of breastfeeding to support infant growth. When mothers and infants are healthy, breast milk is sufficient to support adequate infant growth and health during the first months of life. The main variables that affect the duration of breast-feeding, nutrition and suckling frequency, are susceptible to interventions by health services. The results reinforce the need to care for maternal nutrition during pregnancy and to provide the support that women need to sustain a high suckling frequency.

Contraceptive efficacy of lactational amenorrhea in urban Chilean women.

The contraceptive efficacy of breastfeeding was assessed in 236 healthy urban women who were followed at monthly intervals during the first postpartum year. Proportional hazard models were used to evaluate the influence of time postpartum, menstrual status and breastfeeding pattern upon the risk of pregnancy. Time and menstrual status had a highly significant effect on this risk. Those women who remained in amenorrhea had cumulative probabilities of pregnancy of 0.9% and 17% at 6 and 12 months postpartum, respectively. In those who recovered menstrual cycles, the risk rose to 36% and 55% at 6 and 12 months, respectively. Milk supplementation also increased significantly the risk when considered alone but not when time and/or menstrual status were included in the analysis. However, amenorrheic women who introduced bottle feeding, had a higher risk of pregnancy after 6 months postpartum than those who remained fully nursing. The analysis was unable to detect a significant influence of the nursing frequency. The results confirm that lactational amenorrhea is an effective contraceptive during the first six months postpartum. The first postpartum bleeding marks a great increase in the risk of pregnancy. Supplementation also increases the risk, particularly in amenorrheic women.

Breastfeeding pattern and the duration of lactational amenorrhea in urban Chilean women.

The influence of the breastfeeding pattern and several clinical variables upon the duration of postpartum amenorrhea was assessed in a group of healthy women selected for having had a normal pregnancy and delivery and being highly motivated for prolonged breastfeeding on demand. 676 women who were fully nursing at the second month postpartum entered the study. Supplements were administered to 11% and 48% of the infants by the end of the 3rd and 6th month, respectively. The first bleeding was experienced before the end of the sixth month postpartum by 57% of the cases. Supplementation had a strong negative influence while nursing frequency had a significant positive influence upon the length of amenorrhea. Notwithstanding, a frequency of 8+ suckling episodes per 24 h could not maintain amenorrhea in around half of the subjects. Age and parity had a moderate negative influence upon the risk of experiencing the first postpartum bleeding. Maternal weight and ponderal index, infant sex, birth weight and growth rate showed no significant influence upon the length of amenorrhea. In this urban population selected for having the highest motivation and best breastfeeding performance, the association of breastfeeding with amenorrhea was weak in comparison with what has been described for other populations. The risk of experiencing the first bleeding was reduced while fully breastfeeding with a high number of nursing episodes per day and night, particularly in older women with higher parity. But even in such situation 25% and 50% of the women had started to cycle by the end of the fifth and eight postpartum month.

Lactational amenorrhea and the recovery of ovulation and fertility in fully nursing Chilean women.

The probability of experiencing the first postpartum bleeding, the first ovulation and the risk of pregnancy during exclusive breastfeeding was assessed in a selected group of urban Chilean women. Admission criteria included having had a normal pregnancy and a vaginal term delivery of a healthy infant and the desire to maintain breastfeeding for as long as possible. The risk of bleeding and the recovery of ovulation was assessed in 48 women selected for being amenorrheic and fully nursing at day 75 postpartum and their willingness to participate in the blood sampling protocol. The first bleeding and ovulation was experienced while fully nursing by 28% and 26% of these subjects, respectively, at day 180 postpartum. The probability of experiencing the first bleeding and the probability of pregnancy during full nursing were calculated for 236 women not contracepting who were enrolled during the first month postpartum. The cumulative probability of bleeding and of pregnancy was 52% and 9.4% at day 180 postpartum, respectively. The risk of pregnancy was less than 2% in the subset of amenorrheic cases. In this urban population selected for having the highest motivation and best breastfeeding performance, the association of breastfeeding with infertility was too weak to serve as an effective birth spacer, except for the period of lactational amenorrhea. When the first postpartum bleeding took place before the sixth postpartum month in fully nursing women, it had a good predictive value to indicate the onset of a higher risk period.

Fertility regulation in nursing women: VIII. Progesterone plasma levels and contraceptive efficacy of a progesterone-releasing vaginal ring.

The objectives of this trial were to test the contraceptive efficacy and measure progesterone plasma levels of women using progesterone-releasing rings during lactation. Two types of rings delivering an average of about 5 mg or 10 mg of progesterone per day were tested in 128 healthy nursing women. A control group was formed by 127 Copper T users. Rings were inserted at day 60 postpartum and replaced every 3 months with a new one. Initially progesterone plasma levels were around 10 nmol/l and 15 nmol/l for rings releasing 5 and 10 mg per day, respectively, and decreased slightly after 30 days. Levels observed in subsequent segments of use approximated those of the first segment. These levels are within the range shown to inhibit fertility in lactating women. One pregnancy was diagnosed in 739 woman-months of progesterone ring use, and none occurred in 794 woman-months of Copper T use, which contrasts with the high incidence of pregnancy in a group of untreated nursing women where 19 pregnancies resulted during 677 woman-months. No deleterious effects were detected lactation and infant growth or maternal and infant health. It is concluded that the vaginal rings releasing progesterone are a suitable contraceptive method for lactating women.

Fertility regulation in nursing women: VII. Influence of NORPLANT levonorgestrel implants upon lactation and infant growth.

The objective of this study was to test the influence of NORPLANT implants upon lactation and infant growth. The results obtained during the first postpartum year are reported. One-hundred women were enrolled in the implant group. The control group was formed by 100 women who received a Copper T IUD. Treatments were administered at day 55 +/- 3. At admission all subjects were in exclusive breastfeeding with an adequate weight increase of the infant. No significant differences were found between the treated and control groups in the percentage of women in full nursing at different postpartum intervals, except for the 12th month postpartum where a lower percentage of cases from the NORPLANT group was in the full nursing category. No difference was found in the time of weaning. The infants showed a normal weight gain rate in both groups although the girls from the NORPLANT group showed a significantly lower daily weight increase during the 4th month than the girls from the IUD group. No pregnancies were diagnosed. No women asked for implant removal during the first year. No serious side effects related to treatment were detected. Bleeding irregularities were rare during breastfeeding which is in contrast with what occurs in non-nursing women treated with NORPLANT implants. Levonorgestrel concentrations found in milk were variable and individual values ranged from 23 to 311 pg/ml. The dose received by the infant can be estimated around 15 to 18 ng/Kg/day during the first month of treatment when the higher plasma values of levonorgestrel are observed. These levels is conjunction with the clinical observations reported here minimize the potential problems associated with levonorgestrel transference through maternal milk. Nevertheless, long-term studies are required to settle this matter and until more information is available, NORPLANT implant use in lactating women should be limited to cases who require a highly effective contraceptive method and where non-hormonal methods of similar effectiveness are contraindicated or unacceptable.

Fertility regulation in nursing women. VI. Contraceptive effectiveness of a subdermal progesterone implant.

Six progesterone pellets implanted subdermally were tested as contraceptive method for lactating women. One pregnancy was diagnosed in 1614 woman-months of observation, a failure rate which was similar to that observed in a contemporary group of Copper T users. Nineteen pregnancies were diagnosed in the 677 woman-months observed in untreated lactating women. The progesterone implants were effective when administered either at 30, 60 or 240 days after delivery. The duration of the effective life was 5 months and fertility was quickly restored afterwards. There were no deleterious effects upon maternal or infant health or upon lactation and the rate of child growth. The main problem encountered was the occurrence of pellet expulsion at a variable rate which appeared related to the manufacturing procedure.

Growth pattern of selected urban Chilean infants during exclusive breast-feeding.

This report describes the growth pattern of healthy, low middle and low socioeconomic class Chilean infants during exclusive breast-feeding. Two-hundred forty-two infants who were on exclusive breast-feeding at day 30 postpartum entered the study. Of these, 59% were fully nursing at 6 months and grew at a normal rate without receiving either supplementary milk or nondairy food. Supplementary feedings were administered in 27% of cases because of suspected primary inadequate milk output and in 14% of cases for other reasons such as pregnancy, illness, maternal work, or self-prescription. Full nursing provided the highest rate of weight increase during the first 3 months of life and a greater weight gain for boys than for girls up to the age of 6 months. Gastrointestinal pathology, malnourishment, or hospitalization were rare events in this population. It is concluded that maternal milk alone, if produced in sufficient amounts, can maintain normal growth up to the 6th month of life. The study supports the choice of exclusive breast-feeding on demand plus child growth monitoring up to 6 months over routine prescription of supplements at earlier times particularly where supplement administration fails to meet individual requirements.

PIP: This report describes the growth pattern of healthy, low middle and low socioeconomic class Chilean infants during exclusive breastfeeding. 242 infants who were on exclusive breastfeeding at day 30 postpartum entered the study. Of these, 59% were fully nursing at 6 months and grew at a normal rate without receiving either supplementary milk or nondairy food. Supplementary feedings were administered in 27% of the cases because of suspected primary inadequate milk output and in 14% of cases for other reasons such as pregnancy, illness, maternal work, or self prescription. Full nursing provided the highest rate of weight increase during the 1st 3 months of life and greater weight gain for boys than for girls up to the age of 6 months. Gastrointestinal pathology, malnourishment, or hospitalization were rare events in this population. It is concluded that maternal milk alone, if produced in sufficient amounts, can maintain normal growth up to the 6th month of life. The study supports the choice of exclusive breast feeding on demand plus child growth monitoring up to 6 months over routine prescription of supplements at earlier times particularly where supplement administration fails to meet individual requirements.

Fertility regulation in nursing women: III. Short-term influence of a low-dose combined oral contraceptive upon lactation and infant growth.

The study was designed to test the short-term influence of a low-dose combined oral contraceptive upon lactation and infant growth when treatment was initiated at day 30 postpartum. The contraceptive tested contained ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg. Two control groups were formed by women who received either an oral placebo or an injectable placebo at day 30 postpartum. An exacting list of requirements for admission and continuation in the study was applied to all groups. The oral contraceptive group had a lower percentage of cases in exclusive breastfeeding at day 91 postpartum when compared to both control groups. Infants in the oral contraceptive group showed a significantly lower average absolute weight at days 61 and 91 postpartum and a significantly lower average daily weight increase during the first month of treatment when compared to both control groups. It was concluded that the oral contraceptive tested had a negative influence upon lactation and child growth.