Weeks Of Postconceptional Age Research Articles

Clinical characteristics of preterm ovarian hyperstimulation syndrome: seven cases from China and 14 cases from the literature

Preterm ovarian hyperstimulation syndrome (POHS) is a rare condition with only a few reported cases. The objective of this study is to investigate the clinical characteristics of 21 POHS cases (seven from China and 14 from the literature). Suspected patients (n = 7) were referred for further confirmation and data on demographics, family history, clinical manifestations (edema developed in the vulva, the hypogastric site and the upper leg), serum and sonographic assessments (ovarian cyst/cysts, gonadotropins, and estradiol levels), the natural course of patients were documented. We did not observe substantial differences in clinical manifestations among POHS patients from China relative to that from the literature. Preterm female newborns developed edema in the vulva, the hypogastric site and the upper leg at 30–39+6 weeks of post-conception age (PCA) as the major clinical manifestations. The characteristic also included high gonadotropins and estradiol, and ovarian cysts. This condition can self-resolve. Clinical manifestations of POHS patients from China are similar to those from the literature. The pathognomonic signs of POHS include vulvar, hypogastric, and upper leg edema developed at 30–39+6 PCA along with high gonadotropins and E2 values and the presence of ovarian cysts in preterm female newborns and the syndrome can self-resolve.

Echocardiographic analysis of left ventricular function in term and preterm neonates at week 40 of postconceptional life.

BACKGROUND Both gestational and chronological age of the neonate may influence and impair the function of the delicate and immature myocardium. However, the transition from fetal to neonatal circulation in preterm neonates is poorly understood. AIMS This study aimed to compare left ventricular (LV) systolic and diastolic function between premature neonates at expected term and term neonates during the postnatal cardiovascular transitional period. METHODS Using echocardiography, we assessed systolic and diastolic function of the LV in 89 preterm neonates at week 40 of postconceptional age and 29 term neonates after closure of the patent ductus arteriosus (PDA) and on the 28th day of life. Based on M‑mode images, we measured myocardial thickness and fractional shortening (FS%). Using pulsed‑wave Doppler echocardiography, we estimated cardiac output, myocardial performance index (MPI), and LV diastolic function (E and A waves, E/A ratio). Systolic and diastolic function was also assessed by tissue Doppler imaging. RESULTS Compared with term neonates on the 28th day of life, preterm neonates had reduced myocardial thickness (P ≤0.04), FS% (P = 0.002), and cardiac output (P = 0.01). However, preterm neonates had a lower MPI than term neonates after PDA closure (P <0.001) and on the 28th day of life (P = 0.02). The E/A ratio and S' wave values were similar in preterm and term neonates (P >0.05). CONCLUSIONS Preterm neonates at 40 weeks of postconceptional age have preserved systolic and diastolic function of the LV.

Cardiovascular and respiratory physiology in children.

Children are at increased risk of perioperative respiratory and cardiovascular complications because of their unique respiratory and cardiovascular physiology compared to adults. Anaesthesia can exaggerate respiratory deterioration in young children because of their inability to control respiration and inherent susceptibility to rapid desaturation, airway obstruction, early respiratory fatigue and lung atelectasis. Premature infants (less than 60 weeks of postconceptional age) can be exposed to the danger of prolonged apnoea and consequent worsening of respiratory function. The transitional phase of circulation is vulnerable to revert to persistent foetal circulation in neonates. Myocardium and autonomic control of the heart is immature and different in neonates and infants compared to older children and adults and are predisposed to inadvertent life-threatening haemodynamic changes during the perioperative period. In this review article, we discuss respiratory and cardiovascular physiology in neonates, infants and younger children and their differences with older children and adults. We mainly focus on transitional physiology of both respiratory and cardiovascular system in newborns and infants and the deleterious changes that may occur during anaesthesia or perioperatively.

Experience of Various Types of Keratoplasty in Children

The purpose: to determine the features of different stages of active retinopathy prematurely according to fluorescent angiography data.Patients and methods. In 2011–2017, 271 angiographic studies were performed in 207 premature infants born at 25–33 weeks of gestation with 710–1980 grams weight at birth, with different stages of active ROP in age of live 3–12 weeks (30-39 weeks of post-conceptual age). A voluntary informed consent to perform the examination was received from the legal representatives of all patients. FAG was performed using retinal pediatric digital video system “RetCam-3” with built-in angiographic unit under mask anesthesia, in the presence of anesthesiologist-resuscitator, under the monitor control of the respiratory and cardiovascular systems of the child.Results. Unfavorable types of active ROP are characterized by the specific manifestations that are not defined by the standard ophthalmologic methods: early flat neovascularization, the presence of small tortuous peripheral vessels with signs of leakage, reperfusion areas with an apparent lack of capillaries and shunts. This opens up the opportunities for early detection of stages of the disease requiring therapeutic measures. The aggressive posterior ROP is distinguished by a variety of angiographic patterns, the most important feature is the massive loss of the retinal capillary bed in the vascularized retina. FAG data about latent neovascularization and ischemic zones of the retina represent the particular value in the prediction of active ROP course.Conclusion. The obtained results could allow to make the most differentiated approach to the management of children with active ROP, timely and effectively predict the course of the disease and to performed adequate treatment based on objective indications.

Fluorescence Angiography to Determine the Features of Active Retinopathy of Prematurity Course

The purposeis to determine the features of different stages of active retinopathy prematurely according to fluorescent angiography data.Patients and methods. In 2011–2017, 271 angiographic studies were performed in 207 premature infants born at 25– 33 weeks of gestation with 710–1980 grams weight at birth, with different stages of active ROP in age of live 3–12 weeks (30– 39 weeks of post-conceptual age). A voluntary informed consent to perform the examination was received from the legal representatives of all patients. FAG was performed using retinal pediatric digital video system «RetCam-3» with built-in angiographic unit under mask anesthesia, in the presence of anesthesiologist-resuscitator, under the monitor control of the respiratory and cardiovascular systems of the child.Results. Unfavorable types of active ROP are characterized by the specific manifestations that are not defined by the standard ophthalmologic methods: early flat neovascularization, the presence of small tortuous peripheral vessels with signs of leakage, reperfusion areas with an apparent lack of capillaries and shunts. This opens up the opportunities for early detection of stages of the disease requiring therapeutic measures. The aggressive posterior ROP is distinguished by a variety of angiographic patterns, the most important feature is the massive loss of the retinal capillary bed in the vascularized retina. FAG data about latent neovascularization and ischemic zones of the retina represent the particular value in the prediction of active ROP course.Conclusion. The obtained results could allow to make the most differentiated approach to the management of children with active ROP, timely and effectively predict the course of the disease and to performed adequate treatment based on objective indications.

Abnormal findings in brainstem auditory evoked response at 36–37 weeks of postconceptional age in babies with neonatal chronic lung disease

AimTo examine brainstem auditory function at 36–37weeks of postconceptional age in preterm infants who are diagnosed to have neonatal chronic lung disease (CLD). Study designPreterm infants, born at 31 and less weeks of gestation, were studied at 36–37weeks of postconceptional age when they were diagnosed to have neonatal CLD. Brainstem auditory evoked response (BAER) was recorded and analyzed at different click rates. ResultsCompared with healthy controls at the same postconceptional age, the CLD infants showed a slightly increase in BAER wave V latency. However, the I-V, and III–V interpeak intervals in the CLD infants were significantly increased. The III–V/I–III interval ratio was also significantly increased. The amplitudes of BAER waves III and V in the CLD infants tended to be reduced. These BAER findings were similar at all 21, 51 and 91/s clicks, although the abnormalities tended to be more significant at higher than at low click rates. ConclusionAt 36–37weeks of postconceptional age, BAER was abnormal in preterm infants who were diagnosed to have neonatal CLD. This suggests that at time when the diagnosis of CLD is made there is functional impairment, reflecting poor myelination, in the brainstem auditory pathway in preterm infants with neonatal CLD.

Myocardial performance index (Tei index) in term and preterm neonates during the neonatal period.

The myocardial performance index (MPI) is a noninvasive method to measure global systolic and diastolic myocardial function. In both term and premature neonates, changes in the systolic and diastolic function of the left ventricle (LV) and right ventricle (RV) reflect the degree of neonatal myocardial immaturity and the co-existence of foetal circulation. To assess MPI (or Tei indices) of both ventricles in term and preterm newborns, and to observe MPI trends throughout the neonatal period. Heart ultrasound imaging was performed on the first day of life (DOL), after patent ductus arteriosus (PDA) closure, and on the 28th DOL, in 29 term and 29 preterm newborns. RVMPI and LVMPI were measured within the preterm group at 40 weeks of post-conception age (PCA). A statistically significant reduction in RVMPI was observed in both term and preterm newborns. In term newborns, the RVMPI value on the first DOL was 0.42 ± 14, dropping to 0.29 ± 0.09 after PDA closure, and finally reaching 0.22 ± 0.09 on the 28th DOL. The respective RVMPI values for the preterm newborns were 0.44 ± 0.15, 0.30 ± 0.12, and 0.21 ± 0.08. Little variability in the mean values of LVMPI was observed in both groups throughout the neonatal period. The LVMPI for term neonates in successive measurements was 0.37 ± 0.10, 0.39 ± 0.07, and 0.37 ± 0.11, respectively, and for the preterm neonates it was 0.37 ± 0.10, 0.35 ± 0.09, and 0.36 ± 0.10, respectively. The MPI values from preterm newborns taken at 40 weeks PCA (RVMPI = 0.28 ± 0.09; LVMPI = 0.37 ± 0.05) were comparable to those measured in term newborns after PDA closure. Observed postnatal changes in RVMPI correspond to changes in ventricular function, reflecting the haemodynamic changes of the transitional circulation. The relatively small postnatal changes in LVMPI in term and preterm newborns may reflect an immature myocardium. The RVMPI and LVMPI values at 40 weeks PCA in preterm newborns correlate best with MPI values in term newborns just after PDA closure.

Development of sleep/wake, activity and temperature rhythms in newborns maintained in a neonatal intensive care unit and the impact of feeding schedules

Biological rhythms in infants are described as evolving from an ultradian to a circadian pattern along the first months of life. Recently, the use of actigraphy and thermistors with memory has contributed to the understanding of temporal relations of different variables along development. The aim of this study was to describe and compare the development of the rhythmic pattern of wrist temperature, activity/rest cycle, sleep/wake and feeding behavior in term and preterm newborns maintained in a neonatal intensive care unit (NICU). MethodsNineteen healthy preterm and seven fullterm newborns had the following variables monitored continuously while they were in the NICU: activity recorded by actigraphy, wrist temperature recorded with a thermistor and observed sleep and feeding behavior recorded by the NICU staff with diaries. Subjects were divided in 3 groups according to their gestational age at birth and rhythmic parameters were compared. ResultsA dominant daily rhythm was observed for wrist temperature since the first two weeks of life and no age relation was demonstrated. Otherwise, a daily pattern in activity/rest cycle was observed for most preterm newborns since 35 weeks of postconceptional age and was more robust in term babies. Feeding and sleep/wake data showed an almost exclusive 3h rhythm, probably related to a masking effect of feeding schedules. ConclusionsWe found that wrist temperature develops a daily pattern as soon as previously reported for rectal temperature, and with acrophase profile similar to adults. Moreover, we were able to find a daily rhythm in activity/rest cycle earlier than previously reported in literature. We also suggest that sleep/wake rhythm and feeding behavior follow independent developmental courses, being more suitable to masking effects.

Each niche has an actor: multiple stem cell niches in the preterm kidney.

The preterm kidney cannot be simply considered as a kidney small in size: as compared to the adult kidney, the developing organ of the preterm infant is characterized by marked differences regarding the architecture and cell components. At macroscopy, fine linear demarcations indenting the renal surface characterize the fetal and preterm kidney. At microscopy, multiple major architectural changes differentiate the developing kidney from the adult one: a large capsule with a high cellularity; the branching ureteric bud, extending from the hilum towards the renal capsule; striking morphological differences among superficial (just born) and deep (more mature) glomeruli; persistence of remnants of the metanephric mesenchyme in the hylum; incomplete differentiation of developing proximal and distal tubules. At cellular level, kidneys of preterm infants are characterized by huge amounts of stem/precursor cells showing different degrees of differentiation, admixed with mature cell types. The most striking difference between the preterm and adult kidney is represented by the abundance of stem/progenitor cells in the former. Multiple stem cell niches may be identified in the preterm kidney, including the capsule, the sub-capsular nephrogenic zone, the cap mesenchyme embracing the ureteric bud tips, the cortical and medullary interstitium, and the hilar zone in proximity of the ureteric origin. The sub-capsular area represents the major stem cell niche in the prenatal kidney. It has been defined “blue strip”, due to the scarcity of cytoplasm of the undifferentiated stem/progenitors, which appear as small cells arranged in a solid pattern. All these data taken together, the morphological approach to the analysis of the preterm kidney appears completely different from that typically utilized in kidney biopsies from adult subjects. Such a different structure should be taken into account when evaluating renal function in a preterm infant in clinical practice. Moreover, a better knowledge of molecular biology of the blue strip stem/progenitor cells could be at the basis of a new “endogenous” regenerative medicine, finalized to maintain and protect the nephrogenic potential of preterm infants till the 36th week of post-conceptional age, allowing them to escape oligonephronia and chronic kidney disease later in life.

Association between Hemodynamically Significant Patent Ductus Arteriosus and Bronchopulmonary Dysplasia

To assess whether the duration and magnitude of the shunt with patent ductus arteriosus (PDA) are related to a higher incidence of bronchopulmonary dysplasia (BPD) or death. A total of 242 infants ≤ 28 weeks gestational age were evaluated retrospectively between 2007 and 2012; 105 (43.3%) developed BPD or died (group 1) and 137 (56.6%) did not (group 2). A review of all echocardiographic evaluations performed from birth up to 36 weeks of postconceptional age or final ductal closure was carried out, to detect the presence of PDA, and estimate the severity of ductal shunt through the "PDA staging system" proposed by McNamara and Sehgal. Group 1 presented with a hemodynamically significant ductus arteriosus (DA) (E3 and/or E4-PDA) for a longer period of time vs group 2: 4.8 vs 2.3 days, respectively (P < .001). Persistence of a nonsignificant DA (E2) was not associated with development of BPD (P = .16). Each week of a hemodynamically significant DA represented an added risk for BPD (OR 1.7), and the duration of a small, nonsignificant DA (E2) did not. Surgical ligation of PDA itself was not found to be an independent risk factor for BPD. In the subgroup of patients who received ligation, a later ligation (33 vs 23 days) and a prolonged PDA were the only factors associated to BPD or death. A shared scoring system of the severity of ductal shunt is helpful to correctly evaluate the association between PDA morbidities, to compare scientific studies, and to guide treatment.

Changes in hearing threshold between 28 and 42 weeks of age in babies born at under 30 weeks of gestation

This study aimed to describe changes in hearing thresholds in babies born below 30 weeks of gestation at 28-42 weeks of postconceptional age, detect differences between gestational ages and explore the prevalence of hearing impairment. The threshold of brainstem auditory evoked response (BAER) was obtained longitudinally at 28-42 weeks of postconceptional age in 71 babies born at 23-29 weeks of gestation. The BAER threshold was 28 decibels above normal hearing level (dB nHL) at 28 weeks of postconceptional age and decreased to 13 dB nHL at 39-42 weeks. The threshold was slightly higher in babies born at 23-26 weeks of gestation than in those born at 27-29 weeks at most postconceptional ages studied. From 28 to 36 weeks, the threshold decreased at 0.98 dB/week. At term, BAER threshold elevation (>20 dB nHL) occurred in 12 (16.9%) of the 71 babies. The hearing threshold of babies born at 23-29 weeks of gestation decreased from 28 dB at 28 weeks of postconceptional age to 13 dB at 42 weeks. There were no major differences between gestational ages. During the preterm period, the threshold changed at around 1 dB/week. At term, one in six babies had hearing impairment.

Two mutations in surfactant protein C gene associated with neonatal respiratory distress.

Multiple mutations of surfactant genes causing surfactant dysfunction have been described. Surfactant protein C (SP-C) deficiency is associated with variable clinical manifestations ranging from neonatal respiratory distress syndrome to lethal lung disease. We present an extremely low birth weight male infant with an unusual course of respiratory distress syndrome associated with two mutations in the SFTPC gene: C43-7G>A and 12T>A. He required mechanical ventilation for 26 days and was treated with 5 subsequent doses of surfactant with temporary and short-term efficacy. He was discharged at 37 weeks of postconceptional age without any respiratory support. During the first 16 months of life he developed five respiratory infections that did not require hospitalization. Conclusion. This mild course in our patient with two mutations is peculiar because the outcome in patients with a single SFTPC mutation is usually poor.

The significance of fetal inflammatory response syndrome in early and later adaptation of premature infants.

Intrauterine infection may induce the fetal inflammatory response syndrome (FIRS) and may cause cerebral palsy and bronchopulmonary dysplasia in newborns. The aim of the study was to evaluate the importance of FIRS for the early and later adaptation of preterms. Hundred and fifty-eight preterm infants, born at 22-34 weeks of gestation, were investigated at Vilnius University Children hospital in 2007-2009. The data were evaluated at the first week after birth and at 36-37 weeks of post conceptual age. The levels of IL-6, tTNF-α (total), tVEGF-A (total), aTNF-α (active) and aVEGF-A (active) were determined. Correlation between IL-6 and tTNF-α from umbilical blood and the degree of respiratory distress syndrome (RDS) was found (p < 0.001). The concentration of tTNF-α >345 pg/ml and IL-6 >12.7 pg/ml was determined allowing to predict the lethal outcome. The correlation between the concentration of the inflammatory markers IL-6 and tTNF-α in umbilical cord blood at 22-34 weeks of gestation and acute RDS, and the death of preterms was determined. Significant values of umbilical cord blood IL-6 and tTNF-α concentration for predicting the lethal outcome in the later adaptation of preterms were determined.

Perioperative management and post-operative course in preterm infants undergoing vitreo-retinal surgery for retinopathy of prematurity: A retrospective study.

Background:Premature infants scheduled for surgery under general anesthesia are more prone to cardio-respiratory complications. Risk factors include post-conception age (PCA), cardiac and respiratory disease, anemia and opioid administration. This retrospective study evaluates the perioperative management and post-operative course (apnea and bradycardia) in premature infants undergoing surgery for retinopathy of prematurity (ROP).Materials and Methods:We analyzed the pre-operative data, anesthesia chart and post-operative course of 52 former premature infants for 56 general anesthesia exposures for ROP surgery.Results:At the time of procedure, median PCA was 51 (36-60) weeks. 71% of the infants were above 46 weeks of PCA. Five infants had cardiac disease and four had a history of convulsion. Four infants had a pre-operative history of apneic spells. The airway was secured with either endotracheal tube (46) or supraglottic device (10). Fentanyl (0.5-1 μg/kg), paracetamol, topical anesthetic drops and/or peribulbar block were administered for analgesia. Extubation was performed in the operating room for 54 cases. Three infants had apnea post-operatively. Seven infants were shifted to neonatal intensive care unit either for observation or due to delayed recovery, persistent apneic spells and pre-existing cardio-respiratory disease.Conclusion:In the present study, intravenous paracetamol and topical anesthetics reduced the total intra-operative opioid requirement, which resulted in low incidence of post-operative apnea. Regional anesthesia may be considered in infants with high risk of post-operative apnea. Infants with PCA > 42 weeks and without any co-morbidity can be managed in post-anesthesia care unit.

Preterm ovarian hyperstimulation syndrome presented with vaginal bleeding: a case report

Preterm ovarian hyperstimulation syndrome (POHS) is an uncommon disorder characterized by prematurity, hypogastric and upper leg swelling of various intensities, high serum estradiol and gonadotropin levels, and ovarian follicular cyst/cysts. In this paper, we present the first case of POHS presenting with vaginal bleeding. A female infant was born via spontaneous vaginal delivery at 25 weeks of gestation with a birth weight of 610 g. At 36 weeks of post-conception age, she developed breast enlargement, swelling of the clitoral hood, labia major and minor, hypogastrium and upper legs. Several weeks later, vaginal bleeding started and lasted 3 days. The vaginal bleeding continued to occur at monthly intervals. The elevated levels of gonadotropins and estrogens, vulvar swelling and cysts in both ovaries confirmed the diagnosis of preterm ovarian hyperstimulation syndrome.

Postnatal percentile growth charts for Indian appropriate for gestational age (AGA) very low birth weight babies

To develop postnatal percentile growth charts for Indian very low birth weight (VLBW) appropriate for gestational age (AGA) babies till 37 weeks post conceptional age (PCA). Prospective, mixed longitudinal study in 105 VLBW AGA (male 73 and female 32) babies weighing <1500 g and <34 weeks gestation born over 1 year. All were weighed daily until discharge and then weekly till 37 weeks of PCA. The percentile weight curves were computed in four categories : ≤28 weeks, 29-30, 31-32 and 33 weeks, and a total of seven percentile distributions (3rd, 10th, 25th, 50th, 75th, 90th& 97th) were generated. Entire data were subjected to Tanner's 1951 method to compute mean and standard deviation for body weight. The arithmetic mean served the 50(th) percentile. All babies at birth were <50th centile as per Lubchenco's intrauterine growth chart. This pattern was more evident in higher gestation (31-32 and 33 weeks) than lower gestation (≤28 and 29-30 weeks). At 37 weeks PCA, all were <10th centile and the lowest was in ≤28 weeks gestation. Our babies are born smaller, and growth rate is slower than their western counterparts. Babies at lowest gestation had slowest postnatal growth. Hence, we need a separate growth chart for our babies.

21. Analysis of newborn EEG recorded at 40th week of postconceptional age

21. Analysis of newborn EEG recorded at 40th week of postconceptional age

Influence of postconceptional age on universal newborn hearing screening in NICU-babies.

The feasibility of universal newborn hearing screening (UNHS) using automated auditory brainstem response (AABR) devices in the neonatal intensive care unit (NICU) is already well demonstrated. The aim of this study was to find out whether the postconceptional age (PCA) of the babies at the time of the AABR measurement has an influence on the measuring results and to determine the earliest time point for a reliable hearing screening in preterm neonates. Hearing screening measurements of 634 neonates (NICU-Babies) were included. We had complete data for 577 of these babies. The babies were born between 24 and 42 weeks of gestation in the years 2007–2008 and were screened in the Neonatal Unit of the Marburg University hospital. In this group, the hearing screening had been performed at or after 32 weeks of PCA. The AABR measurements showed a specificity of 93.9% (babies tested between 32 and 34 weeks of PCA), 95.8% (tested between 35 and 37 weeks), 95.9% (tested between 38 and 40 weeks of PCA) and 92.1% (tested after 40 weeks of PCA). Hearing screening yields reliable results at 32 weeks PCA. Therefore, an UNHS can be already performed before term without risking a higher rate of false positive results. However, individual factors such as cardiorespiratory and temperature stability of the baby should be considered.

The In Utero and in the Postnatal Period Growth in Human Newborns

We made an analysis of several published curves concerning the human fetal and postnatal growth assessed by the three classical parameters including their velocity changes: the body weight, the length and the head circumference. The called fetal curves have a diagnostic purpose on the normality of growth during the fetal life. They derived from measurements go from 25 to 42 weeks. Among these diagnostic charts, the best from a mathematical and statistical points of views is the one of publishes by “Dombrowski”. Several other analyzed fetal curves may be criticized for not meeting all the criteria of a statistical normal population, mainly concerning the body weight. The called combined fetal and postnatal curves go from 25 to 60 weeks. They allow to make an appreciation of the normal of postnatal growth; they take into account the interruption of fetal life and the adaptation of growth for the priority of growth follows a different vector in this type of situations. Among these combined charts, the “Gairdner” and “Battisti” meet the criteria for all parameters. The analysis of velocity (their variability over time) of the different parameters of growth considered individually or as ratios between them has also been useful. The clinician having in care fragile neonates (those born before 30 weeks or below 1000g or those combining a prematurity and a fetal growth restriction) has an important task. It is to offer the best nutrition to them and to see if their growth is optimal as this can be important for the future. The clinician needs hence to plot longitudinally, on an appropriate curve , the three parameters of growth (body weight, length and head circumference). That should be done on a combined chart instead diagnostic curve. On the other hand, a reliable ratio emerged has a highly correlated index to optimal growth, and it can be used from 25 to 60 weeks of post-conceptional age (PCA) : d BW g/d HC cm = 44 PCA – 1138 (r = 0.973, p < 0.00001). By using that formula derived by two important and easy parameters (the body weight and the head circumference), on can appreciate the adequacy of growth whatever the considered moment in that period of life.

Comparison of pressure‐, flow‐, and NAVA‐Triggering in pediatric and neonatal ventilatory care

To compare conventional trigger modes (pressure and flow trigger) to neurally adjusted ventilatory assist (NAVA), a novel sensing technique, and to observe the patient-ventilator interactions during these modes. In this prospective, crossover comparison study in tertiary care pediatric and neonatal intensive care unit, 18 patients (age from 30 weeks of postconceptional age to 16 years) needing mechanical ventilation were randomized. Three patients were excluded from the analysis because of problems in data collection. Patients were ventilated with three different trigger modes (pressure, flow, NAVA), for 10 min each. Patients were randomly allocated to six groups according to the order of trigger modes used. The primary end point was the time in asynchrony between the patient and the ventilator. Secondary end points were peak and mean airway pressures (MAP), breathing frequency, tidal volume (TV), and vital parameters during each trigger mode. The proportion of time in asynchrony was significantly shorter in the NAVA group (8.8%) than in the pressure (33.4%) and flow (30.8%) groups (P < 0.001 for both). In the NAVA group, the peak inspiratory pressure was 2 to 1.9 cmH(2) O lower than in the pressure and flow groups, respectively (P < 0.05 for both) and the breathing frequency was 10 breaths/min higher than in the pressure group (P = 0.001). There was a tendency toward a lower MAP (P = 0.047) but the mean TV was about the same (6.4-6.8 ml/kg) in all three groups (P = 0.55). There were no differences in oxygen saturation or vital parameters between the groups. NAVA offers a novel way of sensing patients' spontaneous breathing and significantly improves short-term patient-ventilator synchrony in a pediatric population.