Feasibility study of a novel portable digital radiography system modified for fluoroscopy in the neonatal intensive care unit.

BACKGROUND: A portable radiographic system capable of fluoroscopic imaging in the neonatal intensive care unit (NICU) potentially benefits critically ill neonates by eliminating the need to transport them to a fluoroscopy suite. OBJECTIVE: To evaluate whether a portable bedside fluoroscopy system in the NICU can deliver comparable image quality at a similar dose rate to a standard system in a fluoroscopy suite. MATERIALS AND METHODS: In phase A, 20 patients <3 years of age and scheduled to undergo upper gastrointestinal series (upper GI) or voiding cystourethrograms (VCUG) in the radiology fluoroscopy suite were recruited to evaluate a portable fluoroscopic unit. A modified portable radiographic system with a cassette-sized detector and an in-room fluoroscopy system were sequentially used in the same examination. Four radiologists compared the image quality of 20 images from each system using the Radlex score (1-4) for five image quality attributes. The radiation dose rates for the portable and in-suite systems were collected. In phase B, fluoroscopy studies were performed in 5 neonates in the NICU and compared to the 20 previous neonatal studies performed in the department. Clinical workflow, examination time, fluoroscopy time, scattered radiation dose and patient radiation dose were evaluated. RESULTS: In phase A, average dose rates for in-room and portable systems were equivalent, (0.322 mGy/min and 0.320 mGy/min, respectively). Reader-averaged Radlex scores for in-room and portable systems were statistically significantly greater (P<0.05) for all attributes on the portable system except for image contrast. In phase B, scattered radiation from the average fluoroscopy time (26 s) was equivalent to the scattered radiation of 2.6 portable neonatal chest radiographs. Procedure time and diagnostic quality were deemed equivalent. The average dose rate in the NICU with the portable system was 0.21 mGy/min compared to 0.29 mGy/min for the in-room system. CONCLUSION: The portable fluoroscopy unit is capable of providing comparable image quality at equivalent dose levels to an in-room system for neonates with minimal risks to the staff and other patients in the NICU.

Selective Head versus Whole Body Cooling Treatment of Hypoxic-Ischemic Encephalopathy: Comparison of Electroencephalogram and Magnetic Resonance Imaging Findings.

OBJECTIVE: This study aimed to compare the utility of electroencephalogram (EEG) and brain magnetic resonance imaging (MRI) to detect brain dysfunction and injury across a cohort of newborn infants treated with selective head cooling (SHC) or whole body cooling (WBC). STUDY DESIGN: Therapeutic hypothermia (TH) is a standard neuroprotection tool for hypoxic-ischemic encephalopathy (HIE) in neonates. Sixty-six newborns, SHC (n = 22) and WBC (n = 44), were studied utilizing standardized scoring systems for interpretation of EEG and MRI based on the severity of the findings. RESULTS: SHC- and WBC-treated groups did not differ significantly amongst most of the baseline parameters. EEGs obtained postcooling were abnormal in 58 of 61 (95%) infants. The severity of the EEG background changes (depressed and undifferentiated background) was more prevalent in the SHC (8/21 [38%]) than in the WBC group (5/40 [13%]). Brain MRIs showed HIE changes in 26 of 62 (42%) newborns treated with TH. MRI abnormalities of basal ganglia, thalamic, and parenchymal lesions were more common in the SHC (5/19) versus the WBC group (3/43); p = 0.04. CONCLUSION: EEG abnormalities and MRI findings of HIE were more prevalent in the SHC than in the WBC group. WBC may offer better or at least similar neuroprotection to infants with HIE.

The New York pilot newborn screening program for lysosomal storage diseases: Report of the First 65,000 Infants.

PURPOSE: We conducted a consented pilot newborn screening (NBS) for Pompe, Gaucher, Niemann-Pick A/B, Fabry, and MPS 1 to assess the suitability of these lysosomal storage disorders (LSDs) for public health mandated screening. METHODS: At five participating high-birth rate, ethnically diverse New York City hospitals, recruiters discussed the study with postpartum parents and documented verbal consent. Screening on consented samples was performed using multiplexed tandem mass spectrometry. Screen-positive infants underwent confirmatory enzymology, DNA testing, and biomarker quantitation when available. Affected infants are being followed for clinical management and long-term outcome. RESULTS: Over 4 years, 65,605 infants participated, representing an overall consent rate of 73%. Sixty-nine infants were screen-positive. Twenty-three were confirmed true positives, all of whom were predicted to have late-onset phenotypes. Six of the 69 currently have undetermined disease status. CONCLUSION: Our results suggest that NBS for LSDs is much more likely to detect individuals at risk for late-onset disease, similar to results from other NBS programs. This work has demonstrated the feasibility of using a novel consented pilot NBS study design that can be modified to include other disorders under consideration for public health implementation as a means to gather critical evidence for evidence-based NBS practices.

Duodenal atresia: not always a double bubble.

A newborn infant with a prenatal diagnosis of duodenal atresia and abdominal radiographs demonstrating air in distal bowel is presented. An upper gastrointestinal series revealed complete duodenal obstruction and duodenal atresia was confirmed at surgery. The significance of distal bowel gas and the embryological development of this unusual entity is discussed.

Is there an advantage of using pressure support ventilation with volume guarantee in the initial management of premature infants with respiratory distress syndrome? A pilot study.

OBJECTIVE: To evaluate the feasibility of using the pressure support ventilation with volume guarantee (PSV-VG) as an initial ventilatory mode in preterm infants with respiratory distress syndrome (RDS) after surfactant treatment to achieve accelerated weaning of peak inspiratory pressure (PIP) and mean airway pressure (MAP). STUDY DESIGN: Initial 24-hour ventilatory parameters were compared in two groups of preterm infants managed by PSV-VG and the synchronized intermittent mandatory ventilation (SIMV) mode in a randomized controlled pilot study after surfactant treatment for RDS. A total of 16 babies were randomized to PSV-VG (1198+/-108 g [mean+/-SEM]; 27.9+/-0.6 weeks) and 18 babies to SIMV (birth weight 1055+/-77 g; gestational age 27.4+/-0.5 weeks). Repeated measures analysis of variance was used to compare serial values of PIP and MAP in the two groups. RESULTS: The PIP and MAP decreased over time (p<0.001) during the first 24 hours after surfactant administration in both groups but the decrease in MAP was faster in the SIMV group compared to PSV-VG group (p=0.035). The median numbers of blood gases during the first 24 hours were four and two in the SIMV and PSV-VG groups, respectively (p<0.001). The overall outcomes were not significantly different between the two groups. CONCLUSION: PSV-VG did not offer any ventilatory advantage over SIMV in the initial management of surfactant-treated premature newborns with RDS except for minimizing the number of blood gases.

Short-chain fatty acids induce colonic mucosal injury in rats with various postnatal ages.

Short chain fatty acids (SCFAs) may play a role in the pathogenesis of neonatal necrotizing enterocolitis. To evaluate the injurious effect of SCFAs on the colonic mucosa of rats at various postnatal developmental stages, we studied a total of 170 newborn Sprague-Dawley rats at postnatal ages days 3, 9, and 23. A 1.8-F silastic catheter or umbilical catheter was inserted rectally deep into the proximal colon of the rats. Rats from each of the three postnatal age groups were randomly divided to receive one of the following distinct SCFA solutions: acetic acid, butyric acid, propionic acid, or a mixture of above SCFAs solutions. An additional subgroup of rats from each of the age groups received normal saline as a control. The concentration of each SCFA solution was 300 mM, and the pH of all solutions was adjusted to 4.0. The volume of administered solution was 0.1 mL/10 g of body weight. After 24 h, all rats were killed and the daily weight change was recorded and proximal colon was collected for histologic examination. A histologic injury score was used to quantify the severity of mucosal injury. The severity of mucosal injury induced by luminal SCFAs administration decreased as the rats matured; by postnatal day 23, the injury caused by SCFAs was minimal. Thus, the severity of the colonic mucosal injury induced by luminal SCFAs is maturation dependent; the immature state of the mucosal defense in early postnatal age in newborn rat may explain its greater vulnerability to luminal SCFAs.

Vitamin A supplementation ameliorates butyric acid-induced intestinal mucosal injury in newborn rats.

Vitamin A (vit A) plays an important role in wound healing and therefore may help in repairing of intestinal mucosal injury. The purpose of this study was to determine if vit A supplementation could promote healing in intestinal mucosal injury as commonly seen in neonatal necrotizing enterocolitis (NEC). Mild intestinal mucosal injury was induced in 10-day-old Sprague-Dawley rats by luminal administration of 1.5% butyric acid (BA) at pH 4.0. Normal saline at the same pH was administered as control. Immediately after administrations of BA or normal saline, animals were randomly assigned to receive high dose vit A (20,000 IU/kg for one dose, i.p.), low dose vit A (5,000 IU/kg for two doses) or vehicle. Animals were followed for 48 hours and then sacrificed for histological examination. Rats with BA-induced intestinal mucosal injury had a reduction in daily weight gain (p < 0.05). Vit A supplementation significantly improved the daily weight gain in the rats with BA-induced intestinal mucosal injury and the effect is dose dependent. At sacrifice, the colon wet weight was significantly heavier and the histological injury scores from both ileum and proximal colon higher in the rats with BA-induced intestinal mucosal injury. All of those parameters were improved with vit A supplementation. We conclude that vit A supplementation ameliorates BA induced-intestinal mucosal injury in newborn rats.

Variable effects of short chain fatty acids and lactic acid in inducing intestinal mucosal injury in newborn rats.

BACKGROUND: Short chain fatty acids and lactic acid are colonic bacterial fermentation products. METHODS: To evaluate the effects of these organic acids on the intestinal mucosa, a total of 72 newborn Sprague-Dawley rats (10 days old) were studied. A 3.5F catheter was inserted per rectum 4.0 cm deep into the proximal colon for organic acid administration at a volume of 0.1 ml/10 g body weight. The pH of organic acid solutions and normal saline was adjusted to 4.0. Group 1 (n = 10) received normal saline as a control. Group 2 (n = 11) received 150 mM acetic acid. Group 3 (n = 11) received 300 mM acetic acid. Group 4 (n = 10) received 150 mM butyric acid. Group 5 (n = 11) received 300 mM butyric acid. Group 6 (n = 7) received 150 mM lactic acid, and group 7 (n = 12) received 300 mM lactic acid. Animals were killed 24 hours after colonic installation of test solutions. RESULTS: Both 300 mM acetic acid and 300 mM butyric acid were associated with impaired weight gain, increased colon wet weight, and increased histologic injury scores in the colon and distal ileum (P < 0.05, analysis of variance). Both 150 mM acetic acid and butyric acid at 150 mmol/L induced minimal injury in the colon and distal ileum. Neither 150 mM nor 300 mM lactic acid induced any identifiable gross or microscopic intestinal mucosal injury. CONCLUSION: Luminal short chain fatty acids can induce dose-dependent intestinal mucosal injury in newborn rats, resembling the pathology seen in neonatal necrotizing enterocolitis. Overproduction/accumulation of short chain fatty acids, but not lactic acid, in the proximal colon and/or distal ileum may play a role in the pathogenesis of necrotizing enterocolitis in premature infants.