Qualitative assessment of nurse satisfaction in the paediatric cardiac ICU.

The objective of this qualitative assessment, utilising the constant comparative method, was to identify satisfiers and dissatisfiers that influence paediatric cardiac ICU nurse retention and recognise areas for improvement. Interviews for this study were performed in a single, large academic children's hospital from March of 2020 through July of 2020. Each bedside paediatric cardiac ICU nurse underwent a single semi-structured interview. Among 12 interviews, four satisfiers were identified: paediatric cardiac ICU patient population, paediatric cardiac ICU care team, personal accomplishment, and respect. Four dissatisfiers were identified: moral distress, fear, poor team dynamics, and disrespect. Through this process of inquiry, grounded theory was developed regarding strategies to improve paediatric cardiac ICU nurse retention. Tactics outlined here should be used to support retention in the unique environment of the paediatric cardiac ICU.

Longitudinal characterization of olfactomedin-4 expressing neutrophils in pediatric patients undergoing bone marrow transplantation.

Sepsis is an important cause of morbidity and mortality in pediatric patients. Increased expression of olfactomedin-4 (OLFM4), a glycoprotein contained within a subpopulation of neutrophils, has been associated with complicated course in sepsis. The factors that regulate OLFM4 expression are unknown. Here, we followed children undergoing bone marrow transplantation (BMT) to document the percentage of neutrophils that express OLFM4 over time. This population was selected because of the ability to observe nascent neutrophils following engraftment, perform frequent blood sampling, and the children are at high risk for clinical complications that may associate with changes in percentage of OLFM4+ neutrophils. We found a surprising degree of variability of OLFM4 expression between patients. In the weeks following initial neutrophil recovery we also saw great variability in OLFM4 expression within individual patients, indicating that multiple external factors may modify OLFM4 expression. We identified decreased expression of CD64 (a marker associated with response to infection), in OLFM4+ neutrophils. This is the first study to demonstrate fluctuation in OLFM4 expression within patients and provides insight into possible mechanisms for OLFM4 regulation in nascent neutrophils.

Juvenile OLFM4-null mice are protected from sepsis.

Pediatric sepsis is a leading cause of morbidity and mortality in children. One of the most common and devastating morbidities is sepsis-related acute kidney injury (AKI). AKI was traditionally thought to be related to low perfusion and acute tubular necrosis. However, little acute tubular necrosis can be found following septic AKI, and little is known about the mechanism of septic AKI. Olfactomedin-4 (OLFM4) is a secreted glycoprotein that marks a subset of neutrophils. Increased expression of OLFM4 in the blood is associated with worse outcomes in sepsis. Here, we investigated a pediatric model of murine sepsis using murine pups to investigate the mechanisms of OLFM4 in sepsis. When sepsis was induced in murine pups, survival was significantly increased in OLFM4-null pups. Immunohistochemistry at 24 h after the induction of sepsis demonstrated increased expression of OLFM4 in the kidney, which was localized to the loop of Henle. Renal cell apoptosis and plasma creatinine were significantly increased in wild-type versus OLFM4-null pups. Finally, bone marrow transplant suggested that increased OLFM4 in the kidney reflects local production rather than filtered from the plasma. These results demonstrate renal expression of OLFM4 for the first time and suggest that a kidney-specific mechanism may contribute to survival differences in OLFM4-null animals.

Isolating red flags to enhance diagnosis (I-RED): An experimental vignette study.

OBJECTIVE: To investigate effects of a cognitive intervention based on isolation of red flags (I-RED) on diagnostic accuracy of 'do-not-miss diagnoses.' DESIGN: A 2 × 2 randomized case vignette-based experiment with manipulation of I-RED strategy between subjects and case complexity within subjects. SETTING: Two university-based residency programs. PARTICIPANTS: One-hundred and nine pediatric residents from all levels of training. INTERVENTIONS: Participants were randomly assigned to the I-RED vs. control group, and within each group, they were further randomized to the order in which they saw simple and complex cases. The I-RED strategy involved an instruction to look for a constellation of symptoms, signs, clinical data or circumstances that should heighten suspicion for a serious condition. MAIN OUTCOME MEASURES: Primary outcome was diagnostic accuracy, scored as 1 if any of the three differentials given by participants included the correct diagnosis, and 0 if not. We analyzed effects of I-RED strategy on diagnostic accuracy using logistic regression. RESULTS: I-RED strategy did not yield statistically higher diagnostic accuracy compared to controls (62 vs. 48%, respectively; odd ratio = 2.07 [95% confidence interval, 0.78-5.5], P = 0.14) although participants reported higher decision confidence compared to controls (7.00 vs. 5.77 on a scale of 1 to 10, P < 0.02) in simple but not complex cases. I-RED strategy significantly shortened time to decision (460 vs. 657 s, P < 0.001) and increased the number of red flags generated (3.04 vs. 2.09, P < 0.001). CONCLUSIONS: A cognitive strategy of prompting red flag isolation prior to differential diagnosis did not improve diagnostic accuracy of 'do-not-miss diagnoses.' Given the paucity of evidence-based solutions to reduce diagnostic error and the intervention's potential effect on confidence, findings warrant additional exploration.

Glutathione-S-transferase P1 may predispose children to a decline in pulmonary function after stem cell transplant.

RATIONALE: Pulmonary complications after hematopoietic stem cell transplant (SCT) are associated with increased mortality. Genetic markers for those at risk for pulmonary impairment post-SCT have not been widely investigated. METHODS: Forty-nine patients were retrospectively selected from a single institution's biorepository with linked clinical data. All subjects performed pre-SCT PFTs. Genotyping was conducted using the Infinium Exome-24 BeadChip. Four single nucleotide polymorphisms (SNPs) were selected (rs1800871, rs1695, rs1800629, rs12477314) and evaluated for association with PFT parameters as change over time from baseline. Associations between SNPs and PFT parameters were assessed and adjusted for the following confounding variables: age, gender, and race. RESULTS: Using the recessive genetic model, patients with one or two minor alleles for the glutathione S-transferase P1 (GSTP1) SNP rs1695 had a lower decline in FEV1 and FEF25-75 at 1-year post-SCT compared to patients who were homozygous for the ancestral allele (adjusted P-values <0.01 and 0.02, respectively). No other SNPs were significantly associated with other PFT parameters. CONCLUSIONS: Our findings suggest that GSTP1 genotype may be associated with lung function during the first year post-SCT. Identifying and investigating genes that predispose patients to pulmonary complications after SCT may allow for more personalized patient management based on pre-emptive genetic testing. The glutathione S-transferase gene merits further investigation.

Escherichia coli Bacteremia, Epididymo-Orchitis, and Scrotal Abscess in a Neonate.

Epididymo-orchitis (EO) is a rare but important cause of scrotal swelling in pediatric patients. EO is caused by bacteremia leading to hematogenous seeding or ascending infection of the urinary tract. EO can be associated with abscess, bacteremia, and other serious infections, and must be distinguished from other causes of scrotal swelling such as testicular torsion. We present a case of a 16-day-old male with EO, scrotal abscess, and bacteremia from Escherichia coli.

Measurement of pancreatic islet cell proliferation by heavy water labeling.

We describe a sensitive technique for measuring long-term islet cell proliferation rates in vivo in rats. Pancreatic islets were isolated and the incorporation of deuterium ((2)H) from heavy water ((2)H(2)O) into the deoxyribose moiety of DNA was measured by GC-MS. The results of heavy water labeling and BrdU staining were compared. The two methods were highly correlated (r = 0.9581, P < 0.001). Based on long-term heavy water labeling, approximately 50% of islet cells divided in rats between 8 and 15 wk of age. Of interest, long-term BrdU administration suppressed proliferation of islet cells significantly, but not of bone marrow cells. Physiological evidence further supported the validity of the method: older animals (24 wk old) had 60% lower islet cell proliferation rates than younger rats (5 wk old), and partial (50%) pancreatectomy increased proliferation by 20%. In addition, cholecystokinin-8 treatment significantly stimulated proliferation in pancreatectomized rats only. In summary, heavy water labeling is a quantitative approach for measuring islet cell proliferation and testing therapeutic agents.

In vivo measurement of microtubule dynamics using stable isotope labeling with heavy water. Effect of taxanes.

Microtubules are dynamic polymers with central roles in the mitotic checkpoint, mitotic spindle assembly, and chromosome segregation. Agents that block mitotic progression and cell proliferation by interfering with microtubule dynamics (microtubule-targeted tubulin-polymerizing agents (MTPAs)) are powerful antitumor agents. Effects of MTPAs (e.g. paclitaxel) on microtubule dynamics have not yet been directly demonstrated in intact animals, however. Here we describe a method that measures microtubule dynamics as an exchange of tubulin dimers into microtubules in vivo. The incorporation of deuterium ((2)H(2)) from heavy water ((2)H(2)O) into tubulin dimers and polymers is measured by gas chromatography/mass spectrometry. In cultured human lung and breast cancer cell lines, or in tumors implanted into nude mice, tubulin dimers and polymerized microtubules exhibited nearly identical label incorporation rates, reflecting their rapid exchange. Administration of paclitaxel during 24 h of (2)H(2)O labeling in vivo reduced (2)H labeling in polymers while increasing (2)H in dimers, indicating diminished flux of dimers into polymers (i.e. inhibition of microtubule dynamic equilibrium). In vivo inhibition of microtubule dynamics was dose-dependent and correlated with inhibition of DNA replication, a stable isotopic measure of tumor cell growth. In contrast, microtubule polymers from sciatic nerve of untreated mice were not in dynamic equilibrium with tubulin dimers, and paclitaxel increased label incorporation into polymers. Our results directly demonstrate altered microtubule dynamics as an important action of MTPAs in vivo. This sensitive and quantitative in vivo assay of microtubule dynamics may prove useful for pre-clinical and clinical development of the next generation of MTPAs as anticancer drugs.