Respiratory Syncytial Virus Bronchiolitis Before and After COVID-19 Pandemic: Has the Immunity Debt Been Paid Off?

BACKGROUND: Our aim was to hypothesize that the COVID-19 pandemic influenced the characteristics of viral bronchiolitis by comparing the last 3 epidemics with 3 pre-COVID-19 epidemics in infants hospitalized with bronchiolitis. METHODS: We prospectively enrolled 637 consecutive infants (median age 3.0 ± 2.1 months, 58.5% males), hospitalized for bronchiolitis during 6 consecutive annual epidemic seasons from 2017 to 2023. All parents of the children were given a structured anamnestic questionnaire. A nasopharyngeal aspirate was tested for 15 respiratory viruses. As measures of severity, we evaluated the O2 supplementation and the admission at the pediatric intensive care unit. RESULTS: A total of 166 were hospitalized with bronchiolitis in 2017-2018, 97 in 2018-2019, 69 in 2019-2020, 0 in 2020-2021, 129 in 2021-2022 and 176 in 2022-2023. Taking together the 332 bronchiolitis cases hospitalized during the 3 prepandemic seasons, they peaked between December and January; after the flat curve in 2020-2021, the cases of bronchiolitis peaked in November 2021 and in December 2022. While the 2021-2022 season registered a less severe clinical presentation, O2 supplementation and pediatric intensive care unit admissions increased in 2022-2023 with respect to the prepandemic seasons (P < 0.001). CONCLUSIONS: This study represents an important scientific demonstration of the impact of primary prevention measures on the epidemiology of viral infections; their fluctuations were related to the intensity of restrictive measures and to the changing trend of respiratory viruses. It is essential to predict the real temporal trend of bronchiolitis in order not to leave high-risk children uncovered and to guide hospitals to maintain a high level of readiness.

Diagnostic accuracy of multimodal noninvasive follow-up for pediatric ulcerative colitis: A single-center prospective study.

OBJECTIVES: Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) often requiring endoscopic evaluations, which can be uncomfortable and costly, especially for children. This study aimed to evaluate the diagnostic accuracy of a noninvasive approach combining fecal calprotectin (FCP), colonic ultrasonography (US), and colon capsule endoscopy (CCE) compared with standard ileocolonoscopy in pediatric UC. METHODS: UC children were enrolled and underwent FCP and US on Day 0, followed by CCE on Day 1 and ileocolonoscopy on Day 2. All procedures were performed by operators who were blinded to the patient's clinical history and all test results. The accuracy for disease activity and extension of each technique and their combination was assessed and compared. Tolerability and safety were also evaluated. RESULTS: Thirty-two patients were enrolled (15 males, mean age 13.2 ± 3.2 years). CCE showed a sensitivity of 95% and specificity of 100% in detecting colonic inflammation, with positive predictive value (PPV) and negative predictive value (NPV) of 100% and 92%, respectively. US demonstrated a sensitivity of 85% and specificity of 92%, with PPV and NPV of 94% and 79%. The combination of FCP, US, and CCE achieved 95% sensitivity and 100% specificity, with PPV of 100% and NPV of 92%. The noninvasive approach was better tolerated than colonoscopy (p < 0.05), and no serious adverse events were reported. CONCLUSION: The noninvasive approach combining fecal calprotectin (FCP), ultrasonography, and colon capsule endoscopy demonstrated high diagnostic accuracy and better tolerability compared with standard ileocolonoscopy in pediatric ulcerative colitis follow-up. Further multicenter studies are needed to confirm these findings and evaluate the reproducibility of this noninvasive approach.

A Treat-to-Target Strategy Guided by Pan-Enteric Evaluation in Children With Crohn's Disease Improves Outcomes at 2 Years.

BACKGROUND AND AIMS: It is uncertain whether a treat-to-target approach could be an effective strategy for improving outcomes in children with Crohn's disease (CD). Previously, we reported mucosal healing (MH) and deep remission rates throughout the intestinal tract by performing 3 pan-enteric capsule assessments and using a treat-to-target strategy over 52 weeks in children with CD. This report describes the outcomes of this approach at 104 weeks. METHODS: Children with known CD who completed the 52-week protocol repeated pan-enteric capsule endoscopy (PCE) at 104 weeks. Results at weeks 52 and 104 were compared, and long-term outcomes between patients, with and without MH, were calculated using an intention-to-treat analysis of clinical relapse, need for steroids, treatment escalation, hospitalization, and surgery. RESULTS: Of the previous study cohort of 48 patients, 46 (96%) were available for this extension study (28 [61%] of 46 with MH and 18 [39%] of 46 without MH at 52 weeks). When evaluated at 104 weeks, MH was maintained in 93% of patients with MH at 52 weeks. In the intention-to-treat analysis, complete MH at 52 weeks was associated with reduced risk of steroid use (log-rank P < .0001), treatment escalation (log-rank P < .0001), hospitalization (log-rank P < .0001), and clinical relapse (log-rank P < .0001). CONCLUSIONS: When a PCE-based, treat-to-target strategy is employed, MH is sustainable (93%) over a 1-year period and is correlated with improved patient outcomes, including reduced need for steroids, treatment escalation, hospitalization, and clinical relapses at 104 weeks.ClinicalTrials.gov number: NCT03161886.

Hyperinflammatory syndrome in a paediatric patient with a recent diagnosis of HIV/AIDS infection: hemophagocytic lymphohistiocytosis or immune reconstitution syndrome?

INTRODUCTION: Haemophagocytic lymphohistiocytosis is a rare and life-threatening condition caused by uncontrolled immune activation leading to excessive inflammation and tissue destruction. It could either be due to a primary genetic defect or be triggered by secondary causes such as infections, autoimmune diseases, rheumatological diseases or post-transplant immunosuppression. We here report the case of a 4-year-old child with a recent AIDS diagnosis who developed a severe systemic inflammation. CASE REPORT: We here report the case of a 4-year-old child with a recent AIDS diagnosis who was admitted to the ER with acute respiratory failure due to Pneumocystis jiroveci infection and Aspergillosis; the following microbiological assessment also showed a CMV, HSV, EBV and HHV-7 coinfection. On the 51st day after she'd started antiretroviral therapy, 39th after she'd followed a course of Bactrim and Caspofungin for PJI and Ambisome for pulmonary Aspergillosis, she started presenting fever, unresponsive to broad-spectrum antibiotic therapy. She also presented worsening of her clinical conditions, with evidence at the laboratory assessments of progressive raise in inflammatory indexes, coagulopathy, trilinear cytopenia and hyperferritinemia. To perform the differential diagnosis between IRIS and HLH, HLA-DR on T cells was studied, turning out negative for IRIS. Therefore, in the suspicion of HLH, a bone marrow aspirate and biopsy were performed with evidence of trilinear cytopenia, prevalence of T-cells and macrophages with signs of phagocytosis. She was started on high-dose steroids and Anakinra for a total of 29 days, resulting in prompt apyrexia and progressive improvement of her clinical conditions and laboratory results. CONCLUSION: To the best of our knowledge there is poor literature available about the differential diagnosis of HLH and IRIS, therefore medical management in the concurrence of these two conditions needs to be further investigated, especially in a setting where immunological testing is not quickly available. The clinical differences between these pathologies are blurred and the bone marrow biopsy within marker for IRIS helped us to distinguish these two entities.

Clinical profiles of acute arterial ischemic neonatal stroke.

INTRODUCTION: Perinatal stroke includes a heterogeneous group of early focal neurological injuries affecting subsequent brain development, often resulting in motor sequelae, symptomatic epilepsies, and cognitive, language and behavioral impairment. The incidence of perinatal stroke is about 1/3500 live birth. EVIDENCE ACQUISITION: A PubMed and SCOPUS search strategy included the entries "neonatal ischemic stroke" OR "perinatal ischemic stroke" and the age of the filter under 18 years and January 2000-August 2022. EVIDENCE SYNTHESIS: The cumulative literature analysis highlighted 3880 published patients (from 98 articles) with stroke, mainly presenting with clinical or electro-graphical seizures (2083 patients). The mean age at presentation was 2,5±2,4 days (data available for 1182 patients). Stroke occurred in the first week of life in 1164 newborns. The mainly involved ischemic areas were within the territories of the middle cerebral artery (1403 patients). Predisposing risk factors included fetal/newborn factors (1908 patients), dystocial birth (759 patients), maternal (678 patients), and placental factors (63 patients). No thrombolysis and/or endovascular treatments were performed, while data about other pharmacological treatments were restricted to a single article. The death occurred in 29 newborns. Motor, neurocognitive and language impairment were cumulatively reported in 875 patients. Epileptic seizures during the follow-up were reported in 238 cases. CONCLUSIONS: The literature analysis highlighted that every term newborn presenting with acute neurological signs and symptoms during the first week of life should always be considered for the identification of an ischemic stroke.

Analysis of Knowledge, Attitudes and Behaviours of Health Care Workers towards Vaccine-Preventable Diseases and Recommended Vaccinations: An Observational Study in a Teaching Hospital.

Background: Recommended vaccinations are the cheapest and most effective measure to reduce the risk of transmission and related complications, especially in high-risk healthcare settings. This study aimed to evaluate the knowledge, attitudes and behaviours of HCWs in relation to national recommendations. Methods: A transversal study was conducted through administration of a questionnaire by personal interview. The following care units were involved: Paediatric, Neonatal, Cardiac Surgery and General Intensive Care Units and Infectious Diseases Unit. Results: The study sample comprised 308 HCWs. Half the sample were aware of the vaccination recommendations, with occupation and age found to be predictive factors (OR = 9.38, 95%CI: 2.07−42.41; OR = 0.36, 95%CI: 0.22−0.60). A higher percentage defined the diseases as a risk for their patients' health, although this perception was lower in the over-40 age group. In several cases, there were statistically significant differences between the care units (p < 0.001). Around three-quarters of the sample agreed that vaccination should be mandatory; willingness to undergo a future booster vaccination was statistically correlated with the variables of age and care unit (p < 0.001, p = 0.03). Conclusion: The protection of health in the workplace can be achieved through some strategic actions, such as the implementation of educational strategies, and protocols for the monitoring of immunocompetence and the improvement of vaccination.

Maintenance Therapy With the Lowest Effective Dose of Oral Viscous Budesonide in Children With Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an immune-mediated condition characterized by symptoms of esophageal dysfunction and an eosinophilic inflammation of the esophagus.1 Swallowed topical steroids represent one of the possible strategies for inducing and maintaining remission in EoE.2 To date, a validated maintenance strategy has yet to be defined, especially in children. The available evidence suggests decreasing the dose after a successful induction therapy.3 No study has reported the efficacy of a continuous progressive dose reduction; thus, it is unknown if all patients need to use the same dosages and for how long.4,5.

The starting rate for high-flow nasal cannula oxygen therapy in infants with bronchiolitis: Is clinical judgment enough?

OBJECTIVES: To determine whether in infants with bronchiolitis admitted to a pediatric intensive care unit (PICU) the starting rate for high-flow nasal cannula (HFNC) therapy set by the attending physicians upon clinical judgment meets patients' peak inspiratory flow (PIF) demands and how it influences respiratory mechanics and breathing effort. METHODOLOGY: We simultaneously obtained respiratory flow and esophageal pressure data from 31 young infants with moderate-to-severe bronchiolitis before and after setting the HFNC rate at 1 L/kg/min (HFNC-1), 2 L/kg/min (HFNC-2) or upon clinical judgment and compared data for PIF, respiratory mechanics, and breathing effort. RESULTS: Before HFNC oxygen therapy started, 16 (65%) infants had a PIF less than 1 L/kg/min (normal-PIF) and 15 (45%) had a PIF more than or equal to 1 L/kg/min (high-PIF). Normal-PIF-infants had higher airway resistance (p < .001) and breathing effort indexes (e.g., pressure rate product per min [PTP/min], p = .028) than high-PIF-infants. Starting the HFNC rate upon clinical judgment (1.20-2.05 L/kg/min) met all infants' PIFs. In normal-PIF-infants, the clinically judged flow rate increased PIF (p = .081) and tidal volume (p = .029), reduced airway resistance (p = .011), and intrinsic positive end-expiratory pressure (p = .041), whereas, in both high-PIF and normal-PIF infants, it decreased respiratory rate (p < .001) and indexes of breathing effort such as PTP/min (in normal-PIF infants, p = .004; in high-PIF infants, p = .001). The 2 L/kg/min but not 1 L/kg/min rate induced similar effects. CONCLUSIONS: The wide PIF distribution in our PICU population of infants with bronchiolitis suggests two disease phenotypes whose therapeutic options might differ. An initial flow rate of nearly 2 L/kg/min meets patients' flow demands and improves respiratory mechanics and breathing effort.

Nasopharyngeal tubes in pediatric anesthesia: Is the flow-dependent pressure drop across the tube suitable for calculating oropharyngeal pressure?

BACKGROUND: Nasopharyngeal tubes are useful in pediatric anesthesia for insufflating oxygen and anesthetics. During nasopharyngeal tube-anesthesia, gas insufflation provides some positive oropharyngeal pressure that differs from the proximal airway pressure owing to the flow-dependent pressure drop across the nasopharyngeal tube (ΔPNPT ). AIMS: This study aimed to investigate whether ΔPNPT could be used for calculating oropharyngeal pressure during nasopharyngeal tube-assisted anesthesia. METHODS: In a physical model of nasopharyngeal tube-anesthesia, using Rohrer's equation, we calculated ΔPNPT for three nasopharyngeal tubes (3.5, 4.0, and 5.0 mm inner diameter) under oxygen and several sevoflurane in oxygen combinations in two ventilatory scenarios (continuous positive airway pressure and intermittent positive pressure ventilation). We then calculated oropharyngeal pressure as proximal airway pressure minus ΔPNPT . Calculated and measured oropharyngeal pressure couples of values were compared with the root mean square deviation to assess accuracy. We also investigated whether oropharyngeal pressure accuracy depends on the nasopharyngeal tube diameter, flow rate, gas composition, and leak size. Using ΔPNPT charts, we tested whether ΔPNPT calculation was feasible in clinical practice. RESULTS: When we tested small-diameter nasopharyngeal tubes at high-flow or high-peak inspiratory pressure, proximal airway pressure measurements markedly overestimated oropharyngeal pressure. Comparing measured and calculated maximum and minimum oropharyngeal pressure couples yielded root mean square deviations less than 0.5 cmH2 O regardless of ventilatory modality, nasopharyngeal tube diameter, flow rate, gas composition, and leak size. CONCLUSION: During nasopharyngeal tube-assisted anesthesia, proximal airway pressure readings on the anesthetic monitoring machine overestimate oropharyngeal pressure especially for smaller-diameter nasopharyngeal tubes and higher flow, and to a lesser extent for large leaks. Given the importance of calculating oropharyngeal pressure in guiding nasopharyngeal tube ventilation in clinical practice, we propose an accurate calculation using Rohrer's equation method, or approximating oropharyngeal pressure from flow and pressure readings on the anesthetic machine using the ΔPNPT charts.

Floating Bone Phenomenon in Pierre Robin Sequence.

After a failed mandibular osteodistraction, the wrong positioned mandible of a few patients with Pierre Robin sequence returned in the most functional position and regained a proper symmetry, without external intervention. The study aims to explain this self-adjustment and introduce the floating bone phenomenon.The inclusion criteria were severe micrognathia, Fast and Early Mandibular Distraction Osteogenesis protocol, postoperative mandibular wrong positioning, presurgery, immediate postsurgery, and long-term computed tomography scan. Five patients were included. The considered parameters were the distance between mandibular dental centerline and midsagittal facial axis, the rotation of the mandibular body, the magnitude of elongation, and the lowering of the mandibular body.Three patients went from a decentralization >4 mm in the activation phase to a normalization of the said value in the follow-up. In the same period, the interincisal point of 2 patients moved respectively from 0.5 mm on the left and 0.8 mm on the right to 1.2 mm and 1.6 mm on the right, respectively. The rotation of the mandibular body was meanly 25.6° among all patients. The mean value of the distraction was 14.1 mm. A difference of about 4.4 mm between the left and the right side was measured. The lowering of the mandible varied between 2.8 and 12.6 mm.All patients improved their symmetry. Four of them improved in all the measured parameters, while 1 patient presented a worsening in the decentralization of the interincisal point.The floating bone phenomenon could break new grounds in the management of patients with Pierre Robin sequence.

Increased T-helper Cell 2 Response in Infants With Respiratory Syncytial Virus Bronchiolitis Hospitalized Outside Epidemic Peak.

AIM: To test the hypothesis that the balance of type-1/type-2 immune response differs between infants hospitalized with respiratory syncytial virus (RSV) bronchiolitis during the peak months and those during the nonpeak months. METHODS: We prospectively enrolled 90 unrelated full-term previously healthy infants hospitalized during the first year of life for RSV sole bronchiolitis over 2 epidemics (November 2016 to April 2017 and October 2017 to April 2018). We stratified infants as follows: hospitalized during the peak months (n: 71) and during the nonpeak months (n: 19). The frequencies of CD4+ producing interferon (IFN)-γ and interleukin (IL)-4 and of CD8+ producing IFN-γ T cells were measured by flow cytometry from infant peripheral whole blood. The T-helper cell (Th2) polarization index was calculated as the ratio between CD4+ T cells producing IL-4 and CD4+ T cells producing IFN-γ. RESULTS: Infants hospitalized during nonpeak months were significantly less frequently breast-fed, had a higher eosinophils count, a significantly higher percentage of CD4+ T cells producing IL-4 and higher Th2 polarization index than infants hospitalized during the peak months. CONCLUSIONS: We elucidated the presence of different endotypes in infants with RSV sole bronchiolitis. Previously healthy full-term infants hospitalized during the nonpeak months seem to be more likely those with a possible predisposition to atopy.

Bevacizumab-containing regimen in relapsed/progressed brain tumors: a single-institution experience.

AIM: The aim of the study is to assess tumor response, treatment-related toxicities, progression-free survival (PFS), and overall survival (OS) in patients with relapsed/refractory brain tumors treated with bevacizumab-containing regimen. METHODS: Patients that had received I and II line treatments with or without megatherapy were included. Doses and schedule were as follows: bevacizumab (BVZ) 10 mg/kg i.v. with irinotecan (IRI) 150 mg/m2 i.v. every 2 weeks ± temozolamide (TMZ) 200 mg/m2 p.o. daily for 5 days every 4 weeks. TMZ was omitted in heavily pretreated cases. RESULTS: Between 2013 and 2018, 12 patients (3F/9M), median age 161 months (range 66-348), affected with medulloblastoma (n 7), or low-grade glioma (n 2), or high-grade glioma (n 3), received BVZ/IRI association (median courses 20, range 4-67); 3 of them continued single-agent BVZ (median courses 23, range 8-39). TMZ (median courses 8, range 2-26) was administered in eight patients and then stopped in three of them because of myelotoxicity or lack of compliance. Treatment was well tolerated. After 3 months, two complete responses, two partial responses, seven stable diseases, and one progressive disease were observed. Nine cases experienced an improvement in neurological symptoms. Median time to progression was 11 months (95% confidence interval, 4-18 months). Six-month and 2-year PFS were 75% and 42%, respectively. The OS is 33%; interestingly, two cases (one medulloblastoma and one high-grade glioma) are progression-free off-therapy since 30 and 48 months, respectively. CONCLUSIONS: BVZ/IRI association ± TMZ showed encouraging therapeutic activity and low toxicity in this series of relapsed/refractory brain tumors.

A 12-Week Maintenance Therapy with a New Prepared Viscous Budesonide in Pediatric Eosinophilic Esophagitis.

BACKGROUND: A new prepared oral viscous budesonide (PVB) has been effective in inducing clinical and histological remission in pediatric eosinophilic esophagitis (EoE). AIMS: To evaluate the efficacy of a 12-week maintenance therapy on clinical, endoscopic, and histological remission using half of the dose used in the induction therapy. METHODS: We prospectively enrolled pediatric patients with active EoE. After 12 weeks of induction therapy with PVB (< 150 cm: 2 mg/day; ≥ 150 cm: 4 mg/day) patients received a maintenance dose of half of the dose used in the induction therapy (1 mg or 2 mg) for another 12 weeks. A 12-week follow-up was then performed in all patients after the end of therapy. Endoscopy was performed at weeks 0, 12, 24, and 36. Symptoms, endoscopy, and histology scores were also calculated. Serum cortisol was evaluated during the treatment period. RESULTS: We enrolled 20 children (15 males; median age 10 years; range 4-17). After the 12-week induction therapy 18 patients (90%) were in remission, with a significant decrease in the median peak of eosinophil count/HPF as well as a marked reduction in clinical, endoscopic, and histological scores (p < 0.01). At the end of the maintenance therapy (week 24), 17 patients (85%) were still in remission, while there were only 9 at week 36 (45%). No significant changes in cortisol levels were observed during the study period. CONCLUSIONS: The 12-week maintenance treatment with the half the dose of PVB was effective in sustaining remission at week 24; however, no reduction in the rate of relapse after suspension of treatment occurred.

A Treat to Target Strategy Using Panenteric Capsule Endoscopy in Pediatric Patients With Crohn's Disease.

BACKGROUND & AIMS: Pan-enteric capsule endoscopy (PCE) is effective for assessment of small intestinal and colonic Crohn's disease (CD) in pediatric patients. We aimed to determine whether PCE can be used to monitor mucosal healing and deep remission, in a treat to target strategy for pediatric patients with CD. METHODS: We performed a prospective study of 48 children with a diagnosis of CD at a tertiary care pediatric gastroenterology unit; 46 patients were included in the final analysis. Biomarker, imaging, and PCE analyses were performed at baseline and after 24 and 52 weeks. Small bowel and colonic mucosal healing were defined by Lewis scores <135 and simple endoscopic score for CD ≤1, respectively. Clinical remission was defined as defined as a pediatric CD activity index score <10 and biomarker-based remission based on normal levels of biomarkers; deep remission was defined as a combination of clinical remission, biomarker-based remission, and mucosal healing. Treatments were adjusted based on findings from PCE (imaging was considered only for patients with negative findings from PCE). Therapies were introduced, optimized, switched, or combined at the discretion of treating clinicians. The primary outcome was the ability of PCE to assess mucosal healing and deep remission at 3 timepoints and to guide a treat to target strategy. RESULTS: PCE detected inflammation in 34 patients (71%) at baseline, 22 patients (46%) at week 24, and 18 patients (39%) at week 52 (P for comparison among timepoints <.05). Findings from PCE led to a change in therapy for 34 patients (71%) at baseline and 11 patients (23%) at 24 weeks, whereas only 2 patients with negative results from PCE (4%) changed therapies based on findings from imaging. When the treat to target strategy was applied, proportions of patients with mucosal healing and deep remission increased from 21% at baseline, to 54% at week 24, to 58% at week 52 (P for comparison among timepoints <.05); 2 patients (4%) did not respond to treatment. CONCLUSION: In a prospective study of 48 children with CD, we found a treat to target strategy, based on findings from PCE, to significantly increase the proportions of patients with mucosal healing and deep remission. CLINICAL TRIAL: gov no: NCT03161886.

Early Post-cooling Brain Magnetic Resonance for the Prediction of Neurodevelopmental Outcome in Newborns with Hypoxic-Ischemic Encephalopathy.

AIM AND OBJECTIVES: This study aimed to evaluate the predictive role of early post-cooling brain magnetic resonance for developmental outcome in newborns with hypoxic-ischemic encephalopathy. MATERIALS AND METHODS: A retrospective cohort study was performed on 29 consecutive patients through magnetic resonance evaluation (visual analysis of the images and scoring of the detected lesions; mean diffusivity of semioval centre and lenticular nuclei; and area under the curve of basal ganglia N-acetylaspartate at proton magnetic resonance spectroscopic imaging) and Griffiths Mental Development Scales-third edition at 12 and 24 months. RESULTS: Brain magnetic resonance was performed at a mean age of 5.7 ± 3.7 days. Newborns with no/minor magnetic resonance abnormalities had a better developmental outcome than patients with moderate or severe lesions. Structural and spectroscopic abnormalities in basal ganglia resulted in the most significant predictors for an unfavorable outcome. CONCLUSION: Normal magnetic resonance in early post-cooling phases is strongly associated with a favorable developmental outcome.

Combined multichannel intraluminal impedance and pH monitoring is helpful in managing children with suspected gastro-oesophageal reflux disease.

BACKGROUND: Gastro-oesophageal reflux is very common in the paediatric age group. There is no single and reliable test to distinguish between physiologic and pathological gastro-oesophageal reflux, and this lack of clear distinction between disease and normal can have a negative impact on the management of children. AIMS: To evaluate the usefulness of 24-h oesophageal pH-impedance study in infants and children with suspected gastro-oesophageal reflux disease. METHODS: Patients were classified by age groups (A-C) and reflux-related symptoms (typical and atypical). All underwent pH-impedance study. If the latter suggested an abnormal reflux, patients received therapy in accordance with NASPGHAN/ESPGHAN recommendations, while those with normal study had an additional diagnostic work-up. The efficacy of therapy was evaluated with a specific standardized questionnaire for different ages. RESULTS: The study was abnormal in 203/428 patients (47%) while normal in 225/428 (53%). Of those with abnormal study, 109 exhibited typical symptoms (54%), and 94 atypical (46%). The great majority of the patients with abnormal study were responsive to medical anti-reflux therapy. CONCLUSIONS: We confirm the utility of prolonged oesophageal pH-impedance study in detecting gastro-oesophageal reflux disease in children and in guiding therapy. Performing oesophageal pH-impedance monitoring in children with suspected gastro-oesophageal reflux disease is helpful to establish the diagnosis and avoid unnecessary therapy.

A flow-leak correction algorithm for pneumotachographic work-of-breathing measurement during high-flow nasal cannula oxygen therapy.

Measuring work of breathing (WOB) is an intricate task during high-flow nasal cannula (HFNC) therapy because the continuous unidirectional flow toward the patient makes pneumotachography technically difficult to use. We implemented a new method for measuring WOB based on a differential pneumotachography (DP) system, equipped with one pneumotachograph inserted in the HFNC circuit and another connected to a monitoring facemask, combined with a leak correction algorithm (LCA) that corrects flow measurement errors arising from leakage around the monitoring facemask. To test this system, we used a mechanical lung model that provided data to compare LCA-corrected respiratory flow, volume and time values with effective values obtained with a third pneumotachograph used instead of the LCA to measure mask flow leaks directly. Effective and corrected volume and time data showed high agreement (Bland-Altman plots) even at the highest leak. Studies on two healthy adult volunteers confirmed that corrected respiratory flow combined with esophageal pressure measurements can accurately determine WOB (relative error < 1%). We conclude that during HFNC therapy, a DP system combined with a facemask and an algorithm that corrects errors due to flow leakages allows pneumotachography to measure reliably the respiratory flow and volume data needed for calculating WOB.