Nasal high flow therapy introduction lowers reintubation risk in a Peruvian paediatric intensive care unit.

AIM: We examined the impact of introducing high-flow nasal oxygen therapy (HFNT) on children under five with post-extubation respiratory failure in a paediatric intensive care unit (PICU) in Peru. METHODS: This quasi-experimental study compared clinical outcomes before and after initial HFNT deployment in the PICU at Instituto Nacional de Salud del Niño in Lima in June 2016. We compared three groups: 29 received post-extubation HFNT and 17 received continuous positive airway pressure (CPAP) from 2016-17 and 12 historical controls received CPAP from 2012-16. The primary outcome was the need for mechanical ventilation. Adjusted hazard ratios (aHR) and 95% confidence intervals (95% CI) were calculated via survival analysis. RESULTS: High-flow nasal oxygen therapy and CPAP did not alter the need for mechanical ventilation after extubation (aHR 0.47, 95% CI 0.15-1.48 and 0.96, 95% CI 0.35-2.62, respectively) but did reduce the risk of reintubation (aHR 0.18, 95% CI 0.06-0.57 and 0.14, 95% CI 0.03-0.72, respectively). PICU length of stay was 11, 18 and 37 days for CPAP, HFNT and historical CPAP and mortality was 12%, 7% and 27%, respectively. There was no effect on the duration of sedative infusions. CONCLUSION: High-flow nasal oxygen therapy provided effective support for some children, but larger studies in resource-constrained settings are needed.

Key considerations prior to nasal high flow deployment in a Peruvian PICU from providers' perspectives.

AIM: Implementation of healthcare interventions in resource-limited settings remains challenging. This exploratory qualitative study describes social and institutional factors to consider prior to nasal high flow deployment in a middle-income country. METHODS: Researchers conducted eight nursing focus groups and four semi-structured physician interviews at Instituto Nacional de Salud del Niño in Lima, Peru. Participants were identified via purposive sampling. Data were transcribed, translated and coded using a rigorous and iterative process. Pertinent themes were identified using thematic analysis with Dedoose software. RESULTS: Thirty-nine nurses and four physicians participated in focus groups and interviews, respectively. Participants identified five major factors: (i) Adequate training, (ii) Clinician buy-in, (iii) Resource-limited setting, (iv) Local social context and (v) Organizational change management. To create buy-in, physicians and nurses emphasised the need to recognise benefit of the intervention and agree with clinical practice standardization. Physicians and nurses described barriers specific to resource-limited settings, including unreliable supply chain, whereas nurses shared concerns about increasing workload and physician-nurse social hierarchy. Participants recognised the importance of team commitment and ongoing interdisciplinary communication for sustainability. CONCLUSION: While some factors to consider prior to deployment of healthcare technology are universal, resource-limited settings have unique implementation barriers.

Agreement Between the World Health Organization Algorithm and Lung Consolidation Identified Using Point-of-Care Ultrasound for the Diagnosis of Childhood Pneumonia by General Practitioners.

PURPOSE: The World Health Organization (WHO) case management algorithm for acute lower respiratory infections has moderate sensitivity and poor specificity for the diagnosis of pneumonia. We sought to determine the feasibility of using point-of-care ultrasound in resource-limited settings to identify pneumonia by general health practitioners and to determine agreement between the WHO algorithm and lung consolidations identified by point-of-care ultrasound. METHODS: An expert radiologist taught two general practitioners how to perform point-of-care ultrasound over a seven-day period. We then conducted a prospective study of children aged 2 months to 3 years in Peru and Nepal with and without respiratory symptoms, which were evaluated by point-of-care ultrasound to identify lung consolidation. RESULTS: We enrolled 378 children: 127 were controls without respiratory symptoms, 82 had respiratory symptoms without clinical pneumonia, and 169 had clinical pneumonia by WHO criteria. Point-of-care ultrasound was performed in the community (n = 180), in outpatient offices (n = 95), in hospital wards (n = 19), and in Emergency Departments (n = 84). Average time to perform point-of-care ultrasound was 6.4 ± 2.2 min. Inter-observer agreement for point-of-care ultrasound interpretation between general practitioners was high (κ = 0.79, 95 % CI 0.73-0.81). The diagnosis of pneumonia using the WHO algorithm yielded a sensitivity of 69.6 % (95 % CI 55.7-80.8 %), specificity of 59.6 % (95 % CI 54.0-65.0 %), and positive and negative likelihood ratios of 1.73 (95 % CI 1.39-2.15) and 0.51 (95 % CI 0.30-0.76) when lung consolidation on point-of-care ultrasound was used as the reference. CONCLUSIONS: The WHO algorithm disagreed with point-of-care ultrasound findings in more than one-third of children and had an overall low performance when compared with point-of-care ultrasound to identify lung consolidation. A paired approach with point-of-care ultrasound may improve case management in resource-limited settings.

Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis.

BACKGROUND: Guidelines do not currently recommend the use of lung ultrasound (LUS) as an alternative to chest X-ray (CXR) or chest computerized tomography (CT) scan for the diagnosis of pneumonia. We conducted a meta-analysis to summarize existing evidence of the diagnostic accuracy of LUS for pneumonia in adults. METHODS: We conducted a systematic search of published studies comparing the diagnostic accuracy of LUS against a referent CXR or chest CT scan and/or clinical criteria for pneumonia in adults aged ≥18 years. Eligible studies were required to have a CXR and/or chest CT scan at the time of evaluation. We manually extracted descriptive and quantitative information from eligible studies, and calculated pooled sensitivity and specificity using the Mantel-Haenszel method and pooled positive and negative likelihood ratios (LR) using the DerSimonian-Laird method. We assessed for heterogeneity using the Q and I2 statistics. RESULTS: Our initial search strategy yielded 2726 articles, of which 45 (1.7%) were manually selected for review and 10 (0.4%) were eligible for analyses. These 10 studies provided a combined sample size of 1172 participants. Six studies enrolled adult patients who were either hospitalized or admitted to Emergency Departments with suspicion of pneumonia and 4 studies enrolled critically-ill adult patients. LUS was performed by highly-skilled sonographers in seven studies, by trained physicians in two, and one did not mention level of training. All studies were conducted in high-income settings. LUS took a maximum of 13 minutes to conduct. Nine studies used a 3.5-5 MHz micro-convex transducer and one used a 5-9 MHz convex probe. Pooled sensitivity and specificity for the diagnosis of pneumonia using LUS were 94% (95% CI, 92%-96%) and 96% (94%-97%), respectively; pooled positive and negative LRs were 16.8 (7.7-37.0) and 0.07 (0.05-0.10), respectively; and, the area-under-the-ROC curve was 0.99 (0.98-0.99). CONCLUSIONS: Our meta-analysis supports that LUS, when conducted by highly-skilled sonographers, performs well for the diagnosis of pneumonia. General practitioners and Emergency Medicine physicians should be encouraged to learn LUS since it appears to be an established diagnostic tool in the hands of experienced physicians.

Developing a reference of normal lung sounds in healthy Peruvian children.

PURPOSE: Lung auscultation has long been a standard of care for the diagnosis of respiratory diseases. Recent advances in electronic auscultation and signal processing have yet to find clinical acceptance; however, computerized lung sound analysis may be ideal for pediatric populations in settings, where skilled healthcare providers are commonly unavailable. We described features of normal lung sounds in young children using a novel signal processing approach to lay a foundation for identifying pathologic respiratory sounds. METHODS: 186 healthy children with normal pulmonary exams and without respiratory complaints were enrolled at a tertiary care hospital in Lima, Peru. Lung sounds were recorded at eight thoracic sites using a digital stethoscope. 151 (81%) of the recordings were eligible for further analysis. Heavy-crying segments were automatically rejected and features extracted from spectral and temporal signal representations contributed to profiling of lung sounds. RESULTS: Mean age, height, and weight among study participants were 2.2 years (SD 1.4), 84.7 cm (SD 13.2), and 12.0 kg (SD 3.6), respectively; and, 47% were boys. We identified ten distinct spectral and spectro-temporal signal parameters and most demonstrated linear relationships with age, height, and weight, while no differences with genders were noted. Older children had a faster decaying spectrum than younger ones. Features like spectral peak width, lower-frequency Mel-frequency cepstral coefficients, and spectro-temporal modulations also showed variations with recording site. CONCLUSIONS: Lung sound extracted features varied significantly with child characteristics and lung site. A comparison with adult studies revealed differences in the extracted features for children. While sound-reduction techniques will improve analysis, we offer a novel, reproducible tool for sound analysis in real-world environments.

Performance and usability of a new mobile application for measuring respiratory rate in young children with acute lower respiratory infections.

OBJECTIVES: Respiratory rate (RR) measurement is critical to diagnosing pneumonia in resource-constrained settings, but accurate RR measurement is challenging. The acute lower respiratory illness treatment and evaluation (ALRITE) mobile phone application (app), designed to help healthcare workers (HCWs) manage pediatric respiratory illnesses, includes a semiautomated RR counter. This study aimed to evaluate the accuracy and usability of the ALRITE RR counter and a commercially available RR counter app, RRate, with a reference standard. METHODS: This was a cross-sectional observational study of HCWs. Participants used both apps to measure the RR of pediatric patients from standardized videos. The reference standard was determined by consensus of a manual 1-min count by two providers. We assessed agreement using Spearman's rank correlation coefficient and constructed Bland-Altman plots to determine bias and limits of agreement. Participants completed a usability survey. RESULTS: Thirty-nine HCWs participated. The agreement between the apps and reference standard (Spearman's coefficient) was 0.83 (95% confidence interval [CI]: 0.78-0.87) for ALRITE and 0.62 (95% CI: 0.52-0.70) for RRate. ALRITE had a bias of -2 breaths/min (lower limit of agreement [LoA] -16 to +12) and RRate had a bias of -0.4 breaths/min (LoA -24 to +23) compared to the reference standard. Both apps had a poorer agreement at higher RRs. Based on usability survey responses, 95% found ALRITE easy to use. CONCLUSIONS: The ALRITE RR counter has acceptable accuracy for counting RR in infants with respiratory distress, appears to be more accurate than a commercially available option, and was user-friendly. The ALRITE RR counter is a promising tool for meriting evaluation in real-world settings.

Tracheal pressure generated by high-flow nasal cannula in 3D-Printed pediatric airway models.

OBJECTIVE: Heated and humidified high flow nasal cannula (HFNC) is an increasingly used form of noninvasive respiratory support with the potential to generate significant tracheal pressure. The aim of this study was to quantify the pressure generated by HFNC within the trachea in anatomically correct, pediatric airway models. METHODS: 3D-printed upper airway models of a preterm neonate, term neonate, toddler, and small child were connected to a spontaneous breathing computerized lung model at age-appropriate ventilation settings. Two commercially available HFNC systems were applied to each airway model at increasing flows and the positive end-expiratory pressure (PEEP) was recorded at the level of the trachea. RESULTS: Increasing HFNC flow produced a quadratically curved increase in tracheal pressure in closed-mouth models. The maximum flow tested in each model generated a tracheal pressure of 7 cm H2O in the preterm neonate, 10 cm H2O in the term neonate, 9 cm H2O in the toddler, and 24 cm H2O in the small child. Tracheal pressure decreased by at least 50% in open-mouth models. CONCLUSIONS: HFNC was found to demonstrate a predictable flow-pressure relationship that achieved sufficient distending pressure to consider treatment of pediatric obstructive sleep apnea and tracheomalacia in the closed-mouth models tested.

Standardized Extubation and High Flow Nasal Cannula Training Program for Pediatric Critical Care Providers in Lima, Peru.

Introduction: Acute lower respiratory tract infections are the top cause of nonneonatal mortality in children under 5 years of age. Since many resource-limited settings lack basic pediatric respiratory support modalities, introducing respiratory technology in these settings may improve survival. Unfortunately, data suggest that many interventions in these settings are not sustainable and that after several months, local staff are no longer comfortable using newly implemented technology. Methods: We aimed to create training modules for implementation of a standardized extubation process and high flow nasal cannula for physician and nurse providers at a tertiary care center in Lima, Peru. This training curriculum combined a didactic lecture with hands-on practicum and clinical case discussion over multiple sessions spanning a year. We created all materials in English and translated to Spanish for use. Participants completed evaluations after the training program to determine whether objectives were met. This training was intended for critical care providers but could be modified for other audiences. Results: A total of 76 providers (12 attending/fellow critical care physicians, 40 bedside nurses, eight pediatric residents, and 14 medical technicians) participated in this multiday training. Almost all (75, 99%) participants felt the objectives were clearly stated, and 70 (92%) felt objectives were met. Discussion: We have provided materials to help instructors set up and implement a standardized training curriculum with recommended timing and improvements based on feedback. The tools provided allow for adaptation depending on the instructors' primary objectives, language of audience (English or Spanish), and learners' level of training.

Knowledge acquisition and retention after a high flow training programme in Peru: a quasi-experimental single group pre-post design.

OBJECTIVE: Respiratory infections remain the leading infectious cause of death in children under 5 and disproportionately affect children in resource-limited settings. Implementing non-invasive respiratory support can reduce respiratory-related mortality. However, maintaining competency after deployment can be difficult. Our objective was to evaluate the effectiveness of a comprehensive multidisciplinary high-flow training programme in a Peruvian paediatric intensive care unit (PICU). DESIGN: Quasi-experimental single group pre-post intervention study design. SETTING: Quaternary care PICU in a resource-constrained setting in Lima, Peru. PARTICIPANTS: Attending physicians, fellows, paediatric residents, registered nurses, respiratory therapists and medical technicians working in the PICU were invited to participate. INTERVENTIONS: Concurrent with initial high-flow deployment, we implemented a training programme consisting of lectures, case-based discussion and demonstrations with baseline, 3-month and 12-month training sessions. Pre-training and post-training assessment surveys were distributed surrounding all training sessions. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was achieving minimum competency (median score of 80%) on the high flow training assessment tool. Secondary outcomes included knowledge acquisition (differences in pre-baseline and post-baseline training assessments), short-term retention (differences in post-baseline and pre-3-month refresher training assessments) and long-term retention (differences in post-3-month refresher and pre-12-month refresher training assessments). RESULTS: Eighty participants (50% nurses, 15% ICU physicians and 34% other providers) completed the baseline assessment. Participants showed improvement in overall score and all subtopics except the clinical application of knowledge after baseline training (p<0.001). Participants failed to retain minimum competency at 3-month and 12-month follow-up assessments (70% (IQR: 57-74) and 70% (IQR: 65-74), respectively). After repeat training sessions, overall knowledge continued to improve, exceeding baseline performance (78% (IQR: 70-87), 83% (IQR: 74-87) and 87% (IQR: 83-91) at baseline, 3 and 12 months, respectively). CONCLUSION: This study suggests the need for repeat training sessions to achieve and maintain competency after the implementation of new technology.

Effect of High-Flow Nasal Cannula on Expiratory Pressure and Ventilation in Infant, Pediatric, and Adult Models.

BACKGROUND: Heated and humidified high-flow nasal cannula (HFNC) is a widely used form of respiratory support; however, data regarding optimal flows for a given patient size or disease state are lacking. A comprehensive study of the physiologic effects of HFNC is needed to better understand the mechanisms of action. The objective of the current study was to quantify the effect of HFNC settings in age-specific, anatomically correct nasal airways and spontaneously breathing lung models. We hypothesized that there is an effect of flow on pressure and ventilation. METHODS: Three-dimensionally printed upper airway models of a preterm neonate, term neonate, toddler, small child, and adult were affixed to the ASL 5000 test lung to simulate spontaneous breathing with age-appropriate normal ventilation parameters. CO2 was introduced to simulate profound hypercapneic respiratory failure with an end-tidal partial pressure of carbon dioxide (PETCO2 ) of 90 ± 1 mm Hg. Two commercially available HFNC systems were applied to the airway models, and PEEP, inspired CO2, and exhaled CO2 (PETCO2 ) were recorded for 6 min across a range of flow. RESULTS: Increasing HFNC flow provided a non-linear increase in PEEP in closed-mouth models, with maximum tested flows generating 6 cm H2O in the preterm neonate to 20 cm H2O in the small child. Importantly, PEEP decreased by approximately 50% in open-mouth models. Increasing HFNC flow improved expiratory CO2 elimination to a certain point, above which continued increases in flow had minimal additional effect. This change point ranged from 4 L/min in the preterm neonate to 10 L/min in the small child. CONCLUSIONS: These findings may help clinicians understand the effects of HFNC at different settings and may inform management guidelines for patients with respiratory failure.

Building a Prediction Model for Radiographically Confirmed Pneumonia in Peruvian Children: From Symptoms to Imaging.

BACKGROUND: Community-acquired pneumonia remains the leading cause of death in children worldwide, and current diagnostic guidelines in resource-poor settings are neither sensitive nor specific. We sought to determine the ability to correctly diagnose radiographically confirmed clinical pneumonia when diagnostics tools were added to clinical signs and symptoms in a cohort of children with acute respiratory illnesses in Peru. METHODS: Children < 5 years of age with an acute respiratory illness presenting to a tertiary hospital in Lima, Peru, were enrolled. The ability to predict radiographically confirmed clinical pneumonia was assessed using logistic regression under four additive scenarios: clinical signs and symptoms only, addition of lung auscultation, addition of oxyhemoglobin saturation (Spo2), and addition of lung ultrasound. RESULTS: Of 832 children (mean age, 21.3 months; 59% boys), 453 (54.6%) had clinical pneumonia and 221 (26.6%) were radiographically confirmed. Children with radiographically confirmed clinical pneumonia had lower average Spo2 than those without (95.9% vs 96.6%, respectively; P < .01). The ability to correctly identify radiographically confirmed clinical pneumonia using clinical signs and symptoms was limited (area under the curve [AUC] = 0.62; 95% CI, 0.58-0.67) with a sensitivity of 66% (95% CI, 59%-73%) and specificity of 53% (95% CI, 49%-57%). The addition of lung auscultation improved classification (AUC = 0.73; 95% CI, 0.69-0.77) with a sensitivity of 75% (95% CI, 69%-81%) and specificity of 53% (95% CI, 49%-57%) for the presence of crackles. In contrast, the addition of Spo2 did not improve classification (AUC = 0.73; 95% CI, 0.69-0.77) with a sensitivity of 40% (95% CI, 33%-47%) and specificity of 72% (95% CI, 68%-75%) for an Spo2 ≤ 92%. Adding consolidation on lung ultrasound was associated with the largest improvement in classification (AUC = 0.85; 95% CI, 0.82-0.89) with a sensitivity of 55% (95% CI, 48%-63%) and specificity of 95% (95% CI, 93%-97%). CONCLUSIONS: The addition of lung ultrasound and auscultation to clinical signs and symptoms improved the ability to correctly classify radiographically confirmed clinical pneumonia. Implementation of auscultation- and ultrasound-based diagnostic tools can be considered to improve diagnostic yield of pneumonia in resource-poor settings.

Lung ultrasound as a diagnostic tool for radiographically-confirmed pneumonia in low resource settings.

BACKGROUND: Pneumonia is a leading cause of morbidity and mortality in children worldwide; however, its diagnosis can be challenging, especially in settings where skilled clinicians or standard imaging are unavailable. We sought to determine the diagnostic accuracy of lung ultrasound when compared to radiographically-confirmed clinical pediatric pneumonia. METHODS: Between January 2012 and September 2013, we consecutively enrolled children aged 2-59 months with primary respiratory complaints at the outpatient clinics, emergency department, and inpatient wards of the Instituto Nacional de Salud del Niño in Lima, Peru. All participants underwent clinical evaluation by a pediatrician and lung ultrasonography by one of three general practitioners. We also consecutively enrolled children without respiratory symptoms. Children with respiratory symptoms had a chest radiograph. We obtained ancillary laboratory testing in a subset. RESULTS: Final clinical diagnoses included 453 children with pneumonia, 133 with asthma, 103 with bronchiolitis, and 143 with upper respiratory infections. In total, CXR confirmed the diagnosis in 191 (42%) of 453 children with clinical pneumonia. A consolidation on lung ultrasound, which is our primary endpoint for pneumonia, had a sensitivity of 88.5%, specificity of 100%, and an area under-the-curve of 0.94 (95% CI 0.92-0.97) when compared to radiographically-confirmed clinical pneumonia. When any abnormality on lung ultrasound was compared to radiographically-confirmed clinical pneumonia the sensitivity increased to 92.2% and the specificity decreased to 95.2%, with an area under-the-curve of 0.94 (95% CI 0.91-0.96). CONCLUSIONS: Lung ultrasound had high diagnostic accuracy for the diagnosis of radiographically-confirmed pneumonia. Added benefits of lung ultrasound include rapid testing and high inter-rater agreement. Lung ultrasound may serve as an alternative tool for the diagnosis of pediatric pneumonia.

Lung ultrasound for the diagnosis of pneumonia in children: a meta-analysis.

BACKGROUND AND OBJECTIVE: Pneumonia is the leading cause of death of children. Diagnostic tools include chest radiography, but guidelines do not currently recommend the use of lung ultrasound (LUS) as a diagnostic method. We conducted a meta-analysis to summarize evidence on the diagnostic accuracy of LUS for childhood pneumonia. METHODS: We performed a systematic search in PubMed, Embase, the Cochrane Library, Scopus, Global Health, World Health Organization-Libraries, and Latin American and Caribbean Health Sciences Literature of studies comparing LUS diagnostic accuracy against a reference standard. We used a combination of controlled key words for age <18 years, pneumonia, and ultrasound. We identified 1475 studies and selected 15 (1%) for further review. Eight studies (765 children) were retrieved for analysis, of which 6 (75%) were conducted in the general pediatric population and 2 (25%) in neonates. Eligible studies provided information to calculate sensitivity, specificity, and positive and negative likelihood ratios. Heterogeneity was assessed by using Q and I(2) statistics. RESULTS: Five studies (63%) reported using highly skilled sonographers. Overall methodologic quality was high, but heterogeneity was observed across studies. LUS had a sensitivity of 96% (95% confidence interval [CI]: 94%-97%) and specificity of 93% (95% CI: 90%-96%), and positive and negative likelihood ratios were 15.3 (95% CI: 6.6-35.3) and 0.06 (95% CI: 0.03-0.11), respectively. The area under the receiver operating characteristic curve was 0.98. Limitations included the following: most studies included in our analysis had a low number of patients, and the number of eligible studies was also small. CONCLUSIONS: Current evidence supports LUS as an imaging alternative for the diagnosis of childhood pneumonia. Recommendations to train pediatricians on LUS for diagnosis of pneumonia may have important implications in different clinical settings.

Computerised lung sound analysis to improve the specificity of paediatric pneumonia diagnosis in resource-poor settings: protocol and methods for an observational study.

INTRODUCTION: WHO case management algorithm for paediatric pneumonia relies solely on symptoms of shortness of breath or cough and tachypnoea for treatment and has poor diagnostic specificity, tends to increase antibiotic resistance. Alternatives, including oxygen saturation measurement, chest ultrasound and chest auscultation, exist but with potential disadvantages. Electronic auscultation has potential for improved detection of paediatric pneumonia but has yet to be standardised. The authors aim to investigate the use of electronic auscultation to improve the specificity of the current WHO algorithm in developing countries. METHODS: This study is designed to test the hypothesis that pulmonary pathology can be differentiated from normal using computerised lung sound analysis (CLSA). The authors will record lung sounds from 600 children aged ≤5 years, 100 each with consolidative pneumonia, diffuse interstitial pneumonia, asthma, bronchiolitis, upper respiratory infections and normal lungs at a children's hospital in Lima, Peru. The authors will compare CLSA with the WHO algorithm and other detection approaches, including physical exam findings, chest ultrasound and microbiologic testing to construct an improved algorithm for pneumonia diagnosis. DISCUSSION: This study will develop standardised methods for electronic auscultation and chest ultrasound and compare their utility for detection of pneumonia to standard approaches. Utilising signal processing techniques, the authors aim to characterise lung sounds and through machine learning, develop a classification system to distinguish pathologic sounds. Data will allow a better understanding of the benefits and limitations of novel diagnostic techniques in paediatric pneumonia.