Clinical predictors of acute radiological pneumonia and hypoxaemia at high altitude

Severity and mortality of acute respiratory failure in pediatrics: A prospective multicenter cohort in Bogotá, Colombia

Background and Aims

Acute respiratory failure (ARF) is the most frequent cause of cardiorespiratory arrest and subsequent death in children worldwide. There have been limited studies regarding ARF in high altitude settings. The aim of this study was to calculate mortality and describe associated factors for severity and mortality in children with ARF.

Methods

The study was conducted within a prospective multicentric cohort that evaluated the natural history of pediatric ARF. For this analysis three primary outcomes were studied: mortality, invasive mechanical ventilation, and pediatric intensive care unit (PICU) length of stay. Eligible patients were children older than 1 month and younger than 18 years of age with respiratory difficulty at the time of admission. Patients who developed ARF were followed at the time of ARF, 48 h later, at the time of discharge, and at 30 and 60 days after discharge. It was conducted in the pediatric emergency, in-hospital, and critical-care services in three hospitals in Bogotá, Colombia, from April 2020 to June 2021.

Results

Out of a total of 685 eligible patients, 296 developed ARF for a calculated incidence of ARF of 43.2%. Of the ARF group, 90 patients (30.4%) needed orotracheal intubation, for a mean of 9.57 days of ventilation (interquartile range = 3.00-11.5). Incidence of mortality was 6.1% (n = 18). The associated factors for mortality in ARF were a history of a neurologic comorbidity and a higher fraction of inspired oxygen at ARF diagnosis. For PICU length of stay, the associated factors were age between 2 and 5 years of age, exposure to smokers, and respiratory comorbidity. Finally, for mechanical ventilation, the risk factors were obesity and being unstable at admission.

Conclusions

ARF is a common cause of morbidity and mortality in children. Understanding the factors associated with greater mortality and severity of ARF might allow earlier recognition and initiation of prompt treatment strategies.

Clinical predictors of hypoxic pneumonia in children from the Eastern Highlands Province, Papua New Guinea: secondary analysis of two prospective observational studies

Background

Pneumonia is the leading cause of death in young children globally and is prevalent in the Papua New Guinea highlands. We investigated clinical predictors of hypoxic pneumonia to inform local treatment guidelines in this resource-limited setting.

Methods

Between 2013 and 2020, two consecutive prospective observational studies were undertaken enrolling children 0-4 years presenting with pneumonia to health-care facilities in Goroka Town, Eastern Highlands Province. Logistic regression models were developed to identify clinical predictors of hypoxic pneumonia (oxygen saturation <90% on presentation). Model performance was compared against established criteria to identify severe pneumonia.

Findings

There were 2067 cases of pneumonia; hypoxaemia was detected in 36.1%. The strongest independent predictors of hypoxic pneumonia were central cyanosis on examination (adjusted odds ratio [aOR] 5.14; 95% CI 3.47-7.60), reduced breath sounds (aOR 2.92; 95% CI 2.30-3.71), and nasal flaring or grunting (aOR 2.34; 95% CI 1.62-3.38). While the model developed to predict hypoxic pneumonia outperformed established pneumonia severity criteria, it was not sensitive enough to be clinically useful at this time.

Interpretation

Given signs and symptoms are unable to accurately detect hypoxia, all health care facilities should be equipped with pulse oximeters. However, for the health care worker without access to pulse oximetry, consideration of central cyanosis, reduced breath sounds, nasal flaring or grunting, age-specific tachycardia, wheezing, parent-reported drowsiness, or bronchial breathing as suggestive of hypoxaemic pneumonia, and thus severe disease, may prove useful in guiding management, hospital referral and use of oxygen therapy.

Funding

Funded by Pfizer Global and the Bill & Melinda Gates Foundation.

Defining hypoxaemia from pulse oximeter measurements of oxygen saturation in well children at low altitude in Bangladesh: an observational study

Background

WHO defines hypoxaemia, a low peripheral arterial oxyhaemoglobin saturation (SpO₂), as <90%. Although hypoxaemia is an important risk factor for mortality of children with respiratory infections, the optimal SpO₂ threshold for defining hypoxaemia is uncertain in low-income and middle-income countries (LMICs). We derived a SpO₂ threshold for hypoxaemia from well children in Bangladesh residing at low altitude.

Methods

We prospectively enrolled well, children aged 3–35 months participating in a pneumococcal vaccine evaluation in Sylhet district, Bangladesh between June and August 2017. Trained health workers conducting community surveillance measured the SpO₂ of children using a Masimo Rad-5 pulse oximeter with a wrap sensor. We used standard summary statistics to evaluate the SpO₂ distribution, including whether the distribution differed by age or sex. We considered the 2.5th, 5th and 10th percentiles of SpO₂ as possible lower thresholds for hypoxaemia.

Results

Our primary analytical sample included 1470 children (mean age 18.6±9.5 months). Median SpO₂ was 98% (IQR 96%–99%), and the 2.5th, 5th and 10th percentile SpO₂ was 91%, 92% and 94%. No child had a SpO₂ <90%. Children 3–11 months had a lower median SpO₂ (97%) than 12–23 months (98%) and 24–35 months (98%) (p=0.039). The SpO₂ distribution did not differ by sex (p=0.959).

Conclusion

A SpO₂ threshold for hypoxaemia derived from the 2.5th, 5th or 10th percentile of well children is higher than <90%. If a higher threshold than <90% is adopted into LMIC care algorithms then decision-making using SpO₂ must also consider the child’s clinical status to minimise misclassification of well children as hypoxaemic. Younger children in lower altitude LMICs may require a different threshold for hypoxaemia than older children. Evaluating the mortality risk of sick children using higher SpO₂ thresholds for hypoxaemia is a key next step.

Clinical predictors of radiological pneumonia: A cross-sectional study from a tertiary hospital in Nepal

Background

Despite readily availability of vaccines against both Hemophilus influenzae and Pneumococcus, pneumonia remains the most common cause of morbidity and mortality in children under the age of five years in Nepal. With growing antibiotic resistance and a general move towards more rational antibiotic use, early identification of clinical signs for the prediction of radiological pneumonia would help practitioners to start the treatment of patients. The main aim of this study was to reassess the clinical predictors of pneumonia in Nepal.

Methods

This cross-sectional study was conducted between June 2015 and November 2015 at Tribhuvan University Teaching Hospital, a tertiary hospital in Kathmandu, Nepal. Children aged 3–60 months with a clinical diagnosis of pneumonia by a physician were enrolled in the study. Radiological pneumonia was identified and categorized as per World Health Organization guidelines by an experienced radiologist blinded to patient characteristics. We calculated sensitivity and specificity of clinical signs and symptoms for radiological pneumonia.

Results

Out of 1021 children with fever, 160 cases were clinically diagnosed as pneumonia and were enrolled for this study. Among the enrolled patients, 61% had radiological pneumonia. Tachypnea had the highest sensitivity of 99%, while bronchial breathing had the highest specificity of 100%. During univariate analysis, grunting, wheezing, nasal discharge, decreased breath sounds, noisy breathing and hypoxemia were associated with radiological pneumonia. Only hypoxemia remained an independent predictor when adjusted for all the factors.

Conclusion

Tachypnea was the most sensitive sign, whereas bronchial breathing was most specific sign for radiological pneumonia.

[Factors associated to high-flow nasal cannula treatment failure in pediatric patients with respiratory failure in two pediatric intensive care units at high altitude]

INTRODUCTION

Acute respiratory failure is the leading cause of hospitalization in pediatrics. High-flow nasal cannulas (HFNCs) offer a new alternative, but the evidence and indications are still debated. The performance of HFNCs at high altitude has not been described to date.

OBJECTIVE

To describe the use of HFNCs in pediatric patients admitted with respiratory failure and explore the factors associated with treatment failure.

METHODOLOGY

A prospective cohort study was carried out in patients between 1 month and 18 years of age managed with HFNCs. The demographic and treatment response data were recorded at baseline and after 1, 6 and 24hours. The number of failures was determined, as well as the length of stay, complications and mortality. Patients with treatment failure were compared with the rest.

RESULTS

A total of 539 patients were enrolled. Infants (70.9%) of male sex (58.4%) and airway diseases such as asthma and bronchiolitis (61.2%) were more frequent. There were 53 failures (9.8%), with 21 occurring in the first 24hours. The median length of stay was 4 days (IQR 4); there were 5 deaths (0.9%) and 13 adverse events (epistaxis) (2.2%). Improvement was observed in vital signs and severity over time, with differences in the group that failed, but without interactions. The final logistic model established an independent relationship of failure between the hospital (OR 2.78, 95%CI 1.48-5.21) and the initial respiratory rate (OR 1.56, 95%CI 1.21-2.01).

CONCLUSIONS

HFNCs afford good clinical response, with few complications and a low failure rate. The differences found between institutions suggest a subjective relationship in the decision of therapy failure.

Clinical signs of hypoxaemia in children aged 2 months to 5 years with acute respiratory distress in Switzerland and Senegal

BACKGROUND

Hypoxaemia is a predictor of pneumonia-related mortality. WHO published recommendations for oxygen therapy based on clinical signs which state that, when oxygen is plentiful, it should be given to children with central cyanosis, inability to drink, severe chest indrawing, RR >70 breaths/min, grunting with every breath (in young infants) or those who display head nodding. These guidelines, however, are based on a few studies only.

AIM

To assess the accuracy of combinations of clinical signs which predict hypoxaemia in pre-school children aged 2 months to 5 years with acute respiratory distress in hospitals in Switzerland and Senegal.

METHODS

This observational study was conducted in four emergency units, two in Switzerland and two in Senegal. Patients aged 2 months to 5 years with acute respiratory distress were eligible for inclusion. Clinical signs were compared with transcutaneous blood saturation levels (SaO₂).

RESULTS

About 111 children were assessed, 67 in Switzerland and 44 in Senegal. The prevalence of hypoxaemia was 13%. Twelve models of combined symptoms were analysed. The WHO model, for when oxygen supply is ample, had the highest diagnostic performance with a sensitivity of 0.93 and a specificity of 0.60.

CONCLUSIONS

Clinical signs alone are unreliable for the detection of hypoxaemia. The current WHO model, for ample oxygen supply proved to be the best clinical predictor, although a great number of non-hypoxaemic children were unnecessarily treated because of the low specificity of this model.

Cough sound analysis - a new tool for diagnosing pneumonia

Pneumonia kills over 1,800,000 children annually throughout the world. Prompt diagnosis and proper treatment are essential to prevent these unnecessary deaths. Reliable diagnosis of childhood pneumonia in remote regions is fraught with difficulties arising from the lack of field-deployable imaging and laboratory facilities as well as the scarcity of trained community healthcare workers. In this paper, we present a pioneering class of enabling technology addressing both of these problems. Our approach is centered on automated analysis of cough and respiratory sounds, collected via microphones that do not require physical contact with subjects. We collected cough sounds from 91 patients suspected of acute respiratory illness such as pneumonia, bronchiolitis and asthma. We extracted mathematical features from cough sounds and used them to train a Logistic Regression classifier. We used the clinical diagnosis provided by the paediatric respiratory clinician as the gold standard to train and validate our classifier against. The methods proposed in this paper could separate pneumonia from other diseases at a sensitivity and specificity of 94% and 75% respectively, based on parameters extracted from cough sounds alone. Our method has the potential to revolutionize the management of childhood pneumonia in remote regions of the world.

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.

Clinical features for diagnosis of pneumonia in children younger than 5 years: a systematic review and meta-analysis

BACKGROUND

Pneumonia is the biggest cause of deaths in young children in developing countries, but early diagnosis and intervention can effectively reduce mortality. We aimed to assess the diagnostic value of clinical signs and symptoms to identify radiological pneumonia in children younger than 5 years and to review the accuracy of WHO criteria for diagnosis of clinical pneumonia.

METHODS

We searched Medline (PubMed), Embase (Ovid), the Cochrane Database of Systematic Reviews, and reference lists of relevant studies, without date restrictions, to identify articles assessing clinical predictors of radiological pneumonia in children. Selection was based on: design (diagnostic accuracy studies), target disease (pneumonia), participants (children aged <5 years), setting (ambulatory or hospital care), index test (clinical features), and reference standard (chest radiography). Quality assessment was based on the 2011 Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. For each index test, we calculated sensitivity and specificity and, when the tests were assessed in four or more studies, calculated pooled estimates with use of bivariate model and hierarchical summary receiver operation characteristics plots for meta-analysis.

FINDINGS

We included 18 articles in our analysis. WHO-approved signs age-related fast breathing (six studies; pooled sensitivity 0·62, 95% CI 0·26-0·89; specificity 0·59, 0·29-0·84) and lower chest wall indrawing (four studies; 0·48, 0·16-0·82; 0·72, 0·47-0·89) showed poor diagnostic performance in the meta-analysis. Features with the highest pooled positive likelihood ratios were respiratory rate higher than 50 breaths per min (1·90, 1·45-2·48), grunting (1·78, 1·10-2·88), chest indrawing (1·76, 0·86-3·58), and nasal flaring (1·75, 1·20-2·56). Features with the lowest pooled negative likelihood ratio were cough (0·30, 0·09-0·96), history of fever (0·53, 0·41-0·69), and respiratory rate higher than 40 breaths per min (0·43, 0·23-0·83).

INTERPRETATION

Not one clinical feature was sufficient to diagnose pneumonia definitively. Combination of clinical features in a decision tree might improve diagnostic performance, but the addition of new point-of-care tests for diagnosis of bacterial pneumonia would help to attain an acceptable level of accuracy.

FUNDING

Swiss National Science Foundation.

Oxygen therapy for lower respiratory tract infections in children between 3 months and 15 years of age

BACKGROUND

Treatment for lower respiratory tract infections (LRTIs) includes administering complementary oxygen. The effectiveness of oxygen therapy and of different delivery methods remains uncertain.

OBJECTIVES

To determine the effectiveness and safety of oxygen therapy and oxygen delivery methods in the treatment of LRTIs and to define the indications for oxygen therapy in children with LRTIs.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE, EMBASE and LILACS from March 2008 to October 2014.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or non-RCTs comparing oxygen versus no oxygen therapy or different methods of oxygen delivery in children with LRTI aged from three months to 15 years. To determine the indications for oxygen therapy, we included observational studies or diagnostic test accuracy studies.

DATA COLLECTION AND ANALYSIS

Three review authors independently scanned the search results to identify studies for inclusion. Two authors independently performed the methodological assessment and the third author resolved any disagreements. We calculated risk ratios (RRs) and their 95% confidence intervals (CIs) for dichotomous outcomes and adverse events (AEs). We performed fixed-effect meta-analyses for the estimation of pooled effects whenever there was no heterogeneity between included RCTs. We summarised the results reported in the included observational studies for the clinical indicators of hypoxaemia.

MAIN RESULTS

In this review update, we included four studies (479 participants) assessing the efficacy of non-invasive delivery methods for the treatment of LRTI in children and 14 observational studies assessing the clinical sign indicators of hypoxaemia in children with LRTIs.Three RCTs (399 participants) compared the effectiveness of nasal prongs or nasal cannula with nasopharyngeal catheter; one non-RCT (80 participants) compared head box, face mask, nasopharyngeal catheter and nasal cannula. The nasopharyngeal catheter was the control group. Treatment failure was defined as number of children failing to achieve adequate arterial oxygen saturation. All included studies had a high risk of bias because of allocation methods and lack of blinded outcome assessment.For nasal prongs versus nasopharyngeal catheter, the pooled effect estimate for RCTs showed a worrying trend towards no difference between the groups (two RCTs; 239 participants; RR 0.93, 95% CI 0.36 to 2.38). Similar results were shown in the one non-RCT (RR 1.0, 95% CI 0.44 to 2.27). The overall quality of this evidence is very low. Nasal obstruction due to severe mucus production was different between treatment groups (three RCTs, 338 participants; RR 0.20, 95% CI 0.09 to 0.44; I(2) statistic = 0%). The quality of this evidence is low.The use of a face mask showed a statistically significant lower risk of failure to achieve arterial oxygen > 60 mmHg than the nasopharyngeal catheter (one non-RCT; 80 participants; odds ratio (OR) 0.20, 95% CI 0.05 to 0.88).The use of a head box showed a non-statistically significant trend towards a reduced risk of treatment failure compared to the nasopharyngeal catheter (one non-RCT; OR 0.40, 95% CI 0.13 to 1.12). The quality of this evidence is very low.To determine the presence of hypoxaemia in children presenting with LRTI, we assessed the sensitivity and specificity of nine clinical signs reported by the included observational studies and used this information to calculate likelihood ratios. The results showed that there is no single clinical sign or symptom that accurately identifies hypoxaemia.

AUTHORS' CONCLUSIONS

It appears that oxygen therapy given early in the course of pneumonia via nasal prongs at a flow rate of 1 to 2 L/min does not prevent children with severe pneumonia from developing hypoxaemia. However, the applicability of this evidence is limited as it comes from a small pilot trial.Nasal prongs and nasopharyngeal catheter are similar in effectiveness when used for children with LRTI. Nasal prongs are associated with fewer nasal obstruction problems. The use of a face mask and head box has been poorly studied and it is not superior to a nasopharyngeal catheter in terms of effectiveness or safety in children with LRTI.Studies assessing the effectiveness of oxygen therapy and oxygen delivery methods in children with different baseline risks are needed.There is no single clinical sign or symptom that accurately identifies hypoxaemia in children with LRTI. The summary of results presented here can help clinicians to identify children with more severe conditions.This review is limited by the small number of trials assessing oxygen therapy and oxygen delivery methods as part of LRTI treatment. There is insufficient evidence to determine which non-invasive delivery methods should be used in children with LRTI and low levels of oxygen in their blood.

Cough sound analysis can rapidly diagnose childhood pneumonia

Pneumonia annually kills over 1,800,000 children throughout the world. The vast majority of these deaths occur in resource poor regions such as the sub-Saharan Africa and remote Asia. Prompt diagnosis and proper treatment are essential to prevent these unnecessary deaths. The reliable diagnosis of childhood pneumonia in remote regions is fraught with difficulties arising from the lack of field-deployable imaging and laboratory facilities as well as the scarcity of trained community healthcare workers. In this paper, we present a pioneering class of technology addressing both of these problems. Our approach is centred on the automated analysis of cough and respiratory sounds, collected via microphones that do not require physical contact with subjects. Cough is a cardinal symptom of pneumonia but the current clinical routines used in remote settings do not make use of coughs beyond noting its existence as a screening-in criterion. We hypothesized that cough carries vital information to diagnose pneumonia, and developed mathematical features and a pattern classifier system suited for the task. We collected cough sounds from 91 patients suspected of acute respiratory illness such as pneumonia, bronchiolitis and asthma. Non-contact microphones kept by the patient's bedside were used for data acquisition. We extracted features such as non-Gaussianity and Mel Cepstra from cough sounds and used them to train a Logistic Regression classifier. We used the clinical diagnosis provided by the paediatric respiratory clinician as the gold standard to train and validate our classifier. The methods proposed in this paper could separate pneumonia from other diseases at a sensitivity and specificity of 94 and 75% respectively, based on parameters extracted from cough sounds alone. The inclusion of other simple measurements such as the presence of fever further increased the performance. These results show that cough sounds indeed carry critical information on the lower respiratory tract, and can be used to diagnose pneumonia. The performance of our method is far superior to those of existing WHO clinical algorithms for resource-poor regions. To the best of our knowledge, this is the first attempt in the world to diagnose pneumonia in humans using cough sound analysis. Our method has the potential to revolutionize the management of childhood pneumonia in remote regions of the world.

Community-Acquired Pneumonia in the Conjugate Vaccine Era

Community-acquired pneumonia (CAP) remains one of the most common serious infections encountered among children worldwide. In this review, we highlight important literature and recent scientific discoveries that have contributed to our current understanding of pediatric CAP. We review the current epidemiology of childhood CAP in the developed world, appraise the state of diagnostic testing for etiology and prognosis, and discuss disease management and areas for future research in the context of recent national guidelines.

The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

Oxygen saturation in healthy children aged 5 to 16 years residing in Huayllay, Peru at 4340 m

Hypoxemia is a major life-threatening complication of childhood pneumonia. The threshold points for hypoxemia vary with altitude. However, few published data describe that normal range of variation. The purpose of this study was to establish reference values of normal mean Sao(2) levels and an approximate cutoff point to define hypoxemia for clinical purposes above 4300 meters above sea level (masl). Children aged 5 to 16 yr were examined during primary care visits at the Huayllay Health Center. Huayllay is a rural community located at 4340 m in the province of Pasco in the Peruvian Andes. We collected basic sociodemographic data and evaluated three outcomes: arterial oxygen saturation (Sao(2)) with a pulse oximeter, heart rate, and respiratory rate. Comparisons of main outcomes among age groups (5-6, 7-8, 9-10, 11-12, 13-14, and 15-16 yr) and sex were performed using linear regression models. The correlation of Sao(2) with heart rate and respiration rate was established by Pearson's correlation test. We evaluated 583 children, of whom 386 were included in the study. The average age was 10.3 yr; 55.7% were female. The average Sao(2), heart rate, and respiratory rate were 85.7% (95% CI: 85.2-86.2), 80.4/min (95% CI: 79.0-81.9), and 19.9/min (95% CI: 19.6-20.2), respectively. Sao(2) increased with age (p < 0.001). No differences by sex were observed. The mean minus two standard deviations of Sao(2) (threshold point for hypoxemia) ranged from 73.8% to 81.8% by age group. At 4300 m, the reference values for hypoxemia may be 14.2% lower than at sea level. This difference must be considered when diagnosing hypoxemia or deciding oxygen supplementation at high altitude. Other studies are needed to determine whether this reference value is appropriate for clinical use.

Impact of HIV on standard case management for severe pneumonia in children

It is estimated that 2 million children under 5 years of age die from pneumonia each year and that half of these deaths occur in sub-Saharan Africa. Over 85% of the more than 2.3 million children living with HIV worldwide reside in sub-Saharan Africa. HIV infection is likely to have a major impact on current recommendations for the standard case management of pneumonia in children and is the rationale for undertaking this review of published studies. The studies identified indicate an overall sixfold (range 2.5-13.5-fold) increase in pneumonia-related fatality in HIV-infected compared with HIV-uninfected African infants and children. They are more likely to have disease due to mixed infection and from a wider range of pathogens including Pneumocystis pneumonia, TB and cytomegalovirus. Scaling-up of the implementation of strategies that prevent HIV and Pneumocystis pneumonia remains an important strategy to reduce the burden of HIV-related pneumonia in the region. Research is urgently required to address the most effective pneumonia case management strategy in HIV-infected infants and children.

The prevalence of hypoxaemia among ill children in developing countries: a systematic review

Hypoxaemia is a common complication of childhood infections, particularly acute lower respiratory tract infections. In pneumonia-a disease that disproportionately impacts developing countries, and accounts for more than two million deaths of children worldwide-hypoxaemia is a recognised risk factor for death, and correlates with disease severity. Hypoxaemia also occurs in severe sepsis, meningitis, common neonatal problems, and other conditions that impair ventilation and gas exchange or increase oxygen demands. Despite this, hypoxaemia has been overlooked in worldwide strategies for pneumonia control and reducing child mortality. Hypoxaemia is also often overlooked in developing countries, mainly due to the low accuracy of clinical predictors and the limited availability of pulse oximetry for more accurate detection and oxygen for treatment. In this Review of published and unpublished studies of acute lower respiratory tract infection, the median prevalence of hypoxaemia in WHO-defined pneumonia requiring hospitalisation (severe and very severe classifications) was 13%, but prevalence varied widely. This corresponds to at least 1.5 to 2.7 million annual cases of hypoxaemic pneumonia presenting to health-care facilities. Many more people do not access health care. With mounting evidence of the impact that improved oxygen systems have on mortality due to acute respiratory infection in limited-resource health-care facilities, there is a need for increased awareness of the burden of hypoxaemia in childhood illness.

Oxygen therapy for lower respiratory tract infections in children between 3 months and 15 years of age

BACKGROUND

Usual practice in lower respiratory tract infections (LRTIs) includes administering complementary oxygen. The effectiveness of oxygen therapy and different methods of delivery is unknown. This review contributes to the rational use of oxygen in the treatment of LRTIs.

OBJECTIVES

To determine in the treatment of LRTIs: the effectiveness of oxygen therapy and oxygen delivery methods; the safety of these methods; and indications for oxygen therapy.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2008, issue 2); MEDLINE (January 1966 to March 2008); EMBASE (1990 to December 2007); and LILACS (January 1982 to March 2008).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing oxygen versus no oxygen therapy or methods of oxygen delivery for hypoxaemic LRTIs in children (3 months to 15 years of age). To determine indications for oxygen therapy, observational studies were included.

DATA COLLECTION AND ANALYSIS

We assessed 551 titles. No studies comparing oxygen versus no oxygen were found. Four RCTs comparing delivery methods and 12 observational studies assessing the accuracy of clinical signs indicating hypoxaemia were eligible. A meta-analysis of the RCTs comparing oxygen delivery methods was performed.

MAIN RESULTS

Three studies assessed the effectiveness of nasal prongs (NP) versus nasopharyngeal catheters (NPC). The pooled estimate effect showed no differences (OR 0.96; 95% CI 0.48 to 1.93) in treatment failure (number of children failing to achieve adequate SaO2). One study compared the effectiveness of NP versus nasal catheter (NC). No differences were found in treatment failure (the mean number of episodes of desaturation/child: NC group 2.75, SD +/- 2.18 episodes/child; NP group 3, SD +/- 2.5 episodes/child, p = 0.64). Another study compared face mask (FM) and head box (HB) versus NPC. Use of FM showed lower risk of treatment failure (failure to achieve PaO2 > 60 mmHg) than the NPC (OR 0.20; 95% CI 0.55 to 0.88). As did the use of HB compared with NPC (OR 0.40; 95% CI 0.13 to 1.12).Studies assessing the accuracy of signs and/or symptoms indicating hypoxaemia showed that cyanosis, grunting, difficulty in feeding and mental alertness have better specificity in predicting hypoxaemia and its results were consistent among studies.

AUTHORS' CONCLUSIONS

NP and NPC seem to be similar in effectiveness and safety when used in patients with LRTI. There is no single clinical sign or symptom that accurately identifies hypoxaemia. Studies identifying the most effective and safe oxygen delivery method are needed.

Postnatal cardiopulmonary adaptations to high altitude

Postnatal cardiopulmonary adaptations to high altitude constitute a key component of any set of responses developed to face high altitude hypoxia. Such responses are required ultimately to meet the energy demands necessary for adequate functioning at cell and organism level. After a brief insight on general and cardiopulmonary comparative studies in growing and adult organisms, differences and possible explanations for varying cardiopulmonary pathology, pulmonary artery hypertension, persistent right ventricular predominance and subacute high altitude pulmonary hypertension in different populations of children living at high altitude are discussed. Potential long-term implications of early chronic hypoxic exposure on later diseases are also presented. It is hoped that this review will help the practicing physician working at high altitude to make informed decisions concerning individual pediatric patients, specifically with regard to diagnosis and management of altitude-related cardiopulmonary pathology. Finally, plausibility and the knowledge-base of public health interventions to reduce the risks posed by suboptimal or inadequate postnatal cardiopulmonary responses to high altitude are discussed.

Case management of childhood pneumonia in developing countries

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality in children worldwide. Appropriate management depends on accurate assessment of disease severity, and for the majority of children in developing countries the assessment is based on clinical signs alone. This article reviews recent evidence on clinical assessment and severity classification of pneumonia and reported results on the effectiveness of currently recommended treatments.

METHODS

Potential studies for inclusion were identified by Medline (1990-2006) search. The Oxford Center for Evidence Based Medicine criteria were used to describe the methodologic quality of selected studies.

RESULTS

In the included studies the sensitivity of current definitions of tachypnea for diagnosing radiologic pneumonia ranged from 72% to 94% with specificities between 38% and 99%; chest indrawing had reported sensitivities of between 46% and 78%. Data provide some support for the value of current clinical criteria for classifying pneumonia severity, with those meeting severe or very severe criteria being at considerably increased risk of death, hypoxemia or bacteremia. Results of randomized controlled trials report clinically defined improvement at 48 hours in at least 80% of children treated using recommended antibiotics. However, a limitation of these data may include inappropriate definitions of treatment failure.

CONCLUSION

Particularly with regard to severe pneumonia, issues that specifically need to be addressed are the adequacy of penicillin monotherapy, or oral amoxicillin or alternative antibiotics; the timing of introduction of high-dose trimethoprim-sulfamethoxazole in children at risk for or known to be infected by HIV and the value of pulse oximetry.

Hypoxemia in children with pneumonia and its clinical predictors

OBJECTIVES

To assess the prevalence of hypoxemia in children, 2 months to 5 years of age, with pneumonia and to identify its clinical predictors.

METHODS

Children between 2-60 months of age presenting with a complaint of cough or difficulty breathing were assessed. Hypoxemia was defined as an arterial oxygen saturation of < 90% recorded by a portable pulse oximeter. Patients were categorized into groups: cough and cold, pneumonia, severe pneumonia and very severe pneumonia.

RESULTS

The prevalence of hypoxemia (SpO2 of < 90%) in 150 children with pneumonia was 38.7%. Of them 100% of very severe pneumonia, 80% of severe and 17% of pneumonia patients were hypoxic. Number of infants with respiratory illness (p value = 0.03) and hypoxemia (Odds ratio = 2.21, 95% CI 1.03, 4.76) was significantly higher. Clinical predictors significantly associated with hypoxemia on univariate analysis were lethargy, grunting, nasal flaring, cyanosis, and complaint of inability to breastfeed/drink. Chest indrawing with 68.9% sensitivity and 82.6% specificity was the best predictor of hypoxemia.

CONCLUSION

The prevalence and clinical predictors of hypoxemia identified validate the WHO classification of pneumonia based on severity. Age < 1 year in children with ARI is an important risk factor for hypoxemia.

Airway infectious disease emergencies

Upper and lower respiratory infections are encountered commonly in the emergency department. Visits resulting from occurrences of respiratory disease account for 10% of all pediatric emergency department visits and 20% of all pediatric hospital admissions. Causes of upper airway infections include croup, epiglottitis, retropharyngeal abscess, cellulitis, pharyngitis, and peritonsillar abscesses. Lower airway viral and bacterial infections cause illnesses such as pneumonia and bronchiolitis. Signs and symptoms of upper and lower airway infections overlap, but the differentiation is important for appropriate treatment of these conditions. This article reviews the varied clinical characteristics of upper and lower airway infections.

Blood gas analysis and chest x-ray findings in infants and preschool children with acute airway obstruction

BACKGROUND

The importance of SaO2 in the assessment of respiratory distress in bronchial asthma has been reported.

OBJECTIVES

To evaluate the correlation between blood gas analysis and chest X-ray lung opacities in young children presenting with acute respiratory symptoms.

METHODS

Eighty patients (43 males and 37 females aged 0.5-24 months; mean+/-SD 9.1+/-7.2 months), either with acute wheezing respiratory symptoms and/or with crackles were enrolled in our study. In all children, blood gas analysis and chest X-rays were performed within 12 h following admission to the emergency department.

RESULTS

In 55 children (68.75%) chest X-rays demonstrated lung opacities. Subjects with normal X-rays had paO2 and SaO2 higher than subjects with lung opacities (p<0.0001 and p=0.0001, respectively). Children with lung opacities almost always presented paO2<80 mm Hg. Sensitivity and specificity for the presence of lung opacities of paO2<80 mm Hg were 81 and 90%, respectively, while sensitivity and specificity of SaO2<95% were 92 and 40%, respectively. paO2<80 mm Hg in association with SaO2<95% had a positive predictive value for the diagnosis of pneumonia of 90.9%.

CONCLUSIONS

Our study suggests that blood gas analysis, particularly paO2, may help in predicting the presence of lung opacities in patients aged less than 2 years. However, chest X-rays may still be needed to define the actual extension of opacities as well as the possible concomitant presence of complications.

Identifying children with pneumonia in the emergency department

Emergency physicians need to clinically differentiate children with and without radiographic evidence of pneumonia. In this prospective cohort study of 510 patients 2 to 59 months of age presenting with symptoms of lower respiratory tract infection, 100% were evaluated with chest radiography and 44 (8.6%) had pneumonia on chest radiography. With use of multivariate analysis, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) of the clinical findings significantly associated with focal infiltrates were age older than 12 months (AOR 1.4, CI 1.1-1.9), RR 50 or greater (AOR 3.5, CI 1.6-7.5), oxygen saturation 96% or less (AOR 4.6, CI 2.3-9.2), and nasal flaring (AOR 2.2 CI 1.2-4.0) in patients 12 months of age or younger. The combination of age older than 12 months, RR 50 or greater, oxygen saturation 96% or less, and in children under age 12 months, nasal flaring, can be used in determining which young children with lower respiratory tract infection symptoms have radiographic pneumonia.

Defining pneumonia in critically ill infants and children

OBJECTIVE

To define pneumonia in critically ill children in the intensive care unit setting for surveillance of infection and for the design, conduct, and evaluation of clinical trials in the prevention and therapy of lower respiratory tract infections in this population.

DESIGN

Summary of the literature with review and consensus by experts in the field.

RESULTS

A variety of diagnostic criteria from the medical literature, professional societies, and governmental health agencies and regulators were identified. Very few of these diagnostic criteria have been validated for use in children. We propose definitions for definite, possible, and probable pneumonia that build on identified definitions in the literature and use combinations of symptoms, signs, and laboratory criteria. Gaps in knowledge were identified.

CONCLUSIONS

Although pneumonia is one of the most common diagnoses in critically ill children, there have been few studies validating diagnostic criteria. Definitions for definite, probable, and possible community-acquired pneumonia and nosocomial pneumonia were achieved by consensus of experts based on guidelines from governmental agencies, professional organizations, and published literature. Future research should determine the utility of these definitions in the critically ill child and adapt them accordingly.

Pneumonia in HIV-infected and HIV-uninfected children in developing countries

PURPOSE OF REVIEW

Pneumonia is a leading cause of illness and death in children younger than 5 years in developing countries, accounting for approximately 20% of childhood deaths. The HIV epidemic has sharply increased the incidence, severity, and mortality of childhood pneumonia in the developing world, particularly in sub-Saharan Africa. This article reviews recent findings on the epidemiology, clinical features, and management of HIV-infected and -uninfected children with pneumonia in developing countries.

RECENT FINDINGS

Bacterial infection remains a major cause of pneumonia mortality; in HIV-infected children, a broader spectrum of pathogens including gram-negative infections and Pneumocystis jiroveci occurs. Mycobacterium tuberculosis is an important cause of acute pneumonia among children from high tuberculosis prevalence areas. Use of case management guidelines substantially reduces neonatal, infant, and under-5 mortality and pneumonia-specific mortality in developing countries. New advances in therapy include the use of short-course antibiotics and high-dose amoxicillin twice daily for ambulatory treatment of HIV-negative children with pneumonia. New preventive interventions include the development of conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae, but these are not widely affordable nor available in developing countries. Despite a lower efficacy in HIV-infected children, these vaccines still protect against disease in a significant proportion of children. Available preventive interventions including micronutrient supplementation with zinc and vitamin A, and immunization as contained in the WHO Expanded Program of Immunization can substantially reduce the burden of childhood pneumonia.

SUMMARY

Urgent measures to implement existing available, effective interventions for prevention and treatment of childhood pneumonia and achieve high coverage rates in developing countries are needed.

The inter-observer agreement of examining pre-school children with acute cough: a nested study

Background

The presence of clinical signs have implications for diagnosis, prognosis and treatment. Therefore, the aim of this study was to examine the inter-observer agreement of clinical signs in pre-school children presenting to primary care.

Methods

A nested study comparing two clinical assessments within a prospective cohort of 256 pre-school children with acute cough recruited from eight general practices in Leicestershire, UK. We examined agreement (using kappa statistics) between unstandardised and standardised clinical assessments of tachypnoea, chest signs and fever.

Results

Kappa values were poor or fair for all clinical signs (range 0.12 to 0.39) with chest signs the most reliable.

Conclusions

Primary care clinicians should be aware that clinical signs may be unreliable when making diagnosis, prognosis and treatment decisions in pre-school children with cough. Future research should aim to further our understanding of how best to identify abnormal clinical signs.

The validity of clinical criteria in predicting pneumonia among children under five years of age

BACKGROUND

Pneumonia is a major cause of morbidity and mortality, especially among infant and young children. Early diagnosis and treatment is essential to reduce the risk. To achieve this, physicians require high quality diagnostic indicators. The aim of the present study is to assess the validity of clinical symptoms and signs in predicting pneumonia among children below the age of 5 years.

PATIENTS AND METHODS

This is a case series study for a sample of 103 children aged 4 days-59 months who were admitted to Al-Khanssa Teaching Hospital, Mosul, Iraq, suffering from respiratory symptoms and for whom a chest x-ray was requested. Sensitivity, specificity, predictive values and likelihood ratios were estimated for each clinical criterion.

RESULTS

Pneumonia was diagnosed on radiological bases in about 70% of the patients. All symptoms had high sensitivity with very low specificity. The best positive predictive values for symptoms were for fast and difficult breathing. However, the signs of Crackle, Tachypnoea, nasal flarring and chest indrawing yielded the best sensitivity estimates. Moreover, a body temperature of ≥38 °C was the best single predictor of pneumonia with a sensitivity of 67% and specificity of 75.8%. The absence of the 3 signs (nasal flaring, chest indrawing and crackles) ruled out pneumonia effectively. The sensitivity of this combination of signs was 98.6%. Detecting a body temperature ≥38 °C and grunting simultaneously was adequate to confirm the disease.

CONCLUSIONS

The study suggests that using clinical criteria in combination could improve physicians' prediction of pneumonia among children.

Cardiopulmonary transition in the high altitude infant

The perinatal cardiopulmonary transition at high altitude differs from that at sea level because oxygen plays a fundamental role in the developmental changes from fetus to newborn infant. Under conditions of high altitude hypoxia, arterial oxygen saturations are lower, breathing patterns and maturation of respiratory control reflexes differ, and regression of fetal characteristics of the pulmonary vasculature proceeds more slowly. Several aspects of transition vary not only with postnatal age and altitude, but also with population group, suggesting an effect of genetic adaptation on perinatal physiology. Exposure to chronic high altitude hypoxia during the perinatal transition also results in apparent lifelong alterations in respiratory reflex responses and pulmonary vasoreactivity. Disruption of the normal process of cardiopulmonary transition can result in symptomatic high altitude pulmonary hypertension. The exaggerated hypoxemia associated with acute respiratory infections in young infants still undergoing transition contributes to infant mortality at high altitude.

Pediatric pneumonia

Respiratory disease is common in pediatrics and diagnosing pneumonia may be clinically challenging. Changes in pneumococcal resistance and immunization practices continue to change the incidence and etiologies of pneumonia. Careful attention to epidemiologic, seasonal, and specific pediatric clinical factors and using adjunct radiographs and laboratory tests should guide the emergency physician in his or her management strategy, including selection of antibiotics and inpatient or outpatient disposition.

The use of pulse oximetry to exclude pneumonia in children

The objective of this study was to determine whether pulse oximetry alone or in conjunction with the clinical examination is predictive of pneumonia in children who present to the emergency department with respiratory complaints. A retrospective comparison of children with radiographic pneumonia with children with respiratory complaints and negative chest radiography was used. The study took place in an emergency department of a large academic, tertiary care hospital. All children less than 24 months of age who presented with a respiratory complaint and underwent chest radiography during a 1-year period were included. Charts of children with radiographic pneumonia were compared with charts of children without pneumonia, retrospectively. Data abstracted onto data collection forms included: pulse oximetry measurement, vital signs, general appearance, lung examination, and final radiology interpretation of chest radiographs. Pneumonia was defined as a chest radiograph showing any opacity consistent with pneumonia as read by a board-prepared or -certified radiologist. A total of 803 children qualified for the study. Radiograph interpretations were available for 762, and 10.5% were found to have radiographic pneumonia. The median pulse oximetry reading of children with radiographic pneumonia was 97% (interquartile range 95th-98th percentile) compared with 98% (interquartile range 96th-99th percentile) in the control group. Forty-five percent (35 of 78) of the children with radiographic pneumonia showed oxygen saturations of 98% or higher with greater than 10% (8 of 78) displaying oxygen saturations of 100%. By using logistic regression, pulse oximetry was not found to be a statistically significant predictive variable for radiographic pneumonia. Pulse oximetry could not be used to rule out the presence of radiographic pneumonia in children less than 2 years of age who presented with respiratory complaints.

Oxygen saturation and heart rate in healthy school children and adolescents living at high altitude

This study was conducted to establish reference values for percent oxygen saturation of hemoglobin (SaO2, %) and heart rate (HR, bpm) in children living at high altitude (4,100 m) and to relate possible differences in the variables with ethnic origin. Healthy children from a mine-located school (Tintaya, n = 417), a nearby school (Marquiri, n = 474), and a rural Andean community (Nuñoa, n = 373) were investigated. The samples included different ethnic combinations, with the Nuñoa children having a predominant Quechua ancestry. Mean SaO2 for all ages was substantially lower in all high altitude children compared to values considered normal for sea level. Among the three samples, SaO2 was higher (91.3 +/- 2.7) and HR was lower (84.8 +/- 13.6) in Nuñoa than in Tintaya (SaO2, 89.8 +/- 2.5; HR, 91.7 +/- 14.9) and Marquiri (SaO2, 89.6 +/- 3.1; HR, 88.5 +/- 12.9) (P < 0.05). There was no sex difference and only a weak age-dependent trend for SaO2. Values considered abnormal at sea level were observed in all healthy high-altitude children. Higher SaO2 and lower HR in Nuñoa children may suggest a better degree of acclimatization to altitude.

Clinical predictors of hypoxaemia in Gambian children with acute lower respiratory tract infection: prospective cohort study

OBJECTIVES

To determine clinical correlates and outcome of hypoxaemia in children admitted to hospital with an acute lower respiratory tract infection.

DESIGN

Prospective cohort study.

SETTING

Paediatric wards of the Royal Victoria Hospital and the hospital of the Medical Research Council's hospital in Banjul, the Gambia.

SUBJECTS

1072 of 42 848 children, aged 2 to 33 months, who were enrolled in a randomised trial of a Haemophilus influenzae type b vaccine in the western region of the Gambia, and who were admitted with an acute lower respiratory tract infection to two of three hospitals.

MAIN OUTCOME MEASURES

Prevalence of hypoxaemia, defined as an arterial oxygen saturation <90% recorded by pulse oximetry, and the relation between hypoxaemia and aetiological agents.

RESULTS

1072 children aged 2-33 months were enrolled. Sixty three (5.9%) had an arterial oxygen saturation <90%. A logistic regression model showed that cyanosis, a rapid respiratory rate, grunting, head nodding, an absence of a history of fever, and no spontaneous movement during examination were the best independent predictors of hypoxaemia. The presence of an inability to cry, head nodding, or a respiratory rate >/= 90 breaths/min formed the best predictors of hypoxaemia (sensitivity 70%, specificity 79%). Hypoxaemic children were five times more likely to die than non-hypoxaemic children. The presence of malaria parasitaemia had no effect on the prevalence of hypoxaemia or on its association with respiratory rate.

CONCLUSION

In children with an acute lower respiratory tract infection, simple physical signs that require minimal expertise to recognise can be used to determine oxygen therapy and to aid in screening for referral. The association between hypoxaemia and death highlights the need for early recognition of the condition and the potential benefit of treatment.

Predictors of hypoxaemia in hospital admissions with acute lower respiratory tract infection in a developing country

Since oxygen has to be given to most children in developing countries on the basis of clinical signs without performing blood gas analyses, possible clinical predictors of hypoxaemia were studied. Sixty nine children between the ages of 2 months and 5 years admitted to hospital with acute lower respiratory tract infection and an oxygen saturation (Sao2) < 90% were compared with 67 children matched for age and diagnosis from the same referral hospital with an Sao2 of 90% or above (control group 1), and 44 unreferred children admitted to a secondary care hospital with acute lower respiratory infection (control group 2). Using multiple logistic regression analysis, sleepiness, arousal, quality of cry, cyanosis, head nodding, decreased air entry, nasal flaring, and upper arm circumference were found to be independent predictors of hypoxaemia on comparison of the cases with control group 1. Using a simple model of cyanosis or head nodding or not crying, the sensitivity to predict hypoxaemia was 59%, and the specificity 94% and 93% compared to control groups 1 and 2, respectively; 80% of the children with an Sao2 < 80% were identified by the combination of these signs. Over half of the children with hypoxaemia could be identified with a combination of three signs: extreme respiratory distress, cyanosis, and severely compromised general status. Further prospective validation of this model with other datasets is warranted. No other signs improved the sensitivity without compromising specificity. If a higher sensitivity is required, pulse oximetry has to be used.