Inhaled furosemide in hospitalized infants with viral bronchiolitis: a randomized, double-blind, placebo-controlled pilot study

Evaluating the Placebo Status of Nebulized Normal Saline in Patients With Acute Viral Bronchiolitis: A Systematic Review and Meta-analysis

IMPORTANCE

In therapeutic trials for acute viral bronchiolitis, consistent clinical improvement in groups that received nebulized normal saline (NS) as placebo raises the question of whether nebulized NS acts as a treatment rather than a placebo.

OBJECTIVE

To measure the short-term association of nebulized NS with physiologic measures of respiratory status in children with bronchiolitis by analyzing the changes in these measures between the use of nebulized NS and the use of other placebos and the changes before and after nebulized NS treatment.

DATA SOURCES

MEDLINE and Scopus were searched through March 2019, as were bibliographies of included studies and relevant systematic reviews, for randomized clinical trials evaluating nebulized therapies in bronchiolitis.

STUDY SELECTION

Randomized clinical trials comparing children 2 years or younger with bronchiolitis who were treated with nebulized NS were included. Studies enrolling a treatment group receiving an alternative placebo were included for comparison of NS with other placebos.

DATA EXTRACTION AND SYNTHESIS

Data abstraction was performed per PRISMA guidelines. Fixed- and random-effects, variance-weighted meta-analytic models were used.

MAIN OUTCOMES AND MEASURES

Pooled estimates of the association with respiratory scores, respiratory rates, and oxygen saturation within 60 minutes of treatment were generated for nebulized NS vs another placebo and for change before and after receiving nebulized NS.

RESULTS

A total of 29 studies including 1583 patients were included. Standardized mean differences in respiratory scores for nebulized NS vs other placebo (3 studies) favored nebulized NS by -0.9 points (95% CI, -1.2 to -0.6 points) at 60 minutes after treatment (P < .001). There were no differences in respiratory rate or oxygen saturation comparing nebulized NS with other placebo. The standardized mean difference in respiratory score (25 studies) after nebulized NS was -0.7 (95% CI, -0.7 to -0.6; I2 = 62%). The weighted mean difference in respiratory scores using a consistent scale (13 studies) after nebulized NS was -1.6 points (95% CI, -1.9 to -1.3 points; I2 = 72%). The weighted mean difference in respiratory rate (17 studies) after nebulized NS was -5.5 breaths per minute (95% CI, -6.3 to -4.6 breaths per minute; I2 = 24%). The weighted mean difference in oxygen saturation (23 studies) after nebulized NS was -0.4% (95% CI, -0.6% to -0.2%; I2 = 79%).

CONCLUSIONS AND RELEVANCE

Nebulized NS may be an active treatment for acute viral bronchiolitis. Further evaluation should occur to establish whether it is a true placebo.

Systematic review of instruments aimed at evaluating the severity of bronchiolitis

OBJECTIVE

No recent studies have performed a systematic review of all available instruments aimed at evaluating the severity of bronchiolitis. The objective of the present study was to perform a systematic review of instruments aimed at evaluating the severity of bronchiolitis and to evaluate their measurement properties.

METHODS

A systematic search of the literature was performed in order to identify studies in which an instrument for evaluating the severity of bronchiolitis was described. Instruments were evaluated based on their reliability, validity, utility, endorsement frequency, restrictions in range, comprehension, and lack of ambiguity.

RESULTS

A total of 77 articles, describing a total of 32 different instruments were included in the review. The number of items included in the instruments ranged from 2 to 26. Upon analyzing their content, respiratory rate turned out to be the most frequently used item (in 26/32, 81.3% of the instruments), followed by wheezing (in 25/32, 78.1% of the instruments). In 18 (56.3%) instruments, there was a report of at least one of their measurement properties, mainly reliability and utility. Taking into consideration the information contained in the instruments, as well as their measurement properties, one was considered to be the best one available.

CONCLUSIONS

Among the 32 instruments aimed at evaluating the severity of bronchiolitis that were identified and systematically examined, one was considered to be the best one available. However, there is an urgent need to develop better instruments and to validate them in a more comprehensive and proper way.

Transcutaneous PCO2 monitoring in infants hospitalized with viral bronchiolitis

Our objective was to assess within a feasibility study the correlation and agreement of transcutaneous carbon dioxide (PtcCO2) monitoring with venous carbon dioxide (PvCO2) in infants with bronchiolitis in the emergency room (ER) and pediatric department. Sixty infants (aged 3.6 ± 3.3 months) admitted to our ER with bronchiolitis were included. PtcCO2 measurements (SenTec Digital Monitoring System) collected prospectively were compared with simultaneous PvCO2 drawn for patient care. Analysis included 100 measurements. The correlation of PtcCO2 and PvCO2 (r = 0.71, p < 0.001) was good, and the agreement (mean difference ± standard deviation of the differences 1.9 ± 7.0 mmHg) was adequate; average PtcCO2 was slightly lower than PvCO2. Changes in PtcCO2 and PvCO2 for consecutive measurements within each patient correlated (r = 0.41, p < 0.01). The level of PtcCO2 correlated with disease severity clinical score (p < 0.001).

CONCLUSIONS

PtcCO2 monitoring was feasible in the ER and pediatric department and was found to have a good correlation and adequate agreement with PvCO2 in infants with bronchiolitis. Because the standard deviation of the differences was relatively high, though comparable to the literature, we suggest that PtcCO2 should not replace blood gas but rather serve as a complementary tool for trending and for real-time continuous assessment of the CO2 levels.

Recent advances in management of bronchiolitis

Background

Bronchiolitis is one of the major causes for hospital admissions in infants. Managing bronchiolitis, both in the outpatient and inpatient setting remains a challenge to the treating pediatrician. The effectiveness of various interventions used for infants with bronchiolitis remains unclear.

Need and purpose

To evaluate the evidence supporting the use of currently available treatment and preventive strategies for infants with bronchiolitis and to provide practical guidelines to the practitioners managing children with bronchiolitis.

Methods

A search of articles published on bronchiolitis was performed using PubMed. The areas of focus were diagnosis, treatment and prevention of bronchiolitis in children. Relevant information was extracted from English language studies published over the last 20 years. In addition, the Cochrane Database of Systematic Reviews was searched.

Results and Conclusions

Supportive care, comprising of taking care of oxygenation and hydration, remains the corner-stone of therapy in bronchiolitis. Pulse oximetry helps in guiding the need for oxygen administration. Several recent evidence-based reviews have suggested that bronchodilators or corticosteroids lack efficacy in bronchiolitis and should not be routinely used. A number of other novel therapies (such as nebulized hypertonic saline, heliox, CPAP, montelukast, surfactant, and inhaled furosemide) have been evaluated in clinical trials, and although most of them did not show any beneficial results, some like hypertonic saline, surfactant, CPAP have shown promising results.

Clinical pharmacology of furosemide in neonates: a review

Furosemide is the diuretic most used in newborn infants. It blocks the Na⁺-K⁺-2Cl⁻ symporter in the thick ascending limb of the loop of Henle increasing urinary excretion of Na⁺ and Cl⁻. This article aimed to review the published data on the clinical pharmacology of furosemide in neonates to provide a critical, comprehensive, authoritative and, updated survey on the metabolism, pharmacokinetics, pharmacodynamics and side-effects of furosemide in neonates. The bibliographic search was performed using PubMed and EMBASE databases as search engines; January 2013 was the cutoff point. Furosemide half-life (t_1/2) is 6 to 20-fold longer, clearance (Cl) is 1.2 to 14-fold smaller and volume of distribution (Vd) is 1.3 to 6-fold larger than the adult values. t_1/2 shortens and Cl increases as the neonatal maturation proceeds. Continuous intravenous infusion of furosemide yields more controlled diuresis than the intermittent intravenous infusion. Furosemide may be administered by inhalation to infants with chronic lung disease to improve pulmonary mechanics. Furosemide stimulates prostaglandin E2 synthesis, a potent dilator of the patent ductus arteriosus, and the administration of furosemide to any preterm infants should be carefully weighed against the risk of precipitation of a symptomatic patent ductus arteriosus. Infants with low birthweight treated with chronic furosemide are at risk for the development of intra-renal calcifications.

Severity scoring systems: are they internally valid, reliable and predictive of oxygen use in children with acute bronchiolitis?

BACKGROUND

Severity scores are commonly used in research and clinically to assess the severity of bronchiolitis. However, there are limitations as few have been validated. The aim of our study was to: (i) determine the validity and reliability of a bronchiolitis scoring system, and (ii) examine if the score predicted the need for oxygen at 12 and 24 hrs. Children aged <24 months presenting to Royal Darwin Hospital with a clinical diagnosis of bronchiolitis were eligible to participate.

STUDY DESIGN

We reviewed published papers that used a bronchiolitis score and summarized the data in a table. We chose the Tal score that was easy to use and encompassed clinically important parameters. Three research nurses, trained to assess children, used two scoring systems (Tal and Modified-Tal; respiratory rate, accessory muscle use, wheezing, cyanosis, and oxygen saturation), blindly evaluated children within 15 min of each other.

RESULTS

The children's (n = 115) median age was 5.4 months (IQR 2.9, 10.4); 65% were male and 64% were Indigenous. Internal consistency was excellent (Tal: Cronbach α = 0.66; Modified-Tal: α = 0.70). There was substantial inter-rater agreement; weighted kappa of 0.72 (95% CI: 0.63, 0.83) for Tal and 0.70 (95% CI: 0.63, 0.76) for Modified-Tal. For predicting requirement for oxygen at 12 and 24 hrs; area under receiver operating curve (aROC) was 0.69 (95% CI: 0.13, 1.0) and 0.75 (95% CI: 0.34, 1.0), respectively.

CONCLUSION

The Tal and Modified-Tal scoring systems for bronchiolitis is repeatable and can reliably be used in research and clinical practice. Its utility for prediction of O2 requirement is limited.

Treatment of bronchiolitis: state of the art

Bronchiolitis is a leading cause of acute illness and hospitalization for infants and young children worldwide. It is usually a mild disease, but the few children developing severe symptoms need to be hospitalized and some will need ventilatory support. To date, the mainstay of therapy has been supportive care, i.e. assisted feeding and hydration, minimal handling, nasal suctioning and oxygen therapy. In recent years the delivery of oxygen has been improved by using a high-flow nasal cannula. At the same time, the discovery of nebulized hypertonic saline enables better airway cleaning with a benefit for respiratory function. The possible role of any pharmacological approach is still debated: many pharmacological therapies tried in the past, ranging from bronchodilators to corticosteroids, were found to offer no benefit in this disease. More recently, nebulized adrenaline demonstrated a short-term benefit. Prophylaxis and prevention, especially in children at high risk of severe infection, such as prematurely born infants and children with bronchopulmonary dysplasia, have a fundamental role in dealing with this disease. In this review, we focus on current recommendations for the management and prevention of bronchiolitis, paying particular attention to the latest literature in search of answers to the questions that remain open.

Intravenous fluids versus gastric-tube feeding in hospitalized infants with viral bronchiolitis: a randomized, prospective pilot study

The American Academy of Pediatrics recommends intravenous fluids for infants with bronchiolitis who are unable to sustain oral feedings. Our randomized, prospective pilot study shows that gastric tube feeding (in 31 infants) is feasible and demonstrated comparable clinical outcomes with intravenous fluids (in 20 infants) among hospitalized infants ≤6 months of age with moderate bronchiolitis.

Clinical pharmacology of the loop diuretics furosemide and bumetanide in neonates and infants

The loop diuretics furosemide and bumetanide are used widely for the management of fluid overload in both acute and chronic disease states. To date, most pharmacokinetic studies in neonates have been conducted with furosemide and little is known about bumetanide. The aim of this article was to review the published data on the pharmacology of furosemide and bumetanide in neonates and infants in order to provide a critical analysis of the literature, and a useful tool for physicians. The bibliographic search was performed electronically using PubMed and EMBASE databases as search engines and March 2011 was the cutoff point. The half-life (t(½)) of both furosemide and bumetanide is considerably longer in neonates than in adults and consequently the clearance (CL) of these drugs is reduced at birth. In healthy volunteers, plasma t(½) of furosemide ranges from 33 to 100 minutes, whereas in neonates it ranges from 8 to 27 hours. The volume of distribution (V(d)) of furosemide undergoes little variation during neonate maturation. The dose of furosemide, administered by intermittent intravenous infusion, is 1 mg/kg and may increase to a maximum of 2 mg/kg every 24 hours in premature infants and every 12 hours in full-term infants. Comparison of continuous infusion versus intermittent infusion of furosemide showed that the diuresis is more controlled with fewer hemodynamic and electrolytic variations during continuous infusion. The appropriate infusion rate of furosemide ranges from 0.1 to 0.2 mg/kg/h and when the diuresis is <1 mL/kg/h the infusion rate may be increased to 0.4 mg/kg/h. Treatment with theophylline before administration of furosemide results in a significant increase of urine flow rate. Bumetanide is more potent than furosemide and its dose after intermittent intravenous infusion ranges from 0.005 to 0.1 mg/kg every 24 hours. The t(½) of bumetanide in neonates ranges from 1.74 to 7.0 hours. Up to now, no data are available on the continuous infusion of bumetanide. Extracorporeal membrane oxygenation (ECMO) is used for a variety of indications including sepsis, persistent pulmonary hypertension, meconium aspiration syndrome, cardiac defects and congenital diaphragmatic hernia. There are two studies of furosemide in neonates undergoing ECMO and only one on the pharmacokinetics of bumetanide under ECMO. When ECMO was conducted for 72 hours, the total amount of furosemide administered was 7.0 mg/kg, and the urine production in the 3 days of treatment was about 6 mL/kg/h, which is the target value. The t(½) of bumetanide in neonates during ECMO was extremely variable. CL, t(½), and V(d) were 0.63 mL/min/kg, 13.2 hours, and 0.45 L/kg, respectively. Furosemide may be administered by inhalation and inhibits the bronco-constrictive effect of exercise, cold air ventilation and antigen challenge. However, inhaled furosemide is not active in infants with viral bronchiolitis and its effect on broncho-pulmonary dysplasia is still uncertain. Furosemide does not significantly increase the risk of failure of patent ductus arteriosus closure when indomethacin or ibuprofen have been co-administered. Infants with low birth weight treated long-term with furosemide are at risk for the development of intra-renal calcification. Furosemide therapy above 10 mg/kg bodyweight cumulative dose had a 48-fold increased risk of nephrocalcinosis. The use of furosemide in combination with indomethacin increased the incidence of acute renal failure. The maturation of the kidney governs the pharmacokinetics of furosemide and bumetanide in the infant. CL and t(½) are influenced by development, and this must be taken into consideration when planning a dosage regimen with these drugs.

Treatment of acute viral bronchiolitis

Acute viral bronchiolitis represents the most common lower respiratory tract infection in infants and young children and is associated with substantial morbidity and mortality. Respiratory syncytial virus is the most frequently identified virus, but many other viruses may also cause acute bronchiolitis. There is no common definition of acute viral bronchiolitis used internationally, and this may explain part of the confusion in the literature. Most children with bronchiolitis have a self limiting mild disease and can be safely managed at home with careful attention to feeding and respiratory status. Criteria for referral and admission vary between hospitals as do clinical practice in the management of acute viral bronchiolitis, and there is confusion and lack of evidence over the best treatment for this condition. Supportive care, including administration of oxygen and fluids, is the cornerstone of current treatment. The majority of infants and children with bronchiolitis do not require specific measures. Bronchodilators should not be routinely used in the management of acute viral bronchiolitis, but may be effective in some patients. Most of the commonly used management modalities have not been shown to have a clear beneficial effect on the course of the disease. For example, inhaled and systemic corticosteroids, leukotriene receptor antagonists, immunoglobulins and monoclonal antibodies, antibiotics, antiviral therapy, and chest physiotherapy should not be used routinely in the management of bronchiolitis. The potential effect of hypertonic saline on the course of the acute disease is promising, but further studies are required. In critically ill children with bronchiolitis, today there is little justification for the use of surfactant and heliox. Nasal continuous positive airway pressure may be beneficial in children with severe bronchiolitis but a large trial is needed to determine its value. Finally, very little is known on the effect of the various interventions on the development of post-bronchiolitic wheeze.

Respiratory viral infections in infants: causes, clinical symptoms, virology, and immunology

In global terms, respiratory viral infection is a major cause of morbidity and mortality. Infancy, in particular, is a time of increased disease susceptibility and severity. Early-life viral infection causes acute illness and can be associated with the development of wheezing and asthma in later life. The most commonly detected viruses are respiratory syncytial virus (RSV), rhinovirus (RV), and influenza virus. In this review we explore the complete picture from epidemiology and virology to clinical impact and immunology. Three striking aspects emerge. The first is the degree of similarity: although the infecting viruses are all different, the clinical outcome, viral evasion strategies, immune response, and long-term sequelae share many common features. The second is the interplay between the infant immune system and viral infection: the immaturity of the infant immune system alters the outcome of viral infection, but at the same time, viral infection shapes the development of the infant immune system and its future responses. Finally, both the virus and the immune response contribute to damage to the lungs and subsequent disease, and therefore, any prevention or treatment needs to address both of these factors.

High volume normal saline alone is as effective as nebulized salbutamol-normal saline, epinephrine-normal saline, and 3% saline in mild bronchiolitis

The objective of this study was to investigate the effectivenesses of nebulized salbutamol, epinephrin, 3% saline, and normal saline (0.9% NaCl) in the treatment of mildly affected infants with acute bronchiolitis. We enrolled 186 children (mean age 9.5 +/- 5.3 months, range 1.5-24 months, 65.1% male) with a first episode of wheezing diagnosed as mild bronchiolitis in emergency department. Patients were randomized in a double-blind fashion to receive 4 ml dose either of 1.5 mg epinephrine plus normal saline (group 1; n = 38) or 1.5 mg epinephrine plus 3% saline (group 2; n = 39) or 2.5 mg salbutamol plus normal saline (group 3; n = 36) or 2.5 mg salbutamol plus 3% saline (group 4; n = 36) or normal saline alone (group 5; n = 37) at 0 and 30 min. Thus, all treatment modalities included high amount of NaCl (72-240 mg). Clinical score, oxygen saturation and heart rate were assessed at 0, 30, 60, and 120 min. After discharge, patients were reassessed by telephone contact at 48 hr and 6 months. The baseline characteristics were similar in all groups (P > 0.05). The outcome of patients at 120 min was found significantly better than the baseline values (P < 0.05). There were no significant differences between the outcome variables of the groups (P > 0.05). No adverse effects attributable to nebulized therapy were seen. In conclusion, all treatment modalities used in this study, including a total of 8 ml normal saline inhalation at 30-min interval showed clinically significant and swift improvement in mildly affected ambulatory infants with acute bronchiolitis.