Role of hyperoxic treatment in cancer.

IMPACT STATEMENT: Tumor hypoxia promotes cancer cell aggressiveness, and is strongly associated with poor prognosis across multiple tumor types. The hypoxic microenvironments inside tumors also limit the effectiveness of radiotherapy, chemotherapy, and immunotherapy. Several approaches to eliminate hypoxic state in tumors have been proposed to delay cancer progression and improve therapeutic efficacies. This review will summarize current knowledge on hyperoxia, used alone or in combination with other therapeutic modalities, in cancer treatment. Molecular mechanisms and undesired side effects of hyperoxia will also be discussed.

Analysis of Patient Visits and Collections After Opening a Satellite Pediatric Emergency Department.

OBJECTIVE: Satellite pediatric emergency departments (PEDs) have emerged as a strategy to increase patient capacity. We sought to determine the impact on patient visits, physician fee collections, and value of emergency department (ED) time at the primary PED after opening a nearby satellite PED. We also illustrate the spatial distribution of patient demographics and overlapping catchment areas for the primary and satellite PEDs using geographical information system. METHODS: A structured, financial retrospective review was conducted. Aggregate patient demographic data and billing data were collected regarding physician fee charges, collections, and patient visits for both PEDs. All ED visits from January 2009 to December 2013 were analyzed. Geographical information system mapping using ArcGIS mapped ED patient visits. RESULTS: Patient visits at the primary PED were 53,050 in 2009 before the satellite PED opened. The primary PED visits increased after opening the satellite PED to 55,932 in 2013. The satellite PED visits increased to 21,590 in 2013. Collections per visit at the primary PED decreased from $105.13 per visit in 2011 to $86.91 per visit in 2013. Total collections at the satellite PED decreased per visit from $155.41 per visit in 2011 to $128.53 per visit in 2013. CONCLUSIONS: After opening a nearby satellite PED, patient visits at the primary PED did not substantially decrease, suggesting that there was a previously unrecognized demand for PED services. The collections per ED visit were greater at the satellite ED, likely due to a higher collection rate.

Cost-effectiveness Analysis of Contralateral Prophylactic Mastectomy Compared to Unilateral Mastectomy with Routine Surveillance for Unilateral, Sporadic Breast Cancer.

BACKGROUND: Contralateral prophylactic mastectomy (CPM) rates in younger women with unilateral breast cancer have more than doubled. Studies of cost and quality of life of the procedure remain inconclusive. METHODS: A cost-effectiveness analysis using a decision-tree model in TreeAge Pro 2015 was used to compare long-term costs and quality of life following unilateral mastectomy (UM) with routine surveillance versus CPM for sporadic breast cancer in women aged 45 years. A 10-year risk period for contralateral breast cancer (CBC), reconstruction, wound complications, cost of routine surveillance, and treatment for CBC were used to estimate accrued costs. In addition, a societal perspective was used to estimate quality-adjusted life years (QALYs) following either treatment for a period of 30 years. Medical costs were obtained from the 2014 Medicare physician fee schedule and event probabilities were taken from recent literature. RESULTS: The mean cost of UM with surveillance was $14,141 and CPM was $20,319. Treatment with CPM resulted in $6178 more in costs but equivalent QALYs (17.93) compared with UM over 30 years of follow-up. Even with worst-case scenario and varying assumptions, CPM is dominated by UM in terms of cost and quality. CONCLUSIONS: From this refined model, UM with routine surveillance costs less and provides an equivalent quality of life. Patients undergoing CPM may eliminate the anxiety of routine surveillance, but they face the burden of higher lifetime medical costs.

Improving Pediatric Education for Emergency Medical Services Providers: A Qualitative Study.

OBJECTIVES: Previous studies have illustrated pediatric knowledge deficits among Emergency Medical Services (EMS) providers. The purpose of this study was to identify perspectives of a diverse group of EMS providers regarding pediatric prehospital care educational deficits and proposed methods of training improvements. METHODS: Purposive sampling was used to recruit EMS providers in diverse settings for study participation. Two separate focus groups of EMS providers (administrative and non-administrative personnel) were held in three locations (urban, suburban, and rural). A professional moderator facilitated focus group discussion using a guide developed by the study team. A grounded theory approach was used to analyze data. RESULTS: Forty-two participants provided data. Four major themes were identified: (1) suboptimal previous pediatric training and training gaps in continuing pediatric education; (2) opportunities for improved interactions with emergency department (ED) staff, including case-based feedback on patient care; (3) barriers to optimal pediatric prehospital care; and (4) proposed pediatric training improvements. CONCLUSION: Focus groups identified four themes surrounding preparation of EMS personnel for providing care to pediatric patients. These themes can guide future educational interventions for EMS to improve pediatric prehospital care. Brown SA , Hayden TC , Randell KA , Rappaport L , Stevenson MD , Kim IK . Improving pediatric education for Emergency Medical Services providers: a qualitative study. Prehosp Disaster Med. 2017;32(1):20-26.

Essentials of Pediatric Emergency Medicine Fellowship: Part 6: Program Administration.

This article is the sixth in a 7-part series that aims to comprehensively describe the current state and future directions of pediatric emergency medicine (PEM) fellowship training from the essential requirements to considerations for successfully administering and managing a program to the careers that may be anticipated upon program completion. This article provides a broad overview of administering and supervising a PEM fellowship program. It explores 3 topics: the principles of program administration, committee management, and recommendations for minimum time allocated for PEM fellowship program directors to administer their programs.

Evaluating the length of stay and value of time in a pediatric emergency department with two models by comparing two different albuterol delivery systems.

OBJECTIVE: Asthma is one of the most common childhood illnesses and accounts for a substantial amount of pediatric emergency department visits. Historically, acute exacerbations are treated with a beta agonist via nebulizer therapy (NEB). However, with the advent of the spacer, the medication can be delivered via a metered dose inhaler (MDI+S) with the same efficacy for mild-to-moderate asthma exacerbations. To date, no study has been done to evaluate emergency department (ED) length of stay (LOS) and opportunity cost between nebulized vs MDI+S. The objective of this study was to compare ED LOS and associated opportunity cost among children who present with a mild asthma exacerbation according to the delivery mode of albuterol: MDI+S vs NEB. METHODS: A structured, retrospective cross-sectional study was conducted. Medical records were reviewed from children aged 1-18 years treated at an urban pediatric ED from July 2007 to June 2008 with a discharge diagnosis International Classification of Disease-9 of asthma. Length of stay was defined: time from initial triage until the time of the guardian signature on the discharge instructions. An operational definition was used to define a mild asthma exacerbation; those patients requiring only one standard weight based albuterol treatment. Emergency department throughput time points, demographic data, treatment course, and delivery method of albuterol were recorded. RESULTS: Three hundred and four patients were analyzed: 94 in the MDI+S group and 209 in the NEB group. Mean age in years for the MDI+S group was 9.57 vs 5.07 for the NEB group (p<0.001). The percentage of patients that received oral corticosteroids was 39.4% in the MDI+S group vs 61.7% in the NEB group (p<0.001). There was no difference between groups in: race, insurance status, gender, or chest radiographs. The mean ED LOS for patients in the MDI+S group was 170 minutes compared to 205 minutes in the NEB group. On average, there was a 25.1 minute time savings per patient in ED treatment time (p<0.001; 95% CI=3.8-31.7). Significant predictors of outcome for treatment time were chest radiograph, steroids, and treatment mode. Opportunity cost analysis estimated a potential cost savings of $213,532 annually using MDI+S vs NEB. CONCLUSION: In mild asthma exacerbations, administering albuterol via MDI+S decreases ED treatment time when compared to administering nebulized albuterol. A metered dose inhaler with spacer utilization may enhance opportunity cost savings and decrease the left without being seen population with improved throughput. LIMITATIONS: The key limitations of this study include its retrospective design, the proxy non-standard definition of mild asthma exacerbation, and the opportunity cost calculation, which may over-estimate the value of ED time saved based on ED volume.

Helium-oxygen therapy for infants with bronchiolitis: a randomized controlled trial.

OBJECTIVE: To compare nebulized racemic epinephrine delivered by 70% helium and 30% oxygen or 100% oxygen followed by helium-oxygen inhalation therapy via high-flow nasal cannula (HFNC) vs oxygen inhalation via HFNC in the treatment of bronchiolitis. DESIGN: Prospective, randomized, controlled, single-blind trial. SETTING: This study was conducted from October 1, 2004, through May 31, 2008, in the emergency department of an urban, tertiary care children's hospital. Patients Infants aged 2 to 12 months with a Modified Wood's Clinical Asthma Score (M-WCAS) of 3 or higher. INTERVENTIONS: Patients initially received nebulized albuterol treatment driven by 100% oxygen. Patients were randomized to the helium-oxygen or oxygen group and received nebulized racemic epinephrine via a face mask. After nebulization, humidified helium-oxygen or oxygen was delivered by HFNC. After 60 minutes of inhalation therapy, patients with an M-WCAS of 2 or higher received a second delivery of nebulized racemic epinephrine followed by helium-oxygen or oxygen delivered by HFNC. Main Outcome Measure Degree of improvement of M-WCAS for 240 minutes or until emergency department discharge. RESULTS: Of 69 infants enrolled, 34 were randomized to the helium-oxygen group and 35 to the oxygen group. The mean change in M-WCAS from baseline to 240 minutes or emergency department discharge was 1.84 for the helium-oxygen group compared with 0.31 for the oxygen group (P < .001). The mean M-WCAS was significantly improved for the helium-oxygen group compared with the oxygen group at 60 minutes (P = .005), 120 minutes (P < .001), 180 minutes (P < .001), and 240 minutes (P < .001). CONCLUSION: Nebulized racemic epinephrine delivered by helium-oxygen followed by helium-oxygen inhalation therapy delivered by HFNC was associated with a greater degree of clinical improvement compared with that delivered by oxygen among infants with bronchiolitis. Trial Registration clinicaltrials.gov Identifier: NCT00116584.

Bedside ultrasound diagnosis of clavicle fractures in the pediatric emergency department.

OBJECTIVES: Clavicle fractures are among the most common orthopedic injuries in children. Diagnosis typically involves radiographs, which expose children to radiation and may consume significant time and resources. Our objective was to determine if bedside emergency department (ED) ultrasound (US) is an accurate alternative to radiography. METHODS: This was a prospective study of bedside US for diagnosing clavicle fractures. A convenience sample of children ages 1-18 years with shoulder injuries requiring radiographs was enrolled. Bedside US imaging and an unblinded interpretation were completed by a pediatric emergency physician (EP) prior to radiographs. A second interpreter, a pediatric EP attending physician with extensive US experience, determined a final interpretation of the US images at a later date. This final interpretation was blinded to both clinical and radiography outcomes. The reference standard was an attending radiologist's interpretation of radiographs. The primary outcome was the accuracy of the blinded US interpretation for detecting clavicle fractures compared to the reference standard. Secondary outcome measures included the interrater reliability of the unblinded bedside and the blinded physicians' interpretations and the FACES pain scores (range, 0-5) for US and radiograph imaging. RESULTS: One-hundred patients were included in the study, of whom 43 had clavicle fractures by radiography. The final US interpretation had 95% sensitivity (95% confidence interval [CI] = 83% to 99%) and 96% specificity (95% CI = 87% to 99%), and overall accuracy was 96%, with 96 congruent readings. Positive and negative predictive values (PPVs and NPVs, respectively) were 95% (95% CI = 83% to 99%) and 96% (95% CI = 87% to 99%), respectively. Interrater reliability (kappa) was 0.74 (95% CI = 0.60 to 0.88). FACES pain scores were available for the 86 subjects who were at least 5 years old. Pain scores were similar during US and radiography. CONCLUSIONS: Compared to radiographs, bedside US can accurately diagnose pediatric clavicle fractures. US causes no more discomfort than radiography when detecting clavicle fractures. Given US's advantage of no radiation, pediatric EPs should consider this application.

Premature departure from the pediatric emergency department: a cohort analysis of process- and patient-related factors.

OBJECTIVE: Previous literature suggests that process-related factors (eg, time of day, patient volume) and patient-related factors (eg, acuity, socioeconomic status) are associated with premature departure from emergency departments. We sought to evaluate the relationship of these and other factors with premature departure in a large, unselected cohort of pediatric emergency department patients. METHODS: This study was a retrospective cohort analysis of visits to a single tertiary site during a 1-year period. Patients' zip codes determined assignment of census-based socioeconomic metrics. Multivariate regression identified factors associated with premature departure. Sensitivity and subset analyses were performed. Return visits within 48 hours after premature departure were also reviewed. RESULTS: There were 46,417 visits, of which 2164 were premature departures. In multivariate analysis, independent predictors of premature departures were arrival time, arrival month, arrival day of week, patient acuity, concurrent premature departures, arrival rate, arrival period average length of stay, and poverty rate. Aside from patient acuity and poverty rate, no patient-related factors were significant in multivariate analysis. These results were robust in sensitivity analysis across different multivariate models. Among premature departures, there were 120 return visits (5.5%), of which 15 were admitted (0.7%). There were no deaths. Acuity was similar between initial and subsequent visits. CONCLUSIONS: Process-related factors and individual patient acuity have the strongest influence on premature departure from the pediatric emergency department. Health care organizations concerned with premature departure should focus efforts on improving pediatric emergency process flow.

Effect of parental overweight and serum leptin levels on the manifestation of overweight in 7-year-old Korean children.

OBJECTIVE: To explore the relationship between children and their parents in terms of various anthropometric parameters and obesity-related hormone levels and to identify early indicators for child obesity. DESIGN: Cross-sectional observational study. SETTING: Urban areas of Korea in 2005. SUBJECTS: A total 124 families with 7-year-old children participated. Anthropometric and blood biochemistry data and information concerning the children's lifestyles, dietary habits and parental and grandparental weight status were obtained. RESULTS: The mean values for all anthropometric parameters were greater in overweight children than in children of normal weight. Very close relationships existed between the anthropometric parameters of children and their parents. Children with two overweight parents showed the highest odds for being overweight (OR 7.62). The strong relationship between overweight children and grandparental and parental overweight, especially on the maternal side, suggests gender differences in the intergenerational transmission of body weight. We also noted a greater risk of being overweight in children with a parent with high serum leptin level. CONCLUSIONS: Grandparental and parental weight status and parental serum leptin levels enable us to identify childhood obesity at an early age and may help to counter the current epidemic of adult obesity.

The anatomic relationship between the common femoral artery and common femoral vein in frog leg position versus straight leg position in pediatric patients.

BACKGROUND: Overlap of the femoral artery (FA) on the femoral vein (FV) has been shown to occur in pediatric patients. This overlap may increase complications such as arterial puncture and failed insertions of central venous lines (CVLs). Knowledge of the anatomic relationship between the FV and FA may be important in avoiding these complications. OBJECTIVES: The objective was to evaluate the anatomic relationship of the FA and FV in straight leg position and frog leg position. METHODS: This was a prospective, descriptive study of a convenience sample of 80 total subjects (16 subjects from each of five predetermined stratified age groups). Each subject underwent a standardized ultrasound examination in both the straight and the frog leg positions. The location of the FA in relation to the FV was measured at three locations: immediately distal, 1 cm distal, and 3 cm distal to the inguinal ligament. Overlap of the FA on the FV and the diameter of the FV was noted at each location. Measurements were repeated in both the straight leg and the frog leg positions. RESULTS: For the left leg, immediately distal to the inguinal ligament, the FV was overlapped by the FA in 36% of patients in straight leg position and by 45% of patients in frog leg position. At 1 cm distal to the ligament, overlap was observed in 75% of patients in straight leg position and 88% of patients in the frog leg position. At 3 cm distal to the ligament, overlap was observed in 93% of patients in straight leg position and 86% of patients in the frog leg position. The percentage of vessels with overlap was similar in the right leg at each location for both the straight and the frog leg positions. Pooled mean (+/-SD) FV diameters for the left leg immediately distal to the inguinal ligament were 0.64 (+/-0.23) cm in the straight leg position and 0.76 (+/-0.28) cm in the frog leg position; at 1 cm distal to the ligament, 0.66 (+/-0.23) and 0.78 (+/-0.29) cm; and at 3 cm distal to the ligament, 0.65 (+/-0.27) and 0.69 (+/-0.29) cm. FV diameters for the right leg were similar to the left. CONCLUSIONS: A significant percentage of children have FAs that overlap their FVs. This overlap may be responsible for complications such as FA puncture with CVL placement. Ultrasound-guided techniques may decrease these risks. Placing children in the frog leg position increases the diameter of the FV visualized on ultrasound.

Psychiatric patients in the pediatric emergency department undergoing routine urine toxicology screens for medical clearance: results and use.

OBJECTIVE: We sought to determine the use and results of urine toxicology screens (UTS) in psychiatric patients undergoing a UTS test for medical clearance in a pediatric emergency department. METHODS: A structured retrospective study was conducted over a 6-month period. All emergency department (ED) charts were reviewed of patients 8 to 17 years who had a UTS. Urine toxicology screens were identified as medically indicated or routine-driven. Medically indicated UTS were patients who presented with seizures, syncope, headache, altered mental status, ingestion, chest pain/palpitation, shortness of breath, sexual assault, or those who were brought in for motor vehicle accident (MVA). Routine-driven UTS were uncomplicated psychiatric patients who presented with aggressive or out of control behavior, intentional self-inflicted wounds, or symptoms of depression, all of whom presented without any evidence of drug or alcohol ingestion or altered mental status. Routine-driven UTS were quantified for positive tests. In addition, we determined the change in management and disposition of those patients. We also determined the concordance of provided drug use history with UTS result. RESULTS: Of the 652 charts reviewed, 267 UTS were medically indicated; 385 were routine-driven. Of the routine-driven UTS group, 254/267 (95%) patients with negative screens and 115/118 (97%) with positive screens were referred for psychiatric treatment after psychiatric evaluation. Fisher exact test of the comparison of the disposition after psychiatric assessment with the UTS result was nonsignificant. The UTS result also had no effect on the type of psychiatric disposition (ie, outpatient therapy, partial hospitalization, inpatient hospitalization). Concordance with provided history of illicit drug use was significant. CONCLUSIONS: Routine-driven UTS in uncomplicated pediatric psychiatric patients being evaluated in the ED offered little additional information, did not influence management, and potentially increased both ED cost and time. Patients with straightforward psychiatric complaints may be medically cleared without a UTS.

Effects of UCP2 and UCP3 variants on the manifestation of overweight in Korean children.

To investigate the associations of uncoupling protein (UCP)2 and UCP3 gene variants with overweight and related traits, we genotyped UCP2-866G>A, UCP2Ala55Val, and UCP3-55C>T in 737 Korean children and 732 adults and collected data regarding anthropometric status and blood biochemistry. Information concerning the children's lifestyles and dietary habits was collected. The UCP2-866G>A and UCP3-55C>T gene variants showed significant associations with BMI level, waist circumference, and body weight in the children but not in the adults. Compared with -866GG carriers, the -866GA and AA carriers showed a strong decreasing trend in the risk for overweight (odds ratio (OR), 0.67; 95% confidence interval (CI), 0.45-1.01; P = 0.053). In comparison with UCP3-55CC carriers, children carrying -55CT and TT showed a significant reduction in the risk of overweight (OR, 0.67; 95% CI, 0.46-0.98; P = 0.039). There was also evidence of interactions between the effects of the combined UCP2-UCP3 genotype and obesity-related metabolic traits. The greatest protective effect against overweight was seen in those with the combined genotype non-UCP2-866GG and non-UCP3-55CC, as compared with those carrying both UCP2-866GG and UCP3-55CC (OR,0.60; 95% CI, 0.38-0.95; P = 0.030). In the subgroup with a low level of physical activity, UCP3-55CC carriers had higher BMI values than UCP3-55T carriers (16.6 +/- 2.3 kg/m(2) vs. 16.1 +/- 1.9 kg/m(2), P = 0.016). Low physical activity may aggravate the susceptibility to overweight in UCP2-866GG and UCP3-55CC carriers.

Jet Injection of 1% buffered lidocaine versus topical ELA-Max for anesthesia before peripheral intravenous catheterization in children: a randomized controlled trial.

BACKGROUND: Peripheral intravenous (PIV) catheter insertion is a frequent, painful procedure that is often performed with little or no anesthesia. Current approaches that minimize pain for PIV catheter insertion have several limitations: significant delay for onset of anesthesia, inadequate anesthesia, infectious disease exposure risk from needlestick injuries, and patients' needle phobia. OBJECTIVE: Comparison of the anesthetic effectiveness of J-Tip needle-free jet injection of 1% buffered lidocaine to the anesthetic effectiveness of topical 4% ELA-Max for PIV catheter insertion. METHODS: A prospective, block-randomized, controlled trial comparing J-Tip jet injection of 1% buffered lidocaine to a 30-minute application of 4% ELA-Max for topical anesthesia in children 8 to 15 years old presenting to a tertiary care pediatric emergency department for PIV catheter insertion. All subjects recorded self-reported visual analog scale (VAS) scores for pain at time of enrollment and pain felt following PIV catheter insertion. Jet injection subjects also recorded pain of jet injection. Subjects were videotaped during jet injection and PIV catheter insertion. Videotapes were reviewed by a single blinded reviewer for observer-reported VAS pain scores for jet injection and PIV catheter insertion. RESULTS: Of the 70 children enrolled, 35 were randomized to the J-Tip jet injection group and 35 to the ELA-Max group. Patient-recorded enrollment VAS scores for pain were similar between groups (P = 0.74). Patient-recorded VAS scores were significantly different between groups immediately after PIV catheter insertion (17.3 for J-Tip jet injection vs 44.6 for ELA-Max, P < 0.001). Blinded reviewer assessed VAS scores for pain after PIV catheter insertion demonstrated a similar trend, but the comparison was not statistically significant (21.7 for J-Tip jet injection vs 31.9 ELA-Max, P = 0.23). CONCLUSION: J-Tip jet injection of 1% buffered lidocaine provided greater anesthesia than a 30-minute application of ELA-Max according to patient self-assessment of pain for children aged 8 to 15 years undergoing PIV catheter insertion.

The anatomic relationship of femoral vein to femoral artery in euvolemic pediatric patients by ultrasonography: implications for pediatric femoral central venous access.

BACKGROUND: Knowledge of the femoral vein (FV) anatomy in pediatric patients is important in the selection of appropriate size central line catheters as well as the approach to central venous access. This knowledge may avoid potential complications during central line access. OBJECTIVES: To describe the relationship of the FV to the femoral artery (FA). To measure FV diameter and FV depth using ultrasonography (US) in newborns, infants, and children up to 9 years of age. METHODS: This study was a prospective descriptive study at a tertiary care children's hospital. A convenience sample of euvolemic children was enrolled aged 0-9 years presenting to an urban pediatric emergency department. All patients underwent a standardized US evaluation using a Sonosite Titan bedside machine by a single emergency physician. The FA and FV were identified by four criteria: relative positions, FV compressibility, FV enlargement by Valsalva maneuver, and absence of FV pulsatility. The position of the FV relative to the FA was described as being completely overlapped by the FA, having partial (<50%) overlap by the FA, and having no overlap by the FA. The FV depth was measured from the skin to the superior border of the vein using the US machine's caliper function. RESULTS: A total of 84 patients were studied. The FV was found to be completely overlapped by the FA in 8% of subjects and partially overlapped by the FA in 4% of subjects. The mean FV diameter ranged from 4.5 mm in young infants to 10.8 mm in patients 9 years of age. The mean FV depth ranged from 6.5 mm in neonates to 11.2 mm in patients 9 years of age. CONCLUSIONS: External landmarks were not always predictive of internal anatomy. The FV was completely or partially overlapped by the FA in 12% of cases. Thus, visualization of femoral vessels should be recommended prior to attempting pediatric femoral central venous access.

The history and physics of heliox.

Since the discovery of helium in 1868, it has found numerous applications in industry and medicine. Its low density makes helium potentially valuable in respiratory care applications, to reduce work of breathing, improve distribution of ventilation, reduce minute volume requirement, and improve aerosol delivery. This review includes a brief history of the use of heliox (a mixture of helium and oxygen) and addresses issues related to the physics of gas flow when heliox is used. Specifically covered are the Hagen-Poiseuille equation, laminar versus turbulent flow, the Reynolds number, orifice flow, Bernoulli's principle, Graham's law, wave speed, and thermal conductivity.

Heliox-driven albuterol nebulization for asthma exacerbations: an overview.

Our understanding of albuterol nebulization driven by helium-oxygen mixture (heliox) has matured with recent advances in clinical therapy, delivery systems, and understanding of dosing; this has led to substantial improvements in delivery as well as refinements of research protocols for asthma exacerbations. This review begins with heliox inhalation therapy and then addresses heliox as a driving gas for nebulization. Technical considerations are reviewed, including optimal gas mixtures, flow-rate adjustment factors, and nebulizer setup.

Helium/oxygen-driven albuterol nebulization in the treatment of children with moderate to severe asthma exacerbations: a randomized, controlled trial.

BACKGROUND: Helium and oxygen mixtures (heliox) increase both pulmonary aerosol delivery and gas delivery relative to oxygen. We aimed to compare the effectiveness of a 70%:30% helium/oxygen (heliox)-driven continuous aerosol delivery versus 100% oxygen-driven delivery in the treatment of asthmatic children with moderate to severe exacerbations. METHODS: We enrolled 30 children aged 2 to 18 years who presented to an urban, pediatric emergency department (ED) with moderate to severe asthma as defined by a pulmonary index (PI) score of > or =8. PI scores can range from 0 to 15. In this randomized, controlled, single-blind trial conducted in a convenience sample of children, all patients in the trial received an initial nebulized albuterol (5 mg) treatment driven by 100% oxygen and a dose of oral prednisone or prednisolone. Subsequently, patients were randomly assigned to receive continuously nebulized albuterol (15 mg/hour) delivered by either heliox or oxygen using a nonrebreathing face mask. The primary outcome measure was degree of improvement as assessed in blinded video-recorded PI scores over 240 minutes (at 30-minute intervals for the first 3 hours) or until ED discharge (if <240 minutes). RESULTS: The mean change in PI score from baseline to 240 minutes or ED discharge was 6.67 for the heliox group compared with 3.33 for the oxygen group. Eleven (73%) patients in the heliox group were discharged from the hospital in <12 hours compared with 5 (33%) patients in the conventional group. CONCLUSION: Continuously nebulized albuterol delivered by heliox was associated with a greater degree of clinical improvement compared with that delivered by oxygen among children with moderate to severe asthma exacerbations.

Aerosol drug delivery using heliox and nebulizer reservoirs: results from an MRI-based pediatric model.

An MRI-based model of the mouth, throat, and upper airways of a 5-year-old boy is used to evaluate methods for increasing the nebulized drug dose delivered to the lungs. Four methods are considered: (1) standard nebulizer delivery with air, (2) delivery with 70/30 helium-oxygen (heliox), (3) delivery with air and an aerosol-conserving reservoir, and (4) delivery with heliox and a reservoir. When comparing air and heliox, delivery flowrates were adjusted so that the aerosols produced were of similar size. The reservoir utilized was the Medicator Aerosol Maximizer (Healthline Medical, Baldwin Park, CA). It conserves the aerosol generated by the nebulizer during exhalation and makes it available for the next inhalation. Technetium-DTPA was utilized. The standard nebulizer driven by air delivered 2.2% of the dose loaded into the nebulizer to the lungs as fine droplets, versus 3.3% for the nebulizer with heliox (50% increase; p = 0.002 vs. air), 2.9% for the nebulizer plus reservoir driven by air (32% increase; p = 0.02 vs. no reservoir), and 4.0% for the nebulizer plus reservoir driven by heliox (82% increase; p = 0.002 vs. air without reservoir). The increased pulmonary dose when heliox was utilized occurred because of decreased deposition within the nebulizer and other delivery equipment. The increased pulmonary dose when the reservoirs were utilized occurred due to a decrease in the dose expelled from the nebulizer by exhalation.