Helium/oxygen-driven albuterol nebulization in the treatment of children with moderate to severe asthma exacerbations: a randomized, controlled trial. Use of heliox-driven nebulizer therapy in the treatment of acute asthma. The effect of heliox in acute severe asthma: a randomized controlled trial. Inhaling beta(2)-agonist with heliox-driven in bronchial asthma. Inhaled heliox does not benefit ED patients with moderate to severe asthma. Evaluation of heliox in children hospitalized with acute severe asthma. A randomized crossover trial. Beneficial effects of albuterol therapy driven by heliox versus by oxygen in severe asthma exacerbation. Albuterol nebulized in heliox in the initial ED treatment of pediatric asthma: a blinded, randomized controlled trial. Prospective randomized trial of heliox-driven continuous nebulizers in the treatment of asthma in the emergency department. The utility of albuterol nebulized with heliox during acute asthma exacerbations.
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.
                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).
                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.
                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. To compare the effectiveness of a helium-oxygen mixture with that of oxygen alone as an aerosolizing gas for beta-agonist therapy in patients with mild to moderate exacerbation of asthma.
                A prospective, single-blinded study was performed in an urban teaching hospital over a period of 5 months. A convenience sample of 205 patients with mild to moderate exacerbation of asthma were enrolled. The participants were randomly assigned to 1 of 2 groups. The first group received 3 doses of albuterol, 5.0 mg aerosolized in 10 L/min of oxygen, 15 minutes apart. The second group received 3 doses of albuterol, 5.0 mg aerosolized in 10 L/min of a 70:30 helium-oxygen mixture (heliox), 15 minutes apart. Peak expiratory flow rate (PEFR), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1 ) were measured before and after each treatment. Only PEFR and FEV1 were used in data analysis.
                Although both the heliox and the oxygen group showed significant improvement in PEFR from baseline after 45 minutes (72% and 70%, respectively), the difference between the 2 groups was clinically and statistically insignificant (P =.56). Similar findings were observed for FEV1. There was no difference in rate of admission or rate of complications between the 2 groups.
                Despite its ability to decrease the turbulent flow in airways and to reach distal pulmonary tissues, heliox had no clinically significant advantage over standard therapy in the treatment of mild to moderate asthma. Further large-scale studies are necessary to determine the clinical efficacy of heliox in this setting. To evaluate the effect of heliox on airflow obstruction and dyspnea in patients with acute severe asthma.
                A prospective, randomized, controlled study.
                A university hospital.
                Twenty-three patients presenting to the emergency department with acute severe asthma were randomized to receive 70%/30% heliox or 30% oxygen.
                Peak expiratory flow (PEF), dyspnea score, heart rate, respiratory rate (RR), and BP were measured at baseline and 20, 120, 240, 360, and 480 min after starting the test gas. After baseline, the PEF was measured by using the gas that was randomized to the treatment program.
                In the first 20 min, there was a 58.4% increase in percent predicted PEF (%PEF) in the heliox group (p<0.001), whereas there was only a 10.1% increase in %PEF for the oxygen group (p>0.1). Eighty-two percent of the heliox group had >25% improvement in %PEF at 20 min, whereas only 17% of the oxygen group did (p<0.01). The next significant improvement in %PEF in the heliox group occurred at 480 min. At the end of the study in the heliox group, the PEF did not significantly (p>0.1) change immediately after the heliox was discontinued (270.6 to 264.2 L/min). In the heliox group in the first 20 min, there was a significant decrease in dyspnea score and RR (p<0.05), but there were no further significant improvements for the rest of the study. In the oxygen group, no variables significantly improved until 360 min.
                Heliox rapidly improves airflow obstruction and dyspnea in patients with acute severe asthma and may be useful as a therapeutic bridge until the corticosteroid effect occurs. To evaluate the effectiveness of a helium-oxygen mixture (79%He- 21%O(2)) as an aerosolizing compressed gas for beta(2)-agonist therapy in patients with an asthma exacerbation.
                Twenty-four patients in the outpatient department with a mild to moderate exacerbation of asthma were enrolled. The patients were randomly divided into an experimental group (13 cases) and a control group (11 cases). The experimental group inhaled Berotec with heliox-driven, and the control group inhaled Berotec with compressed air-driven. Eight hospitalized patients in the respiratory department with severe exacerbation of asthma were enrolled. The patients inhaled Berotec with heliox-driven or compressed air-driven in a random order.
                The results of spirometric parameters and arterial blood-gas analysis were measured. In the mild to moderate asthma patients, no statistical differences between the two groups for forced vital capacity (FVC), forced expired volume in one second (FEV(1)), and expiratory flow in 50% forced vital capacity (FEF(50)) were presented. But the severe patients showed significant differences between heliox-driven and compressed air-driven for FVC, FEV(1), FEF(50) and partial pressure of oxygen (PaO(2)).
                Compared with the traditional inhalation of beta(2)-agonist therapy using compressed air-driven, the method of inhaling beta(2)-agonist with heliox-driven has more obvious benefits for those suffering from severe asthma. This is likely due to the cooperative effects between inhaling heliox on its physical gas properties and improving delivery of beta(2)-agonist in the treatment of exacerbation of severe asthma. nan To determine whether breathing a blend of 70% helium:30% oxygen (heliox) would improve pulmonary function, decrease clinical score, and improve the sensation of dyspnea in children hospitalized with acute severe asthma.
                Prospective, randomized, double-blind, crossover study.
                The inpatient pediatric service of a military, tertiary care, teaching hospital.
                Children 5 to 18 years who required hospital admission for treatment of acute asthma.
                All patients received 5 mg of nebulized albuterol every 1 to 4 h, with a dose given within 30 min of the start of the study, and IV administered methylprednisolone. Patients breathed heliox and a 30% oxygen-enriched air mixture for 15 min each in random order.
                Clinical score, dyspnea score, oxygen saturation, heart rate, and respiratory rate, followed by FVC, FEV1, peak expiratory flow rate (PEFR), and, mean midexpiratory flow rate (FEF25-75) were obtained at study entry, 15 min after breathing the first gas mixture (heliox or air per randomization), 15 min after breathing the second mixture, and again 15 min after stopping the second gas mixture (study end values). Eleven children were enrolled, and all completed the study. There were no significant differences between study entry and study end spirometric values. Using the paired t test, we found no significant differences between mean values (SD) of FEV1 and FVC obtained while breathing heliox vs air; FEV1-heliox, 53% (18%) of the predicted value; FEV1-air, 52% (16%) of the predicted value (p = 0.36); FVC-heliox, 69% (22%) of the predicted value; and FVC-air, 70% (21%) of the predicted value (p = 0.50). The differences in values for PEFSR and FEF25-75 while breathing heliox vs air were small but did reach statistical significance in favor of heliox: PEFR-heliox, 56% (20%) of the predicted value; PEFR-air, 50% (16%) of the predicted value (p = 0.04); FEF25-75-heliox, 32% (13%) of the predicted value; and FEF25-75-heliox, 29% (11%) of the predicted value (p = 0.006). Heliox had no effect on either clinical or dyspnea scores.
                The short-term inhalation of heliox did not benefit this group of children hospitalized with acute, severe asthma. To determine and define the beneficial effects of heliox-driven albuterol therapy on severe asthma exacerbation and clinical factors that affect greater response.
                The authors conducted two randomized, double-blinded, controlled trials in patients with severe asthma exacerbation. The first trial recruited 80 patients in the emergency department (ED). They received three consecutive doses of albuterol delivered by a nebulizer powered by either O(2) (O(2) group) or heliox (He/O(2) = 80:20; heliox group). Changes in peak expiratory flow rate (PEF) were compared, and factors influencing the response to heliox-driven albuterol therapy were identified. The second trial of 80 patients was conducted in older patients, a subpopulation associated with greater response in the first trial.
                In the first trial, the heliox group had more rapid and greater improvement in PEF compared with the O(2) group. There tended to be more patients in the heliox group reaching the predetermined dischargeable PEF (>60% predicted) after three albuterol treatments (odds ratio, 2.58; 95% confidence interval = 1.03 to 6.46; p = 0.069). For patients eventually discharged from the ED, the ED stay was shorter by 10 minutes per patient in the heliox group compared with the O(2) group (p = 0.007). Logistic regression showed older age and lower pretreatment PEF to be associated with favorable heliox responses. The second trial, which recruited older patients (older than 40 years), showed greater improvement in PEF and dyspnea score with heliox-driven albuterol therapy in patients with lower pretreatment PEF.
                Heliox-driven albuterol may be a useful adjunct therapy for older asthmatic patients with severe asthma exacerbation. A prospective blinded, randomized controlled trial was undertaken to compare the initial response of albuterol nebulized in heliox or control in the treatment of moderately severe asthma in children presenting to a pediatric ED.
                Patients were randomized to receive heliox (n = 20) or control (n = 21). The primary outcome was to compare a modified dyspnea index score at 10 and 20 minutes after randomization. Secondary outcomes were to determine if heliox decreased admission rates or endotracheal intubation.
                There was no statistically significant difference found at 10 or 20 minutes after randomization with heliox (P = .169 and P = .062, respectively). No statistical difference in admission rate was found, and no patients required endotracheal intubation in either group.
                Our results demonstrate that albuterol nebulized with heliox offered no clinical benefit over standard therapy in the initial treatment of moderately severe asthma in the ED. The purpose of this study was to evaluate the efficacy of heliox-driven continuous nebulizers in the management of moderate to severe asthma exacerbations in the Emergency Department (ED). The trial was a prospective, randomized, double-blind, controlled trial in a university Emergency Department (volume 65,000 patients/year) of patients 18-55 years of age with acute asthma exacerbations. Patients were placed on continuous nebulizers driven by 70:30 heliox or air with 30% O(2). Respiratory rate, peak expiratory flow rate (PEFR), forced expiratory volume at 1 s (FEV1), and Borg dyspnea scale were measured at 0 and 2 h. Disposition and patient satisfaction were also assessed. A total of 36 patients completed the study (18 heliox, 18 air). There was no difference between groups in baseline variables. There was significant interval improvement within both groups at 2 h in PEFR, FEV1, Borg, and respiratory rate. There was no significant difference between heliox 70:30 and air/oxygen in PEFR [mean between-group improvement difference 17 liters/min, 95% confidence interval (CI) -20-51], FEV1 (0.03 liters/sec, 95% CI -0.22-0.30), or respiratory rate (mean between-group improvement difference 0.5, 95% CI -2.7-3.8). There was a significant improvement in the patients' perceived dyspnea as measured by the Borg dyspnea scale at 2 h in the heliox group (1.6, 95% CI 0.3-3.0). In this trial of patients with moderate-severe asthma exacerbation, heliox-driven continuous nebulizers failed to demonstrate an improvement in respiratory rate, oxygen saturation, PEFR, or FEV1 at 2 h. However, there was a significant improvement in the patients' perceived dyspnea on heliox over air/oxygen measured by the Borg dyspnea scale. Heliox improves lung deposition of inhaled particles when compared with air or oxygen inhalation. We studied the spirometric effects of albuterol nebulized with heliox during emergency room visits for asthma exacerbations. Forty-five patients were randomized to receive albuterol nebulized with oxygen (control) versus heliox (n = 22 control and 23 heliox subjects). At baseline, demographics, outpatient asthma medications, vital signs, oxygen saturation, and forced expiratory volume in one second were not different between the two groups. Three consecutive albuterol treatments were given to each group. The heliox group had a significantly higher heart rate after albuterol nebulization compared with the control group. Following albuterol Treatment 1, the median change in forced expiratory volume in one second was 14.6% in the control group and 32.4% in the heliox group (p = 0.007). After Treatment 2, the results were 22.7% versus 51.5%, respectively (p = 0.007). After Treatment 3, the results were 26.6% versus 65.1%, respectively (p = 0.016). We conclude that during acute asthma exacerbations, albuterol nebulized with heliox leads to a more significant improvement in spirometry when compared with albuterol nebulized with oxygen. This is likely due to the low-density gas improving albuterol deposition in the distal airways.
The existing evidence does not provide support for the administration of helium-oxygen mixtures to all ED patients with acute asthma. At this time, heliox treatment does not have a role to play in the initial treatment of patients with acute asthma. Nevertheless, new evidence suggests certain beneficial effects in patients with more severe obstruction. Since these conclusions are based upon between-group comparisons and small studies, they should be interpreted with caution.