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[High dose steroid inhalation therapy using a large spacer: laboratory and clinical study on usefulness of the 4-puffs/inhalation method].

We investigated whether or not the inhalation method of beclomethasone dipropionate (BDP) influences patient compliance and the clinical effects of therapy in chronic bronchial asthma, together with a basic study on the lung deposition of BDP using a twin Impinger when various numbers of puffs were discharged into three different spacers (Volumatic, InspirEase, Aerochamber). It was clearly shown that only the spacer, Volumatic maintained a high deposition rate of BDP in the lung model with a dose of 4-puffs/inhalation. Eighteen chronic asthmatic patients were studied. The patients inhaled BDP (800-1600 micrograms/day) by 1-puff/inhalation using a large spacer, Volumatic, for 12 weeks, and they then inhaled the same dose of BDP as given in the previous period by 4-puffs/inhalation using the spacer for 16 weeks. We compared the compliance of BDP, attack score, %PEFR and frequency of beta-agonist inhalation between these two periods. The compliance of BDP was markedly improved after changing from 1-puff/inhalation (92.8%) to 4-puffs/inhalation (99.8%). In the 4-puffs/inhalation period, attack score and %PEFR were significantly improved as compared to the 1-puff/inhalation period. The frequency of beta-agonist inhalation use in the 4-puffs/inhalation period was significantly lower than that in the 1-puff/inhalation period. These results indicate that when high dose steroid inhalation is given with a large spacer in chronic asthmatic patients, we should advice them of the appropriate inhalation method in order to obtain good compliance and clinical effects.

Adult↗

[Changes in osmolarity during inhalation with various IPPB and ultrasound devices].

Inhalation of slightly hyperosmolar solutions may result in asthma attacks. "Evaporation" and hence increase of the concentration of the aerosol in continuous atomisation by ultrasound has been known for a long time. The present study aimed at finding out to what extent an osmolarity increase can be detected even with commercial home inhalation devices with an inhalation period of between 3 and 5 minutes. We examined the following instruments: Heyer Sekundant, Bird-Mark 7, Respirator IPPB (supplier: Stephan) Pari-Inahalierboy, Heyer-Prodomo and the compressed-air driven inhalators FT 51 (Heyer) and the ultrasound device US-77 supplied by Heyer. Osmolality was measured with the osmometer Osmomat-030 supplied by Gonoteck. We atomised a mixture of 5 drops Berodual with physiological saline solution and isotonic brine (salt water) from the German spa Bad Ems. All inhalation devices showed after a short time an increase in osmolarity that was lowest with the Inhalierboy and Heyer Prodomo. The Heyer Sekundant and Bird-Mark 7 models showed increases that were a cause for concern. It is recommended on the basis of the results obtained that suppliers should state on their inhalation equipment not only the droplet size and aerosol density but also the increase in osmolarity on atomisation of a reference substance after 3 or 5 minutes, respectively. It would be desirable, in the interests of safe therapy, that the data given for an inhalation equipment should include over and above the usual characteristics the increase in osmolarity per unit of time under defined environmental conditions (see above) on atomisation of a reference solution.

Aerosols↗

[Inhalation therapy for asthma in children. Questions about effectiveness].

A better understanding of childhood asthma, a disease affecting 6 to 10% of the paediatric population, has led to the development inhalation systems which can provide undeniably effective therapy but also raise a certain number of questions as to the quantity of drug actually reaching the pulmonary airways. When aerosols, the reference system, are used with a good inhalation technique, as much as 80% of the active product goes no further than the oral cavity, only 10% reaching the intrapulmonary airways. In addition, the system requires a co-ordination between hand movements and inspiration which is beyond the capacity of children under 7 or 8 years of age. Doses and granulometric flow also vary greatly depending on the propulsion gas. Inhalation chambers mounted on face masks avoid the problem of co-ordinated movements, increasing pulmonary deposition, but real drug delivery in infants who breathe through the nose remains to be determined. Systems which deliver the drug in the form of a powder have also been developed. With these devices, the product is held in a chamber together with carrier particles and is inhaled as inspiration creates air turbulence in the chamber. Minimal inhalation peak is the limiting factor. Nebulizers offer another possibility since no voluntary control of respiration is required, the child breathes at his own rhythm. The drug is nebulized either by a forced air or ultrasound system. Such systems may be very useful for infants but are usually not adapted for toddlers or older children. Despite the lack of precision as to the quantity of drug actually delivered to the pulmonary airways, the use of inhalations has completely changed the quality of life of children with chronic asthma. Further progress will be made through a better understanding of the two most important factors: the child and corticosteroids. Indeed, the child's co-operation (or non-co-operation) is one of the major sources of (un)successful treatment: even the best inhalation system can have little impact on the disease if it is not accepted and used correctly by the child.

Asthma↗

Efficacy of a nicotine inhaler in smoking cessation: a double-blind, placebo-controlled trial.

A non-combustible nicotine inhaler, administered orally, has been developed for treatment of smokers. The inhaler allows weaning from nicotine while maintaining partial reinforcement of the ritual/sensory phenomena of smoking. Subjects were randomly assigned to active (n = 112) and placebo (n = 111) groups. Some behavioral intervention occurred as a function of participation. Strict abstinence (primary outcome criterion) was defined by CO < or = 8 ppm with no slips allowed at any time and cotinine values < or = 14 at 1 year. Survival analysis showed active inhaler was superior to placebo (p < 0.01). Active vs. placebo success rates were: 63% vs. 47% (day 3), 46% vs. 28% (week 1), 36% vs. 19% (week 2), 33% vs. 16% (week 3), 29% vs. 14% (week 6), 24% vs. 10% (3 months), 17% vs. 9% (6 months) and 13% vs. 8% (1 year). chi 2 analyses were significant through 3 months but not at 6 months (p < 0.08) or 1 year. Craving was relieved with active inhalers at day 3 and week 1. Subjects averaged six inhalers/day. Cotinine levels were 57-61% of smoking levels. Common side effects included throat/mouth irritation and coughing. Failure was predicted by early slips. The inhaler is clearly useful for short-term smoking cessation with potential for long-term efficacy. Extended access to the inhaler and relapse prevention training could improve success rates. Another promising approach would be to combine the inhaler with a nicotine patch.

Adult↗

[Inhalation therapy in chronic obstructive bronchial diseases].

A number of different inhalation appliances are available for the inhalation treatment of chronic obstructive bronchial diseases. Electrical aerosol appliances, aerosols providing measured dosage and dry powder inhalers all show good physical properties for creating aerosol particles with an average aerodynamic mass diameter of 2-9 microns, which is a prerequisite for optimum bronchial deposition. Advantages and disadvantages of the principal appliances available on the market are compared. In an overview the action, indications and side effects of beta-2 sympathomimetics, ipratropium bromide, anti-allergens and inhaled steroids are discussed. Both in chronically obstructive pulmonary diseases (COPD) and in chronic asthma, precise patient instructions and the correct use and combination of bronchial dilating medicines and inhaled steroids in asthma, and of beta-2 sympathomimetics and ipratropium bromide in COPD, are important for optimum effect of inhalation treatment. The literature shows that the widespread fear of side effects of steroids applied in inhalant form is unfounded.

Adrenergic beta-Agonists↗

Low-dose inhaled nitric oxide in patients with acute lung injury: a randomized controlled trial.

CONTEXT: Inhaled nitric oxide has been shown to improve oxygenation in acute lung injury. OBJECTIVE: To evaluate the clinical efficacy of low-dose (5-ppm) inhaled nitric oxide in patients with acute lung injury. DESIGN AND SETTING: Multicenter, randomized, placebo-controlled study, with blinding of patients, caregivers, data collectors, assessors of outcomes, and data analysts (triple blind), conducted in the intensive care units of 46 hospitals in the United States. Patients were enrolled between March 1996 and September 1999. PATIENTS: Patients (n = 385) with moderately severe acute lung injury, a modification of the American-European Consensus Conference definition of acute respiratory distress syndrome (ARDS) using a ratio of PaO2 to FiO2 of < or =250, were enrolled if the onset was within 72 hours of randomization, sepsis was not the cause of the lung injury, and the patient had no significant nonpulmonary organ system dysfunction at randomization. INTERVENTIONS: Patients were randomly assigned to placebo (nitrogen gas) or inhaled nitric oxide at 5 ppm until 28 days, discontinuation of assisted breathing, or death. MAIN OUTCOME MEASURES: The primary end point was days alive and off assisted breathing. Secondary outcomes included mortality, days alive and meeting oxygenation criteria for extubation, and days patients were alive following a successful unassisted ventilation test. RESULTS: An intent-to-treat analysis revealed that inhaled nitric oxide at 5 ppm did not increase the number of days patients were alive and off assisted breathing (mean [SD], 10.6 [9.8] days in the placebo group and 10.7 [9.7] days in the inhaled nitric oxide group; P =.97; difference, -0.1 day [95% confidence interval, -2.0 to 1.9 days]). This lack of effect on clinical outcomes was seen despite a statistically significant increase in PaO2 that resolved by 48 hours. Mortality was similar between groups (20% placebo vs 23% nitric oxide; P =.54). Days patients were alive following a successful 2-hour unassisted ventilation trial were a mean (SD) of 11.9 (9.9) for placebo and 11.4 (9.8) for nitric oxide patients (P =.54). Days alive and meeting criteria for extubation were also similar: 17.0 placebo vs 16.7 nitric oxide (P =.89). CONCLUSION: Inhaled nitric oxide at a dose of 5 ppm in patients with acute lung injury not due to sepsis and without evidence of nonpulmonary organ system dysfunction results in short-term oxygenation improvements but has no substantial impact on the duration of ventilatory support or mortality.

Administration, Inhalation↗

Inhaler technique in Turkish people with poor English: a case of information discrimination?

OBJECTIVES: (a) To compare metered dose inhaler (MDI) technique in users with poor English and fluent English, (b) to evaluate two interventions: a translated patient information leaflet (PIL) plus support from an translator (PIL + verbal) and a multimedia touch screen system (MTS) using video clips and own-language instruction. METHODS: (a) Inhaler technique was videotaped and key steps rated blind for 105 fluent English-speakers (FE) and 69 Turkish-speakers with poor English (EP). (b) The EP group was randomised to receive information by MTS (n = 34) or PIL + verbal (n = 35). Inhaler technique was videotaped before and after information. MAIN OUTCOME MEASURES: (a) Global inhaler technique; (b) breathing-in time; (c) co-ordination of inspiration and inhaler actuation. RESULTS: Global technique, co-ordination and breath-holding were all significantly worse in MDI users with poor English. Only 17% of that group had adequate technique compared to over half (62%) of FE. The EP group were significantly less likely than the FE group to report ever seeing the practice nurse about their asthma. After information, global technique was rated as improved in 50% of the MTS group compared to 28% of those given a translated PIL. A further six people (17%) in the PIL group improved after subsequent verbal advice in their own language. Both information methods significantly increased inhaler shaking and mouthpiece checking, but co-ordination only improved in a small number of people. CONCLUSIONS: The study suggests that Turkish-speaking MDI users with poor English may be disadvantaged in terms of access to medicines information in the UK. The acceptability of pharmacy-based support services for this, and other specific language groups should be explored. Multimedia offers an alternative to a translator for brief explanations, particularly for first-time users, but improving poor co-ordination requires individualised "hands on" teaching from health professionals.

Administration, Inhalation↗

A review of the development of Respimat Soft Mist Inhaler.

Respimat Soft Mist Inhaler (SMI) is a new generation inhaler from Boehringer Ingelheim developed for use with respiratory drugs. The device functions by forcing a metered dose of drug solution through a unique and precisely engineered nozzle (the uniblock), producing two fine jets of liquid that converge at a pre-set angle. The collision of these two jets generates the soft mist. The soft mist contains a high fine particle fraction of approximately 65 to 80%. This is higher than aerosol clouds from conventional portable inhaler devices, such as pressurised metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). In addition, the relatively long generation time of the aerosol cloud (approximately 1.5s) facilitates co-ordination of inhalation and actuation--a major problem with pMDIs. These features, together with the slow velocity of the soft mist, result in larger amounts of the drug reaching the lungs and less being deposited in the oropharynx compared with either pMDIs or DPIs. Generation of the soft mist from Respimat SMI is purely mechanical, so propellants are not necessary. The innovative design of Respimat SMI, using water-based drug formulations, ensures patients receive consistent and reliable doses of the drug with each actuation. The device was initially tested in scintigraphic lung deposition studies and produced encouraging results when compared with the chlorofluorocarbon-based pMDI (CFC-MDI). Subsequent clinical studies have confirmed that Respimat SMI is effective and safe in delivering bronchodilators to patients with asthma or chronic obstructive pulmonary disease.

Administration, Inhalation↗

Equivalent asthma control and systemic safety of inhaled budesonide delivered via HFA-134a or CFC propellant in a broad range of doses.

The aim of the present study was to demonstrate an equivalent asthma control and safety of inhaled budesonide 200 microg unit-dose via a spacer device (Jet Spacer, Chiesi Farmaceutici S.p.A.) given with an HFA-134a or CFC propellant in stable patients treated with inhaled corticosteroids. A total number of 270 patients, 134 in the HFA-134a group and 136 in the CFC group, completed a 2-week run-in period and were then randomised to receive a daily dose of inhaled budesonide (low dose: 400 microg, medium dose: 800 microg, high dose: 1200 or 1600 microg), defined on the basis of the dose of previous inhaled steroids given twice daily for 12 weeks. Morning and evening PEFR, intake of rescue salbutamol, number of day-time and night-time asthma attacks, number of night-time awakenings due to asthma and clinical symptoms were recorded daily by patients on diary cards. Pulmonary function tests (FEV1, FVC, PEFR and MEF50) and vital signs were measured at the clinics at study entry, at the start of treatment and after 2, 4, 8 and 12 weeks thereafter. Morning serum cortisol (8.00-10.00 AM) was measured at baseline and in the final visit. Adverse events and vital signs were recorded throughout the total study period. Small increases vs. baseline for lung function (more markedly in the high-dose subsets) and significant decreases of symptoms and use of rescue salbutamol were similarly observed in both groups. Equivalence was demonstrated for the primary endpoint morning PEFR (difference between means = -1.51 l/min; 95% CI: -9.40-6.37 l/min; pre-defined limits: +/- 42.16 l/min, i.e. +/- 10% of the reference LSM) as well as for evening PEFR and FEV1, both in the ITT population or on a per-protocol basis. No statistically significant differences between groups were observed in any of the other efficacy variables. A similar proportion of drug-related adverse events was observed in the two groups, without drug-related serious events in either group. No evidence of adrenal depletion was also noted with both propellants. In conclusion, the budesonide HFA-134a formulation given with a spacer device provided an equivalent asthma control with that of a corresponding CFC product, when administered in stable patients treated with inhaled corticosteroids in a broad range of daily doses. The use of the new propellant did not modify the safety profile of inhaled budesonide.

Administration, Inhalation↗

The ideal inhaler: design and characteristics to improve outcomes.

Inhalation therapy is Likely to continue to dominate asthma treatment. The pressurised metered dose inhaler (pMDI) accounts for most of the inhaler market world-wide, but is inefficient and difficult to use. Dry powder inhalers (DPIs) have several advantages over MDIs. They are breath-activated, easy and convenient to use and environmentally friendly. The Turbuhaler is the most widely used DPI, offering good deposition with sufficient inspiratory flow, but it provides no confirmation of dosing, exhibits high dose variation, has a high intrinsic resistance, and inspiratory flow profile-dependent drug deposition. The Novolizer (VIATRIS, Frankfurt, Germany) is a new DPI which has several characteristics of an 'ideal' inhaler. It is convenient and easy to use, demonstrate and teach, provides accurate and consistent drug delivery and provides patients with feedback of dose taken. The Novolizer is a promising new delivery system for inhalation therapy.

Anti-Asthmatic Agents↗

Inhalation injuries.

Inhalation injuries occur in approximately one-third of all major burns and account for a significant number of deaths in those burn patients each year. Victims die as a result of carbon monoxide poisoning, hypoxia, and smoke inhalation. These deaths can occur without thermal wounds as well as with burn injuries. There are three distinct problems with inhalation injuries: thermal burns of the upper airway, carbon monoxide poisoning, and smoke inhalation. Each has different symptoms and signs, different treatment, and different prognosis. Thermal burns occurring in the upper airway are usually manifested within 48 hours of injury. Diagnosis is made by direct visualization of the upper airway, looking for signs of thermal injury. Admission for observation with humidified oxygen, attentive pulmonary toilet, bronchodilators as needed, and prophylactic endotracheal intubation as indicated are the mainstays of treatment. Resolution of the injury usually occurs within days. Carbon monoxide poisoning, the most common cause of death in inhalation injury, is a result of combustion. Symptoms and signs correlate with blood levels, but arterial blood gases are used to determine the degree of carbon monoxide intoxication. Treatment is based on the principle that carbon monoxide dissociation occurs much faster if the patient is placed on 100% oxygen. Occasionally the patient's symptoms may persist or get worse despite adequate treatment. Smoke inhalation significantly damages normal respiratory physiology, resulting in injury progressing from acute pulmonary insufficiency to pulmonary edema to bronchopneumonia, depending on the severity of exposure. Diagnosis is based on history, but clinical findings, arterial blood gases, and fiberoptic bronchoscopy are helpful. Treatment is supportive with careful attention paid to fluid resuscitation in the patient with burns.(ABSTRACT TRUNCATED AT 250 WORDS)

Burns, Inhalation↗

A review of the specialties that care for inpatient burns and smoke inhalation in the English counties of Lancashire and South Cumbria.

Prevention is by far the best strategy to minimise the burden of burns and smoke inhalation injuries on public health. However, it is inevitable that some injuries will occur despite the best attempts to prevent them. We must, therefore, optimise treatment in order to restore individuals to the best possible condition. Previous experience has shown that a wide range of specialties, many of which are untrained in burn care medicine, are involved in the care of inpatient burns/smoke inhalation victims in the UK. In light of this, a local review of which specialties care for such injuries was conducted for the population of Lancashire and South Cumbria in the north-west of England. Using population-based health authority data from 1997 to 1999, all Hospital Episodes relating to a primary diagnosis of burns or smoke inhalation were ascertained. The results showed that 41% of all burns episodes were treated by specialties other than burns/plastics. The short lengths of stay in non-plastics/burns specialties suggest that relatively minor injuries are being admitted to these units. Analysis of smoke inhalation injuries showed admission to various different specialties. Admission to burn services ensures that key specialties are available for the care of complex burn injuries. These multidisciplinary teams include burn nurses, burn surgeons and burn anaesthetists/intensivists. From the data available, it was not possible to assess the appropriateness of admission of burns and smoke inhalation injuries to the various branches of medicine. In order to assess appropriateness, we need information on severity of injury and outcome of treatment in each specialty. Further research in this area is required since it is concerning that many burns/smoke inhalation injuries are being treated by specialties with no formal training in burn care medicine. This may have major implications for service planning alongside changes in referral patterns.

Burns, Inhalation↗

Metabolic regulation of cardiac output during inhalation anaesthesia in dogs.

BACKGROUND: The metabolic regulation of tissue blood flow manifests itself in a linear relation between blood flow and oxygen consumption, the latter being the independent variable. It is unknown, however, if this fundamental physiological principle operates also during inhalation anaesthesia known to be associated with decreases in both cardiac output (Q) and oxygen consumption (VO2). METHODS: Seven dogs (23-32 kg) with chronically implanted flow probes around the pulmonary artery were repeatedly anaesthetized with halothane, enflurane, isoflurane, sevoflurane, and desflurane at increasing minimum alveolar concentrations (1-3 MAC). Cardiac output (ultrasound transit-time flowmeter) and VO2 (indirect calorimetry) were measured continuously. We also imposed selective changes in Q, and thus of O2 supply, to see if and to what extent this would alter VO2 during anaesthesia (1.5 MAC). RESULTS: In awake dogs under basal metabolic conditions, VO2 was 4.6 +/- 0.1 ml.kg-1.min-1 and Q 105 +/- 3 ml.kg-1.min-1 (mean +/- SEM). During inhalation anaesthesia, VO2 and Q decreased by approximately 30% and 60%, respectively. The concentration-effect relations of both variables did not differ between anaesthetics, yielding a uniform Q/VO2 relation, which was nearly linear in the range (0-2 MAC) with an average slope of 39 +/- 1 (range 30-55). Above 2 MAC, Q decreased more for a given change in VO2, and O2 extraction increased by 50%, indicating compromised oxygen delivery (DO2). Imposed changes in Q, both in awake and anaesthetized dogs, yielded Q/VO2 relations which were notably steeper (slopes 114 to 187) than those observed during inhalation anaesthesia. More important, imposed increases in Q and thus DO2 during anaesthesia (1.5 MAC) to rates comparable to that in the awake state produced a much less than proportional increase in VO2 without restoring it to baseline. CONCLUSIONS: Inhalation anaesthesia is characterized by a uniform Q/VO2 relation with an almost linear course at an anaesthetic concentration up to 2 MAC, regardless of the anaesthetic. Metabolic regulation of blood flow apparently operates also during inhalation anaesthesia up to 2 MAC so that the decrease in VO2 determines Q. This implies that cardiac output alone provides little information on the function of the circulation during inhalation anaesthesia unless related to metabolic demands, i.e. to VO2.

Anesthesia, Inhalation↗

Dose-response relationship and reproducibility of urinary salbutamol excretion during the first 30 min after an inhalation.

AIMS: To determine the reproducibility and dose-response relationship for urinary salbutamol excretion post inhalation. METHODS: Fifteen volunteers inhaled either one, two, three, four or five doses of 100 micro g salbutamol on separate days and then seven of these also repeated each of the one, three and five doses on five occasions. After each study dose urine was collected 30 min post inhalation. RESULTS: The mean (SD) 30 min urinary salbutamol after one, two, three, four and five doses was 2.61 (1.0.), 5.47 (1.59), 8.68 (2.73), 12.34 (3.96) and 15.99 (4.50) micro g, respectively. Statistical analysis revealed a linear relationship (P < 0.001). Mean (SD) coefficient of variation after one, three and five doses was 10.5 (3.6), 10.1 (2.7) and 9.4 (2.3)%. CONCLUSIONS: The 30 min salbutamol urinary excretion post inhalation pharmacokinetic method, to compare inhaled products, is linear with inhaled dose and reproducible.

Administration, Inhalation↗

Combined inhalation of nitric oxide and oxygen in patients with moderate to severe COPD: effect on blood gases.

Inhaled nitric oxide (NO) has been reported to improve oxygenation in patients with COPD if administered in combination with oxygen (O2). Little, however, is known about the variability of these effects and the potential influence of body position. Twenty-six spontaneously breathing patients with moderate to severe COPD inhaled clean air, O2(FiO2, 0.29), 5 ppm NO, 5 ppm NO+O2, 10 ppm NO+O2, 10 ppm NO, and again clean air in an upright position. Blood gas analysis from arterialized capillary blood was performed after each inhalation. Tests were repeated on different days to assess the variability of the response. Furthermore, eight patients were studied in both upright and supine position while inhaling 5 ppm NO in the presence or absence supplemental O2. As compared to clean air, NO led to a mean decrease in PaO2 of -0.9 mmHg at 5 ppm and of -2.8 mmHg at 10 ppm NO. Similarly, NO+O2 led to a dose-dependent fall in PaO2 of -1.8 and -3.6 mmHg, respectively, as compared to O2. Average within-subject variation (SD) of the effects elicited by 5 and 10 ppm NO was 2.4 and 2.3 mmHg without additional O2, and 4.7and 5.3 mmHg with O2. The effects of 5 ppm NO+O2 differed significantly between upright and supine position; as compared to O2 alone, mean (SD) changes were -3.7 +/- 5-8 vs. +1.1 +/- 4.9 mmHg, respectively. Our findings suggest thatthe addition of NO to inhaled oxygen, when given in an upright position, does not lead to an improvement of PaO2 in patients with moderate to severe COPD. Furthermore, it turned out that it was not possible to define responders and non-responders to inhaled NO on an individual basis, since the variability ofthe responses was similar to the mean

Administration, Inhalation↗

Inhaled nitric oxide for premature infants with severe respiratory failure.

BACKGROUND: Inhaled nitric oxide is a controversial treatment for premature infants with severe respiratory failure. We conducted a multicenter, randomized, blinded, controlled trial to determine whether inhaled nitric oxide reduced the rate of death or bronchopulmonary dysplasia in such infants. METHODS: We randomly assigned 420 neonates, born at less than 34 weeks of gestation, with a birth weight of 401 to 1500 g, and with respiratory failure more than four hours after treatment with surfactant to receive placebo (simulated flow) or inhaled nitric oxide (5 to 10 ppm). Infants with a response (an increase in the partial pressure of arterial oxygen of more than 10 mm Hg) were weaned according to protocol. Treatment with study gas was discontinued in infants who did not have a response. RESULTS: The rate of death or bronchopulmonary dysplasia was 80 percent in the nitric oxide group, as compared with 82 percent in the placebo group (relative risk, 0.97; 95 percent confidence interval, 0.86 to 1.06; P=0.52), and the rate of bronchopulmonary dysplasia was 60 percent versus 68 percent (relative risk, 0.90; 95 percent confidence interval, 0.75 to 1.08; P=0.26). There were no significant differences in the rates of severe intracranial hemorrhage or periventricular leukomalacia. Post hoc analyses suggest that rates of death and bronchopulmonary dysplasia are reduced for infants with a birth weight greater than 1000 g, whereas infants weighing 1000 g or less who are treated with inhaled nitric oxide have higher mortality and increased rates of severe intracranial hemorrhage. CONCLUSIONS: The use of inhaled nitric oxide in critically ill premature infants weighing less than 1500 g does not decrease the rates of death or bronchopulmonary dysplasia. Further trials are required to determine whether inhaled nitric oxide benefits infants with a birth weight of 1000 g or more.

Administration, Inhalation↗

Effect of smoke inhalation on viscoelastic properties and ventilation distribution in sheep.

Smoke inhalation injuries are the leading cause of mortality from burn injury. Airway obstruction due to mucus plugging and bronchoconstriction can cause severe ventilation inhomogeneity and worsen hypoxia. Studies describing changes of viscoelastic characteristics of the lung after smoke inhalation are missing. We present results of a new smoke inhalation device in sheep and describe pathophysiological changes after smoke exposure. Fifteen female Merino ewes were anesthetized and intubated. Baseline data using electrical impedance tomography and multiple-breath inert-gas washout were obtained by measuring ventilation distribution, functional residual capacity, lung clearance index, dynamic compliance, and stress index. Ten sheep were exposed to standardized cotton smoke insufflations and five sheep to sham smoke insufflations. Measured carboxyhemoglobin before inhalation was 3.87 +/- 0.28% and 5 min after smoke was 61.5 +/- 2.1%, range 50-69.4% (P < 0.001). Two hours after smoke functional residual capacity decreased from 1,773 +/- 226 to 1,006 +/- 129 ml and lung clearance index increased from 10.4 +/- 0.4 to 14.2 +/- 0.9. Dynamic compliance decreased from 56.6 +/- 5.5 to 32.8 +/- 3.2 ml/cmH(2)O. Stress index increased from 0.994 +/- 0.009 to 1.081 +/- 0.011 (P < 0.01) (all means +/- SE, P < 0.05). Electrical impedance tomography showed a shift of ventilation from the dependent to the independent lung after smoke exposure. No significant change was seen in the sham group. Smoke inhalation caused immediate onset in pulmonary dysfunction and significant ventilation inhomogeneity. The smoke inhalation device as presented may be useful for interventional studies.

Animals↗

Use of inhaler devices in pediatric asthma.

Inhalation is the preferred route for asthma therapy, since it offers a rapid onset of drug action, requires smaller doses, and reduces systemic effects compared with other routes of administration. Unfortunately, inhalation devices are frequently used in an empirical manner rather than on evidence-based awareness.A wide variety of nebulizers are available. Conventional jet nebulizers are highly inefficient, as much of the aerosol is wasted during exhalation. However, incorporating an extra open vent into the system has considerably increased the amount of drug that patients receive. Breath-assisted open vent nebulizers limit the loss of aerosol during exhalation, but are dependent on the patient's inspiratory flow. Ultrasonic nebulizers produce a high mass output and have a short nebulization time, but are inefficient for delivering suspensions or viscous solutions. Adaptive aerosol delivery devices release a precise dose that is tailored to the individual patient's breathing pattern. Nebulizers have several drawbacks, and their use should be limited to patients who cannot correctly manage other devices.Pressurized metered-dose inhalers (pMDI) are practical, cheap and multidose. However, there are several problems with their use. Breath-actuated MDI are easy to use and can be activated by very low flow. However, young children may not be able to use them efficiently. Dry powder inhalers (DPI) are portable and easy to use. They are indicated either for rescue bronchodilator therapy or for regular treatment with inhaled corticosteroids and long-acting bronchodilators. The use of spacers reduces oropharyngeal deposition and improves drug delivery to the lung. Spacers do not require patient coordination, but some general rules must be followed for their optimal use.Thus, the choice of a delivery device mainly depends on the age of the patient, the drug to be administered and the condition to be treated. Proper education is also essential when prescribing an inhalation device.

Administration, Inhalation↗