Inhalation therapy with the nebulizer and MDI (metered-dose inhaler) spacers are two methods that are often used as acute asthma therapy in children. Both methods are aimed at providing asthma drugs directly to target organs so that the effects of treating asthma attacks are immediately achieved. If comparing the advantages of using a nebulizer and MDI spacers, which method is better?

The application of inhalation therapy is comprehensive in the field of pulmonology. Asthma in children is a chronic disease and has the potential to affect the child's quality of life. During an asthma attack, the airway becomes narrow, causing breathing difficulties. Initial therapy for asthma attacks is inhalation therapy to open the airway so that the patient can breathe adequately.

Advantages and disadvantages of inhalation therapy

The advantage of inhaled therapy in the respiratory system is the administration of drugs directly to the target organ, so that the onset of action is faster, requires fewer doses, and does not pass through the first-pass metabolism. However, inhalation therapy requires education to parents and children on how to apply it correctly.

The currently available inhaled asthma drug is the β2 short-acting beta-agonist (SABA). Salbutamol is the first choice drug in mild-to-moderate asthma attacks and can be given at home or first-level health care facilities. Salbutamol dose for nebulizer is 2.5 mg for children aged <5 years, and 5 mg for children over 5 years. While the dose of salbutamol in the form of MDI spacer (100 mcg/spray) can be given 2-6 sprays each attack for children <5 years, and 4-12 sprays for children over 5 years. MDB salbutamol spacer can be given as much as 2 sprays 15 minutes before or during heavy physical activity, such as sports, to prevent exercise-induced asthma / EIA.

Several Types of Inhalation Devices

To provide per-inhalation therapy, inhalation equipment that can release aerosols containing the drug is needed so that the patient can inhale it. Some types of inhalation devices are nebulizers, Metered Dose Inhalers (MDI), or Dry Powder Inhalers (DPI).

A. Nebulizer Devices
The nebulizer's working principle is changing the drug in the form of a solution or suspension into aerosols. There are 3 types of nebulizers, namely:
  1. jet nebulizers, 
  2. ultrasonic nebulizers 
  3. mesh nebulizers.

The disadvantages of nebulizer are: 

  • the technique is not easy to use, 
  • higher costs, 
  • sometimes the drug's dose is incorrect.
Some errors in applying nebulizers at home, which are often encountered, are:
  • the improper assembly of devices, 
  • improper interface selection, 
  • improper fill-volume or flow, 
  • drug spills caused by oblique nebulizers, 
  • failure to place mouthpieces in the mouth during the nebulization process, and leakage around the face.

B. Metered Dose Inhaler (MDI)
MDI is the most widely used inhalation equipment outside the clinic at present.

The MDI advantages are:
small in size, portable, affordable, and convenient to use. 

The MDI disadvantages are:
However, the use of MDI requires adequate coordination between hands and inspirational abilities, so inhalation therapy with MDI must be given to children who can coordinate well.

Errors that often occur in the use of MDI are:
  • Poor coordination between hands and breath,
  • holding breath that is too short,
  • inhaling too fast,
  • less shaking the inhaler,
  • stop suddenly during inhalation,
  • number of sprays in one breath,
  • and spray through the mouth but inhale through the nose.

Since the early 1990s, the use of MDI with spacers began to be used as initial therapy for mild and moderate asthma exacerbations in children. Its use can reduce the number of visitation of children in the emergency room. MDI spacer is considered safe and effective as the initial therapy of asthma in children because it can eliminate the mistakes of using MDI without spacers.

C. Dry Powder Inhaler (DPI)
The working principle of DPI is to change drugs from dry powder to aerosols. The use of DPI requires sufficient inspiratory power (30-90 L / min) to ensure an optimal inhalation dose.
Children under 5 years old have difficulty breathing enough, so they are not advised to use DPI.
Another disadvantage of using DPI is the mistake of blowing DPI, which can cause the powder to come out of the chamber, and cause the medicine powder to become moist so that it is difficult to be broken down into aerosols. Before applying DPI, it is advisable not to shuffle because it can reduce drug levels.

Selection of Inhalation Devices for Children

One of the factors considered in the selection of inhalation devices is the age of the patient.
  • In patients aged 0-3 years, inhalation as reliever or controller, use MDI spacer and nebulizer.
  • In patients aged 3-5 years, use MDI spacers and nebulizers as relievers, whereas controllers DPI can already be used if the child can be cooperative.
  • For children over the age of 5 years, the use of MDI spacers or DPI as the primary therapy for both relief and control is recommended.

Comparison of Nebulizer Use with MDI Spacers at Home

The management of asthma attacks aims to overcome the narrowing of the respiratory tract as quickly as possible. The use of MDI spacers lately is preferred for non-severe, non-life-threatening acute asthma attacks, rather than nebulizers. The reasons are:
  • The use of a nebulizer is more time consuming because children need to sit still for at least 5 minutes, require gas pressure or a source of electricity to drain the drug, increase the risk of cross-infection, and require routine tool maintenance.
  • Nebulizer costs more because it requires disposable masks.
  • The use of MDI spacers can improve patient compliance.
  • MDI is more practical because the drug is released in the spacer after the MDI is shaken and pressed, then the child breathes as usual.
  • MDI can be carried by children everywhere so that it can reduce the cost and dosage of use.
  • MDI spacers produce lower systemic side effects than nebulizers. However, the choice of inhalation device use must be based on the patient's age and indications.

There has been no research on the use of inhalation devices, both nebulizers, and MDI spacers, with settings at home. Some clinical trials stated that treatment in the clinic and the emergency room could be compared to the situation in the community.

A systematic study of 6 trials, subject 491 children aged <5 years with acute exacerbation of asthma in the emergency department, compared the administration of beta-agonists per inhalation using MDI spacers and nebulizers. This study showed a significant decrease in hospitalization in patients using MDI spacers rather than nebulizers (OR, 0.42; 95% CI, 0.24-0.72; P = 0.002). This reduction was even more significant in pediatric patients with moderate to severe exacerbations (OR, 0.27; 95% CI, 0.13-0.54; P = 0.0003). Also, the use of MDI spacers is more effective in increasing a patient's clinical score than using the nebulizer.

Another meta-analysis study by Cochrane, 2013, reviewed 39 clinical trials (1897 pediatric patients) that compared the effectiveness of administering beta-agonists per inhalation using MDI with nebulizers in the emergency room and the community (33 clinical trials), as well as in the inpatient ward (6 clinical trials). The results show that in pediatric patients who use nebulizers are no better than MDI spacers in preventing hospitalization, and pulmonary function outcomes are the same. However, the length of stay in the emergency department is significantly shorter in pediatric patients who use MDI spacers, which is an average of less than 33 minutes, while those using nebulizers require an average stay of 103 minutes.

Applying MDI spacers can be used as the primary choice in administering inhaled drugs to children with acute exacerbation of asthma. Although in terms of pulmonary function outcomes the same, both beta-agonist administration using a nebulizer and MDI spacers, but MDI spacers have more advantages. Some of the advantages of using MDI spacers at home are the effectiveness of shorter use, lower cost, practically it can be used anytime and anywhere, as well as minimal side effects from devices and drugs.