January 2002 / Volume 47 / Number 1 / Page 31
A Survey of Albuterol Administration Practices in Intubated Patients in the Neonatal Intensive Care Unit
INTRODUCTION: Aerosolized albuterol is commonly used in the treatment of neonatal respiratory illnesses. Clinical and in vitro studies have identified numerous factors that affect aerosol drug delivery during neonatal mechanical ventilation, including the choice of metered-dose inhaler (MDI) or nebulizer, the use of a holding chamber, time between actuations, the volume of nebulized solution, and the position and placement of the nebulizer or MDI. Because there is no consensus on the optimal method of administration, there is probably substantial variability among institutions in how aerosolized albuterol is administered to mechanically ventilated infants in the neonatal intensive care unit (NICU). OBJECTIVE: Survey academic medical centers in the United States regarding their practices of administering aerosolized albuterol to intubated newborns in the NICU. METHODS: A survey instrument was developed that queried 18 aspects of albuterol administration in mechanically ventilated infants, including the frequency of MDI and nebulizer use, the average and maximum dose, the time between MDI actuations and following the final actuation, the use of a holding chamber, and the placement location of the holding chamber or nebulizer. Respiratory therapists and respiratory therapy managers having direct knowledge of neonatal clinical practices in their neonatal fellowship program NICUs were surveyed via telephone. Those who did not respond via telephone were surveyed via fax. RESULTS: Eighty institutions were surveyed and there were 68 respondents (85% response rate). Responders averaged 35 ± 13 NICU beds and 11 ± 5 ventilators/d. Nineteen percent of the respondents reported administering albuterol via MDI 100% of the time; 22% use MDIs 75-99% of the time; 9% use MDIs 50-74% of the time; 4% use MDIs 25-49% of the time; and 43% never use MDIs to deliver albuterol. The average dose via MDI was: 1 puff: 30%; 2 puffs: 65%; and 4 puffs: 5%. The maximum dose via MDI was: 2 puffs: 30%; 3 puffs: 14%; 4 puffs: 36%; 6 puffs: 11%; and 8 puffs: 6%. Thirty-one percent of the respondents place the holding chamber in-line with the ventilator circuit, 56% administer the aerosol via manual ventilation, and 13% use both methods. Fifty-six percent place the in-line holding chamber between the endotracheal tube and ventilator circuit, and the other 44% place the in-line holding chamber in the inspiratory limb. The time between MDI actuations depended on whether the holding chamber was placed in-line or the aerosol was administered via manual ventilation (MV): < or = 0.5 min: 18% in-line and 28% MV; 1 min: 47% in-line and 43% MV; 2 min: 6% in-line and 4% MV; 3 min: 6% in-line and 0% MV. Eighty-three percent of respondents indicated that dead space introduced by a holding chamber/spacer was not a concern. Forty-three percent use nebulizers exclusively to administer albuterol to mechanically ventilated patients. Seventy-four percent of centers that nebulize albuterol use a dose of 1.25-2.5 mg. Eighty-eight percent of the surveyed institutions place nebulizers in-line with the ventilator circuit, and the other 12% use manual ventilation to administer the nebulized aerosol. Of those that use in-line nebulization, 95% place the nebulizer in the inspiratory limb of the circuit, and the other 5% place the nebulizer between the endotracheal tube and circuit Y-piece. Among centers that place the nebulizer in the inspiratory limb, 52% place it adjacent to the circuit Y-piece, 36% place it midway upstream in the inspiratory limb, and 12% place it near the humidifier. CONCLUSION: There is substantial variability among NICUs in albuterol administration to mechanically ventilated infants, with the majority of institutions now administering albuterol via MDI.
Key words: albuterol, adrenergic beta agonists, administration, inhalation, nebulizer, ventilator, metered-dose inhaler, MDI, neonatal.
[Respir Care 2002;47(1):31-38]
Albuterol is commonly used in the treatment of neonatal respiratory illnesses such as bronchopulmonary dysplasia. In mechanically ventilated infants, beta agonists decrease respiratory system resistance and PCO2, and increase oxygenation, tidal volume, and respiratory system compliance. One goal in treating mechanically ventilated newborns with aerosolized medication is to optimize drug delivery through the ventilator circuit and to the lungs. Clinical and in vitro studies have identified numerous factors that affect aerosol drug delivery during neonatal mechanical ventilation, including the choice of metered-dose inhaler (MDI) or nebulizer, the use of a holding chamber, time between actuations, the volume of solution nebulized, and the position and placement of the nebulizer or MDI. Despite a substantial amount of research on this subject, there remains a lack of consensus on the optimal method of administering albuterol, and there is probably substantial variability among neonatal intensive care units (NICUs) in the administration of albuterol.
Historically, wet nebulization has been the most common method of administering albuterol to mechanically ventilated neonates. In a 1996 survey (unpublished data), we found that 85% of NICUs never used MDIs. That may have been because of the perceived risks of using MDIs and spacers with small babies. In 1991, the American Respiratory Care Foundation and the American Association for Respiratory Care published an Aerosol Consensus Statement, which stated that “in-line MDIs should not be used in mechanically ventilated infants with a tidal volume less than 100 mL because of the potential hypoxic mixture that results from the volume of chlorofluorocarbon gas released from the MDI.” A more recent statement (1995) by the American Association for Respiratory Care regarding aerosol delivery to neonatal and pediatric patients warns that “additional dead-space volume can occur when a spacer device is placed at the end of an artificial airway.” Despite these warnings, it appears that the use of MDIs in mechanically ventilated patients has increased in recent years. This may be because of the several potential advantages MDIs have over nebulization, including more efficient drug delivery to the lung, no required adjustment of ventilator settings, less risk of aerosolized bacterial contamination associated with nebulizer treatments, less personnel time, and lower hospital costs and charges. Our literature search found no data on how clinicians are administering aerosolized albuterol to mechanically ventilated neonates, nor recent information on the extent of MDI use in NICUs, so we surveyed NICUs at academic medical centers regarding their aerosolized albuterol administration practices with intubated NICU patients.