Albuterol delivery via metered dose inhaler in a spontaneously breathing pediatric tracheostomy model

Tracheostomy decision making: From placement to decannulation

Over the last few decades, greater numbers of tracheostomies have been performed in medically complex and fragile children to manage upper airway obstruction, progressive neuromuscular disorders, abnormal ventilatory drive and to facilitate airway clearance. The optimal timing of tracheostomy tube placement and methods to determine suitable patients for the procedure remain unclear. Caring for children with tracheostomies can have a considerable financial and psychosocial impact on a family. Pediatric patients with tracheostomies have a 2-3 fold greater morbidity and mortality compared to adult patients. Clinicians should provide as much clarity as possible for families on the positive and negative aspects of pediatric tracheotomies and long term mechanical ventilation prior to tracheostomy placement. Tracheostomies are often placed as a bridge, whilst time for healing, growth and other therapies are needed to help overcome the indication for tracheostomy. Suitable investigations used to determine the optimal timing of decannulation remain physician and institution dependent.

Aerosol Delivery to a Critically Ill Patient: A Big Issue Easily Solved by Developing Guidelines

Nowadays, therapeutic aerosols are commonly delivered to mechanically ventilated patients by nebulizers and pressurized metered dose inhaler attached to an adapter or a spacer. Studies with asthmatics and chronic obstructive pulmonary disease patients have confirmed that aerosol delivery during mechanical ventilation is feasible. They have also reported that the inhaled drugs administered during mechanical ventilation provide greater and faster clinical outcomes than when delivering during spontaneous unassisted breathing. Researchers studied factors that would affect aerosol delivery during mechanical ventilation. Even with the tremendous amount of publications in this area, there have still been no recommendations or guidelines released to help respiratory therapists in their decision as to when to deliver aerosol to ventilated patients. Mostly, respiratory therapists read the literature and decide accordingly what to do and which device to use for their patients. This puts the patients at risk of receiving a sub-therapeutic or toxic dose of the inhaled aerosol. Some studies raise an alarm of physician decision upon reading any released publication related to aerosol delivery in mechanical ventilation without a trusted recommendation and guidelines. This increases the need for the development of recommendations and guidelines, by a trusted board or society, for aerosol delivery to such critically ill patients. To summarize, inhaled drugs administered to critically ill patients is of benefit compared to taking the patient off the ventilator and delivering during spontaneous unassisted breathing. However, dependable guidelines are needed to optimize aerosol delivery.

Inhaled salbutamol dose delivered by jet nebulizer, vibrating mesh nebulizer and metered dose inhaler with spacer during invasive mechanical ventilation

BACKGROUND

Patient receiving invasive mechanical ventilation (IMV) may benefit from medical aerosol, but guidance on dosing with different aerosol devices is limited to in-vitro studies. The study was designed to compare aerosol delivery with five different types of aerosol generators during IMV.

METHOD

In randomized design, 60 (30 female) mechanically ventilated chronic obstructive pulmonary disease (COPD) patients were assigned to one of 5 groups. Groups 1-4 received 5000 μg salbutamol using Aerogen Pro (PRO), Aerogen Solo (SOLO), NIVO vibrating mesh and jet nebulizers (JN), respectively, while group 5 received 800 μg (8 puffs) of salbutamol via metered dose inhaler with AeroChamber-MV (MDI-AC). All devices were place in the inspiratory limb of ventilator downstream from humidifier which was switched off while delivery. Patients received the inhaled dose on day 1 and provided urine 30 post dosing. They also recived the same inhaled dose with a filter before the endotracheal tube on day 2. Amount of salbutamol excreted in urine 30 min post inhalation and the amount deposited on the filter from all the COPD patients were determined as indeces of pulmonary deposition and systemic absorption, respectively.

RESULTS

No significant difference was found between the 3 vibrating mesh nebulizers (VMNs). The in-vivo and ex-vivo testing showed that all the VMNs resulted in better aerosol delivery compared to JN (p < 0.01). However, MDI-AC resulted in better aerosol delivery to VMNs but must be accompanied with careful attention and proper delivery of MDI-AC doses by healthcare provider.

CONCLUSIONS

VMNs can be exchanged with each other, with no dose adjustment. However, dose adjustment is a must when replacing VMNs by JN or MDI-AC. This similarity and difference between the 5 aerosol delivery methods suggest that for IMV patients, aerosol delivery methods should be chosen or substituted with care.

In-vitro/in-vivo comparison of inhaled salbutamol dose delivered by jet nebulizer, vibrating mesh nebulizer and metered dose inhaler with spacer during non-invasive ventilation

BACKGROUND

Patients receiving noninvasive ventilation (NIV) may benefit from medical aerosol, but most guidance on dosing with different aerosol devices is limited to in-vitro studies. The study was designed to in-vitro, ex-vivo, and in-vivo compare aerosol delivery during bilevel NIV with three types of aerosol generators: metered dose inhaler with AeroChamber-MV spacer (AC), Aerogen Pro vibrating mesh nebulizer (PRO), and Sidestream jet nebulizer (SIDE).

MATERIALS AND METHOD

A bilevel ventilator with dry single limb circuit and fixed expiratory port was set in spontaneous mode with initial inspiratory and expiratory pressures of 20 and 5 cmH₂0, 1:3 inspiratory-expiratory ratio, and 15 breaths.min^-1. Aerosol generators were placed proximal to facial mask of NIV chronic obstructive pulmonary disease (COPD) patients. 1 mL salbutamol nebulizer solution (5 mg/mL) was nebulized using PRO and SIDE. 12MDI doses, containing 100μg salbutamol each, were delivered using AC. In-vitro aerosol fate and aerodynamic droplet characteristics, in-vivo amount of salbutamol excreted 30 mins and pooled up to 24 h post inhalation in urine from 12 COPD patients (as indices of pulmonary deposition and systemic absorption, respectively) and amount of salbutamol deposited on ex-vivo filters (expected inhalable amount) was determined.

RESULTS

The in-vitro, in-vivo and ex-vivo testing showed that PRO had better aerosol delivery compared to SIDE (p < 0.01). However, with smaller nominal dose MDI with AC resulted in similar aerosol delivery to PRO suggesting better aerosol delivery stress on careful attention and proper delivery by health care provider.

CONCLUSIONS

These similarities and differences between the three aerosol generators tested suggest that aerosol delivery methods should be carefully chosen or substituted in non-invasive ventilated patients.

Inhalation therapy in patients with tracheostomy: a guide to clinicians

INTRODUCTION

Inhalation therapy has become a popular procedure for the treatment of patients with tracheostomy. However, clinicians are faced with many challenges during inhalation therapy because of the many factors affecting aerosol therapy to this patient population, and the lack of literature providing guidance in this area of research. Areas covered: The purpose of this paper is to describe the factors affecting aerosol drug delivery to patients with tracheostomy and to explain how to optimize inhalation therapy through device selection, interface selection and delivery technique in this patient population. Expert commentary: Many factors affect inhalation therapy in this patient population and without understanding the impact of these factors on aerosol drug delivery, clinicians will not be able to provide the treatment properly and patients may not benefit from prescribed medications. In the next 5 years, aerosol medicine will continue to experience tremendous growth with new devices and drug/device combinations. However, these advances will have minimal impact on inhalation therapy in patients with tracheostomy unless we provide guidance and training to clinicians on optimizing aerosol drug delivery to this patient population.

Workshop Report: Aerosol Delivery to Spontaneously Breathing Tracheostomized Patients

The number of pediatric and adult patients requiring tracheostomy has increased. Many of them require aerosol therapy as part of their treatment. Practitioners have little guidance on how to optimize drug delivery in this population. The following is a report of a workshop dedicated to review the current status of aerosol delivery to spontaneously breathing tracheostomized patients and to provide practice recommendations.

Influence of Tracheostomy on Lung Deposition in Spontaneously Breathing Patients

BACKGROUND

Nebulized drugs are frequently administrated through tracheostomy in clinical routine. So far, the amount of drug deposited into the lung in these patients remains unknown. The aim of our pharmacokinetic study was to compare lung delivery of amikacin in the same subjects in two settings: spontaneously breathing through a tracheostomy and through the mouth.

METHODS

Lung delivery was measured by amikacin urinary drug concentration in nine patients who were transitory tracheostomized for the need of a head and neck oncologic surgery. Patients performed two nebulization sessions: with a mouthpiece (MB) and through tracheostomy (TB) using a adapted jet nebulizer (Sidestream^®).

RESULTS AND CONCLUSION

Lung delivery was similar with the two conditions of nebulization (6.5 ± 2.5% vs. 6.3 ± 2.0% of the nominal mass of amikacin, respectively, for MB and TB; p = 0.95). Duration of nebulization was also comparable (19.7 ± 1.6 vs. 20.1 ± 1.8 min, respectively, for mouth and tracheostomy breathing; p = 0.307). The half-life and elimination rate constant were not different between the two settings. We conclude that nebulized therapy can be administered in spontaneously breathing tracheostomized adults patients, with a similar amount of drug delivered to the lung compared with spontaneously mouth breathing patients.