Metered-dose inhalers (MDIs) have been available for more than 50 years and are routinely used to deliver inhalation therapy to patients with asthma and chronic obstructive pulmonary disease. Given the ever-escalating costs of health care, various measures have been targeted by hospitals or health systems to eke out savings. Given the ubiquity of MDIs in the ICU, collaborative efforts by administrators and clinicians have focused on MDIs. These efforts, intended to curb rising costs and waste associated with MDI use, have resulted in a variety of protocols generically referred to as common canister policies (CCPs). While the concept of CCPs came into existence in the mid-1990s, casual observation suggests they are gaining momentum at hospitals and long-term care facilities. Most data regarding CCPs come from abstracts or posters; few studies have been published in peer-reviewed journals. Data on the efficacy and safety of CCPs in the ICU are particularly limited. Although most reports on CCPs have originated in community-based hospitals, some academic medical centers have also explored this concept.
What is common canister policy?
CCPs allow a single MDI canister to be shared among patients in a designated care area (typically a ward or ICU), with each individual having his/her own one-way valve holding chamber or spacer (Larson T, et al. Curr Med Res Opin. 2015;31[4]:853). Each patient care unit or respiratory therapist has a set of inhalers to use until actuations run out, at which point new inhalers are delivered from the pharmacy. Because the holding chamber or spacer is not shared, the risk of patient-to-patient spread of disease is minimized. In addition, the provider involved in administration of the inhaler must follow a standardized cleaning protocol to ensure the common canister is sterilized after each use.
This policy is designed to be used with inhaled therapies delivered by MDI (albuterol, ipratropium, albuterol/ipratropium, fluticasone, budesonide/formoterol, fluticasone/salmeterol). CCP does not apply to other types of inhalers, such as dry powder or mist inhalers, because the use of a separate holding chamber or spacer is not feasible with these devices. CCP savings are realized through a reduction in the number of MDIs purchased and the ability of patients to be charged per inhalation of medication delivered. An alternative CCP practice is to issue an MDI to a single patient and, upon his/her discharge, to clean and reissue the patient’s partially used MDIs to subsequent patients until the medication is exhausted (Liou J, et al. Hosp Pharm. 2014;49:437).
What are the risks and benefits of CCP?
CCP was implemented to minimize costs associated with drug wasting, since patients would not need individual inhalers. Some analysts believe dispensing individual inhalers creates an inherent financial burden as the average length of stay for an acute respiratory hospitalization is 4-5 days (Larson T, et al). This concern appears valid as two studies of MDI and dry powder inhaler use in real-world practice found that 11%-13% of the total amount of drug was utilized, leaving 87%-89% of each device wasted at a cost of approximately $87,000 annually (Larson T, et al; Sakaan S, et al. Hosp Pharm. 2015;50[5]:386).
In addition to cost reductions, one study showed CCP reduced delays in delivery of MDI therapy to patients because the lag time between order entry and delivery of the MDI to the floor was eliminated (Filippelli A, et al. Abstract, ASHP Midyear Clinical Meeting, Dec 1997). In this study, CCP allowed respiratory care practitioners immediate access to the common MDI for their entire shift, creating more efficient delivery of MDI treatments. On a par with findings in prior studies, these investigators observed a 55% reduction in hospital purchase costs for MDIs. Patient-level costs were similarly reduced, as each patient was billed only for the number of doses administered from an MDI, rather than for an entire canister.
While CCP appears to reduce inhaler-related costs, it is still unclear whether CCP increases the risk of iatrogenic infection. There is a particular paucity of information on the use of CCP in high-risk patients – those with cystic fibrosis, those in isolation, patients receiving mechanical ventilation, and those who are post transplant or otherwise immunocompromised (Larson T, et al). These patients have an inherently increased risk of developing nosocomial infections including ventilator-acquired pneumonia. A recent prospective study compared MDI CCP with single-patient MDI use in 353 patients supported by mechanical ventilation. Although CCP was associated with cost savings and similar rates of ventilator-acquired pneumonia, hospital mortality, and length of stay, there was a greater frequency of ventilator-associated events among patients in the CCP arm of the study (Gowan M, et al. Respir Care. 2016 May 3. pii: respcare.04550. [Epub ahead of print]).