Safety of Severe Asthma Care Outside the ICU Assessed

Oct 1 2014

Safety of Severe Asthma Care Outside the ICU Assessed

asthmaClinicians at The Children’s Hospital of Philadelphia have extensive experience in treating children with acute asthma flares, partly due to the tremendous volume of patients with this respiratory condition who come from the urban community nearby. Asthma is one of the leading, serious, chronic illnesses among children in the U.S., and Philadelphia ranks among the top 5 worst asthma cities.

During an asthma exacerbation, a child’s lungs and airways overreact to a certain trigger. The airways’ lining swells, and muscles surrounding the airways constrict. As these air passages narrow and become clogged with mucus, the child’s breathing becomes difficult, as if trying to get air through a pinched straw.

About 2,700 patients are admitted for asthma in a given year at The Children’s Hospital of Philadelphia, accounting for 17 percent of the total admissions. When a child with a severe asthma flare arrives at the emergency room, clinicians initiate one hour of continuous aerosolized albuterol (CAA), a quick-acting beta-agonist bronchodilator, in addition to other therapies, to relieve the patient’s shortness of breath.

If the flare is very severe, clinicians will continue continuous medication delivery when the patient is admitted to the hospital, which in many hospitals occurs in the intensive care unit. Because asthma is such a prevalent pediatric condition, often a patient with severe asthma occupies an intensive care unit (ICU) bed that is in high demand.

Chén Kenyon, MD, an attending physician in the Division of General Pediatrics at CHOP, and colleagues, wanted to find out if these patients are treated safely and effectively with CAA in the non-ICU, inpatient setting, which may free up limited ICU beds for other high acuity patients and offer significant cost-savings. Unfortunately, no published scientific data existed to support this practice, so to begin to answer the question, they conducted a retrospective cohort analysis of electronic medical record data using the CHOP Data Warehouse.

“Using this unique resource, we are able to provide much more granularity than prior studies,” Dr. Kenyon said. “We can pinpoint physician orders and see at what point a particular therapy was ordered and when it was stopped.”

A clinical pathway in place for 18 years at CHOP helps clinicians to streamline and standardize asthma care. It includes a component that allows for CAA to be administered in the non-ICU, inpatient setting for patients with severe asthma who are assessed hourly by trained respiratory therapists and nurses. The researchers combed through physician orders for CAA of 1,300 children ages 2 to 18 treated under this protocol from July 2011 to June 2013. They compared the cohort to 1,700 patients who received intermittent albuterol only and assessed the two groups’ characteristics and rate of adverse outcomes. Results from the study appeared online Sept. 29 in Pediatrics.

“There seemed to be no difference in the prevalence of low potassium or cardiac arrhythmia, two side effects associated with beta-agonists in rare situations,” Dr. Kenyon said. “While patients who received continuous aerosolized albuterol had a higher rate of transfers to the ICU, there was no difference in the rate of intubation. Zero patients in the continuous aerosolized albuterol group were intubated. These findings support the safety – and efficacy – of continuous aerosolized albuterol delivery in the non-ICU setting.”

The researchers also determined that certain factors identified initially in the emergency room predicted which patients would go on to deteriorate clinically and require prolonged therapy. These included comorbid pneumonia and administration of intravenous magnesium or subcutaneous terbutaline in the emergency room. Being acquainted with these characteristics may help clinicians in hospitals without a pediatric intensive care unit (PICU) in terms of recognition of patients at higher risk for clinical deterioration who may benefit from relocation to an institution that does have a PICU, Dr. Kenyon said.

While this retrospective study sets the stage for other hospitals to evaluate how CAA could fit within the context of their asthma protocols, Dr. Kenyon emphasized that CHOP’s success in CAA delivery outside the ICU is, at least in part, due to the support structure and care processes in place. For example, in addition to the standard nurse to patient ratio of 1 to 4 and robust expert respiratory therapy support, a critical assessment team assists front-line providers in the care of patients with severe asthma who have early signs of clinical deterioration.

“This is a first step,” Dr. Kenyon said. “There is still work to be done to figure out who the ideal cohort is for continuous therapy and what resources are necessary to make this practice safe and effective in a non-ICU setting outside of CHOP. But this study provides initial evidence for the safety and effectiveness for institutions that already are providing continuous aerosolized albuterol on their non-ICU units.”

Future studies could aim to reproduce a similar study on a multicenter level, Dr. Kenyon suggested. Researchers could perform further analysis of the data to reveal any potential cost savings that may be associated with centering CAA delivery for severe asthma cases outside the ICU. More evidence also is needed to determine the appropriate length of CAA administration, and if other modes of therapy could help to enhance patients’ recovery so that they spend less time in the hospital.