ICU Staff Critically Ill Drug Allergy Assessment Safe, Effective

Antibiotic allergy assessment and testing for critically ill patients admitted to the ICU can be performed safely and effectively by ICU staff, according to a prospective study published in the Journal of Critical Care.

“Antibiotic allergy assessment should be the responsibility of all antibiotic-prescribing healthcare practitioners,” wrote study author Niall Conlon, MD, of St. James Hospital, and colleagues.

Independent Allergy Assessments

In this single-center study, the authors implemented an ICU antibiotic allergy assessment and testing program independent of clinical immunology/allergy services. Trained ICU staff prospectively identified 71 critically ill patients (62 of whom underwent assessment) with reported antibiotic allergies and assigned them to categories of non-immune-mediated drug reaction or low, intermediate, or high-risk antibiotic allergy.

“These patients had high illness severity scores necessitating use of level 3 ICU interventions such as invasive mechanical ventilation, high-dose vasopressor infusions, and renal replacement therapy,” the authors noted. “This differs significantly from previous studies showing the safety and effectiveness of immunology/allergy specialist-led oral drug challenge to assess low-risk penicillin allergy in patients admitted to the ICU with low illness severity scores receiving a maximum of low-intermediate dose vasopressor infusions.”

The staff members directly delabeled patients with non-immune-mediated drug reactions based on history alone, without further testing. They offered direct enteral drug provocation testing to patients with low-risk allergies to penicillin or non-penicillin antibiotics. For patients with intermediate-risk allergies, they performed skin sensitization testing, followed by enteral drug provocation testing if the skin test was negative. When patients had only parenteral access, the staff members required a negative skin sensitization test before proceeding to intravenous drug provocation testing, even in low-risk cases. They confirmed antibiotic allergy labels for patients assessed as high risk without performing testing.

“In total, 48 of 50 consenting patients (96 %) with either a non-immune, low, or intermediate risk antibiotic allergy were delabeled during the study period,” the researchers reported.

Significant Impact on Antibiotic Prescribing

“The study’s impact on antibiotic prescribing practices was significant,” the authors stated.

They reported that, following delabeling, the proportion of patients receiving penicillin increased from 14% to 64%, while use of broad-spectrum antibiotics such as carbapenems, fluoroquinolones, and glycopeptides decreased significantly.

“This shift is crucial as it may potentially lead to a reduced risk of developing MDROs [multi-drug-resistant organisms] and Clostridium difficile infections, which are associated with broad-spectrum antibiotics. The reduction in the use of these antibiotics also aligns with goals to preserve antibiotic efficacy and combat antibiotic resistance,” the researchers wrote.

The authors identified no allergic reactions during allergy testing, and no adverse events occurred as a result of assessment or testing.

Empowering ICU Staff

“This study highlights the empowerment of non-immunology/allergy staff to assess drug allergy independently,” the authors wrote. “After short, basic training, ICU doctors and nurses can safely assess and test patients with antibiotic allergy labels.”

The researchers noted that their findings provide evidence for expanding antibiotic allergy assessment to broader cohorts of ICU patients and support ICU-led allergy assessments in settings without on-site immunology or allergy services.

“By performing allergy assessments and delabeling, we can optimize antibiotic use and improve patient outcomes independent of specialist immunology or allergy assessments,” the authors concluded, adding, “Further research, including multi-center trials, is needed to validate these findings and explore the implementation of similar frameworks in diverse healthcare settings.”