Community-acquired pneumonia (CAP) is one of the leading causes of hospitalization in the United States, with 6 cases per 1000 persons per year. More than 900,000 episodes per year occur in adults aged 65 years and older. CAP is also one of the leading causes of death with more than 60,000 deaths in the United States per year. Nearly 1 in 4 persons who are hospitalized due to CAP die within the subsequent 30 days. The annual direct medical costs of care are estimated at $10 billion.
In the pre-antibiotic era, Streptococcus pneumoniae (pneumococcus) caused 95% of cases of CAP. Since the 1950s, pneumococcus has been detected less frequently as the cause of CAP, and many other pathogens have been implicated. With the arrival of newer, advanced diagnostic methods, recent studies have demonstrated that respiratory viruses are just as frequent causes of CAP as bacteria. Despite this, nearly all patients diagnosed with CAP receive antibiotic therapy. And while numerous studies have demonstrated the efficacy of 5-7 days of antibiotic therapy for bacterial pneumonia, physicians routinely prescribe 10 days or more of antibiotics.
Given the magnitude of antibiotic use associated with CAP, ensuring the correct diagnosis and appropriate therapy is critical in order to achieve clinical cure while reducing the risk of collateral damage. Some of the negative outcomes associated with unnecessary antibiotic use are increased risk of adverse drug events, increased risk of Clostridium difficile (C. diff) infection, and the propagation of further antibiotic resistance. More than 2 million infections are caused by antibiotic-resistant bacteria, leading to more than 23,000 deaths yearly in the United States alone. As overuse of antibiotics is the main contributor to antibiotic resistance, interventions aimed at reducing unnecessary antibiotic exposure are critical.
One potential strategy to limit the excessive use of antibiotics is the use of biomarkers in order to guide the need for antibiotics at the start of and during therapy to reduce antibiotic exposure without negatively impacting clinical cure. Procalcitonin (PCT) is a biomarker that is released from multiple tissues in response to a systemic bacterial infection. PCT increases quickly within 4-6 hours of the onset of a systemic bacterial infection and falls by 50% daily if the bacterial infection is controlled by effective antibiotics and the immune system. Conversely, PCT release is reduced with viral infections. Thus, PCT is able to help distinguish bacterial causes of pneumonia from viral etiologies and other non-infectious conditions.
PCT has been studied in controlled settings in which it was used to facilitate the decision of whether to start antibiotic therapy in patients with pneumonia and when antibiotics may be discontinued safely. The safety of PCT guidance in pneumonia was proven in the study environment as these randomized studies consistently demonstrated that patients in whom PCT levels were used to guide the decision to prescribe antibiotics received less antibiotic exposure within an increase in failures or death when compared to patients treated at the discretion of their physicians.
However, nearly all of the data demonstrating the safety and efficacy of PCT guidance was obtained from highly controlled study settings, while a paucity of data on the value of PCT in real-world settings exists. Thus, the Antimicrobial Stewardship Program (ASP) at 2 academic medical centers in Pittsburgh, Pennsylvania (Allegheny General Hospital [AGH] and West Penn Hospital [WPH]) developed and implemented a PCT guidance algorithm in an effort to reduce the duration of antibiotic therapy for patients with CAP. An ASP is a team of Infectious Diseases physicians and pharmacists tasked with assisting local care providers to properly use antibiotics with the goal of optimizing clinical cure while minimizing the unintended collateral damage associated with unnecessary antibiotic use.
To enhance compliance with the PCT guidance algorithm, the ASP team members used several educational methods. An email was sent to all physicians notifying providers that AGH and WPH started to offer PCT as a clinical tool while providing background information, clinical trial data, and the proposed role for PCT at AGH and WPH in the management of patients with CAP. The PCT guidance clinical decision-making algorithm was disseminated to all physicians via email and incorporated into the hospitals’ yearly Antibiotic Guide, which is made available in print and on the hospitals’ intranet site. Laminated copies were posted at nursing units and physician work areas and offices. Additionally, numerous educational lectures were delivered to various groups of physicians.
The ASP team members compared management of patients hospitalized with CAP before and after implementation of the PCT guidance algorithm at AGH and WPH. When compared to the pre-PCT group, the average duration of antibiotic therapy decreased from 10 days to 6 days. More patients received an appropriate duration of 7 days or less of therapy in the post-intervention group. Additionally, the average length of hospitalization decreased in the post-intervention group of patients. And while the patients in the post-intervention group received less antibiotic exposure, they did not suffer higher 30-day pneumonia-related re-admission rates when compared to the pre-PCT guidance group.
Thus, in this real-world analysis, the ASP team was able to demonstrate that PCT, when employed with extensive education and ASP guidance, led to shorter durations of total antibiotic therapy and abbreviated duration of hospitalization without negatively impacting hospital re-admissions. This is one of the very few real-world studies evaluating the impact of PCT guidance in the management of CAP.
These findings are described in the article entitled Impact of Procalcitonin Guidance with an Educational Program on Management of Adults Hospitalized with Pneumonia, recently published in The American Journal of Medicine. This work was conducted by Thomas L. Walsh, Briana E. DiSilvio, Crystal Hammer, Moeezullah Beg, Swati Vishwanathan, Daniel Speredelozzi, Matthew A. Moffa, Kurt Hu, Rasha Abdulmassih, Jina T. Makadia, Rikinder Sandhu, Mouhib Naddour, Noreen H. Chan-Tompkins, Tamara L. Trienski, Courtney Watson, Terrence J. Obringer, Jim Kuzyck, and Derek N. Bremmer from the Allegheny Health Network.