Ventilator-associated pneumonia (VAP) is frequently triggered by bacteria that are resistant to antibiotics, and is considered the most prevalent infection acquired in a hospital setting. Although there are guidelines for VAP diagnosis and treatment, therapy still varies significantly among institutions, which may account for increased mortality rates among VAP patients.
In fact, a new restrospective study suggests that prescription errors in antibiotics doses may be the most important factor in determining patient outcomes and mortality.
The study, Ventilator-associated pneumonia: the influence of bacterial resistance, prescription errors, and de-escalation of antimicrobial therapy on mortality rates, was published in The Brazilian Journal of Infectious Diseases.
VAP refers to pneumonia that develops in patients mechanically ventilated at the hospital, more than 48 hours after intubation. This medical procedure compromises the integrity of the lower respiratory tract (oropharynx and trachea), allowing the invasion by microorganisms. The management of this condition still varies greatly between medical institutions.
“The aim of this study was to evaluate factors influencing the mortality of patients diagnosed with VAP, including bacterial resistance, prescription errors, and de-escalation of antimicrobial therapy [interruption or limitation of antibiotic exposure to avoid the occurrence of resistant bacteria],” Dr. Ana Carolina Souza-Oliveira, MD, and her colleagues at Federal University of Uberlândia in Brazil wrote in the study.
The researchers found that de-escalation of antibiotic therapy or presence of multi-drug resistant bacteria (such as Pseudomonas aeruginosa and Acinetobacter baumannii) did not influence mortality. However, the inappropriate antimicrobial loading doses and lack of dosage adjustment for renal function did had an impact on patient survival.
This was “probably due to an inability to reach proper antimicrobial concentrations at the target site,” the authors wrote. “The lack of knowledge and attention in the initial administration of higher doses or at shorter intervals were determinant for the development of unfavorable outcomes among these patients.”
The authors analyzed the ICU medical records of 467 predominantly male patients with an average age of 50, of whom 132 were diagnosed with VAP, according to the criteria established by the American Thoracic Society and the Infectious Diseases Society of America. The records were from Jan. 1 to July 31, 2013.
They analyzed the specifics of the treatment given to these patients, such as whether prescription followed laboratory analyses, or errors in antibiotic administration (choice of antibiotic, dose administered, interval between doses, delay in starting therapy, adjustment to body weight and to renal function), and compared these to the guideline recommendations for treatment therapy.
The negative outcome — a mortality rate of 35 percent among these patients — was found to be due to the toxic levels of antibiotics when the indicated dose was not reduced, and negligence in prescribing an extra dose after hemodialysis. Chronic diseases such as diabetes mellitus and heart and lung disease were also associated with the poor prognosis of patients with VAP.
The results of this study emphasize the negative impact of prescription errors, as these can lead “not only to inadequate clinical response and increased morbidity and mortality, but also (…) to increased bacterial resistance,” the authors wrote.
It is very important to ensure proper VAP treatment and to continually evaluate patients to control whether the clinical response helps patients survive the illness.