Principles of Antibiotic Prescription in Intensive Care Unit Patients and Patients With Acute Renal Failure

Intensive care units (ICUs) are unique because they provide confined accommodations for the critically ill patient, where antibiotic use is extremely common. They are often the center of infections; it is estimated that 37% to 51.2% of all ICU patients are treated for infection during their stay. This increased risk is secondary to the extreme vulnerability of its population; the use of multiple procedures, each with a high potential for infection; and the use of invasive devices distorting the anatomic integrity-protective barriers of patients. In addition, several drugs may be administered that also predispose for infections such as pneumonia (e.g., by reducing the cough and swallow reflexes [sedatives, muscle relaxants]) or distort the normal nonpathogenic bacterial flora (e.g., stress ulcer prophylaxis).

It has been estimated that more than 20% of all nosocomial infections occur in the ICU. In the setting of these nosocomial infections, antimicrobial resistance has emerged as a major concern and an important determinant of outcomes for patients in the ICU. This is largely secondary to the use of inappropriate antibiotics in the increasing presence of organisms that are resistant to current antibiotics. In a study looking at 2000 ICU patients, inadequate antibiotic therapy for nosocomial infections in the ICU occurred in 8.5% and had an associated mortality of 52.1%. According to the EPIC II 1-day prospective point-prevalence study (Extended Prevalence of Infection in Intensive Care) in 1265 participating ICUs (75 countries worldwide), 51% of the 12,796 patients were considered infected, although no subdivision was made for hospital-acquired infections. The pathogens that are causing these infections may be intrinsically resistant to antibiotics but also can cause resistance by inducing or evolving resistance. This has major implications for healthcare in general and particularly in the ICU, where resistant organisms can present major challenges because patients tend to be debilitated and particularly susceptible to nosocomial infection. Such infections often lead to prolonged ICU and hospital stay and consequent increased healthcare costs.