- Rational antibiotic use requires the most specific diagnosis that can be made, knowledge of commonly used antimicrobial agents, and appropriate monitoring of therapy.
- Antimicrobial prophylaxis against bacterial infections is indicated in selected patients undergoing surgical procedures and in those with cardiac valvular disease.
- When suspected infection threatens life or major organ function, antimicrobial therapy should be directed at all infectious possibilities of more than trivial probability until the results of definitive investigations are available.
- Knowledge of the clinical pharmacology of antibiotics commonly prescribed in the intensive care unit is essential for the intensivist.
The importance of antimicrobial drugs in the management of patients admitted to the intensive care unit (ICU) is beyond question. The prevention and treatment of infections in ICU patients pose formidable challenges despite advances in our understanding of the pathophysiology of specific infections, the availability of more rapid, sensitive, and specific diagnostic tests, and an array of potent antimicrobial agents.
Prophylaxis of Infectious Diseases in ICU Patients
The efficacy of short-term systemic antibacterial administration to prevent operative site infections after surgery is well established. Effective prophylaxis requires that the antibacterial agent inhibit specific pathogenic agents that cause the infection and be present at therapeutic concentrations in the operative site at the time the incision is made. It is imperative that surgical wound prophylaxis be prescribed, when appropriate, in the management of ICU patients. Recommended drugs, doses, and duration of prophylaxis for some specific surgical procedures are listed in Table 45-1.1
Table 45–1. Recommended Antibiotic Prophylaxis for Some Commonly Performed Surgical Procedures |Favorite Table|Download (.pdf)
Table 45–1. Recommended Antibiotic Prophylaxis for Some Commonly Performed Surgical Procedures
|Surgical Procedure||Recommended Prophylactic Regimena|
|Cesarean section||Cefazolin (1 g IV) after clamping the cord and 6 and 12 h|
|Prophylaxis is not indicated in uncomplicated elective procedures|
|Uterine irrigation with antibiotics may be comparable to systemic therapy; if irrigating antibiotics are used, 2 g cefoxitin in 1 L normal saline is effective; in patients with β-lactam allergy, metronidazole (500 mg IV) after cord clamping is effective|
|Open reduction of fracture or insertion of hardwareb||Cefazolin (1 g IV) preoperatively and q 6 h (3 doses). Complex (open) fractures are considered contaminated and cefazolin therapy (1 g q 8 h for 10 d beginning at admission) is indicated|
|Laminectomy and spinal fusion||Prophylactic antimicrobials have not proved to be beneficial|
|Amputation of lower limb||Cefoxitin (2 g IV) preoperatively and q 6 h (4 doses)|
|Cholecystectomy||Cefazolin (2 g IV) preoperatively in “high-risk” patients, i.e., >60 y, previous biliary surgery, history of acute symptoms, or jaundice|
|In patients with β-lactam allergy, gentamicin (80 mg IV) preoperatively and q 8 h (3 doses) is effective.|
|Colon surgery||Neomycin and erythromycin base, 1 g of each orally at 1, 2, and 11 PM on the day before surgery|