Window for tPA expands for some
New guidelines call for expanding the poststroke treatment window for using recombinant tissue plasminogen activator (alteplase) in selected patients.
Previous recommendations called for administration of alteplase no more than three hours after stroke onset. In light of new research, the American Heart Association and American Stroke Association have issued a scientific advisory expanding this time window to three to 4.5 hours in patients who are eligible for alteplase. However, in the following groups, the three-hour window still applies
- patients older than age 80,
- patients receiving oral anticoagulation who have an international normalized ratio of 1.7 or less,
- patients with a National Institutes of Health Stroke Scale score over 25, and
- patients with a history of stroke and diabetes.
The guidelines stressed that treatment within three hours is still preferable in all cases, because patients treated earlier are more likely to improve. The full recommendations were published by Stroke on May 28.
Updated guidelines target catheter-related infections
The Infectious Diseases Society of America has issued updated guidelines for the diagnosis and management of intravascular catheter-related infections.
The guidelines, last updated in 2001, address when and how catheter and blood cultures should be done and recommend treatment strategies. Specific recommendations for managing infections include
- Use vancomycin in settings with an elevated prevalence of methicillin-resistant Staphylococcus aureus;
- Use combination antibiotic therapy for multidrug-resistant gram-negative bacilli when catheter-related bloodstream infection (CRBSI) is suspected in patients who are neutropenic, severely ill with sepsis, or known to be colonized with such pathogens until culture data are available;
- Remove long-term catheters from patients with CRBSI associated with conditions including severe sepsis, suppurative thrombophlebitis, endocarditis, bloodstream infection that continues despite 72 hours of antimicrobial therapy to which the infecting microbes are susceptible, or infections due to Staphylococcus aureus, Pseudomonas aeruginosa, fungi, or mycobacteria;
- Remove short-term catheters from patients with CRBSI due to gram-negative bacilli, S. aureus, enterococci, fungi, and mycobacteria.
The guidelines make specific recommendations regarding antibiotic lock therapy; pathogen-specific treatment; management of suppurative thrombophlebitis and persistent bloodstream infection; and detection and management of an outbreak of CRBSI. The guidelines also address how to treat different subtypes of catheter-related infections, including
- short-term peripheral venous catheters;
- nontunneled and long-term central venous catheters;
- implanted catheter-related infections (other than infections related to hemodialysis catheters);
- catheter-related infections in pediatric patients; and
- infections related to hemodialysis catheters.
The guidelines appeared in the July 1 Clinical Infectious Diseases.
New guidance on treating S. aureus infections with vancomycin
The Infectious Diseases Society of America, the American Society of Health-System Pharmacists, and the Society of Infectious Diseases Pharmacists released guidelines for the use of vancomycin in treating Staphylococcus aureus infections, including new recommendations for targeting and adjusting vancomycin therapy.
The guidelines were published online July 1 by Clinical Infectious Diseases. Recommendations include the following
- Initial vancomycin dosages should be calculated based on actual body weight, including for obese patients, while subsequent dosage adjustments should be based on actual serum concentrations. Continuous infusion, as opposed to intermittent dosing, is unlikely to greatly improve outcomes;
- Trough serum vancomycin concentrations are the most accurate method of monitoring the drug's effectiveness, and should be obtained just before the fourth dose, at steady-state conditions;
- Trough serum vancomycin concentrations should always be maintained at >10 mg/L to avoid development of resistance. Concentrations of 15-20 mg/L are recommended;
- A patient should be thought to have vancomycin-induced nephrotoxicity if at least two or three consecutive high serum creatinine concentrations (increase of 0.5 mg/dL or >50% increase from baseline, whichever is greater) are documented after several days of therapy, and absent another explanation;
- Monitoring trough serum vancomycin concentrations to reduce nephrotoxicity is best suited for patients receiving aggressive dose targeting for sustained concentrations of 15-20 mg/L or those who are at risk of toxicity. It is also recommended for patients with unstable renal function and those receiving therapy for more than three to five days;
- Once-weekly monitoring is recommended for hemodynamically stable patients whose goal trough is 15-20 mg/L; and
- Evidence does not support monitoring of peak serum vancomycin levels.