Outpatient parenteral antimicrobial therapy (OPAT) is widely known as the administration of parenteral antimicrobial therapy in at least two doses on different days without intervening hospitalization. Recently, the Infectious Diseases Society of America (IDSA) commissioned a panel of experts to update the 2004 clinical practice guideline on OPAT.


The Update

The updated guideline discusses therapeutic, administration and safety issues relevant to antimicrobial selection. It also includes updated and expanded versions of the prior guideline’s tables outlining features of selected antimicrobials. Infusion methods, delivery options, common adverse drug events, and laboratory monitoring suggestions are also outlined.

Key recommendations from the updated guideline include:

  • In patients with no prior history of allergy to antimicrobials in the same class, the first dose of a new parenteral antimicrobial may be administered at home under the supervision of healthcare personnel who are qualified and equipped to respond to anaphylactic reactions (weak recommendation, very low-quality evidence).
  • In adult patients needing short courses of OPAT (less than 14 days), a midline catheter may be used rather than a central venous catheter (weak recommendation, very low-quality evidence).
  • Mandatory use of a central catheter over a non-central catheter (either a midline or a short peripheral catheter) for OPAT with vancomycin is not necessary (weak recommendation, very low-quality evidence).
  • For patients with advanced chronic kidney disease requiring OPAT, a  tunneled central venous catheter is recommended rather than a peripherally inserted central catheter (strong recommendation, low-quality evidence).
  • It is not necessary to remove a vascular access device if catheter-associated venous thromboembolism develops during OPAT, as long as the catheter remains well positioned and arm pain and swelling decrease with anticoagulation (weak recommendation, very low-quality evidence).
  • Vancomycin blood levels should be measured regularly throughout the course of OPAT treatment (strong recommendation, very low-quality evidence).
  • All patients should have infectious disease expert review prior to initiation of OPAT (strong recommendation, very low-quality evidence).

“We have long assumed that following laboratory tests while patients are on OPAT is important, but the value of effective monitoring (the performance of laboratory tests and the availability of results to the physician or team overseeing the OPAT course) was recently confirmed,” says Anne H. Norris, MD. “The odds of readmission while on OPAT were lower with effective monitoring in one adult study and in one pediatric study. Both of these studies likely underestimated the impact of their interventions, and we were thus able to make this recommendation as a strong one, based on high quality evidence. It is hoped that this evidence will underpin the commitment of resources from healthcare administrators to the valuable work of OPAT oversight.”


OPAT Models of Care

Dr. Norris describes three models of care for the delivery of OPAT, each with their own advantages and drawbacks: home-based, infusion center-based, and skilled nursing facility (SNF)-based (Table).

“Emerging Infections Network surveys confirm that the majority of OPAT in the United States occurs in the home,” says Dr. Norris. “However, the actual model chosen is often dictated by a variety of forces, including the payer (eg, Medicare covers virtually no home infusion services), available resources (competent home nursing is not always accessible; hospital-based infusion suites may not be open on weekends), as well as patient preference, competencies, and available supports.”


Looking Ahead

The guideline panel identified areas of specific interest for future research, says Dr. Norris. “Given the current opiate addiction crisis in the U.S., newer models of care for persons who inject drugs are needed, potentially expanding on nontraditional sites of care and newer technologies and perhaps including telemedicine,” she adds. “Also, in view of the burgeoning application of midline catheters, the safety of their use for OPAT courses of longer than 2 weeks duration should be delineated. The safety of vancomycin delivered through a peripheral catheter should be addressed. Additionally, data on the safety and efficacy of OPAT in infants younger than 1 month are needed. Finally, an OPAT registry should be re-established in the United States to capitalize on the tremendous amount of siloed data accumulating at large OPAT sites and answer the above-mentioned and other questions about the care of patients receiving OPAT.”