By Carol A. Kemper, MD, FACP

Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases, Santa Clara Valley Medical Center

Dr. Kemper reports no financial relationships relevant to this field of study.

Surgeons Really Are Different

SOURCES: Charani E, Ahmad R, Rawson TM, et al. The differences in antibiotic decision-making between acute surgical and acute medical teams: An ethnographic study of culture and team dynamics. Clin Infect Dis 2019;69:12-20.

Szymczak JE. Are surgeons different? The case for bespoke antimicrobial stewardship. Clin Infect Dis 2019;69:21-23.

The success of antimicrobial stewardship (AS) is based on the timely and appropriate use of antibiotics. And yet, feedback and education generally focus on the patient and the type of infection, not the physician or surgeon making the antibiotic choice. It turns out that physicians and surgeons make decisions including decisions about antibiotics in very different ways. For AS to succeed, the authors argued that education and feedback and the guidelines that govern antibiotic choices need to take these “cultural differences” into account.

To understand the decision-making process for choosing an antibiotic regimen, the authors at the Imperial College, London, performed an ethnographic study of their surgical and medical teams at work on the wards. (An ethnographic project means the internists and surgeons were observed in their own habitats). The results were based on 500 direct observations of antibiotic decision-making, which were interpreted based on current antimicrobial stewardship policy and guidelines, as well as 23 face-to-face interviews with key healthcare professionals. The professionals included 14 surgeons and nine internists and pharmacists.

The researchers’ observations yielded some important differences between medical physician teams and surgical teams:

  • Medical teams function in a collaborative capacity, with multiple individuals involved in the decision process. Ward rounds are more discussion-based and less pressured by time to make decisions. This multidisciplinary approach often provides a rational basis for antibiotic choices.
  • On the other hand, the authors observed that the collaborative nature of the medical team’s decisions means that no one person “owns” the decision, which sometimes means the decisions are deferred, or that the person with the most knowledge is over-ridden. This can lead to more prolonged use of broad-spectrum antibiotics.
  • For similar reasons, empirical antibiotics started in the emergency department (ED) often are not re-evaluated immediately by the admitting medical team, who may be reluctant to disturb the initial physician’s choice of antibiotic. Thus, a gap of > 24 hours may occur before the ward team tackles the process of re-evaluating antibiotics the following day. This problem is compounded by the new urgency for starting antibiotics in the ED for any patient with suspected infection or sepsis (which is probably not necessary in one-third of cases). Thus, many patients continue to receive unnecessary antibiotics for their first day of hospitalization.
  • The surgical team functions very differently, with early morning rounds quickly occurring before morning surgery, sometimes in advance of micro data. Generally, decisions are made by one individual the lead surgeon.
  • However, surgeons consider decisions about antibiotics to be a low priority. Therefore, antibiotics simply are not addressed during the more pressured surgical rounds.
  • Rather, “lesser” decisions (like antibiotics) are delegated to a junior member of the surgical team. The junior member of the surgical team is more worried about negative outcomes of making the wrong decision or changing antibiotics. Difficult decisions often are deferred, again leading to more prolonged use of antibiotics.
  • Medical ward rounds included a dedicated pharmacist, who often prompts discussions about antibiotic stewardship and encourages consideration of de-escalation to narrower spectrum or oral antibiotic choices. The same pharmacist is not available for early morning surgical rounds. Decisions about antibiotics end up being delayed when key surgical decision-makers are unavailable in the operating suite later in the day. Further, any discussion about antibiotics tends to occur by phone or text, rather than through an open conversation or an opportunity for education and feedback.

Interventions to improve antibiotic use need to consider the differences in culture between medical and surgical teams, and how to frame educational opportunities and feedback to the different specialties. Pharmacists specializing in antibiotic stewardship need to better engage in surgical ward rounds.

Short-Course Atovaquone/Proguanil for Malaria Prophylaxis

SOURCE: Lau CL, Ramsey L, Mills LC, et al. Drug-free holidays: Compliance, tolerability, and acceptability of a 3-day atovaquone/proguanil schedule for pretravel malaria chemoprophylaxis in Australian travelers. Clin Infect Dis 2019;69:137-143.

Daily atovaquone/proguanil (A/P) is one of the more commonly used regimens for malaria prophylaxis in travelers. The usual regimen is one tablet (250 mg/100 mg A/P) daily beginning one to two days before arriving in a malaria risk area and continuing for seven days following departure. This means that travelers, some of whom are young and healthy and otherwise taking no medication, are taking a pill every day of their trip. Needless to say, studies have found compliance with malaria prophylaxis to be poor. In one study, researchers observed that only 59% of Australian travelers took their A/P, and less than one-third of these were fully complaint.

The pharmacokinetics of A/P suggest a different approach. Both drugs have long elimination half-lives (two to three days and 14-20 hours, respectively). Larger treatment doses have provided malaria protection for more than four weeks.

The compliance and tolerability of treatment dose A/P (four tablets daily × three days), completed at least one day prior to departure, was observed in 233 adult travelers recruited from four different travel medicine clinics in Australia. Travelers were visiting countries with low-to-medium malaria risk for four weeks or less. The average age of the travelers was 44 years, and 51.2% were female. Compliance with the three-day regimen was remarkably good at 97.7%.

Side effects were common (43%), but generally mild to moderate and limited to the first or second day of medication. In descending order of frequency, side effects included nausea (25%), diarrhea (17%), fatigue (9%), headache (6%), and dizziness (6%). The median duration of side effects was two days, and no one experienced side effects lasting more than four days. Side effects limited daily activities for three people, although only two individuals failed to complete the three-day regimen because of side effects.

Follow-up phone calls to 205 participants (88%) revealed that none of the participants developed malaria during or after their trip.

A three-day malaria prophylaxis regimen taken before departure appears to be a perfect solution. Given the efficacy and improved compliance, fewer travelers would develop malaria, and many travelers would have the blessing of a medication- and side-effect-free trip at a lower cost.

The High Cost of Chronic Lyme Treatment

SOURCE: Goodlet KJ, Fairman KA. Adverse events associated with antibiotics and intravenous therapies for post-Lyme disease syndrome in a commercially insured sample. Clin Infect Dis 2018;67:1568-1574.

The researchers evaluated a large, commercially insured group of “chronic Lyme disease” patients, now characterized as post-Lyme disease syndrome (PLDS) for prolonged antibiotic use and complications. Investigators derived the data from medical and pharmacy claims from a large database (Truven Health Market Scan), based on ICD 9/10 codes and DRG hospital codes. They based observations on the 90-day incident rates for adverse events for PLDS patients at least six months following their initial Lyme diagnosis. Researchers compared data for patients receiving parenteral, oral, or no antibiotic therapy at least six months following their initial diagnosis. Oral antibiotics prescribed within a period 14 days before to 14 days following a Lyme diagnosis were not included in the analysis. Of the 123,687 unique patients with at least one claim for Lyme, 13,444 (10.9%) met criteria for PLDS with available data at least six months later.

Composite adverse event incident rates were significantly higher for patients receiving either parenteral or oral antibiotic therapy compared to the no-treatment group (18.7%, 16.8%, and 13.4%; P = 0.019). The three most common adverse events were infection, gastrointestinal side effects, and electrolyte abnormalities. The prevalence of infection was significantly higher in the parenteral antibiotic group (22%), compared with the oral group (17.7%), although the prevalence of Clostridium difficile enterocolitis was similar. Emergency room visits and hospital stays also were significantly higher in the parenteral treatment group. When treatment was given intravenously, the all-cause incidence of emergency room visits was 11.3% compared with 2.2% for the oral antibiotic group and 3.4% for the no-treatment group. Seven percent of those receiving parenteral antibiotics required hospitalization, generally for infection and/or electrolyte abnormalities.

The authors admitted this study may be limited by the observation that patients with more compelling symptoms may be more likely to receive parenteral therapy and, thus, also may have more complications. Also, it is possible that patients in this parenteral group received antibiotics for reasons other than Lyme disease. However, the results of this study are consistent with other clinical studies of chronic Lyme disease treatment, although the authors believe their data to be more robust and more “real world,” based on a larger, commercially insured patient group.