By Richard R. Watkins, MD, MS, FACP, FIDSA, FISAC

Professor of Internal Medicine, Northeast Ohio Medical University; Division of Infectious Diseases, Cleveland Clinic Akron General, Akron, OH

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

SYNOPSIS: A retrospective cohort study found that infectious disease consultation for patients with candidemia resulted in lower 90-day mortality. This was likely a result of strong adherence to guideline- and evidence-based management and the low number of patients who were not treated.

SOURCE: Mejia-Chew C, O’Halloran JA, Olsen MA, et al. Effect of infectious disease consultation on mortality and treatment of patients with Candida bloodstream infections: A retrospective, cohort study. Lancet Infect Dis 2019;19:1336-1344.

Infectious disease (ID) consultation has been shown to improve outcomes for Staphylococcus aureus bacteremia, including decreased mortality.1 Mejia-Chew and colleagues sought to determine whether ID consultation would improve mortality similarly in patients with candidemia, as well as what specific aspects of management were associated with patients who did and did not receive ID consultation.

The study was a retrospective cohort analysis that included patients ≥ 18 years of age diagnosed with candidemia between Jan. 1, 2002, and Dec. 31, 2015, from a single tertiary referral center in St. Louis. Patients who died within the first 24 hours of the index blood culture with Candida spp. were excluded, since an ID consultation would have been difficult to obtain in that time frame. ID consultation was defined to include patients who received the consultation 24 hours before and up to seven days after the index blood culture collection date. For patients who did not receive treatment, three categories were established: culture regarded as a contaminant, clinician unaware, and patient left the hospital against medical advice (AMA) before treatment could be started. The primary outcome measured was the 90-day all-cause mortality in patients with candidemia who received ID consultation vs. those who did not.

The analysis included 1,691 patients. Of these, 776 (45.9%) received an ID consultation and 915 (54.1%) did not. Over time, the proportion of patients with ID consultations increased. More patients in the ID consultation group were admitted to the intensive care unit (ICU) (16% vs. 10%). There was no difference between the two groups in the species of Candida that was isolated or in the selection of the initial antifungal agent. The rate of non-treatment was lower in the ID consultation group (13/776, 2%) than in the no-consultation group (128/915, 14%; P < 0.0001). The reasons for no treatment in the ID consultation group were that the culture was thought to be a contaminant in four patients, the culture results were unknown to the treating physician in eight patients, and one patient left AMA.

Nonpharmacological management differed between the two groups. Central line removal was more common in the ID consultation group (76% vs. 59%), as was the use of echocardiography (56% vs. 33%) and ophthalmological evaluation (53% vs. 17%). The 90-day mortality was lower in the ID consultation group (29% vs. 51%; P < 0.0001). Of the 141 untreated patients, 94 (67%) were dead by day 90. ID consultation was associated with a hazard ratio (HR) of 0.81 by the propensity-score model (95% confidence interval, 0.73-0.91; P < 0.0001), which translated to a 19% survival benefit.

COMMENTARY

Candidemia is associated with high mortality, making appropriate management crucial for patient survival. This is evident in the present study with the finding that 67% of patients with candidemia who were not treated died within 90 days. Although it is likely that not all of these deaths can be attributed to the candidiasis, this grim result highlights the seriousness of Candida in the bloodstream. Therefore, it is disconcerting that in four cases of candidemia, the ID consultant thought it was a contaminant, and no treatment was given. Clearly, this is a quality improvement situation where peer-to-peer feedback is needed.

The Infectious Diseases Society of America guidelines provide evidence-based recommendations for the management of patients with candidemia.2 The key factors include source control, such as catheter removal; prompt initiation of antifungal therapy; appropriate duration of therapy; and the need for medical interventions, such as an ophthalmological evaluation and cardiac imaging. Indeed, following the guidelines has been shown previously to lead to improved patient outcomes.3 Presumably, most ID consultants are well-versed on the guidelines, and adherence to them likely explains the improvement in mortality observed in the study by Mejia-Chew and colleagues.

The main strength of the study is the size of the cohort, which is the largest to explore the association between ID consultation and mortality in patients with candidemia. However, there are a few limitations to note. First, like all retrospective analyses, it may have been influenced by unmeasured confounding variables. Second, since it was conducted at a single center, the results might not be generalizable to other settings. For example, it is more common outside of the United States for clinical microbiologists to play a more active role in advising physicians who are managing patients with serious infections, such as candidemia. Finally, selection bias could have affected the results, as some patient populations were underrepresented in each group.

ID consultants play a crucial role in the management of patients with candidemia. As the study by Mejia-Chew and colleagues demonstrates, ID consultation leads to improved 90-day mortality and, therefore, should be the standard of care for all patients with candidemia.

REFERENCES

  1. Bai AD, Showler A, Burry L, et al. Impact of infectious disease consultation on quality of care, mortality, and length of stay in Staphylococcus aureus bacteremia: Results from a large multicenter cohort study. Clin Infect Dis 2015;60:1451-1461.
  2. Pappas PG, Kauffman CA, Andes DR, et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis 2016;62:e1-50.
  3. Patel M, Kunz DF, Trivedi VM, et al. Initial management of candidemia at an academic medical center: Evaluation of the IDSA guidelines. Diagn Microbiol Infect Dis 2005;52:29-34.