A retrospective comparison of broad spectrum and pathogen-directed antimicrobial treatment of acute respiratory distress syndrome in HIV/AIDS patients.

Abstract

Globally, HIV (Human Immunodeficiency virus) prevalence is highest in Sub-Saharan Africa (WHO, 2015). Acute respiratory failure is the leading cause for admission and mortality in the ICU (Intensive Care Unit) for HIV infected patients (Sarkar and Rasheed, 2013). There appear to be no formal or standardized antimicrobial treatment guidelines for treating ARDS (Acute Respiratory Distress Syndrome) in patients with AIDS (Acquired Immunodeficiency Disease Syndrome). METHOD: This retrospective descriptive comparative study employed chart review in order to compare patient outcomes of HIV infected patients, admitted with an ARDS diagnosis to the ICU of a private hospital in Richards Bay (Kwazulu-Natal) between January and December 2013, following one of two treatment regimens: 1) pathogen-directed antimicrobial treatment or 2) broad spectrum antimicrobial treatment. Total population sampling was performed for this study and data was collected by means of data collection sheets. The included patients (n=30) were allocated to either one of the two treatment groups based on the antimicrobial treatment they received in the ICU (broad spectrum antimicrobial treatment, n = 12 and pathogen-directed antimicrobial treatment, n = 18). The main outcome parameter for this study was survival rate to ICU discharge. The secondary outcome parameters were length of ICU stay and duration of antimicrobial therapy. The outcomes were compared both culture “blind” (without taking culture results into consideration) and cultures revealed (for patients with the same culture result). RESULTS: From the sample of 30 included patients there were 18 survivors (broad spectrum antimicrobial treatment, n = 7 and pathogen-directed antimicrobial treatment, n = 11). For the culture “blind” analysis, there was a significant difference in patient outcome for the main outcome parameter (p < α; α = 0.05) as well as for the secondary outcome parameters (H ≥ 3.84 (critical value); α = 0.05). 50% surviving patients in the broad spectrum treatment group were discharged by 43 days in the ICU (median survival rate) and 50% surviving patients in the pathogendirected treatment group were discharged by 17 days in the ICU. The median length of ICU stay was 43 days for the broad spectrum treatment group and 17 days for the pathogen-directed group. The median duration of antimicrobial treatment was 3 43 days for the broad spectrum group and 17 days for the pathogen-directed group. For the cultures “revealed” analysis no formal statistical tests were performed due to small sample size (five surviving patients). For the broad spectrum treatment group, 100% surviving patients were discharged by 7 days in the ICU and for the pathogen-directed group, 100% surviving patients were discharged by 32 days in the ICU. The median length of ICU stay was 11 days for the broad spectrum group and 21 days for the pathogen-directed group. The median duration of antimicrobial treatment was 11 days for the broad spectrum group and 21 days for the pathogendirected group. CONCLUSION: This study revealed that there is a difference in patient outcome for the two antimicrobial treatments (broad spectrum and pathogen-directed). The culture “blind” analysis indicated that the pathogen-directed antimicrobial treatment is the treatment with the best outcome for AIDS patients with ARDS in the ICU, but the cultures “revealed´ analysis indicated to opposite, with broad spectrum antimicrobial treatment the treatment with the best patient outcome. In the latter case, however, no formal statistical tests were performed due to small sample size. The pathogen-directed approach will be the recommended treatment approach for treating ARDS among AIDS patients in the ICU for the draft in-house guideline. This approach resulted in better patient outcomes for the culture “blind” analysis. It is also the approach that theoretically limits the risk of antimicrobial resistance (van der Eeden et al., 2005). However, a larger study is necessary in order to confirm these results.