Impact of delayed antimicrobial therapy in septic ITU patients

Introduction

There is evidence that early delivery of antibiotics following the recognition of severe sepsis leads to decreased morbidity and indeed mortality. It is estimated that 36,800 people die annually in the UK as a result of severe sepsis, claiming more lives than bowel and breast cancer combined [1]. Patients admitted to ICUs with severe sepsis have a 39.8% risk of death [2], and for each hour delay in antibiotic administration, a 7.6% increase in mortality [3]. The Surviving Sepsis Campaign 2008 recommends that appropriate antimicrobial therapy be administered within 1 hour following recognition of severe sepsis [4].

Methods

We conducted a prospective audit of consecutive patients with severe sepsis admitted to an ITU between February and June 2010. The patients were identified as those who fulfilled two or more components of the systemic inflammatory response syndrome (SIRS) criteria, and had evidence of organ dysfunction requiring critical care. Compliance to the Surviving Sepsis Campaign's antibiotic care bundle was audited. The relationship between time of antibiotic administration and mortality was also determined.

Results

During the study period, 33 patients out of 187 admissions met the inclusion criteria. The population demographics are illustrated in Table 1. The mean time from fulfilling SIRS criteria to delivery of antibiotics was 4.32 hours. Only eight (25%) of the patients received antibiotics within the hour, with the mortality rate for this group being 25%. Those patients who received antibiotics after 4 hours had a lower mortality rate than the group that received antibiotics after 12 hours (67% vs. 80%). See Figure 1.

Table 1 Demographic characteristics of 33 patients with septic shock treated in an ICU

Figure 1

Time from diagnosis of severe sepsis to antibiotics. Line represents percentage of mortality, and bars represent number of cases in each outcome category for time periods.

Conclusions

Our results support published evidence that a delay in antibiotic delivery greater than 1 hour is associated with increased mortality in patients treated in the ITU. As a result of this study we have developed a standardized sepsis protocol to integrate into the AE triage pro forma, as well as a pathway to help instigate treatment earlier to those patients identified as septic on the wards. Recruitment period has not concluded. More data analysis will be presented later.