C. Patel1, M. Swartz1, J. Tomasek1, L. Vincent1, W. Hallum2, J. Holcomb1 1University Of Texas Health Science Center At Houston,Houston, TX, USA 2Memorial Hermann Hospital,Houston, TX, USA
Introduction: When delivered according to the appropriate schedule, antibiotics (Abs) improve outcomes. Missing doses of Abs is a well described but an inadequately recognized issue. We hypothesized that missing doses of Abs decreases quality of care.
Methods: A retrospective study on all patients admitted to the Shock Trauma ICU from February to June 2015 was performed. Patients prescribed a course of Abs were evaluated, those given prophylactic or one dose were excluded. A missed Ab dose was one planned but never given (a completely missed dose) or a dose that was not given within an hour before or after the planned time (an off-schedule missed dose). Abs given ± one hour is the standard ICU guideline. There were valid and non-valid reasons for completely missing a dose. Valid examples included a change in the order, doses held by an MD, high drug levels or dosing conflict. Non-valid examples included patient off unit and unknown. Patient outcomes included a positive culture, sepsis, ventilator, ICU and hospital days and mortality. Multiple statistical methods were used as appropriate, significance was set as p<0.05.
Results: 280 patients were admitted, 200 met inclusion criteria and 8167 doses of Abs were ordered. 8% of patients (16/200) did not miss any Ab doses, 38% (77/200) had off-schedule missed doses, 43% (86/200) missed a dose for non-valid reasons and 10% (21/200) missed doses for valid reasons. The median Ab doses ordered for those who did not miss doses was 4 (3, 6), while 26 (9, 53) were ordered for those who did miss doses (p<0.0001). All demographic data (age, BMI, ISS) were similar between patients who did and did not miss doses of Abs.
8167 total doses of Abs were ordered and 25% were missed. 21% of doses (1729/8167) were off-schedule, 2.3% (189/8167) were completely missed for non-valid reasons, and 1.3% (113/8167) were completely missed for valid reasons. Among off-schedule doses (1729/8167), the median number of hours off-schedule was 2 (2, 2) for both late doses and early doses.
Unadjusted analysis showed that patients who missed Abs had a higher rate of sepsis (p=0.01), while those who missed a dose of Abs for non-valid reasons spent more days on a ventilator (p=0.03) and in the hospital (p<0.0001) than patients who did not miss any doses.
Adjusting for age, gender, BMI, ISS and doses of Abs showed that those who completely missed a dose for non-valid reasons spent 50% more days in the hospital (p=0.01) than patients who did not miss any doses of Abs, while patients who only had off-schedule missed doses spent 54% more days in the hospital (p=0.004). Sepsis, mortality, days on ventilator, and days in the STICU were not significant when adjusted for covariates.
Conclusion: Missing doses of antibiotics (both completely and off-schedule) correlated with a substantial increase in length of hospital stay. To optimize quality of care, methods to improve compliance with antibiotic dosing schedules should be investigated.