IV antibiotic prescribing in surgical patients: an audit

Antimicrobial resistance is an increasing problem and therefore it is essential that antimicrobials are used prudently.(1) The Northern Health and Social Care Trust (NHSCT) has a hospital policy that guides all clinical staff involved in the treatment of adult patients presenting with infections. The policy ‘First Line Empirical Antibiotic Therapy in Hospitalised Adults’ includes guidelines for the treatment of community-acquired pneumonia, hospital-acquired pneumonia, urinary tract infections, intra-abdominal infections, sepsis, soft tissue infections and meningitis. This policy also includes several appendices providing further information on intravenous (IV) to oral switch, monitoring of serum antibiotic levels and dose reduction in renal impaired patients. Research conducted in Antrim Area Hospital in 2006 indicated that overall compliance with hospital antibiotic policy was 70%.(2)

There is increased pressure on hospital beds, therefore it is important to optimise the length of hospital stay thereby reducing costs and improving efficiency. One way this can be done is by early switch from IV to oral antibiotics. This has previously shown to facilitate early discharge without any adverse effect on patient outcome.(3) Advantages of switching from IV to oral antibiotics at an appropriate time includes reduced hospital length of stay, reduced hospital costs, reduced infections at injection sites, and reduced morbidity and mortality.(2)

In January 2013, the trust introduced a consultant microbiologist-led ward round. This ward round included input from a specialist antimicrobial pharmacist and it was expected that this initiative would improve compliance with hospital antibiotic policy and increase adherence to the IV to oral switch.

The objective of this audit was to compare adherence to hospital antibiotic policy and adherence to the IV to oral switch one month after the introduction of a consultant microbiologist-led ward round to results obtained in the same period in 2012.

The study was carried out in the surgical wards in the NHSCT, which serves a population of approximately 460,000. The hospital site used was Antrim area hospital where 54 surgical beds are split between two wards and cover both emergency and elective surgery.

Data was collected after the morning ward round (approximately 12 pm) for a five-day period in January 2012 and again using the same format for five days in February 2013. Patients who were receiving treatment with IV antibiotics were included in the audit and followed until the cessation of their antibiotic course or discharge from the hospital. Patients who were transferred from the surgical wards to another speciality were excluded from the data. The data was collected from patient charts using a standard data collection form and included recording of laboratory data: white cell count and C-reactive protein, observation data: temperature and respiratory rate, diagnosis from the notes, and if/when criteria was met to switch from IV to oral antibiotics. Adherence to the NHSCT antibiotic policy was also assessed.

Data were collected from 11 patients across the surgical wards in 2012 and from 19 patients in 2013. 64% of patients that were included in the 2012 data were male, and compared to 47% in the 2013 data. The age of the patients was also collected and indicated that 55% of the patients from the 2012 audit were over 65, and compared to 47% in the 2013 data.

The most common diagnosis recorded was for intra-abdominal sepsis and 45% of patients in 2012 were treated with IV antibiotics for this indication. The 2013 data indicated that 47% of patients were treated with IV antibiotics for intra-abdominal sepsis. Other indications were: prophylaxis for surgery, cellulitis, hospital-acquired pneumonia, and urinary tract infections that had not responded to first line treatment.

The results show that adherence to antimicrobial policy in 2013 was 87.5% which was an increase from the 2012 audit (64%). The result for the total percentage of patients switched from IV to oral antibiotics was 6.25% compared with 2012, where 37% of patients were switched. Although this was a dramatic reduction in the number of patients switched, the compliance with the IV to oral switch was 69% compared with the 2012 audit of 55%. This shows that the reduction was a result of patients not meeting the criteria to be switched from IV to oral antibiotics. The average length of IV antibiotic course was 6.13 days. This compares to the 2012 audit, which showed an average of 6.50 days.

While the audit showed improvements in adherence to antimicrobial policy, it did not meet the target of 90%. The figure obtained in this audit showed an improvement from previous audits, which showed 70% in 2009 and 64% in 2012. Those patients who received antibiotics outside the antibiotics policy tended to be prescribed broad-spectrum antibiotics such as piperacillin/tazobactam (Tazocin®) where narrower spectrum antibiotics, such as trimethoprim, for UTI might have been sufficient.

With antimicrobial ward rounds starting to take place across the surgical wards, an improvement with hospital antimicrobial policy should be seen.

The total percentage of patients switched from IV to oral antibiotics was much lower in 2013 than the previous audit in 2012, but this does not take into account the appropriateness of switch from IV to oral therapy. When the figures for compliance with IV to oral switch were analysed, an improvement from the previous audit can be seen, with 69% compliance compared with the previous audit with 55% compliance.

However, there is still a considerable need for improvement where step-down is appropriate that will result in improved patient experience, reduced length of stay, and financial savings. Improved documentation in the medical notes would help to improve this issue, as it was noted during the data collection process that in many medical notes there was no plan in regard to antibiotic duration. Reasons for not stepping down were also poorly documented. For those patients who were stepped down from IV to oral a reason for doing so was not documented. This led to inconsistency where one patient was stepped down to oral antibiotics while another patient with identical symptoms and laboratory data was not stepped down and continued on IV antibiotics for several more days.

Finally, the duration of IV antibiotics was recorded. This was not initially planned in the audit but was recorded as part of the data collection. It showed that the average length of IV antibiotic therapy had decreased from 6.50 days to 6.13 days, which re-enforces the data showing better compliance with the IV to oral therapy. It also shows that IV antibiotic duration is being assessed earlier and inappropriate durations of antibiotics have decreased. There were still a few IV antibiotic regimes that had prolonged length of course but with the continuation of the antimicrobial ward round, this should hopefully decrease in frequency.

It is anticipated that adherence to the IV to oral switch will improve with the continuation of the consultant microbiologist ward rounds and this will be re-audited in six months.