INTRODUCTION

Administration of a correct dose of antibiotics is pivotal in the adequate treatment of life-threatening infections [1]. Depending on the antibiotic class, both the time above the minimal inhibitory concentration of the antibiotic (MIC) or the peak concentration of the antibiotic, can be influenced by the posology of the prescribed antibiotic treatment [2]. Thus inadequate dosing can lead to treatment failure or unwanted toxicity, and on a community level to selection of resistant strains [3]. Hospitalized patients are often treated with Intravenous (IV) antibiotics, because of their critical illness or the inability to swallow oral medication. Intravenous therapy can be achieved by intermittent IV infusion, IV push administration or continuous infusion regimens [4]. It has been demonstrated that tubing residuals impact the administration of adequate drug doses [5]. We evaluated whether slow IV push injection is superior to intermittent IV infusion for antibiotics in a theoretical model. Based on these findings we describe the implementation process of this administration protocol in a large size non-university hospital (1.403 beds) in Belgium, with its benefits and disadvantages.

MATERIALS AND METHODS

The intermittent infusion system for antibiotics used in our hospital (AZ Delta hospital, Roeselare, Belgium) consists of a side infusion with the antibiotic agent to be administered dissolved in 50 mL of fluid (preferably saline 0.9%), connected to the main infusion system with an Intrafix® SafeSet (B.Braun, Melsungen, Germany). Baxter (Braine l’Alleud, Germany) viaflo 50 mL saline 0.9% is preferably used to dilute the antibiotic agent (commonly manufactured as freeze-dried powder vial) for intermittent infusion. For IV push injection, the antibiotics are dissolved in the smallest amount of aqua for injection (10 or 20 mL) and administered in a syringe, directly connected to a side port of the main infusion system. This side port is flushed with saline 0.9% (10 mL) before and after bolus injection.For time-controlled infusion, a syringe with the drug solution is placed in an automated infusion pump and connected to the main infusion system using a 1 × 3 mm, LL M/F 200 cm infusion pump extension (Dialex Biomedica, Bilzen, Belgium).All Antibiotics on the formulary of the hospital were evaluated for their aptness (based on the package leaflet or clinical expertise) to be administered by slow IV push injection. The following antibiotics can be administered in IV push injection in our hospital: amoxicillin, amoxicillin/clavulanic acid, aztreonam, cephazoline, cefepim, ceftazidim, ceftriaxon, flucloxacillin, meropenem, penicillin G and temocillin. Piperacillintazobactam, vancomycin, clarithromycin, clindamycin, cotrimoxazole, aminoglycosides and quinolones were excluded from this technique.An analysis of the nursing practice was performed per administration moment for the two techniques under examination. Furthermore the financial impact of this was also briefly considered, with emphasis on the materials used.

RESULTS

Residual volume calculation and impact on net dose administered For the intermittent infusion system the total residual solution present in the infusion system was 20 mL in a clinical setting [6] (air chamber, tubing and flask); after forced evacuation of the air chamber (actually not safe in a clinical setting but frequently used practice) this still was 12 mL. This was measured in an in vitro test environment. For the slow IV push technique, there was no residual volume as the syringe is connected directly to the 3-way tap of the infusion system, after injection de side port is flushed by saline 0.9% (10 mL). For time-controlled infusion system the residual volume was 1.25 mL. Table 1 summarizes some standard treatment regimens and the impact of the administration system on the actual dose administered. Changes to the work flow Based on the theoretical calculations of net dose loss of the antibiotics considered, a change in practice was made with the emphasis on IV push injection. The nephrology ward was selected as pilot ward, based experience with vascular access. Clear instructions were developed by the hospital clinical pharmacists and the vascular access nurse for the slow IV push administration: A video with the procedure was developed and made accessible through YouTube [7] and summary of the technique on a poster with listing of the different antibiotics, do’s and don’ts. Practice in this ward showed that, although a 3 minute presence bedside was required to perform, less interventions were needed as compared to the intermittent infusion technique (installing side infusion, stopping side infusion) resulting in time saving for the nurse. In our hospital, the material cost saving for slow bolus administration versus intermittent infusion was calculated at 105.928 EUR per year.