AUDITING AND IMPROVING THE QUALITY OF ANTIBIOTIC PROPHYLAXIS IN SURGERY

3. AUDITING AND IMPROVING THE QUALITY OF ANTIBIOTIC PROPHYLAXIS IN SURGERY

3.1. Surveying the quality of antibiotic prophylaxis in practice

Assessing the quality of the actual practice of antibiotic prophylaxis in surgery is relatively easy. In fact, if one considers performing studies on quality of antimicrobial prescribing in hospital, it is a sensible decision to start with this particular area. Before embarking on an extensive investigation of the whole

Improving Prescribing in Surgical Prophylaxis 191 wise to perform a pilot investigation. Such a pilot should start with collecting

the relevant data of a small series of postoperative patients (e.g., ten patients that are currently admitted) on a surgical ward. The data needed are:

● Age, gender, bodyweight, and length ● Diagnosis/indication for surgery ● Kind of surgery ● Comorbidity (including recent use of antibiotics; known drug allergy) ● Liver tests and renal function (preoperative) ● Antibiotic(s) given for prophylaxis ● Dosis ● Time of administration ● Administered by whom ● Starting time of operation ● Duration of operation ● Blood loss ● Additional dosages of antibiotic.

Collection of these data should be performed in a casual way, so as not to induce a change in prescribing behaviour. When these data have been col- lected, the actual quality review can start. To this end, use of the algorithm of Gyssens et al. (1992) is recommended (Figure 1). In addition, the prevailing local hospital guideline on antibiotic prophylaxis should be available.

The following patient vignette may serve as an example on how to perform the review.

A 72 year old female, weight 83 kg, length 163 cm Diagnosis: stenosis of sigmoid colon due to recurrent diverticulitis Surgical procedure: resection of sigmoid colon Comorbidity: non-insulin dependent type 2 diabetes; no antibiotic usage; no drug allergy; normal liver tests, estimated creatinine clearance 70 ml/min Antibiotic prophylaxis: ceftazidime; Dose: 1 g Time of administration: 11:10 am Administered iv by a nurse on the ward Start of operation: 1:20 pm Duration of operation: 2 hours and 45 min Blood loss 400 ml.

3.2. No additional antibiotics

Review of the case history described above, with the help of the algorithm will yield the following results.

● The data are adequate. It concerns a procedure with a contaminated wound,

192 Jos W. M. van der Meer and Marjo van Kasteren

Start

Sufficient

VI Stop yes

no

data

AD justified

V Stop yes

no

Alternative more

yes

IVa

effective no

Alternative less

yes

IVb

toxic no

Alternative less

narrower spectrum

IVd

no Duration

yes

too long

IIIa

no Duration

yes

too short

IIIb

no

Correct dose

Correct interval

Correct route

If not in categories

II-IV

Figure 1. Flow chart for quality-of-use assessment of antimicrobial drug prescriptions according to Gyssens et al. (1992). Reprinted with permission.

Improving Prescribing in Surgical Prophylaxis 193 ● The patient only received ceftazidime and no anti-anaerobic coverage; thus

there is an alternative which is more effective; we score IVa. ● Let us assume that the hospital guideline recommends cefazolin with

metronidazole for this type of surgical procedure. ● Although metronidazole adds a little toxicity to cefazolin, toxicity is not an

issue here. ● Ceftazidime is considerably more expensive than cefazolin: we score IVc.

● Also, the spectrum of ceftazidime is too wide: we score IVd. ● Since only one dose was given, the duration is correct. ● The dose is correct. Since there was only one dose given, the dosis interval

is not applicable. The administration of the drug is correct. ● The patient received the prophylaxis on the ward. This is of course not ideal,

since the surgical procedure may be delayed, as in this case. The time elapsed between the injection and the operation is more than 2 hr. We score I.

● This case already points to serious problems that need urgent attention. First of all, the administration of a third generation cephalosporin does

raise the question, “Is this structural or incidental? Is the mistake with the person who has been giving the order or with the nurse administering the drug (e.g., insufficient knowledge of different cephalosporins)?” More cases from the same ward are needed to see what is wrong.

3.3. Further quality assessment

If the pilot survey of antibiotic prophylaxis in surgery appears to meet with poor quality, it is necessary to describe the sequence of events that has pre- ceded the actual prescribing practice. Within that context, barriers that inter- fere with this chain of events and with the actual implementation of the antibiotic policy should be looked for.

The sequence starts with the formulation of the guideline (often by a mul- tidisciplinary hospital committee that makes use of already existing national or international guidelines to formulate local guidelines). In respect of the acceptance of the guideline, it is important to check whether key players of the surgical disciplines were involved in the decision-making at this stage. An important next step is the issuing of the guideline, its acceptance by the pro- fessionals and its implementation in daily practice.

It is an important question whether barriers (defined as factors that limit or restrict complete physician adherence to a guideline [Cabana et al., 1999]) are present. Such barriers may be physician related, patient related, or system related. Physician-related barriers have to do with knowledge, attitude, or

194 Jos W. M. van der Meer and Marjo van Kasteren behaviour. According to Cabana et al. (1999) lack of knowledge comes down

to lack of awareness and lack of familiarity with the guideline. The amount of information, the time needed to become and stay informed, and the accessibil- ity to the guidelines are critical issues here. Attitude has to do with lack of agreement with the guideline, lack of outcome expectancy, and perhaps worst of all, inertia. With regard to attitude there is the crucial influence of supervi- sors and local opinion leaders: their involvement and endorsement is essential. Behaviour, which is a consequence of knowledge and attitude is strongly influ- enced by external factors, for example, patient demands and factors in the system such as financial constraints and bureaucracy.

For the assessment of quality, each of these factors that may pose a barrier should be given critical attention.

3.4. How to intervene?

Once the quality is assessed and the barriers that interfere with it have been identified, a plan can be made for intervention. As an example, the intervention studies as published by Gyssens et al. (1996, 1997) may serve. In that study, rather poor timing of the preoperative antibiotic dose was found. In the analysis a critical factor was that nobody really felt responsible for the administration of the antibiotic. This was due to lack of knowledge of the sur- geons (not sufficiently aware of the importance of antibiotic timing [Classen et al., 1992]) and a lack of involvement on the side of the anaesthesiologists and a lack of communication between surgeons and anaesthesiologists. The successful intervention consisted of the education of surgeons, anaesthesiolo- gists, and nurses.

In a recent multicentre study of surgical antimicrobial prophylaxis in the Netherlands (van Kasteren et al., 2003), it was found that the most important barriers to local guideline adherence were lack of awareness due to ineffective distribution of the most recent version of the guidelines, lack of agreement by surgeons with the local hospital guidelines, and environmental factors, such as organizational constraints in the surgical suite and in the ward. Especially, adherence to guidelines on dosing interval and timing needs improvement.

In conclusion, it is clear that meticulous analysis of all steps is necessary to design and install effective intervention. Most often a set of interventional measures is necessary. The effect of the intervention should be assessed. Such assessment should be performed relatively shortly after the intervention, but also later, to see whether the effect of the intervention lasts. After all, it is human to fall back to one’s old routines and mistakes.

Improving Prescribing in Surgical Prophylaxis 195