Improving Surgical Antimicrobial Prophylaxis

In the following article, Dr Mushira Enani discusses AMS in the context of surgical prophylaxis.

Surgical Site Infections (SSIs) are a major contributor to patient injury, mortality and health care costs. The goal of Surgical Antimicrobial Prophylaxis (SAP) is to prevent SSIs by reducing the burden of bacteria at the surgical site throughout the operative procedure.

In the skin/epidermis, there are two types of bacteria to be considered when a patient undergoes surgery.

• Transient bacteria (normal flora) are on the surface of the skin and are easily removed with surgical antiseptic techniques (Iodine, Alcohol)
• Resident bacteria – reside deeper in the dermis, normally in the hair follicles.

The resident bacteria are targeted by SAP and are what you want to minimise these when you give antibiotics pre-operatively. SAP needs to be administered in the right way to ensure that it achieves the best serum and tissue concentration to control the bacteria that may cause an SSI. Despite evidence of the effectiveness of antimicrobials to prevent SSIs, studies have demonstrated errors and variation in selection, timing, dosing, and duration of surgical antimicrobial prophylaxis (SAP) across the globe.

The CATS acronym should be used to remember ways in which the risk of SSIs can be reduced:

1) Clippers – remove hair

2) Antibiotics – given prophylactically with the right timing and concentration

3) Temperature control

4) Sugar – glycaemic control (important in diabetics)

In order to look at SAP procedure in your institution, it is important to be aware of the Key Performance Indicators (KPIs).

The two studies that show the evidence for these KPIs are at the bottom of this page in the see also section.

Case Study

• 74 year old female who is diabetic, hypertensive (DM/HTN) and morbidly obese.

She is admitted to the hospital in order to try and control her diabetes, but two weeks later she undergoes emergency CABG (coronary artery bypass graft) with MVR/ TVR. The operation is 9 hours long and bypass time is 177 minutes.

Write in the comments section the factors which make this patient at risk of SSI?

Two weeks later she develops a deep sternal SSI and mediastinitis requiring a VAC machine. Two days later she undergoes another operation for wound debridement. Her sternal wires were removed, three pockets of puss were found, and debridement was done. Her wound was closed with tension sutures and a mediasrinal drain, pleura drain and hemovac drains left in place.

This example shows the need for correct SAP. This was a preventable infection with bad consequences. Up to 60% of SSIs are preventable – this is why it is so important to apply CATS and optimise antimicrobial prophylaxis.

How can you improve SAP in your institution?