Chlorhexidine cuts surgical site infections

1 April 2010

CLINICAL BOTTOM LINE:

Surgical site preparation with 2% chlorhexidine in 70% alcohol reduces surgical site infection by 40% compared to povidine iodine.

CLINICAL SCENARIO:

It is time to update the theatre protocols for general surgery. Some surgeons want to use chlorhexidine for surgical site preparation whilst others prefer povidine iodine. Is one more effective than the other or are they similar?

QUESTION:

Among patients having minor surgery, what is the effect of chlorhexidine surgical scrub on surgical site infections compared to povidine iodine?

SEARCH STRATEGY:

PubMed – Clinical queries (therapy/narrow specific search): chlorhexidine.

CITATION:

Dariouche RO et al. Chlorhexidine-alcohol versus povidine-iodine for surgical site antispesis. New Engl J Med 2010; 362:18-21.

STUDY SUMMARY:

Two arm, parallel group, multicentre, pragmatic, randomised, controlled trial conducted in six university-affiliated hospitals in the USA. Overall, 1003 patients were assessed for eligibility and 897 randomised. Patients had to be 18 years or older and undergoing clean-contaminated surgery (colorectal, GI, biliary, thoracic, gynaecologic or urologic). Exclusion criteria were: allergy to chlorhexidine, alcohol or iodophors; evidence of infection at or adjacent to operative site; inability to follow patient’s course for 30 days after surgery. After discharge patients were called once a week until 30 days follow-up complete; prompt assessment arranged if any surgical site infection suspected.

Intervention (n=431):

Skin scrubbed pre-operatively at surgical site with applicator that contained 2% chlorhexidine and 70% isopropyl alcohol (Chloraprep). More than one applicator used if coverage area exceeded 33x33cm2.

Control (n=466):

Skin scrubbed pre-operatively at surgical site and then painted with aqueous solution of 10% povidine-iodine (Scrub Care Prep Tray).

Outcomes:

Primary outcome measure was any surgical site infection occurring within 30 days after clean- contaminated surgery. Surgical site infection followed definition by CDC criteria. Secondary outcomes included types of surgical site infection (superficial, deep incisional, or organ space), adverse and serious adverse events.

Validity:

Individual patients randomised by computer-generated randomisation without blocking (stratified by hospital). Allocation concealment was not reported, although surgeon was masked to allocation until after patient brought to operating room. Patients and assessors who diagnosed surgical site infection blinded to treatment group. Follow up was 91% (similar in both groups) and analysis on an intention-to-treat basis – only those that were randomised and had the surgery included in ITT analysis; per-protocol analysis also conducted (36 patients excluded because received clean surgery, seven died before 30 days follow-up and four dropped out of study). Groups were similar at baseline. Overall the methodological quality of the study was high.

RESULTS:

There were significantly fewer infections in the chlorhexidine-treated group (table). The difference was maintained for both superficial and deep incisional surgical site infections, but there was no difference in organ space infection rates or in rates of sepsis from surgical site infection. There were similar numbers of adverse and serious adverse events.

COMMENTS:

  • Pragmatic trial (virtually any patients undergoing clean-contaminated surgery eligible), so similar to real-world clinical practice.
  • ITT defined as those that received surgery and the antiseptic – analysis still significant when excluded patients included in the denominator.
  • Conducted in hospitals, not primary care clinics, but would expect no reason for chlorhexidine not to be similarly effective in minor procedures.
  • Chlorhexidine products available in New Zealand – expect results should apply to all 2% chlorhexidine and alcohol products, not just Chlorprep.
  • Cost-effectiveness analysis reported. Cost of product needs to be considered.

Reviewer: Dr Andrew Jull, RN PhD, Nurse Advisor – Quality, Auckland District Health Board and Associate Professor (School of Nursing).