Situation: A 60-year-old man is admitted the day before an elective open abdominal operation under general anesthesia. He has type 2 diabetes mellitus and hypertension. He has no history of delayed gastric emptying, no gastrointestinal symptoms, and no known drug allergies. Hair removal at the incision site is ordered. On the morning of surgery the nurse uses electric clippers instead of a razor. What is the reason for this choice?

Shaving with a razor causes microscopic cuts in the skin that bacteria colonize, raising the risk of surgical site infection. When hair must be removed, clippers are used immediately before surgery, and only if necessary.

Core mechanism
A razor blade removes hair by cutting at or just below the skin surface. In doing so, it commonly creates microscopic skin abrasions and nicks that are not visible to the naked eye. These tiny breaks in the epidermis allow skin flora such as Staphylococcus aureus and other resident bacteria to enter, colonize, and multiply. Because the surgical incision will also disrupt the skin barrier, any preexisting microtrauma from shaving increases the total bacterial burden at the operative site and raises the risk of a surgical site infection ^[1][2][4].

The key reason clippers are preferred is that they cut hair above the skin surface without traumatizing the epidermis, thereby avoiding the microscopic wounds where bacteria can proliferate. This is the central infection-prevention principle behind the correct answer.

Why the other options are incorrect
Option 1 is false because razors actually cut hair closer to the skin than clippers; clippers leave a short stubble above the skin. Option 3 is not the reason for choosing clippers, because hair removal should be performed as close to the time of surgery as possible, not the night before. Option 4 is unsupported by the evidence; the concern with razors is mechanical skin injury, not a direct chemical interaction that weakens chlorhexidine.

Clinical application and timing
Current evidence indicates that hair should be removed only when it will interfere with the incision, closure, or dressing application. When removal is necessary, electric clippers with a single-use or disinfected head are the recommended method ^[2][4]. The timing also matters: hair removal should occur as close to the surgical incision time as possible, ideally on the day of surgery, because longer intervals allow any skin disruption to become colonized with bacteria.

In the scenario, the patient is admitted the day before an elective open abdominal operation. The nurse uses clippers on the morning of surgery rather than the night before, which reflects the principle that minimizing the interval between hair removal and incision reduces the opportunity for bacterial multiplication ^[2][4].

Evidence summary
A Cochrane review comparing preoperative hair removal methods found that when hair removal is required, clippers are associated with fewer surgical site infections than razors. The review also noted that avoiding hair removal altogether may be appropriate when hair does not interfere with the procedure ^[2][4]. A quasi-randomized trial in inguinal hernia surgery similarly compared razor and clipper use and evaluated postoperative surgical site infection as an outcome, supporting the clinical concern about razor-induced skin trauma ^[1].

Comparison point	Razor	Electric clipper
Cutting level	At or below skin surface	Above skin surface, leaving short stubble
Skin trauma	Microscopic cuts and abrasions are common	Minimal epidermal trauma
Infection risk	Higher risk of surgical site infection	Lower risk of surgical site infection
Recommended timing	Not recommended	Immediately before surgery if removal is necessary

Watch out! Do not assume that hair removal is always required. The safest approach is to leave hair intact unless it will directly interfere with the incision, wound closure, or dressing adhesion. Key point! If hair must be removed, use clippers, not a razor, and perform the clipping as close to the operative time as possible to minimize the window for bacterial colonization ^[2][4].