Do Uncomplicated Lacerations Need To Be Closed Within Six Hours?

Dr. Keller,
What do you think of the rule for lacerations that says a laceration has to be sutured within six hours or it cannot be sutured at all? At our facility, we send lots of inmates to the ER for simple cuts because the PA isn’t scheduled to be at the facility until the next day. If a cut is 10 hours old, why can’t it be fixed?  Where did this rule come from?
Kim A.

Thanks for the question, Kim. The short answer to this question is that that this belief is a myth. Uncomplicated lacerations can, indeed, wait more than 6 hours to be repaired.

“There is a common misconception that all wounds must be either sutured within a few hours or left open and relegated to slow healing and an unsightly scar.”  Roberts and Hedges’ Clinical Procedures in Emergency MedicineUnknown

Early in my medical career, I was taught the same rule, only I heard that it was the Eight Hour Rule. I remember patients coming to the ER where I was working as an orderly being told that their laceration could not be sutured because it was, say, ten hours old. I was told that the reason for this was that the risk of infection goes up way up with laceration age and after eight hours, they mostly all got infected. Wrong-o!

The first inkling I had that this is not true was when I was doing my Emergency Medicine residency and was taught about “Delayed Primary Closure.”Delayed primary closure works like this: Let’s say you are faced with a really dirty laceration. Let’s say, for example, that the patient is a dairy worker and the wound has cow manure in it. Believe me, you do NOT want to suture this wound right away!  Instead, what you do is to clean the wound thoroughly, pack the wound with a saline dressing and send the patient home. A day or two later, you check the open wound. If it still looks good, you again place a moist dressing. On day 3-5, if the wound looks clean with no signs of infection, you then sew it up. (Details about Delayed Primary Closure can be found in Roberts: Roberts and Hedges’ Clinical Procedures in Emergency Medicine, 6th ed.; Chapter 34 – Principles of Wound Management >> Closure>>Delayed Primary or Secondary Closure).

Note that this dirty wound was eventually sutured not just longer than 8 hours but up to five (5) days later! If you believe in the original 8-hour rule, this leads to the logical head scratcher that if a wound is ten hours old and is clean and uncomplicated, we can’t sew it up; but if it is grossly dirty, then we can—by doing delayed primary closure. Hmmmm.

Fortunately, we have more to go on than just this comparison to delayed primary closure. The timing of wound closure has actually been studied several times. Here is a sampling:

1. Prediction of traumatic wound infection with a neural network-derived decision model (2003, American Journal of Emergency Medicine) These researchers report that wounds can be repaired up to 24 hours, at least.

2. The impact of wound age on the infection rate of simple lacerations repaired in the emergency department (2012, Injury). This article is a meta-analysis of 418 studies on wound infections related to age. The authors concluded “The existing evidence does not support the existence of a golden period nor does it support the role of wound age on infection rate in simple lacerations.

3. Traumatic lacerations: what are the risks for infection and has the ‘golden period’ of laceration care disappeared? (2014, Emergency Medicine Journal) These researchers evaluated a wide variety of factors relating to wound infections and determined that “There were no differences in infection rates for lacerations closed before or after 12 hours.” (Actually, if you read the article, there was a small difference. The wounds closed after 12 hours in this study actually had a lower infection rate!)

So the literature is clear: You can forget all about any golden period for laceration repair, whether six hours, eight hours or even longer.  If an inmate gets an uncomplicated laceration in the middle of the night, you don’t necessarily have to send him to the ER. It is perfectly appropriate to apply a saline dressing and have the wound sutured at a convenient time the next day.

Of course, these should be uncomplicated wounds. Examples of complicating factors that might lead you to send the patient to the ER immediately include:

1. Bleeding that cannot be controlled
2. Wounds that penetrate into joints
3. Wounds associated with other significant injuries, like broken bones
4. Lacerations of deep structures such as tendons, nerves or deep anatomical layers
5. Lacerations with retained foreign bodies
6. Human bites (As discussed here)

Free Online Medical Education on Laceration Repair

I have noticed that many practitioners in correctional medicine are “rusty” or even have never had adequate training in suturing and wound closure techniques. Closing The Gap is a wonderful free web site devoted to teaching principles of suturing. It has sections on basic suturing techniques, such as basic interrupted sutures, mattress sutures and running sutures, as well as more advanced stuff for those interested.

Definitely bookmark this site in the “Education” folder on your browser!

As always, I express my own opinions on this site. Feel free to disagree! I could be wrong. But if you do, please tell us why in comments!

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