Field Suturing: When to Suture, Basic Technique, and What You Need

The Case Against Premature Suturing

Before getting into technique, understand what you are committing to when you suture.

Suturing closes a wound permanently until the sutures are removed. Any bacteria, debris, or devitalized tissue sealed inside will multiply without drainage. A sutured wound that becomes infected is significantly more dangerous than the same wound left open — the infection cannot drain, it tracks along tissue planes, and it may require surgical debridement that would not have been necessary if the wound had been left open.

This is why the decision to suture requires judgment, not just technique. Ask yourself:

• Is the wound genuinely too large or gaping for strips?
• Is it definitely clean and well-irrigated?
• Is it fresh enough (under 6-8 hours for most wounds, 12 hours for face)?
• Is there no possibility of getting professional care in the next 24-48 hours?

If the answer to all four is yes, and you have the materials and training, suturing is appropriate.

Materials Required

Suture Thread

Suture thread comes on a needle attached to the thread (atraumatic, or "swaged," sutures). The needle and thread together are packaged sterile.

For field kits, stock:

• 3-0 nylon on a curved cutting needle: general skin closure on trunk, back, extremities
• 4-0 nylon on a curved cutting needle: face, hands, areas needing finer work
• 2-0 nylon or polypropylene: scalp lacerations where strength matters more than fineness

Needle types:

• Cutting needle (triangular cross-section): cuts through skin. Use for skin closure.
• Taper needle (round cross-section): used for internal layers, gut, and muscle. Not for skin.

Nylon monofilament is the standard. It does not absorb water, does not harbor bacteria in its structure, is easy to handle, and has low tissue reactivity. It must be removed — it does not dissolve.

Do not use: multifilament silk (wicks bacteria), braided synthetic thread for skin (infection risk), or any non-sterile thread.

Instruments

Minimum required:

• Needle driver (needle holder): a locking hemostat-style clamp with serrated jaws for gripping the suture needle
• Iris scissors or suture scissors for cutting thread
• Tissue forceps (toothed Adson or thumb forceps) for handling wound edges without crushing them
• Clean gloves

In an extreme emergency without a needle driver, artery forceps (hemostats) can grip the needle, but they damage it.

Cannot substitute: fingers for driving the needle. You will not maintain control, you risk needlestick injury, and you cannot generate enough directional force for proper placement.

Anesthesia

Suturing a conscious person without anesthesia is inhumane and impractical — the patient will involuntarily withdraw from the needle, making precise placement impossible.

Lidocaine 1% or 2% is the standard. Infiltrate the wound edges: insert the needle into the wound edge at 45 degrees, aspirate briefly (verify you are not in a vessel), then slowly inject while withdrawing the needle. Raise a wheal of anesthetic in the subcutaneous tissue on both sides of the wound. Wait 3-5 minutes for full effect.

If lidocaine is not available: topical anesthetics like LMX4 cream (4% lidocaine) applied to the wound surface for 30-60 minutes provide partial anesthesia for superficial work. Less effective for deeper wounds.

Without anesthesia, limit your suturing to wounds where the alternatives (uncontrolled bleeding, complete wound dehiscence) are worse than the procedural pain.

Sterile Technique

You cannot achieve surgical sterility in the field. What you can do is minimize contamination:

1. Wash hands thoroughly, use clean gloves
2. Clean the skin around the wound with betadine or alcohol swab — not in the wound, around it
3. Drape the wound area with clean material if available
4. Open suture packages onto a clean surface without touching the suture thread with bare hands
5. Do not put down an instrument and pick it back up after it contacts a non-sterile surface

Perfect is the enemy of good here. Clean technique in a field setting is vastly better than no closure and no technique.

The Simple Interrupted Suture

The interrupted suture is the foundation technique. Each suture is placed and tied independently. If one suture fails or needs to be removed, the others remain intact. It handles virtually all wound types a non-surgeon will encounter.

Placement

1. Grasp the needle in the needle driver approximately two-thirds of the way from the tip to the thread end. The needle should be perpendicular to the jaws, secured firmly.

2. Position the needle perpendicular to the wound edge, approximately 4-5mm from the wound edge (further for thick skin or under-tension wounds, closer for thin skin or delicate areas).

3. Enter the skin with the needle at 90 degrees to the skin surface. This is critical. A needle entering at an angle creates a stitch that inverts the wound edge — the opposite of what you want.

4. Using a pronating wrist motion (turning the wrist to follow the curve of the needle), drive the needle through the dermis and subcutaneous tissue, emerging in the wound space.

5. Release the needle from the driver, regrasp the exposed needle tip from inside the wound, and complete the arc — driving the needle through the opposite wound edge, entering from inside and emerging on the skin surface at the same depth and distance from the wound edge as the entry point.

6. Pull the thread through until approximately 2-3cm of tail remains on the entry side.

Tying the Knot

The instrument tie is easier to learn than a hand tie:

1. Wrap the thread coming from the wound twice around the needle driver jaws (counterclockwise).
2. Grasp the tail end of the thread with the needle driver.
3. Pull the tail through the loops. Pull both ends in opposite directions until the knot seats on the skin surface. Do not pull too hard — the wound edge should approximate, not strangulate.
4. This is the first throw. Add two more single throws in alternating directions (clockwise, then counterclockwise) to lock the knot.
5. Cut the tail ends at approximately 5-7mm from the knot. Long enough to grasp for removal, short enough not to catch on everything.

Suture Spacing and Number

Place sutures 5-7mm apart for face wounds, 8-10mm apart for trunk and extremity wounds. Cover the entire length of the wound — do not leave gaps at the ends.

The wound edges should be slightly everted (rounded upward) after closure, not flat or inverted. Everted wounds heal with a better cosmetic outcome because the scar flattens over time. Inverted wounds heal as a depressed scar.

Common Beginner Errors

Suturing too tightly. The most common mistake. Tight sutures cause tissue strangulation, blanching, necrosis at the wound edges, and dramatic scarring. The wound edges should touch, not be compressed together. Remember: tissue swells for 24-48 hours post-injury. A suture that looks right will be too tight by the next day.

Shallow passes. Not getting the needle deep enough fails to capture the dermis on both sides, creating a weak closure that pulls through. Enter at 90 degrees, go through dermis on both sides.

Unequal depth on the two sides. If you enter 5mm deep on one side and 10mm deep on the other, the wound edge will step — one side will be higher than the other. Symmetrical placement is the goal.

Not approximating edges before tying. Before you tie the knot, use your forceps to press both wound edges to the midline. You are confirming the placement is correct before committing.

Suturing too close to the wound edge. If you place the suture 2mm from the wound edge instead of 5mm, it pulls through. Standard placement is 4-5mm from edge on most wounds.

Removal

Sutures remain in place for:

• Face: 5-7 days
• Scalp: 7-10 days
• Trunk: 10-14 days
• Extremities: 14 days
• Over joints: 14-21 days

To remove: grasp the knot with forceps. Insert one blade of sharp scissors under the knot loop, between the knot and the skin surface. Cut the thread on one side of the knot only. Pull the knot upward — this draws the subcutaneous portion of the thread out through the skin surface rather than pulling the surface-contaminated portion through the tissue.

Cutting both sides creates two pieces that must each be separately extracted, and you may leave a fragment.

Post-Suture Monitoring

Check sutured wounds daily:

• Normal for 24-48 hours: mild redness, swelling, bruising around the wound
• Concerning: redness expanding beyond the immediate wound edge, increased warmth, pus forming under sutures, fever, wound opening despite sutures
• Indication to open the wound: any sign of infection. Open the wound by removing the sutures, irrigate thoroughly, and allow it to drain as an open wound. An open infected wound heals better than a sutured one.

Building the Skill Before You Need It

Suturing is a manual skill. Reading about it prepares you intellectually. Doing it prepares you practically.

Training options:

• Suture practice kits: foam pads or fake skin designed for suture practice. Available for $30-50.
• Suture/wound closure courses: TCCC (Tactical Combat Casualty Care), WFR (Wilderness First Responder), or dedicated suturing workshops
• Meat from the butcher: pork belly skin closely approximates human tissue thickness and resistance

Practice the instrument tie until you can do it in under 30 seconds. Practice placing ten sutures on foam without looking at the knot. Practice with gloves on, because you will always be wearing gloves in real use.

The first time you suture a real wound should not be the first time you have ever sutured anything.