Wound care

Infection kills more people from wounds than the original injury does. In a hospital, a contaminated laceration gets irrigated, debrided, and observed by trained staff. In the field or during a grid-down scenario, you are the hospital. The difference between a wound that heals and one that sends bacteria into the bloodstream is usually irrigation volume, closure timing, and daily inspection discipline — not antibiotics, not fancy dressings.

Educational use only

This page provides general educational information for emergency preparedness scenarios when professional medical care is unavailable. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider. Use this information at your own risk.

Wound assessment

Before treating anything, classify the wound. Each type carries a different infection risk and a different approach to cleaning and closure.

Abrasion: Friction removes the outer skin layers. The wound bed is usually contaminated with road debris, dirt, or gravel. No closure required — the priority is thorough scrubbing to remove embedded particles. An abrasion that is not scrubbed clean will heal with embedded debris (traumatic tattooing) and may become infected.

Laceration: A cut through skin, ranging from superficial to deep. A shallow laceration through the epidermis and upper dermis can close on its own or with strips. A deep laceration that reaches the fat layer or muscle requires closure and monitoring for dead space underneath. Jagged-edged lacerations from blunt trauma carry more contamination than clean knife cuts.

Puncture wound: A narrow, deep channel driven by a nail, wire, thorn, or blade. The opening is small but the depth is deceptive. Punctures are among the most dangerous wounds to manage because the narrow track traps bacteria and debris deep in tissue, irrigation cannot fully reach the base, and the entry wound closes over quickly — sealing contamination inside. Never close a puncture wound. Leave it open, irrigate as deeply as possible, and watch obsessively for infection.

Avulsion: A flap of skin or tissue is partially or completely torn away. If the flap is still attached and blood supply appears intact (the tissue is pink, not white or black), fold it back into position and hold with a light dressing. Do not remove it — even a badly damaged flap may survive with intact subdermal vessels. If the flap is fully detached and small, keep it moist in saline-soaked gauze in case a surgeon can reattach it; otherwise treat the wound bed as an open wound.

Bite wound (animal or human): Among the highest-risk wound types. The oral cavity contains aggressive bacteria — Pasteurella multocida from dog and cat bites, Eikenella corrodens from human bites — that flourish in closed tissue. Do not close bite wounds, especially on the hand. Irrigate aggressively, leave open, and start antibiotics (amoxicillin-clavulanate, or doxycycline as second choice) if available. Cat bites are more dangerous than they look; the narrow puncture tooth drives bacteria deep and seals shut.

Crush injury: Caused by a heavy impact that compresses tissue rather than cutting it. The external wound may look minor while significant damage exists underneath — dead muscle, hidden bleeding, and disrupted microcirculation. Infection risk is high because crushed dead tissue is a feeding ground for bacteria. Watch for swelling that continues to worsen after the first 24–48 hours, which can indicate compartment syndrome — see fractures and splinting for assessment protocol.

Depth and contamination decision grid

Wound type	Closure?	Antibiotic coverage?	Watch for
Clean abrasion	No — leave open	Not usually	Retained debris; reassess at 48 h
Clean laceration, <6–8 h old	Yes — strips or sutures	Not usually	Infection signs
Laceration, >8–12 h old	Delayed or none	Consider	Infection first, close later if clean
Puncture	No	Yes if deep or dirty	Abscess forming under skin
Bite (dog, cat, human)	No	Yes — start now	Rapid cellulitis within 12–24 h
Avulsion with attached flap	Approximate; do not remove flap	Consider	Flap necrosis, dark color
Crush injury	No	Consider	Progressive swelling, numbness

Irrigation and cleaning

Irrigation is the single most effective intervention in wound care. Research from the American College of Surgeons defines high-pressure lavage as 35–70 pounds per square inch (psi). This range removes bacteria and debris without driving contaminants deeper or damaging viable tissue — pressures above 70 psi begin to cause tissue injury. The trick is achieving adequate pressure with available equipment.

Building your irrigation setup

A 35–50 mL syringe with an 18–19 gauge angiocatheter tip or blunt needle produces approximately 25–40 psi when you push the plunger firmly with both hands. A 20 mL syringe with an 18-gauge angiocatheter delivers approximately 12–13 psi — still within the low-end therapeutic range and acceptable when that is all you have. A squeeze bottle with a small-diameter tip produces unpredictable pressure. Do not use a squeeze bottle for contaminated wounds if a syringe is available.

Saline vs. clean water: Normal saline (0.9% sodium chloride) is the gold standard because its osmolality matches tissue fluids, preventing cell damage. In field conditions, clean potable water is an acceptable substitute for most wounds. Use it rather than waiting for saline. Do not use hydrogen peroxide — it damages healing tissue and is no better at reducing infection than saline.

Irrigation procedure

Put on gloves. If gloves are unavailable, wash your hands thoroughly with soap and water for at least 20 seconds.
Fill a 35–60 mL syringe with saline or clean water. Attach an 18–19 gauge tip.
Hold the syringe tip 1–2 inches (2.5–5 cm) from the wound surface — not pressed against it.
Push the plunger firmly and continuously. Aim the stream into the deepest visible part of the wound.
Use at least 100–250 mL of fluid per inch (2.5 cm) of estimated wound depth as a practical baseline. Recheck debris removal and refill repeatedly until the effluent runs clear.
For contaminated wounds with visible dirt or debris, physically scrub the wound bed with a gauze pad after irrigation to dislodge embedded particles. Scrub firmly — gentle dabbing does not remove adherent contamination.
For abrasions, use a stiff-bristled brush or coarse gauze and scrub the wound surface under running water. This is painful but necessary to remove embedded particles.
For puncture wounds: insert the syringe tip gently into the wound entrance and irrigate into the channel with each syringe fill. You will not reach the bottom, but you will reduce the bacterial load at accessible depths.
Blot the wound dry with clean gauze after irrigation. Do not rub.

Field note

If you have no syringe, a clean plastic bag with a pinhole, a water bottle with a small-hole cap, or a squeeze bottle can approximate low-pressure irrigation. Fill, squeeze firmly, aim at the wound. It is imperfect but far better than no irrigation. Volume matters more than perfect pressure.

Wound closure options

Closing a wound brings the edges together to reduce dead space, protect the bed, and speed healing. But a closed wound that is contaminated creates an abscess. The decision to close must account for wound age, wound type, contamination level, and available supplies.

When NOT to close

Do not close any of the following, regardless of appearance: - Puncture wounds - Animal or human bites - Any wound more than 8–12 hours old (or more than 24 hours on the face, which has excellent blood supply) - Any wound with visible signs of infection: pus, surrounding redness expanding past the wound margin, warmth, fever - Heavily contaminated wounds that you cannot be certain are clean after irrigation - Wounds over joint spaces (high tension prevents closure strips from holding)

Wounds that should not be closed may be managed as delayed primary closure — irrigate and dress daily, and close with strips once they remain clean for 72–96 hours and infection has not developed.

Closure strips (Steri-Strips or butterfly closures)

The right tool for most field lacerations. They reduce infection risk compared to sutures because they do not puncture the skin. They are appropriate for: - Clean, low-tension lacerations less than 1 inch (2.5 cm) long - Shallow wounds not extending into fat or muscle - Wounds in areas with loose, mobile skin (forehead, shin) - Wounds in patients where the risk of suturing-related infection is high

Applying closure strips:

Dry the wound edges completely. Strips do not adhere to wet skin. Use gauze to blot moisture, and if available, apply a small amount of tincture of benzoin to the skin immediately adjacent to the wound (not inside it) to improve adhesion.
Hold the wound edges together with your fingers, bringing them into full contact.
Apply the first strip perpendicular to the wound, anchoring one end 1/2 inch (1.2 cm) from the wound edge on one side. Pull gently across and press the other end down 1/2 inch (1.2 cm) on the opposite side.
Apply strips every 1/4 inch (6 mm) along the wound length.
Apply a second layer of strips parallel to the wound on each side, connecting the ends of the perpendicular strips to form a ladder pattern. This redistributes tension and prevents the strips from peeling off.
Do not cover strips with occlusive tape — the wound needs to breathe.

Sutures (if trained and equipped)

Sutures are appropriate for deep lacerations with dead space underneath, wounds with wound edges that cannot be approximated by strips, and scalp lacerations. The suturing technique itself (simple interrupted) requires training and practice. If you have not practiced on a suturing kit beforehand, strips are safer. A poorly placed suture in contaminated tissue creates an abscess under a false seal.

Staples are faster than sutures for long scalp lacerations and trunk wounds and carry a similar infection risk to sutures. They are less useful on face, hands, or over joints where skin is thin or under tension.

Dressing and bandaging

A wound dressing has three functional layers. Get this wrong and the dressing either sticks to the healing wound bed (damaging it on removal) or does not absorb enough drainage and becomes a moist bacterial medium.

The three-layer system

Layer 1 — Non-adherent contact layer: Sits directly on the wound bed. Petroleum-impregnated gauze (Adaptic, Xeroform), silicone dressings, or a commercial non-stick pad. This layer protects the healing tissue from being pulled off when the dressing is changed. Do not use plain dry gauze directly on a wound bed — it adheres to granulation tissue.

Layer 2 — Absorbent layer: Standard gauze pads (2×2 or 4×4 inch / 5×5 or 10×10 cm). These absorb drainage and wick it away from the wound surface. Use more than one pad for heavily draining wounds.

Layer 3 — Securing wrap: Conforming bandage roll (Kerlix, Kling) or self-adhesive cohesive wrap. Wrap snugly but not tight enough to impair circulation. A test: you should be able to slide one finger under the wrap easily. Check capillary refill — press on the nail bed distal to the dressing and release; color should return in under 2 seconds.

Dressing change frequency

First 24 hours: Leave the first dressing undisturbed unless it becomes soaked, falls off, or becomes visibly contaminated. Disturbing a fresh wound disrupts early clot formation.
24–72 hours: Change daily or when the outer layer is saturated.
After 72 hours with no infection signs: Every 48–72 hours. Healing wounds need less frequent changes once granulation (new pink tissue) begins forming.
Any time: If the dressing is wet from external contamination, falling off, has visible pus underneath, or the patient reports significant increase in pain.

Wet wounds and maceration

A constantly wet wound bed is as dangerous as a dry one. Prolonged moisture softens healthy skin around the wound (maceration), making it fragile and susceptible to infection. If a wound drains heavily, increase the absorbent layer thickness. If a wound is on a limb that gets wet (sweat, rain, water work), seal the dressing edges with tape and change it promptly if it gets wet.

Monitoring for infection

Infection begins at the cellular level before any visible sign appears. By the time you see redness or pus, the process is already 24–48 hours along. Understanding the timeline helps you catch it earlier.

Infection timeline

Time since injury	What is happening	What you see
0–24 hours	Normal inflammatory response	Redness and warmth at wound edge; swelling; this is expected
24–48 hours	Bacterial colonization of wound bed	Wound may produce cloudy discharge; normal wound fluid is clear to straw-colored
48–72 hours	Early infection, if present	Increasing redness beyond the wound margin; increasing pain rather than decreasing; yellow-green or opaque discharge
3–5 days	Spreading cellulitis	Redness expanding outward daily; marked warmth; red borders you can trace; fever above 100.4°F (38°C)
5–7 days	Systemic involvement	Fever above 102°F (38.9°C); red streaks running from wound toward trunk; lymph node swelling in groin, armpit, or neck
7+ days	Bacteremia / sepsis risk	Confusion, rapid heart rate, falling blood pressure, extreme weakness

What to look at daily

Every wound assessment takes less than two minutes. Do it the same time each day.

Remove the dressing. Note the smell — infected wounds have a distinctive foul odor that clean wounds do not.
Observe the wound discharge: clear or lightly pink is normal. Cloudy yellow, green, or brown discharge indicates infection.
Measure the redness boundary. Mark it with a pen or note a landmark. If redness has expanded since yesterday, that wound is actively infected.
Check skin temperature around the wound: hot and radiating outward is abnormal beyond 48 hours.
Check for red streaks (lymphangitis) running from the wound toward the body core. These are a sign that bacteria are in the lymphatic vessels and moving toward systemic circulation. This is an emergency — it requires antibiotics immediately and evacuation if available.
Check the patient's temperature. Fever above 100.4°F (38°C) associated with a wound requires antibiotic treatment.
Re-dress with a fresh dressing after assessment.

Field note

Use a permanent marker to outline the edge of any redness on the skin. Date and time the line. This simple technique turns a subjective "it looks bigger" into objective documentation — either the redness is outside the line tomorrow or it is not. Hospital emergency departments use this same technique for tracking cellulitis.

Escalation criteria

Some wounds cannot be managed in the field regardless of your skill level. Knowing when to stop trying is as important as knowing how to treat.

Escalate immediately (seek professional care urgently, or administer antibiotics without delay if unavailable):

Red streaks extending from the wound toward the body core (lymphangitis)
Fever above 102°F (38.9°C) associated with a wound
Swelling that is hard, tense, and disproportionate to the injury, especially if accompanied by intense pain — possible abscess requiring drainage
Wound discharge that is thick, copious, and foul-smelling despite daily cleaning
Any wound on the hand, foot, or over a joint that is not improving after 72 hours — these locations have high infection consequence

Escalate urgently (arrange transport or begin antibiotics, do not delay dressing changes):

Wounds with numbness, tingling, or loss of movement distal to the injury — possible nerve or tendon damage
Wounds that actively bleed with each dressing change despite appropriate treatment
Any wound in an immunocompromised person (diabetes, HIV, steroid use) that is not improving within 48 hours — immune suppression dramatically accelerates infection

Manage and monitor (continue field care, no immediate escalation):

Normal redness and warmth at the wound edge within 48 hours
Clear to slightly cloudy discharge in a wound with no odor
Mild pain that is decreasing over the first 48–72 hours

For the intersection of wound infection and systemic illness management, see infection. For bleeding control before wound care can begin, see bleeding control.

Wound care kit

Assemble a wound module inside your home medical kit. Every item below serves a specific function — there is no padding on this list.

Item	Quantity	Function
Saline solution (0.9%), 500 mL bag or bottle	2–4	Irrigation; wound rinse
35–60 mL syringes	4	High-pressure irrigation delivery
18–19 gauge angiocatheters or blunt irrigating tips	6	Achieve 25–40 psi from syringe
Non-adherent dressings (Adaptic, Telfa), 3×3 inch (7.5×7.5 cm)	20	Contact layer — prevents wound bed disruption
Gauze pads, 4×4 inch (10×10 cm), sterile	30	Absorbent layer; wound cleaning
Gauze pads, 2×2 inch (5×5 cm), sterile	20	Smaller wounds; packing support
Conforming gauze roll (Kerlix), 3 inch (7.5 cm)	6	Securing wrap layer
Medical tape (1 inch / 2.5 cm)	2 rolls	Securing dressings
Closure strips (Steri-Strips), 1/4 inch × 3 inch (6 mm × 7.5 cm)	4 packs	Primary closure for clean lacerations
Tincture of benzoin swabs	10	Adhesion enhancement for strips
Nitrile gloves (medium and large)	10 pairs	Universal precautions
Irrigation splash guard (optional)	1	Protect eyes during high-pressure flush
Permanent marker	1	Track cellulitis margins
Penlight	1	Wound depth inspection
Stiff-bristled scrub brush (sterile or clean)	2	Abrasion decontamination
Antiseptic wipes (chlorhexidine or povidone-iodine)	20	Skin surface prep around wound

Wound care readiness checklist

Assemble the wound module and store it in the home medical kit
Practice the irrigation setup — fill a 35 mL syringe, attach the tip, and practice pushing pressure on a wet sponge before you need to do it on a wound
Memorize the wounds-not-to-close list: punctures, bites, old wounds, contaminated wounds, infected wounds
Stock a permanent marker specifically for tracking cellulitis margins
Review the infection timeline table monthly — it is easy to forget that redness in the first 48 hours is expected, while redness at day 3–5 is not
Cross-reference your antibiotic stock: amoxicillin-clavulanate covers bite wounds; the dental kit's amoxicillin is second choice
Know when escalation is not optional — red streaks, high fever, numbness distal to wound

Good wound care keeps the bacteria out, supports the body's own healing, and catches the 10% of wounds that are heading in the wrong direction before they turn into a systemic problem. For injury scenarios where bleeding control must happen before wound care is possible, see bleeding control. For the downstream problem of a wound that progresses to systemic infection, see infection.