Trauma
Question 131 of 180
A 27 year old man presents to the Emergency Department after falling through a glass door. He has sustained multiple lacerations to both arms. There are no haemodynamic concerns and there is no suggestion of any arterial or nerve injuries. You plan to close the wounds using sutures under local anaesthesia. You have access to 1% lidocaine without adrenaline. Assuming the patient weighs 70 kg, what is the theoretical maximum dose of lidocaine in this patient?
Answer:
- The maximum dose of lidocaine is 3 mg/kg (without adrenaline).
- Therefore the maximum theoretical dose is 70 x 3 = 210 mg.
- 1% lidocaine solution contains 10 mg/ml, therefore the maximum safe volume of 1% lidocaine that can be used in this patient is 21 ml.
Wound Management
Trauma
Last Updated: 3rd October 2022
Definitions
- Abrasion
- Abrasions (grazes or scrapes) are typically the result of tangential blunt force trauma exerting a dragging or frictional force to the superficial skin. Abrasions do not usually penetrate the full thickness of the epidermis, but may do so focally. Abrasions may bleed due to interruption of the dermal papillae. Typically, the end opposite to the point of impact shows heaped up epidermis (and therefore may have some forensic significance in determining the direction of the apparent force). Abrasions can be of varying type such as directional (brush type) resulting from contact with a rough surface (e.g. “road rash”) or finger nail scratches which are often short and curved. Assessment of age of abrasions in isolation may be difficult, but the absence of bleeding, the presence of scabbing, along with the appearance of any associated bruising may be helpful.
- Bruise
- Bruises are extravascular collections of blood caused by various types of blunt force. They may be patterned and can reproduce the shape of the weapon or object responsible (e.g a shoe or fingertip bruises where a grip has been applied. Sometimes a characteristic tramline bruise results from forceful contact with a rounded or squared-off weapon such as a baseball bat. However, the bleeding can track under the skin which leads to pattern disruption. Bruises are often larger where the skin is lax or there is underlying bone (in contrast to the palms or sole of the feet where the skin is thick bruises are seldom seen). In these areas, the bruise may enlarge and track over time. It is important to appreciate this phenomenon if your examination takes place sometime after the injury occurred. For example, a large bruise to the anterior scalp or forehead can track into the periorbital soft tissues, which could be misinterpreted as the site of the initial impact. Assessment of the age of the bruise is not always reliable. Colour changes do not occur in a predictable or linear fashion. The most helpful colour is yellow, which does not appear in bruises less than about 18 hours old.
- Haematoma
- Haematomas are palpable collections of blood, usually in muscle and soft tissue. A common example is the periorbital haematoma or “black eye”. This is often caused by a direct blow, in which case there may be an associated abrasion or laceration. Other causes include the tracking of blood from bruise to the forehead or an orbital plate fracture from contrecoup damage after fall-related impact to the back of the scalp. The scalp should be checked carefully for such injuries and imaging requested as required.
- Bite
- Bites are a pattern of injury produced by human or animal dentitions and associated structures. Bite marks are classified as a form of crush injury because the tooth compresses the skin which leaves an indentation or break. The injury usually consists of abraded and bruised components and often have a curved profile. Bites can be a useful source of DNA and can be expertly analysed by forensic odontologists. Because of the potential for DNA evidence, before cleaning such an injury wet and dry swabs (to capture saliva and DNA) should be considered if clinically feasible and after discussion with the Police.
- Laceration
- Lacerations are full thickness tears to the skin caused by blunt force trauma where the tissues are crushed or torn apart by the object or weapon.
- Lacerations typically exhibit the following features:
- Often gaping
- May be irregular, but can also be linear
- Associated bruising (from being crushed)
- Associated abrasions to the edges
- Tissue bridges in depth of the wound (in contrast the incised wounds)
- Rarely self-inflicted
- Presence of intact hairs which cross the wound (in contrast to incised wounds)
- Relatively little blood loss (unless on the scalp or intra-orally)
- Can be associated with fractures (e.g. underlying depressed skull fracture)
- Incised wounds
- Incised wounds follow sharp force trauma and maybe divided into stab (or puncture) wounds and cuts (or slash) wounds. A stab wound is deeper than it is long but a cut is longer than it is deep. The shape of the wound can sometimes give an indication of the type of object used to inflict it, e.g. a knife or sharp edge of a broken glass, but this may be difficult to determine in slash wounds. An incised wound can be caused by anything sharp which impacts the body with sufficient force to penetrate the skin. Wounds from heavy blades such as axes and machetes can have components of both lacerations and incised wounds.
- Incised wounds typically exhibit the following characteristics:
- The skin wound is often linear, but can be jagged and irregular for example if caused by broken glass or bottles or if the knife has moved in the wound
- The wound edges are cleanly divided
- There is often no adjacent bruising of the skin edges
- Hair follicles are cleanly cut
- The wound bleeds when the injury is sustained. Bleeding can be heavy if vessels are involved.
- Petechiae
- Although not strictly an injury, the documentation of the presence or absence of pinpoint petechial haemorrhages (or petechiae) can prove to be of central forensic importance. Petechiae may develop after alleged airway obstruction or from the application of forceful neck pressure (strangulation). These need to be documented and photographed at the earliest opportunity as they will disappear quickly. If a patient is seen in circumstances where an asphyxial component of an assault is reported, it is important to examine the face, especially around the eyes and eyelids, after makeup has been removed. Petechiae can best be seen inside the eyelids, and in the mouth. It is important to specifically look for petechiae or else these may easily be missed. Other injuries relevant to the alleged assault, such as fingernail abrasions and fingertip bruising around the external airway and on the neck must also be carefully looked for.
Documentation
Clinical notes are extremely useful if recorded correctly in cases of alleged assault. Better note keeping will ensure medical records and police reports are of high standard, helpful to the courts and useful to doctors required to give evidence relying on their notes as a reminder of the case.
Documentation of an injury should include:
- Documentation of where and when examination took place.
- Documentation of a verbatim account of how the patient alleges the injury was sustained.
- Accurate documentation of the type of injury (and consider whether this matches the alleged mechanism of injury.)
- Documentation of the shape of the injury, its location and measurement from a fixed anatomical point. It is recommended that a ruler, scale, or tape measure is used to accurately measure the size of injuries and also measure the distance from a fixed structure. Ideally, photographs should be taken before any treatment is commenced. Body maps can be used to document where the injuries are.
- Documentation of colour.
- Documentation of the presence or absence of active bleeding or clot.
- Documentation of whether it appears to be showing signs of healing.
- Documentation of what treatment, if any, was given.
Management of lacerations
- Disinfect skin around wound using an antiseptic but avoid getting antiseptic in wound
- Keep hair out of wound
- If debriding or exploring the wound, anaesthetise the area. The pain from infiltrating local anaesthetic can be reduced by:
- Using a 25–gauge needle
- Warming the anaesthetic before infiltration
- Infiltrating through the cut edge of the wound into the subdermal tissue
- Infiltrating slowly
- Debride devitalised tissue and remove as much foreign material as possible; inspect for damage to underlying structures
- Refer for radiography if there is a possible foreign body remaining in the wound after cleaning, including all injuries caused by glass
- Irrigate the wound with normal saline
- If there is no underlying injury or foreign body, treat fresh wounds by primary closure as soon as possible. Consider the most appropriate method of wound closure, taking into account the location and severity of the wound, the available expertise and materials, and the age, health, and preference of the person with the wound:
- Steristrips
- Steristrips can be used to close wounds 5 cm or shorter when there are no risk factors for infection AND the wound edges are easily apposed without leaving any dead space AND the wound is not subject to excessive flexing, tension or wetting.
- Always use adhesive strips on pretibial flaps (not tissue adhesive or sutures).
- Medical glue
- Medical glue can be used to close wounds 5 cm or shorter when there are no risk factors for infection AND the wound edges are easily apposed without leaving any dead space AND the wound is not subject to excessive flexing, tension or wetting.
- Particularly useful in children with superficial or scalp wounds; do not use in wounds near the eyes or over joints.
- Sutures
- Preferred for all lacerations longer than 5 cm, or those 5 cm or shorter when: the wound is subject to excessive flexing and tension (such as over joints or thick dermis), or wetting OR when deep dermal sutures are required, to allow low-tension apposition of wound edges.
- Medical staples
- Quick and easy to use but produce a poorer cosmetic result than other methods of closure.
- Particularly suited to scalp wounds.
- Steristrips
- Apply a dressing after closing the wound
- Some wounds may require secondary closure (no intervention, heals by granulation) or delayed primary closure (surgical closure 3 - 5 days after injury). Wounds not usually suitable for primary closure in the ED include:
- Stab wounds to the trunk and neck
- Wounds with associated tendon, joint or neurovascular involvement
- Wounds with associated crush injury or significant devitalised tissue
- Other heavily contaminated or infected wounds
- Most wounds > 12 hours old
- Consider tetanus immunisation status and prophylaxis
- Arrange follow up for removal of closure method, if necessary:
- For lacerations closed by sutures, remove stitches after:
- 3–5 days for wounds on the head
- 10–14 days for wounds over joints
- 7–10 days for wounds at other sites
- For lacerations closed by adhesive strips, advise the person to remove these themselves with similar timeframes as above.
- For lacerations closed by tissue adhesive, advise the person that this will slough off naturally after 7-10 days.
- For lacerations closed by sutures, remove stitches after:
- Provide verbal and written advice to patient:
- Seek medical attention of they develop signs or symptoms of infection
- Take simple analgesia if the wound is painful or likely to become painful
- Keep the wound clean and dry
Wound infection
- Management of laceration that is at high risk of infection:
- Dress but do not close a laceration that is at high risk of infection; prevent apposition of wound edges by packing the laceration with a non-adherent dressing
- Consider the need for prophylactic antibiotics
- Review 3 - 5 days after presentation and close if there are no signs of infection
- Risk of infection in people with a laceration is increased with:
- Wound contaminated with soil, faces, body fluid or pus.
- Wound length of more than 5 cm.
- Foreign body present before cleaning of wound.
- Diabetes mellitus.
- Oral corticosteroid treatment and other causes of immunosuppression.
- Age older than 65 years.
- Stellate shape or jagged wound margins.
- Wound location on the lower extremity.
- Presentation more than 6 hours after injury
- Signs of infection:
- Localised signs
- Redness
- Heat
- Swelling
- Increase in pain
- Discharge
- Friable tissue
- Possible general malaise, fever, rigors and lymphadenopathy
- Localised signs
- Management of infected laceration:
- Dress but do not close a laceration that is infected; prevent apposition of wound edges by packing the laceration with a non-adherent dressing
- Prescribe antibiotic treatment for 5–7 days
- Treat contaminated lacerations (with soil, faeces, saliva or purulent exudate) with co-amoxiclav (or erythromycin/clarithromycin + metronidazole if penicillin allergic)
- Treat clean lacerations (no history or evidence of contamination or foreign body) with flucloxacillin (or erythromycin/clarithromycin if penicillin allergic)
- Take a swab of the wound before starting antibiotic treatment
- Review 3 - 5 days after presentation and close if there are no further signs of infection
- If infection develops after closure of laceration:
- Remove sutures or adhesive strips and incise if it is not draining
- Take swabs from any discharge for microbiological investigation and start empirical antibiotic therapy while awaiting results
Complications
- Vascular damage
- Nerve damage
- Tendon/tendon sheath damage
- Bony injury or fracture
- Retained foreign body
- Wound infection
- Tetanus
- Scarring and cosmetic damage
Suspecting non-accidental injury
Although rare, suspect child maltreatment ifa child has lacerations, abrasions, or scars and the explanation is inconsistent or unreliable.
- Examples include lacerations, abrasions, or scars:
- On the neck, ankles, or wrists, that look like ligature marks.
- On the eyes, ears, or sides of the face.
- On areas usually protected by clothing (such as the back, chest, abdomen, axilla, and genital area).
- With a symmetrical distribution.
- That are multiple.
- On a child who is not independently mobile.
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- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
