Events Surrounding the Injury

Timing of the Injury
It is best to close an open wound within 6 hours of injury. Do not close
a wound after 6 hours because the risk of infection becomes unacceptably
high.
Wounds on the face are exceptions to this rule. The face has an excellent
blood supply, which makes infection less likely. In addition, cosmetic
concerns are important. It is therefore acceptable to close a
wound on the face that is older than 6 hours (perhaps up to 24 hours or
at most 48 hours), as long as you can clean it thoroughly.
Nature of the Injury
• A wound caused by a clean knife has a low risk of infection.
• Adirty wound carries a risk for tentanus. Wood may break off and
leave pieces behind, increasing the risk for subsequent infection if
the wound is not explored and washed out thoroughly.

• Any wound that may contain a foreign body should be explored and
the foreign body removed.
• Animal bites, especially cat bites, often penetrate more deeply than
you think. Bites on the hand should raise concern about involvement
of an underlying joint. Oral bacteria may cause severe infections (see
chapter 36, “Hand Infections”). Always consider the risk of rabies.
• Human bites also are associated with specific oral bacteria that may
cause serious infections (see chapter 36, “Hand Infections”).
• If any object penetrated the patient’s clothing or shoes before piercing
the skin, the chance for infection is increased because pieces of
clothing may become embedded in the underlying tissues. If an
object penetrated the patient’s tennis shoes, be concerned about a
possible pseudomonal infection.
• Crush injuries may be associated with greater underlying damage
than initially appreciated (see chapter 35, “Crush Injury”).
• Gunshot wounds: see chapter 37, “Gunshot Wounds.”
• Thermal or electrical injury: see chapter 20, “Burns.”
Concerns about Tetanus
Table 2. Risks for Tetanus


Concerns about Rabies
Be aware of the risk of rabies in the area where you work. Some countries—
England, for example—have no cases of rabies because of tight
animal controls. In most other countries, rabies is a real concern.
The primary animals associated with rabies infections include bats,
raccoons, skunks, and foxes. Because different areas have a different
risk for specific animals, know your area. Dogs and cats also can be infected;
be sure to ask if the animal has been vaccinated against rabies.
Livestock, rodents (e.g., rats, mice, squirrels), and rabbits are almost
never associated with a risk of rabies.

If you have fears that the animal is rabid:
1. Thoroughly clean the wound with soap and water.
2. Administer human rabies immunoglobulin, 20 IU/kg total. If possible,
administer one-half of this around the wound, and give the rest
in the gluteal area intramuscularly (IM).
3. Administer one of the three types of rabies vaccines currently available:
1.0 ml IM in the deltoid area of adults and older children, outer
thigh (not gluteal area) in younger children. Repeat on days 3, 7, 14,
and 28.

About the Patient

Tetanus Immunization Status
Tetanus is a devastating disease, causing muscle spasms that can lead
to muscle rigidity and seizures. Without adequate treatment, one in
three adults with tetanus will die. Although immunization has made
tetanus uncommon, it always lurks in the background.
If the patient has not had a tetanus booster within 5 years, and the
wound is tetanus-prone (see Table 2), a booster should be given. If the
wound is not tetanus-prone but the patient has not had a tetanus
booster within 10 years, a booster should be given. Patients who have
never been immunized need human tetanus immunoglobulin as well as
tetanus toxoid followed by completion of the full tetanus toxoid series.


Note: Tetanus toxoid and immunoglobulin must be kept refrigerated at
all times during transport from the factory. This requirement may be a
problem in remote areas.
Pulsatile Bleeding at Time of Injury
Even if the patient is not bleeding at the time of your examination, the
history of bright red, pulsatile bleeding at the time of injury implies an
arterial injury. Athorough vascular exam is required, and formal surgical
wound exploration is almost always indicated.
Medical Illnesses
Patients with diabetes are more prone to infections and wound-healing
problems. Encourage diabetic patients to keep glucose levels well controlled
to decrease the risk of complications. Malnourished patients
and patients with human immunodeficiency infection (HIV) or a history
of cancer also have wound-healing difficulties.
Smoking History
Tobacco smoking dramatically decreases circulation to the skin and
slows down the wound-healing process. Medical professionals have a
duty to tell all patients not to smoke. But the patient with an open
wound should be specifically warned that smoking interferes with and
perhaps prevents the healing process. Smoking also increases the risk
for wound complications and poor cosmetic outcome.

EVALUATION OF AN ACUTE WOUND

KEY FIGURE:
Irrigating a wound


This chapter explains the basics for evaluation and treatment of an
acute wound. Proper evaluation helps to determine the appropriate
next step—formal wound exploration or wound closure.
The first step is to control blood loss and evaluate the need for other
emergency procedures (see chapter 5, “Evaluation of the Acutely
Injured Patient”). The second step is to obtain a thorough history
about the patient and the events surrounding the injury.

Needle Thoracostomy

Needle thoracostomy is a life-saving procedure that is easy to do in patients
with tension pneumothorax. All health care providers should be
aware of this technique.
If conscious, the patient with tension pneumothorax is severely short
of breath and blood pressure is low. If unconscious, the patient may
simply be hypotensive and not breathing well.
If you listen over the chest for breath sounds, you may appreciate a
loss of breath sounds on the side of the pneumothorax, but this may be
difficult to appreciate in the emergency setting.

Another method is to feel the patient’s neck. The trachea shifts away
from the side with the tension pneumothorax.
If you cannot hear breath sounds in either side of the chest, the trachea
is in the midline, and the patient is in shock, treat both sides of the
chest. The patient may have bilateral tension pneumothoraces.
Equipment Needed
1. Large catheter for intravenous access (12 or 14 gauge). A large-bore
needle can be used if a catheter is not available, but the catheter is
safer. The needle can injure an underlying structure more easily.
2. Betadine, if available.
Procedure
1. Apply Betadine to the chest. Simply pour it on—this is an emergency!
2. Place the catheter, with the needle in place, into the affected side of
the chest at the second interspace in the midclavicular line (the
imaginary line drawn perpendicular to the clavicle at its midpoint).
3. Locate the second interspace.
• The second interspace is the space between ribs 2 and 3.
• It can be located by feeling for the spot on the breastbone (sternum)
where the manubrium and sternum meet (the point where
you can feel an elevation in the bone as you rub your fingers up
and down the breastbone).
• Move your fingers to the right or left chest (depending on where
the problem is). You should be at the second interspace when you
are at the midclavicular line.
4. The intercostal vessels run just below each rib. To prevent injury to
these vessels, the catheter should be inserted into the chest at the
second interspace just above the third rib.
5. If you inserted a catheter, remove the needle, but leave the catheter
in place. You will hear a big whoosh from the escaping air.
6. Leave the catheter in place until help arrives.
7. If you used a needle, you should hear the air escape as soon as you
enter the pleural space. Leave the needle in place until help arrives.
8. The patient requires a chest tube for definitive treatment of the
pneumothorax, but you may have just saved the patient’s life.


Emergency needle thoracostomy. At the midclavicular line, insert a large (14-
gauge) needle or vascular catheter into the chest at the second interspace just
above the third rib. You will hear a large rush of air when the needle enters the
chest.

Bibliography
1. Creech O, Pearce CW: Stab and gunshot wounds of the chest. Am J Surg 105: 469–483,
1963.
2. Melio FR: Priorities in the multiple trauma patient. Emerg Med Clin North Am
16:29–43, 1998.
3. Simon RR, Brenner BE: Emergency Procedures and Techniques, 3rd ed. Baltimore,
Williams & Wilkins, 1994, pp 71–75.
4. Walls RM: Cricothyroidotomy. Emerg Med Clin North Am 6:725–736, 1988.
5. Walls RM: Management of the difficult airway in the trauma patient. Emerg Med Clin
North Am 16:45–61, 1998.

Case Study

An 18-year-old man is brought into the hospital after being stabbed in
the right upper arm with an icepick. He complains of pain in the arm
but otherwise seems to be uninjured. You roll up his sleeve to examine
the arm and see entrance and exit sites. Since he has good pulses in
the extremities, you think that he is stable. While you are doing some
paperwork, he becomes very short of breath and hypotensive. What
happened?
If you had removed his shirt, you would have seen that the puncture
went through the arm and into the right chest. A pneumothorax developed.
Because he was young and healthy, he was able to tolerate it
until the pressure built up in the chest cavity. At that point he developed
a tension pneumothorax—a true emergency!
Only when the patient is stable from the perspective of the ABCs can you undertake
specific evaluation of more obvious injuries.

ABCs of Trauma Care

Following the ABCs (airway, breathing, circulation) and DE (disability
and exposure) of trauma care prevents you from getting sidetracked by
the patient’s obvious injury (arm fracture, for example) and thereby
missing a more life-threatening but less obvious injury.
Airway
An open airway (i.e., the path from the nose/mouth to the lungs) is
vital for the patient to be able to breathe. You need to determine

quickly whether the airway is blocked. Blockage may be due to the
tongue, vomit, blood, or foreign bodies.
Signs of Airway Obstruction
In patients breathing on their own, signs of airway obstruction include
noisy breathing on inspiration and retractions of the supraclavicular
space (area above the clavicle) or intercostal space (between the
ribs) with attempts at respiration. In nonbreathing patients, it may be
difficult to diagnose airway obstruction. You must look directly into
the mouth and examine for signs of obstruction.
How to Maintain an Open Airway
• Clear out any blood or vomitus in the mouth.
• In an unconscious patient, the tongue may obstruct the airway because
of loss of tone in the muscles of the lower jaw (mandible).
• Proper patient positioning often relieves obstruction due to a posteriorly
displaced tongue.
• To position the tongue forward, gently lift the chin to bring the
mandible forward. Be careful not to extend the cervical spine (because
of concerns about possible undiagnosed cervical spine injury).
• An artificial oral or nasal airway tube can be useful, but in a conscious
patient it may cause gagging and agitation. Use with caution—
such devices are not comfortable.
• Intubation with an endotracheal tube is often the best way to maintain
an open airway.
• When intubation is impossible, a surgical airway (cricothyroidotomy
or tracheotomy) is required.
Surgical Cricothyroidotomy. A cricothyroidotomy is done only in
emergency situations when no other means is available to maintain an
open airway. The following guidelines are helpful:
1. The cricothyroid membrane can be located by running your finger
down the center of the neck and feeling the wide thyroid cartilage
(Adam’s apple). The depression just below the Adam’s apple is
where you want to place the incision. The rings of the trachea are
palpable just below this area.
2. Try to clean the area with Betadine.
3. If you have time, inject the skin with lidocaine and epinephrine to
decrease bleeding from the skin edges and to make the procedure a
little easier to perform.

                                                 












Emergency cricothyroidotomy. A, The larynx is stabilized between the left thumb
and middle finger. The tip of the index finger is inserted over the cricothyroid
membrane. Keep the index finger in this position to identify the position of the
cricothyroid membrane as you perform the procedure. B, The endotracheal tube
in position. (From Simon RR, Brenner BE (eds): Emergency Procedures and
Techniques, 3rd ed. Baltimore, Williams & Wilkins, 1994, with permission.)

4. The neck should be in neutral position with the chin held slightly
forward.
5. Hold the thyroid cartilage between your thumb and middle finger
(actually you are stabilizing the larynx). Use your index finger to
help identify the cricothyroid membrane.
6. Using a no. 15 knife blade, make a horizontal incision no more than
2 cm long, just below the Adam’s apple. Be sure to stay in the
center of the neck. Do not make this incision too large, or you may
injure a nearby vein, thereby causing significant bleeding and
making the procedure very difficult.
7. Staying in the midline, gently push the knife so that it goes through
the cricothyroid membrane. Do not push inward too far; use only
the knife tip. You do not want to injure the esophagus, which is immediately
behind the trachea.
8. Insert the back of the knife handle (not the blade) through the
opening that you have just made, and rotate the handle to enlarge
the opening.
9. Place the largest possible pediatric endotracheal tube through the
opening. Give oxygen and ventilate the patient through this tube.
10. Secure the tube in place with tape or sutures.

Breathing
Breathing relates to getting oxygen to the tissues. All patients with any
possibility of having sustained a head injury or with an altered level of
consciousness should be given supplemental oxygen, which usually
can be administered with a face mask or nasal prongs.
Listen for bilateral breath sounds, demonstrating that both lungs are inflated
(see “tension pneumothorax” below). Problems that interfere with
oxygen getting to the tissues are often related to significant chest trauma.
Circulation
Circulation pertains to the patient’s blood pressure and secure intravenous
access. Start an intravenous line with the largest available
catheter, and hang a liter of 0.9% saline.
The most common reason for hypotension (low blood pressure) in a trauma
patient is blood loss, either external or internal. Control obvious hemorrhage.
Be careful of scalp wounds—a lot of blood can be lost from
the scalp. A closed fracture of the femur can result in the loss of a
liter of blood into the tissues of the thigh, which may not be immediately
obvious.
A head injury in and of itself does not cause hypotension. Look for another
source. In contrast, a spinal cord injury can result in profound
hypotension without blood loss (see “Neurogenic shock” below) because
of loss of vascular tone.
How to Determine Blood Pressure
Without a Working Blood Pressure Cuff
Feel for palpable pulses at the wrist (radial artery), groin (femoral
artery), and neck (carotid artery).



Other Causes of Hypotension/Shock that Can Lead
to Death if not Quickly Diagnosed
Tension pneumothorax occurs when the lung has collapsed and air surrounds
the lung. If the air is not removed and the lung reexpanded, buildup
of pressure in the chest may cause the lung, great vessels, and even

heart to be compressed and pushed to the opposite side. This process impairs
blood flow to and from the heart and leads to hypotension.
Cardiac tamponade is a build-up of fluid in the sac around the heart. It
can lead to cardiac dysfunction and shock.
Neurogenic shock occurs with an injury that causes paralysis—i.e., a
spinal cord injury, not a head injury. Because of the loss of nerve input,
the blood vessels dilate. Even with minimal blood loss, the patient
cannot maintain proper vascular tone, and hypotension develops.
Acute myocardial infarction (heart attack) or any cause of cardiac dysfunction
can result in hypotension.
Disability
The following brief exam helps to evaluate patients for the presence of
a neurologic deficit:
1. Check the pupils. Are they equal, round, and reactive to light?
2. Is the patient conscious?
3. Can the patient move the fingers and toes?
4. For patients with a suspected head injury, the Glasgow Coma Score
(GCS) should be determined. Fifteen, the highest (best) score, indicates
that the patient is awake and alert; three, the lowest (worst)
score, indicates that the patient is unconscious and unresponsive.



Add up the points. An uninjured patient who is not intoxicated should
score 15 points. A score of 13 points may indicate minor injury; scores
of 9–12, moderate injury; and scores < 8, severe injury.

Caution: Do not assume that a low GCS is due to intoxication. Adrunk
person can definitely have a serious head injury. Do a thorough workup
(usually a computed tomography [CT] scan is required).
Exposure
All clothing should be removed so that the patient is fully exposed.
Removal of clothing allows you to examine the patient thoroughly for
signs of injury. It may seem silly, but you do not want to be fooled.
Patients usually are lying on their back during the evaluation. To examine
the back for evidence of spine injury, log-roll the patient (i.e.,
roll the patient in one motion, keeping the back straight and preventing
any twisting motion of the spine).

EVALUATION OF THE ACUTELY INJURED PATIENT

KEY FIGURES:
Emergency cricothyrotomy
Emergency needle thoracostomy


This book primarily describes treatments for stable patients who have
a specific injury or problem wound. They have been evaluated previously
by a general surgeon, trauma surgeon, or emergency department
physician, who has ruled out other, more life-threatening
injuries.
Because health care providers cannot know what situation they may
face, all of us must be aware of how to evaluate a patient with potentially
serious injuries. This chapter provides basic principles for the important,
life-saving initial evaluation and treatment of a patient who
may have suffered a serious traumatic injury. It is not intended to be a
full, detailed description of first-line treatments, but it does provide
useful information for all health care providers.
Be sure to get as detailed a history as possible (from the patient, family,
or whoever brought the patient to medical attention), but do not waste
time. Your primary objective is to identify and treat potentially lifethreatening
injuries.

Postexposure Treatment

Exposure to potentially infectious blood or body fluids includes needlesticks,
splashing of fluids in the face or eyes, and contact with body
fluids or blood through an open wound on your skin. Although intact
skin is usually a good protective barrier, irritated or chapped skin (for
example, from cold weather) can be penetrated by some viruses. If, despite
following all of the above recommendations, you are exposed to
potentially infectious blood or body fluids, certain steps can be taken
to decrease your risk for becoming ill.
• If you are exposed to HBV and have not been previously vaccinated:
Hepatitis B immunoglobulin (HBIG) should be given (5.0 ml
intramuscularly). HBIG is most effective when administered within
24 hours of a needlestick, but some protection is still afforded if it is
given in the first few days after exposure. You also should begin the
HBV vaccination regimen.
• If you are exposed to HCV: Unfortunately, there is no way to prevent
infection after HCV exposure. However, close observation is warranted,
and at the first sign of hepatitis, interferon therapy should be
instituted. Although early interferon therapy, before any signs or
symptoms of hepatitis have developed, does not prevent illness, once
signs and symptoms become apparent, interferon may prevent serious
illness.
• If you are exposed to HIV: If you have access to drugs used to treat
HIV infection, a short course of medication is often recommended
after a significant exposure. Usually, exposure to infected urine does
not warrant treatment. Recommendations for treatment usually are
related to the patient’s HIV titer and to the healthcare worker’s
degree of exposure. For example, a hollow needlestick from a patient
with a high HIV titer definitely warrants postexposure treatment—
optimally, a combination of zidovudine, 200 mg 3 times/day;
lamivudine, 150 mg 2 times/day, and indinavir, 800 mg 3 times/day.
All are given orally.
Bibliography
1. Gilbert DN, Moellering RC, Sande MA (eds): The Sanford Guide to Antimicrobial
Therapy, 29th ed. Vermont, Antimicrobial Therapy Inc., 1999, pp 112, 128.
2. www.cdc.gov/epo/mmwr (Postexposure prophylaxis).
3. www.osha.gov (Universal precautions).
4. www.who.int (World Health Organization surveillance statistics).

Simple Precautions that Make a Difference

•Wash your hands before and after examining every patient. This is
the single most important way to prevent the spread of infectious
diseases.
•Wear gloves. Gloves should be worn whenever you anticipate contact
with mucous membranes, open wounds, or body substances
(e.g., urine, feces, blood). Also wear gloves when handling items
soiled with blood or body fluids or performing any type of invasive
procedure. Do not go from patient to patient wearing the same pair
of gloves. Gloves are not a substitute for proper hand washing. After
removing your gloves, remember to wash your hands.
• Double-glove whenever possible during procedures involving
sharp instruments. Double gloves may feel uncomfortable at first,
but you will get used to them. Try wearing a glove a half size larger
next to your skin, and wear your regular size over the larger glove.

• Wear goggles. Eye protection is always advisable during procedures.
Get your own pair, and keep them in your pocket. You will be
amazed at how much material accumulates on the lenses, even when
you are not aware that any material has been sprayed. The goggles
used for racket sports are quite comfortable and often very useful.
When you wear a mask over your mouth, the goggles may fog up because
exhaled air escapes from under the mask around the edges of
your nose. To prevent your lenses from fogging, tape the mask to
your cheeks and to the bridge of your nose to prevent air escape.
• Get vaccinated against HBV. All healthcare providers should be immunized
against HBV. The vaccine is 95% effective in preventing infection.
The current vaccine is completely artificial, i.e., no human
products are part of the vaccine. There is no chance of contracting
HBV, HCV, or HIV from the vaccine. The vaccine is administered as a
series of three intramuscular injections. The second dose is given 1
month after the first injection, and the third dose is given 6 months
after the first injection.
• Observe proper use and disposal of all sharp instruments. Needles
for injection should not be recapped by hand. Accidents often occur
during manual recapping. Keep the cap on your tray, and slide the
needle back into the cap when you have finished using it. Do not
attempt to bend needles or other sharp objects. Use your instruments
when placing sutures—not your fingers! Suturing is often difficult
for the novice, but get in the habit of using only instruments
to hold and reposition the needle. With practice, this technique becomes
easier. Do not leave needles or other sharp instruments lying
around. Always place them in a container marked “sharp instruments”
after use.
• Adequately sterilize all reusable materials. This practice is vital to
protect healthcare providers and their patients from serious infectious
diseases. Never reuse needles or syringes without properly sterilizing
them.
• Keep all countertops and other surfaces clean. It is important to regularly
clean all surfaces that may have become contaminated by
blood or other body fluids. HBV can survive for at least 1 week in
dried blood on various surfaces. Adisinfectant made of dilute bleach
should be used for regular cleaning.

Scope of the Problem

These statistics are presented not to scare you, but to emphasize that
the risk is genuine.
Human Immunodeficiency Virus
World Prevalence: Over 47 million people worldwide have been infected
with HIV since the start of the epidemic. In 1998, HIV caused
over 2 million deaths. In some countries in Africa, 1 in 4 people is infected
with HIV. Ninety-five percent of cases occur in the developing
world.
Prevalence in the U.S. Approximately 1 in 200 people carries HIV.

Hepatitis B Virus
World Prevalence. There are over 350 million chronic carriers of HBV
worldwide. In developing nations, 8–15% of the population are chronic
carriers. This percentage drops to less than 5% in developed nations.
Five to ten percent of chronically infected people will develop chronic
liver disease that may lead to death.
Prevalence in the U.S. Approximately 1 million people are chronically
infected with HBV.
Hepatitis C Virus
World Prevalence. Three percent of the world’s population is infected
with HCV. There are more than 170 million chronic carriers of HCV.
About 50–70% of infected people will develop chronic liver disease.
HCV infection is the leading disease necessitating liver transplantation.
Prevalence in the U.S. Approximately 4 million people are chronically
infected with HCV.
Delta Hepatitis Virus
The delta hepatitis virus (HDV) primarily affects patients infected with
HBV. Apatient infected with both HBV and HDV has an increased risk
for the development of fulminant hepatitis compared with a patient infected
with HBV alone (the risk doubles to 20%). About 70–80% of
people infected with HBV and HDV develop chronic hepatitis.
Prevalence in the U.S. Unknown

PROTECTING YOURSELF FROM INFECTIOUS DISEASES

Healthcare providers are at risk for contracting serious infectious diseases.
Although the human immunodeficiency virus (HIV) is often
the most feared, the hepatitis B virus (HBV) and hepatitis C virus
(HCV) are actually much more contagious than HIV, because a
smaller inoculum can cause infection.
Healthcare workers who are inexperienced at technical procedures
and find themselves having to treat open wounds and perform invasive
procedures are especially at risk for two important reasons. First,
treatment of an open wound almost always necessitates exposure to
blood and body fluids. Blood and body fluids represent the primary
mode of transmission of these contagious agents. Second, the treatment
of open wounds and the performance of even simple procedures
(for example, suturing) involves the use of sharp instruments.
Inexperience on the part of the healthcare provider is a major risk
factor contributing to an accidental needlestick or other traumatic
injury during such procedures.

For Information Only: Additional Blocks for Procedures on the Upper Extremity

These procedures are technically more difficult and require special equipment.
Although discussed for completeness, they are beyond the realm of
a health care provider without expertise in delivering anesthesia.
Bier Block
In a Bier block, also called intravenous regional anesthesia, the affected
hand or forearm is exsanguinated and an upper arm tourniquet is inflated.
The venous circulation of the hand or forearm is then filled with
lidocaine via a catheter placed in a hand vein before exsanguination. In
this manner, the hand and forearm are anesthetized. The block lasts
about 45–60 minutes.
Warning: The tourniquet must work perfectly. If the tourniquet does
not hold its pressure, the injected lidocaine may become systemic and
cause serious side effects (e.g., seizures, cardiac arrhythmias/arrest). In
addition, for a very short procedure (< 15–20 minutes), the lidocaine in
the veins will still be at too high a concentration for the tourniquet to
be deflated. Usually, the tourniquet can be released safely after 25–30
minutes.

Axillary Block
An axillary block essentially anesthetizes the proximal portions of the

nerves that become the median, ulnar, and radial nerves in the forearm
and hand. Technically these portions of the nerves are called the cords
of the brachial plexus. The axillary block is commonly used to provide
anesthesia for hand procedures.
Usually a mixture of lidocaine and bupivacaine is used for infiltration.
An axillary block is useful for procedures that take up to 21⁄2 hours.
The landmark for injection of the anesthetic is the axillary artery, which
is easy to feel in the inner aspect of the upper arm. However, injecting
in the vicinity of the axillary artery is not without risk; possible complications
include injury to the artery or accidental intra-arterial injection.
A nerve stimulator can be used to help to identify the nerve and
thereby lessen these risks. Even so, an axillary block should be done
only by health care providers with expertise in delivering anesthesia.
Bibliography
1. Cousing MJ, Bridenbaugh PO: Neural Blockade in Clinical Anesthesia and
Management of Pain, 3rd ed. Philadelphia, Lippincott Williams & Wilkins, 1997.
2. Longnecker DE, Morgan GE, Tinker JH: Principles and Practices of Anesthesiology,
2nd ed. St. Louis, Mosby, 1997.

Sedation

Sedation can be a useful adjunct to local anesthetic. A sedative decreases
the patient’s anxiety about the upcoming procedure and increases
the patient’s cooperation. This, in turn, makes the procedure
easier and safer to perform.
In the setting of exploring or closing a wound, the purpose of sedative
medications is not to put the patient to sleep, but to make him or her
somewhat drowsy and less anxious.
Caution: Sedative medications can cause respiratory depression.
Always start with small doses, and gradually give additional medication
until the desired amount of sedation is obtained. Patients should
be monitored closely (blood pressure, heart rate, and respiratory rate)
during and for at least 1 hour after the procedure is completed.
There are many sedatives from which to choose. The following table
gives information about two commonly used benzodiazepines.

IV = intravenous, IM = intramuscular.

Nerve Blocks for Facial Injuries

The nerves that supply sensation to the areas most commonly affected
by facial trauma exit the skull along a line drawn perpendicular to the
midpoint of the pupil. These nerves, designated as V1, V2, and V3, are
branches of the fifth cranial (trigeminal) nerve.
Lidocaine and/or bupivacaine can be used for facial nerve blocks. Add
bicarbonate if it is available. Epinephrine is often a useful addition to
the anesthetic solution.
V1: Supraorbital Nerve Block
The supraorbital nerves supply sensation to the upper eyelid and overlying
forehead. A supraorbital nerve is located on each side of the face.
Anatomy. If you divide the supraorbital rim into thirds, the supraorbital
nerve exits the skull at the point where the central and medial
thirds meet.
Procedure
1. Insert the needle into the eyebrow overlying the point where the
nerve exits the skull.
2. Inject 1 ml of anesthetic solution into the superficial tissues.
3. Advance the needle downward to the bone. You will feel the needle
hitting against a hard surface when it meets the bone.
4. Back the needle 1–2 mm away from the bone, and inject another 2–3
ml of local anesthetic.


Anatomy of the trigeminal nerve branches (V1, V2, and V3). These nerves provide
sensation to the face and are amenable to nerve blocks.

V1: Supratrochlear Nerve Block
The supratrochlear nerve supplies sensation to the medial upper
eyelid, upper nose, and medial forehead.
Anatomy. The supratrochlear nerve exits the skull along the medial
aspect of the supraorbital rim just lateral to the area where the rim
meets the nose.
Procedure
1. Insert the needle into the soft tissues overlying the point where you
expect the nerve to exit the skull.
2. Inject 1 ml of anesthetic solution into the superficial tissues.
3. Advance the needle tip downward to the bone.
4. Back the needle 1–2 mm away from the bone, and inject another 1–2
ml of the solution.



Caution: For a forehead wound above the medial third of the eyebrow,
both the supraorbital nerve and supratrochlear nerve probably need to
be blocked on the side of the injury.
V2: Infraorbital Nerve Block
The infraorbital nerves supply sensation to the upper lip, cheek, lateral
aspect of the nose, and lower eyelid. There is one nerve on each side of
the face.
Anatomy. The infraorbital nerve comes out of the skull about 1⁄2 cm
below the orbital rim along the vertical line drawn perpendicular to
the midpoint of the pupil.
Procedure
1. Insert the needle into the cheek skin at the point where the vertical
line drawn perpendicular to the midpoint of the pupil meets a horizontal
line drawn from the bottom of the nose.
2. Advance the needle tip 2–3 mm into the tissues.
3. Inject 1 ml of solution.
4. Advance the needle tip further, going in a slightly superior direction
as you pass through the tissues until you hit the underlying bone.
The tip ultimately should travel superiorly about 1 cm.
5. Back the needle out 1–2 mm, and inject another 2–3 ml of the anesthetic.
V3: Mental Nerve Block
The mental nerves supply sensation to the lower lip and the skin immediately
below it. There is one mental nerve on each side of the
face.
Anatomy. The mental nerve exits from the mandible a few mm below
and 5–10 mm lateral to the inferior aspect of the lower canine tooth
root.
Procedure.
1. The mental nerve block is performed in the mouth.
2. Insert the needle into the mucosa a few mm below and 5–7 mm lateral
to the root of the lower canine tooth.
3. Advance the needle tip until it hits the bone.
4. Inject 2–3 ml of solution.
Nerve Block Overview

Nerve Blocks for Hand Injuries

Lidocaine, bupivacaine, or a combination of the two solutions can be
used. Add bicarbonate if it is available. Epinephrine should not be used
for anesthetizing the hand and fingers.
Digital Block
A digital block is the best way to evaluate and treat a wound on the
finger. The digital nerves supply sensation to the volar and dorsal surfaces
of the finger.
Anatomy. Each finger and the thumb have two digital nerves that
travel with the digital vessels along the lateral and medial sides of the
digit. Look at your own finger from the side, bend it at the two joints
(distal interphalangeal [DIP] and proximal interphalangeal [PIP]
joints). The line that connects the joint creases is a good estimate of
where each digital nerve runs.


Digital nerve block, dorsal approach. Care must be taken to ensure that the
anesthetic is not injected entirely circumferentially around the finger.
(Illustration by Elizabeth Roselius. From Green DP, et al: Operative Hand Surgery,
4th ed. New York, Churchill Livingstone, 1999, with permission.)

Procedure
1. The injection is done from the dorsal (not volar) surface near the
metacarpophalangeal (MCP) knuckle.
2. Insert the needle into the web space, when present (the thumb and
little finger are not bordered on both sides by web spaces).
3. Aim the needle toward the MCP joint of the affected finger, moving
in a volar direction.
4. Be careful not to inject too superficially on the volar side, or your injection
will miss the area around the nerve.
5. Inject 2–3 ml of solution into each side of the affected finger.
6. Infiltrate 1–2 ml along the dorsal skin of the digit, just distal to the
MCP knuckle.


Pattern of sensory innervation of major peripheral nerves. (From Jurkiewicz
MJ, et al (eds): Plastic Surgery: Principles and Practice. St. Louis, Mosby,
1990, with permission.)

Wrist Block
Three nerves supply sensation to the hand: the median nerve, ulnar
nerve, and superficial branch of the radial nerve. If you infiltrate around
all three nerves, you effectively anesthetize the entire hand. If an injury
is within the distribution of any one or two nerves, simply infiltrate
around the nerves that you need to anesthetize, based on the injury.
Median Nerve
The median nerve supplies sensation to the volar surface of the hand,
from the lateral half of the ring finger to the thumb, and to the dorsal
aspect of the fingers distal to the PIP joint, from the lateral half of the
ring finger to the thumb.
Anatomy. At the wrist the median nerve lies between the palmaris
longus (PL) and flexor carpi radialis (FCR) tendons. If the PL is absent
(15% of the population), the landmark for injection is just medial to the
FCR tendon.


Wrist block, median nerve. PL = palmaris longus, FCR = flexor carpi radialis.
(Illustration by Elizabeth Roselius. From Green DP, et al (eds): Operative Hand
Surgery, 4th ed. New York, Churchill Livingstone, 1999, with permission.)

Procedure
1. Have the patient flex the wrist. The FCR and PL (if present) become
noticeable in the distal forearm; the FCR is the more lateral of the
two tendons.
2. Insert the needle just proximal to the wrist crease and medial to the
FCR tendon.
3. Draw back on the syringe and slowly inject 3–5 ml of anesthetic in the tissues
deep to the skin.
4. If the patient describes minor tingling, the needle is in the proper
position. If the patient describes electric shocks or severe pain, the
needle may be in the nerve. Stop injecting the anesthetic, and back
the needle out a few mm before continuing to inject the anesthetic
solution. Do not inject the anesthetic directly into the nerve.
Ulnar Nerve
The ulnar nerve supplies the remainder of the volar surface of the hand
and the volar and dorsal surfaces of the ring and little fingers. The
dorsal ulnar side of the hand is innervated by a branch of the ulnar
nerve that comes off proximal to the wrist in the distal forearm.
Anatomy. At the wrist, the ulnar nerve lies with the ulnar artery lateral
to the flexor carpi ulnaris (FCU) tendon. The artery is lateral to the
nerve.


Procedure
1. Have the patient flex the wrist. The FCU is palpable along the
medial edge of the distal forearm.
2. Insert the needle just proximal to the wrist crease and just lateral to
the FCU tendon.
3. Draw back on the syringe before injecting the anesthetic to ensure that the
needle is not in the ulnar artery. If blood is drawn back, remove the
needle and hold pressure over the area for several minutes.
4. Slowly inject 1–2 ml of local anesthetic.
5. To block the nerve branch that supplies sensation to the dorsal
aspect of the hand, inject 1 ml of local anesthetic subcutaneously in
the tissues overlying the ulnar nerve.
6. Advance the needle onto the dorsum of the wrist, and inject another
3–4 ml. Go about halfway around the wrist on the dorsal surface.
Superficial Branch of the Radial Nerve
The superficial branch of the radial nerve supplies sensation to the
dorsum of the hand from the ring finger to the thumb; the dorsum of
the thumb; and the dorsum of the index, middle, long, and ring fingers
to the PIP joint.
Anatomy. The superficial branch of the radial nerve often has several
branches traveling in the tissues of the dorsolateral surface of the distal
forearm and wrist.

Procedure
1. Feel for the radial artery pulse in the distal forearm, approximately
2 cm proximal to the wrist crease.
2. Insert the needle laterally to the point where you feel the pulse, and
inject 1–2 ml of local anesthetic subcutaneously. Draw back on the syringe
before injection.
3. Advance the needle into the tissues on the dorsum of the distal forearm.
4. Inject an additional 3–4 ml of solution halfway around the dorsal
surface of the wrist.

How to Administer the Local Anesthetic

Direct Infiltration Around the Wound
In many cases, injecting the anesthetic agent around the wound is
an easy and reliable way to anesthetize the area. It is best to use as
small a needle as possible. The bigger the number, the smaller the
needle: use a 25- or 27-gauge needle, and inject slowly. Injection of
the anesthetic agent can be painful, and a slower injection rate
causes less pain.
You can inject directly into the wound to get the anesthetic into the surrounding
skin if the wound is reasonably clean. Alternatively, inject in
the noninjured skin along the outside of the wound. Inject until you
see the skin start to swell.
One technique is to push the needle into the tissues completely to the
hub, and then slowly infiltrate the anesthetic as you bring the needle
out of the tissues. Be sure to allow enough time for the agent to take
effect before starting your procedure (at least 5 minutes).

Nerve Blocks
In some areas of the body, discrete nerves that are responsible for sensation
to the injured area are easy to locate. In these instances, local
anesthesia can be infiltrated around (not into) the sensory nerve for
pain control to the area around the wound. This approach is advantageous
because the patient needs to undergo fewer injections than if
you anesthetize the entire wound margins directly.
Nerve blocks are also a good choice when the wound is deep, because
they often give a more complete block of the entire area, not
just the skin. This approach is especially appropriate for larger
wounds, because it usually requires less anesthetic agent than direct
infiltration.
Whenever possible, use a relatively small needle (23- or 25-gauge) for
the injection. Always draw back on the syringe before injecting the anesthetic.
The nerves that you are blocking often are located near blood
vessels.
Caution: You are probably injecting the anesthetic directly into the
nerve if the patient complains of strong electric shocks or severe pain
radiating along the distribution of the nerve. Stop the injection immediately
and reposition the needle.
It usually takes a few minutes longer for the anesthetic to take effect
than with direct wound injection. Often you must wait 10–15 minutes
after giving a nerve block before proceeding with the procedure.

Safety Hints

Caution about injections: It is quite dangerous to insert the syringe
needle in the wrong place and inject the solution into an artery by mistake.
A good habit to develop when giving any type of injection is to
draw back on the syringe (i.e., pull back on the plunger) before injecting the
solution. If you draw back and get blood, reposition the needle and
draw back again. This technique prevents an accidental intra-arterial
injection, which can cause serious complications. If you draw back
blood with the initial insertion, you have not created a major problem.
Because you are using a small needle, you should not do significant
damage to the blood vessel, but you may need to hold pressure over
the area for a few minutes to decrease bruising.
Caution about maximal safe dosage: Be aware of how much you are
injecting to avoid exceeding the safe doses. Average-sized wounds (up
to 4–5 cm) usually present no problem, but it is easy to forget about
dosage concerns when you are working on larger wounds. All anesthetic
agents have systemic as well as local effects. The safe dosage is
based on the total weight of the patient (thus the maximal doses are
given as mg of agent/kg of patient body weight). Overdose can lead to
seizures and even cardiovascular collapse or death due to the myocardial
depressant and vasodilator effects of these agents.

Injectable Local Anesthetics

The easiest and most reliable way to anesthetize a wound is to inject a
local anesthetic. There are two techniques: (1) direct injection of the
local anesthetic agent into the area around the wound and (2) injection
of the anesthetic agent around a sensory nerve that supplies sensation
to the injured area. Both methods are addressed below, but first the two
most commonly used anesthetic agents are discussed. Neither needs to
be refrigerated, which is important in the rural setting.
Lidocaine (Lignocaine)
Lidocaine is the most commonly used and least expensive agent. The
usual total dose that can safely be given is 3–5 mg/kg body weight. Do
not give more than this amount at one time. The anesthesia becomes effective
after 5–10 minutes and lasts, on average, from 45 minutes to 1 hour.
Bupivacaine (Marcaine)
Bupivacaine is a longer-acting agent than lidocaine, but it is also more
expensive. The usual total dose that can safely be administered at one
time is 2.0–3.0 mg/kg. Bupivacaine takes a few minutes longer to
become effective than lidocaine (10–15 vs. 5–10 minutes), but its effect
can last 2–4 hours.
The longer duration of effect can be valuable. Some wounds take more
than 1 hour to clean and suture. In addition, bupivacaine gives residual
pain control after the procedure is completed. Hand injuries are especially
prone to pain, making bupivacaine a good choice for treating
hand and finger injuries.
If both lidocaine and bupivacaine are available, they can be mixed together
in equal parts and administered with one syringe. This combination
gives the advantages of the quicker onset of anesthesia from the
lidocaine with the longer duration of action of the bupivacaine.
Calculating the Amount to Administer
To calculate the mg dose, multiply the ml of solution that you plan to
give by the concentration of the solution (mg/ml). The following table

converts the commercially available anesthetic solutions to the mg/ml
concentration of the anesthetic agent.
Concentration of Agent in Commercially Available Anesthetic Solutions


Example: You expect to inject 30 ml of 1.0% lidocaine to anesthetize a
relatively large wound:
30 ml × 10 mg/ml = 300 mg of lidocaine
The patient is a 70-kg man. A 70-kg man can receive 3–5 mg/kg or
210–350 mg of lidocaine. Your 30-ml dose is on the high end of the
“safe” range.
Additives
It is sometimes useful to add additional drugs to the local anesthetic
solutions to optimize their effect.
Bicarbonate
Both lidocaine and bupivacaine are acidic and therefore painful when
injected. One way to lessen this pain is to add injectable sodium bicarbonate
to the local anesthetic solution. Your patient will be grateful for
this extra step. It is essential to use commercially prepared bicarbonate
for injections. Do not try home-grown formulations. Be careful: adding
too much bicarbonate to the anesthetic solution can lead to the formation
of crystals. The proper mixtures are as follows:
• Lidocaine: add 1 ml of bicarbonate to each 9 ml of lidocaine before
injection.
• Bupivacaine: add 1 ml of bicarbonate to each 19 ml of bupivacaine
before injection.
Epinephrine
Epinephrine is a vasoconstrictor that shrinks blood vessels and thus
reduces bleeding from the wound and surrounding skin edges. This
makes wound examination and repair easier to perform. Epinephrine
also decreases absorption of the anesthetic agent, which
may allow safe injection of more than the usually recommended

amount of anesthetic agent. Epinephrine requires 5–7 minutes to take
effect. The maximal dosages of lidocaine and bupivacaine with epinephrine
are as follows:
• Lidocaine with epinephrine increases to 7 mg/kg, and its effect lasts
11⁄2–2 hours.
• Bupivacaine with epinephrine: dosing essentially stays the same at
2.0–3.0 mg/kg, and its effect still lasts 2–4 hours.
Lidocaine and bupivacaine are available in solutions premixed with
epinephrine , but you can add it to the anesthetic solution yourself. Be
very careful, however, because the amount of epinephrine to add is
very small:
1. Add 0.25 ml of 1:1000 epinephrine to 50 ml of local agent (50 ml is
the usual-sized vial). This will give a 1:200,000 dilution—safe for
most procedures.
2. Err on the side of adding a little less rather than a little more if you
are drawing the epinephrine with a syringe larger than 1 ml.
Contraindications to Adding Epinephrine
In certain circumstances the vasoconstricting effects of epinephrine can
be detrimental and may lead to tissue loss. Examples include:
• Digital block (numbing the whole finger)
• On the tip of the nose
• On the penis
• Injury that results in a very ragged and irregular laceration. Epinephrine
worsens the already compromised circulation of the skin edges.
Indications for Adding Epinephrine
• Straight cut with healthy-looking skin edges
• On the face, oral mucosa, and scalp, which have excellent blood circulation
Overview of Anesthetic Agents: Dosage and Duration of Action




* You can add the same amount of bicarbonate to solutions with epinephrine as you add to plain solutions
without epinephrine (see above for proper amounts).

Topical Agents

Topical agents (agents applied on top of the surrounding skin and absorbed
into the area to provide anesthesia without injections) are now
available. However, they are quite expensive and can be used only on
the surface, not deep within an open wound. They can be quite effective
for performing simple excisions or starting intravenous lines.
Although topical agents may become important in the future, because
of their expense and limited usefulness, they are not discussed further
in this chapter.

Application of cold works for only a few minutes but may allow
enough time to place one or two stitches. Cold also may help by decreasing
the pain of local anesthetic injection. It can be especially useful
in children. Have the patient hold ice over the area for 5 minutes before
injection. Another way to apply cold is to spray the area with ethyl
chloride solution.

LOCAL ANESTHESIA

KEY FIGURES:
Digital block/anatomy                     Ulnar nerve infiltration
Sensation to hand                           Facial block:
Median nerve infiltration skeleton


Full surgical evaluation of a wound and suture placement can be
quite painful. You must anesthetize the injured area to perform these
procedures properly. The administration of a local anesthetic allows
you to evaluate and treat wounds in the emergency department or
clinic. If you are unable to attain adequate pain control, the patient
should be taken to the operating room for exploration under general
anesthesia.
Local anesthetics work by reversibly blocking nerve conduction. They
primarily block the sensation of sharp pain; they do not block pressure
sensation. Therefore, in an area that has been adequately anesthetized,
the patient will not feel the sharp needle stick during suture placement
but may feel a vague sensation of pressure. This information should be
shared with the patient.
The duration of effect depends on how long the agent stays in the immediate
working area before being absorbed into the circulation or
broken down by the surrounding tissues.

Undermining Skin Edges

To undermine skin edges, you cut beneath the skin along the edge of a
wound to free the skin from its deep tissue attachments. The purpose
is to increase skin mobility, which is important for a tension-free
wound closure. It is also a necessary skill for performing local flaps.
Technique
Pinch the tissues around the edge of the wound with the forceps to
ensure that the local anesthetic is still working. Give additional anesthetic
as required. Lift the skin edge with the forceps, and with a knife
or a scissors cut into the deep subcutaneous tissue along the length of
the wound (try to stay at the same depth) until the skin has the required
mobility.
An alternative method involves separating the skin and subcutaneous
tissue from the underlying muscle. The plane of dissection is just above
the fascia, the thin layer of connective tissue that overlies the muscle.
By undermining the skin along this deeper plane, you may encounter
less bleeding than if you cut directly into the subcutaneous tissue layer.
Bibliography
Edgerton M: The Art of Surgical Technique. Baltimore, Williams & Wilkins, 1988.

Sharp Dissection

Sharp dissection is a technique for separating the tissues using a knife
or scissors. You must be careful not to cut accidentally an important
structure. For healthcare providers without surgical expertise, sharp
dissection should be used primarily in emergencies, for making a hole
in the neck to create an airway, or for trying to enlarge a deep hole to
control life-threatening bleeding. In addition, sharp dissection is used
for undermining tissues (see below) or excising a lesion.

Blunt Dissection

Blunt dissection is a technique for gently separating tissues while
avoiding injury to important nearby structures such as blood vessels,
nerves, or veins. Unless you use too much force, subcutaneous tissue
and muscle will separate easily, while the surrounding nerves, vessels,
and tendons will remain intact. For healthcare providers with
limited surgical skills, blunt dissection is the technique of choice for
separating tissues (for example, in exploring a wound or operating on
a hand).
Blunt Dissection Technique
Insert the closed blunt tips of a scissors or the closed jaws of a clamp into
the tissues (to a depth of approximately 1–2 cm). Then gently open the
instrument. This action separates the tissues. Any fibrotic connections

that are not important structures can then be safely cut with the scissors.
Repeat these maneuvers as needed.
Alternatively, you can gently use your index finger covered with a
gauze pad to separate tissues. This technique is especially useful for
elevating a skin flap off an underlying muscle.

How to Manage Bleeding from a Blood Vessel

1. Apply pressure. Application of pressure is always a good first choice.
It prevents further blood loss and may allow the vessel to clot,
thereby stopping the bleeding. Try this technique for at least 5–7 minutes.
If it is unsuccessful, the following alternatives should be tried.
2. If you have access to an electrocautery unit. If the vessel is a vein or
small (1–2 mm) artery, grab it with the tips of a metal clamp and
touch the clamp with the cautery device. Be sure that your gloves
are intact and that the clamp is applied only to the vessel.
3. If you do not have access to an electrocautery unit or if the vessel is
a larger vein or larger (3–4 mm) artery, the end of the vessel should
be tied off with a suture for secure hemostasis. There are two basic
techniques for tying off a vessel (see figures on following pages).

Regular Tie
Regular ties are adequate for most veins and small (2–3 mm) arteries.
Grasp the end of the vessel with a small clamp, and gently hold the
vessel away from the surrounding tissues. Pass a piece of 3-0 or 4-0 silk
or Vicryl suture material (the needle is not needed) around the vessel
and under the clamp. Tie the suture securely, placing at least 3 or 4 knots.


Four major steps (A–D) in tying off a vessel with the regular stitch. (From
Edgerton M: The Art of Surgical Technique. Baltimore, Williams & Wilkins,
1988, with permission.)

Stick Tie
A stick tie is a more secure technique to control bleeding from a blood
vessel. It is especially useful for arteries, because the thicker wall and
increased interior pressure of an artery can cause a regular tie to come
off of the vessel.
Grasp the end of the artery with a small clamp, and gently lift the
vessel. Use a 3-0 or 4-0 silk or Vicryl suture with a needle (a tapered
needle is best). Pass the needle through the center of the vessel just
under the clamp. Bring both ends of the suture toward yourself (again,
under the clamp), and tie the suture securely (just once).
Now take one of the suture ends and pass it completely around the vessel,
making sure to pass the string under the clamp. Again, tie the suture. As
you are tightening it, remove the clamp. Finish with 3–4 more knots.


Stick tie: a more secure way to control bleeding from a blood vessel. (From
Edgerton M: Art of Surgical Technique. Baltimore, Williams & Wilkins, 1988,
with permission.)

What to Do about Bleeding from the Skin Edges

1. Apply pressure. Most bleeding from skin edges stops on its own
after pressure is applied over the area for a few minutes with a
gauze pad.
2. If you have access to an electrocautery device. An electrocautery
device applies an electrical current that coagulates the tissue and
stops bleeding. When this device is used, the patient must be attached
to a grounding pad. Wipe away the blood, and touch the
bleeding spot with the cautery device. The bleeding usually stops. If
you see bleeding from a small blood vessel, grab it with the tips of a
metal clamp. Then touch the clamp with the cautery device. Be sure
that the clamp is not touching any surrounding tissue. The current
will pass through the clamp and burn the surrounding tissue as well.
Caution: Be sure that your gloves are intact before touching the clamp
with the cautery device. If you have a hole in the glove on the hand holding
the clamp, you will get zapped when you touch the clamp with the
cautery device. You may experience a painful, small burn in your finger
or even feel the electric current pass through your body.
3. Close the wound with a continuous locking suture. This technique
places more tension on the skin edges than the usual continuous closure
and often stops the bleeding. A continuous locking suture is
often quite useful to control a bleeding scalp wound.
How to Place Continuous Locking Sutures
For the typical continuous suture technique, the thread should always
remain behind the needle. With the locking technique, the thread lies in front
of the needle as it comes out of the tissues. The suture, therefore, comes out
of the tissues inside the loop. When the stitch is pulled through the
loop, it places the suture material along the outside skin edge, putting
pressure on the tissue. The pressure helps to control bleeding.


Top, Continuous locking suture. Bottom, Continuous nonlocking suture. Note
the differences in where the suture loop comes out of the skin relative to the
needle as well as the appearance of the sutures on the skin.

Making an Incision

Many of the procedures explained in subsequent chapters of this book
involve making incisions into the skin. Whether it be to remove a suspicious
lesion or to create a flap for wound coverage, you must learn
how to make an incision safely and efficiently. You will use a knife with
a very sharp blade. It is important to know how to use the knife properly
to prevent accidental injury to the patient or yourself.
Which Blade to Use
Knife blades come in various sizes (see figure below). There is no orderly
scale to follow as with needle sizes. A no. 11 blade comes to a sharp
point, whereas a no. 15 blade has a rounded end. A no. 10 blade is twice
the size of the no. 15, and a no. 20 blade is bigger than the no. 10. It can
be confusing, but most blades come with a picture on the packaging.

Commonly used knife blades. A, no. 11 blade; B, no. 15 blade; C, no. 10 blade.

Table 1. Deciding Which Blade to Use


* This table describes the optimal knife blade to use if you have a choice of sizes. If you do not have
the luxury of choice, any blade can be used for almost any situation.

Holding the Knife
For safety, use a blade only when it is attached to a handle. Some disposable
knives come with the blade already attached to the handle.
When they are not available, you may have to put the blade onto a
knife handle yourself. Never touch the blade with your fingers; it is
very sharp. Use a clamp or needle holder to grasp the blade, and position
it onto the handle.
Hold the handle with your dominant hand, as if you were using a writing
instrument. To have the best control over the instrument, hold the
handle 3–4 cm away from where the blade meets the handle.


Hold the knife like a writing instrument 3–4 cm behind the point where the
blade meets the handle.

Using the Knife
When you are about to make the incision, place the tissue under some
tension. Use the index finger and thumb of your nondominant hand to
push down on the skin, spread it apart, and make the skin taut. This
technique makes the skin easier to incise.

Make the incision with the flat part of the knife, not the very tip. Push
the blade down with just enough pressure to cut through the skin. You
do not have to go exactly to the proper depth with the first cut. It is
better to be too timid than too forceful. If you use too much force to
make the incision, your knife may penetrate too deeply into the tissues
and accidentally cut an important structure.
Which Side to Incise First
When you have to make two incisions (for example, to remove a suspicious
skin lesion), look at their orientation. If they are to be made one
above the other (for example, if you are working on the side of the leg),
do the bottom skin incision first. If the top incision is made first, blood
from the skin edges will drip down and obscure the area below. The presence
of the blood makes it more difficult to perform the lower incision.