Advertisement Upgrade to remove ads

burns

Approx 1 MILLION burn injuries each year in US ~ 700,000 ED visits
45,000 deaths/year—3rd leading cause of accidental death in US
In 2006, fire killed more Americans than all US natural disasters combined Thermal, chemical, radiation, side
The most common types of burns are thermal burns. Soft tissue is typically burned when it is exposed to temperatures above 115ºF (46°C). The extent of damage depends on surface temperature and contact duration.

Burns Overview:
Severity based on depth, extent, and location
Care and follow-up dependent on these factors
Must consider associated injuries and trauma (smoke inhalation, CO poisoning, etc)
Must also consider psychological impact
And, as with other trauma in children, geriatric patients, etc—consider abuse

Thermal Burns

Flame
Contact
Scalding
Heat
Pathophys:


Thermal energy denatures and coagulates protein, resulting in irreversible tissue destruction. Surrounding this zone of coagulation is an area of decreased tissue perfusion.
Tissue in this zone is potentially salvageable, provided that resuscitative efforts are successful in restoring perfusion to the area.
Perfusion is increased at the outer margins of the burn. Tissue in this zone will recover as long as the patient does not experience prolonged hypoperfusion.
Systemic capillary leak usually persists for 18 to 24 hours. Protein is lost from the intravascular space during the first 12 to 18 hours after a burn, after which vascular integrity improves.
In large burns, up to 15 percent of red blood cells may be destroyed locally and an additional reduction of 25 percent of the red blood cell mass may occur due to decreased red cell survival time. This reduction in oxygen carrying capacity may exacerbate burn shock.

Immediately following the burn injury, vasoactive mediators (such as cytokines, prostaglandins, and oxygen radicals) are released from damaged tissue.

Increased capillary permeability results in extravasation of fluid into the interstitial space around the burn.

Patients with large burns (≥15 to ≥20%) develop systemic responses to these mediators.

For patients with 40% TBSA or more, myocardial depression can occur. As a result, patients with major burns may become hypotensive (burn shock) and edematous (burn edema).

skin anatomy

Largest organ "in" the body
Primary functions:
Thermoregulation
Prevention of fluid loss
Barriers to infection
Sensory information about environment
Artist's palette for tattoos
Gives women an excuse to purchase excessive amounts of moisturizer.

Epidermis: This is the outermost layer of skin composed of cornified epithelial cells. Outer surface cells die and are sloughed off as newer cells divide at the stratum germinativum.

Dermis: This is the middle layer of skin composed of primarily connective tissue. It contains capillaries that nourish the skin, nerve endings, and hair follicles.

Hypodermis: This is a layer of adipose and connective tissue between the skin and underlying tissues.

Subcutaneous fat, bone, etc...

depth of injury

Old method of categorizing burns (1st degree, 2nd degree, 3rd degree, etc) is replaced by:
Superficial
Superficial partial thickness
Deep partial thickness
Full thickness

Re-evaluation in burn depth may be required in the first 24-72hrs, especially in "thin" skin:
Age <5, >55, volar surface of arms, medial thighs, perineum, ears...

superficial

AKA 1st degree burn
Involves only epidermis
Skin is red, dry, painful
No blisters, blanches with pressure
Heals in 4-7 days without scarring Aka 1st degree. Red dry, painful. Most common epidermis. Blanching. Heal in about a wk, usually no scarring involved.

Superficial partial thickness

AKA 2nd degree burn
Involves epidermis and extends into dermis
Skin is red, moist, painful, and blisters may be present
Blanching is still present
Heals in 14-21 days without scarring.

Starts to extend into the dermis and get blistering. Red, very painful, often have blisters, still have blanching, often no scarring. Take longer to heal. Break down of collagen in the dermis

Superficial partial-thickness:
-cause scald (spill or splash) short flash.
-Appearance=blisters moist, red, weeping blanches w/ pressure
-sensation= painful to temperature and air
-healing time= 7-20 days

Deep partial thickness:

Involves epidermis and deeper into dermis
Skin is whitish or yellowish, pressure can be felt but there is usually no overt pain.
Blanching is absent, 2-point discrimination is diminished.
Healing may take 21 days to three months, and scarring is common.
May be difficult to differentiate from full thickness
-Can be almost less painful in the primary area of the burn. Can feel pressure. The surrounding area can be more superficial and there for more painful than primary site. Burn center. Take a long time to heal
-
Deep partial-thickness
cause- Scald (spill), Flame, Oil, Grease
Appearance- Blisters (easily unroofed), Wet or waxy dry, Variable color (patchy to cheesy white to red), Does not blanch with pressure
Sensation- Perceptive of pressure only
Healing time- >21 days

Full thickness:

Charred and black to pale and waxy white, leathery, painless (except in surrounding area of more superficial burns).

Will not heal spontaneously—skin grafting is required.

-Severe, beyond the epidermis into the sub-q. nerve endings are gone they don't feel anything. Wont heal on their own need skin grafting. 4th degree,can receive amputation
-
Full-thickness
Cause= Scald (immersion), Flame, Steam, Oil, Grease, Chemical, Electrical
Appearance- depth
Sensation- Deep pressure only
Healing time- never (if >2 % total body surface area)

4th degree burn:

Extends into deeper tissue (fat, bone, muscle)—may require amputation.

superficial

Superficial-
cause=ultraviolet exposure very short flash.
Appearance=dry, red, blanches w/ pressure
Sensation= painful
Healing time= 3-6 days

Extent of injury

Total body surface area (TBSA)
Used ONLY for burns more severe than superficial*
Rule of nines
Lund & Bowder diagram—improves estimations for children as their head size relative to the rest of the body is of a higher percentage than in adults.
A person's hand (including fingers) can be used to estimate 1% total BSA

Lund and Browder chart:

Lund and Browder chart:
entire head neck (9% front and back)
Entire Chest and Abdomen (18%)
One entire arm (9% front and back)
One entire leg (18% front and back)
Entire back and buttocks (18%)
One entire arm (9% front and back)
Face-3%
Upper arm- 2%
Forearm- 1%
Chest 13%
Palm- 1%
Tummy-5%
Penis 1%
Thigh-4%
Calf-3%
Foot- 1 ¾%
Butt cheek - 2% each

% based on age-
Birth - 1yr: head 19, thigh-5.5, leg-5
1-4yr: head 17, thigh- 6.5, leg- 5
5-9 yr: head-14, thigh-8, leg-5.5
10-14yrs: head-11, thigh-8.5, leg- 6
15yrs: head-9, thigh-9m leg-6.5
Adult: head-7, thigh- 9.5, leg- 7

location of injury

Circumferential burns
Burns covering joints
Burns involving the face (eyes), hands, feet, genitalia/perineum


Depth, surface area and location and other special circumstances in an effort to determine appropriate level of care.Examples of severe burns. Over joints can lead to contracture and long term problems.

ABA burn injury severity grading system

minor:
Criteria-<10% TBSA burn in adults<5% TBSA burn in young or old<2% full-thickness burn
-Outpatient
Moderate:
criteria- 10 to 20% TBSA burn in adults, 5 to 10% TBSA burn in young or old, 2 to 5% full-thickness burn, High voltage injury, Suspected inhalation injury, Circumferential burn, Medical problem predisposing to infection (eg, diabetes mellitus, sickle cell disease)
-admit to hospital
Major:
Criteria- >20% TBSA burn in adults, >10% TBSA burn in young or old, >5% full-thickness burn, High voltage burn, Known inhalation injury, Any significant burn to face, eyes, ears, genitalia, or joints, Significant associated injuries (fracture or other major trauma)
-refer to burn center

- TBSA: total body surface area; burn: partial or full-thickness; young or old: <10 or >50 years old; adults: >10 or <50 years old. Adapted from American Burn Association, J Burn Care Rehabil 1990; 11:98 and Hartford, CE, Total Burn Care, Philadelphia, WB Saunders, 1996.

referral to a burn center

Partial thickness burns >10% of BSA
Burns that involve the face, hands, feet, genitalia, perineum
Any electrical or chemical burns
Burns with associated smoke inhalation injuries
Burns in patients with pre-existing medical conditions that could complicate the management, could prolong the recovery or could affect mortality
Any patients with burns and associated trauma (fractures) in which the burn injury poses the greater risk of mortality or morbidity
Burned children in hospitals WITHOUT qualified personnel or equipment for the care of children
Burn injury in patients who require special social, emotional or long-term rehabilitative intervention
American Burn Association; www.ameriburn.org

"minor" burn df:

Partial thickness <10% of BSA in patients 10-50yrs old
Partial thickness <5% of BSA in patients under 10 or over 50yrs old, Full thickness burns <2% of BSA in any patient without other injury, Isolated injury
May NOT involve face, hands, feet, perineum or genitalia, May NOT cross major joints
May NOT be circumferential
Should err on the side of caution to reduce risk of complications and adverse outcomes.
-Approach:Cool burns immediately in cool/room temperature water, Pain management (NSAIDs, opiods—these hurt, may use IV pain rx), Clean burns with mild soap and water., Larger blisters (>2cm), or blisters that have a likelihood of rupturing (over a joint), or blisters that are painful should be drained and debrided.
Topical antibiotic ointments should be applied
Silver sulfadiazine (1%) [silvadene] is most common (not if <2yr old), Can also use bacitracin, triple antibiotic ointment or honey
Tetanus immunization or tetanus Ig
At final phase of healing, non-perfumed moisturizing cream (Vasline Intensive Care ®, Eucerin ®, Nivea ® can be applied until natural lubricating mechanisms return. Avoid lanolin
Lanolin is a greasy yellow substance secreted by the sebaceous glands of wool-bearing animals, with the vast majority of it used by humans coming from domestic sheep.
-Basic dressing:NON-adherent dressing (adaptic, etc) after antibiotic ointment, Second layer of fluffed gauze
Third layer of elastic gauze, Must individually wrap fingers/toes to prevent adherence/maceration, When to change dressing?, No clear recommendation
Once daily, Whenever soaked with exudates or fluids, whenever dirty .

Follow-up: Surveillance for infection, contracture, scarring, pain control
F/u in 24hrs, then, if pt reliable, up to a week later.
Sooner if ANY concerns for compliance, infection, etc.
Infection:
How to tell if a wound is infected?
Burn is already red, swollen, painful.
Watch for lymphangitis, fever, malaise, anorexia.
Burn infections should be treated aggressively with admission and IV abx.
Non-superficial burns have higher risk of infection 2/2 decreased neutrophil activity, impaired T lymphocyte activity and cytokine imbalance

moderate or severe burns

Assessment and treatment of severe burns occurs simultaneously with trauma resuscitation.
Initial management focuses on stabilizing the airway, breathing, and circulation (ABC's).
The primary evaluation includes assessing for evidence of respiratory distress and smoke inhalation injury, evaluating cardiovascular status, looking for other injuries, and determining the depth and extent of burns.
Hot and burned clothing and debris is removed.
Early transfer to a burn center should be arranged when injuries meet the criteria for major burns.
Burn patients may sustain single or multisystem trauma and should be evaluated accordingly.
-Synge facial hair, voice changes, possible edema in the larynx
-Initial approach:A: Airway
B: Breathing
C: Circulation
D: Disability
E: Expose
XFr: Transfer

A/B-Airway & Breathing

Airway—ensure an adequate and patent airway
Smoke inhalation can rapidly lead to airway edema
Inhalation injury remains the most common cause of death in burn victims.
The risk of inhalation injury increases with the extent of the burn and is present in two-thirds of patients with burns greater than 70 percent of the TBSA

Signs of smoke inhalation injury:

Carbonaceous sputum
Singed facial or nasal hairs
Facial burns
Oropharyngeal edema
Voice changes

Assume injury in any person confined in a fire environment

Intubate as needed, otherwise, high-flow O2

C->circulation

IV access is important—any burn pt w/ >15% BSA can be hypovolemic
Insert 2 large bore IV lines—"okay" to access injured skin, but not preferred.
IO!
Foley catheter to assess hydration status

Fluid resuscitation

In the acute phase, burn victims require copious fluids
Parkland Formula (renamed "Consensus Formula")
With Lactated ringers
2-4mL x %BSA x W in Kg = volume of fluid in 24hrs (from injury, not arrival)
half in 1st 8hrs, then remaining over following 16hrs
Foley catheter to monitor urine output (should be 0.5ml/kg/hr) to assess adequate hydration
Galveston Formula (for pediatrics) uses total body surface area instead of weight in Kg...
- Use LR for IV. Careful not to load them too fast w/ fluids, can have SE and complications if you put the fluids in too fast.

Parkland formula

A 70kg man with a 20% TBSA burn will require:
4mL x 70kg x 20(%) = 5600mL of LR
2800mL in 1st 8hrs, then 2800mL over 16hrs

D/E-Disability/Expose:

Remove burned clothing/jewelry

Secondary Survey:

Cool burned skin with "COOL" or room temp water
If burned area is >10% BSA, must monitor for hypothermia , may need to administer warmed IVF
Pain management with opiates, Anxiolysis with benzodiazepines
-Moderate and severe burns (ie, full thickness or large surface area partial thickness) require a complete laboratory and diagnostic workup, including the following:
CBC, Chemistry profile (especially BUN and Cr to determine renal function), Liver function tests
Arterial blood gases with carboxyhemoglobin levels
Coagulation profile, Urine analysis—BhCG if female!
Type and screen-, Creatine phosphokinase (CPK) and urine myoglobin levels (in electrical injuries) (The presence of myoglobin can signify muscle breakdown as well as impending kidney impairment.)
CXR, ECG
HX: What burned (chemicals?), Location of fire (enclosed or open space), Explosion/trauma?, Alcohol or drugs?, AMPLE , ALLERGY - allergy to drugs
MEDS - prescription and non-prescription drugs
PREVIOUS - significant PMHX, surgeries, etc
LAST - last intake & last output
EVENT - events leading up to this crisis
TX: Trauma/surgical consult
Wound care as above—unless imminent transfer to burn center, Antibiotics as above—unless imminent transfer to burn center, If transfer is iminent—wrap wounds in clean sheet
Tetanus booster or Ig

hospitalization guidelines

Admit patients suspected of inhalation injury for observation; fiberoptic bronchoscopy is useful if the diagnosis is in doubt. Pulmonary dysfunction causes more than 75 percent of fire-related deaths. Initial evaluations may be normal in patients with inhalation injury who subsequently develop severe respiratory distress.
Check for carbon monoxide poisoning; treatment with hyperbaric oxygen may be necessary.
Admit patients with moderate to severe burns.
Admit patients with circumferential partial or full-thickness burns.
Patients at greater risk for development of infection of nonsuperficial burns; such as diabetics and the elderly, generally should be hospitalized.
Patients with a high voltage injury who have an abnormal electrocardiogram (nonspecific ST-T wave changes most commonly) are at increased risk for cardiac arrhythmias and should be observed until the ECG normalizes.
Children with burns from suspected abuse should be hospitalized.

circumferential burns:

The eschar is tough and rigid. As edema forms in the injured extremity following the burn, the eschar restricts outward expansion of the tissue. As a result, interstitial pressure rises to the point that vascular flow is compromised. In short, the eschar behaves like a tourniquet. Incising the eschar allows return of flow and prevents further ischemic injury. Full-thickness burns are insensate so there is no need for the use of topical anesthetics.

Compression requiring escharotomy typically occurs 12-24 hours after an injury.
Perform escharotomy along the lateral aspect of the extremity with a linear and lengthwise incision. Use of an electrocautery simplifies the procedure and can reduce the amount of bleeding.
The incision should go completely through the eschar. The subcutaneous fat will appear to bubble up into the escharotomy wound.
Bleeding is minimal and is easily controlled by pressure.
Upon completion of the escharotomy, a dressing with antibiotics is placed on the wound and the extremity is elevated to help maintain homeostasis.

If the chest is involved and the eschar compromises ventilatory motion, perform an escharotomy involving the anterior chest. Incisions are made along the costal margin, along the anterior axillary lines, and across the top of the chest, freeing up the anterior chest wall.

hospitalized burn patients:

Patients with severe burns have metabolic rates 100 to 150% higher than normal.
Managing a hypermetabolic state
-propanol- Inhibition of peripheral lipolysis, Decreased myocardial rate and work by catecholamine blockade
-IGF-1/BP-3: Modulator for action of GH, Induction of protein anabolism
-GH:Increased collagen content and tensile strength of skin, Protein anabolism in muscle and albumin production in liver
-Insulin:Simulation of "fed state" with decreased protein breakdown and glycogen deposition
-Oxandrolone/ Testosterone/ Ketaconazole: Anabolic steroids, increased constitutive protein synthesis

GH = Growth hormone, IGF-1/BP-3 = Insulin like growth factor 1/binding protein 3.

Signs of SEPSIS (HHOTIE):

Hyperventilation
Hyperglycemia
Obtundation
Thrombocytopenia
Intolerance of Enteral feeding (diarrhea, illeus

Prevention

Smoke detectors
Hot water temperature control
Light fuse, get away

Burn depth1-3rd degree

1st degree (superficial)
• Involves only epidermis
• Skin is red, dry, painful
• No blisters, blanches with pressure
• Heals in 4-7 days without scarring
2nd degree (partial thickness)
Superficial
• Involves epidermis and extends into dermis
• Skin is red, moist, painful, and blisters may be present
• Blanching is still present
• Heals in 14-21 days without scarring
Deep Partial
• Involves epidermis and deeper into dermis
• Skin is whitish or yellowish, pressure can be felt but there is usually no overt pain.
• Blanching is absent, 2-point discrimination is diminished.
• Healing may take 21 days to three months, and scarring is common.
• May be difficult to differentiate from full thickness
3rd degree (full thickness)
• Charred and black to pale and waxy white, leathery, painless (except in surrounding area of more superficial burns).
• Will not heal spontaneously—skin grafting is required.

Burn and shock

• Large (≥15% to 20% TBSA) injuries, capillary leakage becomes systemic, producing total body edema and severely depleting circulating volume.

24 fluid resuss calc

• Parkland Formula (renamed "Consensus Formula")
• With Lactated ringers
• 2-4mL x %BSA x W in Kg = volume of fluid in 24hrs (from injury, not arrival)
o half in 1st 8hrs, then remaining over following 16hrs
• Foley catheter to monitor urine output (should be 0.5ml/kg/hr) to assess adequate hydration
• Galveston Formula (for pediatrics) uses total body surface area instead of weight in Kg...
- CR's df:➢ Calculate the fluid resuscitation over the first 24-hour period in burn patient utilizing the parkland formula.
o 2-4mL x %BSA x Wt (Kg)
o Example: 70Kg man w/ 20% TBSA
• 4mL x 70kg x 0.20 = 5600mL (half of which should e given in the first 8° and the rest over the remaining 16°

Escharotomy

• Escharotomy - an incision made through the rigid, leathery eschar
• Fluid accumulating beneath the constricted eschar of a deep burn increases tissue hydrostatic pressure. This often results in compromised circulation.

CR's Ans:o Fluid continues to leak; swelling occurs and collects under the eschar layer of a full thickness burn increasing hydrostatic pressure. This can lead to ischemia of tissue distal to burn or the compression of the chest cavity making it difficult to breath w/o adequate chest expansion
o Eschatology is performed by cutting through the rigid/leather eschar layer to relieve the compression

burn referral

• Partial thickness burns >10% of BSA
• Burns that involve the face, hands, feet, genitalia, perineum
• Any electrical or chemical burns
• Burns with associated smoke inhalation injuries
• Burns in patients with pre-existing medical conditions that could complicate the management, could prolong the recovery or could affect mortality
• Any patients with burns and associated trauma (fractures) in which the burn injury poses the greater risk of mortality or morbidity
• Burned children in hospitals WITHOUT qualified personnel or equipment for the care of children
• Burn injury in patients who require special social, emotional or long-term rehabilitative intervention

CR's-ans:the criteria for referral to a Burn Center
o Partial thickness burns >10% TBSA
o Involve hands, feet, face, genitalia, perineum
o Electrical/chemical burns
o Smoke inhalation injuries
o With pre-existing conditions that complicate management, affect mortality, or that prolong recovery
o Burns w/ associated trauma & the burn poses a greater risk of mortality/ morbidity
o Burned children when facility does not have proper equipment to take care of children
o When patient requires special social/emotional/long-term rehab intervention

infection burn, most common

• Pneumonia is the MOST COMMON, and often the most troublesome, infection seen in burn patients.

nutricional support

• Aggressive nutritional support due to protein malnutrition and immune compromise
• Enternal feeding is superior to IV
• High-protein liquid diet; using "customized" products for burn victims (usually 1.5 to 2.0 g/protein/kg/daily).

CR's ans:o Enteral feeding tube w/ a high protein liquid diet until oral intake is adequate

burn class-cr

Identify and recognize the classification/description of the different burns based on depth and appearance.
1st degree/superficial/epidermal burns:
• Involves only the dermis
• Skin is red/dry/painful
• No blisters/blanches w/ pressure
2nd degree/partial thickness burns:
• Superficial partial
• Involves epidermis & extends into the dermis
• Skin is red/moist/painful
• Blanching is still present as well as blisters
• Deep partial
• Involves epidermis & extends deep into the dermis
• Skin is whiteish/yellowish
• Pressure but no overt pain
• Blanching is absent/2 point discrimination is diminished
3rd degree/full thickness:
• Involves epidermis/dermis & may extend into subQ layer
• Skin is charred & black-pale w/ waxy white/leathery/painless area
➢ Identify and recognize the Lund and Browder diagram for estimating total body surface area (TBSA). (Study lecture diagram)
o Be able to calculate the TBSA involved, given a burn scenario

Define burn shock and recognize the clinical presentation.
o With large burns (≥ 15% TBSA) capillary damage & leakage leads to systemic edema & severely depleting circulatory volume
o Hct rises, protein levels fall, severe edema, hypotension, elevated HR, diminished peripheral pulse, and other signs of Hypovolemic shock occur

which burn won't blister?
3rd degree burn
2nd degree burn
1st degree burn

3rd degree burn - full thickness
Charred and black to pale and waxy white, leathery, painless (except in surrounding area of more superficial burns).
Will not heal spontaneously—skin grafting is required.

2nd degree burn -
partial thickness
- Involves epidermis and extends into dermis
Skin is red, moist, painful, and blisters may be present
Blanching is still present
Heals in 14-21 days without scarring

Deep partial
Involves epidermis and deeper into dermis
Skin is whitish or yellowish, pressure can be felt but there is usually no overt pain.
Blanching is absent, 2-point discrimination is diminished.
Healing may take 21 days to three months, and scarring is common.
May be difficult to differentiate from full thickness


1st degree burn - superficial or epidermal
Involves only epidermis
Skin is red, dry, painful
No blisters, blanches with pressure
Heals in 4-7 days without scarring

Lund and Browder diagram used for?
A) Survival percentage from burn
B) Surface area of burn
C) Depth of burn
D) Morbidity from burn

B

A patient has a burn covering the backside of both legs and the front of his right leg (including feet) What is the surface area involved?
A)18%
B) 27%
C) 42%
D) 52%

B----27%
-each side of each leg is 9%
-so right leg is 18% and add the front side of his right leg = 27%

Which of the following does not always need to be referred to a burn center?
A) BSA > 5 %
B) Burns that involve the face, hands, feet, genitalia, perineum
C) Electrical or chemical burns
D) Burns with associated smoke inhalation injuries

A) BSA > 5 % - >10% should go to burn center
Also should go to burn center
Burns in patients with pre-existing medical conditions that could complicate the management, could prolong the recovery or could affect mortality
Any patients with burns and associated trauma (fractures) in which the burn injury poses the greater risk of mortality or morbidity
Burned children in hospitals WITHOUT qualified personnel or equipment for the care of children
Burn injury in patients who require special

A 70 kg man has a burn that covers 40% of his body. How much fluid does he need in the first 8 hours?
A) 2800 ml of normal saline
B) 5600 ml of normal saline
C) 2800 ml of lactated ringers
D) 5600 ml of lactated ringers

D) 5600 ml of lactated ringers
4 ml x 70 kg x 40 % = 11200
Give half in first 8 hours and half in the next 16 hours (calculated from time of injury)
Usually lacatated ringers
Formula is 2-4 ml (in your lecture they used 4)

What is an escharotomy and when would you use it?

An escharotomy is a surgical procedure used to treat full thickness (third-degree) circumferential burns. Since full thickness burns are characterized by tough, leathery eschar, an escharotomy is used primarily to combat compartment syndrome. Following a full thickness burn, as the underlying tissues are rehydrated, they become constricted due to the eschar's loss of elasticity, leading to impaired circulation distal to the wound.
An escharotomy is performed by making an incision through the eschar to expose the fatty tissue below. Due to the residual pressure, the incision will often widen substantially.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set