Chapter 24: Burns
Harding: Lewis’s Medical-Surgical Nursing, 11th Edition
MULTIPLE CHOICE
1. When assessing a patient who spilled hot oil on the right leg and foot, the nurse notes dry, pale, and hard skin. The patient states
that the burn is not painful. What term would the nurse use to document the burn depth?
a. First-degree skin destruction
b. Full-thickness skin destruction
c. Deep partial-thickness skin destruction
d. Superficial partial-thickness skin destruction
ANS: B
With full-thickness skin destruction, the appearance is pale and dry or leathery, and the area is painless because of the associated
nerve destruction. Erythema, swelling, and blisters point to a deep partial-thickness burn. With superficial partial-thickness burns,
the area is red, but no blisters are present. First-degree burns exhibit erythema, blanching, and pain.
DIF: Cognitive Level: Understand (comprehension)
TOP: Nursing Process: Assessment
MSC: NCLEX: Physiological Integrity
2. On admission to the burn unit, a patient with an approximate 25% total body surface area (TBSA) burn has the following initial
laboratory results: Hct 58%, Hgb 18.2 mg/dL (172 g/L), serum K+ 4.9 mEq/L (4.8 mmol/L), and serum Na+ 135 mEq/L (135
mmol/L). Which of the following prescribed actions should be the nurse’s priority?
a. Monitoring urine output every 4 hours
b. Continuing to monitor the laboratory results
c. Increasing the rate of the ordered IV solution
d. Typing and crossmatching for a blood transfusion
ANS: C
The patient’s laboratory results show hemoconcentration, which may lead to a decrease in blood flow to the microcirculation unless
fluid intake is increased. Because the hematocrit and hemoglobin are elevated, a transfusion is inappropriate, although transfusions
may be needed after the emergent phase once the patient’s fluid balance has been restored. On admission to a burn unit, the urine
output would be monitored more often than every 4 hours (likely every hour).
DIF: Cognitive Level: Analyze (analysis)
MSC: NCLEX: Physiological Integrity
TOP: Nursing Process: Planning
3. A patient is admitted to the burn unit with burns to the head, face, and hands. Initially, wheezes are heard, but an hour later, the
lung sounds are decreased, and no wheezes are audible. What action should the nurse take?
a. Encourage the patient to cough and auscultate the lungs again.
b. Notify the health care provider and prepare for endotracheal intubation.
c. Document the results and continue to monitor the patient’s respiratory rate.
d. Reposition the patient in high-Fowler’s position and reassess breath sounds.
ANS: B
The patient’s history and clinical manifestations suggest airway edema, and the health care provider should be notified at once so
that intubation can be done rapidly. Placing the patient in a more upright position or having the patient cough will not address the
problem of airway edema. Continuing to monitor is inappropriate because immediate action should occur.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
4. A patient with severe burns has crystalloid fluid replacement ordered using the Parkland formula. The initial volume of fluid to be
given in the first 24 hours is 30,000 mL. The initial rate of administration is 1875 mL/hr. After the first 8 hours, what rate should
the nurse infuse the IV fluids?
a. 219 mL/hr
b. 625 mL/hr
c. 938 mL/hr
d. 1875 mL/hr
ANS: C
Half of the fluid replacement using the Parkland formula is administered in the first 8 hours and the other half over the next 16
hours. In this case, the patient should receive half of the initial rate, or 938 mL/hr.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
5. During the emergent phase of burn care, which assessment is most useful in determining whether the patient is receiving adequate
fluid infusion?
a. Check skin turgor.
b. Monitor daily weight.
c. Assess mucous membranes.
d. Measure hourly urine output.
ANS: D
When fluid intake is adequate, the urine output will be at least 0.5 to 1 mL/kg/hr. The patient’s weight is not useful in this situation
because of the effects of third spacing and evaporative fluid loss. Mucous membrane assessment and skin turgor also may be used,
but they are not as adequate in determining that fluid infusions are maintaining adequate perfusion.
DIF: Cognitive Level: Analyze (analysis)
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
TOP: Nursing Process: Evaluation
1
6. A patient has just been admitted with a 40% total body surface area (TBSA) burn injury. To maintain adequate nutrition, the nurse
should plan to take which action?
a. Administer vitamins and minerals intravenously.
b. Insert a feeding tube and initiate enteral nutrition.
c. Infuse total parenteral nutrition via a central catheter.
d. Encourage an oral intake of at least 5000 kcal per day.
ANS: B
Enteral nutrition can usually be started during the emergent phase at low rates and increased over 24 to 48 hours to the goal rate.
During the emergent phase, the patient will be unable to eat enough calories to meet nutritional needs and may have a paralytic
ileus that prevents adequate nutrient absorption. Vitamins and minerals may be given during the emergent phase, but these will not
assist in meeting the patient’s caloric needs. Parenteral nutrition increases the infection risk, does not help preserve gastrointestinal
function, and is not routinely used in burn patients unless the gastrointestinal tract is not available for use.
DIF: Cognitive Level: Apply (application)
MSC: NCLEX: Physiological Integrity
TOP: Nursing Process: Planning
7. Which nursing action prevents cross contamination when the patient’s full-thickness burn wounds to the face are exposed?
a. Using sterile gloves when removing dressings.
b. Keeping the room temperature at 70° F (20° C).
c. Wearing gown, cap, mask, and gloves during care.
d. Giving IV antibiotics to prevent bacterial colonization.
ANS: C
Use of gowns, caps, masks, and gloves during all patient care will decrease the possibility of wound contamination for a patient
whose burns are not covered. When removing contaminated dressings and washing the dirty wound, use nonsterile, disposable
gloves. The room temperature should be kept at 85° F for patients with open burn wounds to prevent shivering. Systemic
antibiotics are not well absorbed into deep burns because of the lack of circulation.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
8. A nurse is caring for a patient who has burns of the ears, head, neck, and right arm and hand. The nurse should place the patient in
which position?
a. Place the right arm and hand flexed in a position of comfort.
b. Elevate the right arm and hand on pillows and extend the fingers.
c. Assist the patient to a supine position with a small pillow under the head.
d. Position the patient in a side-lying position with rolled towel under the neck.
ANS: B
The right hand and arm should be elevated to reduce swelling and the fingers extended to avoid flexion contractures (even though
this position may not be comfortable for the patient). The patient with burns of the ears should not use a pillow for the head because
this will put pressure on the ears, and the pillow may stick to the ears. Patients with neck burns should not use a pillow or rolled
towel because the head should be kept in an extended position to avoid contractures.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
9. A patient with circumferential burns of both legs develops a decrease in dorsalis pedis pulse strength and numbness in the toes.
Which action should the nurse take first?
a. Monitor the pulses every hour.
b. Notify the health care provider.
c. Elevate both legs above heart level with pillows.
d. Encourage the patient to flex and extend the toes.
ANS: B
The decrease in pulse and numbness in a patient with circumferential burns shows decreased circulation to the legs and the need for
an escharotomy. Monitoring the pulses is not an adequate response to the decrease in circulation. Elevating the legs or increasing
toe movement will not improve the patient’s circulation.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
10. Esomeprazole is prescribed for a patient who incurred extensive burn injuries 5 days ago. Which nursing assessment would best
evaluate the effectiveness of the drug?
a. Bowel sounds
b. Stool frequency
c. Stool occult blood
d. Abdominal distention
ANS: C
H2 blockers and proton pump inhibitors are given to prevent Curling’s ulcer in the patient who has sustained burn injuries. Proton
pump inhibitors usually do not affect bowel sounds, stool frequency, or appetite.
DIF: Cognitive Level: Apply (application)
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
TOP: Nursing Process: Evaluation
2
11. Which prescribed drug is best for the nurse to give before scheduled wound debridement on a patient with partial-thickness burns?
a. ketorolac
b. lorazepam (Ativan)
c. gabapentin (Neurontin)
d. hydromorphone (Dilaudid)
ANS: D
Opioid pain medications are the best choice for pain control. The other drugs are used as adjuvants to enhance the effects of
opioids.
DIF: Cognitive Level: Analyze (analysis)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
12. A young adult patient who is in the rehabilitation phase after having deep partial-thickness face and neck burns has been having
difficulty with body image over the past several months. Which statement by the patient best indicates that the problem is
resolving?
a. “I’m glad the scars are only temporary.”
b. “I will avoid using a pillow, so my neck will be OK.”
c. “Do you think dark beige makeup will cover this scar?”
d. “I don’t think my boyfriend will want to look at me now.”
ANS: C
The willingness to use strategies to enhance appearance is an indication that the disturbed body image is resolving. Expressing
feelings about the scars shows a willingness to discuss appearance but not resolution of the problem. Because deep partial-thickness
burns leave permanent scars, a statement that the scars are temporary shows denial rather than resolution of the problem. Avoiding
using a pillow will help prevent contractures, but it does not address the problem of disturbed body image.
DIF: Cognitive Level: Apply (application)
MSC: NCLEX: Psychosocial Integrity
TOP: Nursing Process: Evaluation
13. A patient admitted with burns over 30% of the body surface 2 days ago now has dramatically increased urine output. Which action
should the nurse plan to support maintaining kidney function?
a. Monitoring white blood cells (WBCs).
b. Continuing to measure the urine output.
c. Assessing that blisters and edema have subsided.
d. Encouraging the patient to eat adequate calories.
ANS: B
The patient’s urine output indicates that the patient is entering the acute phase of the burn injury and moving on from the emergent
stage. At the end of the emergent phase, capillary permeability normalizes, and the patient begins to diurese large amounts of urine
with a low specific gravity. Although this may occur at about 48 hours, it may be longer in some patients. Blisters and edema begin
to resolve, but this process requires more time. WBCs may increase or decrease, based on the patient’s immune status and any
infectious processes. The WBC count does not indicate kidney function. Although adequate nutrition is important for healing, it
does not ensure adequate kidney functioning.
DIF: Cognitive Level: Apply (application)
MSC: NCLEX: Physiological Integrity
TOP: Nursing Process: Planning
14. A patient with burns covering 40% total body surface area (TBSA) is in the acute phase of burn treatment. Which snack would be
best for the nurse to offer to this patient?
a. Bananas
b. Orange gelatin
c. Vanilla milkshake
d. Whole grain bagel
ANS: C
A patient with a burn injury needs high-protein and high-calorie food intake, and the milkshake is the highest in these nutrients.
The other choices are not as nutrient dense as the milkshake. Gelatin is likely high in sugar. The bagel is a good carbohydrate
choice but low in protein. Bananas are a good source of potassium but are not high in protein and calories.
DIF: Cognitive Level: Analyze (analysis)
MSC: NCLEX: Physiological Integrity
TOP: Nursing Process: Planning
15. A patient has just arrived in the emergency department after an electrical burn from exposure to a high-voltage current. What is the
priority nursing assessment?
a. Oral temperature
b. Peripheral pulses
c. Extremity movement
d. Pupil reaction to light
ANS: C
All patients with electrical burns should be considered at risk for cervical spine injury, and assessment of extremity movement will
provide baseline data. The other assessment data are necessary but not as essential as determining the cervical spine status.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Assessment
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
3
16. An employee spills industrial acid on both arms and legs at work. What action should the occupational health nurse take?
a. Remove nonadherent clothing and wristwatch.
b. Apply an alkaline solution to the affected area.
c. Place a cool compress on the area of exposure.
d. Cover the affected area with dry, sterile dressings.
ANS: A
With chemical burns, the first action is to remove the chemical from contact with the skin as quickly as possible. Remove
nonadherent clothing, shoes, watches, jewelry, glasses, or contact lenses (if the face was exposed). Flush the chemical from the
wound and surrounding area with copious amounts of saline solution or water. Covering the affected area or placing cool
compresses on the area will leave the chemical in contact with the skin. Application of an alkaline solution can cause more injury.
DIF: Cognitive Level: Apply (application)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
17. A patient who has burns on the arms, legs, and chest from a house fire has become agitated and restless 8 hours after being
admitted to the hospital. Which action should the nurse take first?
a. Stay at the bedside and reassure the patient.
b. Administer the ordered morphine sulfate IV.
c. Assess orientation and level of consciousness.
d. Use pulse oximetry to check oxygen saturation.
ANS: D
Agitation in a patient who may have suffered inhalation injury might indicate hypoxia, and this should be assessed by the nurse
first. Administration of morphine may be indicated if the nurse determines that the agitation is caused by pain. Assessing level of
consciousness and orientation is appropriate but not as essential as determining whether the patient is hypoxemic. Reassurance is
not helpful to reduce agitation in a hypoxemic patient.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
18. A patient arrives in the emergency department with facial and chest burns caused by a house fire. Which action should the nurse
take first?
a. Auscultate for breath sounds.
b. Determine the extent and depth of the burns.
c. Give the prescribed hydromorphone (Dilaudid).
d. Infuse the prescribed lactated Ringer’s solution.
ANS: A
A patient with facial and chest burns is at risk for inhalation injury and assessment of airway and breathing is the priority. The other
actions will be completed after airway management is assured.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
19. A patient with extensive electrical burn injuries is admitted to the emergency department. Which prescribed intervention should the
nurse implement first?
a. Assess pain level.
b. Place on heart monitor.
c. Check potassium level.
d. Assess oral temperature.
ANS: B
After an electrical burn, the patient is at risk for life-threatening dysrhythmias and should be placed on a heart monitor. Assessing
the oral temperature and pain is not as important as assessing for dysrhythmias. Checking the potassium level is important, but it
will take time before the laboratory results are back. The first intervention is to place the patient on a heart monitor and assess for
dysrhythmias so that they can be monitored and treated if necessary.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
20. Eight hours after a thermal burn covering 50% of a patient’s total body surface area (TBSA), the nurse assesses the patient. The
patient weighs 92 kg (202.4 lb). Which information would be a priority to communicate to the health care provider?
a. Blood pressure is 95/48 per arterial line.
b. Urine output of 41 mL over past 2 hours.
c. Serous exudate is leaking from the burns.
d. Heart monitor shows sinus tachycardia of 108.
ANS: B
The urine output should be at least 0.5 to 1.0 mL/kg/hr during the emergent phase, when the patient is at great risk for hypovolemic
shock. The nurse should notify the health care provider because a higher IV fluid rate is needed. BP during the emergent phase
should be greater than 90 mm Hg systolic and the pulse rate should be less than 120 beats/min. Serous exudate from the burns is
expected during the emergent phase.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Assessment
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
4
21. Which patient should the nurse assess first?
a. A patient with burns who reports a level 8 (0 to 10 scale) pain.
b. A patient with smoke inhalation who has wheezes and altered mental status.
c. A patient with full-thickness leg burns who is scheduled for a dressing change.
d. A patient with partial thickness burns who is receiving IV fluids at 500 mL/hr.
ANS: B
This patient has evidence of lower airway injury and hypoxemia and should be assessed at once to determine the need for O2 or
intubation (or both). The other patients should be assessed as rapidly as possible, but they do not have evidence of life-threatening
complications.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Multiple Patients
TOP: Nursing Process: Assessment
MSC: NCLEX: Safe and Effective Care Environment
22. Which patient is most appropriate for the burn unit charge nurse to assign to a registered nurse (RN) who has floated from the
hospital medical unit?
a. A patient who has twice-daily burn debridements to partial-thickness facial burns.
b. A patient who just returned from having a cultured epithelial autograft to the
chest.
c. A patient who has a 15% weight loss from admission and will need enteral
feedings.
d. A patient who has blebs under an autograft on the thigh and has an order for bleb
aspiration.
ANS: C
An RN from a medical unit would be familiar with malnutrition and with administration and evaluation of response to enteral
feedings. The other patients need burn assessment and care that is more appropriate for staff who regularly care for burned patients.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Delegation
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
23. A patient who was found unconscious in a burning house is brought to the emergency department by ambulance. The nurse notes
that the patient’s skin color is bright red. Which action should the nurse take first?
a. Insert two large-bore IV lines.
b. Check the patient’s orientation.
c. Place the patient on 100% O2 using a nonrebreather mask.
d. Assess for singed nasal hair and dark oral mucous membranes.
ANS: C
The patient’s history and skin color suggest carbon monoxide poisoning, which should be treated by rapidly starting O 2 at 100%.
The other actions can be taken after the action to correct gas exchange.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
24. The nurse is reviewing laboratory results on a patient who had a large burn 48 hours ago. Which result requires priority action by
the nurse?
a. Hematocrit of 53%
b. Serum sodium of 147 mEq/L
c. Serum potassium of 6.1 mEq/L
d. Blood urea nitrogen of 37 mg/dL
ANS: C
Hyperkalemia can lead to life-threatening dysrhythmias. The patient needs cardiac monitoring and immediate treatment to lower
the potassium level. The other laboratory values are also abnormal and require changes in treatment, but they are not as
immediately life threatening as the elevated potassium level.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Assessment
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
5
25. The charge nurse observes the following actions being taken by a new nurse on the burn unit. Which action by the new nurse would
require immediate intervention by the charge nurse?
a. The new nurse uses clean gloves when applying antibacterial cream to a burn
wound.
b. The new nurse obtains burn cultures when the patient has a temperature of 95.2°
F (35.1° C).
c. The new nurse gives PRN fentanyl (Sublimaze) IV to a patient 5 minutes before a
dressing change.
d. The new nurse calls the health care provider when a nondiabetic patient’s serum
glucose is elevated.
ANS: A
Sterile gloves should be worn when applying medications or dressings to a burn. Hypothermia is an indicator of possible sepsis,
and cultures are appropriate. Nondiabetic patients may need insulin because stress and high-calorie intake may lead to temporary
hyperglycemia. Fentanyl peaks 5 minutes after IV administration and should be used just before and during dressing changes for
pain management.
DIF: Cognitive Level: Apply (application)
OBJ: Special Questions: Delegation
TOP: Nursing Process: Implementation
MSC: NCLEX: Safe and Effective Care Environment
26. Which nursing action is a priority for a patient who has suffered a burn injury while working on an electrical power line?
a. Inspect the contact burns.
b. Check the blood pressure.
c. Stabilize the cervical spine.
d. Assess alertness and orientation.
ANS: C
Cervical spine injuries are often associated with electrical burns. Therefore, stabilization of the cervical spine takes precedence
after airway management. The other actions are also included in the emergent care after electrical burns, but the most important
action is to avoid spinal cord injury.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
27. Which action will the nurse include in the plan of care for a patient in the rehabilitation phase after a burn injury to the right arm
and chest?
a. Keep the right arm in a position of comfort.
b. Avoid the use of sustained-release narcotics.
c. Teach about the purpose of tetanus immunization.
d. Apply water-based cream to burned areas frequently.
ANS: D
Application of water-based emollients will moisturize new skin and decrease flakiness and itching. To avoid contractures, the joints
of the right arm should be positioned in an extended position, which is not the position of comfort. Patients may need to continue
the use of opioids during rehabilitation. Tetanus immunization would have been given during the emergent phase of the burn
injury.
DIF: Cognitive Level: Apply (application)
MSC: NCLEX: Physiological Integrity
TOP: Nursing Process: Planning
28. A young adult patient who is in the rehabilitation phase 6 months after a severe face and neck burn tells the nurse, “I’m sorry that
I’m still alive. My life will never be normal again.” Which response should the nurse make?
a. “Most people recover after a burn and feel satisfied with their lives.”
b. “It’s true that your life may be different. What concerns you the most?”
c. “Why do you feel that way? It will get better as your recovery progresses.”
d. “It is really too early to know how much your life will be changed by the burn.”
ANS: B
This response acknowledges the patient’s feelings and asks for more assessment data that will help in developing an appropriate
plan of care to assist the patient with the emotional response to the burn injury. The other statements are accurate but do not
acknowledge the anxiety and depression that the patient is expressing.
DIF: Cognitive Level: Apply (application)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Assessment
MSC: NCLEX: Psychosocial Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
6
SHORT ANSWER
1. An 80-kg patient with burns over 30% of total body surface area (TBSA) is admitted to the burn unit. Using the Parkland formula
of 4 mL/kg/%TBSA, what is the IV infusion rate (mL/hour) for lactated Ringer’s solution that the nurse will give during the first 8
hours?
ANS:
600 mL
The Parkland formula states that patients should receive 4 mL/kg/%TBSA burned during the first 24 hours. Half of the total volume
is given in the first 8 hours and then the remaining half is given over 16 hours: 4 × 80 × 30 = 9600 mL total volume; 9600/2 = 4800
mL in the first 8 hours; 4800 mL/8 hr = 600 mL/hr.
DIF: Cognitive Level: Apply (application)
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
2. The nurse estimates the extent of a burn using the rule of nines for a patient who has been admitted with deep partial-thickness
burns of the anterior trunk and the entire left arm. What percentage of the patient’s total body surface area (TBSA) has been
injured?
ANS:
27%
When using the rule of nines, the anterior trunk is considered to cover 18% of the patient’s body and the anterior (4.5%) and
posterior (4.5%) left arm equals 9%.
DIF: Cognitive Level: Understand (comprehension)
TOP: Nursing Process: Assessment
MSC: NCLEX: Physiological Integrity
OTHER
1. In which order will the nurse take these actions when doing a dressing change for a partial-thickness burn wound on a patient’s
chest? (Put a comma and a space between each answer choice [A, B, C, D, E].)
a. Apply sterile gauze dressing.
b. Document wound appearance.
c. Apply silver sulfadiazine cream.
d. Give IV fentanyl (Sublimaze).
e. Clean wound with saline-soaked gauze.
ANS:
D, E, C, A, B
Because partial-thickness burns are very painful, the nurse’s first action should be to give pain medications. The wound will then
be cleaned, antibacterial cream applied, and covered with a new sterile dressing. The last action should be to document the
appearance of the wound.
DIF: Cognitive Level: Analyze (analysis)
OBJ: Special Questions: Prioritization
TOP: Nursing Process: Implementation
MSC: NCLEX: Physiological Integrity
Copyright © 2020, Elsevier Inc. All Rights Reserved.
7