Sunday, July 30, 2017
Schizophrenia could largely be the result of defective cells
"It was through studies of mice with human glial cells that we succeeded in testing how dysfunctional glial cells may cause abnormalities in the formation of the brain's neural networks, which may in turn cause severe anxiety, anti-social behaviour and severe sleep problems," says lead researcher Steven Goldman
Glial cells come in a variety of forms and can be found throughout the nervous system, taking on a bunch of supportive tasks to allow the nerve cells do what they do... best – pass on messages. This could be in the form of support, wrapping themselves around the nerves, or by surrounding the nerves to clean up stray chemical messages.
While dysfunctional helper cells have been associated with schizophrenia before, it's been assumed to be less important than abnormalities in the neurons themselves.
In this research the scientists took glial progenitor cells from patients diagnosed with schizophrenia and transplanted them into the brains of young mice. They then compared them with the same kinds of cells taken from subjects without schizophrenia.
That way they could be confident that similar behaviours in the mice were the product of the same pathology in humans.
Sure enough, the stem cells derived from the subjects with schizophrenia showed an unusual pattern of migration as they spread through the mice brains, leading to lower numbers of a type of glial cell that was responsible for mopping up neurotransmitter chemicals in the gaps between neurons.
The research hints at a faulty mechanism telling the glial cells where to stop and change into cells that perform their jobs.
When the mice were observed for behavioural differences, they showed clear signs of anxiety, sleep disruption, and anhedonia.
The Minding Brain
Mother's epigenetic memory is essential for the development and survival of the new generation.
The Minding Brain
Epigenetic mechanisms modulated by envir...onmental cues such as diet, disease or our lifestyle take a major role in regulating the DNA by switching genes on and off. Epigenetic marks transmitted from the mother are a fine-tuned mechanism to control gene activation during the complex process of early embryogenesis
It has long been thought that these epigenetic modifications never cross the border of generations. Scientists assumed that epigenetic memory accumulated throughout life is entirely cleared during the development of sperms and egg cells.
Just recently a handful of studies stirred the scientific community by showing that epigenetic marks indeed can be transmitted over generations, but exactly how, and what effects these genetic modifications have in the offspring is not yet understood.
It has been long debated if epigenetic modifications accumulated throughout the entire life can cross the border of generations and be inherited to children or even grand children.
Now researchers from the Max Planck Institute of Immunobiology and Epigenetics in Freiburg show robust evidence that not only the inherited DNA itself but also the inherited epigenetic instructions contribute in regulating gene expression in the offspring.
They discovered that embryos lacking H3K27me3 during early development could not develop to the end of embryogenesis. "It turned out that, in reproduction, epigenetic information is not only inherited from one generation to another but also important for the development of the embryo itself,"
It seems, virtually, that inherited epigenetic information is needed to process and correctly transcribe the genetic code of the embryo," explains Fides Zenk.
In our body we find more than 250 different cell types. They all contain the exact same DNA bases in exactly the same order; however, liver or nerve cells look very different and have different skills. What makes the difference is a process called epigenetics.
Epigenetic modifications label specific regions of the DNA to attract or keep away proteins that activate genes. Thus, these modifications create, step by step, the typical patterns of active and inactive DNA sequences for each cell type.
Moreover, contrary to the fixed sequence of 'letters' in our DNA, epigenetic marks can also change throughout our life and in response to our environment or lifestyle. For example, smoking changes the epigenetic makeup of lung cells, eventually leading to cancer. Other influences of external stimuli like stress, disease or diet are also supposed to be stored in the epigenetic memory of cells.
At the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, Germany used fruit flies to explore how epigenetic modifications are transmitted from the mother to the embryo
The Max Planck researchers found that H3K27me3 modifications labeling chromatin DNA in the mother's egg cells were still present in the embryo after fertilization, even though other epigenetic marks are erased. "This indicates that the mother passes on her epigenetic marks to her offspring. But we were also interested, if those marks are doing something important in the embryo,"
Our study indicates that we inherit more than just genes from our parents. It seems to be that we also get a fine-tuned as well as important gene regulation machinery that can be influenced by our environment and individual lifestyle
Saturday, July 29, 2017
காலம் காலமாய் பெண்.
Vidya Subramaniam
பல நூறாண்டுக்கு முன்.
அவளுக்கு சிறு வயதுதான். பால்ய விவாகம். புருஷன் மரணித்து விட்டான்.
அவனை எரியூட்டத் தூக்கிச் செல்லும் போது அவளையும் சிங்காரித்து அழைத்துச்
சென்றார்கள். அவளுக்கு அதில் விருப்பமில்லை. என்னை விட்டு விடுங்கள்
என்று கெஞ்சினாள். அவளை யாரும் விட்டு விடுவதாயில்லை. அவள் உடலில்
நடுக்கம். கண்களில் பயம். அவள் வாழ விரும்பினாள். ஆனால் சமூகம் அவளை
புருஷனின் சிதையில் தள்ளிக் கொன்று தெய்வமாக்கியது.
பின்னர்
ராஜாராம் மோகன்ராய் முயற்சியால் பிரிட்டிஷ் அரசு சதி சடங்கிற்குத் தடை
விதித்தது. சமூகம் கணவனை இழந்த பெண்ணை வேறு எப்படியெல்லாம் சித்ரவதை
செய்யலாம் என யோசித்தது. கணவனை இழந்த சின்னஞ்சிறுமிக்குக் கூட
மொட்டையடித்து, நார்மடி உடுத்தச் செய்து, ஜாக்கெட் அணியத் தடை விதித்து
அவள் அழகைச் சிதைத்து, நான்கு சுவருக்குள் முடக்கியது. வட இந்தியாவில்
கைம்பெண்களை வீட்டிலிருந்தே வெளியேற்றி அவர்களுக்கான தனியிடத்தில் விட்டுச்
செல்லும் வழக்கமும் இருந்தது.
காலம் கொஞ்சம் மாறியது.
மொட்டையடிப்பதும் நார்மடியுடுத்தச் செய்வதும் குறைய, சமூகம் வெள்ளைப்
புடவையளித்து மகிழ்ந்தது. பொட்டிடவும் பூச்சூடவும், வளையணியவும் தடை
விதித்தது. பின்னர் அதிலிருந்தும் தப்பித்தாள்.
ஆயினும் இன்றும்
சடங்குகள் என்ற பெயரில் சமூகம் புருஷனை இழந்த பெண்களைக் காயப் படுத்திக்
கொண்டேதான் இருக்கிறது. மனைவியை இழந்த ஆண்களுக்கு ஏன் இவ்விதமான எந்தச்
சடங்குகளும் இல்லை?
என் அத்தையின் அழகு இருபத்தோரு வயதில்
சிதைக்கப் பட்டது. தலை முண்டனம் செய்யப்பட்டு நார்மடி உடுத்தச் செய்தது.
ஜாக்கெட் மறுக்கப்பட்டது. என் அத்தை மனதால் எத்தகைய காயமும் உடலால் எத்தகைய
கூச்சமும் அடைந்திருப்பாள் என்று, இப்போது கூட நான் அவளை நினைத்து
அழுவதுண்டு.
ஒரு காலத்தில் பால்ய விவாகம் செய்யப்பட்ட. சிறுமி தன்
துரதிருஷ்டத்தால் கணவனை இழந்து விட்டால், பிறந்த வீட்டுக்கு அனுப்பப்
பட்டாள். அவளை இறுதி வரை பார்த்துக் கொள்ளும் பொறுப்பை அவளது சகோதரர்
ஏற்பர். இதன் அடையாளமாய் அவளது கணவன் இறந்த பத்தாம் நாளன்று பத்து பரத்தி
குளித்து விட்டு வரும் அப்பெண்ணின் தோளில் சகோதரன் ஒரு புடவை
போர்த்துவான். என் கணவர் இறந்த பத்தாம் நாளன்று என் அம்மாவிடம் நான்
உறுதியாகச் சொன்னேன், நான் யாரையும் சார்ந்திருக்கப் போவதில்லை என்பதால்
எனக்கு புடவை போர்த்தக் கூடாது என்று. ஆனாலும் புடவைக்கு பதில் என் கையில்
நூற்றியோரு ரூபாயைக் கொடுக்கச் செய்தார்கள். அந்தக் காசை அங்கேயே தானம்
பண்ணி விட்டுத்தான் வீடு வந்தேன்.
இன்னொரு கேவலமான சடங்கு....பத்து
நாளுக்குள் ஒரு முறை அப்பெண்ணை பிறந்த வீட்டுக்கு அழைத்துச் செல்வார்கள்.
அவள் கால் வைக்கும் இடமெல்லாம் பாலும் நெல்லும் தெளிப்பார்கள். எதற்கு
இவ்வழக்கம் என்று இதன் அர்த்தம் கூடத் தெரியாது எனக்கு. மிகக்கேவலமான
சடங்கு இது. இப்படிச் செய்து விட்டால் அப்பெண் எப்போது வேண்டுமானாலும்
பிறந்த வீடு செல்லலாமாம். ஏன் இதைச் செய்யாமல் அவள் சென்று வந்தால்
என்னவாகி விடும்? எனக்குப் புரியவில்லை. என் அம்மா அழுது ஆகாத்தியம் பண்ணி
என்னை அழைத்துச் சென்றாள். வெறுப்போடு சென்று வந்தேன். ஆனால் என் தம்பி
மனைவி இச்சடங்கு வேண்டாம் என மறுத்த போது எனக்கு சந்தோஷமாக இருந்தது.
ஆயினும் தம்பியின் உடல் கொண்டு செல்லப்பட்டதும் வாசலில் நமஸ்கரிக்கச்
சென்றவளிடம் ஒரு உறவுப் பெண், "சுசிலா..தலைலேர்ந்து கிளிப்பை அவுத்துட்டு,
தலையை விரிச்சுப் போட்டுக்கோ என்று உத்தரவிட்டபோது எனக்குள்
ஆத்திரத்தோடு கனன்று எரிந்த அக்னி.......! அதோடு நமஸ்கரித்தால் என்னவாகி
விடும்? அவள் அவிழ்த்து வைத்த அந்த தலை கிளிப் இன்னும் சீந்துவாரின்றி
காம்பவுண்ட் சுவர் மீது கிடக்கிறது.
ஏன்? .....ஏன் ஏதோ ஒரு
விதத்தில் பெண்ணைக் காயப்படுத்திக் கொண்டே இருக்கிறது இச்சமூகம்? ஒரு
மரணத்தை இயல்பாய் ஏற்றுக் கொண்டு அவள் வாழ முற்பட்டால் கூட, சடங்கு
சமபிரதாயம் என்ற போர்வையில் எதற்கு அவளைத் துன்புறுத்திக் கொண்டே
இருக்கிறது? மனதால் என்றைக்கு மனிதர் மேன்மையடைவர்?
BURN ASSESSMENT AND MANAGEMENT
A burn is an injury caused by thermal, chemical, electrical or
radiation energy. A scald is a burn caused by contact with a hot liquid
or steam but the term 'burn' is often used to include scalds.
Most
burns heal without any problems but complete healing in terms of
cosmetic outcome is often dependent on appropriate care, especially
within the first few days after the burn. Most simple burns can be
managed in primary care but complex burns and all major burns warrant a
specialist and skilled multidisciplinary approach for a successful
clinical outcome.
Epidemiology
- UK admission rate is 0.29 per 1,000 with burns or smoke inhalation (see separate Inhalation Injury article).
- In the UK, it is estimated that each year about 250,000 people with burn injuries present to primary care teams.
- The number of burns-related deaths in the UK averages 300 a year.
Risk factors
- Highest rates are seen in children under the age of 5 and the elderly over the age of 75.
- About 50% of burns and scalds occur in the kitchen.
- Infants and toddlers are at high risk of scalds from pulling hot beverages over themselves and at particular risk of burns from touching irons, hair straighteners or oven hobs.
I. Assessing Severity of Burn Injury
A. Functions of the Skin
1. maintains fluid and electrolyte balance
2. protects the body from invasion
3. regulates body temperature
B. Anatomy
1. epidermis
2. dermis (includes epidermal appendages)
3. subcutaneous tissue
4. fascia and muscle
C. Assessment of Burn Depth – related to temperature, time of exposure, and thickness of skin
1. First degree burn
a. caused by sunburn or flash
b. involves epidermal layer only
c. usually appears red to pink
d. is painful to touch
e. may become slightly edematous
f. heals in 3-5 days (rarely leaves any scar)
g. does NOT count in the burn size calculation
2. Second degree burn (partial-thickness)
a. usually caused by flash, scalds, or brief contact with hot object
b. involves the epidermis and part of the dermis
c. has vesicles and bullae
d. moist appearance – usually red to pale pink
e. tactile and pain sensibility is intact – very painful
f. develops significant edema
g. heals in 7-21+ days with variable amounts of scarring
3. Third degree burn (full-thickness)
a. usually caused by flame, high intensity flash, electricity, chemicals, or prolonged contact with hot liquids or hot objects
b. extends through the epidermis and dermis
c. usually appears white, brown or black; may have thrombosed veins
d. wound appears dry
e. elasticity of the wound is destroyed, so wound becomes leathery and feels firm to the touch
f. marked edema and decreased elasticity may necessitate escharotomies
g. generally painless to touch
4. Escharotomies
a. longitudinal incisions through eschar that release constriction
b. may be necessary in presence of full-thickness circumferential burns of an extremity or chest.
c. assess adequacy of circulation (pulse, capillary refill, movement, numbness, tingling, pain) and elevate
5. Zones of injury
a. zone of coagulation
b. zone of stasis
c. zone of hyperemia
D. Estimation of Burn Size -- calculating per cent Total Body Surface Area burned (%TBSA)
1. Rule of Nines
Adults Infants
head and neck 9% 18%
each upper extremity 9% 9%
anterior trunk 18% 18%
posterior trunk 18% 18%
each lower extremity 18% 14%
perineum 1% 1%
100% 100%
2. Lund and Browder Chart (see attached)
3. Rule of the Palm
a. the patient’s anterior hand is approximately 1% of his body surface area
b. useful in estimating burn size of splash-injuries or small burns
E. Burns of Special Areas
1. face, ears
2. hands
3. feet
4. joints
5. perineum
II. Care of Some Special Types of Injuries
A. Tar, wax
B. Chemical injuries
1. pathophysiology
2. treatment
3. chemical burns to the eyes
C. Electrical injuries
1. pathophysiology
2. problems associated with electrical injuries
a. types of wounds
- contact points (entry and exit)
- arc wounds
- flame burns
b. cardiac
c. pulmonary
d. gastrointestinal
e. renal
f. neurologic
g. musculoskeletal
3. sequelae of electrical injuries
D. Burns associated with Child Abuse
1. history requiring closer evaluation
2. appearance of suspicious burns
3. documentation required
III. Smoke Inhalation
A. Carbon Monoxide poisoning (kills during and immediately following the fire)
1. CO from the fire combines with the circulating hemoglobin, bumping the oxygen from its receptor sites
2. signs of CO poisoning include confusion, dizziness, headache, nausea
3. treatment: administration of 100% oxygen
B. Upper airway obstruction
1. burns of the face, mouth, tongue, pharynx results in massive edema formation and the potential for airway obstruction
2. edema continues to develop for up to about 24 hours
3. treatment: intubate to mechanically maintain airway patency
4. edema will usually decrease at about post-burn day #3, and the patient may then be able to be extubated
C. Pulmonary injury from the chemicals inhaled
1. patient develops ARDS over the first 24 hours post-injury
2. pneumonia may also occur (sometimes as late as 10 days post-burn)
IV. Fluid Resuscitation
A. Pathophysiology of “Burn Shock”
1. fluid shifts
2. decreased cardiac output
3. electrolyte and hematologic alterations
4. renal effects
5. central nervous system effects
6. compensation for “burn shock”
a. effects on skin
b. effects on gut
B. Fluid Resuscitation (in the first 24 hours post-burn)
1. Baxter (or Parkland) formula:
(4ml of Ringers Lactate) x (% burn) x (kg weight) = mls required in first 24 hrs
½ is given in the first 8 hours (calculated from time patient was burned)
¼ is given in the second 8 hours
¼ is given in the third 8 hours
EXAMPLE: 4 ml / 70 kg / 50% TBSA = 14,000 ml fluid resuscitation required
(7 liters given in first 8 hours)
2. IV access guidelines:
a. < 15% TBSA: oral fluids are satisfactory unless electrical burn or other injuries
b. 15-40% TBSA: secure one large bore IV in upper extremity; add another if transport will be longer than 45 minutes
c. > 45% TBSA: secure 2 large bore IV lines in upper extremities
3. Pediatrics (children 0-3 years) – add maintenance fluids as D5¼ NS to Baxter formula
4. Evaluation of adequacy of fluid resuscitation
a. alert sensorium
b. adequate urine output (>30 ml/hr in adult; 1 ml/kg/hr in children up to 30 kg)
c. slightly high normal pulse, usually about 100
d. normal blood pressure for age
e. relief of paralytic ileus or nausea
V. Initial Treatment
A. History for initial assessment
1. type of burn
2. history of flame burns / closed-space accident?
3. circumstances surrounding the injury (LOC, seizure, fall, crash, blast)
4. pre-existing diseases and medications
5. first aid measures already taken
B. Emergent Care
1. maintain an adequate airway and begin oxygen
2. assess for associated life-threatening injuries
3. initiate fluid therapy
4. insert foley catheter to monitor hourly urine output (burns >25% TBSA)
5. insert nasogastric tube (burns > 20% if air transport is planned)
6. keep patient warm (!)
7. elevate burned extremities; monitor pulses
8. tetanus prophylaxis
9. pain management (small IV doses only)
10. psychological support of patient and family
C. Advanced Burn Life Support Burn Center Referral Criteria:
1. full-thickness (3rd degree) burns
2. partial-thickness (2nd degree) burns >10% TBSA
3. burns of special areas
a. face, hands, feet, genitalia, or across major joints
b. circumferential full-thickness burns of an extremity or trunk
4. electrical injuries
5. chemical injuries
6. patients with inhalation injury in addition to burns
7. patients with pre-existing disease
8. patients with concomitant trauma
Transport
Wrap patient in dry sheet and blanket for transfer (sterile if you have it; clean if you don’t)
No ice or (cold) soaks
Don’t apply topical antibiotics before transport, unless transfer is delayed.
VI. Wound Care
A. Initial wound care
1. isolation: scrubs or gown, mask, gloves
2. cleanse wounds; blisters are usually debrided if patient will be admitted
3. shave as needed; never shave eyebrows
4. topical agents as ordered (not usually necessary at referring hospital)
B. Daily wound care
1. pain medication is needed prior to dressing changes
2. dressings may usually be soaked off
3. remove any old cream and gently wash wounds
4. debride any loose tissue
5. reapply topicals and dressings as ordered
C. Assess daily for signs of infection
1. cellulitis (redness, heat, swelling)
2. darkening of the eschar
3. odor
4. purulence or greenish drainage
5. deterioration of a healing wound
D. Assess for early signs of sepsis
1. disorientation
2. decreased urine output
3. metabolic acidosis
4. tachypnea
5. tachycardia
6. paralytic ileus or vomiting
7. hyperglycemia
8. hyper- or hypo-thermia
E. Debridement
1. if you can get between dead and viable tissue, the dead tissue should be removed
2. mechanical debridement by nurses should not cause bleeding
3. some debris will come off with coarse mesh gauze dressing changes
4. most patients are not debrided under general anesthesia in the OR
a. tangential excision – shave layer by layer until a bleeding (viable) bed is produced (to maximize tissue salvage)
b. primary or fascial excision – separate tissue at fascial layer to minimize blood loss
F. Topical Antibiotics
1. Silver sulfadiazine (Silvadene, Flamazine, Thermazine, SSD)
a. a water-soluble cream which is locally non-toxic
b. bactericidal spectrum against a wide range of gram+ and gram- organisms and candida albicans
c. pain-free application
d. softens the eschar; may combine with exudate to form a gelatinous layer
e. few side effects: is generally applied once daily
2. Mafenide acetate (Sulfamylon)
a. a water soluble cream or, or a powder that may be mixed with saline
b. bacterial spectrum: gram+, gram – organisms, some anaerobes, but not yeast
c. hypersensitivity reactions (rashes) to sulfa are sometimes seen
3. Bacitracin and other petroleum ointments
a. “benign” topicals which mostly contain moisture
b. microbes may become resistant
c. typically used for scrapes and abrasions
4. Muperacin (Bactroban)
a. an ointment used against gram+ organisms
b. used when methacillin resistant staph aureus (MRSA) is found in wounds
c. should also be applied to nares, when used
5. Silver Nitrate (bulky wet dressings)
a. AgNO3 isn’t used much anymore because it stains everything black
b. A 0.5% solution of AgNO3 in water – keep dressings wet so that concentration of AgNO3 doesn’t increase (concentrated AgNO3 is caustic to wounds)
c. water-soaked dressings are uncomfortable and can leech electrolytes
6. Acticoat
a. a slow-release silver-impregnated dressing
b. silver is released by water (either from the wound or exogenously applied) for about 3 days
c. is being used on shallow wounds and donor sites to decrease dressing changes
G. Grafting
1. Xenograft or Heterograft (used as a biologic dressing)
a. animal skin (usually pig) which is used as a temporary wound coverage
b. is applied to a clean shallow wound, to protect it until it heals
c. dries and separates from the wound, as the wound heals underneath
2. Allograft or Homograft (used as a biologic dressing)
a. non-self human skin (usually cadaver) which is used as temporary wound cover
b. if left in place long enough (> 5 days) it will become vascularized, and will have to be excised in OR to remove it
c. if left in place long enough, patient may develop a rejection reaction to it
d. used to “buy time” and temporarily close a wound until patient’s own skin is available
e. used as a “test graft” to determine if a wound is ready to accept a skin graft
3. Autograft
a. skin taken from one area of the patient’s body to another
b. sheet graft
- whole graft is laid intact on wound
- used in cosmetic areas of the body (face, neck, hands)
- require meticulous care post-op to prevent fluid accumulation beneath it
c. meshed graft
- passed through a machine that creates slits in it – so it can be expanded
- is often wrapped, with no dressing changes, for first 3-5 days after application
d. donor site – area that gives up skin used in skin graft
- is often more painful than burn wounds
- may be covered with a dressing or topical; heals by epithelialization
4. Integra
a. is placed on a newly excised wound (after all dead tissue is removed)
b. becomes vascularized, forming a “neodermis” over about 3 weeks
c. is grafted with thin epidermal grafts after the new dermis develops
VII. Rehabilitation
A. Beings at the time of admission
B. Prevention of contractures
1. exercising
2. positioning
3. splinting to maintain stretch
C. Minimizing scarring
1. elasticized circular bandage initially
2. custom fitted pressure garments
3. may require silicone inserts
D. The nature of scars
1. can’t easily predict who will scar, but partial thickness wounds that heal over more than 3 weeks tend to scar the most
2. scars will become redder and firmer 6-8 weeks after the wound heals; then will begin to blanche out and soften over about a 1-year period
3. Scars may tingle, itch or burn as they mature
E. Other post-hospitalization issues
1. body-image changes
2. role changes
3. uncomfortable sensations in burns
4. changes in sweating pattern
5. fatigue
6. return to work / school
7. PTSD
F. Interventions
1. motivational strategies
2. reconstructive surgery
3. tissue expanders
4. make-up consultation
5. tattooing (for color match)
6. support groups
Referral to a specialist burns unit
All complex injuries should be referred - particularly:- Age under 5 years or over 60 years.
- Site of injury: face, hands, perineum, any flexure (including neck or axilla) and circumferential dermal burns or a full-thickness burn of the limb, torso or neck.
- Inhalation injury.
- Mechanism of injury:
- Chemical burns affecting over 5% total body surface area burned (over 1% for hydrofluoric acid burns).
- Exposure to ionising radiation.
- High-pressure steam injury.
- High-tension electrical injury.
- Suspected non-accidental injury in a child.
- Large affected area:
- Age under 16 years: over 5% total body surface area burned.
- Age 16 years or older: over 10% total body surface area burned.
- Co-existing conditions - eg, serious medical conditions, pregnancy or associated fractures, head injury or crush injuries.
Further management
- Circulatory insufficiency caused by a circumferentially burned limb is best relieved by escharotomy. Escharotomies are usually not required within the first six hours of burn injury.
- Fasciotomy: seldom required, but may be necessary to restore circulation for patients with associated skeletal trauma, crush injury, high-voltage electrical injury or burns involving tissue beneath the investing fascia.
- Gastric tube insertion: if there is nausea, vomiting, abdominal distention, or if more than 20% of the total body surface area is burnt.
- Analgesia and sedation:
- Severely burned patients may be restless and anxious from hypoxaemia or hypovolaemia rather than pain. The patient then responds better to oxygen or increased fluid administration rather than to narcotic analgesics or sedatives that may mask the signs of hypoxaemia or hypovolaemia.
- Intravenous narcotic analgesics and sedatives may be administered in small, frequent doses.
- Wound care:
- Partial-thickness (second-degree) burns are painful when air currents pass over the burned surface. Gently covering the burn with clean linen relieves the pain and deflects air currents.
- Do not break blisters or apply an antiseptic agent.
- Any applied medication must be removed before appropriate antibacterial topical agents can be applied.
- Application of cold compresses may cause hypothermia. Do not apply cold water to a patient with extensive burns.
- Antibiotics: should be reserved for the treatment of infection.
- Tetanus: determination of immunisation status is very important.
- Full-thickness burns: require excision and grafting unless they are less than 1 cm in diameter. Grafting is required within three weeks in order to minimise scarring. Therefore, early referral is essential.
- After healing:
- The area of healed burns should be moisturised and massaged to reduce dryness.
- A high-factor sun cream should be used to prevent further damage and pigmentation changes.
Chemical burns
- Can result from exposure to acidic, alkaline or petroleum products.
- Alkali burns tend to be deeper and more serious than acid burns.
- Immediately flush away the chemical with large amounts of water for at least 20 to 30 minutes (longer for alkali burns). Alkali burns to the eye require continuous irrigation during the first eight hours after the burn.
- If dry powder is still present on the skin, brush it away before irrigation with water.
Electrical burns
- Are often more serious than they appear on the surface.
- Rhabdomyolysis results in myoglobin release, which can cause acute kidney injury. If the urine is dark, start therapy for myoglobinuria immediately.
- Fluid administration should be increased to ensure a urinary output of at least 100 ml/hour in the adult.
- Metabolic acidosis should be corrected by maintaining adequate perfusion and adding sodium bicarbonate.
Complications
- Respiratory distress from smoke inhalation or a severe chest burn.
- Fluid loss, hypovolaemia and shock.
- Infection.
- Increased metabolic rate leading to acute weight loss.
- Increased plasma viscosity and thrombosis.
- Vascular insufficiency and distal ischaemia from a circumferential burn of limb or digit.
- Muscle damage from an electrical burn may be severe even with minimal skin injury; rhabdomyolysis may cause acute kidney failure.
- Poisoning from inhalation of noxious gases released by burning (eg, cyanide poisoning due to smouldering plastics).
- Haemoglobinuria and renal damage.
- Scarring and possible psychological consequences. Hypertrophic scarring is more common following deeper burns treated by surgery and skin grafting than with superficial burns.
Prognosis
- Will depend on depth of burn and the body surface area affected.
- Superficial burns usually heal within two weeks without surgery.
- Risk factors for death include age over 60 years, more than 40% of body surface area affected and inhalation injury.
- Death may result from severe extensive burns or electric shock.
Prevention
There are many important aspects of prevention of burns, including:- Safety in the workplace.
- Safety in the home, including regularly checking smoke alarms.
- Good parenting to protect children.
- Care of the frail elderly and the socially isolated.
- Prevention of sunburn: appropriate duration and timing of sunbathing, sun protection creams and regulation of tanning booths. See separate Sunburn article.
courtesy:
Fran O’Donnell, RN, BSN
Burns/Plastics Clinical Nurse Educator
Harborview Medical Center
Burns/Plastics Clinical Nurse Educator
Harborview Medical Center
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