Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / @xirurgi_2025 / @xirurgi_2025 - 863 - файл
.pdf
172
https://t.me/med1917
172
CHAPTER20 Electrical injuries
Introduction toelectrical injuries
Electrical injuries account for 3– 5% of all admissions to major burn centres.
Injuries often involve deeper tissues in addition to skin, resulting in high
morbidity and mortality.
Classification
• Low voltage (<1,000 volts)— primary involvement of skin and
surrounding tissue
• High voltage (>1,000 volts)— associated with underlying deep tissue
injury including muscles, nerves, tendons, and bone
• Lightening injury— contains millions of volts of electricity lasting 1/ 10th
to 1/ 1000th of a second. The pathognomonic sign of a lightning strike is
a dendritic, arborescent, or fern- like branching erythematous pattern on
the skin (Lichtenberg gures)
Electricity is categorized into alternating current (AC) and direct current
(DC). AC is considered more dangerous as it causes muscle tetany. Flexor
muscles are generally stronger than extensors, forcing the subject to hold
on to the source of current rendering them unable to let go. Alternatively,
DC contact results in a singular rigorous muscle contraction, often thrusting
the victim away from the source.
Pathophysiology
The three major mechanisms of electricity- induced injury are as follows:
• Electrical energy causes direct tissue damage and alters cell membrane
resting potential
• Electrical energy is converted into thermal energy, causing permanent
tissue destruction and coagulative necrosis
• Mechanical injury with direct trauma resulting from falls or violent
muscle contraction
Electrical burns may cause injury via direct contact, electrical arcs, ame,
or ash injury.
Severity of injury is inversely proportional to the cross- sectional area of
the body part involved. Thus the most severe injuries are often seen at the
wrist and ankle with severity decreasing proximally.
https://t.me/med1917
CLINICAL FEATURES OFHIGH VOLTAGE INJURIES
Clinical features ofhigh voltage injuries
When performing the physical examination, remember to keep a high index
of suspicion for concealed injury.
Integumentary
‘Kissing burn’ at the exor creases; Lichtenberg gures in lightening injury;
mouth burn (age <4).
Neurological
Transient confusion; amnesia; paraesthesia; seizures; paralysis; autonomic
dysfunction.
Cardiovascular
Arrhythmias:DC current usually causes asystole while AC current usually
causes ventricular brillation; arrest; direct cardiac damage.
Respiratory
Respiratory arrest:due to either chest wall muscle paralysis or injury to the
respiratory control centre in the brain.
Musculoskeletal
Compartment syndrome; avulsion fractures; costochondritis;
rhabdomyolysis.
Renal
Acute kidney injury.
173
174
https://t.me/med1917
174
CHAPTER20 Electrical injuries
Workup
Investigation and treatment of electrical injuries depends on whether a highvoltage or low- voltage injury has been sustained. When it is not clear, assume a high- voltage injury and full workup.
Investigations
Full blood count; electrolytes; liver function tests; blood urea nitrogen and
creatinine; urinalysis:urine myoglobin; creatinine kinase; serum myoglobin;
arterial blood gas (ABGs); cardiac enzymes; ECG:The most common abnormalities seen on ECG are sinus tachycardia, non- specic ST- and T- wave
changes, heart blocks, and prolongation of the QT interval. Indications for
cardiac monitoring include (a)loss of consciousness (b)ECG abnormality
and/ or evidence of ischaemia, (c)documented dysarrythmia either before
or after admission to the ED, (d)CPR at the scene of injury.
Imaging studies
Patients who are found unconscious require cervical spine, chest, and pelvis
X- rays. X- rays of the extremities may be required when injury is apparent.
Head, neck, chest, abdominal, and pelvic computed tomography scans may
be required in individual cases.
Compartment syndrome
A low threshold for decompression is required in suspected cases. Clinical
features include pain with passive motion (non- localized, severe, deep,
exaggerated), paraesthesias, pallor, paralysis, and poikilothermia. Loss of
pulse is a late nding. Examinations for the aforementioned signs/ symptoms
should commence immediately after injury and again with regular intervals
within the rst 48 hours post burn as this time frame has the highest risk for
the development of increased compartment pressures.
If suspected, fasciotomy is immediately warranted.
https://t.me/med1917
INPATIENT CARE
Immediate care
It is of utmost importance to establish safety at the scene of injury before
providing care. As with all trauma injuries, begin the initial assessment with
primary survey of airway, breathing, and circulation.
Fluid resuscitation
Fluid resuscitation should commence as soon as possible. Hourly assessment of urinary output is mandatory. If urine is tea coloured or dark,
myoglobinuria is likely. These patients should be aggressively resuscitated
with Hartmann’s solution to maintain urine output of approximately 100
mL/ h or greater in an adult to minimize tubular obstruction. Mannitol is
administered for osmotic diuresis. Sodium bicarbonate can be used for
the alkalinzation of urine. If myoglobinuria is unlikely, resuscitation with
Hartmann’s solution to produce a urine output of >0.5 mL/ kg/ h is appropriate. Urine myoglobin levels are monitored.
Cardiac injury is assessed by ECG, troponin levels, and echocardiography.
Muscle injury is assessed by creatinine phosphokinase and myoglobin levels.
Skeletal injury is assessed by physical examination and X- rays. Neurological
injury is assessed by examination and head CT.
Inpatient care
Admission to a specialized burn unit is warranted in all high voltage and lightning injuries. Admission following low- voltage electrical injury is selective.
Wound care
Wound care of an electrical injury is similar to care for burn injury. Silver
sulfadiazine is used as a topical agent.
Fasciotomy
Fasciotomy of the injured area is required in suspected cases of compartment syndrome as it serves as both a diagnostic and therapeutic tool.
A second examination is performed 24– 48 hours later. The decision to
debride the wound or amputate is made at this time. If debridement is
chosen, all devitalized and necrotic tissue is removed. Indeterminate tissue
is left for re- evaluation 1– 2days later.
175
176
https://t.me/med1917
176
CHAPTER20 Electrical injuries
Complications
Infections, persistent arrhythmias, compartment syndrome, cataracts, acute
kidney injury, complex regional pain syndromes, neurological injury, neuropathic pain, rhabdomyolysis, need for amputation.
Further reading
Arnoldo BD, Purdue GF. The diagnosis and management of electrical injuries. Hand Clinics
2009;25:469– 79.
Rai J, Jeschke MG, Barrow RE, Herndon DN. Electrical injuries:a 30- year review. Journal of Trauma
1999;46:93– 6.
https://t.me/med1917
Chapter21
177
Radiation burns
Introduction to radiation burns 178
Localized irradiation 179
Whole body irradiation 180
Immediate management 181
Further treatment 182
Further reading 182
178
https://t.me/med1917
178
CHAPTER21 Radiation burns
Introduction toradiation burns
Radiation burns are caused by ionizing radiation, as electromagnetic radiation (X- rays or gamma rays) or particles (alpha or beta), measured in grays
(Gy). Ionization produces free radicals, causing DNA damage, cell death,
and malignant change.
Radiation burns may be a consequence of radiotherapy or medical
imaging using beam energy. Although rare, they can be caused by intentional radiation release such as a nuclear weapon, additionally causing eye
or thermal injuries and should be included in the total body surface area
(TBSA); they can also result from accidents, such as the Fukishima nuclear
reactor disaster, Japan 2011. Burns from isotopes (
used for brachytherapy are more common.
Radiation is emitted evenly from a source. The amount of radiation encountered decreases rapidly with distance (intensity α 1/ distance2). As radiation passes through matter, eg. tissue, it transfers energy to it (linear
energy transfer (LET)). The higher the LET, the higher the absorbed radiation dose, measured in grays, with increased ionization of biological tissue
(Table 21.1).
Table21.1 Radiation types
Particle Penetration Skin eect
Alpha α Little penetration. Travels a few cm
Beta γ Higher range. Travels less than a
Gamma γ Poor ionization. High penetrance,
Neutron High kinetic energy, ready
X- ray Longer wave length than γ Dependent on power of
Data sourced from Waghmare CW. Radiation burn– From mechanism to management. Burns
39(2):212– 19, Copyright © 2013 Elsevier Ltd and ISBI, with permission from Elsevier
in air and stopped by clothes or a
sheet of paper
Very high ionization
metre in air and can be stopped by
a 1- cm sheet of aluminium
travelling far distances, requiring
centimetres of lead or metres of
concrete
penetrance
192
Iridium or 60Cobolt)
Unable to penetrate horny
skin. Harmful if inhaled,
ingested or prolonged skin
contact
Localized but severe skin
damage
Dependent on power
of γ ray
Often lethal with high
cell damage causing
unsalvageable skin damage
and necrosis
X- ray
https://t.me/med1917
LOCALIZED IRRADIATION
Localized irradiation
Signs of skin damage are progressive and dependent on total exposure.
Assessment of severity is dicult due to delayed signs requiring frequent
review. Medical radiation therapy is fractionated with the maximum dose
focused a minimum of 0.5 cm below the surface to spare normal tissue.
Higher doses (>25 Gy) are absorbed by the skin, causing collagen deposition and radiation brosis.
First- degree thermal burn equivalent
• >2 Gy:Mild transient erythema with onset in minutes to hours,
resolving in 48 hours, eg. in sustained interventional radiology
procedures >2 hours
• >6 Gy:Recurrence of more severe erythema after 2– 3 weeks with dry
desquamation or hair loss. Larger doses aect sebaceous glands causing
dry scaly skin
Second- degree thermal burn equivalent
• >18 Gy:Moist desquamation of the skin with blisters after a few weeks.
This may resolve up to 50days after exposure or develop into necrosis
Full- thickness burn
• >25 Gy:Initially pruritus and rash, full- thickness skin ulceration and skin
necrosis may occur from vascular insuciency as cumulative exposure
irrevocably damages the microvascular structure. May encompass
underlying structures such as muscle
179
180
https://t.me/med1917
180
CHAPTER21 Radiation burns
Whole- body irradiation
Acute radiation syndrome
• 1– 4 Gy:Describes the whole- body eect of radiation, beginning within
hours of exposure with fatigue, fever, headache, nausea, vomiting, and
diarrhoea. Alatent period (up to 3– 5days) follows this with other
overlapping syndromes. Time from exposure to symptom onset can
help estimate clinically the patient’s total radiation dose
Haematopoietic syndrome
• Exposure 1– 4 Gy:Bone marrow is sensitive to radiation, resulting
in pancytopaenia, with haemorrhage (thrombocytopenia) and
opportunistic infections (granulocytopaenia)
Gastrointestinal syndrome
• 1– 12 Gy:Onset of watery diarrhoea within hours as gut epithelium is
damaged, allowing bacterial translocation and sepsis, bowel ischaemia
and third spacing of uids causing hypovolaemia and acute renal failure
Neurovascular syndrome
• 15– 30 Gy:Irradiation causes profound hypovolaemia from inammatory
mediators and nitrous oxide release or loss of vascular epithelium.
Variable neurological symptoms are noted, with cardiovascular collapse,
respiratory distress and death.
• Bone marrow failure may occur at exposure of 30 Gys and a radiation
dose of 40 Gy is inevitably fatal
https://t.me/med1917
IMMEDIATE MANAGEMENT
Immediate management
• The immediate intervention should be to prevent further patient
exposure and skin ionization. In a major incident, swift triaging is
required. Usually, a major radiation exposure that is survivable is not
immediately lethal and concomitant injuries should be prioritized
according to ATLS guidelines
• Healthcare workers should limit their time near the source and wear
personal protective equipment (PPE). Radioactive material is very
unlikely to be a risk to emergency or medical personnel
• Casualties must be removed from the area of greatest radiation
contamination to limit exposure, if possible upwind and in the open air.
Typically, casualties with suspected radiation exposure would receive
decontamination near the scene, unless requiring immediate hospital
treatment. Most contamination will be conned in outer clothing, which
should be removed where possible, from head to foot, to minimize
inhalation risk. Underwear should also be removed if suspected of
contamination
• Wounds should be irrigated with plentiful amounts of saline to dilute
radioactive particles. Abrasive decontamination should be avoided if
possible. Care should be given not to spread contaminated uid to
unexposed tissue and showers are more appropriate than bathing the
patient. Irrigation should be continued until minimal readings or no
further change is found with a Geiger counter
• Patients should be treated under strict isolation precautions. Health care
workers treating or assessing such patients should have all skin covered,
wearing full gowns, with a mask, cap, shoe covers, and double gloves,
changing in an anteroom. Outer gloves should be changed frequently,
to avoid spreading contaminants to the patient’s normal tissue and to
avoid cross- contamination. Discarded protective gear and contaminated
items should be removed after use and placed in clearly marked plastic
containers for disposal. Geiger counters or other radiation detection
devices should be used to assess treatment areas regularly to detect
contaminants requiring decontamination
• On assessment, a full blood count should be taken immediately and at
12 hours post exposure. Alymphocyte reduction by more than half or
lymphopaenia indicates a signicant radiation exposure, with the patient
at risk of opportunistic infections. Apatient’s radiation exposure can
be estimated by the onset and severity of clinical symptoms along with
the concentration of dicentric chromosome aberrations in peripheral
lymphocytes
181
Соседние файлы в папке @xirurgi_2025