Hazard [Health Devices Oct 1980;9(12):312-8]
Despite a great deal of care and concern by medical, surgical, and
engineering personnel, inadvertent skin destruction in the operating room and intensive
care areas continues to occur. These injuries may lead to prolonged morbidity, extended
hospitalization, and increased cost, in addition to damaging the patient's trust in the
hospital and medical staff to the extent that legal redress is sought.
We receive an average of three reports per month involving skin
destruction. The literature on this subject is rather scarce and fragmented. We believe
that a comprehensive review of the mechanisms of such injuries will prove helpful in
recognizing, investigating, and preventing them.
While the usual appearance of intraoperative skin injury is that of a
full- or partial-thickness burn, thermal or electrical sources are not always involved. It
is therefore misleading (and in many cases inaccurate) to refer to an injury as a
"burn." "Lesion" is a more appropriate term that allows the
consideration of other causes. Descriptions of some major causative mechanisms follow.
ESUs frequently cause injuries in the operating room. Few surgical
personnel understand the principles of operation of ESUs, and many are not fully aware of
the necessary safety precautions. Following is a chronological list of Health Devices
articles that address these issues:
ECRI. Electrosurgical units (Evaluation). Health Devices 1973;
ECRI. Danger! Electrosurgical units at work (Hazard). Health Devices
ECRI. Patient burns and ECG monitors. Health Devices 1973; 2:219.
ECRI. Electrosurgery and laparoscopy (Hazard). Health Devices 1973;
ECRI. Disposable electrosurgical active handles (Evaluation). Health
Devices 1973; 2:256.
ECRI. Disposable electrosurgical return electrodes (Evaluation). Health
Devices 1973; 2:264.
ECRI. Incorrect connection of electrosurgical cables (Hazard). Health
Devices 1974; 3:201.
ECRI. Electrosurgical units (Evaluation). Health Devices 1977;
ECRI. Electrosurgical unit safety. Health Devices 1977; 6:119.
ECRI. Disposable electrosurgical return electrodes (Consultant's Corner). Health
ECRI. Disposable electrosurgical dispersive electrodes (Evaluation). Health
Devices 1979; 8:43.
ECRI. Electrosurgical burns and laparoscopy. Health Devices 1980;
The following works also originated at ECRI:
Knickerbocker GG. ESU safety: Purchasing, preventive maintenance, incident
investigation. Medical Instrumentation 1980; 14(Sep-Oct):257.
Knickerbocker GG, Skreenock JJ. Electrosurgical equipment. In: Cook and
Webster, eds. Therapeutic electrosurgery. Englewood Cliffs, N.J.: Prentice-Hall
(accepted for publication in 1981).
Skreenock JJ. Electrosurgical quality assurance: The view from the OR
table. Medical Instrumentation 1980;14(Sep-Oct):261.
While electrosurgical burns are common, the mechanisms of skin destruction
discussed in the following sections are equally important. In our estimation, they are
responsible for at least as many accidental injuries as electrosurgery.
Even low DC voltages can result in skin damage (Leeming, 1970).
In one case reported to us, faulty DC circuitry in the warning circuit of
an ESU resulted in burns from the application of 14 volts DC. Such burns are the result of
electrolysis of skin moisture (physiologic saline), which produces sodium hydroxide at the
negative electrode, resulting in localized full-thickness skin lesions. We approximate
these conditions in our laboratory and documented the additional possibility of skin
discoloration from prolonged contact with the terminals of a 9-volt battery.
We recommend that DC devices for patient care be given the same close
scrutiny for electrical safety that AC devices have received. Additionally, we strongly
recommend that unprotected battery terminals not be placed in prolonged contact with the
skin. This could occur, for example, if the battery cover were missing from an ECG
telemetry transmitter or from a transcutaneous electric nerve stimulator (TENS) worn by
Thermal burns constitute another major group of injuries during surgery.
One common mechanism is prolonged contact with a moderate heat source, such as a
Although many factors determine whether skin destruction results from
exposure to a hot surface, the most important factors are temperature and exposure time.
The lowest direct-contact temperature responsible for a cutaneous burn in humans is 44° C (Moritz, 1947), with irreversible injury occurring after six
hours of exposure. Below this threshold temperature, blood flow to the tissue tends to
affect temperature distribution in the skin only slightly. However, once the threshold
temperature has been reached, ischemia caused by pressure or surgical technique may well
increase the rate at which injury occurs. Higher temperatures may cause injury within
proportionately shorter times. Therefore, full-thickness injury may result from either
brief exposure to intense heat or prolonged exposure to moderate temperatures.
Reports of incidents and our own investigations have revealed that most
direct-contact thermal skin injuries occur during lengthy surgical procedures in which
hyperthermia blankets are used and which involve extracorporeal circulation or
cross-clamping of the aorta. In cases where excessive temperatures were known to be
present, the thermal injury presented a linear pattern of burns (usually full thickness)
that exactly matched the pattern of tubing in the hyperthermia blanket. Injuries tended to
be concentrated in sites where pressure was greatest, such as over the sacrum. Such a
pattern is consistent with one of moderate, but repeated, thermal injury combined with
low-grade ischemia (from either the surgical techniques employed or pressure).
We are also aware of many incidents in which a linear pattern of injury
appeared, corresponding to the hyperthermia blanket tubing, but the unit was not used in a
heating mode and its temperature control circuitry was operating properly. In these cases,
pressure (discussed later) was the probable cause of injury. The weight of the patient's
body increased the pressure on tissue touching the water-filled ridges of the blanket.
We found in our first evaluation of hypo/hyperthermia machines (Health
Devices, Vol. 1, p. 52) that most of the units built before 1971 lacked a backup
thermostat to prevent heating past physiologically tolerable limits. Units of such design
were implicated in multiple incidents of patient injury, resulting in publication of
hazard reports (Health Devices, Vol. 1, p. 190; Vol. 3, p. 232). Even more recent
units having backup thermostats are occasionally involved in patient injuries, but these
tend to result from operator error combined with improper maintenance (Health Devices,
Vol. 3, pp. 229, 231).
Routine inspection and preventive maintenance are essential to ensure safe
operation of these devices (Health Devices, Vol. 3, p. 222), and user education and
vigilance during use are critical. Other helpful measures include the interposition of
fabric between the hyperthermia blanket and the patient and assurance that no creases or
folds that might concentrate heat are present in the blanket.
The temperature of the heating fluid should be constantly monitored and
never allowed to exceed 42° C. Judicious use and proper
maintenance of modern hyperthermia devices should markedly decrease the incidence of
Irradiant devices may also cause thermal injury. We have investigated
incidents in which high-intensity examination lamps used in conjunction with radiant
warmers have caused second-degree burns on neonates. Malfunctioning or improperly
maintained radiant warmers have also caused burns.
It should not, however, be unquestionably assumed that a radiant device
used on a patient was responsible for a lesion. For example, Fleishman (1977) reported
that a supine neonate's dorsal side was "burned" by a radiant warmer because a
disposable diaper had been placed under the patient with the plastic against the skin.
(This was done to catch the urine for volume measurement.) The physician theorized that
the sides of the plastic layer exposed to radiant energy became hot and transmitted the
heat to the plastic touching the skin. This theory is not plausible, however, since a thin
plastic sheet is a very poor heat conductor and the areas of the plastic sheet in contact
with the patient were shaded from irradiation. The physician apparently did not think it
significant that the patient had been lying in a pool of urine (contained in the diaper)
for several hours. In our opinion, the urine, and not the radiant warmer, was responsible
for the "burn."
Other sources of irradiant energy that have resulted in burns include
pediatric transilluminators (McArtor, 1979) and high-density operating room lamps when
used without heat filters (Stoner, 1976). Similar incidents have been reported by hospital
members of the Health Devices System.
Transcutaneous oxygen electrodes also have been associated with thermal
injury (Hardman, 1980). These electrodes and transcutaneous carbon dioxide electrodes
contain a heater that maintains electrode temperature at about 44°
C, the threshold for contact thermal injury of human skin after six hours. Current
clinical procedures call for repositioning the electrode every four hours. However, this
criterion does not account for any inaccuracies of the thermostat, and it may be
insufficient for some neonates and elderly patients with sensitive skin. On these
patients, we suggest more frequent electrode relocation to prevent burns. Even with these
precautions, burns beneath electrodes still occur, and reports from the field indicate
that they are not uncommon. The medical staff must weigh the risk of thermal burns against
the advantages of using the electrodes (as opposed to performing routine blood gas
Prepping and Degreasing Agents
Chemicals may be toxic to the skin or may interact with other substances
in exothermic reactions to cause skin destruction. Loss of the lipid protective covering
of the skin resulting from preoperative bathing and the use of degreasing agents, such as
Freon or ether, makes the skin particularly vulnerable to irritation.
Chemical injuries may appear quite similar to thermal burns and tend to
occur where the agent pools or is in constant contact with the skin, especially if mild
heat or pressure is applied. Characteristic locations of injuries from pooled prepping
agents are areas in contact with a hyperthermia blanket and areas beneath a tourniquet.
Merthiolate (thimerosal) is a common cause of skin destruction. In
addition to its irritative properties, Merthiolate in contact with an aluminum dispersive
electrode produces aluminum oxide and heat, leading to thermochemical burn (Health
Devices, Vol. 2, p. 271). Freon and isopropyl alcohol, in combination with gentle
pressure and mild heat from a hyperthermia blanket, have resulted in injury (Klein, 1976).
Tincture of iodine may cause chemical injuries if allowed to remain on an
infant's sensitive skin or if confined under an occlusive or acetone-containing spray
dressing (Morgan-Hughes, 1978).
An agent which may result in an epidemic pattern of skin injury is
ethylene oxide (EtO), a gas commonly used to sterilize heat-sensitive OR materials. An
outbreak of skin damage resulted from incompletely aerated patient gowns sterilized with
EtO (Biro, 1974). Such injury resembles "scalded skin syndrome" and occurs in
pressure areas. Using an incompletely aerated EtO-sterilized device, such as an anesthesia
mask or hyperthermia blanket, on the patient may result in skin injury, especially if the
skin is moist (Health Devices, Vol. 5, p.130).
Preventing chemical injury to the skin requires care on the part of the
surgeon and the operating room staff. All prepping agents should be applied with great
care and should not be allowed to pool beneath the patient or beneath a tourniquet.
Special care should be taken to avoid contact between Merthiolate (thimerosal) solution
and aluminum dispersive electrodes. OR supervisory personnel should ensure that proper
aeration procedures are followed for all materials sterilized with EtO. Such precautions
should eliminate all but the occasional idiosyncratic reaction.
An often unrecognized source of skin destruction in the OR is prolonged
immobility and pressure, which can lead to pressure necrosis. These injuries may resemble
those caused by an ESU or hyperthermia unit; in fact, many lesions were originally
suspected of having been caused by these devices. Most such injuries result from prolonged
immobility, in which tissue pressure exceeds the critical closing pressure of subcutaneous
blood vessels, so tissue ischemia exceeds physiologic tolerance.
Hicks (1971) reported a 13% incidence of pressure sores following surgery.
Such injuries tend to be more common in the elderly, probably because of increased tissue
fragility, poor overall physical condition, and low perfusion, but Hicks also noted that
69% of skin ulcers occurred in patients under age 60, with 30% under 19 years of age. A
common factor in all cases was prolonged operative time. Gendron (1980) concluded that
operative times of two hours or less were not likely to result in pressure necrosis, while
procedures lasting longer than three hours predisposed the patient to skin injury from
Alopecia (loss of hair) caused by prolonged immobilization of the head has
also been documented following cardiovascular (Lawson, 1976; Elder, 1977) and
gynecological (Poma, 1979) procedures. These injuries occur early in the postoperative
period as edema and a very painful seroma of the occipital scalp, followed by ulceration
and transient or permanent localized hair loss.
Even moderate pressures applied for as little as one hour have caused
ischemic injury in experimental animals (Kosiak, 1961). Such pressures are routinely
exceeded over bony prominences in the supine human. Obesity offers no real protection;
while the pressure may be somewhat lessened by fat, wider areas are at risk (Foster,
Conventional operating table pads are not capable of adequately protecting
against pressure sores (Souther, 1971). However, Gendron's study during a one-year trial
has shown that the use of a full-length silicone gel pad proved effective in preventing
serious pressure injuries in surgical procedures lasting longer than three hours. Gendron
considered other static or dynamic pressure relief devices to be unacceptable for surgical
application due to concerns over electrical safety, positional stability, and/or asepsis.
These devices included water-filled pads, convoluted foam pads, sheepskins, air
mattresses, vacuum splints, and alternating pressure pads. We agree that these devices are
not well suited for use during surgery.
One disadvantage of the silicone gel pad is that warming or cooling the
patient may prove difficult since the hyperthermia blanket must be placed under the gel
pad (placing the gel pad under the hyperthermia blanket will not provide the desired
cushioning). Prewarming or precooling the gel pad before placing the patient on it may
alleviate this problem, but long "lag" times on further intraoperative demands
for warming or cooling should be expected.
Straps used to secure the patient during surgery are another source of
pressure. Once tightened, they may cause excessive pressure on the skin directly beneath
them and/or add to forces exerted elsewhere on the patient. The inadvertent placement of a
strap over an ESU dispersive electrode or an ECG electrode is particularly hazardous. In
such cases, the strap may press the electrode's electrical connector (usually a small
metal disc) against the skin with considerable force, resulting in a pressure sore. This
is more serious with an ESU dispersive electrode because the force may distort the
electrode's shape and prevent adequate dispersion of current. Nonuniform current
dispersion can create "hot spots" beneath the electrode that may result in burns
from high current densities.
Plastic adhesive drapes should be removed carefully from patients with
particularly fragile skin to prevent tearing of the skin (Frazier, 1971).
Shearing forces also contribute to pressure sores. If the position of the
operating table is changed while the patient is anesthetized, the weight of the torso
tends to move the body in the direction indicated, while the skin may be fixed by
friction. Skin destruction is particularly likely in the sacral area, where the blood
supply to the posterior tissues exits the well-anchored deep fascia into the looser
subcutaneous fascia. Angulation occurs, and thrombosis of the affected vessels with
ischemic ulceration may result. (Reichel, 1978).
While the silicone gel pads may adequately distribute pressure while
meeting other qualifications for surgical use, ancillary measures will continue to be
necessary. Special care should be taken in those cases in which a hypotensive or ischemic
period might be expected. Alterations of the operating table should be kept to a minimum.
If repositioning the patient is necessary after induction of anesthesia, it should be
performed with care, and the patient should be lifted into position, rather than rolled or
tugged, to avoid shearing forces. Reducing the operating time, if possible, would be
helpful. The head position of supine patients should be changed by the anesthesiologist
every 30 minutes to avoid occipital alopecia.
Accidental skin destruction continues to occur with regrettable frequency.
When an incident occurs, it may be very difficult to identify the contributing factors.
Avoid the tendency to assume that a particular device, such as an ESU or hyperthermia
blanket, was at fault. Consider very carefully the possibility of multiple causes, any one
of which would not have caused the lesions.
Conduct a thorough etiological investigation as soon as possible. Document
the clinical circumstances in which the injury occurred, and take color photographs of the
lesion as soon as it is discovered and periodically as it heals. The circumstances of the
incident and any characteristic patterns of skin destruction may help identify the
Very complex investigations and those which may involve legal action or
simple defensiveness on the part of staff members may require the assistance of objective,
competent outside investigators. Whether for legal reasons or not, an investigation should
be conducted with the objective of preventing similar occurrences.
The summary below "Help Prevent Skin Injury" lists ways to prevent
skin injury to patients. The table summarizes the mechanisms of inadvertent skin
destruction and provides general guidelines for incident investigation and prevention. It
is limited to the OR but is not intended to be inclusive.
Help Prevent Skin
Skin injuries on surgical patients
may occur by one or more of the mechanisms listed below.
Before the procedure:
- Examine electrosurgical equipment and accessories for damaged insulation,
cables, or connectors and cracked, dirty, or bent return plates*
- Place return electrode* close to the surgical site and ensure good patient contact
- Keep ECG electrodes and patient temperature probes far from the surgical
site and the return electrode*
- Keep electrosurgical cables clipped away from the
patient and from monitoring cables
- Prevent battery terminals (e.g., on an ECG telemetry
transmitter) from contacting patient's skin; ensure battery cover is in
During the procedure:
- Activate the electrosurgical unit only when touching
blade to tissue
- Avoid unnecessary or prolonged activation
- Do not continue to increase power settings if you
are not getting desired results look for other problems
- Check contact with return electrode* after repositioning patient
- Protect unused active electrodes
Hypo/hyperthermia unit operation and
- Maximum backup thermostat setting should be 42°
- Ensure proper placement of patient temperature probe
(also check after repositioning patient)
- Watch both circulating water temperature* and patient temperature
- Place a sheet between hypo/hyperthermia blanket and patient**
PO2 and PCO2 electrode operation and use:
- Maximum operating temperature should not exceed
- Move electrode to new site at least every three hours
Radiant warmer and lamp
- Use automatic mode for safer warming
- Secure temperature probe to a skin surface that
faces the heater, never beneath the patient or in the rectum
- Do not estimate the heat reaching the patient with
your hand—this method is not reliable
- Heat from OR and examining lamps is cumulative; be
cautious when using several lights simultaneously
- "Cold" fiberoptic light sources can burn
do not leave light source on when endoscope is not being used for viewing
- Do not allow mercury-containing compounds such as Merthiolate
(thimerosal) to contact aluminum electrodes the resultant thermochemical
heating may injure the patient
- Do not allow degreasing agents or prepping solutions
to pool beneath patient or to contact electrodes
- Aerate all
EtO-sterilized materials completely before
- Check OR table mattress for sufficient thickness
- Consider placing a thin silicone gel pad between
patient and hypo/hyperthermia blanket for long procedures
- Avoid leaning heavily on patient for prolonged
- Ensure that skin is not being stretched or pulled
after adjusting patient or table position
- Change patient's head position every 30 minutes to
- Be sure that circulation is not restricted by the patient's position or
* Also called dispersive electrode, ground plate, patient plate,
butt plate, grounding plate.
** For lengthy procedures, also consider placing a thin silicone gel pad on
top of the hypo/hyperthermia blanket to reduce pressure.
OR Skin Injuries: Common Sources and Prevention
Mechanism of Injury
Device or Agent
Lesion beneath dispersive electrode
Gel and position dispersive electrode properly.
Lesion at ECG electrode
|Avoid placement of ECG electrodes in current path between ESU active and dispersive electrodes. Keep ESU cables away from ECG leads.
||Lesion occurs after repeated requests by surgeon to increase power
||If unit not performing normally, check continuity of all leads, connectors, and dispersive electrodes.
Low voltage DC
ECG telemetry transmitter
Lesion from prolonged contact with exposed battery terminals
Cover battery terminals
|Lesions on buttocks, back, thighs, back of knee, calves and heels; hypo/hyperthermia unit turned on
Limit blanket temperature to minimum required to warm patient. Maximum temperature of backup thermostat should be £ 42+C.
Lesion beneath electrode
Move electrode to new site every 3 hours. Maximum operating temperature should not exceed 44+C.
Prepping and degreasing agents
Acetone, ether, Freon, alcohol, providing-iodine, tincture of iodine. Hibitane (chlorhexidine digluconate), Merthiolate (thimerosal)
Lesion on buttocks, edge of back, dorsal thigh and knee
Do not allow prepping agents to pool beneath patient.
Aluminum ESU dispersive electrode
Lesion at electrode site when Merthiolate (thimerosal) contacted electrode, causing exothermic reaction
|Do not allow Merthiolate or other mercury-containing compounds to contact aluminum electrodes.
Ethylene oxide (EtO)
Lesions around mouth following line of anesthesia mask contact
Aerate ALL EtO sterilized goods properly before use.
Pressure and shearing forces
Lesions on back and buttocks that follow lines of blanket, but unit not used for heating during procedure
|Consider using a thin silicone gel pad over blanket for long procedures.
Lesions on buttocks, back of heels; OR table position adjusted after patient was anesthetized
Consider using a thin silicone gel pad over blanket for long procedures. Be sure that skin is not being pulled or stretched after adjusting table or patient position.
Bald spot forms on head several days after procedure
Change head position every 30 minutes.
Lesion on arm; patient's arm was tucked under sheet at side during procedure; ESU not used
|Avoid leaning heavily on patient for prolonged periods.
Lesion on leg near area under positioning strap
Be sure that positioning straps are not restricting circulation.
* These personnel are the most
capable of preventing skin injury under the given circumstances. The
clinical engineer is responsible for periodic inspection and preventive
maintenance of the equipment.
** Operator vigilance is important throughout the procedure.
- Electrodes, Electrosurgical [15-579]
- Electrosurgical Units [11-490]
- Germicides [18-159]
- Hypo/Hyperthermia Blankets [12-067]
- Hypo/Hyperthermia Units [12-068]
- Lights, Examination [12-276]
- Oxygen Monitors, Transcutaneous [12-592]
- Pressure Pads [12-936]
- Restraints [13-346]
- Transilluminators [14-130]
- Warmers, Radiant [13-248]
Cause of Device-Related Incident
Device factors: Design error/labeling error;
Device failure; Device interaction; Improper maintenance, testing, repair, or lack or
failure of incoming inspection; Manufacturing error
User errors: Failure to read
label; Inappropriate reliance on automated feature;
Incorrect clinical use; Incorrect control settings
system failure: Use of inappropriate devices
Mechanism of Injury or
Burn (electrical, thermal, chemical)