Facilitating benefit, minimising risk: Responsibilities of the surgical practitioner during electrosurgery

This article will explore the role of the surgical practitioner in providing best care for the patient, by discussing electrosurgical intervention (ESI). It will exemplify the technological aspect of the role. Management of ESI equipment, and its inherent risks, will be shown to relate directly to the practitioner's role. Some safety claims for ESI equipment will be analysed, demonstrating the need for a theatre practitioner to establish the validity of sources that inform practice. The roles of circulating practitioner and scrubbed practitioner will be elucidated, with exploration of professional and ethical responsibilities to the patient, themselves and colleagues.

Sequential activation of multiple grounding pads reduces skin heating

Radio frequency (RF) tumor ablation has become an accepted treatment modality for tumors not amenable to surgery. The need for larger ablation zones has required increase in RF generator power, with current generation devices delivering 200-250 W. Skin burns due to ground pad heating have become a common complication and are now a limiting factor for further increase in ablation zone and generator power. We performed ex vivo experiments with three ground pads (5 x 5 cm) placed on a tissue phantom. We applied 100 W of power for 12 min between the pads, and an RF electrode while we measured leading edge temperature below each pad, and temperature profile on the pads using temperature-sensitive LCD-paper. We compared conventional operation (i.e. simultaneous connection of all three pads) to sequential activation of the pads where each pad is only active for approximately 0.5 s. The timing during sequential activation was adjusted to keep leading edge temperature equal between the pads. Temperature rise below the leading edge for proximal, middle and distal ground pad was 10.7 +/- 1.04, 1.0 +/- 0.15 and 0.3 +/- 0.07 degrees C for conventional operation, and 4.8 +/- 0.16, 4.4 +/- 0.20 and 4.5 +/- 0.35 degrees C for sequentially activated operation. The maximum leading edge temperature rise was more than twice as high for conventional compared to switched operation (p<0.001). Sequential activation of multiple ground pads resulted in reduced maximum leading edge temperature, and allows control of each pad such that leading edge temperature of all pads is the same. This may reduce the incidence of ground pad burns by allowing each pad to reach same temperatures independent of location, and may allow higher power RF generators due to reduced skin heating.

Demystifying biphasic defibrillation

This technology is making defibrillators less likely to injure patients. Here's what you need to know.

NFPA 70E: Performing the electrical flash hazard analysis

Arc flash hazards pose a serious risk to employee safety; proper safe work practices must be utilized. Electrical equipment > or = 50 volts must be deenergized and locked out/tagged out prior to servicing and maintenance unless doing so would increase hazards or is infeasible. Remember, convenience is not an acceptable reason for keeping equipment energized during servicing and maintenance. If electrical equipment must remain energized during Servicing and maintenance, NFPA 70E should be consulted to determine flash hazard boundaries as well as required PPE. Finally, circuit breakers and electrical disconnects must be marked to warn qualified employees of potential arc flash hazards.

Safety technologies for laparoscopic monopolar electrosurgery; devices for managing burn risks

The use of monopolar electrosurgery during laparoscopy has many benefits. But it also creates the risk that high-frequency leakage currents could travel from the active electrode to patient tissue, causing burns. In some cases, these burns can be serious and even lead to life-threatening complications. In this Evaluation, we review four products designed to reduce the risk of leakage-current burns during these procedures. One of the products is an active-electrode shaft with a brightly colored inner layer of insulation, making it easier to spot insulation breaks that could allow leakage currents. Two of the products use high DC voltage to detect full-thickness breaks in electrode insulation. The other product is an active-electrode shielding system that provides protection during a procedure by conducting potentially dangerous leakage current away from the patient. We rate one product Preferred and the others Acceptable. However, we don't believe that any of these technologies are essential to safe monopolar laparoscopic electrosurgery. If these technologies are used, they should be viewed only as supplemental safety measures, not as a substitute for the general safe practices required during these procedures.

Higher currents, greater risks: preventing patient burns at the return-electrode site during high-current electrosurgical procedures

Patient burns at the site of the return electrode are a well-known, and generally well-managed, risk of electrosurgery. However, the use of newer electrosurgical devices and techniques that apply higher currents to the patient for longer periods of time has created a new set of burn risks. And the safety measures that have proven effective during conventional electrosurgery can not necessarily be relied on to prevent return-electrode-site burns during these high-current, long-activation-time electrosurgical procedures. In this article, we explain the hazards and detail the factors that can increase the risks of return-electrode-site injuries for a given procedure. We also provide recommendations to help facilities and clinicians minimize those risks.

[Magnetic resonance imaging of the brain in patients with cardiac pacemakers. Experimental and clinical investigations at 1.5 Tesla]

PURPOSE

In-vitro and In-vivo evaluation of feasibility and safety of MRI of the brain at 1.5 T in patients with implanted pacemakers (PM).

MATERIALS AND METHODS

24 PM models and 45 PM electrodes were tested In-vitro with respect to translational forces, heating of PM leads, behaviour of reed switch (activated vs. deactivated) and function at a 1.5 T MRI-system (actively shielded, maximum field gradient: 30 mT/m; rise time: 150 T/m/s). Based on these results, 63 MRI examinations in 45 patients with implanted PM were performed. Prior to MRI the PM were re-programmed in an asynchronous mode. The maximum SAR of MRI-sequences was limited to 1.2 W/kg. Continuous monitoring of ECG and pulse oximetry was performed during MRI. PM inquiry was performed prior to MRI, immediately after MRI and -- to assess long-term damages -- three months after the MRI exams, including determination of stimulation thresholds to assess potential thermal myocardial injuries at the lead tips.

RESULTS

Translational forces (F (max) < or = 560 mN) and temperature increase (DeltaT (max) < or = 2.98 degrees C) were in a range which does not represent a safety concern from a biophysical point of view. No changes to the programmed parameters of the PM or damage of PM components were observed neither In-vitro (n = 0/24) nor In-vivo (n = 0/63). Despite the strong magnetic field, the reed switch remained deactivated in 54 % (13/24) of the cases during In-vitro simulated MRI exams of the brain. All patient studies (n = 63/63) could be completed without any complications. Atrial and ventricular stimulation thresholds (expressed as pulse duration at 2-fold rheobase) did not change significantly immediately post-MRI nor in the 3 months follow-up (pre-MRI: 0.17 ms +/- 0.13 ms, post-MRI: 0.18 ms +/- 0.14 ms, 3 months follow-up: 0.17 ms +/- 0.12 ms).

CONCLUSION

MRI of the brain at 1.5 Tesla can be safely performed in carefully selected clinical circumstances when appropriate strategies are used (re-programming the PM to an asynchronous mode, continuous monitoring of ECG and pulse oximetry, limiting the SAR value of the MRI sequences, cardiological stand-by). Based on these studies, implanted PM should not longer be regarded as an absolute contraindication for MRI at 1.5 T.

The effect of prophylactic topical steroid cream on the incidence and severity of cutaneous burns following external DC cardioversion

INTRODUCTION

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a prospective double-blinded controlled study to determine whether the application of steroid cream prior to cardioversion reduces their incidence and severity.

MATERIALS AND METHODS

Two hours before elective DC cardioversion, we applied betamethasone 0.1% cream or placebo cream over sternal and apical pad sites in 56 patients, with patients acting as their own controls. Two hours after cardioversion, a separate blinded observer measured the visual analogue pain score (VAS), sensory and pain detection thresholds, skin temperature and erythema index at sternal and apical pad sites.

RESULTS

The study had an 80% power to detect a 50% difference in VAS at 2 h, accepting an alpha error of 0.05. There was no difference between pain at 2 or 24 h, skin temperature, erythema index, sensory and pain detection thresholds at pad sites treated with steroid cream or control.

CONCLUSION

Topical betamethasone 0.1% cream applied 2 h before elective DC cardioversion is no more effective than placebo at reducing the pain and inflammation from cardioversion burns.

The effect of topical non-steroidal anti-inflammatory cream on the incidence and severity of cutaneous burns following external DC cardioversion

INTRODUCTION

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a study to determine whether the application of non-steroidal anti-inflammatory cream prior to cardioversion reduces their incidence and severity.

MATERIALS AND METHODS

Two hours before elective DC cardioversion, we randomised 55 patients to receive ibuprofen 5% cream or placebo cream over sternal and apical pad sites, with patients acting as their own controls. Two hours after cardioversion an independent blinded observer measured skin temperature, erythema index, and minimum sensory and pain detection thresholds at sternal and apical pad sites. Visual analogue pain score (VAS) for each site was recorded at 2 h and 24 h post-cardioversion.

RESULTS

There was a statistically significant difference between pain measured by VAS, skin temperature and pain detection threshold measured at pad sites with pre-applied ibuprofen 5% cream and those with pre-applied aqueous cream, after elective DC cardioversion.

CONCLUSION

Prophylactic application of topical ibuprofen 5% cream 2h prior to elective DC cardioversion reduces pain and inflammation. Consideration should be given to use of prophylactic application of topical ibuprofen as routine treatment for elective DC cardioversion.

MRT-induzierte Verbrennung bei Tätowierungen

Skin burns to patients with tattoos during MRI procedures are reported but rare complications. MRI scans are being used more often also as diagnostic procedures in trauma patients. In this article we present the case of a patient after trauma of the vertebral column who experienced burning pain at the site of a tattoo on the distal femur during the MRI examination, necessitating cessation of this procedure. Based on this example we discuss possible pathomechanisms of MRI-induced skin burns to patients with tattoos. It becomes clear that patients have to be asked about possible tattoos before MRI scans and should be informed about possible pain development.

Impedance-gradient electrode reduces skin irritation induced by transthoracic defibrillation

A new type of disposable external defibrillation electrode has been developed to reduce the skin irritation commonly associated with defibrillation and synchronised cardioversion. This design employs an impedance gradient to reduce the proportion of current delivered to the electrode periphery. The temperature distribution under the new electrode was compared with that of four other types of commercially available electrodes after repeated high-energy biphasic defibrillation discharges to domestic swine. Skin temperature distributions were acquired using non-invasive thermography. Measurements of the maximum temperature rise at each electrode site, taken 3.6s after the fifth defibrillation discharge, demonstrated that the new impedance-gradient electrode produced 50-60% less skin heating than two of the three uniform-impedance electrode designs. Histological examination of erythematous sites excised 24 h after defibrillation quantified the associated skin damage using a scoring protocol developed for this study. In contrast to previous studies, histological examinations demonstrated second-degree skin burns following defibrillation. The new electrode design, however, induced 44-46% less skin damage than two of the traditional uniform-impedance electrodes.

Modern Concepts of Treatment and Prevention of Electrical Burns

Electric injuries account for 1,000 deaths in the United States, with a mortality rate of 3--15%. As the widespread use of electricity and injuries from it increase, all health professionals involved in burn care must appreciate its physiological and pathological effects as well as management of electrical current injury. Electric current exists in two forms: alternating current and direct current. The effects of electricity on the body are determined by seven factors: (1) type of current, (2) amount of current, (3) pathway of current, (4) duration of current, (5) area of contact, (6) resistance of the body, and (7) voltage. Electrical accidents can be divided into less than 1,000 V (low-voltage accidents) and greater than 1,000 V (high-voltage accidents). In any electrical accident, the witness must turn off the power source and initiate treatment at the scene of the injury. Low-voltage electric burns almost exclusively involve either the hands or oral cavity. Surgical treatment will vary with the severity of the injury. Burns caused by contact with a high-voltage alternating electric circuit conforms to two types: burns from an electric arc and burns from an electric current. High-voltage electric current injuries have a wide variety of systemic manifestations, including neurologic complications, cardiovascular and pulmonary manifestations, vascular damage, and abdominal, bone, eye and joint complications. An organized approach to the management of these complications is outlined in this article. The best treatment of burn injuries remains prevention. Because the majority of burn injuries are due to occupational electrical injuries, the regional burn centers must work effectively with industry to prevent these potentially life-threatening accidents.

[Indoor electric burns in children]

BACKGROUND

Electric burns are serious public health problems that comprise 3.5% of the burns that refer to the hospital. By biting and sucking the electric cords, mouth and lip burns occur in the children. The mortality rate is 90% in the children who had cardiac arrest before coming to the hospital. In this study, the electric burns that were followed-up in our clinic were reported.

MATERIAL AND METHODS

Four cases with electric burns followed-up in our clinic between September 2002 February 2003; were assessed. The cases were called back to control one and six months after the burn incident and the indoor precautions required were appraised.

RESULTS

The mean ages of two male and two female children were respectively 23.6+/-10.6 months (10 - 36 months). Two of the four cases with burns had played with electric plugs and the other two had bitten the cords. The indoor precautions had still not been taken at the first and six months of the follow up period.

CONCLUSIONS

House visits are important since the preventive measures are not usually taken at home. In consideration of higher incidence of exposure to indoor accidents during childhood, the best way to avoid accidents is to take preventive measures against them.

Burn centers should be involved in prevention of occupational electrical injuries

Electrical injuries are uncommon, comprising 10% of our regional burn center admissions during a 9-year period. The purpose of this study was to determine the incidence, type, and location of occupation-related electrical injuries in an attempt to focus our injury prevention and outreach efforts. We retrospectively reviewed the medical records of patients with electrical injuries admitted to our burn center from January 1992 through March 2000, with focused analysis on those patients admitted with occupation-related electrical injuries. Of the 95 patients admitted for electrical burns, 81% (n = 77) were occupational injuries. This rate of injury suggests that prevention efforts should be directed at work sites and partnerships should be developed between burn centers and businesses to reduce the incidence of injuries.