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Objective The purpose of this study was to assess the level of skill of laparoscopic surgeons in electrosurgery.
Design Subjects were asked to complete a practical diathermy station and a written test of electrosurgical knowledge.
Setting Tests were held in teaching and non-teaching hospitals.
Sample Twenty specialists in obstetrics and gynaecology were randomly selected and tested on the Monash University gynaecological laparoscopic pelvi-trainer. Twelve candidates were consultants with 9–28 years of practice in operative laparoscopy, and 8 were registrars with up to six years of practice in operative laparoscopy. Seven consultants and one registrar were from rural Australia, and three consultants were from New Zealand.
Methods Candidates were marked with checklist criteria resulting in a pass/fail score, as well as a weighted scoring system. We retested 11 candidates one year later with the same stations.
Main outcome measures No improvement in electrosurgery skill in one year of obstetric and gynaecological practice.
Results No candidate successfully completed the written electrosurgery station in the initial test. A slight improvement in the pass rate to 18% was observed in the second test. The pass rate of the diathermy station dropped from 50% to 36% in the second test.
Conclusion The study found ignorance of electrosurgery/diathermy among gynaecological surgeons. One year later, skills were no better.
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Electrosurgery units have become a necessity in operating theatres. Stray current resulting from insulation failure, direct coupling, capacitive coupling and other malfunction of electrosurgical units may compromise patient safety. At the 1993 meeting of the American College of Surgeons, 54% of the 506 surgeons surveyed reported they knew of a colleague who had encountered electrosurgery complications.1 These types of incidents are prevalent in laparoendoscopic procedures, where a surgeon's field of view restricts the visibility of an electrosurgical instrument to only its tip. Injuries to non-targeted tissues are therefore unnoticed as they occur along the shaft of the instrument and are unrecognised. They are often diagnosed post-operatively if the patient presents with peritonitis, haemorrhage, organ or vessel perforation or infection.2
Electrosurgical incidents arising from stray currents can be minimised with the use of appropriate technology such as return electrode monitoring systems, active electrode monitoring units and tissue response generators.3–5 These measures will not, however, prevent all electrosurgical burns. Additional contributors to electrosurgical incidents are poor technique and inadequate knowledge of the principles of electrosurgery. Surgeons must therefore be provided with adequate training in electrosurgery.3
Surgeons must be aware of the type and age of the electrosurgical unit used, its safety mechanisms, the operative environment and the type of tissue cauterised as they are legally responsible. Oxygen-enriched atmospheres in otolaryngology, for instance, require minimal power settings and sparing use of supplemental oxygen in an effort to prevent flash fires.6 In open surgery, non-hazardous operating environments are essential. A patient treated for appendicitis was set on fire caused by the heat from the electrosurgical instrument which ignited a skin cleaning solution. The flames were doused with a couple of buckets of water.7 This incident occurred not long after a similar case where the electrosurgical instrument ignited a sterilising solution during a caesarean section.8
We designed a prospective study testing electrosurgical skill and theoretical diathermy knowledge.
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Twenty specialists of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) participated in this study. Candidates were chosen randomly after advertising in our specialist College of Obstetricians and Gynaecologists newsletters and journals. Eight were registrars (levels 1, 3, 4, 5 and 6) with up to six years of practice in operative laparoscopy. The frequency with which registrars performed operative laparoscopy at the time of testing ranged from zero to ‘more than once per week’. Twelve candidates were FRANZCOG consultants with 9–28 years of practice in operative laparoscopy, which they performed between ‘once in two weeks’ to ‘more than once per week’. Six consultants were from rural areas. The age of candidates ranged from 27 to 60 years. All candidates were right-handed.
Eleven subjects were retested after one year. Two candidates from New Zealand and four from interstate were unable to travel to Melbourne to be retested. Two other Melbourne-based consultants and one registrar left for overseas and interstate posts, respectively, following the initial test.
The endoscopic visualisation system was a three-chip endoscopic camera, laparoscope, camera control unit and camera light source. Both the visualisation system and one laparoscopic training box used by the study were provided by N. Stenning & Co. (Sydney, Australia). Another laparoscopic trainer used in the study, ZOE Gynecologic Simulator, was purchased from Gaumard Scientific (Miami, Florida, USA). Stainless steel laparoscopic instruments such as 5 mm laparoscopic forceps and haemostatic clip applicators were supplied by N. Stenning & Co. Laparoscopic scissors, diathermy scissors, ligating loops and laparoscopic bags were supplied by Tyco Healthcare (Sydney, Australia).
The diathermy station and the four electrosurgery questions were designed in consultation with senior laparoscopic surgeons. The four electrosurgery questions were based on the text in the ‘Principles of electrosurgery’ booklet by Valleylab.4 The diathermy station was then designed to test practical electrosurgery skills other than those already tested in written form. The tasks were presented to consultant laparoscopic surgeons for testing and approval prior to being used on a larger sample.
Prior to starting the electrosurgery test, candidates were provided with the ‘Principles of electrosurgery’ booklet. The test was comprised of the following:
20 minutes reading time for the ‘Principles of electrosurgery’ booklet and a description of the two tasks,
practical diathermy station,
theoretical electrosurgery station: answering four electrosurgery questions based on the text in the booklet,4
which remained with the candidate during the test and could be re-read during the test.
Assessment in the context of assessing surgical skills has two main aims: (1) to indicate competence in specific laparoscopic tasks; and (2) to provide adequate feedback for individuals to improve in these tasks to a competent standard. A grade does not indicate to the individual exactly what he/she needs to do to improve to a competent standard. A pass/fail assessment scheme with specific written or verbal feedback on areas to be improved provides useful feedback that individuals can act upon. For comparison with the pass/fail assessment scheme, a weighted scoring method was used to derive a candidate's score for each task, as well as a final score in electrosurgery.
Both pass/fail and scoring methods of assessment used a checklist model for the two electrosurgery stations. In the pass/fail assessment model, a pass was awarded for a task only if all checklist items for that task were satisfied. In the scoring model, a grade for each task was derived by adding the points for each checklist item satisfied for that task. The practical diathermy station and a written station on electrosurgery, along with their checklist items, were:
Practical diathermy station (5 minutes)
The candidate was asked to cut out a premarked volume of tissue on a piece of steak, using monopolar scissors.
the power setting was <55 W
In the context of this exercise, monopolar diathermy settings >55 W were found to be damaging to the targeted tissue, causing excessive charring, and sparking for power settings above 70 W.
not too much tissue was grasped
The instrument is designed not to function if too much tissue is grasped. The surgeon should be aware that this is intentional.
task was completed on time
cut and/or coagulation were used
brief/intermittent activation was used
Prolonged instrument activation will char and damage tissue. Excessive smoke will obscure the camera view.
Each checklist item listed above was worth 0.2 points.
Written electrosurgery station
Question 1 (5 minutes)
The candidate was asked to:
The surgeon must be aware of the current path and the purpose of a patient pad when using monopolar diathermy, due to safety concerns. Monopolar diathermy is more dangerous than bipolar surgery.
The two items listed above constitute the assessment checklist. The first item was worth 0.7 points and the second item 0.3 points.
Question 2 (5 minutes)
The candidate was asked to:
Describe bipolar electrosurgery.
Draw a bipolar circuit showing the direction of current.
The surgeon must be aware of the current path and the absence of a patient pad when using bipolar diathermy, due to safety concerns.
The two items listed above constitute the assessment checklist. The first item was worth 0.7 points and the second item 0.3 points.
Question 3 (5 minutes)
The candidate was asked to list all nine steps which can be taken to avoid electrosurgical patient complications in minimally invasive surgery.
These nine steps include the major electrosurgical safety concerns which all surgeons should know and include the following, as outlined in the ‘Principles of electrosurgery’ booklet4:
Inspect insulation carefully
Use lowest possible power setting
Use a low voltage waveform (cut)
Use brief intermittent activation
Do not activate in open circuit
Do not activate in close proximity or direct contact with another instrument
Use bipolar electrosurgery where appropriate
Select an all metal cannula system as the safest choice
Utilise available technology (tissue response generator, active electrode monitoring) to eliminate concerns about insulation failure and capacitive coupling
The nine items listed above constitute the assessment checklist. Each item was worth 0.11 points.
Question 4 (5 minutes)
The candidate was asked to describe what potentially was the most dangerous electrosurgical practice in laparoscopic surgery and how it can be avoided.
Identify one of the three most dangerous electrosurgical practices in laparoscopic surgery as outlined in the ‘Principles of electrosurgery’ booklet4
: direct coupling, insulation failure and capacitive coupling.
The majority of electrosurgical complications occur due to the three safety considerations listed. Most of these complications could be avoided with appropriate technology and awareness.
Describe how the named dangerous electrosurgical practice can be avoided.
In the pass/fail assessment model, a ‘pass’ was awarded for each question if the answer was correct and complete. A candidate passed the overall written electrosurgery station if all four questions were passed.
In the weighted scoring model, questions 1 and 2 were testing basic knowledge of electrosurgery and were worth 0.2 points each. Questions 3 and 4 tested more advanced electrosurgery knowledge and were worth 0.3 points each. The total score for the written electrosurgery station was thus EStotal= (Q1 points)*0.2 + (Q2 points)*0.2 + (Q3 points)*0.3 + (Q4 points)*0.3. The total score for each candidate was (diathermy station points)*0.5 + (ES station points)*0.5. A ‘pass’ in the weighted scoring system was defined as a score greater than or equal to 80%.
The examiner was blinded to the candidates' experience and was of a non-medical background. A checklist based assessment instrument further ensured that observations of candidates' performance other than those specified did not introduce bias.
Eleven candidates were retested one year later. The test was identical.
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In the pass/fail assessment model, the pass rate of candidates on the practical monopolar diathermy station was 56%, with a median completion time of 125 seconds (25th centile of 91 seconds and 75th centile of 175 seconds). Of those who passed, 60% were consultants and 40% registrars. Eighty-nine percent of candidates satisfactorily completed the task in 5 minutes. The fastest recorded time was 43 seconds.
A number of factors contributed to such a low pass rate. The first and most damaging was that 16% of candidates chose a power setting in the range of 80–120 W. Another 16% of candidates grasped too much tissue. An additional 11% did not use electrosurgery cut and/or coagulation functions but cut the tissue mechanically.
One year later, the pass rate of the practical diathermy station dropped to 36%. Equal numbers of consultants and registrars passed this station. On this retest, all candidates completed the task in the prescribed time. The median time to completion was 101 seconds (25th and 75th centiles of 112 and 174 seconds, respectively).
A written test of knowledge in electrosurgery revealed that no candidate could successfully complete this task. Questions 3 and 4, which focussed mainly on issues of safety in electrosurgery, were the deciding factors in this result with respective pass rates of 20% and 16%(Fig. 1) on the initial test. Even though the individual pass rates for questions 1, 2, 3 and 4 were 90%, 90%, 20% and 16%, respectively, a candidate had to pass all four questions in order to pass the written station. The overall pass rate of 0% for the written electrosurgery station indicates that no candidate could answer all four electrosurgery questions.
Question 3 required the candidates to list nine safety checks outlined in the electrosurgery booklet they were provided with. Only 65% could name some of these safety checks; 15% gave an incorrect answer. Although 74% of subjects could name one of the three most dangerous electrosurgical practices in question 4, only 16% knew how to avoid it.
The pass rate for the written electrosurgery station improved marginally in the follow up test to 18%. Candidates who passed this task were all registrars, indicating that the success rate of registrars was greater than that of consultants. The pass rate for each of the individual four questions (Fig. 1) also improved. As described previously, even though the individual pass rates for questions 1, 2, 3 and 4 were 100%, 91%, 36% and 27%, respectively, a candidate had to pass all four questions in order to pass the written station.
In the weighted scoring assessment model, the pass rate of candidates on the initial and follow up tests followed the same modest improvement as the pass rate of candidates in the pass/fail model (Table 1). The pass rates arising from the scoring model, however, were greater than those recorded with the pass/fail model, resulting in the overall pass rates of 45% on both the initial and follow up tests compared with 0% and 9%, respectively, recorded with the pass/fail model (Table 1). The overall success rate of consultants on the initial (89%) and follow up tests (60%) was higher than that of registrars, 11% and 40%, respectively. Interestingly, the success rate of consultants declined in one year of usual practice, while that of registrars improved.
Table 1. Pass rates of candidates on the pass/fail and weighted scoring assessment models.
|Task||Pass rate (%) on weighted scoring model (initial test)||Pass rate (%) on pass/fail model (initial test)||Pass rate (%) on weighted scoring model (follow up test)||Pass rate (%) on pass/fail model (follow up test)|
|Practical diathermy station||72||56||91||36|
|Written electrosurgery station|
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This study has unexpectedly shown that there is ignorance of electrosurgery among surgical specialists in obstetrics and gynaecology. Although the candidates were aware of the basic differences between monopolar and bipolar electrosurgery, they demonstrated very poor knowledge of electrosurgical safety and hazard prevention. No improvement occurred in one year as shown by retest of 11 candidates.
Ninety-five percent of candidates in the initial and all candidates in the follow up assessment reported using monopolar diathermy prior to the test, yet their pass rates were 56% and 36% in the initial test and the retest, respectively. This outcome reveals inconsistency in the performance of candidates indicating partial knowledge of the correct use of monopolar diathermy. The result is in agreement with the candidates' theoretical knowledge of electrosurgery. This remained low even though it improved slightly from a pass rate of 0% to 18% over a period of one year.
The pass/fail assessment model was chosen as the most appropriate assessment instrument in the context of assessing surgical skills. A weighted scoring assessment model is presented for comparison. The greatest concern raised by the use of a marking scheme is the different and erroneous ways in which the final grade can be interpreted. The following marking scheme illustrates the inadequacies of a scoring system in the assessment of surgical skill in this context. In our scoring system, each of the five components of the practical diathermy station was worth 0.2 marks. Candidate 6 received a score of 0.6 in the initial test with three components correct. The two incorrect components of the station were grasping too much tissue, thus significantly reducing the effect of the diathermy machine, and being unable to cut out a piece of steak in less than 5 minutes. In the follow up test, the same candidate received a score of 0.8, suggesting improvement in performance, and competence in this assessment task, since 80% was defined as a ‘pass’. This would, however, be a false indication of competence. Although this candidate completed four components correctly, s/he still used a power setting of only 5 W to cut a piece of steak, resulting in insignificant diathermy effect and having to resort to using diathermy scissors to manually cut out the meat. This candidate's knowledge of electrosurgery has clearly not improved, even though the scoring system would seem to suggest improvement. Our pass/fail assessment model correctly identified both attempts at the diathermy task as ‘fail’.
The strengths of our study design incorporate both the theoretical and practical knowledge of electrosurgery ensuring test consistency and comprehensiveness. The practical diathermy station revealed aspects of electrosurgical technique that could not be tested in a written format. These include grasping the right volume of tissue, choosing appropriate power settings and using brief intermittent activation. The diathermy station also verified that candidates' theoretical knowledge was applied in practice. Repeating the same stations one year later proved to be a valuable tool in validating the initial results.
The limitations of this study include the testing and retesting of rural surgeons and the restricted number of practical diathermy tasks. Co-ordination of a larger trial proved to be difficult within a period of one year due to the availability of the subjects and surgical equipment. One suggestion on the improvement of the electrosurgery test would be to include theoretical questions based on case studies of most common endoscopic gynaecology procedures (i.e. ovarian cysts, endometriosis and ectopic pregnancies). Another suggestion would be to include additional diathermy tasks comprised of the simulation of electrosurgical incidents in future tests. This will further test the surgeons' abilities to recognise and manage electrosurgical complications.
In laparoscopic surgery where 85% of surgeons use electrosurgical instruments, the incidence of electrosurgical complications has risen from approximately 0.23% in 1970s to 0.5% in 1990s.5 This trend has prompted the formation of a Laparoscopic Litigation Group in the United States.2
Electrosurgical injuries are sometimes difficult to diagnose. Many are only diagnosed post-operatively. Perforation of the bowel, small intestine and liver, and injuries to the bile duct, hepatic ducts, arteries and veins require surgical interventions.1 These and many other electrosurgical complications are well documented in literature, as are the recommendations for safe practice.1,5,9,10 As our study shows, the core of the problem is the lack of fundamental knowledge of electrosurgery among surgeons and an effective program to improve this clinical skill.
We suggest at least three recommendations to improve electrosurgery knowledge. Formal inclusion of electrosurgery in specialist surgical Royal College training programs would be valuable. Secondly, our program described here could be used to drive learning by retesting surgeons every six months. Surgeons could progress along their individual learning curve to achieve their Olympic Games-style ‘Personal Best’ in electrosurgery skill. And lastly, surgeons could practice basic and advanced electrosurgery tasks on virtual reality surgical simulators. Simulators provide surgeons with a safe training environment and can enhance the learning experience by displaying immediate feedback to the user.