High voltage testing of laparoscopic accessories

1. High voltage testing of laparoscopic accessories Bruce Morrison Hunter Area Health Service John Hunter Hospital Newcastle, NSW

2. Outline • Particular Issues arising with laparoscopic instruments • Background to the NSW DOH guidelines on testing laparoscopic instruments • Development of the guideline • Application of the guideline • Where to next ?

3. Minimally invasive surgery - introduced in early 60’s • Advantages • less blood loss • low complication rate • minimal post op pain and discomfort • early discharge • reduced recovery time due to minimal tissue damage • Disadvantages • can be more expensive • electrosurgical burns can be a complication • Surgeons take longer to master the technique

4. The ESU • Provides cut and coagulation power • Should be functional and appropriately adjusted • Output power and waveform should be in accord with manufacturers’ specifications • Return electrode should be appropriately connected to the patient • Lead integrity to the instruments in essential

5. The laparoscope • Types of instruments • Forceps • Hooks • Scissors • Monopolar and bipolar • Leads • single • double

6. Parts of the instrument • Parts which make contact with the patient • conductive parts • non-conductive parts • Parts which do not make contact with the patient • handles • terminations

7. Laparoscopic Instruments A selection filmed (somewhat poorly) in the CSSD at John Hunter Hospital - after cleaning and washing and prior to testing before packaging and sterilising

16. Risks to the patient • Burns • operator induced • insulation breakdown • direct • capacitive coupled • Limited field of view • large sections of the leads and instruments are not in the surgeon’s field of view (90%)

17. Background to the NSW guideline • Patient incident - electrosurgical burns? • Reference to the NSW Healthcare Complaints Commission • NSW HCCC asks BEAG (NSW) for advice • BEAG gives preliminary advice • preliminary advice published as 97/20 • considered advice published as 98/17

18. Development of the guideline • Preliminary discussions lead to publication of Information Bulletin 97/20 • Bulletin widely distributed • reference to further work by BEAG • hospitals begin to expect testing will be done • NPCE working party develops a document aimed at providing good guidance for testing • Revision 2 sent to DOH and becomes Information Bulletin 98/17

19. Application of the guideline • Guideline recommended testing by BME • Original high voltage testers “dangerous” • BME had done what testing was previously done • Problems with tagging and tracking • How often should instruments and leads be tested

20. Older style high voltage tester

21. A newer “safe” HV tester

22. Testing in the CSSD • Newer “safe” testers allow testing in the CSSD • OK for use by CSSD? • Training • Industrial issues • Why test in CSSD? • no problems with tagging • no requirement to track instruments and leads • nothing is missed • safe instrument is presented to the patient every time

23. Where to now? • Development of Ver 3 of the guideline • Publication by NSW DOH • Version 3 contains … • information on “safe” testers • recommendations for testing in CSSD • voltages and currents for testing • Version 3d is almost ready to go!

24. Need to assure the insulation integrity of the non-conductive parts which make contact with the patient Visual inspection is not adequate High voltage testing is required to detect insulation breakdown

26. Testing laparoscopic instruments Practical experience from NSW Testing statistics Test jigs & all that jazz . . .

27. Testing protocols • From the NSW Guideline • 3.0 kV rms 50Hz or 4.2 kV dc • 0.5 mA current limit • Compromise between • safety • voltages found in laparoscopic surgery • recommendations in AS-3894.1 1991

28. Why 3 kV rms? • All reinsulated instruments can withstand this test voltage. • Newly manufactured or reinsulated instruments typically withstand voltages greater than 8kV rms. • 3kV is probably a higher voltage than needed, but leaves some margin for deterioration of insulating properties during the use of the instrument.

29. Who is testing? • BME departments • in almost all Area Health Services • Outside contractors • very few • CSSD staff • Hunter Area Health Service • Politics of testing • use of the guideline for industrial purposes

30. How often are they testing? • Every use - HAHS • Monthly - many city hospitals • Quarterly - some city and many country hospitals • Never - one city Area Health Service • Mostly in theatre • all in one sweep

31. Equipment? • All respondents using the Hi-Pot 140 high voltage tester • 4 kV dc • Very high output impedance • Audible and visual breakdown indicators • Very few using test jigs

32. Test methods Some more less than perfect home snaps in the CSSD at John Hunter Hospital

44. Testing results Hunter Area Health Service Western & South-Western Sydney Area Health Services

48. Final thoughts on testing . . . • Manufacturers’ test methods • 8 kV in saline bath • What parts of an instrument should we test? • Should leads be tested? • Packaging after testing - care required! • What of Electroshield type devices? • Who should test - BME or CSSD? • The future of tracking?

49. Questions and discussion