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

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 ?

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

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

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

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

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

Risks to the patient Burns Limited field of view 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%)

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

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

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

Older style high voltage tester

A newer “safe” HV tester

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

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!

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

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

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

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.

Who is testing? BME departments Outside contractors CSSD staff 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

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

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

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

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

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?

Questions and discussion