DIAG IM3 - Page 334

15 Instrument Care www.vetinst.com Instrument Care Cleaned lubricated instruments are ready for packaging. Always carry out a visual check at this stage – are the cutting edges of scissors free of damage, do the jaws of artery forceps & needleholders meet correctly with no signs of twisting for example. Check that all thumbscrews are tight, as in Gelpi & Stifle Distractor joints The majority of surgical instruments are made of Stainless Steel. There are many different types of stainless steel alloys (60+), with varying amounts of Nickel & Chromium to increase resistance to corrosion. All types of stainless steel will corrode under certain conditions – ‘stainless’ is a little misleading. The proportions of the various constituents affect the characteristics of the final steel, along with the degree of hardening applied. Surgical instruments must be hard enough to take and keep a cutting edge (e.g. scissors) or have a certain spring (e.g. artery forceps). The steel possessing these qualities contains less chromium and more carbon than orthopaedic implants, which are made of steel with the primary characteristic of resistance to corrosion, making it too soft for instruments. The penalty is that this type of higher carbon stainless steel (called Martensitic) is much more likely to corrode and stain. Joint showing wear due to inadequate lubrication Also look for fine cracks in instruments, for example across the box joints in Artery Forceps. The parts of the steel likely to rust are protected by a thin layer of chromium oxide which is produced by the chromium part of the steel. Actions which encourage the production of chromium oxide minimise corrosion. Actions which either physically or chemically destroy this layer of chromium oxide encourage rusting or staining. Maximising the chromium oxide layer is the basis of sound instrument care. This layer thickens with age and increases the resistance of your instruments to corrosion – in new instruments it is relatively thin. This is why you may have marking problems with new instruments but y W"BW2&RfP( 2Wr7G'VVG2v&R&RFW&Bb&&FRFWFW&vVG2FWVFRV'&6FBFR6'&6fRVf&VBbFRWF6fRWF2ࠤVVFVFW"vFFvVBw0&B6vr7&6pb&v6FV'&0FvVBFV26VB&R6VBf"&W""F76VBbB2v@&7F6RF7FW&ƗRFV2&Vr6VBf"&W"&W&W'2&WV&P6W'Ff6FRbFV6F֖FF&R6VBvF7G'VVG2@7G'VVG26VBWfW"&R6VBWB6VB6FFࠤV6Vr&F6( 27FW727G'VVG0rVG2B&6Rw&726RFV'&2g&7G'VVG2v&vFW"BB( 2F2v6wVFR&FV2bRFP7G'VVG2V6&FW"F6VVFFVǒgFW"W6RFWv&RV6&FW"F6VbVgBFG'FW&R&RFW&2f"6r7G'VVG2f"WF6frW VV62&R6ǒW6VBrvFWF6fRfvRF@&V6VBFRW6RbVFW&VBf'&7227G'VVBw&22&W6GVFWFW&vVG2B&V6W266W6Rb6&R&VFVBFvRFW 7G'VVG2F76&RWF6f&R7G'VVBw&rf'&726֖ FF76&RG&W2&Rf&Rࠣ"0rWFVǒ7V&W&vR7G'VVG2V秖R&6VBWWG&FWFW&vVB( 26f"FR7V6fVBFWFW&vVB7G'V7F2prVFǒ67'V"7G'VVG2vF6gB'&7FVB''W6F&VfR&Vrf6&R6VWrFR7G'VVBVFW"FR7W&f6RbFPFWFW&vVBF&VGV6R7&W6RR6VW"''W67G'VVG0vFVV7V6GFVFFG2b&F6WG2ࠥ7FW&Ɨ6FFRWF6fR2fW'7FRVf&VBf"W"7G'VVG2FR6&FbVBb7GW&R&FW26'&6B7Fr'F7V&ǒbFW&R&R&W6GVFWFW&vVG2WF2w&rFW&2F026G'VRvW&RFvFW"7FVBbF7FVB"FV֖W&Ɨ6VBvFW 2W6VBFRWF6fR֖W&FW6G27G'VVG2&RV6vFǐ2vV2FW&fW&rvF&BgV7FWF2FW&RFff7VBF&VfR6&WfVF2&WGFW"F7W&RࠣB rVfRg&FRV秖R6WFB&6RF&VvǒFvFW f"BV7B2֖WFW2RvFVǒ6RFR7G'VVG2VG&626Vr&Ff R֖WFW2"2W"6VW"7G'V7FVb rVfRg&&FB6WFb76R"gFW"7FWBbVG&62f&RFV&6R7G'VVG2F&VvǒvFW&fV@F7FVBvFW"ࠥ'W7BFR7FVW2bW"WF6fRvG&6fW"FW 7G'VVG26WF6fRFV6R2'FB&VwV"6W'f6pV7W&W2FRWF6fR2v&r6'&V7Fǒf7WVWF6fW2V&VfR&W6GV7FVg&62BB2'FBFBF&V7F0&RfvVBB76W2&R6WFVB&VwV&ǒ6V6FRF"6V0VFvVBB&W6RbV6W76'bƖ6&RFW"6RG&b&VfFRvFW"F&VwV&ǒvFF7FVBvFW"RvV&P7W'&6VBvB6W2WBr@r'vF6V6VFFrvR( 2VfrFVF"G'v&W7VBvFW"7GFrࣂrV'&6FRvFVFW"7&7W&v67G'VVB"6Rখ7G'VVB֖Ʋ&F( 2frF&V7F2f"&GV7BW6VBࠤbW"62&R6֖rWBbFRWF6fRvWBF&VvFVFW&R276R&&VbRVVBF7VFW"WF6fRVvVW"f"Gf6RvWB7F&vRv&W7VB6'&6BFvRFW"7G'VVG2ࠥFVWW"7G'VVG2V6FFFW&R&R6R&62'VW0v66VB&RfvVBࠥ6( 27F&RW"7G'VVG26VG'V'&6FVBb&FV7FVBBFWvvfRRV'2b6W'f6RvBV7Ffr7G'VV@6&R&F6vWFVB7G'VVBƖfR6fRWB&W7VB7W&vV2rFRW"7G'VVG2vF6&R( 2G&r67&F6rWF2vFvRFR7W&f6Rb7G'VVG2B&VGV6RFV"&W67F6RF6'&6"0rF&RvF6&Rb7G'VVG2&R7F&VBFFWv6'&FRFVƖ6FR7G'VVG26VB&R6VBvF&FV7FfRF2b6Ɩ6P7F&vR&6W'G2F7FFV&GFƖr&VBv2R7W&PVg7G'VVG2&RB7F&VBFbƖvFW"WVVB2Pr6RFVFFvBFWvW&RFW6vVBf"'FW'f&6W2&R@VVFVFW'2"v&RGv7FW'2&R7WGFW'2&RBFW6vVBF7W@v&RBB7WGFW'2fR6R&Frf"&V6&&FPW6RvFvR7G'VVG2BfƖFFRv'&FW2BtfB֗rFffW&VBWF2vV&6W76r7G'VVG2( 2VW6&RFVBGW7G&f6bV֖VFV26W&FRg&Ч7FW72'F7V&ǒVG&626VW'23