MACRODUCT SWEAT COLLECTION SYSTEM
Contents
1. MACRODUCT SWEAT COLLECTION SYSTEM Model 3700 SYS instruction service manual AN M 2551 7 revA COPYRIGHT 2004 WESCOR INC 11 TABLE OF CONTENTS section 1 INTRODUCTION 1 1 User s Manual Overview pp 3 1 2 Our Valued Customers Ne 4 1 3 Important User Information 5 1 4 System Components pp 6 1 5 Webster Sweat Inducer pp 8 1 6 Pilogel lontophoretic discs seem 12 1 7 Macroduct Sweat Collector en 16 section 2 SWEAT INDUCTION AND COLLECTION 251 Inducing Sweat ar len aede ts 21 2 2 Collecting Sweat Ne 27 2 3 Abbreviated Instructions ee 33 section 3 SWEAT ANALYSIS 3 1 An overview to Sweat Analysis pp 37 111 TABLE OF CONTENTS section 4 TROUBLESHOOTING AND MAINTENANCE 4 1 Troubleshooting Procedures 4 2 Cleaning the Electrodes 4 3 Replacing Inducer Batteries APPENDIX A Specifications APPENDIX B Supplies and Replacement Parts APPENDIX C A Perspective on the Sweat Test References iv SECTION 1 INTRODUCTION SECTION 1 INTRODUCTION 1 1 User s Manual Overview This manual covers the complete laboratory procedure for the laboratory diagnosis of cystic fibrosis through examination of sweat electrolyte con centration The steps preliminary to sweat analysis sweat stimulation and collection are accomplished using the Macroduct Sweat Collection System CAUTION2. Never attempt sweat collection until you are thoroughly familiar with the procedures and cau tionary information detailed in this manual Abbreviated instructions printed elsewhere are provided for reference only and should not be used as a substitute for the complete informa tion contained in this manual SECTION 1 INTRODUCTION 1 2 To Our Valued Customer Thank you for purchasing the Macroduct Sweat Collection System We are confident that this is the finest sweat testing system in the world As the acknowledged world leader in sweat testing products for the laboratory diag nosis of cystic fibrosis Wescor is dedicated to providing customer support in all aspects of the use of this product and sweat testing theory and practice From the beginning our goal has been to identify problems in sweat testing delineate the precise cause of false diagnosis and then to devise innovative solutions We have accomplished this with the added benefit of vastly simpli fying procedures while remaining within the strict boundaries of acceptable accuracy Wescor is ready to help you resolve any difficulty with the operation or per formance of the Macroduct system If you cannot resolve a problem using the information in this manual please contact us Wescor Inc 459 South Main Street Logan Utah 84321 5294 USA TELEPHONE 435 752 6011 TOLL FREE 800 453 2725 FAX 435 752 4127 E MAIL service wescor com WEBSITE www wescor com PLEASE NO
3. into a spiral The base of the sweat gland is 2 to 3 mm beneath the surface of the skin Fluid secreted by the gland creates hydraulic pressure that moves the fluid upward through the sweat duct to emerge from the skin as sweat When sweat surfaces beneath a Macroduct collector this same hydraulic pressure forces it into the air free interface be tween the skin and the concave surface of the collector Since the pressure of the skin against the collector surface is greatest at the rim and decreases inwardly toward the center the secreted sweat is directed to the orifice and into the plastic macroduct After attachment sweat becomes visible in the spiral tube of Macroduct within one to four minutes depending upon the relative elasticity of the skin and the subject s sweating rate NOTE For best results the stimulated skin area should cover deep flesh such as rea sonably thick musculature Thin skin sections overlaying palpable tendons or bony structures are not suitable as collection sites The emergent sweat is turned blue by contact with a small amount 10 nanomoles of blue water soluble dye FDC certified food color applied to the Macroduct collection surface This allows easy assessment of the volume produced at any time during collection This dye does not interfere with sweat chloride assay by colorimetry The dye contributes slightly to the osmolality and sodi um content of the sweat sample Even with a low sweat y
4. is extremely wide You can vary collection time to maximize the BLUE COLORED SWEAT sweat yield but with most individuals very little additional sweat can be collected after 45 to 60 minutes SPIRAL TUBE CALIBRATION DIAGRAM 29 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat USE TWISTING MOTION WHILE INSERTING BLUNT NEEDLE INTO THE END OF THE MICRO BORE TUBING 30 NOTE Inadequately tightened collector straps can be detected simply by pressing the collector very firmly against the skin If the advancing menis cus of sweat in the spiral tube moves by more than 2 3 millimeters attach the strap more firmly REMOVE AND STORE SWEAT SAMPLE NOTE The following procedure must be done while the Macroduct collector is still firmly strapped to the limb Removing the complete device before detaching the tub ing may create a vacuum that will draw the collected sweat from the tubing and seriously reduce sample volume FOLLOW THESE INSTRUCTIONS CLOSELY Q Remove the protective transparent cover by inserting a pointed tool into one of the cut out sections and prying upward The nippers supplied with the Macroduct system will work well b Insert the blunt needle approximately 5 mm into the open end of the Macroduct microbore tubing using a twisting motion see illustration Alternatively lift the open outer end of the micro bore tubing and pull one or two inches of the tu
5. of iontophore sis as the current is reduced to zero If the circuit is broken even briefly during ion tophoresis current flow ceases and the alarm sounds If this occurs switch the inducer to STOP 0 Check leads and electrodes for fis sures breaks etc See Section 4 for com plete information SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat PREPARE MACRODUCT SWEAT COLLEC TOR DURING IONTOPHORESIS Open one end of the plastic wrapper and slide the Macroduct sweat collector slightly out ofthe package and thread a Macroduct strap of suitable size through one slot so that the hook side of the strap faces away from the Macroduct collection surface DO NOT TOUCH THE COLLECTION SURFACE GRASP MACRODUCT WITH PLASTIC WRAPPER REMOVE ELECTRODES AT COMPLETION OF IONTOPHORESIS lontophoresis proceeds automatically for approximately 51 2 minutes after RUN is acti vated At completion an audible tone sounds briefly and the instrument turns itself off Remove the negative black electrode first and then clean the exposed area of skin Before removing the positive red electrode mark around the stimulated area with an alcohol based felt marker to ensure proper placement of the Macroduct sweat collector Remove the positive red electrode REMOVE THE BLACK ELECTRODE FIRST 27 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat 3 CLEAN THE SKIN UNDER THE POSITIVE RED ELECTROD
6. same hydraulic pressure that causes sweat to move from the base of the sweat gland to the skin surface There is no harvesting procedure during which the integrity of the sweat specimen is liable to be compromised by human error or other factors Notes Regarding Sweat Yield Technologists experienced with the Gibson and Cooke pad absorption method of sweat collection often raise the question of the 100 mg Rule or some variation which requires a minimum sweat volume for the analytical result to be valid To the extent that such requirements were imposed to mitigate the error possibilities of the pad absorption method they may be disregarded since Macroduct collection is free of such errors On the other hand some authorities have suggested that the minimum yield rules were promulgated because low sweating rates are associat ed with anomalous electrolyte concentrations and therefore may give rise to a misleading diagnostic result In order to establish an equivalent minimum yield threshold for Macroduct one must take into account the differences in electrode size area and the recommended collection times for the two methods Applying these ratios shows that an average collection of 50 uL in 15 minutes using Macroduct is equivalent to a yield in terms of sweating rate of approximately 350 mg by the pad absorption method Conversely the sweat yield with Macroduct corresponding to the 100 mg Rule is approximately 15
7. used electrical conductivity as the analytical procedure and the direct skin chloride electrode system These methods were highly innovative were pro cedurally simpler than the Gibson and Cooke method and were commercially successful They nevertheless failed in their objective to eliminate false diagnostic results Wide adoption of the new sweat testing methods exacerbated the problem evoking a storm of criticism in the professional literature with calls for a return to the pad absorption reference method 3 In the United States C F referral centers operating under accreditation of the Cystic Fibrosis Foundation were forbidden to use any sweat testing method other than the QPIT These early attempts to produce a simplified sweat testing system failed for two principal reasons 1 error intrinsic to the method of collection and beyond the control of the operator or 2 extreme susceptibility to variations in operator technique Further progress was stymied until these factors had been fully investigated and iden tified through research findings published in the late 70 s 5 6 In 1978 Wescor introduced the Model 3500 Webster Sweat Collection System Its unique heated collection cup operated at a temperature slightly warmer than the skin This prevented the con densate error that was intrinsic to all previous cup collection sys tems It was the first simplified sweat collection method worthy of comparison to the Gibson and Cooke
8. E Clean the stimulated skin and the surround ing area thoroughly with purified water to remove salt then blot dry There should be a distinct redness under the red electrode Proceed to Step 4 immediately 4 ATTACH MACRODUCT SWEAT COLLEC TOR FIRMLY TO LIMB Apply the concave surface of the Macroduct collector precisely over the area of skin contacted by the Pilogel disc The red dened area of skin will generally be larger than the sweat stimulated area Thread the free end of the strap around the limb and through the opening Then tighten the strap until the collector is very firmly attached with strap pressure pulling as evenly as possible from each end of the collector Check for collector displacement during attachment and adjust if necessary 28 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat If a child attempts to disturb the collector overwrap the device with an elastic ban dage For neonate sweat collections where the limbs are extremely small overwrap the collector firmly with a 2 or 3 inch wide elas tic bandage This ensures a continuous and firm contact between the collector and the skin and greatly improves the probability of a successful collection Macroduct allows you to visually assess sweat production at any time by reference to the spiral tube calibration diagram A 30 minute collection time usually yields 50 60 microliters of sweat although variance among individuals
9. TE Wescors Authorized European Representative for matters relating to the Medical Device Directive is MT Promedt Consulting GmbH AltenhofstraBe 80 D 66386 St Ingbert Germany Tel 49 6894 581020 Fax 49 6894 581021 email info mt procons com SECTION 1 INTRODUCTION 1 3 Important User Information APPLICATION The Macroduct System is intended for laboratory use by qualified personnel for stimulation and collection of sweat for analysis in the diagnosis of cystic fibrosis Anyone operating Macroduct must be thoroughly familiar with the proce dures and cautionary information detailed in this manual before attempting to use this equipment SPECIFICATION OF SAFE USE Using this device in a manner not specified by Wescor Inc may impair the safety protection designed into the equipment and may lead to injury Do not use where flammable anesthetic is present or in any oxygen enriched environment STATEMENT OF ENVIRONMENTAL LIMITS This equipment is designed to be safely operated at 5 to 35 C maximum relative humidity 80 EXPLANATION OF SYMBOLS FOUND ON EQUIPMENT I Run Stop International Attention Symbol Calls attention to important information and instructions in the user s manual Type BF equipment complying with Medical Equipment Safety Standard EN60601 1 O Current Flow Indicator p Low Battery Indicator SECTION 1 INTRODUCTION 1 4 System Components Webster Sweat In
10. a result the sweat test generally ranks as one of the least popular laboratory procedures that a med ical technologist must administer The sweat test is actually a composite of three separate sequential procedures that must be accomplished without interventional error In order they are 1 Sweat Stimulation 2 Sweat Collection and 3 Sweat Analysis The 1959 pad absorption method of Gibson and Cooke introduced pilocarpine iontophoresis as a preferential method of sweat stimulation replacing the dangerous practice of sweat stimulation by induced hyperpyrexia The method is also known as the Quantitative Pilocarpine lontophoresis Test or QPIT Because the pad absorption method has withstood the test of time it is considered by many to be the reference method for sweat test ing Unfortunately the method is long and tedious requiring many steps where human error can intervene Laboratorians in C F cen ters who specialize in this method of sweat testing develop the req visite skills to maintain consistently accurate results but in out lying clinics and hospitals where the test is requested only on an 57 APPENDIX A Perspective on the Sweat Test occasional basis the chances of obtaining a false result have proven to be unacceptably high The need for a simpler method spawned the development of alter native procedures during the late 60 s and early 70 s Principally among these were the cup collection systems which
11. as utilizing pilocarpine by iontophoresis Pediatrics 23 545 1959 Gibson L E The decline of the sweat test Clin Pediatr 12 450 1973 Rosenstein B J Langbaum T S Gordes E and Bruislow S W Cystic fibrosis problems encountered with sweat testing JAMA 240 1987 1978 Denning C R Huang N N Cuasay L R Shwachman H Tocci P Warwick W J and Gibson L E Cooperative study comparing three methods of performing sweat tests to diagnose cystic fibrosis Pediatrics 66 752 1980 Webster H L and Lochlin H Cystic fibrosis screening by sweat analysis A critical review of techniques Med J Aust 1 923 1977 Webster H L and Barlow W K New approach to cystic fibrosis diagnosis by use of an improved sweat induction col lection system and osmometry Clin Chem 27 385 1981 APPENDIX C References 8 Webster H L Laboratory diagnosis of cystic fibrosis CRC Critical Reviews in Clinical Laboratory Sciences CRC Press Florida 18 313 1983 Barlow W K and Webster H L A sim plified method of sweat collection for diagnosis of cystic fibrosis Cystic Fibrosis Horizons Proceedings of the 9th International Cystic Fibrosis Congress Brighton England June 9th 15th 1984 D Lawson ed John Wiley 8 Sons New York 204 1984 10 Carter E P Barrett A D Heeley A F and Kuzemko J A Improved sweat test method for the diagnosis of cystic fibr
12. b Retain the strap and discard the col lector body 7 CLEAN THE ELECTRODES Remove and discard the Pilogel discs Clean the electrodes with purified water and wipe dry See Section 4 2 32 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 3 Abbreviated Instructions CAUTION These instructions are intended for reference only Never attempt sweat induction and collection until you have read and thoroughly understand the complete procedures detailed in the instruction manual 1 ASSEMBLE EQUIPMENT AND SUPPLIES 2 INSPECT ELECTRODES AND CONNECT TO INDUCER 3 CLEAN THE SELECTED SKIN AREAS 4 INSTALL PILOGEL DISCS IN BOTH ELECTRODES 5 ATTACH THE ELECTRODES TO LIMB 6 ACTIVATE IONTOPHORESIS 7 PREPARE MACRODUCT SWEAT COLLECTOR DURING IONTOPHORESIS 8 REMOVE ELECTRODES AT COMPLETION OF IONTOPHORESIS 9 CLEAN THE SKIN UNDER THE POSITIVE RED ELECTRODE 10 ATTACH MACRODUCT SWEAT COLLECTOR FIRMLY TO STIMULATED SKIN SITE 11 REMOVE AND STORE SWEAT SAMPLE 12 REMOVE AND DISCARD MACRODUCT RESIDUE 13 CLEAN ELECTRODES 33 34 SECTION 3 SWEAT ANALYSIS 35 36 The procedures described up to this point in the manual provide the laboratorian with an undiluted sweat sample By virtue of the specif ic safeguards against condensation and evap oration error the sample is fully representative of the patient s secretion and is therefore a valid specimen for analysis Sodium and or Chloride Analysis These are the tradi
13. be free from the adhesive base before attaching the tube to the blunt needle of the syringe Position the plunger at mid point before inserting it into the tubing Do not squeeze the dispenser or syringe body or move the syringe plunger at any time during attachment or during the following procedure SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat Grasp the tubing where it is attached to the needle and pull the tubing away HOLD THE TUBING WHERE IT from the collector body until the tubing ATTACHES TO THE SYRINGE NEEDLE is completely uncoiled and extending outward from the point of attachment Use the provided nippers to sever the tube as close as possible to the collec tor surface d Immediately after severing the tubing carefully draw the sweat into the tube one or two inches This is to prevent any loss of sweat from the cut end due to expansion of air in the syringe body It also allows you to cut off the tightly coiled end of the microbore tubing for easier handling OR If using the Sweat Check Analyzer attach the end of the tube to the Sweat Chek intake for analysis Refer to instructions in the Sweat Chek instruc tion manual e Expel the sweat specimen into the cup and immediately install the cover to protect the specimen 31 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 2 Collecting Sweat 6 REMOVE AND DISCARD COLLECTOR BODY Detach the collector body from the patient s lim
14. ce fractures etc See Section 3 2 Electrode strap pressure should promote firm contact between the skin and the gel disc Straps should not be tight enough to crush the disc between skin and electrode 3 Leave skin slightly wet after washing the area where the electrode will be attached OR Add a drop of water to either the skin or the pilogel surface after installation in the electrode NOTE Although these recommendations are designed to prevent burns during iontophoresis there is no guarantee they will not occur Any institution pro viding sweat tests should thoroughly explain this possibility to parents and obtain a written waiver from them prior to iontophoresis Besides limiting liability from an unfortunate incident parents thus warned can make an informed decision about testing their child and are less likely to be upset if a burn occurs 15 SECTION 1 INTRODUCTION 1 7 Macroduct Sweat Collector BLUE COLORED SWEAT 16 The Macroduct Sweat Collector is a disposable plastic device with a shallow concave undersurface that covers the skin area previous ly stimulated by pilocarpine iontophoresis The collection surface is contoured such that when firmly applied to the stimulated area the skin bulges into the concavity leaving no air space At the apex of the conical surface a tiny orifice leads to a small bore plastic tube or duct having an inside diameter of approximately 0 64 mm and coiled
15. contains many references to high resistance in certain racial types where the skin is highly pigmented In field sweat testing such problems could arise where children of these racial types are involved In such cases the unusually thick stratum corneum and dryness of the skin often confers electrical resistance sufficient to shut down the circuit In the past with simple battery and rheostat devices the operator could increase the applied voltage to dangerously high levels in order to overcome this resistance and reach the desired current level thus greatly increasing the possibility of a serious burn This is not possible with Wescor s 3700 Sweat Inducer Laboratories that frequently experience these high skin resistance char acteristics should use a specially modified Model 3700 Inducer delivering 1 0 mA current This allows the applied voltage to remain safely below the shut down level The iontophoretic time on this modified Sweat Inducer is extended to 7 5 minutes to maintain the pilocarpine delivery characteristics for maximum sweat yield Contact Wescor for further information and to have this specially modified loan instrument sent to perform the sweat test 65 66 INDEX A Abbreviated Instructions 33 Alarm Tone s disabling 11 high circuit resistance 9 41 high skin resistance 9 low battery 9 41 open circuit 11 26 B Batteries disposing of 45 low weak 9 10 26 indicator 10 replacing 41 42 45 C Circuit Res
16. ducer Velcro Electrode Attachment Strap red Velcro Electrode Attachment Strap black Electrode Set Set 3 Nippers Supply Kit for 6 sweat tests 12 Pilogel Discs 6 Macroduct Sweat Collectors 6 Small Sealable containers Sweat Dispenser Macroduct Strap Extra Large 39 cm Macroduct Strap Large 25 cm Macroduct Strap Medium 18cm Macroduct Strap Small 14 cm SECTION 1 INTRODUCTION 1 4 System Components CATALOG NUMBER 3700 SYS DESCRIPTION UNIT CATALOG NO Webster Sweat Inducer 1 each Model 3700 Electrode Set 1 each 320566 Electrode Attachment Strap red 1 each RP 044 Electrode Attachment Strap black 1 each RP 045 Supplies kit for 6 sweat tests 1 2 Pilogel Discs 1 each SS 032 6 Macroduct Sweat Collectors 6 Small Sealable containers or eu sun us ee A E e 1 each SS 131 SECTION 1 INTRODUCTION 1 5 Webster Sweat Inducer FLOW The Webster Sweat Inducer is an integral part of the Macroduct Sweat Collection System Its design is based on years of clinical experience research and product development with patient safety and comfort given paramount importance It is a fully automatic unit featuring advanced electronic cir cuitry and many fail safe and operator conve nience features How It Works When the RUN STOP switch is moved to th
17. e I position a brief tone signals that external electrode circuit resistance is acceptable and that the instru ment has begun to deliver iontophoretic current Current delivery is confirmed by a green CURRENT FLOW INDICATOR The tone sounds again briefly at the completion of iontophoresis lontophoretic current rises to 1 5 mA during a 17 30 second interval remains at 1 5 mA for 5 min utes then decreases in the final 6 seconds to zero at which time the instrument switches off This profiling of iontophoretic current prevents the sensation of electrical shock that results when cur rent changes abruptly The CURRENT FLOW indi cator is wired in series with the electrodes During the complete iontophoretic sequence the total electrical charge delivered to the positive electrode is approximately 450 millicoulombs or 78 millicoulombs cm Due to impurities in the agar Pilogel discs contain sodium and other cations in total molar concentrations approximately equal to that of the pilocarpinium ion These therefore com pete with each other for transport of electrical charge which produces an approximately 50 reduction in the amount of pilocarpine that would have been delivered to the glands in the absence of such salts However sufficient drug is transport ed to produce maximal sweat stimulation SECTION 1 INTRODUCTION 1 5 Webster Sweat Inducer FAULT CONDITIONS To maximize safety the inducer continuously mon itors the c
18. e reagent reservoirs that provide maximum protection from burns eliminate the problem of bridging and are extremely simple and easy to use Macroduct sweat collection combined with a modern single step micro analytical procedure provides a diagnostic result having the highest confidence level in the history of laboratory sweat testing The Macroduct Sweat Collection System has been unequivocally approved by the U S Cystic Fibrosis Foundation for sweat stimula tion and collection In keeping with Wescor s commitment of excellence still further improvements have now been made in the Macroduct system The new Model 3700 Webster Sweat Inducer has all of the fail safe and convenience features of its predecessor the Model 3600 but does not require a separate charging unit or access to AC power for recharging It is powered by a pair of ordinary 9 volt alkaline batter es that have sufficient capacity for up to a thousand separate ion tophoretic procedures Additional descriptive details and information covering each of the Macroduct Sweat Collection System components are found throughout this manual U S Patent No 4 383 529 References 1 Gibson L E The sweat abnormality in cystic fibrosis Textbook of Cystic Fibrosis J D LLoyd Still ed John Wright pub PSG Inc Littleton Mass 3 7 1983 Gibson L E and Cooke R E A test for concentration of electrolytes in sweat in cystic fibrosis of the pancre
19. edin Lama LS pmo as 1ea Macroduct Sweat Collector SS 142 53 54 APPENDIX C A PERSPECTIVE ON THE SWEAT TEST 23 56 APPENDIX A Perspective on the Sweat Test The sweat test provides laboratory confirmation of the clinical diagnosis of cystic fibrosis It originated in the early 1950 s following the discovery that children afflicted by the disease are prone to acute hyponatremia during hot weather This occurs because of an abnormally high salt concentration in their eccrine sweat ranging from three to five times higher than that of normal children The prospect of obtaining a sweat specimen for analysis of its salt or electrolyte content is conceptually simple but practical obsta cles to accomplishment of the diagnostic objective have made sweat testing one of the most controversial and criticized of all labo ratory procedures This stems mainly from the fact that the test has traditionally been associated with a large number of false results most of which fall into the equivocal borderline or positive range Complications connected to sweat testing resulted in some fatalities in the early days and include numerous incidences of skin burns to patients and minor allergic reactions Vociferous debate has raged among clinicians and researchers as to the efficacy of various sweat testing methods often with little apparent regard for the concerns of the beleaguered individual who must actually conduct the test As
20. he lower portion of the flexor aspect of the forearm This generally has a very high density of sweat glands provided the limb is not so small as to prevent proper attachment of the Macroduct collector NOTE Do not place the electrode so close to the wrist that tendons or bone are palpable just be neath the skin Reasonably thick musculature is necessary for a proper interface with the Macroduct collector If the limb is tiny place the red electrode on the upper portion of the flexor aspect of the forearm nearer the elbow or even the upper arm If the entire arm is too small to attach the collector such as a premature infant use the inner thigh In this case constrain the infant from flexing the knee during collection to avoid a loss of interface between the skin and the collector Attach the negative BLACK electrode at any other convenient position on the arm or to the leg on the same side of the body SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat The selected site must be free of breaks fissures or observable abnormality in the skin There should be no sign of inflammation Apart from exacerbating the complaint there is the possibility of contamination of the sweat by serous exudates The area must be as wrinkle free and hairless as possible Clean the skin at the selected sites to remove dirt fatty material and loose dead cells to minimize the electrical impedance of the skin To do t
21. here as burn injury may result Dispose of in accordance with applicable laws and ordinances 45 46 APPENDIX A SPECIFICATIONS 47 48 APPENDIX A Specifications MODEL 3700 WEBSTER SWEAT INDUCER Power Supply 2 x 9 V alkaline batteries EDA ANSI 1604A lontophoresis Current 1 5 mA automatic lontophoresis Time 5 minutes 25 seconds maximum automatic at operat ing current Current Control a Current profile controlled 20 second rise time 5 second fall time b Provides full current at resistance up to 20 000 ohms c Fail safe limited by circuit design Fault Indication Audible tone Current Flow Indicator Green LED series connected with the electrodes Pr a ia lead wires polarized locking connector ES m NETTE pola M nn uec d uu an rU Bee A mee 49 50 APPENDIX B SUPPLIES AND REPLACEMENT PARTS 51 52 APPENDIX B UNIT DESCRIPTION CATALOG NO PS MO unse A Da et rod O SO ese eec a Juke RR Lo MN O OO AGORA rn aiiai delas MN Li NN id e on ann LR c NEN LE ON iE NN 1 ea Supply Kit materials for 6 sweat tests SS 032 Containing 12 ea Pilogel Discs 6 ea Macroduct Sweat Collectors 6 ea Small Sealable Containers 1 ea Macroduct Strap Small 14 cm SS 128 ee Macsodue Sep Mecum SO NEM I Li cs cons e dd ee A ad cuc N NENNEN E ana O GEL M
22. his Swab the area vigorously with alcohol then with plenty of purified water b Leave the skin wet where the Pilogel disc is to be attached OR Place a drop of water on the skin or on the surface of the Pilogel disc just before attachment This will ensure uniform contact over the area and reduce the possibility of a burn NOTE Be sure that you are familiar with the 1 SWAB WITH ALCOHOL 2 SWAB WITH PURIFIED WATER precautions found in Section 1 6 23 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat 24 4 INSTALL PILOGEL DISCS ON BOTH ELEC TRODES Pilogel discs have a diameter slightly larger than the inside diameter of the electrode skirt to provide a tight fit Be sure to press firmly all around the outer perimeter of the disc to achieve uniform air free contact with the electrode This may shave small slivers of gel from the outside of the disc as it is seated against the electrode This is normal Do not be concerned if the Pilogel disc has a tendency to bulge away from the stainless steel electrode at the center Attachment to the limb will flatten it against the electrode WARNING Pilogel discs should be refrigerated at 2 to 8 C DO NOT FREEZE Never use discs that have been frozen or that are cracked WARNING Never attach an electrode to the skin without Pilogel Direct skin to metal contact will burn the patient Refer to Section 1 6 for additional infor
23. ield of only 20 uL this contribution will not exceed 1 5 mmol kg or 1 0 mmol L respectively and is negligible The spiral collection tube capacity is approximately 85 microliters This is adequate for average sweat production levels 50 to 60 microliters in thirty minutes of collection This volume is sufficient for all current methods of sweat analysis see Notes Regarding Sweat Yield p 17 At the end of the collection period the collector must remain on the limb until the pristine sweat specimen is removed by severing the plastic tube at its attachment point See complete instructions in Section 2 before attempting this procedure SECTION 1 INTRODUCTION 1 7 Macroduct Sweat Collector Advantages of Macroduct a By preventing any exposure to an air space the collected sweat is not subject to condensate error b Evaporation of sweat can only occur atthe advancing meniscus in the plastic collecting duct This has been found by measurement to pro duce a negligible loss of 0 1 microliters per hour c The operator can gauge the amount of sweat produced at any time a unique and unprecedented feature that eliminates guesswork in deciding the duration of the collection period d The patient has complete mobility during the collection period The collector can be over wrapped with an elastic bandage to keep curious young fingers from causing mischief e Macroduct collects sweat passively and automatically driven by the
24. istance 9 26 65 Chloride Analysis 37 Control Switch s ON OFF RUN 8 27 START 9 STOP 8 9 Condensate Error 17 37 Conductivity diagnostic sweat analysis by 17 37 58 62 Current Flow Indicator 8 26 46 Customer Service 4 Cystic Fibrosis 3 56 60 D Diagnosing Cystic Fibrosis 4 Dye in sweat sample 16 37 E Electrode s attachment 13 bridging 13 circuit 8 26 cleaning 21 32 41 44 faulty 42 installing Pilogel discs in 23 24 negative black 22 27 53 pins 21 positive red 8 22 27 28 53 maintenance 11 strap s 15 25 41 53 lead wires 11 21 26 46 Evaporation Error 37 H High Skin Resistance 8 63 Hyponatremia 56 lontophoresis 8 9 12 27 burns during 14 15 23 24 current 8 9 25 sequence description 8 L Lead Wires see electrode lead wires Low Batteries 9 10 42 45 M Macroduct Sweat Collection System 8 56 60 collector 16 26 27 28 32 53 58 59 straps 27 28 30 53 replacement parts 53 supplies 53 Osmolality diagnostic sweat analysis by 37 67 INDEX P Pilocarpine Webster Sweat Inducer 6 7 8 41 46 57 iontophoresis see iontophoresis 63 nitrate 12 electrode plug 21 Pilogel lontophoretic Discs 12 14 15 electronics 45 46 23 24 25 32 41 53 63 instructions for use 21 27 63 repair 4 43 R RUN Switch 8 9 10 26 42 S Sodium Analysis 37 Specifications safe use 5 environmental 5 system 49 Spiral microbore Collection T
25. mation SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat 5 ATTACH THE ELECTRODES TO LIMB Place each strap so that the stud of the elec trode protrudes through the rivet of the strap with the hook portion of the short tab facing upward away from the skin Secure the elec trode firmly so that the gel surface is pressed flat against the skin There should be moder ate pressure to minimize discomfort but do not tighten enough to crush the gel disc ELECTRODE STUD NOTE Individuals vary in their sensitivity to iontophoretic current Most subjects feel nothing more than a slight prickling sensation during iontophoresis If a child complains or if an infant shows signs of distress tighten the strap to increase pressure against the skin 25 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat 26 WEBSTER SWEAT INDUCER A AA Fl ana 6 ACTIVATE IONTOPHORESIS Push the control switch to the RUN I posi tion and hold momentarily until you hear a short beep A steady tone indicates exces sive external circuit resistance a break in the line or weak batteries If this occurs move the control switch to STOP 0 and correct the fault condition before proceeding Section 4 If everything is normal the CURRENT FLOW indicator reaches full brightness in approxi mately 20 seconds and diminishes in bright ness during the last 5 seconds
26. method and it enjoyed con siderable commercial success The Webster system was a significant breakthrough in the effort to develop a modern sweat collection system worthy of displacing the venerated method of Gibson and Cooke Despite the fact that the heated cup solved the most significant problem connected to cup collection of sweat it was nevertheless burdened by a problem common to all cup collection systems i e the need to harvest sweat accumulated under the cup during the collection period Wescor s commitment to resolve this problem eventually led U S Patent No 4 266 556 58 APPENDIX C A Perspective on the Sweat Test to a significant breakthrough in the collection phase of the sweat test the invention of the Macroduct Sweat Collector Vested in Wescor s scientific and engineering staff is a combination of many years experience in laboratory sweat testing and in the development of modern electronic laboratory instrumentation These professional talents were marshalled in support of the com pany s commitment to achieve objectives that it believed were essential to advancing laboratory sweat testing from the era of the 1950 s to the present day 1 Eliminate all intrinsic sources of error concomitant to previous collection methods 2 Ensure impeccable accuracy in the diagnostic result by reducing human error potential to the lowest possible level 3 Maximize patient safety and comfort 4 Maximize operator c
27. most completely of electrolytes it provides a convenient single measurement assessment of sweat electrolyte level Extensive trials with hospital patients have shown that the normal range in children is approximately 50 to 150 mmol kg and the CF patients show values in excess of 200 mmol kg with an average of 270 mmol kg Electrical Conductivity Wescor s Sweat Chek Sweat Conductivity Analyzer was designed to measure conductivi ty of Macroduct collected samples Field test ing in clinics in the U S A and in the United Kingdom testify to its simplicity economy and accuracy in the diagnosis of cystic fibrosis The results show clearly that conductivity osmolali ty and chloride have equal capacity to distin guish between normal and CF subject groups and are therefore equivalent as diagnostic indi cators A detailed account of the nature of sweat con ductivity the clinical trial results and its status in the international clinical laboratory scene is presented in the Sweat Chek User s Manual 37 38 SECTION 4 MAINTENANCE AND TROUBLESHOOTING 39 40 SECTION 4 MAINTENANCE AND TROUBLESHOOTING 4 1 Troubleshooting Aside from electrode cleaning there is no regular periodic maintenance required in the Model 3700 Webster Sweat Inducer If the system appears to malfunction use the following information to identify and remedy the problem SYMPTOM PROBABLE CAUSE SOLUTION Nothing happens when High circuit re
28. nducer until it has been checked Return to Wescor for service if needed Low batteries Replace batteries See Section 4 3 If the malfunction has been traced to a faulty electrode replacement parts can be ordered from Wescor APPENDIX B If the malfunction has been traced to the electronics or cannot be isolated following the above procedures the inducer and electrodes should be returned to Wescor for inspection and repair 42 SECTION 4 TROUBLESHOOTING AND MAINTENANCE 4 1 Troubleshooting DO NOT OPEN the case and attempt repairs dur ing the one year warranty period except when authorized and instructed by Wescor service per sonnel To do otherwise will void the inducer war ranty We strongly recommend that you return any malfunctioning unit to Wescor for service even after the warranty has expired Repairs made by electronic technicians who are not completely familiar with the fail safe features of this device may render such features inoperable Since the instrument is small enough to be shipped by airmail or UPS factory repair service will inevitably be the fastest and least expensive method of repair 43 SECTION 4 TROUBLESHOOTING AND MAINTENANCE 4 2 Cleaning the Electrodes Electrodes must be cleaned following each ionto phoresis procedure 1 Remove remaining Pilogel disc material from electrodes 2 Use a cotton ball or swab with purified water to thoroughly clean each electrode 3 If the electr
29. o sis Arch Dis Child 59 10 919 922 Oct 1984 Sens D A Simmons M A and Spicer S S The analysis of human sweat pro teins by isoelectric focusing Sweat Collection utilizing the macroduct system demonstrates the presence of previously unrecognized sex related proteins Pediatr Res 19 8 873 878 1985 12 Webster H L Improved pilocarpine reservoir for use in sweat testing Clin Chem 28 2182 1982 61 62 APPENDIX D PROCEDURE FOR HIGH SKIN RESISTANCE 63 64 APPENDIX D Procedure for High Skin Resistance Almost all of the electrical resistance in an iontophoretic circuit is provid ed by the two skin areas involved and is due to the relatively dry dead cell layer of the epidermis which varies in thickness according to body position and also between individuals When iontophoresis begins the resistance is high but rapidly reduces as the ducts begin to carry salt containing sweat to the skin surface In the great majority of cases the standard pre cleaning procedure of a brisk rub with alcohol and water to remove excess skin oils a vigorous wash to remove as much dead cell material as possible and a final wetting of the involved areas just before applying Pilogel will lower resistance to satisfactory levels Special Procedure for Exceptional Resistance lontophoretic shut down by the 3700 Sweat Inducer due to very high resistance is quite rare However the physiological literature
30. ode appears dirty after an extend ed idle period or will not clean with steps 1 and 2 try using a small round piece of light duty cleaning pad such as 3M Scotch Bright 7445 to buff the electrode surface CAUTION Never use harsh abrasives such as steel wool sandpaper or emery cloth to clean electrodes Never scrape electrodes with metal tools NOTE When needed the instrument case and electrode cable can be cleaned using a damp cloth soaked in a 10 household bleach or mild soap solution Avoid excessive moisture to the instrument 44 SECTION 4 TROUBLESHOOTING AND MAINTENANCE 4 3 Replacing Inducer Batteries The battery compartment for the Webster Sweat Inducer is on the bottom of the unit To access and replace the batteries 1 Slide the battery access panel out and away from the case 2 Remove the foam spacer from the end of the batteries 3 Carefully remove each battery from its connectors Dispose of batteries properly see below NOTE Always replace both batteries at the same time 4 Insert two new 9 volt batteries type EDA ANSI 1604A Be sure the batteries are correctly aligned and seated in the connectors 5 Replace the foam spacer at the end of the batteries 6 Replace the battery compartment lid BATTERY CARE AND DISPOSAL WARNING Do not connect improperly charge or dispose of in fire Batteries can explode or leak Do not carry batteries loose in your pocket or elsew
31. onvenience within the strictures imposed by objectives 1 2 and 3 During the development of the Macroduct system Wescor s research team conducted a comprehensive and detailed review of every aspect of the sweat test with the object of simplifying the pro cedure to the greatest degree possible Laboratory research and experimentation led to a better understanding of the parameters governing stimulation by pilocarpine iontophoresis and ultimately to the development of a fully automatic electronic sweat inducer that requires no judgmental decisions or adjustments by the operator A review of all currently available methods for sweat analysis was made in order to identify the procedure s most suitable for use with the unique new method of collection With the introduction of the Model 3600 Macroduct Sweat Collection System in 1983 all of the comprehensive objectives had been suc cessfully accomplished Paramount among the system s several unique and novel features was the innovative Macroduct disposable sweat collector 8 9 10 11 U S Patent No 4 542 751 U K Patent No 2116850 39 60 APPENDIX A Perspective on the Sweat Test The Macroduct sweat collector preserves absolute integrity in the collected sweat specimen and gives the unprecedented advantage of visual quantitation of the volume of sweat collected at any time during the collection period Other unique features of the system include the unique Pilogel 12 pilocarpin
32. possibility of electrical burns to the skin The Pilogel disc fits snugly into the recess of the electrode preventing disc separation from the electrode This virtually eliminates any possibility of a burn from direct metal to skin contact BURNS DURING IONTOPHORESIS The Macroduct Sweat Collection System has be come perhaps the most frequently used system in hospitals and clinics worldwide While the Macroduct system is clearly superior to previous methods burns during iontophoresis have not been totally eliminated Based on reports from practitioners we estimate a frequen cy of 1 burn in 50 000 iontophoretic procedures Burn descriptions vary from tiny black pinholes in the skin to crater like third degree burns two to three millimeters in diameter In most of the reported cases the children have exhibited no sign of pain or discomfort during iontophoresis and the burn was not discovered until the electrodes were removed Parents must be informed and allowed to read the Information for Parents included with the Macroduct supply kit You should also have them sign an appropriate release form before perform ing this procedure If the procedures outlined in the manual are followed correctly burns should be extremely rare SECTIONA INTRODUCTION 1 6 Pilogel Iontophoretic Discs We strongly recommend the following burn prevention procedures 1 Do not use Pilogel discs that have an unusu al appearan
33. rode while the disc under the negative electrode completes the electrical circuit The Pilogel system provides monumental improve ments in patient safety efficiency of sweat stimula tion and convenience to the operator 12 SECTION 1 INTRODUCTION 1 6 Pilogel Iontophoretic Discs EFFICIENT SWEAT PRODUCTION Reliable uniform gel to skin contact ensures delivery of pilocarpine over the whole skin area thus providing total gland stimulation and maximal sweat yield Despite being mostly water and presenting a wet surface to the skin Pilogel discs do not exude fluid even under the pressure applied during limb attachment This eliminates any possibility of bridging Gel fitted electrodes may be placed in close proximity without risking a short circuit a great advantage when dealing with neonates Pilogel eliminates the need to apply gauze or paper pads The discs are immediately ready for use There is no need to prepare or store reagent solutions With Pilogel the electrodes once fitted require no further attention during iontophoresis 13 SECTION 1 INTRODUCTION 1 6 Pilogel Iontophoretic Discs 14 ENSURING PATIENT SAFETY The Macroduct system represents a dramatic im provement in patient safety over previous sweat induction and collection methods Pilogel discs provide an air free continuous conduction medium and even distribution of current over the stimulated skin area reducing the
34. sistance will be accompanied by switch is pushed to RUN I an audible alarm Completely dead batter ies Check and replace if necessary Low battery light comes on and Low batteries Replace batteries alarm sounds when switch is pushed to RUN See Section 4 3 Alarm alternates from high to low pitch Open Circuit Make sure the electrodes are clean and unmarked If necessary clean or replace electrodes See Section 5 2 Make sure electrodes are strapped secure ly to the patient s limb If alarm continues arrange a short circuit at the inducer con nector by holding the two electrodes with Pilogel disks installed against each other The Pilogel disks should be facing each other and touching If the unit still does not operate check electrodes and wires for open connec tions If the inducer will not function with the connector shorted return itto Wescor for service Alarm with steady tone High skin resistance Since the inducer has a fixed limit for acceptable resistance try using another area of skin that may offer lower resistance or scrub the skin vigorously to remove as much dead epithelial cell material as possible See Appendix B 41 SECTION 4 TROUBLESHOOTING AND MAINTENANCE 4 1 Troubleshooting SYMPTOM Alarm has multiple alternating pitches much like a siren LOW BATTERY light flashes after ion tophoresis and audio warning signal sounds PROBABLE CAUSE SOLUTION Overcurrent indication Do not use i
35. sulation If electrode wires insulation or the plastic electrode housing exhibit cracks or breaks the electrode set should be replaced Wipe Stainless Steel Electrodes Check for cracks in lead wires NOTE If you activate the run switch while the electrodes are not attached to the patient s limb an open circuit alarm will sound To disable the open cir cuit alarm push the switch to the STOP position 11 SECTION 1 INTRODUCTION 1 6 Pilogel Iontophoretic Discs The traditional reagent solutions for pilocarpine iontophoresis are pilocarpine nitrate and sodium nitrate These have been applied either to absorbent fabric such as gauze or to discs of thick paper that are then interposed between the electrode surfaces and the skin Such reagent reservoirs have always presented problems to both operators and patients Pilogel iontophoretic discs were developed specifi cally to overcome these and other problems They consist of a solid agar gel that is 96 water into which is dissolved 0 5 pilocarpine nitrate and a trace of antifungal compounds The discs are approximately 6 mm thick and sized to fit snugly into the standard Wescor recessed electrodes Pilogel is supplied in a resealable vial containing 12 discs intended for one time use suf ficient for 6 iontophoretic sweat stimulations Discs are used in both positive and negative elec trodes Sweat stimulation occurs under the positive elect
36. tional sweat test analytes Sodium may be measured on Macroduct sam ples by adding an aliquot of the sweat sample 5 or 10 uL to an appropriate volume of lithium sulphate diluent and directly aspirating this solution into a flame photometer that does not automatically predilute Sodium assay in itself is not a reliable method in CF diagnosis because there is some overlap between nor mal and abnormal groups It is usually per formed together with chloride which has in the past been determined using micro titration with mercuric nitrate an old method that requires prohibitively large sample volumes for accept able accuracy In recent times coulometric titration requiring as little as 10 uL is often used lon specific electrodes can be employed but these usually require sample dilution to a point where sensitivity is compromised A sim ple colorimetric method is available that requires only 5 uL of undiluted sweat and is not affected by the minute amount of dye that is present in Macroduct specimens Osmolality A modern approach to diagnostic sweat analy sis that is more rapid and more sensitive is the measurement of osmolality using the Wescor Vapro Vapor Pressure Osmometer This instrument can provide an osmolality value on a little as 5 uL of undiluted sweat within 1 5 SECTION 3 SWEAT ANALYSIS 3 1 An Overview to Sweat Analysis minutes Since osmolality indicates total solute concentration which in sweat is made up al
37. uL 17 18 SECTION 2 SWEAT INDUCTION AND COLLECTION 19 20 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat WARNING Due to the possibility of an explosion never attempt iontophoresis on a patient receiving oxy gen enriched respiratory therapy in an enclosed space With medical approval remove the patient from that environment during iontophoresis ASSEMBLE EQUIPMENT AND SUPPLIES Make certain everything is on hand for the complete procedure In addition to the com plete Macroduct Sweat Collection System you will need a supply of pure water alcohol and cotton balls or gauze pads INSPECT ELECTRODES AND CONNECT TO INDUCER ELECTRODES Clean the electrodes if necessary see Section 5 2 Check wires and insulation for cracks or fraying Replace electrodes if wires insulation or plastic housing are cracked or frayed Press the electrode plug into the jack on the sweat inducer panel You must engage the positive negative alignment pins correctly to do so Tighten the locking ring to secure the connection 21 SECTION 2 SWEAT INDUCTION AND COLLECTION 2 1 Inducing Sweat 22 RED ELECTRODE TINY INFANT PLACEMENT RED ELECTRODE 3 CLEAN THE SELECTED SKIN AREAS The positive RED electrode must be placed correctly for successful sweat collec tion Locate it on an area of skin with a high density of sweat glands for optimum sweat yield The preferred site is t
38. ubing 16 29 30 cutting 31 STOP Switch 8 9 10 11 46 Sweat analysis 4 31 37 56 60 chloride assay 16 transporting to analyzer 31 volume 16 29 yield 17 29 Sweat continued collection 4 16 17 27 29 collector 6 7 16 17 dispenser 6 7 30 53 electrolytes in 56 evaporation 17 induction 4 12 13 salt concentration in 56 63 stimulation 12 13 21 26 test 17 37 53 56 60 Sweat Chek Analyzer 31 37 System components 6 7 T Tuberculin Syringe 30 31 68
39. urrent If an unexpected condition is detected the current turns off and an alarm sounds This alarm continues until you move the switch to STOP 0 A fault condition can occur if one of the electrodes becomes detached An alarm may also be due to low batteries see next page See Section 4 for more detail of fault conditions and alarms SECTION 1 INTRODUCTION 1 5 Webster Sweat Inducer LOW BATTERIES The alarm sounds if the batteries are low when the switch is moved to RUN I In this case the amber LOW BATTERY indicator will also be illuminated and the inducer will not start The alarm continues until the control switch is moved to the STOP 0 position WERSTERSWEATINDUCER If batteries get low during iontophoresis the instru m nn Ox ment completes the cycle using remaining power WESOR in the batteries but at the end of the cycle the tone sounds and the LOW BATTERY indicator flashes To disable the LOW BATTERY alert push the switch to the STOP 0 position LOw aaTTERFY Replace batteries before attempting another iontophoresis cycle See Section 4 3 10 SECTION 1 INTRODUCTION 1 5 Webster Sweat Inducer ELECTRODES The high grade stainless steel electrodes require only minimal maintenance This consists of clean ing them with purified water after each use so they will be ready for the next procedure See Section 4 2 Lead wires should be periodically inspected for breaks or cracks in the in
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