Urethral Catheter Insertion Forces: A Comparison of Experience
and Training
Benjamin K. Canales, Derek Weiland, Scott Reardon, Manoj Monga
Department of Urology (BKC), University of Florida, Gainsville, Florida, USA and Department of Urology (DW, SR, MM), University of Minnesota, Minneapolis, Minnesota, USA
ABSTRACT
Purpose:This study was undertaken to evaluate the insertion forces utilized during simulated placement of a urethral catheter by healthcare individuals with a variety of catheter experience.
Materials and Methods: A 21F urethral catheter was mounted to a metal spring. Participants were asked to press the tub-ing sprtub-ing against a force gauge and stop when they met a level of resistance that would typically make them terminate
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Results:$WRWDORI¿IW\VHYHQKHDOWKFDUHSURIHVVLRQDOVSDUWLFLSDWHGLQWKHVWXG\8URORJ\VWDIIQ KDGWKHORZHVWDYHU
-DJHLQVHUWLRQIRUFHIRUDQ\JURXSDWr1HZWRQV10HGLFDOVWXGHQWVQ KDGWKHOHDVWDPRXQWRIH[SHULHQFH r\HDUVDQGWKHKLJKHVWDYHUDJHLQVHUWLRQIRUFHUDQJHRIr 3.7 N. Health care workers with greater than 25 years
H[SHULHQFHXVHGVLJQL¿FDQWO\OHVVIRUFHGXULQJFDWKHWHULQVHUWLRQVr1FRPSDUHGWRDOOJURXSVS Conclusions:We propose the maximum force that should be utilized during urethral catheter insertion is 5 Newtons. This force deserves validation in a larger population and should be considered when designing urethral catheters or creating
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for health care professionals in training.
Key words: urinary catheterization; urethral catheter; educational models
Int Braz J Urol. 2009; 35: 84-9
INTRODUCTION
The insertion of a urethral catheter is one of the most commonly performed hospital procedures. )RUWKH\HDUWKH&HQWHUIRU'LVHDVH&RQWURO HVWLPDWHG WKDW RYHU ¿YH PLOOLRQ XUHWKUDO FDWKHWHU -L]DWLRQVZHUHDWWHPSWHGLQWKH8QLWHG6WDWHV,Q PRVWKRVSLWDOVWKLVSURFHGXUHLVSHUIRUPHGZLWKRXW a standardized training protocol and by a variety of healthcare workers with varying degrees of ex-perience. We hypothesized that we could establish competency parameters for professionals in-training
by measuring urethral catheter exertion forces and FRPSDULQJKHDOWKFDUHSURYLGHUH[SHULHQFH,QDGGL -WLRQZHZRXOGJDWKHULQIRUPDWLRQWKDWPD\DIIHFW not only the future design of catheters and virtual simulators but also the rate of urethral trauma and stricture.
MATERIALS AND METHODS
0LQQHDSROLV0186$ZHUHLQYLWHGWRSDUWLFLSDWH LQRXUVWXG\LIWKH\FRXOGEHVWUDWL¿HGLQWRRQHRIVL[ JURXSV*URXS8URORJLVW0'*URXS1RQ 8URORJLVW0'*URXS8URORJ\5HVLGHQW)HOORZ 0'*URXS1RQ8URORJ\5HVLGHQW)HOORZ0' *URXS0HGLFDO6WXGHQWDQG*URXS5HJLVWHUHG 1XUVH3DUWLFLSDQWVZHUHDVNHG³3XVKLQWKHFDWK -eter until you feel a level of resistance that would make you stop if you were putting in a real urethral catheter”. Participants held the catheter at the same marked area and were instructed and monitored by the same two researchers to ensure procedure conformity. 7KHSURFHGXUHZDVUHSHDWHG¿YHWLPHVVHULDOO\E\DOO groups.
7KHWXEHXVHGLQVLPXODWLRQZDVDSRO\ROH¿Q
FDWKHWHU)RXWHUFLUFXPIHUHQFH)LQQHUFLUFXP -IHUHQFHZLWKDPHWDOVSULQJ´[´[´ZLUH WKLFNQHVVPRXQWHGRQWKHGLVWDOHQGRIDFRPSUHVVLRQ IRUFHJDXJH([WHFK70'LJLWDO)RUFH*DXJHPRGHO
)LJXUH 3HDN FRPSUHVVLRQ IRUFHV LQ 1HZWRQV1ZHUHUHFRUGHGDQGSDUWLFLSDQWVZHUH blinded to their own results.
The statistical software package SAS was XVHGIRUDOOFDOFXODWLRQV6$6,QVWLWXWH,QF&DU\ 1&9HUVLRQ *URXS PHDQ FRPSDULVRQV ZHUH
FDOFXODWHG E\ DQ XQSDLUHG WZRVLGHG 6WXGHQW W WHVW$QDO\VLVRIYDULDQFH$129$ZDVDSSOLHGWR compare different groups with respect to continuous YDULDEOHV&KDQJHLQIRUFHRYHU\HDUVRIH[SHULHQFH was estimated by regressing the force applied by each VXEMHFWDQGREWDLQLQJDEHVW¿WOLQHE\OLQHDUUHJUHV -VLRQ5HVXOWVZHUHFRQVLGHUHGVLJQL¿FDQWLIWKHSYDOXH ZDV
RESULTS
Fifty-seven healthcare workers participated LQWKLVVWXG\)LJXUH,QGLYLGXDOXUHWKUDOFDWKHWHU insertion force was averaged by group and ranged IURP WR 1 8URORJLVWV *URXS KDG WKH ORZHVWDYHUDJHIRUFHLQVHUWLRQIRUFHV1r 2.0 1ZKLOHPHGLFDOVWXGHQWV*URXSKDGWKHKLJKHVW
DYHUDJHLQVHUWLRQIRUFHV1r17KHGLIIHU
-ence in the amount of simulated force used to insert DFDWKHWHUZDVVLJQL¿FDQWO\KLJKHUIRUWKHPHGLFDO VWXGHQWVFRPSDUHGWRHYHU\RWKHUJURXSS 7KHGLIIHUHQFHLQSYDOXHVZDVDOVRVLJQL¿FDQWZKHQ FRPSDULQJXURORJLVWVWRXURORJ\UHVLGHQWV*URXS S DQGUHJLVWHUHGQXUVHV*URXSS 7R HYDOXDWH IRU VXEMHFWH[SHFWDQF\ HIIHFW RQHZD\$129$ZDVSHUIRUPHGFRPSDULQJIRUFH YHUVXV DWWHPSW IRU DWWHPSWV )LJXUH 1R VWDWLVWLFDOO\VLJQL¿FDQWGLIIHUHQFHZDVIRXQGEHWZHHQ PHDQVRIJURXSVUDQJH11S ([SHULHQFHZDVWKHQSORWWHGLQGHSHQGHQWRIPHGLFDO JURXSLQDELYDULDWH¿WJUDSKYHUVXVIRUFHDQGUHVXOWV ZHUH H[DPLQHG XVLQJ$129$ )LJXUH ,Q WKLV OLQHDUFRUUHODWLRQSDUWLFLSDQWH[SHULHQFHDORQHU H[SODLQHGDSSUR[LPDWHO\RIWKHREVHUYHG YDULDWLRQLQIRUFHS+HDOWKFDUHZRUNHUV ZLWKPRUHWKDQ\HDUVH[SHULHQFHQ KDGWKH
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compared to those with less than 25 years experience
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COMMENTS
The urethral catheter is an instrument as old as WKH¿HOGRIXURORJ\(YLGHQFHRIFDWKHWHUXVHLQ*UHHFH FDQEHIRXQGLQWKH+LSSRFUDWLF:ULWLQJVa%&
,Q'U)UHGHULFN(%)ROH\GHVFULEHGWKH ¿UVWPRGHUQXUHWKUDOFDWKHWHUE\GLSSLQJFRDJXODWLQJ latex onto metal forms to create a dual-port balloon FDWKHWHU&RPSRQHQWVRIPRGHUQXUHWKUDOFDWK-eters have evolved into a combination of silicone
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'HVSLWHWKHSXEOLFDWLRQVRIDQXUVHFOLQLFDO SUDFWLFHJXLGHOLQHDQGWKHLPSDFWRIQXUVLQJHGXFD
-Figure 2 – Average urethral catheter insertion force in Newtons, by group.
WLRQDOSURJUDPVQRVWDQGDUGL]HGPHWKRGIRUWUDLQ -ing health care workers in catheter placement exists. 0RVWQHZKHDOWKFDUHHPSOR\HHVZKHWKHUWKH\DUH VWXGHQWVRUUHVLGHQWVDUHJXLGHGWKURXJKWKHSURFHVV of patient preparation and catheterization by someone ZLWKFDWKHWHUH[SHULHQFH'XULQJWKHDFWXDOSURFHGXUH KRZHYHURQO\WKHKHDOWKFDUHZRUNHUDGYDQFLQJWKH catheter can feel the resistance given by the catheter. Although improvements in catheter design and com-SRVLWLRQKDYHRFFXUUHGLDWURJHQLFXUHWKUDOLQMXU\LQ SDUWLFXODUXUHWKUDOVWULFWXUHFRQWLQXHVWRRFFXUIDU WRRFRPPRQO\)HQWRQHWDOIRXQGWKDWXUHWKUDO catheter placement was the cause of approximately RIDOOXUHWKUDOVWULFWXUHGLVHDVH,QDGGLWLRQ XUHWKUDOUHFWDO¿VWXODVXUHWKUDOSHUIRUDWLRQSURVWDWLF EOHHGLQJUHTXLULQJVXUJLFDOLQWHUYHQWLRQDQGEODGGHU perforation have all been reported as consequences RI LPSURSHUO\ LQVHUWHG XUHWKUDO FDWKHWHUV 7KHUHIRUHZHDWWHPSWHGWRJHQHUDWHD³QRUPDOFXUYH´ of catheter forces that could be used for modeling purposes and potential competency parameters.
)URPDGHVLJQVWDQGSRLQWLWLVLPSRUWDQWWR
emphasize that we have measured only one element RIFDWKHWHULQVHUWLRQIRUFHXVHG%HFDXVHRXUPHWKRG RIVLPXODWLRQGRHVQRWLQYROYHUHVLVWDQFHZHFKRVH WRXVHWKHSRO\PHU³SRO\ROH¿Q´DVLWLVPRUH¿UP than a silicone or latex catheter and does not buckle
prior to the participant reaching the point of maximal IRUFH$QDO\VLVE\DWWHPSW)LJXUHLQGLFDWHGWKDW QRPRUHIRUFHZDVDSSOLHGRQWKH¿UVWDWWHPSWWKDQ RQWKHODVWDWWHPSWVXJJHVWLQJWKDWERWKWKHPDWHULDO used and the study design yielded reproducible and precise results.
,QWXLWLYHO\ LW PDNHV VHQVH WKDW D SURSHUO\ placed catheter should not require a great deal of IRUFHWRWUDYHUVHWKHXUHWKUD,QVXSSRUWRIWKLVWKH experienced urologists had the lowest catheter
inser-WLRQIRUFHVRIDOORXUJURXSVr10RUHVXU
-SULVLQJZDVWKH¿QGLQJWKDWKHDOWKFDUHZRUNHUVZLWK more than 25 years experience had even lower forces
r1ZLWKVWDWLVWLFDOVLJQL¿FDQFH%HFDXVH
RIWKLVZHSURSRVHWKDWWKHUDQJHRIr1EH
considered the standard-of-care model in regards to urethral catheter insertion force. Future clinical stud-ies should evaluate not only force but also the ability for providers to appreciate and adapt to variances in DFOLQLFDOSUHVHQWDWLRQVXFKDVFDWKHWHUUHVLVWDQFH DQDWRP\EORRG\UHWXUQRUSDWLHQWGLVFRPIRUW
Several catheter methods of simulation have EHHQGHYLVHGEXWQRVLPXODWLRQPHWKRGIXOO\UHFUH -ates the sense of catheterization of the female or male. 'HVSLWHWKHLUVKRUWFRPLQJVFDWKHWHUVLPXODWRUVKDYH been shown to reduce both risk and pain experienced by patients in addition to avoiding urethral injuries
6LQFH PDQ\ 86 PHGLFDO VFKRROV KDYH WKH insertion of a urethral catheter as a core clinical com-SHWHQF\VLPXODWRUVFRXOGOLNHO\KHOSVWXGHQWV learn this core concept before actually practicing on a real patient. As the use of simulated medical trainers ULVHVLQWKLVFRXQWU\LWLVRXUKRSHWKDWWKLVGDWDFDQEH used to help industry sector and medical programs in designing simulation devices that give feedback dur-LQJXUHWKUDOFDWKHWHULQVHUWLRQ)URPDFRVWVWDQGSRLQW 0RUJDQHWDOVKRZHGWKDWPHGLFDOVLPXODWRUWUDLQLQJ devices are worth the extra expense in regards to both VWXGHQWDQGIDFXOW\VDWLVIDFWLRQ$OWKRXJKPRVWRI the medical simulator published data involves medical VWXGHQWVWKLVWHFKQRORJ\FRXOGHDVLO\EHDSSOLHGWR QXUVLQJVWXGHQWVZKRDUHPXFKPRUHOLNHO\WRSODFH URXWLQHFDWKHWHUVWKDQSK\VLFLDQVDUHQHZVXUJLFDO RUPHGLFDOUHVLGHQWVDQGRUDVFRPSHWHQF\WHVWLQJ for physicians.
2XUVWXG\KDVVRPHOLPLWDWLRQV7KRXJKXWL-lization of an in vitro model allows standardization of WHFKQLTXHDQGPHDVXUHPHQWLWGRHVQRWDFFRXQWIRU signs of excess force that could be noted in a clinical WULDOVXFKDVSDWLHQWUHSRUWLQJRIGLVFRPIRUWEORRG DWWKHXUHWKUDOPHDWXVRUFDWKHWHUWLSUHVLVWDQFH,Q DGGLWLRQWRIRUFHXUHWKUDOLQMXU\UDWHVPD\LQFUHDVH by higher catheterization intervals or in high risk PDOH SRSXODWLRQV VXFK DV EHQLJQ SURVWDWLF K\SHU -SODVLDRUSURVWDWHFDQFHU3RO\ROH¿QPDWHULDOLV slightly stiffer than silicone and latex materials used LQFDWKHWHUVDQGZDVVHOHFWHGVSHFL¿FDOO\VRWKHFDWK -HWHUZRXOGQRWEXFNOHGXULQJWHVWLQJ,WZRXOGEHRI YDOXHWRYDOLGDWHWKHIRUFHUDQJHGH¿QHGLQWKLVVWXG\ in a clinical trial of a larger group of providers using commercially available catheters.
CONCLUSION
,QFRQFOXVLRQDVKHDOWKFDUHZRUNHUVDFTXLUH PRUHH[SHULHQFHVLJQL¿FDQWO\OHVVIRUFHLVXVHGGXU -LQJXUHWKUDOFDWKHWHULQVHUWLRQV%DVHGRQRXU¿QGLQJV we propose that the maximum force that should be utilized during urethral catheter insertion is 5 New-WRQV7KLV IRUFH VKRXOG EH FRQVLGHUHG WKH ³XSSHU limit” utilized for urethral catheter insertion. Future YDOLGDWLRQLQODUJHUSRSXODWLRQVVXFKDVPHDVXUH-ments in cadavers or anesthetized patients undergoing
QRQXURORJLFVXUJHU\ZRXOGEHZDUUDQWHGWRHYDOXDWH the range of forces used during normal circumstances. +RZHYHUFOLQLFDOPHDVXUHPHQWVRIWKLVW\SHPD\QRW QHFHVVDULO\KHOSUH¿QHWKH³XSSHUOLPLW´WKDWVKRXOG be avoided unless they are collected from experienced SUDFWLWLRQHUV2YHUDOOXQGHUVWDQGLQJXUHWKUDOFDWKHWHU insertion forces may aid in the design of future cath-HWHUVLQWKHFUHDWLRQRIFDWKHWHUVLPXODWRUVDQGLQ establishing competency parameters for health care SURIHVVLRQDOVGXULQJWUDLQLQJDQGRUUHFHUWL¿FDWLRQ
ACKNOWLEDGEMENT
7R'U-RKQ-&DUORZZKRDVVLVWHGLQWKH statistical analysis.
CONFLICT OF INTEREST
Financial support by PercSys®3HUFXWDQHRXV
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handmade instrument to infection-prevention device.
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possible complications and their prevention and
EDITORIAL COMMENT
This work is a highly valuable unprecedented initiative towards systemization of urethral catheter insertion. Although urethral catheter insertion is a FRPPRQ SURFHGXUH WR GDWH WKHUH LV QR GH¿QLWLYH standardization.
The use of diverse groups in the study serves to show that aptitude in catheter placement implicates an extremely long learning curve for all healthcare SURYLGHUVLQGHSHQGHQWRIWKHLUVSHFLDOL]DWLRQ8O
-WLPDWHO\WKLVVWXG\VKRZVWKDWHYHQLIRWKHUIDFWRUV FDQOHDGWRODWHFRPSOLFDWLRQVWKHIRUFHXVHGLQWKH placement of the catheter is the principal factor lead-ing to acute complications.
/DVWO\WKLVVWXG\VHUYHVDVDVWDUWLQJSRLQWIRU creation of catheter simulators designed for healthcare ZRUNHUV+RZHYHUDVGRFXPHQWHGE\WKHDXWKRUV more studies must be conducted in order to validate all these data.
Dr. João P. Martins de Carvalho Section of Urology Fluminense Federal University (UFF) Niteroi, Rio de Janeiro, Brazil E-mail: carvalho.jpm@gmail.com
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of iatrogenic rupture of the urethra with a retrovesical
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Accepted after revision: October 13, 2008
Correspondence address:
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