The Laryngoscope C 2015 The American Laryngological, V
Rhinological and Otological Society, Inc.
Impact of Lean on Surgical Instrument Reduction: Less Is More Todd J. Wannemuehler, MD; Alhasan N. Elghouche, MD; Mimi S. Kokoska, MD, MHCM, FACS, CPE; Christopher R. Deig, BA; Bruce H. Matt, MD, MS, FAAP, FACS Objectives/Hypothesis: To determine whether instrument sets that are frequently used by multiple surgeons can be substantially reduced in size with consensus. Study Design: Prospective quality improvement study using Lean Six Sigma for purposeful and consensual reduction of non–value-added instruments in adenotonsillectomy instrument sets. Methods: Value stream mapping was utilized to determine instrumentation usage and reprocessing workflow. Preintervention instrument utilization surveys allowed consensual and intelligent set reduction. Non–value-added instruments were targeted for waste elimination by placement in a supplemental set. Times for pre- and postintervention instrument assembly, Mayo setup, and surgery were collected for adenotonsillectomies. Postintervention satisfaction surveys of surgeons and staff were conducted. Results: Adenotonsillectomy sets were reduced from 52 to 24 instruments. Median assembly times were significantly reduced from 8.4 to 4.7 minutes (P 90% regarding the intervention. Set build cost was reduced by $1,468.99 per set. Conclusions: Lean Six Sigma improves efficiency and reduces waste by empowering team members to improve their environment. Instrument set reduction is ideal for waste elimination because of tool accumulation over time and instrument obsolescence as newer technologies are adopted. Similar interventions could easily be applied to larger sinus, mastoidectomy, and spine sets. Key Words: Lean, Six Sigma, instrument, quality, assembly, adenotonsillectomy. Level of Evidence: NA Laryngoscope, 125:2810–2815, 2015
INTRODUCTION Lean Six Sigma “Lean” is a process improvement methodology developed in the automotive industry to eliminate wasted time, effort, and resources to reduce costs, improve quality, and add value.1–3 Whereas Lean focuses
From the Department of Otolaryngology–Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, Indiana, U.S.A. (T.J.W., A.N.E., M.S.K., C.R.D., B.H.M.); and Aurora Health Care Medical Group, Milwaukee, Wisconsin, U.S.A. (M.S.K.). Editor’s Note: This Manuscript was accepted for publication May 8, 2015. Presented at the Triological Society Combined Otolaryngology Spring Meeting, Boston, Massachusetts, U.S.A., April 25, 2015. Todd J. Wannemuehler contributed to study design, data collection, data analysis and interpretation, article drafting, and article revision; Alhasan N. Elghouche to data collection, data analysis, article drafting, and article revision; Mimi S. Kokoska to study design, data collection, article drafting, and article revision; Christopher R. Deig to data analysis and interpretation, article drafting, and article revision; and Bruce H. Matt to study design, data collection, article drafting, and article revision. Submitted and exempted by the Indiana University Institutional Review Board. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Bruce H. Matt, MD, Department of Otolaryngology–Head and Neck Surgery, Indiana University School of Medicine, 1120 W. Michigan Street, Gatch Hall Suite 200, Indianapolis, IN 46202. E-mail: [email protected] DOI: 10.1002/lary.25407
Laryngoscope 125: December 2015
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on adding value, Six Sigma ensures that Lean changes are implemented effectively and without adverse effect.4 The process leading to a given outcome is a value stream.5 Lean Six Sigma (LSS) utilizes “value stream mapping,” which arranges all steps involved within a “current state” process; this facilitates recognition and subsequent elimination of wasteful steps to effect valuable change.6 The new value stream resulting after elimination of wasteful elements is the “future state” and facilitates observation of the value added within the redesigned process.4
Using LSS in Otolaryngology–Head and Neck Surgery Lin et al. employed LSS principles in clinic to reduce time from patient arrival to evaluation by care providers, increase timely patient visits, and reduce excess patient motion.7 Matt et al. demonstrated that office-based biopsies of head and neck masses decreased time to diagnosis, patient travel, and unnecessary laboratory and imaging studies. This enhanced patient convenience and staff satisfaction while reducing costs and risks associated with diagnosis.8 Collar et al. instituted automated paging and enhanced paperwork availability to streamline perioperative processes, effectively reducing unutilized operating room (OR) time.9 Cima et al. enhanced scheduling systems and improved prerequisite evaluation to reduce OR turnover time and redundant
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
Fig. 1. Value stream map: current state adenotonsillectomy instrument set usage. OR 5 operating room. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
information gathering.10 Fairbanks enhanced perioperative efficiency by eliminating physical barriers between the admission area, ORs, and Post Anesthetic Care Unit (PACU).11 Sterile processing personnel at one institution eliminated departmental wasted space, which increased productivity by 16%.12
Purpose of This Study These examples demonstrate the range of applications of LSS across all steps in otolaryngology patient management. Studies tend to apply numerous changes to elicit reductions in case time or turnaround time. One opportunity yet to be explored is implementation of an easily enacted, focused, and precise change to reduce waste and add value; such a change is especially valuable if it is sustainable and may be extrapolated to other settings. High-volume surgical procedures provide opportunities for streamlining with LSS principles. Adenotonsillectomy is among the most frequently performed surgical procedures by the otolaryngologist–head and neck surgeon, with especially high volumes routinely performed at tertiary care centers. Our adenotonsillectomy instrument sets contain >50 instruments, each requiring precleaning by sterile processing personnel before machine washing, accounting during set assembly, and subsequent set sterilization. Less than 10 instruments typically make their way to the Mayo stand. Comparatively, our outpatient surgical center sets contain only 35 instruments; this variance between inpatient and outpatient sets should elicit suspicion for systemic waste. Many superfluous Laryngoscope 125: December 2015
instruments are remnants of the preferences of nowretired surgeons. Intuitive instrument set changes are commonly implemented in surgical settings without organized data collection and analysis. This study aims to accurately investigate the effects of intelligent instrument reduction on Mayo stand setup time, operative time, instrument assembly time, and processing costs while evaluating surgeon and scrub personnel satisfaction with instrument reduction.
MATERIALS AND METHODS At our institution, >700 adenotonsillectomies were performed in 2012, with 850 instrument sets processed in the same timeframe. The current state for preparation, utilization, and subsequent processing of adenotonsillectomy instruments was analyzed and arranged in a value stream map (Fig. 1). Five of the seven wastes recognized by Lean were targeted for elimination: waiting (time wasted between process steps), transport (transport of unnecessary components), inventory (superfluous unused components), motion (unnecessary activity by workers processing components), and overprocessing (unnecessarily processing components).1
Staff Utilization Surveys and Set Alterations To proceed with an intelligent and consensual adenotonsillectomy set reduction, an initial visual utilization survey was distributed to the five staff surgeons routinely performing adenotonsillectomies. Subjective ranking for approximate frequencies of specific instrument utilization during adenotonsillectomies was provided. By this method, the instrument set was reduced from the current state of 52 instruments to the future state of 24 value-added instruments, with the other 28 non– value-added instruments transferred into a supplemental set
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
2811
Fig. 2. Instrument tray: current versus future state. The current state adenotonsillectomy instrument set (large gray box) includes all 52 instruments, subdivided into the future state instrument set (yellow, 24 instruments) and supplemental set (red, 28 instruments). [Color figure can be viewed in the online issue, which is available at www. laryngoscope.com.] (Fig. 2). In the future state, both the reduced adenotonsillectomy set and the supplemental set are brought to the OR, but only the former is opened.
Assembly Time The sterile processing facility utilizes an electronic tracking system for instrument sets that automatically aggregates and stores decontamination/prewashing times, assembly times, and sterilization times. Of the individual processes within instrument sterilization, the assembly time is most dependent on instrument set size, and it was thus selected as the dependent variable to analyze. Data mined from the electronic tracking system included dates of assembly and assembly length. Data were collected in two periods. As retrospective data were easily mined, the current state (preintervention) period extended from August 1, 2013 through March 8, 2014. The future state (postintervention) period extended from March 9, 2014 through May 12, 2014.
periods were established, each lasting approximately 2 months. An initial purely observational period lasting from November 2013 through December 2013 habituated observed personnel to being timed. The preintervention period then extended from January 9, 2014 through March 8, 2014. The postintervention period extended from March 9, 2014 through May 20, 2014. Preliminary analysis of the trend of decreasing Mayo setup times suggested that the Hawthorne effect and/or improved precision of timing methods diminished during the preintervention data collection period.
Satisfaction Surveys At the conclusion of the study, anonymous electronic surveys were distributed to staff surgeons and to the scrub personnel to determine their responses to various questions, including overall satisfaction with the instrument reduction.
Fiscal and Statistical Analysis Mayo Setup Time and OR Case Time For Mayo setup times and case times, data were collected using standardized preintervention and postintervention data sheets located in the ORs; the case date, staff surgeon, and relevant times were documented by the OR circulator. For Mayo setup times, the start time was defined as time of sterile towel placement on the Mayo stand, whereas stop time was defined as time of last instrument placement on the Mayo stand. The case start time was defined as time of placement of the drape and towel head-wrap, whereas the stop time was defined as time of drape and towel head-wrap removal at case completion. Only adenotonsillectomies (not isolated tonsillectomy or adenoidectomy) were documented. Because of the concern for the Hawthorne effect (personnel adjusting their behavior because they are aware that they are being observed), a total of three separate data collection
Laryngoscope 125: December 2015
2812
Previous studies have emphasized estimations arising from OR time saved as a basis for determining annual opportunity revenue9–11; this study instead seeks to determine the opportunity savings primarily in sterile processing assembly time without incurring prolonged operative times. Sterile supply labor cost per minute was calculated to be $0.27. SPSS 22 (IBM, Armonk, NY) was utilized for all statistical analysis. Due to the presence of nonparametric data sets with a strong positive skew, a natural log transformation was performed for case times and Mayo stand setup times. For case times, the observational and preinterventional groups were pooled due to having no significant difference using an independent-samples twotailed t-test (P >.05) and having similar deviations and distribution. Independent-samples two-tailed t-tests were performed to compare the current state and future state case times. One-way analysis of variance was used to compare Mayo stand times, and a Tamhane post hoc analysis was utilized due to a lack of
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
Fig. 3. Median assembly times of current state and future state are significantly different: ****P
Rhinological and Otological Society, Inc.
Impact of Lean on Surgical Instrument Reduction: Less Is More Todd J. Wannemuehler, MD; Alhasan N. Elghouche, MD; Mimi S. Kokoska, MD, MHCM, FACS, CPE; Christopher R. Deig, BA; Bruce H. Matt, MD, MS, FAAP, FACS Objectives/Hypothesis: To determine whether instrument sets that are frequently used by multiple surgeons can be substantially reduced in size with consensus. Study Design: Prospective quality improvement study using Lean Six Sigma for purposeful and consensual reduction of non–value-added instruments in adenotonsillectomy instrument sets. Methods: Value stream mapping was utilized to determine instrumentation usage and reprocessing workflow. Preintervention instrument utilization surveys allowed consensual and intelligent set reduction. Non–value-added instruments were targeted for waste elimination by placement in a supplemental set. Times for pre- and postintervention instrument assembly, Mayo setup, and surgery were collected for adenotonsillectomies. Postintervention satisfaction surveys of surgeons and staff were conducted. Results: Adenotonsillectomy sets were reduced from 52 to 24 instruments. Median assembly times were significantly reduced from 8.4 to 4.7 minutes (P 90% regarding the intervention. Set build cost was reduced by $1,468.99 per set. Conclusions: Lean Six Sigma improves efficiency and reduces waste by empowering team members to improve their environment. Instrument set reduction is ideal for waste elimination because of tool accumulation over time and instrument obsolescence as newer technologies are adopted. Similar interventions could easily be applied to larger sinus, mastoidectomy, and spine sets. Key Words: Lean, Six Sigma, instrument, quality, assembly, adenotonsillectomy. Level of Evidence: NA Laryngoscope, 125:2810–2815, 2015
INTRODUCTION Lean Six Sigma “Lean” is a process improvement methodology developed in the automotive industry to eliminate wasted time, effort, and resources to reduce costs, improve quality, and add value.1–3 Whereas Lean focuses
From the Department of Otolaryngology–Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, Indiana, U.S.A. (T.J.W., A.N.E., M.S.K., C.R.D., B.H.M.); and Aurora Health Care Medical Group, Milwaukee, Wisconsin, U.S.A. (M.S.K.). Editor’s Note: This Manuscript was accepted for publication May 8, 2015. Presented at the Triological Society Combined Otolaryngology Spring Meeting, Boston, Massachusetts, U.S.A., April 25, 2015. Todd J. Wannemuehler contributed to study design, data collection, data analysis and interpretation, article drafting, and article revision; Alhasan N. Elghouche to data collection, data analysis, article drafting, and article revision; Mimi S. Kokoska to study design, data collection, article drafting, and article revision; Christopher R. Deig to data analysis and interpretation, article drafting, and article revision; and Bruce H. Matt to study design, data collection, article drafting, and article revision. Submitted and exempted by the Indiana University Institutional Review Board. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Bruce H. Matt, MD, Department of Otolaryngology–Head and Neck Surgery, Indiana University School of Medicine, 1120 W. Michigan Street, Gatch Hall Suite 200, Indianapolis, IN 46202. E-mail: [email protected] DOI: 10.1002/lary.25407
Laryngoscope 125: December 2015
2810
on adding value, Six Sigma ensures that Lean changes are implemented effectively and without adverse effect.4 The process leading to a given outcome is a value stream.5 Lean Six Sigma (LSS) utilizes “value stream mapping,” which arranges all steps involved within a “current state” process; this facilitates recognition and subsequent elimination of wasteful steps to effect valuable change.6 The new value stream resulting after elimination of wasteful elements is the “future state” and facilitates observation of the value added within the redesigned process.4
Using LSS in Otolaryngology–Head and Neck Surgery Lin et al. employed LSS principles in clinic to reduce time from patient arrival to evaluation by care providers, increase timely patient visits, and reduce excess patient motion.7 Matt et al. demonstrated that office-based biopsies of head and neck masses decreased time to diagnosis, patient travel, and unnecessary laboratory and imaging studies. This enhanced patient convenience and staff satisfaction while reducing costs and risks associated with diagnosis.8 Collar et al. instituted automated paging and enhanced paperwork availability to streamline perioperative processes, effectively reducing unutilized operating room (OR) time.9 Cima et al. enhanced scheduling systems and improved prerequisite evaluation to reduce OR turnover time and redundant
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
Fig. 1. Value stream map: current state adenotonsillectomy instrument set usage. OR 5 operating room. [Color figure can be viewed in the online issue, which is available at www.laryngoscope.com.]
information gathering.10 Fairbanks enhanced perioperative efficiency by eliminating physical barriers between the admission area, ORs, and Post Anesthetic Care Unit (PACU).11 Sterile processing personnel at one institution eliminated departmental wasted space, which increased productivity by 16%.12
Purpose of This Study These examples demonstrate the range of applications of LSS across all steps in otolaryngology patient management. Studies tend to apply numerous changes to elicit reductions in case time or turnaround time. One opportunity yet to be explored is implementation of an easily enacted, focused, and precise change to reduce waste and add value; such a change is especially valuable if it is sustainable and may be extrapolated to other settings. High-volume surgical procedures provide opportunities for streamlining with LSS principles. Adenotonsillectomy is among the most frequently performed surgical procedures by the otolaryngologist–head and neck surgeon, with especially high volumes routinely performed at tertiary care centers. Our adenotonsillectomy instrument sets contain >50 instruments, each requiring precleaning by sterile processing personnel before machine washing, accounting during set assembly, and subsequent set sterilization. Less than 10 instruments typically make their way to the Mayo stand. Comparatively, our outpatient surgical center sets contain only 35 instruments; this variance between inpatient and outpatient sets should elicit suspicion for systemic waste. Many superfluous Laryngoscope 125: December 2015
instruments are remnants of the preferences of nowretired surgeons. Intuitive instrument set changes are commonly implemented in surgical settings without organized data collection and analysis. This study aims to accurately investigate the effects of intelligent instrument reduction on Mayo stand setup time, operative time, instrument assembly time, and processing costs while evaluating surgeon and scrub personnel satisfaction with instrument reduction.
MATERIALS AND METHODS At our institution, >700 adenotonsillectomies were performed in 2012, with 850 instrument sets processed in the same timeframe. The current state for preparation, utilization, and subsequent processing of adenotonsillectomy instruments was analyzed and arranged in a value stream map (Fig. 1). Five of the seven wastes recognized by Lean were targeted for elimination: waiting (time wasted between process steps), transport (transport of unnecessary components), inventory (superfluous unused components), motion (unnecessary activity by workers processing components), and overprocessing (unnecessarily processing components).1
Staff Utilization Surveys and Set Alterations To proceed with an intelligent and consensual adenotonsillectomy set reduction, an initial visual utilization survey was distributed to the five staff surgeons routinely performing adenotonsillectomies. Subjective ranking for approximate frequencies of specific instrument utilization during adenotonsillectomies was provided. By this method, the instrument set was reduced from the current state of 52 instruments to the future state of 24 value-added instruments, with the other 28 non– value-added instruments transferred into a supplemental set
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
2811
Fig. 2. Instrument tray: current versus future state. The current state adenotonsillectomy instrument set (large gray box) includes all 52 instruments, subdivided into the future state instrument set (yellow, 24 instruments) and supplemental set (red, 28 instruments). [Color figure can be viewed in the online issue, which is available at www. laryngoscope.com.] (Fig. 2). In the future state, both the reduced adenotonsillectomy set and the supplemental set are brought to the OR, but only the former is opened.
Assembly Time The sterile processing facility utilizes an electronic tracking system for instrument sets that automatically aggregates and stores decontamination/prewashing times, assembly times, and sterilization times. Of the individual processes within instrument sterilization, the assembly time is most dependent on instrument set size, and it was thus selected as the dependent variable to analyze. Data mined from the electronic tracking system included dates of assembly and assembly length. Data were collected in two periods. As retrospective data were easily mined, the current state (preintervention) period extended from August 1, 2013 through March 8, 2014. The future state (postintervention) period extended from March 9, 2014 through May 12, 2014.
periods were established, each lasting approximately 2 months. An initial purely observational period lasting from November 2013 through December 2013 habituated observed personnel to being timed. The preintervention period then extended from January 9, 2014 through March 8, 2014. The postintervention period extended from March 9, 2014 through May 20, 2014. Preliminary analysis of the trend of decreasing Mayo setup times suggested that the Hawthorne effect and/or improved precision of timing methods diminished during the preintervention data collection period.
Satisfaction Surveys At the conclusion of the study, anonymous electronic surveys were distributed to staff surgeons and to the scrub personnel to determine their responses to various questions, including overall satisfaction with the instrument reduction.
Fiscal and Statistical Analysis Mayo Setup Time and OR Case Time For Mayo setup times and case times, data were collected using standardized preintervention and postintervention data sheets located in the ORs; the case date, staff surgeon, and relevant times were documented by the OR circulator. For Mayo setup times, the start time was defined as time of sterile towel placement on the Mayo stand, whereas stop time was defined as time of last instrument placement on the Mayo stand. The case start time was defined as time of placement of the drape and towel head-wrap, whereas the stop time was defined as time of drape and towel head-wrap removal at case completion. Only adenotonsillectomies (not isolated tonsillectomy or adenoidectomy) were documented. Because of the concern for the Hawthorne effect (personnel adjusting their behavior because they are aware that they are being observed), a total of three separate data collection
Laryngoscope 125: December 2015
2812
Previous studies have emphasized estimations arising from OR time saved as a basis for determining annual opportunity revenue9–11; this study instead seeks to determine the opportunity savings primarily in sterile processing assembly time without incurring prolonged operative times. Sterile supply labor cost per minute was calculated to be $0.27. SPSS 22 (IBM, Armonk, NY) was utilized for all statistical analysis. Due to the presence of nonparametric data sets with a strong positive skew, a natural log transformation was performed for case times and Mayo stand setup times. For case times, the observational and preinterventional groups were pooled due to having no significant difference using an independent-samples twotailed t-test (P >.05) and having similar deviations and distribution. Independent-samples two-tailed t-tests were performed to compare the current state and future state case times. One-way analysis of variance was used to compare Mayo stand times, and a Tamhane post hoc analysis was utilized due to a lack of
Wannemuehler et al.: Lean Impact on Surgical Instrument Reduction
Fig. 3. Median assembly times of current state and future state are significantly different: ****P
