Advertisement
Cardiothoracic surgical education and training| Volume 146, ISSUE 5, P1028-1032, November 2013

Process improvement in cardiac surgery: Development and implementation of a reoperation for bleeding checklist

      Objective

      High-performing health care organizations differentiate themselves by focusing on continuous process improvement initiatives aimed at enhancing patient outcomes. Reoperation for bleeding is an event associated with considerable morbidity risk. Hence, our primary objective was to develop and implement a formal operative checklist to reduce technical reasons for postoperative bleeding.

      Methods

      From January 1, 2011, through June 30, 2012, 5812 cardiac surgical procedures were performed at Cleveland Clinic (Cleveland, OH). A multidisciplinary team developed a simple, easy-to-perform hemostasis checklist based on the most common sites of bleeding. An extensive educational in-service was performed before limited, then universal, checklist implementation. Geometric charts were used to track the number of cases between consecutive reoperations for bleeding. We compared these before (phase 0) and after the first limited implementation phase (phase 1) and the universal implementation phase (phase 2) of the checklist.

      Results

      The average number of cases between consecutive reoperations for bleeding increased from 32 in phase 0 to 53 in both phase 1 (P = .002) and phase 2 (P = .01).

      Conclusions

      A substantial reduction in reoperation for bleeding cases followed implementation of a formalized hemostasis checklist. Our findings underscore the important influence of memory aids that focus attention on surgical techniques to improve patient outcomes in a complex, operative work environment.

      CTSNet classification

      Abbreviations and Acronyms:

      CABG (coronary artery bypass grafting), WHO (World Health Organization)
      A continuous drive for improved quality of care through process improvement is a feature of high-performing health care systems. Institution of patient safety initiatives that strive to further reduce complications associated with complex operative procedures is the ideal. Patient safety checklists attempt to standardize critical and often complex processes to avoid error and improve outcomes. Although common in other industries, and a prominent feature of the early days of cardiac surgery, checklists have only recently been adopted as part of work flow processes in the health care environment.
      • Hales B.M.
      • Pronovost P.J.
      The checklist–a tool for error management and performance improvement.
      Benefits of checklist implementation in the health care setting include reduced patient morbidity, fewer errors, and improved team dynamics.
      • Wolff A.M.
      • Taylor S.A.
      • McCabe J.F.
      Using checklists and reminders in clinical pathways to improve hospital inpatient care.
      • Calland J.F.
      • Turrentine F.E.
      • Guerlain S.
      • Bovbjerg V.
      • Poole G.R.
      • Lebeau K.
      • et al.
      The surgical safety checklist: lessons learned during implementation.
      • Haynes A.B.
      • Weiser T.G.
      • Berry W.R.
      • Lipsitz S.R.
      • Breizat A.H.
      • Dellinger E.P.
      • et al.
      A surgical safety checklist to reduce morbidity and mortality in a global population.
      • Semel M.E.
      • Resch S.
      • Haynes A.B.
      • Funk L.M.
      • Bader A.
      • Berry W.R.
      • et al.
      Adopting a surgical safety checklist could save money and improve the quality of care in U.S. hospitals.
      • de Vries E.N.
      • Prins H.A.
      • Crolla R.M.
      • den Outer A.J.
      • van Andel G.
      • van Helden S.H.
      • et al.
      Effect of a comprehensive surgical safety system on patient outcomes.
      • Lingard L.
      • Regehr G.
      • Orser B.
      • Reznick R.
      • Baker G.R.
      • Doran D.
      • et al.
      Evaluation of a preoperative checklist and team briefing among surgeons, nurses, and anesthesiologists to reduce failures in communication.
      • van Klei W.A.
      • Hoff R.G.
      • van Aarnhem E.E.
      • Simmermacher R.K.
      • Regli L.P.
      • Kappen T.H.
      • et al.
      Effects of the introduction of the WHO “Surgical Safety Checklist” on in-hospital mortality: a cohort study.
      Approximately 2% to 8% of patients return to the operating room for bleeding after admission to the intensive care unit after cardiac surgical interventions.
      • Mehta R.H.
      • Sheng S.
      • O'Brien S.M.
      • Grover F.L.
      • Gammie J.S.
      • Ferguson T.B.
      • et al.
      Reoperation for bleeding in patients undergoing coronary artery bypass surgery: incidence, risk factors, time trends, and outcomes.
      • Hall T.S.
      • Brevetti G.R.
      • Skoultchi A.J.
      • Sines J.C.
      • Gregory P.
      • Spotnitz A.J.
      Re-exploration for hemorrhage following open heart surgery differentiation on the causes of bleeding and the impact on patient outcomes.
      • Karthik S.
      • Grayson A.D.
      • McCarron E.E.
      • Pullan D.M.
      • Desmond M.J.
      Reexploration for bleeding after coronary artery bypass surgery: risk factors, outcomes, and the effect of time delay.
      • Dacey L.J.
      • Munoz J.J.
      • Baribeau Y.R.
      • Johnson E.R.
      • Lahey S.J.
      • Leavitt B.J.
      • et al.
      Northern New England Cardiovascular Disease Study Group. Reexploration for hemorrhage following coronary artery bypass grafting: incidence and risk factors.
      • Choong C.K.
      • Gerrard C.
      • Goldsmith K.A.
      • Dunningham H.
      • Vuylsteke A.
      Delayed re-exploration for bleeding after coronary artery bypass surgery results in adverse outcomes.
      Our investigation of these reoperations revealed that they were associated with increased morbidity, mortality, and resource use.
      • Vivacqua A.
      • Koch C.G.
      • Yousuf A.M.
      • Nowicki E.R.
      • Houghtaling P.L.
      • Blackstone E.H.
      • et al.
      Morbidity of bleeding after cardiac surgery: is it blood transfusion, reoperation for bleeding, or both?.
      Bleeding resulting from technical factors was the root cause of most (>70%) of these reoperations; the remainder were related to coagulopathy.
      We subsequently initiated a major focus on process improvement to reduce the need for reoperation due to technical factors. We hypothesized that increased attention to intraoperative hemostasis would reduce postoperative bleeding. Hence, our primary objective was to develop and implement a formal operative checklist to reduce technical reasons for postoperative bleeding.

      Methods

      Checklist Development

      Our prior work revealed that the most common sites for bleeding identified at reoperation were the mediastinum, sternum, internal thoracic artery bed, and coronary anastomosis sites.
      • Vivacqua A.
      • Koch C.G.
      • Yousuf A.M.
      • Nowicki E.R.
      • Houghtaling P.L.
      • Blackstone E.H.
      • et al.
      Morbidity of bleeding after cardiac surgery: is it blood transfusion, reoperation for bleeding, or both?.
      Multidisciplinary team meetings were held for checklist development with senior cardiac surgical staff, a cardiac surgery resident (G.L.) and fellow (A.V.), and anesthesiologists. The objective was to develop a simple, easy- to-perform checklist that could be integrated into the operative work flow (Figures 1 and 2). Simplicity, we believed, was key for trainees to transform the checklist into unconscious habits. Specifically, the checklist was devised to be used just before anticipated chest closure, which universally is performed by surgical trainees. Individual patient consent was waived by the Cleveland Clinic (Cleveland, Ohio) Institutional Review Board.
      Figure thumbnail gr1
      Figure 1Reoperation for bleeding checklist.
      Figure thumbnail gr2
      Figure 2Process flow diagram for development and implementation of the reoperation for bleeding checklist. CT, Cardiothoracic; OR, operating room.

      Checklist Implementation

      Phase 0: Prechecklist

      From January 1, 2011, through June 30, 2011, 2080 cardiac surgical procedures were performed at Cleveland Clinic. Before initiating the reoperation for bleeding checklist, a cardiac surgery resident (G.L.) and fellow (A.V.) were recruited as “champions” to provide other residents and fellows with formal educational sessions on morbidity related to reoperation for bleeding, desire to reduce its prevalence, and specifics of the checklist. Surgical nurse clinicians and operating room nurses were also in-serviced.

      Phase 1: Limited implementation

      From July 1, 2011, through October 31, 2011, 1296 cardiac surgical procedures were performed. The checklist was implemented in a single surgeon's operating room. More important, however, all cardiac surgical residents and fellows received the educational in-service before initiation of phase 1 because of surgical rotations and night call, which may have placed them in the phase 1 staff surgeon's rooms. After initiation of phase 1, feedback was obtained from the cardiac surgical team on ease of checklist use and suggestions for further improvement.

      Phase 2: Universal implementation

      After 4 months with the single surgeon in phase 1, the checklist was universally implemented in all cardiac surgical operating rooms. From November 1, 2011, through June 30, 2012, 2436 cardiac surgical procedures were performed, all using the checklist.
      The patient population over these time frames was consistent: phase 1, n = 2080, with 17% coronary artery bypass grafting (CABG), 52% isolated valve, 17.1% CABG/valve combination, and 15% other cases; and phases 2 and 3, n = 3732, with 15% CABG, 54% isolated valve, 17.3% CABG/valve combination, and 14% other cases.

      Measurement and Analysis

      We defined reoperation for bleeding as a return to the cardiac operating rooms for bleeding or tamponade after admission to the intensive care unit following the primary surgical procedure. The decision to reoperate was based on total chest tube drainage and its rate, hemodynamic status, and staff surgeon decision.
      Prevalence of reoperation for bleeding was measured and presented on a geometric chart. Geometric charts are commonly used to track rare events and measure the number of cases between their consecutive occurrences; in our case, this was the number of cases between occurrences of reoperation for bleeding.
      • Benneyan J.C.
      Number-between g-type statistical quality control charts for monitoring adverse events.
      • Benneyan J.C.
      Performance of number-between g-type statistical control charts for monitoring adverse events.
      • Kaminsky F.C.
      • Benneyan J.C.
      • Davis R.D.
      • Burke R.J.
      Statistical control charts based on a geometric distribution.
      Larger numbers on the geometric chart demonstrate better performance and fewer occurrences of these rare events. In this study, we counted the number of cases between consecutive cases of reoperation for bleeding and compared the averages before (phase 0) and after checklist implementation using a 2-sample, 2-sided t-test and the Wilcoxon rank-sum test. The primary analysis compared phase 0 with the entire postimplementation period (phases 1 and 2). A secondary analysis compared phase 0 with phase 2 (after universal implementation).

      Results

      The geometric chart measuring the number of cases between consecutive reoperations for bleeding is shown in Figure 3, with larger numbers indicating process improvement (ie, fewer reoperations for bleeding).
      Figure thumbnail gr3
      Figure 3Geometric chart displaying the number of cases between reoperations for bleeding.
      After introduction of the checklist, the average number of cases between consecutive reoperations for bleeding increased from 32 in phase 0 to 53 in both phase 1 (P = .002) and phase 2 (P = .01). Continuous improvement was observed after universal implementation (phase 0 vs phase 2), with the average number of cases between consecutive reoperations for bleeding at 53 (Table 1). The effect was evident, however, immediately after limited implementation of the checklist (phase 1), likely because of the effect of having educated all surgical residents, fellows, and support staff about the checklist, even though they were not all rotating on the phase 1 surgeon's service.
      Table 1Number of cases between consecutive reoperations for bleeding before and after checklist initiation
      VariablePrechecklistPostchecklistP value
      Compared with prechecklist geometric statistic.
      After universal implementation onlyP value
      Compared with prechecklist geometric statistic.
      Dates1/1/2011-6/30/20117/1/2011-6/30/201211/1/2011-6/30/2012
      Total No.208037322436
      Geometric statistic
       Mean32 ± 3553 ± 43P1 = .002
      P1 is the P value with untransformed data, and P2 is the P value after the data were log transformed to reduce skewness.
      53 ± 47P1 = .011
      P1 is the P value with untransformed data, and P2 is the P value after the data were log transformed to reduce skewness.
      P2 = .004P2 = .033
       Median (quartile 25, quartile 75)18 (11, 39)43 (21, 77)P < .00143 (16, 82)P = .009
      Compared with prechecklist geometric statistic.
      P1 is the P value with untransformed data, and P2 is the P value after the data were log transformed to reduce skewness.
      There were 2080 cases before July 1, 2011 (before educational in-services and checklist implementation), with 65 reoperations for bleeding (3.1%). After that date, there were 3732 cases, with 70 reoperations for bleeding (1.9%) (P = .003).

      Discussion

      We report a substantial reduction in reoperation for bleeding events after introduction of a hemostasis checklist. Reason
      • Reason J.
      Human Error.
      describes checklists as “cognitive prostheses.” Cognitive errors in clinical decision making are reported to be at the root of many mistakes.
      • Croskerry P.
      Cognitive forcing strategies in clinical decisionmaking.
      Stress, cognitive fatigue, and complex cases may influence proper decision making.
      • Hales B.M.
      • Pronovost P.J.
      The checklist–a tool for error management and performance improvement.
      • Sexton J.B.
      • Thomas E.J.
      • Helmreich R.L.
      Error, stress, and teamwork in medicine and aviation: cross sectional surveys.
      • Hockey G.R.
      • Sauer J.
      Cognitive fatigue and complex decision making under prolonged isolation and confinement.
      The operative environment, in particular with trainees, is a milieu where high stress, fatigue, and need for quick decision making intersect, an ideal situation for checklists.
      Unexpectedly, and perhaps because of both simplicity of the checklist and extent of education leading up to its implementation, reoperations for bleeding declined even during the time of checklist implementation for only 1 surgeon's cases (phase 1). Evidence suggests that both universal awareness via educational initiatives and increased emphasis on technical factors via the checklist led to fewer reoperations for bleeding. This is the desired effect for process improvement initiatives.
      Checklists are meant to standardize often complex processes and serve as cognitive aids for error reduction.
      • Hales B.M.
      • Pronovost P.J.
      The checklist–a tool for error management and performance improvement.
      They consist of systematically rank-ordered criteria whose overarching goal is standardization and improved outcomes. Although checklists are increasingly used in health care, they have not been as widely adopted as in other industries, for cited reasons of limiting physician autonomy and difficulty in standardizing processes that are inherently variable.
      • Hales B.M.
      • Pronovost P.J.
      The checklist–a tool for error management and performance improvement.
      Use of checklists in the surgical setting has been associated with reduced postoperative complications and mortality. Weiser and colleagues
      • Weiser T.G.
      • Haynes A.B.
      • Dziekan G.
      • Berry W.R.
      • Lipsitz S.R.
      • Gawande A.A.
      Effect of a 19-item surgical safety checklist during urgent operations in a global patient population.
      prospectively examined postoperative complications and hospital mortality before and after implementation of the 19-item World Health Organization (WHO) Surgical Safety Checklist in urgent operative cases. Significant reductions in both complications and mortality were reported after checklist implementation, with complications reduced from 18.4% to 11.7% and mortality reduced from 3.7% to 1.4%. In a general surgical setting of hospitals with high standards of care, de Vries and colleagues
      • de Vries E.N.
      • Prins H.A.
      • Crolla R.M.
      • den Outer A.J.
      • van Andel G.
      • van Helden S.H.
      • et al.
      Effect of a comprehensive surgical safety system on patient outcomes.
      also reported reductions in surgical complications and mortality associated with use of a surgical checklist. Haynes and colleagues
      • Haynes A.B.
      • Weiser T.G.
      • Berry W.R.
      • Lipsitz S.R.
      • Breizat A.H.
      • Dellinger E.P.
      • et al.
      A surgical safety checklist to reduce morbidity and mortality in a global population.
      reported a significant reduction in complications and mortality with use of the WHO checklist in a global population. Others have published similar results.
      • Askarian M.
      • Kouchak F.
      • Palenik C.J.
      Effect of surgical safety checklists on postoperative morbidity and mortality rates, Shiraz, Faghihy Hospital, a 1-year study.
      Checklists have been reported to provide benefits beyond traditional morbidity and mortality outcomes, including cost savings, improved team dynamics, and creation of a culture of safety. Semel and colleagues
      • Semel M.E.
      • Resch S.
      • Haynes A.B.
      • Funk L.M.
      • Bader A.
      • Berry W.R.
      • et al.
      Adopting a surgical safety checklist could save money and improve the quality of care in U.S. hospitals.
      reported potential cost savings from reduced postoperative complications if the WHO checklist was instituted in the United States.
      Calland and colleagues
      • Calland J.F.
      • Turrentine F.E.
      • Guerlain S.
      • Bovbjerg V.
      • Poole G.R.
      • Lebeau K.
      • et al.
      The surgical safety checklist: lessons learned during implementation.
      examined the utility and adaptability of procedural checklists in the surgical setting to test whether they can increase the frequency of safety-critical behaviors. The authors noted that checklists may be beneficial for error reduction, improved teamwork, and situational awareness in what they termed safety-critical processes, such as the complex operative environment. Their results showed similar patient outcomes with and without use of the checklists; however, they reported that the checklist intervention group had higher team-positive behaviors.
      Buzink and colleagues
      • Buzink S.N.
      • van Lier L.
      • de Hingh I.H.
      • Jakimowicz J.J.
      Risk-sensitive events during laparoscopic cholecystectomy: the influence of the integrated operating room and a preoperative checklist tool.
      examined the effect of implementing a checklist on equipment- and instrument-related events in the setting of laparoscopic cholecystectomies. They noted that the combination of integrated operating room systems and checklists might favorably influence operating room efficiency and surgical outcomes. Their results showed that this combined setting had a stronger effect than an integrated operating room alone. Use of the checklists also raised safety awareness among operating room team members.
      Lingard and colleagues
      • Lingard L.
      • Regehr G.
      • Orser B.
      • Reznick R.
      • Baker G.R.
      • Doran D.
      • et al.
      Evaluation of a preoperative checklist and team briefing among surgeons, nurses, and anesthesiologists to reduce failures in communication.
      reported improvements in communication, with a decline in the number of communication failures per procedure after implementation of checklist-structured team meetings. Use of a 5-point Likert scale questionnaire before and after introduction of safety briefings resulted in positive staff attitudes toward these briefings.
      • Ali M.
      • Osborne A.
      • Bethune R.
      • Pullyblank A.
      Preoperative surgical briefings do not delay operating room start times and are popular with surgical team members.
      In a systematic review of safety checklists, Ko and colleagues
      • Ko H.C.
      • Turner T.J.
      • Finnigan M.A.
      Systematic review of safety checklists for use by medical care teams in acute hospital settings–limited evidence of effectiveness.
      suggested that they were associated with some improvements in patient safety; however, the results were not consistent. The authors suggested that variations in checklist design and individual settings created an inability to summarize trends across studies. Nevertheless, they noted a potential benefit in terms of improving protocol adherence.

      Clinical Implications

      Conley and colleagues
      • Conley D.M.
      • Singer S.J.
      • Edmondson L.
      • Berry W.R.
      • Gawande A.A.
      Effective surgical safety checklist implementation.
      reported that the success of surgical checklists was influenced by a hospital's ability to effectively implement them, along with educational efforts regarding their use and the rationale for their implementation. Education was necessary for getting “buy-in” from the surgical staff. Others who have reported on the benefits of checklists have also integrated key features for success, such as multidisciplinary teams and educational efforts.
      • Wolff A.M.
      • Taylor S.A.
      • McCabe J.F.
      Using checklists and reminders in clinical pathways to improve hospital inpatient care.
      Educational in-services and clear communication on the importance of the initiative to patient care allowed for successful implementation of our checklist. Teams were multidisciplinary, which allowed for buy-in from those involved. We were cognizant of prior perceptions that might surface, such as “checklist fatigue” in the operative setting. We communicated that the clinical time involved averaged less than 5 minutes. Several other investigators have highlighted key aspects of checklist development, along with suggestions for piloting the checklist before more widespread implementation.
      • Hales B.
      • Terblanche M.
      • Fowler R.
      • Sibbald W.
      Development of medical checklists for improved quality of patient care.
      • Verdaasdonk E.G.
      • Stassen L.P.
      • Widhiasmara P.P.
      • Dankelman J.
      Requirements for the design and implementation of checklists for surgical processes.
      The Accreditation Council for Graduate Medical Education has specific recommendations for practice-based learning competencies that involve trainee engagement in quality improvement methods aimed at implementing initiatives for practice improvement. Our thoracic and cardiovascular surgical resident (G.L.) and fellow (A.V.) spearheaded the educational in-service and implementation and feedback sessions throughout the course of the process improvement initiative. They were an integral part of project development and learned to develop and implement process improvement plans, understand use of process control and Pareto and geometric charts, engage multidisciplinary teams, and obtain and receive feedback for the duration of the improvement initiative.

      Study Limitations

      Reoperation for bleeding necessitating a return to the cardiac operating room for bleeding or tamponade was based on total chest tube drainage and its rate, hemodynamic status, and staff surgeon decision. We did not have information on the specific amount of chest tube drainage; however, the cardiac surgical attending surgeons and intensive care unit care teams were consistent throughout the process improvement initiative. Our institution does not have a rigorous or standardized algorithm to aid decision making on whether a patient should be returned to the operating room for bleeding. In addition, we do not capture the actual amount of chest tube drainage in our electronic medical record. Our goal was not to measure blood product use for the duration of the study period, but rather to focus on intraoperative practices that could reduce the need for reoperation for bleeding.

      Conclusions

      We observed a significant reduction in reoperation for bleeding after implementing a formalized surgical checklist. Our findings underscore the important influence of memory aids that focus attention on surgical techniques to improve patient outcomes in our complex work environment.

      References

        • Hales B.M.
        • Pronovost P.J.
        The checklist–a tool for error management and performance improvement.
        J Crit Care. 2006; 21: 231-235
        • Wolff A.M.
        • Taylor S.A.
        • McCabe J.F.
        Using checklists and reminders in clinical pathways to improve hospital inpatient care.
        Med J Aust. 2004; 181: 428-431
        • Calland J.F.
        • Turrentine F.E.
        • Guerlain S.
        • Bovbjerg V.
        • Poole G.R.
        • Lebeau K.
        • et al.
        The surgical safety checklist: lessons learned during implementation.
        Am Surg. 2011; 77: 1131-1137
        • Haynes A.B.
        • Weiser T.G.
        • Berry W.R.
        • Lipsitz S.R.
        • Breizat A.H.
        • Dellinger E.P.
        • et al.
        A surgical safety checklist to reduce morbidity and mortality in a global population.
        N Engl J Med. 2009; 360: 491-499
        • Semel M.E.
        • Resch S.
        • Haynes A.B.
        • Funk L.M.
        • Bader A.
        • Berry W.R.
        • et al.
        Adopting a surgical safety checklist could save money and improve the quality of care in U.S. hospitals.
        Health Aff (Millwood). 2010; 29: 1593-1599
        • de Vries E.N.
        • Prins H.A.
        • Crolla R.M.
        • den Outer A.J.
        • van Andel G.
        • van Helden S.H.
        • et al.
        Effect of a comprehensive surgical safety system on patient outcomes.
        N Engl J Med. 2010; 363: 1928-1937
        • Lingard L.
        • Regehr G.
        • Orser B.
        • Reznick R.
        • Baker G.R.
        • Doran D.
        • et al.
        Evaluation of a preoperative checklist and team briefing among surgeons, nurses, and anesthesiologists to reduce failures in communication.
        Arch Surg. 2008; 143 (discussion 18): 12-17
        • van Klei W.A.
        • Hoff R.G.
        • van Aarnhem E.E.
        • Simmermacher R.K.
        • Regli L.P.
        • Kappen T.H.
        • et al.
        Effects of the introduction of the WHO “Surgical Safety Checklist” on in-hospital mortality: a cohort study.
        Ann Surg. 2012; 255: 44-49
        • Mehta R.H.
        • Sheng S.
        • O'Brien S.M.
        • Grover F.L.
        • Gammie J.S.
        • Ferguson T.B.
        • et al.
        Reoperation for bleeding in patients undergoing coronary artery bypass surgery: incidence, risk factors, time trends, and outcomes.
        Circ Cardiovasc Qual Outcomes. 2009; 2: 583-590
        • Hall T.S.
        • Brevetti G.R.
        • Skoultchi A.J.
        • Sines J.C.
        • Gregory P.
        • Spotnitz A.J.
        Re-exploration for hemorrhage following open heart surgery differentiation on the causes of bleeding and the impact on patient outcomes.
        Ann Thorac Cardiovasc Surg. 2001; 7: 352-357
        • Karthik S.
        • Grayson A.D.
        • McCarron E.E.
        • Pullan D.M.
        • Desmond M.J.
        Reexploration for bleeding after coronary artery bypass surgery: risk factors, outcomes, and the effect of time delay.
        Ann Thorac Surg. 2004; 78 (discussion 34): 527-534
        • Dacey L.J.
        • Munoz J.J.
        • Baribeau Y.R.
        • Johnson E.R.
        • Lahey S.J.
        • Leavitt B.J.
        • et al.
        Northern New England Cardiovascular Disease Study Group. Reexploration for hemorrhage following coronary artery bypass grafting: incidence and risk factors.
        Arch Surg. 1998; 133: 442-447
        • Choong C.K.
        • Gerrard C.
        • Goldsmith K.A.
        • Dunningham H.
        • Vuylsteke A.
        Delayed re-exploration for bleeding after coronary artery bypass surgery results in adverse outcomes.
        Eur J Cardiothorac Surg. 2007; 31: 834-838
        • Vivacqua A.
        • Koch C.G.
        • Yousuf A.M.
        • Nowicki E.R.
        • Houghtaling P.L.
        • Blackstone E.H.
        • et al.
        Morbidity of bleeding after cardiac surgery: is it blood transfusion, reoperation for bleeding, or both?.
        Ann Thorac Surg. 2011; 91: 1780-1790
        • Benneyan J.C.
        Number-between g-type statistical quality control charts for monitoring adverse events.
        Health Care Manag Sci. 2001; 4: 305-318
        • Benneyan J.C.
        Performance of number-between g-type statistical control charts for monitoring adverse events.
        Health Care Manag Sci. 2001; 4: 319-336
        • Kaminsky F.C.
        • Benneyan J.C.
        • Davis R.D.
        • Burke R.J.
        Statistical control charts based on a geometric distribution.
        J Qual Technol. 1992; 24: 63-69
        • Reason J.
        Human Error.
        Cambridge University Press, Cambridge, UK1999
        • Croskerry P.
        Cognitive forcing strategies in clinical decisionmaking.
        Ann Emerg Med. 2003; 41: 110-120
        • Sexton J.B.
        • Thomas E.J.
        • Helmreich R.L.
        Error, stress, and teamwork in medicine and aviation: cross sectional surveys.
        BMJ. 2000; 320: 745-749
        • Hockey G.R.
        • Sauer J.
        Cognitive fatigue and complex decision making under prolonged isolation and confinement.
        Adv Space Biol Med. 1996; 5: 309-330
        • Weiser T.G.
        • Haynes A.B.
        • Dziekan G.
        • Berry W.R.
        • Lipsitz S.R.
        • Gawande A.A.
        Effect of a 19-item surgical safety checklist during urgent operations in a global patient population.
        Ann Surg. 2010; 251: 976-980
        • Askarian M.
        • Kouchak F.
        • Palenik C.J.
        Effect of surgical safety checklists on postoperative morbidity and mortality rates, Shiraz, Faghihy Hospital, a 1-year study.
        Qual Manag Health Care. 2011; 20: 293-297
        • Buzink S.N.
        • van Lier L.
        • de Hingh I.H.
        • Jakimowicz J.J.
        Risk-sensitive events during laparoscopic cholecystectomy: the influence of the integrated operating room and a preoperative checklist tool.
        Surg Endosc. 2010; 24: 1990-1995
        • Ali M.
        • Osborne A.
        • Bethune R.
        • Pullyblank A.
        Preoperative surgical briefings do not delay operating room start times and are popular with surgical team members.
        J Patient Saf. 2011; 7: 139-143
        • Ko H.C.
        • Turner T.J.
        • Finnigan M.A.
        Systematic review of safety checklists for use by medical care teams in acute hospital settings–limited evidence of effectiveness.
        BMC Health Serv Res. 2011; 11: 211
        • Conley D.M.
        • Singer S.J.
        • Edmondson L.
        • Berry W.R.
        • Gawande A.A.
        Effective surgical safety checklist implementation.
        J Am Coll Surg. 2011; 212: 873-879
        • Hales B.
        • Terblanche M.
        • Fowler R.
        • Sibbald W.
        Development of medical checklists for improved quality of patient care.
        Int J Qual Health Care. 2008; 20: 22-30
        • Verdaasdonk E.G.
        • Stassen L.P.
        • Widhiasmara P.P.
        • Dankelman J.
        Requirements for the design and implementation of checklists for surgical processes.
        Surg Endosc. 2009; 23: 715-726