Publications

2011

Wadhera RK, Kyle RA, Larson DR, Dispenzieri A, Kumar S, Lazarus HM, Rajkumar V. Incidence, clinical course, and prognosis of secondary monoclonal gammopathy of undetermined significance in patients with multiple myeloma. Blood. 2011;118(11):2985–7. doi:10.1182/blood-2011-04-349175

During the course of multiple myeloma (MM), new monoclonal proteins of an isotype distinct from the original clone, referred to as secondary monoclonal gammopathy of undetermined significance (MGUS), have been described. We report on the frequency, characteristics, and outcome of secondary MGUS. Of the 1942 patients with MM, 128 (6.6%) developed a secondary MGUS, at a median of 12 months from the diagnosis of MM. The median duration of secondary MGUS was 5.9 months. Secondary MGUS was more common in patients after stem cell transplantation than in those who had not undergone such treatment (22.7% vs 1.6%, P < .001). Overall survival was significantly superior in MM patients who developed secondary MGUS compared with the rest of the cohort (73 vs 38 months, respectively; P < .001). The time of onset and the duration of secondary MGUS, as well as failure to resolve spontaneously, had an effect on overall survival and require further study.

2010

Wadhera RK, Rajkumar V. Prevalence of monoclonal gammopathy of undetermined significance: a systematic review. Mayo Clinic proceedings. 2010;85(10):933–42. doi:10.4065/mcp.2010.0337

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma cell disorder that is associated with a lifelong risk of multiple myeloma. We conducted a systematic review of all studies investigating the prevalence and incidence of MGUS in the online database PubMed. The review was conducted from January 6, 2009, through January 15, 2010. The following MeSH search headings were used: monoclonal gammopathy, benign and prevalence; monoclonal gammopathy, benign and incidence; paraproteinemia and prevalence; and paraproteinemia and incidence. Articles were limited to those written in English and published by January 2009. Fourteen studies that met prespecified criteria were included and systematically assessed to identify the most accurate prevalence estimates of MGUS based on age, sex, and race. On the basis of our systematic review, we estimate that the crude prevalence of MGUS in those older than 50 years is 3.2% in a predominantly white population. Studies in white and Japanese populations demonstrate a clear increase in prevalence with age. The prevalence is also affected by sex: 3.7% and 2.9% in white men and women, respectively; and 2.8% and 1.6% in Japanese men and women, respectively. Additionally, MGUS is significantly more prevalent in black people (5.9%-8.4%) than in white people (3.0%-3.6%). We conclude that MGUS is a common premalignant plasma cell disorder in the general population of those older than 50 years. The prevalence increases with age and is affected by race, sex, family history, immunosuppression, and pesticide exposure. These results are important for counseling, clinical care, and the design of clinical studies in high-risk populations.

Parker SEH, Laviana AA, Wadhera RK, Wiegmann DA, Sundt TM. Development and evaluation of an observational tool for assessing surgical flow disruptions and their impact on surgical performance. World journal of surgery. 2010;34(2):353–61. doi:10.1007/s00268-009-0312-z

BACKGROUND: Many researchers have previously explored the correlation between surgical flow disruptions and adverse events in cardiac surgery; however, there is no reliable tool to prospectively categorize surgical flow disruptions and the conditions that predispose a surgical team to adverse events.

METHODS: Two independent raters of different medical and human factors expertise observed 12 cardiovascular operations and iteratively designed a surgical flow disruption tool (SFDT) to characterize surgical flow disruptions and the latent factors that contribute to adverse events. Categories to characterize surgical flow disruptions were created based on human factors models of human error. After the design period, both raters observed ten surgical cases using the tool to assess validity and inter-rater reliability.

RESULTS: Rating agreement (weighted kappa) for each category across the ten surgeries was moderate to very high, resulting in strong inter-rater reliability for each category on the surgical flow disruption tool. Use of the SFDT was simple and clear for observers of diverse backgrounds, including human factors experts and medical personnel.

CONCLUSIONS: This research depicts the development and utility of a tool to analyze surgical flow disruptions in the cardiovascular operating room with satisfactory inter-rater reliability. This tool is an important first step in systematically categorizing and measuring surgical flow disruptions and their impact on patient safety in the operating room.

Wadhera RK, Parker SH, Burkhart HM, Greason KL, Neal JR, Levenick KM, Wiegmann DA, Sundt TM. Is the "sterile cockpit" concept applicable to cardiovascular surgery critical intervals or critical events? The impact of protocol-driven communication during cardiopulmonary bypass. The Journal of thoracic and cardiovascular surgery. 2010;139(2):312–9. doi:10.1016/j.jtcvs.2009.10.048

OBJECTIVE: There is general enthusiasm for applying strategies from aviation directly to medical care; the application of the "sterile cockpit" rule to surgery has accordingly been suggested. An implicit prerequisite to the evidence-based transfer of such a concept to the clinical domain, however, is definition of periods of high mental workload analogous to takeoff and landing. We measured cognitive demands among operating room staff, mapped critical events, and evaluated protocol-driven communication.

METHODS: With the National Aeronautics and Space Administration Task Load Index and semistructured focus groups, we identified common critical stages of cardiac surgical cases. Intraoperative communication was assessed before (n = 18) and after (n = 16) introduction of a structured communication protocol.

RESULTS: Cognitive workload measures demonstrated high temporal diversity among caregivers in various roles. Eight critical events during cardiopulmonary bypass were then defined. A structured, unambiguous verbal communication protocol for these events was then implemented. Observations of 18 cases before implementation including 29.6 hours of cardiopulmonary bypass with 632 total communication exchanges (average 35.1 exchanges/case) were compared with observations of 16 cases after implementation including 23.9 hours of cardiopulmonary bypass with 748 exchanges (average 46.8 exchanges/case, P = .06). Frequency of communication breakdowns per case decreased significantly after implementation (11.5 vs 7.3 breakdowns/case, P = .008).

CONCLUSIONS: Because of wide variations is cognitive workload among caregivers, effective communication can be structured around critical events rather than defined intervals analogous to the sterile cockpit, with reduction in communication breakdowns.

2009

Henrickson SE, Wadhera RK, ElBardissi AW, Wiegmann DA, Sundt TM. Development and pilot evaluation of a preoperative briefing protocol for cardiovascular surgery. Journal of the American College of Surgeons. 2009;208(6):1115–23. doi:10.1016/j.jamcollsurg.2009.01.037

BACKGROUND: Preprocedural briefings have been adopted in many high consequence environments, but have not been widely accepted in medicine. We sought to develop, implement, and evaluate a preoperative briefing for cardiovascular surgery.

STUDY DESIGN: The briefing was developed by using a combined questionnaire and semistructured focus group approach involving five subspecialties of surgical staff (n=55). The results were used to design and implement a preoperative briefing protocol. The briefing was evaluated by monitoring surgical flow disruptions, circulating nurse trips to the core, time spent in the core, and cost-waste reports before and after implementation of the briefing across 16 cardiac surgery cases.

RESULTS: Focus group data indicated consensus among surgical staff concerning briefing benefits, duration, location, content, and potential barriers. Disagreement arose concerning timing of the brief and the roles of key participants. After implementation of the briefing, there was a reduction in total surgical flow disruptions per case (5.4 preimplementation versus 2.8 postimplementation, p=0.004) and reductions in per case average of procedural knowledge disruptions (4.1 versus 2.17, p=0.004) and miscommunication events (2.5 versus 1.17, p=0.03). There was no significant reduction in disruptions because of equipment preparation or disruptions from patient-related issues. On average, briefed teams experienced fewer trips to the core (10 versus 4.7, p=0.004) and spent less time in the core (397.4 seconds versus 172.3 seconds, p=0.006), and there was a trend toward decreased waste (30% versus 17%, p=0.15).

CONCLUSIONS: These findings demonstrate the feasibility of creating a specialty-specific preoperative briefing to decrease surgical flow disruptions and improve patient safety in the operating room.

2008

ElBardissi AW, Wiegmann DA, Henrickson S, Wadhera R, Sundt TM. Identifying methods to improve heart surgery: an operative approach and strategy for implementation on an organizational level. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. 2008;34(5):1027–33. doi:10.1016/j.ejcts.2008.07.007

BACKGROUND: Previous research has found teamwork failures to be strongly associated with the occurrence of surgical error. There have been few efforts to prospectively collect data regarding teamwork failures and technical errors in order to create interventions that would maximize teamwork effectiveness thereby minimizing technical error.

METHODS: Thirty-one cardiac surgical cases were prospectively observed by a trained human factors observer. Events were characterized according to human factors theory and included teamwork failures and technical errors. Surgical team structure was also evaluated in an effort to identify if it had an impact on surgical team performance.

RESULTS: A strong correlation (r=0.67, p<0.001) was recognized between the occurrence of technical error (n=155) and teamwork failures (n=178). Teamwork failures consisted of surgeon-technical team failures (n=90, 51%), procedural information failures (n=36, 20%), surgeon-anesthesiologist failures (n=27, 15%), surgeon-perfusionist failures (n=18, 10%), and failures due to handoffs (n=7, 4%). Teams made up of members that were familiar with the operating surgeon had significantly fewer total event failures (8.6+/-1.6 vs 22+/-3.1, p<0.0001) and teamwork failures (5.6+/-1.8 vs 15.4+/-1.9, p<0.0001) in comparison to those teams where the majority of members were unfamiliar with the operating surgeon.

CONCLUSIONS: These results indicate that the process of cardiac surgery would benefit from interventions to improve teamwork and communication. Such interventions could include preoperative briefings, revised approach to structuring of operative teams to favor members that have gained familiarity with the operating surgeon, standardized communication practices, and postoperative debriefings.

2006

Ingham SC, Wadhera RK, Chu C-H, DeVita MD. Survival of Streptococcus pyogenes on foods and food contact surfaces. Journal of food protection. 2006;69(5):1159–63.

Streptococcus pyogenes causes septic sore throat in millions of Americans each year and may be transmitted from food handlers to food contact surfaces, foods, and consumers. This study examined the individual survival of six S. pyogenes strains on food contact surfaces (plastic and ceramic plates, plastic cups, and stainless steel utensils) held at 21 degrees C for 2 h and on tomatoes stored aerobically at 21 degrees C for 2 h and at 5 degrees C for 24 h. Survival of a cocktail of the six S. pyogenes strains was also evaluated on vacuum-packaged ready-to-eat meats and cheeses held at 21 degrees C for 8 h and at 5 degrees C for 24 h. Populations generally did not change on tomatoes, cheeses, or beef bologna; however, there were small (0.1 to 0.7 log CFU) but statistically significant decreases (P < 0.05) in average S. pyogenes populations on turkey luncheon meat and beef summer sausage stored for 8 h at 21degrees C and on beef summer sausage stored for 24 h at 5 degrees C. On food contact surfaces, average populations either decreased slightly (P > or = 0.05) or remained constant, with the exception of three strains that significantly decreased in number on ceramic plates (P < 0.05; average decreases, 0.3 log CFU). Results of this study suggest the importance of preventing the contamination of foods and food contact surfaces with S. pyogenes by infected workers.

2005

This study was conducted to evaluate small-scale hot-water postpackaging pasteurization (PPP) as a postlethality (post-cooking) treatment for Listeria monocytogenes on ready-to-eat beef snack sticks and natural-casing wieners. Using a commercially available plastic packaging film specifically designed for PPP applications and 2.8 liters of boiling water (100 degrees C) in a sauce pan on a hot plate, an average reduction in L. monocytogenes numbers of > or = 2 log units was obtained using heating times of 1.0 min for individually packaged beef snack sticks (three brands) and 4.0 min for packages of four sticks (two brands) and seven sticks (three brands). Average product surface temperatures, measured as soon as possible after PPP and opening the package, were 47 to 51.5, 58 to 61.5, and 58.5 to 61 degrees C for the beef snack sticks packages of one, four, and seven sticks per package, respectively. A treatment of 7.0 min for packages of four natural-casing wieners (three brands) achieved L. monocytogenes reductions of > or = 1.0 log unit and average product surface temperature of 60.5 to 63.5 degrees C. Cooked-out fat and moisture resulting from tested treatments ranged from 0.2 to 1.1% by weight for beef snack sticks and from 0.4 to 1.2% by weight for natural-casing wieners. For natural-casing wieners, PPP had no detrimental effect on overall product desirability to consumers; results suggested that PPP may significantly enhance appearance of this product. However, for beef snack sticks the cooking out of fat and moisture during PPP had a significant negative effect on consumer opinions of product appearance.

Food regulatory agencies advise against thawing frozen meat and poultry at room temperature. In this study, whole chickens (1,670 g) and ground beef (453 and 1,359 g) were inoculated with Salmonella serovars, Escherichia coli O157:H7, and Staphylococcus aureus on the surface (all products) and in the center (ground beef). After freezing at -20 degrees C for 24 h, products were thawed at 22 or 30 degrees C for 9 h. Pathogen growth was predicted using product time and temperature data and growth values from the U.S. Department of Agriculture Agricultural Research Service Pathogen Modeling Program 7.0 predictive models of pathogen growth. No pathogen growth was predicted for whole chicken or 1,359 g of ground beef thawed at 30 degrees C or 453 g of ground beef thawed at 22 degrees C. Growth (< or = 5 generations) was predicted for 453 g of ground beef at 30 degrees C. Inoculation study data corroborated the predictions. No growth occurred on whole chickens or 1,359-g portions of ground beef thawed at 30 degrees C for 9 h. Pathogen numbers increased an average of 0.2 to 0.5 log on the surface of 453-g ground beef portions thawed for 9 h at 22 or 30 degrees C. Our results suggest that thawing > or = 1,670 g of whole chicken at < or = 30 degrees C for < or = 9 h and thawing >453 g ground beef portions at < or = 22 degrees C for < or = 9 h are not particularly hazardous practices. Thawing smaller portions at higher temperatures and/or for longer times cannot be recommended, however. Use of values derived from the Pathogen Modeling Program 7.0 model provided realistic predictions of pathogen growth during thawing of frozen ground beef and chicken.