Publications by Year: 2010

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.