Sundt, Thoralf M.

Background: Communication breakdowns are a common cause of adverse events in high consequence industries. It has become increasingly evident that within healthcare systems that poor communication is the causal factor of a large percentage of sentinel events. Methods: All communication exchanges between surgeon and perfusionist were monitored via observation for 18 cardiovascular surgery cases. Breakdowns were analyzed by stage and type of breakdown and a communication protocol designed based on the breakdowns. The protocol was then implemented, and use of the protocol was then monitored for 16 cardiovascular surgery cases. Results: Breakdowns decreased at each stage of cardiovascular surgery. Specific types of breakdowns decreased dramatically, most by more than half. Conclusions: This study shows that protocolizing communication can have a profound impact on communication breakdowns in the cardiovascular surgery operating theatre.

Background: Many researchers have previously explored the correlation between surgical flow disruptions (distractions and interruptions) and error in cardiac surgery, however there is no reliable tool to prospectively categorize surgical flow disruptions and the conditions that predispose a surgical team to error. Methods and Results: Two independent raters of different medical and human factors expertise observed 12 cardiovascular operations and iteratively designed a tool to characterize surgical flow disruptions and the latent factors that contribute to error. Categories to characterize surgical flow disruptions were based on human factors models of human error. Following the design period, both raters observed 10 surgical cases using the tool, to assess validity and inter-rater reliability. Rating agreement (weighted kappa) for each category across the 10 surgeries was moderate to very high, resulting in strong inter-rater reliability for each category on the surgical flow disruption tool (SFDT). 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.

Cardiopulmonary bypass machines (CBM's), first developed in 1953, are commonly used during heart surgery to oxygenate blood and circulate it throughout the body while the heart is stopped. Although several advances have occurred in the engineering of perfusion pumps, the interface design of CBM's has not changed appreciably for several decades. The growing awareness of human error in medicine has highlighted the role that poorly designed medical devices can play in producing errors that cause patient harm. The purpose of this study, therefore, was to identify issues related to CBM design that may predispose surgical teams to make errors. The study utilized multiple research methods including observations, heuristic evaluations, structured interviews and usability assessments. Results revealed several fundamental design problems associated CBM displays, controls, alarms, and component integration, as well as communication and procedural issues. These data provide valuable information for redesigning CBM's to reduce errors and improve patient safety.

Surgical flow disruptions can significantly increase the probability of surgical errors. However, little is known about the frequency and nature of surgical flow disruptions, making the development of evidence-based interventions extremely difficult. The goal of this project was to prospectively study surgical errors and their relationship to surgical flow disruptions within the context of cardiac surgery. A trained observer recorded surgical errors and flow disruptions during 31 cardiac operations over a three-week period. Flow disruptions were then reviewed and analyzed by an interdisciplinary team of surgical and human factors experts. Results revealed that flow disruptions consisted of teamwork/communication failures, equipment and technology problems, extraneous interruptions, training-related distractions, and resource accessibility issues. Errors increased significantly with increases in flow disruptions. Teamwork/communication failures were the strongest predictor of surgical errors. These findings provide preliminary data for developing evidenced-based error management and patient safety programs within cardiac surgery.

Errors with serious consequences continue to occur at a high rate in many surgical specialties. In this study, the Human Factors Analysis and Classification System (Wiegmann & Shappell, 2003) was used to develop a structured interviewing tool for prospectively assessing the systemic factors that may predispose operating room (OR) personnel to making errors. Approximately 50% (n = 68) of all staff involved in patient care within the cardiac surgery OR at our institution participated, with an equal proportion represented across staff specialties (Surgeons, Anesthesiologists, Nurses, Perfusionists and Technicians). Results identified a variety of potential error-producing factors present in the OR setting. While such factors were viewed by OR staff as occurring infrequently, significant relationships between the estimated frequency of systemic problems and specific error forms were identified. These findings can inform both the development of theoretical models of surgical error, as well as the practice of developing targeted intervention programs.

Background— Constrictive pericarditis (CP) is a disabling disease, and usually requires pericardiectomy to relieve heart failure. Reversible CP has been described, but there is no known method to predict the reversibility. Pericardial inflammation may be a marker for reversibility. As a pilot study, we assessed whether cardiac magnetic resonance imaging pericardial late gadolinium enhancement (LGE) and inflammatory biomarkers could predict the reversibility of CP after antiinflammatory therapy. Method and Results— Twenty-nine CP patients received antiinflammatory medications after cardiac magnetic resonance imaging. Fourteen patients had resolution of CP, whereas 15 patients had persistent CP after 13 months of follow-up. Baseline LGE pericardial thickness was greater in the group with reversible CP than in the persistent CP group (4±1 versus 2±1 mm, P =0.001). Qualitative intensity of pericardial LGE was moderate or severe in 93% of the group with reversible CP and in 33% of the persistent CP group ( P =0.002). Cardiac magnetic resonance imaging LGE pericardial thickness ≥3 mm had 86% sensitivity and 80% specificity to predict CP reversibility. The group with reversible CP also had higher baseline C-reactive protein and erythrocyte sedimentation rate than the persistent CP group (59±52 versus 12±14 mg/L, P =0.04 and 49±25 versus 15±16 mm/h, P =0.04, respectively). Antiinflammatory therapy was associated with a reduction in C-reactive protein, erythrocyte sedimentation rate, and pericardial LGE in the group with reversible CP but not in the persistent CP group. Conclusions— Reversible CP was associated with pericardial and systemic inflammation. Antiinflammatory therapy was associated with a reduction in pericardial and systemic inflammation and LGE pericardial thickness, with resolution of CP physiology and symptoms. Further studies in a larger number of patients are needed.

Background— Few data exist on long-term outcomes of elderly patients after aortic valve replacement. We evaluated latest follow-up information for patients ≥70 years of age after aortic valve replacement. Methods and Results— Late overall survival of 2890 consecutive patients ≥70 years of age who underwent aortic valve replacement between January 1993 and December 2007 was reviewed retrospectively, analyzed, and stratified by preoperative and intraoperative variables. Observed 5-, 10-, and 15-year late postoperative survival was lower than generally expected (68%, 34%, and 8% versus 70%, 42%, and 20%, respectively; P <0.001). Independent predictors of late death included older age, renal failure, diabetes mellitus, stroke, myocardial infarction, immunosuppression, prior coronary artery bypass grafting, implanted pacemaker, lower ejection fraction, hypertension, and New York Heart Association class III or IV. After stratification by age–comorbidity risk score, 10-year survival for the lowest-risk group (n=946 [33%]) was similar to expected survival (55% versus 55%; P =0.50), but for the highest-risk group (n=564 [20%]), survival was significantly lower than expected (9% versus 26%; P <0.001). For 229 pairs of propensity-matched patients with mechanical or biological prostheses, survival was not significantly different (67%, 40%, and 19% versus 71%, 45%, and 7% at 5, 10, and 15 years, respectively; P =0.81). Structural deterioration of bioprostheses occurred in 64 patients (2.4%). Conclusions— Survival of elderly patients after aortic valve replacement is influenced by age and preoperative comorbidities; 33% at lowest risk had overall survival similar to that of an age- and sex-matched general population. There was no sufficient evidence that valve type affected survival. Structural deterioration of aortic bioprostheses was rare.

The fine structure of the microvasculature in areas of focal cerebral ischemia was studied in squirrel monkeys and the changes in areas of impaired and unimpaired microvascular filling, as defined by carbon perfusion, were compared. Microcirculatory obstruction became evident three hours following middle cerebral artery (MCA) occlusion and appeared to be partly the result of compression of capillaries by perivascular glial swelling and developing cerebral edema. Slight endothelial swelling was a common finding. Intraluminal membrane-bound bodies were occasionally identified but they did not appear to be producing significant obstruction. The tight endothelial junctions remained intact and there was no evidence of accelerated micropinocytosis. Severe neuronal injury frequently preceded the development of the microvascular obstruction and was more widespread than the zones of impaired perfusion.

The sequential synaptic alterations which occur during the early phase of developing cortical infarction in the squirrel monkey were studied with the electron microscope. Mild swelling of a few dendritic terminals and clumping of synaptic vesicles were the earliest detectable changes, being present at 45 minutes. The two basic patterns of degeneration of the terminal boutons were shrinkage and swelling, with shrinkage being the predominant response. Many of the shrunken boutons became electron-dense, resembling the changes present in anterograde axonal degeneration. The alterations which developed in the dendritic terminals were relatively unimpressive. Disruption of axosomatic synapses occurred at an earlier stage and was more severe than that of axodendritic synapses. Reduction in the number of synaptic vesicles was first observed at six hours and appeared to be progressive. The edema which developed was morphologically distinct from both "vasogenic" and "cytotoxic" edema in that there was early and progressive enlargement of the extracellular space.

Smooth muscle strips from rabbit subarachnoid arteries did not respond to catecholamines in concentrations which caused strips from skin, mesentery, and kidney vessels to contract. The strips from subarachnoid arteries responded to serotonin, histamine, and angiotensin II but not to bradykinin, acetylcholine, methacholine, and adenosine phosphate compounds. Heart and lung vascular strips did not respond to catecholamines but responded to acetylcholine; cardiac strips responded to dilute methacholine. Lung strips often failed to respond to histamine in usual concentrations and did respond to bradykinin. The subarachnoid strips had a distinactive pattern of respone as compared to vascular tissue from other organs. Results of other isolated vessel studies are reviewed along with pertinent investigations of cerebral autoregulation, vasospasm, and autonomic nerves. The possible significance of these findings is discussed.