Keith E. Littlewood

Model for End-Stage Liver Disease Predicts Mortality for Tricuspid Valve Surgery

BACKGROUND Patients undergoing tricuspid valve surgery have a mortality of 9.8%, which is higher than expected given the complexity of the procedure. Despite liver dysfunction seen in many patients with tricuspid disease, no existing risk model accounts for this. The Model for End-Stage Liver Disease (MELD) score accurately predicts mortality for abdominal surgery. The objective of this study was to determine if MELD could accurately predict mortality after tricuspid valve surgery and compare it to existing risk models. METHODS From 1994 to 2008, 168 patients (mean age, 61 +/- 14 years; male = 72, female = 96) underwent tricuspid repair (n = 156) or replacement (n = 12). Concomitant operations were performed in 87% (146 of 168). Patients with history of cirrhosis or MELD score 15 or greater (MELD = 3.8*LN [total bilirubin] + 11.2*log normal [international normalized ratio] + 9.6*log normal [creatinine] + 6.4) were compared with patients without liver disease or MELD score less than 15. Preoperative risk, intraoperative findings, and complications including operative mortality were evaluated. Statistical analyses were performed using chi(2), Fishers exact test, and area under the curve (AUC) analyses. RESULTS Patients with a history of liver disease or MELD score of 15 or greater had significantly higher mortality (18.9% [7 of 37] versus 6.1% [8 of 131], p = 0.024). To further characterize the effect of MELD, patients were stratified by MELD alone. No major differences in demographics or operation were identified between groups. Mortality increased as MELD score increased, especially when MELD score of 15 or greater (p = 0.0015). A MELD score less than 10, 10 to 14.9, 15 to 19.9, and more than 20 was associated with operative mortality of 1.9%, 6.8%, 27.3%, and 30.8%, respectively. By multivariate analysis, MELD score of 15 or greater remained strongly associated with mortality (p = 0.0021). The MELD score predicted mortality (AUC = 0.78) as well as the European System for Cardiac Operative Risk Evaluation logistic risk calculator (AUC = 0.78, p = 0.96). CONCLUSIONS The MELD score predicts mortality in patients undergoing tricuspid valve surgery and offers a simple and effective method of risk stratification in these patients.

Perioperative Management of the Adult with Cystic Fibrosis

Since cystic fibrosis (CF) was first differentiated from celiac disease in 1938, the medical care of patients with CF has substantially improved. These improvements have resulted in a significant increase in median survival and the quality of life experienced by patients. The resultant increase in survival has caused the “average” CF patient to be a young adult and not a child. The gene that causes CF was first identified in 1989 and is the first gene discovered by positional cloning. Unfortunately, gene therapy for CF has not been successful, although it continues to hold great promise for future patient care. Although pulmonary disease is responsible for more than 90% of the morbidity and mortality in patients with CF, they also experience pancreatic disease, including diabetes mellitus, bone disease, hepatobiliary disease, and genitourinary disease. The optimal perioperative management of patients with CF requires an understanding of the relevant pathophysiology and the unique challenges presented by these patients. We reviewed these concepts, including special considerations such as liver and lung transplantation and pregnancy.

A Simulation Course on Lifesaving Techniques for Third-year Medical Students

Background: The University of Virginia School of Medicine discontinued animal vivisection in February 2004 for teaching lifesaving procedures to third-year medical students. Consequently, a 1-day course using simulation technology was developed to meet objectives previously covered in the animal laboratory. The authors sought to evaluate the course and hypothesized that the students’ confidence in lifesaving procedures as well as their acceptance of simulation technology as a teaching tool would increase. Methods: The course was designed in a two-session format. The first session (first half of the day) concentrated on individual procedure skills, utilizing part-task trainers. The second session (second half of the day) used a Medical Education Technologies Inc. (METI) Emergency Care Simulator (ECS) full-body patient simulator to present a major trauma scenario. The study design was a prospective, pretest-posttest study without a control group. A 10-question pre and post survey used a Likert scale to explore students’ confidence in their skills as well as their acceptance of simulation technology. A course evaluation used a similar Likert scale for evaluation of the course substations, the trauma scenario, and students’ self-assessment of their skill levels as well as a 100% point scale for an overall rating of the course. Results: A total of eight 1-day courses were successfully held over 2 years with a total enrollment of 240 students utilizing 20 instructors inclusive of faculty, residents, and other emergency medicine health care providers. For the pre and post survey results, there was a significant increase in students’ confidence in performing lifesaving procedures as well as their acceptance of simulation as a teaching tool (P < 0.05 for each question with pre n = 222 and post n = 226). For the course evaluation results (n = 190), all of the course substations were rated in the good to excellent range and the course received an overall score of 97.55 ± 7.23% out of 100%. Furthermore, students reported a significant increase in their skill level (P < 0.05). Conclusion: This lifesaving techniques course utilizing simulation technology successfully covered objectives previously taught with animal vivisection, increased students’ confidence levels in performing lifesaving procedures and was highly accepted by the medical students.

High-fidelity simulation is superior to case-based discussion in teaching the management of shock

Background: Case-based discussion (CBD) is an established method for active learning in medical education. High-fidelity simulation has emerged as an important new educational technology. There is limited data from direct comparisons of these modalities. Aims: The primary purpose of this study was to compare the effectiveness of high-fidelity medical simulation with CBD in an undergraduate medical curriculum for shock. Methods: The subjects were 85 third-year medical students in their required surgery rotation. Scheduling circumstances created two equal groups. One group managed a case of septic shock in simulation and discussed a case of cardiogenic shock, the other group discussed septic shock and experienced cardiogenic shock through simulation. Student comprehension of the assessment and management of shock was then evaluated by oral examination (OE). Results: Examination scores were superior in all comparisons for the type of shock experienced through simulation. This was true regardless of the shock type. Scores associated with patient evaluation and invasive monitoring, however, showed no difference between groups or in crossover comparison. Conclusions: In this study, students demonstrated better understanding of shock following simulation than after CBD. The secondary finding was the effectiveness of an OE with just-in-time deployment in curriculum assessment.

The effect of the intrathoracic pressure regulator on hemodynamics and cardiac output.

The intrathoracic pressure regulator (ITPR) (CirQLator; Advanced Circulatory Systems Inc, Roseville, Minn) is a novel, noninvasive device intended to increase cardiac output and blood pressure in hypovolemic or cardiogenic shock by generating a continuous low-level intrathoracic vacuum in between positive pressure ventilations. Although there are robust data supporting the benefit of the ITPR in multiple animal models of shock, the device has not been used in humans. The goals of this study were to evaluate both the safety and efficacy of the ITPR in humans. Twenty patients undergoing coronary artery bypass graft surgery were enrolled in this phase 1 study. Intraoperative use of both pulmonary artery pressure monitoring and transesophageal echocardiography (TEE) was required for study inclusion. Hemodynamic variables as well as TEE measurements of left ventricular performance were collected at baseline and after the ITPR device was activated, before surgical incision. Thermodilution cardiac output increased significantly with the application of the ITPR (4.9 vs. 5.5 L/min; P = 0.017). Similarly, cardiac output was measured by TEE (5.1 vs. 5.7 L/min; P = 0.001). There were significant increases in pulmonary artery systolic blood pressures (35 vs. 38 mmHg; P < 0.001) and mean pulmonary artery pressures (24 vs. 26 mmHg; P = 0.008). There were no significant differences in systemic blood pressures, left ventricular volumes, stroke volume, or ejection fraction as measured by TEE. Using two different measurement techniques, application of the ITPR increased cardiac output in normovolemic anesthetized patients who underwent coronary artery bypass graft before sternotomy. These data suggest that the ITPR has the potential to safely and effectively increase cardiac output in humans.

Designing and evaluating an effective theory-based continuing interprofessional education program to improve sepsis care by enhancing healthcare team collaboration

Abstract Continuing interprofessional education (CIPE) differs from traditional continuing education (CE) in both the learning process and content, especially when it occurs in the workplace. Applying theories to underpin the development, implementation, and evaluation of CIPE activities informs educational design, encourages reflection, and enhances our understanding of CIPE and collaborative practice. The purpose of this article is to describe a process of design, implementation, and evaluation of CIPE through the application of explicit theories related to CIPE and workplace learning. A description of an effective theory-based program delivered to faculty and clinicians to enhance healthcare team collaboration is provided. Results demonstrated that positive changes in provider perceptions of and commitment to team-based care were achieved using this theory-based approach. Following this program, participants demonstrated a greater appreciation for the roles of other team members by indicating that more responsibility for implementing the Surviving Sepsis guideline should be given to nurses and respiratory therapists and less to physicians. Furthermore, a majority (86%) of the participants made commitments to demonstrate specific collaborative behaviors in their own practice. The article concludes with a discussion of our enhanced understanding of CIPE and a reinterpretation of the learning process which has implications for future CIPE workplace learning activities.

Recreating simulation scenarios for interprofessional education: an example of educational interprofessional practice

Abstract High-fidelity simulation has proliferated in healthcare education. Once a novelty, simulation is now a mainstay of many curricula and even required by some accrediting bodies. Interprofessional behaviors, manifested through interprofessional education and practice are believed to improve patients’ lives. The exciting potential of simulation-interprofessional education (SIM-IPE) is now being explored. This report details a SIM-IPE experience from a university medical simulation center and Schools of Nursing and Medicine. Circumstances required an existing scenario to be “retrofitted” for interprofessional education. Key decision points, challenges and practices are highlighted in the hope that they may be of use to other simulation educators.

Using simulation to study speaking up and team performance

May 2013 • Volume 116 • Number 5 www.anesthesia-analgesia.org 1183 Using Simulation to Study Speaking Up and Team Performance to a different threshold, but our general conclusion is that length of ICU stay remains a factor to take into consideration before using succinylcholine for critically ill patients. We performed a clinical not a pharmacologic study2 and found it impossible to precisely measure the peak potassium concentration. The resulting bias however should be an observed lower peak concentration and thus an underestimated ΔK and underestimated correlation between ΔK and length of ICU stay. In some cases, ΔK was surprisingly negative, independent of ΔpH, but these data are actual clinical observations with the usual assay and interspecimen variability. Finally, some points are superimposed in the scatter plot, and all 153 results were analyzed. In conclusion, we continue to consider that the length of ICU stay is an additional risk factor for hyperkalemia after administration of succinylcholine in critically ill patients.

Comments on ‘Emotion, cognitive load and learning outcomes during simulation training’

Editor – The recent report by Fraser et al. represents pioneering work in developing understanding of cognitive load within simulation education. We applaud this effort and wish to offer comments on its interpretation. Firstly, the authors state ‘...training must be considered suboptimal when 25–30% of students fail to recognise a cardiac murmur...’ Thereafter, this standard is presumably the basis for restatements of simulation’s ‘failure to improve’. This is problematic. Without a comparator pre-experience assessment, it is not possible to know the actual effect of the simulation encounter. These Year 1 medical students actually fared remarkably well in comparison with previously reported advanced learners and clinicians. The implied expectation that Year 1 students should perform better than doctors in training or practice requires justification.

Endotracheal cuff leakage: a simple solution for an occasionally serious problem

To the Editor: We describe a possible solution for managing a cuff leak of a double-lumen endotracheal tube (DLT) used for an open thoracotomy. After induction of general anesthesia, the trachea of a 69-yr-old patient was intubated uneventfully with clear visualization of the vocal cords. A 39Fr left-sided DLT (Mallinckrodt Broncho-Cath TM , Tyco Healthcare Group, Pleasanton, CA, USA) was used. The patient was positioned in a left lateral decubitus position, and the correct DLT position was bronchoscopically verified. Within 15 min of skin incision, a significant leak of the endobronchial cuff was identified. The cuff leak was managed with a nasal cannula connected to an oxygen flowmeter. One of the two nasal prongs was then connected to the pilot balloon of the defective cuff via a well-fitting three-way stopcock. The other nasal prong was connected to an iv extension tubing (Baxter Extension Set, Baxter Healthcare Corporation, Deerfield, IL, USA) (86 cm long, 2.4 mm internal diameter). The end of the tubing was placed into a water-filled bottle 20 cm under the water’s surface. We then carefully inflated the endobronchial cuff of the DLT with oxygen at a flow rate of 2 Lmin -1 . The cuff appeared to maintain adequate pressure. Lung isolation was confirmed by direct inspection of the surgical field, equalization of delivered and exhaled tidal volumes, and bronchoscopic inspection of the cuff. No clinical changes in vital signs or signs of aspiration were present during the remainder of the procedure, which was confirmed by x-ray postoperatively. The system lasted until the end of the surgical procedure 1.5 hr later.