Elizabeth B. Fortescue

Age, Size, and Lead Factors Alone Do Not Predict Venous Obstruction in Children and Young Adults with Transvenous Lead Systems

Background: Venous occlusion is a recognized complication of transvenous pacing, and lead cross‐sectional area indexed to body surface area (BSA) has been used to predict venous obstruction in children.

Pediatric Medication Errors: What Do We Know? What Gaps Remain?

Patient safety is an increasingly well-recognized public health problem. The Institute of Medicine’s report entitled To Err Is Human1 initially drew widespread attention to this issue by estimating that approximately 44 000–98 000 deaths each year result from medical mistakes in hospitals. These estimates came from 2 main studies: the Harvard Medical Practice Study and the Colorado-Utah Study.2–4 Even though controversy surrounds the extrapolation of these numbers to national estimates, most agree that patient safety can be significantly improved.2,3 The Harvard Medical Practice Study found that medication errors are the most frequent type of medical errors, comprising over 19% followed by wound infections (14%) and technical complications (13%).2,3 This finding prompted further study of medication errors in adult inpatients, documenting a medication error rate of 5/100 medication orders, with 7 in 100 errors having a potential for injury (potential adverse drug event [ADE]) and 1 in 100 errors resulting in an ADE.5 A later Adverse Drug Event Prevention Study documented 6.5 ADEs per 100 adult admissions.6 Other studies demonstrated that ADEs are costly and can have severe sequelae,7,8 as well as high frequencies of medication errors in adult outpatients.9,10 In comparison, relatively few studies of medication errors have focused on children. In this article, we discuss why children are particularly prone to errors and review pediatric studies of medication errors. We then explore potential prevention strategies using a systems-based approach as advocated by the Institute of Medicine report, Crossing the Quality Chasm.11 This report identified 6 specific aims for quality improvement in health care, with safety leading the list, and emphasized that ensuring safety requires a systems-based approach to the development and

Comparison of modern steroid-eluting epicardial and thin transvenous pacemaker leads in pediatric and congenital heart disease patients.

AbstractObjective: Optimal pacemaker lead choice in pediatric patients eligible for either epicardial or transvenous leads remains unclear. We compared performances of modern thin transvenous (TTV) and steroid-eluting epicardial (SEE) leads in patients followed at one pediatric center. Methods: Retrospective review of patients with qualifying leads implanted from August 1997 to March 2004. Threshold energy (TE) at implant and follow-up, sensing thresholds, lead complications, and repeat pacing-related procedures were analyzed. Lead performances were compared using t-tests, Wilcoxon rank-sum tests and Cox regression. Survival curves were plotted using Kaplan-Meier analysis. Results: A total of 370 implant procedures, 521 leads, and 1549 visits were evaluated. In all, 256 leads were SEE (49%, 184 implants) and 265 were TTV (51%, 186 implants). Median follow-up was 29 months (range 1–80 months). Patients with SEE systems were younger at implant (6 vs. 17 yrs, p < 0.001), and more had congenital heart defects (82% vs. 57%, p < 0.001). At follow-up, ventricular TEs were higher for SEE leads at implant (p < 0.001), 1 month (p < 0.001), and up to 4 years (p = 0.019). When compared across all follow-up durations combined, TTV TEs were significantly lower than SEE TEs for both atrial and ventricular leads (p < 0.001). A total of 70 repeat procedures were performed in 60 patients during the study period, which comprised 18% of SEE and 14% of TTV system patients (p = NS). In all, 18 TTV and 19 SEE leads failed (p = NS). Estimated freedom from lead failure at 1, 3, and 5 years was 97%, 88%, 85% for TTV leads and 96%, 92%, and 58% for SEE leads (log rank P = NS). Conclusions: Both SEE and TTV leads showed good mid-term performance and survival in our cohort. Higher TEs seen for SEE leads, especially ventricular and unipolar leads, may result in higher current drain and thus more generator replacements than TTV systems. Lead failure rates were comparable across lead types. TTV leads offer a promising alternative to SEE systems in terms of performance for young patients without intracardiac shunting who do not require open-chest surgery for another indication.

Development and validation of a clinical prediction rule for major adverse outcomes in coronary bypass grafting

In this study, we develop and internally validate a clinical prediction rule for in-hospital major adverse outcomes, defined as death, renal failure, reinfarction, cardiac arrest, cerebrovascular accident, or coma, in patients who underwent coronary artery bypass grafting (CABG). All adult patients (n = 9,498) who underwent a CABG and no other concomitant surgery at 12 academic medical centers from August 1993 to October 1995 were included in the study. We assessed in-hospital major adverse outcomes and their predictors using information on admission, coronary angiography, and postoperative hospital course. Predictor variables were limited to information available before the procedure, and outcome variables were represented only by events that occurred postoperatively. We developed and internally validated a clinical prediction rule for any major adverse outcome after CABG. The rules ability to discriminate outcomes and its calibration were assessed using receiver-operating characteristic analysis and the Hosmer-Lemeshow goodness-of-fit statistic, respectively. A major adverse outcome occurred in 6.5% of patients in the derivation set and 7.2% in the validation set. Death occurred in 2.5% of patients in the derivation set and 2.2% in the validation set. Sixteen variables were independently correlated with major adverse outcomes, with the risk score value attributed to each risk factor ranging from 2 to 12 points. The rule stratified patients into 6 levels of risk based on the total risk score. The spread in probability between the lowest and highest risk groups of having a major adverse outcome was 1.7% to 32.3% in the derivation set and 2.2% to 22.3% in the validation set. The prediction model performed well in both outcome discrimination and calibration. Thus, this clinical prediction rule allows accurate stratification of potential CABG candidates before surgery according to the risk of experiencing a major adverse outcome postoperatively.

To Close or Not to Close: The Very Small Patent Ductus Arteriosus

Patent ductus arteriosus (PDA) accounts for approximately 10% of all congenital heart diseases, with an incidence of at least 2-4 per 1000 term births. Closure of the large, hemodynamically significant PDA is established as the standard of care, and can be performed safely and effectively using either surgical or transcatheter methods. The appropriate management of the very small, hemodynamically insignificant PDA is less clear. Routine closure of such defects has been advocated to eliminate or reduce the risk of infective endocarditis (IE). However, the risk of IE in patients with a small PDA appears to be extremely low, and IE is treatable. Although closure of the small PDA is generally safe and technically successful, it is unknown whether this treatment truly improves the risk:benefit balance compared with observation. In this article, we review the published literature on the natural history and treatment outcomes in individuals with a PDA, the epidemiology and outcomes of IE, particularly in association with PDA, and the rationale and evidence for closure of the very small PDA.

Prediction rules for complications in coronary bypass surgery: a comparison and methodological critique.

BACKGROUND Clinical prediction rules have been developed that use preoperative information to stratify patients according to risk of complications after cardiac surgery. OBJECTIVES To assess the methodological standards and performance of 7 models. PARTICIPANTS The validation portion of the Quality Measurement and Management Initiative (QMMI) cohort included a random sample of all adult patients (n = 3,261) who underwent coronary artery bypass grafting (CABG) surgery not involving valvular or other concomitant procedures at 12 medical centers from August 1993 to October 1995. OUTCOME MEASURES Methodological standards used for model comparison were adapted from published criteria. Model performance was assessed by receiver-operating characteristic (ROC) analysis, and calibration was evaluated with the Hosmer-Lemeshow (HL) statistic and observed-expected plots. METHODS We performed cross-validation by applying the published criteria for the development of each model to the validation subset of the QMMI cohort and by assessing the performance of each model in discriminating outcomes. RESULTS Wide variations existed in the methodologies used to develop and validate the 5 additive scores evaluated. Cross-validation of all 5 additive scores revealed degradation in their abilities to discriminate outcomes. The 2 logistic models examined performed similarly to the additive scores examined in predicting mortality. CONCLUSIONS Substantial variation existed both in the methodologies used to develop models and in the ability of the models to predict outcomes. Models developed at single institutions or using fewer patients may be less generalizable when applied to diverse clinical settings. Additive and logistic regression models performed similarly, as assessed by ROC and HL analyses.

The Boston Marathon Study: a novel approach to research during residency.

Resident physicians from a pediatric academic training program developed a hospital-wide research project in an effort to enhance their residency research experience. In this model, residents themselves assumed primary responsibility for each stage of a large prospective clinical research study. The project, which was integrated successfully into the residency program, enabled a large group of residents, with mentorship from a dedicated faculty member, to benefit from a structured clinical research experience while providing the flexibility necessary to meet the demands of a busy residency curriculum. Careful topic selection with a well-defined end point, faculty involvement, resident collegiality, and institutional support were factors identified by study leaders as central to the success of this model.

Major adverse outcomes after percutaneous transluminal coronary angioplasty: a clinical prediction rule

In this study, we developed and internally validated a clinical model for predicting major adverse outcomes in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) using a multi-institutional prospective cohort study involving all adult patients who underwent PTCA at 12 participating institutions from August 1993 to October 1995. A major adverse outcome, defined as death, renal failure, myocardial infarction, cardiac arrest, stroke, or coma, occurred in 3.3 and 3.2% of patients in the derivation and validation sets, respectively. Death occurred in 1.5% in both sets. Fourteen variables were independently correlated with major adverse outcomes. The rule, which stratifies PTCA patients into six levels of risk based on the severity score, showed excellent discrimination (receiver-operating characteristic curve area 0.82) and calibration (Hosmer-Lemeshow chi-square statistic P =.90) and performed well on internal validation. This rule allows accurate preprocedure stratification of PTCA candidates according to their risk of suffering a major adverse outcome.

Keeping the Pace

Can you feel the pulse of an excited heart, perhaps after winning a race, or falling in love? The extra thumps and tickles, the flurry of flutters that accompany such emotional highs?