Marked variability in susceptibility to ventricular fibrillation in an experimental commotio cordis model.

BACKGROUND: Precordial blows in sports and daily activities can trigger ventricular fibrillation (VF) (commotio cordis). Whereas chest wall blows are common, commotio cordis is rare. Although factors such as timing, location, orientation, and energy of impact are critically important, we also hypothesize that there is individual susceptibility to commotio cordis. Using our model of commotio cordis, we evaluated individual animal susceptibility to VF induction and assessed animal characteristics that might be involved. METHODS AND RESULTS: This retrospective analysis included 139 juvenile swine (weight, 8 to 54 kg) that were anesthetized and placed prone in a sling to receive chest wall strikes with a ball propelled at 30 to 40 mph. Each animal received a minimum of 4 impacts directly over the cardiac silhouette, all timed to a narrow vulnerable window during cardiac repolarization. Of 1274 total impacts, 360 impacts (28%) resulted in VF. There was wide variability in individual animal susceptibility to VF. In 38 animals, none of the impacts resulted in VF (range, 4 to 18 impacts per animal). The majority of animals (91; 65%) were induced into VF with <30% of the strikes. In fact, only 19 animals (14%) had >50% occurrence of VF with chest wall impacts, and only 7 (5%) had >80% occurrence of chest impacts that induced VF. In the animal-based analysis, individual correlates of VF included animal weight, mean impact velocity, mean left ventricular pressure generated by the blow, mean QRS duration, mean QTc, and QTc variability. In multivariable analysis, mean left ventricular pressure generated by the blow, mean QRS duration, and QTc variability remained significant correlates of risk, and number of impacts gained statistical significance such that animals with more impacts were less susceptible to VF. CONCLUSIONS: Swine display a wide range of individual vulnerability to VF triggered by chest wall impact, with a distinct minority being uniquely susceptible. Mild abnormalities in cardiac depolarization and repolarization might underlie this susceptibility. Such individual susceptibility may also be present in humans and contribute to the rarity of commotio cordis.

Pediatric violence-related injuries in Boston: results of a city-wide emergency department surveillance program.

CONTEXT: Violence-related injuries among children are common, but age-based incidence data are not easily available. OBJECTIVES: To describe injuries due to violence in a population-based case series of children and to estimate injury incidence. DESIGN: Prospective surveillance of children residing in Boston, Mass, who received pediatric emergency department treatment for violence-related injury during a 4-year period beginning April 15, 1995. SETTING: Pediatric emergency departments in Boston. PATIENTS: Children aged 3 through 18 years who came to a hospital emergency department between April 1995 and April 1999. Violence-related injuries were defined as those resulting from a situation of conflict involving 2 or more persons with intent to harm, as assessed by health care personnel caring for the patients. Self-inflicted injuries and injuries caused by child abuse (including any injury resulting from a conflict with a parent or guardian) were excluded. Homicides of Boston children aged 3 through 18 years who were killed during the study period were included based on police data. MAIN OUTCOME MEASURE: Population-based violence-related injury rates. RESULTS: There were 2035 injury-related visits caused by violence, which reflects a rate of 52.7 (95% confidence interval, 50.5-54.9) per 10 000 person-years. Most injuries were relatively minor; 6.4% of visits resulted in admission. The youth violence-related injury rate in Boston declined at an average rate of 12% annually during the period studied. CONCLUSION: Pediatric emergency department monitoring of violence-related injury in Boston suggests that childhood injuries due to violence declined during the late 1990s.

The impact of a pharmacist intervention on 6-month outcomes in depressed primary care patients.

The object of the study was to evaluate outcomes of a randomized clinical trial (RCT) of a pharmacist intervention for depressed patients in primary care (PC). We report antidepressant (AD) use and depression severity outcomes at 6-months. The RCT was conducted between 1998 and 2000 in 9 eastern Massachusetts PC practices. We studied 533 patients with major depression and/or dysthymia as determined by a screening test done at the time of a routine PC office visit. The majority of participants had recurrent depressive episodes (63.5% with >/=4 lifetime episodes), and 49.5% were taking AD medications at enrollment. Consultation in person and by telephone was performed by a clinical pharmacist who assisted the primary care practitioner (PCP) and patient in medication choice, dose, and regimen, in accordance with AHCPR depression guidelines. Six-month AD use rates for intervention patients exceeded controls (57.5% vs. 46.2%, P =.03). Furthermore, the intervention was effective in improving AD use rates for patients not on ADs at enrollment (32.3% vs. 10.9%, P =.001). The pharmacist intervention proved equally effective in subgroups traditionally considered difficult to treat: those with chronic depression and dysthymia. Patients taking ADs had better modified Beck Depression Inventory (mBDI) outcomes than patients not taking ADs, (-6.3 points change, vs. -2.8, P =.01) but the outcome differences between intervention and control patients were not statistically significant (17.7 BDI points vs. 19.4 BDI points, P =.16). Pharmacists significantly improved rates of AD use in PC patients, especially for those not on ADs at enrollment, but outcome differences were too small to be statistically significant. Difficult-to-treat subgroups may benefit from pharmacists' care.

Description of a clinical pharmacist intervention administered to primary care patients with depression.

The objective of this article is to provide a detailed description of interactions between patients with depression and pharmacists. Analysis was conducted on patients from the intervention arm (n=268) of an randomized controlled trial that evaluated the impact of a clinical pharmacist on the outcomes for depressed primary care patients from nine metropolitan Boston practices. The main outcome measure was the amount of intervention time spent with patients, physicians, and other activities. Details of the behavioral intervention and a categorization of the activities are offered. Pharmacists reported 978 encounters with 268 patients in 6 months. Eighty percent of patient encounters occurred by telephone. Initial encounters took 45 min if in person and 13.3 min if by telephone. Subsequent encounters followed a similar pattern. Follow-up visits occurred 2.3 times per patient. Physician contact took considerably less time. In total, the pharmacist intervention took 70.3 min per patient over 6 months; 42.2% of encounters involved an activity related to non-antidepressant medication and 85% of encounters involved general support. Other activities (education, advocating antidepressants, and motivating adherence) occurred in at least 50% of encounters. Pharmacists repeated intervention activities in the same category approximately two to three times. Interventions to improve the care of depression in primary care patients must anticipate encountering intense needs for information, personal support, and help negotiating the healthcare system. Research that identifies relationships between the components (active ingredients) of an intervention and the outcomes of care will benefit future intervention strategies and contribute to improved and efficient care.

The pancake phenomenon contributes to the inaccuracy of margin assessment in patients with breast cancer.

BACKGROUND: To determine the effect on margin evaluation for patients with breast cancer, we prospectively quantified the "flattening" of the breast specimen after surgical removal. METHODS: The volume and height of 100 consecutive breast biopsy specimens were recorded independently by the operating surgeon and the pathologist. Five factors were analyzed that were thought to contribute to changes in specimen dimensions: patient age, breast tissue density, mammographic lesion type, specimen size, and the use of compression during specimen radiography. RESULTS: After surgical removal, mean volume and height of the breast specimens decreased from 46 cm(3) to 29 cm(3) (30%) and from 2.6 cm to 1.4 cm (46%), respectively. Flattening of the breast specimens occurred in all subgroups studied. CONCLUSIONS: Breast specimens are flattened after surgical removal, losing almost 50% of their original height. This "pancake" phenomenon has important implications for the accuracy of margin analysis.

Risk factors associated with the development of skin cancer after liver transplantation.

Skin cancer is a well-recognized long-term complication of transplantation and immunosuppression. Although risk factors for the development of skin cancer in the general population are well defined, risk factors for the development of these lesions have not been identified clearly in the liver transplant population. We surveyed 151 liver transplant (LTx) recipients for risk factors associated with cutaneous malignancies in the general population. Variables included were: demographics, primary liver disease, severity of disease at LTx, immunosuppression history, complexion, hair color, eye color, tanning profile, number of moles, occupational history, sun exposure history, sunburn history, family history of skin cancer, and any history of removed skin lesions. All skin cancers were confirmed histologically. There were 86 documented skin cancers in 34 patients: 56 squamous cell, 23 basal cell and 7 melanomas. Median follow-up was 1490 days. In a univariate analysis, age, male gender, red hair, brown eyes, primary sclerosing cholangitis (PSC), primary biliary cirrhosis (protective), cyclosporine, number of second degree sunburns, and frequent lifetime sun exposure were associated with the development of new skin cancers. In a multivariate model, age, male gender, red hair, brown eyes, PSC, and cyclosporine remain the strongest predictors. The incidence of skin cancer after liver transplantation is underestimated. In particular, there is a higher incidence of squamous cell carcinoma compared with the general population. Recipients with identified risk factors may be candidates for prophylactic treatment and should be followed more intensively after liver transplantation.

Patient protection and risk selection: do primary care physicians encourage their patients to join or avoid capitated health plans according to the patient's health status?

BACKGROUND: Individual physicians who are paid prospectively, as in capitated health plans, might tend to encourage patients to avoid or to join these plans according to the patient's health status. Though insurance risk selection has been well documented among organizations paid on a prospective basis, such physician-level risk selection has not been studied. OBJECTIVE: To assess physician reports of risk selection in capitated health plans and explore potentially related factors. DESIGN AND PARTICIPANTS: National mailed survey of primary care physicians in 1997-1998, oversampling physicians in areas with more capitated health plans. RESULTS: The response rate was 63% (787 of 1,252 eligible recipients). Overall, 44% of physicians reported encouraging patients either to join or to avoid capitated health plans according to the patients' health status: 40% encouraged more complex and ill patients to avoid capitated plans and 23% encouraged healthier patients to join capitated plans. In multivariable models, physicians with negative perceptions of capitated plan quality, with more negative experiences in capitated plans, and those who knew at each patient encounter how they were being compensated had higher odds of encouraging sicker patients to avoid capitated plans (odds ratios, 2.0, 2.2, and 2.0; all confidence intervals >1). CONCLUSIONS: Many primary care physicians report encouraging patients to join or avoid capitated plans according to the patient's health status. Although these physicians' recommendations might be associated primarily with concerns about quality, they can have the effect of insulating certain health plans from covering sicker and more expensive patients.

Clinical utility of blood cultures drawn from central venous or arterial catheters in critically ill surgical patients.

OBJECTIVE: To determine the sensitivity, specificity, and predictive values of cultures done with blood drawn through a central venous or arterial catheter compared with peripheral venipuncture. DESIGN: Retrospective cohort study of critically ill surgical patients in whom samples for paired cultures were drawn through a central venous or arterial catheter and peripheral venipuncture. SETTING: Tertiary-care, university-affiliated medical center. PATIENTS: Two hundred seventy-one patients hospitalized on a surgical and a cardiothoracic intensive care unit between November 1994 and August 1997. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blinded assessments of culture results done by two physicians were used as the gold standard. Sensitivity, specificity, and positive and negative predictive values were compared for culture of blood from catheters and culture of blood from peripheral venipuncture. Of 499 observations, 426 were catheter-negative/venipuncture-negative, 19 were catheter-positive/venipuncture-positive, 18 were catheter-negative/venipuncture-positive, and 36 were catheter-positive/venipuncture-negative pairs. For catheter draws compared with peripheral venipuncture, sensitivity was 78% (confidence interval [CI], 65% to 90%) and 65% (CI, 50% to 79%) (p = .2), specificity was 95% (CI, 94% to 97%) and 98% (CI, 97% to 99%) (p = .002), positive predictive value was 63% (CI, 51% to 76%) and 78% (CI, 64% to 91%) (p = .1) and negative predictive value was 98% (CI, 96% to 99%) and 97% (CI, 95% to 98%) (p = .3). When central venous specimens as differentiated from arterial catheter specimens were compared with peripheral venipuncture, the difference between positive predictive values reached statistical significance (61% and 82%; p = .04). CONCLUSIONS: In critically ill surgical patients, cultures of blood drawn through a catheter are less specific than those obtained from a peripheral venipuncture. Both types of cultures have an excellent negative predictive value. Positive predictive value of cultures of blood drawn through a catheter is low and, when obtained from a central line, statistically less than from a peripheral venipuncture. Additional cultures seem to be necessary for the proper interpretation of a positive culture drawn through a catheter in critical care patients.