Patel et al evaluate cardiac rehabilitation referral patterns using computerized physician order entry systems. At a large academic hospital, poor cardiac rehabilitation referral and enrollment ...patterns markedly improved after implementing a computerized physician order entry-based cardiac rehabilitation referral system. The simple and automated nature of this referral system allowed for it to be rapidly implemented without obstructing the flow of patient care. As part of a trend towards computerized medical records, similar automated referral strategies could easily be adopted by other hospitals, which could lead to substantial improvements in patient outcomes via greater utilization of cardiac rehabilitation programs.
There has been a recent resurgence of interest in the study and application of computerized neural networks within the broad field of artificial intelligence. These "intelligent machines" are modeled ...after biological nervous systems and are fundamentally different from the many computerized expert systems that previously have been introduced as clinical decision-making aids. The authors describe a neural network designed and trained to predict the probability of acute myocardial infarction (AMI) based on the analysis of paired sets of cardiac enzymes. The neural network predicted 24 of 24 (100%) AMIs and 27 of 29 (93%) No-AMIs when compared with a pathologist's interpretation of the patient's laboratory data (P less than 0.000001). The authors attempted to validate the network's diagnoses by two independent methods. When compared with echocardiogram and EKG for diagnosis of AMI, the neural network agreed with the cardiologist's interpretation in 12 of 14 (86%) AMIs and 1 of 3 (33%) No-AMIs, but the correlation was not statistically significant. Using autopsy outcome for validation, the neural network agreed with the anatomic evidence in 24 of 26 (92%) AMIs and 4 of 6 (67%) No-AMIs (P = 0.001). The authors conclude that neural networks can be successfully applied to the analysis of cardiac enzyme data and suggest that broader applications exist within the domain of clinical decision support.
Aortic regurgitation and mitral stenosis are hemody-namically similar, insofar as both result in passive ventricular filling across a narrow orifice driven by a declining pressure gradient. Because ...mitral stenosis is successfully characterized by Doppler ultrasound determination of the velocity half-time, or time constant, aortic regurgitation might be quantified in an analogous fashion. Eighty-six patients with diverse causes of aortic regurgitation underwent continuous wave Doppler examination before cardiac catheterization or urgent aortic valve replacement. The Doppler velocity half-time was defined as the time required for the diastolic aortic regurgitation velocity profile to decay by 29%, whereas catheterization pressure half-time was calculated as the time required for transvalvular pressure to decay by 50%.
Doppler velocity and catheterization pressure half-times were linearly related (r = 0.91). Doppler velocity half-times were inversely related to regurgitant fraction (r = −0.88). Angiographic severity (1+ = mild to 4 + = severe) was also inversely related to pressure and velocity half-time; a Doppler half-time threshold of 400 ms separated mild (1 +, 2 +) from significant (3 +, 4 +) aortic regurgitation with high specificity (0.92) and predictive value (0.90). The Doppler velocity half-time was independent of pulse pressure, mean arterial pressure, ejection fraction and left ventricular end-diastolic pressure. Estimation of transvalvular aortic pressure half-time utilizing continuous wave Doppler ultrasound is a reliable and accurate method for the noninvasive evaluation of the severity of aortic regurgitation.
From this discussion, several conclusions can be drawn. First, with advancing age there is a decrease in cardiovascular responsiveness and, more specifically, there is a decrease in ...catecholamine-stimulated chronotropic and inotropic responses. This decreased function has its biochemical correlate in the observation that cyclic AMP levels are decreased in response to isoproterenol infusion in cells or tissues derived from aged organisms. Second, although most work on human circulating cells suggests that beta-adrenergic receptor densities are unchanged, measurements of beta-adrenergic receptor concentrations in various cells from various animals (predominantly rats) have yielded conflicting results. Some of this disparity could be due to the observation that local concentrations of norepinephrine, such as those found intramyocardially, may be very different from those in circulating plasma. Indeed, whereas circulating norepinephrine levels tend to rise with age, the intramyocardial norepinephrine levels tend to fall with senescence. Thus, circulating lymphocytes may or may not be an appropriate model to reflect the catecholamine milieu to which other tissues may be exposed. Accordingly, a note of caution must be entered in terms of extrapolating findings regarding the levels of human lymphocyte beta-adrenergic receptors and cyclic AMP activity to those found, for example, in the human heart. Furthermore, it is likely that age-related changes in adrenergic function may be the result of changes in coupling of receptors to the adenylate cyclase system, as suggested by Feldman and co-workers, and/or changes in steps distal to cyclase activation, as suggested by Guarnieri and colleagues.
We performed a prospective, blinded, controlled study to test the hypothesis that supine cross-table lateral chest roentgenograms might have an advantage over conventional lateral chest ...roentgenograms for the detection of pericardial effusion using the epicardial fat stripe sign. In comparison with echocardiography as the gold standard, we found that supine cross-table lateral chest roentgenograms had greater sensitivity (51%) for pericardial effusions than conventional lateral chest roentgenograms (sensitivity, 31%). Specificity was essentially the same for both techniques. A large pericardial effusion was more readily detected by supine cross-table lateral chest roentgenograms (86%) than by the conventional lateral chest roentgenograms (36%). We conclude that a supine cross-table lateral chest roentgenogram should be included in the evaluation of patients with suspected pericardial effusion or in patients in whom a large cardiac silhouette is detected on a standard chest roentgenogram.
The focus of new research efforts to improve the morbidity and mortality associated with acute myocardial infarction (AMI) has turned to adjuvant agents that show promise of improving outcomes ...following coronary thrombolysis. We enrolled 162 patients with AMI in a randomized trial comparing front-loaded tissue-plasminogen activator (t-PA) plus weight-adjusted heparin with anisoylated plasminogen streptokinase activator complex (APSAC) without heparin as well as standarddose (325 mg) and low-dose (81 mg) aspirin. The primary end point was an in-hospital morbidity profile; secondary end points were clinical and angiographic patency and hemorrhagic events. Selected sites performed an electrocardiographic substudy to determine the time to 50% ST-segment recovery and the time to steady state. Although the trial was terminated when the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries-I trial showed that t-PA had a significant mortality advantage over streptokinase, important trends were evident. Patients given t-PA and heparin were better anticoagulated (p = 0.001), yet AP-SAC-treated patients had more bleeding complications. The primary end point favored t-PA (25.4% vs 31.3%), and the secondary end points were similar in both groups. In the electrocardiographic substudy, the t-PA group achieved both 50% ST-segment recovery and steady-state recovery sooner than the APSAC group. Patients taking low-dose aspirin had lower in-hospital mortality and less recurrent ischemia but more strokes than the standard-dose aspirin group. Thus, this trial demonstrated trends favoring front-loaded t-PA with weight-adjusted heparin over APSAC without heparin in the treatment of AMI. The use of low-dose aspirin did not appear to impose a loss of protection from adverse events, nor did standard-dose aspirin increase serious bleeding.
Background: Intraoperative blood loss and postoperative anemia have been a concern when more than 1500 ml of lipoplasty material is aspirated. Blood loss is minimal when the targeted area is ...infiltrated with large volumes of dilute lidocaine and epinephrine. However, little quantitative data are available regarding the intraoperative blood loss and postoperative hemoglobin drop.
Methods: In this prospective study 38 consecutive women were investigated with preoperative measurement of hemoglobin, platelet count, prothrombin time, activated partial thromboplastin time, and postoperative measurement of hemoglobin. Hemoglobin and whole blood volume were calculated from the infranatant portion of the lipoplasty aspirate. All procedures were done with the patient under general anesthesia.
Results: The mean (±SD) volume of lipoplasty aspirate material was 2900±14702.8 ml (range 1000 to 5800 ml). The mean (±SD) whole blood volume in lipoplasty aspirate per case was 36±50.82 ml (range 1.2 to 251 ml). The mean (±SD) fall in hemoglobin was 0.93±0.92 gm/dl (range 0.2 to 4.3 gm/dl). The volume of whole blood loss was estimated to be 12.4 ml in each 1000 ml of lipoplasty aspirate. No blood transfusions were required.
Conclusion: Data show that blood loss with the tumescent technique is remarkably low. Use of this technique permits large-volume lipoplasty aspirate and minimizes the need for blood transfusion.
To evaluate operating room (OR) costs associated with the 2 available morcellators in the United States in a matched cohort and to determine benign prostatic hyperplasia surgeon's morcellator ...preference.
Patients from 2013, the last year our institution exclusively used the VersaCut device, were matched 1:1 with the most recent patient cohort, utilizing the Wolf Piranha morcellator. Cost of morcellation including the expense of OR time and disposable instrument costs were calculated. A survey to the Endourological Society e-mail listserv was sent to determine morcellator preference.
We identified 142 patients who underwent holmium laser enucleation of the prostate in 2013. When compared with the VersaCut group, morcellation efficiency (4.4 vs 7.0 g/min, P <.01) and expense of OR time ($1420.80 vs $992.21, P <.005) both favored the Piranha morcellator system even when the costs of disposable instruments were factored into the analysis ($1338.81 vs $1637.50, P <.05).
A total of 126 urologists responded to the survey. Of these, 56 (44.5%) perform transurethral prostate enucleations, which included 48 (86%) holmium. More endourologists use the VersaCut (n = 33, 59%) than the Piranha (n = 24, 43%) morcellator. Qualities that impacted the preference of morcellator included the preferred device is safer, faster, easier to use, reusable, and less expensive.
We identified a significant improved efficiency and improved cost savings utilizing the Piranha morcellator even when controlling for disposable costs. Of the endourologists who responded to the survey, less than half perform transurethral enucleation. Morcellator preference is largely based on safety, efficiency, and ease of use, whereas cost and reusablility were of lesser importance.
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