Clinical experience and predicting survival in coronary disease.

To study the accuracy with which long-term prognosis can be predicted in patients with coronary artery disease, prognostic predictions obtained from a large, diverse sample of practicing cardiologists were compared with predictions from a multivariable statistical model. Test samples of 10 patients each were selected from a large series of medically treated patients with significant coronary disease. Using detailed clinical summaries, 49 cardiologists each predicted the probability of 3-year survival and infarction-free survival for 10 patients. Cox regression models, developed using patients who were not in the test samples, were also used to predict corresponding outcome probabilities for each test patient. Overall, the model estimates of prognosis were significantly better than the doctors' predictions. The rank correlation of model predictions with 3-year survival was 0.60, compared with 0.52 for the physicians. Model predictions added significant prognostic information to the doctors' predictions, whereas the converse was not true. Where predictions were made by multiple doctors, the inter-physician variability was substantial. Neither practice characteristics nor extent of clinical experience significantly affected the physicians' predictive accuracy. In coronary artery disease, statistical models developed from carefully collected data can provide prognostic predictions that are more accurate than predictions of experienced clinicians made from detailed case summaries.

Hemorrhagic complications associated with the use of intravenous tissue plasminogen activator in treatment of acute myocardial infarction.

PURPOSE: Little attention has been paid to the importance of clinical factors associated with bleeding complications caused by the use of thrombolytic agents. The goal of our study was to examine clinical and hematologic factors associated with an increased risk of bleeding in a prospectively observed population that received intravenous tissue plasminogen activator for acute myocardial infarction. PATIENTS AND METHODS: Bleeding complications were evaluated in 386 consecutive patients treated with 150 mg of tissue plasminogen activator over six to eight hours for acute myocardial infarction. All patients also underwent immediate cardiac catheterization. RESULTS: Quantitation of blood loss during the patients' hospital stay included a median drop in hematocrit of 11.4 points, a median nadir hematocrit of 31.2, a 14 percent rate of significant clinically evident bleeding, and a 31 percent rate of transfusion of two or more units of blood. All of these parameters were much more severe in patients treated with coronary artery bypass surgery. Access site hematoma was the most common source of bleeding (45 percent of patients), whereas 8 percent had gastrointestinal bleeding, two patients had retroperitoneal bleeding, and two patients had intracranial bleeding. The median nadir fibrinogen was 1.3 g/liter. Multiple linear regression models were used to investigate the relationship between clinical variables, including multiple hematologic measurements, and measures of the amount of blood loss. The use of coronary artery bypass grafting was the variable most closely associated with hemorrhage. Other invasive procedures (angioplasty and intra-aortic balloon pumping) were also associated with increased bleeding. Among the patient descriptors examined, lighter weight, older age, female sex, and history of hypertension were associated with greater blood loss. Of laboratory coagulation parameters, only nadir fibrinogen levels were significantly associated with more bleeding. CONCLUSION: Careful clinical evaluation may improve assessment of the risk/benefit ratio of thrombolytic therapy.

Identification of the optimal electrocardiographic leads for detecting acute epicardial injury in acute myocardial infarction.

Current coronary care electrocardiographic (ECG) monitoring techniques are aimed at detection of cardiac arrhythmias rather than myocardial ischemia. However, in patients with acute myocardial infarction (AMI) who undergo reperfusion therapy, monitoring ST-segment deviation could provide an early noninvasive indicator of coronary artery reocclusion. In this study, the admission 12-lead ECGs of patients with initial AMI were used to propose optimal lead locations for ST-segment monitoring. The study population was selected from consecutive Duke University Medical Center admissions during 1965 to 1981 who met the following inclusion criteria: chest pain for no more than 8 hours, initial AMI documented by ECG and 3 of 4 enzyme criteria, greater than or equal to 0.1 mV (1 mV = 10 mm) of ST elevation in at least 1 of the standard 12 leads (not aVR) on admission ECG, and no ECG evidence of conduction disturbances, ventricular hypertrophy or tachycardia. ST-segment deviation was quantified; AMI location was assigned based on the lead with maximal deviation. Of the 80 patients who had an inferior AMI, lead III was both the most frequent location for ST elevation (94%) and the most common site with maximal ST deviation. Lead V2 had the highest incidence of ST-segment depression (60%). In the 68 patients who had an anterior AMI, lead V2 had the highest frequency of ST elevation (99%). Leads V2 and V3 were the most common sites of maximal elevation. Thus, for monitoring ST deviation, leads III and V2 may be superior to leads II and V1, which are commonly used in arrhythmia monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of initial ST-segment deviation for prediction of final electrocardiographic size of acute myocardial infarcts.

The decision to administer thrombolytic therapy for limitation of acute myocardial infarction (AMI) size must occur when only the history, physical examination and 12-lead electrocardiogram of a patient are available. A method that could quickly assess the amount of jeopardized myocardium would greatly aid the physician. This study developed formulas from 68 anterior and 80 inferior AMI patients using the extent of initial ST-segment deviation (ST delta) to predict the final AMI size estimated by the Selvester QRS score in a population not receiving reperfusion therapy. Inclusion required: initial anterior or inferior AMI; admission electrocardiogram less than or equal to 8 hours after the onset of symptoms with evidence of epicardial injury; elevated creatine kinase-MB; a predischarge electrocardiogram taken greater than or equal to 72 hours after admission; and no AMI extension before the predischarge electrocardiogram. The extent of epicardial injury was quantified by counting the number of leads with greater than or equal to 0.1 mm ST delta, by the sum (sigma) of ST delta in all leads and by the sigma ST delta in the lead groups associated with each AMI location. These results were compared to the AMI size estimated from the predischarge electrocardiogram. Univariable and multivariable analyses generated these formulas for AMI size: anterior = 3[1.5 (number leads ST increases) - 0.4]; inferior = 3[0.6 (sigma ST increases II, III, aVF) + 2.0]. Thus, formulas based on quantitative measurements of ST delta on the admission electrocardiogram are predictive of final QRS-estimated AMI size, and may be useful in determining the efficacy of acute reperfusion therapy.

Results of high dose intravenous urokinase for acute myocardial infarction.

To determine the outcome of patients after treatment with high-dose intravenous urokinase (3 million U) 102 patients were prospectively evaluated in the setting of acute myocardial infarction. The first 61 patients received intravenous urokinase as a continuous infusion and the last 41 patients were treated with an initial 1.5 million U intravenous bolus. Sixty-two percent of all patients had patent infarct-related arteries by the time of immediate angiography (median time 2.2 hours), which was performed in all patients. There was no significant difference in patency rates between patients treated with or without an initial intravenous bolus. Twenty-eight (28%) patients developed clinical evidence of recurrent ischemia (death, reocclusion, emergency angioplasty, urgent bypass surgery) during hospitalization, whereas only 7 (7%) developed angiographically documented reocclusion. Of 28 patients who failed to achieve successful reperfusion at the time of immediate catheterization, rescue angioplasty was technically successful in establishing reperfusion in all but 1 patient. No significant improvement in median global left ventricular function was seen between immediate (48%) and follow-up catheterization (48%). Significant bleeding complications were unusual except in 1 patient who experienced an intracranial hemorrhage. Eight (8%) patients died during hospitalization. Therefore, the use of high-dose intravenous urokinase in patients with acute myocardial infarction is associated with a 62% patency rate, a low incidence of reocclusion and bleeding complications and a high technical success rate with rescue angioplasty at the time of immediate catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of two dose regimens of intravenous tissue plasminogen activator for acute myocardial infarction.

Two dosing schedules of intravenous tissue plasminogen activator (t-PA) for acute myocardial infarction were compared in a multicenter trial. At 2.95 +/- 1.1 hours from onset of chest pain, 386 patients received 150 mg of intravenous t-PA. For the first 178 patients (group A), 60 mg were given in the first-hour dose and the remaining 90 mg were infused over 7 hours. In the subsequent 208 patients (group B), the first-hour dose was 1.0 mg/kg and the remaining 150 mg were given over 5 hours. At initial angiography 94 +/- 30 minutes into therapy, the infarct vessel patency was 64% in group A versus 75% in group B (p = 0.02). By final angiography with up to 4 selective contrast injections, patency was 68% versus 77%, respectively (p = 0.06). Repeat angiography at 7 to 10 days demonstrated reocclusion in 17% of group A and 13% of group B patients (p = 0.35). There was no difference in fibrinogen nadir or mean hematocrit drop between the 2 groups: 120 mg/dl and 11 points, respectively, in group A compared with 120 mg/dl and 10 points in group B. However, bleeding was reduced in group B patients as evident by a decrease in requirement for greater than or equal to 2 units of packed red blood cell transfusion (group A 36%, group B 27%, p = 0.05) and lower incidence of gastrointestinal bleeding (group A 12%, group B 4%, p = 0.002). To further study the importance of weight adjustment, patients were divided into 2 groups according to weight (less than or equal to 90 kg versus greater than 90 kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalosporin therapy in intraabdominal infections. A multicenter randomized, comparative study of cefotetan, moxalactam, and cefoxitin.

Three broad-spectrum cephalosporins (cefotetan, moxalactam, and cefoxitin) proved effective in this randomized, prospective trial for treatment of 303 surgical patients with moderately severe regional peritonitis.

Comprehensive rehabilitation after burn injury.

Comprehensive rehabilitation of patients after burn injury requires the organized application of sound, recognized principles. The basic concerns are the prevention of loss of joint motion, loss of muscle mass, and the prevention of anatomic deformities. Important considerations are starting the rehabilitative program as early as possible after injury and avoiding techniques that unduly immobilize the patient or parts of the body. The use of early active motion to the patient and all movable joints, along with appropriate positioning while at rest, is crucial to a successful program. Passive exercising along with the use of restraints and splints is necessary in certain patients.

A review of skin meshers.

Before the widespread clinical acceptance of mesh skin grafting, expansion of full thickness skin had already been reported. The senior authors, who performed the first mesh skingrafts, have tried several variations of instruments starting with a flat block, later using a roller device with staggered cuts (Mesh Dermatome type I), and further a roller with continuous cuts and a grooved carrier (Mesh Dermatome II). Now interchangeable rollers for different expansions (Zimmer Skin Mesher) and several other genuine meshers are available. Other innovations from the literature are mentioned. This article gives a classification and details of the different models. The basic principles are reviewed. A general formula is presented, allowing objective comparison of skin meshers.

Implementation of parameters in the expansion ratio of mesh skin grafts.

Expansion of a mesh skin graft depends on factors pertaining to the graft itself as well as on parameters of the meshing device. With regard to the graft, we examine the efficiency of graft handling and thickness of the skin graft. With regard to the parameters of the meshing apparatus, which determine the expansion ratio: (1) d equals the distance between the cutting blades, which will become the width of the mesh ribbons and is an underestimated parameter for expansion; and (2) L equals the length of cut, which determines proportionally the expansion ratio. This length defines the maximal distance of the raw square of the expanded mesh and therefore the healing time by epithelialization. The authors present a mathematical formula of expansion ratio that allows for an objective comparison of skin meshing apparatuses. It is concluded that optimal mesh skin grafting is based on mathematical principles rather than on inventive instrumentation. Furthermore, an analysis of the mechanical parameters as given by the manufacturers is important in anticipating healing time per expansion ratio.

Staged reconstruction of flexor tendons with a silicone rod and a "pedicled" sublimis transfer.

We report the results in 11 cases of secondary flexor tendon reconstruction, employing a silicone rubber rod and a sublimis/profundus tenorrhaphy in the first stage, then hinging out the sublimis tendon on the profundus motor at the second stage. Achievement of a healed proximal tenorrhaphy before the second stage allows (1) inspection of the proximal tenorrhaphy (with assessment of its location, apperance, and strength) and (2) early postoperative motion in a controlled range (with greater confidence in the proximal tenorrhaphy, as rupture after free tendon grafting is not uncommon. The functional results attained were comparable to those in other series of secondary flexor tendon reconstructions.

Accidental hydrofluoric acid burns of the hand.

A case report of accidental hydrofluoric acid burns that involve dermal tissue of the hand is presented. Prompt medical treatment for this accident resulted in minimal disfigurement and minimal paresthesia and disability. Protocols for essential treatment and precautions for personnel working in dental laboratories where hydrofluoric acid is used have been discussed.

Rehabilitation after burn injury.

Optimal rehabilitation of patients after burn injury requires the organised application of sound, recognised principles. The basic concerns are the prevention of loss of joint motion, loss of muscle mass, and the prevention of anatomical deformities. Important considerations are starting the rehabilitative programme as early as possible after injury and avoiding techniques which unduly immobilise the patient or parts of the body. The use of early active motion to the patient and all movable joints, along with appropriate positioning while at rest, is crucial to a successful programme. Passive exercising along with the use of restraints and splints are necessary in certain patients.

The simulation of an ex utero intrapartum procedure to extracorporeal membrane oxygenation.

We report a case of using simulation to aid in the performance of ex utero intrapartum treatment (EXIT) procedure to extracorporeal membrane oxygenation (ECMO). A primigravid with a fetus who was diagnosed with hypoplastic left heart syndrome was scheduled for an EXIT to ECMO procedure to be done by members of her obstetrical and neonatal teams. It would be the first time any of the members of the 2 teams would work together. Simulation was used to allow all involved parties to experience the procedure before the live operation. In addition, the simulation enabled the interdisciplinary teams to work with each other, identify possible complications, and further plan the coordination during the event. The EXIT to ECMO surgery was completed successfully. The use of low-fidelity, cost-effective simulation during a surgical rehearsal can give a surgical team critical advantage when performing a rare and/or complex procedure.