Biomedical subjects
Publications and source records attributed to J A Caprini.
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Prophylaxis against postoperative venous thromboembolism should be tailored according to the patient's level of risk. However, risk assessment is not yet in widespread use in surgical practice. In this study, 538 general surgical patients were prospectively assessed based on a scoring system containing 20 risk factors. Depending on the total risk factor score, the patients were grouped into low (0 to 1, 34.5%), moderate (2 to 4, 48.5%), or high risk (more than 4, 17.2%) categories. Statistically significant (p less than 0.0001) correlation was found between our results and those of three existing risk assessment systems. Overall, of the 538 patients, 37.2% received prophylaxis; 10%, 42.1%, and 76% received prophylaxis in the low-, moderate-, and high-risk categories, respectively. Mechanical prophylactic modalities (graduated elastic compression and sequential intermittent compression) were preferred over pharmacologic modalities. These results suggest that implementation of prophylaxis remains underutilized despite published reports, including NIH guidelines. Our results indicate that the majority of surgical patients seen in this suburban hospital have two or more risk factors for developing venous thromboembolism.
In summary we have developed a VTE risk assessment system for medical patients based on our prior experience in surgical patients. In this model we divide individuals into low, moderate, and high-risk categories. We realize that our system needs further validation with appropriate diagnostic endpoints to correlate the actual occurrence of venous thromboembolism with the predicted risk on the basis of our score system. Nevertheless, the proposed model reflects one approach to achieving a prophylaxis tailored to the patients' risk.
The approach to thrombosis prophylaxis must be individualized according to the patient's risk factors, pathophysiology, planned surgical procedure, and specific medical problems. Based on an assessment of all these variables, the previously recommended modalities can be used alone or in combination, according to the particular needs of the patient. No one method will be completely effective in all patients or all situations. Only through deliberate evaluation and implementation of the appropriate available modalities will the greatest level of thrombosis prophylaxis be achieved.
We simultaneously evaluated platelet and fibrinolytic parameters to assess their individual and combined contributions to postoperative blood loss in cardiopulmonary (CP) bypass patients. Platelet count, platelet aggregability, hematocrit, plasminogen (PLG) concentration, alpha 2-antiplasmin (AP) concentration, free protease activity (fPA), and antithrombin-III (AT-III) were measured in nine patients undergoing surgery using cardiopulmonary bypass. Chest tube drainage was used as the measure of postoperative blood loss. Hematocrit, platelet count, PLG, AP, and AT-III all decreased during CP bypass, with PLG and AT-III decreasing much more than dilution. During CP bypass, platelet aggregability to ADP did not change significantly from pre-bypass, but aggregability to arachidonic acid (AA) decreased significantly. Following protamine administration there was a large increase (83%) in fPA, the platelet count showed a further drop (from 61% to 50% of pre-bypass levels), and platelet aggregability decreased significantly (from 95% to 34% of pre-bypass levels for ADP, and from 55% to 11.9% for AA). Chest tube drainage during the first four postoperative hours correlated positively (p less than 0.05) with the combination of increase in free protease activity and decrease in platelet count. The total chest tube drainage correlated significantly with the combination of decrease in platelet count and the decrease in platelet aggregability. These combinations of changes correlated significantly with postoperative blood loss whereas the individual changes did not.(ABSTRACT TRUNCATED AT 250 WORDS)
During the past decade, we have learned a great deal about the etiology, pathogenesis, diagnosis, and treatment of thromboembolic disease. Subcutaneous heparin has emerged as a major deterrent worldwide for thrombosis prevention but is associated with the potential risk of bleeding and cannot be used in certain patient situations. External compression modalities have emerged as major alternate forms of prophylaxis. We have learned that these devices stimulate the fibrinolytic system, prevent stasis and the endothelial injury that can accompany extreme venous distention. Since they are not associated with bleeding or other serious complications, they are attractive methods for most surgeons, including those performing delicate or complex surgical procedures. Independent studies worldwide have demonstrated their effectiveness in reducing deep vein thrombosis, as recognized by the NIH Consensus Development Panel, and the evidence is compelling that DVT efficacy is a valid marker for PE efficacy. Since these devices reduce the incidence of deep vein thrombosis, they almost certainly must prevent pulmonary emboli; however, a properly designed protocol should be conducted to validate these assumptions. Evidence suggests that full-leg sequential compression is superior to calf compression, but further study is necessary. We believe that a hospital-wide plan, including risk-factor assessment and application of clinical management guidelines, including all available modalities, is important to provide the maximum protection of patients with the lowest risk of side effects. Such a program has been very successful in our community.
This study consisted of 52 patients admitted for orthopedic surgery and 28 patients admitted for general surgery, who were treated with Sequential Compression Devices (SCD) and Thromboembolic Deterrent Stockings (TEDS) and monitored for the development of deep vein thrombosis (DVT). Coagulation and fibrinolytic profiles were carried out on these patients preoperatively, and on days one, three, and six postoperatively. All patients were followed by I-125-Fibrinogen scanning, Venous Doppler, and Impedance Plethysmography studies for clot detection. In the orthopedic surgery group, six (11.5%) developed DVT, and in the general surgery group, one (3.6%) developed DVT. No patients developed pulmonary embolism. The combined incidence of DVT was 8.8 per cent. A variety of parameters was measured in order to determine whether compression devices prevent a fibrinolytic shut-down commonly seen in the postsurgical patient. A combination of three assays was found to be significant in demonstrating a fibrinolytic response. These parameters were a post-surgical decrease in the plasminogen level, an increase in the level of free protease activity postoperatively, and an increase in the level of tissue plasminogen activator after surgery. 56.3 per cent of all patients treated with SCD and TEDS showed a fibrinolytic response on postoperative day one by a combination of all three of these parameters. In the group of patients that developed DVT none showed an increase in free protease activity, and five of seven showed no significant decrease in plasminogen and no increase in tissue plasminogen activator. Patients who developed thrombosis had measurable differences in their fibrinolytic system compared to those without postoperative thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)
This report summarizes a 14-year experience with 219 patients referred for sinus tract extraction of retained common duct stones. The patients ranged from 18 to 94 years of age and 60 per cent were women. Forty seven per cent of patients were seen within 6 weeks postoperatively and 79 per cent within 3 months of surgery. Sixty four per cent of patients had a single stone; the remainder had multiple stones, sludge or ductal debris. Sinus tract manipulation under fluoroscopic control was done using a variety of baskets, catheters and instruments, including endoscopy, along with pre- and post-manipulation intravenous antibiotics. Routine testing and cultures are done and useful when clinical biliary sepsis occurs (1%). Meticulous postextraction cholangiography has contributed to our success and is an important part of the procedure, usually done 24 hours after the last manipulation. Successful extraction occurred during a single session in 125 of 219 patients (57%); 60 of 219 patients required two extraction sessions. Four patients spontaneously passed stones. The remaining patients required three to seven sessions before the extraction was considered complete. Successful extraction of all stones and debris from patients' biliary ducts occurred in 210 of 219 cases (96%). Five of the nine failures occurred in the first one hundred patients (1974-1979) and all required reoperation. Failure occurred in four of the last one hundred patients (1979-1986) and all were successfully treated by ERCP extraction. Two deaths occurred very early in our series and were related to advanced biliary sepsis at the time of the initial presentation.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood samples from 23 subjects with chronic renal failure and 19 controls were tested using thrombelastography and other hematologic tests. The uremic subjects were divided into two groups, those who had not yet begun maintenance hemodialysis treatments (12 subjects) and those who had (11 subjects). Compared to those from control subjects, the thrombelastograms from the uremic subjects consistently indicate normal clotting times but significantly elevated amplitudes. The increased amplitudes correlate positively in the dialyzed uremic group with both platelet count and fibrinogen concentration and correlate negatively in both uremic groups with hematocrit. Thrombelastography demonstrates a hypercoagulability in these samples in vitro, despite the prolonged bleeding time that commonly occurs in uremic subjects.
Thrombelastography was used to quantitatively compare the clot-lysing efficiency of 6 different plasminogen activators, using human whole blood, pooled normal plasma, and platelet rich plasma. The activators compared were the B-chain-streptokinase complex, the plasmin-streptokinase complex, the mini-plasminogen-streptokinase complex, tissue plasminogen activator, streptokinase, and urokinase. The most efficient activator found was the B-chain-streptokinase complex. This complex was 4.0 times more effective than streptokinase, 3.0 times more effective than the plasmin-streptokinase complex, 1.3 times more effective than the mini-plasminogen-streptokinase complex, 2.3 times more effective than tissue plasminogen activator, and 16.0 times more effective than urokinase. Although there were differences in both the coagulation and fibrinolysis thrombelastographic patterns between plasma and whole blood, the comparative efficiencies of each activator were the same with either plasma or blood. The B-chain-streptokinase complex was evaluated as a thrombolytic agent in clot-lysis experiments in the jugular vein in the dog model, using a thrombelastographic method to determine the minimum dose of activator necessary for clot-lysis. With 6 dogs infused locally with 0.25 mg (8000 I.U.) of the plasmin-streptokinase complex, the cumulative clot-lysis was 18.0 +/- 3.0% with the first dose, 33.0 +/- 2.1% with the second dose, and 55.2 +/- 8.6% with the third dose. With 6 dogs infused locally with 0.03 mg (2000 I.U.) of the B-chain-streptokinase complex, the cumulative clot-lysis was 30.6 +/- 6.4% with the first dose, 54.4 +/- 9.6% with the second dose, and 80.2 +/- 9.0% with the third dose.
A successful outcome for the patient who hemorrhages after surgery is based on the recognition of bleeding, the specific diagnosis of bleeding sites and disorders, and the management of bleeding by control measures and replacement of blood lost (Table III). The best preventative measures include careful preoperative assessment of historical and physical findings along with appropriate laboratory tests.
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Between July 1975 and June 1979, 194 patients with State II or III breast carcinoma were randomized to receive either L-phenylalanine mustard (L-PAM), cyclophosphamide and 5-fluorouracil and prednisolone (CFP), or CFP and BCG. Sixty-one patients have recurred despite the adjuvant chemoimmunotherapy trial. Fifty-three are evaluable for survival and 36 for response to chemo-hormonal therapy. Those treated with a chemo-hormonal regimen for their first recurrence exhibited a 53% objective response rate to cytotoxic therapy or a 35% response to hormonal therapy. Prior exposure to L-PAM, cyclophosphamide, or 5-fluorouracil did not preclude response to "salvage" therapy regimens containing those agents. Neither menopausal status, estrogen receptor content, size of the primary tumor, adjuvant treatment, nor extent of the recurrence had any effect on subsequent survival. Overall, the entire group exhibited median survival of 37 months from initial diagnosis and 13 months from recurrence. Unlike recurrent Hodgkin's disease, there was no demonstrable relationship between the length of the disease-free interval and the likelihood of subsequent response to cytotoxic or hormonal treatment. Comparison is made to the results of "salvage" therapy administered after three other large adjuvant treatment series.
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The authors recently encountered a patient with omental anisakiasis who presented with features of acute appendicitis and who made an uneventful recovery following resection of an inflammatory omental mass containing the larva(e). Anisakiasis refers to infestation of humans by species of marine nematode larvae belonging to the subfamily Anisakinae. Although this condition is rarely reported in the United States, it has been well described both in Holland and in the Orient. Several publications in the Japanese literature have detailed the morphology of the parasite and the clinical symptoms of infestation. The source of infestation is most often raw or uncooked fish, the latter widely enjoyed as a foodstuff in the Orient, but less popular in the United States. With the growing popularity of "sushi" bars and the increasing numbers of Americans developing a taste for raw fish, this condition may become more prevalent in the future.
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Patients with stage II or III carcinoma of the breast were assigned to one of three adjuvant chemotherapy and chemoimmunotherapy treatment groups following radical or modified radical mastectomy. This study compares the efficacy of single drug treatment (melphalan) versus multiple drug regimens (CFP and CFP + BCG). In the initial phase of the project participants in the melphalan group showed a higher recurrence rate than those in the CFP and CFP + BCG groups. The recurrence rate of the melphalan group was 4.4 times higher than the recurrence rate of the combined polychemotherapy arms. However, after the initial phase, the recurrence rates for the polychemotherapy arms steadily increased and approached the dropping rate of the melphalan group. Currently (247 weeks after the beginning of the study and nine months after the last patient accrual), 194 patients have been treated (median follow-up time of 101 weeks), and no significant differences can be detected between the three treatment arms using any of the following criteria: disease-free interval, proportion of recurrence and recurrence rate. The only factors which are significant with respect to recurrence are the two prognostic factors: tumor size and degree of nodal involvement. The two chemotherapy groups, CFP and CFP + BCG, show no significant difference with respect to recurrence rate along the entire span of the study.
Thrombelastography, although proven as a useful research tool has not been evaluated for its clinical utility against common coagulation laboratory tests. In this study we compare the thrombelastographic measurements with six common tests (the hematocrit, platelet count, fibrinogen, prothrombin time, activated thromboplastin time and fibrin split products). For such comparisons, two samples of subjects were selected, 141 normal volunteers and 121 patients with cancer. The data was subjected to various statistical techniques such as correlation, ANOVA, canonical and discriminant analysis to measure the extent of the correlations between the two sets of variables and their relative strength to detect blood clotting abnormalities. The results indicate that, although there is a strong relationship between the thrombelastographic variables and these common laboratory tests, the thrombelastographic variables contain additional information on the hemostatic process.