Preoperative platelet count and postoperative blood loss in patients undergoing hip surgery: an inverse correlation.

In a previous study we tried to assess the clinical usefulness of platelet count (PlC) to confirm whether postoperative pulmonary embolism could be suspected early. Unexpectedly, the 19 patients who subsequently developed pulmonary embolism had significantly lower mean PlC levels even before surgery. In an attempt to discover whether the preoperative PlC levels were associated with a different incidence of postoperative blood loss, we decided to retrospectively study the relationship between preoperative PlC levels and the consequences of blood loss. There were 459 consecutive patients undergoing hip surgery. After excluding 5 patients who died during the first 3 postoperative days, and 16 patients who bled from a definitive anatomic site, there were 438 patients. Blood loss was considered to be excessive when two or more of the following conditions were present: (1) total transfusion requirements exceeding 1,000 ml whole blood or 2 units of packed red cells; (2) a drop in hemoglobin level of 5 g/dl or more, and (3) a hemoglobin level below 8 g/dl at any moment during the first 8 postoperative days. Blood loss was considered to be excessive in 91 patients. Preoperative PlC levels were significantly lower in these patients as compared to patients without the condition (204 +/- 52 vs. 236 +/- 79 x 10(9) liter-1; p = 0.0002). When patients were classified according to the quartiles of preoperative PlC, the odds ratio of developing excessive blood loss was 0.69 (95% CI: 0.38-1.26) in patients in the second quartile; 0.57 (95% CI: 0.30-1.06) in the third quartile, and 0.27 (95% CI: 0.13-0.57) in patients in the highest quartile. After adjusting for age, sex, type of surgery and type of prophylaxis, the preoperative PlC levels maintained a statistically significant inverse correlation with postoperative blood loss.

Effects of long-term therapy with either heparin or low-molecular-weight heparin on serum lipid levels. A prospective study.

Beside the anticoagulant and antithrombotic activity, heparin also exerts a lipolytic activity. In a prospective study on patients with venous thromboembolism and some contraindications to coumarin therapy, a low-molecular-weight heparin (Fragmin) was compared to unfractioned (UF) heparin in terms of both efficacy and safety. A secondary aim was to study the influence of both types of heparin on serum lipid levels. Sixty-six consecutive patients who were not taking concomitant treatment with lipid-lowering drugs entered the study. Patients received treatment with either UF heparin, 10,000 IU s.c., b.d., or Fragmin 5,000 IU anti-factor Xa s.c., b.d. for a period of 3 or 6 months, according to whether the initial diagnosis was deep venous thrombosis or pulmonary embolism. Each patient was followed up at 6-weekly intervals, and blood samples were obtained at discharge, and then 6 and 12 weeks after discharge. Finally, a further sample was obtained 3 months after therapy was discontinued. Total cholesterol levels increased significantly in both groups of patients: levels increased from 193 +/- 56 to 246 +/- 63 mg/dl in the UF heparin group (p < 0.001), and from 189 +/- 53 to 222 +/- 47 mg/dl in the Fragmin group (p < 0.05). The increase was mostly due to a very strong increase in HDL cholesterol levels in patients receiving UF heparin (from 46 +/- 12 to 71 +/- 23 mg/dl; p < 0.000005). Three months after discharge, HDL cholesterol levels were significantly higher in patients taking UF heparin than in patients in Fragmin (p = 0.006). By contrast, patients on Fragmin exhibited a significant increase in LDL cholesterol levels: from 112 +/- 39 to 139 +/- 37 mg/dl; p < 0.01.

Platelet count, antiplatelet therapy and pulmonary embolism--a prospective study in patients with hip surgery.

Pulmonary embolism (PE) is a serious complication following hip surgery. Trials of antiplatelet thromboprophylaxis indicated a substantial reduction in PE rate, and we prospectively studied the effect of a combination of low-dose heparin and two different antiplatelets. Furthermore, our experience in previous studies suggested that platelet count (PC) levels could be useful to reliably suspect PE at a very early stage, and we prospectively tried to confirm our previous findings. Ours is a prospective study in 459 consecutive patients operated on because of hip fracture (265) or elective hip replacement (194), aimed to determine: 1) whether the benefits of antiplatelets plus heparin on PE outweigh the risks; 2) to assess the clinical usefulness of PC monitoring in these patients, so as to confirm whether PE could be recognized early. It was a prospective, randomized, double-blind study. All patients received unfractioned heparin (7500 IU sc twice daily, starting 2 h before operation). In addition, they received aspirin (200 mg thrice daily, with meals), Triflusal (300 mg thrice daily, with meals), or placebo. Real time B-mode ultrasonography (US) was performed on all patients on the 8-9th day after surgery. Venography was performed in patients with normal US, if clinical symptoms suggested venous thrombosis. Twelve out of the 459 patients (2.6%) had to discontinue prophylaxis, because of major bleeding (6 patients), or gastric intolerance (6 patients). There were no significant differences between groups in either deep vein thrombosis (26 patients (18%) with aspirin, 18 (12%) with Triflusal, 26 (17%) with placebo), or PE development (7 patients (5%) with aspirin, 3 (2%) with Triflusal, 8 (5%) taking placebo).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary embolism in patients with upper extremity DVT associated to venous central lines--a prospective study.

We performed a prospective study in 86 consecutive patients with central vein catheter-related deep venous thrombosis (DVT) of the upper extremity, to evaluate the prevalence of pulmonary embolism (PE), and to identify clinical variables that would increase the likelihood of developing PE in an individual patient. Since upper-extremity DVT was established, all patients received intravenous heparin therapy. Then, a ventilation-perfusion lung scan was obtained within 24 h of DVT diagnosis, whether respiratory symptoms were present or not. Six points of clinical information were recorded on entering in the study, and then compared with the scintigraphic findings: age, sex, the underlying disease, the catheter material, the character of the infusate, and the duration of cannulation. Thirteen patients were considered to have PE. Sixty-six patients were finally classified as having a normal lung scan, and 7 patients were excluded from the study (because of indeterminate lung scan 6; because of femoropopliteal thrombosis simultaneously present 1). Two out of the 13 patients with PE subsequently died because of recurrent, massive embolism, despite adequate heparin therapy. PE was more commonly present in patients with polyvinyle chloride or polyethylene catheters (10/38, 26%) as compared to patients with either polyurethane or siliconized catheters (3/41, 7%; p < 0.05, Chi-Square test; Odds Ratio = 4.52, 95% CI 1.01-23.07). We conclude that PE is not a rare event in these patients, and it may be life-threatening even despite adequate heparin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrent pulmonary embolism in patients treated because of acute venous thromboembolism: a prospective study.

OBJECTIVE: To evaluate the risk of pulmonary embolism (PE) despite adequate heparin therapy in a large series of patients with acute deep venous thrombosis and/or pulmonary embolism. DESIGN: Prospective study. SETTING: University Hospital Germans Trias i Pujol, Badalona, Spain. MATERIALS: 348 patients admitted because of deep venous thrombosis in the lower limbs and/or pulmonary embolism. A baseline lung scan was obtained initially in every patient, whether the original diagnosis was PE or deep vein thrombosis (DVT). Repeat chest X-ray and lung scans were obtained routinely at 8 days of heparin onset. OUTCOME MEASURES: The primary trial endpoint was a finding of confirmed, clinically apparent recurrent PE; in addition, laboratory evidence of subclinical PE at the repeat scan was also considered. RESULTS: PE recurrences were found in 23/348 patients (7%). No significant differences were found in age and sex distribution, or in the degree of DVT proximity between patients who developed and those who did not develop recurrences. Recurrent PE was more commonly found in patients with scintigraphic evidence of PE on admission, irrespectively of the original diagnosis being DVT or PE (18/151 vs. 3/155; p = 0.0005, Fisher's exact test). Recurrences were also more common in patients in whom thrombosis developed in the absence of any known risk factor (10/70 vs. 13/278; p = 0.007). The logistic regression analysis confirmed the statistical significance of these two clinical variables. CONCLUSIONS: Pulmonary embolism despite adequate heparin therapy is not an uncommon event. It appears possible to identify a subgroup of patients at a higher risk, and, modify treatment accordingly.

Comparison of subcutaneous unfractionated heparin with a low molecular weight heparin (Fragmin) in patients with venous thromboembolism and contraindications to coumarin.

Intravenous heparin followed by oral anticoagulant therapy (e. g. with coumarin) is still the most widely used treatment for deep venous thromboembolism. Self-administered subcutaneous injections of heparin have been thought of as a promising alternative to coumarin, but the high doses required for ongoing prophylaxis have raised concerns about the possible development of bone disease. Certainly, long-term heparin therapy has been reported to cause osteoporosis in both laboratory animals and humans. This study aimed to compare the efficacy and safety of unfractionated (UF) heparin with that of a low molecular weight heparin (Fragmin, Kabi Pharmacia) in the prevention of recurrent deep venous thrombosis (DVT) and pulmonary embolism (PE) in a consecutive series of patients with contraindications to coumarin therapy. The patients comprised 40 men and 40 women, aged between 19 and 92 years (mean age, 68 years). They had all previously been diagnosed as having acute DVT and had been treated with conventional doses of heparin while in hospital. All patients had at least one of the following conditions: recent blood loss (either spontaneous or during admission while receiving heparin therapy); active gastroduodenal ulcer disease; psychological or physical inability or unwillingness to understand and accept the need for regular laboratory monitoring during coumarin treatment; chronic alcoholism; dementia; pregnancy; recent neurosurgery, and pericardial effusion; or were over 80 years of age. They were randomly allocated to receive either UF heparin, 10,000 IU s.c. b.d., or Fragmin, 5000 IU anti-Factor Xa s.c. b.d., for a period of 3-6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet count in acute pulmonary embolism: its relationship to recurrences.

We have prospectively studied a large series of patients with acute venous thromboembolism, trying to correlate pulmonary embolism (PE) recurrences to a number of clinical variables, and platelet count behavior. A baseline lung scan was obtained initially in every patient. Repeated chest X-ray and lung scans were obtained routinely 8 days after heparin onset. The primary trial endpoint was confirmed, clinically apparent recurrent PE; in addition, laboratory evidence of subclinical PE at the repeat scan was also considered. PE recurrences were found in 26/180 patients, and 3 out of these patients died because of massive, recurrent PE. No significant differences were found in age and sex distribution, or in the degree of deep vein thrombosis proximity between patients who did or did not develop recurrences. There were, however, differences between groups in platelet count: No differences were found in baseline counts, but mean values were significantly lower by the 8th day when recurrences had appeared (229 +/- 86 x 10(9) liters-1 versus 314 +/- 129 x 10(9) liters-1; p < 0.005). The sensitivity, specificity, positive predictive value and negative predictive value for platelet count decrease were 52, 71, 21 and 91%, respectively. Thus, platelet count cannot be reliably used for individual cases, but our findings add to the pathophysiological picture of the disease.

Venographic assessment of deep vein thrombosis and risk of developing post-thrombotic syndrome: a prospective study.

It is well known that patients with deep vein thrombosis (DVT) constitute a risk group for development of pulmonary embolism. However, the relation of DVT and the extent thereof with the subsequent sequelae (post-thrombotic syndrome) are insufficiently investigated. We have prospectively studied a series of consecutive patients admitted because of DVT on lower limbs, trying to correlate venographic findings during acute DVT with post-thrombotic (PTS) symptoms that develop later. Seventy-nine patients (84 limbs) with acute DVT were followed-up in our out-patient clinic at 4-monthly intervals for 3 years. At each visit patients were carefully examined regarding the appearance of PTS symptoms and/or signs from the DVT-affected leg. Three years after discharge, presence of PTS signs was assessed according to a simple scoring system. And then correlated to venographic findings during acute DVT. Patients were classified as having no (37 legs), mild (30 legs), or severe PTS signs (17 legs). Patients with popliteal vein involvement showed a significantly higher incidence of PTS 3 years later (P < 0.001). The risk of PTS also increased as DVT extent increased (P < 0.001). Nevertheless, the logistic regression analysis showed that DVT location explained all the differences (P < 0.001). In other words, DVT extent was overriden by the significance of DVT location, being popliteal the only location that showed a relevant contribution to the PTS incidence (95% confidence interval = 2.49-71.5).

Platelet count and venous thromboembolism. A useful test for suspected pulmonary embolism.

We have previously reported that patients with deep vein thrombosis (DVT) and scintigraphic evidence of pulmonary embolism (PE) had a fall in platelet count, as compared with their levels before thrombosis had developed. Otherwise, no changes were found in DVT patients without embolism. We recently conducted a prospective study with a larger series of patients and studied platelet count behavior in 189 consecutive patients with acute venous thromboembolism (VTE) in whom a baseline blood cell count was available (obtained before thromboembolism developed). We found no significant differences in baseline platelet counts between groups. However, at the time of VTE diagnosis the analysis of variance demonstrated that mean platelet count was significantly higher in patients without embolism as compared with PE patients (p less than 0.001). On the other hand, no differences were found between patients with silent PE and those with clinically obvious PE. When patients with postoperative VTE and those with nonpostoperative VTE were analyzed separately, mean platelet count increased only in postoperative DVT patients without embolism (p less than 0.001). In the absence of a previous intervention, DVT did not produce any change in platelet count, while PE significantly reduced platelet number (p less than 0.008). In DVT patients without respiratory symptoms of embolism, we suggest that a lung scan should be performed when platelet count is lower than baseline value. For patients with a higher count, the probability of finding PE is very low, and scintigraphy is not cost-effective.