Incidences of fatal postoperative pulmonary embolism after prophylaxis with dextran 70 and low-dose heparin: an international multicentre study.

A total of 4352 patients were admitted to a prospective'' randomised multicentre trial comparing the prophylactic efficacy of dextran 70 and low-dose heparin against fatal pulmonary embolism after elective operations for general, orthopaedic, urological, and gynaecological conditions. Out of 3984 patients correctly admitted, 1993 were allocated to receive dextran 70 and 1991 to receive low-dose heparin. Withdrawal of prophylaxis because of bleeding or technical difficulties occurred more often in the heparin group, but allergic reactions were more common in the dextran group. Of the 75 patients who died within 30 days after operation, 38 had been given dextran and 37 low-dose heparin. Necropsy was performed in 33 and 32 of these cases respectively. In six patients in each group pulmonary embolism was the sole or a contributory cause of death. Of these, five patients in the dextran group and two in the heparin group had received a full course of prophylaxis. There was no statistically significant difference between the two treatment groups in the incidence of fatal pulmonary embolism after a full course of prophylaxis.     

Dextran and intermittent pneumatic compression in prevention of postoperative deep vein thrombosis: multiunit trial.

Seven general surgical units co-operated in a clinical trial of dextran 70 and pneumatic calf compression alone and in combination in the preventing of 125I-fibrinogen-detectable deep vein thrombosis in 305 patients. Both dextran regimens were significantly more effective than pneumatic compression alone. Pulmonary embolism was diagnosed in 14 patients, but there was no significant difference in incidence among the three treatment groups. In patients receiving dextran there was no greater median operative blood loss but there was a significantly greater incidence of postoperative bleeding complications.     

Effect of intravenous dextran 70 and pneumatic leg compression on incidence of postoperative pulmonary embolism.

The incidence of pulmonary embolism and deep vein thrombosis was measured in 50 matched pairs of patients undergoing common surgical procedures with preoperative and postoperative ventilation-perfusion lung scans and the fibrinogen uptake test. One patient in each pair was treated with intravenous dextran 70 and pneumatic leggings. The incidence of pulmonary embolism among the treated patients was significantly reduced from 24% to 8%, but the incidence of deep vein thrombosis was not significantly reduced (34% to 24%).     

Low molecular weight heparin in prevention of perioperative thrombosis.

OBJECTIVE--To determine whether prophylactic treatment with low molecular weight heparin reduces the incidence of thrombosis in patients who have had general or orthopaedic surgery. DESIGN--Meta-analysis of results from 52 randomised, controlled clinical studies (29 in general surgery and 23 in orthopaedic surgery) in which low molecular weight heparin was compared with placebo, dextran, or unfractionated heparin. SUBJECTS--Patients who had had general or orthopaedic surgery. INTERVENTION--Once daily injection of a low molecular weight heparin compared with placebo, dextran, or unfractionated heparin. MAIN OUTCOME MEASURES--Incidence of deep venous thrombosis, pulmonary embolism, major haemorrhages, and death. RESULTS--The results confirm that low molecular weight heparins are more efficacious for the prophylactic treatment of deep venous thrombosis than placebo (common odds ratio 0.31, 95% confidence interval 0.22 to 0.43; p < 0.001) and dextran (0.44, 0.30 to 0.65; p < 0.001). The results suggest that low molecular weight heparins are also more efficacious than unfractionated heparin (0.85, 0.74 to 0.97; p = 0.02), with no significant difference in the incidence of major haemorrhages (1.06, 0.93 to 1.20; p = 0.62). CONCLUSIONS--Low molecular weight heparins seem to have a higher benefit to risk ratio than unfractionated heparin in preventing perioperative thrombosis. However, it remains to be shown in a suitably powered clinical trial whether low molecular weight heparin reduces the risk of fatal pulmonary embolism compared with heparin.     

Dextran 70 in Prophylaxis of Postoperative Venous Thrombosis. A Controlled Trial

A controlled prospective trial was carried out in a group of 80 women undergoing gynaecological surgery and thought to be at risk of developing postoperative venous thrombosis. The patients, who had been randomly allocated to prophylaxis with either dextran 70 or warfarin, were well matched in age, weight and other predisposing factors.In the warfarin group, 12 out of 40 patients developed deep vein thrombosis, six of these episodes being classified as major and six as minor. In the dextran 70 group, 4 out of 40 patients developed deep vein thrombosis, all of them minor. The protective effect of dextran 70 is significantly better than that of warfarin (P<0·01) as used in the present study.     

Comparison of Streptokinase and Heparin in Treatment of Isolated Acute Massive Pulmonary Embolism

Massive pulmonary embolism was confirmed by pulmonary arteriography in 23 patients. All were seen between 2 and 48 hours after the onset of embolism and none had pre-existing cardiorespiratory disease. Fifteen were treated with streptokinase and eight with heparin. Factors which might influence prognosis and rate of resolution were similar in the patients in each group, and there was no significant difference between the groups in terms of pretreatment haemodynamic or arteriographic findings. Haemodynamic and arteriographic findings after treatment for 72 hours provided an objective measurement of resolution, which was significantly greater in the streptokinase-treated patients. There was no mortality in either group, but treatment had to be changed in two heparin-treated patients because of clinical deterioration. The principal complication of treatment, seen more often in the streptokinase-treated patients, was bleeding from cut-down or operation sites.     

Electron microscopic pathological patterns of alveolar septum in acute dextran-induced and alloxan-induced pulmonary edema in dogs

We studied the incidence of electron microscopic pathological patterns of the alveolar septum observed 30 min after induction of pulmonary edema by dextran-70 infusion (6 dogs, dextran group) and by alloxan injection (6 dogs, alloxan group). For comparable amounts of extravascular lung water in both dextran and alloxan groups, which were twice as much as control group (6 dogs), we characterized the pathological changes. The incidence of the electron microscopic pathological patterns that appeared in dextran group compared with that in control group was significantly high in terms of the widening of the interstitial space, dispersion and disarray of collagen fibrils, and erythrocytes in the interstitial space. The incidence in alloxan group compared with that in control group was significantly high in terms of the swelling of epithelial cells and endothelial cells as well as the widening of the interstitial space, and dispersion and disarray of collagen fibrils. We conclude that dextran causes interstitial changes exclusively and alloxan causes cellular changes primarily coupled with secondary interstitial changes in acute pulmonary edema.     

Diagnostic Accuracy in Venous Thrombosis

A group of 111 surgical patients at high risk of venous thrombosis were studied after operation by independent clinical assessment and with ¹²⁵I-fibrinogen to detect venous thrombosis. Almost half of the patients developed venous thrombosis. Of these, two-thirds were not suspected clinically despite careful scrutiny. In the patients in whom a clinical diagnosis of venous thrombosis was made this diagnosis was falsely positive in a quarter. More than half of all thrombotic episodes were detectable on the day after operation.The prevalence of venous thrombosis, together with the difficulty in diagnosing it, strongly supports the argument that a reduction in the incidence of pulmonary embolism must depend on widespread adoption of effective prophylaxis, especially in the large number of patients at high risk of venous thrombosis. Prophylactic trials must be objectively assessed, and it is in this field that the ¹²⁵I-fibrinogen technique probably has the most to offer.     

Geneva量表在肺栓塞诊断中的意义

随着认识水平的提高,已发现肺栓塞是临床很常见的疾病。对于如何更好地进行肺栓塞危险性的评估和组织相对复杂的检查,Geneva量表将是临床非常实用的工具。Geneva量表更精确和稳定,较少受临床经验的影响。对于合并慢性阻塞性肺病的患者诊断也有意义。同时,对于预测肺栓塞后3月内不良事件也有价值,临床试验证实对CT检查阴性患者Geneva量表评分为低中度危险不进行抗凝治疗也是安全的。本文将对目前国际上对Geneva量表的应用进展做一综述。     

Cost-effectiveness of primary and secondary prevention of fatal pulmonary embolism in high-risk surgical patients.

Because death due to pulmonary embolism is relatively rare following general surgery, many question the need for prophylaxis. In addition, there has been reluctance to apply new interventions whose cost-effectiveness has not been adequately evaluated. A cost-effectiveness analysis based on over 1000 high-risk patients undergoing abdominothoracic surgery, with effectiveness measured in terms of numbers of deaths from pulmonary embolism averted, has shown subcutaneous administration of heparin in low doses starting 2 hours before the operation to be the most cost-effective of several active approaches to prophylaxis. It averted seven of the eight deaths expected without active prophylaxis per 1000 such patients and cost half as much as the traditional approach of intervening only when venous thromboembolism becomes clinically apparent. Intravenous administration of dextran, although effective, was expensive, and leg scanning with iodine-125-labelled fibrinogen was extremely expensive. Intermittent pneumatic compression of the legs was inexpensive, but, as with leg scanning, its effectiveness has not been determined in randomized trials.     

Failure of low-dose heparin to prevent significant thromboembolic complications in high-risk surgical patients: interim report of prospective trial. Groote Schuur Hospital Thromboembolus Study Group.

The efficacy of low-dose subcutaneous heparin (5000 IU eight-hourly) is being studied in a single-centre, prospective randomised trial of patients aged over 40 submitted to major elective intra-abdominal surgery. The trial end-points are the objectively defined incidence and extent of deep vein thrombosis (as seen on uptake of 125I-labelled fibrinogen, Doppler ultrasonography, and bilateral ascending phlebography) and non-fatal pulmonary embolus (as measured by preoperative spirometry and preoperative and postoperative chest radiography and perfusion lung scanning performed on a routine, unselected basis). An interim analysis of the first 200 patients indicates that low-dose heparin significantly reduces the incidence of calf-vein thrombosis but does not reduce the incidence of proximal segment thrombosis or non-fatal pulmonary embolism. Thus the routine use of low-dose heparin prophylaxis in all major surgical procedures in patients aged over 40 may not be advisable.     

Prevention of Recurrent Pulmonary Embolism

Fifty patients have been studied by bilateral phlebography following their first, or sometimes recurrent, pulmonary embolus. Nineteen were found to have fresh loose peripheral thrombus, and in eight of them the thrombus looked big enough to cause a major pulmonary artery obstruction and death. These 19 patients were treated by vein ligation in addition to anticoagulants.The incidence of recurrent embolism in the trial group is significantly lower than that found in a retrospective study of 50 patients treated with anticoagulants only. It is suggested that anticoagulants will not prevent all recurrent pulmonary emboli, and that phlebography, and if necessary surgery, should be part of the routine investigation and treatment of all patients after their first pulmonary embolus.     

肺血栓栓塞症患者栓塞面积和临床特征的相关性分析

目的:分析肺血栓栓塞症患者栓塞面积和临床特征的相关性。方法:将哈尔滨医科大学附属第二医院呼吸内科2007年1月-2011年12月收治的78例肺血栓栓塞症患者作为研究对象,并根据其栓塞面积分为大面积组(38例)和小面积组(40例),观察和比较两组患者的临床症状、临床体征、危险因素分布、血气分析结果、D-二聚体水平。结果:大面积组呼吸困难、心悸、晕厥的发生率均显著高于小面积组,呼吸急促、发绀的发生率均明显高于小面积组患者,Pa O2和Pa CO2均显著低于小面积组,差异均具有统计学意义(P0.05)。半定量乳胶聚集法测定的D-二聚体值在两组之间未见明显统计学差异,免疫比浊法测定的D-二聚体值在大面积组明显高于小面积组,且具有统计学差(P0.05)。结论:(1)呼吸困难、晕厥、心悸、呼吸急促、血压下降、发绀可提示大面积肺血栓栓塞症的发生;(2)Pa O2和Pa CO2明显减低提示大面积肺栓塞可能性较大;(3)D-二聚体是否能提示肺栓塞面积大小可能与其测量方法有关,需进一步研究,但对排除肺栓塞有重要意义。     

Point-of-care versus central testing of hemoglobin during large volume blood transfusion

Hypoxic preconditioning (HPC) may protect multiple organs from various injuries. We hypothesized that HPC would reduce lung injury in patients undergoing thoracoscopic lobectomy. In a prospective randomized controlled trial, 70 patients undergoing elective thoracoscopic lobectomy were randomly allocated to the HPC group or the control group. Three cycles of 5-min hypoxia and 3-min ventilation applied to the nondependent lung served as the HPC intervention. The primary outcome was the PaO2/FiO2 ratio. Secondary outcomes included postoperative pulmonary complications, pulmonary function, and duration of hospital stay. HPC significantly increased the PaO2/FiO2 ratio compared with the control at 30 min after one-lung ventilation and 7 days after operation. Compared with the control, it also significantly improved postoperative pulmonary function and markedly reduced the postoperative hospital stay duration. No significant differences between groups were observed in the incidence of pulmonary complications or overall postoperative morbidity. HPC improves postoperative oxygenation, enhances the recovery of pulmonary function, and reduces the duration of hospital stay in patients undergoing thoracoscopic lobectomy. This study was registered in the Chinese Clinical Trial Registry (ChiCTR-IPR-17011249) on April 27, 2017.     

Heparin Prophylaxis against Fatal Postoperative Pulmonary Embolism

Low-dose heparin prophylaxis against fatal pulmonary embolism has been studied in a random and prospective trial in 300 patients over the age of 50 who underwent major surgery. A dose of 5,000 IU mucous heparin sodium given two hours preoperatively and for five days post operatively prevented fatal pulmonary embolism in all 156 patients so treated, whereas out of 144 patients in the unheparinized group 6 (4·2%) died of pulmonary embolism. This difference is statistically significant. There was no increase in operative or post-operative bleeding or in the formation of wound haematomas in the heparinized group.     

Low-dose heparin prophylaxis against fatal pulmonary embolism.

A prospective randomised controlled trial in 500 patients over the age of 50 who were undergoing major surgery showed that low-dose subcutaneous heparin was an effective prophylactic measure against fatal pulmonary embolism. None of the 252 patients who received perioperative heparin cover died of fatal pulmonary embolism while eight of the 236 who did not receive heparin prophylaxis died of fatal pulmonary embolism. These results were statiscally significant (P less than 0.01).     

Local streptokinase administration in massive pulmonary embolism

Five patients with acute massive pulmonary embolism were treated with streptokinase administered via the pulmonary artery as close as possible to the embolus. Streptokinase (Awelysin) was infused at a loading dose of 250,000 IU followed by a maintenance dose of 100,000 IU/hour under haemodynamic and angiographic control. In four of five patients (two patients with cardiogenic shock) the clinical signs, pulmonary artery pressure and the angiographic findings improved or they normalised within 5-12 hours. In one patient with recurrent embolisation over three weeks the clinical condition improved gradually, although the angiographic findings improved only slightly. The results demonstrate that local thrombolysis of acute massive pulmonary embolism is a highly effective form of treatment.     

Thromboembolic Complications in Myelomatosis

Fourteen cases of myelomatosis associated with major thromboembolic complications are reported. Six patients died of pulmonary embolism, seven had deep-vein thrombosis as a presenting symptom, and three had evidence of amyloidosis. A preliminary estimate of the incidence of thromboembolism based on 376 patients admitted so far to the Medical Research Council''s myelomatosis trial is about 3%, while pulmonary embolism accounted for about 3% of all deaths. Possibly a hypercoagulable state and the presence of amyloidosis may be important in the pathogenesis of this complication.     

利伐沙班用于急性肺栓塞的抗凝效果及对血清Hcy、BNP、TnI与D-D水平的影响

目的:探讨利伐沙班用于急性肺栓塞的抗凝效果及对血清脑钠肽(Brain natriuretic peptide,BNP)、肌钙蛋白I (Troponin I,TnI)、D-二聚体(D-Dimer,D-D)、同型半胱氨酸(homocysteine,Hcy)水平的影响。方法:选择2014年2月至2017年12月在我院进行治疗的(高)中危组急性肺栓塞患者106例,并将其随机分为观察组和对照组。对照组皮下注射低分子肝素钙搭配华法林治疗,观察组予以利伐沙班治疗,观察和比较两组患者的临床疗效、治疗前后血清BNP、TnI、D-D、Hcy水平的变化及不良反应的发生情况。结果:治疗后,观察组患者总有效率为94.37%,显著高于对照组(42.10%,P0.05);观察组患者血清BNP、TnI、D-D、Hcy及肺动脉收缩压水平均显著低于对照组(P0.05),而动脉收缩压、动脉血氧分压水平较对照组水平显著升高(P0.05)。结论:利伐沙班应用于治疗急性肺栓塞的抗凝效果显著优于低分子肝素钙搭配华法林治疗,其可有效降低患者血清BNP、TnI、D-D、Hcy水平以及肺动脉收缩压。     

Subcutaneous injections and intravenous infusion of sodium salt of heparin in the treatment of thrombosis of deep veins of the lower extremities

Ninety-four patients with deep vein thrombosis of inferior limbs were randomly allocated to receive sodium heparin either by subcutaneous injections or by continuous intravenous infusion for six days. No significant difference was observed in the therapeutic efficiency as judged by phlebographic examinations and in rate of symptomatic pulmonary embolism between the two groups. There was one instance of major bleeding in the subcutaneous group. Minor bleedings occurred in 10 of the 48 patients treated with subcutaneous heparin and in 13 of the 46 patients receiving intravenous heparin. The results showed that subcutaneous injections of sodium heparin are as effective and safe as continuous intravenous infusion of this drug in the treatment of deep vein thrombosis.