Disseminated intravascular coagulation and antithrombin III depression in acute fatty liver of pregnancy.

OBJECTIVE: Acute fatty liver of pregnancy has been associated with a syndrome of marked depression of antithrombin III and disseminated intravascular coagulation. We sought to identify the clinical importance of this accelerated coagulation. STUDY DESIGN: The medical records of patients with acute fatty liver of pregnancy identified during the period of 1982 to 1994 were retrospectively reviewed. RESULTS: Twenty-eight patients with acute fatty liver of pregnancy were identified for an incidence of 1:6692 births. Laboratory evidence of persistent disseminated intravascular coagulation was found in all patients tested. Six patients had clinical bleeding, all associated with genital tract injury. Twenty-three of twenty-three patients tested had markedly decreased antithrombin III levels (average 11%, normal range 80% to 100%). Seven patients received antithrombin III transfusions, which was associated with a significant transient rise in the plasma level. Compared with patients not transfused, however, there was a similar clinical outcome. CONCLUSION: Profoundly depressed antithrombin III levels and laboratory evidence of disseminated intravascular coagulation were present in all cases of acute fatty liver of pregnancy but rarely influenced clinical outcome unless there was concomitant genital tract injury. Antithrombin III transfusions increased plasma levels, but no definite clinical benefit was established in this series because of the small number of cases.

Anticardiolipin antibodies in acquired immunodeficiency syndrome.

We undertook a prospective study of IgG and IgM anticardiolipin antibodies (ACAs) to determine their clinical significance in patients with acquired immunodeficiency syndrome (AIDS). IgG ACAs were found in 24 (92.3%) of 26 patients with AIDS who were hospitalized for pulmonary complaints (group 1) and in 13 (93%) of 14 patients with AIDS-related complex (group 2). In addition, 17 (94%) of 18 patients with AIDS (group 3) who had coagulation tests and were studied retrospectively had IgG ACAs. The prevalence of IgG ACAs in these three groups was significantly higher than in healthy controls, but was comparable to that in 31 consecutive patients with systemic lupus erythematosus (67.7%). The mean titer of IgG ACAs in group 1 was higher than in groups 2 and 3 but was not different from that in the patients with systemic lupus erythematosus. The frequency and titer of IgM ACAs in group 1 (7.6%) or group 2 (14.3%) were not significantly different from those in normal controls (4.7%). In contrast, half of the patients in group 3 had low-titer IgM ACAs. The serum titer of IgG ACAs in patients with AIDS with thrombocytopenia was significantly higher than it was in those with normal platelet counts. There was no association between ACAs and Pneumocystis carinii pneumonia or other infections, cancer, thrombosis, positive VDRL test, or presence of the lupus anticoagulant. The prevalence and titer of IgG or IgM ACAs were not associated with abnormal results of any coagulation test. Although we found IgG ACAs to be associated with thrombocytopenia in AIDS, their presence does not carry exactly the same clinical significance as it does in systemic lupus erythematosus. The high prevalence of ACAs in AIDS, in AIDS-related complex, and in otherwise healthy contacts with antibodies to human immunodeficiency virus suggests that their occurrence may be related to the underlying human immunodeficiency virus infection.

Endothelial-dependent fibrinolysis in subjects with the lupus anticoagulant and thrombosis.

To investigate the hypothesis that diminished endothelial fibrinolytic activity contributes to the pathogenesis of thrombosis in patients with the lupus anticoagulant (LA), we assessed the ability of endothelium to release tissue-type plasminogen activator (t-PA) in response to standardized venous occlusion (VO) of the arm, and the extent of inhibition of t-PA, in 11 subjects with LA and a history of thrombosis and in 36 healthy normal subjects. The mean rise in plasma t-PA antigen after VO, the mean plasma free t-PA activity after VO, and the mean plasma t-PA inhibitor level prior to VO were not significantly different in subjects with LA and thrombosis and in normal subjects. Four subjects with LA and thrombosis (36%), and five of 36 healthy control subjects (14%) generated no detectable free t-PA activity after VO ("non-responders"); this difference was not statistically significant. All four "non-responders" with LA and thrombosis had normal t-PA antigen release after VO, indicating that the lack of detectable free t-PA activity after VO was due to increased inhibition of released t-PA. We conclude that abnormally reduced endothelial fibrinolytic activity is not present in the majority of subjects with LA and thrombosis. In the subset of subjects with LA and thrombosis who generate no detectable t-PA activity after VO, a stimulatory effect of LA on endothelial production of t-PA inhibitor cannot be excluded.

Reliability of selective pulmonary arteriography in the diagnosis of pulmonary embolism.

To test the reliability of conventional selective pulmonary arteriography in the diagnosis of pulmonary embolism, three angiographers reviewed the arteriograms of a series of 60 patients retrospectively, independently, and without benefit of additional data. Pulmonary arteriograms had been interpreted as positive for pulmonary embolism in 25 of these patients during their hospitalizations. Angiographers A, B, and C judged the arteriograms of 24, 29, and 25 patients, respectively, as positive for pulmonary embolism. Mean interobserver agreement was 86%. Interobserver agreement was not associated significantly with the quality of the arteriogram or with selective injection of a lobar vs a pulmonary artery, but was associated strongly with the magnitude of thromboembolism. All angiographers agreed that the arteriograms were positive in 18 cases of pulmonary embolism graded as massive, lobar, or segmental, but agreed in only two of 15 cases graded as subsegmental. We conclude that conventional selective pulmonary arteriography is reliable in the detection of embolus in segmental or larger pulmonary arteries. Observer disagreement becomes considerable for embolus limited to subsegmental pulmonary arteries, indicating that emboli of this size are at the resolution limit of the technique.

Defibrination during warfarin therapy in a man with protein C deficiency.

A 57 year old man presented with apparently spontaneous lower extremity deep vein thrombosis and pulmonary embolism. He was treated in conventional fashion with intravenous heparin and oral warfarin. After 4 daily doses of warfarin the prothrombin and proconvertin (P+P) time was within therapeutic range, and heparin was stopped. Over the next six hours complete defibrination occurred, associated with severe bleeding complications. Functional protein C measured after normalization of routine coagulation tests averaged 40% of normal, and was only 3.5% of normal immediately prior to the episode of defibrination. We conclude that the very low functional protein C levels seen immediately prior to defibrination were caused by a combination of pre-existent protein C deficiency and warfarin therapy, and directly predisposed to defibrination once heparin was stopped, despite "therapeutic" warfarin anticoagulation. Exacerbation of intravascular coagulation should be considered a potential prothrombotic effect of warfarin therapy in protein C deficient individuals.

Comparison of physician and pharmacist management of anticoagulant therapy of inpatients.

The management of anticoagulant therapy for hospitalized patients by seven certified pharmacist prescribers and one physician was compared. Eighty-one consecutive patients referred to the anticoagulation service were randomly assigned to two groups. For patients in the pharmacist-prescriber group, the physician independently monitored laboratory results and simulated heparin and warfarin doses. The roles of pharmacist and physician were reversed for patients in the physician-prescriber group. According to an established protocol, adjustments in heparin sodium infusion rate were based on activated partial thromboplastin time (PTT); warfarin sodium dosage was adjusted using a proconvertin and prothrombin (P&P) method. Heparin doses, warfarin doses, and clotting-test results were compared for patients in the two prescriber groups; simulated and actual doses also were compared. Patients were observed for complications of anticoagulant therapy. There were no significant differences in the mean heparin and warfarin doses administered to patients in the two prescribed groups. Similarly, PTT and number of days to reach therapeutic P&P were not significantly different. Within each group, the mean prescribed and simulated heparin doses were not significantly different. There were no episodes of major bleeding, but four patients in the pharmacist-prescriber group had minor bleeding. While the results are not applicable to all pharmacists or all settings, the certified pharmacist prescribers in this study adjusted anticoagulant therapy as well as an experienced physician.

Warfarin necrosis of the skin and subcutaneous tissue of the male external genitalia.

Gangrene of the male external genitalia is an uncommon urologic problem with a limited differential diagnosis. To the etiologic spectrum we add warfarin-induced penile gangrene. Pathophysiology, diagnosis and treatment are discussed.

Severe depression of antithrombin III associated with disseminated intravascular coagulation in women with fatty liver of pregnancy.

Serial coagulation studies were done in four women with acute fatty liver of pregnancy. All had coagulopathy, laboratory evidence of diffuse intravascular coagulation, and marked depletion of plasma antithrombin III. Two of these women had persistent intravascular coagulation for 4 days after delivery. The others had prompt control of intravascular coagulation coincident with elevation of the antithrombin III concentration by plasma transfusion. Severe antithrombin III depression may be a major cause of the persistent intravascular clotting and can be corrected by plasma transfusion.

Improved methods for estimating initial heparin infusion rates.

Two methods of calculating heparin infusion rates for patients with venous thrombotic disease were compared; one method was based on a one-compartment pharmacokinetic model, the other on patient weight. Sixty-eight patients with presumed thromboembolic disease were started on continuous i.v. heparin sodium (porcine) using an infusion pump. Patients were divided into two groups--the infusion rate of Group I was based on patient weight (77 units/kg/4 hrs) and the infusion rate of Group 2 was determined by a pharmacokinetic equation based on a one-compartment heparin model. Heparin effect was measured by an activated partial thromboplastin time (APTT). The initial heparin infusion rate for Group 1 (4,784 +/- 672 units/4 hrs) was significantly greater (p less than 0.039, two-sample t-test) than that for Group 2 (4,413 +/- 779 units/4 hrs), but the variances of the rates were not significantly different (p = 0.40, ratio of variance F-test). Both methods for estimating initial heparin infusion rates gave mean APTT values in the center of the therapeutic range, but the variance in the APTTs of Group 2 patients was significantly smaller (p = 0.004) than that of Group 1. The pharmacokinetic model was more precise and reliable. This model should be valuable for insuring heparin's therapeutic effect without exposing patients to the potential risk of hemorrhage.

Factor V anticoagulants: clinical, biochemical, and immunological observations.

A patient who had received multiple transfusions for complications of acute hemorrhagic pancreatitis developed a potent factor V anticoagulant with bleeding due to defective hemostasis. Despite its potency, the anticoagulant disappeared within 15 days of its first manifestation. A second patient with adenocarcinoma of the colon developed an anticoagulant to factor V postoperatively after a single blood transfusion. The anticoagulants appeared to react stoichiometrically with factor V in normal plasma in vitro. They had the physicochemical properties of immunoglobulins, and their activity was neutralized by antihuman immunoglobulin antiserum. One anticoagulant appeared to be slightly more active against homologous than against autologous factor V, but it also inhibited heterologous factor V. Both anticoagulants progressively inactivated intrinsic prothrombin activator formed from normal reagents in the incubation mixture of the thromboplastin generation test, thus confirming that factor V is required for the effective action of the intrinsic prothrombin activator. Since the anticoagulants were immunoglobulins whose activity was consumed in their reaction with factor V, consumption of anticoagulant activity was used to detect factor V antigenic material in test materials. Human serum without factor V clotting activity was found to consume anticoagulant activity, i.e., to contain inactive factor V antigenic material. Plasma from two patients with hereditary factor V deficiency (parahemophilia) failed to consume significant anticoagulant activity. Thus, the lack of factor V activity in these patients represents a deficiency of factor V molecules rather than the synthesis of a defective molecule with impaired clotting activity.