Acute and Chronic “Defibrination” in Obstetrical Practice

In case thromboplastic material (amniotic fluid, tissue fragments, activated coagulation factors or certain bacterial products) enters the maternal circulation, excessive and diffuse intravascular coagulation often with secondary fibrinolysis will occur in a sufficient degree to decrease the fibrinogen concentration in the blood below the hemostatic level. If this disseminated coagulation is precipitous, blockade of the microcirculation and quick defibrination will result with shock and a definitive bleeding syndrome (amniotic fluid embolism, premature separation of placenta, septic abortion). In subacute and chronic situations (foeto-maternal blood passage in hetero-specific pregnancy, retention of death foetus, hydatiform mole) external bleeding is not necessarily overt and the correct diagnosis often remains undiscovered.

The laboratory diagnosis is difficult and more so as the clinical situation requires urgent therapy. The finding of reduced levels of some coagulation factors (factors IV, VIII) a low platelet count and the detection of products of fibrinolysis (fibrin split products) in the serum indicate the occurrence of disseminated intravascular coagulation.

Treatment will be different in chronic and acute cases but aims in both to eliminate rapidly the source of thromboplastin release. In acute cases of premature separation of the placenta, fibrinogen under cover of heparin can be administered and shock combated with agents increasing cardiac output and causing peripheral vasodilatation. In septic abortion immediate administration of antibiotics and hysterectomy are probably the best advice.

Usefulness of and a Simple Method for Serial Successive Fibrinogen Determinations in Human Pathology

Serial, successive determinations of the fibrinogen content are valuable tools in the management of hypofibrinogenemia syndromes. A detailed description is given of the FPT-test, which has been demonstrated to be a simple and accurate method for serial quantitation of the normally-reactive fibrinogen.

The Streptokinase Reactivity Test. I. Standardization

1. An attempt was made to standardize a method which determines the reactivity of a given blood sample with streptokinase (SKRT).

2. The nature of the thrombin and streptokinase used can greatly influence the test.

3. The 20 minutes value is less influenced by a number of parameters than other points on the streptokinase versus lysis time plot.

Enhancing the Fibrinolytic Activity in Human Blood by Occlusion of Blood Vessels

The lytic activity was measured in blood obtained from a superficial elbow vein when a cuff with a known pressure was attached above the elbow and compared with the activity in the blood taken at the same moment from the control arm without any pressure.

1. Using a pressure 20 mm above the systolic pressure, no enhancement could be obtained in the first 10 minutes.

2. Using a diastolic or systolic pressure during 3 minutes, the fibrinolytic activity was about 2.8 times the activity in the control sample.

3. Using a pressure halfway the diastolic and systolic, the fibrinolytic activity after 3 minutes was about 3.5 times, and after 10 minutes about 11 times the activity in the control sample.

Disappearance of Factor V Activity after Incubation of Plasma with Heparin and Heparinoids

1. Heparin and heparinoids, added to oxalated or citrated plasma produce in this plasma an inactivation of factor V; this inactivation is progressive and directly related to the length of incubation.

The rate of inactivation of factor V is directly proportional to the quantity of anticoagulant added.

2. When quantities with identical anticoagulant activity in the thromboplastin-calcium clotting time are compared, heparin proves to have a stronger effect than heparinoids.

3. The inactvation of factor V in plasma by heparin or heparinoïds is an irreversible process, which cannot be nullified by addition of protamine sulphate.

Propriétés coagulantes d’hémolysats erythrocytaires

1. L’hémolysat érythrocytaire possède une activité coagulante, démontrée dans les tests globaux de la coagulation.

2. Cette activité ne peut pas être expliquée par une contamination plaquet-taire des préparations d’hémolysat.

3. L’hémolysat ne contient pas de thrombine, de prothrombine, facteur VII, facteur anti-hémophilique, ni de facteur IX. Il est par contre légèrement contaminé par le facteur V, probablement d’origine plasmatique.

4. L’activité de l’hémolysat est située surtout dans la première phase de la coagulation sanguine, c. à d. la formation de la thromboplastine. Son rôle est à peu près identique à celui du facteur thromboplastique des thrombocytes.

5. L’hémolysat préparé à partir du sang du cordon ombilical montre une activité très prononcée, qui n’est pas retrouvée dans le test de la formation de la thromboplastine.

6. Les hémolysats préparés du sang de différents animaux sont les plus actifs sur les plasmas de la même espèce.

7. Les hémolysats préparés du sang d’hémophiles du type A ou B, de malades atteints d’anémies hémolytiques, et de malades traités aux dérivés coumariniques ont une activité coagulante normale.

Comparison of Quantification Methods of111In-Labelled Platelet Deposition in Peripheral Bypass Grafts

The action of antithrombotic drugs can be evaluated by measuring the deposition of111In-labelled platelets on peripheral bypass grafts several days after injection. This evaluation can be performed qualitatively (visual interpretation on the daily images) or quantitatively. Four different methods which calculate the ratio of platelet uptake with a reference region are compared: two methods use a gamma camera and two a detector. A blood sample or the region under the sternal angle are used as reference. The daily ratio of the counts, recorded by a gamma camera in a region of interest covering the graft, and the blood radioactivity interpolated from a platelet survival curve appears to be the most reliable method. The information of all the ratios can be combined in a single thrombogenicity index which reflects the daily rise of a linear or exponential regression versus time.