Ove Karlsson

Prospective Longitudinal Study of Thromboelastography and Standard Hemostatic Laboratory Tests in Healthy Women During Normal Pregnancy

BACKGROUND:Hemostatic disorders are common in obstetric complications. Thromboelastography (TEG®) simultaneously measures coagulation and fibrinolysis within 10 to 20 minutes. Our primary aim in this prospective longitudinal study was to obtain knowledge about physiological changes in TEG® variables during normal pregnancy and 8 weeks postpartum. The secondary aims were to compare TEG® variables during pregnancy with TEG® variables 8 weeks postpartum and gestational weeks 10 to 15 and to correlate TEG® variables to standard laboratory analyses. METHODS:Blood samples were collected from 45 healthy pregnant women at gestational weeks 10 to 15, 20 to 22, 28 to 30, and 38 to 40, and at 8 weeks postpartum. The following TEG® analyses were performed: time until start of clotting (TEG®-R), time until 20-mm clot firmness (TEG®-K), angle of clotting (TEG®-Angle), maximum amplitude (TEG®-MA), and lysis after 30 minutes (TEG®-LY30). Activated partial thromboplastin time, prothrombin time, soluble fibrin, antithrombin, D-dimer, and platelet count were analyzed. RESULTS:Compared to 8 weeks postpartum TEG®-R was at least 0.9 minutes shorter (upper limit 99% confidence intervals) until gestational weeks 28 to 30 and the mean reduction varied between 23%–26%. TEG®-K was at least 0.1 minutes shorter throughout pregnancy and the mean reduction varied between 18%–35%. TEG®-Angle was at least 2.5 degrees greater during pregnancy and the mean increase varied between 12%–20%. TEG®-MA was also at least 0.4 mm greater during pregnancy and the mean increase varied between 6%–8%. TEG®-LY30 was at least 0.03% lower during gestational weeks 28 to 30 and 38 to 40 and the mean reduction varied between 67%–73%. The routine coagulation laboratory values were within normal pregnant limits. There were no or weak correlations between TEG® and the laboratory variables. CONCLUSIONS:TEG® demonstrates increased coagulability and decreased fibrinolysis during pregnancy. There was a faster initiation of hemostasis, with a minor increase in clot strength. Fibrinolysis decreased during late pregnancy. Alternative cutoff limits for TEG® variables may be required during pregnancy. Standard hemostatic laboratory tests were as expected during pregnancy. Future studies are needed to ascertain whether viscoelastic methods are preferable to standard hemostatic tests for the diagnosis of coagulopathy during obstetric hemorrhage.

Major obstetric haemorrhage: monitoring with thromboelastography, laboratory analyses or both?

BACKGROUND Haemorrhage is a common cause of morbidity and mortality in the obstetric population. The aim of this study was to compare the use of thromboelastography and laboratory analyses to evaluate haemostasis during major obstetric haemorrhage. A secondary aim was to evaluate correlations between the results of thromboelastography, laboratory analyses and estimated blood loss. METHODS Forty-five women with major obstetric haemorrhage and 49 women with blood loss <600 mL were included. The following thromboelastography analyses were performed: time to start of clotting (TEG-R), time to 20 mm of clot firmness (TEG-K), rate of clot growth (TEG-Angle), maximum amplitude of clot (TEG-MA) and lysis after 30 min (TEG-LY30). In addition, platelet count, activated partial thromboplastin time, prothrombin time, fibrinogen, antithrombin and D-dimer were measured. RESULTS Thromboelastography variables reflecting clot stability and fibrinolysis were decreased in women with massive obstetric haemorrhage compared to women with normal bleeding, while clot initiation was accelerated. Laboratory analyses also showed impaired haemostasis with the most pronounced differences in platelet count, fibrinogen concentration and antithrombin activity. The strongest correlations existed between fibrinogen and TEG-MA and between estimated blood loss and TEG-MA, fibrinogen and antithrombin, respectively. CONCLUSIONS Impaired haemostasis, demonstrated by thromboelastography and laboratory analyses, was found after an estimated blood loss of 2000 mL. Thromboelastography provides faster results than standard laboratory testing which is advantageous in the setting of on-going obstetric haemorrhage. However, laboratory analyses found greater differences in coagulation variables, which correlated better with estimated blood loss.

Fibrinogen plasma concentration before delivery is not associated with postpartum haemorrhage: a prospective observational study

BACKGROUND Low plasma fibrinogen concentration has been linked to postpartum haemorrhage. The primary aim of this study was to assess whether fibrinogen concentration at admission before labour is associated with severe postpartum haemorrhage. Secondary aims were to describe fibrinogen concentration before and after labour and to identify predictors for severe postpartum haemorrhage. METHODS 1951 healthy women were included in a prospective observational study. Fibrinogen concentration was determined at admission to the labour ward and in a subgroup of women (n=80) also after the placenta was delivered. Bleeding volume postpartum was estimated by weighing surgical sponges and pads and by measuring collected blood. Predictors for severe postpartum haemorrhage (>1000 ml) were identified with bivariate and multivariate regression analyses. RESULTS Mean fibrinogen concentration was 5.3 (SD 0.8) g litre(-) (1). Median estimated blood loss was 450 (range 70-4400) ml and 250 (12.8%) women bled >1000 ml. Fibrinogen concentration was not correlated with postpartum haemorrhage in the entire cohort (r(s)=0.003, P=0.90) or in any subgroup. Fibrinogen concentration was not associated with bleeding >1000 ml (odds ratio 1.01 (CI 95% 0.85-1.19), P=0.93) and did not differ significantly before and after delivery. Oxytocin stimulation, instrumental delivery, Caesarean section and exploration of uterus were identified as independent predictors of haemorrhage >1000 ml. CONCLUSIONS Fibrinogen plasma concentration at admission before labour does not predict severe postpartum haemorrhage in a general obstetric population. Fibrinogen concentration does not decrease significantly during normal labour. Excessive postpartum bleeding is mainly as a result of obstetric complications.

Experience of Point-of-Care Devices in Obstetrical Care

During pregnancy and puerperium, there are pronounced hemostatic changes characterized by increased coagulability and decreased fibrinolysis. In addition, hemostasis can change dramatically during obstetric complications. Several reports have described substandard management of hemostatic defects in this setting and state the need for guidelines and better care. Point-of-care devices can assess hemostatic status and are especially suitable in perioperative settings. Using point-of-care devices, no time is required for transportation, allowing faster availability of results and providing potential for better care of the patient. This article will demonstrate the use of a viscoelastic method in six different patients; five with impaired hemostasis, and where the use of viscoelastic method contributes or should have contributed to better care. The cases represent patients with normal delivery; postpartum hemorrhage (PPH); PPH with low fibrinogen; placental abruption; preeclampsia with hemolysis, elevated liver enzymes, low platelet count syndrome; and finally, one patient with sepsis. This article also shows the need for good practices and good supervision to implement the devices in patient care.

Striking decrease in blood loss with a urologist-assisted standardized multidisciplinary approach in the management of abnormally invasive placenta

Abstract Objective: The aim of this study was to investigate the outcome of a standardized multidisciplinary approach using a modified surgical technique in the management of abnormally invasive placenta (AIP), with special reference to blood loss and the need for transfusion. Materials and methods: Data were collected retrospectively in women managed with a recently adopted multidisciplinary strategy using a modified surgical approach, involving a urologist (study group: 10 patients). Women managed before the introduction of this standardized management served as a control group (nine patients). Comparisons were made between the study group and the control group. The main outcome measures were blood loss and the need for transfusion in the two groups. Results: Standardized multidisciplinary management, involving a modified surgical technique performed by a urologist, decreased blood loss in the study group compared with the control group [median 1400 ml (range 400–3000 ml) vs median 8000 ml (2300–40000 ml); p < .001]. It also decreased postoperative complications and the need for transfusion of blood products. Conclusions: Standardized multidisciplinary management of patients with AIP, using a modified surgical technique, reduces the risks of massive obstetric hemorrhage, the need for massive transfusion and the risk of postoperative complications. Involving an experienced urologist appears to be of paramount importance in the management of AIP.

Cerebrospinal fluid levels of insulin, leptin, and agouti-related protein in relation to BMI in pregnant women.

During pregnancy, metabolic interactions must be adapted, though neuroendocrine mechanisms for increased food intake are poorly understood. The objective of this study was to characterize differences in insulin, leptin, and agouti‐related protein (AgRP) levels in serum and cerebrospinal fluid (CSF) in pregnant women with normal weight (NW) and pregnant women with overweight (OW) or obesity (OB). Placenta as a source for increased peripheral AgRP levels during pregnancy was also investigated.