Meconium and amniotic fluid embolism: effects on coagulation in pregnant mini-pigs

Early treatment with Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes) ameliorates post-partum hemorrhage with coagulopathy caused by amniotic fluid embolism in rabbits

BACKGROUND

Amniotic fluid embolism is an unpredictable and sometimes lethal complication of childbirth. Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes), which were developed as a platelet substitute, may be useful to control postpartum hemorrhage with consumptive coagulopathy.

OBJECTIVE

This study aimed to establish a hemodynamically stable amniotic fluid embolism animal model and evaluate the efficacy of H12-ADP-liposome infusion in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism-involved coagulopathy.

STUDY DESIGN

Pregnant New Zealand white rabbits (28th day of pregnancy or normal gestation period of 29-35 days) underwent cesarean delivery, followed by intravenous administration of amniotic fluid (a total of 3.0 mL administered in 4 doses over 9 minutes). Thereafter, uncontrolled postpartum hemorrhage was induced by transecting the right midartery and concomitant vein in the myometrium. After initial bleeding for 5 minutes, rabbits received isovolemic fluid resuscitation through the femoral vein with an equivalent volume of blood loss every 5 minutes for 60 minutes. The transfusion regimens included platelet-rich plasma, platelet-poor plasma, and a bolus administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion (8 rabbits per group). Moreover, 60 minutes after initiation of bleeding, rabbits received surgical hemostasis by ligation of bleeding vessels, except in cases with spontaneous hemostasis.

RESULTS

The administration of amniotic fluid caused thrombocytopenia (56±3 × 103/μL) and prolonged both clotting time (before administration: 130.0±3.0 to 171.0±5.0 seconds) and prothrombin time (4.5±0.1 to 4.7±0.1 seconds). After the initial 5-minute bleeding in the rabbits, the mean arterial pressure fell to 43±2 mm Hg. Platelet-poor plasma transfusion alone further prolonged clotting time and prothrombin time at 60 minutes (192.0±10.0 and 5.2±0.1 seconds, respectively) with decreasing mean arterial pressure to <40 mm Hg. By contrast, the administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion reduced the prolonged clotting time (153.0±5.0 seconds) and prothrombin time (4.9±0.1 seconds) similar to platelet-rich plasma transfusion (154.0±11.0 and 4.9±0.1 seconds, respectively) at 60 minutes. These rabbits maintained a mean arterial pressure of >45 mm Hg throughout the experiment. H12-ADP-liposome infusion and platelet-poor plasma transfusion and platelet-rich plasma transfusion yielded spontaneous hemostasis in 4 of 8 rabbits, whereas platelet-poor plasma transfusion did not stop bleeding in any of the rabbits. The total blood loss was 59±17 mL in the H12-ADP-liposomes and platelet-poor plasma group, which was half of that in the platelet-poor plasma group (124±10 mL).

CONCLUSION

H12-ADP-liposome infusion may be effective in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism, resulting in mitigation of consumptive coagulopathy.

The role of sonographic head circumference in the occurrence of subgaleal hemorrhage following vacuum delivery

OBJECTIVE

Subgaleal hemorrhage (SGH) is a severe neonatal morbidity that is associated with vacuum-assisted delivery (VAD). Large sonographic head circumference (sHC) was previously associated with complicated VAD. Nevertheless, the association of large sHC with SGH formation following VAD is underreported. We aim to evaluate the role of sonographic head circumference (sHC) with SGH formation following attempted VAD.

METHODS

A retrospective case-control study. Cases comprised singleton pregnancies for whom attempted VAD resulted in SGH with an sHC measured within 2 weeks from delivery. Controls were VAD deliveries which not resulted in SGH, with an sHC measured within 2 weeks from delivery. We matched controls in a 1:1 ratio by gestational age, parity and year of delivery.

RESULTS

Overall, 118 women were included in the SGH study group and were matched to 118 controls. Baseline maternal and fetal characteristics were similar between the groups except for higher neonatal birth weight in the SGH group (median 3422 vs. 3195 grams, p = .001). sHC did not vary between groups (median 336 mm in SGH groups vs. 333, p = .08). Rate of sHC >90th and >95th percentile did not significantly differ between the groups (13.6% vs. 8.5%, 6.8% vs. 3.4%, p = .21, p = .37, for SGH vs. controls, respectively). In multivariate regression analysis, sHC was not found to be independently associated with SGH - aOR (95% CI) 1.004 (0.97-1.03). Receiver operating characteristic curves of sHC for SGH formation underlined an area under the curve of 0.58 (95% CI) (0.51-0.65).

CONCLUSIONS

sHC is not associated with SGH formation following VAD.

Risk factors associated with subgaleal hemorrhage in neonates exposed to vacuum extraction

INTRODUCTION

Subgaleal hemorrhage (SGH) is a life-threatening neonatal condition that is strongly associated with vacuum assisted delivery (VAD). The factors associated with the development of SGH following VAD are not well-established. We aimed to evaluate the factors associated with the development of SGH following attempted VAD.

MATERIAL AND METHODS

A retrospective case-control study of women who delivered at a tertiary university-affiliated medical center in Jerusalem, Israel, during 2009-2018. Cases comprised all parturients with singleton pregnancies for whom attempted VAD resulted in neonatal SGH. A control group of VAD attempts was established by matching one-to-one according to gestational age at delivery, parity and year of delivery. Fetal, intrapartum and vacuum procedure characteristics were compared between the groups.

RESULTS

In all, 313 (89.5%) of the 350 attempted VAD were nulliparous. Baseline maternal and fetal characteristics were similar between the groups except for higher neonatal birthweight in the SGH group. In multivariate logistic regression analysis, only six independent risk factors were significantly associated with the development of SGH: second-stage duration (for each 30-minute increase, adjusted odds ratio [OR] 1.13; 95% confidence intervals [CI] 1.04-1.25; P = .006), presence of meconium-stained amniotic fluid (adjusted OR 2.61; 95% CI 1.52-4.48; P = .001), presence of caput succedaneum (adjusted OR 1.79; 95% CI 1.11-2.88; P = .01), duration of VAD (for each 3-minute increase, adjusted OR 2.04; 95% CI 1.72, 2.38; P < .001), number of dislodgments (adjusted OR 2.38; 95% CI 1.66-3.44; P < .001), and fetal head station (adjusted OR 3.57; 95% CI 1.42-8.33; P = .006). Receiver operating characteristic curves showed that VAD duration of ≥15 minutes had a 96.7% sensitivity and 75.0% specificity in predicting SGH formation, with an area under the curve equal to .849.

CONCLUSIONS

Vacuum duration, the number of dislodgments, the duration of second stage of delivery, fetal head station, the presence of caput succedaneum and the presence of meconium were found to be independently associated with SGH formation.

Amniotic fluid as a potent activator of blood coagulation and platelet aggregation: Study with rotational thromboelastometry

INTRODUCTION

Pulmonary thromboembolism (PTE) is a leading cause of maternal death and frequently occurs during early puerperium. Amniotic fluid components are frequently observed in the maternal circulation in parturition; however, it currently remains unclear whether amniotic fluid contamination in maternal blood is related to the high incidence of PTE in early postpartum.

OBJECTIVES

To examine the influence of amniotic fluid on blood coagulation and fibrinolysis systems with thromboelastometry.

MATERIALS AND METHODS

Twenty-one pregnant women were recruited. We used whole citrated blood in ROTEM® (Tem Innovations GmbH, Munich, Germany), including the non-activated assay (NATEM), assessments for extrinsic (EXTEM) and intrinsic pathways (INTEM), fibrin polymerization (FIBTEM), and hyperfibrinolysis (APTEM), with amniotic fluid contamination, and measured the clotting time (CT), clot formation time (CFT), alpha, amplitude at 10 min (A10), maximum clot firmness (MCF), and lysis indices at 30 min (LI30) and 60 min (LI60).

RESULTS

Short CT in all assays as well as short CFT, high alpha, and increased A10 and MCF in NATEM were observed with amniotic fluid contamination. A10 and MCF as well as LI30 and LI60 decreased in EXTEM. Decreased LI60 with the mixture of amniotic fluid was not improved by tranexamic acid in APTEM.

CONCLUSIONS

Amniotic fluid accelerated thrombin production and activated platelet aggregation without inducing hyperfibrinolysis in whole blood. The activated tissue factor pathway with amniotic fluid produced soft and fragile clots due to its influence on platelets, which may be associated with, at least partly, the high incidence of PTE in early puerperium, particularly after cesarean section.

Meconium-stained amniotic fluid: a risk factor for postpartum hemorrhage

Background/aim

Clinical data with respect to the impact of meconium on the risk of maternal hemorrhage are scarce. Therefore, in this study, we aimed to determine whether meconium-stained amniotic fluid (MSAF) represents a risk factor for postpartum hemorrhage (PPH) after vaginal delivery in a large unselected population.

Patients and methods

A retrospective cohort study evaluated 78,542 consecutive women who had a vaginal delivery between 24th and 44th weeks of gestation. The women who had undergone cesarean section were excluded to avoid possible bias. Postpartum blood loss was measured with graduated blood sack. Postpartum blood loss between 1,000 and 2,000 mL and >2,000 mL were classified as moderate and severe PPH, respectively.

Results

A total of 74,144 patients were available for analysis. According to the color of amniotic fluid (AF), two groups of patients were identified: MSAF (n=10,997) and clear AF (n=63,147). The rates of severe and massive PPH were found to be significantly higher in the MSAF group than that of clear AF group (OR=1.3, 95% CI: 1.2-1.5, p<0.001 and OR=2.5, 95% CI: 1.5-4.2, p<0.001). Operative vaginal delivery rate was found to be higher in the MSAF group than that of clear AF group, but the difference was only borderline significant (OR=1.5, 95% CI: 1.0-2.2, p=0.05). There were no significant differences between the MSAF and the clear AF groups with respect to episiotomies, second- or third-degree perineal tears, vaginal-perineal thrombus, cervical lacerations, vaginal births after cesarean section, twin deliveries, and placental retention rates.

Conclusion

To the best of our knowledge, this is the first clinical study that has investigated the role of MSAF as a risk factor for PPH after vaginal delivery in an unselected population. Our results suggest that MSAF is significantly associated with higher risk of moderate and severe PPH than clear AF.

Pathogenesis and management of peripartum coagulopathic calamities (disseminated intravascular coagulation and amniotic fluid embolism)

Acute coagulopathic peripartum calamities are relatively rare but contribute importantly to maternal morbidity and mortality in the Western world. Abruptio placenta, amniotic fluid embolism, and retained fetal or placental material may lead to fulminant intravascular activation of coagulation which results in thromboembolic complications and consumption coagulopathy causing severe hemorrhage. The central underlying pathophysiological pathway in the coagulopathy associated with these syndromes is the occurrence of tissue factor, released from the placenta and amniotic fluid, in the circulation, in combination with low levels of physiological anticoagulant factors during pregnancy. The diagnosis of DIC may be made trough conventional composite scoring systems employing routine coagulation tests, whereas for the diagnosis of amniotic fluid embolism measurement of insulin like growth factor binding protein-1 seems promising. Therapy is aimed at removing the precipitating factor combined with supportive adjunctive treatment options.

[Amniotic fluid embolism: an update]

Amniotic fluid embolism (AFE) results from the passage of fœtal and amniotic fragments into the maternal circulation, occurring mostly within minutes before or after delivery. Although maternal and fœtal mortality of AFE remains high (about 40%), AFE should no longer be considered as having an ineluctable fatal course. Diagnosis is often made upon clinical presentation but histological confirmation is difficult owing favorable outcome and because an autopsy has not been performed. Identification of squamous cells in the maternal circulation could not confirm the diagnosis because of their possible maternal origin. High plasma level of insulin-like growth factor-binding protein-1 (IGFBP-1) has recently been identified as a biomarker of amniotic fluid passage into the maternal circulation and might therefore be used to confirm the diagnosis when lung tissue histology is not available. Treatment of AFE remains supportive with a special focus on correction of the coagulopathy and search for acute core pulmonale. In this later case, physicians should consider initiating an extracorporeal life support when facing a patient with refractory shock. Finally, caution is needed with the use of recombinant factor VIIa in this context.

Amniotic fluid embolism-apropos two consecutive cases

Amniotic fluid embolism (AFE) is a sporadic, unpredictable, and usual fatal obstetric complication. The paper deals with two cases of maternal deaths because of AFE verified by medicolegal autopsy. In both the cases, several known risk factors associated with AFE, such as increased maternal age (41 and 35 years), diabetes, augmented labor, and cesarean delivery, were identified. Clinical features were typical, including sudden onset of cardiovascular and respiratory symptoms. In the patient who survived longer, both clinical and autopsy signs of disseminated intravascular coagulopathy were present, while they were absent in the case where death occurred rapidly. This paper describes briefly the particular features to look for at autopsy and stresses the importance of histology examination and staining techniques.

Maternal death following cardiopulmonary collapse after delivery: amniotic fluid embolism or septic shock due to intrauterine infection?

PROBLEM

The amniotic fluid embolism (AFE) syndrome is a catastrophic complication of pregnancy frequently associated with maternal death. The causes and mechanisms of disease responsible for this syndrome remain elusive.

METHOD OF STUDY

We report two cases of maternal deaths attributed to AFE: (1) one woman presented with spontaneous labor at term, developed intrapartum fever, and after delivery had sudden cardiovascular collapse and disseminated intravascular coagulation (DIC), leading to death; (2) another woman presented with preterm labor and foul-smelling amniotic fluid, underwent a Cesarean section for fetal distress, and also had postpartum cardiovascular collapse and DIC, leading to death.

RESULTS

Of major importance is that in both cases, the maternal plasma concentration of tumor necrosis factor-alpha at the time of admission to the hospital and when patients had no clinical evidence of infection was in the lethal range (a lethal range is considered to be above 0.1 ng/mL).

CONCLUSION

We propose that subclinical intraamniotic infection may be a cause of postpartum cardiovascular collapse and DIC and resemble AFE. Thus, some patients with the clinical diagnosis of AFE may have infection/systemic inflammation as a mechanism of disease. These observations have implications for the understanding of the mechanisms of disease of patients who develop cardiovascular collapse and DIC, frequently attributed to AFE. It may be possible to identify a subset of patients who have biochemical and immunological evidence of systemic inflammation at the time of admission, and before a catastrophic event occurs.

Amniotic fluid embolism

Amniotic fluid embolism is one of the most catastrophic complications of pregnancy. First described in 1941, the condition is exceedingly rare and the exact pathophysiology is still unknown. The etiology was thought to be embolic in nature, but more recent evidence suggests an immunologic basis. Common presenting symptoms include dyspnea, nonreassuring fetal status, hypotension, seizures, and disseminated intravascular coagulation. Early recognition of amniotic fluid embolism is critical to a successful outcome. However, despite intensive resuscitation, outcomes are frequently poor for both infant and mother. Recently, aggressive and successful management of amniotic fluid embolism with recombinant factor VIIa and a ventricular assist device, inhaled nitric oxide, cardiopulmonary bypass and intraaortic balloon pump with extracorporeal membrane oxygenation have been reported and should be considered in select cases.

Blood component therapy in obstetrics

Hemorrhage is the leading cause of intensive care unit admission and one of the leading causes of death in the obstetric population. This emphasizes the importance of a working knowledge of the indications for and complications associated with blood product replacement in obstetric practice. This article provides current information regarding preparation for and administration of blood products, discusses alternatives to banked blood in the obstetric population, and introduces pharmacological strategies for treatment of hemorrhage.

Meconium passage in utero: mechanisms, consequences, and management

Meconium passage in newborn infants is a developmentally programmed event normally occurring within the first 24 to 48 hours after birth. Intrauterine meconium passage in near-term or term fetuses has been associated with fetomaternal stress factors and/or infection, whereas meconium passage in postterm pregnancies has been attributed to gastrointestinal maturation. Despite these clinical impressions, little information is available on the mechanism(s) underlying the normal meconium passage that occurs immediately after birth or during the intrauterine period of fetal development. Birth itself is a stressful process and it is possible that fetal stress-mediated biochemical events may regulate the meconium passage occurring either during labor or after birth. Aspiration of meconium during intrauterine life may result in or contribute to meconium aspiration syndrome (MAS), representing a continued leading cause of perinatal death. This article reviews aspects of meconium passage in utero, its consequences, and management.

Intravenous pyruvic acid application in minipigs partially protects acetylcholine-esteratic but not butyrylcholine-esteratic activity in plasma from inhibition by paraoxon

Intoxications with organophosphorus compounds such as paraoxon (POX) are frequent. Oximes are the only enzyme reactivators clinically available. In vitro and in vivo studies have shown that l-lactate reduces the inhibition of plasma acetylcholine-esteratic activity (AChEA) (in vitro and in vivo) and plasma butyrylcholine-esteratic activity (BChEA) (at least in vitro and possibly in vivo) by POX. However, a short infusion of 10 g of lactate was unable to elevate the plasma lactate level for >3 h. In this study we tested a substance related to l-lactate, i.e. pyruvic acid. The purpose of this animal experimental study (female minipigs with historical control group) was to determine in vivo whether intravenous (i.v.) pyruvic acid application under normoxic/normocapnic/normohydrogenaemic conditions is able to elevate blood lactate levels and whether it is able to protect AChEA and BChEA from POX inhibition. Animals were anaesthetized, intubated and mechanically ventilated. Each received 1 mg kg(-1) body wt. of POX in 50 ml of saline over 50 min and 10 g (ca. 0.5 g kg(-1) body wt.) of i.v. pyruvic acid in 50 ml of saline over 50 min. They were compared with a historical control group of six animals that received only 1 mg kg(-1) body wt. of POX in 50 ml of saline over 50 min. In central venous blood measurements of plasma AChEA and BChEA, the measurements were performed before (baseline), immediately after POX (50 min after start) and 110, 170, 230, 290, 530 and 1010 min after the start of infusion. A 10 g aliquot of i.v. pyruvic acid had a statistically significant protective effect in vivo on AChEA but not on BChE activity. Further study of the in vivo effects of pyruvic acid and l-lactate after paraoxon intoxication and a formal comparison with standard oxime therapy seems warranted. Also, a combination therapy with l-lactate and pyruvic acid in vivo should be investigated.

Intravenous L-lactate application in minipigs partially protects acetylcholinesteratic but not butyrylcholinesteratic activity in plasma from inhibition by paraoxon

OBJECTIVE

Intoxications with organophosphorous compounds such as paraoxon, an inhibitor of serine hydrolases, mainly butyrylcholinesterase and acetylcholinesterase, are frequent. Oximes are the only enzyme reactivators clinically available. In vitro studies have shown that L(+)-lactate reduces the inhibition of acetylcholinesteratic (AChEA) and butyrylcholinesteratic activity of plasma (BChEA) by paraoxon.

DESIGN

The purpose of this in vivo study was to determine whether intravenous L(+)-lactate application under normoxic/normocapnic/normohydrogenemic conditions is able to protect AChEA and BChEA from paraoxon inhibition.

SETTING

University research institute.

SUBJECTS

Eighteen female minipigs.

INTERVENTIONS

Animals were anesthetized, intubated, and mechanically ventilated. Every animal received 1 mg of paraoxon per kilogram of body weight in 50 mL of saline over 50 mins. In addition to receiving paraoxon, six pigs of 18 received 2.5 g (0.125 g kg-1 of body weight) of intravenous L(+)-lactate in 50 mL of saline over 50 mins, and six other pigs received 10 g of L(+)-lactate (0.5 g kg-1 of body weight), whereas the six remaining served as controls.

MEASUREMENTS AND MAIN RESULTS

In central venous blood, plasma acetylcholinesteratic and butyrylcholinesteratic activity were measured before paraoxon (baseline, 0 mins), immediately after paraoxon (50 mins after start), and 110, 170, 230, 290, 530, and 1010 mins after the start of infusion. Although 10 g of intravenous L(+)-lactate application had a statistically significant protective effect in vivo on AChEA, 2.5 g did not. No significant protective effect on BChEA was achieved with either 2.5 g or 10 g of L(+)-lactate.

CONCLUSIONS

Ten grams of L(+)-lactate can increase AChEA when administered simultaneously with paraoxon. Further study of the in vivo effects of L(+)-lactate after paraoxon intoxication and a formal comparison with standard oxime therapy seem warranted. Also, methods for achieving a prolonged elevated lactate concentration in vivo should be investigated.

[Amniotic fluid embolism: successful evolution course after uterine arteries embolization]

A 28-year-old woman, G3P3, who was otherwise healthy and had taken no medication and had no known allergy, was admitted to our hospital for delivery after a normal pregnancy. An epidural catheter was inserted for analgesia and labour was induced with oxytocin. Two hours later, she suffered a sudden cardiac arrest. She was immediately treated and, since a normal cardiac rhythm and a blood pressure of 90 mmHg has been obtained 30 minutes later, a 3750 g child was delivered by caesarean section. Soon after delivery, a life-threatening uterine haemorrhage appeared, due to DIC. Evolution was favourable, after bilateral uterine arteries embolization had been performed. The diagnosis of amniotic fluid embolism was established by the clinical course, the absence of local cause and the presence of a large number of amniotic cells in the mother's peripheral blood. Tryptase blood concentration was normal in the mother's blood.

Fatal amniotic fluid embolism diagnosed histologically

Although the mortality of amniotic fluid embolism remains very high, there are more and more reports of patients surviving after prompt and aggressive therapy. However its pathogenesis is controversial, and, in some cases, an anaphylactic reaction to the amniotic fluid rather than the hemodynamic changes following mechanical obstruction by an embolus has been proposed as the underlying pathophysiological mechanism. In this paper we describe a case of amniotic fluid embolism with florid clinical features and a difficult and delayed diagnosis. On autopsy, clear-cut histological changes of amniotic fluid embolism were found.

Disseminated intravascular coagulation: a review of etiology, pathophysiology, diagnosis, and management: guidelines for care

The pathophysiologic mechanisms, clinical, and laboratory manifestations of DIC are complex in part due to interrelationships within the hemostasis system. Only by clearly understanding these extraordinarily complex pathophysiologic interrelationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. Many therapeutic decisions to be made are controversial and lack validation. Nevertheless, newer antithrombotic agents, and agents that can block, blunt, or modify cytokine activity and the activity of vasoactive substances appear to be of value. The complexity and variable degree of clinical expression suggests that therapy should be individualized depending on the nature of DIC, age, etiology of DIC, site and severity of hemorrhage or thrombosis and hemodynamics and other appropriate clinical parameters. At present, treatment of the triggering event, low-dose heparin or antithrombin concentrate and wise choice of components when indicated appear to be the most effective modes of therapy.

Kinetics of intravenous L-lactic acid in anaesthetized minipigs under normoxic/normocapnic/normohydrogenaemic conditions

A mild and transitory increase in L-lactic acid (LAC) levels can be achieved by LAC infusion under normoxic/normocapnic/normohydrogenaemic conditions. This increase is probably sufficient to confer some protection to cholinesterases from inhibition by organophosphates.

Syndromes of disseminated intravascular coagulation in obstetrics, pregnancy, and gynecology. Objective criteria for diagnosis and management

This article presents current understanding of the causes, pathophysiology, clinical, and laboratory diagnosis, and management of fulminant and low-grade DIC, as they apply to obstetric, pregnant, and gynecologic patients. General medical complications leading to DIC, which may often be seen in these patients, are also discussed. Considerable attention has been given to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiologic interrelationships can the obstetrician/gynecologist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. Objective clinical and laboratory criteria for diagnosis of DIC have been outlined to eliminate unnecessary confusion and the need to make empiric decisions regarding the diagnosis. Particularly in the obstetric patient, if a condition is observed that is associated with DIC, or if any suspicion of DIC arises from either clinical or laboratory findings, it is imperative to monitor the patient carefully with clinical and laboratory tools to assess any progression to a catastrophic event. In most instances of DIC in obstetric patients, the disease can be ameliorated easily at early stages. Many therapeutic decisions are straightforward, particularly in obstetric and gynecologic patients. For more serious and complicated cases of DIC in these patients, however, efficacy and choices of therapy will remain unclear until more information is published regarding response rates and survival patterns. Also, therapy must be highly individualized according to the nature of DIC, patient's age, origin of DIC, site and severity of hemorrhage or thrombosis, and hemodynamic and other clinical parameters. Finally, many syndromes that are often categorized as organ-specific disorders and are sometimes identified as independent disease entities, such as AFE syndrome, HELLP syndrome, adult shock lung syndrome, eclampsia, and many others, either share common pathophysiology with DIC or are simply a form of DIC. These entities represent the varied modes of clinical expression of DIC and illustrate the diverse clinical and anatomic manifestations of this syndrome.

Administration of autologous fetal membranes: Effects on the coagulation in pregnant mini-pigs

OBJECTIVE: A hallmark of the so-called amniotic fluid embolism is the induction of coagulation defects. Entry of meconium-free autologous amniotic fluid into the circulation, however, is innocuous. Little is known about the true causative agent or agents. The purpose of this study was to assess the effects of homogenized autologous fetal membranes (FM) on the coagulation system in the mini-pig model. DESIGN: Laboratory study. SETTING: University institute animal laboratory. SUBJECTS: Six near-term pregnant, Göttingen-bred mini-pigs. INTERVENTIONS: After induction of general anesthesia, FM were col-lected from all animals by cesarean section. Animals received 2 g FM (shredded and suspended in lactated Ringer's solution) via an ear vein. MEASUREMENTS: Blood samples were taken from a central vein before administration (baseline), immediately after administration, every 10 mins until 90 mins after administration, and every 20 mins until 150 mins after administration. The following parameters were measured: platelets, partial thromboplastin time, prothrombin time index, fibrinogen, factors II, V, VII, VIII, IX, X, XI, antithrombin III, and protein C. The values relative to baseline in the FM group were compared with a historical control group by rank order test. A p <.05 was considered significant. MAIN RESULTS: In the FM group (compared with the control group), platelets were lower; partial thromboplastin time was prolonged; fibrinogen was lower; prothrombin time index was lower (ie, prothrombin time was prolonged); protein C and antithrombin III were lower; and activity levels of factors V and VII were lower. The levels of factors II, VIII, IX, X, and XI showed a trend toward lower activity in the FM group, but the differences were not statistically significant. CONCLUSIONS: FM can activate coagulation in mini-pigs. The laboratory parameter changes seen are typical for disseminated intravascular coagulation. However, the full clinical picture of amniotic fluid embolism and disseminated intravascular coagulation could not be elicited despite the high dose of FM used.