Amniotic fluid embolism and isolated disseminated intravascular coagulation

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.

Pathogenic factors associated with development of disseminated intravascular coagulopathy (DIC) in a tertiary academic hospital in South Africa

Introduction

Disseminated intravascular coagulopathy (DIC) is a thrombotic microangiopathy arising from consumption of both coagulation factors and platelets. DIC is triggered by a number of clinical conditions including severe infection, trauma and obstetric complications. Early diagnosis and treatment of the underlying condition is paramount. A high clinical index of suspicion is needed to ensure that patients at risk of developing DIC are appropriately investigated.

Methods

In order to establish the clinical conditions most frequently associated with DIC, we reviewed all DIC screens received at a tertiary hospital in Johannesburg, South Africa over a 1 year period.

Results

The commonest clinical condition associated with DIC in our population was infection with 84% of patients infected with an identified pathogen. The most frequently diagnosed pathogen was HIV followed by Mycobacterium tuberculosis and other bacterial infections. In the majority of cases, bacteria were isolated from blood cultures. In 47 patients, HIV was the only pathogen which could be isolated. A relative risk ratio of 2.73 and an odds ratio of 29.97 was attributed to HIV for development of a DIC. A malignancy was present in 51 of the patients of which approximately 60% had co-existing infection. No cause could be attributed in 30 patients.

Conclusion

Infection was identified in the majority of the patients diagnosed with DIC in this study. HIV showed the highest relative risk ratio of all pathogens although previous studies have not suggested that HIV was strongly associated with DIC. In almost half of the HIV infected patients, there was no other pathogen isolated despite extensive investigation. This suggests that HIV has a strong association with the development of DIC, warranting further research into the relationship between HIV and disseminated microvascular thrombosis.

Amniotic Fluid Embolism with Isolated Coagulopathy: A Report of Two Cases

Amniotic Fluid Embolism (AFE) is a catastrophic complication of pregnancy with high mortality rate. The most common clinical presentation is an abrupt onset of cardiopulmonary collapse. Here, we present an uncommon variant involving isolated disseminated intravascular coagulation that developed without antecedent cardiopulmonary disturbances. Both patients developed symptoms soon after delivery. Blood test was sent at 14 minutes postpartum for the second patient due to suspected amniotic fluid embolism. Fetal components were observed in the uterine veins of the lower uterine segments in both cases. Amniotic fluid embolism with disseminated intravascular coagulopathy typically progresses faster than disseminated intravascular coagulopathy associated with other causes and symptoms. It usually develops within two hours of delivery. Prompt recognition and treatment of this entity is crucial to survival.

Clinical course of disseminated intravascular coagulopathy-type amniotic fluid embolism: A report of three cases

Amniotic fluid embolism (AFE) is a rare complication of pregnancy and its mortality rate is high. There have been few reports of AFE with presence of severe coagulopathy and incoagulable bleeding, and absence of cardiopulmonary symptoms or limited cardiopulmonary symptoms, followed by massive blood loss during delivery. Such cases have been referred to as disseminated intravascular coagulopathy-type AFE, and the characteristics of this condition have been presented previously. Here we report three cases that fulfilled the diagnostic characteristics of disseminated intravascular coagulopathy-type AFE.

Amniotic fluid embolism complicating medical termination of pregnancy

BACKGROUND

Amniotic fluid embolism is always a severe complication and generally occurs during labour or immediately after childbirth.

CLINICAL FEATURES

We report the case of a patient falling victim to amniotic fluid embolism after the medical termination of her pregnancy at 24 weeks of amenorrhea following the discovery of a teratoma-carrying foetus. The amniotic fluid embolism diagnosis was strongly suspected in the face of the sudden onset of severe arterial hypotension, hypoxic respiratory distress, a coma state and disseminated intravascular coagulopathy immediately after the delivery. Additional tests were conducted to support the diagnosis: cytological testing of a peripheral venous sample and maternal broncho-alveolar lavage fluid, dosing of tryptase and alpha-fetoprotein levels as well as screening for insulin-like growth factor binding protein 1.

CONCLUSION

Amniotic fluid embolism is a rare and difficult diagnosis, especially in unconventional settings, yet it can be facilitated by screening for amniotic markers and tryptase.

Role of dexmedetomidine in IL-4 and IFN-γ expression in rats with multiple organ dysfunction syndrome induced by postpartum bleeding

Bleeding-induced multiple organ dysfunction syndrome (MODS) is one of the major causes of death in pregnant women. MODS is thought to result from an inappropriate generalized host inflammatory response to a variety of acute insults. In this study we established a MODS model in postpartum rats, in which MODS was induced by the combination of induced hypotension for 60 min and clamping of the superior mesenteric artery for a period of 40 min. We sacrificed all the rats 24 h after dexmedetomidine (DEX) treatment. Thymus, spleen, and mesenteric lymph node tissue were collected to detect interferon-γ (IFN-γ) and interleukin-4 (IL-4) protein expression; lung and intestine tissue were collected to measure IFN-γ and IL-4 gene expression. In the present study, IFN-γ and IL-4 mRNA were increased in the lungs and intestines of the MODS rats. DEX administration decreased IFN-γ and IL-4 mRNA expression. IFN-γ and IL-4 expression for the thymus, spleen, and mesenteric lymph nodes were higher in the MODS postpartum rats relative to control rats, and these expression levels decreased upon DEX administration, But there were no significant differences between DEX doses. In conclusion DEX administration appeared to reduce IFN-γ and IL-4 protein expression in thymus, spleen, and mesenteric lymph node tissue and reduce IFN-γ and IL-4 gene expression in the lungs and intestines in the MODS postpartum rats but was not dose-dependent.

From appearance to essence: 10 years review of atypical amniotic fluid embolism

PURPOSE

Amniotic fluid embolism (AFE) is an unpredictable and unpreventable complication of maternity. The presentation may range from relatively subtle clinical events to sudden maternal cardiac arrest. However, the neglected diagnosis of non-classical form of AFE (atypical AFE) is very common. The aim of this study was to examine population-based regional data from Suzhou, China. Based on the analysis of all available case reports, we put forward an outline of atypical AFE and investigate whether any variation identified could be ascribed to methodology.

METHODS

Retrospective study from January 2004 to December 2013, 53 cases was identified from the database of Center for Disease Control (CDC) in the city of Suzhou. We investigated the presentations of atypical AFE and maternal characteristics with potential factors underlying AFE. Multiple-regression analysis was used to calculate adjusted odds ratios (ORs) and 95 % confidence intervals (CIs).

RESULTS

The incidence of AFE was 6.91 per 100,000 deliveries (53/766,895). Seventeen deaths occurred, a mortality rate of 32 %. Atypical AFE may as the earlier stage or mild form of AFE, there was no death case in the study with timely remedy. The atypical AFE appear is obstetric hemorrhage and/or pulmonary and renal dysfunction postpartum. Hyperfibrinolysis and coagulopathy may the early laboratory findings of atypical AFE. Atypical and classical AFE shared the same risks, such as advanced maternal age, placental abnormalities, operative deliveries, eclampsia, cervical lacerations, and induction of labor.

CONCLUSION

Staying alert to premonitory symptoms of AFE is critical to turn it to a remediable disease. Patient complaints such as breathlessness, chest pain, feeling cold, distress, panic, a feeling of nausea, and vomiting should elicit close attention. The management of a suspected episode of amniotic fluid embolism is generally considered to be supportive. Hysterectomy must be performed if there is further progression of symptoms. Due to advances in acute care, mortality has decreased in recent years, highlighting the importance of early detection and treatment.

Protein S deficiency present in a pregnant woman with dyspnea, abdominal pains, restlessness, agitation and hypofibrinogenemia

Hypofibrinogenemia is rare in pulmonary thromboembolism. A pregnant woman with dyspnea, abdominal pain, restlessness, agitation and protein S deficiency exhibited normal blood oxygenation and high D-dimer (370 μg/mL) and undetectable fibrinogen levels in the blood. The pathogenesis responsible for present findings may have some features similar to amniotic fluid embolism.

C1 esterase inhibitor activity in amniotic fluid embolism

OBJECTIVES

Amniotic fluid embolism exhibits activation of the complement system and the kallikrein-kinin and coagulofibrinolytic systems. C1 esterase inhibitor is a major inhibitor of C1 esterase and can inhibit plasma kallikrein and also factors XIIa and XIa. Its activity has been shown to be significantly lower in pregnancy and labor than in the nonpregnant state. The purpose of this study was to determine C1 esterase inhibitor activity levels in amniotic fluid embolism.

DESIGN

Retrospective study.

SETTING

A single university-based center.

PATIENTS

One hundred six cases with amniotic fluid embolism in a total of 194 singleton pregnant women between January 2010 and December 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred six cases of amniotic fluid embolism had applied to the Japan amniotic fluid embolism registration center in Hamamatsu University School of Medicine between January 2010 and December 2011. In amniotic fluid embolism cases, 85 cases were nonfatal and 21 cases were fatal. Eighty-eight women who delivered without amniotic fluid embolism were regarded as a control. C1 esterase inhibitor activity levels were significantly lower in amniotic fluid embolism patients (30.0% ± 1.8%) than in control women (62.0% ± 2.0%) (p < 0.0001). C1 esterase inhibitor activity levels in fatal amniotic fluid embolism cases (22.5% ± 3.4%) were significantly lower than those in nonfatal amniotic fluid embolism cases (32.0% ± 2.1%) (p < 0.05).

CONCLUSIONS

These results demonstrated that low C1 esterase inhibitor activity levels were closely associated with the pathogenesis of amniotic fluid embolism suggesting that C1 esterase inhibitor activity levels have potential as a prognosis factor of amniotic fluid embolism.

Amniotic fluid embolism: the known and not known

Amniotic fluid embolism was first recognized in 1926, in a Brazilian journal case report, on the basis of large amounts of fetal material in the maternal pulmonary vasculature at autopsy. The first English language description appeared in 1941 and consisted of eight parturients dying suddenly in which, once again, fetal material was seen in the pulmonary vasculature. A control group of 34 pregnant women dying of other recognized causes did not have fetal material in their lungs. The incidence of recognized, serious illness is on the order of two to eight per 100,000, with a mortality rate ranging from 13% to 35%. The diagnosis rests largely on one or more of four clinical signs: circulatory collapse, respiratory distress, coagulopathy, and seizures/ coma. The only confirmatory laboratory test remains autopsy findings although serum tests for fetal antigen, insulin-like growth factor binding protein-1, and complement are currently being investigated. One of the paradoxes of diagnosis is that fetal material in the pulmonary circulation at autopsy is specific for amniotic fluid embolism, while the same finding in the living is not. The mechanism of disease remains uncertain although the best available evidence suggests that complement activation might have a role. In contrast, mast cell degranulation probably is not a mechanism, so amniotic fluid embolism is not an anaphylaxis or anaphylactoid reaction as has been occasionally suggested. Perhaps the greatest unknown is not why 1 in 50,000 pregnant women develop what appears to be an immune response to their fetus, but rather why the other 49,999 do not?

Current concepts of immunology and diagnosis in amniotic fluid embolism

Amniotic fluid embolism (AFE) is one of the leading causes of maternal mortality and morbidity in developed countries. Current thinking about pathophysiology has shifted away from embolism toward a maternal immune response to the fetus. Two immunologic mechanisms have been studied to date. Anaphylaxis appears to be doubtful while the available evidence supports a role for complement activation. With the mechanism remaining to be elucidated, AFE remains a clinical diagnosis. It is diagnosed based on one or more of four key signs/symptoms: cardiovascular collapse, respiratory distress, coagulopathy, and/or coma/seizures. The only laboratory test that reliably supports the diagnosis is the finding of fetal material in the maternal pulmonary circulation at autopsy. Perhaps the most compelling mystery surrounding AFE is not why one in 20,000 parturients are afflicted, but rather how the vast majority of women can tolerate the foreign antigenic presence of their fetus both within their uterus and circulation?

Amniotic fluid embolism: an evidence-based review

We conducted an evidence-based review of information about [corrected] amniotic fluid embolism (AFE). The estimated incidence of AFE is 1:15,200 and 1:53,800 deliveries in North America and Europe, respectively. The case fatality rate and perinatal mortality associated with AFE are 13-30% and 9-44%, respectively. Risk factors associated with an [corrected] increased risk of AFE include advanced maternal age, placental abnormalities, operative deliveries, eclampsia, polyhydramnios, cervical lacerations, [corrected] and uterine rupture. The hemodynamic response in [corrected] AFE is biphasic, with initial pulmonary hypertension and right ventricular failure, followed by left ventricular failure. Promising therapies include selective pulmonary vasodilators and recombinant activated factor VIIa. Important topics for future research are presented.

Amniotic Fluid Embolism: A Comparison between Patients Who Survived and Those Who Died

This study aimed to investigate comparative clinical courses for a series of women with amniotic fluid embolism (AFE) and to assess factors associated with patient survival. Clinical courses of nine patients with AFE in a single tertiary centre were reviewed. AFE was diagnosed when a woman presented with typical clinical symptoms accompanied by abnormal laboratory tests (including abnormal coagulation) or at autopsy when fetal debris was found in the maternal pulmonary arteries. Five patients survived and four died. The first clinical manifestations of AFE were variable; dyspnoea was noted in only four patients. Other signs were state of shock, abdominal pain and uterine atony. The mean ± SD interval between the onset of clinical manifestations and treatment was significantly shorter for survivors (48.0 ± 36.3 min) than for non-survivors (137.5 ± 49.7 min). The number of failed organs was significantly fewer for the survivors compared with the non-survivors. AFE was accompanied by a wide variety of clinical manifestations, but early diagnosis and treatment appeared to be the most critical factors associated with survival.

[Amniotic fluid embolism during curettage for a pregnancy arrest. Case report]

Amniotic fluid embolism is always a serious complication during the peripartum period. We report the case of an amniotic fluid embolism during curettage for a pregnancy arrest at 13 weeks. The diagnosis was confirmed by the presence of epithelial cells into the maternal blood.

[Amniotic fluid embolism: successful evolution course of isolated disseminated intravascular coagulation and early biological diagnosis]

Amniotic embolism is a sudden, unexpected and devastating complication of pregnancy. The diagnosis is usually made on the basis of clinical presentation after excluding differential diagnosis or at autopsy in the event of death of the parturient. We need to develop simple, non-invasive, sensitive tests for a reliable and early diagnosis. We report the case of a 34-year-old woman, who presented soon after delivery, an isolated disseminated intravascular coagulation with severe haemorrhage, an haemostatic hysterectomy was required. A 3370 g child was delivered by caesarean section. The patient survived without sequelae. The diagnosis of amniotic embolism was established by the presence of amniotic cells in the maternal central venous blood as well as in the bronchoalveolar fluid.

Emergency obstetric hysterectomy in Kuwait: a clinico pathological analysis

The major objective of this study is to analyze the histological findings in emergency obstetric hysterectomy specimens and correlate them with the clinical diagnosis, epidemiological factors and number of tissue blocks examined. The records of all peripartum hysterectomy specimens examined between 1995 and 2001 in the Department of Pathology, Al-Sabah Hospital Kuwait were analyzed. A minimum of ten blocks from the cervix or lower uterine segment was arbitrarily regarded as adequate. Fifty-eight patients had peripartum hysterectomies (incidence of 0.07% of all deliveries) out of which 65% were aged between 30 and 40 years. The number of hysterectomy increased with parity up to five and then declined. The number of blocks examined varied from 2 to 53. Satisfactory pathology was found in 40 and absent in 18 cases. There were 33 adherent placentas. Amniotic fluid embolism (AFE) was found in seven patients. Adequate tissue blocks (>or=10) were significantly associated with positive pathological findings. P value <0.05.

Labor induction with dinoprostone or oxytocine and postpartum disseminated intravascular coagulation: a hospital-based case-control study

OBJECTIVE

This study was undertaken to test the hypothesis of an association between pharmacologic agents used for labor induction, in particular dinoprostone, and postpartum disseminated intravascular coagulation (DIC).

STUDY DESIGN

A retrospective hospital-based case-control study. Adjusted odds ratios (AOR) were calculated by a conditional logistic regression.

RESULTS

Forty valid cases of postpartum DIC were compared against 197 matched controls. Labor was induced in 17% of controls, and 56% of cases (AOR = 7.2; 95% CI: 2.1-24.6). The association was observed for both dinoprostone (AOR = 6.7; 95% CI: 1.7-26.5) and oxytocin (AOR = 8.4; 95% CI: 1.4-50.9). Other risk factors identified were as follows: a maternal age older than 34 years (AOR = 9.5; 95% CI: 2.4-37.7), complications during pregnancy (AOR = 5.5; 95% CI: 1.3-22.8), and a gestational age of over 40 weeks (AOR = 3.5; 95% CI: 1.1-11.1). Such factors were shown to also have an interaction with the induction of labor. Oxytocin augmentation showed a negative association (AOR = 0.1; 95% CI: 0.02-0.4). The absolute risk attributable to induction was estimated in 5 per 10,000 deliveries.

CONCLUSION

The pharmacologic induction of labor is associated with an increased risk of postpartum DIC, regardless the substance used. Although the absolute risk seems to be quite low, the obstetricians should not neglect it, in particular for the special risk groups identified.

Fetal bradycardia and disseminated coagulopathy: atypical presentation of amniotic fluid emboli

We present a parturient who developed an atypical case of amniotic fluid emboli presented by sudden fetal bradycardia, followed by maternal disseminated coagulopathy. The typical feature of cardiopulmonary collapse was absent in this patient implying that in some cases of amniotic fluid emboli (AFE), fetal hypoxia or acidemia is unrelated to maternal cardiopulmonary status.

[Amniotic fluid embolism suspected in a case of seizure and mild uterine haemorrhage with activation of coagulation and fibrinolysis]

After a normal pregnancy and labour in a 29-year-old parturient, a single seizure followed by a transient headache was observed during the uterine revision for placental retention. Mild uterine haemorrhage of 150 ml per hour without any uterine atony was associated with activation of clotting and fibrinolysis (decrease of fibrinogen, elevated fibrin soluble complexes and D-dimers). A ten fold value of foetal blood cells in maternal serum suggested the diagnosis of amniotic fluid embolism. Atypical forms of amniotic fluid embolism and their diagnosis are discussed.

Two cases of hemorrhage secondary to amniotic fluid embolus managed with uterine artery embolization

PURPOSE

To describe the anesthetic management of two cases of amniotic fluid embolus (AFE) and disseminated intravascular coagulation (DIC) who underwent bilateral uterine artery embolization to control their postpartum hemorrhage.

CLINICAL FEATURES

We report the clinical course and management of two women who suffered sudden cardiorespiratory events during labour. The first patient had a cardiac arrest whereas the second developed respiratory failure and altered neurological status. They were diagnosed as having had an AFE. Both of these events were accompanied by severe postpartum hemorrhage and DIC. They suffered prolonged bleeding and received massive transfusions. Successful management of hemorrhage was optimized by uterine artery embolization, thus avoiding ongoing problems with bleeding and possible hysterectomy. The role of uterine artery embolization is described, along with its advantages and anesthetic considerations.

CONCLUSION

Women with severe postpartum hemorrhage, with or without DIC, should be considered for uterine artery embolization.

[Amniotic fluid embolism during labor]

Amniotic fluid embolism is an unpredictable but dramatical complication of pregnancy that occurs when amniotic fluid enter into the maternal circulation. The classical clinical feature is acute respiratory distress, circulatory distress, seizures and coagulopathy. However there is no routine laboratory diagnosis, so that is a diagnosis of exclusion. We report here the case of a patient, on labor with an epidural analgesia who suddenly suffered from seizures, circulatory arrest, and haemorrhage. A symptomatic management was instituted and a caesarean section was performed. An haemostatic hysterectomy was required. The patient survived without any sequelae. Neurological outcome of the child is still reserved.

[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.

Multiple organ dysfunction syndrome (MODS) in the obstetric population

Multiple organ dysfunction syndrome (MODS) has the potential to negatively affect obstetric outcomes of critically ill maternity patients. This pathophysiologic condition may often be indistinguishable from that which occurs during normal pregnancy. The normal adaptations of pregnancy, in their exaggerated form, may cause functional change to become dysfunctional in the maternal patient. Although pregnancy is considered a state of health, MODS is a grave condition with terminal outcomes. Regional perfusion deficits in oxygen and global defects of volume are two potential pathologic sequelae. Many general medical and obstetric causes may be identified. An exaggerated systemic inflammatory response syndrome (SIRS) precedes this patterned process of death. This article will apply current theories, assessment, and treatment practices of MODS to the obstetrical populace.

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.

Amniotic fluid embolus: a review of the research literature

The diagnosis of Amniotic Fluid Embolus (AFE) is often missed clinically leading to the incorrect attribution of a major post-partum haemorrhage, which may accompany AFE, to uterine atony. This paper reviews the research on AFE with particular emphasis on the clinical presentation and diagnosis; both before and after death. It begins by dealing with the difficulty of defining AFE due to confusion about the underlying pathophysiological events. As this paper will demonstrate, the theory that AFE is an embolic event is no longer valid. A description of the clinical manifestations is provided so that these can be explained by the contemporary theory of AFE as an 'anaphylactoid' reaction. Finally, the difficulties of diagnosis, particularly laboratory diagnosis, will be discussed. The research indicates that it is not possible to accurately diagnose AFE, either, pre or post mortem, by any currently available laboratory tests. Because of better diagnosis it is now known that AFE in not uncommon and, if it is diagnosed early, a much higher rate of intact survival can be achieved than was previously thought possible.

Amniotic fluid embolus: a review of the literature

PURPOSE

To review the literature since 1979 to determine the natural history, etiology, diagnosis and potential treatment of amniotic fluid embolus (AFE).

SOURCE

English language articles and books published between June 1976 and June 1998 were identified by a computerized medline search using the title or text word amniotic fluid embolus. This same search strategy was repeated and updated to October 1999 by an independent individual using both Medline and Embase. The search was also expanded to include Science Citation Index listing Morgan's 1979 review article. All relevant publications were retrieved and their bibliographies were scanned for additional sources.

PRINCIPAL FINDINGS

Randomized controlled trials are not possible with amniotic fluid emboli. The majority of the literature consists of clinical reports combined with occasional limited reviews. Knowledge obtained from these reports suggests that amniotic fluid emboli present as a spectrum of disease that ranges from a subclinical entity to one that is rapidly fatal. Because cases are sporadic and the diagnosis is often unconfirmed, little progress has been made towards understanding its etiology or defining the risk factors. Present management is empirical and directed towards the maintenance of oxygenation, circulatory support and the correction of coagulopathy.

CONCLUSION

Amniotic fluid embolus continues to be a life-threatening but potentially reversible complication unique to pregnancy. It cannot be predicted nor prevented. Review of the literature reveals that there are no standardized investigational methods or protocols to confirm the diagnosis in suspected cases.

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.