Amniotic fluid embolism: the known and not known

Nonthrombotic Pulmonary Embolism Associated With Non-Hodgkin Lymphoma

Nonthrombotic pulmonary embolism (NTPE) challenges the medical community with its diverse etiologies and potential life-threatening implications. The classification section delves into the multifaceted nature of NTPE, which includes various embolic agents that traverse the vascular system. From air and fat emboli to tumor and amniotic fluid emboli, this exploration of diverse etiologies sheds light on the complexity of NTPE. Diagnostic methods play a crucial role in the effective management of NTPE. This article describes a range of traditional and cutting-edge diagnostic techniques, from computed tomography angiography to novel biomarkers, enabling the accurate and timely identification of NTPE. NTPE treatment options are diverse and patient-specific, requiring customized approaches to address varying embolic sources. Anticoagulation, embolus removal, and emerging interventions under study are discussed, providing clinicians with a comprehensive understanding of management strategies. This article uncovers the rare but captivating association between NTPE and non-Hodgkin lymphoma. Although rare, documented cases have sparked curiosity among researchers and medical practitioners. We explore potential pathophysiological connections, discussing challenges and considerations when encountering this unique scenario. In conclusion, this captivating review encapsulates the multifaceted realm of NTPE, covering its classification, diagnostics, and treatment modalities. Moreover, it presents a fascinating connection with non-Hodgkin lymphoma. This article offers a comprehensive and concise review of NTPE, guiding readers through its intricate classification, diagnostic approaches, and therapeutic interventions.

Nontrombotic Pulmonary Embolism: Different Etiology, Same Significant Consequences

Nontrombotic pulmonary embolism represents the embolization of different types of materials (cells, organisms, gas, foreign material) into pulmonary circulation. The disease is uncommon, and clinical presentation together with laboratory findings are nonspecific. Its pathology is usually misdiagnosed based on imaging findings as pulmonary thromboembolism, but the correct diagnosis is essential because different therapeutic approaches are required. In this context, knowledge of the risk factors associated with nontrombotic pulmonary embolism and specific clinical symptoms is fundamental. Our objective was to discuss the specific features of the most common etiologies of nontrombotic pulmonary embolism, gas, fat, amniotic fluid, sepsis and tumors, to provide assistance for a rapid and correct diagnosis. Because the most common etiologies are iatrogenic, knowledge of the risk factors could be an important tool for prevention or rapid treatment if the disease develops during different procedures. The diagnosis of nontrombotic pulmonary embolisms represent a laborious challenge, and endeavors should be made to prevent development and increase awareness of this disease.

Practical use of C1 esterase inhibitor concentrate for clinical amniotic fluid embolism

Amniotic fluid embolism (AFE) causes consumption coagulopathy, which requires a massive transfusion to save the mother's life. The preparation of such a massive transfusion is too time-consuming in extremely emergent clinical settings and occasionally leads to devastating side effects such as transfusion-associated acute lung injury. C1 esterase inhibitor (C1INH) is a protein with the ability to inhibit complement, coagulation and kinin pathways. The C1INH concentration in AFE patients is low, and it has been speculated that the administration of C1INH concentrate could have a striking and beneficial effect on AFE patients in critical condition by ameliorating their perturbed coagulation system. We report the case of a 32-year-old Japanese AFE patient in whom deteriorated vital signs and coagulopathy recovered within minutes after an injection of C1INH concentrate. C1INH concentrate can quickly revive the deteriorated vital signs and the atonic uterus that stem from AFE and may reduce the total amount of transfusion.

Squamous cell carcinoma antigen as a novel candidate marker for amniotic fluid embolism

AIM

We aimed to evaluate the clinical usefulness of serum squamous cell carcinoma (SCC) antigen for the diagnosis of amniotic fluid embolism (AFE).

METHODS

Sera and information of 20 patients with AFE (autopsy-proven AFE, four cases; clinical AFE, 16 cases) were obtained from the Japan Amniotic Fluid Embolism Registration Center at Hamamatsu University School of Medicine. As controls, we included 74 gestational-age-matched healthy women who gave birth to healthy newborns during the period from December 2012 to January 2014. Receiver-operator curves (ROC) were used to evaluate the diagnostic performance of SCC levels for prediction of AFE.

RESULTS

Serum SCC antigen levels in women with autopsy-proven AFE (112.0 ± 169.4 ng/mL, P = 0.001) and clinical AFE (9.5 ± 10.3 ng/mL, P = 0.004) were significantly higher than those in healthy controls with normal delivery (4.4 ± 2.2 ng/mL). On ROC analysis, the optimal cut-off value for SCC antigen levels was 7.15 ng/mL, for which the sensitivity and specificity for AFE prediction was 60.0% and 89.2%, respectively (area under the ROC, 0.785; 95% confidence interval, 0.663-0.908; P < 0.001).

CONCLUSION

Serum SCC antigen may be a promising predictor of the entry of amniotic fluid into the maternal circulation, potentially serving as a candidate marker for noninvasive diagnosis of AFE.

Maternal collapse: Challenging the four-minute rule

Introduction

The current approach to, cardiopulmonary resuscitation of pregnant women in the third trimester has been to adhere to the “four-minute rule”: If pulses have not returned within 4 min of the start of resuscitation, perform a cesarean birth so that birth occurs in the next minute. This investigation sought to re-examine the evidence for the four-minute rule.

Methods

A literature review focused on perimortem cesarean birth was performed using the same key words that were used in formulating the “four-minute rule.” Maternal and neonatal injury free survival rates as a function of arrest to birth intervals were determined, as well as actual incision to birth intervals.

Results

Both maternal and neonatal injury free survival rates diminished steadily as the time interval from maternal arrest to birth increased. There was no evidence for any specific survival threshold at 4 min. Skin incision to birth intervals of 1 min occurred in only 10% of women.

Conclusion

Once a decision to deliver is made, care providers should proceed directly to Cesarean birth during maternal cardiac arrest in the third trimester rather than waiting for 4 min for restoration of the maternal pulse. Birth within 1 min from the start of the incision is uncommon in these circumstances.

•

Half of maternal/fetal pairs who are delivered by Cesarean birth within 25 min survive without injury.

•

The injury free survival rate for both has a roughly linear decrease as the time interval from arrest to birth increases.

•

Very few babies could be delivered within 1 min of the Cesarean section incision.

This information suggests that the current cardio-pulmonary resuscitation guideline in pregnancy, known as the four-minute rule, needs to be changed. Injury free survival for both mother and baby decreases steadily from the moment of cardiac arrest until cesarean birth. Furthermore, in actual practice, the baby usually cannot be delivered within 1 min of the start of surgery. Once a decision for delivery has been made, Cesarean birth should be initiated promptly without waiting for 4 min. In practice, the recommendation to proceed to cesarean birth without delay is also likely to result in less confusion than the current “Four-Minute rule.”