Acute respiratory distress syndrome in pregnancy

Acute Respiratory Failure in Pregnancy

Respiratory failure may affect up to 1 in 500 pregnancies, due to pregnancy-specific conditions, conditions aggravated by the pregnant state, or other causes. Management during pregnancy is influenced by altered maternal physiology, and the presence of a fetus influencing imaging, and drug therapy choices. Few studies have addressed the approach to invasive mechanical ventilatory management in pregnancy. Hypoxemia is likely harmful to the fetus, but precise targets are unknown. Hypocapnia reduces uteroplacental circulation, and some degree of hypercapnia may be tolerated in pregnancy. Delivery of the fetus may be considered to improve maternal respiratory status but improvement does not always occur.

A biomarker for bacteremia in pregnant women with acute pyelonephritis: soluble suppressor of tumorigenicity 2 or sST2

Objective: Sepsis is a leading cause of maternal death, and its diagnosis during the golden hour is critical to improve survival. Acute pyelonephritis in pregnancy is a risk factor for obstetrical and medical complications, and it is a major cause of sepsis, as bacteremia complicates 15-20% of pyelonephritis episodes in pregnancy. The diagnosis of bacteremia currently relies on blood cultures, whereas a rapid test could allow timely management and improved outcomes. Soluble suppression of tumorigenicity 2 (sST2) was previously proposed as a biomarker for sepsis in non-pregnant adults and children. This study was designed to determine whether maternal plasma concentrations of sST2 in pregnant patients with pyelonephritis can help to identify those at risk for bacteremia.Study design: This cross-sectional study included women with normal pregnancy (n = 131) and pregnant women with acute pyelonephritis (n = 36). Acute pyelonephritis was diagnosed based on a combination of clinical findings and a positive urine culture. Patients were further classified according to the results of blood cultures into those with and without bacteremia. Plasma concentrations of sST2 were determined by a sensitive immunoassay. Non-parametric statistics were used for analysis.Results: The maternal plasma sST2 concentration increased with gestational age in normal pregnancies. Pregnant patients with acute pyelonephritis had a higher median (interquartile range) plasma sST2 concentration than those with a normal pregnancy [85 (47-239) ng/mL vs. 31 (14-52) ng/mL, p < .001]. Among patients with pyelonephritis, those with a positive blood culture had a median plasma concentration of sST2 higher than that of patients with a negative blood culture [258 (IQR: 75-305) ng/mL vs. 83 (IQR: 46-153) ng/mL; p = .03]. An elevated plasma concentration of sST2 ≥ 215 ng/mL had a sensitivity of 73% and a specificity of 95% (area under the receiver operating characteristic curve, 0.74; p = .003) with a positive likelihood ratio of 13.8 and a negative likelihood ratio of 0.3 for the identification of patients who had a positive blood culture.Conclusion: sST2 is a candidate biomarker to identify bacteremia in pregnant women with pyelonephritis. Rapid identification of these patients may optimize patient care.

[Prone position in the third trimester of pregnancy during the COVID-19 era: a transdisciplinary approach.]

There is very limited evidence regarding the use of prone position as part of the treatment of severe ARDS in pregnant patients. Currently, recommendations for invasive ventilatory management in this population are very scarce and are based on the extrapolation of conclusions obtained in studies of non-pregnant patients. The available literature asserts that the anatomy and physiology of the pregnant woman undergoes complex adaptive changes that must be considered during invasive ventilatory support and prone position. With prone ventilation, the benefits obtained for the couple far outweigh the eventual risks. Adequate programming of the mechanical ventilator correlates with a clear and simple concept: individualization of support. In any case, the decision on the timing of termination of pregnancy should be based on adequate multidisciplinary clinical judgment and should be supported by strict monitoring of the product.

Fetal death as an outcome of acute respiratory distress in pregnancy, during the COVID-19 pandemic: a population-based cohort study in Bahia, Brazil

BACKGROUND

Fetal loss is one of the most serious adverse outcomes of pregnancy. Since the onset of the COVID-19 pandemic, Brazil has recorded an unprecedented number of hospitalizations of pregnant women due to acute respiratory distress (ARD), thereby, we aimed to assess the risk of fetal deaths associated to ARD during pregnancy in Bahia state, Brazil, in the context of the COVID-19 pandemic.

METHODS

This is an observational population-based retrospective cohort study, developed with women at or after 20 weeks of pregnancy, residents in Bahia, Brazil. Women who had acute respiratory distress (ARD) in pregnancy during the COVID-19 pandemic (Jan 2020 to Jun 2021) were considered 'exposed'. Women who did not have ARD in pregnancy, and whose pregnancy occurred before the onset of the COVID-19 pandemic (Jan 2019 to Dec 2019) were considered 'non-exposed'. The main outcome was fetal death. We linked administrative data (under mandatory registration) on live births, fetal deaths, and acute respiratory syndrome, using a probabilistic linkage method, and analyzed them with multivariable logistic regression models.

RESULTS

200,979 pregnant women participated in this study, 765 exposed and 200,214 unexposed. We found four times higher chance of fetal death in women with ARD during pregnancy, of all etiologies (adjusted odds ratio [aOR] 4.06 confidence interval [CI] 95% 2.66; 6.21), and due to SARS-CoV-2 (aOR 4.45 CI 95% 2.41; 8.20). The risk of fetal death increased more when ARD in pregnancy was accompanied by vaginal delivery (aOR 7.06 CI 95% 4.21; 11.83), or admission to Intensive Care Unit (aOR 8.79 CI 95% 4.96; 15.58), or use of invasive mechanical ventilation (aOR 21.22 CI 95% 9.93; 45.36).

CONCLUSION

Our findings can contribute to expanding the understanding of health professionals and managers about the harmful effects of SARS-CoV-2 on maternal-fetal health and alerts the need to prioritize pregnant women in preventive actions against SARS-CoV-2 and other respiratory viruses. It also suggests that pregnant women, infected with SARS-CoV-2, need to be monitored to prevent complications of ARD, including a careful assessment of the risks and benefits of early delivery to prevent fetal death.

Extracorporeal life support in pregnant and postpartum women with COVID-19-related acute respiratory distress syndrome

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) is an intervention used for patients with acute respiratory distress syndrome (ARDS) from COVID-19 who have failed conventional ventilatory strategies. Very few studies have given insight into the outcomes of pregnant and postpartum patients requiring ECMO support.

METHODS

Single center, retrospective, observational study of female pregnant and postpartum patients suffering COVID-19 ARDS and requiring ECMO.

RESULTS

Eight SARS-CoV-2 positive patients were identified. The average age was 31 ± 4 years, with Body Mass Indices (BMI) and SOFA scores ranging between 32-49 and 8-11, respectively. Two patients were pregnant at the time of ECMO initiation, two were peripartum, and four were postpartum. Five patients (63%) had bleeding, and one patient had a hysterectomy. Seven patients (88%) were supported by V-V ECMO and one with V-A ECMO. Patients had between one and three circuit exchanges due to oxygenator failure or clots in the circuit. All patients were in ICU between 7 and 74 days, with hospital length of stay between 8 and 81 days. All patients were weaned off ECMO and were successfully discharged from the hospital. All newborns were born via cesarean section, and all survived to discharge.

CONCLUSION

Our study shows a 100% neonatal and maternal survival rate demonstrating that ECMO in this patient population is safe. These patients should be transferred to experienced high-volume ECMO centers with the ability to perform emergent cesarean sections. ECMO should be considered a life-saving therapy for pregnant women with severe COVID-19 with an overall excellent maternal and neonatal survival rate.

Pregnancy and Severe ARDS with COVID-19: Epidemiology, Diagnosis, Outcomes and Treatment

Pregnancy-related acute respiratory distress syndrome (ARDS) is fast becoming a growing and clinically relevant subgroup of ARDS amidst global outbreaks of various viral respiratory pathogens that include H1N1-influenza, severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS), and the most recent COVID-19 pandemic. Pregnancy is a risk factor for severe viral-induced ARDS and commonly associated with poor maternal and fetal outcomes including fetal growth-restriction, preterm birth, and spontaneous abortion. Physiologic changes of pregnancy further compounded by mechanical and immunologic alterations are theorized to impact the development of ARDS from viral pneumonia. The COVID-19 sub-phenotype of ARDS share overlapping molecular features of maternal pathogenicity of pregnancy with respect to immune-dysregulation and endothelial/microvascular injury (i.e., preeclampsia) that may in part explain a trend toward poor maternal and fetal outcomes seen with severe COVID-19 maternal infections. To date, current ARDS diagnostic criteria and treatment management fail to include and consider physiologic adaptations that are unique to maternal physiology of pregnancy and consideration of maternal-fetal interactions. Treatment focused on lung-protective ventilation strategies have been shown to improve clinical outcomes in adults with ARDS but may have adverse maternal-fetal interactions when applied in pregnancy-related ARDS. No specific pharmacotherapy has been identified to improve outcomes in pregnancy with ARDS. Adjunctive therapies aimed at immune-modulation and anti-viral treatment with COVID-19 infection during pregnancy have been reported but data in regard to its efficacy and safety is currently lacking.

Acute Respiratory Distress Syndrome in Pregnancy: Updates in Principles and Practice

Acute respiratory failure occurs in 0.05% to 0.3% of pregnancies and is precipitated by pulmonary and nonpulmonary insults. Acute respiratory distress syndrome (ARDS) is the rapid onset of hypoxemic respiratory failure associated with bilateral pulmonary opacities on chest imaging attributed to noncardiogenic pulmonary edema. The pathophysiological features of ARDS include hypoxemia, diminished lung volumes, and decreased lung compliance. While there is a paucity of data concerning ARDS in the pregnant individual, management principles do not vary significantly between pregnant and nonpregnant patients. The following review will discuss the diagnosis and management of the pregnant patient with ARDS.

RANKL up-regulated by progesterone aggravates lipopolysaccharide-induced acute lung injury during pregnancy

Acute lung injury (ALI) is a common acute respiratory disease with high morbidity and mortality rate in pregnant women. Receptor activator of NF-κB ligand (TNFSF11, also known as RANKL) exerts either pro-inflammatory or anti-inflammatory effects on the immune response. LPS administration reduced the survival time (n = 10, p < 0.01), increased wet/dry ratio (n = 10, p < 0.001) and lung injury score (n = 10, p < 0.001), the elevated proportions of plasmacytoid dendritic cells (pDCs) (n = 10, p < 0.0001), tissue-resident DCs (resDCs) (n = 10, p < 0.0001), macrophages (n = 10, p < 0.0001), and neutrophils (n = 10, p < 0.0001), and the expressions of costimulatory molecules and inflammation cytokines (n = 10, p < 0.05) in lungs of pregnant mice, compared with non-pregnant mice. In vitro, progesterone up-regulated the expression of RANKL (n > 6, p < 0.05) on pulmonary fibroblasts. The results of cytokine arrays showed that the cytokines associated with inflammatory response and leukocyte differentiation were decreased in pulmonary fibroblasts after treatment with anti-RANKL neutralizing antibody, compared with control pulmonary fibroblasts. More notably, we found that Tnfsf11^-/- pregnant mice had longer survival durations (n = 10, p < 0.01), lower lung injury scores (n = 10, p < 0.05^), and lower immune cell infiltration (n = 10, p < 0.05). These data imply that the RANKL/RANK axis plays an essential role in LPS-induced ALI during pregnancy possibly through a variety of pathways.

Acute respiratory distress and amniotic fluid embolism in pregnancy

Respiratory failure in pregnant and postpartum women is uncommon, but it is one of the leading causes of maternal admission into the intensive care unit and is associated with high mortality. The underlying causes include sequelae of underlying medical conditions, such as congenital heart diseases, but it is more often related to acute respiratory distress syndrome from obstetric complications like pre-eclampsia, effect of treatment like tocolysis, coincidental to pregnancy like transfusion-related acute lung injury, and accidental like amniotic fluid embolism. The pathophysiological mechanisms involved in many of these conditions remain to be clearly established, but maternal inflammatory response and activation of the immune and complement systems appear to play leading roles. Prompt recognition of maternal respiratory distress and related manifestations and aggressive and adequate supportive treatment, especially cardiopulmonary resuscitation, ventilation, maintenance of circulation, and timely termination of the pregnancy, play key roles in achieving survival of both mother and foetus.

Clinical decision analysis of elective delivery vs expectant management for pregnant individuals with COVID-19-related acute respiratory distress syndrome

BACKGROUND

Pregnant individuals are vulnerable to COVID-19-related acute respiratory distress syndrome. There is a lack of high-quality evidence on whether elective delivery or expectant management leads to better maternal and neonatal outcomes.

OBJECTIVE

This study aimed to determine whether elective delivery or expectant management are associated with higher quality-adjusted life expectancy for pregnant individuals with COVID-19-related acute respiratory distress syndrome and their neonates.

STUDY DESIGN

We performed a clinical decision analysis using a patient-level model in which we simulatedpregnant individuals and their unborn children. We used a patient-level model with parallel open-cohort structure, daily cycle length, continuous discounting, lifetime horizon, sensitivity analyses for key parameter values, and 1000 iterations for quantification of uncertainty. We simulated pregnant individuals at 32 weeks of gestation, invasively ventilated because of COVID-19-related acute respiratory distress syndrome. In the elective delivery strategy, pregnant individuals received immediate cesarean delivery. In the expectant management strategy, pregnancies continued until spontaneous labor or obstetrical decision to deliver. For both pregnant individuals and neonates, model outputs were hospital or perinatal survival, life expectancy, and quality-adjusted life expectancy denominated in years, summarized by the mean and 95% credible interval. Maternal utilities incorporated neonatal outcomes in accordance with best practices in perinatal decision analysis.

RESULTS

Model outputs for pregnant individuals were similar when comparing elective delivery at 32 weeks' gestation with expectant management, including hospital survival (87.1% vs 87.4%), life-years (difference, -0.1; 95% credible interval, -1.4 to 1.1), and quality-adjusted life expectancy denominated in years (difference, -0.1; 95% credible interval, -1.3 to 1.1). For neonates, elective delivery at 32 weeks' gestation was estimated to lead to a higher perinatal survival (98.4% vs 93.2%; difference, 5.2%; 95% credible interval, 3.5-7), similar life-years (difference, 0.9; 95% credible interval, -0.9 to 2.8), and higher quality-adjusted life expectancy denominated in years (difference, 1.3; 95% credible interval, 0.4-2.2). For pregnant individuals, elective delivery was not superior to expectant management across a range of scenarios between 28 and 34 weeks of gestation. Elective delivery in cases where intrauterine death or maternal mortality were more likely resulted in higher neonatal quality-adjusted life expectancy, as did elective delivery at 30 weeks' gestation (difference, 1.1 years; 95% credible interval, 0.1 - 2.1) despite higher long-term complications (4.3% vs 0.5%; difference, 3.7%; 95% credible interval, 2.4-5.1), and in cases where intrauterine death or maternal acute respiratory distress syndrome mortality were more likely.

CONCLUSION

The decision to pursue elective delivery vs expectant management in pregnant individuals with COVID-19-related acute respiratory distress syndrome should be guided by gestational age, risk of intrauterine death, and maternal acute respiratory distress syndrome severity. For the pregnant individual, elective delivery is comparable but not superior to expectant management for gestational ages from 28 to 34 weeks. For neonates, elective delivery was superior if gestational age was ≥30 weeks and if the rate of intrauterine death or maternal mortality risk were high. We recommend basing the decision for elective delivery vs expectant management in a pregnant individual with COVID-19-related acute respiratory distress syndrome on gestational age and likelihood of intrauterine or maternal death.

Veno-venous Extracorporeal Membrane Oxygenation for pregnant women with Acute Respiratory Distress Syndrome: a narrative review

Acute respiratory distress syndrome remains an uncommon condition during pregnancy. In patients with severe acute respiratory distress syndrome, when oxygenation or ventilation cannot be supported sufficiently using best practice conventional mechanical ventilation and additional therapies, veno-venous extracorporeal membrane oxygenation may be considered. In the past two decades, there has been increasing adoption of this technique to support adult patients with refractory acute respiratory distress syndrome. However, its use for the management of pregnant women is rare and remains a challenge. This narrative review addresses acute respiratory distress syndrome and its management during pregnancy, and then focuses on indications, contraindications, challenges, potential complications, and outcomes of the use of veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome in the pregnant patient.

Extracorporeal Membrane Oxygenation for Pregnant and Postpartum Patients

Extracorporeal membrane oxygenation (ECMO) has seen increasing use for critically ill pregnant and postpartum patients over the past decade. Growing experience continues to demonstrate the feasibility of ECMO in obstetric patients and attest to its favorable outcomes. However, the interaction of pregnancy physiology with ECMO life support requires careful planning and adaptation for success. Additionally, the maintenance of fetal oxygenation and perfusion is essential for safely continuing pregnancy during ECMO support. This review summarizes the considerations for use of ECMO in obstetric patients and how to address these concerns.

Acute Respiratory Failure and Mechanical Ventilation in Women With COVID-19 During Pregnancy: Best Clinical Practices

Symptomatic pregnant women with coronavirus disease-2019 (COVID-19) are at increased risk of severe disease and death compared with symptomatic nonpregnant females of reproductive age. Among those who become critically ill, profound acute hypoxemic respiratory failure is the dominant finding. Significant morbidity and mortality from COVID-19 are largely due to acute viral pneumonia that evolves to acute respiratory distress syndrome. Admission of these patients with critical disease to an intensive care unit and initiation of invasive mechanical ventilation may be indicated. Effective ventilatory support can be challenging in the COVID-19 patient population, even more so when the need occurs in a woman during pregnancy. Key respiratory changes during pregnancy are reviewed. Principles related to maternal-fetal oxygen transport, assessment of ventilation and oxygenation status, and oxygenation goals are also reviewed. Selected concepts related to mechanical ventilatory support for the woman with COVID-19 and acute respiratory failure during pregnancy are presented including indications for ventilatory support, noninvasive support, and invasive ventilator management. Challenges in providing care to this patient population are identified as well as strategies to address them going forward.

A Detailed Review of Critical Care Considerations for the Pregnant Cardiac Patient

Maternal cardiovascular disease is a leading cause of maternal death worldwide and recently, maternal mortality has increased secondary to cardiovascular causes. Maternal admissions to critical care encompass 1%-2% of all critical care admissions, and although not common, the management of the critically ill pregnant patient is complex. Caring for the critically ill pregnant cardiac patient requires integration of pregnancy-associated physiologic changes, understanding pathophysiologic disease states unique to pregnancy, and a multidisciplinary approach to timing around delivery as well as antenatal and postpartum care. Herein we describe cardiorespiratory changes that occur during pregnancy and the differential diagnosis for cardiorespiratory failure in pregnancy. Cardiorespiratory diseases that are either associated or exacerbated by pregnancy are highlighted with emphasis on perturbations secondary to pregnancy and appropriate management strategies. Finally, we describe general management of the pregnant cardiac patient admitted to critical care.

Ethical challenges in management of critically ill pregnant patients with coronavirus disease 2019 (COVID-19)

Despite the overwhelming number of coronavirus disease 2019 (COVID-19) cases worldwide, data regarding the optimal clinical guidance in pregnant patients is not uniform or well established. As a result, clinical decisions to optimize maternal and fetal benefit, particularly in patients with critical COVID-19 in the early preterm period, continue to be a challenge for obstetricians. There is often uncertainty in clinical judgment about fetal monitoring, timing of delivery, and mode of delivery because of the challenge in balancing maternal and fetal interests in reducing morbidity and mortality. The obstetrician and critical care team should empower pregnant patients or their surrogate decision maker to make informed decisions in response to the team's clinical evaluation. A clinically grounded ethical framework, based on the concepts of the moral management of medical uncertainty, beneficence-based obligations, and preventive ethics, should guide the decision-making process.

[Principles of intensive medical care in pregnant patients]

As the incidence of diseases during pregnancy or in the puerperium necessitating intensive medical care is very low, intensive care physicians are faced with a multitude of unfamiliar challenges in the treatment of this patient collective. The physiological and pathophysiological alterations during pregnancy induce some specific features with respect to the intensive medical treatment of pregnant or postpartum patients. Therefore, the first article in this CME series summarizes the most important principles and current recommendations on the care of pregnant or postpartum patients who need intensive medical treatment, always under consideration of the well-being of mother and child. The second article describes the diagnostics and treatment of special selected pathologies.

Risk Factors for Fetal Death and Maternal AP Severity in Acute Pancreatitis in Pregnancy

Background: Acute pancreatitis in pregnancy is a rare but highly life-threatening gestational and perinatal disease. Objective: This study aimed to identify the risk factors for fetal death and acute pancreatitis severity. Methods: This retrospective cohort study enrolled patients with acute pancreatitis in pregnancy in our center from January 1, 2012, to August 1, 2020, and classified them according to two clinical endpoints, fetal outcome and disease severity. The groups were examined and compared according to gestational week, etiology, gravidity and parity, complications in pre- and post-delivery, and medical history. Logistic regression analysis was performed to identify the independent risk factors for fetal death and acute pancreatitis severity. Results: Of the 90 enrolled patients, 28 (31.1%) had fetal death and 43 (47.8%) had severe acute pancreatitis. Logistic regression analysis showed that pre-delivery acute respiratory distress syndrome (OR, 5.8; 95% CI, 1.5-22.4; p = 0.010) and gestational week (OR, 0.9; 95% CI, 0.8-1.0; p = 0.011) were risk factors for fetal death. Gestation week (OR, 1.2; 95% CI, 1.1-1.3; p = 0.003) and fetal intrauterine death (OR, 5.9; 95% CI, 1.8-19.4; p = 0.003) were risk factors for severe acute pancreatitis. Conclusions: Pre-delivery acute respiratory distress syndrome and gestational week were independent risk factors for fetal death. Fetal intrauterine death and gestational week were independent risk factors for severe acute pancreatitis.

Pregnancy-specific transcriptional changes upon endotoxin exposure in mice

Objectives Pregnant women are more susceptible to certain infections; however, this increased susceptibility is not fully understood. Herein, systems biology approaches were utilized to elucidate how pregnancy modulates tissue-specific host responses to a bacterial product, endotoxin. Methods Pregnant and non-pregnant mice were injected with endotoxin or saline on 16.5 days post coitum (n=8-11 per group). The uterus, cervix, liver, adrenal gland, kidney, lung, and brain were collected 12 h after injection and transcriptomes were measured using microarrays. Heatmaps and principal component analysis were used for visualization. Differentially expressed genes between groups were assessed using linear models that included interaction terms to determine whether the effect of infection differed with pregnancy status. Pathway analysis was conducted to interpret gene expression changes. Results We report herein a multi-organ atlas of the transcript perturbations in pregnant and non-pregnant mice in response to endotoxin. Pregnancy strongly modified the host responses to endotoxin in the uterus, cervix, and liver. In contrast, pregnancy had a milder effect on the host response to endotoxin in the adrenal gland, lung, and kidney. However, pregnancy did not drastically affect the host response to endotoxin in the brain. Conclusions Pregnancy imprints organ-specific host immune responses upon endotoxin exposure. These findings provide insight into the host-response against microbes during pregnancy.

Descriptive Acute Respiratory Distress Syndrome (ARDS) in adults with imported severe Plasmodium falciparum malaria: A 10 year-study in a Portuguese tertiary care hospital

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe complication of malaria that remains largely unstudied. We aim to describe the development of ARDS associated with severe P. falciparum malaria, its management and impact on clinical outcome.

METHODS

Retrospective observational study of adult patients admitted with severe P. falciparum malaria in an Intensive Care Unit (ICU) of a tertiary care hospital from Portugal from 2008 to 2018. A multivariate logistic regression analysis was used to identify factors associated with the development of ARDS, defined according to Berlin Criteria. Prognosis was assessed by case-fatality ratio, nosocomial infection and length of stay.

RESULTS

98 patients were enrolled, of which 32 (33%) developed ARDS, a median of 2 days after starting antimalarial medication (IQR 0-4, range 0-6). Length of stay in ICU and in hospital were significantly longer in patients who developed ARDS: 13 days (IQR 10-18) vs 3 days (IQR 2-5) and 21 days (IQR 15-30.5) vs 7 days (IQR 6-10), respectively. Overall case-fatality ratio in ICU was 4.1% and did not differ between groups. The risk of ARDS development is difficult to establish.

CONCLUSION

ARDS is a hard to predict late complication of severe malaria. A low threshold for ICU admission and monitoring should be used. Ideally patients should be managed in a centre with experience and access to advanced techniques.

Acute Respiratory Distress Syndrome as an Organ Phenotype of Vascular Microthrombotic Disease: Based on Hemostatic Theory and Endothelial Molecular Pathogenesis

Acute respiratory distress syndrome (ARDS) is a life-threatening noncardiogenic circulatory disorder of the lungs associated with critical illnesses such as sepsis, trauma, and immune and collagen vascular disease. Its mortality rate is marginally improved with the best supportive care. The demise occurs due to progressive pulmonary hypoxia and multi-organ dysfunction syndrome (MODS) with severe inflammation. Complement activation is a part of immune response against pathogen or insult in which membrane attack complex (MAC) is formed and eliminates microbes. If complement regulatory protein such as endothelial CD59 is underexpressed, MAC may also cause pulmonary vascular injury to the innocent bystander endothelial cell of host and provokes endotheliopathy that causes inflammation and pulmonary vascular microthrombosis, leading to ARDS. Its pathogenesis is based on a novel "two-path unifying theory" of hemostasis and "two-activation theory of the endothelium" promoting molecular pathogenesis. Endotheliopathy activates two independent molecular pathways: inflammatory and microthrombotic. The former triggers the release inflammatory cytokines and the latter promotes exocytosis of unusually large von Willebrand factor multimers (ULVWF) and platelet activation. Inflammatory pathway initiates inflammation, but microthrombotic pathway more seriously produces "microthrombi strings" composed of platelet-ULVWF complexes, which become anchored on the injured endothelial cells, and causes disseminated intravascular microthrombosis (DIT). DIT is a hemostatic disease due to lone activation of ULVWF path without activated tissue factor path. It leads to endotheliopathy-associated vascular microthrombotic disease (EA-VMTD), which orchestrates consumptive thrombocytopenia, microangiopathic hemolytic anemia, and MODS. Thrombotic thrombocytopenic purpura (TTP)-like syndrome is the hematologic phenotype of EA-VMTD. ARDS is one of organ phenotypes among MODS associated with TTP-like syndrome. The most effective treatment of ARDS can be achieved by counteracting the activated microthrombotic pathway based on two novel hemostatic theories.

Infección por SARS-CoV-2 en la paciente obstétrica: una perspectiva desde el cuidado crítico

La nueva infección por coronavirus (COVID-19) se constituye en el principal problema de salud pública en el mundo. Entre el 5 y el 30% de los pacientes afectados por esta enfermedad requieren manejo en una unidad de cuidado intensivo. Se han generado diferentes publicaciones con recomendaciones para la población general. Sin embargo, en la población obstétrica la evidencia científica es reducida, aún más cuando se trata de infección por COVID-19 en escenarios de cuidado intensivo obstétrico. Por esta razón, se realizó una revisión narrativa no sistemática de la literatura utilizando como fuente de información MEDLINE, sociedades científicas y los repositorios de la Organización Mundial de la Salud y el Ministerio de Salud y Protección Social de Colombia, con el objetivo de describir algunas sugerencias para el manejo de una paciente embarazada con COVID-19 en una unidad de cuidado intensivo. Se resalta que la atención debe ser realizada por un equipo interdisciplinario, bajo monitorización materna y fetal cuando corresponda, vigilando los niveles de saturación de oxígeno y la hemodinamia materna para minimizar la hipoxemia fetal. Se describen recomendaciones sobre algunos tópicos relevantes en el escenario crítico, como la intubación oportuna, la utilización adecuada de los equipos de protección personal (EPP), el manejo de la falla circulatoria, las estrategias restrictivas de fluidos y/o vasopresores, entre otros.

Recent advances in the diagnosis and management of sepsis in pregnancy

Background: Maternal sepsis accounts for 11% of all maternal deaths worldwide. It is the third most common direct cause of maternal death and is a major contributor to other common causes of maternal death, such as haemorrhage and thromboembolism. Methods: This review addresses important topics, including the epidemiology, risk factors, prevention, diagnosis, care bundles and management of maternal sepsis, including antibiotic treatment, and critical care interventions such as extracorporeal membrane oxygenation. Preventative measures that have had an impact on maternal sepsis as well as future research directions are also covered in this review. Case studies of maternal sepsis which highlight key learning points relevant to all clinicians involved in the management of obstetric patients will also be presented. Results: Although, historically, maternal death from sepsis was considered to be a problem for low-income countries, severe obstetric morbidity and maternal death from sepsis are increasing in high-income countries. The global burden of maternal sepsis and the obstetric-related and patient-related risk factors and the likely sources are presented. Recent changes in definition and nomenclature are outlined, and challenges in diagnosis and identification are discussed. Conclusions: Following maternal sepsis, early diagnosis and early intervention are critical to save lives and prevent long-term adverse sequelae. Dogma surrounding critical care interventions in pregnancy is being challenged, and future research is warranted to maximise therapeutic options available for maternal septic shock.

Primary Prenatal Care: Screening, Prevention, and Treatment of Viral Infections

Prenatal care providers are responsible for a basic understanding of the viral contagions that place women and fetal well-being at risk during pregnancy. This article reviews the evidence-based routine prenatal screening guidelines for previously unrecognized maternal infection, counseling toward risk reduction, recommended maternal immunizations, and the management of maternal and fetal complications of some viral exposures and infections.

Recognition and Management of Sepsis in the Obstetric Patient

Sepsis is one of the principal causes of maternal mortality in obstetrics. Physiologic changes that occur during pregnancy create a vulnerable environment, predisposing pregnant patients to the development of sepsis. Furthermore, these changes can mask sepsis indicators normally seen in the nonobstetric population, making it difficult to recognize and treat sepsis in a timely manner. The use of maternal-specific early warning tools for sepsis identification and knowledge of appropriate interventions and their effects on the mother and fetus can help clinicians obtain the best patient outcomes in acute care settings. This article outlines the signs and symptoms of sepsis in obstetric patients and discusses treatment options used in critical care settings.

Invasive Pulmonary Adenocarcinoma with Lepidic Growth Pattern in a Pregnant Patient

Among the differential diagnoses that should be considered in acute respiratory failure (ARF) are infectious processes, autoimmune diseases, interstitial pulmonary fibrosis, and pulmonary neoplasia. Timely diagnosis of lung neoplasia is complicated in the early stages. An opportune diagnosis, as well as the specific treatment, decrease mortality. ARF occurs 1 in 500 pregnancies and is most common during the postpartum period. Among the specific etiologies that cause ARF during pregnancy that must be considered are: (1) preeclampsia; (2) embolism of amniotic fluid; (3) peripartum cardiomyopathy; and (4) trophoblastic embolism. The case of a 36-year-old patient with a 33-week pregnancy and ARF is presented. The patient presented dyspnea while exerting moderate effort that progressed to orthopnea and type 1 respiratory insufficiency. Imaging studies showed bilateral alveolar infiltrates and predominantly right areas of consolidation. Blood cultures, a galactomannan assay and IgG antibodies against mycoplasma pneumoniae, were reported as negative. Autoimmune etiology was ruled out through an immunoassay. A percutaneous pulmonary biopsy was performed and an invasive pulmonary adenocarcinoma with lepidic growth pattern (i.e. lepidic pulmonary adenocarcinoma, LPA) result was reported. This etiology is rare and very difficult to recognize in acute respiratory failure cases. After infectious, autoimmune and interstitial lung fibrosis have been excluded the clinician must suspect of lung cancer in a patient with acute respiratory failure and chest imaging compatible with the presence of ground-glass nodular opacities, a solitary nodule or mass with bronchogram, and lung consolidation. In the presence of acute respiratory failure, the suspicion of pulmonary neoplasia in an adult of reproductive age must be timely. Failure to recognize this etiology can lead to fatal results.

Acute Respiratory Distress Syndrome in Pregnant Women

OBJECTIVE

To estimate the rate of acute respiratory distress syndrome (ARDS) in pregnant patients as well as to investigate clinical conditions associated with mortality.

METHODS

We used the Nationwide Inpatient Sample from 2006 to 2012 to identify a cohort of pregnant patients who underwent mechanical ventilation for ARDS. A multivariate model predicting in-hospital mortality was created.

RESULTS

A total of 55,208,382 hospitalizations from the 2006-2012 Nationwide Inpatient Samples were analyzed. There were 2,808 pregnant patients with ARDS who underwent mechanical ventilation included in the cohort. The overall mortality rate for the cohort was 9%. The rate of ARDS requiring mechanical ventilation increased from 36.5 cases (95% confidence interval [CI] 33.1-39.8) per 100,000 live births in 2006 to 59.6 cases (95% CI 57.7-61.4) per 100,000 live births in 2012. Factors associated with a higher risk of death were prolonged mechanical ventilation (adjusted odds ratio [OR] 1.69, 95% CI 1.25-2.28), renal failure requiring hemodialysis (adjusted OR 3.40, 95% CI 2.11-5.47), liver failure (adjusted OR 1.71, 95% CI 1.09-2.68), amniotic fluid embolism (adjusted OR 2.31, 95% CI 1.16-4.59), influenza infection (OR 2.26, 95% CI 1.28-4.00), septic obstetric emboli (adjusted OR 2.15, 95% CI 1.17-3.96), and puerperal infection (adjusted OR 1.86, 95% CI 1.28-2.70). Factors associated with a lower risk of death were: insurance coverage (adjusted OR 0.56, 95% CI 0.37-0.85), tobacco use (adjusted OR 0.53, 95% CI 0.31-0.90), and pneumonia (adjusted OR 0.70, 95% CI 0.50-0.98).

CONCLUSION

In this nationwide study, the overall mortality rate for pregnant patients mechanically ventilated for ARDS was 9%. The rate of ARDS requiring mechanical ventilation increased from 36.5 cases (95% CI 33.5-41.8) per 100,000 live births in 2006 to 59.6 cases (95% CI 54.3-65.3) per 100,000 live births in 2012.

Respiratory Considerations Including Airway and Ventilation Issues in Critical Care Obstetric Patients

Critical care management of the obstetric patient can present unique challenges. Parturients who present with respiratory distress can suffer from a multitude of etiologies, and each diagnosis must be pursued as appropriate to the clinical picture. Normal physiologic changes of pregnancy may obscure the presentation and diagnosis, and irrelevant of the cause, pregnancy may complicate the management of hypoxic and hypercarbic respiratory failure in this patient population. In addition to these concerns, both anticipated and unanticipated difficult airway management, including difficulty ventilating and intubating, are more common during pregnancy and may be encountered during endotracheal tube placement.

Management of Infection for the Obstetrician/Gynecologist

Pregnant women have an increased morbidity and mortality for certain illnesses owing to the physiologic and immunologic changes in pregnancy. Certain infections are common during pregnancy, including urinary tract infections and pneumonia. Others are uncommon, but yield increased severity, including influenza. Human immunodeficiency virus, although it does not increase in pathogenesis during pregnancy, requires specific attention and management in the context of pregnancy.

Successful provision of inter-hospital extracorporeal cardiopulmonary resuscitation for acute post-partum pulmonary embolism

Mortality during pregnancy in a well-resourced setting is rare, but acute pulmonary embolism is one of the leading causes. We present the successful use of extracorporeal cardiopulmonary resuscitation (eCPR) in a 22-year old woman who experienced cardiopulmonary collapse following urgent caesarean section in the setting of a sub-massive pulmonary embolus. Resources and personnel to perform eCPR were not available at the maternity hospital and were recruited from an adjacent pediatric hospital. Initial care used low blood flow extracorporeal membrane oxygenation (ECMO) with pediatric ECMO circuitry, which was optimized when the team from a nearby adult cardiac hospital arrived. Following ECMO support, the patient experienced massive hemorrhage which was managed with uterotonic agents, targeted transfusion, bilateral uterine artery embolisation and abdominal re-exploration. The patient was transferred to an adult unit where she remained on ECMO for five days. She was discharged home with normal cognitive function. This case highlights the role ECMO plays in providing extracorporeal respiratory or mechanical circulatory support in a high risk obstetric patient.

Extracorporeal Membrane Oxygenation in Pregnant and Postpartum Women With H1N1-Related Acute Respiratory Distress Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE

To assess available evidence regarding the use of extracorporeal membrane oxygenation (ECMO) in pregnant and postpartum women with acute respiratory distress syndrome (ARDS) secondary to H1N1 infection.

DATA SOURCES

Databases from MEDLINE (U.S. National Library of Medicine, 1946 to April 1, 2015), the Cochrane Library Controlled Trials Register, ClinicalTrials.gov, and Web of Science were queried for studies on ECMO in pregnant or postpartum patients with ARDS. Search terms included: "ARDS," "ECMO," "pregnant," and "postpartum."

TABULATION, INTEGRATION, AND RESULTS

All relevant references in any language were reviewed. Literature for inclusion and methodologic quality were reviewed based on the meta-analyses and systematic reviews of observational studies (Meta-analysis Of Observational Studies in Epidemiology) guidelines. Of 266 citations, five retrospective studies (39 patients) fulfilled our inclusion criteria. No randomized controlled trials were found. The pooled estimate of the survival rate among pregnant and postpartum patients who received ECMO for ARDS secondary to H1N1 was 74.6% (95% confidence interval [CI] 60.7-88.6%). Neonatal outcomes were reported in two studies and the rate of live birth was 70% (95% CI 43.7-95.2). Heterogeneity was not significant among studies (I ranged from 0% to 21%; P>.25).

CONCLUSION

The role of ECMO in pregnant and postpartum women with ARDS from H1N1 remains unclear and the benefits suggested from our review should be interpreted with caution.

Intensive care and pregnancy: Epidemiology and general principles of management of obstetrics ICU patients during pregnancy

In developed countries, the rate of obstetric ICU admissions (admission during pregnancy or the postpartum period) is between 0.5 and 4 per 1000 deliveries and the overall case-fatality rate is about 2%. The most two common causes of obstetric ICU admissions concerned direct obstetric pathologies: obstetric hemorrhage and hypertensive disorders of pregnancy. This review summarized the principles of management of critically ill pregnant patient. Its imply taking care of two patients in the same time. A coordinated multidisciplinary team including intensivists, anesthesiologists, obstetricians, pediatricians and pharmacists is therefore necessary. This team must work effectively together with regular staff aiming to evaluate daily the need to maintain the patient in intensive care unit or to prompt delivery. Keeping mother and baby together and fetal well-being must be balanced with the need of specialized advanced life support for the mother. The maternal physiological changes imply various consequences on management. The uterus aorto-caval compression implies tilting left the parturient. In case of cardiac arrest, uterus displacement and urgent cesarean delivery are needed. The high risk of aspiration and difficult tracheal intubation must be anticipated. Even during acute respiratory distress syndrome, hypoxemia and permissive hypercapnia must be avoided due to their negative impact on the fetus. Careful analysis of the benefit-risk ratio is needed before all drug administration. Streptococcal toxic shock syndrome and perineal fasciitis must be feared and a high level of suspicion of sepsis must be maintained. Finally the potential benefits of an ultrasound-based management are detailed.

Sepsis during pregnancy or the postpartum period

Sepsis is an important cause of maternal morbidity and mortality worldwide. Early recognition and timely treatment are the key to ensuring a favourable outcome. This article reviews recent literature about definitions, pathophysiology, incidence, diagnosis, management, treatment, prevention and outcome of sepsis during pregnancy and the postpartum period.

Critical Illness in Pregnancy: Part II: Common Medical Conditions Complicating Pregnancy and Puerperium

The first of this two-part series on critical illness in pregnancy dealt with obstetric disorders. In Part II, medical conditions that commonly affect pregnant women or worsen during pregnancy are discussed. ARDS occurs more frequently in pregnancy. Strategies commonly used in nonpregnant patients, including permissive hypercapnia, limits for plateau pressure, and prone positioning, may not be acceptable, especially in late pregnancy. Genital tract infections unique to pregnancy include chorioamnionitis, group A streptococcal infection causing toxic shock syndrome, and polymicrobial infection with streptococci, staphylococci, and Clostridium perfringens causing necrotizing vulvitis or fasciitis. Pregnancy predisposes to VTE; D-dimer levels have low specificity in pregnancy. A ventilation-perfusion scan is preferred over CT pulmonary angiography in some situations to reduce radiation to the mother's breasts. Low-molecular-weight or unfractionated heparins form the mainstay of treatment; vitamin K antagonists, oral factor Xa inhibitors, and direct thrombin inhibitors are not recommended in pregnancy. The physiologic hyperdynamic circulation in pregnancy worsens many cardiovascular disorders. It increases risk of pulmonary edema or arrhythmias in mitral stenosis, heart failure in pulmonary hypertension or aortic stenosis, aortic dissection in Marfan syndrome, or valve thrombosis in mechanical heart valves. Common neurologic problems in pregnancy include seizures, altered mental status, visual symptoms, and strokes. Other common conditions discussed are aspiration of gastric contents, OSA, thyroid disorders, diabetic ketoacidosis, and cardiopulmonary arrest in pregnancy. Studies confined to pregnant women are available for only a few of these conditions. We have, therefore, reviewed pregnancy-specific adjustments in the management of these disorders.

Maternal Sepsis and Septic Shock

The year 2015 marked the 200th anniversary of the birth of Ignaz Semmelweis, the Hungarian physician who identified unhygienic practices of physicians as a major cause of childbed fever or puerperal sepsis. Although such practices have largely disappeared as a factor in the development of chorioamnionitis and postpartum or puerperal endometritis, it is appropriate that this article on sepsis in pregnancy acknowledges his contributions to maternal health. This review describes the incidence and mortality of sepsis in pregnancy, methods to identify and define sepsis in this population, including scoring systems, causes, and sites of infection during pregnancy and parturition and management guidelines.

Anesthetic management of parturient with thoracic kyphoscoliosis, malaria and acute respiratory distress syndrome for urgent cesarean section

The management of cesarean section in kyphoscoliotic patient is challenging. The respiratory changes and increased metabolic demands due to pregnancy may compromise the limited respiratory reserves in such patients. Presence of other comorbidities like malaria and respiratory tract infection will further compromise the effective oxygenation. We report a case of kyphoscoliosis along with malaria and acute respiratory distress syndrome for urgent cesarean section.

Acute respiratory failure in pregnancy

Respiratory failure affects up to 0.2% of pregnancies, more commonly in the postpartum period. Altered maternal respiratory physiology affects the assessment and management of these patients. Respiratory failure may result from pregnancy-specific conditions such as preeclampsia, amniotic fluid embolism or peripartum cardiomyopathy. Pregnancy may increase the risk or severity of other conditions, including thromboembolism, asthma, viral pneumonitis, and gastric acid aspiration. Management during pregnancy is similar to the nonpregnant patient. Endotracheal intubation in pregnancy carries an increased risk, due to airway edema and rapid oxygen desaturation following apnea. Few data are available to direct prolonged mechanical ventilation in pregnancy. Chest wall compliance is reduced, perhaps permitting slightly higher airway pressures. Optimizing oxygenation is important, but data on the use of permissive hypercapnia are limited. Delivery of the fetus does not always improve maternal respiratory function, but should be considered if benefit to the fetus is anticipated.

Mechanical ventilation in critically-ill pregnant women: a case series

BACKGROUND

Approximately 0.1-0.2% of pregnancies are complicated by respiratory failure requiring mechanical ventilatory support, but few data exist to inform clinical management. This study aimed to characterize current practice and the effect of delivery on respiratory function.

METHODS

A retrospective review was performed of pregnant women who received mechanical ventilation for more than 24h, from four intensive care units in institutions with large-volume obstetric units.

RESULTS

Data were collected from 29 patients with a mean gestation at intensive care unit admission of 25.3 ± 6 weeks. Tidal volumes were 7.7 ± 1.7 mL/kg predicted body weight. Estimated respiratory system compliance was reduced, but was higher in four patients ventilated for neurological conditions without lung disease. Three maternal and three neonatal deaths occurred. Ten patients delivered while on ventilatory support: one spontaneous delivery, four for obstetric indications and five for worsening maternal condition. Following delivery of these 10 patients, three demonstrated a greater than 50% decrease in oxygenation index and five a greater than 50% increase in compliance. No characteristics identified which patients may benefit from delivery.

CONCLUSIONS

Review of current practice in four centers suggests that mechanical ventilation in pregnant patients follows usual guidelines applicable to non-pregnant patients. Delivery was associated with modest improvement in maternal respiratory function in some patients. Any potential benefit of delivery in improving maternal physiology must be weighed against the stress of delivery. The risks of premature birth for the fetus must be weighed against continued exposure to maternal hypoxemia and hypotension.

[Non-invasive mechanical ventilation in postoperative patients. A clinical review]

Non-invasive ventilation (NIV) is a method of ventilatory support that is increasing in importance day by day in the management of postoperative respiratory failure. Its role in the prevention and treatment of atelectasis is particularly important in the in the period after thoracic and abdominal surgeries. Similarly, in the transplanted patient, NIV can shorten the time of invasive mechanical ventilation, reducing the risk of infectious complications in these high-risk patients. It has been performed A systematic review of the literature has been performed, including examining the technical, clinical experiences and recommendations concerning the application of NIV in the postoperative period.

Critical care in pregnancy--is it different?

In the first part of this review, the epidemiology of obstetric critical care is discussed. This includes the incidence of severe morbidity in pregnancy, identification of critically ill and potentially critically ill patients, the incidence of obstetric ICU admissions, the type of critical illness by stage of pregnancy, ICU admission diagnoses, the severity of illness in obstetric ICU patients compared to non-obstetric patients, ICU mortality of obstetric patients, the ICU proportion of total maternal mortality, and the causes of death for obstetric patients in ICU. In the second part, the management of obstetric patients who happen to be admitted to a general ICU is discussed. Rather than focusing on the management of particular obstetric conditions, general principles of ICU management will be discussed as applied to obstetric ICU patients. These include drug safety, monitoring the fetus, management of the airway, sedation, muscle relaxation, ventilation, cardiovascular support, thromboprophylaxis, and radiology and ethical issues.

Acute respiratory distress syndrome in a pregnant woman with systemic lupus erythematosus: a case report

When the disease activity of systemic lupus erythematosus (SLE) is controlled appropriately, a pregnant woman who has lupus is able to carry safely to term and deliver a healthy infant. While the physiology of a healthy pregnancy itself influences ventilatory function, acute pulmonary distress may decrease oxygenation and influence both mother and fetus. Though respiratory failure in pregnancy is relatively rare, it remains one of the leading conditions requiring intensive care unit admission in pregnancy and carries a high risk of maternal and fetal morbidity and mortality, not to mention the complexity caused by lupus flare. We report a case of SLE complicated with lupus pneumonitis and followed by acute respiratory distress during pregnancy. Though there is a high risk of maternal and fetal morbidity and mortality, maternal respiratory function improved after cesarean section and treatment of the underlying causes. The newborn had an extremely low birth weight but was well at discharge.

The peripheral whole-blood transcriptome of acute pyelonephritis in human pregnancya

OBJECTIVE

Human pregnancy is characterized by activation of the innate immune response and suppression of adaptive immunity. The former is thought to provide protection against infection for the mother, and the latter, tolerance against paternal antigens expressed in fetal cells. Acute pyelonephritis is associated with an increased risk of acute respiratory distress syndrome and sepsis in pregnant (vs. nonpregnant) women. The objective of this study was to describe the gene expression profile (transcriptome) of maternal whole blood in acute pyelonephritis.

METHOD

A case-control study was conducted to include pregnant women with acute pyelonephritis (n=15) and women with a normal pregnancy (n=34). Affymetrix HG-U133 Plus 2.0 arrays (Affymetrix, Santa Clara, CA, USA) were used for gene expression profiling. A linear model was used to test the association between the presence of pyelonephritis and gene expression levels while controlling for white blood cell count and gestational age. A fold change of 1.5 was considered significant at a false discovery rate of 0.1. A subset of differentially expressed genes (n=56) was tested with real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) (cases, n=19; controls, n=59). Gene ontology and pathway analyses were applied.

RESULTS

A total of 983 genes were differentially expressed in acute pyelonephritis: 457 were upregulated and 526 were downregulated. Significant enrichment of 300 biological processes and 63 molecular functions was found in pyelonephritis. Significantly impacted pathways in pyelonephritis included (a) cytokine-cytokine receptor interaction, (b) T-cell receptor signaling, (c) Jak-STAT signaling, and (d) complement and coagulation cascades. Of 56 genes tested by qRT-PCR, 48 (85.7%) had confirmation of differential expression.

CONCLUSION

This is the first study of the transcriptomic signature of whole blood in pregnant women with acute pyelonephritis. Acute infection during pregnancy is associated with the increased expression of genes involved in innate immunity and the decreased expression of genes involved in lymphocyte function.