Neurogenic pulmonary edema

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

Successful management of pulmonary edema secondary to accidental electrocution in a young dog

BACKGROUND

Human records describe pulmonary edema as a life-threatening complication of electric shock. Successful management requires prompt recognition and intensive care. However, in companion animals, electrocutions are rarely reported, even though domestic environments are full of electrical devices and there is always the possibility of accidental injury. Therefore, it is important for veterinarians to know more about this condition in order to achieve successful patient outcomes.

CASE PRESENTATION

A 3-month-old male Labrador Retriever was presented with a history of transient loss of consciousness after chewing on a household electrical cord. On admission, the puppy showed an orthopneic position with moderate respiratory distress. Supplemental oxygen via nasal catheter was provided, but the patient showed marked worsening of respiratory status. Point-of-care ultrasound exams suggested neurogenic pulmonary edema due to electrical shock close to the central nervous system and increased B-lines without evidence of cardiac abnormalities. Mechanical ventilation of the patient was initiated using volume-controlled mode with a tidal volume of 9 to 15 ml/kg until reaching an end-tidal carbon dioxide ≤ 40 mm Hg, followed by a stepwise lung-recruitment maneuver in pressure-controlled mode with increases of the peak inspiratory pressure (15 to 20 cm H2O) and positive end-expiratory pressure (3 to 10 cm H2O) for 30 min, and return to volume-controlled mode with a tidal volume of 15 ml/kg until reaching a peripheral oxygen saturation ≥ 96%. Weaning from the ventilator was achieved in six hours, and the patient was discharged two days after admission without neurological or respiratory deficits.

CONCLUSIONS

We present a rather unusual case of a neurogenic pulmonary edema subsequent to accidental electrocution in a dog. Timely diagnosis by ultrasound and mechanical ventilation settings are described. Our case highlights that pulmonary edema should be considered a potentially life-threatening complication of electrical shock in small animal emergency and critical care medicine.

Pathophysiology of acute lung injury in patients with acute brain injury: the triple-hit hypothesis

It has been convincingly demonstrated in recent years that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after ABI. The pathophysiology of the bidirectional brain-lung interactions is multifactorial and involves inflammatory cascades, immune suppression, and dysfunction of the autonomic system. Indeed, the systemic effects of inflammatory mediators in patients with ABI create a systemic inflammatory environment ("first hit") that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery, and infections ("second hit"). Moreover, accumulating evidence supports the knowledge that gut microbiota constitutes a critical superorganism and an organ on its own, potentially modifying various physiological functions of the host. Furthermore, experimental and clinical data suggest the existence of a communication network among the brain, gastrointestinal tract, and its microbiome, which appears to regulate immune responses, gastrointestinal function, brain function, behavior, and stress responses, also named the "gut-microbiome-brain axis." Additionally, recent research evidence has highlighted a crucial interplay between the intestinal microbiota and the lungs, referred to as the "gut-lung axis," in which alterations during critical illness could result in bacterial translocation, sustained inflammation, lung injury, and pulmonary fibrosis. In the present work, we aimed to further elucidate the pathophysiology of acute lung injury (ALI) in patients with ABI by attempting to develop the "double-hit" theory, proposing the "triple-hit" hypothesis, focused on the influence of the gut-lung axis on the lung. Particularly, we propose, in addition to sympathetic hyperactivity, blast theory, and double-hit theory, that dysbiosis and intestinal dysfunction in the context of ABI alter the gut-lung axis, resulting in the development or further aggravation of existing ALI, which constitutes the "third hit."

Insights into Hemodynamic Features of Survivors and the Deceased with Acute Brain Injury: A Step Forward Tailored Treatment

BACKGROUND

Pulmonary artery catheters are widely used for hemodynamical monitoring in critically ill patients. Acute brain injury is among the severe conditions treated in an intensive care unit. The advanced monitoring of hemodynamical parameters, fluid balance and adequate administered treatment based on those values are components of goal-directed therapy.

METHODS

A prospective observational study included adult patients who were hospitalized in the ICU due to acute bran injury, excluding brain oedema after cardiac arrest. Each patient had PAC inserted and hemodynamic data were collected during the first 3 days of the ICU stay every 6 h. Patients were divided into two groups based on the endpoint: the survivors and the deceased.

RESULTS

Length of stay in hospital differed between patiens. All patients, regardless of their outcome, had noradrenaline administered. The initial values of PAP differed between the groups (p = 0.05). There were positive correlations noticed between noradrenaline dose, CVP and fluid balance when compared to PCWP in a group of survivors and a positive correlation in the fluid balance when compared to PAP and PVRI. Lactate serum concentrations presented a correlation with the dose of noradrenaline in both groups.

CONCLUSIONS

Upon acute brain injury, values of PVRI and PAP increase. This is corelated with fluid load and worsened by an excessive fluid treatment in the case of an inconsiderate approach for stabilizing the patient hemodynamically. PAC may present limited advantages in terms of PAP and PVRI control during the treatment.

Neurogenic pulmonary edema following Endoscopic third Ventriculostomy in patient with Hydrocephalous; case report

INTRODUCTION AND IMPORTANCE

Neurogenic pulmonary edema (NPE) post endoscopic third ventriculostomy (ETV) is rare but fatal. Acute central brain injury complications are the most frequent cause.in this case uncommonly occur post ETV procedure. Prevalence of NPE varies 2-49 %.

CASE PRESENTATION

A teen with hydrocephalus visited Operation Theater for ETV. An airway of Mallapathy ΙΙ & short neck. General anesthesia (GA) Induced & tracheal intubation succeeded on the second try. Until the surgery was over, the vital signs were normal. Patient recovered while suctioning oropharengial, pink frozen sputum observed through endotracheal tube (ETT). In the meantime, the O2 saturation ↓from 99 to 63 %, the heart rate (HR) ↓ but BP↑. Chest auscultation revel crackle. Spot diagnoses of NPE were treated with 100%O₂, 20 mg of furosemide intravenously, mild hyperventilation after a hr. O₂ saturation ↑ to 89 %. Patient moved to ICU with 100 % O₂ by mask 2 h later. X-ray confirms the diagnosis. Furosemide, head up & 100 % O₂ are still being used during treatment. 24 h later O₂ saturation maintained to 92 to 94 %. After 48 h patient transferred to regular ward with stable condition.

CLINICAL DISCUSSION

Rare yet lethal NPE is typically brought on by serious Brain injury. It happened here after the ETV surgery. We think that irrigation fluid and endoscopic stimulation may be the triggers. Hence there may be question with irrigation fluid and endoscopic stimulation.

CONCLUSION

Early detection and therapy of NPE following an ETV procedure helps to prevent serious complications. Considering the volume of endoscopic irrigation and optimize endoscopic stimulation.

Prediction of Postoperative Pulmonary Edema Risk Using Machine Learning

Postoperative pulmonary edema (PPE) is a well-known postoperative complication. We hypothesized that a machine learning model could predict PPE risk using pre- and intraoperative data, thereby improving postoperative management. This retrospective study analyzed the medical records of patients aged > 18 years who underwent surgery between January 2011 and November 2021 at five South Korean hospitals. Data from four hospitals (n = 221,908) were used as the training dataset, whereas data from the remaining hospital (n = 34,991) were used as the test dataset. The machine learning algorithms used were extreme gradient boosting, light-gradient boosting machine, multilayer perceptron, logistic regression, and balanced random forest (BRF). The prediction abilities of the machine learning models were assessed using the area under the receiver operating characteristic curve, feature importance, and average precisions of precision-recall curve, precision, recall, f1 score, and accuracy. PPE occurred in 3584 (1.6%) and 1896 (5.4%) patients in the training and test sets, respectively. The BRF model exhibited the best performance (area under the receiver operating characteristic curve: 0.91, 95% confidence interval: 0.84-0.98). However, its precision and f1 score metrics were not good. The five major features included arterial line monitoring, American Society of Anesthesiologists physical status, urine output, age, and Foley catheter status. Machine learning models (e.g., BRF) could predict PPE risk and improve clinical decision-making, thereby enhancing postoperative management.

The Lung Microbiome: A New Frontier for Lung and Brain Disease

Due to the limitations of culture techniques, the lung in a healthy state is traditionally considered to be a sterile organ. With the development of non-culture-dependent techniques, the presence of low-biomass microbiomes in the lungs has been identified. The species of the lung microbiome are similar to those of the oral microbiome, suggesting that the microbiome is derived passively within the lungs from the oral cavity via micro-aspiration. Elimination, immigration, and relative growth within its communities all contribute to the composition of the lung microbiome. The lung microbiome is reportedly altered in many lung diseases that have not traditionally been considered infectious or microbial, and potential pathways of microbe-host crosstalk are emerging. Recent studies have shown that the lung microbiome also plays an important role in brain autoimmunity. There is a close relationship between the lungs and the brain, which can be called the lung-brain axis. However, the problem now is that it is not well understood how the lung microbiota plays a role in the disease-specifically, whether there is a causal connection between disease and the lung microbiome. The lung microbiome includes bacteria, archaea, fungi, protozoa, and viruses. However, fungi and viruses have not been fully studied compared to bacteria in the lungs. In this review, we mainly discuss the role of the lung microbiome in chronic lung diseases and, in particular, we summarize the recent progress of the lung microbiome in multiple sclerosis, as well as the lung-brain axis.

Hiding in plain sight? A review of post-convulsive leukocyte elevations

During physiological stress responses such as vigorous exercise, emotional states of fear and rage, and asphyxia, the nervous system induces a massive release of systemic catecholamines that prepares the body for survival by increasing cardiac output and redirecting blood flow from non-essential organs into the cardiopulmonary circulation. A curious byproduct of this vital response is a sudden, transient, and redistributive leukocytosis provoked mostly by the resultant shear forces exerted by rapid blood flow on marginated leukocytes. Generalized convulsive seizures, too, result in catecholamine surges accompanied by similar leukocytoses, the magnitude of which appears to be rooted in semiological factors such as convulsive duration and intensity. This manuscript reviews the history, kinetics, physiology, and clinical significance of post-convulsive leukocyte elevations and discusses their clinical utility, including a proposed role in the scientific investigation of sudden unexpected death in epilepsy (SUDEP).

Neurogenic Pulmonary Edema Presenting as a Pulmonary Entity

Acute dyspnea is one of the most common presentations in acute/emergency settings, and acute pulmonary edema remains a leading cause in adults resulting from either cardiogenic or non-cardiogenic etiologies. Neurogenic pulmonary edema (NPE) is one of the less common forms of non-cardiogenic pulmonary edema seen in emergency departments, neurology units, or intensive care units. It usually develops rapidly following significant neurological insult seen in patients with intracranial hemorrhage, traumatic brain injuries, and epileptic seizures. It is less commonly seen after a multitude of other sudden catastrophic neurologic insults. Here, we report a case study of a 32-year-old female with a history of epilepsy since childhood who was admitted to our respiratory admission unit on two separate occasions with acute NPE and type I respiratory failure after a witnessed tonic-clonic seizure episode. Although the clinical features of NPE and the results of investigations can mimic more common cardiorespiratory conditions, an accurate and timely diagnosis is vital for the appropriate emergency management and to improve the patient's outcome.

DNase-1 Treatment Exerts Protective Effects in Neurogenic Pulmonary Edema via Regulating the Neutrophil Extracellular Traps after Subarachnoid Hemorrhage in Mice

It has been reported that neutrophil extracellular traps (NETs) involve inflammation, coagulation and cell death. Acute lung injury is also considered to be connected with NETs. Deoxyribonuclease I (DNase-1), a clinical medication for the respiratory system, has been reported to degrade cell-free DNA (cfDNA), which is the main component of NETs. Herein, we did research to clarify the therapeutic value of DNase-1 in NPE after SAH. In this model, we found that the treatment of DNase-1 remarkably decreased lung water, neutrophilic infiltration and inflammation. In addition, DNase-1 inhibited the NETs and proinflammatory subtype transition of the macrophages. Moreover, the depletion of neutrophil also verified the role of NETs in NPE. Our results suggest that DNase-1 has the potential to effectively relieve the NPE after SAH and to be a clinical drug for use after SAH.

Role of autonomic system imbalance in neurogenic pulmonary oedema

Neurogenic pulmonary oedema (NPE) is a life-threatening complication that develops rapidly and dramatically after an injury to the central nervous system (CNS). The autonomic system imbalance produced by severe brain damage may play an important role in the development of NPE. Activation of the sympathetic nervous system and inhibition of the vagus nerve system are essential prerequisites for autonomic system imbalance. The more severe the damage, the more pronounced the phenomenon. Sympathetic hyperactivity is associated with increased release of catecholamines from peripheral sympathetic nerve endings, which can cause dramatic changes in haemodynamics and cause pulmonary oedema. On the other hand, the abnormal inflammatory response caused by vagus nerve inhibition may also play an important role in the pathogenesis of NPE. The perspective of autonomic system imbalance seems to perfectly integrate the existing pathogenesis of NPE and can explain the entire development progression of NPE.

Risk factors of COVID-19 in subjects with and without mental disorders

BACKGROUND

Subjects with mental disorders are at a higher risk of various pandemic, but no specific studies concerning on screening and comparing the risk factors of COVID-19 for subjects with and without mental disorders, and the role of different classes of mental disorders with respect to the COVID-19.

METHODS

This study comprised 42,264 subjects with mental disorders and 431,694 subjects without. Logistic regression was used to evaluate the associations of exposure factors with COVID-19 risk. Interaction terms were employed to explore the potential interaction effect between mental disorders and each exposure factor on COVID-19 risk.

RESULTS

Mental disorders increased 1.45-fold risk of COVID-19 compared with non-mental disorders. There were significant interaction effects between mental disorders and age, sex, ethnicity, health ratings, socioeconomic adversity, lifestyle habits or comorbidities on COVID-19 risk. Subjects with and without mental disorders shared some overlapping risk factors of COVID-19, including the non-white ethnicity, socioeconomic adversity and comorbidities. Subjects without mental disorders carry some specific risk and protective factors. Among subjects with mental disorders, the COVID-19 risk was higher in subjects with a diagnosis of organic/symptomatic mental disorders, mood disorders, and neurotic, stress-related and somatoform disorders than that of their counterparts. Age, amount of alcohol consumption, BMI and Townsend deprivation showed non-linear increase with COVID-19 risk.

LIMITATIONS

Absence of replication.

CONCLUSIONS

Subjects with mental disorders are vulnerable populations to whom more attention should be paid. Public health guidance should focus on reducing the COVID-19 risk by advocating healthy lifestyle habits and preferential policies in populations with comorbidities.

Combined neurogenic pulmonary oedema and atypical Takotsubo cardiomyopathy in a patient with ischaemic stroke: a unique case report

BACKGROUND

Neurogenic pulmonary oedema (NPO) and Takotsubo cardiomyopathy are rare complications of ischaemic stroke. They are considered to be due to an excess catecholamine release after sympathetic nervous stimulation following stroke onset. Among the different types of Takotsubo cardiomyopathy, apical ballooning is recognized as the typical form, but three atypical patterns have been described (midventricular, basal, and focal) which are more commonly observed in patients with neurological disorders.

CASE SUMMARY

A 78-year-old woman was treated with intravenous alteplase and underwent mechanical thrombectomy for ischaemic stroke. During the procedure, her respiratory condition quickly worsened requiring invasive mechanical ventilation because of a wide and persistent reduction of the inspiratory oxygen fraction/arterial partial oxygen pressure ratio. Transthoracic echocardiography revealed moderate left ventricular systolic dysfunction with akinesis of the septal-apical and inferior-apical segments. Coronary angiography excluded obstructive lesions and/or evidence of acute plaque rupture. Ventriculography confirmed akinesis/dyskinesis of the inferior segment of the left ventricular apex associated with normal kinesis of the remaining segments. Chest X-ray revealed an infiltrative shadow on both lungs. After 24 h from NPO onset, her respiratory function improved and she was finally discharged on Day 7 without neurological defects. Left ventricular systolic dysfunction was reversible and ejection fraction normalized in 3 months.

DISCUSSION

It is a very rare case of simultaneous NPO and Takotsubo cardiomyopathy following ischaemic stroke. Moreover, it is unique in that it is the first observation of NPO associated with an atypical pattern of Takotsubo cardiomyopathy, which is more frequent in patients with neurological disorders. A rapid recognition and treatment are essential for patient survival.

Brain-lung interactions and mechanical ventilation in patients with isolated brain injury

During the last decade, experimental and clinical studies have demonstrated that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after brain injury (BI). The pathophysiology of these brain–lung interactions are complex and involve neurogenic pulmonary oedema, inflammation, neurodegeneration, neurotransmitters, immune suppression and dysfunction of the autonomic system. The systemic effects of inflammatory mediators in patients with BI create a systemic inflammatory environment that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery and infections. Indeed, previous studies have shown that in the presence of a systemic inflammatory environment, specific neurointensive care interventions—such as MV—may significantly contribute to the development of lung injury, regardless of the underlying mechanisms. Although current knowledge supports protective ventilation in patients with BI, it must be born in mind that ABI-related lung injury has distinct mechanisms that involve complex interactions between the brain and lungs. In this context, the role of extracerebral pathophysiology, especially in the lungs, has often been overlooked, as most physicians focus on intracranial injury and cerebral dysfunction. The present review aims to fill this gap by describing the pathophysiology of complications due to lung injuries in patients with a single ABI, and discusses the possible impact of MV in neurocritical care patients with normal lungs.

Diagnosis and Management of Status Epilepticus

Seizures are among the most common neurological presentations to the emergency room. They present on a spectrum of severity from isolated new-onset seizures to acute repetitive seizures and, in severe cases, status epilepticus. The latter is the most serious, as it is associated with high morbidity and mortality. Prompt recognition and treatment of both seizure activity and associated acute systemic complications are essential to improve the overall outcome of these patients. The purpose of this review is to provide the current viewpoint on the diagnostic evaluation and pharmacological management of patients presenting with status epilepticus, and the common associated systemic complications.

Association Between Oxygen Partial Pressure Trajectories and Short-Term Outcomes in Patients With Hemorrhagic Brain Injury

Objectives: Arterial hyperoxia is reportedly a risk factor for poor outcomes in patients with hemorrhagic brain injury (HBI). However, most previous studies have only evaluated the effects of hyperoxia using static oxygen partial pressure (PaO₂) values. This study aimed to investigate the association between overall dynamic oxygenation status and HBI outcomes, using longitudinal PaO₂ data.

Methods: Data were extracted from the Medical Information Mart for Intensive Care III database. Longitudinal PaO₂ data obtained within 72 h of admission to an intensive care unit were analyzed, using a group-based trajectory approach. In-hospital mortality was used as the primary outcomes. Multivariable logistic models were used to explore the association between PaO₂ trajectory and outcomes.

Results: Data of 2,028 patients with HBI were analyzed. Three PaO₂ trajectory types were identified: Traj-1 (mild hyperoxia), Traj-2 (transient severe hyperoxia), and Traj-3 (persistent severe hyperoxia). The initial and maximum PaO₂ of patients with Traj-2 and Traj-3 were similar and significantly higher than those of patients with Traj-1. However, PaO₂ in patients with Traj-2 decreased more rapidly than in patients with Traj-3. The crude in-hospital mortality was the lowest for patients with Traj-1 and highest for patients with Traj-3 (365/1,303, 209/640, and 43/85 for Traj-1, Traj-2, and Traj-3, respectively; p < 0.001), and the mean Glasgow Coma Scale score at discharge (GCS_dis) was highest for patients with Traj-1 and lowest in patients with Traj-3 (13 [7–15], 11 [6–15], and 7 [3–14] for Traj-1, Traj-2, and Traj-3, respectively; p < 0.001). The multivariable model revealed that the risk of death was higher in patients with Traj-3 than in patients with Traj-1 (odds ratio [OR]: 3.3, 95% confidence interval [CI]: 1.9–5.8) but similar for patients with Traj-1 and Traj-2. Similarly, the logistic analysis indicated the worst neurological outcomes in patients with Traj-3 (OR: 3.6, 95% CI: 2.0–6.4, relative to Traj-1), but similar neurological outcomes for patients in Traj-1 and Traj-2.

Conclusion: Persistent, but not transient severe arterial hyperoxia, was associated with poor outcome in patients with HBI.

Beyond the Brain: Peripheral Interactions after Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability, and there are currently no pharmacological treatments known to improve patient outcomes. Unquestionably, contributing toward a lack of effective treatments is the highly complex and heterogenous nature of TBI. In this review, we highlight the recent surge of research that has demonstrated various central interactions with the periphery as a potential major contributor toward this heterogeneity and, in particular, the breadth of research from Australia. We describe the growing evidence of how extracranial factors, such as polytrauma and infection, can significantly alter TBI neuropathology. In addition, we highlight how dysregulation of the autonomic nervous system and the systemic inflammatory response induced by TBI can have profound pathophysiological effects on peripheral organs, such as the heart, lung, gastrointestinal tract, liver, kidney, spleen, and bone. Collectively, this review firmly establishes TBI as a systemic condition. Further, the central and peripheral interactions that can occur after TBI must be further explored and accounted for in the ongoing search for effective treatments.

Application of adverse outcome pathway networks to integrate mechanistic data informing the choice of a point of departure for hydrogen sulfide exposure limits

Acute exposure to hydrogen sulfide initiates a series of hallmark biological effects that occur progressively at increasing exposure levels: odor perception, conjunctivitis, olfactory paralysis, "knockdown," pulmonary edema, and apnea. Although effects of exposure to high concentrations of hydrogen sulfide are clear, effects associated with chronic, low-level exposure in humans is under debate, leading to uncertainty in the critical effect used in regulatory risk assessments addressing low dose exposures. This study integrates experimental animal, observational epidemiology, and occupational exposure evidence by applying a pathway-based approach. A hypothesized adverse outcome pathway (AOP) network was developed from 34 studies, composed of 4 AOPs sharing 1 molecular initiating events (MIE) and culminating in 4 adverse outcomes. A comparative assessment of effect levels and weight of evidence identified an AOP leading to a biologically-plausible, low-dose outcome relative to the other outcomes (nasal lesions, 30 ppm versus olfactory paralysis, >100 ppm; neurological effects, >80 ppm; pulmonary edema, >80 ppm). This AOP (i.e. AOP1) consists of the following key events: cytochrome oxidase inhibition (>10 ppm), neuronal cell loss (>30 ppm), and olfactory nasal lesions (defined as both neuronal cell loss and basal cell hyperplasia; >30 ppm) in rodents. The key event relationships in this pathway were supported by moderate empirical evidence and have high biological plausibility due to known mechanistic understanding and consistency in observations for diverse chemicals.

Management of child after traumatic epidural hematoma with pulmonary edema and arrhythmia

We present a case of severe neurogenic pulmonary edema and arrhythmia complicating management of a 7-year-old child with acute epidural hematoma and impending cerebral herniation. The underlying mechanisms for this are discussed as well as management of severe neurogenic pulmonary edema. We emphasize the need to recognize this rare complication early and institute prompt aggressive management.

Is autonomic dysreflexia a cause of respiratory dysfunction after spinal cord injury?

INTRODUCTION

Spinal cord injury (SCI) often leads to impairment of the respiratory system. In fact, respiratory insufficiency is a significant cause of mortality and morbidity following SCI, related to the extent and level of the neurologic injury and its effects on the respiratory muscles (reduction in respiratory muscle strength and fatigue due to a reduction in inspiratory capacity, atelectasis and ineffective coughing). Less commonly recalled is the fact that autonomic dysreflexia (AD) is the result of parasympathetic imbalance. However, AD results from a massive, unrestrained outpouring of norepinephrine from the peripheral sympathetic ganglia. More accurately, the vagal (parasympathetic) response to this sympathetic discharge may have been responsible for the respiratory changes reported. This is not described in medical literature, although breathing difficulty is named as a common symptom and sign. The objective of this report is to describe a clinical case for the first time, that of T4 AIS (American spinal injury association impairment scale) A in which AD leads to acute respiratory insufficiency.

CASE REPORT

A patient with prior history of spinal cord injury, T4 AIS A, was admitted to the Inpatient Unit to improve her respiratory function and autonomy and to discontinue the ventilation maintained after an episode of pneumonia. The patient developed AD during the rehabilitation programme, namely during hamstring stretching exercises. Besides persistent hypertension, cutaneous rash, hyperhidrosis and light-headedness, the patient was diagnosed with acute respiratory insufficiency, with desaturation and hypercapnia. The patient fully recovered, in terms of the signs and symptoms of AD, with the cessation of noxious stimulation and oxygen administration.

DISCUSSION

To date, the association between AD and acute respiratory insufficiency has not been described in spinal cord injury or rehabilitation literature. This case draws attention for the first time to the possibility that respiratory insufficiency is one of the signs associated with episodes of AD and highlights the need to look at this possibility.

Neurogenic pulmonary edema

AIM

We report a case of neurogenic pulmonary edema in a patient who sustained a severe traumatic brain injury in a motorbike accident and review the current literature with regards to the management of neurogenic pulmonary edema (NPE).

METHODS

A 17 year old male was involved in a motorbike collision into a tree. Copious amounts of pink frothy sputum was noted on scene. Rapid sequence intubation was performed on scene and video laryngoscopy demonstrated profuse frothy secretions welling up from the larynx.

RESULTS

The patient underwent emergency external ventricular drain insertion for intracranial pressure (ICP) monitoring. Intracranial pressures remained refractorily high and a decompressive bifrontal craniectomy was performed on the subsequent day. He was tracheostomised on admission day 24 and discharged from ICU on day 34.

DISCUSSION

Neurogenic pulmonary edema is defined as acute respiratory distress triggered by severe sympathetic discharge from acute compromise in the central nervous system. Rapid intervention with intubation is often necessary to protect the airways and facilitate diagnostic evaluation. Reduction of ICP and supportive mechanical ventilation to improve oxygenation is necessary. Positive end-expiratory pressure should be carefully applied to balance recruitment of alveoli and minimisation of ICP. Although NPE is estimated to resolve within 72 h in more than half of patients, prognosis is generally poor due to the severity of the underlying brain injury, with estimated mortality rates of between 60 and 100%.

CONCLUSION

Neurogenic pulmonary edema is a potentially life-threatening complication of severe brain injury and should be recognised early to facilitate management.

Pulmonary Edema in COVID19-A Neural Hypothesis

In COVID-19, lung manifestations present as a slowly evolving pneumonia with insidious early onset interstitial pulmonary edema that undergoes acute exacerbation in the late stages and microvascular thrombosis. Currently, these manifestations are considered to be only consequences of pulmonary SARS-CoV-2 virus infection. We are proposing a new hypothesis that neurogenic insult may also play a major role in the pathogenesis of these manifestations. SARS-CoV-2 mediated inflammation of the nucleus tractus solitarius (NTS) may play a role in the acute exacerbation of pulmonary edema and microvascular clotting in COVID-19 patients.

Neurogenic pulmonary edema following febrile status epilepticus in a 22-month-old infant with multiple respiratory virus co-detection: a case report

BACKGROUND

Neurogenic pulmonary edema is a rare but serious complication of febrile status epilepticus in children. Comprehensive screening for viral pathogens is seldomly performed in the work-up of febrile children.

CASE PRESENTATION

A 22-month-old girl presented with her first episode of febrile status epilepticus, after which she developed acute pulmonary edema and respiratory failure. After the termination of seizure activity, the patient was intubated and managed on mechanical ventilation in the emergency room. The resolution of respiratory failure, as well as the neurological recovery, was achieved 9 h after admission, and the patient was discharged 6 days after admission without any complications. Molecular biological diagnostic methods identified the presence of human coronavirus HKU1, influenza C virus, and human parainfluenza virus 2 from the patient's nasopharyngeal specimens.

CONCLUSIONS

Neurogenic pulmonary edema following febrile status epilepticus was suspected to be the etiology of our patient's acute pulmonary edema and respiratory failure. Timely seizure termination and rapid airway and respiratory intervention resulted in favorable outcomes of the patient. Molecular biological diagnostic methods identified three respiratory viruses; however, their relevance and association with clinical symptoms remain speculative.

Lung injury in brain ischemia/reperfusion is exacerbated by mechanical ventilation with moderate tidal volume in rats

Ischemic stroke is one of the most frequent causes of injury in the central nervous system which may lead to multiorgan dysfunction, including in the lung. The aim of this study was to investigate whether brain ischemia/reperfusion with or without mechanical ventilation leads to lung injury. Male Sprague-Dawley rats were assigned to four groups: Sham, 1-h brain ischemia (MCAO)/24-h reperfusion (I/R), mechanical ventilation with moderate tidal volume (MTV), and I/R+MTV. The pulmonary capillary permeability (K_fc) was measured in the isolated perfused lung. Mean arterial blood pressure (MAP), heart rate (HR), blood-gas variables, histopathological parameters, lung glutathione peroxidase, and TNF-α were measured. K_fc in the I/R, MTV, and I/R+MTV groups were higher than that in the Sham group. In the I/R, MTV, and I/R+MTV groups, arterial partial pressures of oxygen and the arterial partial pressure of oxygen/fraction of inspired oxygen ratios were lower, whereas arterial partial pressures of carbon dioxide were higher than those in the Sham group. The histopathological score in the I/R group was more than that in the Sham group, and in the MTV and I/R+MTV groups were higher than those in the Sham and I/R groups. Furthermore, there were stepwise rises in TNF-α in the I/R, MTV, and I/R+MTV groups, respectively. There was no significant difference in MAP between groups. However, HR in the MTV group was higher than that in the Sham group. Brain ischemia/reperfusion leads to pulmonary capillary endothelial damage and the impairment of gas exchange in the alveolar-capillary barrier, which is exacerbated by mechanical ventilation with moderate tidal volume partially linked to inflammatory reactions.

Cardiopulmonary failure in children infected with Enterovirus A71

Enterovirus A71 (EV-A71) is one of the causative pathogens of hand, foot, and mouth disease (HFMD), which may cause severe neurological and cardiopulmonary complications in children. In this review, we discuss the pathogenesis, clinical manifestations, management strategy, and clinical outcomes of cardiopulmonary failure (CPF) in patients with EV-A71 infection.

The pathogenesis of CPF involves both catecholamine-related cardiotoxicity following brainstem encephalitis and vasodilatory shock due to cytokine storm. Sympathetic hyperactivity, including tachycardia and hypertension, are the early clinical manifestations of cardiopulmonary involvement, which may progress to pulmonary edema/hemorrhage and/or CPF. The management strategy comprises multidisciplinary supportive treatment, including fluid management, positive pressure ventilation support, and use of milrinone, vasopressors, and inotropes. Some patients may require extracorporeal membrane oxygenation. Major neurological sequelae are almost inevitable once a child develops life-threatening illness. Long-term care of these children is an important medico-social issue.

May sevoflurane prevent the development of neurogenic pulmonary edema and improve the outcome? Or as a new sedation method for severe brain injury patients

Neurogenic pulmonary edema (NPE) is a life-threatening complication that develops rapidly and dramatically after injury to the central nervous system (CNS). Severe primary brain injury and subsequent secondary brain injury cascade events are thought to be involved in the development of NPE. Activation of the sympathetic nervous system and release of vasoactive substances are also essential prerequisites for NPE. We hypothesize that sevoflurane may be an effective treatment for preventing the development of NPE. Sevoflurane may play a role in protecting brain and lung tissue after acute brain injury through its sympatholytic, antioxidative, ion channel stabilizing, anti-inflammatory, anti-apoptotic, and pulmonary protection effects. It has the potential to be used as a sedative in the neurosurgical intensive care unit (NICU), which can help maintain nervous system and cardiopulmonary function in patients with acute brain injury to improve prognosis. Sevoflurane also has the advantages of fast induction of anesthesia, rapid drug metabolism, little interference to the cardiovascular system, and controllable depth of anesthesia. If our hypothesis is supported by further experiments, use of sevoflurane may open a new door for the treatment of acute brain injury and NPE.

Clinical Features of Neurogenic Pulmonary Edema in Patients with Subarachnoid Hemorrhage

OBJECTIVE

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by acute onset after central nervous system injury. Here, we investigated the clinical features of NPE in patients with subarachnoid hemorrhage (SAH).

METHODS

We retrospectively analyzed a total of 350 patients with SAH who were treated at our hospital from April 2014 to September 2017. Patient demographics, aneurysm size and location, clinical characteristics, and patient outcomes were reviewed and compared between an NPE and a non-NPE group.

RESULTS

Sixteen patients (4.6%) presented with NPE at admission. Ten of these (62.5%) recovered from NPE immediately, and ventilatory support was withdrawn within 2 days from onset. A univariate analysis showed that patients with NPE were younger (P = 0.04), had a higher rate of vertebral artery dissection (P < 0.01), more severe World Federation of Neurosurgical Societies (WFNS) grades (P = 0.01), and lower systolic blood pressure on admission (P = 0.01). A multivariate analysis revealed significant differences in the frequency of vertebral artery dissection (odds ratio 4.83, 95% confidence interval 1.50-15.56, P < 0.01) and in WFNS grades (odds ratio 3.73, 95% confidence interval 1.02-13.66, P = 0.04) between the groups. No significant group differences were found in other factors including heart rate, radiographic sign (Fisher grade), aneurysm size and location, blood sample tests on admission, and neurologic outcomes.

CONCLUSIONS

Vertebral artery dissection and severe WFNS grade on admission were confirmed as significant risk factors for NPE. However, neurologic outcomes at discharge did not differ between groups, suggesting that poor outcomes due to NPE could be reduced by appropriate diagnosis and treatment.

Acute Opiate Overdose: An Update on Management Strategies in Emergency Department and Critical Care Unit

BACKGROUND

Opioids are natural, semisynthetic, or synthetic substances that act on opioid receptors in the central nervous system. Clinically, they are prescribed for pain management. Opioid overdose (OOD) occurs when the central nervous system and respiratory drive are suppressed because of excessive consumption of the drug. Symptoms of OOD include drowsiness, slow breathing, pinpoint pupils, cyanosis, loss of consciousness, and death. Due to their addictive potential and easy accessibility opioid addiction is a growing problem worldwide. Emergency medical services and the emergency department often perform initial management of OOD. Thereafter, some patients require intensive care management because of respiratory failure, metabolic encephalopathy, acute kidney injury, and other organ failure.

AREAS OF UNCERTAINTY

We sought to review the literature and present the most up-to-date treatment strategies of patients with acute OOD requiring critical care management.

DATA SOURCES

A PubMed search was conducted to review all articles between 1950 and 2017 and the relevant articles were cited.

RESULTS & CONCLUSIONS

Worldwide, approximately 69,000 people die of OOD each year, and approximately 15 million people have opioid addiction. In the United States, death from OOD has increased almost 5-fold from 2001 to 2013. OOD leading to intensive care unit admission has increased by 50% from 2009 to 2015. At the same time, the mortality associated with these admissions has doubled. The management strategies include airway management, use of reversal agents, assessing and treating coingestions and associated complications, treatment of opioid withdrawal with alpha-agonists, and psychosocial support to help with opiate addiction and withdrawal. This warrants awareness among clinicians regarding the adverse effects associated with opioid use, management strategies, and calls for a multidisciplinary approach to treating these patients.

Neurogenic Pulmonary Edema Following a Seizure: A Case Report and Literature Review

Acute pulmonary edema is one of the frequent causes of dyspnea encountered in everyday practice. It is broadly attributed to be either cardiogenic or noncardiogenic. It is usually treated with diuretics in addition to other medications depending on the underlying pathology. Here, we report a case of a female patient who presented with shortness of breath after developing a seizure. Further investigations excluded cardiogenic etiology and showed critically low phenytoin level. It improved within 48 h of supportive care without giving diuretics favoring the diagnosis of neurogenic pulmonary edema as the primary pathology. The goal of our case report is to keep neurogenic pulmonary edema in mind, and hence provide the appropriate management, when dealing with similar cases.

Neurogenic Stunned Myocardium: A Case Report and Brief Review

BACKGROUND

Neurogenic stunned myocardium (NSM) is a condition in a group of stress cardiomyopathies with evolving nomenclature that includes Takotsubo cardiomyopathy. It manifests through electrocardiogram changes, cardiac enzyme elevation, and regional or global kinetic wall motion abnormalities.

CASE REPORT

We present a 43-year-old female with a subarachnoid hemorrhage who developed persistent hypotension and tachycardia secondary to neurogenic stress cardiomyopathy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is important to consider NSM in any patient with neurologic pathology and undifferentiated shock. Early recognition in the emergency department setting can yield valuable data to guide the treatment and improve clinical outcomes in these patients.

Let's talk SUDEP

Sudden unexplained death in epilepsy (SUDEP) is a devastating complication of epilepsy which was under-recognized in the recent past despite its clear importance. In this review, we examine the definition of SUDEP, revise current pathophysiological theories, discuss risk factors and preventative measures, disclose tools for appraising the SUDEP risk, and last but not least dwell upon announcing and explaining the SUDEP risk to the patients and their caretakers. We aim to aid the clinicians in their responsibility of knowing SUDEP, explaining the SUDEP risk to their patients in a reasonable and sensible way and whenever possible, preventing SUDEP. Future studies are definitely needed to increase scientific knowledge and awareness related to this prioritized topic with malign consequences.

Neurogenic pulmonary edema following seizures: A retrospective computed tomography study

INTRODUCTION

Data on the frequency and clinical relevance of neurogenic pulmonary edema (NPE) following epileptic seizures are limited. The aim of the present study was to analyze computed tomography (CT) examinations in patients with previous seizures.

METHOD

Incidence of NPE and related clinical factors were retrospectively assessed in patients admitted because of epileptic seizures who underwent thoracic CT imaging as part of emergency diagnostics.

RESULTS

Between January 2010 and January 2016, we included all patients admitted with the International Classification of Diseases (ICD) diagnosis code of epileptic seizure or epilepsy and who underwent CT imaging, including visualization of the lungs, as part of emergency diagnostics. Of the 47 included patients, 26 patients had suffered from generalized convulsive seizures (GCS), 17 patients had focal seizures with impaired and 4 without impaired consciousness. Signs of NPE were present in 5 out of 47 patients; all 5 patients had GCS prior to thoracic CT scan (i.e., 19% of patients with GCS). In four out of five cases, a single seizure was described; in one case, the seizure was only partially witnessed, but the indirect clinical signs strongly suggested a GCS. Related factors such as the initial respiratory rate or the initial pCO2 value were not significantly different in patients with and without signs of NPE.

CONCLUSIONS

The highly selected and biased patient group warrants caution in the interpretation of the study results. Our data, however, confirm that signs of NPE appear to be rather frequent in patients with GCS. Its clinical significance as regards morbidity and sudden death in epilepsy is discussed.

Takotsubo Cardiomyopathy and Neurogenic Pulmonary Edema After Carotid Endarterectomy

BACKGROUND

Takotsubo cardiomyopathy (TCM) and neurogenic pulmonary edema (NPE) are rare complications of an acute ischemic stroke. In particular, TCM and NPE following carotid endarterectomy (CEA) are extremely rare. In general, TCM- and NPE-associated ischemic strokes are caused by excess catecholamine release after sympathetic nervous stimulation following stroke onset, but the mechanism triggering this stimulation is still unknown.

CASE DESCRIPTION

An 88-year-old man underwent left CEA for symptomatic carotid artery stenosis (North American Symptomatic Carotid Endarterectomy Trial, 65%). After the surgery, his respiratory condition rapidly worsened, and chest radiography revealed an infiltrative shadow on both lung fields. Transthoracic echocardiography revealed left ventricular dysfunction, suggesting TCM. Postoperative magnetic resonance imaging revealed a small infarction in the left anterior insular cortex. Eventually, his respiratory and cardiac functions gradually improved. He was finally discharged on his own from the hospital on postoperative day 9.

CONCLUSIONS

We described a very rare case of TCM and NPE following CEA. The mechanisms of TCM and NPE involve excess catecholamine release after sympathetic nervous stimulation. Our findings suggest that surgery-associated transient ischemia and reperfusion injury to the left insular cortex stimulate sympathetic nerves.

Early low-anticoagulant desulfated heparin after traumatic brain injury: Reduced brain edema and leukocyte mobilization is associated with improved watermaze learning ability weeks after injury

BACKGROUND

Unfractionated heparin administered immediately after traumatic brain injury (TBI) reduces brain leukocyte (LEU) accumulation, and enhances early cognitive recovery, but may increase bleeding after injury. It is unknown how non-anticoagulant heparins, such as 2,3-O desulfated heparin (ODSH), impact post-TBI cerebral inflammation and long-term recovery. We hypothesized that ODSH after TBI reduces LEU-mediated brain inflammation and improves long-term neurologic recovery.

METHODS

CD1 male mice (n = 66) underwent either TBI (controlled cortical impact [CCI]) or sham craniotomy. 2,3-O desulfated heparin (25 mg/kg [25ODSH] or 50 mg/kg [50ODSH]) or saline was administered for 48 hours after TBI in 46 animals. At 48 hours, intravital microscopy visualized rolling LEUs and fluorescent albumin leakage in the pial circulation, and the Garcia Neurologic Test assessed neurologic function. Brain edema (wet/dry ratio) was evaluated post mortem. In a separate group of animals (n = 20), learning/memory ability (% time swimming in the Probe platform quadrant) was assessed by the Morris Water Maze 17 days after TBI. Analysis of variance with Bonferroni correction determined significance (p < 0.05).

RESULTS

Compared with CCI (LEU rolling: 32.3 ± 13.7 LEUs/100 μm per minute, cerebrovascular albumin leakage: 57.4 ± 5.6%), both ODSH doses reduced post-TBI pial LEU rolling (25ODSH: 18.5 ± 9.2 LEUs/100 μm per minute, p = 0.036; 50ODSH: 7.8 ± 3.9 LEUs/100 μm per minute, p < 0.001) and cerebrovascular albumin leakage (25ODSH: 37.9 ± 11.7%, p = 0.001, 50ODSH: 32.3 ± 8.7%, p < 0.001). 50ODSH also reduced injured cerebral hemisphere edema (77.7 ± 0.4%) vs. CCI (78.7 ± 0.4 %, p = 0.003). Compared with CCI, both ODSH doses improved Garcia Neurologic Test at 48 hours. Learning/memory ability (% time swimming in target quadrant) was lowest in CCI (5.9 ± 6.4%) and significantly improved in the 25ODSH group (27.5 ± 8.2%, p = 0.025).

CONCLUSION

2,3-O desulfated heparin after TBI reduces cerebral LEU recruitment, microvascular permeability and edema. 2,3-O desulfated heparin may also improve acute neurologic recovery leading to improved learning/memory ability weeks after injury.

The spectrum of acute cardiopulmonary events associated with multiple sclerosis exacerbations

Diverse acute neurological injuries may cause acute cardiopulmonary events including neurogenic pulmonary edema (NPE) and neurogenic stunned myocardium (NSM). The mechanism is probably mediated by sympathetic nervous system activation. Focal central nervous system (CNS) lesions, such as demyelinating lesions in multiple sclerosis (MS), may also cause cardiopulmonary disturbances. We aim to review the acute cardiopulmonary events associated with MS relapses. We performed a literature search using PubMed, and selected case reports of acute cardiac and/or pulmonary events related to MS exacerbations. We grouped these events into three categories: 1) NPE with normal cardiac function; 2) NSM and Takotsubo cardiomyopathy (TTC); 3) coexisting myocardial dysfunction and pulmonary edema. In some cases, cardiac and pulmonary symptoms preceded the onset of neurological symptoms. The majority of cases were associated with acute demyelinating lesions located in the medulla. Acute brainstem MS relapses, with demyelinating lesions affecting the medulla, may cause acute cardiac and pulmonary events presumably secondary to sympathetic hyperstimulation. Specific regions in the medulla that regulate cardiac function, systemic blood pressure and pulmonary hydrostatic pressure seem to be responsible for these events.

Pulmonary Complications After Spontaneous Aneurysmal Subarachnoid Hemorrhage: Experience from Barrow Neurological Institute

OBJECTIVE

Because the clinical course of spontaneous aneurysmal subarachnoid hemorrhage (aSAH) can be compromised by pulmonary complications, we sought to review posttreatment outcomes in aSAH patients with and without pulmonary complications.

METHODS

Patient demographic, clinical, and outcome data (March 2003-January 2007) were analyzed retrospectively. Patients underwent microsurgical or endovascular treatment for aSAH; pulmonary complications were reported. Outcomes were assessed using the Glasgow Outcome Scale (GOS) scores at the 1-year, 3-year, and 6-year follow-up visits.

RESULTS

The cohort comprised 471 patients (mean age, 53.7 ± 12.4 years; men, 332/471 [70%]). The mean Glasgow Coma Scale (GCS) score at presentation was 11.9 ± 3.0. Of 471 patients, 47% (n = 223) presented with a Hunt and Hess score of ≥3 and 76% (n = 357) with a Fisher grade of 3. Treatment was clipping for 69% (279/407) and coiling for 31% (128/407) of patients. Pulmonary complications occurred in 210 of 471 (45%) patients. Nearly one-half of patients were discharged to home (215/471, 46%), and more than one-half had a good outcome defined as a GOS score of 5 at their 1-year (226/403, 56%), 3-year (217/397, 55%), and 6-year (203/380, 53%) follow-up visits. Logistic regression showed age and GCS scores as outcome predictors at all time points, whereas pulmonary complications predicted poor outcome only at the 1-year follow-up visit.

CONCLUSIONS

Pulmonary problems represent the most common nonneurologic medical complications after aSAH. Despite advances in critical care, pulmonary complications represented predictors of short-term poor outcome only at the 1-year follow-up visit, whereas the medical history of the patient became more relevant for prognosis in long-term follow-up.

Dexmedetomidine Protects Against Traumatic Brain Injury-Induced Acute Lung Injury in Mice

Background

Traumatic brain injury (TBI) leads to acute lung injury (ALI), in which the inflammatory response plays an important role in its pathophysiology. Recent studies suggest that dexmedetomidine (Dex) plays a protective role in acute inflammatory diseases. However, whether Dex has a protective effect on TBI-induced ALI is not clear. The aim of this study was to investigate the effect of Dex on TBI-induced ALI in mice.

Material/Methods

Mice were randomly divided into 5 groups: 1) sham group; 2) TBI group; 3) TBI+Dex group; 4) TBI+atipamezole (Atip) group; and 5) TBI+Dex+Atip group. Dex (50 μg/kg) was intraperitoneal injected immediately after TBI. The α₂ adrenergic antagonist Atip (250 μg/kg) was intraperitoneal injected 15 minutes prior to Dex treatment. Then 24 hours later, the protein concentration in the bronchoalveolar lavage fluid (BALF), lung wet to dry weight ratio, hematoxylin and eosin (H&E) staining of lungs, the level of high-mobility group box protein 1(HMGB1) in serum, and the receptor for advanced glycation end products (RAGE) expression in lung were detected.

Results

Dex ameliorated the score of lung histological examination, as well as the severity of pulmonary edema and permeability. Moreover, Dex was observed to significantly suppress the expression of HMGBI and RAGE. However, the protective effects of Dex were partially reversed by the administration of Atip.

Conclusions

Dex may protect against TBI-induced ALI via the HMGB1-RAGE signal pathway, and this protective effect is partly dependent on its α₂ adrenoceptor agonist action.

Identification of Pulmonary Edema in Forensic Autopsy Cases of Sudden Cardiac Death Using Fourier Transform Infrared Microspectroscopy: A Pilot Study

Many studies have proven the usefulness of biofluid-based infrared spectroscopy in the clinical domain for diagnosis and monitoring the progression of diseases. Here we present a state-of-the-art study in the forensic field that employed Fourier transform infrared microspectroscopy for postmortem diagnosis of sudden cardiac death (SCD) by in situ biochemical investigation of alveolar edema fluid in lung tissue sections. The results of amide-related spectral absorbance analysis demonstrated that the pulmonary edema fluid of the SCD group was richer in protein components than that of the neurologic catastrophe (NC) and lethal multiple injuries (LMI) groups. The complementary results of unsupervised principle component analysis (PCA) and genetic algorithm-guided partial least-squares discriminant analysis (GA-PLS-DA) further indicated different global spectral band patterns of pulmonary edema fluids between these three groups. Ultimately, a random forest (RF) classification model for postmortem diagnosis of SCD was built and achieved good sensitivity and specificity scores of 97.3% and 95.5%, respectively. Classification predictions of unknown pulmonary edema fluid collected from 16 cases were also performed by the model, resulting in 100% correct discrimination. This pilot study demonstrates that FTIR microspectroscopy in combination with chemometrics has the potential to be an effective aid for postmortem diagnosis of SCD.

Neurogenic pulmonary oedema secondary to vertebral artery dissection while playing tennis

We present a case of a patient who developed vertebral artery dissection (VAD) while playing tennis and presented with neurogenic pulmonary oedema. The case highlights two important points: acute pulmonary oedema as an unusual presenting feature of VAD and VAD, an important cause of stroke in young people, as being associated with playing low-impact sports such as tennis. These associations, independent of each other, are under-recognised and can lead to a delay in diagnosis.

Naloxone dosage for opioid reversal: current evidence and clinical implications

Opioid-related mortality is a growing problem in the United States, and in 2015 there were over 33,000 opioid-related deaths. To combat this mortality trend, naloxone is increasingly being utilized in a pre-hospital setting by emergency personnel and prescribed to laypersons for out-of-hospital administration. With increased utilization of naloxone there has been a subsequent reduction in mortality following an opioid overdose. Reversal of opioid toxicity may precipitate an opioid-withdrawal syndrome. At the same time, there is a risk of inadequate response or re-narcotization after the administration of a single dose of naloxone in patients who have taken large doses or long-acting opioid formulations, as the duration of effect of naloxone is shorter than that of many opioid agonists. As out-of-hospital use of this medication is growing, so too is concern about effective but safe dosing.

Postictal neurogenic pulmonary edema: Case report and brief literature review

Cardiopulmonary complications associated with epilepsy are generally associated with generalized tonic–clonic seizures, as a consequence of systemic adrenergic discharge and release of inflammatory mediators. We present a case of a 34-year-old woman with a history of Focal epilepsy since adolescence, who presented self-limited pulmonary edema following a focal to bilateral tonic–clonic seizure with subsequent resolution of the symptoms. We also made a brief review of neurogenic pulmonary edema, its proposed pathophysiology, treatment and its relation with sudden unexpected death in epilepsy (SUDEP).

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Neurogenic pulmonary edema can be fatal and its early identification allows the initiation of medical surveillance and management.

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Seizures are a rare cause of pulmonary edema and may be recurrent.

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NPE is associated with recurrent seizures and longer epileptic seizure.

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Treatment of NPE centers on resolution of CNS injury and ventilation support.