Contribution of α - and β -Adrenergic Mechanisms to the Development of Pulmonary Edema

Cardiogenic pulmonary edema - is it lone cardiogenic? "Missing link" between hemodynamic and other existing mechanisms

The current traditional pathophysiologic concept of pulmonary edema of cardiogenic origin explains its development by a hydrostatic effect due to increased pulmonary capillary pressure resulting in fluid flux to alveolar and interstitial areas from capillaries. However, several experimental studies and clinical data of poor response to hemodynamic and diuretic treatment in many scenarios provide further evidence of the involvement of several other contributing factors to the development of cardiogenic pulmonary edema. Several experimental and clinical studies have found that sympathetic overactivity with elevated plasma catecholamine concentrations may play an important role in the development of cardiovascular-associated pulmonary edema. Catecholamine-induced pulmonary injury may be one of the key mechanisms in acute cardiogenic pulmonary edema triggering proinflammatory cytokine overactivation, oxidative stress and myocardial injury. In the everyday treatment of acute heart failure, physicians should consider the possibility of other noncardiogenic mechanisms involved in the progression of acute pulmonary edema, particularly catecholamine overactivity, lymphatic drainage, inflammatory and oxidative stress, high surfactant protein. The classic, hemodynamic treatment approach in pulmonary edema with the coexistence of other contributing factors may not provide adequate clinical benefit during treatment.

The Double-Edged Sword: Naloxone-Induced Noncardiogenic Pulmonary Edema

Naloxone-induced noncardiogenic pulmonary edema (NCPE) is a scarcely reported side effect that can occur after naloxone administration. We present a case of a 46-year-old male who presented to the emergency department for further management of an opioid overdose, who developed acute hypoxic respiratory failure after several doses of naloxone. The rapid deterioration of the patient's respiratory status required increased supplemental oxygen, with plane film radiography suggesting diffuse pulmonary edema. This case emphasizes the importance of understanding the significant side effects of a lifesaving drug and the implications they carry now that naloxone is available without prescription.

Beta-Adrenergic Blockade in Critical Illness

Catecholamine upregulation is a core pathophysiological feature in critical illness. Sustained catecholamine β-adrenergic induction produces adverse effects relevant to critical illness management. β-blockers (βB) have proposed roles in various critically ill disease states, including sepsis, trauma, burns, and cardiac arrest. Mounting evidence suggests βB improve hemodynamic and metabolic parameters culminating in decreased burn healing time, reduced mortality in traumatic brain injury, and improved neurologic outcomes following cardiac arrest. In sepsis, βB appear hemodynamically benign after acute resuscitation and may augment cardiac function. The emergence of ultra-rapid βB provides new territory for βB, and early data suggest significant improvements in mitigating atrial fibrillation in persistently tachycardic septic patients. This review summarizes the evidence regarding the pharmacotherapeutic role of βB on relevant pathophysiology and clinical outcomes in various types of critical illness.

Factors Associated with In-Hospital Death in Patients with Killip Class 3 Acute Myocardial Infarction

The clinical outcomes in acute myocardial infarction (AMI) patients with Killip class 3 are often inconsistent with those in the literature, and the factors associated with poor outcomes have not been sufficiently investigated. The purpose of this study was to identify factors associated with in-hospital death in AMI patients with Killip class 3. We included 205 AMI patients with Killip class 3, and divided them into a survived group (n = 189) and in-hospital death group (n = 16). The primary objective was to identify factors associated with in-hospital death using multivariate analysis. Age was significantly younger in the survived group than in the in-hospital death group (73.1 ± 11.2 versus 83.2 ± 6.2 years, P < 0.001). Systolic blood pressure (SBP) was significantly higher in the survived group than in the in-hospital death group (150.0 ± 31.2 versus 124.8 ± 25.3 mmHg, P = 0.002). The prevalence of TIMI thrombus grade ≥ 2 was significantly greater in the in-hospital death group than in the survived group (56.3 versus 22.2%, P = 0.005). In multivariate logistic regression analysis, in-hospital death was significantly associated with age [odds ratio (OR) 1.168, 95% confidence interval (CI) 1.061-1.287, P = 0.002] and TIMI thrombus grade ≥ 2 (versus ≤ 1: OR 5.743, 95% CI 1.717-19.214, P = 0.005), and inversely associated with SBP on admission (per 10 mmHg increase: OR 0.764, 95% CI 0.613-0.953, P = 0.017). In conclusion, in-hospital death was associated with age and coronary thrombus burden, and was inversely associated with SBP on admission in patients with Killip class 3. It may be important to recognize these high risk features to improve the clinical outcomes of patients with Killip class 3.

Application of α2 -adrenergic agonists combined with anesthetics and their implication in pulmonary intravascular macrophages-insulted pulmonary edema and hypoxemia in ruminants

Alpha₂ -adrenergic agonists have been implicated in the development of pulmonary edema (PE) and sustained hypoxemia that lead to life-threatening pulmonary distress in ruminants, especially with sensitive and compromised animals. Recently, there is limited understanding of exact mechanism underlying pulmonary alterations associated with α₂ -adrenergic agonist administration. Ruminants have a rich population of pulmonary intravascular macrophages (PIMs) in the pulmonary circulation, which may be involved in the development of pulmonary alveolo-capillary barrier damage. Hence, the central thesis of this review is overviewing the literatures regarding the systemic use of α₂ -adrenergic agonists in domestic ruminants, focusing on their pulmonary side effects, especially on the influence of PIMs on the lung. At this moment, further studies are needed to provide a clear emphasis and better understanding of the potential role of PIMs in the lung pathophysiology associated with α₂ -adrenergic agonists. These preliminary studies would be potentially to develop future medications and intervention targets that may be helpful to alleviate or prevent the critical striking pulmonary effects, and thereby improving the safety of α₂ -agonist application in ruminants.

Beta-Adrenergic Blockers as a Potential Treatment for COVID-19 Patients

More than 15 million people have been affected by coronavirus disease 2019 (COVID-19) and it has caused 640 016 deaths as of July 26, 2020. Currently, no effective treatment option is available for COVID-19 patients. Though many drugs have been proposed, none of them has shown particular efficacy in clinical trials. In this article, the relationship between the Adrenergic system and the renin-angiotensin-aldosterone system (RAAS) is focused in COVID-19 and a vicious circle consisting of the Adrenergic system-RAAS-Angiotensin converting enzyme 2 (ACE2)-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (which is referred to as the "ARAS loop") is proposed. Hyperactivation of the ARAS loop may be the underlying pathophysiological mechanism in COVID-19, and beta-adrenergic blockers are proposed as a potential treatment option. Beta-adrenergic blockers may decrease the SARS-CoV-2 cellular entry by decreasing ACE2 receptors expression and cluster of differentiation 147 (CD147) in various cells in the body. Beta-adrenergic blockers may decrease the morbidity and mortality in COVID-19 patients by preventing or reducing acute respiratory distress syndrome (ARDS) and other complications. Retrospective and prospective clinical trials should be conducted to check the validity of the hypothesis. Also see the video abstract here https://youtu.be/uLoy7do5ROo.

Exacerbation of ozone-induced pulmonary and systemic effects by β2-adrenergic and/or glucocorticoid receptor agonist/s

Agonists of β₂ adrenergic receptors (β₂AR) and glucocorticoid receptors (GR) are prescribed to treat pulmonary diseases. Since ozone effects are mediated through the activation of AR and GR, we hypothesized that the treatment of rats with relevant therapeutic doses of long acting β₂AR agonist (LABA; clenbuterol; CLEN) and/or GR agonist (dexamethasone; DEX) would exacerbate ozone-induced pulmonary and systemic changes. In the first study, male 12-week-old Wistar-Kyoto rats were injected intraperitoneally with vehicle (saline), CLEN (0.004 or 0.02 mg/kg), or DEX (0.02 or 0.1 mg/kg). Since dual therapy is commonly used, in the second study, rats received either saline or combined CLEN + DEX (each at 0.005 or 0.02 mg/kg) one day prior to and on both days of exposure (air or 0.8ppm ozone, 4 hr/day x 2-days). In air-exposed rats CLEN, DEX or CLEN + DEX did not induce lung injury or inflammation, however DEX and CLEN + DEX decreased circulating lymphocytes, spleen and thymus weights, increased free fatty acids (FFA) and produced hyperglycemia and glucose intolerance. Ozone exposure of vehicle-treated rats increased bronchoalveolar lavage fluid protein, albumin, neutrophils, IL-6 and TNF-α. Ozone decreased circulating lymphocytes, increased FFA, and induced hypeerglycemia  and glucose intolerance. Drug treatment did not reverse ozone-induced ventillatory changes, however, lung effects (protein and albumin leakage, inflammation, and IL-6 increase) were exacerbated by CLEN and CLEN + DEX pre-treatment in a dose-dependent manner (CLEN > CLEN + DEX). Systemic effects induced by DEX and CLEN + DEX but not CLEN in air-exposed rats were analogous to and more pronounced than those induced by ozone. These data suggest that adverse air pollution effects might be exacerbated in people receiving LABA or LABA plus glucocorticoids.

Immersion pulmonary oedema: a cardiological perspective

It is postulated that immersion pulmonary oedema (IPE) occurs because of combinations of factors that each increase the hydrostatic pressure gradient between the pulmonary capillaries and the alveoli. The factors, by definition, include the effects of immersion, particularly raised central blood volume and hence cardiac filling pressures. Breathing against a negative pressure is important but the magnitude of the effect depends on the relation of the diver's lung centroid to the source of the breathing gas and the breathing characteristics of diving equipment. Other factors are cold-induced vasoconstriction, exertion and emotional stress, but variations of the responses of individuals to these stimuli are important. Hypertension is the most frequent cardiovascular disease predisposing to IPE but other medical conditions are implicated in some patients.

Argon reduces the pulmonary vascular tone in rats and humans by GABA-receptor activation

Argon exerts neuroprotection. Thus, it might improve patients’ neurological outcome after cerebral disorders or cardiopulmonary resuscitation. However, limited data are available concerning its effect on pulmonary vessel and airways. We used rat isolated perfused lungs (IPL) and precision-cut lung slices (PCLS) of rats and humans to assess this topic. IPL: Airway and perfusion parameters, oedema formation and the pulmonary capillary pressure (P_cap) were measured and the precapillary and postcapillary resistance (R_post) was calculated. In IPLs and PCLS, the pulmonary vessel tone was enhanced with ET-1 or remained unchanged. IPLs were ventilated and PCLS were gassed with argon-mixture or room-air. IPL: Argon reduced the ET-1-induced increase of P_cap, R_post and oedema formation (p < 0.05). PCLS (rat): Argon relaxed naïve pulmonary arteries (PAs) (p < 0.05). PCLS (rat/human): Argon attenuated the ET-1-induced contraction in PAs (p < 0.05). Inhibition of GABA_B-receptors abolished argon-induced relaxation (p < 0.05) in naïve or ET-1-pre-contracted PAs; whereas inhibition of GABA_A-receptors only affected ET-1-pre-contracted PAs (p < 0.01). GABA_A/B-receptor agonists attenuated ET-1-induced contraction in PAs and baclofen (GABA_B-agonist) even in pulmonary veins (p < 0.001). PLCS (rat): Argon did not affect the airways. Finally, argon decreases the pulmonary vessel tone by activation of GABA-receptors. Hence, argon might be applicable in patients with pulmonary hypertension and right ventricular failure.

Intraoperative hemodynamics monitoring in a patient with pheochromocytoma multisystem crisis: a case report

Background

Pheochromocytoma is a rare catecholamine-secreting tumor. To evaluate the intraoperative hemodynamics with precision is difficult.

Case presentation

A 42-year-old man, who suddenly developed a life-threatening pheochromocytoma multisystem crisis that occurred during preoperative prophylactic medication, underwent urgent bilateral adrenalectomy. For the purpose of evaluating the intraoperative hemodynamics, we monitored both pulmonary artery catheter-based cardiac output (PACO) and arterial pressure-based cardiac output (APCO; FloTrac™). APCO fluctuated in poor agreement with the change in PACO, especially in the state of cytokine storming.

Conclusions

Overall, the value of stroke volume variation derived from FloTrac™ changed in tandem with the intraoperative volume status, indicating its utility as a marker of circulatory hemodynamics.

Anesthesia for myelomeningocele surgery in fetus

BACKGROUND

Administering anesthesia for prenatal repair of myelomeningocele reveals several issues that are unique to this new form of treatment. This includes issues such as fetal well-being, surgical conditions and monitoring, among others. Exploring, analyzing, and understanding the different variables that are involved will help us reduce the high level of risk associated with this surgery.

OBJECTIVE

This review provides a systematic approach to the issues that are faced by anesthesiologists during fetal surgery.

Pheochromocytoma Multisystem Crisis Behaving Like Interstitial Pneumonia: An Autopsy Case

Pheochromocytoma multisystem crisis is a rare and life-threatening disease that is associated with numerous symptoms and which is also difficult to diagnose. We herein report an autopsy case of a 61-year-old man who died due to pheochromocytoma multisystem crisis. The patient complained of vomiting and breathlessness. Computed tomography showed a shadow-like region with a similar appearance to interstitial pneumonia. The patient was diagnosed with takotsubo cardiomyopathy induced by severe lung disease based on the results of echocardiography and coronary angiography. The patient was treated for interstitial pneumonia. However, his condition rapidly deteriorated and he died 6 hours after arrival. We were later informed of his extremely high catecholamine serum levels. We found pheochromocytoma with hemorrhage at autopsy. The patient's lungs showed acute passive congestion with edema and extravasation.

Elevated blood plasma levels of epinephrine, norepinephrine, tyrosine hydroxylase, TGFβ1, and TNFα associated with high-altitude pulmonary edema in an Indian population

Biomarkers are essential to unravel the locked pathophysiology of any disease. This study investigated the role of biomarkers and their interactions with each other and with the clinical parameters to study the physiology of high-altitude pulmonary edema (HAPE) in HAPE-patients (HAPE-p) against adapted highlanders (HLs) and healthy sojourners, HAPE-controls (HAPE-c). For this, seven circulatory biomarkers, namely, epinephrine, norepinephrine, tyrosine hydroxylase, transforming growth factor beta 1, tumor necrosis factor alpha (TNFα), platelet-derived growth factor beta beta, and C-reactive protein (CRP), were measured in blood plasma of the three study groups. All the subjects were recruited at ~3,500 m, and clinical features such as arterial oxygen saturation (SaO₂), body mass index, and mean arterial pressure were measured. Increased levels of epinephrine, norepinephrine, tyrosine hydroxylase, transforming growth factor-beta 1, and TNFα were observed in HAPE-p against the healthy groups, HAPE-c, and HLs (P<0.0001). CRP levels were decreased in HAPE-p against HAPE-c and HLs (P<0.0001). There was no significant difference or very marginal difference in the levels of these biomarkers in HAPE-c and HLs (P>0.01). Correlation analysis revealed a negative correlation between epinephrine and norepinephrine (P=4.6E−06) in HAPE-p and positive correlation in HAPE-c (P=0.004) and HLs (P=9.78E−07). A positive correlation was observed between TNFα and CRP (P=0.004) in HAPE-p and a negative correlation in HAPE-c (P=4.6E−06). SaO₂ correlated negatively with platelet-derived growth factor beta beta (HAPE-p; P=0.05), norepinephrine (P=0.01), and TNFα (P=0.005) and positively with CRP (HAPE-c; P=0.02) and norepinephrine (HLs; P=0.04). Body mass index correlated negatively with epinephrine (HAPE-p; P=0.001) and positively with norepinephrine and tyrosine hydroxylase in HAPE-c (P<0.05). Mean arterial pressure correlated positively with TNFα in HAPE-p and norepinephrine in HLs (P<0.05). Receiver operating characteristic curve analysis yielded a positive predictive value for these biomarkers with HAPE (area under the curve >0.70, P<0.05). The results clearly suggest that increased plasma levels of these circulatory biomarkers associated with HAPE.

Cross-talk between the inflammatory response, sympathetic activation and pulmonary infection in the ischemic stroke

The immune system response and inflammation play a key role in brain injury during and after a stroke. The acute immune response is responsible for secondary brain tissue damage immediately after the stroke, followed by immunosuppression due to sympathetic nervous system activation. The latter increases risk of infection complications, such as pneumonia. The pneumonia-related inflammatory state can release a bystander autoimmune response against central nervous system antigens, thereby initiating a vicious circle. The aim of this review is to summarize the relationship between ischemic stroke, sympathetic nervous system activation and pulmonary infection.