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Interventional Neuroradiology : Journal... May 2024Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized condition characterized by thunderclap headache with or without other neurological...
BACKGROUND
Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized condition characterized by thunderclap headache with or without other neurological deficits and diffuse vasoconstriction of cerebral arteries. Altered cerebrovascular tone may produce hemorrhage or stroke.
METHODS
A retrospective review of patients with RCVS at our institution (2000-2023) yielded one case of pseudoaneurysm secondary to RCVS.
RESULTS
Diagnostic cerebral angiogram demonstrated diffuse multifocal segmental narrowing consistent with RCVS and a left M4 pseudoaneurysm in proximity to the cortical hemorrhage. The pseudoaneurysm was treated with branch vessel sacrifice using nBCA glue in a 1 : 3 ratio with ethiodized oil. After securing the source of hemorrhage, the patient received an intra-arterial infusion of Verapamil.
CONCLUSION
This unique presentation of pseudoaneurysm secondary to RCVS in this patient highlights the impact of hemodynamic alteration as a possible source of bleeding and demonstrates a potential management strategy. Endovascular management with nBCA glue embolization successfully treated this lesion.
PubMed: 38748537
DOI: 10.1177/15910199241251907 -
Journal of Bronchology & Interventional... Jul 2024Bleeding is a known complication during bronchoscopy, with increased incidence in patients undergoing a more invasive procedure. Phenylephrine is a potent... (Observational Study)
Observational Study
BACKGROUND
Bleeding is a known complication during bronchoscopy, with increased incidence in patients undergoing a more invasive procedure. Phenylephrine is a potent vasoconstrictor that can control airway bleeding when applied topically and has been used as an alternative to epinephrine. The clinical effects of endobronchial phenylephrine on systemic vasoconstriction have not been clearly evaluated. Here, we compared the effects of endobronchial phenylephrine versus cold saline on systemic blood pressure.
METHODS
In all, 160 patients who underwent bronchoscopy and received either endobronchial phenylephrine or cold saline from July 1, 2017 to June 30, 2022 were included in this retrospective observational study. Intra-procedural blood pressure absolute and percent changes were measured and compared between the 2 groups.
RESULTS
There were no observed statistical differences in blood pressure changes between groups. The median absolute change between the median and the maximum intra-procedural systolic blood pressure in the cold saline group was 29 mm Hg (IQR 19 to 41) compared with 31.8 mm Hg (IQR 18 to 45.5) in the phenylephrine group. The corresponding median percent changes in SBP were 33.6 % (IQR 18.8 to 39.4) and 28% (IQR 16.8 to 43.5) for the cold saline and phenylephrine groups, respectively. Similarly, there were no statistically significant differences in diastolic and mean arterial blood pressure changes between both groups.
CONCLUSIONS
We found no significant differences in median intra-procedural systemic blood pressure changes comparing patients who received endobronchial cold saline to those receiving phenylephrine. Overall, this argues for the vascular and systemic safety of phenylephrine for airway bleeding as a reasonable alternative to epinephrine.
Topics: Humans; Phenylephrine; Retrospective Studies; Bronchoscopy; Male; Female; Middle Aged; Aged; Vasoconstrictor Agents; Hypertension; Blood Pressure
PubMed: 38745445
DOI: 10.1097/LBR.0000000000000968 -
Cureus Apr 2024Symmetrical peripheral gangrene (SPG) is a rare yet severe condition characterized by peripheral ischemic lesions without significant vascular occlusion. Its clinical... (Review)
Review
Symmetrical peripheral gangrene (SPG) is a rare yet severe condition characterized by peripheral ischemic lesions without significant vascular occlusion. Its clinical presentation includes peripheral cyanosis, mottling, and symmetrical ischemia of distal limbs, often progressing to gangrene. Recent years have seen a rise in SPG cases, with mortality rates ranging from 40% to 90%. The condition is associated with systemic diseases, such as sepsis, vasculitis, and coagulopathy. DIC frequently complicates SPG, reflecting a disturbed procoagulant-anticoagulant balance and depletion of natural anticoagulants. While vasopressor therapy, particularly high-dose administration, has been implicated in SPG pathogenesis due to sustained vasoconstriction or idiosyncratic responses, recent evidence suggests it may not be the underlying cause. Studies indicate a low incidence of ischemic limb necrosis associated with high-dose vasopressors, with DIC and shock liver potentially explaining limb ischemia instead. The characteristic temporal interval between the onset of shock liver and limb ischemic necrosis suggests a more complex pathophysiology. The role of infectious agents, such as bacteria and viruses, in SPG pathogenesis is under investigation, with both direct vascular invasion and immune-mediated mechanisms proposed. Diagnosis involves ruling out other causes of acral gangrene through clinical examination, laboratory tests, imaging studies, and biopsy. Treatment strategies aim to halt disease progression, eliminate causative factors, and prevent complications. While anticoagulants, vasodilators, and adjunctive therapies like hyperbaric oxygen show promise, the efficacy of interventions varies, emphasizing the need for individualized management. Notably, hemoadsorption has emerged as a promising treatment, demonstrating significant improvement in SPG cases. Amputation remains a last resort option in irreversible cases. Early recognition and multidisciplinary management are crucial for improving outcomes. Further research is needed to better understand SPG's etiology and develop effective treatments through collaborative efforts.
PubMed: 38741803
DOI: 10.7759/cureus.58117 -
Purinergic Signalling May 2024Vascular P2Y receptors mediate many effects, but the role of individual subtypes is often unclear. Here we discuss how subtype-selective antagonists and receptor... (Review)
Review
Vascular P2Y receptors mediate many effects, but the role of individual subtypes is often unclear. Here we discuss how subtype-selective antagonists and receptor knockout/knockdown have helped identify these roles in numerous species and vessels. P2Y receptor-mediated vasoconstriction and endothelium-dependent vasodilation have been characterised using the selective antagonists, MRS2179 and MRS2216, whilst AR-C118925XX, a P2Y receptor antagonist, reduced endothelium-dependent relaxation, and signalling evoked by UTP or fluid shear stress. P2Y receptor knockdown reduced endothelial signalling and endothelial P2Y receptor knockout produced hypertensive mice and abolished vasodilation elicited by an increase in flow. UTP-evoked vasoconstriction was also blocked by AR-C118925XX, but the effects of P2Y receptor knockout were complex. No P2Y receptor antagonists are available and P2Y knockout did not affect the vascular actions of UTP and UDP. The P2Y receptor antagonist, MRS2578, identified endothelial P2Y receptors mediating vasodilation, but receptor knockout had complex effects. MRS2578 also inhibited, and P2Y knockout abolished, contractions evoked by UDP. P2Y receptors contribute to the myogenic tone induced by a stepped increase in vascular perfusion pressure and possibly to the development of atherosclerosis. The P2Y receptor antagonists, NF157 and NF340, inhibited ATP-evoked signalling in human endothelial cells. Vasoconstriction mediated by P2Y/P2Y and P2Y receptors was characterised using the antagonists, cangrelor, ticagrelor, AR-C67085 and MRS2211 or PPTN respectively. This has yet to be backed up by receptor knockout experiments. Thus, subtype-selective antagonists and receptor knockout/knockdown have helped identify which P2Y subtypes are functionally expressed in vascular smooth muscle and endothelial cells and the effects that they mediate.
PubMed: 38740733
DOI: 10.1007/s11302-024-10016-z -
American Journal of Physiology.... Jul 2024Blood flow to the active muscles and arterial blood pressure (ABP) increase during dynamic exercise, whereas blood flow to inactive organs (e.g., splanchnic organs and...
Blood flow to the active muscles and arterial blood pressure (ABP) increase during dynamic exercise, whereas blood flow to inactive organs (e.g., splanchnic organs and inactive limbs) declines. Aging leads to exaggerated ABP responses to exercise in females, but whether this is related to greater splanchnic vasoconstriction is unknown. This study sought to clarify the effect of aging in females on celiac artery blood flow during dynamic light-intensity exercise. Twelve healthy young females (YF: 20 ± 2 yr, mean ± SD) and 12 healthy older females (OF: 71 ± 4 yr) performed dynamic knee-extension and knee-flexion exercises at 30% of heart rate reserve for 4 min. The absolute changes from baseline (Δ) for mean arterial blood pressure (MAP), celiac artery mean blood flow (celMBF), and celiac vascular conductance (celVC) during exercise were calculated. ABP was measured using an automated sphygmomanometer, and celMBF was recorded by Doppler ultrasonography. The increase in MAP during exercise was greater in OF than in YF (YF: +14 ± 7 mmHg, OF: +24 ± 13 mmHg, = 0.028). The celMBF decreased during exercise in both groups, but there was no significant difference in the response between YF and OF (YF: -93.0 ± 66.1 mL/min, OF: -89.6 ± 64.0 mL/min, = 0.951). The celVC also decreased during exercise and remained lower than baseline during exercise. However, the response was not different between YF and OF (YF: -1.8 ± 1.0 mL/min/mmHg, OF: -1.5 ± 0.6 mL/min/mmHg, = 0.517). These results demonstrate that aging in females has minimal influence on splanchnic artery hemodynamic responses during dynamic light-intensity exercise, suggesting that exaggerated ABP responses during exercise in OF are not due to greater splanchnic vasoconstriction. During exercise, the splanchnic arteries vasoconstrict, contributing to blood flow redistribution and the blood pressure response. Blood pressure responses to exercise are exaggerated with aging in females; however, the physiological mechanism responsible has not been clarified. We show that celiac artery blood flow changes during light-intensity dynamic exercise do not differ with age in females. This indicates the exaggerated blood pressure to exercise with aging is likely not due to a difference in splanchnic vasoconstriction.
Topics: Humans; Female; Celiac Artery; Exercise; Aging; Young Adult; Aged; Regional Blood Flow; Splanchnic Circulation; Blood Flow Velocity; Arterial Pressure; Vasoconstriction; Blood Pressure; Adult; Age Factors
PubMed: 38738294
DOI: 10.1152/ajpregu.00012.2024 -
Journal of Intensive Care May 2024To optimize right ventricular-pulmonary coupling during veno-arterial (VA) ECMO weaning, inotropes, vasopressors and/or vasodilators are used to change right ventricular...
BACKGROUND
To optimize right ventricular-pulmonary coupling during veno-arterial (VA) ECMO weaning, inotropes, vasopressors and/or vasodilators are used to change right ventricular (RV) function (contractility) and pulmonary artery (PA) elastance (afterload). RV-PA coupling is the ratio between right ventricular contractility and pulmonary vascular elastance and as such, is a measure of optimized crosstalk between ventricle and vasculature. Little is known about the physiology of RV-PA coupling during VA ECMO. This study describes adaptive mechanisms for maintaining RV-PA coupling resulting from changing pre- and afterload conditions in VA ECMO.
METHODS
In 13 pigs, extracorporeal flow was reduced from 4 to 1 L/min at baseline and increased afterload (pulmonary embolism and hypoxic vasoconstriction). Pressure and flow signals estimated right ventricular end-systolic elastance and pulmonary arterial elastance. Linear mixed-effect models estimated the association between conditions and elastance.
RESULTS
At no extracorporeal flow, end-systolic elastance increased from 0.83 [0.66 to 1.00] mmHg/mL at baseline by 0.44 [0.29 to 0.59] mmHg/mL with pulmonary embolism and by 1.36 [1.21 to 1.51] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Pulmonary arterial elastance increased from 0.39 [0.30 to 0.49] mmHg/mL at baseline by 0.36 [0.27 to 0.44] mmHg/mL with pulmonary embolism and by 0.75 [0.67 to 0.84] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Coupling remained unchanged (2.1 [1.8 to 2.3] mmHg/mL at baseline; - 0.1 [- 0.3 to 0.1] mmHg/mL increase with pulmonary embolism; - 0.2 [- 0.4 to 0.0] mmHg/mL with hypoxic pulmonary vasoconstriction, p > 0.05). Extracorporeal flow did not change coupling (0.0 [- 0.0 to 0.1] per change of 1 L/min, p > 0.05). End-diastolic volume increased with decreasing extracorporeal flow (7.2 [6.6 to 7.8] ml change per 1 L/min, p < 0.001).
CONCLUSIONS
The right ventricle dilates with increased preload and increases its contractility in response to afterload changes to maintain ventricular-arterial coupling during VA extracorporeal membrane oxygenation.
PubMed: 38734616
DOI: 10.1186/s40560-024-00730-6 -
Journal of Clinical Anesthesia Sep 2024Three linked clinical observations prompted our current understanding of perioperative heat balance. The first was the extraordinarily rapid decrease in core temperature... (Review)
Review
Three linked clinical observations prompted our current understanding of perioperative heat balance. The first was the extraordinarily rapid decrease in core temperature after induction of general anesthesia which led to an understanding of redistribution hypothermia. The second was the linear reduction in core temperature during the subsequent 2-3 h which led to an understanding of anesthetic effects on metabolic heat production and factors that influence cutaneous heat loss. And the third was the observation that core temperature reaches a plateau at about 34.5 °C which led to the understanding that thermoregulatory vasoconstriction re-emerges when patients become sufficiently hypothermic, and that arteri-venous shunt constriction constrains metabolic heat to the core thermal compartment.
Topics: Humans; Body Temperature Regulation; Anesthesia, General; Hypothermia; Body Temperature; Perioperative Period; Vasoconstriction
PubMed: 38733707
DOI: 10.1016/j.jclinane.2024.111496 -
Diagnostics (Basel, Switzerland) Apr 2024More than half of patients hospitalized with liver cirrhosis are dealing with an episode of acute kidney injury; the most severe pattern is hepatorenal syndrome due to... (Review)
Review
More than half of patients hospitalized with liver cirrhosis are dealing with an episode of acute kidney injury; the most severe pattern is hepatorenal syndrome due to its negative prognosis. The main physiopathology mechanisms involve renal vasoconstriction and systemic inflammation. During the last decade, the definition of hepatorenal syndrome changed, but the validated criteria of diagnosis are still based on the serum creatinine level, which is a biomarker with multiple limitations. This is the reason why novel serum and urinary biomarkers have been intensively studied in recent years. Meanwhile, the imaging studies that use shear wave elastography are using renal stiffness as a surrogate for an early diagnosis. In this article, we focus on the physiopathology definition and highlight the novel tools used in the diagnosis of hepatorenal syndrome.
PubMed: 38732353
DOI: 10.3390/diagnostics14090938 -
International Journal of Molecular... Apr 2024Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of... (Review)
Review
Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID.
Topics: Humans; COVID-19; SARS-CoV-2; Lung; Pulmonary Embolism; Hypertension, Pulmonary; Post-Acute COVID-19 Syndrome; Thrombosis
PubMed: 38732160
DOI: 10.3390/ijms25094941 -
Cells May 2024Norbormide (NRB) is a -selective toxicant, which was serendipitously discovered in 1964 and formerly marketed as an eco-friendly rodenticide that was deemed harmless to... (Review)
Review
Norbormide (NRB) is a -selective toxicant, which was serendipitously discovered in 1964 and formerly marketed as an eco-friendly rodenticide that was deemed harmless to non- species. However, due to inconsistent efficacy and the emergence of second-generation anticoagulants, its usage declined, with registration lapsing in 2003. NRBs' lethal action in rats entails irreversible vasoconstriction of peripheral arteries, likely inducing cardiac damage: however, the precise chain of events leading to fatality and the target organs involved remain elusive. This unique contractile effect is exclusive to rat arteries and is induced solely by the endo isomers of NRB, hinting at a specific receptor involvement. Understanding NRB's mechanism of action is crucial for developing species-selective toxicants as alternatives to the broad-spectrum ones currently in use. Recent research efforts have focused on elucidating its cellular mechanisms and sites of action using novel NRB derivatives. The key findings are as follows: NRB selectively opens the rat mitochondrial permeability transition pore, which may be a factor that contributes to its lethal effect; it inhibits rat vascular K channels, which potentially controls its -selective vasoconstricting activity; and it possesses intracellular binding sites in both sensitive and insensitive cells, as revealed by fluorescent derivatives. These studies have led to the development of a prodrug with enhanced pharmacokinetic and toxicological profiles, which is currently undergoing registration as a novel efficacious eco-sustainable -selective toxicant. The NRB-fluorescent derivatives also show promise as non-toxic probes for intracellular organelle labelling. This review documents in more detail these developments and their implications.
Topics: Animals; Rats; Rodenticides; Humans; Vasoconstriction; Mitochondrial Permeability Transition Pore
PubMed: 38727324
DOI: 10.3390/cells13090788