Botulinum Toxin in the Treatment of Vasopressor-associated Symmetric Peripheral Gangrene

Relationship Between Symmetrical Peripheral Gangrene Patients and Using Vasopressors in the Intensive Care Unit

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.

Emerging Medical Therapies in Rosacea: A Narrative Review

Rosacea is a chronic inflammatory disease with a multifactorial pathogenesis. The wide spectrum of clinical phenotypes, including erythema, telangiectasia, inflammatory papules and pustules, and phyma, demand an individualized approach to treatment. This narrative review offers an updated reference for rosacea management by covering the latest developments in both topical and systemic treatments, including data from newly approved therapies, updates to current treatment modalities and ongoing clinical trials. Although use of benzoyl peroxide as a treatment for rosacea has typically been limited due to irritation, the improved tolerability due to microencapsulation of benzoyl peroxide 5% cream provides a new therapeutic option for patients with rosacea. Minocycline foam and topical ivermectin cream add to our armamentarium of treatment options, particularly for inflammatory papules and pustules. Sarecycline has a narrower spectrum of antibacterial activity, which might reduce the development of antibiotic resistance and disruption of the microbiome compared to other oral antibiotics. Brimonidine gel and oxymetazoline cream provide topical options for redness and flushing. There is emerging evidence about the role of hydroxychloroquine and intradermal botulinum toxin A, which may improve rosacea through their effects on mast cells. The clinical trials pipeline includes agents with a variety of mechanisms, including mast cell stabilization, antimicrobial, anti-inflammatory, and vasoconstrictive effects. However, the clinical pipeline for rosacea appears limited, and there remain important unmet needs for patients with more recalcitrant rosacea or phymatous disease. In addition, there is a need for comparative effectiveness studies to identify the highest value treatment approaches for patients with rosacea.

Experimental study of the effects of nitroglycerin, botulinum toxin A, and clopidogrel on bipedicled superficial inferior epigastric artery flap survival

Beneficial effects could be achieved by various agents such as nitroglycerin, botulinum toxin A (BoTA), and clopidogrel to improve skin flap ischaemia and venous congestion injuries. Eighty rats were subjected to either arterial ischaemia or venous congestion and applied to a bipedicled U-shaped superficial inferior epigastric artery (SIEA) flap with the administration of nitroglycerin, BoTA, or clopidogrel treatments. After 7 days, all rats were sacrificed for flap evaluation. Necrotic area percentage was significantly minimized in flaps treated with clopidogrel (24.49%) versus the ischemic flaps (34.78%); while nitroglycerin (19.22%) versus flaps with venous congestion (43.26%). With ischemia, light and electron microscopic assessments revealed that nitroglycerin produced degeneration of keratinocytes and disorganization of collagen fibers. At the same time, with clopidogrel administration, there was an improvement in the integrity of these structures. With venous congestion, nitroglycerin and BoTA treatments mitigated the epidermal and dermal injury; and clopidogrel caused coagulative necrosis. There was a significant increase in tissue gene expression and serum levels of vascular endothelial growth factor (VEGF) in ischemic flaps with BoTA and clopidogrel, nitroglycerin, and BoTA clopidogrel in flaps with venous congestion. With the 3 treatment agents, gene expression levels of tumor necrosis factor-α (TNF-α) were up-regulated in the flaps with ischemia and venous congestion. With all treatment modalities, its serum levels were significantly increased in flaps with venous congestion and significantly decreased in ischemic flaps. Our analyses suggest that the best treatment option for ischemic flaps is clopidogrel, while for flaps with venous congestion are nitroglycerin and BoTA.

Botulinum Toxin A for the Treatment of Sympathomimetic Pressor-Induced Digital Hand Ischemia in the Critically Ill Intensive Care Unit Patient

Vasopressor-induced ischemia of the hand, while relatively rare, is a severe complication in critically ill intensive care unit (ICU) patients requiring high concentrations of sympathomimetic pressors and often results in digit necrosis and amputation. Currently, there are no widely accepted approaches for treating this cause of peripheral digital ischemia. Case reports have demonstrated that reducing the concentration of vasopressors that patients are given may reverse the progression of ischemic events prior to necrosis. While this approach is at odds with the principle of "life over limb," it demonstrates that digit necrosis can be reversed, resulting in improved outcomes. Here, we present a therapeutic strategy for treating digital limb ischemia in the septic ICU patient without the need to lower systemic vasopressor dose by using locally injected botulinum toxin A into ischemic hands.