Exploring a New Pathophysiological Association in Acne Vulgaris and Metabolic Syndrome: The Role of Biogenic Amines and Glutathione Peroxidase.

Background and Objectives: Metabolic disorders cause many skin issues, including acne vulgaris. This research investigated the function of glutathione peroxidase (GTPx) and biogenic amines as a potential novel pathophysiological link between metabolic syndrome (MetS) and acne vulgaris. Materials and Methods: The patients were distributed into two groups: metabolic precondition (MPG, n = 78) and control (CG, n = 81). To determine the extent of acne and metabolic preconditioning, patients were subjected to extensive clinical/paraclinical investigations. Additionally, catecholamine levels in urine and GTPx levels in blood were measured. Results: Mild acne was more common in the CG (32.1 vs. 6.4, p < 0.001), and severe acne was more common in the MPG (61.54 vs. 25.9, p < 0.001), with the average age being substantially higher in the MPG (23.81 vs. 21.05, p = 0.002). Significant variations were observed in the paraclinical levels for catecholamines (p < 0.05). In the MPG, most severe acne patients were overweight (52.1%), insulin-resistant (48.8%), or obese (47.9%). Moderate acne was most often linked to obesity (56%), overweight (44%), and insulin resistance (20%). Patients with severe acne (48.83%) had a considerably greater incidence of insulin resistance syndrome (p = 0.039) than those with moderate or severe acne (20%). The presence of two or three metabolic disorders considerably raised the risk of severe acne. Significant differences between groups were observed only in the subgroup of patients with severe acne, with lower values in the MPG (p = 0.015). Significant differences between groups were observed regarding the subgroup of patients with severe acne, with lower DTPx values in the MPG. At the group level, only CG patients with severe acne had reduced GTPx levels. Significant differences in catecholamine values were seen between groups (p < 0.05), independent of acne severity, except for adrenaline in mild acne patients (p = 0.059). Conclusions: The complex connection between GTPx and catecholamines in MetS suggests a significant role of these factors in the pathogenesis of acne associated with this condition, opening new perspectives in the research and treatment of acne in the context of MetS.

Effect of propranolol on temporomandibular joint pain in repeatedly stressed rats.

Stress substantially increases the risk of developing painful temporomandibular disorders (TMDs) by influencing the release of endogenous catecholamines. Propranolol, an antagonist of ß-adrenergic receptors, has shown potential in alleviating TMD-associated pain, particularly when the level of catecholamines is elevated. The aim of this study was to explore whether intra-articular propranolol administration is effective in diminishing temporomandibular joint (TMJ) pain during repeated stress situations. Additionally, we investigated the effect of repeated stress on the expression of genes encoding ß-adrenoceptors in the trigeminal ganglion. In the present study, rats were exposed to a stress protocol induced by sound, then to the administration of formalin in the TMJ (to elicit a nociceptive response), followed immediately afterward by different doses of propranolol, after which the analgesic response to propranolol was evaluated. We also assessed the levels of beta-1 and beta-2 adrenergic receptor mRNAs (Adrb1 and Adrb2, respectively) using reverse transcription-quantitative PCR (RT-qPCR). Our findings revealed that propranolol administration reduces formalin-induced TMJ nociception more effectively in stressed rats than in non-stressed rats. Furthermore, repeated stress decreases the expression of the Adrb2 gene within the trigeminal ganglion. The findings of this study are noteworthy as they suggest that individuals with a chronic stress history might find potential benefits from ß-blockers in TMD treatment.

Trial watch: beta-blockers in cancer therapy.

Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological source, stress triggers a physiological response that is mediated by the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medullary axis. The resulting release of glucocorticoids and catecholamines into the systemic circulation leads to neuroendocrine and metabolic adaptations that can affect immune homeostasis and immunosurveillance, thus impairing the detection and eradication of malignant cells. Moreover, catecholamines directly act on ß-adrenoreceptors present on tumor cells, thereby stimulating survival, proliferation, and migration of nascent neoplasms. Numerous preclinical studies have shown that blocking adrenergic receptors slows tumor growth, suggesting potential clinical benefits of using ß-blockers in cancer therapy. Much of these positive effects of ß-blockade are mediated by improved immunosurveillance. The present trial watch summarizes current knowledge from preclinical and clinical studies investigating the anticancer effects of ß-blockers either as standalone agents or in combination with conventional antineoplastic treatments or immunotherapy.

Smooth Emergence from General Anesthesia after Deep Extubation in a Pediatric Patient Diagnosed with Catecholaminergic Polymorphic Ventricular Tachycardia: A Case Report.

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic disorder where catecholamine causes bidirectional ventricular tachycardia, potentially leading to cardiac arrest. In patients undergoing surgery, sympathetic responses can be triggered in situations associated with surgical stimulations as well as high anxiety before the surgery, anesthetic maneuvers such as endotracheal intubation and extubation, and postoperative pain. Therefore, planning for surgery demands meticulous attention to anesthesia during the perioperative period in order to prevent potentially life-threatening arrhythmias. Case: We discuss a case of an 11-year-old male pediatric patient with known CPVT who required elective strabismus surgery for exotropia involving both eyes. After thorough planning of general anesthesia to minimize catecholamine response, sufficient anesthesia and analgesia were achieved to blunt the stressful response during intubation and maintained throughout the surgical procedure. Complete emergence was achieved after deep extubation, and the patient did not complain of pain or postoperative nausea and vomiting. Conclusions: Anesthesiologists should not only be able to plan and manage the catecholamine response during surgery but also anticipate and be prepared for situations that may lead to arrhythmias before and after the procedure. In certain cases, deep extubation can be beneficial as it reduces hemodynamic changes during the extubation process.

Angiotensin II in liver transplantation (AngLT-1): protocol of a randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Catecholamine vasopressors such as norepinephrine are the standard drugs used to maintain mean arterial pressure during liver transplantation. At high doses, catecholamines may impair organ perfusion. Angiotensin II is a peptide vasoconstrictor that may improve renal perfusion pressure and glomerular filtration rate, a haemodynamic profile that could reduce acute kidney injury. Angiotensin II is approved for vasodilatory shock but has not been rigorously evaluated for treatment of hypotension during liver transplantation. The objective is to assess the efficacy of angiotensin II as a second-line vasopressor infusion during liver transplantation. This trial will establish the efficacy of angiotensin II in decreasing the dose of norepinephrine to maintain adequate blood pressure. Completion of this study will allow design of a follow-up, multicentre trial powered to detect a reduction of organ injury in liver transplantation. METHODS AND ANALYSIS: This is a double-blind, randomised clinical trial. Eligible subjects are adults with a Model for End-Stage Liver Disease Sodium Score ≥25 undergoing deceased donor liver transplantation. Subjects are randomised 1:1 to receive angiotensin II or saline placebo as the second-line vasopressor infusion. The study drug infusion is initiated on reaching a norepinephrine dose of 0.05 µg kg-1 min-1 and titrated per protocol. The primary outcome is the dose of norepinephrine required to maintain a mean arterial pressure ≥65 mm Hg. Secondary outcomes include vasopressin or epinephrine requirement and duration of hypotension. Safety outcomes include incidence of thromboembolism within 48 hours of the end of surgery and severe hypertension. An intention-to-treat analysis will be performed for all randomised subjects receiving the study drug. The total dose of norepinephrine will be compared between the two arms by a one-tailed Mann-Whitney U test. ETHICS AND DISSEMINATION: The trial protocol was approved by the local Institutional Review Board (#20-30948). Results will be posted on ClinicalTrials.gov and published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.govNCT04901169.

Catecholamine-induced hypertensive crises: current insights and management.

Phaeochromocytomas and paragangliomas (PPGLs) release catecholamines leading to catecholamine-induced hypertensive (CIH) crises, with blood pressure greater than or equal to 180/120 mm Hg. CIH crises can be complicated by tachyarrhythmias, hypotension, or life-threatening target organ damage while treatment remains undefined, often requiring co-management between endocrinologists and cardiologists. Furthermore, biochemical diagnosis of a PPGL as a cause of a CIH crisis can be difficult to identify or confounded by comorbid conditions, potentially resulting in misdiagnosis. Here, we combine relevant evidence, 60 years of collective clinical experience, insights derived from assessing over 2600 patients with PPGL, and supplementary outcomes from 100 patients (treated at the National Institutes of Health) with a CIH crisis to inform diagnosis and treatment of CIH crises. Recognising that disparities exist between availability, cost, and familiarity of various agents, flexible approaches are delineated allowing for customisation, given institutional availability and provider preference. A CIH crisis and its complications are readily treatable with available drugs, with effective intervention defining an avenue for mitigating consequent morbidity and mortality in patients with PPGL.

[Distributive shock]. / Distributiver Schock.

In shock there is a significant mismatch between oxygen supply and consumption. In recent years the classification of forms of shock has been established based on pathophysiological and clinical aspects. The term distributive shock includes septic, anaphylactic and neurogenic shock. All these forms share a distinct vasoplegia with a relative volume deficiency. The adequate treatment of patients with distributive shock includes a rapid diagnosis and a consistent emergency treatment consisting of volume and catecholamine administration as well as additional specific emergency procedures when necessary.

Multimodal strategy to counteract vasodilation in septic shock.

Early initiation of a multimodal treatment strategy in the management of vasopressors during septic shock has been advocated to reduce delays in restoring adequate organ perfusion and to mitigate side effects associated with the administration of high-dose catecholamines. We provide a review that summarises the pathophysiology of vasodilation, the physiologic response to the vascular response, and the different drugs used in this situation, focusing on the need to combine early different vasopressors. Fluid loading being insufficient for counteracting vasoplegia, norepinephrine is usually the first-line vasopressor used to restore hemodynamics. Norepinephrine sparing is discussed in further detail through the concomitant use of adrenergic, vasopressinergic, and renin-angiotensin systems and the optimisation of endothelial reactivity with methylene blue. A blueprint for the construction of new studies is outlined to address the question of vasopressor selection and timing in septic shock.

Endocrinological disorders in acute kidney injury: an often overlooked field of clinical research.

Acute kidney injury (AKI) is a common comorbidity, affecting approximately one in five hospitalized adults. The kidney is the site for the production, metabolism or excretion of most hormones, including the production of erythropoietin (EPO), the active form of vitamin D, renin, thrombopoietin, and the excretion of insulin, catecholamines, gastrin and many other hormones. Therefore, it is reasonable to say that AKI can have a considerable impact on the endocrine system. Although the effects of AKI on various parameters, including cardiovascular parameters, serum electrolytes and acid-base disorders, neuro-humoral mechanisms and neurological outcomes have been extensively studied, the endocrinological consequences of AKI are understudied. Thyroid dysfunction, mainly euthyroid sick syndrome, hypo/hyperglycemia, bone mineral disorders, changes in EPO and atrial natriuretic peptide (ANP) levels are commonly found in AKI. EPO, thyroxine and ANP administration have been evaluated as potential tools to prevent or treat AKI with varying success, while the effects of AKI on some key hormones, including cortisol and insulin, have never been studied. Aim of this narrative review is to illustrate what is known and what is not known about the endocrinological outcomes of AKI. Few clinical trials are ongoing: however, there is a clear need for large-scale randomized controlled trials investigating the endocrinological consequences of AKI.

Risk factors of cytokine release syndrome: stress, catecholamines, and beyond.

Cytokine release syndrome (CRS) is a severe clinical syndrome marked by drastic elevation of inflammatory cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF). Despite the current empirical therapeutic strategies, prediction of CRS onset and identification of high-risk individuals are not satisfactory due to poor understanding of the mechanisms underlying CRS-related immune dysfunction and risk factors for CRS. Recent studies have suggested that conditions such as stress, obesity, diabetes, and hypertension may contribute to the development of CRS. Here, we discuss potential connections between these conditions and CRS pathogenesis, with a focus on stress hormone catecholamine-mediated effects, hoping that the design of CRS therapeutic approaches ensues from a renewed perspective.

Hydrocortisone may act through the angiotensin II receptor-2 level in patients with catecholamine-resistant septic shock.

BACKGROUND: This study aimed to compare the serum angiotensin II and its receptor levels (AT1, AT2) in septic patients with catecholamine-responsive or resistant. The effect of hydrocortisone treatment on angiotensin II levels in the catecholamine-resistant septic patients was evaluated. METHODS: This prospective observational study enrolled 40 patients diagnosed with septic shock based on sepsis-3 criteria. Patients were divided into two groups according to the noradrenalin infusion rate required to keep the mean arterial pressure above 65 mmHg: control group and hydrocortisone group (control group: below 0.5 µg/kg/min, hydrocortisone group: above 0.5 µg/kg/min). Serum angiotensin II, AT1, AT2 levels were measured at the time of diagnosis (A), one hour after hydrocortisone treatment (B), and three days later (C). RESULTS: In the catecholamine-resistant group, angiotensin II and AT1 levels were higher than the catecholamine-responder group in all periods. The sensitivity and specificity of AT-1 was observed to be high in all periods. AT2 levels decreased after hydrocortisone treatment in the catecholamine-resistant group and cut-off value was found 11%. CONCLUSIONS: It was concluded that angiotensin II and AT1 can be used as a biomarker of refractory septic shock and hydrocortisone may provide their blood pressure correcting effect by reducing AT2 level in these patients. AT2 can be a therapeutic target in the catecholamine-resistant septic shock patients.

Physical Exercise Exerts Neuroprotective Effect on Memory Impairment by Mitigate the Decline of Striatum Catecholamine and Spine Density in a Vascular Dementia Rat Model.

OBJECTIVE: The present study aims to investigate the underlying neurochemical mechanism of physical exercise on striatum synapsis and memory function in vascular dementia model. METHODS: 32 Sprague-Dawley (SD) rats were randomly divided into 4 groups: control group (C group, n = 6), vascular dementia group (Vascular dementia group, n = 7), physical exercise and vascular dementia group (Exe-VD group, n = 6), physical exercise and black group (Exe group, n = 6). 4 weeks of voluntary wheel running were used as pre-exercise training. Vascular dementia model was established by bilateral common carotid arteries occlusion (BCCAo) for 1 week. Passive avoidance test (PAT) were used to test memory function. The level of striatum catecholamine in the microdialysate were detected by enzyme linked immunosorbent assy (ELISA). Golgi staining was used to analyze striatum neuronal spine density. RESULTS: Behavioral data indicated that 4 weeks of physical exercise ameliorated memory impairment in vascular dementia model. Striatum catecholamine level significantly decreased in VD group when compared with C group (P < .001). But this phenomenon can be rescue by physical exercise (P < .001). In addition, compared with C group, neuronal spine density significantly decreased in VD group (P < .01), but 4 weeks of physical exercise can rescue this phenomenon (P < .05). CONCLUSION: 4 weeks of physical exercise improves memory function by mitigate the decline of striatum catecholamine and spine density in VD model.

Can Pediatric Heart Failure Therapy Be Improved? Yes It Can, But .

Given the heterogenous etiology of pediatric heart failure (pHF), evidence-based studies improving pHF are unlikely. A paradigm shift towards updated medicine-based evidence is therefore necessary. In view of the life expectancy of children, cardiac regeneration strategies are required. Therefore, age- and disease-related differences in myocardial (receptor) physiology require individualized precision medicine. First-line diuretic therapy, adopted from the treatment of adults with HF with no chance for recovery, should be questioned in the treatment of pHF with potential for recovery. Inadequate use of diuretics is a common reason for additional stimulation of the neurohumoral axis. Consecutive intravascular volume depletion led to an inadequate treatment with ß-blocker and renin-angiotensin-aldosterone antagonists. Given the age-related catecholamine-driven cardiovascular (patho-) physiology, highly selective ß1-blockers (bisoprolol) protect against ß1-(noradrenaline)-related myocytic apoptosis and necrosis, but allow ß2-receptor-mediated myocardial regeneration. Based on its high safety-efficacy profile with rarely seen adverse effects but easily monitorable efficacy by the surrogate of heart rate (reduction), bisoprolol is our first-line drug in infancy. Reduced heart rate economizes the heart and full body oxygen consumption and extends the diastolic filling and coronary perfusion time. Based on our many years of institutional experience, physicians should be encouraged to use ß1-selected blockers in infants with dilated cardiomyopathy and hypoplastic left heart syndrome after stage-1 procedure, but also to treat ventricular septal defects with a significant left-to-right shunt. In summary, individualized pHF therapy is the prerequisite for a causal treatment to improve HF symptoms, but above all for the most functional regeneration possible.

The pharmacotherapeutic options in patients with catecholamine-resistant vasodilatory shock.

INTRODUCTION: Septic and vasoplegic shock are common types of vasodilatory shock (VS) with high mortality. After fluid resuscitation and the use of catecholamine-mediated vasopressors (CMV), vasopressin, angiotensin II, methylene blue (MB), and hydroxocobalamin can be added to maintain blood pressure. AREAS COVERED: VS treatment utilizes a phased approach with secondary vasopressors added to vasopressor agents to maintain an acceptable mean arterial pressure (MAP). This review covers additional vasopressors and adjunctive therapies used when fluid and catecholamine-mediated vasopressors fail to maintain target MAP. EXPERT OPINION: Evidence supporting additional vasopressor agents in catecholamine-resistant VS is limited to case reports, series, and a few randomized control trials (RCTs) to guide recommendations. Vasopressin is the most common agent added next when MAPs are not adequately supported with CMV. VS patients failing fluids and vasopressors with cardiomyopathy may have cardiotonic agents such as dobutamine or milrinone added before or after vasopressin. Angiotensin II, another class of vasopressor, is used in VS to maintain adequate MAP. MB and/or hydroxocobalamin, vitamin C, thiamine, and corticosteroids are adjunctive therapies used in refractory VS. More RCTs are needed to confirm the utility of these drugs, at what doses, which combinations and in what order they should be given.

The Molecular Mechanism of Exercise for Treatment of Patients with Major Depression: A Preliminary Report on the Dynamics of Metabolites of Nitric Oxide and Catecholamines.

BACKGROUND: There has been increasing evidence that exercise therapy is effective in the treatment and prevention of major depression (MD). However, the basic molecular mechanisms underlying the effects of exercise on MD remain unclear. We conducted a preliminary study to clarify the effect of exercise therapy on MD, focusing on the dynamics of nitric oxide (NO) and catecholamine metabolites, which have been found to be associated with MD. METHODS: Eleven outpatients with mild to moderate MD and 37 healthy controls (HC) were included in the study. The participants' clinical records and questionnaires were screened for their past medical history. For their exercise therapy, the participants were instructed to walk the equivalent of 17.5 kcal/kg/week for 8 weeks. Blood samples were collected from all participants at baseline, 4 weeks, and 8 weeks after the start of exercise therapy, and plasma metabolites of NO (NOx), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) were analyzed. We also assessed the 17-item Hamilton Rating Scale for Depression (HRSD-17) in patients with MD. A mixed-effects regression model was used to compare the mean values by time (baseline, 4, and 8 weeks) for the three corresponding groups (NOx, MHPG, and HVA). RESULTS: HRSD-17 scores decreased significantly in the MD group after 8 weeks of exercise therapy. NOx and MHPG increased, but there was no significant change in HVA in the MD group after the exercise therapy. NOx decreased after exercise, and HVA increased significantly from baseline after 4 weeks of exercise but decreased after 8 weeks of exercise in the HC group. CONCLUSIONS: The effects of exercise on NOx, MHPG, and HVA may differ between MD and HC. The potential mechanisms for the benefits of walking exercise in MD patients will be the subject for future research.

Selepressin in Septic Shock.

ABSTRACT: Sepsis and septic shock usually show a high mortality rate and frequently need of intensive care unit admissions. After fluid resuscitation, norepinephrine (NE) is the first-choice vasopressor in septic shock patients. However, high-NE doses are associated with increased rates of adverse effects and mortality. In this perspective, many authors have proposed the administration of non-adrenergic vasopressors (NAV). Selepressin is a selective vasopressin type 1A (V1A) receptor agonist and may be a valid option in this field, because it can decrease NE requirements and also limit the deleterious effects induced by high doses of catecholamines. Only few clinical data actually support selepressin administration in this setting. Here, we review the current literature on this topic analyzing some pathophysiological aspects, the rationale about the use of NAV, the possible use of selepressin differentiating animal, and human studies. Various issues remain unresolved and future trials should be focused on early interventions based on a multimodal activation of the vasopressive pathways using both alpha and V1A receptors pathways.

Influence of Timing and Catecholamine Requirements on Vasopressin Responsiveness in Critically ill Patients with Septic Shock.

Introduction: Despite its widespread use, there is a paucity of data to guide the optimal use of arginine vasopressin (AVP) in critically ill patients with septic shock. Methods: This multicenter retrospective cohort study conducted in critically ill adults sought to evaluate the role of catecholamine requirements and timing on responsiveness to AVP. Responsiveness was defined as both a decrease in ≥ 50% of catecholamine requirements and no decrease in mean arterial pressure (MAP) at 4 hours post-AVP initiation. Primary outcomes of interest included the proportion of patients who started AVP within 4 hours after starting catecholamine therapy, as well as baseline norepinephrine (NE) equivalents (< 15, 15-39, or ≥ 40 mcg/min). Multivariate analyses and logistic regression were performed to identify other factors associated with AVP responsiveness. Results: There were 300 patients included in this study, with 74 patients being responders and 226 being non-responders. There was no significant difference in the number of patients who received AVP within 4 hours from catecholamine initiation between responders and non-responders (35% vs. 42%, P = 0.29). There were more patients in the non-responder group requiring ≥ 40 mcg/min of NE equivalents at AVP initiation (30% vs. 16%, P = 0.023). Stress dose steroid use was less common in responders (35% vs. 52%, P = 0.011), which was consistent with logistic regression analysis (OR 0.56, 95% 0.32-0.98, P = 0.044). Clinical outcomes between responders and non-responders were similar, apart from ICU (5.4% vs. 19.5%) and hospital (5.4% vs. 20.4%) mortality being lower in responders (P = 0.0032 and P = 0.0002, respectively). Conclusion: Shorter times to AVP initiation was not associated with responsiveness at 4 hours post-catecholamine initiation, although non-responders tended to require higher doses of NE equivalents at time of AVP initiation. Concomitant corticosteroids were associated with a lower likelihood of AVP responsiveness.

Pharmacoepigenetics of hypertension: genome-wide methylation analysis of responsiveness to four classes of antihypertensive drugs using a double-blind crossover study design.

Essential hypertension remains the leading risk factor of global disease burden, but its treatment goals are often not met. We investigated whether DNA methylation is associated with antihypertensive responses to a diuretic, a beta-blocker, a calcium channel blocker or an angiotensin receptor antagonist. In addition, since we previously showed an SNP at the transcription start site (TSS) of the catecholamine biosynthesis-related ACY3 gene to associate with blood pressure (BP) response to beta-blockers, we specifically analysed the association of methylation sites close to the ACY3 TSS with BP responses to beta-blockers. We conducted an epigenome-wide association study between leukocyte DNA methylation and BP responses to antihypertensive monotherapies in two hypertensive Finnish cohorts: the GENRES (https://clinicaltrials.gov/ct2/show/NCT03276598; amlodipine 5 mg, bisoprolol 5 mg, hydrochlorothiazide 25 mg, or losartan 50 mg daily) and the LIFE-Fin studies (https://clinicaltrials.gov/ct2/show/NCT00338260; atenolol 50 mg or losartan 50 mg daily). The monotherapy groups consisted of approximately 200 individuals each. We identified 64 methylation sites to suggestively associate (P < 1E-5) with either systolic or diastolic BP responses to a particular study drug in GENRES. These associations did not replicate in LIFE-Fin . Three methylation sites close to the ACY3 TSS were associated with systolic BP responses to bisoprolol in GENRES but not genome-wide significantly (P < 0.05). No robust associations between DNA methylation and BP responses to four different antihypertensive drugs were identified. However, the findings on the methylation sites close to the ACY3 TSS may support the role of ACY3 genetic and epigenetic variation in BP response to bisoprolol.

Association of Catecholamine Dose, Lactate, and Shock Duration at Vasopressin Initiation With Mortality in Patients With Septic Shock.

OBJECTIVES: To determine the association of catecholamine dose, lactate concentration, and timing from shock onset at vasopressin initiation with in-hospital mortality. DESIGN: Retrospective, observational study using segmented and multivariable logistic regression to evaluate the associations of catecholamine dose, lactate concentration, and timing from shock onset at vasopressin initiation with in-hospital mortality. SETTING: Multiple hospitals within the Cleveland Clinic Health System. PATIENTS: Adult patients who met criteria for septic shock based on the U.S. Centers for Disease Control and Prevention Adult Sepsis Event definition. INTERVENTIONS: All patients received continuous infusion vasopressin as an adjunct to catecholamine vasopressors. MEASUREMENTS AND MAIN RESULTS: In total, 1,610 patients were included with a mean Acute Physiology and Chronic Health Evaluation III 109.0 ± 35.1 and Sequential Organ Failure Assessment 14.0 ± 3.5; 41% of patients survived the hospital admission. At the time of vasopressin initiation, patients had median (interquartile range) lactate concentration 3.9 mmol/L (2.3-7.2 mmol/L), norepinephrine-equivalent dose 25 µg/min (18-40 µg/min), and 5.3 hours (2.1-12.2 hr) elapsed since shock onset. The odds of in-hospital mortality increased 20.7% for every 10 µg/min increase in norepinephrine-equivalent dose up to 60 µg/min at the time of vasopressin initiation (adjusted odds ratio, 1.21 [95% CI, 1.09-1.34]), but no association was detected when the norepinephrine-equivalent dose exceeded 60 µg/min (adjusted odds ratio, 0.96 [95% CI, 0.84-1.10]). There was a significant interaction between timing of vasopressin initiation and lactate concentration (p = 0.02) for the association with in-hospital mortality. A linear association between increasing in-hospital mortality was detected for increasing lactate concentration at the time of vasopressin initiation, but no association was detected for time elapsed from shock onset. CONCLUSIONS: Higher norepinephrine-equivalent dose at vasopressin initiation and higher lactate concentration at vasopressin initiation were each associated higher in-hospital mortality in patients with septic shock who received vasopressin.