Distributed dynamic event-triggered algorithm for optimization problem with time delay.

This paper focuses on studying the optimization problem of multi-agent systems (MAS) under undirected graph. To reduce the communication frequency among agents, a zero-gradient-sum (ZGS) algorithm based on dynamic event-triggered (DET) mechanism is investigated. The event-triggered condition of each agent only uses its own state information and the neighbor's state information at the previous triggering instants, without requiring continuous state information from the neighbor. In addition, the designed algorithm allows for the sampling period to be arbitrarily large. The Lyapunov method is utilized to derive the sufficient conditions that incorporate time delay and parameters. As the event is only checked at the periodic moment, zeno behavior can be directly excluded. Finally, numerical simulations demonstrate the effectiveness of the theoretical results.

Influences of Genetic and Environmental Factors on Chronic Migraine: A Narrative Review.

PURPOSE OF REVIEW: In this narrative review, we aim to summarize recent insights into the complex interplay between environmental and genetic factors affecting the etiology, development, and progression of chronic migraine (CM). RECENT FINDINGS: Environmental factors such as stress, sleep dysfunction, fasting, hormonal changes, weather patterns, dietary compounds, and sensory stimuli are critical triggers that can contribute to the evolution of episodic migraine into CM. These triggers are particularly influential in genetically predisposed individuals. Concurrently, genome-wide association studies (GWAS) have revealed over 100 genetic loci linked to migraine, emphasizing a significant genetic basis for migraine susceptibility. In CM, environmental and genetic factors are of equal importance and contribute to the pathophysiology of the condition. Understanding the bidirectional interactions between these elements is crucial for advancing therapeutic approaches and preventive strategies. This balanced perspective encourages continued research into the complex gene-environment nexus to improve our understanding and management of CM.

Fixed-time event-triggered control for multi-agent systems with input delay.

An in-depth study on the fixed-time event-triggered obstacle avoidance consensus control in heterogeneous USV-AUV systems with input delay and uncertain disturbances are conducted in this paper. When initial state of the system fails to achieve consensus, the desired heterogeneous USV-AUV formation can be achieved by fixed-time consensus control, within a fixed predetermined time, regardless of the initial states. Besides, an event-triggered communication strategy among the agents is introduced in the system, significantly reducing communication energy consumption. By employing the proposed control strategy, the Zeno behavior also can be avoided. Additionally, an obstacle avoidance control algorithm for the heterogeneous USV-AUV system based on improved artificial potential fields (IAPF) is designed, which helps in avoiding both static and dynamic obstacles. Compared to existing research, this algorithm reduces control input jitter, resulting in smoother obstacle avoidance paths. Through extensive simulation experiments and comparisons with other methods, effectiveness and superiority of the proposed algorithm is validated.

Comparative study of diabetic ketoacidosis in the elderly and non-elderly patients: A nine-year experience from an academic hospital in North India.

BACKGROUND AND AIMS: Despite an increasing prevalence of the aged population with diabetes in low-middle-income countries, there is limited literature on geriatric hyperglycemic emergencies. The present study aimed to compare the spectrum and outcomes of diabetic ketoacidosis (DKA) between elderly and non-elderly adult patients in India. METHODS: Seventy-seven elderly patients (≥60 years) were compared to 477 non-elderly patients (13-59 years) with DKA admitted to the medical emergency, Postgraduate Institute of Medical Education and Research, Chandigarh, India, between January 2014 and December 2022. Clinical features, laboratory parameters, precipitating factors, and in-hospital outcomes were reviewed. RESULTS: Elderly patients less commonly had vomiting and abdominal pain than non-elderly patients (31.3 % vs. 66.2 %, 27.3 % vs. 60.1 %, respectively) and typically presented with dyspnea (48.5 %), altered mental status (47.8 %), and fever (46.3 %). Ketonemia and metabolic acidosis were significantly more marked in non-elderly patients, whereas elderly patients frequently had anemia, hypoalbuminemia, and renal dysfunction. The most common precipitations of geriatric DKA were infections (70.1 %), followed by treatment non-adherence (66.2 %) and non-infectious disorders (35.1 %). Infections and non-infectious disorders were significantly more frequent in elderly patients than in non-elderly patients. Respiratory and urinary tract infections were prevalent in both age groups. In-hospital survival was 74.9 % (n = 415) and remained lower in older patients (48.1 % vs. 79.2 %, P-value <0.001). The independent prognostic factors were age (OR 1.030, 95 % CI 1.006-1.054, P = 0.014), Glasgow coma scale (OR 0.789, 95 % CI 0.717-0.869, P <0.001), and infection trigger (OR 6.635, 95 % CI 2.852-15.441, P <0.001). CONCLUSION: Older patients with DKA present atypically, frequently have precipitation with infections and noninfectious disorders, and have poor outcomes.

Is intimate partner abuse underestimated as a precipitating factor for venous thromboembolism in women?

Major and minor trauma increase the risk of venous thromboembolism (VTE), but violence against young women is not reported as a precipitating factor for thrombosis. Here, we report 20 cases of first VTE events in women of childbearing age after evidence of intimate partner violence. Other risk factors for VTE were often associated. In most cases, women did not report this state of violence at the first consultation and their doctors did not suspect it. We imagine that it is an underdiagnosed situation and should call for a systematic evaluation. Screening for intimate partner abuse could have significant consequences, both on protecting women who are affected by it and better evaluating the risk of bleeding with anticoagulant treatment in this situation.

Precipitating Factors and Outcome of Diabetic Ketoacidosis among Children and Adolescents with Type-1 Diabetes Mellitus.

OBJECTIVE: To determine the precipitating factors and outcomes of diabetic ketoacidosis (DKA) among patients with type 1 diabetes mellitus. STUDY DESIGN: An analytical study. Place and Duration of the Study: Department of Paediatrics, National Institute of Child Health, Karachi, Pakistan, from July to December 2022. METHODOLOGY: Children of either gender aged up to 18 years and presenting with DKA with a known diagnosis of type-1 diabetes were enrolled. Demographic, clinical, and anthropometric characteristics of all children were noted. Laboratory investigations were sent to the institutional laboratory. Presenting features, precipitating factors, severity of DKA, and outcomes noted. RESULTS: Among 131 children, 101 (77.1%) were girls. The socio-economic status of 75 (57.3%) patients was the lower middle. Celiac disease was the commonest associated disease noted in 23 (17.6%) patients. A total of 123 (93.9%) children were using basal plus bolus types. Adherence to diabetes-related drug therapy was seen in 105 (80.2%) patients. At the time of presentation, vomiting, fever, abdominal pain, and respiratory distress were the most frequent presenting features reported in 77 (58.8%), 67 (51.1%), 42 (32.1%), and 34 (26.0%) patients, respectively. The most common precipitating factors for DKA were infection/illness (n=90, 68.7%) and missed insulin dose (n=16, 12.2%); no cause was identified in 25 (19.1%) patients. The mean duration of hospital stay was 5.25±2.4 days. Four patients could not survive. CONCLUSION: The most common precipitating factor for the current episode of DKA were infection or illness, or missed insulin dose. Vomiting, fever, abdominal pain, and respiratory distress were the most frequent presenting features. In-hospital mortality was found to be 3% in DKA patients. KEY WORDS: Diabetic ketoacidosis, Type-1 diabetes mellitus, Insulin, Vomiting, Abdominal pain.

Information theory and headache triggers.

OBJECTIVES: This secondary analysis evaluated the information content exhibited by various measurement strategies of commonly perceived causes, or "triggers," of headache attacks. BACKGROUND: When evaluating triggers of primary headache attacks, the variation observed in trigger candidates must be measured to compare against the covariation in headache activity. Given the numerous strategies that could be used to measure and record headache trigger variables, it is useful to consider the information contained in these measurements. METHODS: Using previously collected data from cohort and cross-sectional studies, online data sources, and simulations, the Shannon information entropy exhibited by many common triggers was evaluated by analyzing available time-series or theoretical distributions of headache triggers. The degree of information, reported in bits, was compared across trigger variables, measurement strategies, and settings. RESULTS: A wide range of information content was observed across headache triggers. Due to lack of variation, there was little information, near 0.00 bits, in triggers like red wine and air conditioning. Most headache triggers exhibited more information when measured using an ordinal scale of presence/degree (e.g., absent, mild, moderate, severe) versus a present/absent binary coding. For example, the trigger "joy" exhibited 0.03 bits when assessed using binary coding but 1.81 bits when coded using an ordinal scale. More information was observed with the use of count data (0.86 to 1.75 bits), Likert rating scales (1.50 to 2.76 bits), validated questionnaires (3.57 to 6.04 bits), weather variables (0.10 to 8.00 bits), and ambulatory monitoring devices (9.19 to 12.61 bits). CONCLUSIONS: Although commonly used, all binary-coded measurements contain ≤1.00 bit of information. Low levels of information in trigger variables make associations with headache activity more difficult to detect. Assessments that balance information-rich measurements with reasonable participant burden using efficient formats (e.g., Likert scales) are recommended to enhance the evaluation of the association with headache activity.

Precipitating factors of bradycardia after remdesivir administration: ICU admission and cutoff value for declining heart rate.

BACKGROUND: Despite increasing concerns about the association between remdesivir and bradycardia in severe coronavirus disease 2019 (COVID-19) patients receiving remdesivir, information on its clinical course and precipitating factors is limited. Our aim was to investigate possible triggers of bradycardia after remdesivir administration. METHODS: We retrieved the medical records of hospitalized severe and critical COVID-19 patients who received remdesivir from May 1, 2021 to June 30, 2021. Bradycardia was defined as two episodes of a heart rate (HR) < 60 bpm in 24 h. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the discriminability of heart rate pattern on the occurrence of bradycardia. The precipitating factors of bradycardia were examined by a logistic regression model. RESULTS: Regardless of bradycardia status, the median heart rate dropped during remdesivir treatment (from 85 to 72 bpm, p < 0.001), with the heart rate dropping considerably within the first two days of remdesivir treatment. Among various heart rate descriptors, HR ratiomin (d2-d1) had the best discrimination (AUC = 0.7336), and a reduction in HR ratiomin (d2-d1) by 14.65% was associated with bradycardia. Intensive care unit (ICU) admission was associated with an increased risk of bradycardia (odds ratio: 3.41; 95% CI: 1.12-10.41). CONCLUSIONS: In severe COVID-19 patients receiving remdesivir, the risks of bradycardia were influenced by a substantial reduction in heart rate during the first two days of remdesivir treatment and ICU admission. These findings suggest that clinical practitioners should intensively monitor heart rates during remdesivir treatment.

Association of pre-hospital precipitating factors with short- and long-term outcomes of acute heart failure patients: A report from the WET-HF2 registry.

BACKGROUND: Interest in clinical course preceding heart failure (HF) exacerbation has grown, with a greater emphasis placed on patients' clinical factors including precipitant factor (PF). Large-scale studies with precise PF documentation and temporal-outcome variation remain limited. METHODS: We reviewed prospectively collected 2412 consecutive patient-level records from a multicenter Japanese registry of hospitalized patients with HF (West Tokyo Heart Failure2 Registry: 2018-2020). Patients were categorized based on PFs: behavioral (i.e., poor adherence to physical activity, medicine, or diet regimen), treatment-required (i.e., anemia, arrhythmia, ischemia, infection, thyroid dysfunction or other conditions as suggested exacerbating factors), and no-PF. The composite outcomes of HF rehospitalization and death within 1 year after discharge and HF rehospitalization were individually assessed. RESULTS: Median patient age was 78 years (interquartile range: 68-85 years), and 1468 (61%) patients had documented PFs, of which 356 (15%) were considered behavioral. The behavioral PF group were younger, more male and had past HF hospitalization history compared to those in the other groups (all p < 0.05). Although risk of in-hospital death was lower in the behavioral PF group, their risk of composite outcome was not significantly different from the treatment-required group (hazard ratio [HR] 1.19 [95% confidence interval {CI} 0.93-1.51]) and the no-PF group (HR 1.28 [95%CI 1.00-1.64]). Furthermore, the risk of HF rehospitalization was higher in the behavioral PF group than in the other two groups (HR 1.40 [95%CI 1.07-1.83] and HR 1.39 [95%CI 1.06-1.83], respectively). CONCLUSION: Despite a better in-hospital prognosis, patients with behavioral PFs were at significantly higher risk of HF rehospitalization.

Case Report: Localized bullous pemphigoid induced by local triggers: a case series and a proposal for diagnostic criteria based on a literature review.

Introduction: Localized bullous pemphigoid (LBP) is an infrequent bullous pemphigoid (BP) variant restricted to a body region. According to the most compelling evidence, LBP occurs in patients with pre-existent serum antibodies against the basement membrane zone, which occasionally acquire the capacity to induce disease after the influence of different local factors acting as triggers. Methods: We hereby present a multicenter cohort of 7 patients with LBP developed after local triggers: radiotherapy, thermal burns, surgery, rosacea, edema and a paretic leg. In addition, we conducted a review of the literature, and we propose a set of diagnostic criteria for LBP, also based on our case series and the 2022 BP guidelines from the European Academy of Dermatology and Venereology. Results: During follow-up, three of the patients from our series evolved to a generalized BP, with only one requiring hospitalization. Our literature search retrieved 47 articles including a total of 108 patients with LBP, with a 63% with a potential local precipitating factor previous to their diagnosis. LBP mostly affected older females, and a subsequent generalized progression occurred in 16.7% of the cases. The most frequently involved areas were the lower limbs. Radiation therapy and surgery were responsible for the inducement of nearly 2 in 3 cases of LBP. We observed a significantly higher risk of generalization in cases where the trigger led to the developing of LBP earlier (p=0.016). Our statistical analysis did not detect any other prognosis factor for generalization when assessing direct immunofluorescence, histological and serological results, or other patient related factors. Conclusion: LBP should be suspected in patients with recurrent localized bullous eruptions. The presence of a trauma history in the same anatomic area is reported in most cases.

Physical injuries as triggers for self-harm: a within-individual study of nearly 250 000 injured people with a major psychiatric disorder.

BACKGROUND: Although there is robust evidence for several factors which may precipitate self-harm, the contributions of different physical injuries are largely unknown. OBJECTIVE: To examine whether specific physical injuries are associated with risks of self-harm in people with psychiatric disorders. METHODS: By using population and secondary care registers, we identified all people born in Finland (1955-2000) and Sweden (1948-1993) with schizophrenia-spectrum disorder (n=136 182), bipolar disorder (n=68 437) or depression (n=461 071). Falls, transport-related injury, traumatic brain injury and injury from interpersonal assault were identified within these subsamples. We used conditional logistic regression models adjusted for age and calendar month to compare self-harm risk in the week after each injury to earlier weekly control periods, which allowed us to account for unmeasured confounders, including genetics and early environments. FINDINGS: A total of 249 210 individuals had been diagnosed with a psychiatric disorder and a physical injury during the follow-up. The absolute risk of self-harm after a physical injury ranged between transport-related injury and injury from interpersonal assault (averaging 17.4-37.0 events per 10 000 person-weeks). Risk of self-harm increased by a factor of two to three (adjusted OR: 2.0-2.9) in the week following a physical injury, as compared with earlier, unexposed periods for the same individuals. CONCLUSIONS: Physical injuries are important proximal risk factors for self-harm in people with psychiatric disorders. CLINICAL IMPLICATIONS: Mechanisms underlying the associations could provide treatment targets. When treating patients with psychiatric illnesses, emergency and trauma medical services should actively work in liaison with psychiatric services to implement self-harm prevention strategies.

Vértigo en gestantes: presentación clínica, impacto en la calidad de vida y factores asociados / Vertigo in pregnancy: clinical presentation, impact on quality of life and associated factors

OBJETIVO: Evaluar las características clínicas, el impacto en la calidad de vida y los factores asociados con vértigo en gestantes hospitalizadas en una institución de alta complejidad. MÉTODO: Estudio transversal. Se realizó una encuesta dirigida a la presencia de vértigo y sus características clínicas en 2020-2021. La calidad de vida se evaluó con el cuestionario Dizziness Handicap Inventory (DHI). El análisis estadístico incluyó un modelo lineal generalizado. RESULTADOS: De 103 mujeres, el 19,4% indicaron vértigo principalmente en el segundo trimestre de gestación (60%), con una mediana de 3,5 (rango intercuartil: 1,5-7,5) episodios. Fueron referidos vértigos episódicos asociados con cambios posicionales (40%), acompañados de inestabilidad (60%), cefalea (60%), fotopsias (55%) y tinnitus (45%). Las mujeres con vértigo presentaron mayor frecuencia de discapacidad moderada a grave en las dimensiones del DHI emocional (30 vs. 2,4%; p = 0,001), funcional (40 vs. 2,4%; p < 0,001) y física (55 vs. 2,4%; p < 0,001) en comparación con las mujeres sin la patología. La hospitalización durante el embarazo Razón de proporción (RP): 4,02; intervalo de confianza del 95% [IC95%]: 1,64-9,85; p = 0,002) y la presencia de vértigo pregestacional (RP: 2,37; IC95%: 1,15-4,88; p = 0,019) se identificaron como factores asociados. CONCLUSIONES: La alta frecuencia de vértigo en las gestantes sugiere la importancia de estudiar esta condición durante el embarazo, para lograr un manejo integral y generar acciones de prevención y control efectivas.

OBJECTIVE: To evaluate clinical characteristics, impact on quality of life and factors associated with vertigo in pregnant women hospitalized in a highly complex institution. METHOD: A cross-sectional study was conducted in 2021-2022. One focused survey including Dizziness Handicap Inventory (DHI) was performed. The statistical analysis was performed using a generalized lineal regression. RESULTS: 103 patients were included, 19.4% indicated vertigo mostly during the second semester (60%). A median of 3.5 episodes was obtained (RIC: 1.5-7.5). Positional and episodic vertigos (40%) associated with unsteadiness (60%), headache (60%), photopsia (55%) and tinnitus (45%) were described. DHI in pregnant females with vertigo compared to those without vertigo, presented higher rates of moderate to severe disability in the emotional (30 vs. 2.4%: p = 0.001), functional (40 vs. 2.4%; p < 0.001) and physical (55 vs. 2.4%; p < 0.001) dimensions. Hospitalizations during the pregnancy (RP: 4.02; 95%CI: 1.64-9.85; p = 0.002) and previous episodes before pregnancy (RP: 2.37; 95%CI: 1.15-4.88; p = 0.019) were identified as associated factors with current vertigo episodes. CONCLUSIONS: The high frequency of vertigo in pregnant women suggests the importance of studying this condition during pregnancy, to achieve comprehensive management and generate effective prevention and control actions.

Precipitating factors in patients with spontaneous coronary artery dissection: Clinical, laboratoristic and prognostic implications.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) often presents with acute coronary syndrome and underlying pathophysiology involves the interplay between predisposing factors and precipitating stressors, such as emotional and physical triggers. In our study we sought to compare clinical, angiographic and prognostic features in a cohort of patients with SCAD according to the presence and type of precipitating stressors. METHODS: Consecutive patients with angiographic evidence of SCAD were divided into three groups: patients with emotional stressors, patients with physical stressors and those without any stressor. Clinical, laboratoristic and angiographic features were collected for each patient. The incidence of major adverse cardiovascular events, recurrent SCAD and recurrent angina was assessed at follow-up. RESULTS: Among the total population (64 subjects), 41 [64.0%] patients presented with precipitating stressors, including emotional triggers (31 [48.4%] subjects) and physical efforts (10 [15.6%] subjects). As compared with the other groups, patients with emotional triggers were more frequently female (p = 0.009), had a lower prevalence of hypertension (p = 0.039] and dyslipidemia (p = 0.039), were more likely to suffer from chronic stress (p = 0.022) and presented with higher levels of C-reactive protein (p = 0.037) and circulating eosinophils cells (p = 0.012). At a median follow-up of 21 [7; 44] months, patients with emotional stressors experienced higher prevalence of recurrent angina (p = 0.025), as compared to the other groups. CONCLUSIONS: Our study shows that emotional stressors leading to SCAD may identify a SCAD subtype with specific features and a trend towards a worse clinical outcome.

Learning headache triggers through experience: A laboratory study.

OBJECTIVE: To examine how individuals may learn headache trigger beliefs through sequential symbolic pairings of trigger candidates and headache attacks. BACKGROUND: Learning from experience may be a major source of information about headache triggers. Little is known about learning-based influences on the establishment of trigger beliefs. METHODS: This cross-sectional, observational study included N = 300 adults with headache who participated in a laboratory computer task. First, participants rated the chances (0%-100%) that encountering specific triggers would lead to experiencing a headache. Then, 30 sequential images with the presence or absence of a common headache trigger were presented alongside images representing the presence or absence of a headache attack. The primary outcome measure was the cumulative association strength rating (0 = no relationship to 10 = perfect relationship) between the trigger and headache using all previous trials. RESULTS: A total of N = 296 individuals completed 30 trials for each of three triggers, yielding 26,640 total trials for analysis. The median [25th, 75th] association strength ratings for each of the randomly presented headache triggers were 2.2 [0, 3] for the Color Green, 2.7 [0, 5] for Nuts, and 3.9 [0, 8] for Weather Changes. There was a strong association between the "true" cumulative association strength and corresponding ratings. A 1-point increase on the phi scale (i.e., no relationship to perfect relationship) was associated with a 1.20 (95% CI: 0.81 to 1.49, p < 0.0001) point increase in association strength rating. A participant's prior belief about the potency of a trigger affected their perceived rating of the accumulating evidence, accounting for 17% of the total variation. CONCLUSION: In this laboratory task, individuals appeared to learn trigger-headache associations through repeated exposures to accumulating symbolic evidence. Prior beliefs about the triggers appeared to influence ratings of the strength of relationships between triggers and headache attacks.

Precipitating Factors and Outcome of Hepatorenal Syndrome in Liver Cirrhosis.

INTRODUCTION: Hepatorenal syndrome (HRS) is a functional renal failure due to intense renal vasoconstriction that frequently develops in patients with cirrhosis. Past studies reported that in almost half of the cases of HRS, one or more precipitating factors can be identified. We conducted a study to determine the Precipitating factors and outcome of hepatorenal Syndrome in liver cirrhosis. MATERIALS: This cross-sectional analytical study was conducted in tertiary care centre. A total of 62 consecutive patients admitted with HRS were included in this study. All adult patients admitted with diagnosis chronic liver disease with hepatorenal syndrome after applying exclusion criteria. The precipitants of HRS were correlated with the type of HRS; length of hospital stay and mortality. RESULT: Among the 62 subjects, 52% were alcoholics who were predominantly male and they had alcoholic cirrhosis. 21% and 16% were affected by hepatitis B and C respectively. Remaining 11% of them had non-alcoholic fatty liver disease. Bacterial infection and Large volume paracentesis had the longest duration of stay 16 ± 2 days and 12 deaths, GI bleed was around 12 ± 1 days and 4 deaths, ug induced HRS had 8 ± 2 days and 2 deaths, unknown factors were 5 ± 2 days. CONCLUSION: Patients presenting with two or more precipitating factors and advanced grade of HE had a prolonged hospital stay and increased mortality rate. Spontaneous bacterial infection was the most common precipitating factor at our centre. References Ginès A, Escorsell A, Ginès P, et al. Incidence, predictive factors, and prognosis of the hepatorenal syndrome in cirrhosis with ascites. Gastroenterology 1993;105(1):229-236. Arroyo V, Ginès P, Alexander L, et al. Definition and diagnostic criteria of refractory ascites and hepatorenal syndrome in cirrhosis. International Ascites Club. Hepatology 1996;23(1):164- 176.

The worn-out syndrome: Uncertainties in late working life triggering retirement decisions.

In recent decades, the extension of individuals' working life has been construed as an important policy issue in Western Europe. Here, retirement causes have been thoroughly researched in a quantitative way, but there is a dearth of qualitative studies on the subject. Through ethnographic fieldwork, we study the complex pathways that lead to the retirement of senior employees in the finance and production industries in Denmark. In particular in the finance industry, we find an insidious uncertainty haunting senior employees regarding their capacity and reputation. We term this uncertainty worn-out syndrome, demonstrating how many interlocutors fear that they are beginning to be seen as worn out, for example, less productive, less motivated, and too old to work. To some extent, this syndrome resembles the impostor syndrome, but it differs in one important aspect: the senior employees are mostly confident about their own skills. Worn-out syndrome is triggered by stereotypes and implicit ageist remarks by colleagues and managers. We show that the worn-out syndrome appears in at least three different ways: as a fear of already being worn out, as a fear of being perceived as worn out by colleagues and managers, and as a fear of becoming worn out in the future without realizing it in time. We argue that current retirement decisions are often fueled by this syndrome and that it leads to abrupt and untimely retirement decisions.

Intraoperative hypovolemia as a possible precipitating factor for pituitary apoplexy: a case report.

BACKGROUND: Pituitary apoplexy is acute infarction with or without hemorrhage of the pituitary gland. It is a rare but potentially life-threatening emergency that most commonly occurs in the setting of pituitary adenoma. The mechanisms underlying pituitary apoplexy are not well understood, but are proposed to include factors of both hemodynamic supply and adenoma demand. In the case of patients with known pituitary macroadenomas undergoing major surgery for other indications, there is a theoretically increased risk of apoplexy in the setting of "surgical stress." However, risk stratification of patients with nonfunctioning pituitary adenomas prior to major surgery is challenging because the precipitating factors for pituitary apoplexy are not completely understood. Here we present a case in which intraoperative hypovolemia is a possible mechanistic precipitating factor for pituitary apoplexy. CASE PRESENTATION: A 76-year-old patient with a known hypofunctioning pituitary macroadenoma underwent nephrectomy for renal cell carcinoma, during which there was significant intraoperative blood loss. He became symptomatic with ophthalmoplegia on the second postoperative day, and was diagnosed with pituitary apoplexy. He was managed conservatively with cortisol replacement therapy, and underwent therapeutic anticoagulation 2 months after pituitary apoplexy for deep vein thrombosis. His ophthalmoplegia slowly resolved over months of follow-up. Pituitary apoplexy did not recur with therapeutic anticoagulation. CONCLUSIONS: When considering the risk of surgery in patients with a known pituitary macroadenoma, an operation with possible high-volume intraoperative blood loss may have increased risk of pituitary apoplexy because intraoperative hypovolemia may precipitate ischemia, infarction, and subsequent hemorrhage. This may be particularly relevant in the cases of elective surgery. Additionally, we found that we were able to therapeutically anticoagulate a patient 2 months after pituitary apoplexy for the management of deep vein thrombosis without recurrence of pituitary apoplexy.

Implant connection and abutment selection as a predisposing and/or precipitating factor for peri-implant diseases: A review.

Peri-implant mucosal integration is becoming a critical aspect for long term implant health and can be triggered the selection of implant components. The aim of this review is therefore to investigate the evidence concerning implant connection and abutment characteristics (abutment materials, design, handling) as predisposing or precipitating factor for peri-implant mucositis and peri-implantitis. Although the evidence that these features can directly predispose/precipitate peri-implant diseases is limited, there are -few- studies showing a potential role of the implant connection, trans-mucosal configuration, and handling in the development of early bone loss and/or peri-implantitis. With bone level implants, conical internal connections (with inherent platform switching) might be preferred over internal flat-flat and external connections to decrease the risk of early bone loss and potentially the risk of peri-implant disease. Moreover, there is a trend suggesting moving the prosthetic interface coronally (to the juxta-mucosal level) as soon as possible to reduce the number of disconnections and to limit the risk of cements remnants. This can be achieved by choosing a tissue-level implant or to place a trans-mucosal abutment (one abutment-one time approach) to optimize the peri-implant soft tissue seal. In absence of evidence for the biocompatibility regarding several restorative materials, biocompatible materials such as titanium or zirconia should be preferred in the trans-mucosal portion. Finally, higher implants (≥2mm) with an emergence angle below 30° seem more favourable. It should however be noted that some of this information is solely based on indirect information (such as early bone loss) and more research is needed before making firm recommendations about abutment choice. [Correction added on 13 March 2023, after first online publication: 'longer implants (≥2mm)' was changed to 'higher implants (≥2mm)' in this version.].