Preoperative Screening at the Outpatient Clinic: Predicting cardiac risk in noncardiac surgery

The first chapter of this thesis analyzes perioperative cardiovascular mortality in noncardiac surgery at the Erasmus Medical Center, Rotterdam, The Netherlands. The performance of Lee et al’s index in predicting perioperative cardiovascular mortality is validated in a 10-year surgical cohort of patients undergoing noncardiac surgery. Based on the results of chapter one, the analysis of perioperative mortality risk factors is continued in chapter two. In this chapter, over one million Dutch patients undergoing noncardiac surgery between 1991-2002 were studied. The influence of well known perioperative risk factors in high risk patients was analyzed in the general noncardiac surgical population, and the impact of surgery related risk on perioperative mortality was further clarified. The total cohort was used to derive and validate a newly constructed perioperative risk index to accurately predict all-cause mortality in noncardiac surgery

Neural Correlates of Intentional Communication

We know a great deal about the neurophysiological mechanisms supporting instrumental actions, i.e., actions designed to alter the physical state of the environment. In contrast, little is known about our ability to select communicative actions, i.e., actions directly designed to modify the mental state of another agent. We have recently provided novel empirical evidence for a mechanism in which a communicator selects his actions on the basis of a prediction of the communicative intentions that an addressee is most likely to attribute to those actions. The main novelty of those findings was that this prediction of intention recognition is cerebrally implemented within the intention recognition system of the communicator, is modulated by the ambiguity in meaning of the communicative acts, and not by their sensorimotor complexity. The characteristics of this predictive mechanism support the notion that human communicative abilities are distinct from both sensorimotor and linguistic processes

Brain Mechanisms Underlying Human Communication

Human communication has been described as involving the coding-decoding of a conventional symbol system, which could be supported by parts of the human motor system (i.e. the “mirror neurons system”). However, this view does not explain how these conventions could develop in the first place. Here we target the neglected but crucial issue of how people organize their non-verbal behavior to communicate a given intention without pre-established conventions. We have measured behavioral and brain responses in pairs of subjects during communicative exchanges occurring in a real, interactive, on-line social context. In two fMRI studies, we found robust evidence that planning new communicative actions (by a sender) and recognizing the communicative intention of the same actions (by a receiver) relied on spatially overlapping portions of their brains (the right posterior superior temporal sulcus). The response of this region was lateralized to the right hemisphere, modulated by the ambiguity in meaning of the communicative acts, but not by their sensorimotor complexity. These results indicate that the sender of a communicative signal uses his own intention recognition system to make a prediction of the intention recognition performed by the receiver. This finding supports the notion that our communicative abilities are distinct from both sensorimotor processes and language abilities

Cerebral coherence between communicators marks the emergence of meaning

How can we understand each other during communicative interactions? An influential suggestion holds that communicators are primed by each other’s behaviors, with associative mechanisms automatically coordinating the production of communicative signals and the comprehension of their meanings. An alternative suggestion posits that mutual understanding requires shared conceptualizations of a signal’s use, i.e., “conceptual pacts” that are abstracted away from specific experiences. Both accounts predict coherent neural dynamics across communicators, aligned either to the occurrence of a signal or to the dynamics of conceptual pacts. Using coherence spectral-density analysis of cerebral activity simultaneously measured in pairs of communicators, this study shows that establishing mutual understanding of novel signals synchronizes cerebral dynamics across communicators’ right temporal lobes. This interpersonal cerebral coherence occurred only within pairs with a shared communicative history, and at temporal scales independent from signals’ occurrences. These findings favor the notion that meaning emerges from shared conceptualizations of a signal’s use

Perioperative care of the older patient

Nearly 60% of the Dutch population undergoing surgery is aged 65 years and over. Older patients are at increased risk of developing perioperative complications (e.g., myocardial infarction, pneumonia, or delirium), which may lead to a prolonged hospital stay or death. Preoperative risk stratification calculates a patient's risk by evaluating the presence and extent of frailty, pathophysiological risk factors, type of surgery, and the results of (additional) testing. Type of anesthesia, fluid management, and pain management affect outcome of surgery. Recent developments focus on multimodal perioperative care of the older patient, using minimally invasive surgery, postoperative anesthesiology rounds, and early geriatric consultation

Frailty and functional outcomes after open and endovascular procedures for patients with peripheral arterial disease:A systematic review

Background: Frailty has been associated with postoperative complications and mortality across surgical specialties, including vascular surgery. However, the influence of frailty on postoperative functional outcomes is unclear. We sought to determine the influence of frailty on functional outcomes after open or endovascular vascular procedures in patients with peripheral arterial disease. Methods: This systematic review was conducted according to the PRISMA guidelines. Eligible articles were identified through database searches of Pubmed and EMBASE in April 2017. Studies reporting on frailty and functional outcomes after vascular interventions for peripheral artery disease (PAD) were included. Outcomes of interest were dependency in activities of daily living (ADL), dependent mobility, discharge destination, disability-free survival, and quality of life. Individual studies were assessed for quality and risk of bias using the Quality in Prognosis Studies tool. Results: Eight studies met the eligibility criteria and were included. The risk of bias was low in two studies, intermediate in three studies, and high in three studies. Methods for frailty assessment were different for each study. Frailty was a predictor for discharge to a higher level of care, dependent mobility, and dependency in ADL after vascular procedures for PAD. Both frailty models and individual frailty characteristics seem to be associated with these adverse functional outcomes. Conclusions: Despite a limited amount of literature and an overall intermediate quality of the included studies, this systematic review shows an association between frailty and adverse functional outcomes after peripheral arterial procedures for PAD, including discharge to a care facility, dependent mobility, and a decline in ADL functioning

COVID-19 vaccination in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by low platelet count and increased bleeding risk. COVID-19 vaccination has been described as risk factor for de novo ITP, but the effects of COVID-19 vaccination in patients with ITP are unknown. Our aims were to investigate the effects of COVID-19 vaccination in ITP patients on platelet count, bleeding complications and ITP exacerbation (any of: ≥50% decline in platelet count; or nadir platelet count 20% decrease from baseline; or use of rescue therapy). Platelet counts of ITP patients and healthy controls were collected immediately before, 1 and 4 weeks after first and second vaccination. Linear mixed-effects modelling was applied to analyze platelet counts over time. We included 218 ITP patients (50.9% female, mean age 55 years and median platelet count of 106x109/L) and 200 healthy controls (60.0% female, mean age 58 years and median platelet count of 256x109/L). Platelet counts decreased by 6.3% after vaccination. We observed no difference in decrease between the groups. Thirty ITP patients (13.8%, 95%CI 9.5%-19.1%) had an exacerbation and 5 (2.2%, 95%CI 0.7%-5.3%) suffered from a bleeding event. Risk factors for ITP exacerbation were platelet count <50x109/L (OR 5.3, 95%CI 2.1-13.7), ITP treatment at time of vaccination (OR 3.4, 95%CI 1.5-8.0) and age (OR 0.96 per year, 95%CI 0.94-0.99). Our study highlights safety of COVID-19 vaccination in ITP patients and importance of close monitoring platelet counts in a subgroup of ITP patients. ITP patients with exacerbation responded well on therapy

Preoperative anaemia and outcome after elective cardiac surgery:a Dutch national registry analysis

Background: Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery. Methods: A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis. Results: In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4–1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3–1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4–2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction. Conclusions: Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes