Preoperative assessment of postoperative delirium: a cross-sectional study of patients and anesthesiologists in Canada.

PURPOSE: We sought to evaluate 1) patient- and anesthesiologist-reported rates of postoperative delirium (POD) risk discussion during preoperative meetings, 2) patients' and anesthesiologists' ratings of the importance of POD, and 3) predictors of patient-reported discussion of POD risk during preoperative meetings. METHODS: In this multicentre two-part cross-sectional survey study, patients ≥ 65 yr scheduled to undergo elective noncardiac surgery completed a five-minute survey after preoperative anesthesia consultation. Patients were asked about their perception of POD importance, and whether they discussed or were assessed for POD risk. Anesthesiologists were surveyed using self-administered surveys circulated via institutional email lists. Anesthesiologists were asked about the frequency of POD risk assessment and discussion in older adults, tools used, and perception of POD-screening barriers. RESULTS: Four hundred and twelve (of 510 approached) patients (50% male; mean age, 73 yr) and 267 anesthesiologists (of 1,205 invited via e-mail) participated in this study conducted in five Canadian hospitals. Postoperative delirium screening and discussion was reported by 88/412 (22%) patients and 229/267 (86%) anesthesiologists. Postoperative delirium was rated as "somewhat-extremely" important by 64% of patients. A previous history of delirium, higher education, the number of daily medications, and longer surgical duration were associated with POD discussion. On average, anesthesiologists rated the importance of POD at 8/10, and 42% ranked "patient risk factors" as the top reason prompting discussion. CONCLUSION: The combined evaluation of patients' and anesthesiologists' perspectives provides valuable information on preoperative POD screening and risk assessment, and highlights areas for improvement in the current practice. Most factors we identified to be associated with higher odds of POD discussion are recognized risk factors of POD.

RéSUMé: OBJECTIF: Nous avons cherché à évaluer 1) les taux de discussion concernant le risque de delirium postopératoire (DPO) déclarés par les patient·es et les anesthésiologistes lors des rencontres préopératoires, 2) les évaluations des patient·es et des anesthésiologistes de l'importance de DPO, et 3) les prédicteurs d'une discussion telle que rapportée par les patient·es sur le risque de DPO pendant les rencontres préopératoires. MéTHODE: Dans ce sondage transversal multicentrique en deux parties, les patient·es ≥ 65 ans devant subir une chirurgie non cardiaque non urgente ont rempli un sondage de cinq minutes après la consultation d'anesthésie préopératoire. Les patient·es ont été interrogé·es sur leur perception de l'importance du DPO et si leur risque de DPO avait été discuté ou évalué. Des sondages auto-administrés ont été distribués aux anesthésiologistes via les listes de courriels institutionnelles. Ce sondage interrogeait les anesthésiologistes quant à la fréquence de l'évaluation et de la discussion des risques de DPO chez les personnes âgées, aux outils utilisés et à la perception des obstacles au dépistage de DPO. RéSULTATS: Quatre cent douze (des 510 personnes approchées) patient·es (50 % d'hommes; âge moyen, 73 ans) et 267 anesthésiologistes (sur 1205 invité·es par courriel) ont participé à cette étude menée dans cinq hôpitaux canadiens. Le dépistage et la discussion sur le delirium postopératoire ont été signalés par 88/412 (22 %) des patient·es et 229/267 (86 %) des anesthésiologistes. Le delirium postopératoire a été jugé « assez ­ extrêmement ¼ important par 64 % des patient·es. Des antécédents de delirium, des études supérieures, le nombre de médicaments quotidiens et une durée chirurgicale plus longue ont été associés à la discussion sur le DPO. En moyenne, les anesthésiologistes ont évalué l'importance du DPO à 8/10, et 42 % ont classé les « facteurs de risque liés au/à la patient·e ¼ comme la principale raison suscitant la discussion. CONCLUSION: L'évaluation combinée des points de vue des patient·es et des anesthésiologistes fournit des informations précieuses sur le dépistage préopératoire des DPO et l'évaluation des risques, et met en évidence les domaines à améliorer dans la pratique actuelle. La plupart des facteurs que nous avons identifiés comme étant associés à des probabilités plus élevées de discussion sur le DPO sont des facteurs de risque reconnus de DPO.

Postoperative pain and pain management and neurocognitive outcomes after non-cardiac surgery: a protocol for a series of systematic reviews.

BACKGROUND: Postoperative delirium (POD) is common after non-cardiac surgery in older adults and can result in increased risk of adverse outcomes including postoperative cognitive dysfunction (POCD). Pain after surgery is also frequent and can persist as chronic postsurgical pain (CPSP). Evidence is inconsistent and controversial on whether acute and chronic postsurgical pain, and different postoperative pain management strategies (including opioid versus opioid-sparing strategies), is associated with the occurrence of POD and POCD. In this protocol, we propose a series of systematic reviews to answer the following research questions: In adults undergoing non-cardiac surgery, (1) is acute postsurgical pain associated with POD and/or POCD? (2) Are opioid-sparing/avoidance strategies of acute postoperative pain management associated with lower incidence and/or severity of POD and POCD, compared to predominantly opioid-based strategies? (3) Is CPSP associated with POCD? (4) Are opioid-sparing management strategies of CPSP associated with lower incidence and/or severity of POCD compared to standard of care or strategies not aiming at reduced opioid use? METHODS: We will search MEDLINE, EMBASE, Cochrane (CENTRAL), CINAHL, and PSYCHINFO. According to the research question, we will include cohort and case-control studies (questions 1 and 3) or randomized controlled trials and non-randomized studies (questions 2 and 4). The risk of bias will be assessed independently and in duplicate using the revised Cochrane risk-of-bias tool, the Newcastle-Ottawa Scale, and the Joanna-Briggs Institute critical appraisal checklist. Disagreements will be resolved by a third reviewer. Findings will be reported narratively, and where possible and appropriate, meta-analyses will be performed. Certainty of evidence will be assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. We will conduct the reviews in accordance with the guideline of the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols. DISCUSSION: Our systematic reviews will summarize available evidence to date on the association of postoperative pain and its management strategies with the incidence of POD and POCD in non-cardiac surgery. We will evaluate the existing evidence and its limitations and inform the design of future interventional studies comparing the effects of different pain management strategies on postoperative neurocognitive outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021192105.

Amino acid changes during transition to a vegan diet supplemented with fish in healthy humans.

PURPOSE: To explore whether changes in dietary protein sources can lower plasma branched-chain amino acids (BCAAs), aromatic amino acids and sulfur amino acids (SAAs) that are often elevated in the obese, insulin-resistant state and in type 2 diabetes. METHODS: Thirty-six subjects (mean age 31 ± 2 years) underwent a voluntary abstinence from meat, poultry, eggs, and dairy products for 6 weeks, while enriching the diet with fish, in fulfillment of a religious fast. Subjects were assessed 1 week before the fast (V1), 1 week after initiation of the fast (V2) and in the last week of the fast (V3). Thirty-four subjects completed all three visits. RESULTS: Fasting plasma BCAAs decreased at V2 and remained low at V3 (P < 0.001 for all). Valine showed the greatest decline, by 20 and 19 % at V2 and V3, respectively. Phenylalanine and tryptophan, but not tyrosine, also decreased at V2 and V3. The two proteinogenic SAAs, methionine and cysteine, remained stable, but the cysteine product, taurine, decreased from 92 ± 7 µmol/L to 66 ± 6 (V2; P = 0.003) and 65 ± 6 µmol/L (V3; P = 0.003). A progressive decline in plasma glutamic acid, coupled with an increase in glutamine, was observed. Plasma total and LDL cholesterol decreased at V2 and V3 (P < 0.001 for all). CONCLUSION: Changing dietary protein sources to plant- and fish-based sources in an ad libitum setting lowers the plasma BCAAs that have been linked to diabetes risk. These findings point to habitual diet as a potentially modifiable determinant of fasting plasma BCAA concentrations.

The Impact of Selective Dopamine D2, D3 and D4 Ligands on the Rat Gambling Task.

Gambling is an addictive disorder with serious societal and personal costs. To-date, there are no approved pharmacological treatments for gambling disorder. Evidence suggests a role for dopamine in gambling disorder and thus may provide a therapeutic target. The present study therefore aimed to investigate the effects of selective antagonists and agonists of D2, D3 and D4 receptors in a rodent analogue of the Iowa gambling task used clinically. In this rat gambling task (rGT), animals are trained to associate different response holes with different magnitudes and probabilities of food pellet rewards and punishing time-out periods. As in the Iowa gambling task, the optimal strategy is to avoid the tempting high-risk high-reward options, and instead favor those linked to smaller per-trial rewards but also lower punishments, thereby maximizing the amount of reward earned over time. Administration of those selective ligands did not affect decision making under the rGT. Only the D4 drug had modest effects on latency measures suggesting that D4 may contribute in some ways to decision making under this task.

Dopamine D3 receptors in the basolateral amygdala and the lateral habenula modulate cue-induced reinstatement of nicotine seeking.

Dopamine D3 receptors are implicated in cue-induced relapse to drug seeking. We have previously shown that systemic administration of a selective D3 antagonist reduces cue-induced reinstatement of nicotine seeking in rats. The current study sought to investigate potential neural substrates mediating this effect. The D3 antagonist SB-277011-A (0.01-1 µg/0.5 µl/side) infused into the basolateral amygdala or the lateral habenula, but not the nucleus accumbens, significantly attenuated cue-induced reinstatement of nicotine seeking. Moreover, infusion of SB-277011-A (1 µg/0.5 µl/side) into the basolateral amygdala or lateral habenula had no effect on food self-administration. Together with the finding that systemic SB-277011-A had no effect on extinction responding, this suggests that the effects observed here were on reinstatement and cue seeking, and not due to nonspecific motor activation or contextual-modified residual responding. The further finding of binding of [(125)I]7-OH-PIPAT to D3 receptors in the lateral habenula and in the basolateral amygdala is consistent with an important role of D3 receptors in these areas in nicotine seeking. It was also found that systemic administration of the selective D2 antagonist L741626 decreased cue-induced reinstatement, consistent with a role of D2 and D3 receptors in modulating this behavior. The current study supports an important role for D3 receptors in the basolateral amygdala and lateral habenula in cue-induced reinstatement.

Varenicline decreases nicotine self-administration and cue-induced reinstatement of nicotine-seeking behaviour in rats when a long pretreatment time is used.

Effects of varenicline (Champix), a nicotinic partial agonist, were evaluated on subjective effects of nicotine (drug discrimination), motivation for nicotine taking (progressive-ratio schedule of intravenous nicotine self-administration) and reinstatement (cue-induced reinstatement of previously extinguished nicotine-seeking behaviour). Effects on motor performance were assessed in rats trained to discriminate nicotine (0.4 mg/kg) from saline under a fixed-ratio (FR 10) schedule of food delivery and in rats trained to respond for food under a progressive-ratio schedule. At short pretreatment times (5-40 min), varenicline produced full or high levels of partial generalization to nicotine's discriminative-stimulus effects and disrupted responding for food, while there were low levels of partial generalization and no disruption of responding for food at 2- or 4-h pretreatment times. Varenicline (1 and 3 mg/kg, 2-h pretreatment time) enhanced discrimination of low doses of nicotine and to a small extent decreased discrimination of the training dose of nicotine. It also dose-dependently decreased nicotine-taking behaviour, but had no effect on food-taking behaviour under progressive-ratio schedules. Finally, varenicline significantly reduced the ability of a nicotine-associated cue to reinstate extinguished nicotine-seeking behaviour. The ability of varenicline to reduce both nicotine-taking and nicotine-seeking behaviour can contribute to its relatively high efficacy in treating human smokers.

The selective dopamine D3 receptor antagonist SB 277011-A, but not the partial agonist BP 897, blocks cue-induced reinstatement of nicotine-seeking.

The dopamine D3 receptor (DRD3) has been suggested to be involved in the mechanisms underlying stimulus-controlled drug-seeking behaviour. Ligands acting as DRD3 antagonists (SB 277011-A) or DRD3 partial agonists (BP 897) have shown some promise for reducing the influence of drug-associated cues on motivational behaviour. Here, effects of SB 277011-A and BP 897 were evaluated on cue-induced reinstatement of nicotine-seeking in rats. The effects of BP 897 on nicotine self-administration under a fixed-ratio 5 (FR5) schedule of reinforcement were also evaluated. SB 277011-A (1-10 mg/kg) was able to block cue-induced reinstatement of nicotine-seeking, indicating that DRD3 selective antagonism may be an effective approach to prevent relapse for nicotine. In contrast, BP 897 did not block the cue-induced reinstatement of nicotine-seeking or nicotine-taking under the FR5 schedule. In a control study, rats did not respond to the light stimuli without nicotine delivery, indicating that the responding for the drug-associated cues was induced by the previous pairing of light stimuli with nicotine's effects. These findings validate the role of DRD3 on reactivity to drug-associated stimuli and suggest that the DRD3 antagonist, but perhaps not the DRD3 partial agonist, could be used to prevent relapse in tobacco smokers.