Vagus nerve damage increases alcohol intake and preference in a nonpreferring rat line: Relationship to vagal regulation of the hypothalamic-pituitary-adrenal axis.

BACKGROUND: Clinical and preclinical research indicates that gastric weight loss surgeries, such as Roux-en-Y gastric bypass surgery, can induce alcohol use disorder (AUD). While numerous mechanisms have been proposed for these effects, one relatively unexplored potential mechanism is physical damage to the gastric branch of the vagus nerve, which can occur during bypass surgery. Therefore, we hypothesized that direct damage to the gastric branch of the vagus nerve, without altering other aspects of gastric anatomy, could result in increased alcohol intake. METHODS: To test this hypothesis, we compared alcohol intake and preference in multiple models in male Sprague-Dawley rats that received selective gastric branch vagotomy (VX) with rats who underwent sham surgery. Because the vagus nerve regulates hypothalamic-pituitary-adrenal (HPA) axis function, and alterations to HPA function are critical to the escalation of non-dependent alcohol intake, we also tested the hypothesis that gastric VX increases HPA function. RESULTS: We found that VX increases alcohol intake and preference in the every-other-day, two-bottle choice test and increases preference for 1 g/kg alcohol in the conditioned place preference test. The effects were selective for alcohol, as sucrose intake and preference were not altered by VX. We also found that VX increases corticotropin releasing factor (CRF) mRNA in the paraventricular nucleus of the hypothalamus (PVN), increases putative PVN CRF neuronal action potential firing, and increases corticosterone levels. CONCLUSIONS: Overall, these findings suggest that the vagus nerve may play a critical role in regulating HPA axis function via modulation of PVN CRF mRNA expression and putative PVN CRF neuronal activity. Furthermore, disruptions to vagal regulation of HPA axis function may increase alcohol intake and preference.

Nurse anesthetists' preferences for anesthesiologists' participation in patient care at a large teaching hospital.

STUDY OBJECTIVE: Certified registered nurse anesthetists (CRNAs) can evaluate anesthesiologists with whom they work clinically using a psychometrically reliable and valid scale. Use of such a scale to evaluate performance depends on knowing thresholds for minimum and ideal anesthesiologist performance. DESIGN: Cohort study. SETTING: One large teaching hospital. MEASUREMENTS: 379 CRNA evaluations of anesthesiologists' performance, and associated thresholds for minimum and ideal scores, performed over 15 weeks. MAIN RESULTS: The anesthesiologists' performance score was less than the CRNA's minimum score for the evaluation (i.e., too little anesthesiologist participation in patient care) for 25% (95) of the CRNA evaluations. The score was greater than the CRNA's ideal score for the evaluation (i.e., excessive participation in patient care) for 28% (106) of evaluations. Anesthesiologists' performance was assessed as not meeting expectations 53% of the time. Even if every anesthesiologist performed consistently at the same level, ≥50% of CRNAs would have been dissatisfied (187), not significantly different from observed (P = 0.34). Consistent results were found when the unit of analysis was individual CRNA. Among the 22 CRNAs who provided ≥10 evaluations, the median level of anesthesiologist performance was either less than the individual CRNA's mean minimum acceptable performance (8/22) or greater than their mean ideal performance (9/22), with overall dissatisfaction, 77%. Among the CRNA-anesthesiologist pairs working together, most did so less than once per month (76%, 1242/1635). CONCLUSIONS: In this single-center study at a large teaching hospital, broad heterogeneity among CRNAs in their expectations for anesthesiologist collaborative practice was found. Anesthesiologists adjusting their behavior based on individual CRNA preferences was impractical because specific CRNA-anesthesiologist pairs work together infrequently. Future studies should examine consistency among organizations and whether changes in expectations, and perhaps less dissatisfaction, can be achieved by communication of results for CRNA preferences for anesthesiologists' participation in patient care and discussing shared expectations among the CRNAs and anesthesiologists.

Nurse anesthetists' evaluations of anesthesiologists' operating room performance are sensitive to anesthesiologists' years of postgraduate practice.

STUDY OBJECTIVE: The first aim of this study was to test whether a 7 item evaluation scale developed by our department's certified registered nurse anesthetists (CRNAs) was psychometrically reliable. The second aim was to test whether anesthesiologists' performance changed with their years of postgraduate experience. DESIGN, SETTING, MEASUREMENTS: Sixty-two University of Iowa CRNAs evaluated 81 anesthesiologists during one weekend. Anesthesiologists' scores were adjusted for CRNA rater leniency. Anesthesiologists' scores were tested for sensitivity to CRNA-anesthesiologist case-specific variables. Scores also were tested against anesthesiologists' years of postgraduate experience. The latter association was tested for sensitivity to case-specific variables, anesthesiologists' clinical supervision scores provided by residents, and anesthesiologist clinical assignment variables. MAIN RESULTS: The 7 items demonstrated a single-factor structure, allowing calculation of mean score over the 7 items. Individual anesthesiologist scores were reliable when scores were provided by at least 10 different CRNAs. Anesthesiologists' scores (mean 3.34 [SD 0.41]) were not affected by the interval since last CRNA-anesthesiologist interaction, number of interactions, or case-specific variables. There was a negative association between leniency-adjusted anesthesiologist scores and years of anesthesiologist postgraduate practice (coefficient -0.20 per decade, t = -19.39, P < 0.0001). The association remained robust when accounting for case-specific variables, resident clinical supervision scores, and overall clinical assignment variables. CONCLUSIONS: Anesthesiologists' operating room performance can be evaluated reliably by non-physician anesthesia providers (CRNAs). The evaluation process can be done reliably and validly using an assessment scale consisting of only a few (<10) items and with evaluations by only a few individuals (≥10 CRNA raters). There is no indication evaluations provided by CRNAs were significantly influenced by the interval between interaction and evaluation, number of interactions, or other case-specific variables. From CRNAs' perspectives, on average, as anesthesiologists gain experience, anesthesiologists' behaviors in the operating room change, providing CRNAs with less direct assistance in patient care.