Building computational virtual reality environment for anesthesia

In this paper, a Computational Virtual Reality Environment for Anesthesia (CVREA) is proposed. Virtual reality, data mining, machine learning techniques will be explored to develop (1) an immersive and interactive training platform for anaesthetists, which can greatly improve their training and learning performance; (2) a knowledge learning environment which collects clinical data with greater richness, process data with more efficacy, and facilitate knowledge discovery in anaesthesiology.

Dietary omega 3 fatty acids decrease intraocular pressure with age by increasing Aqueous outflow

Purpose: To determine whether there is an association between dietary omega-3 (ω-3) fatty acid intake, age, and intraocular pressure (IOP) caused by altered aqueous outflow. Methods: Sprague–Dawley rats were fed either ω-3–sufficient (ω-3⁺) or ω-3–deficient (ω-3^–) diets from conception. The diets had 7% lipid content. The ω-3⁺ diet contained safflower, flaxseed, and tuna oils (5.5:1.0:0.5), and the ω-3^– diet contained safflower oil only. Intraocular pressure was measured at 5 to 40 weeks of age under light anesthesia (ω-3⁺, n = 39; ω-3^–, n = 48). Aqueous outflow was determined at 45 weeks in a subgroup of animals (ω-3⁺, n = 15;ω-3^–, n = 22) using pulsed infusion. Ciliary body tissues (n = 6 per group) were assayed for fatty acid content by thin-layer and gas-liquid chromatography in both diet groups. Results: Animals raised on ω-3⁺ diets had a 13% decrease in IOP at 40 weeks of age (13.48 ± 0.32 mm Hg vs. 15.46 ± 0.29 mm Hg; P < 0.01). When considered as a change in IOP relative to 5 weeks of age, the ω-3⁺ group showed a 23% decrease (P < 0.001). This lower IOP in the ω-3⁺ diet group was associated with a significant increase (+56%; P < 0.001) in outflow facility and a decrease in ocular rigidity (–59%; P < 0.001). The ω-3⁺ group showed a 3.3 times increase in ciliary body docosahexaenoic acid (P < 0.001). Conclusions: Increasing dietary ω-3 reduces IOP with age because of increased outflow facility, likely resulting from an increase in docosanoids. This indicates that dietary manipulation may provide a modifiable factor for IOP regulation. However, further studies are needed to consider whether this can modify the risk for glaucoma and can play a role in treatment of the disease.

Horizons revealed : post anaesthetic nurse care for prisoner-patients

This qualitative study revealed the experiences of registered nurses who cared for prisoner-patients in a major public hospital setting. The study found that caring for prisoner-patients is an emotionally draining experience where knowing or imagining the prisoner-patient's crime subtly provokes registered nurses to give reactive and perfunctory care that straddles real and ideal perspectives.

Altered responsiveness of the kidney to activation of the renal nerves in fat-fed rabbits

We tested whether mild adiposity alters responsiveness of the kidney to activation of the renal sympathetic nerves. After rabbits were fed a high-fat or control diet for 9 wk, responses to reflex activation of renal sympathetic nerve activity (RSNA) with hypoxia and electrical stimulation of the renal nerves (RNS) were examined under pentobarbital anesthesia. Fat pad mass and body weight were, respectively, 74% and 6% greater in fat-fed rabbits than controls. RNS produced frequency-dependent reductions in renal blood flow, cortical and medullary perfusion, glomerular filtration rate, urine flow, and sodium excretion and increased renal plasma renin activity (PRA) overflow. Responses of sodium excretion and medullary perfusion were significantly enhanced by fat feeding. For example, 1 Hz RNS reduced sodium excretion by 79 ± 4% in fat-fed rabbits and 46 ± 13% in controls. RNS (2 Hz) reduced medullary perfusion by 38 ± 11% in fat-fed rabbits and 9 ± 4% in controls. Hypoxia doubled RSNA, increased renal PRA overflow and medullary perfusion, and reduced urine flow and sodium excretion, without significantly altering mean arterial pressure (MAP) or cortical perfusion. These effects were indistinguishable in fat-fed and control rabbits. Neither MAP nor PRA were significantly greater in conscious fat-fed than control rabbits. These observations suggest that mild excess adiposity can augment the antinatriuretic response to renal nerve activation by RNS, possibly through altered neural control of medullary perfusion. Thus, sodium retention in obesity might be driven not only by increased RSNA, but also by increased responsiveness of the kidney to RSNA.

Taking the sting out of darting : Risks, restraint drugs and procedures for the chemical restraint of Southern Hemisphere otariids

The need to manage otariid populations has necessitated the development of a wide range of capture methods. Chemical restraint by remote drug delivery (i.e., darting) is a highly selective method that can be used to facilitate otariid capture in a range of scenarios, when other methods may be impracticable. However, the risks associated with darting otariids are not widely known and guidelines necessary to promote and refine best practice do not exist. We review the risks associated with darting and in light of our findings, develop darting guidelines to help practitioners assess and minimize risks during capture, anesthesia and recovery. Published studies reveal that mortalities associated with darting predominantly result from complications during anesthetic maintenance (e.g., prolonged respiratory depression, apnea, or hyperthermia), rather than from complications during capture or recovery. In addition to monitoring vital signs and proper intervention, the risk of irreversible complications during anesthesia can be reduced by administering drug doses that are sufficient to enable the capture and masking of animals, after which anesthetic depth can be regulated using gas anesthesia.

Toward a standard approach to measurement and reporting of perioperative mortality rate as a global indicator for surgery

INTRODUCTION: The proportion of patients who die during or after surgery, otherwise known as the perioperative mortality rate (POMR), is a credible indicator of the safety and quality of operative care. Its accuracy and usefulness as a metric, however, particularly one that enables valid comparisons over time or between jurisdictions, has been limited by lack of a standardized approach to measurement and calculation, poor understanding of when in relation to surgery it is best measured, and whether risk-adjustment is needed. Our aim was to evaluate the value of POMR as a global surgery metric by addressing these issues using 4, large, mixed, surgical datasets that represent high-, middle-, and low-income countries. METHODS: We obtained data from the New Zealand National Minimum Dataset, the Geelong Hospital patient management system in Australia, and purpose-built surgical databases in Pietermaritzburg, South Africa, and Port Moresby, Papua New Guinea. For each site, we calculated the POMR overall as well as for nonemergency and emergency admissions. We assessed the effect of admission episodes and procedures as the denominator and the difference between in-hospital POMR and POMR, including postdischarge deaths up to 30 days. To determine the need for risk-adjustment for age and admission urgency, we used univariate and multivariate logistic regression to assess the effect on relative POMR for each site. RESULTS: A total of 1,362,635 patient admissions involving 1,514,242 procedures were included. More than 60% of admissions in Pietermaritzburg and Port Moresby were emergencies, compared with less than 30% in New Zealand and Geelong. Also, Pietermaritzburg and Port Moresby had much younger patient populations (P < .001). A total of 8,655 deaths were recorded within 30 days, and 8-20% of in-hospital deaths occurred on the same day as the first operation. In-hospital POMR ranged approximately 9-fold, from 0.38 per 100 admissions in New Zealand to 3.44 per 100 admissions in Pietermaritzburg. In New Zealand, in-hospital 30-day POMR underestimated total 30-day POMR by approximately one third. The difference in POMR if procedures were used instead of admission episodes ranged from 7 to 70%, although this difference was less when central line and pacemaker insertions were excluded. Age older than 65 years and emergency admission had large, independent effects on POMR but relatively little effect in multivariate analysis on the relative odds of in-hospital death at each site. CONCLUSION: It is possible to collect POMR in countries at all level of development. Although age and admission urgency are strong, independent associations with POMR, a substantial amount of its variance is site-specific and may reflect the safety of operative and anesthetic facilities and processes. Risk-adjustment is desirable but not essential for monitoring system performance. POMR varies depending on the choice of denominator, and in-hospital deaths appear to underestimate 30-day mortality by up to one third. Standardized approaches to reporting and analysis will strengthen the validity of POMR as the principal indicator of the safety of surgery and anesthesia care.