Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Four Failures of Deliberating Groups

Many groups make their decisions through some process of deliberation, usually with the belief that deliberation will improve judgments and predictions. But deliberating groups often fail, in the sense that they make judgments that are false or that fail to take advantage of the information that their members have. There are four such failures. (1) Sometimes the predeliberation errors of group members are amplified, not merely propagated, as a result of deliberation. (2) Groups may fall victim to cascade effects, as the judgments of initial speakers or actors are followed by their successors, who do not disclose what they know. Nondisclosure, on the part of those successors, may be a product of either informational or reputational cascades. (3) As a result of group polarization, groups often end up in a more extreme position in line with their predeliberation tendencies. Sometimes group polarization leads in desirable directions, but there is no assurance to this effect. (4) In deliberating groups, shared information often dominates or crowds out unshared information, ensuring that groups do not learn what their members know. All four errors can be explained by reference to informational signals, reputational pressure, or both. A disturbing result is that many deliberating groups do not improve on, and sometimes do worse than, the predeliberation judgments of their average or median member

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Cryopreservation of Day 8 equine embryos after blastocyst micromanipulation and vitrification

Pregnancy rates after cryopreservation of large equine blastocyst stage embryos have remained lower than other domesticated livestock species. It is generally accepted that the embryonic capsule is the primary barrier to cryoprotectant entry into the embryo proper and techniques need to be developed to circumvent this obstacle. Therefore, the objective of this study was to develop an efficient Day 8 equine embryo cryopreservation protocol through blastocyst micromanipulation and vitrification. Grade 1 and 2 embryos recovered from mares (n = 15) 8 days after ovulation were used in these experiments. In experiment 1, the effect of either one- or two-puncture treatments before aspiration of blastocoel fluid and exposure to vitrification solutions was evaluated. No difference was detected in mean embryo volume across treatment groups after exposure to vitrification solutions or after 1, 24, 48, and 72 hours of culture. Percent of embryos re-expanding at 24 hours and percent of embryos showing diameter increase at 48 and 72 hours during in vitro culture were 100%, 83%, and 75% compared with 93%, 67%, and 50% for one- and two-puncture treatment groups, respectively. Capsule loss was 25% for one-puncture and 50% for two-puncture treatment groups. In experiment 2, no difference was detected in mean embryo volume for indirect introduction (aspiration of blastocoel fluid + equilibration) and direct introduction (injection of cryoprotectant into blastocoel cavity) treatment groups, after exposure to dilution solution or to culture medium. There was no difference in mean embryo volume for the indirect and direct introduction treatment groups after 1, 24, 48, and 72 hours of culture. Percent of embryos re-expanding at 24 hours and percent of embryos showing diameter increases at 48 and 72 hours during in vitro culture were 100%, 76.9%, and 69.2%, respectively, for both treatment groups. Those embryos subjected to the direct introduction treatment had a higher (P = 0.05) percent capsule loss (70%) compared with the indirect introduction treatment group (31%). The pregnancy rate after transfer of vitrified expanded Grade 1 blastocysts using the indirect introduction method was 83% (5/6). Three pregnancies were allowed to continue to term and resulted in the birth of three healthy foals. The vitrification protocol used in this study has the potential to become a key tool for the successful cryopreservation of equine expanded blastocysts

The relationship between body condition score and ultrasonic fat measurements in mares of high versus low body condition

This study was conducted to correlate body condition score (BCS) in mares with ultrasonic measurements of subcutaneous fat taken at four locations (tailhead, rump, 13th rib, and withers), and to determine which site might be the most reliable area of measurement. Twenty-four light horse mares were assigned to either a high BCS group (8.0-9.0) or a low BCS group (3.0-3.5). From September to December 1999, mares were full grazed or restricted to reach their respective target BCS; they were then maintained at that BCS until the following May. Ultrasonic fat measurements were recorded every 14 days from September to May. Over time, mares in the low BCS group lost subcutaneous fat and mares in the high BCS group deposited subcutaneous fat at all four locations (P \u3c .02). In both the high and low BCS groups, subcutaneous fat at the rump changed much less over the course of the experiment than did the amount of subcutaneous fat at the tailhead, 13th rib, and withers. Correlation coefficients (r) between BCS and subcutaneous fat thickness were: 0.87, 0.84, 0.82, and 0.86 for the tailhead, rump, 13th rib, and withers, respectively. The tailhead area accounted for the majority of the variation in BCS (R2 = 0.75). Overall, 78% of the variation could be accounted for when the 13th rib and withers were combined with the tailhead; however, the rump did not significantly contribute or account for variation. This study shows that body condition score and subcutaneous fat measurements are correlated, especially at the tailhead area. Application of the system developed by Henneke et al, 1 with particular emphasis on the amount of fat in areas such as the tailhead, 13th rib, and withers, can provide an accurate estimate of the condition and/or body fat content of a mare

Pregnancy Rates Following Low-Temperature Storage of Large Equine Embryos Before Vitrification

© 2018 Elsevier Inc. Satisfactory pregnancy rates can now be achieved following the cryopreservation of large equine embryos. Nonetheless, its wide application might be limited by the fact that the cryopreservation of large equine embryos requires a specialized micromanipulation equipment and micromanipulation/vitrification skills. Alternatives should be developed to increase its utilization and widespread application in the commercial equine industry. To determine if large equine embryos are able to remain viable during transport from farms to specialized centers for embryo cryopreservation, we evaluated pregnancy rates following the low-temperature storage of large equine embryos before vitrification. Grade 1 embryos (n = 37) were randomly assigned to six treatments consisting of day of collection (Day 7 or 8 after ovulation) and cooling for 0, 12, or 24 hours before vitrification in a factorial design. Pregnancy rates of Day 7 embryos cooled for 12 and 24 hours were 55.5% and 75%, respectively. Pregnancy rates of Day 8 embryos cooled for 12 and 24 hours were 0 and 16.6%, respectively. Day 7 cooled embryos resulted in higher pregnancy rate compared with Day 8 cooled embryos (64.7% and 7.7%, respectively; P \u3c.05). Pregnancy rate comparison of cooled embryos grouped by diameter showed that embryos \u3c550 μm resulted in a higher pregnancy rate compared with embryos \u3e550 μm (71.4% and 12.5% respectively; P \u3c.05). In conclusion, Day 7 equine embryos up to 550 μm can be cooled to temperatures of 9–12°C for 12 or 24 hours before vitrification and result in satisfactory pregnancy rates

Sex ratio of bovine embryos and calves originating from the left and right ovaries

An asymmetric distribution of the sexes within the left and right uterine horns has been described in multiple species. A series of experiments were conducted to evaluate the sex ratio (% male) of calves gestated in the left and right uterine horns, as well as the sex ratio of embryos originating from the left and right ovaries of cattle. The sex ratio of calves gestated in the right uterine horn of naturally mated cows was significantly higher compared with the sex ratio of calves gestated in the left uterine horn. In addition, the sex ratio of the left and right uterine horns differed significantly from parity. The sex ratio of embryo transfer calves born following transfer to the left and right uterine horns was not significantly different. Additionally, the proportion of male embryos collected from the right uterine horns was significantly greater than from the left uterine horns of superovulated cows. The sex ratio of embryos collected from the left and right uterine horns of unilaterally ovariectomized cows was not significantly different. However, more female than male embryos were produced when left ovary oocytes fertilized in vitro. In conclusion, the results of these experiments demonstrate that a significantly greater proportion of males are gestated in the right uterine horn of cattle and a greater proportion of females in the left. Additionally, the data indicate that sex-specific selection pressure may be applied to embryos by ovarian factors rather than by the uterine environment. © 2009 by the Society for the Study of Reproduction, Inc

Evaluation of Capsule Permeability in the Equine Blastocyst

Recipient pregnancy rates following transfer of frozen-thawed blastocyst stage equine embryos remain low. To date, no protocol has been developed that would allow successful cryopreservation of this stage of embryos. These experiments characterized the amount of glycerol entering equine embryos after incubation in 1.4 M and 3.4 M glycerol solutions using tritiated glycerol and a liquid scintillation counter. Blastocyst stage equine embryos (n = 27) were collected and incubated for 15 minutes in either 1.4 M (n = 14) or 3.4 M (n = 13) tritiated glycerol solutions. Disintegrations per minute were then determined, and the percent glycerol uptake was calculated for each embryo. Percent glycerol uptake for 1.4 M or 3.4 M glycerol treatment groups was not different (P = .68). However, it was higher (P = .05) in embryos with a diameter of ≤600 μm (3.6%) compared with embryos with a diameter of \u3e600 μm (0.4%). We concluded that glycerol more readily permeates into embryos with a diameter of ≤600 μm that do not possess a fully functional capsule compared with embryos with a diameter of \u3e600 μm with a fully formed capsule. © 2012 Elsevier Inc