Spatial patterns of the surf zone hyperbenthic fauna of Valdivia Bay (Ecuador)

The present research is a first attempt to study the hyperbenthic fauna of the surf zone of Valdivia Bay (South East Pacific - Ecuador), an exposed low tide terrace - rip beach. The aims of the study were to contribute to the inventory of the surf zone fauna of the tropical southeast Pacific coast, to investigate spatial distribution patterns along the bay and to search for possible tidal effects on the hyperbenthic composition. Samples were taken during daylight with a hyperbenthic sledge on 6 consecutive days in August 1999 at high tide, low tide and mid tide. The hyperbenthic community was characterized by quantifying the higher taxa, their density and the relative composition of the dominant groups. No tidal effect could be observed, but two main geographically distinct hyperbenthic assemblages were distinguished along the bay, related to hydrodynamic factors (local current velocity, intertidal beach slope and suspended particulate matter). In the turbulent northern part of the bay the highest densities were encountered and hyperbenthos was, next to the dominant mysid Metamysidopsis sp., mainly composed of planktonic organisms (calanoid copepods, chaetognaths and fish eggs). In the calmer southern part of the bay Metamysidopsis sp. dominated as well, but the community was completed with other mysid species, and early life stages of Brachyura and fish. Most striking was the general dominance of the mysid Metamysidopsis sp. in all the samples (97%, max. density of 62000 ind. 100 m-2) and the high amount of unknown species. Penaeid shrimp larvae, important for the local shrimp industry, were only found in very low densities during the sampling period (˜1%). Compared to other studies on the whole surf zone hyperbenthic community of sandy beaches, the average densities encountered in Valdivia Bay can be considered to be relatively high (2500-6000 ind. 100 m-2). Although limited in time and performed with a limited taxonomic resolution, the results indicate a high contribution of early life stages of invertebrate and fish species to the biodiversity of the intertidal hyperbenthic community in comparison with temperate regions

Safety of hospital discharge before return of bowel function after elective colorectal surgery

Background: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien\u2013Dindo classification system. Results: A total of 3288 patients were included in the analysis, of whom 301 (9\ub72 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4\u20137) and 7 (6\u20138) days respectively (P < 0\ub7001). There were no significant differences in rates of readmission between these groups (6\ub76 versus 8\ub70 per cent; P = 0\ub7499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0\ub790, 95 per cent c.i. 0\ub755 to 1\ub746; P = 0\ub7659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34\ub77 versus 39\ub75 per cent; major 3\ub73 versus 3\ub74 per cent; P = 0\ub7110). Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients