Phosphorus release from intact soil monoliths of manure-amended fields under simulated snowmelt flooding.

Anaerobic conditions developed in soils with flooding can enhance the release of soil P to overlying water, but little information is available for soils with a long history of manure application. We examined the P release from manure-amended soils under simulated snowmelt flooding. Intact monoliths from manured (solid swine manure [SSM] or liquid swine manure [LSM]) and unamended (control) field plots were collected from Carman, Manitoba. Monoliths were frozen for 7 d, thawed, flooded, and incubated at 4 ± 1 °C. Redox potential, pH, and concentrations of dissolved reactive P (DRP), Ca, Mg, Fe, and Mn in pore water and floodwater were determined weekly up to 56 d after flooding (DAF) and at 84 DAF. Redox potential decreased with DAF with a greater and more rapid decrease in SSM (from ∼300 to <0 mV by 84 DAF) compared with LSM and control (∼100 mV by 84 DAF). Pore water and floodwater DRP concentrations were significantly greater in manured treatments than in the control at all DAFs and in SSM than in LSM for most DAF. Whereas floodwater DRP concentrations remained relatively stable in the control treatment, concentrations in manured treatments increased substantially from the onset of flooding to 35-42 DAF (threefold to fourfold increase) and remained relatively stable thereafter. Significantly greater P release from SSM- than from LSM-treated monoliths was due to greater input of P and the higher organic matter content in SSM-treated soils. These favored the rapid development of anaerobic conditions that further induced P release.

Temperature and freezing effects on phosphorus release from soils to overlying floodwater under flooded-anaerobic conditions.

Increased phosphorus (P) availability under flooded, anaerobic conditions may accelerate P loss from soils to water bodies. Existing knowledge on P release to floodwater from flooded soils is limited to summer conditions and/or room temperatures. Spring snowmelt runoff, which occurs under cold temperatures with frequent freeze-thaw events, is the dominant mode of P loss from agricultural lands to water bodies in the Canadian Prairies. This research examined the effects of temperature on P dynamics under flooded conditions in a laboratory study using five agricultural soils from Manitoba, Canada. The treatments were (a) freezing for 1 wk at -20 °C, thawing and flooding at 4 ± 1 °C (frozen, cold); (b) flooding unfrozen soil at 4 ± 1 °C (unfrozen, cold); and (c) flooding unfrozen soil at 20 ± 2 °C (warm). Pore water and surface water were collected weekly over 8 wk and analyzed for dissolved reactive phosphorus (DRP), pH, calcium, magnesium, iron (Fe), and manganese (Mn). Soils under warm flooding showed enhanced P release with significantly higher DRP concentrations in pore and surface floodwater compared with cold flooding of frozen and unfrozen soils. The development of anaerobic conditions was slow under cold flooding with only a slight decrease in Eh, whereas under warm flooding Eh declined sharply, favoring reductive dissolution reactions releasing P, Fe, and Mn. Pore water and floodwater DRP concentrations were similar between frozen and unfrozen soil under cold flooding, suggesting that one freeze-thaw event prior to flooding had minimal effect on P release under simulated snowmelt conditions.

Patient Engagement and Cost Savings Achieved by Automated Telemonitoring Systems Designed to Prevent and Identify Surgical Site Infections After Joint Replacement.

BACKGROUND: We designed two telemonitoring text and voice messaging interventions, EpxDecolonization (EpxDecol) and EpxWound, to improve management of orthopedic joint replacement patients at Washington University. We reviewed the use of these tools for a period of 88 weeks. METHODS: Cohorts of 1,392 and 1,753 participants completed EpxDecol and EpxWound, respectively. All patients who completed EpxDecol also completed EpxWound. We assessed patient use of and satisfaction with these interventions. A return on investment (ROI) analysis was conducted to determine the cost savings generated by EpxWound and EpxDecol. RESULTS: The proportions of patients who responded daily to EpxDecol and EpxWound were 91.9% and 77.7%, respectively, over the lengths of each intervention. The percent of daily responders declined <5% during each intervention. Ultimately, 88.4% of EpxDecol patients and 67.8% of EpxWound patients responded to ≥80% of all messages. Median patient survey responses (n = 1,246) were 9/9 (best possible) for care, 8/9 for improved communication, and 5/9 (perfect number) for number of messages received. ROI analysis for this 88-week period showed that using EpxDecol and EpxWound to engage patients (instead of nurses calling patients) saved the equivalent of 2.275 full-time nursing equivalents per week. We calculated net savings of $260,348 with an ROI of 14.85x for 1,753 patients over 88 weeks. One-year cost savings from these interventions were $153,800 with an ROI of 14.79x. CONCLUSIONS: EpxDecol and EpxWound may serve important roles in the perioperative process for orthopedic joint reconstruction surgery given high patient usage of and satisfaction with these interventions. Implementing EpxDecol and EpxWound for a large patient population could yield substantial cost savings and ROI.

Accessible Communication Tools for Surgical Site Infection Monitoring and Prevention in Joint Reconstruction: Feasibility Study.

BACKGROUND: The National Surgical Quality Improvement Program logs surgical site infections (SSIs) as the most common cause of unplanned postoperative readmission for a variety of surgical interventions. Hospitals are making significant efforts preoperatively and postoperatively to reduce SSIs and improve care. Telemedicine, defined as using remote technology to implement health care, has the potential to improve outcomes across a wide range of parameters, including reducing SSIs. OBJECTIVE: The purpose of this study was to assess the feasibility and user satisfaction of two automated messaging systems, EpxDecolonization and EpxWound, to improve perioperative care in a quality improvement project for patients undergoing total joint replacement. METHODS: We designed two automated text messaging and calling systems named EpxDecolonization, which reminded patients of their preoperative decolonization protocol, and EpxWound, which monitored pain, wound, and fever status postoperatively. Daily patient responses were recorded and a post-usage survey was sent out to participants to assess satisfaction with the systems. RESULTS: Over the 40-week study period, 638 and 642 patients were enrolled in EpxDecolonization (a preoperative decolonization reminder) and EpxWound (a postoperative surgical site infection telemonitoring system), respectively. Patients could be enrolled in either or both EpxDecolonization and EpxWound, with the default option being dual enrollment. The proportion of sessions responded to was 85.2% for EpxDecolonization and 78.4% for EpxWound. Of the 1280 patients prescribed EpxWound and EpxDecolonization, 821 (64.14%) fully completed the postoperative system satisfaction survey. The median survey score (scale 1-9) was 9 for patient-rated overall care and 8 for whether the telemonitoring systems improved patient communication with providers. The majority of patients (69.0%, 566/821) indicated that the systems sent out an ideal number of messages (not too many, not too few). CONCLUSIONS: EpxDecolonization and EpxWound demonstrated high response rates and improved patient-rated communication with providers. These preliminary data suggest that these systems are well tolerated and potentially beneficial to both patients and providers. The systems have the potential to improve both patient satisfaction scores and compliance with preoperative protocols and postoperative wound monitoring. Future efforts will focus on testing the sensitivity and specificity of alerts generated by each system and on demonstrating the ability of these systems to improve clinical quality metrics with more authoritative data.