Implementation of a standardized nurse initiated protocol to manage severe hypertension in pregnancy.

Objectives: Hypertensive disorders of pregnancy are a leading cause of maternal morbidity and mortality, studies have shown that standardized protocols for treating severe hypertension improves outcomes. Our goal was to examine the effects of a protocol for treating severe hypertension.Methods: Using quality improvement methodology, we developed an evidence-based nurse-initiated protocol for management of severe hypertension. We used a before and after study design, with the primary outcome of time to administration of antihypertensive medications and time to achieve blood pressure control. Secondary outcomes included medication usage, time to repeat blood pressure, and proportion of women receiving appropriate treatment. Statistical analysis was completed with Stata, using data medians, 95% confidence intervals and a rank-sum test.Results: Data was collected for 5 months before and 5 months after protocol implementation, with 67 patients included before and 125 patients after implementation. The median time to treatment of severe range blood pressure decreased from 25 min before to 11 min after protocol implementation, p <.001. Twenty-four% of women were treated within 15 min before and 60.6% were treated within 15 min after protocol implementation. Median time required to regain sustained mild range blood pressure was reduced from 45 min before to 41 min after protocol implementation, p = .004. 67.5% of women regained mild range blood pressure within 60 min before and 81.9% achieved blood pressure control within 60 min after protocol implementation. These improved outcomes were evident within the first month after protocol implementation and remained stable throughout the follow-up period.Discussion: Implementation of an evidence-based nurse-initiated protocol for the treatment of severe hypertension in pregnancy decreases the time required to administer antihypertensive medication, time required to regain blood pressure control and nonbeneficial clinical variation. In addition, these benefits were achieved rapidly within a large hospital setting.

Uncertainties in data and models to describe event dynamics of agricultural sediment and phosphorus transfer.

Mathematical models help to quantify agricultural sediment and phosphorus transfers and to simulate mitigation of pollution. This paper develops empirical models of the dominant sediment and phosphorus event dynamics observed at high resolution in a drained and undrained, intensive grassland field-scale lysimeter (1 ha) experiment. The uncertainties in model development and simulation are addressed using Generalized Likelihood Uncertainty Estimation. A comparison of suspended solids (SS) and total phosphorus (TP) samples with a limited number of manual repeats indicates larger data variability at low flows. Quantitative uncertainty estimates for discharge (Q) are available from another study. Suspended solids-discharge (SS-Q) hysteresis is analyzed for four events and two drained and two undrained fields. Hysteresis loops differ spatially and temporally, and exhaustion is apparent between sequential hydrograph peaks. A coherent empirical model framework for hysteresis, where SS is a function of Q and rate of change of Q, is proposed. This is evaluated taking the Q uncertainty into account, which can contribute substantially to the overall uncertainty of model simulations. The model simulates small hysteresis loops well but fails to simulate exhaustion of SS sources and flushing at the onset of events. Analysis of the TP-SS relationship reveals that most of the variability occurs at low flows, and a power-law relationship can explain the dominant behavior at higher flows, which is consistent across events, fields, and pathways. The need for further field experiments to test hypotheses of sediment mobilization and to quantify data uncertainties is identified.

Evaluating colloidal phosphorus delivery to surface waters from diffuse agricultural sources.

Colloid-facilitated phosphorus (P) delivery from agricultural soils in different hydrological pathways was investigated using a series of laboratory and field experiments. A soil colloidal P test was developed that yields information on the propensity of different soils to release P attached to soil colloids. The relationship between turbidity of soil extracts and total phosphorus (TP) was significant (r2 = 0.996, p < 0.001) across a range of agricultural soils, and a strong positive relationship (r2 = 0.86, p < 0.001) was found between "colloidal P" (H2O-CaCl2 extracts) and turbidity. Linear regression of the proportion of fine clay (<2 microm) for each soil type evaluated against the (H2O-CaCl2) colloidal P fraction gave a weak but positive relationship (r2 = 0.38, p = 0.082). The relative contribution of different particle-size fractions in transporting P in agricultural runoff from grassland soils was evaluated using a randomized plot experiment. A significant difference (p = 0.05) in both TP and reactive phosphorus (RP) in subsurface flow was recorded for different particle-size fractions, with most TP transferred either in association with the 2-microm fraction or with the 0.001-microm or smaller fractions. Total P concentrations in runoff were higher from plots receiving P amendments compared with the zero-P plots; however, these differences were only significant for the >0.45-microm particle-size fractions (p = 0.05), and may be evidence of surface applications of organic and inorganic fertilizers being transferred through the soil either as intact organic colloids or attached to mineral particles. Our results highlight the potential for drainage water to mobilize colloids and associated P during rainfall events.