A randomized controlled trial of sleep study surveillance with targeted autoregulated positive airway pressure therapy for obstructive sleep apnea in pregnancy.

BACKGROUND: Obstructive sleep apnea is associated with adverse pregnancy outcomes. The impact therapy for obstructive sleep apnea has on these pregnancy outcomes remains under investigated. OBJECTIVE: This study aimed to determine the effects of targeted autoregulated positive airway pressure in women at risk of obstructive sleep apnea on adverse pregnancy outcomes, cost, and natural history of obstructive sleep apnea. STUDY DESIGN: Pregnant women at high risk of obstructive sleep apnea were randomized to either a sleep study screening group receiving autoregulated positive airway therapy or a group not screened for obstructive sleep apnea receiving standard obstetrical care (control). Women in the sleep study-screened group received a sleep study at 2 periods during pregnancy, early (6-16 weeks of gestation) and late (27-33 weeks of gestation), with initiation of autoregulated positive airway therapy if their Apnea Hypopnea Index indicated ≥5 events per hour. Women of both groups had a sleep study 3 months after delivery. The primary outcome was effect on adverse pregnancy outcomes, a composite of hypertension, preterm birth, low birthweight, stillbirth, and diabetes mellitus. The secondary outcomes included obstructive sleep apnea severity and hospital costs. RESULTS: Among 193 women randomized (100 in the sleep study-screened group and 93 in the control group; 6 lost to follow-up), there was no significant difference in composite adverse pregnancy outcomes (46.4% screened vs 43.3% control; P=.77), hypertension (23.7% screened vs 32.0% control; P=.25), preterm birth (13.4% screened vs 10.0% control; P=.5), low birthweight (5.2% screened vs 6.7% control; P=.76), stillbirth (1% screened vs 0% control; P=1), gestational diabetes (19.6% screened vs 13.3% control; P=.33), or mean cost ($12,185 screened vs $12,607 control). The Apnea Hypopnea Index increased throughout pregnancy, peaking at 3 months after delivery (P<.001). There were 24 subjects (25.8%) who had a new diagnosis of obstructive sleep apnea, with 6 in whom autoregulated positive airway was prescribed. The autoregulated positive airway compliance rates were poor with usage rates ranging from 2% (1 of 64 days) to 43% (6 of 14 days). CONCLUSION: Targeted autoregulated positive airway therapy for obstructive sleep apnea did not decrease composite adverse pregnancy outcomes or hospital costs in the sleep study-screened high-risk pregnancy group compared with the group that received no obstructive sleep apnea screening. However, a small sample size, low autoregulated positive airway prescription rates, and poor compliance resulted in difficulty in drawing a definitive conclusion. The prevalence and severity of obstructive sleep apnea worsened throughout pregnancy, with the highest rates detected in the postpartum period. Large, multicenter clinical trials that are adequately powered are needed.

A prospective observational study of bacteraemia in adults admitted to an urban Mozambican hospital.

BACKGROUND: Bacteraemia is a common cause of fever among patients presenting to hospitals in sub-Saharan Africa. The worldwide rise of antibiotic resistance makes empirical therapy increasingly difficult, especially in resource-limited settings. OBJECTIVES: To describe the incidence of bacteraemia in febrile adults presenting to Maputo Central Hospital (MCH), an urban referral hospital in the capital of Mozambique, and characterise the causative organisms and antibiotic susceptibilities. We aimed to describe the antibiotic prescribing habits of local doctors, to identify areas for quality improvement. METHODS: Inclusion criteria were: (i) ≥18 years of age; (ii) axillary temperature ≥38°C or ≤35°C; (iii) admission to MCH medical wards in the past 24 hours; and (iv) no receipt of antibiotics as an inpatient. Blood cultures were drawn from enrolled patients and incubated using the BacT/Alert automated system (bioMérieux, France). Antibiotic susceptibilities were tested using the Kirby-Bauer disc diffusion method. RESULTS: Of the 841 patients enrolled, 63 (7.5%) had a bloodstream infection. The most common isolates were Staphylococcus aureus, Escherichia coli, and non-typhoidal Salmonella. Antibiotic resistance was common, with 20/59 (33.9%) of all bacterial isolates showing resistance to ceftriaxone, the broadest-spectrum antibiotic commonly available at MCH. Receipt of insufficiently broad empirical antibiotics was associated with poor in-hospital outcomes (odds ratio 8.05; 95% confidence interval 1.62 - 39.91; p=0.04). CONCLUSION: This study highlights several opportunities for quality improvement, including educating doctors to have a higher index of suspicion for bacteraemia, improving local antibiotic guidelines, improving communication between laboratory and doctors, and increasing the supply of some key antibiotics.

Eleven-year trend in acetanilide pesticide degradates in the Iowa River, Iowa.

Trends in concentration and loads of acetochlor, alachlor, and metolachlor and their ethanasulfonic (ESA) and oxanilic (OXA) acid degradates were studied from 1996 through 2006 in the main stem of the Iowa River, Iowa and in the South Fork Iowa River, a small tributary near the headwaters of the Iowa River. Concentration trends were determined using the parametric regression model SEAWAVE-Q, which accounts for seasonal and flow-related variability. Daily estimated concentrations generated from the model were used with daily streamflow to calculate daily and yearly loads. Acetochlor, alachlor, metolachlor, and their ESA and OXA degradates were generally present in >50% of the samples collected from both sites throughout the study. Their concentrations generally decreased from 1996 through 2006, although the rate of decrease was slower after 2001. Concentrations of the ESA and OXA degradates decreased from 3 to about 23% yr. The concentration trend was related to the decreasing use of these compounds during the study period. Decreasing concentrations and constant runoff resulted in an average reduction of 10 to >3000 kg per year of alachlor and metolachlor ESA and OXA degradates being transported out of the Iowa River watershed. Transport of acetochlor and metolachlor parent compounds and their degradates from the Iowa River watershed ranged from <1% to about 6% of the annual application. These trends were related to the decreasing use of these compounds during the study period, but the year-to-year variability cannot explain changes in loads based on herbicide use alone. The trends were also affected by the timing and amount of precipitation. As expected, increased amounts of water moving through the watershed moved a greater percentage of the applied herbicides, especially the relatively soluble degradates, from the soils into the rivers through surface runoff, shallow groundwater inflow, and subsurface drainage.

Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins.

BACKGROUND: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10 000 Mg in 1992 to more than 80 000 Mg in 2007. The greatest intensity of glyphosate use is in the midwestern United States, where applications are predominantly to genetically modified corn and soybeans. In spite of the increase in usage across the United States, the characterization of the transport of glyphosate and its degradate aminomethylphosphonic acid (AMPA) on a watershed scale is lacking. RESULTS: Glyphosate and AMPA were frequently detected in the surface waters of four agricultural basins. The frequency and magnitude of detections varied across basins, and the load, as a percentage of use, ranged from 0.009 to 0.86% and could be related to three general characteristics: source strength, rainfall runoff and flow route. CONCLUSIONS: Glyphosate use in a watershed results in some occurrence in surface water; however, the watersheds most at risk for the offsite transport of glyphosate are those with high application rates, rainfall that results in overland runoff and a flow route that does not include transport through the soil.

Comparison of fate and transport of isoxaflutole to atrazine and metolachlor in 10 Iowa rivers.

Isoxaflutole (IXF), a newer low application rate herbicide, was introduced for weed control in corn (Zea mays) to use as an alternative to widely applied herbicides such as atrazine. The transport of IXF in streamwater has not been well-studied. The fate and transport of IXF and two of its degradation products was studied in 10 Iowa rivers during 2004. IXF rapidly degrades to the herbicidally active diketonitrile (DKN), which degrades to a biologically inactive benzoic acid (BA) analogue. IXF was detected in only four, DKN in 56, and BA in 43 of 75 samples. The concentrations of DKN and BA were approximately 2 orders of magnitude less than those of the commonly detected triazine and acetamide herbicides and their degradation products. Concentrations of IXF, DKN, and BA were highest during the May through June postplanting period. The concentration ratio of BA/DKN was similar to the deethylatrazine/atrazine ratio with smaller ratios occurring during May and June. The relative temporal variation of DKN and BA was similar to that observed for atrazine and deethylatrazine. This study shows that low application rate herbicides can have similar temporal transport patterns in streamwater as compared to more widely applied herbicides but at lower concentrations.

Stability of low levels of perchlorate in drinking water and natural water samples.

Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined-the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 microg l(-1) perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples.

Herbicides and herbicide degradation products in Upper Midwest agricultural streams during August base-flow conditions.

Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and Minnesota streams during base-flow conditions in August 1997. Atrazine, the most frequently detected herbicide (94%), was present at relatively low concentrations (median 0.17 microg L(-1)). Metolachlor was detected in 59% and cyanazine in 37% of the samples. Seven of nine compounds detected in more than 50% of the samples were degradation products. The total concentration of the degradation products (median of 4.4 microg L(-1)) was significantly greater than the total concentration of parent compounds (median of 0.26 microg L(-1)). Atrazine compounds were present less frequently and in significantly smaller concentrations in streams draining watersheds with soils developed on less permeable tills than in watersheds with soils developed on more permeable loess. The detection and concentration of triazine compounds was negatively correlated with antecedent rainfall (April-July). In contrast, acetanalide compounds were positively correlated with antecedant rainfall in late spring and early summer that may transport the acetanalide degradates into ground water and subsequently into nearby streams. The distribution of atrazine degradation products suggests regional differences in atrazine degradation processes.