Laying it on thick: Ecosystem effects of sediment placement on a microtidal Rhode Island salt marsh.

Heightened recognition of impacts to coastal salt marshes from sea-level rise has led to expanding interest in using thin-layer sediment placement (TLP) as an adaptation tool to enhance future marsh resilience. Building on successes and lessons learned from the Gulf and southeast U.S. coasts, projects are now underway in other regions, including New England where the effects of TLP on marsh ecosystems and processes are less clear. In this study, we report on early responses of a drowning, microtidal Rhode Island marsh (Ninigret Marsh, Charlestown, RI) to the application of a thick (10-48 cm) application of sandy dredged material and complimentary extensive adaptive management to quickly build elevation capital and enhance declining high marsh plant species. Physical changes occurred quickly. Elevation capital, rates of marsh elevation gain, and soil drainage all increased, while surface inundation, die-off areas, and surface ponding were greatly reduced. Much of the marsh revegetated within a few years, exhibiting aspects of classic successional processes leading to new expansive areas of high marsh species, although low marsh Spartina alterniflora recovered more slowly. Faunal communities, including nekton and birds, were largely unaffected by sediment placement. Overall, sediment placement provided Ninigret Marsh with an estimated 67-320 years of ambient elevation gain, increasing its resilience and likely long-term persistence. Project stakeholders intentionally aimed for the upper end of high marsh plant elevation growth ranges to build elevation capital and minimize maintenance costs, which also resulted in new migration corridors, providing pathways for future marsh expansion.

An Evaluation of Fish Tissue Monitoring Alternatives for Mercury and Selenium: Fish Muscle Biopsy Samples Versus Homogenized Whole Fillets.

Fish contaminant studies with human health protection objectives typically focus on muscle tissue, recognizing that fillets are the commonly consumed tissue fraction. Muscle biopsy punch sampling for mercury analysis has recently been used as an alternative to harvesting fish for fillets; however, there is limited information comparing fillet plug results to whole fillet results. This study was conducted to address that data gap and to test the applicability of plugs for monitoring associated with United States Environmental Protection Agency's fish tissue-based mercury and selenium water quality criteria. The mercury phase included 300 fillet homogenates and 300 field-extracted plug samples from 60 fish, and the selenium phase included 120 fillet homogenates and 120 plugs from 30 fish. Both phases showed that there were no statistically significant differences between fillet plug and homogenized fillet results at the community level; however, a selenium plug monitoring alternative must employ a sufficiently sensitive analytical method and consider total solids. Plug and fillet sampling alternatives have inherent advantages and disadvantages. Fillet sampling provides sufficient mass to consider multiple contaminants but requires fish to be harvested. Plug sampling only provides adequate mass for a single analyte but may allow fish survival, although additional research is needed on survival following plug removal.

Recent Carbon Storage and Burial Exceed Historic Rates in the San Juan Bay Estuary Peri-Urban Mangrove Forests (Puerto Rico, United States).

Mangroves sequester significant quantities of organic carbon (C) because of high rates of burial in the soil and storage in biomass. We estimated mangrove forest C storage and accumulation rates in aboveground and belowground components among five sites along an urbanization gradient in the San Juan Bay Estuary, Puerto Rico. Sites included the highly urbanized and clogged Caño Martin Peña in the western half of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part. Radiometrically dated cores were used to determine sediment accretion and soil C storage and burial rates. Measurements of tree dendrometers coupled with allometric equations were used to estimate aboveground biomass. Estuary-wide mangrove forest C storage and accumulation rates were estimated using interpolation methods and coastal vegetation cover data. In recent decades (1970-2016), the highly urbanized Martin Peña East (MPE) site with low flushing had the highest C storage and burial rates among sites. The MPE soil carbon burial rate was over twice as great as global estimates. Mangrove forest C burial rates in recent decades were significantly greater than historic decades (1930-1970) at Cañno Martin Peña and Piñones. Although MPE and Piñones had similarly low flushing, the landscape settings (clogged canal vs forest reserve) and urbanization (high vs low) were different. Apparently, not only urbanization, but site-specific flushing patterns, landscape setting, and soil fertility affected soil C storage and burial rates. There was no difference in C burial rates between historic and recent decades at the San José and La Torrecilla lagoons. Mangrove forests had soil C burial rates ranging from 88 g m-2 y-1 at the San José lagoon to 469 g m-2 y-1 at the MPE in recent decades. Watershed anthropogenic CO2 emissions (1.56 million Mg C y-1) far exceeded the annual mangrove forest C storage rates (aboveground biomass plus soils: 17,713 Mg C y-1). A combination of maintaining healthy mangrove forests and reducing anthropogenic emissions might be necessary to mitigate greenhouse gas emissions in urban, tropical areas.

Recent Nitrogen Storage and Accumulation Rates in Mangrove Soils Exceed Historic Rates in the Urbanized San Juan Bay Estuary (Puerto Rico, United States).

Tropical mangrove forests have been described as "coastal kidneys," promoting sediment deposition and filtering contaminants, including excess nutrients. Coastal areas throughout the world are experiencing increased human activities, resulting in altered geomorphology, hydrology, and nutrient inputs. To effectively manage and sustain coastal mangroves, it is important to understand nitrogen (N) storage and accumulation in systems where human activities are causing rapid changes in N inputs and cycling. We examined N storage and accumulation rates in recent (1970 - 2016) and historic (1930 - 1970) decades in the context of urbanization in the San Juan Bay Estuary (SJBE, Puerto Rico), using mangrove soil cores that were radiometrically dated. Local anthropogenic stressors can alter N storage rates in peri-urban mangrove systems either directly by increasing N soil fertility or indirectly by altering hydrology (e.g., dredging, filling, and canalization). Nitrogen accumulation rates were greater in recent decades than historic decades at Piñones Forest and Martin Peña East. Martin Peña East was characterized by high urbanization, and Piñones, by the least urbanization in the SJBE. The mangrove forest at Martin Peña East fringed a poorly drained canal and often received raw sewage inputs, with N accumulation rates ranging from 17.7 to 37.9 g -2 y-1 in recent decades. The Piñones Forest was isolated and had low flushing, possibly exacerbated by river damming, with N accumulation rates ranging from 18.6 to 24.2 g -2 y-1 in recent decades. Nearly all (96.3%) of the estuary-wide mangrove N (9.4 Mg ha-1) was stored in the soils with 7.1 Mg ha-1 sequestered during 1970-2017 (0-18 cm) and 2.3 Mg ha-1 during 1930-1970 (19-28 cm). Estuary-wide mangrove soil N accumulation rates were over twice as great in recent decades (0.18 ± 0.002 Mg ha-1y-1) than historically (0.08 ± 0.001 Mg ha-1y-1). Nitrogen accumulation rates in SJBE mangrove soils in recent times were twofold larger than the rate of human-consumed food N that is exported as wastewater (0.08 Mg ha-1 y-1), suggesting the potential for mangroves to sequester human-derived N. Conservation and effective management of mangrove forests and their surrounding watersheds in the Anthropocene are important for maintaining water quality in coastal communities throughout tropical regions.

Nitrogen isotope fractionation in a continuous culture system containing phytoplankton and blue mussels.

An experiment was conducted to examine the fractionation of nitrogen stable isotopes in a continuous culture system containing field collected estuarine phytoplankton and blue mussels, Mytilus edulis. Nitrate and phosphate were added to culture vessels at concentrations above ambient levels and nitrogen isotope ratios (δ15N) were measured in particulate matter (PM) and blue mussels over the course of the 15-day experiment. The added nutrients resulted in large productivity and chlorophyll increases in the system. Study results indicate that rapid and significant nitrogen isotope fractionation can occur during incorporation by phytoplankton grown under conditions of excess dissolved inorganic nitrogen, as shown by δ15N values depleted by as much as 9‰ in PM from the higher nutrient treatments. These lower δ15N values were also reflected in mussels exposed to culture vessels effluents. Therefore, nitrogen concentration needs to be considered when using δ15N values in biota as indicators of anthropogenic nitrogen inputs.

Revised fish aging techniques improve fish contaminant trend analyses in the face of changing Great Lakes food webs.

Incorporation of fish age into the assessment of status and trends for persistent, bioaccumulative and toxic chemicals in the Great Lakes has become an important step for the U.S. EPA's Great Lakes Fish Monitoring and Surveillance Program (GLFMSP). A slowing in the rate of decline for total PCBs in Lake Huron beginning in 2000, led the Program to complete a retrospective analysis to assess how chemical contamination may be influenced by fish age. Analytical results suggest that fish age is an important variable when assessing contaminant trends and that the Program needed to revise its compositing scheme to group fish according to age, rather than by length, prior to homogenization and chemical analysis. An Interlaboratory comparison study of multiple age structures was performed to identify the most appropriate age estimation structure for the Program. The lake trout (Salvelinus namaycush) maxillae was selected, over the otolith, as the most precise, accurate, and rapidly assessed structure for the Program when compared between laboratories and against the known age from the coded wire tag (CWT). Age-normalization practices can now be implemented when assessing contaminant concentrations and trends for the GLFMSP.

Trends in nitrogen isotope ratios of juvenile winter flounder reflect changing nitrogen inputs to Rhode Island, USA estuarine systems.

Nitrogen isotope ratios (δ15N) in juvenile winter flounder, Pseudopleuronectes americanus, were used to examine changes in nitrogen inputs to several Rhode Island, USA estuarine systems. Fish were collected over two three-year periods with a ten-year interval between sampling periods (2002-2004 and 2012-2014). During that interval numerous changes to nutrient management practices were initiated in the watersheds of these estuarine systems including the upgrade of several major wastewater treatment facilities that discharge to Narragansett Bay, which significantly reduced nitrogen inputs. Following these reductions, the δ15N values of flounder in several of the systems decreased as expected; however, isotope ratios in fish from upper Narragansett Bay significantly increased. We believe that low δ15N values measured in 2002-2004 were related to concentration-dependent fractionation at this location. Increased δ15N values measured between 2012 and 2014 may indicate reduced fractionation or that changes in wastewater treatment processes altered the nitrogen isotopic ratios of the effluents.

Integrating Monitoring and Genetic Methods To Infer Historical Risks of PCBs and DDE to Common and Roseate Terns Nesting Near the New Bedford Harbor Superfund Site (Massachusetts, USA).

Common and roseate terns are migratory piscivorous seabirds with major breeding colonies within feeding range of the polychlorinated biphenyl (PCB)-contaminated New Bedford Harbor (NBH, MA, USA) Superfund site. Our longitudinal study shows that before PCB discharges into NBH ceased (late 1970s), tern eggs had very high but variable PCB concentrations. However, egg concentrations of PCBs as well as DDE (1,1-bis(p-chlorophenyl)-2,2-dichloroethene), the degradation product of the ubiquitous global contaminant DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane), have since declined. Rate constants for temporal decline of PCB congeners in tern eggs varied inversely with log10KOW (n-octanol-water partition coefficient), shifting egg congener patterns away from those characterizing NBH sediment. To estimate the toxic effects on tern eggs of PCB dioxin-like congener (DLC) exposures, we extrapolated published laboratory data on common terns to roseate terns by characterizing genetic and functional similarities in species aryl hydrocarbon receptors (AHRs), which mediate DLC sensitivity. Our assessment of contaminant risks suggests that terns breeding near NBH were exposed historically to toxic levels of PCBs and DDE; however, acute effects on tern egg development have become less likely since the 1970s. Our approach demonstrates how comparative genetics at target loci can effectively increase the range of inference for chemical risk assessments from tested to untested and untestable species.

Does Better Specimen Orientation and a Simplified Grading System Promote More Reliable Histologic Interpretation of Serrated Colon Polyps in the Community Practice Setting? Results of a Nationwide Study.

INTRODUCTION: Colonoscopic surveillance guidelines for serrated polyps (SPs) are predicated upon the histologic characteristics of the index polyp. However, discrimination between SP subtypes [hyperplastic polyps vs. sessile serrated adenoma/polyps (SSA/P)] is often unreliable. MATERIALS AND METHODS: We studied the impact of (1) a novel tissue orientation method, performed in the endoscopy laboratory, whereby polyps are flattened in a small paper envelope immediately after resection (modified protocol); and (2) 2012 consensus-modified criteria (CM-2012). These interventions were compared with conventional tissue-handling protocol (CP) and traditional 2008 World Health Organization criteria (WHO). Twenty blinded community pathologists from around the United States scored 100, independent, 0.5 to 2.0 cm, proximal colonic SPs randomly selected from a 2-site tissue section archive. We compared interobserver agreement and diagnostic grading. RESULTS: Interobserver agreement was higher using CM-2012 than WHO criteria (absolute agreement: 13% vs. 4%, P<0.01; 75% agreement: 54% vs. 38%, P<0.01). Interobserver agreement was higher with the modified protocol than with CP (WHO absolute agreement: 6% vs. 2%, P>0.05; WHO 75% agreement: 46% vs. 30%, P>0.05, and CM-2012 absolute agreement: 20% vs. 6%, P=0.07; CM-2012 75% agreement: 66% vs. 42%, P=0.03). Compared with WHO, use of CM-2012 criteria resulted in fewer diagnoses of "indeterminate"; more diagnoses of SSA/P (P<0.01); and "upgraded" the diagnosis from hyperplastic polyps to SSA/P in approximately 7% of cases. These observations were independent of polyp size, patient gender, and study site. CONCLUSIONS: Simple enhancements to postresection SP handling and diagnostic criteria markedly improve interobserver agreement of SP diagnosis among nongastrointestinal community pathologists. This finding, if confirmed, has important implications for SP colonoscopy surveillance guidelines.

A simple tissue-handling technique performed in the endoscopy suite improves histologic section quality and diagnostic accuracy for serrated polyps.

BACKGROUND AND STUDY AIMS: Surveillance intervals after colonoscopic resection of serrated polyps are partially predicated on the histology of the polyp(s) removed during the index exam. Histologic discrimination between sessile serrated adenomas/polyps (SSA/P) and hyperplastic polyps is challenging. We devised and tested a simple tool--an envelope--that gastroenterologists can integrate into routine colonoscopy practice to address this problem. METHODS: In the "modified protocol," immediately after polypectomy each serrated polyp was flattened and enclosed in a paper envelope before being placed in formalin. In the pathology laboratory, each polyp was sectioned after processing. A two-site, prospective, randomized, single-blinded trial was performed to compare this modified protocol with the conventional protocol. Serrated polyps located proximal to the splenic flexure and 5-20 mm in diameter were included. A novel orientation score that measured the number of well-oriented crypts per unit area of polyp (higher orientation score = better orientation) was validated. Orientation score, SSA/P diagnosis rate, and inter-pathologist agreement were measured. RESULTS: A total of 375 polyps were enrolled, of which 264 were identified for analysis. The mean orientation scores in the modified and conventional protocol groups were 3.11 and 1.13, respectively (P < 0.0001). SSA/Ps were diagnosed in 103/135 cases (76.3%) in the modified protocol group vs. 54/129 (41.9%) in the conventional protocol group (P < 0.0001). Inter-pathologist agreement was higher with the modified than the conventional protocol (77.0% vs. 62.8%; P = 0.015). CONCLUSION: Standard polyp handling techniques may be sub-optimal for interpretation of serrated polyps resected at colonoscopy, and may lead to inadvertent histologic "under-grading" of many lesions. Our intervention improved histopathologic interpretation and increased the SSA/P diagnosis rate.

A morphologic analysis of sessile serrated polyps observed during routine colonoscopy (with video).

BACKGROUND: Proximal colorectal cancer may arise from sessile serrated polyps (SSPs), which are often inconspicuous during colonoscopy. The gross morphologic characteristics of SSPs have not been systematically described, and this omission may contribute to colonoscopists overlooking them. OBJECTIVES: To analyze the gross morphologic characteristics of SSPs detected during routine colonoscopy. DESIGN: Retrospective analysis of high-resolution endoscopic video clips depicting SSPs in situ. SETTING: Outpatient gastroenterology practice. PATIENTS: A total of 124 subjects undergoing surveillance or screening colonoscopy after split-dose bowel preparation. INTERVENTIONS: Analysis of 158 SSPs performed by using validated descriptors. MAIN OUTCOME MEASUREMENTS: The prevalence of morphologic characteristics related to polyp shape, color, and texture. RESULTS: A total of 158 SSPs were studied. For 7 visual descriptors, a κ coefficient of ≥ 0.7 was achieved, indicating good to excellent intraobserver agreement. The most prevalent visual descriptors were the presence of a mucous cap (63.9%), rim of debris or bubbles (51.9%), alteration of the contour of a fold (37.3%), and interruption of the underlying mucosal vascular pattern (32.3%). The most common "sentinel signs" were the presence of a mucous cap and alteration of the contour of a mucosal fold (each 24.6%), rim of debris or bubbles (21.7%), and a dome-shaped protuberance (20.3%). When comparing SSPs with adenomatous polyps, the frequencies of 5 of 7 morphologic characteristics and the distribution of sentinel signs differed (P < .01). LIMITATIONS: Single-site, retrospective analysis. CONCLUSIONS: SSPs exhibit distinct, variable morphologic characteristics. Many do not display classic features such as a mucous cap. Enhanced appreciation of these morphologic characteristics may improve SSP detection and thereby colorectal cancer prevention.

The detection of premalignant colon polyps during colonoscopy is stable throughout the workday.

BACKGROUND: Recent studies have shown that colonoscopic polyp detection decreases as the workday progresses. This may reflect time-dependent factors such as colonoscopist fatigue and decreased colon cleanliness, which can be addressed through adaptations in colonoscopy practice. OBJECTIVE: To test for time-of-day differences in adenomatous polyp (AP) and sessile serrated polyp (SSP) detection in a practice that uses split-dose bowel preparation and moderated daily colonoscopist procedure loads. DESIGN: Retrospective chart review. SETTING: Community-based, group gastroenterology practice. PATIENTS: This study involved 2439 patients undergoing surveillance or screening colonoscopy. INTERVENTION: Colonoscopy. MAIN OUTCOME MEASUREMENTS: Detection rate of all premalignant polyps (PMPs), and of APs and SSPs, individually. RESULTS: A total of 1183 PMPs were identified in 1486 eligible patients (mean PMP/colonoscopy = 0.80; PMP detection rate = 47%). In univariate and multivariate analyses, PMP detection as well as detection of APs or SSPs individually did not vary significantly in relation to the hour of the day. In a binary comparison of morning (am) versus afternoon (pm) procedures, the total polyp detection rate was 67% and 66%, respectively. For PMPs, APs, SSPs, and hyperplastic polyps (HPs), the am and pm detection rates were 46% and 47%, 41% and 44%, 8% and 8%, and 27% and 24%, respectively. Bowel preparation quality was independent of time of day and was rated excellent or good in 86% to 87% of cases. LIMITATIONS: Retrospective, nonrandomized study. CONCLUSION: Stable PMP, AP, SSP, and HP detection rates throughout the workday occur under certain practice conditions, including the use of split-dose bowel preparation and/or moderated daily colonoscopist procedure loads.

Is gastroduodenal biopsy safe in patients receiving aspirin and clopidogrel?: a prospective, randomized study involving 630 biopsies.

GOALS: To assess prospectively the bleeding risk attributable to gastroduodenal biopsy in subjects taking antiplatelet medications. BACKGROUND: No prospective data exist regarding the bleeding risk attributable to endoscopic biopsy in patients taking antiplatelet agents. A majority of Western endoscopists withdraw antiplatelet agents before upper endoscopy, despite expert guidelines to the contrary. STUDY: We performed a prospective, single-blind, randomized study in healthy volunteers participating in a larger study regarding the effect of antiplatelet agents on gastroduodenal mucosal healing. Multiple gastroduodenal biopsies were performed during 2 esophagogastroduodenoscopy in subjects dosed with aspirin enteric-coated 81 mg once daily or clopidogrel 75 mg once daily. Data for endoscopic bleeding, clinical bleeding, blood vessel size, and depth of biopsy in histology specimens were collected. RESULTS: Four hundred and five antral biopsies and 225 duodenal biopsies were performed during 90 esophagogastroduodenoscopy in 45 subjects receiving aspirin or clopidogrel. Median maximum blood vessel diameter per biopsy was 31.9 µ (range: 9.2 to 133.8). About 50.8% of biopsy specimens breached the muscularis mucosa. In the clopidogrel group, no bleeding events were noted after 350 biopsies [upper confidence limit (UCL) for probability of bleeding=0.0085]. In the aspirin group, there were no clinical events (UCL=0.0106) and one minor endoscopic bleeding event (UCL=0.0169). CONCLUSIONS: Consistent with expert guidelines, the absolute risk attributable to gastroduodenal biopsy in adults taking antiplatelet agents seems to be low. Half of routine biopsies enter submucosa. The largest blood vessels avulsed during biopsy correspond to midsized and large arterioles and venules.

Routine management of stricture after gastric bypass and predictors of subsequent weight loss.

BACKGROUND: Gastrojejunal anastomotic stricture is the most commonly occurring short-term complication after Roux-en-Y gastric bypass. Endoscopic balloon dilation is the first-line treatment for stricture. However, an optimal dilation protocol has not been identified. This study aimed to document routine management of stricture after laparoscopic gastric bypass and its impact on postoperative weight loss. METHODS: Charts of patients who underwent gastric bypass from 2000 to 2006 were reviewed using a standardized abstraction form. Patients with stricture were matched with control subjects based on age +/-5 years, gender, and preoperative body mass index (BMI +/- 5). Patients with at least 6 months of follow-up assessment were included in the study. RESULTS: Of the 113 patients included in the study, 20% were male, 26% black, 19% Hispanic, and 51% white. Their mean age was 42 +/- 10 years (range, 22-66 years). The mean preoperative BMI was 47.0 +/- 5.4 kg/m(2) for the case group and 46.6 +/- 5.5 kg/m(2) for the control group (p = 0.3). After adjustment for patient characteristics, using a larger balloon was associated with reduced odds of stricture recurrence (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.12-0.85; p = 0.02). All the patients were without signs or symptoms of stricture at the last follow-up visit (20 +/- 17 months). Weight loss was similar between the two groups. The percentage of estimated weight loss (%EWL) at 12 months postoperatively was 66% for the study participants and 67% for the control subjects (p = 0.5). Baseline alcohol use and higher preoperative BMI were associated with a higher BMI 6 months postoperatively (p = 0.004 and p < 0.001, respectively). CONCLUSIONS: Initial dilation with a larger balloon is safe and may prevent stricture recurrence. Further study of modifiable risk factors for reduced weight loss after surgery, such as alcohol use, may improve patient outcomes.

Primary prevention of adverse gastroduodenal effects from short-term use of non-steroidal anti-inflammatory drugs by omeprazole 20 mg in healthy subjects: a randomized, double-blind, placebo-controlled study.

The effectiveness of low-dose omeprazole as primary prevention of gastrointestinal adverse events due to episodic use of non-selective NSAIDs was evaluated. Healthy adults aged 50-75 who did not take chronic NSAIDs were randomized to a 6.5-day treatment of naproxen 500 mg twice daily plus omeprazole 20 mg daily or naproxen 500 mg twice daily plus placebo. Seventy subjects were enrolled (mean age 58.6 years, proportion >60 = 41.4%). Subjects receiving naproxen plus omeprazole developed fewer gastroduodenal ulcers compared to subjects receiving naproxen plus placebo (11.8% vs. 46.9%, P = 0.002). Likewise, naproxen plus omeprazole was associated with a decreased risk of ulceration and/or >5 erosions (38.2% vs. 81.3%, P < or = 0.001), and a smaller change in dyspepsia score. Considering their relatively low cost, ready availability, and favorable safety profile, low-dose PPI co-prescription in healthy adults requiring short-term therapy with non-selective NSAIDs may be reasonable.

Endoscopic sedation in the United States: results from a nationwide survey.

OBJECTIVES: The introduction of new sedative agents as well as a desire for improved patient satisfaction and greater efficiency has changed the practice of endoscopic sedation. This survey was designed to provide national and regional data on endoscopic sedation and monitoring practices within the United States. METHODS: A 22-item survey regarding current practices of endoscopy and sedation was mailed to 5,000 American College of Gastroenterology physician members nationwide. RESULTS: A total of 1,353 questionnaires (27.1%) were returned. Respondents performed an average of 12.3 esophagogastroduodenoscopies (EGDs) and 22.3 colonoscopies per wk. Endoscopic procedures were performed within a hospital setting (55.2) more often than at an ambulatory center (35.8%) or private office (8.8%). The vast majority of EGDs and colonoscopies (>98%) were performed with endoscopic sedation. Almost three quarters (74.3%) of the respondents used a narcotic and benzodiazepine for sedation, while propofol was preferred by 25.7%. Sedation practices varied considerably within different geographic regions of the United States. Respondents routinely monitored vital signs and pulse oximetry (99.2% and 98.6%, respectively), and supplemental oxygen was administered to all patients during EGD by 72.7% of endoscopists. Endoscopist satisfaction with sedation was greater among those using propofol than conventional sedation (10 vs 8, p < 0.0001). CONCLUSIONS: During the past 15 yr, the volume of procedures performed by endoscopists in the United States has increased two- to fourfold. Propofol is currently being used for sedation in approximately one quarter of all endoscopies in the United States. The findings from this survey may help in the formulation of updated policies and practice guidelines pertaining to endoscopic sedation.

Moderate level sedation during endoscopy: a prospective study using low-dose propofol, meperidine/fentanyl, and midazolam.

BACKGROUND: Propofol provides several benefits over benzodiazepine and narcotic agents as a sedative medication for endoscopic procedures, including faster recovery and improved patient satisfaction. However, its use generally has been limited to anesthesiologists because of the risks associated with deep sedation. METHODS: One hundred patients undergoing colonoscopy or EGD were sedated with low-dose propofol, midazolam, and fentanyl (or meperidine). Depth of sedation was assessed at 2-minute intervals by an independent observer by using the American Society of Anesthesiologists criteria. Recovery time was determined by using paired neuropsychometric tests. A post-procedure satisfaction survey and 24-hour follow-up questionnaires were administered. RESULTS: For colonoscopy and EGD, respectively, the mean propofol dose was 98 mg and 79 mg, the mean midazolam dose was 0.9 mg and 0.8 mg, the mean fentanyl dose was 69 mcg and 63 mcg, and the mean meperidine dose was 42 mg (for both procedures). There were 628 assessments of the level of sedation performed during 74 colonoscopies and 101 assessments during 26 EGDs. The level of sedation was minimal in 77%, moderate in 21%, and deep in 2% of assessments. Nine of the 13 episodes of deep sedation were recorded during colonoscopy and 4 during EGD. In no instance was more than a single assessment of deep sedation recorded during one procedure. Ninety-eight percent of patients were satisfied with the sedation, and 71% returned to their usual activities within 2 hours of discharge. There was no serious adverse event. CONCLUSIONS: Endoscopic sedation with low-dose propofol, a narcotic agent, and midazolam produces a moderate level of sedation. The quality of sedation and measures of recovery are comparable with the results reported with standard-dose propofol.

Propofol for endoscopic sedation: A protocol for safe and effective administration by the gastroenterologist.

BACKGROUND: There is increasing interest in the use of propofol, an ultrashort-acting hypnotic agent, for sedation during endoscopic examinations. A protocol was developed for administration of propofol, combined with small doses of midazolam and meperidine, for endoscopic sedation under the direction of a gastroenterologist. Initial experience with using this protocol is described. METHODS: A total of 819 consecutive endoscopic examinations under sedation with propofol, midazolam, and meperidine (or fentanyl), in adherence with the sedation protocol, were reviewed retrospectively. RESULTS: There were 638 colonoscopies and 181 EGDs; 89% of patients were classified as American Society of Anesthesiologists (ASA) class I or II. Mean dosages of medications were: propofol 63 (33.5) mg, meperidine 48 (7.2) mg, and midazolam 1 (0.12) mg. The dose of propofol was inversely correlated with age and ASA class, and positively correlated with patient weight and duration of examination. Hypotension (>20 mm Hg decline in either systolic or diastolic blood pressure) developed in 218 (27%) patients, and hypoxemia (oxygen saturation <90%) developed in 75 (9%). All episodes of hypotension and hypoxemia were transient, and no patient required administration of a pharmacologic antagonist or assisted ventilation. The average time for recovery after colonoscopy and after EGD was, respectively, 25 minutes and 28 minutes. All EGDs and 98% of colonoscopies were completed successfully. CONCLUSIONS: On the basis of this initial experience, it is believed that propofol, potentiated by small doses of midazolam and meperidine, can be safely and effectively administered under the direction of a gastroenterologist. Additional research will be necessary to determine whether propofol is superior to the current methods of sedation.