The role of serratus anterior plane and pectoral nerves blocks in cardiac surgery, thoracic surgery and trauma: a qualitative systematic review.

Serratus anterior plane and pectoral nerves blocks are recently described alternatives to established regional anaesthesia techniques in cardiac surgery, thoracic surgery and trauma. We performed a systematic review to establish the current state of evidence for the analgesic role of these fascial plane blocks in these clinical settings. We identified relevant studies by searching multiple databases and trial registries from inception to June 2019. Study heterogeneity prevented meta-analysis and studies were instead qualitatively summarised and stratified by type of surgery and comparator. We identified 51 studies: nine randomised control trials; 13 cohort studies; 19 case series; and 10 case reports. The majority of randomised controlled trials studied the serratus anterior plane block in thoracotomy or video-assisted thoracoscopic surgery, with only two investigating pectoral nerves blocks. The evidence in thoracic trauma comprised only case series and reports. Results indicate that single-injection serratus anterior plane and the pectoral nerves blocks reduce pain scores and opioid consumption compared with systemic analgesia alone in cardiothoracic surgery, cardiac-related interventional procedures and chest trauma for approximately 6-12 h. The duration of action appears longer than intercostal nerve blocks but may be shorter than thoracic paravertebral blockade. Block duration may be prolonged by a continuous catheter technique with potentially similar results to thoracic epidural analgesia. There were no reported complications and the risk of haemodynamic instability appears to be low. The current evidence, though limited, supports the efficacy and safety of serratus anterior plane and the pectoral nerves blocks as analgesic options in cardiothoracic surgery.

Agricultural conservation planning framework: 2. Classification of riparian buffer design types with application to assess and map stream corridors.

A watershed's riparian corridor presents opportunities to stabilize streambanks, intercept runoff, and influence shallow groundwater with riparian buffers. This paper presents a system to classify these riparian opportunities and apply them toward riparian management planning in hydrologic unit code 12 watersheds. In two headwater watersheds from each of three landform regions found in Iowa and Illinois, high-resolution (3-m grid) digital elevation models were analyzed to identify spatial distributions of surface runoff contributions and zones with shallow water tables (SWTs) (within 1.5 m of the channel elevation) along the riparian corridors. Results were tabulated, and a cross classification was applied. Classes of buffers include those primarily placed to (i) trap runoff and sediment, (ii) influence shallow groundwater, (iii) address both runoff and shallow groundwater, and (iv) maintain/improve stream bank stability. Riparian buffers occupying about 2.5% of these six watersheds could effectively intercept runoff contributions from 81 to 94% of the watersheds' contributing areas. However, extents of riparian zones where a narrow buffer (<10 m wide) would adequately intercept runoff but where >25 m width of buffer vegetation could root to a SWT varied according to landform region ( < 0.10). Yet, these wide-SWT riparian zones were widespread and occupied 23 to 53% of the lengths of stream banks among the six watersheds. The wide-SWT setting provides opportunities to reduce dissolved nutrients (particularly NO-N) carried via groundwater. This riparian classification and mapping system is part of a ArcGIS toolbox and could provide a consistent basis to identify riparian management opportunities in Midwestern headwater catchments wherever high-resolution elevation data are available.

Agricultural conservation planning framework: 1. Developing multipractice watershed planning scenarios and assessing nutrient reduction potential.

Spatial data on soils, land use, and topography, combined with knowledge of conservation effectiveness, can be used to identify alternatives to reduce nutrient discharge from small (hydrologic unit code [HUC]12) watersheds. Databases comprising soil attributes, agricultural land use, and light detection and ranging-derived elevation models were developed for two glaciated midwestern HUC12 watersheds: Iowa's Beaver Creek watershed has an older dissected landscape, and Lime Creek in Illinois is young and less dissected. Subsurface drainage is common in both watersheds. We identified locations for conservation practices, including in-field practices (grassed waterways), edge-of-field practices (nutrient-removal wetlands, saturated buffers), and drainage-water management, by applying terrain analyses, geographic criteria, and cross-classifications to field- and watershed-scale geographic data. Cover crops were randomly distributed to fields without geographic prioritization. A set of alternative planning scenarios was developed to represent a variety of extents of implementation among these practices. The scenarios were assessed for nutrient reduction potential using a spreadsheet approach to calculate the average nutrient-removal efficiency required among the practices included in each scenario to achieve a 40% NO-N reduction. Results were evaluated in the context of the Iowa Nutrient Reduction Strategy, which reviewed nutrient-removal efficiencies of practices and established the 40% NO-N reduction as Iowa's target for Gulf of Mexico hypoxia mitigation by agriculture. In both test watersheds, planning scenarios that could potentially achieve the targeted NO-N reduction but remove <5% of cropland from production were identified. Cover crops and nutrient removal wetlands were common to these scenarios. This approach provides an interim technology to assist local watershed planning and could provide planning scenarios to evaluate using watershed simulation models. A set of ArcGIS tools is being released to enable transfer of this mapping technology.

Central venous catheter-related blood stream infections in patients receiving intravenous iloprost for pulmonary hypertension.

Catheter-related blood stream infection (CR-BSI) in patients with pulmonary hypertension (PH) receiving intravenous iloprost via an indwelling central line has previously not been fully described. Recent studies have suggested a link between the pH of prostanoid infusions and the rate and nature of CR-BSI. We have investigated CR-BSI in patients receiving intravenous iloprost at our unit. Databases and hospital records were interrogated for all patients receiving intravenous iloprost between September 2007 and June 2012. Fifty-nine patients received intravenous iloprost via an indwelling central catheter with a total of 23,072 treatment days. There were 15 episodes of CR-BSI, identified using a systematic screening protocol, involving 11 patients giving an overall CR-BSI rate of 0.65/1,000 treatment days. CR-BSI rate for Gram-positive organisms was 0.26/1,000 treatment-days and for Gram-negative organisms was 0.39/1,000 treatment-days. The pH of iloprost in typical dosing regimens was comparable to the pH used in standard-diluent treprostinil and dissimilar to alkaline epoprostenol infusions. The proportion of Gram-negative CR-BSI was similar to that reported for standard-diluent treprostinil. CRP was normal on admission in 33 % of cases of confirmed CR-BSI and remained normal in 13 % of cases. CR-BSI rates with intravenous iloprost are comparable to those observed for other prostanoids. The high proportion of Gram-negative organisms observed and the neutral pH of iloprost infusions support the previously hypothesised link between pH and antimicrobial activity. Although usually elevated during a CR-BSI, CRP may be normal in early infection and a normal result cannot completely exclude infection.

Introduction of a mandatory pre-block safety checklist into a regional anaesthesia block room service: a quality improvement project.

Wrong-side block is an uncommon yet potentially preventable complication of regional anaesthesia. One strategy for reducing the incidence of wrong-side block is to introduce an additional check into the pre-block workflow in the form of a block 'time out' or 'stop before you block'. In the aftermath of a wrong-side block incident at our institution, the mandatory use of a pre-block safety checklist was successfully introduced into the workflow of the block room. Compliance with the checklist rose from 31% in the six-month pre-intervention phase to over 90% in the six-month post-intervention phase. This was achieved without any negative effect on block efficacy, theatre efficiency, complication rates or patient satisfaction. The high rate of checklist utilisation was associated with an increased rate of ultrasound video documentation. This suggests that there may be collateral benefit to using a pre-block safety checklist in addition to merely reducing the risk of wrong-side block.

Specificity study to evaluate induction of aberrant crypts in murine colons.

We have previously reported on our findings of aberrant crypts (AC) in the colons of rodents treated with a colon carcinogen. In this report, the specificity of AC formation was assessed by testing a variety of agents for their ability to induce AC in the colons of CF1 and C57BL/6J mice. In addition, the ability of each of the agents to induce nuclear aberrations (NA) was assessed and compared with the AC data. The test agents included hydrazines, polycyclic aromatic hydrocarbons, aromatic amines, and nitrosocompounds. The colons were assessed for AC 2 or 4 weeks following a single treatment with the test agent. Of the seven agents that induced AC formation, five were colon carcinogens and the other two were agents believed to be carcinogenic to organs other than the colon. None of the five agents believed to be noncarcinogens induced AC whereas three of them did induce NA in at least one of the strains of mice tested. Comparison of AC and NA induction for each test agent showed that all agents that induced AC also induced NA and that the converse was not true. The findings of the present study indicate that AC are induced specifically in response to colon carcinogens and support our contention that AC are preneoplastic lesions.

Aberrant crypts: potential preneoplastic lesions in the murine colon.

Murine colons treated with the colon carcinogen azoxymethane (AOM) have been reported to contain aberrant crypts (AC), which are characterized by their larger size and wider pericryptal zones. The methodology used to visualize AC consists of staining the fixed, unsectioned colonic mucosa with methylene blue and transillumination of the luminal surface at a magnification of 40x. The objective of the present studies was to determine if AC demonstrate characteristics to support our hypothesis that they are putative preneoplastic lesions. Studies were designed to determine the time of occurrence of AC (Study I), the induction of AC in response to varying dosages of AOM ranging from 0.0 to 10.0 mg/kg body weight (Study II), and the effect of a high fat diet (20% fat by weight) on the number and size of AC (Study III). In all studies 4-6-week-old female CF1 mice were used. In addition C57BL/6J female mice were used in Study I. The major findings were as follows: (a) the time period required to form AC was approximately 2 weeks following a single AOM injection (5 mg/kg); (b) a dose-dependent increase in the induction of AC was noted in response to AOM from none in the control group to a plateau level of 2.90 +/- 0.38 foci at a dose of 5.0 mg/kg; (c) in comparison to the low fat group, the high fat group had a greater (P less than 0.05) mean number of foci of AC per 5 cm of colon (15.67 +/- 1.32 vs. 11.44 +/- 1.44) and a larger (P less than 0.05) mean size of foci of AC (0.0296 +/- 0.0012 mm vs. 0.0249 +/- 0.0012 mm) after 16 weeks on the respective diets; and (d) preliminary histological appearance of foci of AC revealed mild atypia to unequivocal dysplasia. The findings of the present study are consistent with the hypothesis that AC are putative preneoplastic lesions.

Sequential analyses of the growth and morphological characteristics of aberrant crypt foci: putative preneoplastic lesions.

The main objective of the present study was to sequentially analyze growth and morphological characteristics of aberrant crypt foci (ACF) in the rat colon. Sprague-Dawley rats were given a single injection of a carcinogenic dose of 1,2-dimethylhydrazine-HCl and at varying time points ranging from 2 to 57 weeks, groups of 5 rats were terminated. The number and crypt multiplicity of ACF were determined in the distal 8 cm of the colon. In addition, ACF were processed for histology and then graded for the presence of nuclear atypia using a score of 0-4. The findings of the present study demonstrated that ACF exhibit the characteristics expected for precursor lesions. ACF were present at all time intervals in large numbers in the colons of rats treated with 1,2-dimethylhydrazine-HCl and were present when adenocarcinomas were observed. The number of ACF with 4 or more crypts and those exhibiting a higher grade (grade 4) of nuclear atypia increased significantly at or beyond 19 weeks. These features of ACF, particularly the presence of nuclear atypia indicative of dysplasia, provide strong support for the hypothesis that ACF are precursor lesions of chemically induced colon cancer.

Ultrafast Pockels cells for the infrared.

The design and performance of a 2.25-cm(2)-aperture Pockels cell system for 10-mum radiation is described. Pulses as short as 90 ps can be reliably generated with this device.

Downstream approaches to phosphorus management in agricultural landscapes: regional applicability and use.

This review provides a critical overview of conservation practices that are aimed at improving water quality by retaining phosphorus (P) downstream of runoff genesis. The review is structured around specific downstream practices that are prevalent in various parts of the United States. Specific practices that we discuss include the use of controlled drainage, chemical treatment of waters and soils, receiving ditch management, and wetlands. The review also focuses on the specific hydrology and biogeochemistry associated with each of those practices. The practices are structured sequentially along flowpaths as you move through the landscape, from the edge-of-field, to adjacent aquatic systems, and ultimately to downstream P retention. Often practices are region specific based on geology, cropping practices, and specific P related problems and thus require a right practice, and right place mentality to management. Each practice has fundamental P transport and retention processes by systems that can be optimized by management with the goal of reducing downstream P loading after P has left agricultural fields. The management of P requires a system-wide assessment of the stability of P in different biogeochemical forms (particulate vs. dissolved, organic vs. inorganic), in different storage pools (soil, sediment, streams etc.), and under varying biogeochemical and hydrological conditions that act to convert P from one form to another and promote its retention in or transport out of different landscape components. There is significant potential of hierarchically placing practices in the agricultural landscape and enhancing the associated P mitigation. But an understanding is needed of short- and long-term P retention mechanisms within a certain practice and incorporating maintenance schedules if necessary to improve P retention times and minimize exceeding retention capacity.

Evaluation of ChloraPrep (2% chlorhexidine gluconate in 70% isopropyl alcohol) for skin antisepsis in preparation for blood culture collection.

OBJECTIVES: Blood culture contamination is a significant adverse event. This study evaluated whether using ChloraPrep (2% alcoholic chlorhexidine) instead of 70% isopropyl alcohol wipes reduced contamination rates on two Medical Assessment Units (MAU1 and MAU2). METHODS: ChloraPrep was introduced for 2 to 3-month intervention periods, initially on MAU1 and MAU2 and subsequently on MAU1 only. Contamination rates were compared with a matched time period in the preceding year and the three month period before ChloraPrep introduction. Education regarding venepucture technique was delivered. RESULTS: Contamination rates for the time matched pre-intervention period were 17.3% (51/295), MAU1 and 13.5% (31/230), MAU2. During the initial period of ChloraPrep use, rates declined (MAU1; 6.6% [P<0.001], MAU2; 8.5% [P=0.11] both Fisher's Exact Test). However, rates had already started to fall prior to ChloraPrep introduction. There was a non-significant difference between contamination rates in the comparator period immediately prior to ChloraPrep introduction and rates during the first intervention period (MAU1 and MAU2; P>0.05). During the second intervention period, absence of ChloraPrep on MAU2 did not significantly affect contamination (P=0.41) on this ward. CONCLUSIONS: ChloraPrep skin antisepsis did not give a significant reduction in blood culture contamination, but education may have led to the trend to lower contamination.

Effect of disulfiram on 1,2-dimethylhydrazine- and azoxymethane-induced aberrant crypt foci.

We have previously reported a method for visualizing the mucosal surface of fixed unsectioned rodent colons at the crypt level and have identified lesions, termed aberrant crypt foci (ACF), in the colons of carcinogen-treated rodents. We hypothesized that ACF represent the precursor lesions (PL) of colon cancer. In the present study, the effect of feeding disulfiram (DSF) added to a semi-synthetic diet (0.5% or 1% by wt) on 1,2-dimethylhydrazine (DMH) and azoxymethane (AOM) induced ACF was investigated. DSF has been shown to inhibit DMH and AOM-induced colon cancer. Therefore, it was reasoned that if ACF represent PL then their induction and growth should also be inhibited by DSF. CF1 female mice were randomly divided into three groups of 30 each. Group 1 was fed a diet containing 1% DSF for 9 days prior to and 1 day after receiving a single i.p. injection of either DMH, AOM or saline. Group 2 was fed a diet containing 1% DSF for 9 days prior to and 14 days after receiving a single i.p. injection of DMH, AOM or saline, whereas group 3 received control diet throughout the experimental duration. All animals were killed 5 weeks after receiving the injections. It was observed that feeding DSF, for 9 days prior to and for either 1 day or 14 days after the administration of a single injection of DMH, resulted in a complete inhibition of ACF. DSF feeding for 9 days prior to and 1 day after AOM injection resulted in a significantly greater number of ACF compared to the control group (12 +/- 2.3 vs 7.2 +/- 1.2); whereas DSF feeding for a longer duration (i.e. 9 days prior to and 14 days after AOM treatment) was associated with a significantly lower number of ACF compared to those fed DSF for only one day after AOM treatment (4.1 +/- 0.6 vs 12.4 +/- 2.3) and a lower number compared to the control group (4.1 +/- 0.6 vs 7.2 +/- 1.2).

Dose response and proliferative characteristics of aberrant crypt foci: putative preneoplastic lesions in rat colon.

Foci of aberrant crypts (ACF) have been identified in the unsectioned methylene blue stained rodent colons and hypothesized to represent precursor lesions of colon cancer. In the present study, induction and growth characteristics of ACF were investigated in response to a single injection of varying dosages of 1,2-dimethylhydrazine-2HCl (DMH), a colon carcinogen. Female Sprague-Dawley rats were given a single injection of DMH (5-150 mg/kg). Two and 19 weeks after the injection, animals were killed and their distal 10 cm of colons were enumerated for the number and crypt multiplicity of ACF. Number of ACF increased with increasing dosages of DMH plateauing at 100 mg/kg. However, percentage of ACF exhibiting different crypt multiplicity (1 to greater than 4) were similar among different dose groups. Aberrant crypts and normal crypts were enumerated for total number of cells and number and distribution of S-phase cells along the crypt height 19 weeks after DMH injection after autoradiography. The labeling index (LI) (percentage of S-phase cells) and LI along the crypt height were determined. Compared to the surrounding normal crypts, aberrant crypts exhibited significantly higher (P less than 0.05) number of cells (1122 +/- 81 versus 411 +/- 28) and higher (P less than 0.05) LI (21 +/- 1 versus 12 +/- 1). For the eight ACF analysed in the present study, the distribution of S-phase cells in the aberrant crypts were similar to that of normal crypts in that S-phase cells were restricted to the lower two-thirds of the crypts rather than distributed throughout the height of the crypts as reported for adenomatous epithelium.

Aberrant crypts, putative precancerous lesions, in the study of the role of diet in the aetiology of colon cancer.

Progress in the field of diet and colon cancer would be greatly enhanced by the development of a methodology which allowed for the identification and quantification of the early precursor lesions of colon cancer. Recently we described a method (Bird, 1987) consisting of staining the fixed, unsectioned colon with methylene blue for viewing the mucosal surface with the aid of a light microscope. With this methodology we observed early focal lesions in the colons of rodents which had been treated with a colon carcinogen but no lesions in the colons of control rodents. We termed these lesions aberrant crypts (AC). Based on our preliminary observations we hypothesized that AC represent precursor lesions of colon cancer. The findings from our subsequent studies (summarized in this paper) support this contention. We therefore suggest that evaluation of the characteristics of AC will further our understanding of the carcinogenic process as it occurs in the rodent colon and will provide a basis for the investigation of the role of diet in the aetiology of the disease.

Measurement of the proliferative status of colonic epithelium as a risk marker for colon carcinogenesis: effect of bile acid and dietary fiber.

The proliferative status of mouse colonic epithelium, as affected by dietary fibers with or without cholic acid (CA), was studied by autoradiography and the metaphase arrest technique. In the first study, groups of mice were fed natural ingredient (laboratory chow) or semisynthetic diets containing 0% (control) or 0.2% (test) CA. After the mice were fed two weeks, the effect of CA was significantly more pronounced in the semisynthetic diet group than in the natural ingredient diet group with respect to labeled cells/crypt section (7.8 +/- 0.8 vs. 2.9 +/- 0.4) and mitotic figure (MF)/crypt section (3.0 +/- 0.5 vs. 1.8 +/- 0.2). In the second study, diets formulated to contain 5 or 10% cellulose (C), pectin (P), or wheat bran (WB) with or without CA (0.2%) were fed to animals for two weeks and colonic proliferative indices were measured. When compared with 5% C group, the 10% WB group exhibited lower labeling index (LI) values (4.2 +/- 0.5 vs. 6.4 +/- 1.0) and the 10% P group exhibited higher LI values (10.0 +/- 1.1 vs. 6.4 +/- 1.0). CA-induced increases in the LI and MF values responded independently in some cases to dietary fiber. Among the CA-treated groups, only the 10% P diet resulted in lower LI when compared with the 5% C group (p less than 0.05) (7.4 +/- 0.8 vs. 12.5 +/- 2.8) but had no effect on MF/crypt section. However, the 5 or 10% WB diet resulted in lower MF values (1.7 +/- 0.2 and 1.8 +/- 0.6 vs. 2.6 +/- 0.3). A long-term feeding study comparing 10% P with 10% C diets also demonstrated that the LI was elevated in the 10% P group without any effect on the mitotic activity of the colonic epithelium. This paradoxical finding suggests that the value of the LI and/or mitotic index as a risk marker of colon carcinogenesis should be further investigated.