Prophylactic nasogastric decompression after abdominal surgery

BACKGROUND

Routine use of nasogastric tubes after abdominal operations is intended to hasten the return of bowel function, prevent pulmonary complications, diminish the risk of anastomotic leakage, increase patient comfort and shorten hospital stay.

OBJECTIVES

To investigate the efficacy of routine nasogastric decompression after abdominal surgery in achieving each of the above goals.

SEARCH STRATEGY

Search terms were nasogastric, tubes, randomised, using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (Central), and references of included studies, from 1966 through 2006.

SELECTION CRITERIA

Patients having abdominal operations of any type, emergency or elective, who were randomised prior tot he completion of the operation to receive a nasogastric tube and keep it in place until intestinal function had returned, versus those receiving either no tube or early tube removal, in surgery, in recovery or within 24 hours of surgery. Excluded will be randomised studies involving laparoscopic abdominal surgery and patient groups having gastric decompression through gastrostomy.

DATA COLLECTION AND ANALYSIS

Data were abstracted onto a form that assessed study eligibility, as defined above, quality related to randomizations, allocation concealment, study size and dropouts, interventions, including timing and duration of intubation, outcomes that included time to flatus, pulmonary complications, wound infection, anastomotic leak, length of stay, death, nausea, vomiting, tube reinsertion, subsequent ventral hernia.

MAIN RESULTS

33 studies fulfilled eligibility criteria, encompassing 5240 patients, 2628 randomised to routine tube use, and 2612 randomised to selective or No Tube use. Patients not having routine tube use had an earlier return of bowel function (p<0.00001), a decrease in pulmonary complications (p=0.01) and an insignificant trend toward increase in risk of wound infection (p=0.22) and ventral hernia (0.09). Anastomotic leak was no different between groups (p=0.70). Vomiting seemed to favour routine tube use, but with increased patient discomfort. Length of stay was shorter when no tube was used but the heterogeneity encountered in these analyses make rigorous conclusion difficult to draw for this outcome. No adverse events specifically related to tube insertion (direct tube trauma) were reported. Other outcomes were reported with insufficient frequency to be informative.

AUTHORS' CONCLUSIONS

Routine nasogastric decompression does not accomplish any of its intended goals and so should be abandoned in favour of selective use of the nasogastric tube.

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

BACKGROUND

Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhea and colitis.

OBJECTIVES

The aim of this review is to establish the efficacy of antibiotic therapy for C. difficile-associated diarrhea (CDAD), to identify the most effective antibiotic treatment for CDAD in adults and to determine the need for stopping the causative antibiotic during therapy.

SEARCH STRATEGY

MEDLINE (1966 to 2006), EMBASE (1980 to 2006), Cochrane Central Database of Controlled Trials and the Cochrane IBD Review Group Specialized Trials Register were searched using the following search terms: "pseudomembranous colitis and randomized trial"; "Clostridium difficile and randomized trial"; "antibiotic associated diarrhea and randomized trial".

SELECTION CRITERIA

Only randomized, controlled trials assessing antibiotic treatment for CDAD were included in the review. Probiotic trials are excluded. The following outcomes were sought: initial resolution of diarrhea; initial conversion of stool to C. difficile cytotoxin and/or stool culture negative; recurrence of diarrhea; recurrence of fecal C. difficile cytotoxin and/or positive stool culture; patient response to cessation of prior antibiotic therapy; sepsis; emergent surgery: fecal diversion or colectomy; and death.

DATA COLLECTION AND ANALYSIS

Data were analyzed using the MetaView statistical package in Review Manager. For dichotomous outcomes, relative risks (RR) and 95% confidence intervals (CI) were derived from each study. When appropriate, the results of included studies were combined for each outcome. For dichotomous outcomes, pooled RR and 95% CI were calculated using a fixed effect model, except where significant heterogeneity was detected, at which time the random effects model was used. Data heterogeneity was calculated using MetaView.

MAIN RESULTS

Twelve studies (total of 1157 participants) involving patients with diarrhea who recently received antibiotics for an infection other than C. difficile were included. The definition of diarrhea ranged from at least two loose stools per day with an associated symptom such as rectal temperature > 38 (o)C, to at least six loose stools in 36 hours. Eight different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin and bacitracin. In paired comparisons, no single antibiotic was clearly superior to others, though teicoplanin, an antibiotic of limited availability and great cost, showed in some outcomes significant benefit over vancomycin and fusidic acid, and a trend towards benefit compared to metronidazole. Only one placebo controlled trial was done and no conclusions can be drawn from it due to small size and classification error. Only one study investigated synergistic antibiotic combination, metronidazole and rifampin, and there was no advantage to the drug combination.

AUTHORS' CONCLUSIONS

Current evidence leads to uncertainty whether mild CDAD needs to be treated. Patients with mild CDAD may resolve their symptoms as quickly without treatment. The only placebo-controlled study shows vancomycin's superior efficacy. However, this result should be treated with caution due to the small number of patients enrolled and the poor methodological quality of the trial. The Johnson study of asymptomatic carriers also shows that placebo is better than vancomycin or metronidazole for eliminating C. difficile in stool during follow-up. If one does decide to treat, then two goals of therapy need to be kept in mind: improvement of the patient's clinical condition and prevention of spread of C. difficile infection to other patients. Given these two considerations, one should choose the antibiotic that brings both symptomatic cure and bacteriologic cure. In this regard, teicoplanin appears to be the best choice because the available evidence suggests that it is better than vancomycin for bacteriologic cure and has borderline superior effectiveness in terms of symptomatic cure. Teicoplanin is not readily available in the United States, which must be taken into account when making treatment decisions in that country.

Quality of life in colorectal cancer patients with hepatic arterial infusion (HAI) pumps

19602

Background: More than half of patients diagnosed with colorectal cancer will develop hepatic metastases. Most patients with hepatic metastases will recur within two years after resection. Hepatic arterial infusion (HAI) pumps deliver regional treatment. However, very few studies quantitatively explore the patient's experience of living with an HAI pump and how this experience impacts HAI-related quality of life (QOL). This study explored the impact of HAI pump treatment on patient's overall QOL within the specific domains of physical, psychological, social, and functional well-being. Methods: Twenty-five colorectal cancer patients treated with HAI pumps completed an HAI pump- specific QOL assessment tool at one data collection time point. The QOL assessment tool items were derived from the investigator's previous QOL research with this patient population [Blair et al., 2002, Annals of Surgical Oncology]. Demographic, disease and QOL data were summarized using descriptive statistics. Results: Of the 25 patients accrued, 32% were receiving treatments through their HAI pump and 68% were not. There were no significant difference in QOL between treatment status, gender, and age (<65 or = 65). Currently treated pump patients experienced more appetite changes (p=0.03), sleep changes (p=0.08), and more restrictions in traveling (p=0.08). Male patients had more concerns with lifting heavy items (p=0.05), while female patients had more concerns with isolation (p=0.17) and changes in the type of clothing worn (p=0.16). Younger patients had more concerns with vigorous activity (p=0.01), bending (p=0.08), and were more self-conscious of their appearance with the pump (p=0.01). Conclusions: Overall, in this study, colorectal cancer patients with HAI pumps reported good QOL and were satisfied with their overall treatment experience. Although there was no comparative statistical analysis performed in this study, several QOL concerns remain worrisome for patients. Defining these specific QOL concerns in HAI patients will enhance clinical understanding of their unique experience with this treatment modality and impact patient management. This will enable further development of educational tools and research to test interventions to support HAI patients and sustain their QOL.

No significant financial relationships to disclose.

Bcl-2 family proteins are essential for platelet survival

Platelets are relatively short-lived, anucleated cells that are essential for proper hemostasis. The regulation of platelet survival in the circulation remains poorly understood. The process of platelet activation and senescence in vivo is associated with processes similar to those observed during apoptosis in nucleated cells, including loss of mitochondrial membrane potential, caspase activation, phosphatidylserine (PS) externalization, and cell shrinkage. ABT-737, a potent antagonist of Bcl-2, Bcl-X(L), and Bcl-w, induces apoptosis in nucleated cells dependent on these proteins for survival. In vivo, ABT-737 induces a reduction of circulating platelets that is maintained during drug therapy, followed by recovery to normal levels within several days after treatment cessation. Whole body scintography utilizing ([111])Indium-labeled platelets in dogs shows that ABT-737-induced platelet clearance is primarily mediated by the liver. In vitro, ABT-737 treatment leads to activation of key apoptotic processes including cytochrome c release, caspase-3 activation, and PS externalization in isolated platelets. Despite these changes, ABT-737 is ineffective in promoting platelet activation as measured by granule release markers and platelet aggregation. Taken together, these data suggest that ABT-737 induces an apoptosis-like response in platelets that is distinct from platelet activation and results in enhanced clearance in vivo by the reticuloendothelial system.

Malone antegrade continent enema: an alternative to resection in severe defecation disorders

PURPOSE

This study was designed to evaluate patient self-reported outcome of the Malone antegrade continent enema at a single institution in patients suffering from severe defecatory disorders.

METHODS

A total of 18 patients (15 females; median age, 31 (range, 12-63) years) underwent a Malone antegrade continent enema (August 1999 to September 2004). The Malone antegrade continent enema technique has been previously described; however, in this series emphasis was placed on method appendix tunneling. Patients' charts were reviewed and follow-up telephone interviews were conducted. Indications for Malone antegrade continent enema were chronic constipation (n = 12), intractable fecal incontinence (n = 5), or both (n = 1). The underlying pathology included neurogenic (n = 2), congenital (n = 4), postsurgery-related (n = 4), irritable bowel syndrome (n = 6), and megarectum (n = 2). The appendix (n = 17) or cecum (n = 1) was used as a conduit.

RESULTS

The mean follow-up was 18.5 (range, 3-67) months. Fourteen patients (78 percent) still use the Malone antegrade continent enema routinely and report good functional outcome. Three patients (20 percent) required stoma creation as subsequent alternate treatment. A total of 10 patients experienced 12 complications: 3 perioperative (infections) and 9 postoperative Malone antegrade continent enema use/nonuse complications (4 stomal orifice strictures, 2 fecal impactions, 2 appendiceal perforations, and 1 irrigation catheter knot). No patient experienced leakage from the appendiceal stoma. During the follow-up interval, one patient underwent proctectomy for megarectum. No failures occurred in patients with congenital or neurogenic disorders.

CONCLUSIONS

Malone antegrade continent enema is a reasonable option for the treatment of select patients with severe defecation disorders. Good functional patient self-reported outcome was achieved by 78 percent of patients. The social inconvenience of stoma leakage is avoided with appropriate surgical technique. Malone antegrade continent enema is one option that provides a less invasive surgical alternative than colectomy or ileostomy for severe defecation disorders.

Non surgical therapy for anal fissure

BACKGROUND

Because of the disability associated with surgery for anal fissure and the risk of incontinence, medical alternatives for surgery have been sought. Most recently, pharmacologic methods that relax the anal smooth muscle, to accomplish reversibly what occurs in surgery, have been used to obtain fissure healing.

OBJECTIVES

To assess the efficacy and morbidity of various medical therapies for anal fissure.

SEARCH STRATEGY

Search terms include "anal fissure randomized". Timing from 1966 to May 2006. Further details of the search below.

SELECTION CRITERIA

Studies in which participants were randomized to a non-surgical therapy for anal fissure. Comparison groups may include an operative procedure, an alternate medical therapy or placebo. Chronic fissure, acute fissure and fissure in children are included in the review. Atypical fissures associated with inflammatory bowel disease or cancer or anal infection are excluded.

DATA COLLECTION AND ANALYSIS

Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and drop-outs, therapies, supportive measures (applied to both groups), dosing and frequency and cross-overs. Dichotomous outcome measures included Non-healing of the fissure (a combination of persistence and recurrence), and Adverse events (including incontinence, headache, infection, anaphylaxis). Continuous outcome measures included measures of pain relief and anorectal manometry.

MAIN RESULTS

48 different comparisons of the ability of medical therapies to heal anal fissure have been reported in 53 RCTs. Eleven agents were used (nitroglycerin ointment (GTN), isosorbide dinitrate, Botulinum toxin (Botox), diltiazem, nifedipine (Calcium channel blockers or CCBs), hydrocortisone, lignocaine, bran, minoxidil, indoramin, and placebo) as well as anal dilators and surgical sphincterotomy.GTN was found to be marginally but significantly better than placebo in healing anal fissure (48.6% vs. 37%, p < 0.004), but late recurrence of fissure was common, in the range of 50% of those initially cured. Botox and CCBs were equivalent to GTN in efficacy with fewer adverse events. No medical therapy came close to the efficacy of surgical sphincterotomy, though none in these RCTs was associated with the risk of incontinence.

AUTHORS' CONCLUSIONS

Medical therapy for chronic anal fissure, acute fissure and fissure in children may be applied with a chance of cure that is marginally better than placebo, and, for chronic fissure in adults, far less effective than surgery.

Hepatic artery adjuvant chemotherapy for patients having resection or ablation of colorectal cancer metastatic to the liver

BACKGROUND

Colorectal cancer metastatic to the liver, when technically feasible, is resected with a moderate chance of cure. The most common site of failure after resection is within the remaining liver. With this pattern of clinical failure in mind and in order to enhance survival, chemotherapy has been delivered directly to the liver post resection via the hepatic artery.

OBJECTIVES

To assess the effect of post hepatic resection hepatic artery chemotherapy on overall survival. Secondary objectives include adverse events related to the chemotherapy, the risk of intra-hepatic tumour recurrence and tumour free survival.

SEARCH STRATEGY

Randomised trials were sought in MEDLINE; the Cochrane Central Register of Controlled Trials; the Cochrane Hepato-Biliary Group Controlled Trials Register; and through contact of trial authors and reference lists using key words: Colorectal, cancer, hepatic metastases, hepatic artery, chemotherapy. Searches were performed in May, 2006.

SELECTION CRITERIA

Trials in which patients having resection of colorectal cancer metastatic to the liver were randomised either to hepatic artery chemotherapy or any alternative treatment.

DATA COLLECTION AND ANALYSIS

Survival data were obtained principally from abstraction from survival curves in published studies using the method of Parmar. A study specific log hazard ratio and then combined effect log hazard ratio were calculated, as well as a combined Kaplan-Meier survival probability curve.

MAIN RESULTS

Seven randomised trials addressed this issue, encompassing 592 patients. No significant advantage was found in the meta-analysis for hepatic artery chemotherapy measuring overall survival and calculating survival based upon "intention to treat" (lnHR = 0.0848; favouring the control group, 95% confidence interval = -0.1189 to 0.2885, or a Hazard Ratio of 1.089, an 8.9% survival advantage for the control group, 95% CI of the HR = 0.887-1.334). Adverse events related to the hepatic artery therapy were common, including five therapy related deaths. Intra-hepatic recurrence was more frequent in the control group (97 patients versus 43 in the HAI group), though denominators are not reported, and additional outcomes could not be subjected to a combined analysis.

AUTHORS' CONCLUSIONS

Though recurrence in the remaining liver happened less in the hepatic artery chemotherapy group, overall survival was not improved, and even favoured the control group, though not significantly. This added intervention cannot be recommended at this time.

Bacteriology swab in primary total hip arthroplasty-- does it have a role?

Infection in joint replacement is a devastating complication, and in spite of the advances in surgery, it remains a challenge. The rate of deep infection following primary hip/knee arthroplasty is between 1% and 2%. The aim of this study was to determine whether obtaining bacteriology swabs at the time of surgery could help in further reducing the rate of infection following joint arthroplasty. A bacteriology swab of the synovial fluid was taken after opening the capsule of the hip joint and was sent for culture and sensitivity. Out of 142 swabs sent, four (2.1%) were found to be positive. Three of these patients were treated with antibiotics after obtaining sensitivities. None of the patients developed deep infection. Bacteriology swab in primary joint arthroplasty may have a role and may help in further reducing the incidence of deep infection in joint replacement surgery.

Limits on spin-independent interactions of weakly interacting massive particles with nucleons from the two-tower run of the cryogenic dark matter search

We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 (12) kg d for the Ge (Si) targets after cuts, averaged over recoil energies 10-100 keV for a weakly interacting massive particle (WIMP) mass of 60 GeV/c2. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10(-43) cm2 from Ge and 3 x 10(-42) cm2 from Si, for a WIMP mass of 60 GeV/c2. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results and constrains predictions of supersymmetric models.

The evolution of Titan's mid-latitude clouds

Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal that the horizontal structure, height, and optical depth of Titan's clouds are highly dynamic. Vigorous cloud centers are seen to rise from the middle to the upper troposphere within 30 minutes and dissipate within the next hour. Their development indicates that Titan's clouds evolve convectively; dissipate through rain; and, over the next several hours, waft downwind to achieve their great longitude extents. These and other characteristics suggest that temperate clouds originate from circulation-induced convergence, in addition to a forcing at the surface associated with Saturn's tides, geology, and/or surface composition.

Operative procedures for fissure in ano

BACKGROUND

Operative techniques commonly used for fissure in ano include: anal stretch, open lateral sphincterotomy, closed lateral sphincterotomy, posterior midline sphincterotomy and to a lesser extent dermal flap coverage of the fissure. Reports of direct comparisons between operative techniques for anal fissure are variable in their results. These reports are either subject to selection bias (in non-randomized studies) or observer bias (in all studies) or have inadequate numbers of patients enrolled to answer the question of efficacy.

OBJECTIVES

To determine the best technique for fissure surgery.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials and MEDLINE (1965-2005) were searched. The list of cited references in all included reports and several study authors also were helpful in finding additional comparative studies.

SELECTION CRITERIA

All reports in which there was a direct comparison between at least two operative techniques were reviewed and when more than one report existed for any given pair, that report was included. If crude data were not presented in the report, the authors were contacted and crude data obtained.

DATA COLLECTION AND ANALYSIS

The two most commonly used end points in all reported studies were persistence of the fissure and post operative incontinence of flatus. These are the only two endpoints included in the meta-analysis.

MAIN RESULTS

Twenty-four trials encompassing 3475 patients are included in this review . Anal stretch has a higher risk of fissure persistence than internal sphincterotomy and also a significantly higher risk of minor incontinence than sphincterotomy. The combined results of open versus closed partial lateral internal sphincterotomy show little difference between the two procedures both in fissure persistence and risk of incontinence.

AUTHORS' CONCLUSIONS

Anal stretch and posterior midline internal sphincterotomy should probably be abandoned in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open and closed partial lateral internal sphincterotomy appear to be equally efficacious. More data are needed to assess the effectiveness of posterior internal sphincterotomy, anterior levatorplasty, wound suture or papilla excision.

Prophylactic nasogastric decompression after abdominal surgery

BACKGROUND

Routine use of nasogastric tubes after abdominal operations is intended to hasten the return of bowel function, prevent pulmonary complications, diminish the risk of anastomotic leakage, increase patient comfort and shorten hospital stay.

OBJECTIVES

To investigate the efficacy of routine nasogastric decompression after abdominal surgery in achieving each of the above goals.

SEARCH STRATEGY

Search terms were nasogastric, tubes, randomised, using MEDLINE, EMBASE, Cochrane Controlled Trials Register, and references of included studies.

SELECTION CRITERIA

Patients having abdominal operations of any type, emergency or elective, who were randomised prior tot he completion of the operation to receive a nasogastric tube and keep it in place until intestinal function had returned, versus those receiving either no tube or early tube removal, in surgery, in recovery or within 24 hours of surgery. Excluded will be randomised studies involving laparoscopic abdominal surgery and patient groups having gastric decompression through gastrostomy.

DATA COLLECTION AND ANALYSIS

Data were abstracted onto a form that assessed study eligibility, as defined above, quality related to randomizations, allocation concealment, study size and dropouts, interventions, including timing and duration of intubation, outcomes that included time to flatus, pulmonary complications, wound infection, anastomotic leak, length of stay, death, nausea, vomiting, tube reinsertion, subsequent ventral hernia.

MAIN RESULTS

28 studies fulfilled eligibility criteria, encompassing 4194 patients, 2108 randomised to routine tube use, and 2087 randomised to selective or No Tube use. Patients not having routine tube use had an earlier return of bowel function (p<0.00001), an insignificant trend toward decrease in pulmonary complications (p=0.07) and an insignificant trend toward increase in risk of wound infection (p=0.08) and ventral hernia (0.09). Anastomotic leak was no different between groups (p=0.70). Patient comfort, nausea, vomiting and length of stay seemed to favour No Tube, but the heterogeneity encountered in these analyses make rigorous conclusion difficult to draw for these outcomes. No adverse events specifically related to tube insertion (direct tube trauma) were reported. Other outcomes were reported with insufficient frequency to be informative.

AUTHORS' CONCLUSIONS

Routine nasogastric decompression does not accomplish any of its intended goals and so should be abandoned in favour of selective use of the nasogastric tube.

Prophylactic nasogastric decompression after abdominal surgery

BACKGROUND

Routine use of nasogastric tubes after abdominal operations is intended to hasten the return of bowel function, prevent pulmonary complications, diminish the risk of anastomotic leakage, increase patient comfort and shorten hospital stay.

OBJECTIVES

To investigate the efficacy of routine nasogastric decompression after abdominal surgery in achieving each of the above goals.

SEARCH STRATEGY

Search terms were nasogastric, tubes, randomised, using MEDLINE, EMBASE, Cochrane Controlled Trials Register, and references of included studies.

SELECTION CRITERIA

Patients having abdominal operations of any type, emergency or elective, who were randomised prior tot he completion of the operation to receive a nasogastric tube and keep it in place until intestinal function had returned, versus those receiving either no tube or early tube removal, in surgery, in recovery or within 24 hours of surgery. Excluded will be randomised studies involving laparoscopic abdominal surgery and patient groups having gastric decompression through gastrostomy.

DATA COLLECTION AND ANALYSIS

Data were abstracted onto a form that assessed study eligibility, as defined above, quality related to randomizations, allocation concealment, study size and dropouts, interventions, including timing and duration of intubation, outcomes that included time to flatus, pulmonary complications, wound infection, anastomotic leak, length of stay, death, nausea, vomiting, tube reinsertion, subsequent ventral hernia.

MAIN RESULTS

28 studies fulfilled eligibility criteria, encompassing 4194 patients, 2108 randomised to routine tube use, and 2087 randomised to selective or No Tube use. Patients not having routine tube use had an earlier return of bowel function (p<0.00001), an insignificant trend toward decrease in pulmonary complications (p=0.07) and an insignificant trend toward increase in risk of wound infection (p=0.08) and ventral hernia (0.09). Anastomotic leak was no different between groups (p=0.70). Patient comfort, nausea, vomiting and length of stay seemed to favour No Tube, but the heterogeneity encountered in these analyses make rigorous conclusion difficult to draw for these outcomes. No adverse events specifically related to tube insertion (direct tube trauma) were reported. Other outcomes were reported with insufficient frequency to be informative.

AUTHORS' CONCLUSIONS

Routine nasogastric decompression does not accomplish any of its intended goals and so should be abandoned in favour of selective use of the nasogastric tube.

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

BACKGROUND

Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhea and colitis.

OBJECTIVES

The aim of this review is to establish the efficacy of antibiotic therapy for C. difficile-associated diarrhea (CDAD), to identify the most effective antibiotic treatment for CDAD in adults and to determine the need for stopping the causative antibiotic during therapy.

SEARCH STRATEGY

MEDLINE (1966 to 2003), EMBASE (1980 to 2003), Cochrane Central Database of Controlled Trials and the Cochrane IBD Review Group Specialized Trials Register were searched using the following search terms: "pseudomembranous colitis and randomized trial"; "Clostridium difficile and randomized trial"; "antibiotic associated diarrhea and randomized trial".

SELECTION CRITERIA

Only randomized, controlled trials assessing antibiotic treatment for CDAD were included in the review. Probiotic trials are excluded. The following outcomes were sought: initial resolution of diarrhea; initial conversion of stool to C. difficile cytotoxin and/or stool culture negative; recurrence of diarrhea; recurrence of fecal C. difficile cytotoxin and/or positive stool culture; patient response to cessation of prior antibiotic therapy; sepsis; emergent surgery: fecal diversion or colectomy; and death.

DATA COLLECTION AND ANALYSIS

Data were analyzed using the MetaView statistical package in Review Manager. For dichotomous outcomes, relative risks (RR) and 95% confidence intervals (CI) were derived from each study. When appropriate, the results of included studies were combined for each outcome. For dichotomous outcomes, pooled RR and 95% CI were calculated using a fixed effect model, except where significant heterogeneity was detected, at which time the random effects model was used. Data heterogeneity was calculated using MetaView.

MAIN RESULTS

Of eleven studies identified, two were subsequently excluded because patients were stool positive for C. difficile, but did not have diarrhea or because the study was not a randomized controlled trial. All of the remaining nine studies involved patients with diarrhea who recently received antibiotics for an infection other than C. difficile. The definition of diarrhea ranged from at least two loose stools per day with an associated symptom such as rectal temperature > 38(o)C, to at least six loose stools in 36 hours. In terms of symptomatic cure, metronidazole, bacitracin and fusidic acid were not shown to be less effective than vancomycin. Teicoplanin may be slightly more effective than vancomycin with a relative risk of 1.21 [95% CI 1.00 to 1.46] and a p-value of 0.06. In terms of initial symptomatic resolution, vancomycin is more effective than placebo with a relative risk of 6.75 [95% CI 1.16 to 48.43] and a p-value of 0.03. This result should be interpreted with caution given the small number of patients in this comparison (12 in the vancomycin group and nine in the placebo group) and the poor methodological quality of the trial. Metronidazole, bacitracin, teicoplanin, fusidic acid and rifaximine are as effective as vancomycin for initial symptomatic resolution. The other secondary outcomes measured in this review: surgery, sepsis and death occurred infrequently in all of the studies.

AUTHORS' CONCLUSIONS

Current evidence leads to uncertainty whether mild CDAD needs to be treated. Patients with mild CDAD may resolve their symptoms as quickly without treatment. The only placebo-controlled study shows vancomycin's superior efficacy. However, this result should be treated with caution due to the small number of patients enrolled and the poor methodological quality of the trial. The Johnson study of asymptomatic carriers also shows that placebo is better than vancomycin or metronidazole for eliminating C. difficile in stool during follow-up. If one does decide to treat, then two goals of therapy need to be kept in mind: improvement of the patient's clinical condition and prevention of spread of C. difficile infection to other patients. Given these two considerations, one should choose the antibiotic that brings both symptomatic cure and bacteriologic cure. In this regard, teicoplanin appears to be the best choice because the available evidence suggests that it is better than vancomycin for bacteriologic cure and has borderline superior effectiveness in terms of symptomatic cure. Teicoplanin is not readily available in the United States, which must be taken into account when making treatment decisions in that country.

First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory

We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

Identification and morphological classification of horizontal, bipolar, and amacrine cells within the zebrafish retina

Horizontal, bipolar, and amacrine cells in the zebrafish retina were morphologically characterized using DiOlistic techniques. In this method, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-coated microcarriers are shot at high speed onto the surfaces of living retinal slices where the DiI then delineates axons, somata, and dendrites of isolated neurons. Zebrafish retinal somata were 5-10 microm in diameter. Three horizontal cell types (HA-1, HA-2, and HB) were identified; dendritic tree diameters averaged 25-40 microm. HA somata were round. Cells classified as HA-2 were larger than HA-1 cells and possessed an axon. HB somata were flattened, without an axon, although short fusiform structure(s) projected from the soma. Bipolar cells were separated into 17 morphological types. Dendritic trees ranged from 10 to 70 microM. There were six B(on) types with axon boutons only in the ON sublamina of the inner plexiform layer (IPL), and seven B(off) types with axon boutons or branches only in the OFF sublamina. Four types of bistratified bipolar cells displayed boutons in both ON and OFF layers. Amacrine cells occurred in seven types. A(off) cells (three types) were monostratified and ramified in the IPL OFF sublamina. Dendritic fields were 60-150 microM. A(on) pyriform cells (three types) branched in the ON sublamina. Dendritic fields were 50-170 microM. A(diffuse) cells articulated processes in all IPL strata. Dendritic fields were 15-90 microM. These findings are important for studies examining signal processing in zebrafish retina and for understanding changes in function resulting from mutations and perturbations of retinal organization.

The relationship between temperature and neuronal characteristics

The purpose of this study was to determine a relationship between surface temperature of the limb and neuronal characteristics of the median and ulnar nerves in non-impaired individuals. Previous literature demonstrates that there is a negative correlation between distal latency and amplitude and temperature while a positive correlation exists between nerve conduction velocity and temperature. It is a common clinical practice to externally manipulate the temperature of a cold limb. Thirty-six participants (21 male, 15 female,) with an age range between 20-38 years old (mean age = 26.6) completed the study. Temperature of the limb was not manipulated by the researchers prior to testing and was measured at the distal wrist crease using a surface probe. Relationship was determined using a Pearson product-moment coefficient of correlation. A significant negative correlation existed for median distal sensory latency (DSL), ulnar DSL, ulnar motor amplitude (CMAP), and ulnar sensory amplitude (SNAP). The investigators conclude that temperature is a factor to consider when performing nerve conduction studies. The researchers suggest using mathematical correction factors to compensate for a cool limb rather than external heating.

Broadband polarization correction with programmable liquid-crystal modulator arrays

We demonstrate a novel method of parallel, multiwavelength state-of-polarization (SOP) correction. Using a new liquid-crystal modulator array design, we are able to rotate the distorted input SOP spectrum to a fixed linear state on a wavelength-by-wavelength basis. We report experimental correction of up to 25.5-dB polarization-dependent loss over a 13-nm bandwidth around 1550 nm.

Hepatic artery adjuvant chemotherapy for patients having resection or ablation of colorectal cancer metastatic to the liver

BACKGROUND

Colorectal cancer metastatic to the liver, when technically feasible, is resected with a moderate chance of cure. The most common site of failure after resection is within the remaining liver. With this pattern of clinical failure in mind and in order to enhance survival, chemotherapy has been delivered directly to the liver post resection via the hepatic artery.

OBJECTIVES

To assess the effect of post hepatic resection hepatic artery chemotherapy on overall survival. Secondary objectives include adverse events related to the chemotherapy, the risk of intra-hepatic tumour recurrence and tumour free survival.

SEARCH STRATEGY

Randomised trials were sought in MEDLINE; the Cochrane Central Register of Controlled Trials; the Cochrane Hepato-Biliary Group Controlled Trials Register; and through contact of trial authors and reference lists using key words: Colorectal, cancer, hepatic metastases, hepatic artery, chemotherapy. Searches were performed in December 2003.

SELECTION CRITERIA

Trials in which patients having resection of colorectal cancer metastatic to the liver were randomised either to hepatic artery chemotherapy or any alternative treatment.

DATA COLLECTION AND ANALYSIS

Survival data were obtained principally from abstraction from survival curves in published studies using the method of Parmar. A study specific log hazard ratio and then combined effect log hazard ratio were calculated, as well as a combined Kaplan-Meier survival probability curve.

MAIN RESULTS

Seven randomised trials addressed this issue, encompassing 592 patients. No significant advantage was found in the meta-analysis for hepatic artery chemotherapy measuring overall survival and calculating survival based upon "intention to treat" (lnHR = 0.0848; favouring the control group, 95% confidence interval = -0.1189 to 0.2885, or a Hazard Ratio of 1.089, an 8.9% survival advantage for the control group, 95% CI of the HR = 0.887 - 1.334). Adverse events related to the hepatic artery therapy were common, including five therapy related deaths. Intra-hepatic recurrence was more frequent in the control group (97 patients versus 43 in the HAI group), though denominators are not reported, and additional outcomes could not be subjected to a combined analysis.

REVIEWERS' CONCLUSIONS

Though recurrence in the remaining liver happened less in the hepatic artery chemotherapy group, overall survival was not improved, and even favoured the control group, though not significantly. This added intervention cannot be recommended at this time.

Programmable polarization-independent spectral phase compensation and pulse shaping

We report the first use of a double-layer liquid crystal modulator array for spectral phase pulse shaping that operates independent of polarization. Such insensitivity to polarization is crucial for fiber applications, e.g., dispersion compensation.

The impact of abnormal fetal echocardiography on expectant parents' experience of pregnancy: a pilot study

To examine the impact of an abnormal fetal echocardiogram (echo) on parental attitudes, emotions and coping strategies. Group interviews were performed for women and their male partners who had a fetal echo and were found to have a fetal congenital heart defect. The women and men were separated into four different focus groups. The interviews were tape recorded, transcribed and analyzed. The women expressed strong emotions of guilt, fear and sadness or hopelessness. They coped by attaching and bonding to the fetus, and were realistic about the future. The women began grieving at the time of the fetal echo. The men experienced emotions of anger and anxiety. They coped by remaining optimistic, and focused on supporting their wives. Men grieved after the birth of the baby. The fetal echo was felt to be beneficial and not harmful by the parents. The fetal echo led to significant changes in the couples' perceptions of themselves and their relationships. Clinicians performing fetal imaging must be aware of parental affective responses and coping mechanisms in order to provide the required psychological support.