Biomedical subjects

Paul Bassett

Publications and source records attributed to Paul Bassett.

11 recordsLinked to original sources

PubMed2006

Position changes improve visibility during colonoscope withdrawal: a randomized, blinded, crossover trial.

BACKGROUND: Adequate distension is essential to maximize neoplasia detection during colonoscope withdrawal. Position changes may improve distension but are often not performed in routine practice. OBJECTIVE: To assess whether routine position changes improve luminal distension during colonoscope withdrawal. DESIGN: Randomized, blinded, crossover trial. SETTING: Single tertiary-referral center, United Kingdom. PATIENTS: Fourteen patients attending for routine colonoscopy. INTERVENTIONS: Videotaped, back-to-back examination of colon proximal to rectosigmoid junction in left lateral position only, then with position changes: left lateral for the cecum to the hepatic flexure, supine for the transverse colon, and right lateral for the splenic flexure and the descending colon, or vice versa. MAIN OUTCOME MEASUREMENTS: Luminal distension as scored by a blinded video reviewer. Luminal distension was scored on a scale of 1 to 5 for each colonic area: 1, complete collapse; 5, widely distended to limit of view. A score of 2 or less was considered inadequate for diagnosis. RESULTS: Scores for the 2 examinations from the blinded video reviewer were significantly higher in the transverse, the splenic flexure, and the descending colon, P = .02, .002, and <.001, respectively. Without position changes, 6 of 14 of patients (43%) would have had a nondiagnostic distension score (1 or 2) in at least 1 colonic area, P = .03. LIMITATIONS: Nonvalidated scoring system for luminal distension, however, good agreement between endoscopist and blinded reviewer, weighted kappa 0.53, 95% confidence interval 0.38-0.69. CONCLUSIONS: Position change, a cost-neutral intervention, during colonoscope withdrawal improved luminal distension between hepatic flexure and sigmoid-descending junction and has the potential to reduce adenoma and early cancer miss rates.

Colon↗

PubMed2006

The effect of different macronutrient infusions on appetite, ghrelin and peptide YY in parenterally fed patients.

BACKGROUND & AIMS: Patients receiving parenteral nutrition (PN) still feel hungry despite adequate provision of calories intravenously. It is not known whether PN or its constituent macronutrients acutely affect appetite and to what degree this may be mediated by ghrelin and peptide YY (PYY). METHODS: Six medically stable patients (four men) with intestinal failure receiving PN received an isocaloric 200 kcal infusion on three separate occasions following a 12 h fast. The infusions consisted of either carbohydrate (10% dextrose), fat (10% intralipid) or mixed protein/carbohydrate (PN). Changes in ghrelin and peptide YY levels and changes in subjective symptoms of hunger, satiety and nausea during each macronutrient infusion were assessed. RESULTS: None of the three infusions acutely affected subjective symptoms of hunger, satiety and nausea (P>0.05 ANOVA). Ghrelin levels decreased significantly during dextrose [-19.1 (-35.9, -12.4), regression coefficient (95% CI), P<0.001] and parenteral nutrition infusions [-18.2 (-26.8, -9.6), P<0.001]. Lipid infusion had no effect on ghrelin levels but led to a significant decrease in PYY [-0.076 (-0.0123, -0.028), P=0.004]. Dextrose and PN infusion had no significant effect on PYY levels. CONCLUSIONS: Dextrose and PN infusions decrease ghrelin levels. Lipid infusion does not affect ghrelin levels but in contrast to oral nutrients leads to a significant decrease in PYY. Despite these changes, in patients receiving PN, macronutrient infusions do no acutely affect appetite.

Adult↗

PubMed2006

Automated insufflation of carbon dioxide for MDCT colonography: distension and patient experience compared with manual insufflation.

OBJECTIVE: The purpose of our study was to compare the effects of automated and manual carbon dioxide insufflation before CT colonography on distention and patient acceptance. SUBJECTS AND METHODS: One hundred forty-one symptomatic subjects underwent CT colonography using either an automated device (n = 47) or a manual method (n = 94) for carbon dioxide insufflation. CT data sets were assessed retrospectively in consensus by two blinded observers who graded distention for six colonic segments using a 4-point scale. An additional assessment of the overall clinical adequacy of distention (yes/no) was also made, and any learning curve was sought. Each patient completed a validated 24-point patient questionnaire reflecting patient satisfaction and discomfort. Distention scores, clinical adequacy, and questionnaire responses were analyzed using ordered logistic regression, Fisher's exact test, and the Mann-Whitney test statistic, respectively. RESULTS: Automated insufflation significantly improved distention overall (p = 0.001). For individual segments, distention was significantly improved in the sigmoid (p = 0.007) and descending (p < 0.001) colons when the patient was supine; and in the sigmoid (p = 0.02), descending (p = 0.001), and transverse (p = 0.02) colons when supine and prone positions were combined. No significant difference was seen in the clinical adequacy of distention, nor was there evidence of any learning curve for either insufflation method. Subjects were more weary after automated insufflation (p = 0.03), but no significant difference was seen for the remaining 23 questionnaire items or for feelings of bloating or discomfort. CONCLUSION: Automated carbon dioxide insufflation significantly improves colonic distention compared with manual insufflation. Benefit is greatest in the left colon, particularly when the patient is supine. Patient acceptance is similar to that for manual insufflation.

Aged↗

PubMed2006

Polyp measurement using CT colonography: agreement with colonoscopy and effect of viewing conditions on interobserver and intraobserver agreement.

OBJECTIVE: This article presents inter- and intraobserver agreement for estimates of polyp diameter using CT colonography, including the effects of different visualization displays and prior experience. MATERIALS AND METHODS: Four observers, three of whom had prior experience with CT colonography, estimated the maximum diameter of 48 polyps using three different visualization displays: 2D colonography window, 2D abdominal window, and 3D surface rendering. Each re-measured a subset of 10 polyps. Polyps measured 2 to 12 mm according to a colonoscopic reference. Inter- and intraobserver agreement and agreement with the reference measurement were determined using the Bland-Altman method, paired Student's t testing, analysis of variance, and analysis of covariance (ANCOVA), and by calculating the components of variance. RESULTS: CT measurements overestimated polyp diameter, a phenomenon found least using the 2D abdominal display. Generally, 95% limits of agreement encompassed different size categories for individual polyps: the widest spanned 14.6 mm (-4.6 mm to 10.0 mm) for an experienced observer using the 3D display. When using the 2D abdominal display, no significant difference was found between estimates and the reference value for the other two experienced observers (p = 0.83 and 0.23). All the observers' measurements were significantly different from the reference when using the 3D display (p < 0.001). The novice was significantly different from the experienced observers in some analyses. Inter- and intraobserver agreement were poorest for the 3D display. CONCLUSION: Measurement of polyp diameter from CT colonography is subject to variation contingent on the observer's experience and the viewing display used. Although 3D visualization display is commonly used for polyp detection, it should not be used for measurement.

Colonic Polyps↗

PubMed2005

Quantitative assessment of colorectal cancer perfusion using MDCT: inter- and intraobserver agreement.

OBJECTIVE: The objective of our study was to determine inter- and intraobserver agreement of MDCT colorectal cancer perfusion measurements. SUBJECTS AND METHODS: Thirty-one patients (17 men, 14 women; median age, 69 years) with proven colorectal cancer were examined prospectively using MDCT. A 65-sec dynamic study (cine mode, 4 x 5 mm collimation) was acquired through the tumor after i.v. contrast administration (100 mL of iopamidol 350, 5 mL/sec). Tumor blood volume, blood flow, mean transit time, and permeability measurements were determined by two independent observers using commercial software. Inter- and intraobserver agreement was assessed using the Bland-Altman test. RESULTS: The mean difference for interobserver agreement (95% limits of agreement) was -0.81 mL/100 g tissue (-3.14 to 1.52); -9.94 mL/100 g tissue/min (-51.43 to 32.65); -1.09 sec (-7.05 to 4.86); and -2.90 mL/100 g tissue/min (-11.48 to 5.68) for blood volume, blood flow, mean transit time, and permeability, respectively. The intraclass correlation coefficient was 0.83, 0.89, 0.89, and 0.80, respectively. The mean difference for intraobserver agreement (95% limits of agreement) was 0.12 mL/100 g tissue (-1.90 to 2.14); 0.02 mL/100 g tissue/min (-13.13 to 13.17); -0.19 sec (-3.19 to 2.81); and 0.00 mL/100 g tissue/min (-2.45 to 2.45) for observer 1 and 0.26 mL/100 g tissue (-1.46 to 1.98); 4.47 mL/100 g tissue/min (-26.65 to 35.59); -0.21 sec (-2.48 to 2.06); 1.08 mL/100 g tissue/min (-4.92 to 7.08) for observer 2. The intraclass correlation coefficient was 0.86, 0.98, 0.97, 0.98 for observer 1 and 0.93, 0.96, 0.99, and 0.94, respectively, for observer 2. CONCLUSION: There is greater inter- than intraobserver agreement for CT vascular perfusion measurements of primary colorectal cancer, which must be addressed for reliable clinical application in therapeutic monitoring.

Adenocarcinoma↗

PubMed2004

CT colonography: effect of experience and training on reader performance.

The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training ( P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow ( P<0.001 and P=0.03, respectively), but increased for the trainee ( P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases.

Clinical Competence↗

PubMed2003

Optimizing colonic distention for multi-detector row CT colonography: effect of hyoscine butylbromide and rectal balloon catheter.

PURPOSE: To investigate the effects of hyoscine butylbromide and an inflatable rectal balloon catheter on luminal distention during computed tomographic (CT) colonography. MATERIALS AND METHODS: One hundred thirty-six subjects undergoing CT colonography were randomized to receive either 20 mg or 40 mg of hyoscine butylbromide or no spasmolytic. Subjects were also independently randomized to undergo CT colonography with an inflatable rectal balloon catheter or a standard thin rectal tube. Multi-detector row CT colonography was performed with patients in prone and supine positions, with colonic segmental distention assessed by a single observer with a four-point scale. A simple assessment of whether distention was adequate for clinical interpretation was also made, and the effect of hyoscine butylbromide and catheter use was examined by using multivariate ordered logistic regression. RESULTS: Administration of hyoscine butylbromide was associated with significantly improved cecal (P =.05), ascending (P =.001), and transverse (P <.001) colonic distention when patients were supine and improved ascending (P <.001) and descending (P <.001) colonic distention when patients were prone. Compared with control subjects, patients given a spasmolytic had odds of 6.49 for clinically adequate distention throughout all colonic segments (P =.001). There was no incremental advantage with use of a 40-mg dose. In contrast, rectal balloon catheter use was not significantly associated with improved distention. CONCLUSION: Hyoscine butylbromide improves colonic distention during CT colonography and should be routinely administered where it is available. Use of a thin rectal tube for insufflation is adequate.

Adult↗

PubMed2003

Intravaginal clindamycin to reduce preterm birth in women with abnormal genital tract flora.

OBJECTIVE: To assess the ability of clindamycin vaginal cream to reduce the incidence of preterm birth in women with abnormal genital tract flora in the second trimester of pregnancy. METHODS: This was a randomized, double-blind, placebo-controlled, tricenter study. A total of 409 women with abnormal genital tract flora on Gram stain of vaginal secretions at 13-20 weeks' gestation were randomized to receive a 3-day course of clindamycin vaginal cream or placebo. Those women who still had abnormal vaginal flora 3 weeks later received a 7-day course of the original study drug (ie, either clindamycin vaginal cream or placebo as per original randomization). The primary outcome measure was the incidence of preterm birth. RESULTS: There was a statistically significant reduction in the incidence of preterm birth in the clindamycin vaginal cream group (4%) compared with placebo (10%) (P <.03). Significantly more babies born preterm (63%) required admission to the neonatal intensive care unit compared with term infants (4%) (P <.001). CONCLUSION: A 2% clindamycin vaginal cream, when compared with placebo administered to women with abnormal genital tract flora before 20 weeks' gestation, can reduce the incidence of preterm birth by 60% and hence the need for neonatal intensive care.

Administration, Intravaginal↗

PubMed2003

Cardiovascular effects at multi-detector row CT colonography compared with those at conventional endoscopy of the colon.

PURPOSE: To compare the cardiovascular effects of computed tomographic (CT) colonography and conventional endoscopy in a group of patients undergoing both procedures. MATERIALS AND METHODS: A total of 144 patients underwent CT colonography followed by flexible sigmoidoscopy (40 patients) or colonoscopy (104 patients). Pulse, blood pressure, and oxygen saturation were measured before, during, and after the procedures. Forty patients also underwent continuous Holter electrocardiographic (ECG) monitoring. Periprocedural pain was assessed by using a handheld counting device. Outcome variables were assessed by using a combination of paired t testing and multilevel linear regression. RESULTS: When a spasmolytic was not used, CT colonography was associated with only a small increase in oxygen saturation (P =.03), while use of a spasmolytic caused an increase in pulse (mean increase, 19.9 beats per minute; P <.001) and diastolic blood pressure (mean increase, 5 mm Hg; P <.001). Compared with that at CT, oxygen saturation decreased significantly during and after colonoscopy and sigmoidoscopy (mean decrease after colonoscopy with sedation, 1.0%; P <.001). Systolic and diastolic blood pressure also decreased during and after colonoscopy (mean systolic decrease after colonoscopy with sedation, 16.6 mm Hg, P <.001; mean diastolic decrease after colonoscopy with sedation, 7.5 mm Hg, P <.001). Patients were 30.3 times more likely to develop bradycardia after endoscopy (95% CI: 2.65, 346; P =.006). Ventricular couplets were significantly higher at endoscopy than at CT in patients with a history of cardiac disease (odds ratio: 72.5 and 95% CI: 4.56, 1,153 at CT vs odds ratio: 14.6 and 95% CI: 0.96, 222 at endoscopy; P =.002). Patients were 1.89 times more likely to register pain during colonoscopy than during CT (95% CI: 1.06, 3.38; P =.03). CONCLUSION: CT colonography had no significant cardiovascular effect other than spasmolytic-induced tachycardia. Endoscopy-and colonoscopy in particular-causes cardiovascular effects that are largely related to sedation. CT colonography is less painful than colonoscopy and is comparable to flexible sigmoidoscopy.

Adult↗

PubMed2003

Acceptance by patients of multidetector CT colonography compared with barium enema examinations, flexible sigmoidoscopy, and colonoscopy.

OBJECTIVE: The purpose of this study was to compare patient acceptance of multidetector CT colonography, total colonoscopy, flexible sigmoidoscopy, and double-contrast barium enema to ascertain any overall preference. SUBJECTS AND METHODS. One hundred sixty-eight patients underwent CT colonography followed by either flexible sigmoidoscopy (n = 59) or colonoscopy (n = 109). A 25-point questionnaire with principal components relating to satisfaction, worry, and physical discomfort was administered after CT colonography and after endoscopy, and a follow-up questionnaire was administered 1 week after the procedures. Questionnaires were also completed by 140 patients undergoing double-contrast barium enema examinations. Responses were compared using Wilcoxon's matched pairs test and the Mann-Whitney test. RESULTS: Overall satisfaction was greater with colonoscopy (p = 0.01), but CT colonography caused less discomfort (p = 0.002), was better tolerated (p = 0.005), and was the preferred follow-up investigation of those expressing a preference (p = 0.003). Compared with flexible sigmoidoscopy, CT colonography caused less pain (p = 0.004), was more acceptable (p = 0.04), and was preferred as the follow-up investigation (p < 0.001). Tolerance of colonoscopy was significantly less in women (p = 0.03), but such was not the case for CT colonography (p = 0.58). Patients undergoing CT colonography were less worried (p < 0.001), were more satisfied (p = 0.001), and suffered less discomfort (p < 0.001) than those having barium enema. CONCLUSION: Patients' experiences with barium enema examinations were significantly worse than with any other test. Although patients were most satisfied with colonoscopy, they reported more pain during both colonoscopy and sigmoidoscopy than during CT colonography, and they also found CT more acceptable. In patients expressing a preference, CT colonography was the preferred follow-up investigation.

Adult↗

PubMed2002

Electromagnetic motion analysis in the assessment of surgical skill: Relationship between time and movement.

INTRODUCTION: Electromagnetic motion analysis is a promising method of assessing surgical skill in a skills-laboratory setting. There is a very strong correlation between movement and time data, and this study was conducted to determine whether this relationship is fixed, or whether it can vary. METHODS: : After a pilot study, four subjects were recruited. Each performed 30 trials of a simple standardized suturing task, alternating between 'normal', 'precise', and 'fast' strategies. The number of movements, and time to complete each task were recorded. RESULTS: Comparing the 'fast' to 'normal' strategies, there was a significant decrease in total number of movements per trial (P < 0.001), and time taken (P < 0.001). Regression analysis was performed to examine the relationship between the time taken and the number of movements, and revealed significant differences between both the fast (P = 0.006), and precise (P = 0.002) strategies, when compared to the normal strategy. DISCUSSION: This study confirms that the relationship between time and movements is not fixed, but varies with the operative strategy adopted for this simple suturing task.

Clinical Competence↗