K. Kraglund

Consistency in Manual Scoring Analysis of Gastrointestinal Pressure Recordings

The aim of the present study was to evaluate the consistency in visual scoring and whether this could be the basis for computer analysis using pattern recognition techniques. We studied the consistency of visual scoring of pressure tracings from the upper gastrointestinal tract with regard to pressure wave identification. The aim was to make such an identification the golden standard for computerized analysis of pressure waves. Pressure recordings containing different phases of contraction activity were evaluated by five trained observers. The inter- and intra-observer agreement was highest in periods with high contraction activity (phase III), both of which were better than 90%. In periods with low contraction activity (phases I and II) this agreement was as low as 49%. The results indicate that forming a learning set for pattern recognition should only be based on visual scoring during phase-III activity.

Quantitative determination of pyloric regurgitation in response to intraduodenal bolus injection.

Employing 99m Tc-colloid and external scanning, a test has been developed to measure duodeno-gastric regurgitation quantitatively. The test is relatively simple and its reproducibility is good. Thirty-two patients with type I gastric ulcer had a median reflux of 14%, significantly higher than nine controls and nine duodenal ulcer patients with a median reflux of 4% and 5%, respectively.

The effect of a new selective a2-adrenoreceptor antagonist, idazoxan, and the agonist, clonidine, on fasting antroduodenal motility in healthy volunteers

Studies were carried out on 16 healthy male volunteers to investigate whether intravenous administration of the α2‐adrenoreceptor antagonist, idazoxan, could affect fasting antroduodenal motility with and without administration of the agonist, clonidine. Contractile activity was recorded using an oral tube with perfused side holes positioned in the stomach and duodenum.

The Relation between Antral Contractile Activity and the Duodenal Component of the Migrating Motility Complex

The aim of the study was to investigate the relationship between antral and duodenal fasting motor activity in 19 healthy volunteers using a perfused tube assembly with side-holes placed in the distal antrum, second part of the duodenum and in the duodenum near the ligament of Treitz. Registrations were performed until the end of the second duodenal phase III. Eighty-two per cent of the duodenal phases III were preceded by antral activity. The duration of duodenal phase III showed a positive correlation to the preceding number of antral contractions (p less than 0.001) as well as to antral phase III (p less than 0.05), but no correlation to the duration of antral phase III was found. The duration of the migrating motility complex (MMC) showed a positive correlation to the duration of duodenal phase III (p less than 0.05), but no correlation to the preceding number of antral contractions were found. It may be concluded that the level of duodenal activity is very dependent on the preceding antral activity.

Radial analysis of duodenal motility recordings in humans

To analyze radial variations in pressure recordings from the human duodenum, we used a catheter with six radially placed side holes with identical dynamic characteristics. Twenty-one hours of fasting pressure recordings were obtained in six volunteers. Computer-based cross-correlation analysis, event detection and counting, amplitude analysis, and concordance analysis were used for comparing the signals of the individual channels. Both the cross-correlation analysis and the counting of events showed radial asymmetry of contractile activity. This asymmetry was not related to any individual channel. The maximum difference between the individual channels was constantly between diametrically opposite spaced channels. The asymmetry was most pronounced during phase-I-like and phase-II-like activity of the migrating motility complex, whereas a much higher degree of cross-correlation and concordance was shown during phase-III-like activity. The results indicate that a greater in-depth analysis of pressure recordings from the small intestine--such as identification of individual events and differentiation between contractions and artefacts--requires that the recordings as a minimum comprise two diametrically placed side holes at each measurement level.

Antroduodenal motility and gastric emptying. Gastroduodenal motility and pH following ingestion of paracetamol

The influence of paracetamol on antroduodenal motility and gastric pH was studied in 11 healthy subjects and the relationship between gastroduodenal motility and gastric emptying rate time, tmax, to peak concentration of serum paracetamol, Cmax, was evaluated. The incidence of antral phase III activity and the duration of phase III was diminished with paracetamol (P < 0.05). The other motility parameters assessed were unchanged.

Intraoperative sphincter of Oddi manometry in patients with gallstones.

In seven patients operated on with cholecystectomy for simple gallstones, sphincter of Oddi manometry was performed during surgery. The sphincter was localized as a zone with elevated base-line pressure and phasic contractile activity. Mean value of the amplitude was 90 mm Hg; wave duration, 4 sec; frequency, 5/min; and base-line pressure, 10 mm Hg. No activity was seen in the antrum or duodenum. The plotting of peak-to-peak intervals in a histogram showed that these were evenly distributed around 6 sec or at integrated multiples of this value. This indicates that the sphincter of Oddi is paced. The origin of the pacing is not yet established.

Influence of Porosity on the Viability of the Neointima

The influence of porosity on the viability of the neointima was evaluated in two types of Dacron vascular prostheses with quite different porosities. It could be concluded that the observed parietal thrombus formation in functioning prostheses, and the dislodgement of the neointima in several of these, might well be attributed to the low porosity of the investigated prostheses, as compared to the recommended value. At the same time it is remarkable that no pronounced difference in the histological picture was observed in the two types of prostheses, despite large differences in their mutual porosities.

Gastric Acid Secretion during Halothane, Chloralose, Pentobarbital and Etomidate Anaesthesia in the Pig

The gastric acid secretion in the awake state of the pig was compared to that during halothane, chloralose, pentobarbital and etomidate anaesthesia. After collection of basal juice, acid secretion was stimulated with pentagastrin in the dosages of 0.25, 1.00 and 4.00 micrograms/kg/h. Halothane strongly inhibited acid secretion, whereas acid secretion during chloralose anaesthesia was enlarged by a factor 6 as compared to that of the awake animal. The mean acid output after receiving pentobarbital was close to that of the awake condition, but the interindividual variation was large. Nearly identical values for acid secretion were found during etomidate anaesthesia, but with much higher consistency in the results. Etomidate anaesthesia seems to be the most suitable method for measurements of gastric acid secretion during anaesthesia in the pig.

The Influence of Measuring Catheter Diameter on Direct Manometry in the Canine Sphincter of Oddi

Sphincter of Oddi manometry was performed in three anesthetized dogs, using different measuring catheter diameters, ranging from 1.0 to 1.9 mm. No differences were seen either in sphincter of Oddi wave amplitude, frequency, and base-line pressure or in common bile duct pressure measured after cannulation during 20 min with catheters of 1.0 and 1.3 mm. However, significant disturbances of these variables were present when the measuring catheter diameter was 1.6 and 1.9 mm. It is concluded that the diameter of the recording catheter is of crucial importance in sphincter of Oddi manometry. In dogs with a body weight of 30-40 kg, the outer diameter should not exceed 1.3 mm.