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Biomedical subjects

S Boesby

Publications and source records attributed to S Boesby.

At least 73 records · Page 4Linked to original sources
PubMed1978

Comparative pressure measurements in the oesophagus by means of in situ tip-transducers and external transducer systems.

Basal gastro-oesophageal sphincter pressures and peak peristaltic pressure amplitudes in the oesophageal body 5 and 15 cm proximal to the gastro-oesophageal sphincter were measured with three different set ups in six healthy volunteers. The in situ tip-transducer measurements were compared to two different external pressure transducers in a perfused catheter system and to an external pressure transducer in a non-perfused catheter system. The in situ tip-transducer recorded higher sphincter pressures and peristaltic amplitudes than those recorded by the perfused and non-perfused systems (P less than 0.01). There was no difference between the pressures recorded by perfused systems in conjunction with the different external transducers. The perfused systems recorded sphincter pressures higher than those recorded by the non-perfused systems (P less than 0.02 and P less than 0.01), whereas the non-perfused system recorded higher peristaltic pressure amplitudes than those recorded by the perfused systems (P less 0.01 and P less than 0.01). The importance of the bend of the in situ tip-transducer was shown experimentally. It is concluded that the ideal system for recording oesophageal pressures is a perfused catheter set-up with minimal compliance. The probe with three side holes at the same level ensures registrations of the lowest occlusion pressure at the measuring point.

Adult↗
PubMed1978

Oesophageal peristalsis. A simple system for the recording of oesophageal peristalsis, and the influence of bolus volume on peak peristaltic pressure amplitude.

Peak oesophageal peristaltic pressure amplitude was recorded in 8 healthy subjects at points 5 and 15 cm proximal to the gastro-oesophageal sphincter, by using an in situ tip-transducer simultaneously with a continuous flush (Intraflo) perfused catheter system with external pressure transducer. Dry swallows and wet swallows of 2.5, 5 and 10ml, respectively, were made in random succession. In all cases the pressures recorded by either system correlated well. In all cases the peristaltic pressure amplitude was significantly higher after the wet swallows. The catheter and flow system used in this study is simple and makes recording of peristaltic pressures independent of the shape of the in situ transducer, and its therefore well suited for measuring the amplitude of oesophageal contractions.

Adult↗
PubMed1978

The effect of HCl infusion in the lower part of the oesophagus on the pharyngo-oesophageal sphincter pressure in normal subjects.

A measuring unit combined with a perfused catheter has been developed for measurement of the pharyngo-oesophageal sphincter pressure. The system is able to register pressure measurements using either intermittent or continuous withdrawal of the catheter, at the same flow rate (0.5 ml/min). Repeated measurements of pharyngo-oesophageal sphincter pressure have been made on eight healthy volunteers. No differences were found in the sphincter pressures measured by the continuous and the intermittent withdrawal techniques (p greater than 0.10); the coefficient of variation was 0.18 for both techniques. The pharyngo-oesophageal sphincter pressure was measured during infusion of 0.1 N HCl (5 ml/min) 5 cm proximally to the gastro-oesophageal sphincter. There was an increase in the pharyngo-oesophageal sphincter pressure after 1 min of infusion (p less than 0.05). Measurements after 5 min and 10 min were no different from the initial value; thus a fall was observed between the first and the fifth minute (p less than 0.05). The observed rise in sphincter pressure may be explained as a response acting to prevent gastro-oesophageal reflux from entering the pharynx.

Adult↗
PubMed1977

Relationship between gastro-oesophageal acid reflux, basal gastro-oesophageal sphincter pressure, and gastric acid secretion.

Twelve-hour continuous pH-recording at the distal end of the oesophagus and measurement of basal gastro-oesophageal sphincter pressure with perfused catheters were carried out in 108 subjects. Fasting gastric secretion, basal secretion, and maximal acid secretion after subcutaneous injection of 6 microgram pentagastrin/kg bodyweight were determined additionally in some of the subjects. There was a significant inverse correlation between the results of continuous pH-recording and basal gastro-oesophageal sphincter pressure, which confirms the relationship between low sphincter pressure and gastro-oesophageal acid reflux. Furthermore, there was a significant direct correlation between the results of continuous pH-recording and the volume of basal secretion and the basal acid output. These findings emphasize the significance of gastric acid secretion for the results of continuous pH-recording. As reflux-preventive surgery may elicit alterations in the variables of acid secretion, the results of continuous pH-recording do not allow conclusions to be drawn with regard to the effectiveness of a surgically established gastro-oesophageal barrier.

Adolescent↗
PubMed1977

Gastro-oesophageal acid reflux in patients with symptomatic hiatus hernia and effect of a modified Belsey MK IV repair on acid reflux.

Twelve-hour continuous recording of pH at the distal end of the oesophagus was carried out in 59 patients with sliding hiatus hernia and symptoms suggestive of gastro-oesophageal reflux, and the results were compared with those obtained in normal subjects. Mean duration of pH less than or equal to 2.3, pH less than or equal to 3, pH less than or equal to 4 and pH less than or equal to 5, expressed in percentages of the total time of recording, was longer in patients than in normal subjects. There was no difference in mean number of reflux episodes between patients and normal subjects. The clearest separation between the two groups was obtained by the variable 'duration of pH less than or equal to 5'. Irrespective of the variable used, the results did not seem to be related to the degree of severity of the symptoms. Individual sensitivity of the oesophageal mucosa, the content of bilious components in the refluxed material, and the semi-quantitative character of the investigation may, in part, account for the results. Furthermore, the same investigation was carried out before and three months after a modified Belsey MK IV repair in 39 patients with hiatus hernia and symptoms indicating surgical treatment. The operation was followed by a reduction in the tendency to acid reflux, probably as a result of an increase in the competence of the gastro-oesophageal region.

Adult↗
PubMed1977

Gastric acid secretion in patients with symptomatic hiatus hernia and effect of a modified Belsey MK IV repair on gastric acid secretion.

Fasting, basal, and pentagastrin-stimulated (6 microgram/kg body weight) gastric acid secretion was assessed in 53 patients with radiologically verified sliding hiatus hernia without stricture formation. There was no difference in the acid secretory variables between patients with heartburn and those with heartburn and pain. A study of the acid secretory variables in 34 patients before and 3 months after a modified Belsey MK IV repair for symptomatic hiatus hernia showed that after the repair the pH of basal secretion had risen, and that the volume of basal secretion as well as basal and peak acid output had been reduced. These changes must probably be ascribed to an unintentional vagotomy during the operation. It is concluded that in the evaluation of a surgically established barrier against gastro-oesophageal reflux in terms of oesophageal pH, changes in gastric acid secretion should be taken into consideration.

Adult↗
PubMed1977

Gastro-oesophageal sphincter pressure, motility and acid clearing. A study of hiatus hernia patients and normal subjects and of the effect of a modified belsey MK IV repair on the results of the manometric and acid-clearing tests.

Basal gastro-oesophageal sphincter pressure was recorded in 68 patients with symptomatic, radiologically verified sliding hiatus hernia, and in 37 healthy subjects. The diameter of the probe was 2.5 mm, and the flow rate 0.5 ml/min. Mean sphincter pressure was lower in patients (6 mm Hg) than in normal subjects (15 mm Hg). In 32 per cent of the patients sphincter pressure was within normal range (8-24 mm Hg), whereas in 68 per cent it was lower than in the normal subjects. There seemed to be no relationship between sphincter pressure and severity of symptoms. Oesophageal acid clearing was investigated in 57 of the patients and in 26 of the normal subjects. Normal subjects clear the bolus of acid in an average of 10 swallows (range 4-16). In patients the incidence of prolonged clearing was greater, but the acid-clearing ability did not seem to be related to the degree of severity of the symptoms. A manometric study was made of 45 patients and an acid-clearing study made of 40 patients, before and 3 months after a modified Belsey MK IV repair for hiatal hernia. Mean postoperative sphincter pressure was higher (10 mm Hg) than the preoperative mean (6 mm Hg), but was still lower than the normal mean. Significant changes in acid-clearing ability could not be demonstrated. The results are inconclusive with regard to the importance of oesophageal motility disturbances for the symptomatology and acid-clearing ability. Thirty-seven out of 45 patients became free of symptoms, and the rest - except 1 (relapse of hernia) - improved.

Adult↗
PubMed1977

Effect of changes in the intragastric milieu on competence of the gastro-oesophageal region. A study in normal subjects.

Acid-reflux studies were carried out in 10 healthy subjects in the basal state, during continuous infusion of pentagastrin (0.015 mug/kg body-weight) after bolus injection of insulin (0.2 IU/kg bodyweight), and after intragastric instillation of 200 ml hydrochloric acid. Basal gastro-oesophageal sphincter pressure and rise in intragastric pressure on leg raising were measured by means of perfused catheters. The increase of intragastric acidity during infusion of pentagastrin and during insulin-induced hypoglycaemia was not accompanied by changes in the competence of the gastro-oesophageal region. Instillation of hydrochloric acid was followed by a significant enhancement of the reflux tendency. Changes in intragastric pressure-rise were not demonstrated in any of the series of investigation. Gastric acid secretion and its significance at the evaluation of the results of reflux studies by means of pH-measuring equipment has not been clarified in patients. It can therefore reasonably be demanded of future acid reflux studies that details have to be stated with regard to acid secretion, and that these should be taken into account at the assessment of the results of the study.

Adult↗
PubMed1977

Continuous oesophageal pH recording and acid-clearing test. A study of reproducibility.

Ten investigations of acid reflux by means of 12-hour continuous pH monitoring at the distal end of the oesophagus, and 10 acid-clearing tests were performed within 6 weeks on the same volunteer with the purpose of examining the reproducibility of the results of these tests. Intragastric pH was studied over 12 hours and proved to be under 3 during the whole period of investigation. For the acid reflux test the coefficient of variation was 0.61-0.94, depending on the criteria for reflux. For the acid-clearing test the coefficient of variation was 0.22. For both tests the results of the separate investigations varied within normal ranges.

Adult↗
PubMed1977

The acid perfusion test. A study in patients with symptomatic hiatus hernia, and of the effect of a modified Belsey MK IV repair on the test.

Acid perfusion with 0.1 n HC1 (5 ml/min for max. 30 min) and simultaneous intragastric instillation of equimolar amounts of sodium bicarbonate were performed in 55 patients with sliding hiatus hernia and symptoms attributable to gastro-oesophageal reflux. Acid perfusion reproduced the patient's spontaneous symptoms, and was thus positive, in 44 per cent of the cases. A positive acid perfusion test means that the patient's spontaneous symptoms may be of oesophageal origin, whereas a negative test does not allow any conclusions. The acid perfusion test was likewise performed before and three months after a modified Belsey MK IV repair in 37 patients with hiatal hernia and symptoms indicating surgical repair. The operation was followed by a reduction in oesophageal acid sensitivity (p less than 0.01).

Adult↗
PubMed1976

The effect of carbachol on resting gastro-oesophageal sphincter pressure and serum gastrin in normal human subjects.

With the purpose of investigating the mechanism of action behind the rise in gastro-oesophageal sphincter pressure induced by cholinergic activity, serum gastrin and sphincter pressure were recorded in 8 normal human subjects before and in relation to administration of carbachol. Carbachol was given subcutaneously in a dose of 4.5 mug per kg body weight. Mean sphincter pressure recorded 15, 30, and 45 minutes after administration of carbachol was significantly higher than the basal mean. The administration of carbachol did not lead to significant changes in serum gastrin and a relationship between serum gastrin and sphincter pressure was not demonstrable. It is concluded, that the carbachol-induced rise in the basal sphincter pressure is not dependent on an increase in serum gastrin, but probably attributable to either direct cholinergic stimulation of the receptors or a cholinergically enhanced sensitivity of the receptors for gastrin. Moreover, it is concluded that carbachol in individual dosages may be a suitable adjuvant in the medical treatment of patients with gastro-oesophageal reflux.

Adult↗
PubMed1976

Effect of barium meal on resting gastro-oesophageal sphincter pressure in normal human subjects.

The effect of ingestion of 250 ml X-ray contrast medium on resting gastrooesophageal sphincter pressure was studied in 10 normal human subjects. Twenty minutes after initiated intake of the contrast medium, a significant fall in sphincter pressure was recorded. In the light of studies on the neurogenic and hormonal regulation of the sphincter pressure it is attempted to account for this effect, and it is concluded that it must be a manifestation of a reflectory relaxation of the sphincter region. From a clinical point of view the consequence must be a demand for standardized conditions with regard to composition and pH of the contrast medium, time schedule and degree of abdominal compression in those cases in which radiological evaluation of the resistance against reflux is called for.

Adult↗
PubMed1975

Gastro-oesophageal acid reflux. Method for 12-hour continuous recording of oesophageal pH with analysis of records.

Description of method for continuous recording of oesophageal pH and automatic, electronic analysis of records. Stability of apparatus has been tested over 12 hours in the laboratory with different buffer solutions and gastric secretions with and without bile, and on 36 patients with oesophageal disorders. Drift of apparatus max. 0.2 pH units. The analyser, dividing the pH range into arbitrary intervals, performs a rapid and reliable analysis of single examinations from variable criteria. The temporal distribution of pH values into the intervals is expressed in percentages of the total time of recording. Reliability of the analyser was tested by analysis of a simulated pH curve on which changes in amplitude corresponded to the most rapid changes seen in practice. Deviation below one per cent. Repeated analyses of the same records showed a coefficient of variation for the various analytical interval to be 10-0.01 per cent. The method allows recording of the number of reflux episodes, duration of each episode and total duration of pH within chosen limits.

Adult↗
PubMed1975

Gastro-oesophageal acid reflux and sphincter pressure in normal human subjects.

Twelve-hour continuous recording of pH at the distal end of the oesophagus and manometric study of the basal gastro-oesophageal sphincter pressure were carried out in 26 normal human subjects. Eighteen of the 26 had 1-33 reflux episodes. The duration of each episode was shorter than 15 min in 16 of these 18 subjects. One single reflux episode lasting 15-30 min occurred in two, and one lasting 30-45 min was recorded in one. The total duration of low pH is expressed in percentages of the total time of recording and is dependent on the criteria used for low pH. On automatic analysis of the course of investigation, pH below 2.3 was found in five, pH below 3 in 17, and pH below 4 and 5, in 18 of the 26 subjects. Basal gastro-oesophageal sphincter pressure flutuated between 8 and 24 mmHg. The results of the study would suggest that in healthy, asymptomatic individuals the gastro-oesophageal barrier against reflux may be periodically incompetent. If contact between acid gastric contents and the oesophageal mucosa is a factor provoking the symptom heartburn, low oesophageal pH need not necessarily give rise to symptoms, i.e. the sensibility to low pH is either individual, or patients with symptoms have considerably more frequent and longer lasting episodes of reflux with low oesophageal pH than have normal subjects.

Adolescent↗