Biomedical subjects

Peter Funch-Jensen

Publications and source records attributed to Peter Funch-Jensen.

23 records · Page 2Linked to original sources

PubMed2003

Gut pain and hyperalgesia induced by capsaicin: a human experimental model.

Human experimental visceral pain models using chemical stimulation are needed for the study of visceral hyperexcitability. Our aim was to stimulate the human gut with chemical activators (capsaicin, glycerol) and measure quantitatively the induced hyperexcitability to painful mechanical gut distension. Ten otherwise healthy subjects with an ileostoma participated. Increasing volumes of capsaicin 50 microg/ml (0.25, 0.5, 0.75, 1.0, 1.5, 2.0, and 3 ml), glycerol (2.5, 5, and 10 ml) or saline (2.5, 5, and 10 ml) intermingled with sham stimuli were randomly applied to the ileum via the stomal opening at three occasions separated by a week. After each application, pain intensity, qualities, and referred pain area were assessed together with the pain threshold to distension of the proximal gut. 'Boring' and 'hot' pain were evoked in all subjects by low doses (median 0.5 ml) of capsaicin. The median pain onset, peak pain, and pain duration were 55, 85, and 420 s, respectively. Referred somatic pain developed around the stomal opening with a correlation between the pain area and pain intensity. After application of capsaicin, significant hyperalgesia was found to distension of the gut (a 28% reduction pressure in pain threshold). No significant manifestations were found after application of glycerol and saline. Application of capsaicin to the human ileum induces pain and mechanical hyperalgesia. Specific activation of nociceptors in the gut mucosa provides new possibilities to study clinical relevant visceral pain mechanisms.

Adult↗

PubMed2003

Induction of non-painful and painful intestinal sensations by hypertonic saline: a new human experimental model.

BACKGROUND AND AIMS: To develop a pain model for chemical stimulation of the human gut. METHODS: In a double-blind experimental study 10 subjects with a previously performed sigmoidostomy were randomised to receive injections with either isotonic or hypertonic saline in the colonic mucosa. In the hypertonic experimental arm, 0.1 ml of 0.9%, 2%, 4%, and 6% and 0.2 ml of 2% and 4% saline were given. In the placebo arm, six 0.9% saline injections of the same quantities were given. In a separate experiment 0.8 ml 4% saline was infused into the mucosa by a pump over a period of 2min. The pain intensity was rated on a 0-10 visual analogue scale with 5 as the pain threshold. RESULTS: The hypertonic saline injections resulted in local as well as referred non-painful and painful sensations in 9 out of the 10 subjects. The evoked sensations were mostly described as a smarting sensation with an intensity of median 1 (range 0-5.6) for 0.1 ml 2% saline to median 2.9 (range 0-6.2) for 0.2 ml 4% saline. Seven subjects reported referred sensations to the abdominal skin. Continuous infusion of 4% saline resulted in a consistent sensory response in all subjects, with a median intensity of 4.1 (range 2.1-8.1). This sensory intensity was reproducible in 70% in a retest experiment after median 7 weeks. In the placebo arm a total of 70 isotonic saline injections only resulted in inconsistent, short-lasting non-painful sensations in three subjects. CONCLUSION: The model represents a safe method for direct chemical activation of the sensory endings in the human gut. The model may be used for pharmacological screening of analgesics and for basic investigations in patients suffering from gastrointestinal diseases.

Adult↗

PubMed2003

Gastric dysrhythmia in infants with gastrointestinal diseases measured by epigastric impedance.

BACKGROUND: Gastrointestinal symptoms have been reported in association with myoelectrical dysrhythmia, where different types of gastric electrical activity have been described. These types of gastric myoelectrical activity and dysrhythmia can be measured by electrogastrography using cutaneous electrodes. Epigastric impedance is a non-invasive method used to study gastric emptying time and gastric phasic activity. At present no study of gastric dysrhythmia, measured with epigastric impedance, has been presented, and the purpose of the present study was to investigate gastric rhythms by means of impedance gastrography in control infants, compared to infants with different gastrointestinal diseases, before and after treatment of their disease. METHOD: 21 patients (age 0-2 months) and 40 healthy infants (age 0-2 months) were investigated. The patients suffered from partial or total intestinal obstruction, necrotizing enterocolitis or pyloric stenosis.All infants were fasting and studied during periods of at least one hour. The patients were examined in the acute state and after treatment when possible. RESULTS: A pathologic result was found in 90% of the patients. A persistent phasic activity pattern was found in 19 of the 21 patients, high frequency phasic activity in 11 of the 21 patients. Short-term phasic activity was only found in 13 out of 40 of the normal infants (32.5%). CONCLUSION: Using epigastric impedance we found that infants with partial or total intestinal obstruction had gastric phasic activity, which was not found in the control infants. The origin of the gastric phasic activity patterns is unknown, but they may be related to electrical control activity.

Electric Impedance↗

PubMed2002

Assessment of technical surgical skills.

OBJECTIVE: To review methods of assessment of technical surgical competence, and to point out the potential benefit of such assessment to training and safe practice. DESIGN: Review of publications about methods of evaluation of technical surgical competence. Studies were identified through MEDLINE using the keywords surgery, assessment, operative skills, training, and competence. The references cited in these studies were reviewed to find out whether any other trials fitted the selection criteria. SETTING: Teaching hospital, Denmark. RESULTS: There are several validated methods that allow objective assessment of operative skills for both open and laparoscopic surgery. CONCLUSIONS: Objective assessment of technical surgical skills is possible and reliable and valid methods are available. There are good reasons to implement evaluation programmes as a part of surgical education.

Clinical Competence↗

PubMed2002

Somatosensory changes in the referred pain area following acute inflammation of the appendix.

BACKGROUND AND AIMS: Abdominal pain provoked by acute gastrointestinal disease may increase the sensitivity in the referred somatic pain area. The aim of this study was to examine sensory changes in the referred pain area during acute appendicitis. SUBJECTS: Twenty patients with clinical symptoms of appendicitis were included; 16 of these had appendicitis confirmed at operation. Ten healthy volunteers served as controls. METHODS: In patients with symptoms of appendicitis, somatic sensitivity was assessed using different stimuli presented in the area of referred pain and in a comparable non-painful area at the contralateral site of the abdomen. In healthy control subjects, the same stimuli were presented to McBurney's point and at a similar area on the left abdomen. The rating to pinprick was determined using a Von Frey hair. The rating to thermal stimuli was tested by warm and cold metal rollers. A constant current stimulator was used to measure the sensation and pain-detection threshold to single and repeated electrical stimuli. The pressure pain threshold was determined by an electronic pressure algometer. RESULTS: Patients (n = 16) with verified appendicitis showed increased ratings to pinprick (50%, P < 0.05) and thermal stimuli (56%, P < 0.05) in the referred pain area. There was a reduction in pain thresholds to single electrical (4.3 v. 8.4 mA, P = 0.001), repeated electrical (3.5 v. 4.6 mA, P = 0.005) and pressure (89 v. 243 kPa, P < 0.001) stimuli in the referred pain area versus the control area. In the control group, no difference was observed between the two areas. The pain thresholds for electrical and pressure stimuli were lower in the referred pain area in patients compared with the same area in controls (P < 0.001). CONCLUSION: Somatosensory hyperalgesia to experimental stimuli was observed in acute appendicitis. We believe that viscerosomatic convergence mechanisms and central nervous system hyperexcitability explain these findings.

Abdominal Pain↗