How does morphine work on colonic motility? An electromyographic study in the human left and sigmoid colon.
ABSTRACT The effect of morphine on colonic motility was investigated by recording the colonic myoelectric spiking activity by means of a 50 cm long silastic tube equipped with 4 bipolar AgAgCl ring electrodes fixed at 10 cm intervals that was introduced into the left colon in 8 healthy subjects by flexible sigmoidoscopy. Tracings were obtained for 1 hour in the fasting state and for another 1 hour after i.m. injection of morphine sulphate 0.15 mg/kg. The different types of spike bursts were compared before and after morphine injection. The control tracings showed that the spiking activity of the colon was made of 2 types: 1)- Rhythmic Stationary Spike Bursts (RSB), that were seen at only one electrode site; 2)- Sporadic Bursts, that were either propagating over all 4 electrodes (SPB) or non propagating (SNPB). Injection of morphine was followed by 1)- a considerable increase in the number of RSB from 107 +/- 43 bursts/hour (mean +/- SEM) to 491 +/- 23 bursts/hour; 2)- the complete disappearance of the SPB dropping from 7.3 +/- 2.0 bursts/hour to 0.3 +/- 0.2 bursts/hour; 3)- no significant change in SNPB (from 52 +/- 4 bursts/hour to 57 +/- 5 bursts/hour). These results indicate that 1)- stimulation of colonic smooth muscle activity by morphine seems to result from an increase in the number of rhythmic stationary bursts; 2)- however inhibition of colonic transit may be related to the decrease in the number of sporadic propagating bursts.
Article: Kombinierte Anästhesieverfahren[Show abstract] [Hide abstract]
ABSTRACT: Die additiven Eigenschaften von Allgemeinanästhesie und Regionalanästhesie werden bei Kombinierten Anästhesieverfahren genutzt, um Nebenwirkungen der Einzelverfahren zu minimieren und zusätzlich positive Effekte zu erreichen. Obwohl diese Kombination nicht neu ist, gibt es bisher keine eindeutigen Empfehlungen bezüglich Indikationen, Kontraindikationen und Durchführung. Von besonderem Interesse ist die Kombination der Allgemeinanästhesie mit einer thorakalen Epiduralanästhesie (TEA) hinsichtlich positiver Effekte auf Hämodynamik, Lungenfunktion, Magen-Darmtrakt und postoperative Streßantwort. Der Nachweis, daß kombinierte Anästhesieverfahren in der Lage sind, die intraoperative Morbidität und Mortalität zu senken, konnte bisher jedoch nicht erbracht werden. Grundsätzlich steht aber mit der zusätzlichen periduralen Anästhesie ein effizientes Verfahren zur postoperativen Schmerztherapie zur Verfügung, so daß im gesamten perioperativen Management vor allem bei Risikopatienten günstige Effekte auf die Rekonvaleszenz gezeigt werden konnten. Da sich durch die Kombination zweier Anästhesieverfahren theoretisch auch die Häufigkeit an Komplikationen erhöhen kann, muß der individuelle perioperativ zu erwartende Nutzen für den Patienten überwiegen. Zur Abschätzung von Nutzen und Risiko müssen die Wirkungsweise und spezifischen Komplikationsmöglichkeiten der Einzelverfahren, aber auch die synergistischen Effekte beider Verfahren bekannt sein und für den einzelnen Patienten abgewogen werden. The additive properties of general and regional anesthetic techniques are brought together in combined anesthesia to minimise side effects of the individual techniques. Despite a wide experience with both used as single anesthetic techniques, no definite recommendations regarding indications, general contraindications and procedure exist for their combination. Beneficial effects on haemodynamics, respiratory function, intestinal motility and postoperative stress response have been demonstrated for a combination of general anesthesia and thoracic epidural anesthesia (TEA). In addition TEA is favourable in the management of postoperative pain, which has advantageous effects on convalescence especially in a high risk patient group. Nevertheless, until now no reduction of perioperative morbidity and mortality has been demonstrated. Since the combination of two anesthesia techniques theoretically increases the rate of complication, the expected benefit for the patient must predominate. To estimate the risks and benefits of combined anesthesia, the anesthesiologist must be familiar with each single method, as well as with the synergistic effects of both techniques in order to evaluate the individual indication.Der Anaesthesist 01/1999; 48(6):359-372. · 0.85 Impact Factor
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ABSTRACT: More than half of those who use opiates suffer from constipation, and withdrawal from opiates produces abdominal cramps and diarrhea in 70% to 85%. These withdrawal symptoms may influence the number of opioid-dependent patients who attempt abstinence and the number who relapse. To characterize the motility correlates of these gastrointestinal symptoms of withdrawal, six patients from a drug treatment program were studied while on maintenance doses of methadone (average of 57.5 mg/d) and during acute naloxone-precipitated withdrawal. Motility was recorded via open-tipped catheters at 30 cm and 15 cm from the anal verge during a 15-minute baseline period and for 15 minutes during mechanical distention of the rectosigmoid colon with a balloon. This sequence was repeated during withdrawal. Subjective symptoms and objective signs of withdrawal assessed at 15-minute intervals showed that all six patients experienced withdrawal. Sigmoid and rectal motility were also assessed in 18 opiate-free control subjects. Long-term methadone use was associated with normal sigmoid and rectal motility under baseline conditions, but methadone users did not show the inhibition in sigmoid motility that normal subjects exhibited following baloon distention. When withdrawal was precipitated by naloxone, methadone users showed significant increases in rectosigmoid motility in association with signs and symptoms of withdrawal.Neurogastroenterology and Motility 06/2008; 2(2):90 - 95. · 2.94 Impact Factor
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ABSTRACT: The effects of different opioid agonists on spontaneous mechanical activity and response to electrical transmural nerve stimulation of both longitudinal and circular muscle strips from the human colon were studied by using a superfusion apparatus to record isometric contractions. Exogenously added opioid agonists did not modify the spontaneous contractile activities of both types of strips. Nerve stimulation induced a triphasic response composed of a first contraction C1 followed by a relaxation C2 and an off-contraction C3; this response was mediated by cholinergic excitatory nerves and non-adrenergic, non-cholinergic (NANC) excitatory and inhibitory nerves. The delta-agonists methionine enkephalin, [D-Pen2, D-Pen5] enkephalin (DPDPE) and the kappa-agonists dynorphin, trans-3,4 dichloro-N-methyl-N-(2-[1 pyrolidinyl]-cyclohexyl) (U-50488H) decreased the amplitudes of the contractions C1 and C3 of both strips in a dose-dependent manner. The selective mu-agonist D-alaglymepheglyol (DAGO) decreased the contraction C1 of longitudinal and circular muscle at high dose (1 μM) and often reduced the relaxation C2 of both types of strips at low dose (0.05 μM), finally, naloxone, but only at higher concentrations (1 μM) decreased the C1 amplitude significantly in circular muscle. In conclusion, these data suggest that mu, delta and kappa opioid receptors are involved in the neuro-regulation of smooth muscle of human colon and that opioid agonists modulate both excitatory and inhibitory neurotransmission through an action on cholinergic and non-adrenergic, non-cholinergic neurons.Neurogastroenterology and Motility 06/2008; 5(4):289 - 297. · 2.94 Impact Factor