Jürgen Fass

Effects of intravenous ketamine on gastrointestinal motility in the dog.

ObjectiveThe purpose of this trial was to clarify the effets of intravenous ketamine at anaesthetic and sub-anaesthetic dosages on gastrointestinal motility.Design20 beagles (group 1: 3 mg/ketamine/kg/h,n=10; group 2: 30 mg ketamine/kg/h,n=10), were investigated. Gastric emptying (nuclide gastric emptying studies, liquid and semi-solid test meal), intestinal transit time (Hydrogen breath test with lactulose) and intestinal motor function (perfusion manometry with 8 measuring ports) were determned. As a control condition, the tests were performed on all dogs in the two groups during infusion of physiological saline solution.ResultsNo significant differences in the motility patterns were present between 3 mg ketamine/kg/h and the control condition. For group 2, a moderately significant (p<0.05) increase in the interdigestive motility index was observed for 30 mg k ketamine/kg/h. However, this did not change the transit criteria. There was no significant difference between ketamine and control condition tests with regard to cycle and phase lengths or the propagation rate of the activity front.ConclusionsWe conclude that ketamine provokes no basic changes in gastrointestinal motility, at either sub-anaesthetic doses. It can there-fore be used to advantage in the continuous postoperative analgesia of intensive care patients, where repeated interventions are necessary and no cardiopulmonary contraindications are present.

Influence of Postoperative Epidural Analgesia with Bupivacaine onIntestinal Motility, Transit Time, and Anastomotic Healing

Epidural application of bupivacaine hasbeen suggested to have a sympatholytic effect on spinal reflexmechanisms that shortens postoperative paralysis and leads to animproved transit time. The influence on anastomitic healing remainscontroversial. Laparotomy was performed in eight dogs. A short segmentof the distal colon was resected and five electrodes were fixed on theserosa to measure the myoelectric activity (e.g., Migrating MyoelectricComplex—MMC). After operation a peridural catheter was placed betweenL7 and the sacral crest. One milliliter of bupivacaine 0.25% for each3 kg of body weight was injected every 4 hours. Barium pellets coatedin wax were placed into the stomach to allow radiographicrepresentation of transit time. After 5 days the colon anastomosis wasresected to measure the bursting pressure. In the peridural analgesiagroup (PDA) we found one small bowel intussusception and one coveredanastomotic leakage. Postoperative PDA led to early and severemyoelectric activity but did not influence the time until the first MMCoccurred (44 ± 0.8 h, PDA; 44.6 ± 1.5 h,control). Neither the transit time to the colon (50.2 ± 1.9h, PDA; 51.7 ± 5.5 h, control) nor the anastomotic healingwas influenced (bursting pressure: 176 ± 21.1 mmHg, PDA; 152± 27.7 mmHg, control). Postoperative epidural analgesia withbupivacaine shortens intestinal paralysis. Early myoelectric activitywith a lack of propulsive activity can cause complications like smallbowel intussusception. Hence early postoperative enteral nutritionafter epidural analgesia is risky. Because the influence of epiduralanalgesia on propulsive motility remains unclear, it seems reasonableto recommend its limited use in colon surgery.

Colon interposition for esophageal replacement: isoperistaltic or antiperistaltic? Experimental results

BACKGROUND Isoperistaltic colon is preferred to antiperistaltic colon for esophageal replacement, but experimental data do not exist to support this practice. METHODS In 7 dogs a 20 cm long colon loop was interposed between the skin and the small bowel, isoperistaltically in 3 dogs and antiperistaltically in 4 dogs. Three months later five strain-gauges were implanted and evacuation was investigated by motility testing, barium studies, and scintigraphy. RESULTS Motility recording showed normal colon motility in the excluded loops. Quiescent states (duration 40.2 +/- 13.6 minutes) were followed by contractile states (duration 7.5 +/- 2.4 minutes, frequency 3.3 +/- 0.6 per minute). The main peristaltic direction of isoperistaltic loops was isoperistaltic, and the main peristaltic direction of antiperistaltic loops was antiperistaltic. Evacuation took place exclusively during the contractile status. Half time emptying was more rapid in isoperistaltic loops (35 +/- 11 vs 69 +/- 16 minutes). The content of antiperistaltic loops was held back by antiperistaltic activity. Application of oatmeal porridge into the loops shortened the quiescent status from 40.2 to 13.2 +/- 4.8 minutes. CONCLUSIONS The colon graft for esophageal replacement is an active system. Food is stored during the quiescent states and evacuated during the contractile states. The original peristaltic direction is preserved so that retroperistalsis in antiperistaltic loops may lead to patient discomfort and pulmonary complications.

The radiation dose to surgical personnel during intraoperative radioimmunoscintimetry

To estimate the radiation exposure to surgical personnel caused by intraoperative radioimmunoscintimetry, we measured dose rates at different distances from patients who had been injected with 950 MBq technetium-99m-labelled intact carcinoembryonic antigen (CEA)-specific antibodies (Szintimun CEA, Behring AG Marburg, FRG) for immunoscintigraphy 24 h earlier. At 0.05 m (corresponding to working positions during surgery) we found 2.0–16.0 μSv h−1 (average 6.4), which is similar to results for nuclear medicine staff. Thus, if radioimmunoscintimetry is to become a routine procedure, according to national regulations in some countries of the European Communities surgical personnel might be regarded as professionally exposed to radiation.

Effects of Intraperitoneal Mitomycin C Adsorbed on Activated Carbon on Adhesion Formation and Mesothelial Cells In Vitro

OBJECTIVE To investigate the incidence of adhesions after intraperitoneal instillation of mitomycin C adsorbed on activated carbon (MMC-CH). DESIGN Animal and laboratory studies. SETTING University hospital, Germany. ANIMALS 90 Sprague-Dawley rats. INTERVENTIONS Laparotomy, small bowel anastomosis, and intraperitoneal instillation of saline (controls, n = 27), activated carbon alone (n = 24) or MMC-CH (n = 26). Cultures of monolayers of human mesothelial cells. MAIN OUTCOME MEASURES Measurements of adhesions by planimetry. Toxicity of mitomycin C alone and charcoal alone in mesothelial cell monolayers as reflected by cell proliferation and measurement of lactate dehydrogenase activity. Concentrations of plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI-1) as measures of the fibrinolytic activity of mesothelial cells. RESULTS Both activated carbon and MMC-CH caused a significant increase of adhesion formation in rats. Activated carbon also reduced the fibrinolytic activity of mesothelial cells, and mitomycin C caused concentration-dependent cytotoxicity in vitro. CONCLUSIONS Activated carbon combined with high concentrations of mitomycin C may cause intraperitoneal infective complications by increasing the rate of adhesion formation and reducing the fibrinolytic activity of mesothelial cells. We recommend a new absorbable carrier for intraperitoneal chemotherapy.

Influence of intraperitoneal therapy with mitomycin C adsorbed on activated carbon on anastomotic and wound healing in rats

In an effort to prevent intraperitoneal dissemination of gastric carcinoma, local chemotherapy with mitomycin C adsorbed to activated carbon (MMC-CH) has been implemented. Results of clinical studies showed improved survival and a reduced systemic toxicity after the use of prophylactic treatment with MMC-CH. A significantly higher rate of intraperitoneal septic complications following MMC-CH therapy was found. The aim of this study was to assess whether intraperitoneal MMC-CH affects wound healing or healing of intestinal anastomoses. Standardized laparotomy was performed in 77 rats. The examinations were performed in 27 animals in the control group, 24 animals in the charcoal group, and 26 animals in the MMC-CH group. The animals and groups were distributed randomly. After an ileal anastomosis was performed, MMC-CH, charcoal, or sodium chloride 0.9% was administered intraperitoneally. After 10 days, collagen content as well as bursting strength/pressure of the fasciotomy and the anastomotic site was examined. Body weight and blood parameters analyzed included hemoglobin level, white blood cell count, platelet count, and total protein. Concerning body weight and hematology, no significant changes were observed. Three of 26 animals in the MMC-CH group, 2/24 in the charcoal group and 1/27 in the control group developed an anastomotic leakage. The bursting pressure of the anastomoses and the bursting strength of the fasciotomy as well as the relative collagen content did not differ significantly after treatment with charcoal or mitomycin C compared to the control group. Local inflammation consisting of charcoal-laden granulomas was detected histologically in the MMC-CH group and to a lesser extent in the charcoal group. In conclusion, no significant influence of intraperitoneal mitomycin C adsorbed on activated charcoal, in terms of its effect systemically or its effect on wound healing, could be demonstrated as a result of slow release. Histological changes seen with the use of activated charcoal suggest that perhaps a more ideal absorbable carrier should be sought.

Proximale Magenresektion mit subtotaler Ösophagektomie versus Gastrektomie beim Cardiakarzinom

Von 1.1.80 bis 30.6.91 wurden 105 Patienten mit Cardiakarzinom operiert. Bis 1985 wurde als Regeleingriff eine Gastrektomie mit Ersatzmagenbildung (Gr. 1, n = 46) durchgefuhrt. 15,2% Anastomosenrezidive waren Anlas, seit 1986 auf eine Magentransposition umzusteigen (Gr. 2, n = 59). Beide Gruppen wiesen bezuglich Alter, Risikofaktoren und Stadienverteilung keine Unterschiede auf. Gruppe 2 hatte signifikant mehr cardiale Komplikationen und eine hohere Klinikletalitat. Bei den Kaplan Maier Uberlebenskurven fand sich fur Gr. 2 bei N1-Tumoren eine signifikant bessere Uberlebenszeit, bei T4-Tumoren, Stadium IV, und R2 Resektionen ein positiver Trend. Die Magentransposition beim Cardiakarzinom hat sich als Regeleingriff bewahrt.