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| 2. |
- Horiuchi, Yoshihito, et al.
(författare)
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Role of histamine release in nonspecific vasodilatation during anodal and cathodal iontophoresis
- 2004
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Ingår i: Microvascular research. - : Elsevier BV. - 0026-2862. ; 67:2, s. 192-196
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Tidskriftsartikel (refereegranskat)abstract
- Nonspecific vasodilatation during iontophoresis is an important confounding factor in experimental pharmacology. In this investigation, we studied the involvement of sensory nerves and histamine-related reactions in causing nonspecific vasodilatation in a model of anodal and cathodal iontophoresis of sodium chloride. Firstly, we applied a mixture of local anesthetic (EMLA) cream to confirm its suppressive effect on nonspecific vasodilatation and to measure its efficacy in three different dosages (duration: 1, 2, and 3 h). We then investigated the role of histamine in nonspecific vasodilatation by giving an oral antihistamine drug (cetirizine) to subjects who had and had not been given EMLA. We found substantial suppression of the nonspecific vasodilatation in all EMLA-treated groups (all dosages) compared with untreated controls (with suppression rates of 60–65%). Dosage had no significant effect. A further suppression of nonspecific vasodilatation was seen after oral cetirizine during anodal and cathodal iontophoresis in both EMLA-treated and untreated groups. The antihistamine effect was most pronounced during anodal iontophoresis. These results suggest a histaminergic increase in perfusion that may be independent of neurogenic mechanisms and depend on polarity (anode or cathode). Local nerve blocks (EMLA) together with cetirizine may therefore be used to reduce nonspecific vasodilatation in both anodal and cathodal iontophoresis.
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| 4. |
- Olofsson, Pia, 1962-
(författare)
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Experimental studies on Damage Control Surgery and Intraabdominal Hypertension
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Damage control surgery (DCS) offers an alternative to the traditional surgical management of complex or multiple injuries in critically injured patients. If a patient survives the initial phase of DCS, complications may occur, one of these being intraabdominal hypertension (IAH) and it´s potential development into the abdominal compartment syndrome.The indications for DCS have been widened and DCS principles can be applied in situations where time and resources are essential factors. The DCS principles of rapidly controlling intestinal spillage have not been evaluated. The aim of the studies in Papers I and II was to evaluate the principles of spillage control of intestinal contents according to the DCS concept and more specifically the effects of early rapid control of multiple bowel perforations on cardiovascular and pulmonary function compared with conventional small bowel resections in an animal model with abdominal trauma. In Paper I the animal model using anaesthetised pigs included a gunshot wound to the abdomen which caused multiple small bowel injuries. Haemorrhagic shock was combined with the gunshot wound in Paper II. The results presented in Paper I showed a significant reduction in rise in systemic vascular resistance and pulmonary vascular resistance, and a trend towards higher cardiac output and lower oxygen consumption in the bowel ligation group. In Paper II the results show a longer persistence of lactic acidaemia in the bowel ligation group. The aim of the study in Paper III was to assess visceral (intestinal, gastric and renal) microcirculation parallel with central haemodynamics and respiratory function during stepwise increases in intraabdominal pressure. In Paper IV we studied mucosal barrier function and morphology in the small bowel and colon of the pigs which were subjected to IAH. The IAP in anaesthetised pigs was increased stepwise using CO2 inflation, by 10 mm Hg at 10-minute intervals up to 50 mm Hg, and followed by exsufflation (Paper III). The microcirculation was selectively studied using a 4-channel laser Doppler flowmeter (Periflex 5000, Perimed, Sweden). The mucosal tissues were mounted in modified Ussing chambers for assessment of barrier function (E.coli K12 uptake and 51Cr-EDTA permeability) (Paper IV). The results showed that the microcirculation of the small bowel mucosa and colon mucosa was significantly less affected compared to the seromuscular layers. The microcirculation of gastric mucosa, renal cortex and the seromuscular layer of small bowel and colon were significantly reduced with each increase. Cardiac output (CO) decreased significantly at IAP levels above 10 mm Hg and the respiratory function data showed an increasing airway pressure and a concomitant reduction in thoracic compliance. Transmucosal passage of E. coli was increased three-fold in the small bowel after ACS with a significant correlation to the degree of mucosal microcirculatory reperfusion after exsufflation. 51Cr-EDTA permeability was unaffected. Bacterial passage in the colon was unchanged, whereas 51Cr-EDTA permeability after ACS increased by up to 181% of baseline and was correlated to significant histopathological changes in the mucosa.In Paper I we have demonstrated that early rapid control of multiple bowel perforations in a model with moderate shock resulted in less impairment of SVR and PVR than conventional resection and anastomosis. The use of DCS principles, however, had no beneficial effect on cardiovascular function when haemorrhagic shock was combined with abdominal missile trauma (Paper II), on the contrary bowel ligation was followed by more prolonged lactic acidosis than conventional repair. The studies in Paper III and IV indicate that the microcirculation of intestinal mucosa and especially small bowel mucosa seem better preserved in response to intraabdominal hypertension caused by CO2 insufflation than other intraabdominal microvascular beds. The short term ACS in this model caused morphological changes in the intestinal mucosa, and mucosal barrier dysfunction. The response pattern concerning barrier function changes after CO2 insufflation differs between small bowel and colonic mucosa. The small bowel mucosa showed increased bacterial passage, and the colonic mucosa an increase in paracellular permeability and secretory response.
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| 5. |
- Olofsson, Pia, et al.
(författare)
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Gastrointestinal microcirculation and cardiopulmonary function during experimentally increased intra-abdominal pressure
- 2009
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 37:1, s. 230-239
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to assess gastric, intestinal, and renal cortex microcirculation parallel with central hemodynamics and respiratory function during stepwise increase of intra-abdominal pressure (IAP). Design: Prospective, controlled animal study. Setting: Research laboratory, University Hospital. Subjects: Twenty-six anesthetized and mechanically ventilated pigs. Interventions: Following baseline registrations, CO2 peritoneum was inflated (n = 20) and IAP increased stepwise by 10 mm Hg at 10 mins intervals up to 50 mm Hg and subsequently exsufflated. Control animals (n = 6) were not insufflated with CO2. Measurements and Main Results: The microcirculation of gastric mucosa, small bowel mucosa, small bowel seromuscular layer, colon mucosa, colon seromuscular layer, and renal cortex were selectively studied at all pressure levels and after exsufflation using a four-channel laser Doppler flowmeter (Periflex 5000, Perimed). Central hemodynamic and respiratory function data were registered at each level and after exsufflation. Cardiac output decreased significantly at IAP levels above 10 mm Hg. The microcirculation of gastric mucosa, renal cortex and the seromuscular layer of small bowel and colon was significantly reduced with each increase of IAP. The microcirculation of the small bowel mucosa and colon mucosa was significantly less affected compared with the serosa (p < 0.01). Conclusions: Our animal model of low and high IAP by intraperitoneal CO2-insufflation worked well for studies of microcirculation, hemodynamics, and pulmonary function. During stepwise increases of pressure there were marked effects on global hemodynamics, respiratory function, and microcirculation. The results indicate that intestinal mucosal flow, especially small bowel mucosal flow, although reduced, seems better preserved in response to intra-abdominal hypertension caused by CO2-insufflation than other intra-abdominal microvascular beds.
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| 6. |
- Olofsson, Pia H., 1962-, et al.
(författare)
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Increased transmucosal uptake of E. coli K12 in porcine small bowel following experimental short term abdominal compartment syndrome
- 2009
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Abdominal compartment syndrome (ACS) may lead to bacterial translocation and possibly be of importance for development of multiorgan failure. However, the underlying mechanisms have not been fully elucidated. In a porcine model we recently demonstrated preserved intestinal mucosal blood flow during experimental short duration ACS. In the present study we used the same model to determine mucosal barrier function and morphology in the small bowel and colon of pigs before and after short term ACS. Methods: The study comprised 12 anaesthetized pigs exposed to experimental ACS and 6 control animals. Via laparotomy, samples of small bowel and colon were taken out for studies before short term ACS, where the abdomen was inflated with CO2 and IAP was increased stepwise by 10 mm Hg at 10-minute intervals up to 50 mm Hg, and again 10 minutes after exsufflation. Mucosal microcirculation was measured by laser Doppler flowmetry, and mucosal tissues were mounted in modified Ussing chambers for assessment of barrier function (E. coli K12 uptake and 51Cr-EDTA permeability). Specimens were also fixed in formaldehyde, stained with eosin-hematoxylin and evaluated blindly using an 8-grade scale for assessment of mucosal damage. Results: Transmucosal passage of E. coli was three-fold increased in the small bowel after ACS (22.6 [18.2 – 54.4] units) vs. baseline (8.1 [2.0 – 13.9]; P< 0.050) with a significant correlation to alterations of mucosal microcirculation. In the colon bacterial passage was unchanged, whereas 51Cr-EDTA permeability after ACS increased to 181% of baseline (P<0.05) and was correlated to significant mucosal histopathological changes (P<0.03). Conclusion: Short term ACS with reperfusion induced significant dysfunction of the intestinal mucosal barrier. The response patterns concerning barrier dysfunction differed between small bowel and colonic mucosa, with increased bacterial passage and paracellular permeability, respectively.
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| 7. |
- Olofsson, Pia, et al.
(författare)
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Multipel Small Bowel Ligation Compared to Conventional Primary Repair after Abdominal Gunshot Wound with Haemorrhagic Shock
- 2009
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Ingår i: Scandinavian Journal of Surgery. - 1457-4969 .- 1799-7267. ; 98:1, s. 41-47
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The aim of this study was to evaluate the effects of early rapid control of multiple bowel perforations on cardiovascular function in combined abdominal missile trauma and haernorrhagic shock compared with conventional surgery. Methods: Eighteen anesthetised pigs were injured with a standardised abdominal missile trauma. The animals were bled to a mean arterial pressure of 50 mm Hg for 30 minutes, after which they were resuscitated and had laparotomy. They were divided into conventional surgery group (n=9) with primary resection and anastomosis of bowel injuries and early rapid multiple bowel ligation group (n=9). Repeated measurement analysis of variance was used for analysis. Results: There was profound hypotension, reduced cardiac output, increased vascular resistance and lactic acidaemia in both groups. Lactic acidaemia persisted longer in the early rapid multiple bowel ligation group. There were no significant differences in mean arterial pressure, cardiac output, stroke volume or systemic vascular resistance between the groups. The mean operation time was significantly shorter in the early rapid multiple bowel ligation group (13.3 (1.5) (SEM) minutes, compared with 116.4 (1.74) (SEM) minutes in the conventional surgery group, p = <0.001). Conclusions: Damage control principles have shortened the operating time in our model but did not improve the cardiovascular function and caused more lactic acidaemia than conventional repair.
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| 8. |
- Rüter, Anders, et al.
(författare)
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A new system for transmission of on-line information from scene of accident and ambulances to hospitals
- 2003
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Ingår i: International Journal of Disaster Medicine. - : Informa UK Limited. - 1503-1438 .- 1651-3037. ; 1:2, s. 127-131
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The 'Swede information system' was introduced in a county with approximately 450,000 inhabitants in April 2000. The implementation of this information system, intended to be operative in major incidents and disasters, has included the introduction of new technologies as well as new standard operating procedures for both ambulance crews and hospital staff. The objective of this study was to see how this information system with digitally mediated transmission was used as a daily routine during a 2-month period, 1 year after its introduction. Methods. The Swede information system sends on-line information from ambulances to emergency wards in the county. The technique used is a LAN (local area net) for communication within the site of the accident, Mobitex® from the ambulances to a data server and from this by Internet to the hospitals. During March and April 2001 all events when an ambulance was dispatched were recorded. All cases when the system was used to notify the receiving hospital were recorded as well as all cases when the ambulance crew alerted the hospital through the alert function. All technical problems and any period of time when the system was 'out of use' were noted. Results. During the period of the study, the system was successfully used to transfer data from the scene to hospital in a total of 3353 missions, including transport of a patient from the scene to an emergency department. Of these, in 150 transports the transferred data served as a base for immediate support on arrival at the hospital that was of critical importance for primary management in the hospital. In all, 2883 different kinds of medical data were transmitted. The local help-desk was notified of problems with the system on 11 occasions; six of these were technical problems and the rest were user-related. The IS Swede system was not operational during parts of 3 days (<5%) of the time. Conclusions. Despite the introduction of new equipment and new standard operating procedures, IS Swede was accepted within the organization to a degree which could be considered operational in major incidents. Technical problems with IS Swede caused only minor disturbances during the study period.
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| 9. |
- Rüter, Anders, et al.
(författare)
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Comparison of an on-line information system with a conventional ambulance file system regarding the retrieval of information after missions
- 2005
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Ingår i: International Journal of Disaster Medicine. - : Informa UK Limited. - 1503-1438 .- 1651-3037. ; 3:1-4, s. 37-40
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To determine if an on-line information system is superior to a conventional ambulance file system regarding the possibility of retrieving information as follow-up in daily use and also with reference to disaster situations. Materials and methods: The study was designed as a prospective study where two systems that have been operational for several years were compared. One system was a system primarily built for on-line registration and the other a conventional ambulance file system. Results: In all aspects data regarding ambulance missions and patients were more thoroughly registered in the conventional file system. Also data were easier to retrieve with less time consumption compared to the on-line system. Conclusion: The on-line information system studied was less accurate for storing and retrieving information than a conventional ambulance file system. Thus, more technical development is needed before this on-line system can be recommended for use in major incidents or disasters.
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