Biomedical subjects

J Thörne

Publications and source records attributed to J Thörne.

At least 19 recordsLinked to original sources

PubMed2002

Outcome of treatment of ruptured abdominal aortic aneurysms depending on the type of hospital.

OBJECTIVE: To compare the outcome of patients operated on acutely for ruptured abdominal aortic aneurysms (AAA) or otherwise symptomatic aortic aneurysms in a university hospital and in two county hospitals by the same group of vascular surgeons. DESIGN: Retrospective study. SETTING: 1 university and 2 county hospitals, Sweden. SUBJECTS: 108 patients operated on urgently for AAA, 81 at the university hospital, and 27 at the county hospitals between January 1992 and December 1998. INTERVENTION: Repair of the AAA. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: 21 of the 81 patients having urgent repair of an AAA at the university hospital (26%) had been transferred from the county hospitals. Thirteen patients were not operated on, 7 because of their poor general condition and great age (median 84 years), 3 who refused operation, and 3 in whom the diagnosis was incorrect. During the same time period a further 27 haemodynamically unstable patients were operated on by the same vascular surgeons at the county hospitals. The on-table mortality for patients with ruptured AAA and shock was 5/43 (12%) at the university hospital and 4/27 (15%) at the county hospitals. The corresponding in-hospital rates were 11/43 (26%) and 11/27 (41%). Mortality was significantly higher if the operation was delayed by more than 45 minutes. The incidence of postoperative complications was the same in both hospitals. CONCLUSION: If a patient with a ruptured AAA and shock is admitted to the county hospital and operated on by a specialist vascular surgeon the outcome is fully acceptable. The difference seems to be related to the postoperative period. To what extent the delay caused by the surgeon's journey to the county hospital has any influence on the outcome is not possible to evaluate.

Adult↗

PubMed2001

Percutaneous transluminal angioplasty of crural arteries: diabetes and other factors influencing outcome.

OBJECTIVE: to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) of the crural arteries. PATIENTS AND METHODS: a retrospective review of patients treated with PTA of at least one crural artery during an 8-year period (1990--1997). RESULTS: one hundred and fifty-five legs in 140 consecutive patients (mean age 74 years, range 38--91 years) were treated. In 76% a more proximal lesion was also treated. After 1 year, results were significantly better in non-diabetics (improvement rate of 66% vs 32%p <0.05). The outcome for patients with a combination of diabetes, heart disease and renal disease was significantly worse compared to all other patients with an improvement rate of only 9% after 1 year. Patients alive and not amputated at 1 year were significantly more common (p <0.05) among non-diabetics (90%), compared to diabetics (66%). The 1-year mortality for the whole group was 15%, significantly higher for diabetic patients (p =0.04). CONCLUSION: PTA of crural arteries produces reasonably good results in non-diabetic patients. Diabetic patients were doing worse than non-diabetics after a year, though 1-month results were not significantly different. Patients with diabetes, heart disease and renal disease make a high-risk group that has a significantly worse outcome.

Adult↗

PubMed2001

Elastic properties of the lung and the chest wall in young and adult healthy pigs.

Understanding of the elastic pressure/volume (Pel/V) curve is still limited in health and disease. The aim of the present study was to elucidate the Pel/V curve and elastance of the respiratory system (ERS) lung (EL) and chest wall (ECW) in healthy pigs. Six young (20.8 kg) and seven adult (58.9 kg), anaesthetized, paralysed and ventilated pigs were studied. Pel/V curves were recorded at zero end-expiratory pressure (ZEEP) and at positive end-expiratory pressure (PEEP) up to 40 cmH2O with a computer controlled ventilator during an insufflation at a low, constant flow. Pel/V curves of the respiratory system showed a complex pattern in both young and adult pigs. During the insufflation, ERS decreased, increased, fell, and increased again. A second Pel/V curve recorded immediately after the first one showed lower elastance and only one early fall in ERS. ECW fell over the initial segment and was then nearly stable. Difference between 1st and 2nd curves reflected changes in EL caused by recruitment during the 1st insufflation. At PEEP, such signs of collapse and recruitment were reduced. A strong tendency to lung collapse contributes to a complex pattern of elastic pressure/volume curves. At low volumes and distending pressures the chest wall contributes significantly to changes in respiratory system elastance.

Aging↗

PubMed2000

Effects of NO inhalation on pulmonary leukocyte sequestration and blood volume in porcine endotoxaemia.

OBJECTIVE: Sequestration and migration of activated neutrophils plays a major role in the pulmonary injury typical of septic shock and the adult respiratory distress syndrome. Inhaled NO may counteract alveolar-capillary damage attributed to activated neutrophils. The present study describes a method to directly demonstrate the effects of NO inhalation on endotoxin-induced sequestration of 99mTc-labelled leukocytes [As(t)] in the lungs of pigs. DESIGN: Prospective controlled study. SETTING: Laboratory for experimental surgery at a university medical centre. SUBJECTS: Anaesthetised and ventilated pigs. INTERVENTIONS: To induce inflammatory shock 26 animals received a continuous endotoxin infusion. Thirteen animals inhaled NO from the start of the experiments, while 13 served as controls. In 13 animals from both groups, leukocytes were labelled in vitro and reinjected, while in the 13 others erythrocytes were labelled in vivo to provide corrections for changes in blood volume. MEASUREMENTS AND RESULTS: The pulmonary distribution of 99mTc-labelled leukocytes or erythrocytes was studied dynamically for 180 min. After correction for changes in pulmonary and heart blood volume (PBV, HBV), leukocyte sequestration curves were generated. Endotoxin induced pulmonary vasoconstriction, reduced PBV, impaired oxygenation, and caused a maximum increase in As(t) of 30% in the lungs. NO inhalation attenuated pulmonary vasoconstriction and the reduction in PBV. The maximum increase in As(t) was reduced to 15% of baseline. CONCLUSIONS: Inhaled NO exerts its main vascular effects in the pulmonary microvasculature, the primary site of physiological neutrophil margination and pathological adhesion of activated leukocytes. Early use of NO inhalation may offer protection against the development of more lasting pulmonary failure in septic shock by reducing leukocyte sequestration in the lungs.

Administration, Inhalation↗

PubMed2000

Intraoperative contamination of synthetic vascular grafts. Effect of glove change before graft implantation. A prospective randomised study.

OBJECTIVES: to investigate the incidence of intraoperative graft contamination, bacterial species and the influence of change of surgeon's gloves on contamination. DESIGN: a prospective randomised study. MATERIALS AND METHODS: forty patients had implantation of synthetic vascular grafts. All patients received intraoperative cloxacillin (2.0 g) or clindamycin (0.6 g) intravenously. The procedures were randomised to two groups: Group 1 - surgeons changed the gloves before the first contact with the vascular prosthesis and Group 2 - operation without glove change. The growth of all bacterial species from graft segments and from the gloves was recorded. The susceptibility to antibiotics was tested. RESULTS: the number of contaminated grafts was similar in the two groups. Growth of bacteria was recorded from 92.5% (37/40) of the graft segments and 33% (51/156) of glove imprints. Of the cultured species, 75% and 47%, respectively, were identified as coagulase-negative staphylococci (CNS). Twenty-eight per cent of CNS were resistant to cloxacillin, 15% to clindamycin, and 10% to cloxacillin and clindamycin. In all, 25% of the CNS strains were resistant to the prophylactic antibiotic used. In 50% of cases, the antibiogram of the CNS strain recovered from gloves agreed with that of the strain harvested from the graft. CONCLUSIONS: a high incidence of graft contamination was found which was not reduced by changing gloves. However, changing gloves did seem to reduce the number of bacterial species.

Aged↗

PubMed1999

Intestinal and hepatic perfusion and metabolism in hypodynamic endotoxic shock. Effects of nitric oxide synthase inhibition.

BACKGROUND: Inhibition of nitric oxide synthase (NOS) has been claimed to be beneficial in septic shock. We investigated the overall and regional effects of a NOS-inhibitor on perfusion and metabolism during severe endotoxic shock. METHODS: Nineteen anaesthetised pigs were catheterised and ultrasonic flow-probes were placed around the portal vein, the hepatic artery, and the superior mesenteric artery. Thirteen animals were given a 3-h infusion of endotoxin; in 6 of these an infusion of NG-nitro-L-arginine-methyl-ester (L-NAME) was started an hour after the start of endotoxin while 7 animals served as controls and received endotoxin only. Six animals were sham operated with no further intervention. RESULTS: Endotoxin produced a hypodynamic shock with pulmonary hypertension. L-NAME did not increase arterial blood pressure, but deepened the fall in cardiac output and enhanced the increase in systemic and pulmonary vascular resistance. The infusion of endotoxin caused a decrease in flows in all regions. The addition of L-NAME induced a further decrease in the mesenteric artery flow only. L-NAME had no additional effect on hepatic artery flow ratio, while a transient decrease was seen in mesenteric flow ratio. Portal flow ratio decreased in the control group only. Global as well as regional oxygen extraction increased in both groups, more so in the L-NAME group. Lactate levels increased with no differences between the groups. CONCLUSION: In hypodynamic endotoxic shock, L-NAME infusion enhanced pulmonary vasoconstriction and increased left ventricular afterload. The resulting hypoperfusion caused an increase in mortality. The effects of L-NAME on global and mesenteric blood flow and metabolism were similar, while L-NAME had no additional effects on hepatic hypoperfusion or oxygen extraction. Thus, nitric oxide does not seem to be a major factor in the preservation of hepatic perfusion during unresuscitated endotoxic shock.

Animals↗

PubMed1999

Percutaneous transluminal angioplasty with or without stenting for femoropopliteal occlusions? A randomized controlled study.

BACKGROUND: To investigate the-one year outcome of PTA and stenting and PTA alone for femoropopliteal occlusions. DESIGN: Randomized prospective study METHODS: 32 patients with femoropopliteal occlusions were randomized into two treatment groups: PTA and Strecker-stent (n=15) and PTA alone (n=17). The median age of the patients was 71 years. All patients had chronic limb ischaemia, 66% had tissue loss, 19% had rest pain and 15% had disabling claudication. The median ABPI was 0.45. The occlusion was confined to the superficial femoral artery in 30 cases and to the popliteal artery in 2 cases. The median length of the occlusions was 7.3 cm. Aspirin (ASA), 160 mg daily, was administrated postoperatively but no anticoagulation was used. The follow-up included: clinical examination, measurement of ABPI and control angiography at 12 months or earlier when necessary (20 patients). RESULTS: There was no mortality or limb loss as a consequence of the treatment. There were six (16%) immediate major complications in five patients. In the PTA group, one patient had a myocardial infarction and three patients needed arteriography due to bleeding. In the stent group, one patient required arteriography and embolectomy. The one-year mortality was 6% and there were no amputations. Four patients (two in each group) were operated on with a femorodistal bypass. The rate of clinical improvement was 71% after PTA and stent and 60% after PTA alone (p=0.17). An increased ABPI (>0.10) was shown in 50% of the stent group and 61% in the PTA group (p=0.17). Angiographic re-occlusions were seen in 33% and 75% in the stent and PTA groups respectively (p=0.17), while the rate of restenosis was significantly higher in the stent group (50% vs 25%) (p=0.033). CONCLUSIONS: Stenting following PTA for femoropopliteal occlusions does not significantly improve neither the clinical state nor the clinical/angiographic patency. The results do not justify any routine placement of stent following PTA in the successfully recanalized femoropopliteal arteries. The low rate of acceptance of a follow-up angiography indicates that this kind of study should preferably use duplex scanning instead of angiography for follow-up.

Aged↗

PubMed1998

[Endovascular technique in aortic aneurysm. A promising alternative to open surgery].

The article consists in a presentation of endovascular surgery for abdominal aortic aneurysm repair in 23 cases. Two cases required conversion to open surgery, but the procedure could be completed in the remaining 21 cases, with a current duration of follow-up of up to 30 months. There was early leakage in one case, and late leakage in five cases. Late conversion has been necessary in three instances, and supplementary endovascular measures have been required in a further two instances. All complications have occurred in those cases operated during the first half of the study period. Modification of the endoprosthesis used and increasing skill have reduced both operation time and the complication rate. Intensive care is no longer required, and the median duration of hospitalisation is three days. Follow-up with magnetic resonance imaging has yielded new and important information.

Aged↗

PubMed1998

Magnetic resonance imaging and MR angiography of endoluminally treated abdominal aortic aneurysms.

OBJECTIVES: To evaluate magnetic resonance imaging (MRI) with gadolinium-based contrast medium-enhanced MR angiography (MRA) for the follow-up of endoluminally treated abdominal aortic aneurysms. DESIGN: MRI/MRA, angiography and computed tomography (CT) were performed 1 month after endoluminal stent-graft placement. MRI/MRA was repeated at 6 and 12 months and angiography and CT were added to confirm unexpected findings. MATERIALS: Fifteen male patients with endoluminally treated abdominal aortic aneurysms. METHODS: MRI with MRA, spiral CT with transverse images and angiography were performed. RESULTS: MRI/MRA demonstrated changes of stent-graft morphology, aortic neck- and aneurysmal diameter, stent-graft blood flow, stent-graft leakage, blood flow in lumbar arteries, intra-aneurysmal thrombus, periaortic inflammation and vertebral body infarction. For most of these features MRI/MRA provided more information than angiography and/or CT. MRI was the only method demonstrating thrombus reorganisation and vertebral body infarction. CONCLUSIONS: MRI with MRA provides the relevant information needed for follow-up of endoluminally treated abdominal aortic aneurysms (AAA). This may be the method of choice because of its use of contrast media with very low nephrotoxicity, lack of ionising radiation and non-invasiveness.

Aged↗

PubMed1998

The effects of nitric oxide inhalation on respiratory mechanics and gas exchange during endotoxaemia in the pig.

BACKGROUND: In the adult respiratory distress syndrome, nitric oxide (NO) inhalation improves oxygenation through reducing ventilation-perfusion mismatching, but detailed information on the pulmonary effects of NO inhalation in septic shock is scarce. The present study investigated the effects of inhaled NO on alveolar dead space (Vdalv) and venous admixture as well as on respiratory system compliance (Crs) and respiratory system resistance (Rrs) in a porcine model of septic shock. Protective effects of NO are discussed. METHODS: Thirteen anaesthetised and ventilated pigs were given an infusion of endotoxin for an observation time of 220 min to induce acute lung injury (ALI). In the NO-early group (n=6), an inhalation of 60 ppm NO was started simultaneously with the endotoxin infusion and continued for 190 min. In 7 control/NO-late animals, 60 ppm NO was administered for 30 min following 190 min of endotoxin infusion. Haemodynamics, single-breath CO2-, pressure-, and flow signals were recorded. RESULTS: Endotoxin induced haemoconcentration, pulmonary vasoconstriction, and a decrease in Crs, while venous admixture, Vdalv, and Rrs increased. In the NO-early group, the pulmonary vasoconstriction was attenuated, no increase in pulmonary venous admixture or in Vdalv was seen before cessation of NO, and the improvements in oxygenation outlasted the NO inhalation. In the control/NO-late group, the NO inhalation reversed the changes in dead space and venous admixture. NO had no effect on the changes in respiratory mechanics. CONCLUSION: In porcine ALI, 60 ppm NO diminishes pulmonary vasoconstriction and improves gas exchange by reducing pulmonary venous admixture and alveolar dead space, but does not prevent a fall in Crs. NO inhalation may help prevent long-lasting pulmonary failure.

Administration, Inhalation↗

PubMed1997

Kidney size estimation in piglets using dimercaptosuccinic acid (DMSA) scintigraphy.

The objective of this study was to validate kidney size measurements obtained by DMSA scintigraphy in kidneys of sizes relevant in paediatric practice. Kidney length, width and volume were measured by DMSA scintigraphy in 10 piglets in vivo and compared with measurements on excised kidneys using callipers, planar scintigraphy and submersion in water. In addition, a kidney phantom was constructed and placed in a torso phantom. The length, width and volume of the kidney phantom were compared with planar and tomographic scintigraphic measurements. The mean overestimation of kidney length by scintigraphy was 1.7% (+/- 1.2%) on excised kidneys and 3.9% (+/- 2.4%) in vivo. The corresponding figures for width measurements were 7.0% (+/- 3.9%) and 7.8% (+/- 4.4%). Tomography volume estimation overestimated the submersion volume by 23% (+/- 12%). Scintigraphic measurements on the phantom over-estimated length by 5%, width by 8% and volume by 11%. Scintigraphic renal length measurements are reliable and differ from the anatomical length by < 4% compared with excised kidneys and < 8% in vivo. Scintigraphic width measurements and volume estimations, especially on small kidneys, are less reliable.

Animals↗

PubMed1997

Differential effects of nitric oxide synthase modulation on porcine systemic and pulmonary circulation in vivo.

OBJECTIVE: To study and compare the effects of inhibiting endothelial nitric oxide synthase on systemic and pulmonary circulation in an in vivo model. DESIGN: Prospective, randomized, controlled study. SETTING: Laboratory for experimental surgery at a university medical center. SUBJECTS: Seventeen anesthetized, mechanically ventilated pigs. INTERVENTIONS: To produce a stable and continuous stimulation of endothelial nitric oxide synthase, an infusion of acetylcholine was given to one group of animals (n = 5) in a dose that decreased mean arterial pressure by 15%. After 45 mins, N(G)-monomethyl-L-arginine (L-NMMA) was given in a dose of 3 mg/kg for 5 mins in order to inhibit the enzyme. A second dose of 10 mg/kg was given 30 mins later. L-arginine was then given in a dose of 100 mg/kg to reverse the inhibition. One group of animals (n = 6) received a single dose of indomethacin (2.5 mg/kg) 15 mins after the start of acetylcholine infusion. L-NMMA and L-arginine were then given. In a control group (n = 5), the effects of L-NMMA and L-arginine were studied without acetylcholine. Circulatory parameters were monitored and resistance indices were calculated via arterial, central venous, and pulmonary artery catheters. MEASUREMENTS AND MAIN RESULTS: In control animals, 3 and 10 mg/kg of L-NMMA induced an increase in mean arterial pressure of 14% and 25%, respectively, with similar increases in systemic vascular resistance. Mean pulmonary arterial pressure increased by 22% and 48%, respectively. Acetylcholine lowered mean arterial pressure by 15% and did not affect the relative changes induced by L-NMMA. Acetylcholine had no effect on pulmonary resting tone but enhanced the pulmonary hypertension and increase in resistance induced by L-NMMA. This enhancement was abolished by indomethacin, which produced systemic hypertension while no effect on pulmonary pressure was seen. CONCLUSIONS: A basal release of nitric oxide contributes to the maintenance of normal vascular tone in the anesthetized pig. Stimulation of endothelial nitric oxide synthase by acetylcholine did not result in any further pulmonary vasodilation as was seen in the systemic circulation. Inhibition of nitric oxide synthase had a greater effect on pulmonary pressure than on systemic pressure. However, this difference was abolished by the administration of indomethacin. Increased nitric oxide release or acetylcholine itself seems to stimulate the production of a vasoconstricting prostanoid in the pulmonary circulation.

Acetylcholine↗

PubMed1996

Biological responses differ considerably between endovascular and conventional aortic aneurysm surgery.

OBJECTIVES: To determine the inflammatory responses in endovascular abdominal aortic aneurysm (AAA) repair and their relation to clinical findings. DESIGN: Prospective non-randomised study. SETTING: University Hospital, Department of Surgery. PATIENTS AND METHODS: Seven patients treated with an endoluminal procedure (AAA-E) and seven patients undergoing conventional surgery (AAA-C) were included. Inflammatory parameters were assessed by measurements of the cytokines interleukin (IL)-1 beta, IL-6, IL-8 and Tumour Necrosis Factor-alpha (TNF-alpha); analyses of complement proteins C1q, C4, C3, C5a and Terminal Complement Complexes (TCC); haematologic parameters and determination of C-reactive protein (CRP). RESULTS: In six of seven patients in the AAA-E group blood pressure decreases were recorded during introduction of the device. IL-6 and CRP levels were found to be significantly higher in AAA-C patients compared to the AAA-E group. On the other hand, high TNF-alpha levels were recorded in the AAA-E group. Less consumption of the complement proteins C1q, C4 and C3 was observed in AAA-E compared to AAA-C patients. Increased C5a levels were recorded in the AAA-C group, whereas only slight fluctuations were noticed in the AAA-E group. TCC levels were unchanged in both groups. CONCLUSION: Endovascular aortic aneurysm repair induced a significant inflammatory response, mainly involving TNF-alpha and differing from the findings during open AAA repair. These inflammatory responses were probably related to blood pressure decreases during the procedures. On the other hand, conventional repair induced responses related to the more extensive surgical trauma and reperfusion injury.

Aged↗

PubMed1996

Nitric oxide inhalation decreases pulmonary platelet and neutrophil sequestration during extracorporeal circulation in the pig.

OBJECTIVE: The inhibiting effect of nitric oxide on the aggregation and adhesion of neutrophils and platelets has been well documented in vitro. In vivo evidence, however, is more scant. In this study, we studied the effects of inhaled nitric oxide on pulmonary cellular sequestration in our sham hemodialysis model. Accumulation of neutrophils and platelets in the lungs has been shown to be an early event in this model. DESIGN: Prospective, randomized, controlled study. SETTING: Animal laboratory at a university medical center. SUBJECTS: Twenty-six anesthetized, mechanically ventilated pigs. INTERVENTIONS: 111Indium-oxine was used to selectively label neutrophils or platelets and the activity over the lungs was followed dynamically with a gamma camera. Sham hemodialysis, using a cuprophan hollow-fiber dialyzer, was instituted via catheters in the femoral vessels. The animals were divided into two main groups: a) the nitric oxide recipient group (n = 12, with platelets labeled in seven animals and neutrophils labeled in five animals); and b) the control group (n = 14, with platelets labeled in seven animals and neutrophils labeled in seven animals). The animals in the former group were given 50 parts per million of nitric oxide in the inspiratory gas from the beginning of dialysis and for 30 mins onward. MEASUREMENTS AND MAIN RESULTS: Inhalation of nitric oxide attenuated the increase in activity over the lungs in both the neutrophil and platelet groups during sham hemodialysis. In addition, an inhibiting effect on the increase in pulmonary pressure was noted. CONCLUSION: Apart from the effects of nitric oxide on central hemodynamics in this model, the scintigraphic findings indicate an in vivo effect of nitric oxide on the accumulation of platelets and neutrophils in the lungs, probably due to inhibition of the adhesion and/or aggregation of these cells.

Adhesiveness↗

PubMed1995

Metabolic response of granulocytes and platelets to synthetic vascular grafts: preliminary results with an in vitro technique.

The metabolism of granulocytes as well as platelets evoked by incubation with different synthetic vascular grafts was monitored during 6-h batch experiments using microcalorimetry. Standard knitted Dacron grafts, ePTFE-grafts, knitted Dacron grafts with collagen impregnation, and knitted Dacron grafts with external collagen-coating were used. The heat production per cell was calculated. A rapid increase of metabolic activity followed by a gradual decrease was demonstrated with both granulocyte suspension and platelet concentrate. Significant differences were obtained between the materials with a maximum response of Dacron grafts with collagen impregnation for both granulocyte and platelet response. The materials had different surface morphologies regarding cell adhesion after incubation as demonstrated with scanning electron microscopy with more pronounced adhesion on the collagen-impregnated grafts. The results suggest that microcalorimetry may be useful for the evaluation of cellular reactions on different biomaterials. However, further studies have to reveal the specificity of the reactions.

Animals↗

PubMed1994

Iloprost attenuates trauma-related pulmonary sequestration of leucocytes and platelets.

The purpose of this study was to investigate the effects of iloprost, a synthetic prostacyclin analogue, on the pulmonary cellular trapping after a standardized soft tissue trauma. In two groups 1 and 2 iloprost was given in doses of 100 ng/kg/min commencing 30 and 20 min respectively prior to trauma and ceasing 10 min after trauma. 111Indium-oxine was used to label neutrophils in 6 animals from each group. Platelets were labelled in 6 and 7 animals respectively. A third group of 11 pigs served as a control and did not receive iloprost. The pulmonary sequestration of platelets and neutrophils was studied dynamically with a gamma camera and directly after trauma was significantly less in group 1 when compared to the control group. A rise in pulmonary vascular resistance and pulmonary arterial pressure was seen in the control group immediately after trauma but this was not evident in the iloprost groups. PaO2 decreased significantly in group 1 and 2 during the iloprost infusion. The results indicate that iloprost attenuates the pulmonary cellular sequestration and changes in central hemodynamics during trauma in this model.

Animals↗

PubMed1994

Circulatory and ventilatory effects of intermittent nitric oxide inhalation during porcine endotoxemia.

The effects of intermittent inhalation of 57 ppm nitric oxide (NO) were studied in eight anesthetized, ventilated pigs given a continuous infusion of Escherichia coli endotoxin. Seven animals served as controls. By administering NO synchronized with inspiration and close to the orotracheal tube, measurable amounts of the toxic metabolite, NO2, in the inspiratory gas mixture were avoided. No direct systemic effects of NO inhalation were seen, but through counteracting pulmonary vasoconstriction, a fall in cardiac output was delayed. Nitric oxide effectively attenuated the initial peak rise in mean pulmonary artery pressure and resistance, both returning to control levels after cessation of NO. These effects were reproduced during later phases of endotoxemia, giving further proof to the role of gaseous NO as a selective pulmonary vasodilator. Nitric oxide diminished pulmonary shunting, but unimpaired oxygenation was preserved only during the first inhalation period. Leukocyte counts decreased drastically and platelet aggregation was enhanced, but after 1.5 hours of endotoxin infusion, platelet hyperaggregation was maintained in the NO group while it decreased in the control group.

Administration, Inhalation↗

PubMed1993

The adhesion of labelled neutrophils on synthetic vascular grafts. An experimental porcine study.

The adhesion of neutrophils onto different vascular grafts was studied in vivo in a pig model. In acute experiments autologous 111In-labelled neutrophils were reinfused after end-to-side implantation of 5 cm, 6 mm internal diameter grafts. The dynamic deposition on each graft was determined for 300 min in vivo. Static measurements in vitro concluded the study. The adhesion was greater in Dacron and collagen coated Dacron grafts compared to expanded polytetrafluoroethylene (ePTFE) and to Dacron grafts coated with a polymer. The segmental activity along all the grafts increased towards the distal anastomosis. The results suggest different inflammatory response to various graft materials.

Animals↗