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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of this study was to investigate the effect of infrarenal aortic cross-clamping and unclamping on gut mucosal perfusion by gastric tonometry and on sigmoid colonic tissue blood flow by laser Doppler flowmetry during abdominal aortic surgery. This was a prospective before-and-after intervention comparison study in a university hospital of 8 male patients, aged 57-87, undergoing elective infrarenal abdominal aortic surgery. Each patient was pretreated with ranitidine. Following general anesthesia, a nasogastric tonometer was inserted into the stomach. The balloon of the tonometer was filled with 2.5 mL of normal saline for gas tension and pH analysis. This process was repeated before and after aortic cross-clamping and unclamping. Gastric mucosal pHi was calculated with the Henderson-Hasselbalch equation from the arterial Hco3- and the tonometrically measured mucosal Pco2. A laser Doppler flow probe was placed in contact with the serosa of the sigmoid colon against the mesentery after the abdomen was opened. Sigmoid colonic tissue blood flow (SCBF) was assessed by the laser Doppler flowmeter. Gastric mucosal pHi by gastric tonometry and colonic tissue blood flow by laser Doppler flowmetry were measured before and after aortic cross-clamping and unclamping. Gastric mucosal pHi decreased significantly 30 minutes after aortic cross-clamping (7.37 +/-0.07) (p < 0.01), 60 minutes after aortic cross-clamping (7.39 +/-0.08) (p < 0.05), and 30 minutes after aortic unclamping (7.37 +/-0.08) (p < 0.01), compared with pHi before aortic cross-clamping (7.50 +/-0.06). Gastric mucosal pHi increased to the original level 60 minutes after aortic unclamping (7.46 +/-0.08). Since a gastric mucosal pH above 7.35 is considered normal, these mean values of pHi were clinically insignificant. However, gastric mucosal pHi decreased below 7.32 in 5 patients during abdominal aortic surgery. Gastric mucosal pHi decreased further to 7.30 in 1 patient following aortic cross-clamping and below 7.30 in 3 patients 30 minutes after aortic unclamping. SCBF decreased significantly after aortic cross-clamping (28.1 +/-4.8 mL/min/100 g) compared with the value before aortic cross-clamping (51.9 +/-11.3 mL/min/100 g) (p < 0.01). Following aortic unclamping, SCBF returned to 41.7 +/-7.4 mL/min/100 g. It is concluded that transient episodes of significant intestinal mucosal ischemia may have been encountered occasionally in patients undergoing abdominal aortic surgery, but a sigmoid colonic tissue blood flow of 41.7 +/-7.4 mL/min/100 g was sufficient to prevent postoperative ischemic colitis regardless of whether there was ligation or no ligation of inferior mesenteric artery among the studied population since none of the patients developed clinically significant ischemic colitis.
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PMID:Assessment of gut mucosal perfusion and colonic tissue blood flow during abdominal aortic surgery with gastric tonometry and laser Doppler flowmetry. 1207 84

A 62-year-old man with grade III ischemia of the legs and occlusion of an aortofemoral shunt underwent axillofemoral bypass and bilateral profundoplasty. During surgery, an aneurysm in the aortic origin of the right common iliac artery ruptured, requiring ligation of the inferior vena cava, the iliac veins and the right common iliac artery. Upon transfer of the patient to the recovery unit, the sigmoid intramucosal pH (pHi) was 6.83 (arterial pH 7.35), the regional CO2 pressure (PrCO2) was 100 mmHg (arterial PCO2 35.2 mmHg), and the lactic acid concentration was 3.6 mmol/L. Ischemic colitis was suspected and colonoscopy confirmed the presence of severe rectal and moderate sigmoid inflammation. An extended sigmoidectomy was performed with colostomy. The patient died from multiorgan failure 48 hours after surgery. Ischemic colitis is a severe complication of aortic surgery. Sigmoid pHi monitoring is non-invasive and highly useful for the early diagnosis of ischemic colitis.
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PMID:[Utility of sigmoid intramucosal pH in the early diagnosis of ischemic colitis after aorta surgery]. 1213 59

Intestinal hypoperfusion is among the factors implicated in sepsis and multiorgan failure. Splanchnic blood flow may be sacrificed to maintain supply to vital organs, even when hemodynamic alterations are minor. The sensitivity of invasive hemodynamic monitoring for detecting intestinal hypoperfusion is low. This paper aims to review current knowledge about indirect measurement of splanchnic perfusion by way of gastrointestinal tonometry. We review the pathophysiology of ischemic intestinal lesions, the basis for gastrointestinal tonometry, and the method. Finally we discuss clinical applications (early diagnosis of ischemic colitis and ischemia of the flap after esophageal reconstruction, weaning from mechanical ventilation, abdominal compartment syndrome, liver transplant, heart surgery, prognostic factors and care of the critically ill patient). An adequate understanding of this monitoring technique and management of information it provides can give an early warning of the intestinal hypoperfusion that precedes other serious systemic complications.
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PMID:[Gastrointestinal tonometry: a new tool for the anesthesiologist]. 1460 68

The colon is the most common site of gastrointestinal ischemia. The condition resolves completely with conservative treatment in most cases, but late diagnosis or severe ischemia can be associated with high rates of complications and death. Once ischemic colitis is diagnosed, serial physical examinations and colonoscopies are helpful to follow the condition. Prompt surgery is required for severe episodes, when conservative measures fail, and for patients with chronic symptoms.
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PMID:Investigation and management of ischemic colitis. 1465 Apr 67

Mesenteric vascular ischemia is a known complication of cocaine use. Although the majority of cases of cocaine-induced mesenteric ischemia present with ischemic colitis and rectal bleeding, several cases have been described presenting only with abdominal pain. We present a case of mesenteric vasoconstriction with angiographic documentation and treatment.
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PMID:Cocaine-induced mesenteric ischemia: treatment with intra-arterial papaverine. 1529 May 79

A 54-year-old woman with acute onset of hematochezia and lower abdominal pain proved to have ischemic colitis associated with the use of naratriptan. The diagnosis was established by colonoscopy with biopsy. There were no other obvious risk factors for intestinal ischemia. The condition resolved within 4 days. Because the use of triptans for the treatment of migraine is increasing, health care providers should be aware of their potential for inducing ischemic colitis.
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PMID:Colonic ischemia associated with naratriptan use. 1536 6

Ischemic colitis resulting in colonic infarction after aortic reconstruction is a highly lethal complication. The etiology and pathogenesis of this condition demonstrate that in many instances it may be prevented. Early recognition, particularly of the transmural ischemic injury is essential. Numerous techniques used during surgery for assessing the adequacy of colonic perfusion have been evaluated and found to be inaccurate in terms of predicting colonic ischemia. The purpose of this study is to assess the main monitoring technique for prediction of ischemic colitis during aortic surgery as: colonic mesenteric Doppler signal, inferior mesenteric arteries stump pressure, sigmoidal intramucosal pH and measurement of mucosal capillary haemoglobin oxygen saturation by reflectance spectrophotometry. A 15-year experience with 1912 patients undergoing abdominal aortic reconstruction was reviewed to determined both the incidence of intestinal ischemia and the clinical anatomic, and technical factors associated with this complication of aortic surgery
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PMID:[Intestinal and colonic ischaemia in the surgery of subdiaphragmatic aorta]. 1538 89

The aim of this study was to determine whether the duration of ischemia affects antipyrine absorption in the large intestine. This was carried out in a rat model of ischemic colitis in which ischemia and associated inflammation was induced by marginal vessel ligation. Blood flow was disrupted by positioning an o-ring around the distal rectum and ligating the marginal vessel at two locations in the hind-gut ligament artery region. Ligation was performed for 1, 2, 3, and 5h. We assessed large intestine damage by measuring key indicators of inflammation, myeloperoxidase (MPO) activity and thiobarbituric acid reactant substrates (TBARS) in the mucosa and by histological staining with hematoxylin-eosin stain. Antipyrine membrane permeability was assessed in Ussing-type diffusion chambers, and related pharmacokinetics were calculated from antipyrine plasma concentration measurements following colon administration of the drug. Vessel ligation caused some sloughing of epithelial cells and elevated the MPO and TBARS levels. Prolonged ligation failed to affect the apparent permeability coefficient (P(app)) of antipyrine. Prolonged ligation, however, gradually increased plasma antipyrine concentrations to near control levels. This increase was paralleled by increases in the absorption rate constant AUC and antipyrine bioavailability. Taken together, these results suggest that the absorption kinetics of antipyrine may depend on blood flow changes in the large intestine that occur with inflammation.
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PMID:Membrane permeability and antipyrine absorption in a rat model of ischemic colitis. 1550 Oct 1

Ischemic colitis is the most common form of intestinal ischemia. It manifests as a spectrum of injury from transient self-limited ischemia involving the mucosa and submucosa to acute fulminant ischemia with transmural infarction that may progress to necrosis and death. Although there are a variety of causes, the most common mechanism is an acute, self-limited compromise in intestinal blood flow. Patients typically have mild abdominal pain and tenderness over the involved segment of bowel. There is usually passage of blood mixed with stool, but hemodynamically significant bleeding is unusual. Although computed tomography may have suggestive findings, colonoscopy is the procedure of choice for diagnosis. Supportive care with intravenous fluids, optimization of hemodynamic status, avoidance of vasoconstrictive drugs, bowel rest, and empiric antibiotics will produce clinical improvement within 1 to 2 days in most patients. Twenty percent of patients will have development of peritonitis or may deteriorate despite conservative management and will require surgery.
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PMID:Ischemic colitis: a clinical review. 1575 53

Ischemic bowel disease exhibits a complex spectrum of clinical presentations and in the athlete the disease may be superimposed on dehydration, hyperthermia, and exhaustion. Physicians caring for athletes should be aware of the manifestations of ischemic bowel disease and the optimum methods of diagnosis and treatment. Abdominal pain and diarrhea are typical initial symptoms of ischemia and these symptoms generally limit further damage. However, symptoms may be overridden in cases of extreme athletic competition or other significant endurance events such as combat. Athletes and coaches should be aware of the danger of ischemic bowel disease. Patients or athletes with recurrent symptoms of abdominal pain and diarrhea during exercise may be at increased risk for ischemic damage. However, no underlying anatomic abnormalities have been noted. Ischemic hemorrhagic gastritis is generally reversible and may be controlled with effective acid blockade. Ischemic colitis generally presents with pain, diarrhea, and bleeding. It is usually mild but may require volume and transfusion support, rarely progressing to need for resection or stricture. Severe presentations with intestinal infarction are rare but potentially life threatening. The athlete is usually able to ultimately resume his or her activities without restriction.
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PMID:Exercise-associated intestinal ischemia. 1576 45


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