Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0278134 (anesthesia)
 110,339 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 46-year-old man underwent cosmetic facial surgery under general anesthesia. He was ventilated by mask with an oxygen-enriched gas mixture for 4 to 6 h and monitored by pulse oximetry. Despite adequate arterial saturation (SaO2 > 90 percent) throughout the procedure, he remained in a deep coma after termination of anesthesia. Initial arterial blood gas analysis revealed a pH of 6.60 and a PaCO2 of 375 mm Hg. The patient was intubated and placed on mechanical ventilation. As his respiratory acidosis resolved, he regained consciousness quickly and recovered without any neurologic deficits. This case of record extreme hypercapnia and review of the literature demonstrates that survival is possible in acute severe respiratory acidosis as long as tissue anoxia and ischemia are prevented. We discuss the tissue effects of acute hypercapnia and newer aspects of the nature of intracellular pH regulation in critical tissues that afford considerable tolerance to acidosis. The dependence of these mechanisms upon active ion transport underscores the importance of adequate tissue oxygenation and perfusion.
 ...
PMID:Resuscitation from severe acute hypercapnia. Determinants of tolerance and survival. 144 82

A major component of the organ injury mediated by toxic oxidants, such as seen following reperfusion of the ischemic liver, is due to the peroxidation of polyunsaturated fatty acids, especially of cell membranes. We utilized the measurement of exhaled breath ethane, a metabolic product unique to oxidant-mediated lipid peroxidation, as a noninvasive indicator of this process in swine liver subjected to warm ischemia/reperfusion. Under rigorously controlled anesthesia conditions, pig livers were subjected to 2 h of warm total ischemia, followed by reperfusion in situ. Expired air was collected and its ethane content quantitated by a novel gas chromatographic technique. The time course of breath ethane generation correlated closely with the appearance of hepatocellular injury as measured by impairment of Factor VII generation and other measures of liver integrity. Moreover, the administration of the specific superoxide free radical scavenger, superoxide dismutase (SOD), significantly attenuated both the elaboration of ethane and the hepatocellular injury. These findings not only provide confirmation of the previously reported link between hepatocellular injury by free radicals generated at reperfusion, but also establish the use of expired breath ethane analysis as a sensitive, specific, and noninvasive indicator of the injury process in real time.
 ...
PMID:Breath ethane: a specific indicator of free-radical-mediated lipid peroxidation following reperfusion of the ischemic liver. 145 76

The treatment of unilateral iliac occlusion remains controversial. We report our experience with femorofemoral bypass (FF) and iliofemoral bypass (IF). One hundred sixty-two FFs and 82 IFs were performed during a 25-year period. Demographic characteristics of the two groups were similar. Operative indications included claudication in 32.1% of FFs and 19.5% of IFs, rest pain in 26.5% of FFs and 36.6% of IFs, ulcer in 8.0% of FFs and 3.7% of IFs, gangrene 13.6% of FFs and 23.2% of IFs, and acute thrombosis in 13.0% of FFs and 3.7% of IFs. Five-year primary and secondary patency rates for all FFs were 56.9% and 65.4% respectively. Those for all IFs were 74.9% and 79.2%. The primary patency rate of FF performed for chronic arterial occlusive disease was 73.3% at 3 years and 60.4% at 5 years and for IF it was 73.4% at 3 years. In the absence of prior arterial surgery in the groin, the primary patency rates of bypasses for chronic arterial occlusive disease were 78.3% for FF and 86.8% for IF at 4 years. Distal endarterectomy and acute ischemia adversely affected patency. The operative mortality rate was 6.2% for FF and 3.7% for IF. Eleven wound complications occurred in the FF group. Seven patients underwent graft removal without limb loss. One minor wound problem occurred in the IF group. Iliofemoral bypass avoids operation on an asymptomatic limb; FF avoids entry in the abdomen or retroperitoneum and can be performed under local anesthesia. In patients in whom either IF or FF is applicable, the choice between these two procedures should be individualized with these factors in mind.
 ...
PMID:Iliofemoral versus femorofemoral bypass: the case for an individualized approach. 146 Jul 10

A possible cerebroprotective effect of halothane was investigated in a canine model of 5-min global cerebral ischemia. In pentobarbital-anesthetized dogs, additional inhalation of 0.5 to 1% halothane prior to ischemia prevented the post-ischemic dysfunction of the vagal component of reflex bradycardia. In contrast, pretreatment with thiopental at 10 mg/kg, i.v. failed to prevent it. The influence of ischemia in the absence of anesthetics was similar to that under barbiturate anesthesia. The results suggest that halothane, but not barbiturate, may actively protect the vagal baroreflex system from ischemia.
 ...
PMID:Protection by halothane of the vagal baroreflex system from transient global cerebral ischemia in dogs. 146 Aug 8

The QRS complex in lead V5 was studied during cardiac surgery. R wave amplitude decreased after induction of anesthesia to approximately 50% to 60% of the preanesthetic level before the institution of CPB (P < 0.001). An rS complex appeared immediately after cardioversion and changed in configuration to an Rs complex 15 to 30 minutes after aortic declamping. The R wave continued to recover toward the preanesthetic level at sternal closure. Patients with coronary artery disease had a poorer recovery of the R wave (P < 0.05) than patients with valvular heart disease; the former recovered to only 50% of the preanesthetic level at sternal closure. Nonsurvivors had much smaller R waves (26.1 +/- 20.5%) than survivors (P < 0.001). The R wave peaked 30 to 40 ms after initiation of the QRS complex, which indicates recovery of conductivity and the activation sequence of the left ventricular (LV) free wall, which is easily disturbed by hypothermia, cardioplegia, and ischemia during aortic cross-clamping. Monitoring QRS complex changes in lead V5 appears to be important on weaning from cardiopulmonary bypass to detect regional ischemia, and also to observe electrophysiologic recovery of the LV free wall.
 ...
PMID:QRS complex changes in the V5 ECG lead during cardiac surgery. 147 59

Acute acalculous cholecystitis is an uncommon but very serious illness, that, if undiagnosed, may lead to gallbladder perforation and death. The condition has numerous causes that result in bile stasis and ischemia leading to inflammation and infection in the gallbladder wall. The bedside diagnosis may be difficult, especially in critically ill patients. Current imaging techniques including ultrasonography, computer tomography, and radionuclide cholescintigraphy are very helpful. Depending on the clinical situation, the gallbladder should either be drained by a surgical or percutaneous cholecystostomy under local anesthesia or removed.
 ...
PMID:Acute acalculous cholecystitis. A review. 147 70

Hyperglycemia is known to worsen the outcome of transient global or forebrain ischemia. The aggravating effect is believed to be mediated by the additional formation of lactate- and of H+. Recent evidence suggests that reactive oxygen species contribute to the damage after brain ischemia. Since acidosis accelerates free radical damage in vitro, we decided to explore if ischemic damage in hyperglycemic subjects is ameliorated by dimethylthiourea (DMTU), an established free radical scavenger. In one series of hyperglycemic rats, we studied whether preischemic administration of DMTU alters the clinical outcome, notably the incidence and frequency of seizures. In two different series, the effect of DMTU on tissue damage was assessed by light microscopy after 15 h of recovery. Longer periods could not be studied since seizures developed. In the first of these series the animals were anesthetized with isoflurane, and in the second with halothane. The latter anesthesia largely suppressed the "early" postischemic seizures, i.e. those occurring after 1-4 h. Dimethylthiourea treatment altered the clinical outcome after ischemia. Thus, the "late" postischemic seizures appeared milder and occurred significantly later than in untreated animals. The fatal outcome was also delayed since treated animals died after 35.5 +/- 8.2 h (mean +/- SD) of recirculation, as compared to 19.8 +/- 3.6 h of recirculation in control animals. However, all DMTU-treated (and control) animals died. In the first morphological series (isoflurane anesthesia) the histopathological analysis was complicated by the occurrence of prefixation seizures; such seizures were recognized in 4/16 animals. When these 4 animals were excluded from the analysis (2 treated and 2 control animals), DMTU pretreatment did not ameliorate the damage, except in the substantia nigra pars reticulata (P < 0.05). In the second series, comprising animals anesthetized with halothane, only one animal out of 16 had "early" seizures, and none showed "late" seizures before death. Among these animals DMTU treatment significantly ameliorated damage to caudoputamen and cingulate cortex (P < 0.01). We conclude that treatment with the free radical scavenger DMTU partly ameliorates ischemic brain damage associated with excessive acidosis, and marginally delays the development of post-ischemic seizures. However, the effects were moderate and could, at least in part, have been caused by nonspecific effects of DMTU. Furthermore, all DMTU-treated animals died. The results thus give little support to the notion that the aggravating effects of acidosis is due to enhancement of free radical production.
 ...
PMID:Effects of dimethylthiourea on ischemic brain damage in hyperglycemic rats. 148 54

Neutrophils (PMN) have been implicated as mediators of the "no-reflow" phenomenon seen in skeletal muscle during reperfusion after ischemia. In order to evaluate the PMN contribution to the changes seen in the microcirculation of skeletal muscle after ischemia, we evaluated PMN velocity using in vivo microscopy in a rat model. After the induction of anesthesia, the right iliac and femoral arteries were isolated. The right anterior tibialis muscle was exposed in situ, covered with a plexiglass disc, and perfused with Kreb's solution. Fluorescein-labeled bovine albumin was given intravenously, which identified the capillaries under microscopic magnification as viewed on the video screen. Acridine orange was then administered intravenously, which selectively fluoresced the PMN. The right iliac and femoral arteries were clamped for ischemia intervals of 5, 10, 15, 20, 25, and 30 min. Acridine orange was given immediately after the arteries were unclamped, after 30 min of reperfusion and after 60 min of reperfusion. PMN velocity was determined by the distance traveled by the PMN over time using the videotape and frame-by-frame review. Results demonstrated no change in PMN velocity (mm/sec) after 5 min of ischemia. After 10, 15, and 20 min of ischemia, PMN velocity initially slowed and then recovered, which was not statistically significant. After 25 min of ischemia, PMN velocity decreased significantly, which persisted (P < 0.05 compared to 5-min ischemia by ANOVA). No flow was seen after 30 min of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:In vivo microscopy of rat skeletal muscle after ischemia using labelled neutrophils (PMN). 149 88

Because the choice of anesthetic technique does not influence the incidence of perioperative myocardial ischemia, reduction of ischemic risk may require specific antianginal therapy. Calcium entry blockers are effective drugs in antianginal therapy. Diltiazem reduces myocardial oxygen demand through decreases in heart rate, inotropy, and systolic function, while increasing myocardial oxygen delivery through coronary vasodilation. These potentially beneficial effects of diltiazem were evaluated in 15 of 29 patients (diltiazem v placebo, double-blind study) scheduled for coronary artery bypass graft surgery. Continuous infusion of diltiazem (0.15 mg/kg bolus followed by 2 micrograms/kg/min), during anesthesia and surgery before cardiopulmonary bypass, significantly reduced the major MVO2 determinants during anesthesia with moderate doses of fentanyl and a benzodiazepine (midazolam in 8 of 14 control patients and 9 of 15 treated patients, or flunitrazepam in the others). Heart rate, mean arterial pressure, and inotropy were decreased during the most stressful events of surgery when plasma diltiazem concentrations were in the therapeutic range (greater than 96 ng/mL). The number of patients with perioperative ischemia was 2 of 15 in the treated group and 4 of 14 in the control group. Provided that diltiazem plasma concentrations are sufficient, it can contribute to lowering the ischemic burden during anesthesia for coronary artery surgery.
 ...
PMID:Hemodynamic effect of calcium channel blockade during anesthesia for coronary artery surgery. 149 96

Patients scheduled for vascular surgery are considered at risk for perioperative cardiac complications. Choice of anesthetic in such patients is guided by a desire not to adversely affect myocardial function. On the basis of data from laboratory studies, thoracic epidural anesthesia (TEA) has been advocated to prevent myocardial ischemia. The aim of this study was to assess whether TEA combined with general anesthesia has any effect on segmental wall motion (SWM) monitored by transesophageal echocardiography in these patients. Patients received alfentanil, midazolam, vecuronium, and 50% N2O in oxygen, and ventilation was controlled after orotracheal intubation; 12.5 mL of 2% lidocaine HCl was injected through an epidural catheter placed at T6-7 or T7-8. Hemodynamic measurements and transesophageal echocardiographic recordings were obtained before and 10, 20, 30, 40, and 60 min after lidocaine injection. Segmental wall motion was graded a posteriori by two independent experts on a predetermined scale (from 1 = normal to 5 = dyskinesia). A decrease greater than or equal to 2 grades was considered an SWM abnormality indicative of ischemia. Thoracic epidural anesthesia induced a decrease in systemic arterial blood pressure, heart rate, and cardiac index. The SWM score decreased slightly from 1.34 +/- 0.68 to 1.27 +/- 0.64 (mean +/- SD) (at 10 and 20 min, respectively) (P less than 0.05). Patients were a posteriori analyzed according to whether they had documented coronary artery disease or not. The SWM score before TEA was significantly higher in patients with documented coronary artery disease (1.51 +/- 0.88 vs 1.17 +/- 0.51, respectively; P less than 0.05) and did not change significantly after TEA.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effect of thoracic epidural anesthesia combined with general anesthesia on segmental wall motion assessed by transesophageal echocardiography. 151 Feb 52


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>