Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 52-year-old male was admitted because of right hemiparesis. Computed tomography scan showed a low-density area in the basal ganglia on the left side. Left carotid angiography showed an aneurysm of the extracranial internal carotid artery at the level of the C1-C2 vertebral body. Right carotid angiography also showed an aneurysm of the extracranial internal carotid artery. Because there were neither steno-occlusive changes in the intracranial vessels nor abnormality in the heart, the right hemiparesis seemed to be due to embolism from the extracranial aneurysm. Aneurysmectomy and end-to-end anastomosis of the left internal carotid artery were performed. Extracranial carotid aneurysms are rare conditions. In surgery on these aneurysms, ischemic changes of the brain during arterial clump must be detected and treated. Hypothermia, induced hypertension, and/or internal shunting have been used during arterial clump. The pathogenesis, symptoms, prognosis, and surgical treatments of these aneurysms are discussed.
 ...
PMID:[Bilateral aneurysms of extracranial internal carotid arteries. Case report]. 172 63

In a prospective study, we analyzed the intraoperative electroencephalographic (EEG) changes during open heart surgery with deep hypothermia in 66 infants aged 6 months or younger, 70% of whom were neonates. Suppression of amplitude and continuity at the nadir of temperature reduction and following rewarming, and the appearance of periodic paroxysmal activity, was compared with neurologic abnormalities before and following operation, patient characteristics, and operation variables. EEG changes disclosed no relationship to abnormal neurologic findings, age at operation, type of anesthetic, duration of cardiopulmonary bypass (CPB), duration of low-flow CPB or cooling, temperature at circulatory arrest (HCA) or low flow, or nasopharyngeal-venous return temperature differences. EEG suppression following rewarming was associated with the use of thiopentone and duration of HCA. Use of thiopentone was also related to decreased levels of alertness at the end of the first postoperative week. We could not demonstrate any association between operation variables, including duration of HCA, and postoperative neurologic findings which include abnormalities of tone, alertness, seizures, generalized pyramidal signs, choreoathetosis, and hemiparesis. Severe hypotonia before operation was associated with continuing severe hypotonia during the postoperative period. EEG changes during cooling for open heart surgery on infants appear to be physiologic, and these plus EEG suppression following HCA or low-flow CPB are not useful predictors of early neurologic morbidity.
 ...
PMID:EEG changes during open heart surgery on infants aged 6 months or less: relationship to early neurologic morbidity. 802 60

Does the use of warm-body perfusion in elderly patients with severe cerebrovascular disease lead to a higher incidence of stroke, due to hypotension secondary to low systemic vascular resistance? Two thousand, three hundred eighty-three (2,383) consecutive myocardial revascularizations were performed (1987-1992) using warm-body (perfusion 37 degrees C), cold-heart surgery (cold cardioplegic arrest). The perfusion pressure was maintained between 50-70 torr; hematocrit was kept around 20%. Prospective data during hospitalization revealed 23 operative deaths (1%), and 24 patients (1%) who developed new neurological signs after surgery. The latter formed three groups: Group I consisted of six patients with severe neurological deficits, who never regained consciousness and died after support systems withdrawal. Group II included 14 patients with postoperative clinical evidence of focal cerebral infarction (9 had hemiplegia, 2 had visual disturbance, and 3 showed alteration of memory), all of whom had residual defects at discharge; Group III was composed of four patients with minor neurological deficits after surgery (hemiparesis, gait disturbance, mental changes) which had cleared up by discharge. These data were compared retrospectively with 1605 patients (1980-1986) undergoing myocardial revascularization with moderate (25-30 degrees C) hypothermia and the same surgical team and operative techniques. Both groups had similar preoperative demographics except the warm group included more elderly patients, higher numbers with unstable angina and poor ejection fraction, and more frequent use of a mammary artery conduit. Neurological complications were 1% and 1.3% for the normothermic and hypothermic perfusion groups respectively. Incremental risk factors of stroke remain: age over 70 years, diffuse atherosclerosis of the aorta, carotid occlusive disease, and severe hypotension during perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Neurological complications during myocardial revascularization using warm-body, cold-heart surgery. 804 89

The intimal disruption is located or extends to the aortic arch in 10-20% of acute type A aortic dissections. Multiple tears are extremely rare. The reported mortality rate of emergency arch replacement varies from 25% to 40%, and therefore many surgeons elect to perform ascending aortic replacement only in these cases. However, with such an approach, the operative mortality rate of 10% is followed by a late mortality rate of up to 30% from residual aneurysm formation. Emergency arch replacement was carried out in five of 14 patients with an acute type A aortic dissection in whom the intimal tear either originated or extended into the arch, or in whom multiple tears existed. The ascending dissections were resected under moderate hypothermia, whereas the arch was explored under profound hypothermia, surface cooling and circulatory arrest. None of these five patients died; one developed slight hemiparesis, but no patient developed recurrent aneurysm in the follow-up period. These results appear to justify this aggressive approach, if it can be performed with an acceptable mortality rate < 25%, by avoiding the late deaths associated with more conservative surgical treatment.
 ...
PMID:Acute type A dissecting aortic aneurysm requiring emergency arch replacement. 807 72

The objective of this study was to improve the ability to detect cerebrovascular complications in patients undergoing complicated neurosurgical procedures using on-line monitoring of cerebral pH with in vivo microdialysis. We employed on-line pH monitoring in patients with a variety of neurosurgical procedures including high-flow bypass surgery, aneurysm clipping, and temporal resection in epilepsy treatment. The pH was monitored with a microdialysis probe, usually inserted into the frontal cortex and pH of the dialysate was measured on-line with a pH electrode. We monitored 17 cases: 12 high-flow extracranial-intracranial (EC-IC) bypass procedures, 3 surgeries to clip large basilar tip aneurysms under protection of hypothermic circulatory arrest, and 2 surgeries for intractable seizure disorders. In the patients undergoing high-flow bypass, the pH remained stable in 5 patients and all had an uneventful outcome. In 3 patients, the pH decreased during surgery. One patient had a severe hemiparesis on awaking from anesthesia. The fall in pH in another patient was corrected when the blood pressure was raised during surgery. The pH was also responsive to changes in intraoperative ventilation and probably also to brain edema with elevation of pH values. In the three patients undergoing basilar tip aneurysm clipping under hypothermic circulatory arrest, the pH fell to 6.41 in one patient. This patient awoke with a mild hemiparesis. In the other two patients, the pH was stable during the hypothermia and neither patient had complications. In the patients undergoing temporal lobectomy and hippocampectomy, the pH fell rapidly with the onset of ischemia. We conclude that it is possible to monitor the cerebral extracellular pH with on-line microdialysis. The information obtained may alert the surgeon to the possibility of impending cerebral ischemia or other complications. However, further experience is needed before the technique can be recommended for general use.
 ...
PMID:Intraoperative on-line monitoring of cerebral pH by microdialysis in neurosurgical procedures. 952 50

Maintaining an adequate cerebral oxygen supply is a serious problem in aortic arch surgery. Deep hypothermic circulatory arrest is the most common method used for cerebral protection, but guarantees only a time-limited safety period. Based on experimental investigations, we applied selective cerebral perfusion via the innominate artery alone with only moderate hypothermia (28 degrees C) and without circulatory arrest in 25 consecutive patients undergoing surgical treatment of an aneurysm (n = 10) or acute type-A dissection (n = 15) involving the aortic valve and arch. In every case a test perfusion was carried out to assess whether the cerebral perfusion achieved would be adequate for the whole operation. In no case was the perfusion inadequate. As a new perioperative monitoring system, we used computer-aided topographical electroencephalometry (CATEEM). There were 18 male and 7 female patients, their age was 47.0 +/- 15.1 years (mean +/- SD). Mean time periods were 155.1 +/- 37.3 min for aortic cross-clamping, and 69.3 +/- 35 min for selective cerebral perfusion. Postoperatively, two patients (8%) revealed a temporary left-sided hemiparesis, and 4 patients (16%) died within 30 days. The overall mortality rate was 16% in a follow-up period of 24.2 +/- 9.5 months. In this small group the CATEEM monitoring enabled an intraoperative selection of patients with sufficient bihemispheric collateral circulation and therefore suitable for simple innominate artery perfusion.
 ...
PMID:An assessment of selective cerebral perfusion via the innominate artery in aortic arch replacement. 955 41

Deep hypothermic cardiocirculatory arrest is the commonest method of brain protection during transverse aortic arch surgery. Its principle drawbacks consist in the limited safe ischemic period and in the coagulative, renal and pulmonary complications related to low body temperatures and prolonged cardiopulmonary bypass time. Different selective cerebral perfusion techniques have recently raised the interest of some surgical teams in an effort to obviate these problems. The authors' initial experiences with 22 patients, ranging in age from 19 to 78 years (mean, 55 +/- 15 years), who underwent ascending aorta and/or aortic arch replacement using selective cerebral perfusion and moderately hypothermic cardiopulmonary bypass are reported here. Acute aortic dissection and atherosclerotic aneurysm were the commonest lesions observed: ascending aorta associated with partial or complete arch replacement was the most widely performed procedure. With regard to the perfusion technique, after regular cardiopulmonary bypass had been established through the iliac vessels, selective cerebral perfusion was started after aortic arch vessels cannulation (innominate artery, bilateral common carotid artery, innominate artery and left common carotid artery, or right common carotid artery) using a single roller pump separately from the systemic circulation, and brain perfusion was achieved by blood cooled at 30 degrees C, at a flow rate that ranged from 300 ml/min to 1500 ml/min, at a perfusion pressure of approximately 65 mmHg, with the patient maintained at moderate hypothermia (30 degrees C rectal). To perform distal aortic repair, if transverse aortic arch or proximal descending aorta cross-clamping was not feasible, cardiopulmonary bypass flow was lowered to 300-350 ml/min and an open anastomosis was performed, while independently assuring cerebral perfusion (six patients). There were three hospital deaths (mortality rate of 13.6%; s.d. 6.0-25.5%; 70% confidence limit), but none because of cerebral accident. No paraplegia occurred. One patient suffered from right hemiparesis, neither renal nor pulmonary complications were observed. Two chest reexplorations were necessary for bleeding, which were partially related to hemocoagulative disorders. In our experience, the technique of moderately hypothermic cardiopulmonary bypass and selective cerebral perfusion in aortic surgery has provided good results with regard to cerebral protection and organ function preservation. Therefore, allowing a prolonged distal aortic reconstruction period, it may be considered as a safe alternative to profound hypothermia associated with cardiocirculatory arrest in aortic arch surgery.
 ...
PMID:Moderately hypothermic cardiopulmonary bypass and selective cerebral perfusion in ascending aorta and aortic arch surgery. Preliminary experience in twenty-two patients. 972 20

To attain satisfactory results in aortic arch surgery a reliable method of cerebral protection, avoidance of emboli, and control of hemorrhage is mandatory. Deep hypothermic circulatory arrest is the most common technique at present but gives only a limited period of protection, whereas a complicated aortic arch operation may require more time than anticipated. Therefore the selective cannulation and perfusion of the innominate artery has not been widely used until now because it is uncertain whether the left hemisphere of the brain is adequately perfused. Between 1990 and 1995, 21 of 69 patients within the last 36 months, consisting of 15 men and 6 women averaging 45 +/- 13.4 years, underwent operative treatment for aneurysm (n = 9) or type A dissection (n = 12) involving the aortic valve and aortic arch; selective innominate perfusion (SCP [i]) in moderate hypothermia (28 degreesC) for brain protection was used. Extended perioperative monitoring included bilateral somatosensory-evoked potentials (SEP), transcranial Doppler sonography (TCD), a computer-aided topographical electro-encephalometry (CATEEM), and analysis of the arterial and venous oxygen saturation and desaturation. Mean time periods were 229.7 +/- 56.5 minutes for extracorporeal circulation, 151.7 +/- 34.1 minutes for aortic cross-clamping, and 67.05 +/- 34.03 for selective cerebral perfusion via the innominate artery. Not once did the intraoperative monitoring reveal hints of cerebral damage due to inadequate perfusion. All patients survived surgery but two could not be weaned from the respirator; one died 2 days and the other 6 days after the operation due to multiple organ failure (MOF). Another two patients died after 13 days due to untreatable septic syndrome with pulmonary insufficiency. All four patients died within 30 days, during which time they had aortic dissection involving the complete aortic arch and severe aortic valvular incompetence (grade IV). There was no late death and follow-up time of 19.76 +/- 8.04 months revealed an overall mortality rate of 19%. Only temporary neurological affections (left-sided hemiparesis) were found in two patients (9.5%). Additionally, we observed neuropsychological disturbances in one of these. Our first experience with selective cerebral perfusion via innominate artery and the attendant CATEEM monitoring for assessment of adequate bilateral cerebral perfusion suggests that this method is a useful addition to the armamentarium in complicated aortic arch surgery.
 ...
PMID:Selective Cerebral Perfusion Via Innominate Artery in Aortic Arch Replacement Without Deep Hypothermic Circulatory Arrest. 982 9

Ischemic cerebrovascular diseases are commonly induced by atherosclerosis and cardiogenic embolization but rarely they occur in association with Takayasu's arteritis and aortic lesion such as aortic dissection and aneurysm. Here we experienced two cases of acute aortic disease complicated by ischemic cerebrovascular disease (CVD). Patient 1 was a 77-year-old male. He complained of dyspnea and left hemiparesis. He was brought to our hospital by ambulance. Left hemiparesis and dyspnea improved soon. The patient only complained of left lower extremity pain and physical examination revealed hypotension. Brain CT showed no abnormality but chest CT revealed aortic dissection. The resection of the intimal tear and replacement of ascending aorta and aortic arch with 28 mm Hemashield graft were performed under hypothermia and selective cerebral perfusion. The postoperative course was uneventful and he has been doing well. Patient 2 was a 67-year-old female. She was found lying unconscious and brought to our hospital by ambulance. Physical examination revealed right hemiparesis and hypotension. Brain CT demonstrated low density area in the left corona radiata and ruptured aortic aneurysm was seen in abdominal CT. Just after the examination, the patient suddenly complained of severe back pain and died despite cardiopulmonary resuscitation. Aortic lesions can manifest ischemic symptom involving multiple organs following their vascular disorder. Aortic dissection rarely occurs in association with ischemic CVD and in that case it is likely to be seen by neurologists. Aortic dissection and aneurysm deteriorate so suddenly that immediate diagnosis and proper treatment are needed.
 ...
PMID:[Two cases of acute aortic disease complicated by ischemic cerebrovascular disease]. 1076 48

Clinical trials for ischemic stroke have been characterized by a disappointing series of negative results, using a panoply of pharmacologic agents. This paper emphasizes five physiologic measures that can be taken to mitigate ischemic brain damage. These are (1) hypothermia, (2) insulin, (3) arterial hyperoxemia, (4) blood pressure control and (5) magnesium. Hypothermia is protective in both focal and global ischemia, even postischemically protecting against selective neuronal necrosis and infarction. The total equation for protection includes the (i) postischemic delay, (ii) depth, and (iii) duration of hypothermia. Insulin operates by lowering glucose levels to the normal range in focal ischemia. It is possible that very low glucose levels are detrimental in focal ischemia with paradoxical augmentation of the infarct size, and that spreading depression plays a role in this. Controlled arterial hyperoxemia seems effective experimentally in reducing infarct size, operating mechanistically by either a direct effect of oxygen, or vasoconstriction causing shunting of blood into the infarct, or both. Blood pressure is a critical determinant of infarct size, and raising blood pressure improves collateral blood flow and reduces stroke size. To be used clinically, however, hemorrhage must be ruled out. The most dramatic clinical effects of blood pressure are seen in aneurysm patients with vasospasm, where minor increases in blood pressure reverse temporary hemiparesis by reducing ischemia. Magnesium is likely the safest NMDA antagonist, with a long history of safe administration to pregnant women with eclampsia. There is potential interaction with insulin, in that magnesium causes hyperglycemia, which requires insulin to counteract it. Magnesium and insulin together have been shown effective in experimental brain ischemia. In the absence of safe and effective pharmacologic neuroprotection agents, clinical trials should be designed and launched to test these physiologic measures, singly and in combination, to reduce brain damage after ischemia.
 ...
PMID:Non-pharmacologic (physiologic) neuroprotection in the treatment of brain ischemia. 1146 80


1 2 Next >>