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)

Induced hypothermia is an interesting and useful adjunct to therapy in many areas of surgery and medicine. To paraphrase Professor Swan (1973), clinical hypothermia 'has a past and some promise for the future'.
 ...
PMID:Surgical hypothermia. 305 38

The effect of manipulating the brain temperature during cerebral ischemia was investigated in Wistar rats subjected to 30 min 4-vessel occlusion. Three brain temperature profiles were compared: 1. Spontaneous decrease in brain temperature during ischemia from 36 to 31 degrees C (spontaneous hypothermia; n = 5); 2. Constant brain temperature of 30 degrees C induced by selective head cooling (induced hypothermia; n = 5); and 3. Constant brain temperature of 36 degrees C induced by selective heating of the head (normothermia; n = 5). The core temperature was maintained constant at 37 degrees C in all groups. In the spontaneously hypothermic brains, 16% of the CA1 neurons survived after 30 min ischemia. Induced hypothermia significantly increased this percentage to 69%, but maintenance of the brain temperature at normothermia decreased neuronal survival to 1%. Normothermia of the brain also led to morphological injury outside the vulnerable regions, greater variability of the morphologic lesions, an increase in mortality, a marked loss of body weight, and prolongation of EEG suppression, as compared to in both hypothermic groups. These findings clearly demonstrate that maintaining the brain temperature at normothermia by selective heating of the head aggravates ischemic injury and, in consequence, should not be used to investigate the effectiveness of protective drugs for brain ischemia.
 ...
PMID:[Temperature effect on ischemic brain injury]. 813 97

During brain ischemia temperature spontaneously declines. In animal experiments this decline is frequently prevented by stabilizing the temperature at the pre-ischemic level, using an external heat source. The present study examines whether this procedure influences the severity of ischemic injury. Wistar rats were submitted to 30-min four-vessel occlusion followed by 7 days recirculation. During ischemia and the 1st h of recirculation various systemic and electrophysiological variables were recorded. Seven days after the ischemia brains were perfusion-fixed for light microscopical examination. Three brain temperature profiles were compared: spontaneous decline of brain temperature during ischemia from 36 degrees to 31 degrees C (spontaneous hypothermia; n = 5); constant brain temperature of 30 degrees C induced by selective head cooling (induced hypothermia; n = 5); and constant brain temperature of 36 degrees C induced by selective head heating (normothermia; n = 5). Core temperature was maintained constant at 37 degrees C in all groups. In spontaneous hypothermia, 19% of CA1 neurons survived after 30-min ischemia. Induced hypothermia significantly increased this percentage to 69% (P < 0.05); maintenance of brain temperature at normothermia decreased neuronal survival to 1%. Normothermia also led to morphological injury outside the vulnerable regions, an increase in mortality, marked loss of body weight and a prolongation of the electroencephalographic suppression. These findings demonstrate that stabilizing brain temperature at a constant normothermic level by an external heart source introduces an aggravating pathological element that may interfere in an unpredictable way with the manifestation or treatment of ischemic injury.
 ...
PMID:Heating of the brain to maintain normothermia during ischemia aggravates brain injury in the rat. 849 58

Changes in cardiac output (CO), systemic venous oxygen saturation (SvO2), systemic oxygen consumption, and urinary output immediately after Fontan procedure were measured in 10 patients at the intensive unit (ICU) to assess the effects of aorusal from anesthesia, hypothermic management, and respiratory condition. The measurements were taken at the following phases; phase A in deep sedation under hypothermia (33-35 degrees C rectal temperature) and controlled ventilation; phase B in mild sedation under normothermia and controlled ventilation; phase C when awake under normothermia and assisted ventilation; phase D when awake under assisted ventilation; phase D when awake under normothermia immediately after extubation; and phase E 24 hours after extubation. Oxygen delivery (O2 Del.) and fractional oxygen fractions were calculated in each phase. Two patients whose SvO2 values were below 55% during the postoperative course needed reoperation for atrioventricular valve regurgitation in one case for PV stenosis in the other case. CO increased significantly (p < 0.05) after extubation (phase D), compared with that of controlled ventilation (phase B). Under hypothermia (phase A), urinary output was relatively higher with lower CO. There was a significant correlation between SvO2 and CO (R = 0.61) in phase A, however there was no correlation in phase E. Fractional oxygen extraction in phase A was significantly lower than in phase B. In conclusion, the continuous SvO2 measurements reflected real-time changes in cardiac output in the immediate post-Fontan patients. Induced hypothermia was beneficial in increasing urinary output presumably through the correction of maldistribution of cardiac output in post-Fontant patients. Arousal from anesthesia and spontaneous ventilation seemed advantageous for increasing cardiac output, hence, early extubation should be encouraged in the management of post-Fontan patients.
 ...
PMID:[Continuous systemic venous oxygen saturation monitoring immediately after Fontan procedure]. 875 86

Induced hypothermia as adjunctive therapy has been the subject of considerable research interest and debate for over fifty years. Recently the first prospective randomized controlled trials were undertaken in humans with severe traumatic brain injury, with supportive results. Another prospective controlled study of induced hypothermia in severe septic adult respiratory distress syndrome also suggested improved outcome. Other studies in patients with anoxic brain injury have been suggested following promising findings in animal models. There have been anecdotal reports of the use of induced hypothermia in a wide range of other neurological injuries. There are significant physiological changes during induced hypothermia, particularly affecting the cardiovascular system. In addition, hypokalaemia, prolonged clotting times and neutropenia may occur. The evidence that induced hypothermia may be hazardous is mostly drawn from the literature on accidental hypothermia occurring in trauma, or patients with sepsis. It is likely that further trials will be conducted and if benefit is confirmed, induced hypothermia may become more widely used in selected patients in the intensive care unit.
 ...
PMID:Induced hypothermia in intensive care medicine. 880 97

Postoperative low cardiac output states are a major cause of postoperative mortality in infants and children following corrective cardiac surgery for congenital heart defects. In this unit, whole body hypothermia has been used since 1979 in the management of these low output states when they are refractory to conventional modes of therapy. Twenty cases treated in this way between July 1986 and June 1990 were reviewed in 1992. The current report reviews the 50 further cases treated with moderate hypothermia between July 1990 and December 1995. The median (range) age of patients was 8 months (0 days-16 years) with a median weight of 4.1 kg (2.5-33 kg). Following cooling, there was a decrease in heart rate (p < 0.001), an increase in mean arterial pressure (p < 0.001) and a decrease in mean atrial pressure (p < 0.001). Significant increases in pH and urine output were also noticed, the increase in urine output being greater in the surviving group (p = 0.02). A decrease in platelet count occurred (p < 0.001) but white blood cell count remained unchanged (p = 0.18). Twenty-five of the 50 patients survived to leave hospital. Induced hypothermia does not appear to be associated with any complications and after the failure of all conventional treatment, it seems likely that the technique may have been beneficial to outcome in some patients.
 ...
PMID:Induced hypothermia in the postoperative management of refractory cardiac failure following paediatric cardiac surgery. 984 77

A brief review about the effects of hypothermia is presented, with regards to the difference between accidental hypothermia and controlled mild hypothermia (Core temperature = 33-35 degrees C). Mild hypothermia does not seem to affect the cardiac performance, while recent experimental reports show potential protective effects on the cardiac muscle during acute infarction. Mild hypothermia improve the outcome of brain function after cardiac arrest and head injury, while experimental reports show a potential protective effect of local spinal cord cooling during ischemic injury. Induced hypothermia of single organ is widely applied in liver resection and in other surgical procedures, further the cardiac ones. In the acute respiratory failure, mild hypothermia may induce a decrease in PaCO2, in sedated and muscle relaxed patients, due to the decrease of metabolic demand. In this setting a mild induced hypothermia potentially may decrease the side effects of therapeutic hypoventilation (permissive hypercapnia) both on haemodynamics and brain circulation. Preliminary data are presented about five ALI/ARDS patients, enclosed in a randomized trial, who were mechanically ventilated and cooled with an air-sheet: three patients died because of underlying disease and two patients survived with complete recovery. Mild controlled hypothermia seems to provide new interesting clinic uses.
 ...
PMID:[Therapeutic applications of hypothermia in intensive care]. 1039 3

This article will discuss how induced hypothermia affects the patient undergoing coronary artery bypass graft surgery. Nursing interventions differ greatly for cardiac procedures done on cardiopulmonary bypass versus off-bypass procedures, such as "keyhole." Induced hypothermia, cardiopulmonary bypass, cardioplegia, and various delivery techniques of cardioplegia, and postoperative hypothermia will be discussed.
 ...
PMID:The effects of hypothermia on coronary artery bypass graft surgery. 1185 60

We studied brain temperature and the effect of mild hypothermia in 58 patients after severe head injury (SHI). Brain tissue oxygen tension (ptiO2), carbon dioxide tension (ptiCO2), tissuie pH (pHti) and temperature (T.br) were measured using a multiparameter probe. Microdialysis was performed to measure glucose, lactate, glutamate, and aspartate in the extracellular fluid. Mild hypothermia (34 degrees-36 degrees C) was employed in 33 selected patients who had persistent increased intracranial pressure (ICP > 20 mmHg). Mild induced hypothermia decreased brain oxygen significantly from 33 +/- 24 mmHg to 30 +/- 22 mmHg (p < 0.05). The ptiCO2 (46 +/- 8 mmHg) was also significantly lower during mild hypothermia (40.4 +/- 4.0 mmHg), p < 0.0001). The pHti increased from 7.13 +/- 0.15 to 7.24 +/- 0.10 (p < 0.0001) under hypothermic conditions. Induced hypothermia may protect patients from secondary ischemic events by lowering the critical ptiO2 threshold, reducing anaerobic metabolism, and decreasing the release of excitatory aminoacids. However, patients with spontaneous brain hypothermia on admission (Tbr < 36.0 degrees C) showed significantly higher levels of glutamate as well as lactate, compared to all other patients, and had a worse outcome. Spontaneous brain hypothermia carries a poor prognosis, and was characterized by markedly abnormal brain metabolic indices.
 ...
PMID:Relationship between brain temperature, brain chemistry and oxygen delivery after severe human head injury: the effect of mild hypothermia. 1187

Induced hypothermia to treat various neurologic emergencies, which had initially been introduced into clinical practice in the 1940s and 1950s, had become obsolete by the 1980s. In the early 1990s, however, it made a comeback in the treatment of severe traumatic brain injury. The success of mild hypothermia led to the broadening of its application to many other neurologic emergencies. We sought to summarize recent developments in mild hypothermia, as well as its therapeutic potential and limitations. Mild hypothermia has been applied with varying degrees of success in many neurologic emergencies, including traumatic brain injury, spinal cord injury, ischemic stroke, subarachnoid hemorrhage, out-of-hospital cardiopulmonary arrest, hepatic encephalopathy, perinatal asphyxia (hypoxic-anoxic encephalopathy), and infantile viral encephalopathy. At present, the efficacy and safety of mild hypothermia remain unproved. Although the preliminary clinical studies have shown that mild hypothermia can be a feasible and relatively safe treatment, multicenter randomized, controlled trials are warranted to define the indications for induced hypothermia in an evidence-based fashion.
 ...
PMID:Mild hypothermia in neurologic emergency: an update. 1279 Jan 23


1 2 3 4 5 Next >>