Effect of long-term mild hypothermia therapy in patients with severe traumatic brain injury: 1-year follow-up review of 87 cases

2000 ◽  
Vol 93 (4) ◽  
pp. 546-549 ◽  
Author(s):  
Ji-Yao Jiang ◽  
Ming-Kun Yu ◽  
Cheng Zhu

Object. The goal of this study was to investigate the protective effects of long-term (3–14 days) mild hypothermia therapy (33–35°C) on outcome in 87 patients with severe traumatic brain injury (TBI) (Glasgow Coma Scale score ≤ 8).Methods. In 43 patients assigned to a mild hypothermia group, body temperatures were cooled to 33 to 35°C a mean of 15 hours after injury and kept at 33 to 35°C for 3 to 14 days. Rewarming commenced when the individual patient's intracranial pressure (ICP) returned to the normal level. Body temperatures in 44 patients assigned to a normothermia group were maintained at 37 to 38°C. Each patient's outcome was evaluated 1 year later by using the Glasgow Outcome Scale. One year after TBI, the mortality rate was 25.58% (11 of 43 patients) and the rate of favorable outcome (good recovery or moderate disability) was 46.51% (20 of 43 patients) in the mild hypothermia group. In the normothermia group, the mortality rate was 45.45% (20 of 44 patients) and the rate of favorable outcome was 27.27% (12 of 44 patients) (p < 0.05). Induced mild hypothermia also markedly reduced ICP (p < 0.01) and inhibited hyperglycemia (p < 0.05). The rates of complication were not significantly different between the two groups.Conclusions. The data produced by this study demonstrate that long-term mild hypothermia therapy significantly improves outcomes in patients with severe TBI.

2005 ◽  
Vol 26 (6) ◽  
pp. 771-776 ◽  
Author(s):  
Ji-Yao Jiang ◽  
Wei Xu ◽  
Wei-Ping Li ◽  
Guo-Yi Gao ◽  
Ying-Hui Bao ◽  
...  

2002 ◽  
Vol 96 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Roberto Imberti ◽  
Guido Bellinzona ◽  
Martin Langer

Object. The aim of this study was to investigate the effects of moderate hyperventilation on intracranial pressure (ICP), jugular venous oxygen saturation ([SjvO2], an index of global cerebral perfusion), and brain tissue PO2 (an index of local cerebral perfusion). Methods. Ninety-four tests consisting of 20-minute periods of moderate hyperventilation (27–32 mm Hg) were performed on different days in 36 patients with severe traumatic brain injury (Glasgow Coma Scale score ≤ 8). Moderate hyperventilation resulted in a significant reduction in average ICP, but in seven tests performed in five patients it was ineffective. The response of SjvO2 and brain tissue PO2 to CO2 changes was widely variable and unpredictable. After 20 minutes of moderate hyperventilation in most tests (79.8%), both SjvO2 and brain tissue PO2 values remained above the lower limits of normality (50% and 10 mm Hg, respectively). In contrast, in 15 tests performed in six patients (16.6% of the studied population) brain tissue PO2 decreased below 10 mm Hg although the corresponding SjvO2 values were greater than 50%. The reduction of brain tissue PO2 below 10 mm Hg was favored by the low prehyperventilation values (10 tests), higher CO2 reactivity, and, possibly, by lower prehyperventilation values of cerebral perfusion pressure. In five of those 15 tests, the prehyperventilation values of SjvO2 were greater than 70%, a condition of relative hyperemia. The SjvO2 decreased below 50% in four tests; the corresponding brain tissue PO2 values were less than 10 mm Hg in three of those tests, whereas in the fourth, the jugular venous O2 desaturation was not detected by brain tissue PO2. The analysis of the simultaneous relative changes (prehyperventilation — posthyperventilation) of SjvO2 and brain tissue PO2 showed that in most tests (75.5%) there was a reduction of both SjvO2 and brain tissue PO2. In two tests moderate hyperventilation resulted in an increase of both SjvO2 and brain tissue PO2. In the remaining 17 tests a redistribution of the cerebral blood flow was observed, leading to changes in SjvO2 and brain tissue PO2 in opposite directions. Conclusions. Hyperventilation, even if moderate, can frequently result in harmful local reductions of cerebral perfusion that cannot be detected by assessing SjvO2. Therefore, hyperventilation should be used with caution and should not be considered safe. This study confirms that SjvO2 and brain tissue PO2 are two parameters that provide complementary information on brain oxygenation that is useful to reduce the risk of secondary damage. Changes in SjvO2 and brain tissue PO2 in opposite directions indicate that data obtained from brain tissue PO2 monitoring cannot be extrapolated to evaluate the global cerebral perfusion.


2005 ◽  
Vol 103 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Tobias Clausen ◽  
Oscar Luis Alves ◽  
Michael Reinert ◽  
Egon Doppenberg ◽  
Alois Zauner ◽  
...  

Object. Glycerol is considered to be a marker of cell membrane degradation and thus cellular lysis. Recently, it has become feasible to measure via microdialysis cerebral extracellular fluid (ECF) glycerol concentrations at the patient's bedside. Therefore the aim of this study was to investigate the ECF concentration and time course of glycerol after severe traumatic brain injury (TBI) and its relationship to patient outcome and other monitoring parameters. Methods. As soon as possible after injury for up to 4 days, 76 severely head-injured patients were monitored using a microdialysis probe (cerebral glycerol) and a Neurotrend sensor (brain tissue PO2) in uninjured brain tissue confirmed by computerized tomography scanning. The mean brain tissue glycerol concentration in all monitored patients decreased significantly from 206 ± 31 µmol/L on Day 1 to 9 ± 3 µmol/L on Day 4 after injury (p < 0.0001). Note, however, that there was no significant difference in the time course between patients with a favorable outcome (Glasgow Outcome Scale [GOS] Scores 4 and 5) and those with an unfavorable outcome (GOS Scores 1–3). Significantly increased glycerol concentrations were observed when brain tissue PO2 was less than 10 mm Hg or when cerebral perfusion pressure was less than 70 mm Hg. Conclusions. Based on results in the present study one can infer that microdialysate glycerol is a marker of severe tissue damage, as seen immediately after brain injury or during profound tissue hypoxia. Given that brain tissue glycerol levels do not yet add new clinically significant information, however, routine monitoring of this parameter following traumatic brain injury needs further validation.


2002 ◽  
Vol 96 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Michael N. Diringer ◽  
Tom O. Videen ◽  
Kent Yundt ◽  
Allyson R. Zazulia ◽  
Venkatesh Aiyagari ◽  
...  

Object. Recently, concern has been raised that hyperventilation following severe traumatic brain injury (TBI) could lead to cerebral ischemia. In acute ischemic stroke, in which the baseline metabolic rate is normal, reduction in cerebral blood flow (CBF) below a threshold of 18 to 20 ml/100 g/min is associated with energy failure. In severe TBI, however, the metabolic rate of cerebral oxygen (CMRO2) is low. The authors previously reported that moderate hyperventilation lowered global hemispheric CBF to 25 ml/100 g/min but did not alter CMRO2. In the present study they sought to determine if hyperventilation lowers CBF below the ischemic threshold of 18 to 20 ml/100 g/min in any brain region and if those reductions cause energy failure (defined as a fall in CMRO2). Methods. Two groups of patients were studied. The moderate hyperventilation group (nine patients) underwent hyperventilation to PaCO2 of 30 ± 2 mm Hg early after TBI, regardless of intracranial pressure (ICP). The severe hyperventilation group (four patients) underwent hyperventilation to PaCO2 of 25 ± 2 mm Hg 1 to 5 days postinjury while ICP was elevated (20–30 mm Hg). The ICP, mean arterial blood pressure, and jugular venous O2 content were monitored, and cerebral perfusion pressure was maintained at 70 mm Hg or higher by using vasopressors when needed. All data are given as the mean ± standard deviation unless specified otherwise. The moderate hyperventilation group was studied 11.2 ± 1.6 hours (range 8–14 hours) postinjury, the admission Glasgow Coma Scale (GCS) score was 5.6 ± 1.8, the mean age was 27 ± 9 years, and eight of the nine patients were men. In the severe hyperventilation group, the admission GCS score was 4.3 ± 1.5, the mean age was 31 ± 6 years, and all patients were men. Positron emission tomography measurements of regional CBF, cerebral blood volume, CMRO2, and oxygen extraction fraction (OEF) were obtained before and during hyperventilation. In all 13 patients an automated search routine was used to identify 2.1-cm spherical nonoverlapping regions with CBF values below thresholds of 20, 15, and 10 ml/100 g/min during hyperventilation, and the change in CMRO2 in those regions was determined. In the regions in which CBF was less than 20 ml/100 g/min during hyperventilation, it fell from 26 ± 6.2 to 13.7 ± 1 ml/100 g/min (p < 0.0001), OEF rose from 0.31 to 0.59 (p < 0.0001), and CMRO2 was unchanged (1.12 ± 0.29 compared with 1.14 ± 0.03 ml/100 g/min; p = 0.8). In the regions in which CBF was less than 15 ml/100 g/min during hyperventilation, it fell from 23.3 ± 6.6 to 11.1 ± 1.2 ml/100 g/min (p < 0.0001), OEF rose from 0.31 to 0.63 (p < 0.0001), and CMRO2 was unchanged (0.98 ± 0.19 compared with 0.97 ± 0.23 ml/100 g/min; p = 0.92). In the regions in which CBF was less than 10 ml/100 g/min during hyperventilation, it fell from 18.2 ± 4.5 to 8.1 ± 0 ml/100 g/min (p < 0.0001), OEF rose from 0.3 to 0.71 (p < 0.0001), and CMRO2 was unchanged (0.78 ± 0.26 compared with 0.84 ± 0.32 ml/100 g/min; p = 0.64). Conclusions. After severe TBI, brief hyperventilation produced large reductions in CBF but not energy failure, even in regions in which CBF fell below the threshold for energy failure defined in acute ischemia. Oxygen metabolism was preserved due to the low baseline metabolic rate and compensatory increases in OEF; thus, these reductions in CBF are unlikely to cause further brain injury.


1999 ◽  
Vol 91 (4) ◽  
pp. 593-600 ◽  
Author(s):  
Nancy R. Temkin ◽  
Sureyya S. Dikmen ◽  
Gail D. Anderson ◽  
Alan J. Wilensky ◽  
Mark D. Holmes ◽  
...  

Object. Seizures frequently accompany moderate to severe traumatic brain injury. Phenytoin and carbamazepine are effective in preventing early, but not late, posttraumatic seizures. In this study the authors compare the safety and effectiveness of valproate with those of short-term phenytoin for prevention of seizures following traumatic brain injury.Methods. The study was a randomized, double-blind, single-center, parallel-group clinical trial. Treatment began within 24 hours of injury. One hundred thirty-two patients at high risk for seizures were assigned to receive a 1-week course of phenytoin, 120 were assigned to receive a 1-month course of valproate, and 127 were assigned to receive a 6-month course of valproate. The cases were followed for up to 2 years.The rates of early seizures were low and similar when using either valproate or phenytoin (1.5% in the phenytoin treatment group and 4.5% in the valproate arms of the study; p = 0.14, relative risk [RR] = 2.9, 95% confidence interval [CI] 0.7–13.3). The rates of late seizures did not differ among treatment groups (15% in patients receiving the 1-week course of phenytoin, 16% in patients receiving the 1-month course of valproate, and 24% in those receiving the 6-month course of valproate; p = 0.19, RR = 1.4, 95% CI 0.8–2.4). The rates of mortality were not significantly different between treatment groups, but there was a trend toward a higher mortality rate in patients treated with valproate (7.2% in patients receiving phenytoin and 13.4% in those receiving valproate; p = 0.07, RR = 2.0, 95% CI 0.9–4.1). The incidence of serious adverse events, including coagulation problems and liver abnormalities, was similar in phenytoin- and valproate-treated patients.Conclusions. Valproate therapy shows no benefit over short-term phenytoin therapy for prevention of early seizures and neither treatment prevents late seizures. There was a trend toward a higher mortality rate among valproate-treated patients. The lack of additional benefit and the potentially higher mortality rate suggest that valproate should not be routinely used for the prevention of posttraumatic seizures.


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