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Biomedical subjects

A Takasu

Publications and source records attributed to A Takasu.

At least 19 recordsLinked to original sources
PubMed2001

Hyperthermia: is it an ominous sign after cardiac arrest?

OBJECTIVE: To clarify the clinical characteristics of hyperthermia at an early stage after resuscitation from cardiac arrest (CA). MATERIALS AND METHODS: We reviewed the medical records of 43 adult patients with non-traumatic out-of-hospital CA, who survived for longer than 24 h after admission to our intensive care unit (ICU) between January, 1995, and December, 1998. The patients were divided into two groups: a clinical brain death (CBD) group (n=23) and a non-CBD group (n=20), and various factors relating to hyperthermia were compared between the two groups. RESULTS: The mean value of peak axillary temperatures within 72 h of admission was 39.8+/-0.9 degrees C for the CBD group, which was significantly greater than 38.3+/-0.6 degrees C for the non-CBD group (P<0.0001). The time of occurrence of the peak axillary temperature was at 19+/-16 h of admission in the CBD group and 20+/-18 h in the non-CBD group (not significantly different). There were no significant differences in risk factors relating to the occurrence of hyperthermia between the two groups, except for the number of patients who received epinephrine at ICU. In 23 patients with a peak axillary temperature of > or =39 degrees C during the first 72 h of hospitalization, brain death was diagnosed in 20 patients, whereas only 3 of 20 patients having a peak axillary temperature of <39 degrees C developed brain death (odds ratio, 37.8; 95% confidence interval, 6.72-212.2). CONCLUSION: Hyperthermia at an early stage after resuscitation from CA may be associated with the outcome of brain death.

Aged↗
PubMed2001

[11C]methionine positron emission tomography for the evaluation of pancreatic exocrine function in chronic pancreatitis.

Positron emission tomography (PET) can be used for the quantitative analysis of amino acid metabolism. The aim of this study was to investigate whether pancreatic exocrine function can be evaluated by [11C]methionine PET in chronic pancreatitis (CP) patients. Dynamic PET scan of the pancreas and liver was performed in eight healthy subjects and seven patients with CP after intravenous (i.v.) injection of [11C]methionine. Simultaneously, duodenal juice was collected with the background of continuous i.v. administration of secretin (125 ng/kg/h). The radioactivity ratio of the pancreas to that of the liver (PLR) was calculated by regions of interest (ROI) analysis. Amylase output and bicarbonate concentration were measured in the duodenal aspirates. The PLR of CP patients was significantly lower than that of healthy subjects at all time points after methionine injection. The PLRs at 4.5 minutes (PLR4.5) after methionine injection were positively correlated with the amylase output, mean bicarbonate concentration, and volume of duodenal aspirates (R = 0.74, 0.69, 0.46). It is concluded that [11C]methionine PET would be a noninvasive method for the evaluation of exocrine pancreatic function, which may represent total amino acids uptake of viable acinar cells in the pancreas.

Adult↗
PubMed2001

Analysis of plasma nitrite/nitrate in human thermal injury.

The aim of this study is to examine the characteristics of nitrite/nitrate (NOx), the final metabolite of nitric oxides, in plasma after burn injury. A total of 83 blood samples were collected from 19 patients on arrival, day 1, day 3, and day 5 after suffering burn injuries and from 7 non-burned volunteers. We measured the NOx levels in plasma using the Griess method, and analyzed the relationships among plasma the NOx levels, the burn-magnitude, and the blood examination data using a stepwise multivariate regression analysis. The plasma NOx levels at hospital-arrival after burns significantly exceeded those of non-burned volunteers, and the NOx levels in the plasma returned to normal range after day 1. Based on the findings of a multivariate analysis, the plasma NOx levels at admission to the hospital were not found to be related to the total burn surface area, the burn index or inhalation injury, but they were significantly related to age. Furthermore, these plasma NOx levels were also related to the platelet count, neutrophil count and blood urea nitrogen. The increase in the plasma NOx level may therefore play an important role in the pathophysiology of elderly burned patients, while the nitric oxide levels in the plasma might also play a role in inhibiting the constriction of microvascular smooth muscle in extensively burned patients.

Adult↗
PubMed2001

[A case of disseminated intravascular coagulopathy (DIC) and multiple organ failure (MOF) after ingestion of hydrochloric acid].

Ingestion of caustic materials causes systemic damages and requires treatment in an intensive care unit. This report presents a case of disseminated intravascular coagulopathy (DIC) and multiple organ failure after ingestion of hydrochloric acid in an attempted suicide. The patient was admitted to the emergency ward within 1 hr after ingestion of 60 ml of 35% hydrochloric acid. Initial blood examination suggested hemolysis without anemia or thrombocytopenia. Arterial blood gas analysis exhibited evident metabolic acidosis with hypoxia. Two hours after ingestion, severe hemolysis, anemia, thrombocytopenia emerged with abnormal results from clotting and fiblinolysis tests, and a diagnosis of DIC was made. Subsequently, conjugate deviation and severe bleeding diathesis appeared. No evidence for gastrointestinal bleeding and brain hemorrhage was obtained in our abdominal echography and brain computed tomography, respectively. In spite of vigorous suppurative therapy including transfusion of blood, fresh frozen plasma, and catecholamines, the patient expired 29 hrs after ingestion. Autopsy was not carried out. Rapid progressive DIC as an acute complication of acid ingestion must be born in mind.

Acidosis↗
PubMed2000

Effects of increased oxygen breathing in a volume controlled hemorrhagic shock outcome model in rats.

It is believed that victims of traumatic hemorrhagic shock (HS) benefit from breathing 100% O(2). Supplying bottled O(2) for military and civilian first aid is difficult and expensive. We tested the hypothesis that increased FiO(2) both during severe volume-controlled HS and after resuscitation in rats would: (1) increase blood pressure; (2) mitigate visceral dysoxia and thereby prevent post-shock multiple organ failure; and (3) increase survival time and rate. Thirty rats, under light anesthesia with halothane (0. 5% throughout), with spontaneous breathing of air, underwent blood withdrawal of 3 ml/100 g over 15 min. After HS phase I of 60 min, resuscitation phase II of 180 min with normotensive intravenous fluid resuscitation (shed blood plus lactated Ringer's solution), was followed by an observation phase III to 72 h and necropsy. Rats were randomly divided into three groups of ten rats each: group 1 with FiO(2) 0.21 (air) throughout; group 2 with FiO(2) 0.5; and group 3 with FiO(2) 1.0, from HS 15 min to the end of phase II. Visceral dysoxia was monitored during phases I and II in terms of liver and gut surface PCO(2) increase. The main outcome variables were survival time and rate. PaO(2) values at the end of HS averaged 88 mmHg with FiO(2) 0.21; 217 with FiO(2) 0.5; and 348 with FiO(2) 1. 0 (P<0.001). During HS phase I, FiO(2) 0.5 increased mean arterial pressure (MAP) (NS) and kept arterial lactate lower (P<0.05), compared with FiO(2) 0.21 or 1.0. During phase II, FiO(2) 0.5 and 1. 0 increased MAP compared with FiO(2) 0.21 (P<0.01). Heart rate was transiently slower during phases I and II in oxygen groups 2 and 3, compared with air group 1 (P<0.05). During HS, FiO(2) 0.5 and 1.0 mitigated visceral dysoxia (tissue PCO(2) rise) transiently, compared with FiO(2) 0.21 (P<0.05). Survival time (by life table analysis) was longer after FiO(2) 0.5 than after FiO(2) 0.21 (P<0. 05) or 1.0 (NS), without a significant difference between FiO(2) 0. 21 and 1.0. Survival rate to 72 h was achieved by two of ten rats in FiO(2) 0.21 group 1, by four of ten rats in FiO(2) 0.5 group 2 (NS); and by four of ten rats of FiO(2) 1.0 group 3 (NS). In late deaths macroscopic necroses of the small intestine were less frequent in FiO(2) 0.5 group 2. We conclude that in rats, in the absence of hypoxemia, increasing FiO(2) from 0.21 to 0.5 or 1.0 does not increase the chance to achieve long-term survival. Breathing FiO(2) 0.5, however, might increase survival time in untreated HS, as it can mitigate hypotension, lactacidemia and visceral dysoxia.

Animals↗
PubMed2000

Adenosine by aortic flush fails to augment the brain preservation effect of mild hypothermia during exsanguination cardiac arrest in dogs - an exploratory study.

Most trauma cases with rapid exsanguination to cardiac arrest (CA) in the field, as well as many cases of normovolemic sudden cardiac death are 'unresuscitable' by standard cardiopulmonary-cerebral resuscitation (CPCR). We are presenting a dog model for exploring pharmacological strategies for the rapid induction by aortic arch flush of suspended animation (SA), i.e. preservation of cerebral viability for 15 min or longer. This can be extended by profound hypothermic circulatory arrest of at least 60 min, induced and reversed with (portable) cardiopulmonary bypass (CPB). SA is meant to buy time for transport and repair during pulselessness, to be followed by delayed resuscitation to survival without brain damage. This model with exsanguination over 5 min to CA of 15-min no-flow, is to evaluate rapid SA induction by aortic flush of normal saline solution (NSS) at room temperature (24 degrees C) at 2-min no-flow. This previously achieved normal functional recovery, but with histologic brain damage. We hypothesized that the addition of adenosine would achieve recovery with no histologic damage, because adenosine delays energy failure and helps repair brain injury. This dog model included reversal of 15-min no-flow with closed-chest CPB, controlled ventilation to 20 h, and intensive care to 72 h. Outcome was evaluated by overall performance, neurologic deficit, and brain histologic damage. At 2 min of CA, 500 ml of NSS at 24 degrees C was flushed (over 1 min) into the brain and heart via an aortic balloon catheter. Controls (n=5) received no drug. The adenosine group (n=5) received 2-chloro-adenosine (long acting adenosine analogue), 30 mg in the flush solution, and, after reperfusion, adenosine i.v. over 12 h (210 microg/kg per min for 3 h, 140 microg/kg per min for 9 h). The 24 degrees C flush reduced tympanic membrane temperature (T(ty)) within 2 min of CA from 37.5 to approximately 36.0 degrees C in both groups. At 72 h, final overall performance category (OPC) 1 (normal) was achieved by all ten dogs of the two groups. Final neurologic deficit scores (NDS; 0-10% normal, 100% brain death) were 5+/-3% in the control group versus 6+/-5% in the adenosine group (NS). Total brain histologic damage scores (HDS) at 72 h were 74+/-9 (64-80) in the control group versus 68+/-19 (40-88) in the adenosine group (NS). In both groups, ischemic neurons were as prevalent in the basal ganglia and neocortex as in the cerebellum and hippocampus. The mild hypothermic aortic flush protocol is feasible in dogs. The adenosine strategy used does not abolish the mild histologic brain damage.

Adenosine↗
PubMed2000

A refractory case of secondary erythermalgia successfully treated with lumbar sympathetic ganglion block.

A 59-year-old Japanese man with myasthenia gravis, who had a 10-year history of temperature-sensitive pain in the lower extremities, i.e. improved by cooling and worsened by warming, consulted us because the pain had become intolerable during the previous 4 months. Bilateral erythema, swelling and large ulcers were noted on the calves, dorsal aspects of the feet, and soles. Laboratory data showed thrombocythaemia and a positive antibody to the acetylcholine receptor, but were negative for antinuclear and antiphospholipid antibodies. A diagnosis of secondary erythermalgia was made because of the clinical features, the laboratory data, and the lack of family history of this disease. Although steroid pulse therapy, oral aspirin and antiserotonin drugs were ineffective, bilateral lumbar sympathetic ganglion block succeeded in relieving the severe pain and curing the ulcers. The clinical course in our patient suggests that sympathetic ganglion block may be one of the most effective treatments for secondary erythermalgia. Although the mechanism of this effect is uncertain, microcirculation disturbance in secondary erythermalgia, if any, may be improved by this block.

Erythromelalgia↗
PubMed2000

Classification of 3D structural character of RNA by hydrogen bond and base stacking.

We are developing a computational system to classify RNA structures by its structural character. Here, an improved grouping algorithm was introduced to the system and the base-stacking pattern (BSP) is used as a criterion for the classification in addition to hydrogen-bond pattern (HBP). 279 conformers of 15 mer RNA hairpin were classified into 89 and 36 groups by HBP and BSP, respectively, suggesting that HBP represents conformational character better than BSP.

Algorithms↗
PubMed2000

Mild or moderate hypothermia, but not increased oxygen breathing, increases long-term survival after uncontrolled hemorrhagic shock in rats.

OBJECTIVE: To test the hypotheses that, for uncontrolled hemorrhagic shock (UHS) in rats, mild hypothermia, compared with normothermia, would increase long-term survival as well as moderate hypothermia, oxygen breathing would increase survival further, and hypothermia and oxygen would mitigate visceral ischemia (dysoxia) during UHS. DESIGN: Prospective, randomized study. SETTING: Animal research laboratory. SUBJECTS: A total of 54 male Sprague-Dawley rats. INTERVENTIONS: Under light anesthesia and spontaneous breathing, rats underwent UHS phase I of 75 mins, with initial withdrawal of 3 mL/100 g of blood over 15 mins, followed by UHS via tail amputation and limited fluid resuscitation to maintain mean arterial pressure at > or =40 mm Hg; resuscitation phase II of 60 mins (from 75 mins to 135 mins) with hemostasis and aggressive fluid resuscitation to normalize hemodynamics; and observation phase III to 72 hrs. Rats were randomly divided into nine groups (n = 6 each) with three rectal temperature levels (38 degrees C [normothermia] vs. 34 degrees C [mild hypothermia] vs. 30 degrees C [moderate hypothermia]) by surface cooling; each with 3 FIO2 levels (0.25 vs. 0.5 vs. 1.0). MEASUREMENTS AND MAIN RESULTS: Hypothermia increased blood pressure compared with normothermia. Increased FIO2 had no effect on blood pressure. Additional blood loss from the tail cut was small, with no differences among groups. Hypothermia and FIO2 of 0.5 decreased visceral hypoxia, as measured by the difference between visceral (liver and jejunum) surface Pco2 and PaCO2 during UHS. Compared with normothermia, mild hypothermia increased the survival time and rate as well as moderate hypothermia (p < .01 by life table), without a significant difference between mild and moderate hypothermia. Increased FIO2 had no effect on survival time or rate. CONCLUSIONS: After severe UHS and resuscitation in rats, mild hypothermia during UHS, compared with normothermia, increases blood pressure, survival time and 72-hr survival rate as well as moderate hypothermia. Mild hypothermia is clinically more feasible and safer than moderate hypothermia. Increased FIO2 seems to have no significant effect on outcome.

Animals↗
PubMed2000

Surface cooling, which fails to reduce the core temperature rapidly, hastens death during severe hemorrhagic shock in pigs.

OBJECTIVE: To examine whether surface cooling (SC) would rapidly decrease the core temperatures and prolong the survival time during volume-controlled lethal hemorrhagic shock in pigs. METHOD: Twelve pigs were randomly assigned to the SC group (group 1, n = 6) or the no cooling control group (group 2, n = 6), after blood withdrawal of 30 mL/kg over 15 minutes, and maintained under spontaneous breathing by light anesthesia with 1.0% halothane. SC was performed by applying ethanol to the skin, blowing with an electric fan, and placing ice packs. Pigs were observed without fluid resuscitation until their death (apnea and no pulse). RESULTS: SC did not lower the rectal temperature (Tr) to 35 degrees C at any time point until death, except one pig; in that animal, Tr was decreased to 34 degrees C after 135 minutes from the start of SC. The survival time was 108 +/- 43 minutes in group 1 and 175 +/- 55 minutes in group 2 (p < 0.05, life table analysis). CONCLUSION: In lightly anesthetized pigs during hemorrhagic shock, SC without resuscitation did not rapidly reduce the core temperature and rather hastened death for reasons that remain to be explored.

Analysis of Variance↗
PubMed1999

Development of a system to classify 3D structural character of RNA.

We are developing a computational system to extract structural character of RNA. We made a program that classifies conformers by recognizing the hydrogen bonding patterns. The program was applied to a set of 279 conformers and they were classified into about 40 groups. The system is expected to be useful for searching structural motifs of RNA and classifying large number of generated conformers in structural modeling process.

Base Pairing↗
PubMed1999

Mild or moderate hypothermia but not increased oxygen breathing prolongs survival during lethal uncontrolled hemorrhagic shock in rats, with monitoring of visceral dysoxia.

OBJECTIVE: To test the hypotheses that during lethal uncontrolled hemorrhagic shock (UHS) in rats compared with normothermia and room air breathing: a) mild hypothermia would prolong survival time as well as moderate hypothermia; b) oxygen breathing would prolong survival further; and c) hypothermia and oxygen would mitigate visceral ischemia (dysoxia) during UHS. DESIGN: Prospective, randomized, controlled laboratory animal study. SETTING: Animal research facility. SUBJECTS: Male Sprague-Dawley rats. INTERVENTION: Fifty-four rats were lightly anesthetized with halothane during spontaneous breathing. UHS was induced by blood withdrawal of 3 mL/100 g over 15 mins, followed by 75% tail amputation with topical application of heparin. Five minutes after tail cut, rats were randomly divided into nine groups (6 rats each) with three rectal temperature levels (38 degrees C [100.4 degrees F; normothermia] vs. 34 degrees C [93.2 degrees F; mild hypothermia] vs. 30 degrees C [86 degrees F; moderate hypothermia]) by surface cooling; each with 3 FIO2 levels (0.25 vs. 0.5 vs. 1.0). Rats were observed without fluid resuscitation until death (apnea and pulselessness). Visceral ischemia was monitored by observing liver and gut surface PCO2. MEASUREMENTS AND MAIN RESULTS: Mean survival time, which was 51 mins in the control group with normothermia and FIO2 of 0.25, was more than doubled with hypothermia, to 119 mins in the combined mild hypothermia groups (p < .05) and to 132 mins in the combined moderate hypothermia groups (p < .05; NS for moderate vs. mild hypothermia). FIO2 had no statistically significant effect on survival time. Increases in visceral surface PCO2 correlated with hypotension (r2 = .22 for intestine and .40 for liver). Transiently, increased FIO2, not hypothermia, mitigated visceral ischemia. CONCLUSIONS: Both mild and moderate hypothermia prolonged survival time during untreated, lethal UHS in rats. Increased FIO2 had no effect on survival. The effects of hypothermia and increased FIO2 during UHS on viscera, the ability to be resuscitated, and outcome should be explored further.

Animals↗
PubMed1999

Hypothermic aortic arch flush for preservation during exsanguination cardiac arrest of 15 minutes in dogs.

BACKGROUND: Trauma victims rarely survive cardiac arrest from exsanguination. Survivors may suffer neurologic damage. Our hypothesis was that a hypothermic aortic arch flush of 500 mL of isotonic saline solution at 4 degrees C, compared with 24 degrees C (room temperature), administered at the start of prolonged exsanguination cardiac arrest (CA) would improve functional neurologic outcome in dogs. METHODS: Seventeen male hunting dogs were prepared under light N2O-halothane anesthesia. The animals were randomized into two groups: group I (n = 9) received 4 degrees C isotonic saline flush and group II (n = 6) received 24 degrees C flush. Two additional dogs received no flush. While spontaneously breathing, the dogs underwent normothermic (tympanic membrane temperature [Ttm] = 37.5 degrees C) exsanguination over 5 minutes to cardiac arrest, assured by electric induction of ventricular fibrillation. After 2 minutes of arrest, the flush was administered over 1 minute into the aortic arch by means of a 13 French balloon-tipped catheter inserted by means of the femoral artery. After 15 minutes of CA, resuscitation was with closed-chest cardiopulmonary bypass, return of shed blood, and defibrillation. For the first 12 hours after CA, core temperature was maintained at 34 degrees C. Mechanical ventilation was continued to 20 hours and intensive care to 72 hours, when final evaluation and perfusion-fixation killing for brain histologic damage scoring were performed. RESULTS: Three dogs in group I were excluded because of extracerebral complications. All 14 dogs that followed protocol survived. During CA, the Ttm decreased to 33.6 +/- 1.2 degrees C in group I and 35.9 +/- 0.4 degrees C in group II (p = 0.002). At 72 hours, in group I, all dogs achieved an overall performance category (OPC) of 1 (normal). In group II, 1 dog was OPC 2 (moderate disability), 3 dogs were OPC 3 (severe disability), and 2 dogs were OPC 4 (coma). Both dogs without flush were OPC 4. Neurologic deficit scores (NDS 0% = normal, 100% = brain death) were 1 +/- 1% in group I and 41 +/- 12% in group II (p < 0.05). The two dogs without flush achieved an NDS of 47% and 59%. Total brain histologic damage scores were 35 +/- 28 in group I and 82 +/- 17 in group II (p < 0.01); and 124 and 200 in the nonflushed dogs. CONCLUSION: At the start of 15 minutes of exsanguination cardiac arrest in dogs, hypothermic aortic arch flush allows resuscitation to survival with normal neurologic function and histologically almost clean brains.

Animals↗
PubMed1999

11C-methionine uptake to the pancreas and its secretion: a positron emission tomography study in humans.

The aim of this study was to investigate the uptake of [11C-methyl]-L-methionine (11C-methionine) in the human pancreas by analyzing dynamic positron emission tomography (PET) images and the duodenal aspirate. A double-lumen tube was inserted in the duodenum and dynamic PET was performed in seven healthy volunteers for 110 min after intravenous (i.v.) injection of 11C-methionine during the continuous i.v. administration of secretin (125 ng/kg/h) and cerulein (30 ng/kg/h). For the calculation of the radioactivity in the pancreas, the regions of interest were set on the PET images. Radioactivity was measured in 10-min fractions of duodenal juice. After i.v. injection, 11C-methionine accumulated in the pancreas within a few minutes, and the radioactivity plateaued during the study. The radiolabeled proteins in the duodenal juice increased linearly 30 min after 11C-methionine injection, but the relative rates of radioactivity in the protein precipitate to the total count in the duodenal juice were 44-48%. From these findings, it was concluded that 11C-methionine accumulation in the pancreas is very rapid after the i.v. administration, and only a part of methionine uptake to the pancreas is incorporated into secretory proteins. The pancreatic 11C-methionine uptake detected by PET may represent a new aspect of exocrine pancreatic function that has not been expressed by the conventional intubation method.

Adult↗
PubMed1998

Duodenal gastrinoma--clinical features and usefulness of selective arterial secretin injection test.

Duodenal gastrinoma is recognized as a relatively common cause of Zollinger-Ellison syndrome, but its clinical and biological features are not well known. Here we report a case of duodenal gastrinoma with lymph node metastasis which was confirmed by pathology examinations. Hypergastrinemia and gastric acid hypersecretion were documented, but the secretin test showed negative results. An enlarged peripancreatic lymph node lying close to the pancreas head was the only positive finding on preoperative imaging studies. The results of the selective arterial secretin injection (SASI) test suggested that the primary tumor was located in the gastrinoma triangle. Finally, surgical exploration was carried out and a submucosal tumor, approximately 15 mm in size, was detected by intraoperative palpation at the posterior wall of the proximal portion of the duodenum. Intraoperative pathology examination demonstrated metastases to regional lymph nodes. The present case calls attention to the unique features of duodenal gastrinomas, which differ from those of pancreatic origin: a highly malignant potential for its small size, and submucosal location in the proximal duodenum. The SASI test is recommended for assessing the location of a primary lesion if it cannot be identified by various conventional imaging studies.

Diagnosis, Differential↗
PubMed1998

Chitin-graft-poly(2-methyl-2-oxazoline) enhanced solubility and activity of catalase in organic solvent.

Catalase from bovine liver was lyophilized from an aqueous solution containing chitin-graft-poly(2-methyl-2-oxazoline) (3), which was synthesized by the reaction of 52% deacetylated chitin (1) with living poly(2-methyl-2-oxazoline) (2). The rate of consumption of H2O2 in chloroform catalyzed by the lyophilized catalase with 3 was enhanced more than 10 times that by catalase without 3. The dispersibility and solubility of lyophilized catalase with 3 in chloroform were improved in comparison with catalase itself.

Animals↗
PubMed1998

Prolonged severe hemorrhagic shock and resuscitation in rats does not cause subtle brain damage.

OBJECTIVE: Some patients who survived severe hemorrhagic shock (HS) seem to exhibit persistent subtle neurobehavioral deficits. This finding is of concern if limited hypotensive fluid resuscitation is applied in hypotensive victims with penetrating trauma. This study was designed to determine whether subtle brain damage would occur in rats after severe prolonged HS. We hypothesized that rats surviving HS with mean arterial pressure (MAP) controlled at 40 mm Hg for 60 minutes would recover with slight permanent brain damage in terms of cognitive function without morphologic loss of neurons and that rats surviving HS with MAP at 30 mm Hg for 45 minutes (60 minutes were not tolerated) would have grossly abnormal brain function and loss of neurons. METHODS: Under light nitrous oxide-halothane anesthesia, spontaneously breathing rats underwent MAP-controlled HS (HS phase I), volume resuscitation to normotension and invasive monitoring to 60 minutes (resuscitation phase II), and observation to 10 days with detailed assessment of cognitive function (observation phase III). Five conscious rats served as normal controls. Three treatment groups were compared: group 1, shams (11 of 12 rats survived to 10 days); group 2, HS at MAP 40 mm Hg for 60 minutes (10 of 17 rats survived); group 3, HS at 30 mm Hg for 45 minutes (10 of 14 rats survived). RESULTS: On post-HS day 10, all normal controls and all survivors of all three groups were functionally normal with overall performance category = 1 (normal) (overall performance category 1 = normal, 5 = death) and neurologic deficit scores < or = 7% (neurologic deficit scores 0-10% = normal, 100% = brain death). Post-HS beam balance, beam walking, and Morris water maze test results in HS groups 2 and 3 showed latencies not significantly different from those in shams and normal controls. Light microscopic scoring of five selectively vulnerable brain regions and other regions in five coronal sections revealed no ischemic (pyknotic, shrunken, eosinophilic) neurons in any of the survivors to 10 days. There was no statistical difference between normal controls, sham animals, and both HS groups in the number of normal neurons counted in the hippocampal CA-1 region in the 10-day survivors. All nonsurvivors died with intestinal necrosis. CONCLUSION: HS at MAP 40 mm Hg for 60 minutes or MAP 30 mm Hg for 45 minutes does not cause subtle functional or histologic brain damage in surviving rats. Controlling MAP at 30 mm Hg carries a risk of sudden cardiac arrest. These data suggest that limited fluid resuscitation, to maintain MAP at about 40 mm Hg, as recommended for victims of penetrating trauma with uncontrolled HS, is safe for the brain.

Animals↗