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1.
Anaesthesist ; 65(6): 430-7, 2016 Jun.
Article in German | MEDLINE | ID: mdl-27221390

ABSTRACT

BACKGROUND: Complications and comorbidities are encodable in the German diagnosis related groups (G-DRG) system and can improve revenues. In this study, secondary diagnoses were identified through drug administrations during anaesthesia and were economically evaluated by regrouping these cases. METHODS: All intraoperative drug administrations from 2008 were extracted from a database. After exclusion of synonyms and procedure-specific drug administrations, all remaining drugs were matched to explicit secondary diagnoses. All cases were regrouped with their newly defined secondary diagnoses by G­DRG grouper software, and changes in cost weight were evaluated. RESULTS: A total of 29 drugs could be assigned to 18 secondary diagnoses. From 22,440 anaesthesia the § 21 data record could be extracted in 1,929 cases and was regrouped with 2,976 secondary diagnoses, according to additional proceeds of 125,330.25 € in 2008 and 103,542.35 € in 2014. Intraoperative secondary diagnoses influence cost weight only in small parts. The average increase in revenue in this study could have been about 50 € per case. From 2008 to 2014 secondary diagnoses were continuously devaluated, although some of them, e. g. afibrinogenemia, have were revaluated. DISCUSSION: Our retrospective method of making a diagnosis and assuming a correct indication of drug administration is inapplicable to daily routine. The anaesthesiologic documentation has to make drug administration and thereby the secondary diagnosis plausible.


Subject(s)
Diagnosis-Related Groups/economics , Intraoperative Complications/diagnosis , Intraoperative Complications/economics , Intraoperative Period , Anesthetics/adverse effects , Cost-Benefit Analysis , Databases, Factual , Documentation , Drug Combinations , Drug Costs , Drug Eruptions/diagnosis , Drug Eruptions/economics , Drug Interactions , Germany , Humans , Retrospective Studies
2.
Neuroscience ; 301: 439-53, 2015 Aug 20.
Article in English | MEDLINE | ID: mdl-26102006

ABSTRACT

Y-box-binding protein (YB-1) is a member of the cold-shock protein family and participates in a wide variety of DNA/RNA-dependent cellular processes including DNA repair, transcription, mRNA splicing, packaging, and translation. At the cellular level, YB-1 is involved in cell proliferation and differentiation, stress responses, and malignant cell transformation. A general role for YB-1 during inflammation has also been well described; however, there are minimal data concerning YB-1 expression in microglia, which are the immune cells of the brain. Therefore, we studied the expression of YB-1 in a clinically relevant global ischemia model for neurological injury following cardiac arrest. This model is characterized by massive neurodegeneration of the hippocampal CA1 region and the subsequent long-lasting activation of microglia. In addition, we studied YB-1 expression in BV-2 cells, which are an accepted microglia culture model. BV-2 cells were stressed by oxygen/glucose deprivation (OGD), OGD-relevant mediators, lipopolysaccharide (LPS), and phagocytosis-inducing cell debris and nanoparticles. Using quantitative polymerase chain reaction (PCR), we show constitutive expression of YB-1 transcripts in unstressed BV-2 cells. The functional upregulation of the YB-1 protein was demonstrated in microglia in vivo and in BV-2 cells in vitro. All stressors except for LPS were potent enhancers of the level of YB-1 protein, which appears to be regulated primarily by proteasomal degradation and, to a lesser extent, by the activation (phosphorylation) of the translation initiation factor eIF4E. The proteasome of BV-2 cells is impaired by OGD, which results in decreased protein degradation and therefore increased levels of YB-1 protein. LPS induces proteasome activity, which enables the level of YB-1 protein to remain at control levels despite enhanced protein ubiquitination. The proteasome inhibitor MG-132 was able to increase YB-1 protein levels in control and LPS-treated cultures. YB-1 upregulation was not accompanied by its translocation from the cytoplasm to the nucleus. YB-1 induction appeared to be related to microglial proliferation because it was partially co-regulated with Ki67. In addition, YB-1 protein levels correlated with microglia phagocytic activity because its upregulation could also be induced by inert NPs.


Subject(s)
Gene Expression Regulation/physiology , Heart Arrest/pathology , Microglia/metabolism , Y-Box-Binding Protein 1/metabolism , Animals , Asphyxia/complications , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Cell Line, Transformed , Disease Models, Animal , Eukaryotic Initiation Factor-4E/genetics , Eukaryotic Initiation Factor-4E/metabolism , Gene Expression Regulation/drug effects , Glial Fibrillary Acidic Protein/genetics , Glial Fibrillary Acidic Protein/metabolism , Glucose/deficiency , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Heart Arrest/etiology , Ki-67 Antigen/metabolism , Lipopolysaccharides/pharmacology , Male , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Microglia/drug effects , Nerve Tissue Proteins/metabolism , Oxygen/metabolism , Proteasome Endopeptidase Complex/metabolism , RNA, Messenger/metabolism , Rats , Rats, Wistar , Y-Box-Binding Protein 1/genetics
3.
Minerva Anestesiol ; 79(6): 617-25, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23511363

ABSTRACT

BACKGROUND: Pneumoperitoneum (PP) by CO2-insufflation causes atelectasis however with maintained or even improved oxygenation. We studied the effect of abdominal insufflation by carbon dioxide (CO2) and air on gas exchange during PP. METHODS: Twenty-seven anesthetized pigs were studied during PP with insufflations to 12 mmHg by either 1/CO2, 2/ air or 3/CO2 during intravenous nitroprusside infusion (SNP) (N.=9 in each group). In 3 pigs in each group, gamma camera technique (SPECT) was used to study ventilation and perfusion distributions, in another 6 pigs an inert-gas technique (MIGET) was used for assessing ventilation-perfusion matching (VA/Q). Measurements were made during anesthesia before and after 60 minutes of PP. RESULTS: CO2-PP caused a shift of blood flow away from dependent, non-ventilated (atelectatic) to ventilated regions. Air-PP caused smaller, and SNP-PP even less shift of lung blood flow. Shunt decreased during CO2-PP (6 ± 1% compared to baseline 9 ± 2%, P<0.05), did not change during Air-PP (10 ± 2%) and increased during SNP-PP (16 ± 2%, P<0.05). PaO2 increased from baseline 35 ± 2 to 41 ± 3 kPa during CO2-PP and decreased to 32 ± 3 kPa during Air-PP and to 27 ± 3 kPa during SNP-PP (P<0.05 for all three comparisons). PaCO2 increased during CO2- and SNP-PP. CONCLUSION: CO2-PP enhanced the shift of blood flow towards better ventilated areas of the lung compared to Air-PP and SNP blunted the effects seen with CO2-PP. SNP may thus have blunted and CO2 potentiated vasoconstriction, by hypoxic pulmonary vasoconstriction or another mechanism.


Subject(s)
Anesthesia, Inhalation/methods , Carbon Dioxide/pharmacology , Pneumoperitoneum, Artificial/methods , Ventilation-Perfusion Ratio/physiology , Air , Anesthesia , Animals , Blood Gas Analysis , Hemodynamics/physiology , Lung/diagnostic imaging , Monitoring, Physiologic , Respiration, Artificial , Respiratory Mechanics/physiology , Swine , Tomography, Emission-Computed, Single-Photon
4.
Acta Anaesthesiol Scand ; 55(7): 887-96, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21689075

ABSTRACT

BACKGROUND: CO(2) -pneumoperitoneum (PP) is performed at varying abdominal pressures. We studied in an animal preparation the effect of increasing abdominal pressures on gas exchange during PP. METHODS: Eighteen anaesthetized pigs were studied. Three abdominal pressures (8, 12 and 16 mmHg) were randomly selected in each animal. In six pigs, single-photon emission computed tomography (SPECT) was used for the analysis of V/Q distributions; in another six pigs, multiple inert gas elimination technique (MIGET) was used for assessing V/Q matching. In further six pigs, computed tomography (CT) was performed for the analysis of regional aeration. MIGET, CT and central haemodynamics and pulmonary gas exchange were recorded during anaesthesia and after 60 min on each of the three abdominal pressures. SPECT was performed three times, corresponding to each PP level. RESULTS: Atelectasis, as assessed by CT, increased during PP and in proportion to abdominal pressure [from 9 ± 2% (mean ± standard deviation) at 8 mmHg to 15 ± 2% at 16 mmHg, P<0.05]. SPECT during increasing abdominal CO(2) pressures showed a shift of blood flow towards better ventilated areas. V/Q analysis by MIGET showed no change in shunt during 8 mmHg PP (9 ± 1.9% compared with baseline 9 ± 1.2%) but a decrease during 12 mmHg PP (7 ± 0.9%, P<0.05) and 16 mmHg PP (5 ± 1%, P<0.01). PaO(2) increased from 39 ± 10 to 52 ± 9 kPa (baseline to 16 mmHg PP, P<0.01). Arterial carbon dioxide (PCO(2) ) increased during PP and increased further with increasing abdominal pressures. CONCLUSION: With increasing abdominal pressure during PP perfusion was redistributed more than ventilation away from dorsal, collapsed lung regions. This resulted in a better V/Q match. A possible mechanism is enhanced hypoxic pulmonary vasoconstriction mediated by increasing PCO(2) .


Subject(s)
Abdomen/physiology , Carbon Dioxide , Pneumoperitoneum, Artificial/methods , Ventilation-Perfusion Ratio , Abdomen/diagnostic imaging , Anesthesia , Animals , Gamma Cameras , Hemodynamics/physiology , Monitoring, Physiologic , Pressure , Pulmonary Atelectasis/physiopathology , Pulmonary Gas Exchange/physiology , Swine , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed
5.
Neuroscience ; 171(3): 869-84, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-20884331

ABSTRACT

We analyzed the long-term consequences of asphyxial cardiac arrest for hippocampal cell proliferation in rats to evaluate if the ischaemia-induced degenerated CA1 region may be repopulated by endogenous (stem) cells. Studies were performed in an asphyxial cardiac arrest model with 5 minutes of asphyxiation and three different survival times: 7, 21, and 90 days. Sham-operated non-asphyxiated rats served as control. Cell proliferation was studied by labeling dividing cells with 5-bromo-2'-deoxy-uridine (BrdU). The neurodegenerative/regenerative pattern at single cell levels was monitored by immunohistochemistry. Alterations of gene expression were analyzed by real-time quantitative RT-PCR. Analysis of BrdU-incorporation demonstrated an increase at 7, 21 as well as 90 days after global ischaemia in the hippocampal CA1 pyramidal cell layer. Similar results were found in the dentate gyrus. Differentiation of BrdU-positive cells, investigated by cell phenotype-specific double fluorescent labeling, showed increased neurogenesis only in the dentate gyrus of animals surviving the cardiac arrest for 7 days. The majority of newcomers, especially in the damaged CA1 region, consisted of glial cells. Moreover, asphyxia seemed to be able to induce the migration of microglia and astroglia from adjacent areas into the damaged area and/or the activation of resident cells. In addition, we show microglia proliferation/activation even 90 days after cardiac arrest. This morphological finding was confirmed by PCR analysis. The results indicate that asphyxia triggers cell proliferation in general and gliogenesis in particular - a possible pro-reparative event. Furthermore, from the finding of microglia proliferation up to 90 days after insult we conclude that delayed cell death processes take place which should be considered for further therapy strategies.


Subject(s)
Asphyxia/pathology , Cell Proliferation , Gliosis/etiology , Hippocampus/pathology , Hypoxia-Ischemia, Brain/etiology , Nerve Regeneration , Neurogenesis , Neuroglia/pathology , Animals , Asphyxia/complications , Asphyxia/etiology , Cell Death/physiology , Gliosis/pathology , Gliosis/prevention & control , Hypoxia-Ischemia, Brain/pathology , Hypoxia-Ischemia, Brain/prevention & control , Male , Nerve Regeneration/physiology , Neurogenesis/physiology , Neuroglia/cytology , Rats , Rats, Wistar
6.
Resuscitation ; 53(2): 189-200, 2002 May.
Article in English | MEDLINE | ID: mdl-12009223

ABSTRACT

An asphyxial cardiac arrest rat model, originally developed for Sprague-Dawley rats, was transferred to a Wistar rat model. Several strain specific life support adjustments, i.e. ventilator settings, anaesthesia, and drug requirements, were necessary to stabilize the model for Wistar rats. Despite these arrangements numerous resuscitation related variables appeared different. Three groups were evaluated and compared: a temperature monitored Wistar group 1 (n=34), a temperature controlled Wistar group 2 (n=26) and a temperature controlled Sprague-Dawley group 3 (n=7). Overall, Wistar rats seem to have more sensitive cardio-circulatory system evidenced by a more rapid development of cardiac arrest (164 vs. 201 s), requiring higher adrenaline/epinephrine doses (10 vs. 5 microg/kg) and requiring more time for recovery after resuscitation (i.e. for return of blood pressure and blood gases). Without strict temperature control (as in groups 2+3 rats) group 1 rats went into spontaneous mild to moderate hypothermia during the first 24 h after restoration of spontaneous circulation (ROSC). Spontaneous hypothermia delayed the development of overall visible CA1 neuronal damage 24-48 h, but did not prevent it; therefore the model seemed to be suitable for future studies. Neuronal damages in the CA1 region in Wistar rats appeared to be more as shrunken cell bodies and pyknotic nuclei before resorption took place, whereas in Sprague-Dawley rats appeared in the same region.


Subject(s)
Brain/pathology , Heart Arrest/blood , Hemodynamics/physiology , Rats, Sprague-Dawley/physiology , Rats, Wistar/physiology , Resuscitation/methods , Animals , Blood Gas Analysis , Disease Models, Animal , Heart Arrest/therapy , Male , Rats , Species Specificity , Temperature
7.
Curr Opin Crit Care ; 7(3): 189-94, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11436526

ABSTRACT

Recovery of normal brain energetic conditions during and after resuscitation from cardiac arrest is critical for survival and good neurologic outcome. This review emphasizes the glucose-driven metabolic processes during and after ischemia and on the post-resuscitation development of secondary energy derangements. It also explores some potential therapeutic interventions designed to attenuate these energy derangements. The article summarizes some bench research and is not intended to provide treatment strategies for clinical application.


Subject(s)
Brain/physiopathology , Cardiopulmonary Resuscitation , Brain/blood supply , Brain/metabolism , Emergency Medical Services , Energy Metabolism , Glucose/metabolism , Humans , Oxygen/metabolism , Regional Blood Flow
8.
Anaesthesiol Reanim ; 26(6): 159-65, 2001.
Article in German | MEDLINE | ID: mdl-11799851

ABSTRACT

In order to expand and combine clinical and basic science research opportunities on cardiac arrest, the Asphyxial Cardiac Arrest Rat Model, originally developed at the International Resuscitation Research Center in Pittsburgh, was introduced and adapted at the University of Magdeburg Medical Center. For better utilization of established morphological and biochemical evaluation techniques, the former Sprague-Dawley rat model was adapted for Wistar rats. Life-support procedures, especially controlled ventilation, had to be adjusted. Wistar rats seem to be more sensitive to asphyxia, resulting in significantly faster-developing cardiac arrest (time from ceasing ventilation to pulselessness: Wistar 2:43 min versus 3:28 min in Sprague-Dawley) and a tendentiously longer resuscitation time (37 versus 23 s). Furthermore, a trend towards a more pronounced secondary blood pressure depression was observed especially during the later half of the first hour after resuscitation. Post-mortem brain evaluations using conventional Nissl and haematoxylin-eosin staining techniques showed--most distinctly in the hippocampal CA1 region--delayed neuronal damage with a peak at 72 hours after resuscitation and with only a few neurons remaining after seven days of survival.


Subject(s)
Cardiopulmonary Resuscitation/methods , Disease Models, Animal , Heart Arrest/therapy , Animals , Blood Pressure/physiology , Brain Death/physiopathology , Heart Arrest/physiopathology , Male , Rats , Rats, Sprague-Dawley , Rats, Wistar , Species Specificity
9.
Resuscitation ; 45(2): 119-31, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10950320

ABSTRACT

We postulate that mitigating the multifactorial pathogenesis of postischemic encephalopathy requires multifaceted treatments. In preparation for expensive definitive studies, we are reporting here the results of small exploratory series, compared with historic controls with the same model. We hypothesized that the brain damage mitigating effect of mild hypothermia after cardiac arrest can be enhanced with thiopental loading, and even more so with the further addition of phenytoin and methylprednisolone. Twenty-four dogs (four groups of six dogs each) received VF 12.5 min no-flow, reversed with brief cardiopulmonary bypass (CPB), controlled ventilation to 20 h, and intensive care to 96 h. Group 1 with normothermia throughout and randomized group 2 with mild hypothermia (from reperfusion to 2 h) were controls. Then, group 3 received in addition, thiopental 90 mg/kg i.v. over the first 6 h. Then, group 4 received, in addition to group 2 treatment, thiopental 30 mg/kg i.v. over the first 90 min (because the larger dose had produced cardiopulmonary complications), plus phenytoin 15 mg/kg i.v. at 15 min after reperfusion, and methylprednisolone 130 mg/kg i.v. over 20 h. All dogs survived. Best overall performance categories (OPC) achieved (OPC 1 = normal, OPC 5 = brain death) were better in group 2 than group 1 (< 0.05) and numerically better in groups 3 or 4 than in groups 1 or 2. Good cerebral outcome (OPC 1 or 2) was achieved by all six dogs only in group 4 (P < 0.05 group 4 vs. 2). Best NDS were 44 +/- 3% in group 1; 20 +/- 14% in group 2 (P = 0.002); 21 +/- 15% in group 3 (NS vs. group 2); and 7 +/- 8% in group 4 (P = 0.08 vs. group 2). Total brain histologic damage scores (HDS) at 96 h were 156 +/- 38 in group 1; 81 +/- 12 in group 2 (P < 0.001 vs. group 1); 53 +/- 25 in group 3 (P = 0.02 vs. group 2); and 48 +/- 5 in group 4 (P = 0.02 vs. group 2). We conclude that after prolonged cardiac arrest, the already established brain damage mitigating effect of mild immediate postarrest hypothermia might be enhanced by thiopental, and perhaps then further enhanced by adding phenytoin and methylprednisolone.


Subject(s)
Anticonvulsants/therapeutic use , Brain/physiopathology , Heart Arrest/physiopathology , Heart Arrest/therapy , Methylprednisolone/therapeutic use , Neuroprotective Agents/therapeutic use , Phenytoin/therapeutic use , Resuscitation , Thiopental/therapeutic use , Animals , Brain Damage, Chronic/prevention & control , Dogs , Drug Therapy, Combination , Male , Time Factors , Treatment Outcome
10.
Neuroreport ; 9(15): 3363-7, 1998 Oct 26.
Article in English | MEDLINE | ID: mdl-9855281

ABSTRACT

Hyperglycemia before ischemia worsens cerebral outcome. The aim of this study was to determine the cerebral effects of giving glucose with or without insulin after asphyxial cardiac arrest. Rats underwent 8 min of asphyxial cardiac arrest. After arrest, Group 1 received NaCl; Group 2, insulin; Group 3, glucose; and Group 4, glucose plus insulin, all intravenously. Neurological deficit (ND) scores were 14+/-10%, 22+/-12%, 12+/-10% and 2+/-2% in Groups 1-4, respectively, 72 h after reperfusion. Overall histological damage (HD) scores were 4, 2, 3 and 1, respectively. Group 4 fared significantly better than group 1 on both scores. Glucose after asphyxial cardiac arrest in rats produces no increased brain damage while glucose plus insulin improves cerebral outcome.


Subject(s)
Asphyxia/drug therapy , Glucose/pharmacology , Hypoglycemic Agents/pharmacology , Hypoxia, Brain/drug therapy , Insulin/pharmacology , Animals , Asphyxia/physiopathology , Blood Glucose , Blood Pressure , Brain/blood supply , Brain/metabolism , Cardiopulmonary Resuscitation , Heart Arrest , Hydrogen-Ion Concentration , Hypoxia, Brain/physiopathology , Rats , Rats, Sprague-Dawley
11.
J Neurotrauma ; 15(5): 323-36, 1998 May.
Article in English | MEDLINE | ID: mdl-9605347

ABSTRACT

In a previous study with this dog model, post-insult hypothermia of 31 degrees C for 5 h prevented secondary intraventricular pressure (IVP) rise, but during 35 degrees C or 38 degrees C, one-half of the dogs developed delayed IVP rise to brain death. We hypothesized that 31 degrees C extended to 48 h would prevent brain herniation. Using epidural balloon inflation, we increased contralateral IVP to 62 mm Hg for 90 min. Controlled ventilation was to 72 h and intensive care to 96 h. Group 1 dogs (n = 10) were normothermic controls (37.5 degrees C). Group 2 dogs (n = 10) were surface-cooled from 15 to 45 min of balloon inflation and maintained at moderate hypothermia (31 degrees C) to 48 h. Rewarming was from 48 to 72 h. Four additional dogs of hypothermia Group 2 had to be excluded from analysis for pneumonia and/or bleeding diathesis. After balloon deflation, IVP increased to 20 mm Hg or greater at 154 +/- 215 (range 15-720) min following the insult in Group 1 and at 1394 +/- 1191 (range 210-3420) min in Group 2 (p = 0.004), still during 31 degrees C but without further increase during hypothermia. Further IVP rise led to brain death in Group 1 in 6 of 10 dogs at 44 +/- 18 (range 21-72) h (all during controlled ventilation); and in Group 2, in 6 of 10 dogs at 87 +/- 11 (range 72-96) h (p = 0.001), all after rewarming, during spontaneous breathing. Survival to 96 h was achieved by 4 of 10 dogs in Group 1, and by 7 of 10 dogs in Group 2 (NS). Three of the six brain deaths in Group 2 occurred at 96 h. The macroscopically damaged brain volume was only numerically smaller in Group 2. The vermis downward shift was 6.8 +/- 3.5 mm in Group 1, versus 4.7 +/- 2.2 mm in Group 2 (p = 0.05). In an adjunctive study, in 4 additional normothermic dogs, hemispheric cerebral blood flow showed post-insult hypoperfusion bilaterally but no evidence of hyperemia preceding IVP rise to brain death. In conclusion, in this model, moderate hypothermia during and for 48 h after temporary epidural brain compression can maintain a low IVP during hypothermia but cannot prevent lethal brain swelling after rewarming and may cause coagulopathy and pulmonary complications.


Subject(s)
Brain Injuries/therapy , Hematoma, Epidural, Cranial/therapy , Hypothermia, Induced , Intracranial Hypertension/therapy , Animals , Brain Edema/physiopathology , Brain Edema/therapy , Brain Injuries/physiopathology , Cardiopulmonary Resuscitation , Cerebrovascular Circulation/physiology , Disease Models, Animal , Dogs , Female , Hematoma, Epidural, Cranial/physiopathology , Hyperemia/physiopathology , Hyperemia/therapy , Intracranial Hypertension/physiopathology , Intracranial Pressure , Treatment Outcome
12.
Toxicol Pathol ; 25(5): 500-5, 1997.
Article in English | MEDLINE | ID: mdl-9323841

ABSTRACT

The incidence and distribution of ischemic (necrotic) neurons in the brains of rats 72 hr after hypoxic ischemia induced via asphyxiation is described and scored. Anesthetized Sprague-Dawley rats (10/group) were endotracheally intubated and had their airways occluded for 6, 8, or 10 min, which resulted, respectively, in approximately 3, 5, or 7 min of pulselessness (MABP < 10 mm Hg). Survival was 10/10, 9/10, and 6/10 in the 6-, 8-, and 10-min groups: deaths occurred within 1 hr after resuscitation. At 72 hr, rats were reanesthetized and their brains were perfusion-fixed with 3% buffered paraformaldehyde. Paraffin-embedded, 5-micron-thick, H&E-stained sections at 5 coronal levels of the brain had shrunken, hypereosinophilic ischemic neurons in 12 anatomic regions. Ischemic neurons were most consistently found in the lateral reticular thalamic nucleus; lateral caudoputamen; CA1 region of the hippocampus; subiculum; and, with longer asphyxia times, among cerebellar Purkinje neurons. Categorical histologic damage scores were assigned to affected regions on the basis of manual counts of ischemic neurons and summed for the whole brain. Brain histologic damage scores were significantly (p < 0.01) different for the 6-, 8-, and 10-min groups (means of 8 +/- 2; 14 +/- 4; and 22 +/- 4). Brain regions where both the number of rats affected and ranked categorical scores for ischemic neurons increased with asphyxia time were the lateral caudoputamen and cerebellar Purkinje neurons.


Subject(s)
Brain/pathology , Hypoxia/pathology , Ischemic Attack, Transient/pathology , Neurons/pathology , Animals , Disease Models, Animal , Male , Neurons/ultrastructure , Rats , Rats, Sprague-Dawley
17.
Crit Care Med ; 24(2 Suppl): S48-56, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8608706

ABSTRACT

Severe traumatic brain injuries are extremely heterogeneous. At least seven of the secondary derangements in the brain that have been identified as occurring after most traumatic brain injuries also occur after cardiac arrest. These secondary derangements include posttraumatic brain ischemia. In addition, traumatic brain injury causes insults not present after cardiac arrest, i.e., mechanical tissue injury (including axonal injury and hemorrhages), followed by inflammation, brain swelling, and brain herniation. Brain herniation, in the absence of a mass lesion, is due to a still-to-be-clarified mix of edema and increased cerebral blood flow and blood volume. Glutamate release immediately after traumatic brain injury is proven. Late excitotoxicity needs exploration. Inflammation is a trigger for repair mechanisms. In the 1950s and 1960s, traumatic brain injury with coma was treated empirically with prolonged moderate hypothermia and intracranial pressure monitoring and control. Moderate hypothermia (30 degrees to 32 degrees C), but not mild hypothermia, can help prevent increases in intracranial pressure. How to achieve optimized hypothermia and rewarming without delayed brain herniation remains a challenge for research. Deoxyribonucleic acid (DNA) damage and triggering of programmed cell death (apoptosis) by trauma deserve exploration. Rodent models of cortical contusion are being used effectively to clarify the molecular and cellular responses of brain tissue to trauma and to study axonal and dendritic injury. However, in order to optimize therapeutic manipulations of posttraumatic intracranial dynamics and solve the problem of brain herniation, it may be necessary to use traumatic brain injury models in large animals (e.g., the dog), with long-term intensive care. Stepwise measures to prevent lethal brain swelling after traumatic brain injury need experimental exploration, based on the multifactorial mechanisms of brain swelling. Novel treatments have so far influenced primarily healthy tissue; future explorations should benefit damaged tissue in the penumbra zones and in remote brain regions. The prehospital arena is unexplored territory for traumatic brain injury research.


Subject(s)
Brain Injuries/therapy , Resuscitation/methods , Animals , Brain Edema/etiology , Brain Injuries/complications , Brain Injuries/physiopathology , Brain Ischemia/etiology , Disease Models, Animal , Dogs , Humans , Hypothermia, Induced/methods , Mice , Rats
18.
Crit Care Med ; 24(2 Suppl): S57-68, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8608707

ABSTRACT

Both the period of total circulatory arrest to the brain and postischemic-anoxic encephalopathy (cerebral postresuscitation syndrome or disease), after normothermic cardiac arrests of between 5 and 20 mins (no-flow), contribute to complex physiologic and chemical derangements. The best documented derangements include the delayed protracted inhomogeneous cerebral hypoperfusion (despite controlled normotension), excitotoxicity as an explanation for selectively vulnerable brain regions and neurons, and free radical-triggered chemical cascades to lipid peroxidation of membranes. Protracted hypoxemia without cardiac arrest (e.g., very high altitude) can cause angiogenesis; the trigger of it, which lyses basement membranes, might be a factor in post-cardiac arrest encephalopathy. Questions to be explored include: What are the changes and effects on outcome of neurotransmitters (other than glutamate), of catecholamines, of vascular changes (microinfarcts seen after asphyxia), osmotic gradients, free-radical reactions, DNA cleavage, and transient extracerebral organ malfunction? For future mechanism-oriented studies of the brain after cardiac arrest and innovative cardiopulmonary-cerebral resuscitation, increasingly reproducible outcome models of temporary global brain ischemia in rats and dogs are now available. Disagreements exist between experienced investigative groups on the most informative method for quantitative evaluation of morphologic brain damage. There is agreement on the desirability of using not only functional deficit and chemical changes, but also morphologic damage as end points.


Subject(s)
Heart Arrest/complications , Hypoxia, Brain/etiology , Hypoxia, Brain/therapy , Resuscitation , Altitude Sickness/physiopathology , Animals , Brain Chemistry , Disease Models, Animal , Dogs , Heart Arrest/therapy , Humans , Hypoxia, Brain/diagnosis , Hypoxia, Brain/physiopathology , Rats , Research
19.
Crit Care Med ; 24(2 Suppl): S69-80, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8608708

ABSTRACT

In 1961, in Pittsburgh, PA, "cerebral" was added to the cardiopulmonary resuscitation system (CPR --> CPCR). Cerebral recovery is dependent on arrest and cardiopulmonary resuscitation times, and numerous factors related to basic, advanced, and prolonged life support. Postischemic-anoxic encephalopathy (the cerebral postresuscitation disease or syndrome) is complex and multifactorial. The prevention or mitigation of this syndrome requires that there be development and trials of special, multifaceted, combination treatments. The selection of therapies to mitigate the postresuscitation syndrome should continue to be based on mechanistic rationale. Therapy based on a single mechanism, however, is unlikely to be maximally effective. For logistic reasons, the limit for neurologic recovery after 5 mins of arrest must be extended to achieve functionally and histologically normal human brains after 10 to 20 mins of circulatory arrest. This goal has been approached, but not quite reached. Treatment effects on process variables give clues, but long-term outcome evaluation is needed for documentation of efficacy and to improve clinical results. Goals have crystallized for clinically relevant cardiac arrest-intensive care outcome models in large animals. These studies are expensive, but essential, because positive treatment effects cannot always be confirmed in the rat forebrain ischemia model. Except for a still-elusive breakthrough effect, randomized clinical trials of CPCR are limited in their ability to statistically document the effectiveness of treatments found to be beneficial in controlled outcome models in large animals. Clinical studies of feasibility, side effects, and acceptability are essential. Hypertensive reperfusion overcomes multifocal no-reflow and improves outcome. Physical combination treatments, such as mild resuscitative (early postarrest) hypothermia (34 degrees C) plus cerebral blood flow promotion (e.g., with hypertension, hemodilution, and normocapnia), each having multiple beneficial effects, achieved complete functional and near-complete histologic recovery of the dog brain after 11 mins of normothermic, ventricular fibrillation cardiac arrest. Calcium entry blockers appear promising as a treatment for postischemic-anoxic encephalopathy. However, the majority of single or multiple drug treatments explored so far have failed to improve neurologic outcome. Assembling and evaluating combination treatments in further animal studies and determining clinical feasibility inside and outside hospitals are challenges for the near future. Treatments without permanent beneficial effects may at least extend the therapeutic window. All of these investigations will require coordinated efforts by multiple research groups, pursuing systematic, multilevel research--from cell cultures to rats, to large animals, and to clinical trials. There are still many gaps in our knowledge about optimizing extracerebral life support for cerebral outcome.


Subject(s)
Heart Arrest/complications , Hypoxia, Brain/etiology , Hypoxia, Brain/therapy , Resuscitation/methods , Animals , Disease Models, Animal , Dogs , Humans , Rats , Time Factors , Treatment Outcome
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