Severe gunshot injuries in a porcine model: impact on central markers of innate immunity

BACKGROUND

the mechanisms behind lipopolysaccharide (LPS) tolerance remain obscure. LPS signals through Toll-like receptor 4 (TLR4) and severe trauma/haemorrhage may influence binding and signalling through this receptor, e.g. by changing membrane expression or by releasing endogenous ligands like High Mobility Group Box 1 (HMGB1). The aim of this study was to examine these relations further in a porcine model with standardized trauma.

METHODS

nine anaesthetized pigs sustained one gunshot through the femur and one pistol shot through the upper abdomen. Blood was sampled before and 90 min after shooting. The samples were stimulated for 4 h with LPS 10 ng/ml or an equivalent amount of normal saline. The leucocyte response was evaluated by measuring the tumour necrosis factor-α (TNF-α) and CXC ligand 8 (CXCL8) in the supernatant. Flow cytometry was used to measure the surface expression of TLR4 on CD14+ monocytes. HMGB1 concentrations were measured in the plasma.

RESULTS

trauma and treatment caused a significant decline in the LPS-stimulated concentrations of TNF-α [4.53 ± 0.24 pg/ml (ln) at 0 min, 3.54 ± 0.35 pg/ml (ln) at 90 min, P=0.026], but did not modify the release of CXCL8. Monocyte TLR4 expression was unchanged. Plasma HMGB1 increased significantly [<0.92 vs. 3.02 ± 0.19 ng/ml (ln), P<0.001]. The concentrations of TNF-α and CXCL8 did not correlate with TLR4 expression or HMGB1 concentrations.

CONCLUSION

the results suggest that trauma-induced LPS tolerance is not primarily regulated by TLR4 expression on circulating CD14+ monocytes or by the release of HMGB1 from damaged tissues.

Capacity of glycine to modulate early inflammatory disturbances after serious gunshot injuries in the pig

OBJECTIVE

Perturbation of immune homeostasis is an important determinant for organ dysfunction following multiple injuries. The aim of this study was to investigate the ability of glycine to influence the immediate post-traumatic inflammatory environment and altered reactivity of circulating leucocytes.

MATERIAL AND METHODS

Twenty pigs were subjected to two standardized gunshots to the abdomen and thigh. Treatment was started immediately. The animals were randomized to receive either glycine 180 mg/kg i.v. over 30 min (n=10) or normal saline (n=10). Blood samples were drawn at baseline and 75 min after injury. In a follow-up study 12 pigs were exposed to an identical trauma. Blood was drawn at the same time-points and stimulated with lipopolysaccharide (LPS) or LPS plus glycine for 2 h in an ex vivo whole blood model.

RESULTS

Selected physiologic variables and organ injury did not differ between groups 75 min after trauma. Reactive oxygen species decreased to 82.7+/-5.5 % of baseline (p<0.05) in the glycine group (unaltered in the controls). Liver glutathione concentrations decreased in parallel in both groups. In vivo production of TNF-alpha and IL-1-beta increased to the same extent regardless of treatment. Trauma induced a strong LPS tolerance. In whole blood challenged with LPS, glycine inhibited cytokine synthesis, but only in samples drawn at baseline.

CONCLUSIONS

Post-traumatic infusion of glycine only modestly influenced the early post-traumatic inflammatory environment. Our ex vivo results confirm previous reports on the anti-inflammatory potential of glycine, but restricted to pre-trauma conditions.

Early time course of altered leukocyte response to lipopolysaccharide and peptidoglycan in porcine gunshot injury

BACKGROUND

Penetrating injuries are frequently combined with polybacterial soiling. Clearance of the microorganisms depends on the ability to activate immune responses, but post-traumatic hyporeactivity of immune cells is almost universal. The aim of this study was to map the early time course of this altered leukocyte reactivity, and to compare the reactions to subsequent Gram-positive or Gram-negative challenges.

METHODS

Twelve juvenile pigs sustained two standardized rounds, one through the right femur and one through the left upper abdomen. First aid treatment and acute surgery were started immediately. Blood samples were drawn before trauma and after 10, 30, 60, and 90 min, and thereafter stimulated in ex vivo whole blood for 3 h with lipopolysaccharide (LPS, 10 ng/ml), peptidoglycan (PepG, 1 microg/ml), or an equivalent amount of normal saline. The leukocyte response was evaluated by measurement of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-8, and IL-10 in the supernatant.

RESULTS

In the post-traumatic in vivo serum, the concentration of TNF-alpha increased steadily (significant after 60 min). A reduced ex vivo reaction to LPS was evident after 10 min, and was statistically significant after 30 min. The lowest levels were reached after 90 min. The ex vivo synthesis of TNF-alpha after stimulation with PepG remained unaltered. A similar development was seen for IL-6. IL-1 beta levels did not change, while IL-8 increased significantly only after 60 and 90 min.

CONCLUSIONS

Trauma almost instantaneously reprogrammed circulating leukocytes. As measured with TNF-alpha, a profound hyporeactivity to LPS, but not to PepG, was induced. In addition, no global down-regulation of leukocyte function was found after stimulation with LPS.

Glycine--an important neurotransmitter and cytoprotective agent

BACKGROUND

Glycine, the simplest of the amino acids, is an essential component of important biological molecules, a key substance in many metabolic reactions, the major inhibitory neurotransmitter in the spinal cord and brain stem, and an anti-inflammatory, cytoprotective, and immune modulating substance.

MATERIAL AND METHODS

Based on available literature, we discuss some of the important biological properties of glycine. In addition, we describe some clinical disorders where glycine plays a central role, either as an essential structural element, or through its metabolism or receptors.

RESULTS

The past few years have witnessed a broadening of glycine research. The traditional prime interest in aspects related to its role as an inhibitory neurotransmitter in the central nervous system has been expanded to equally emphasize other organs and tissues. With the demonstration of glycine-gated chloride channels on neurons in the central nervous system, on most leukocytes, and subsequently on other cells as well, a unifying mechanism of action accounting for many of the widespread effects of glycine has been found.

CONCLUSIONS

Glycine is a simple, easily available, and inexpensive substance with few and innocuous side-effects. The diversity of biological activities is well documented in the literature. Despite this, glycine has only gained a modest place in clinical medicine.

Response of circulating immune cells to major gunshot injury, haemorrhage, and acute surgery

PURPOSE

The purpose of this study was to use an established porcine model to investigate the effects on immune function of severe gunshot injury.

METHODS

Twelve pigs sustained two standardised rounds, one through right femur and one through left upper abdomen. First aid treatment and acute surgery was started immediately. Blood samples were drawn before shooting and after 75 min. Circulating neutrophils were isolated and reactive oxygen species (ROS) measured. Serum levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and IL-10 were determined at 0, 75 min, as well as 2h after incubation with 1 microg/ml endotoxin in an ex vivo whole blood model.

RESULTS

TNF-alpha, IL-1beta, and IL-6 significantly increased at 75 min. ROS in circulating granulocytes tended to increase (NS). Incubation with endotoxin led to a more than 100-fold increase of TNF-alpha pre-trauma, compared to a three-fold increase post-trauma (p<0.0001 between groups). A similar pattern was obtained for IL-1beta, and IL-6. IL-10 was below detection in all samples. The granulocytes maintained their ability to react to the protein kinase C activator phorbol myristate acetate (PMA) after trauma.

CONCLUSION

Severe gunshot injury and peritraumatic stress rapidly activate circulating immune cells, but reduce their capacity to react to a subsequent challenge to endotoxin.

Modest protection of early hydrocortisone treatment in a rat model of volume-controlled haemorrhage

BACKGROUND

Major insults may trigger generalized inflammatory responses that contribute to progressive multiple organ dysfunction. The present study was performed to test the potential of early hydrocortisone treatment to influence these responses as well as organ function following an episode of rapid and profound blood loss.

METHODS

In isoflurane anaesthesia, 35 spontaneously breathing male Sprague-Dawley rats were bled 2.5 ml 100 g-1 body weight over 10 min. Immediately following withdrawal of blood, one group (n = 17) was given 2 mg of hydrocortisone, and the other (n = 18) had the same amount of normal saline. Seventy-five minutes after initiation of bleeding, two-thirds of the blood was retransfused, together with a new injection of hydrocortisone or saline. Thereafter the rats were observed for 2 h. Key mediators of systemic inflammation and plasma markers of organ function and integrity were measured. Internal organs were weighed and scored for visible pathology. Leukocyte infiltration of the liver was counted in a light microscope.

RESULTS

Hydrocortisone reduced the plasma levels of IL-6 (P < 0.05); non-significant reductions of TNF-alpha (P = 0.12) and IL-10 (P = 0.44) were noted. The synthesis of reactive oxygen species in peritoneal cells was unaffected. Relative organ weights and organ injury scores tended to be reduced, but only wet organ weight for the lungs reached statistical significance. Leukocyte infiltration of the liver was equal in both groups. Plasma levels of ALT, AST, alpha-GST and creatinine did not differ significantly between groups. Two of the hydrocortisone treated rats died compared with four controls.

CONCLUSION

Early treatment with hydrocortisone had a limited organ protective effect in this model of controlled haemorrhagic shock. Although a general tendency for better outcome in the hydrocortisone group was noted, clear-cut and significant advantages of the treatment were not obtained.

Moderate hypothermia blunts the inflammatory response and reduces organ injury after acute haemorrhage

BACKGROUND

Reduced body temperature is a common companion to trauma/haemorrhage. Several clinical studies have identified hypothermia as an independent risk variable predisposing to increased morbidity and mortality. At the same time it is known that most enzymatic reactions are downregulated at temperatures below 37 degrees C. Theoretically this should restrain the inflammatory response and protect the host from remote organ injury. The study was performed to test this hypothesis.

METHODS

Twenty-six male Sprague Dawley rats were used for the experiments. Volume controlled haemorrhagic shock was induced by withdrawal of 2.5 ml blood/100 g body weight over 10 min. Half of the animals (n=13) were then cooled to 32.5-33 degrees C, the other half (n=13) were kept normothermic (37.5+/-0.5 degrees C). Seventy-five minutes after initiation of bleeding, two-thirds of the blood was retransfused. Thereafter the rats were observed for 2 h. Key substances of systemic inflammation were determined (plasma values of TNF-alpha, IL-6, IL-10, and corticosterone; reactive oxygen species in peritoneal phagocytes), plasma markers of organ function and integrity (AST, ALT, alphaGST, creatinine, urea), and survival.

RESULTS

Hypothermia reduced the release of IL-6 (P<0.01). The reductions of plasma levels of TNFalpha (P=0.07) and IL-10 (P=0.09) were less clear-cut. The release of reactive oxygen species diminished (P<0.01). Organ injury was ameliorated, as reflected by decreased levels of AST (P<0.01), alphaGST (P<0.01), and creatinine (P<0.01). Both groups experienced an almost identical increase of plasma corticosterone. None of the hypothermic rats died, compared to two normothermic.

CONCLUSION

Moderate hypothermia had an organ protective effect in this model of controlled haemorrhagic shock. This coincided with a significant reduction of the proximal cytokine IL-6 and reactive oxygen species, which conceivably influenced the outcome.

[Steroid treatment of shock lung--tune for re-evaluation?]

BACKGROUND

The acute respiratory distress syndrome (ARDS) is one consequence of the body's systemic inflammatory response to a variety of powerful external stimuli. Glucocorticosteroids are highly effective anti-inflammatory drugs. During the last few years, the molecular mechanisms for their mode of action have been revealed; this has prompted a new wave of interest in corticosteroid treatment of systemic inflammatory states. Several clinical studies have been launched; the results have so far been promising.

MATERIAL AND METHODS

We briefly discuss how new knowledge in this field may influence the use of corticosteroids in the treatment of ARDS. The presentation is illustrated by a case study.

RESULTS

The patient was a 15-year-old boy with life-threatening and therapy-resistant ARDS. He was treated in a respirator in an intensive care unit (ICU). Two weeks after admission to the ICU, his situation was desperate. High-dose corticosteroids were instituted, and during a five days' treatment his condition improved dramatically. After discontinuation of glucocorticoids he made further progress and was discharged from the ICU after another eleven days.

INTERPRETATION

In this particular patient, administration of glucocorticoids had a striking effect. The influence of glucocorticoids on the activation of the transcription factor NF-kappa B and a resulting reduced synthesis of a number of key inflammatory molecules may be one explanation for the positive course.

[Day surgery of hernia]

INTRODUCTION

Reduced economic resources have been a stimulus for increased day-case surgery, and an incentive for improving surgical technique and anaesthetic methods. In hernia surgery it is important to avoid recurrence and reoperation, which seems to be more easily achieved by the use of mesh prosthetics. For anaesthesia, costs may possibly be reduced by the use of spinal blockade instead of general anaesthesia, but also local infiltration anaesthesia is regaining popularity. We found it appropriate to evaluate and compare relevant factors associated with the use of these two anaesthetic techniques in our day-case surgery.

MATERIAL AND METHODS

Evaluation and analysis of the anaesthetic and postoperative notes on 413 adult patients with inguinal hernia operated in local anaesthesia and 121 patients operated in spinal anaesthesia.

RESULTS

Cardiovascular, respiratory and neurological problems were more frequent and more severe in the spinal than in the local anaesthesia group, whereas the need for extra analgesia and sedation perioperatively was higher in the local group. Time spent in the operating room was shorter, and early ambulation appeared to lead to less discomfort in the local anaesthesia group.

INTERPRETATION

The results indicate that local infiltration is a safe, simple and effective technique when used for operations of abdominal hernias in adult patients, and can be recommended for day-case surgery of reducible inguinal hernias.

Asphyxiation versus ventricular fibrillation cardiac arrest in dogs. Differences in cerebral resuscitation effects--a preliminary study

We explored the hypothesis that brain damage after cardiac arrest caused by ventricular fibrillation (VF) needs different therapies than that after asphyxiation, which has been studied less thoroughly. In 67 healthy mongrel dogs of both sexes cardiac arrest (at normothermia) by ventricular fibrillation (no blood flow lasting 10 min) or asphyxiation (no blood flow lasting 7 min) was reversed by normothermic external cardiopulmonary resuscitation, followed by intermittent positive-pressure ventilation for 20 h, and intensive care to 96 h. To ameliorate ischemic brain damage, the calcium entry blocker lidoflazine or a solution of free radical scavengers (mannitol and L-methionine in dextran 40) plus magnesium sulphate, was given intravenously immediately upon restoration of spontaneous circulation. Outcome was evaluated as functional deficit, brain creatine kinase (CK) leakage into the cerebrospinal fluid (CSF) and brain morphologic changes. Lidoflazine seemed to improve cerebral outcome after VF but not after asphyxiation. Free radical scavengers plus magnesium sulphate seemed to improve cerebral outcome after asphyxiation, but not after VF. After VF, scattered ischemic neuronal changes in multiple brain regions dominated, and total brain histopathologic damage scores correlated with final neurologic deficit scores at 96 h (r = 0.66) and with peak CK levels in CSF (r = 0.81). After asphyxiation, in addition to the same ischemic neuronal changes, microinfarcts occurred, and there was no correlation between total brain histopathologic damage scores and neurologic deficit scores or CK levels in CSF.

CONCLUSIONS

Different mechanisms of cardiac arrest, which cause different morphologic patterns of brain damage, may need different cerebral resuscitation treatments.

Cerebral resuscitation from cardiac arrest: pathophysiologic mechanisms

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.

Organ function during early acute renal failure does not predict survival in long-term intensive care

OBJECTIVE

To examine outcome in relation to organ function variables during early acute renal failure (ARF).

DESIGN

Retrospective inception cohort.

SETTING

General intensive care unit (ICU).

PATIENTS

69 consecutive ARF cases verified to have a creatinine clearance below 50 ml/min with no history of previous renal disease.

MAIN OUTCOME MEASURE

ICU survival.

MEASUREMENTS AND RESULTS

Septic severity score (SSS), creatinine clearance, thrombocyte count, bilirubin concentration, cardiac inotropic support, PaO2/FIO2 ratio and oliguria were measured. No differences related to outcome were observed in patients surviving more than 7 days after ARF diagnosis. Patients dying within 7 days of ARF had a significantly higher (worse) SSS. Organ dysfunction was established at the time of ICU admission in the majority of cases.

CONCLUSION

The organ function variables tested in this study are of limited predictive value during the early stage of ARF.

The use of cytosolic enzyme increase in cerebrospinal fluid of patients resuscitated after cardiac arrest. Brain Resuscitation Clinical Trial I Study Group

Levels of brain creatine phosphokinase (CPK), glutamic oxalic transaminase, lactate dehydrogenase, and lactate in lumbar cerebrospinal fluid (CSF) were analyzed as an adjunctive study in a randomized clinical trial evaluating the effects of thiopental loading intravenously in comatose survivors of cardiac arrest. Three hospitals participated and a total of 62 cases of enzyme changes were studied. Enzyme levels but not lactate were higher at 48 hours than at 24 hours after restoration of spontaneous circulation. All enzymes were highly correlated with one another at 24 and 48 hours (P < .001). There was a significant negative correlation between cerebral recovery and increased CPK levels at 24 hours (P < .05), and a highly significant correlation with all three enzyme levels at 48 hours (P < .0001). The increase of cytosolic enzyme activity in lumbar CSF reflects permanent brain damage, and there is a relationship between activity levels and cerebral outcome.

[Drowning--near drowning]

In Norway the number of deaths per year from drowning is approximately nine persons per 100,000, most of them men between 25 and 40 years of age. About 60% of these persons can swim, and 50% of the deaths are related to intake of alcohol. About 6% of the drowned are children, most of them boys. In disaster medicine, drowning is associated with accidents at sea, involving large vessels or small boats, or connected to offshore activities. The important pathological events are directly related to asphyxia, hypoxemia, hypercarbia, pulmonary oedema, and circulatory arrest. This paper describes various aspects of drowning and the pathophysiological processes involved, and discusses differences between drowning and near drowning in fresh water and salt water. Although treatment is basically centred on effective cardiopulmonary resuscitation, there are certain differences with regard to further treatment and fluid/electrolyte management. Hypothermia is often a prominent feature, and if cardiopulmonary resuscitation is successful, hypoxic brain damage may be ameliorated by the fall in body temperature.

[Local frostbites]

Injury from cold is not an uncommon complication in emergency and disaster medicine under arctic or subarctic conditions. Severe local exposure to cold may have a mutilating effect on the parts of the body involved. This paper briefly summarizes relevant pathophysiological features, how cold injuries are classified, the most important clinical findings, complications and aspects of recommended treatment.

[Accidental hypothermia]

Accidental hypothermia is an important clinical condition in emergency and disaster medicine. It is usually classified as mild, moderate, severe, or extreme (body temperature below 18-20 degrees C; no recordable EEG activity). However, exposure time, trauma, serious illness, or the effects of drugs or alcohol may both attenuate and complicate the clinical course. This paper describes exposure mechanisms, the pathophysiologic processes, the body's thermo-regulating mechanism and diagnostic criteria. The author also discusses choice of treatment in the acute stages, during transportation and in hospital. The treatment should take into account not only the degree of hypothermia, but also exposure time, state of consciousness, and complicating factors such as trauma, drugs or alcohol. When hypothermia is associated with cardiac arrest, rewarming by extracorporal support is recommended.

[Electric injuries. Physiopathology and principles of treatment]

This paper describes the basic physical aspects of electricity and the harmful effects of electric shock to the various human organ systems. Treatment of electrical injuries differs from treatment of burns. Damage to muscles and subcutaneous structures necessitates a more aggressive fluid replacement regimen than the one predicted by the commonly used burn fluid resuscitation formulas. It is of paramount importance to avoid renal complications. Early fasciotomy and repeated surgical debridements are often necessary. Routine arrhythmia-monitoring is now considered unnecessary in individuals exposed to low tension alternating current unless arrhythmias requiring treatment are present at the primary medical contact.

[Injuries caused by electricity]

We review a patient material consisting of cases with electrical injuries submitted to Sentralsykehuset i Akershus, Norway over a period of ten years. 18 cases were treated during the period 1 January 1978 to 31 December 1987. All were men, with a mean age of 33 years. All injuries were caused by AC current; seven were low voltage, and 11 high voltage injuries. The low voltage injuries proved to be relatively innocent, but 2/11 with high voltage injuries died. Many of the high voltage patients had severe deep tissue, mainly muscular, damage. The two who died had respiratory arrest, were unconscious on admission and had cardiac arrest. Only one with cardiac arrest on admission and two with respiratory arrest survived; three of the five who were unconscious on admission survived. Optimal treatment of injuries caused by electricity requires a thorough understanding of the special pathophysiology of this condition.

Glucocorticoid treatment does not improve neurological recovery following cardiac arrest. Brain Resuscitation Clinical Trial I Study Group

Glucocorticoids are commonly given to patients with global brain ischemia, although their efficacy has not been proved. The database of the Brain Resuscitation Clinical Trial I, a multi-institutional study designed to evaluate the effect of thiopental sodium therapy on neurological outcome following brain ischemia, was used for a retrospective review of the effects of glucocorticoid treatment on neurological outcome after global brain ischemia. This study included 262 initially comatose cardiac arrest survivors who made no purposeful response to pain after restoration of spontaneous circulation. The standard treatment protocol left glucocorticoid therapy to the discretion of the hospital investigators. This resulted in four patient groups that received either no, low, medium, or high doses of glucocorticoids in the first 8 hours after arrest. Neurological outcome was scored using a modification of the Glasgow Cerebral Performance Category Scale. None of the steroid regimens statistically improved mean group survival rate or neurological recovery rate over that observed in the group that did not receive steroids. The routine clinical practice of administrating glucocorticoids after global brain ischemia may be associated with serious complications and is not justified.

Effect of cardiac arrest time on cortical cerebral blood flow during subsequent standard external cardiopulmonary resuscitation in rabbits

Standard external cardiopulmonary resuscitation (SECPR) produces high cerebral venous and intracranial pressure peaks, low cerebral perfusion pressure, and low cerebral blood flow (CBF). Cerebral viability seems to require 20% of normal CBF, which SECPR cannot reliably generate. We tested the hypothesis that SECPR can produce adequate CBF if started immediately, but not if started after a long period of cardiac arrest (no flow, stasis). Cardiac arrest times of 1, 3, 5, 7 and 9 min were studied in rabbits. We measured unifocal cortical CBF with H2 clearance curves after saturation with H2 10%, O2 50% and N2O 40% by intermittent positive-pressure ventilation (IPPV). Measurements were made during spontaneous circulation (control condition), and then after resaturation immediately before induction of asystole by KCl i.v., and H2 clearance starting at end of arrest time during SECPR-basic life support with IPPV 100% and manual chest compressions (120/min) during asystole. Control cortical CBF was 30-40 ml/100 g brain per min. During asystole and SECPR, CBF greater than 20% normal was achieved only after no-flow of 1 min. After longer arrest (no-flow) times, CBF was less than 20% normal. Values were near zero after 7 and 9 min of cardiac arrest. Decrease in mean arterial pressures (MAP) produced by SECPR during asystole paralleled CBF values. Thus, the longer the preceding period of stasis, the lower the MAP and CBF generated by SECPR without epinephrine. This effect may be the result of anoxia-induced vasoparalysis and stasis-induced increased blood viscosity.

Brain enzyme changes as markers of brain damage in rat cardiac arrest model. Effects of corticosteroid therapy

Apneic asphyxia to cardiac arrest (CA) in rats of 10 min was reversed by cardiopulmonary resuscitation (CPR), and after controlled ventilation and controlled normotension for 20 min, was followed by decapitation and brain freezing, and determination of brain concentrations of cytosolic and lysosomal enzymes. Normal values came from a control group of 10 rats without CA. In 20 rats with CA brain cytosolic enzymes CK, LD, and ASAT decreased post-arrest, while lysosomal enzyme changes were variable (Table I). Brain lactate increased 8-10-fold post-CA. To test the model, effect of methylprednisolone (MP) was studied. The 20 rats with CA were divided into 4 groups: Group I, received placebo pre-CA; Group II, MP 30 mg/kg i.v. pre-CA; Group III, placebo post-CA; and Group IV, MP post-CA. The post-CA MP Group IV was the only one without norepinephrine requirement and with return of EEG activity at 20 min. Brain CK, LD, and ASAT losses post-CA were not different between groups; and showed no differences between MP groups II and IV vs. placebo Groups I and III. When comparing both pre-CA Groups (I and II) with both post-CA Groups (III and IV), post-CA CK and ASAT levels were the same, but LD was higher in the post-CA treatment group. The lysosomal enzymes acid phosphatase, mannosidase, beta-glucuronidase and hexosaminidase showed variable concentration changes post-CA in the four groups, with a trend toward a lesser increase of some after MP or after post-treatment. Brain enzyme changes in our asphyxial CA rat model can serve as markers of brain damage. MP post-CA might enhance cardiovascular and EEG recovery, but does not seem to influence brain enzyme levels at 20 min post-CA.

Brain enzyme levels in CSF after cardiac arrest and resuscitation in dogs: markers of damage and predictors of outcome

Levels of brain creatine kinase (CK), aspartate aminotransferase (ASAT), and lactate dehydrogenase (LD) in CSF after cardiac arrest were studied in dog models. Ventricular fibrillation cardiac arrest lasting 10 min or asphyxiation cardiac arrest lasting 0-10 min was followed by cardiopulmonary resuscitation and 96-h intensive care. Outcome was scored as neurologic deficit (0% = normal, 100% = brain death) and overall performance category (1 = normal, 5 = death). Both measures correlated with EEG return time after asphyxiation cardiac arrest, but not after ventricular fibrillation cardiac arrest. Peak activity of enzymes in CSF at 48-72 h post arrest correlated with outcome, and CK was the best predictor. Brain histopathologic damage score at autopsy 96 h post arrest correlated with CK level in CSF (r = 0.79, n = 39) and neurologic deficit (r = 0.70, n = 50). Ischemic neuronal changes occurred after ventricular fibrillation cardiac arrest of 10 min, and neuronal changes plus microinfarcts occurred after asphyxiation cardiac arrest of 1.5-10 min. Brain enzymes were decreased at 6 h post arrest in regions with worst histologic damage (gray matter of neocortex, hippocampus, caudate nucleus, cerebellum). Brain CK decreased further, ASAT remained low, and LD increased at 72 h after arrest. The temporal changes in CK level paralleled the temporal ischemic neuronal changes in the brain, and time to peak activity was unaffected by the severity of the ischemic insult. Peak activity of individual enzymes in CSF was determined predominantly by the brain concentration, but was also influenced by rate of decomposition. This "chemical brain biopsy method" represents a useful adjunctive tool to predict permanent, severe brain damage during comatose states after cardiac arrest and resuscitation.

Temporal pattern of enzyme changes in cerebrospinal fluid in patients with neurologic complications after open heart surgery

We serially measured creatine kinase (CK), lactate dehydrogenase, aspartate aminotransferase (AST) and lactate from the lumbar cerebrospinal fluid in 14 patients with neurologic complications after open heart surgery with cardiopulmonary bypass (CPB). These analyses revealed a correlation between worsening neurologic deficit and the peak CK (r = .87, p less than .001), AST (r = .75, p less than .01), and lactate (r = .93, p less than .001) levels. Lactate increased before enzymes did. In 12 patients without complications, only lactate was significantly (p less than .005) elevated; however, within this group, CK but not lactate could be used to differentiate patients who later developed subtle mental changes. Although CPB appeared to induce metabolic changes in the brain that could possibly disturb function, severe cerebral damage appeared to require additional global or focal anoxic-ischemic factors. Short hypothermia during bypass did not influence CK, but it was falsely elevated after prolonged hypothermic periods. The testing of these enzymes may be a reliable indicator of the degree of brain damage and the prognosis.

Effects of therapeutic hypothermia on activity of some enzymes in cerebrospinal fluid of patients with anoxic-ischemic brain injury

I assessed the effect of therapeutic hypothermia on the activity in cerebrospinal fluid of creatine kinase (EC 2.7.3.2) and its brain isoenzyme (CK-BB), lactate dehydrogenase (EC 1.1.1.27), and aspartate aminotransferase (EC 2.6.1.1.) as markers of cerebral damage in patients with transient anoxic-ischemic brain injury. Moderate hypothermia (30-32 degrees C) lasting more than 24 h resulted in disproportionately greater activity of creatine kinase during the post-insult period than in patients not treated with hypothermia but having similar insults and outcome (p less than .01 for survivors, and p less than .005 for nonsurvivors). No differences were observed for the thermostable enzymes lactate dehydrogenase and aspartate aminotransferase, which demonstrates that the effect of hypothermia must be taken into account when thermolabile enzymes are used as sole markers of brain damage in such patients.

Effects of therapeutic hypothermia on activity of some enzymes in cerebrospinal fluid of patients with anoxic-ischemic brain injury

I assessed the effect of therapeutic hypothermia on the activity in cerebrospinal fluid of creatine kinase (EC 2.7.3.2) and its brain isoenzyme (CK-BB), lactate dehydrogenase (EC 1.1.1.27), and aspartate aminotransferase (EC 2.6.1.1.) as markers of cerebral damage in patients with transient anoxic-ischemic brain injury. Moderate hypothermia (30-32 degrees C) lasting more than 24 h resulted in disproportionately greater activity of creatine kinase during the post-insult period than in patients not treated with hypothermia but having similar insults and outcome (p less than .01 for survivors, and p less than .005 for nonsurvivors). No differences were observed for the thermostable enzymes lactate dehydrogenase and aspartate aminotransferase, which demonstrates that the effect of hypothermia must be taken into account when thermolabile enzymes are used as sole markers of brain damage in such patients.

Enzyme level changes in the cerebrospinal fluid of patients with acute stroke

Creatine kinase (CK), brain CK (CKBB), lactate dehydrogenase (LD), and aspartate aminotransferase (ASAT) levels were determined in cerebrospinal fluid (CSF) obtained from 35 patients with acute stroke. In patients with transient, minor neurological disturbances, only LD levels increased; in those who remained comatose and died, the levels of all the enzymes, except ASAT, increased. Patients who remained with focal motor defects had increased CK and LD levels, while CKBB and ASAT levels were variable. In most of the CSF samples, muscle CK activity was also detectable, suggestive of a leakage from blood to CSF. The pattern of the enzyme increase could be related to the causative mechanisms for the strokes. The study suggests that CSF enzyme determinations may provide supplementary information as to the extent and severity of brain damage and the recovery potentials of selected patient groups with strokes.

Amelioration of brain damage by lidoflazine after prolonged ventricular fibrillation cardiac arrest in dogs

Calcium entry blockers can ameliorate postischemic cerebral hypoperfusion, protect the myocardium against ischemia, and may protect against early postischemic neurologic deficit. This study documents that a calcium entry blocker, given after cardiac arrest, can ameliorate late postischemic neurologic deficit (ND). Thirty-four dogs received 10 min of ventricular fibrillation, restoration of spontaneous circulation by external cardiopulmonary resuscitation, and standard postarrest intensive care. Eleven of these dogs were given lidoflazine, 1 mg/kg body weight, within 10 min postarrest and again at 8 h and 16 h. Pupillary light reflexes, EEG activity, arterial-cerebrovenous oxygen gradients (O2 demand/supply ratios) and intracranial pressure were the same in both groups. After weaning from controlled ventilation at 24 h, ND scores improved consistently through the 96-h observation period in the lidoflazine-treated dogs. In the control group, ND scores were significantly higher than in the lidoflazine-treated dogs. In the lidoflazine-treated group, 5/11 dogs achieved normal overall performance and none remained comatose, whereas all control dogs had some deficit and 4/11 remained comatose. Delayed neurologic deterioration occurred in 6/11 control and 0/11 lidoflazine-treated dogs. Total mean cerebral histopathologic damage (HD) scores at 96 h were not significantly different between the two groups; however, individual HD scores and maximum cerebro-spinal fluid (brain-specific) creatine-phosphokinase activity--which increases after brain insults--correlated well with 96-h ND scores. In the lidoflazine group, life-threatening dysrhythmias were less frequent and the norepinephrine requirement for blood pressure maintenance was the same as in the control group. Cardiac output remained at prearrest levels in the lidoflazine-treated dogs, but decreased in the control group, particularly during the first 4 h postarrest.

Subarachnoid anaesthesia: comparison of hyperbaric solutions of bupivacaine and amethocaine

Hyperbaric solutions of 0.5% bupivacaine and 0.5% amethocaine (2 and 3 ml) were compared in a double-blind study of 40 patients receiving subarachnoid anaesthesia for urological surgery. The drugs produced similar and satisfactory analgesia in the tested concentrations and volumes. Motor blockade was more profound and longer lasting with amethocaine.

An unusual complication of lithotripsy

The case described illustrates a most unusual course of events due to a perforation in the wall of the bladder during transurethral lithotripsy. Irrigation fluid forced its way retroperitoneally to the mediastinum. The differential diagnostic problems encountered are discussed.

Accidental deep hypothermia due to exposure

Two cases of deep hypothermia due to exposure to cold are described. Although the underlying mechanism and degree of hypothermia were comparable, there was a striking dissimilarity between the observed disturbances of body homeostasis, response to rewarming technique, clinical course and outcome in the two cases. The first case was severely acidotic. She was rewarmed by immersion in warm water, but died from an acute cerebrovascular accident. The second case was moderately intoxicated by alcohol and revealed few disturbing features. She was treated by the use of thermal mattresses and survived without complications.