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Biomedical subjects

L Bossaert

Publications and source records attributed to L Bossaert.

At least 55 records · Page 3Linked to original sources
PubMed1994

Pretreatment with methylprednisolone in coronary artery bypass grafting influences the levels of histamine and tryptase in serum but not in bronchoalveolar lavage fluid.

1. The presence of histamine and tryptase in serum during and after coronary artery bypass grafting may be an indication of the induction of inflammation. 2. One group of patients received no glucocorticoids and a second group received methylprednisolone before extracorporeal circulation. In the steroid group no effects were seen on the basal levels of histamine (2.84 +/- 0.12 ng/ml) and tryptase (0.50 +/- 0.05 ng/ml) during and after surgery. In the other group two peak levels of histamine were observed: one at 10 min after starting extracorporeal circulation (4.19 +/- 1.79 ng/ml) and another at 4 h after surgery (8.26 +/- 4.85 ng/ml). In this group tryptase was only elevated during the period of extracorporeal circulation (1.54 +/- 0.16 ng/ml). 3. There were no differences between the two groups in complement activation. C3a levels rose to 170 +/- 8% and 180 +/- 10% of the initial value in the steroid and non-steroid group, respectively. 4. It was concluded that during surgery mast cells were activated, but since tryptase levels decreased in the post-operative period, the second increase in the histamine level can be explained by activation of basophils or by an unknown mechanism for the release of histamine but not tryptase by mast cells. 5. In the bronchoalveolar lavage fluid the levels of histamine and tryptase showed no differences between the two groups of patients, but histamine was enhanced compared with normal levels.

Bronchoalveolar Lavage Fluid↗
PubMed1993

Thrombolytic therapy.

All patients with symptoms and ECG findings suggestive of acute myocardial infarction (AMI) should be considered for treatment with thrombolytic agents. The decision to use thrombolytic therapy is a clinical judgment based upon a weighing of the potential benefits versus the possible risks. The physician must take into account relative contraindications, age of the patient, area of jeopardized myocardium, and duration of symptoms. Health professionals involved in the care of AMI patients should develop written plans and protocols addressing the following matters: identification of patients with chest pain in the prehospital setting (this applies to hospitals that receive patients from emergency medical services systems), triage of patients in the emergency department, obtaining the 12-lead electrocardiogram, determination of contraindications, authority for ordering thrombolytic therapy, and consultation for atypical cases. There also should be agreed standards for the time interval from arrival in the ED to administration of the thrombolytic agent, as well as a commitment to the prospective monitoring of procedures and times to assure continuous improvement. A time interval for treatment (arrival in ED to administration of drug) of 30 to 60 minutes should be achievable for patients who present with typical symptoms and ECG findings.

Acute Disease↗
PubMed1993

Interleukin-8 production in patients undergoing cardiopulmonary bypass. The influence of pretreatment with methylprednisolone.

Pulmonary dysfunction caused by pulmonary neutrophil sequestration is a frequent postoperative complication in patients undergoing cardiopulmonary bypass (CPB) surgery. It is yet unclear whether treatment with corticosteroids in vivo in these patients can prevent complement-mediated neutrophil activation and sequestration in the lungs. Therefore, we conducted a prospective study in order to investigate whether methylprednisolone (MP) pretreatment (30 mg/kg) could influence the appearance of IL-8 (a recently discovered cytokine with potent neutrophil-chemotactic activity) in the peripheral circulation. We also studied the effects of MP pretreatment on the inflammatory parameters in the bronchoalveolar lavage (BAL) fluid 4 h postoperatively. Although peripheral neutropenia and the rise in IL-8 serum levels was less pronounced in MP-treated than in non-steroid-treated patients, there was no significant difference in albumin, total protein, concentrations of IL-8 and C3a, and the number of neutrophils in the BAL fluid between the two groups. However, when cultured in vitro, alveolar macrophages from patients treated with MP released significantly lower IL-8, both in basal conditions and after stimulation with lipopolysaccharide. Our results show that MP does not prevent (IL-8-mediated) pulmonary neutrophil infiltration after CPB, although it might affect certain aspects of the microvascular lung injury.

Aged↗
PubMed1992

Release of arachidonic acid metabolites from isolated human alveolar type II cells.

Human alveolar type II cells are thought to play a role in the pathogenesis of lung injury. Patterns of mediator release of arachidonic acid metabolism by type II cells were therefore studied after challenge with calcium ionophore A23187, opsonized zymosan and hydrogen peroxide. A time- and concentration dependent release of cyclooxygenase products was observed, with release of PGE2 greater than 6-keto-PGF1 alpha greater than TxB2. Addition of glutathione or bicarbonate further increased the production of PGE2. N-ethylmaleimide, a sulfhydryl (SH) reactant, induced a dose-dependent increase in the release of TxB2 and 6-keto-PGF1 alpha, but not of PGE2. This relates most likely to the SH-dependency and glutathione requirement of the PGE2 isomerase and SH-independence of thromboxane and prostacyclin isomerase.

Arachidonic Acid↗
PubMed1992

Interleukin 8 (IL-8) in the bronchoalveolar lavage fluid from patients with the adult respiratory distress syndrome (ARDS) and patients at risk for ARDS.

A sensitive and specific radioimmunoassay was used to measure interleukin 8 (IL-8) in bronchoalveolar lavage fluids from control subjects, patients with the adult respiratory distress syndrome (ARDS) and patients undergoing coronary bypass surgery, a risk factor for developing ARDS. Concentrations of IL-8, albumin, total protein and numbers of neutrophils were higher in both patient groups than in controls. Levels of IL-8 were significantly correlated with the influx of neutrophils, plasma protein extravasation and with the PaO2/FiO2 ratio. These data suggest that IL-8 may mediate the recruitment of neutrophils from the vascular compartment into the alveolar space and may therefore be an important determinant in neutrophil-mediated lung injury. Since increased levels of IL-8 were also found in BAL fluid from patients at risk in whom ARDS did not develop, other factors are likely to be involved and IL-8, as well as other markers of inflammation, are of little prognostic use.

Adult↗
PubMed1992

Should semi-automatic defibrillators be used by emergency medical technicians in Belgium? The Belgian Cerebral Resuscitation Study Group.

Early external defibrillation is the single most effective intervention in patients with out-of-hospital cardiac arrest. Literature data indicate that instructing emergency medical technicians (EMTs) to use defibrillators is beneficial, provided the local emergency medical system is well organized. We tried to estimate the potential benefit of early defibrillation in some centres in Belgium by retrospectively analyzing the data from the Belgian Cardio-Pulmonary-Cerebral Resuscitation Registry collected between 1983 and 1987 in Belgian centres with a Mobile Intensive Care Unit (MICU). The data show that 2310 out of 3371 patients (69%) were first attended by the EMTs; on subsequent arrival of the MICU-teams, 584 of these 2310 patients i.e. 17% of the whole study population, presented with ventricular fibrillation. Analysis of estimated time factors in these 2310 patients revealed that the median time interval between collapse and start of resuscitation by EMTs was 8 min; the median time interval between collapse and start of MICU-resuscitation attempts was 16 min. The duration of EMT-resuscitation before MICU-arrival was probably more than 5 min and 10 min in 58% and 23% of the cases respectively. It is concluded that EMTs can be expected to reach a substantial number of ventricular fibrillation victims within a few minutes after the collapse and many minutes before arrival of the MICU. Therefore, training of EMTs in the use of semi-automatic defibrillators seems worthwhile in MICU-served regions in Belgium.

Belgium↗
PubMed1991

ST-segment analysis: a useful marker for reperfusion after thrombolysis with APSAC? The Belgian EMS Study Group.

The European Multicentre Study (EMS) assessed coronary reperfusion, functional outcome and safety of anistreplase (anisoylated plasminogen streptokinase activator complex = APSAC) compared to a control group treated with heparin alone in patients with a clinical diagnosis of acute myocardial infarction (AMI). In the Belgian subset of data (n = 103) the reperfusion results, based on non-invasive clinical parameters, were significantly better in the APSAC group: 66% versus 18% in the heparin group (P less than 0.0001). No significant difference was found between the two treatment groups with respect to left ventricular function and adverse events. The purpose of the present study was to analyse the indicative value of ST-segment changes as a possible predictor of reperfusion in threatened myocardial tissue. Two scoring systems were used: the first was based on the combined evaluation of three clinical non-invasive parameters (course of chest pain, ECG evaluation of ST segment changes, reperfusion arrhythmias); the second was based on the changes of the sum of the ST-segment (sigma-ST) evaluations on consecutive 12-lead ECGs. There was a good correlation between the combined clinical scoring system and the residual stenosis on coronary angiography (P less than 0.05) and early CK peak (P less than 0.0001). Analysis of the ECG data revealed that a decrease of greater than or equal to 50% of the sum of ST-elevations (sigma-ST) at 2 h post-treatment in both limb and precordial leads is a fairly useful predictor of reperfusion (sensitivity = 73%, specificity = 63%, predictive value = 88%).

Adult↗
PubMed1989

Bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest. The Cerebral Resuscitation Study Group.

Prevalence of bystander CPR and effect on outcome has been evaluated on 3053 out-of-hospital cardiac arrest (CA) events. Bystander CPR was performed in 33% of recorded cases (n = 998) by lay people in 406 cases (family members 178, other lay people 228) and by bystanding health care workers in 592 cases (nurses 86, doctors 506). Family members and lay people mainly applied CPR in younger CA victims at public places, roadside or at the working place. Sudden infant death syndrome (SIDS) and drowning are highly represented. Health care workers performed CPR mainly in older patients, at public places or at the roadside and especially in case of cardiac or respiratory origin. CA caused by trauma/exsanguination and intoxication/metabolic origin received less bystander CPR (23% resp. 22%). Cardiac arrests receiving bystander CPR are more frequently witnessed and have a shorter access time to the emergency medical service (EMS) system and shorter response time of basic life support (BLS). Advanced life support (ALS) response time is significantly longer. In witnessed arrests of cardiac origin receiving bystander CPR a significantly better late survival was observed. In non-witnessed arrests of cardiac origin early and late survival are significantly higher in patients receiving bystander CPR. In CA events where response time of ALS exceeds 8 min, the beneficial effect of bystander CPR is most significant. Furthermore no deleterious effect of bad technique or inefficient bystander CPR can be demonstrated.

Adult↗
PubMed1989

Evaluation of cardiopulmonary resuscitation (CPR) techniques. The Cerebral Resuscitation Study Group.

The prevalence of different CPR techniques and the use of adjuncts during the resuscitation attempt by the members of the emergency medical service (EMS) system [bystander, emergency medical technician (EMT), ward nurse, tiered nurse or paramedic, mobile intensive care unit (MICU) has been registrated prospectively during a 5-year period by 7 major Belgian EMS systems. A total of 4548 cardiac arrests have been registered, 3083 happened outside and 1465 inside the hospital. Evaluation of the methods used for assessment of quality of the CPR techniques revealed that this approach was biased both by the status of the health care provider and by the outcome of the patient. Nevertheless, it was evident that the well-accepted standards and guidelines for CPR and emergency cardiac care (American Heart Association and Safar) are poorly applied. This seems to be influenced by the qualification, the experience and the training level of the health care provider. In 998 of 3053 studies out-of-hospital arrests (33%) CPR was initiated by bystanders. Of these, 59% were bystanding health care workers. They performed external chest compression (ECC) more frequently than mouth-to-mouth insufflation (MOMO) (poor technique: 16-19%). In 18% the rescuers were family members who applied more MOMO than ECC (poor technique: +/- 50%). Laymen (23%) performed more ECC than MOMO (poor technique: +/- 33%). EMT and ward nurses apply mainly the bag-valve-mask technique. The bag-valve-tube technique is more frequently used by nurses of a tiered system. The MICU-team applies usually the bag-valve-mask prior to intubation.

Electric Countershock↗
PubMed1989

Tolerance and pharmacokinetics of flunarizine after cardiac arrest. The Cerebral Resuscitation Study Group.

Neuronal calcium overloading after complete ischemia-anoxia of the brain might be the primary process initiating chemical cascades which lead to cell death. According to this hypothesis calcium-entry blocking agents act on the final common pathway of brain damage. Flunarizine, a selective calcium-entry blocker (without influence on heart rate and on cardiac contractile force), was administered to 12 unconscious patients, recovering from cardiac arrest (CA) of cardiac origin, according to a strict dose-range infusion protocol. Blood-pressure and heart rate (HR) were recorded before, during (t = 10 min, 20 min) and after (t = 30 min, 2 h, 4 h, 6 h, 8 h) each flunarizine infusion (maximum 4 infusions). A significant, although not clinically relevant, decrease in heart rate was noted during the first infusion. Systolic (SBP) and diastolic blood pressure (DBP) also decreased during the infusion without reaching statistical significance. Plasma levels of flunarizine were determined before and after each infusion (t = 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h). Flunarizine plasma concentrations declined very rapidly after cessation of each infusion. Sequential half-lives were in the order of 11-19 min and 5-7 h, and primarily reflect rates of distribution between the systemic circulation and the rapidly equilibrating tissues such as the brain. No substantial accumulation of flunarizine was described and plasma levels were proportional to the give dose. Therefore, flunarizine pharmacokinetics can be considered as linear for doses up to 50 mg.

Cardiovascular System↗
PubMed1989

Decision making to cease or to continue cardiopulmonary resuscitation (CPR). The Cerebral Resuscitation Study Group.

CPR should be initiated in any patient who has a cardiac arrest. This might improve overall outcome but implies that CPR is started in patients without any virtual chance for long-term survival (LTS). The aim of this study is, by analysing retrospectively 2713 out-of-hospital cardiac arrests (CA), to identify indices which might be of help in the decision making to continue or to discontinue CPR. In an important number of unsuccessful CPR attempts ALS-time did not exceed 20 min. This occurred more frequently in subgroups where limited chances of LTS are expected on clinical grounds. The decision to cease CPR might have been based on other clinical and/or ethical parameters which were not recorded in the registry. This behavior results in a "self-fulfilling prophecy". A subset of patients with limited chances for LTS (0/405) can be identified: patients in electromechanical dissociation (EMD) or asystole on arrival of the mobile intensive care unit (MICU) team, without pupil reaction to light during CPR and with inefficient cardiac massage by the MICU (405/2713). Other patients in EMD or asystole without pupil reaction to light during CPR (1373/2713) but with efficient ECC should be resuscitated for more than 30 min, especially if the patient is gasping during CPR (LTS 27/1373). Patients in EMD or asystole on arrival of the MICU with pupil reaction to light during CPR (236/2713) should have an ALS-time of at least 45 min (LTS 42/236). Cardiac arrests in ventricular fibrillation (VF) (699/2713) should be resuscitated for at least 45 min, especially when gasping during CPR (LTS 119/699).

Ambulances↗
PubMed1989

Lazarus sign and extensor posturing in a brain-dead patient. Case report.

A man was declared brain dead after having sustained a gunshot wound to the head. All clinical criteria for the diagnosis of brain death were met. The electroencephalogram was isoelectric, and four-vessel angiography demonstrated the absence of cerebral blood flow. However, stereotypic spontaneous movements were observed which persisted for several hours. The possible mechanism is discussed and a short review of the literature is given.

Brain Death↗
PubMed1989

[Regional differences in the Belgian national campaign for a citizen CPR education "3 minutes for a life"].

In 1986-1988 the Belgian Red Cross and the Belgian Heart Association organised a nationwide citizen-CPR campaign. In this report regional differences in attitude towards CPR, in perception of promotion and in CPR instruction are studied. In two telephone inquiries (study sample n = 2400) organised with one year interval perception of the promotional efforts of the campaign was studied. During the campaign date on 102,249 trainees (study sample n = 17491) and 9927 courses were collected. For each individual CPR course and trainee an evaluation form was generated, describing the profile of instructor, course and trainee. The telephone inquiries demonstrated that french speaking responders were less prone to personal active involvement in case of an unconscious victim (30% vs 47%) and less frequently planned to attend a CPR course (31% vs 22%) as compared to Flemish responders. Concerning CPR instruction, in the Flemish community 72613 citizens were trained in 5505 courses by 768 instructors. In the french community 29636 people were trained in 4425 courses by 524 instructors. Flemish instructors were less experienced than french instructors in CPR teaching (greater than 25 courses: FI 27%, Fr 41%). The profile of CPR instructors and CPR courses were markedly different in both communities but the trainee and teaching results were identical.

Attitude to Health↗
PubMed1988

Thrombolytic treatment of pulmonary embolism with APSAC.

BRL 26921 (Eminase registered trade mark in Belgium, Germany and The Netherlands) is the p-anisoyl derivative of the primary (human) lys plasminogen-streptokinase activator complex (APSAC). The acyl-enzyme has the theoretical advantage of causing fibrinolysis in situ in the presence of fibrin clotbound plasminogen. It was administered to 34 patients with severe pulmonary embolism (PE) in an open multicentre study. PE was suspected on clinical, blood gas, ECG, and radiographic data. Pulmonary angiograms performed pre- and post-treatment confirmed the diagnosis and were assessed using the Miller Index (MI). Fibrinogen, plasminogen, alpha-2-antiplasmin, fibrinogen degradation products (FDP), activated partial thromboplastin time (APTT), partial thromboplastin time (PTT) were closely monitored before and after each administration of APSAC. Median angiographic improvement was 50% (range 0-94%). The following adverse events were reported: bleeding at puncture sites (n = 12), haematuria (n = 1), epistaxis (n = 3), fever (n = 2). A blood transfusion was given in one patient with an inguinal haematoma. Systemic fibrinogenolysis occurred in 20/28 patients.

Adult↗