Prognostic factors in unintentional mild carbon monoxide poisoning.

OBJECTIVES: To identify early predictors of recovery from mild carbon monoxide poisoning, and to search for qualitative interactions between subsets of patients and treatment effects. DESIGN AND SETTING: Inception cohort study from a 4-year, randomised, controlled trial, which compared normobaric oxygen therapy to the combination of normobaric plus hyperbaric oxygen therapy in 307 patients. Study was conducted at a hyperbaric oxygen therapy referral centre. PATIENTS AND INTERVENTIONS: Victims of unintentional, non-fire-related, domestic, carbon monoxide intoxication were evaluated if the time elapsed from end of exposure to hospital admission was less than 12 h, the carboxyhaemoglobin level was greater than or equal to 10% or 5% for smoker or non-smoker, respectively, and if they did not suffer a loss of consciousness. One course of hyperbaric oxygen therapy or 6-h normobaric oxygen therapy was given. MEASUREMENTS AND RESULTS: The main outcome measure was status at the 1-month recovery. Of the 307 evaluated patients, 206 (67%, 95%CI: 62%-72%) had recovered at 1 month. None of the patients died or suffered severe sequelae. Apathy and headaches were the main moderate sequelae. The multivariate analysis selected dizziness before admission (OR=1.92, [1.17-3.15], p=0.010) and headaches upon hospital admission (OR=2.14, [1.09-4.17], p=0.026) as jointly associated with persistent neurological symptoms. No significant crossover interaction between each combination of these two predictors and treatment effects was observed. CONCLUSIONS: At 1 month after mild carbon monoxide intoxication, victims who presented with dizziness before hospital admission or headaches upon admission have an increased risk of minor persistent neurological symptoms, but almost all patients could resume their former occupation.

Role of replacement fluids in the immediate complications of plasma exchange. French Registry Cooperative Group.

OBJECTIVE: Comparison of side effects (fever shivering and/or allergic reactions, collapse, symptomatic hypocalcaemia) of the different substitution fluids used during therapeutical plasmapheresis. DESIGN: Multicentric retrospective comparative study designed to explore the side effects due to the replacements fluids (albumin alone or associated with dextran 40, modified fluid gelatin, hydroxyethyl starch), and to determine the best combination in patients undergoing plasmapheresis. PATIENTS: 46,895 procedures were performed on 5,167 patients between 1990 and 1994. The analysis concerns 33,962 sessions, divided into two groups (group 1: 21,079 sessions from 1990 to 1992 comparing albumin alone versus combined albumin-macromolecules and the different combinations among these, group 2: 12,883 sessions in 1993-1994 comparing albumin alone versus albumin-hydroxyethyl starch). Because of the diversity of the products used, 13,029 sessions were not studied because groups of small sample sizes were formed. MEASUREMENTS AND RESULTS: In group 1, the comparison of albumin + macromolecules with albumin alone, shows the best haemodynamic tolerance, lower frequency of fever shivering and/or allergic reactions in the albumin alone subgroup. On the other hand, hypocalcaemia is significantly higher in this subgroup. The combinations albumin + dextran 40 (but after hapten inhibition) and albumin + hydroxyethyl starch are equivalent. Albumin + modified fluid gelatin is the combination presenting the highest incidence in terms of allergic manifestations. In group 2, albumin + hydroxyethyl starch versus albumin alone, the former is preferable in terms of the three side effects studied. CONCLUSION: The results of this study show a combination of albumin 4% hydroxyethyl starch to replace plasma during plasma exchange to be the method presenting the lowest morbidity and the best cost/effectiveness ratio.

Validity and reliability of two muscle strength scores commonly used as endpoints in assessing treatment of myasthenia gravis.

Valid and reliable measurements of muscle impairment are needed to assess therapeutic efficacy in patients with generalized myasthenia gravis (MG). In 22 patients we compared the validity and interobserver reliability of two scoring methods commonly used as main endpoints in clinical trials, i.e., the Myasthenic Muscle Score (MMS) ranging from 0 to 100 (normal) and the Quantified Myasthenia Gravis Strength Score (QMGSS) ranging from 0 (normal) to 39. Each score is correlated more with functional scale and less with the patient's self-evaluation. Using intraclass correlation we found strong agreement between observers for both the MMS (r = 0.906) and the QMGSS (r = 0.905). The correlation between MMS and QGMSS was high (r = 0.87). The reliability of neither score depended on any specific item, since the removal of individual items did not significantly alter the intraclass correlation coefficient (ranging from 0.86 to 0.93).

Plasma exchange in France: Epidemiology 2001.

The French plasma exchange registry created in 1985 lists the indications, techniques and complications of the French therapeutic haemapheresis. In 2001 it contains the data of more than 16,700 patients for a total of 153,641 sessions. The indications concern five groups of pathologies (neurology, haematology, nephrology, vasculitis, and endocrinology). Until 2000, the neurology represented the most important group but the use of the high dose IgIV for Guillain-Barre and myasthenia gravis decreased the indications. The haematology became most important group treated because of the increase of the TTP and HUS number treated. The endocrinology (familial hypercholesterolemia) represents at present 10% of the patients treated for 18.7% of the sessions. The vascular access little changed since 1985, the peripheral venous access being the most used. The plasma substitution initially based on the albumin alone was gradually replaced by an association albumin macromolecules, in particular hydroxyethylstarch since 1990. After the observation of the side effects due to starches we observed an increase of the albumin alone use. The immediate complications decreased in half in 15 years. The French plasma exchange registry is the largest world database of haemapheresis with the cooperation of about 80 centres, allowing numerous scientific studies.

14 years of therapeutic plasma exchange in France.

The French Registry for plasma exchange (PE) was set up in 1985. For 14 years it has allowed analysis of the techniques used along with the indications and complications. Recent analysis shows a slight fall in activity as some studies have ended, while the neurological disorders remain the most frequent indications for PE. The important changes observed over the years are the increased use of the centrifugation technique, the development of plasma and whole blood treatment and plasma substitution using a mixture of albumin and pentastarch. The French Registry for PE is the largest such database which, along with the Canadian Registry for therapeutic hemapheresis, allows both retrospective and prospective studies.

Digoxin poisoning and anuric acute renal failure: efficiency of the treatment associating digoxin-specific antibodies (Fab) and plasma exchanges.

Digoxin-specific antibodies (Fab) are currently the treatment of choice for digoxin intoxication. These fragments bind to digoxin, leading to Fab-digoxin complexes, and promote the release of receptor-bound digoxin. These complexes are renally excreted. In the case of anuria, they could be dissociated and lead to renewed intoxication. In this case plasma exchanges are proposed. We report the case of an anuric patient with digoxin intoxication, treated with a Fab injection, followed by a plasma exchange 16 hours later, a second Fab injection was given followed by two plasma exchanges, 38 and 86 hours later. The disappearance of cardiac abnormalities showed the efficiency of the Fab, the drop in serum digoxin concentration and the high digoxin concentration in the exchanged plasma indicate effective elimination. The association of Fab and plasma exchanges could be proposed in the case of digoxin intoxication in the anuric patient.

[Autoimmune myasthenia: recent physiopathological data]. / Myasthénie autoimmune: données physiopathologiques récentes.

AUTOIMMUNE DISEASE: Myasthenia gravis is a one of the rare autoimmune diseases with a well-defined antigen. Autoantibodies directed against the muscular acetylcholine receptor (AChR) play a key role, blocking the acetylchoroquine binding site and provoking accelerated receptor degradation; complement destroys the post-synaptic membrane. Disease severity is correlated with extent of AChR loss. THYMUS: Involvement of the thymus is suggested by the beneficial effect of thymectomy and by histological and functional anomalies (modified cellular composition, abnormally activated lymphocytes, sensitivization of certain lymphocytes to AChR). "ANTIBODY NEGATIVE" DISEASE: The lack of anti-AChR antibodies detectable at immunoprecipitation, evidences the complexity of myastenia gravis pathogenesis. These "antibody-negative" forms are distinct from seropositive forms which have a high frequency of pure occular involvement and from infantile forms where the thymus regresses. "Antibody-negative" myastenia gravis might be mediated by antibodies directed against other endplate tardets. CLINICAL DIVERSITY: Our understanding of mechanisms responsible for the diversity of the clinical expression highlight the role of the AChR polymophism (with and adult and fetal expression). GENETIC PREDISPOSITION: Several factors involved in disease pathogenesis have been identified, including genetic factors: the HLA system, AChR alpha chain gene polymorphism, and immunoglobulin and T-cell antigen-receptor gene polymorphism.

[Respective indications of plasma exchange and high-dose immunoglobulins in polyradiculoneuritis and myasthenia gravis]. / Indications respectives des échanges plasmatiques et de fortes doses d'immunoglobulines dans les polyradiculonévrites et la myasthénie.

The main purpose of plasma exchange is to remove toxic substances. The mechanisms involved appear to be complex. The primary aim of immunoglobulins is to compensate for immunodeficiency, but when given intravenously at high doses, immunoglobulins can also have unexpected immunomodulation effects. Routine therapeutic use of these methods raises the problem of cost and potential morbidity. Two therapeutic trials have demonstrated that plasma exchange in Guillain-Barré syndrome improves outcome when given early. In chronic polyradiculonevritis, plasma exchange and intravenous immunoglobulins have been shown to be equally effective although plasma exchange would give less satisfactory results in patients with polyradiculonevritis and monoclonal IgG. The effect of intravenous immunoglobulins is being evaluated. Plasma exchange has become the gold standard for acute crisis of myasthenia gravis. Recent results suggest that intravenous immunoglobulins could be equally effective in these diseases. Though useful therapeutic tools, the respective indications and optimal doses for these methods remains to be defined.

Behavioral changes in fasting emperor penguins: evidence for a "refeeding signal" linked to a metabolic shift.

This study examines the relationships between metabolic status and behavior in spontaneously fasting birds in the context of long-term regulation of body mass and feeding. Locomotor activity, escape behavior, display songs, body mass, and metabolic and endocrine status of captive male emperor penguins were recorded during a breeding fast. We also examined whether body mass at the end of the fast affected further survival. The major part of the fast (phase II) was characterized by the maintenance of a very low level of locomotor activity, with almost no attempt to escape, by an almost constant rate of body mass loss, and by steady plasma levels of uric acid, beta-hydroxybutyrate, and corticosterone. This indicates behavioral and metabolic adjustments directed toward sparing energy and body protein. Below a body mass of approximately 24 kg (phase III), spontaneous locomotor activity and attempts to escape increased by up to 8- and 15-fold, respectively, and display songs were resumed. This probably reflected an increase in the drive to refeed. Simultaneously, daily body mass loss and plasma levels of uric acid and corticosterone increased, whereas plasma levels of beta-hydroxybutyrate decreased. Some experimental birds were seen again in following years. These findings suggest that at a threshold of body mass, a metabolic and endocrine shift, possibly related to a limited availability of fat stores, acts as a "refeeding signal" that improves the survival of penguins to fasting.

Brain and spinal cord MR imaging in a case of acute disseminated encephalomyelitis.

We describe a case of acute disseminated encephalomyelitis following varicella infection presenting as transverse myelitis. Magnetic resonance imaging revealed diffuse cord swelling and signal increase without gadolinium enhancement and several silent brain lesions, all of which completely resolved at follow-up.

Apheresis registry in France: indications, techniques, and complications. French Registry Study Group.

The French Registry for Plasma Exchange (PE) was set up in 1985. For 13 years it has allowed for the analysis of the techniques used, along with the indications and complications. After a decrease in the number of participating centers due to the heaviness of the data collection mode, the telematic network created in 1991 led to a new increase in participants from 26 in 1990 to 69 in 1998. Follow-up shows a slight fall in activity since some protocols ended, while the neurological pathologies remain the most frequent indicators. The important modifications observed over the years are the increase of the centrifugation technique, the development of plasma treatment, and the plasma substitution by an association of albumin-pentastarch. The French Registry for plasma exchange is the largest data base dealing with therapeutic hemapheresis. The registry set-up through the internet is the first step toward an international data base.

Autoimmune diseases in families of French patients with multiple sclerosis.

Multiple sclerosis (MS) is associated with autoimmune disorders (AIDs) in individual patients, and limited data suggest a possible familial association of MS and AIDs; however, no systematic study has been conducted on the occurrence of AIDs in the families of MS patients. Using a standardized interview focused on AIDs, we obtained the family histories of 357 consecutive patients from our MS clinic. Adequate information was obtained on 1971 first-degree relatives. Fifty-five patients (15.4%) had first-degree relatives with MS (n=22, 6.2%) another AID (n = 30, 8.4%), or both (n = 3, 0.8%). In 16 families (4.5%), at least 3 first-degree relatives had MS or another AID. MS, Grave's disease, rheumatoid arthritis, vitiligo, type 1 insulin-dependent diabetes mellitus, and uveitis, were the most common AIDs in these families. Such multiplex families (families with MS plus AID) are appropriate for identifying susceptibility genes that may be common to MS and other AIDs.