Nicolas Franchitto

Peripheral chemoreflex activation contributes to sympathetic baroreflex impairment in chronic heart failure.

Background: Chemoreflex-mediated sympathetic activation contributes to both initiation and progression of chronic heart failure (CHF). Method: To study the direct role of increased peripheral chemosensitivity in reducing sympathetic baroreflex function in CHF patients, we compared sympathetic baroreflex function, assessed by the slope of the relationship between muscle sympathetic nerve activity (MSNA) and DBP, in CHF patients with augmented (nu200a=u200a18) and normal (nu200a=u200a20) peripheral chemosensitivity. Using a double-blind, randomized, vehicle-controlled study, we examined the effect of chemoreflex deactivation (by breathing 100% oxygen for 15u200amin) on sympathetic baroreflex function in CHF patients with elevated and with normal chemosensitivity. Results: Baseline MSNA was elevated (60.6u200a±u200a3.2 vs. 48.9u200a±u200a3.7u200abursts/min, Pu200a<u200a0.05) and sympathetic baroreflex function impaired (3.06u200a±u200a0.55 vs. 5.51u200a±u200a0.69u200a%bursts/mmHg, Pu200a<u200a0.05) in CHF patients with augmented peripheral chemosensitivity compared with controls. Administration of 100% oxygen led to a significant decrease in MSNA (from 60.5u200a±u200a3.2 to 52.6u200a±u200a3.2u200abursts/min, Pu200a<u200a0.001) and increase in sympathetic baroreflex (from 2.95u200a±u200a0.56 to 6.18u200a±u200a0.77, Pu200a<u200a0.001) in CHF patients with enhanced chemoreflex sensitivity. In contrast, neither room air nor 100% oxygen changed MSNA, hemodynamics or sympathetic baroreflex function in CHF patients with normal chemosensitivity. Conclusion: We report for the first time that increased peripheral chemoreflex sensitivity directly decreases sympathetic baroreflex function in CHF patients. This interaction contributes to sympathetic overactivity and blunted sympathetic baroreflex function of CHF patients and may explain how chemoreceptors contribute to the bad prognosis of CHF patients.

Acute copper sulphate poisoning: A case report and literature review

Voluntary copper poisoning is a rare mode of suicide. We report a case of copper sulphate poisoning in a patient presenting delusions with mystic demands for purification. The initial gastrointestinal symptoms were followed by intravascular haemolysis and renal failure. The course was favourable after symptomatic treatment and specific copper chelation therapy. However, the pathogenesis is not fully understood and with the present state of knowledge, no one treatment can be said to be superior to another. The authors discuss the various treatments of this rare poisoning through a review of the available literature.

Self-Intoxication with Baclofen in Alcohol-Dependent Patients with Co-existing Psychiatric Illness: An Emergency Department Case Series

AIMSnThe aim of the study was to describe the characteristics and management of alcohol-dependent patients with co-existing psychiatric illness seen after self-intoxication with oral baclofen in an emergency department (ED).nnnMETHODSnA retrospective review of medical records of such patients over a 12-month period from January 2012.nnnRESULTSnTwelve such patients were identified, median age 39.5 years. The median supposed ingested dose of baclofen was 340 mg (range 140-800 mg). Three patients who had co-ingested benzodiazepines had a decreased level of consciousness (Glasgow Coma Scale <8) and flumazenil had been given to reverse coma. Blood alcohol concentration, requested for all patients, was positive in three (ranging from 153 to 495 mg/100 ml). Gastric lavage was performed in two cases. All patients made a full recovery. They were discharged from the ED or intensive care unit after psychiatric assessment.nnnCONCLUSIONnBaclofen overdose affects the autonomic and central nervous system. Supportive care is symptom based. Care should be taken when prescribing baclofen with other central nervous system depressants and to patients with past attempted suicide.

Excessive sympathetic activation in heart failure with chronic renal failure: role of chemoreflex activation.

Objective Sympathetic activation contributes both to the initiation and progression of heart failure. The role of chronic renal failure (CRF) in determining sympathetic overactivity in chronic heart failure (CHF) patients is unknown. We tested the hypothesis that in CHF patients, CRF could lead to increase sympathetic activity through tonic activation of excitatory chemoreceptor afferents. Methods We conducted a double-blind, randomized, vehicle-controlled study to examine the effect of chemoreflex deactivation on muscle sympathetic nerve activity in CHF patients with or without CRF. We compared effect of breathing 100% oxygen for 15 min in 15 stable CHF patients with CRF and 15 control CHF patients matched for age, sex, blood pressure and BMI. Results The baseline muscle sympathetic nerve activity was significantly elevated in CHF patients with CRF as compared with simple CHF patients (61 ± 3 versus 42 ± 4 bursts/min; P < 0.01). Administration of 100% oxygen led to a significant decrease in muscle sympathetic nerve activity in CHF patients with CRF (from 61 ± 3 to 55 ± 4 bursts/min; P < 0.05). By contrast, neither 100% oxygen nor room air changed muscle sympathetic nerve activity or hemodynamics in patients with solely CHF. Conclusion Tonic activation of excitatory chemoreflex afferents contributes to increased efferent sympathetic activity to muscle circulation and to blood pressure control in CHF patients with CRF. These findings may have important implications for understanding how CRF contributes to the progression of CHF and increases morbidity and mortality in CHF patients.

Tonic Chemoreflex Activation Contributes to Increased Sympathetic Nerve Activity in Heart Failure–Related Anemia

Sympathetic activation contributes to both the initiation and progression of heart failure. The role of anemia in determining sympathetic overactivity in chronic heart failure (CHF) patients is unknown. We tested the hypothesis that, in CHF patients, anemia could lead to increased sympathetic activity through tonic activation of excitatory chemoreceptor afferents. We conducted a double-blind, randomized, vehicle-controlled study to examine the effect of chemoreflex deactivation on muscle sympathetic nerve activity in CHF patients with and without anemia. We compared the effect of breathing 100% oxygen for 15 minutes in 18 stable CHF patients with anemia and 18 control CHF patients matched for age, sex, blood pressure, and body mass index. Baseline muscle sympathetic nerve activity was significantly elevated in CHF patients with anemia compared with patients with CHF alone (56.0±3.2 versus 45.5±3.1 bursts per minute; P<0.0237). Administration of 100% oxygen led to a significant decrease in muscle sympathetic nerve activity in CHF patients with anemia (from 56.0±3.4 to 50.9±3.2 bursts per minute; P<0.0019). In contrast, neither room air nor 100% oxygen changed muscle sympathetic nerve activity or hemodynamics in patients with CHF alone. We report for the first time direct evidence of increased sympathetic nerve traffic in patients with CHF-related anemia. Sympathetic hyperactivity in patients with CHF and anemia is partially chemoreflex mediated and could explain how anemia contributes to the progression of CHF and increases morbidity and mortality in these patients.

Anesthetic regimen for cardiac function evaluation by echocardiography in mice: comparison between ketamine, etomidate and isoflurane versus conscious state

Mice with genetic alterations are used in heart research for the extrapolation of human diseases. Echocardiography is an essential tool for evaluating cardiac and hemodynamic functions in small animals. The purpose of this study was to compare the effect of different anesthetic regimens and the conscious state on the evaluation of cardiac function by echocardiography. Mice were examined in the conscious state after three days of training, and then for a 7u2009min period after a single intraperitoneal injection of ketamine at 100u2009mg/kg, etomidate at 10, 20 or 30u2009mg/kg, or after inhalation of isoflurane at 1.5% with or without a short period of induction with isoflurane 3%. Intra- and inter-observer variabilities were assessed. The operator’s comfort was also assessed. Heart rate, left ventricular end diastolic diameter, fraction shortening and cardiac output were measured using echocardiography. Ketamine at 5 and 7 min after induction and isoflurane at 3, 5 and 7 min after induction provided good anesthetic conditions and a quick awakening time, and did not influence cardiac performance, whereas the conscious state was associated with a non-physiological sympathetic activation and other anesthetic drugs induced a significant decrease in heart rate. Etomidate 10u2009mg/kg and 20u2009mg/kg were not enough to provide adequate anesthesia. Etomidate 30u2009mg/kg induced a good anesthetic condition but influenced cardiac performance and had a long awakening time. Our results indicate that ketamine and isoflurane with a short induction period are better anesthetic drugs than isoflurane without induction or etomidate for evaluating cardiac function in healthy mice.

Parental cannabis abuse and accidental intoxications in children: prevention by detecting neglectful situations and at-risk families.

Objectives Cannabis intoxication in toddlers is rare and mostly accidental. Our objectives were to focus on the characteristics and management of children under the age of 6 years who were admitted to our emergency department with cannabis poisoning reported as accidental by parents, and to point out the need to consider accidental cannabis ingestions as an indicator of neglect. Methods The medical records of children hospitalized for cannabis poisoning in a pediatric emergency department from January 2007 to November 2012 were retrospectively evaluated. Data collected included age, sex, drug ingested, source of drug, intentional versus accidental ingestion, pediatric intensive care unit or hospital admission, treatment and length of hospital stay, toxicology results, and rate of child protectives services referral. Results Twelve toddlers (4 boys and 8 girls; mean age, 16.6 months) were included. All had ingested cannabis. Their parents reported the ingestion. Seven children experienced drowsiness or hypotonia. Three children were given activated charcoal. Blood screening for cannabinoids, performed in 2 cases, was negative in both, and urine samples were positive in 7 children (70%). All children had favorable outcomes after being hospitalized from 2 to 48 hours. Nine children were referred to social services for further assessment before discharge. Conclusions Cannabis intoxication in children should be reported to child protection services with the aim of prevention, to detect situations of neglect and at-risk families. Legal action against the parents may be considered. Accidental intoxication and caring parents should be no exception to this rule.

Levosimedan improves hemodynamics functions without sympathetic activation in severe heart failure patients: direct evidence from sympathetic neural recording.

Abstract Levosimendan is a new inodilatory agent with calcium sensitizing activity. A major concern regarding the use of inotropic agent in heart failure is their effect on the sympathetic tone. This effect could explain increase in short term mortality with other inotropes. We aimed to assess the effect of levosimendan on sympathetic tone measured directly by microneurogra-phy. In a group of acute decompensated heart failure patients, we assessed cardiac performance by digital plethysmography measurement. Sympathetic tone was assessed through recording of muscle sympathetic nerve activity (MSNA) by micro-neurography. Recording were done blindly, for each patient after dobutamine perfusion was stopped (baseline) and 48 h after levosimendan infusion. Clinical, biological and morphological data were collected. We compared cardiac parameters and MSNA before and after administration of levosimendan. 13 patients were recruited (48 ± 3.6 years). Systolic blood pressure and rate pressure product (mmHg × Beat/min) decreased significantly after levosimendan infusion (P< 0.05). Cardiac output and stroke volume were significantly increased after levosimendan infusion (P< 0.05). A significant decrease of MSNA activity is observed after levosimendan infusion (P< 0.01). Levosimendan induced improvement of cardiac performance, associated with a decreased in MSNA. This study show for the first time that levosimendan has no direct detrimental effect on the sympathetic nervous system.

Medicolegal evaluation of aesthetic impairment: particularities of post-burn scars.

Burns are serious injuries with incidence decreasing with the increasing efficacy of prevention campaigns. Their cause may be non-intentional or criminal. Thanks to advances in burn management, mortality has declined; however, the sequelae are more severe. The medical expert must be familiar with this field in order to carry out precise clinical evaluation so that individual compensation may be determined by the judge. Aesthetic damage, which is purely a non-economic loss, is difficult to assess, as it is dependent on the subjective opinion of the medical expert. The principle of financial compensation for aesthetic impairment is an imperfect one, but it gives victims a satisfactory compensation to which they attach importance. Without detailing the various national compensation systems, we review the burn patients examination by the medical expert with particular attention to the specific characteristics of burn scars, their course and aesthetic impact.

Hyperglycemia is a risk factor for high-grade envenomations after European viper bites (Vipera spp.) in children

Abstract Context: Hyperglycemia has been described in severe scorpion envenomation, we wanted to analyze if it was applicable to viper bites in children. Aim: To describe clinical, biological, and therapeutic characteristics of 83 children bitten by European viper (Vipera spp.) and to confirm that hyperglycemia is a risk factor for high-grade envenomation. Material and methods: A retrospective study was conducted between 2001 and 2014 in the pediatric emergency department of a tertiary level children’s hospital. Collected data were: age and sex of children; day and time of admission; day, time and circumstances of the accident; snake identification; bite location; envenomation severity; presence of fang marks; prehospital care; laboratory abnormalities, use of specific immunotherapy, associated treatments; length of stay; hospital course. Results: Eighty-three children were included (62 boys, 21 girls). The mean age was 7.4u2009±u20093.9 years. Bites were most often located on the lower extremities (66%). The classification of envenomation was: 83% low grade (absent or minor envenomation) and 17% high grade (moderate to severe envenomation). All high-grade envenomations received specific immunotherapy (ViperfavTM, (Aventis Pasteur, MSD, Lyon, France). Being bitten on an upper extremity (odds ratio [OR] 51.1 95% class interval [CI] [6.1–424], pu2009<u20090.0001), during the afternoon (OR 13.4 95% CI [1.7–107.9], pu2009=u20090.015), feeling violent pain (OR 4.2 95% CI [1.1–16.5], pu2009=u20090.023), and high initial plasma glucose level (6.5u2009±u20091.7u2009mmol/L versus 5.0u2009±u20090.9u2009mmol/L, pu2009=u20090.027) were associated with a significant risk of high-grade envenomation. Conclusion: We have confirmed a potential link between initial hyperglycemia and the risk of progression to high-grade envenomation as well as its association with other published predictive factors.