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Biomedical subjects

M Chauvin

Publications and source records attributed to M Chauvin.

At least 37 records · Page 2Linked to original sources
PubMed2004

[The implantable automatic defibrillator].

Technical advances in the design of implantable automatic defibrillators have been constant since the introduction of these devices in the mid 80s. The most obvious advance is the miniaturisation of the devices from which all components have benefited. The capacity of the batteries has improved inversely proportionally to their size, even if the longevity has not always lived up to expectations. The volumic energy of the condensers has improved and their technology also, and their size has decreased. Condensers are still usually made by the electrolytic/aluminium method but tantalum technology is bound to become more generalised because it presents so many advantages. Above all, the circuitry has benefited from the progress of micro-electronics, associating miniaturisation with an increase in more and more complex functions...but requiring more electrical current. Of these functions, algorithms to detect arrhythmias has reduced the number of inappropriate shocks but do not yet have excellent specificity either in single or in dual chamber sensing. Defibrillators incorporating a multisite anti-bradycardiac function are more and more popular because of the close relationship between cardiac failure and sudden death.

Algorithms↗
PubMed2003

Long term effects of oral sustained release morphine on neuropsychological performance in patients with chronic non-cancer pain.

Morphine is increasingly used in patients with chronic non-cancer pain, but a major concern associated with chronic use relates to possible cognitive side-effects. The aim of this long-term prospective study was to evaluate the cognitive impact of oral sustained release morphine in patients with non-cancer pain. A battery of neuropsychological tests to explore attention, psychomotor speed and memory was administered. The effects of morphine on pain, quality of life, mood, subjective memory impairment and side-effects were also investigated. Evaluations were performed at baseline in patients free from opioids and then after 3, 6 and 12 months. Twenty-eight patients were included: 18 received oral sustained morphine (range 40-140 mg/day), ten patients stopped morphine prematurely because of side-effects or insufficient pain relief and were followed as a control group. There was no impairment of any neuropsychological variable over time in the morphine treated patients in comparison with the control group. Two measures of information processing speed - the Stroop interference score and the digit symbol test were improved at 6 and 12 months and there were significant correlations with the pain relief and improvement of mood. Self-reported memory impairment improved notably in responders to morphine. Morphine induced persisting effects on pain, and to a lesser extent on quality of life and mood. The visual analog scale score for side-effects increased at 12 months and essentially consisted of gastrointestinal disorders. This study demonstrates that 12 months treatment with oral morphine does not disrupt cognitive functioning in patients with chronic non-cancer pain and instead results in moderate improvement of some aspects of cognitive functioning, as a consequence of the pain relief and concomitant improvement of well-being and mood.

Administration, Oral↗
PubMed2003

[Laboratory testing measurement of FIO2 delivered by Boussignac CPAP system with an input of 100% oxygen].

INTRODUCTION: CPAP (Continuous Positive Airway Pressure) is one of the treatments of the cardiogenic acute pulmonary edema (cAPE). Among the out-of-hospital used devices, Boussignac CPAP (Vygon) shows a good technical usability, but no analysis of delivered FIO2 is available. OBJECTIVE: To measure the FIO2 delivered to patient, using Boussignac CPAP with an input of 100 vol % oxygen. Type of study. - Measurement in a laboratory testing. MATERIAL AND METHOD: Measurement of delivered FIO2 in a three parameters environment: expiratory positive airway pressure (EPAP), respiratory rate (RR) and required oxygen flow (ROF). Laboratory test: 100 vol % oxygen input, with a ball-type flow regulator for oxygen 0-30 l x min(-1) (Mediline), Boussignac CPAP valve with manometer (Vygon), Michigan test lung, ventilator César (Taema), oxygen analysis (Servomex) with paramagnetic sensor, with a response time < 10 s, pneumotachographe (Fleisch v 2). RESULTS: Under 10 cmH2O EPAP, the required oxygen flow is < or = 30 l x min(-1). Measured FIO2 ranges from 70 to 100 vol %, for a volume per minute < or = 15 l x min(-1) except for a EPAP at 2.5 cmH2O with a rate = 10 c min(-1) and a tidal volume (VT) at 1500 ml where the measured FIO2 is 60 vol %. For a volume per minute > 15 l x min(-1) and < 20 l x min(-1), measured FIO2 ranges from 59 to 83 vol % depending on the variations of RR and VT. CONCLUSION: Boussignac CPAP with 100 vol % oxygen input, delivers high levels of FIO2, especially for volume per minute values usually met in cAPE. The needed oxygen flow is lower than what is usually required by other CPAP flow generators using the venturi effect that may be used in out-of-hospital medical care.

Manometry↗
PubMed2003

[In-hospital cardiac arrest resuscitation: medical and paramedical theory skill assessment in an university hospital].

OBJECTIVES: Theory knowledge and attitude assessment about in-hospital cardiac arrest (CA) basic life support by hospital staff. METHODS: We tested medical and paramedical working staff in a 450 beds university hospital with anonymous questionnaire based on training for basic life support. Questions were about presence of a formation before, clinical signs reached in front of unconscious patient, attitude in front of cardiac-arrest, practical experience with basic life support and ward emergency trolley. RESULTS: Five hundred and seventy one on 996 people answered to handed out questionnaires (57%): 158 from medical staff (Med group) and 413 from nurses "Pmed". Seventy one percent people from "Med" group and 64% from "Pmed" received one time at least training about cardiac-arrest. Front of unconscious patient, no spontaneous breath was reached explicitly by 55% people from Med group and 19% from "Pmed" group and central pulse was reached explicitly by 70% people from "Med" group and 18% from "Pmed" group. Front of CA, 50% people from "Med" group released airway, 75% began ventilation and 86%, External Heart Compression (EHC) and 42% called for rescue. There were respectively 29, 47, 64 and 60% people from "Pmed" group. Eighty-one percent people from "Med" group thought they knew to do ventilation and 82% did it one time at least. Eighty-eight thought they knew to do EHC and 85% did it one time at least. They were respectively 67, 76, 73 and 78% people from Pmed group. Sixty-four per cent of Med group people know that there is emergency trolley in there department versus 89% for "Pmed" group. CONCLUSION: This study showed that theoretical knowledge of hospital staff about cardiac arrest diagnostic and management are insufficient from the point of view of national and international guidelines. Analysis is difficult because of weak response number and knowledge people overestimation.

Allied Health Personnel↗
PubMed2003

Disposable laryngoscope blades do not interfere with ease of intubation in scheduled general anaesthesia patients.

BACKGROUND AND OBJECTIVE: Intubation of the trachea has been a risky cross-contamination procedure over the past decade because no perfect decontamination procedures exist. Infectious agents found on laryngoscopic devices have the potential for devastating spread of the human immunodeficiency virus, hepatitis viruses B and C and transmissible non-conventional agents. The purpose of this prospective observational study was to assess the quality of endotracheal intubation with disposable laryngoscope blades, under normal intubating conditions. METHODS: Anaesthetists were asked to complete daily questionnaires regarding the difficulty of intubation experienced using the Vital View disposable laryngoscope blade (Vital Signs Inc, Totowa, NC, USA). The choice of the type of blade (conventional or disposable blade) for the first attempt at intubation depended only on the operating room assignment. Glottic visualization during laryngoscopy was assessed by the modified Cormack and Lehane classification. Difficult tracheal intubation was evaluated by the intubation difficulty scale (> 5, procedure involving moderate to major difficulty). RESULTS: The anaesthetic staff recorded 219 intubations. One hundred-and-nineteen of first attempts at laryngoscopy were with disposable blades (DB group) and another 100 with conventional blades (CB group). There were no significant differences between the two groups for Cormack and Lehane score 3, for intubation difficulty scale scores > 5 and for intubation difficulty scale score 0. There were 12 blade changes before successful intubation. CONCLUSIONS: In routine use, the Vital View disposable laryngoscope blade appears to be an efficient device because it does not modify the ease of endotracheal intubation in most cases. Nonetheless, it may be advisable to maintain conventional laryngoscopes in reserve for difficult intubations.

Anesthesia, General↗
PubMed2003

Effect of postoperative skin-surface warming on oxygen consumption and the shivering threshold.

Cutaneous warming is reportedly an effective treatment for shivering during epidural and after general anaesthesia. We quantified the efficacy of cutaneous warming as a treatment for shivering. Unwarmed surgical patients (final intra-operative core temperatures approximately 35 degrees C) were randomly assigned to be covered with a blanket (n = 9) or full-body forced-air cover (n = 9). Shivering was evaluated clinically and by oxygen consumption. Forced-air heating increased mean-skin temperature (mean (SD) 35.7 degrees C (0.4) vs. 33.2 degrees C (0.8); p < 0.0001) and lowered core temperature at the shivering threshold (35.7 degrees C (0.2) vs. 36.4 degrees C(0.2); p < 0.0001). Active warming improved thermal comfort and significantly reduced oxygen consumption from 9.7 (4.4) ml x min(-1) x kg(-1) to 5.6 (1.9) ml x min(-1) x kg(-1) (p = 0.038). However, the duration of shivering was similar in the unwarmed (37 min (11)) and active warming (36 min (10)) groups. Core temperature contributed about four times as much as skin temperature to control of shivering. Cutaneous warming improved thermal comfort and reduced metabolic stress in postoperative patients, but did not quickly obliterate shivering.

Adolescent↗
PubMed2003

Protective effects of vitamin C on endothelium damage and platelet activation during myocardial infarction in patients with sustained generation of circulating microparticles.

During myocardial infarction (MI), high levels of circulating procoagulant microparticles (MP) shed from endothelial cells and platelets diffuse prothrombotic and proinflammatory potentials crucial for the coronary prognosis. In addition to conventional treatments, we evaluated whether vitamin C treatment could modify circulating levels of procoagulant MP. Upon admission, 61 patients with MI were prospectively randomized for immediate additional vitamin C treatment. Circulating MP were quantified by functional prothrombinase assay before and after 5 days of vitamin C administration (1 g day-1). The cellular origin of MP was also assessed. In vitamin C-treated patients, the reduction in platelet-derived MP was 10% higher (P = 0.01). In patients with diabetes mellitus, dyslipidemia or more than two cardiovascular risk factors, vitamin C decreased endothelial and platelet-derived MP levels by approximately 70% and 13%, respectively. This early effect on circulating platelet and endothelial-derived MP, testifies to the importance of oxidative stress during MI. Vitamin C could prove beneficial for the outcome of patients at higher thrombotic risk.

Acute Disease↗
PubMed2003

Influence of peroperative opioid on postoperative pain after major abdominal surgery: sufentanil TCI versus remifentanil TCI. A randomized, controlled study.

BACKGROUND: Sufentanil and remifentanil are characterized by two different pharmacokinetic profiles. The aim of this study was to compare the effects of sufentanil and remifentanil administered using target-controlled infusion (TCI) on recovery and postoperative analgesia after major abdominal surgery. METHODS: Thirty adult patients scheduled for open colorectal surgery were included in a prospective, randomized study. Sufentanil TCI (sufentanil group) or remifentanil TCI (remifentanil group) was administered during surgery. In the remifentanil group, 30 min before the anticipated end of surgery, morphine 0.15 mg x kg(-1) was administered i.v. In the sufentanil group, an effect-site concentration of 0.25 ng x ml(-1) was targeted at extubation. In both groups, postoperative pain was controlled by titration of i.v. morphine and then patient-controlled analgesia with morphine. RESULTS: The extubation time was similar in the two groups (mean (SD) 13 (6) and 14 (6) min in the sufentanil and remifentanil groups respectively). Visual analogue scale scores were significantly greater during the first 2 h after tracheal extubation in the remifentanil group than in the sufentanil group. The time to first analgesic request in the postanaesthesia care unit was significantly longer in the sufentanil group than in the remifentanil group (55 (64) (range 2-240) vs 11 (7) (1-29) min; P<0.001). The cumulative morphine dose for titration was significantly greater in the remifentanil group (P<0.01). The cumulative morphine dose used during titration and patient-controlled analgesia was significantly greater in the remifentanil group 4, 12 and 24 h after extubation (P<0.05). CONCLUSION: TCI sufentanil (0.25 ng ml(-1) effect-site concentration at extubation) is more effective than the intraoperative combination of remifentanil TCI infusion with morphine bolus (0.15 mg x kg(-1)) for postoperative pain relief after major abdominal surgery and does not compromise extubation and recovery.

Aged↗
PubMed2003

Randomized prospective study of the analgesic effect of nefopam after orthopaedic surgery.

BACKGROUND: Balanced postoperative analgesia combines non-narcotic drugs and opioids. We organized a large study to evaluate nefopam analgesia and tolerance in combination with morphine for patient-controlled analgesia (PCA) after orthopaedic surgery. METHODS: Two hundred and one patients scheduled to undergo hip arthroplasty were included in this multicentre (n=24), double-blind, randomized study comparing nefopam (20 mg every 4 h for 24 h) with placebo, the first dose being infused peroperatively. The primary outcome measure was the cumulative morphine dose received postoperatively by PCA over 24 h. Secondary outcome measures were the amount of morphine received as a loading dose in the postanaesthesia care unit (PACU) and during the 24-h observation period, and pain assessments using a visual analogue scale (VAS) and a verbal pain scale (VPS), patient's satisfaction with analgesia and treatment tolerance. RESULTS: The two groups were comparable with respect to their characteristics and preoperative pain assessment. PCA-administered morphine over 24 h was significantly less for the nefopam group than the control group (21.2 (15.3) and 27.3 (19.2) mg respectively; P=0.02). This morphine-sparing effect was greater (35.1%) for patients with severe preoperative pain (VAS>30/100). For the entire study period (loading dose and PCA), morphine use was less for the nefopam group (34.5 (19.6) vs 42.7 (23.6) mg; P=0.01). Pain VAS at PACU arrival and during the whole PACU period was significantly lower for the nefopam than for the placebo group (P=0.002 and 0.04 respectively). Patient satisfaction was similar for the nefopam and placebo groups. CONCLUSION: In combination with PCA morphine, nefopam gives significant morphine-sparing with lower immediate postoperative pain scores without major side-effects. This analgesic effect seems to be particularly notable for patients with intense preoperative pain.

Adult↗
PubMed2003

State of the art of pain treatment following ambulatory surgery.

BACKGROUND AND OBJECTIVE: The growth of ambulatory surgical procedures is limited by severe postoperative pain. After particularly painful operative procedures, moderate-to-severe pain is estimated to occur in approximately 30% of patients. Inadequate analgesia may delay or prevent discharge, or result in readmission. Severe postoperative pain also causes extreme discomfort and can prevent sleep, thus contributing to postoperative fatigue. Moreover, postoperative pain limits mobility at home and delays the return to normal activities. The development of effective analgesia for postoperative pain is therefore a priority of modern medicine. RESULTS: The pain experienced during the first days spent at home is related to the magnitude of pain experienced at the hospital. Aggressive analgesic treatment at the hospital is therefore of key importance. This includes pre- and intraoperative administration of analgesics to reduce the pain in the immediate postoperative period, and the use of multimodal, balanced analgesia throughout recovery. Clinical studies have shown that patients who receive both pre- and postoperative analgesia experience greater pain relief than those who receive postoperative analgesia alone. Multimodal analgesia, including the use of anaesthetics, is increasingly important in attempts to avoid the prescription of single strong opioids postoperatively. The use of a non-steroidal anti-inflammatory drug (NSAID) plus an anaesthetic perioperatively has also been shown to be more effective than anaesthetic alone. CONCLUSIONS: Postoperative pain is the most commonly reported complication of ambulatory surgery. Although the number of analgesic techniques seems more limited in outpatient than in inpatient surgery, the combination of analgesic regimens in a multimodal approach may improve postoperative analgesia and functional outcome after ambulatory surgery. The combination of acetaminophen plus tramadol is a useful formulation to prescribe if acetaminophen or NSAIDs alone are ineffective.

Ambulatory Surgical Procedures↗
PubMed2002

Effects of IV morphine in central pain: a randomized placebo-controlled study.

OBJECTIVE: To investigate the effects of IV morphine on central pain syndromes through quantitative sensory testing and to assess the long-term benefit of oral morphine. METHODS: After an initial open titration phase aiming to determine the maximal tolerated dosage of IV morphine, the efficacy of morphine infusion (9-30 mg; mean dosage, 16 mg) was assessed in a double-blind, placebo-controlled and crossover fashion in 15 patients with poststroke- (6 patients) or spinal cord injury- (9 patients) related pain. All of the patients subsequently received sustained oral morphine. RESULTS: Morphine significantly reduced the intensity of brush-induced allodynia but had no effect on other evoked pains (i.e., static mechanical and thermal allodynia/hyperalgesia). The effects of morphine on ongoing pain were not significantly different from those of the placebo, but 7 patients (46%) responded to morphine. There was a correlation between the effects of morphine on spontaneous pain and the decrease of the responses to suprathreshold thermal stimuli on the nonpainful contralateral side, suggesting that these effects were related to the general antinociceptive activity of the drug. The effects of IV morphine were correlated with those of oral morphine at 1 month, but only 3 patients (20%) were still taking morphine after 1 year. CONCLUSIONS: IV morphine induces analgesic effects on some components of central neuropathic pain syndromes, but only a minority of patients may benefit from long-term opioid treatment.

Adult↗
PubMed2002

Esmolol prevents movement and attenuates the BIS response to orotracheal intubation.

BACKGROUND: Beta-adrenergic agonists enhance behavioural and electroencephalographic arousal reactions. We explored whether adding esmolol, a short-acting beta(1)-adrenoceptor antagonist, to propofol anaesthesia modified the bispectral index (BIS) during induction of anaesthesia and orotracheal intubation. METHODS: Fifty patients were randomly allocated, in a double-blind fashion, to receive esmolol 1 mg kg(-1) followed by 250 micro g kg(-1) min(-1) or saline (control). Esmolol or saline was started 6 min after a target-controlled infusion (TCI) of propofol (effect-site concentration 4 micro g ml(-1)). After loss of consciousness, and before administration of vecuronium 0.1 mg kg(-1), a tourniquet was applied to one arm and inflated to 150 mm Hg greater than systolic pressure. Eleven minutes after the TCI began, the trachea was intubated; gross movement within the first min after orotracheal intubation was recorded. BIS was recorded at 10-s intervals. Mean arterial pressure (MAP) and heart rate were measured non-invasively every min. RESULTS: There were no intergroup differences in BIS, heart rate or MAP before laryngoscopy. BIS increased significantly after orotracheal intubation (compared with the pre-laryngoscopy values) in the control group only, with a maximum increase of 40 (SD 18)% vs 8 (11)% in the esmolol group (P<0.01). Maximum changes in heart rate [45 (19)% vs 23 (14)%] and MAP [62 (24)% vs 45 (23)%] with orotracheal intubation were also significantly greater in the control group than in the esmolol group. More patients in the control than in the esmolol group moved after orotracheal intubation (23 vs 12, P<0.01). CONCLUSION: Esmolol not only attenuated haemodynamic and somatic responses to laryngoscopy and orotracheal intubation, but also prevented BIS arousal reactions in patients anaesthetized with propofol.

Adjuvants, Anesthesia↗
PubMed2001

Effects of intravenous and intrathecal sufentanil on a C-fibre reflex elicited by a wide range of stimulus intensities in the rat.

A C-fibre reflex elicited by electrical stimulation within the territory of the sural nerve was recorded from the ipsilateral biceps femoris muscle in anaesthetised, intact rats, and in anaesthetised rats whose brains had been transected at the level of the obex. The temporal evolution of the response was studied by recording recruitment curves built with stimulus intensities from 0 to 10 times threshold. Both i.v. and i.t. sufentanil resulted in dose-dependent depressions of the reflex. Increasing the stimulus intensity from 1.5 to 10 times threshold resulted in an increase in the ED(50) from 0.58 (0.40-0.86) to 2.40 (1.87-3.31) microgram/kg for i.v. sufentanil and from 0.64 (0.46-0.79) to 1.63 (1.29-3.31) microgram/kg for i.t. sufentanil. With increasing stimulus intensity, the dose-response curves showed a progressive shift to the right, but this shift was only slight with the highest intensity stimuli. The ratios for the ED(50)s for i.v. to i.t. sufentanil were near 1. Following i.v. administration, sufentanil also facilitated the C-fibre reflex and produced tonic inter-stimulus discharges. They disappeared after the i.v. injection of naloxone. In the obex-transected rats, the depressive effect of sufentanil increased, while the facilitations and tonic inter-stimulus discharges disappeared. These findings suggest that the analgesic effects of i.v. ant i.t. sufentanil are similar, probably because sufentanil is highly soluble in lipids. Sufentanil-induced facilitations relate to supraspinal actions on motor controls and/or on the descending control of nociceptive transmission.

Analgesics, Opioid↗
PubMed2001

Local and remote effects of hypnotic suggestions of analgesia.

The present study was designed to further characterize hypnotic analgesia and particularly to examine whether the effects are due to a selective alteration of pain perception and are organized somatotopically. Thirty-two healthy volunteers participated in this study. Thermal detection thresholds for warmth and cool stimuli and heat pain thresholds were measured at both the upper and lower left limbs by means of a thermotest. Measurements were performed before, during and after a hypnotic session during which the subjects were administered a French adaptation of the Stanford Hypnotic Susceptibility Scale and then standardized suggestions of analgesia limited to the left foot. Heat pain thresholds were significantly increased at both the lower and upper limbs. Changes at the foot were positively correlated with the hypnotic susceptibility score, while, unexpectedly, changes at the hand were negatively correlated with the susceptibility score. Mean detection thresholds for warmth and cool stimuli were also altered at both the lower and upper limbs during hypnosis, but these modifications were correlated neither with susceptibility nor with the changes in heat pain threshold. These results indicate that hypnotic suggestions can selectively and somatotopically alter pain sensation in highly susceptible subjects. It is also suggested, however, that suggestions of analgesia can induce selective alterations of pain perception in poorly susceptible subjects, although these effects did not appear to be localized 'appropriately'.

Adult↗
PubMed2001

[Quality assurance program for blood products in an out-of-hospital medical care unit].

INTRODUCTION: Transfusion of blood products is part of out-of-hospital medical activity. Despite rare use of transfusion and difficult environment, the rules of transfusion must be respected: follow up to detect blood products, security, and patient's information before and after transfusion, follow up of infectious and immunological consequences. However, the current law and usable documents were not conceived for out-of-hospital emergency care. OBJECTIVE: To improve follow-up of blood product transfusion in out-of-hospital medical care (Smur). STUDY DESIGN: Quality assurance programme. MATERIAL AND METHODS: a) Initial evaluation with a retrospective analysis based on the medical chart of patient for whom transfusion has been performed; b) corrective measures were proposed with creation of a specific document concerning transfusion and guidelines for blood product delivery in the out-of-hospital emergency care; c) evaluation of the impact of these correctives measures. RESULTS: Less than one per cent of patients treated by our Smur needed transfusion, mainly during interhospital transfer. Patients were in a life-threatening situation in 50% of cases. Follow-up improved after implementation of the programme from 25 to 83% of transfused patient (p < 0.001). Despite limitation due to the small number of patients, other parameters also improved. CONCLUSION: The use of specific guidelines and document improves the follow-up of transfusion in out-of-hospital medical care.

Adolescent↗
PubMed2001

Reduced isoflurane consumption with bispectral index monitoring.

BACKGROUND: Bispectral index (BIS) monitoring has been found to decrease the requirements for propofol, sevoflurane and desflurane and to improve recovery. We wanted to assess the effect of BIS monitoring on intraoperative isoflurane utilisation, and the early recovery profile. METHODS: Eighty patients undergoing various surgical procedures were studied. In the first phase of the study, patients were anaesthetised without the use of BIS, the anaesthetists being blinded to the BIS readings, and isoflurane being administered according to standard clinical practice (control group). In a second phase, isoflurane was titrated to maintain a BIS value between 40 and 60 during surgery, and then 60-70 during 15 min prior to the end of surgery (BIS group). Isoflurane consumption was measured. Recovery times and the time to achieve a modified Aldrete score of 9 were recorded. RESULTS: Despite similar mean BIS levels during maintenance of anaesthesia, the cumulative time spent with BIS values between 40 and 60 during maintenance of anaesthesia was significantly longer in the BIS group as compared with the control group (P<0.001). The isoflurane usage in the BIS group was 12-25% lower than in the control group (P<0.05). The time to awakening and extubation were comparable in the two groups. Although the patients were less sedated (P<0.01) during the three postoperative hours in the BIS (vs. control) group, no significant differences were observed in the time to obtain an Aldrete score of 9. CONCLUSION: The addition of BIS to standard monitoring decreases isoflurane consumption. However, we found only a small advantage in using BIS with respect to recovery from isoflurane anaesthesia.

Adult↗