Biomedical subjects

Eric Wodey

Publications and source records attributed to Eric Wodey.

9 recordsLinked to original sources

PubMed2006

An evaluation of a polyamine-deficient diet for the treatment of inflammatory pain.

Polyamines are thought to be involved in the regulation of numerous metabolic and electrophysiological processes in the nervous system. In this study we evaluated the effect of a synthetic polyamine-deficient diet on pain in a carrageenan (Car)-induced inflammatory rat model. Inflammation was induced with a unilateral subcutaneous injection of Car in a plantar hindpaw in rats fed without (control group) or with (deficiency group) a polyamine-deficient diet. Ipsilateral and contralateral hyperalgesia was evaluated using the Randall-Sellito pressure test. Heart rate changes were also recorded under general anesthesia. Then, the effects of a bupivacaine sciatic nerve block and subcutaneous injection of naloxone or ketamine were evaluated for Car-induced hyperalgesia. Data were analyzed using analysis of variance followed by unpaired Student's t-test (significance P < 0.05). Before Car injection, no significant difference was observed in response to mechanical stimuli between the control and the deficiency groups (n = 114 in pooled data). Car injection induced significant ipsilateral and contralateral hyperalgesia in the control groups, whereas a significant analgesic effect appeared in the deficient groups on both the ipsilateral and contralateral hindpaws. This analgesic effect was confirmed by the electrocardiogram recording that showed a significant increase in heart rate in the control group after Car injection compared with the deficiency group that showed a decrease in heart rate under general anesthesia. Bupivacaine sciatic nerve block had no significant effect on hypoalgesia phenomena induced by polyamine deficiency. Naloxone administration had no effect in the control group but reversed the analgesic effect in the deficiency group. Ketamine administration induced a significant analgesic effect in the control group and partly reversed the analgesic effect in the deficiency group. In conclusion, a synthetic polyamine-deficient diet had a significant general analgesic effect on Car-induced mechanical hyperalgesia. The mechanism of analgesic action remains to be elucidated.

Analgesia↗

PubMed2005

Premedication in children: hypnosis versus midazolam.

BACKGROUND: The main objectives of premedication in children are to facilitate the separation from the parents, to reduce preoperative anxiety, to smooth the induction of anesthesia and to lower the risk of postoperative behavioral disorders. The most common technique is sedative premedication with midazolam. Hypnosis enables a state of relaxation to be achieved and has never been evaluated as a premedication technique. The aim of the present study was to evaluate the efficacy of hypnosis on anxiety and perioperative behavioral disorders versus midazolam. METHODS: Fifty children from 2 to 11 years of age were randomized into two groups: group H received hypnosis as premedication; group M were given 0.5 mg x kg(-1) midazolam orally, 30 min before surgery. Preoperative anxiety was evaluated using the Modified Yale Preoperative Anxiety Scale (mYPAS) score when arriving in the department (T1), when entering the operating room (T2), and when fitting the facemask (T3). Postoperative behavioral disorders were evaluated using the Posthospitalization Behavioral Questionnaire (PHBQ) at days 1, 7 and 14. RESULTS: The two groups showed no significant difference preoperatively with the PHBQ: (M) 21 (17-25) vs (H) 20 (8-25) and mYPAS score: (M) 28 (23-75) vs (H) 23 (23-78). The number of anxious children was less during induction of anesthesia in the hypnosis group (T3: 39% vs 68%) (P < 0.05). Postoperatively, hypnosis reduced the frequency of behavior disorders approximately by half on day 1 (30% vs 62%) and day 7 (26% vs 59%). CONCLUSIONS: Hypnosis seems effective as premedication in children scheduled for surgery. It alleviates preoperative anxiety, especially during induction of anesthesia and reduces behavioral disorders during the first postoperative week.

Abdomen↗

PubMed2004

Congenital diaphragmatic hernia: prenatal diagnosis permits immediate intensive care with high survival rate in isolated cases. A population-based study.

OBJECTIVES: To estimate the prognosis of prenatally diagnosed isolated congenital diaphragmatic hernia (PDICDH) treated with 'immediate planned care' (IPC) between 1999 and 2003 in Eastern Brittany. METHODS: The prognosis of PDICDH was compared with the prognosis of the other live-born CDH, either prenatally undiagnosed or not having had IPC. IPC consisted in prenatal lung maturation with corticosteroids, elective caesarean section at 37 weeks, immediate intubation, surfactant, high- frequency ventilation or oscillation, nitric oxide, intravenous prostacyclin, anaesthesia and haemodynamic support. Surgical repair was performed in the NICU 34 h after birth. RESULTS: The incidence of CDH was 0.8 per thousand with a prenatal diagnosis rate of 27/30 (90%), leading to a termination of pregnancy in nine cases. Ten CDH were associated with other malformations. IPC in PDICDH was performed in 12 cases. The survival rate of PDICDH with IPC was 11/12 versus 1/9 in CDH with no IPC or no prenatal diagnosis (p < 0.01). Logistic regression analysis showed that IPC was determinant for survival (p < 0.01). CONCLUSION: Prenatal diagnosis of isolated CDH treated with immediate planned care is associated with a high survival rate. This suggests that prenatal diagnosis associated with specifically adapted postnatal procedure may improve the prognosis of isolated CDH.

Adrenal Cortex Hormones↗

PubMed2003

The relationship between expired concentration of sevoflurane and sympathovagal tone in children.

UNLABELLED: In children, sevoflurane depresses parasympathetic tone during induction more than halothane. The effects of sevoflurane on parasympathetic activity could explain the difference in heart rate (HR) changes described between infants and children. In this study, we sought to determine the relationship between the end-tidal concentration of sevoflurane and sympathetic and parasympathetic tone in children by spectral analysis of RR intervals. Thirty-three children, ASA physical status I, who required elective surgery were studied. In 10 children (Group A), recordings were performed while gradually decreasing the inspired sevoflurane concentration from 8% to the beginning of clinical awakening. In 23 other children (Group B), recordings were performed while children were awake and at a steady-state of 1 and 2 minimum alveolar anesthetic concentration of sevoflurane. A time-varying autoregressive modeling of the interpolated RR sequences was performed, and spectral density in low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.55 Hz) bands was calculated. In Group A, HR slowing paralleled the decrease in expired sevoflurane concentration. Conversely, the decrease in expired concentration of sevoflurane led to an increase in systolic blood pressure (SBP), HF, LF, and LF/HF. The increase in LF/HF preceded the increase in HF. In Group B, the baseline HF power spectrum and normalized values HFnu (HFnu = HF/LF + HF) were significantly increased in children older than 3 yr. Changes in HR induced by sevoflurane were negatively correlated with baseline HF and HFnu (R(2) = 0.6; P < 0.001). These results demonstrate that withdrawal of parasympathetic tone is the main determinant for the change in HR induced by sevoflurane. IMPLICATIONS: The effects of sevoflurane on parasympathetic activity could explain the difference in heart-rate changes described between infants and children during induction. This study describes the changes in heart rate and its variability induced by sevoflurane in children and shows that these changes are related to parasympathetic tone before the induction of anesthesia.

Anesthesia Recovery Period↗

PubMed2002

Perinatal management and outcome of prenatally diagnosed congenital diaphragmatic hernia: a 1995-2000 series in Rennes University Hospital.

OBJECTIVES: To assess the prognosis of prenatally diagnosed congenital diaphragmatic hernia (CDH) during the years 1995-2000 in order to improve prenatal counselling. METHODS: Retrospective study of all 31 cases of women with prenatally diagnosed CDH. RESULTS: Nine pregnancies (29%) were terminated and two fetuses (6%) were stillborn. Ten fetuses (32%) had associated anomalies (four Fryns' syndrome) and four (13%) had underlying chromosomal anomalies. Twenty pregnancies were continued. Seven babies died before surgery either immediately in the delivery room (five between 1 and 45 min), or during the 'stabilisation period' (two babies, 7 and 21 h). Three babies presented with trisomy 18, Fryns' syndrome or transposition of the great arteries with microdeletion 22q11. Thirteen babies had the defect repaired (median 18 h, range 4-72 h) and 12 survived. Mechanical ventilation was required for a median of 12 days. One survivor has cerebral palsy. CONCLUSION: Of 31 prenatally diagnosed CDH cases 38% are alive, of 20 ongoing pregnancies 60% are alive, and of 13 babies who underwent surgery 92% are alive. No baby with associated malformations survived. These numbers need to be known by each member of the counselling team in order to give parents adequate information to make their decision.

Adult↗

PubMed2002

Extrapolation of cardiac index from analysis of the left ventricular outflow velocities in children: implication of the relationship between aortic size and body surface area.

BACKGROUND: It has recently been reported in critically ill patients that a linear relationship exists between cardiac index (CI) measured with thermodilution and mean aortic blood flow velocity (MAFV). This hypothesis can be validated mathematically only if the aortic area (AA index) indexed to body surface area (BSA) remains constant and if the relationship between aortic diameter (PhiAo) and BSA is nonlinear. However, several other equations have described the relationship between BSA and, respectively, PhiAo and aortic area (AA) in children. The aim of this study was to determine if the relationships calculated between BSA and aortic size in children (without left ventricular outflow tract abnormality) could validate the hypothesis that MAFV and CI are well linked linearly, leading to its use to determine CI. METHODS: Two hundred and thirty-two measurements performed in 126 children and infants were retrospectively analysed. PhiAo was measured in the long axis view at the annulus using two-dimensional mode echocardiography with a 5-MHz transducer. Various linear and nonlinear relationships between BSA and, respectively, PhiAo, PhiAoindex, AA and AAindex were determined based on a nonlinear regression method with a model as follows: y=a(xc) + b. The comparisons between regressions were conducted based on the estimation error. RESULTS: The relationships between PhiAo and BSA appeared nonlinear and was well described by: PhiAo=2.96(BSA1/4) - 1.31 with a non-zero y-intercept and PhiAo=1.64(BSA1/2) with a zero y-intercept. In contrast, the relationships between AA and BSA were linear. The AAindex was not linked to BSA and can be considered as constant. The coefficient a of the equation appeared similar to those obtained mathematically with the relationship previously described between MAFV and CI. CONCLUSIONS: The hypothesis that CI can be extrapolated to the measurement of MAFV appears valid as regards the relationships calculated between aortic size and BSA in children without left ventricular outflow tract abnormality.

Adolescent↗

PubMed2002

Monitoring approaches in general anesthesia: a survey.

The aim of this article is to give an overview of recent developments in the field of general anesthesia monitoring. We measure different physiological signals related to the functioning of several nervous systems. Using statistical or signal processing methods, monitors are derived and correlated to the dosage of anesthetic agents and to the status of the patient. Comparisons among existing monitors show that there is no one universal monitor applicable to all general anesthesia--each has its own characteristics and might be useful in particular clinical situations. Modeling of the underlying physiological mechanisms of the anesthesia may help for better understanding the interactions between anesthetic agents and nervous systems. Physiological-model-based general anesthesia monitoring and control can then be considered and optimized for each patient.

Adolescent↗

PubMed2001

Impedance cardiographic waveforms in children: Involvement in left ventricular ejection time determination during anesthesia.

OBJECTIVE: The physiologic basis of the impedance cardiographic (ICG) signal is still a matter of debate. An accurate determination of left ventricular ejection time (LVET) is needed to calculate stroke volume. In children, several shapes of the ICG signal are observed during anesthesia or in critical care. The aim of this study was to determine the relationship between the shape of the ICG signal and various morphologic and hemodynamic determinants obtained with Doppler echocardiography to highlight the effect of the various shapes in the accuracy of LVET determination. DESIGN: Prospective study. SETTING: Pediatric surgery in a university hospital. PATIENTS: 103 children, ASA physical status I or II. INTERVENTIONS: General anesthesia for elective surgery. Measurements: Electrocardiography, ICG, and Doppler echocardiography were recorded simultaneously. Classic hemodynamic variables, such as heart rate, LVET, stroke volume, or systemic vascular resistance, were measured or calculated. A mathematical model of the ICG signal was used to determine the shape of the ICG signal and its potential relationship to various morphologic and hemodynamic determinants. The ICG signal shape was then modeled with the normalized amplitudes (NHA) and phase (NHP) of the three harmonics of the fundamental signal. Analysis was performed with a multiple correspondence analysis. RESULTS: ICG method LVET did not significantly correlate with LVET determined with Doppler or with heart rate. NHA and NHP of the ICG signal were not significantly related to LVET determined with Doppler or to stroke volume. NHA were linked to heart rate and the relative length of the cardiac diastolic period. CONCLUSION: The absence of relationship between LVET determined with Doppler and the main variables defining the shape of the ICG signal highlight the relative limit of stroke volume determination with ICG method. The involvement of the arterial compliance in the ICG signal shape can be discussed in regard to the links between NHA and both heart rate and the relative length of the cardiac diastolic period, respectively.

Journal Article↗

PubMedDate not supplied

Comparison of heart rate response to an epinephrine test dose and painful stimulus in children during sevoflurane anesthesia: heart rate variability and beat-to-beat analysis.

BACKGROUND AND OBJECTIVES: During regional anesthesia, various stimuli leading to an adrenergic response can occur. However, simulation of an epidural test dose by using intravenous administration of epinephrine (EPI) has always been compared with an intravenous saline infusion as the control. The aim of this study was to evaluate the possibility of distinguishing in children the effect on HR by an intravascular epinephrine infusion and a painful stimulus, using heart rate variability (HRV) and beat-to-beat analysis of HR. METHODS: Thirty American Society of Anesthesiologists physical status P I children who required elective surgery were studied. At 1 minimum alveolar concentration (MAC) of sevoflurane, electrocardiogram was recorded continuously. Systolic blood pressure (SBP) was measured every minute. Measurements were performed after an intravenous administration of 0.5 microg/kg of epinephrine and during a small skin surgical incision (SI). Time-varying auto-regressive modeling of the interpolated RR sequences was performed for estimating power spectrum (msec(2)). The HF bands were defined by (0.15-0.4 Hz). RESULTS: Median (range) age and weight of all children were 3.5 (1-10) years and 16 (9-30) kg. EPI produced a lower increase in HR than did SI. SBP increased significantly more than did after SI. T-wave amplitude increased significantly after EPI but not after SI. Sixty seconds after the first change in HR, a secondary decrease (in comparison to control value) can be detected with EPI in contrast to SI. HF spectral power increased significantly after EPI administration but decreased after SI. The sensitivity, specificity, and positive and negative predictive value were respectively for DeltaHR >10 beats per minuteof 56%, 26%, 43%, and 38%; for DeltaSBP >15 mm Hg of 60%, 86%, 81%, and 67%; and for DeltaT-wave amplitude >25% of 86%, 73%, 76%, and 84%. Using detection of the secondary decrease of HR, 60 seconds after the first change in HR, sensitivity, specificity, and positive and a negative predictive value were respectively 96%, 100%, 100%, and 96%. CONCLUSIONS: Detection of the secondary HR decrease, 60 seconds after the first change in HR, allows us to distinguish the effects of a painful stimulus from those related to the epinephrine test dose at 1 MAC of sevoflurane. This secondary HR decrease induced by epinephrine appears primarily because of a compensatory increase in parasympathetic tone.

Adrenergic Agonists↗