Biomedical subjects
Publications and source records attributed to M Dubreuil.
The synthesis of investigations of three salmonellosis outbreaks which occured in France between 1998 and 2000 confirms the role of the consumption of minced beef and highlights the importance of prevention measures.
Bland-Altman analysis for comparison of two methods of clinical measurement is frequently used in scientific publications. This article is more appropriate than the conventional linear regression analysis. This paper gives an overview of the principles for the use of Bland-Altman analysis as well as the specific terminology attached to it. The Bland-Altman comparison analysis is mainly a tool for clinical interpretation. The bias and the agreement limits provide the variation of the values of the technique compared to the other. The difference between the two methods of measurement is plotted against the average obtained with each of the two techniques. Bland-Altman analysis can also be used to check the repeatability of a measurement technique within the same subject and to determine a repeatability coefficient. With an adaptation of the calculation of the agreement limits, the average of multiple measurements for each subject with two measurement techniques can be used for the Bland-Altman analysis.
UNLABELLED: In neurosurgery, estimation of PaCO2 from PETCO2 has been questioned. The aim of this study was to reevaluate the accuracy of PETCO2 in estimating PaCO2 during neurosurgical procedures lasting >3 h and to measure the effect of surgical positioning on arterial to end-tidal CO2 gradient (P[a-ET]CO2) over time. One hundred four neurosurgical patients classified into four groups (supine [SP], lateral [LT], prone [PR], sitting [ST]) were included in a prospective study. PaCO2, PETCO2, and P(a-ET)CO2 were measured after induction of anesthesia (T0), after positioning (T1), each following hour (T2, T3, T4), and at the end of the procedure after return to the SP position (T5). Data are expressed as the mean +/- SD, and statistical analysis used linear regression, the Bland-Altman method, and analysis of variance. The mean durations of positioning and surgery were 4.1+/-1 h and 3.7+/-1.3 h, respectively. We performed 624 simultaneous measurements of PaCO2 (33+/-5 mm Hg) and PETCO2 (27+/-4 mm Hg), leading to a mean P(a-ET)CO2 of 6+/-4 mm Hg. P(a-ET)CO2 of the LT group (7+/-3 mm Hg) was larger (compared with the SP, PR, and ST groups) because of a lower PETCO2 (26+/-4 mm Hg). Negative P(a-ET)CO2 (PETCO2 > PaCO2) occurred 22 times, only in the SP (n = 9) and ST groups (n = 13). Changes in opposite directions of PETCO2 and PaCO2 between two successive measurements were found in 26% of the cases. Correlation coefficients in the four groups (PaCO2 versus PETCO2) were not in good agreement (0.46 to 0.62; P < 0.001). The mean bias was between 5 and 7 mm Hg. The superior (13-15 mm Hg) and inferior (-5 to 0 mm Hg) limits of agreement were too large to expect PETCO2 to replace PaCO2. In conclusion, during neurosurgical procedures of >3 h, capnography should be performed with regular analysis of arterial blood gases for optimal ventilator adjustment. IMPLICATIONS: This study, which aimed to reevaluate the ability of PETCO2 to estimate PaCO2 during neurosurgical procedures according to surgical position, indicates that PETCO2 cannot replace PaCO2 for the following reasons: scattering of individual values; occurrence of negative arterial to end-tidal CO2 gradient (P[a-ET]CO2; PaCO2 and PETCO2 variations in opposite directions; large changes in P(a-ET)CO2 between two samples; and instability of P(a-ET)CO2 over time.
Fibreoptic intubation through the laryngeal mask airway is a recommended technique for the management of a restricted airway. We report the failure of this technique in a 20-month-old infant presenting with McKusick-Kaufman syndrome.
The aim of this clinical audit was to evaluate the home recovery and complications of 104 daycase anaesthetized children, as well as parent satisfaction. A questionnaire, explained at the time of preoperative visit, was given to parents at hospital discharge and returned by mail. Opioids were administered in 19% of the children whereas regional anaesthesia was performed in 28% of cases. In the recovery room, 8% of them suffered pain. At home, pain was the main problem (25%) and vomiting and agitation were found in 9% and 6% of the cases respectively. Parents reported anxiety in 45% of cases, and 14% called their general practitioner. Nevertheless, 94% were satisfied with the anaesthetic. A clinical audit is useful in detecting management deficiencies. Quality of home recovery may be improved by: wider use of perioperative analgesia, systematic prescription of take-home analgesia, designation of a hospital practitioner for advice, and closer collaboration with general practitioners.
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BACKGROUND: Hypoxia may occur in children undergoing upper digestive endoscopy under sedation. The purpose of this study was to compare the occurrence of desaturation during intravenous sedation with that which occurs during general anesthesia. METHODS: Thirty-six patients between 3 months and 6 years old underwent a diagnostic esophagogastroduodenoscopy under sedation (n = 18) or general anesthesia (n = 18). Oxygen pulse oximetry, heart rate, and mean arterial pressure were monitored throughout the procedure. At the end of the procedure, the operator gave the value of the endoscopy satisfaction score on a scale of I (very good conditions) to IV (impossible procedure). RESULTS: The minimum oxygen pulse oximetry value was significantly lower in the sedation group compared with that in the general anesthesia group (89 +/- 5 vs. 97 +/- 1; p < 0.001). In the general anesthesia group, the oxygen pulse oximetry level declined to less than 95% in only one child; but in the sedation group, it declined to less than 95% in 16 patients (5.5% vs. 89%). Nine patients had a profound desaturation in sedation group (oxygen pulse oximetry < 90%); no patients in the general anesthesia group had desaturation (50% vs. 0%). In the general anesthesia group, heart rate and mean arterial pressure remained stable during the whole procedure, whereas in the sedation group, heart rate and mean arterial pressure increased significantly during the procedure. The endoscopy satisfaction score was I in all 18 patients in the general anesthesia group, whereas in the sedation group, it was I in only 2 patients, II in 8 patients, and III in 10 patients. CONCLUSIONS: These results confirm that hypoxia during upper digestive endoscopy in patients under sedation is a frequent occurrence in children. When compared with sedation, general anesthesia is a safer technique that prevents hypoxia and allows the gastroenterologist to perform the endoscopy under better conditions.
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We report a case of total collapse of the upper pharyngeal airway in a slightly premature baby, resulting in a noisy breathing disorder. Primary immaturity of the central nervous system contributing to pharyngeal muscle hypotonia has been implicated in association with the increase in nasal pressure. The infant experienced complete resolution of symptoms a few weeks after the placement of a nasopharyngeal tube. This case report demonstrates the difficulty in diagnosis and management. The developmental spectrum and exploration are reviewed.
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Preoperative normovolaemic acute haemodilution (PNAH) is used to reduce major blood loss during elective surgery. Considerable attention has been paid to colloid osmotic pressure, index of diffusibility and intravascular half-life of the currently available substitutes, but there is little information on their rheological properties from in vivo studies. Forty patients undergoing elective aortic reconstruction were given 4% human albumin (HA), 3.5% dextran 40 (Dxt 40), 6% dextran 60 (Dxt 60), 6% hydroxyethylstarch 200 (HES) or modified fluid gelatin (Gel) during PNAH to produce a packed cell volume (PCV) of approximately 30%. Mean volumes of more than 1000 ml were infused. Blood samples were obtained before infusion, immediately after, and 1.5 h after the end of haemodilution. The following variables were measured: PCV, plasma viscosity, whole blood viscosity at measured and corrected PCV (0.45), and erythrocyte aggregation. Haemodynamic and metabolic variables were determined at the same time. The five substitutes had very different effects on red blood cell aggregation and low shear rate viscosity at corrected PCV. Red blood cell aggregation was reduced in the presence of HA, Dxt 40, but was increased moderately to markedly in the presence of the other substitutes in the following order: HES < Dxt 60 < Gel. The influence of the rheological conditions on tissue oxygenation was assessed by measuring the concentration of lactic acid; this was unchanged after PNAH with HA or Dxt 40, but was increased in the presence of HES, Dxt 60 or Gel.
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Expired CO2 analysis is an important area of anaesthetic monitoring. It ranges from ventilator connection to the estimation of alveolar dead space. In paediatric anaesthesia, end tidal CO2 measurement and analysis as well as PaCO2 estimation are subject to a rather large number of mistakes. Confrontation between the technical specificities of CO2 monitors and the anatomical and physiological distinctive characteristics of the paediatric patient is mainly responsible for the interpretation difficulties encountered. Nevertheless capnography remains fundamental for paediatric ventilation monitoring.
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In pediatric practice, complications due to the laryngeal mask airway (LMA) have been studied with size 2 LMA, but not with size 1 LMA. We, therefore, compared prospectively the complications induced by LMA size 1 and 2 in 141 children aged 21 days to 11 yr. Intraoperative and lowest SpO2 values after removal of LMA were recorded. The following complications were recorded: cough, laryngospasm, bronchospasm, apnea, and airway obstruction. In 14 patients in the size 1 LMA group and 26 patients in the size 2 LMA group, pharyngolaryngeal structures were checked with fiberoptic examination. The number of attempts, complications, intraoperative SpO2, and lowest SpO2 values were similar when using size 1 and size 2 LMA. Fiberoptic examination of size 1 LMA showed a high incidence of impinging of the epiglottis in the LMA bars without airway obstruction. In conclusion, there was no difference in the complication rate between the two pediatric sizes of LMA when used in pediatric patients.
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A microcomputer system was used to reconstruct, in the L5 dorsal root ganglion (DRG) of the rat, the three-dimensional arrangement of primary neurons which had been labelled by application of horseradish peroxidase (HRP) and fluoro-gold (FG) to various muscle nerves of the leg. Analysis of the data and animation of the reconstructed images with commercially available software were instrumental in identifying the preferential intraganglionic locations of the neurons innervating muscles such as the soleus (SOL), the gastrocnemius lateralis (GL), and medialis (GM), or parts of the GM. These locations appeared to be somewhat related to the position of the muscles in the posterior compartment of the leg. Additionally, the study provided quantitative estimates of muscle afferent neuronal populations, allowed a comparison of the labelling performances of HRP and FG, and finally indicated that few DRG neurons project to two different muscles.