Evaluation of least significant changes of pulse contour analysis-derived parameters

BACKGROUND: Many maneuvers assessing fluid responsiveness (minifluid challenge, lung recruitment maneuver, end-expiratory occlusion test, passive leg raising) are considered as positive when small variations in cardiac index, stroke volume index, stroke volume variation or pulse pressure variation occur. Pulse contour analysis allows continuous and real-time cardiac index, stroke volume, stroke volume variation and pulse pressure variation estimations. To use these maneuvers with pulse contour analysis, the knowledge of the minimal change that needs to be measured by a device to recognize a real change (least significant change) has to be studied. The aim of this study was to evaluate the least significant change of cardiac index, stroke volume index, stroke volume variation and pulse pressure variation obtained using pulse contour analysis (ProAQT®, Pulsion Medical System, Germany). METHODS: In this observational study, we included 50 mechanically ventilated patients undergoing neurosurgery in the operating room. Cardiac index, stroke volume index, pulse pressure variation and stroke volume variation obtained using ProAQT® (Pulsion Medical System, Germany) were recorded every 12 s during 15-min steady-state periods. Least significant changes were calculated every minute. RESULTS: Least significant changes statistically differed over time for cardiac index, stroke volume index, pulse pressure variation and stroke volume variation (p \textless 0.001). Least significant changes ranged from 1.3 to 0.7% for cardiac index, from 1.3 to 0.8% for stroke volume index, from 10 to 4.9% for pulse pressure variation and from 10.8 to 4.3% for stroke volume variation. CONCLUSION: To conclude, the present study suggests that pulse contour analysis is able to detect rapid and small changes in cardiac index and stroke volume index, but the interpretation of rapid and small changes of pulse pressure variation and stroke volume variation must be done with caution

Changes in dynamic arterial elastance induced by volume expansion and vasopressor in the operating room: a prospective bicentre study

BACKGROUND: Dynamic arterial elastance (Eadyn), defined as the ratio between pulse pressure variations and stroke volume variations, has been proposed to assess functional arterial load. We evaluated the evolution of Eadyn during volume expansion and the effects of neosynephrine infusion in hypotensive and preload-responsive patients. METHODS: In this prospective bicentre study, we included 56 mechanically ventilated patients in the operating room. Each patient had volume expansion and neosynephrine infusion. Stroke volume and stroke volume variations were obtained using esophageal Doppler, and pulse pressure variations were measured through the arterial line. Pressure response to volume expansion was defined as an increase in mean arterial pressure (MAP) ≥ 10%. RESULTS: Twenty-one patients were pressure responders to volume expansion. Volume expansion induced a decrease in Eadyn (from 0.69 [0.58-0.85] to 0.59 [0.42-0.77]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after volume expansion were related to age, history of arterial hypertension, net arterial compliance and effective arterial elastance. Eadyn value before volume expansion \textgreater 0.65 predicted a MAP increase ≥ 10% with a sensitivity of 76% (95% CI 53-92%) and a specificity of 60% (95% CI 42-76%). Neosynephrine infusion induced a decrease in Eadyn (from 0.67 [0.48-0.80] to 0.54 [0.37-0.68]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after neosynephrine infusion were only related to heart rate. CONCLUSION: Eadyn is a potential sensitive marker of arterial tone changes following vasopressor infusion

End-expiratory occlusion maneuver to predict fluid responsiveness in the intensive care unit : an echocardiographic study

Background In mechanically ventilated patients, an increase in cardiac index during an end-expiratory-occlusion test predicts fluid responsiveness. To identify this rapid increase in cardiac index, continuous and instantaneous cardiac index monitoring is necessary, decreasing its feasibility at the bedside. Our study was designed to investigate whether changes in velocity time integral and in peak velocity obtained using transthoracic echocardiography during an end-expiratory-occlusion maneuver could predict fluid responsiveness. Methods This single-center, prospective study included 50 mechanically ventilated critically ill patients. Velocity time integral and peak velocity were assessed using transthoracic echocardiography before and at the end of a 12-sec end-expiratory-occlusion maneuver. A third set of measurements was performed after volume expansion (500 mL of saline 0.9% given over 15 minutes). Patients were considered as responders if cardiac output increased by 15% or more after volume expansion. Results Twenty-eight patients were responders. At baseline, heart rate, mean arterial pressure, cardiac output, velocity time integral and peak velocity were similar between responders and non-responders. End-expiratory-occlusion maneuver induced a significant increase in velocity time integral both in responders and non-responders, and a significant increase in peak velocity only in responders. A 9% increase in velocity time integral induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 89% (95% CI 72% to 98%) and specificity of 95% (95% CI 77% to 100%). An 8.5% increase in peak velocity induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 64% (95% CI 44% to 81%) and specificity of 77% (95% CI 55% to 92%). The area under the receiver operating curve generated for changes in velocity time integral was significantly higher than the one generated for changes in peak velocity (0.96 ± 0.03 versus 0.70 ± 0.07, respectively, P = 0.0004 for both). The gray zone ranged between 6 and 10% (20% of the patients) for changes in velocity time integral and between 1 and 13% (62% of the patients) for changes in peak velocity. Conclusions In mechanically ventilated and sedated patients in the neuro Intensive Care Unit, changes in velocity time integral during a 12-sec end-expiratory-occlusion maneuver were able to predict fluid responsiveness and perform better than changes in peak velocity

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Concentrations optimales de propofol et de remifentanil pour l'intubation orotrachéale sans curare

BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Effets de la bupivacaïne sur le métabolisme énergétique du coeur de rat hypoxique chronique

BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Nouvelles recommandations d’experts pour l’intubation difficile chez l’adulteI

International audienceUn groupe d’experts réunis par la Société française d’anesthésie et de réanimation (Sfar) a réactualisé la Conférence d’experts sur l’intubation de 2006. Cette réactualisation concerne essentiellement : la préoxygénation, le positionnement des vidéolaryngoscopes, la profondeur de l’anesthésie et de la myorelaxation. On y retrouve également de nouveaux algorithmes tenant compte des différentes situations et un rappel des bonnes pratiques d’extubation

L infiltration cicatricielle continue de lévobupivacaïne chez les souris porteuses de tumeurs cutanées modifie les récidives tumorales

Introduction: Les anesthésiques locaux (AL) interagissent avec des enzymes clefs du métabolisme énergétique cellulaire et pourraient ainsi modifier les récidives locales des tumeurs. Nous posons l hypothèse que la spécificité de cette action repose sur la bioénergétique remaniée des tumeurs. Des études expérimentales ont révélé un effet antiprolifératif des AL sur plusieurs types de cellules cancéreuses sans toutefois expliquer le mécanisme moléculaire impliqué. L objectif de notre étude était d évaluer cette hypothèse d un effet anti-récidive de la lévobupivacaïne (L) sur des tumeurs cutanées de souris (squamous cutaneous carcinoma, SCC). Matériel et Méthodes: Des souris SKH-1 hairless immunocompétentes ont été exposées aux UVB jusqu à obtention d au moins une tumeur cutanée type SCC. Les souris ont été randomisées en trois groupes: Groupe L, Groupe SSI, Groupe Chirurgie. Dans chaque groupe, les souris ont bénéficié :i) d un comptage et d une mesure du volume tumoral total (VTT) des tumeurs cutanées, ii) d une exérèse chirurgicale des tumeurs, iii) d une infiltration locale au niveau des berges des incisions chirurgicales, iv) de la mise en place d un cathéter multiperforé raccordé à une pompe osmotique permettant une infiltration cicatricielle continue pendant 7 jours. Dans le groupe L, l infiltration était réalisée avec de la lévobupivacaïne. Du sérum salé isotonique remplaçait la lévobupivacaine dans le groupe SSI. Les pompes et cathéters d infiltration ont été enlevés sous sédation par isoflurane après 7 jours d infiltration. Les souris ont été surveillées durant 28 jours après la chirurgie. Les récidives des tumeurs cutanées ont été comptées et le VTT mesuré tous les 7 jours, en aveugle du traitement (J7, J14, J21, et J28). Les résultats sont exprimés en médiane [25% 75%] et la significativité était évaluée par le test de Mann Whitney, avec p<0,05 considéré significatif. Résultats: 29 souris ont été incluses : 11 dans le groupe L, 11 dans le groupe SSI, 6 dans le groupe Chirurgie. A J0, le nombre de tumeurs et le VTT ne sont pas significativement différents entre les groupes. A J28, le VTT est significativement inférieur dans le groupe L (39.3 [13,1-53,1] mm3) par rapport au groupe SSI (80,6 [42,0-190,7] mm3) (p=0,023), de même qu à J21 (p=0.009). Le VTT à J28 n est pas différents entre le groupe C et le groupe SSI (p=0.928). Il n y a pas de différence significative entre les groupes concernant le nombre de tumeurs. Discussion: L infiltration cicatricielle continue prolongée durant 7 jours de lévobupivacaïne réduit la taille des récidives tumorales cutanées post-opératoires chez la souris SKH-1. Des études cliniques sont nécessaires pour confirmer ces résultats.Introduction: Local anaesthetics (LA) interact with the cellular energetic metabolism enzymes and could modify the local recurrences of tumours. We formulate the hypothesis that the specificity of this action lies on the rearranged bioenergetics of tumours. Experimental studies have showed an anti-proliferative activity of LA on different cancer cell types, but without explanations of the mechanism involved. The purpose of the study was to assess the hypothesis of an anti-recurrence effect of levobupivacaine on mice squamous cutaneous carcinoma (SCC). Methods: SKH-1 hairless immunocompetent mice have been exposed to UVB until obtaining at least one SCC tumour. Mice have been randomised in three groups: L (levobupivacaine), ISS (isotonic saline solution), S (surgery). Each group get i) a count and a measurement of tumour total volume (TTV) of cutaneous tumours, ii) a surgical excision of the tumours, iii) a local infiltration on the surgical scars, iv) an implementation of a multiperforated catheter supply by an osmotic pump for a continuous scar infiltration during 7 days. In the L group, this infiltration was done with levobupivacaine. Isotonic saline solution replaced levobupivacaine in the ISS group. Pumps and catheters were taken out under sedation after seven days of infiltration. Mice have been observed during 28 days after surgery. Cutaneous tumours recurrences have been counted and the TTV was calculated every seven days, blind of treatment (D7, D14, D21, D28). Results are denominated in median (25-75%) and significance was assess by Mann-Whitney test, with a p<0,05 threshold.: Results: 29 mice have been inclusive: 11 in the L group, 11 in the ISS group, 6 in the S group. At D0, the number of tumors and the TTV were not significantly different between groups. At D28, TTV was smaller in the L group (39.3 [13,1-53,1] mm3) than in the ISS group (80,6 [42,0-190,7] mm3) (p=0,023), likewise at D21 (p=0,009). The D28 TTV was not different beetween C group and SSI group (p=0,928). There is no difference beetween groups regarding the number of tumors. Discussion: Continuous scar infiltration during 7 days with levobupivacaine reduces the cutaneous tumours recurrences after surgery in SKH-1 mice. Clinical studies are necessary to confirm this resultBORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Prévention des lésions d'ischémie-reperfusion par le Sevoflurane au cours des greffes rénales. Essai clinique randomisé SEVORIEN

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF