[Gas embolism and flexible Ecoflac type bag]. / Embolie gazeuse et poche souple de type Ecoflac.

Gas embolism at the end of infusion is a well known hazard, that should have disappeared with the use of flexible bags. However, some cases have been reported after pressure infusion. This experimental study evaluates the risk for gas embolism with Ecoflac type flexible bags. These bags are safe under normal pressure infusion conditions with a pneumatic sleeve, because of their texture and pliability; indeed, only minimal air volumes could be expelled, without any risk even in children. However, to be on the safe side, the manufacturer recommends to expel any residual air before pressure administration. This recommendation applies to any bag containing residual air, and since many people are not aware of this, it is rarely put into practice.

[French and foreign recommendations for the practice of anesthesia-intensive care]. / Recommandations françaises et étrangères sur la pratique de l'anesthésie-réanimation.

UNLABELLED: This article reviews the development of STANDARDS, Recommendations and Guidelines for practice in anaesthesiology in France and other countries. The French society for anaesthesia and intensive care (Sfar) has published, since 1989, 11 basic STANDARDS: 1) Recommendations for the monitoring of patients during anaesthesia (June 1989, amended on January 1994) [APSF Newsletter, Summer 1990, page 22]; 2) Recommendations for postanaesthesia monitoring and care (September 1990); 3) Recommendations for preanaesthesia care (September 1991); 4) Recommendations for anaesthetic apparatus and checking before use (January 1994); 5) Recommendations for the equipment of anaesthesia working places (January 1995); 6) Recommendations for the tasks of the nurse anaesthetist (January 1995); 7) Recommendations for hygiene standards in anaesthesia practice (December 1997); 8) Recommendations for outpatient anaesthesia (September 1990); 9) Recommendations for the practice of obstetrical analgesia (September 1992); 10) Recommendations for interhospital physician-accompanied transfers (December 1992); 11) Recommendations for intrahospital physician-accompanied transfers (February 1994). Additionally the Sfar produced or coproduced 9 Experts' conferences, 15 Consensus conferences and 5 Guidelines for clinical practice.

[Intraoperative ventilatory obstruction by twisting of a reusable coiled expiratory breathing tube]. / Obstruction ventilatoire peropératoire par torsion d'un tuyau spiralé expiratoire réutilisable.

A case of intraoperative subtotal obstruction of a reusable coiled expiratory breathing tube is reported. Partial occlusion by twisting was made possible by detachment of the coil from the external face of the tube after multiple reprocessings with high drying temperatures. A technique for tube checking before reuse is described.

[The "impact factor" of anesthesia and intensive care journals]. / Le "facteur d'impact" des revues d'anesthésie-réanimation.

The "impact factor" (IF) of scientific journals is defined as the number of citations obtained over a one-year period of articles published during the two previous years in a journal, divided by the number of articles published in that journal during the preceding two years. The IF, initially devised as an indicator of the quality of a journal, is at present mainly considered as an indicator of the quality of an article contained in that journal. However the IF of a journal is not equivalent to the actual impact of an article. Therefore the IF is not an accurate tool for assessment of the scientific quality of the author of that article. The IFs of journals published in English are significantly higher than the IFs of those in another language, mainly as English is the language used for international communication and as English speaking authors rarely cite articles published in another language. The IF of the journal of the French society for anaesthesiology and intensive care, the Annales françaises d'anesthésie et de réanimation (Afar), is about seven times below the IF of Anesthesiology, which has the highest IF in the category "Anesthesiology". From 1992 to 1998, the relative impact value of the Afar has increased by 429%. However the absolute value remains low.

[Accessory anesthetic breathing systems: verification before use]. / Circuits anesthésiques accessoires: vérification avant utilisation.

Accessory or ancillary anaesthesia breathing systems can be defined as all those connected to the fresh gas outlet of the anaesthetic apparatus and used instead of the circle system associated with the ventilator, which is the main circuit. They include: the Mapleson systems, the systems with a nonrebreathing valve and the disposable systems with a carbon dioxide absorber. They can be a cause of major accidents when not checked before and monitored during use. This technical note describes techniques of preanaesthetic checking and monitoring during anaesthesia.

[Anesthetic equipment: fresh gas delivery systems. II. Electronic systems]. / Appareil d'anesthésie: systèmes d'alimentation en gaz frais. II. Systèmes électroniques.

OBJECTIVES: To analyse the design, functioning, benefits and drawbacks of electronic fresh gas delivery units (FGDUs) included in anaesthetic machines marketed in France in 1999. DATA SOURCES: Articles were obtained from a Medline review (1980-1999; search terms: anaesthetic machine, flowmeter, vaporizer), textbooks and personal files; specific data were also provided by manufacturers. STUDY SELECTION AND DATA EXTRACTION: The articles were analysed in considering the differences between mechanical and electronic FGDUs. DATA SYNTHESIS: Four anaesthetic machines out of 11 are equipped with electronic FGDUs. In comparison to mechanical units, they include the following benefits: wide range of accurate gas flow, especially in the low flow range, with analog and digital display; intermittent delivery of each gas, which is essential for automated gas delivery and quantitative anaesthesia or target controlled (FET vapor) inhalational anaesthesia; facilitated oxygen ratio control; possibility to print the gas and vapor flows on the automated anaesthetic record; interruption of gas flow when the main switch of the machine is set to off; and absence of risk for retropollution. Three FGDUs out of four are adapted for gas delivery to an accessory (ancillary) anaesthetic circuit. However, only one of them delivers a gas flow up to 30 L.min-1. The specificity of the ADU AS/3 (Datex-Ohmeda) is the bypass vaporizer included in the FGDU with an exchangeable vaporizing chamber (cassette). The specificity of the Julian (Dräger) is the delivery of fresh gas limited to the expiratory phase during mechanical ventilation. The specificity of the the FGDU from Kion (Siemens) is the possibility to act as an open circuit ventilator, similar to a Servoventilator. The specificity of the PhysioFlex is an FGDU included in the circle circuit, each gas and liquid anaesthetic being directly injected into the circuit. Data from the French medical device surveillance commission indicate that the main failures occur in the power supply device and the microprocessor.

[Anesthesia equipment: fresh gas delivery systems. I. Mecanical systems with rotameters and calibrated vaporizers]. / Appareil d'anesthésie: systèmes d'alimentation en gaz frais. I. Systèmes mécaniques avec rotamètres et vaporisateurs calibrés.

OBJECTIVES: To analyse the design, performance, failures, the checking before use of mechanical fresh gas delivery units (FGDUs) equipped with bobbin or ball-flowmeters delivering a continuous gas flow and calibrated vaporizers, marketed in France in 1999. DATA SOURCES: Articles were obtained from a Medline review (1960-1999; search terms: anaesthetic machine, flowmeter, vaporizer), textbooks and personal files; specific data were provided by manufacturers. STUDY SELECTION AND DATA EXTRACTION: The articles were considered for performance data, benefits and drawbacks, and characteristics, as well as the risks carried by mechanical FGDUs. DATA SYNTHESIS: Seven anaesthetic machines out of 11 are equipped with mechanical FGDUs, including rotameters delivering a gas mixture up to 30 L.min-1, calibrated vaporizers and an O2-flush valve delivering at least 500 mL O2 per second (30 L.min-1). These units allow closed circuit anaesthesia. They carry a risk for barotrauma as three out of them can deliver at the gas outlet of the FGDUs a gas mixture at a pressure reaching 3.5 bars and four others at a pressure of 150-200 mmHg. They also carry a risk for hypoxia, either from a preferential leak of oxygen at the corresponding rotameter or the O2-flush valve, or from a leak of fresh gas mixture either in a vaporizer or the selectatec manifold. The vaporizers carry a risk for vapor delivery at a concentration differing notably from the value set on the concentration dial. Therefore their accuracy must be checked periodically and the FGDUs checked for a leak after the addition to or the removal of a vaporizer from the selectatec manifold. The optimal technique for leak detection is the negative pressure test.

Early assessment of transplanted liver function: lignocaine clearance test (MEGX).

The purpose of this study was to assess the value of lignocaine biotransformation into monoethylglycinexylidide (MEGX) and conventional liver function tests in the early post-operative period as an indicator of graft function and as a diagnostic tool for complications after hepatic transplantation. Monoethylglycinexylidide formation, plasma bilirubin, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), factor V index (FVI) and prothrombin time index (PTI) were measured in 71 patients undergoing 80 liver transplantations respectively at 12 (T1), 24 (T2), 48 (T3) and 72 h (T4) after liver graft revascularization. Patients were divided into two group according to the post-operative outcome. Patients with favourable outcome (n = 59) had significantly higher monoethylglycinexylidide synthesis, higher factor V index and prothrombin time index plasma concentrations, lower bilirubin, ASAT and ALAT plasma concentration (P < 0.0001 at T2 and T3) than those with complicated time course (n = 21). Monoethylglycinexylidide synthesis was the best discriminant of a favourable outcome, whereas bilirubin and ALAT concentrations were associated with complications (bilirubin for primary non function [PNF], ALAT for acute rejection). Thus, the combination of parameters at T2 was a very efficient predictor of primary non function, acute rejection and an uncomplicated time course.

[Anesthesia ventilators]. / Ventilateurs d'anesthésie.

OBJECTIVE: To review anaesthesia ventilators in current use in France by categories of ventilators. DATA SOURCES: References were obtained from computerized bibliographic search. (Medline), recent review articles, the library of the service and personal files. DATA SYNTHESIS: Anaesthesia ventilators can be allocated into three groups, depending on whether they readminister expired gases or not or allow both modalities. Contemporary ventilators provide either constant volume ventilation, or constant pressure ventilation, with or without a pressure plateau. Ventilators readministering expired gases after CO2 absorption, or closed circuit ventilators, are either of a double- or a single-circuit design. Double-circuit ventilators, or pneumatical bag or bellows squeezers, or bag-in-bottle or bellows-in-bottle (or box) ventilators, consist of a primary, or driving circuit (bottle or box) and a secondary or patient circuit (including a bag or a bellows or membrane chambers). Bellows-in-bottle ventilators have either standing bellows ascending at expiration, or hanging bellows, descending at expiration. Ascending bellows require a positive pressure of about 2 cmH2O throughout exhalation to allow the bellows to refill. The expired gas volume is a valuable indicator for leak and disconnection. Descending bellows generate a slight negative pressure during exhalation. In case of leak or disconnection they aspirate ambient air and cannot act therefore as an indicator for integrity of the circuit and the patient connection. Closed circuit ventilators with a single-circuit (patient circuit) include a insufflating device consisting either in a bellows or a cylinder with a piston, operated by a electric or pneumatic motor. As the hanging bellows of the double circuit ventilators, they generate a slight negative pressure during exhalation and aspirate ambient air in case of leak or disconnection. Ventilators not designed for the readministration of expired gases, or open circuit ventilators, are generally stand-alone mechanical ventilators modified to allow the administration of inhalational anaesthetic agents.

[Defective gas mixers, a cause of retro-pollution of medical gas distribution pipelines]. / Mélangeurs de gaz défectueux, cause de rétropollution du circuit de distribution des gaz médicaux.

A defective Air/O2 mixer of a ventilator located downstream of the gas outlets of two pipelines is a potential cause of retropollution. Retropollution of O2 with Air or vice versa carries a risk of either a) a hypoxic gas mixture delivery during anaesthesia, including O2-N2O administration, when the O2 pipeline supplies Air instead of O2, or b) a hyperoxic gas mixture delivery in the intensive therapy unit for neonates during administration of a O2-Air mixture, when the Air pipeline supplies O2 instead of Air. A defective O2/N2O flowmeter-mixer of an anaesthesia machine, with N2O flow control by O2 through a differential pressure manometer, can cause retropollution of O2 supply pipeline with N2O or vice versa. The prerequisite for retropollution is the association of three events: build-up of a pressure difference between the two gas lines; defective or absent back-flow check value in the circuit of the gas at a lower pressure; one of the following defects: a) the pressure equilibrating valves of the mixer cannot amend the pressure difference and allow a gas reflow at the gas mixture outlet; b) leak in the diaphragm of a pressure equilibrating valve; c) defective bypass supply valve. The optimal means for the recognition of a pipeline contamination by another gas is the O2 analyzer, especially in anaesthetic areas where the presence of N2O and Air carries the risk of a hypoxic gas mixture delivery. The mixer or flowmeter-mixer responsible for retropollution can be recognized in plunging successively the various quick couplers underwater into a glass, while the others remain connected to their outlets and the mixer set at a O2 concentration of 50 vol% or the flowmeters set at a similar flow. In case of retropollution, the gas reflow produces bubbles. It is recommended: a) in anaesthetic areas to set the O2 pressure at about 0.2 bar above that of Air and the latter at a pressure of about 0.2 bar above that of N2O; b) in intensive therapy units for neonates, to set the Air pressure at about 0.2 bar above that of O2; c) in all areas to disconnect from the gas outlets the devices equipped with a mixer or a flowmeter-mixer when not in use.

[Ventilators for anesthesia. Models available in France. Criteria for choice]. / Appareils d'anesthésie. Modèles disponibles en France. Critères de choix.

This update article discusses the criteria for the choice of an anaesthetic machine and provides a short analysis of the main components of the models commercialized in France in 1994. The following items are considered: the design of the machine, the fresh gas delivery system, the anaesthesia breathing system(s), the ventilator and the waste gas scavenging system, the monitors associated with the machine and other criteria such as facility of learning to run the machine and of its daily use, ease of "in-house" maintenance and quality of after-sales service, cost of the machine and of its use (driving gas, disposable equipment).

Predictive factors of hyperfibrinolytic activity during liver transplantation in cirrhotic patients.

Hyperfibrinolytic activity occurs frequently during liver transplantation in cirrhotic patients. In order to identify those patients at high risk for increased intraoperative blood loss before operation, we determined predictive indicators of hyperfibrinolysis. We studied 56 cirrhotic patients undergoing liver transplantation with the same anaesthetic procedure and transfusion regimen. The preoperative coagulation patterns of the 11 patients who experienced acute intraoperative hyperfibrinolytic activity were compared with those of the 45 patients who did not suffer this complication. Before surgery, patients with intraoperative hyperfibrinolysis had decreased prothrombin time (PT) and euglobulin lysis time (ELT), and increased thrombin time (TT) and fibrinogen degradation products (FDP), whereas alpha angle and maximum amplitude (MA) were reduced on thrombelastography. Stepwise multivariate analysis disclosed three components which were significantly linked with occurrence of hyperfibrinolysis: TT, FDP and MA. Their sensitivity, specificity, positive and negative predictive values demonstrated that patients with FDP > or = 48 mg litre-1 and MA < or = 35 mm before incision had 100% probability of developing hyperfibrinolytic activity during transplantation.

[Arguments for the addition of an oxygen reserve container to the anesthetic equipment]. / Arguments en faveur de l'équipement de l'appareil d'anesthésie d'une bouteille d'oxygène de secours.

In France, the presence of an emergency oxygen cylinder as part of every the anaesthetic machine is not made compulsory by an official regulation. This article provides arguments in favour of such a presence, as recommended by the French Society of Anaesthesia and Intensive care (SFAR).