[Field 4. Environmental safety practice in the intensive care unit. French-speaking Society of Intensive Care. French Society of Anesthesia and Resuscitation]. / Champ 4. Sécurisation du matériel en réanimation. SRLF. SFAR.

Medical devices are known to carry risks from design to scrap. Accident reports in ICU show that medical device account for only 20% of accidents. Formation of users and providing a postmarketing incident reporting are thus essential in health institutions. Clinical and engineering departments should cooperate to produce and secure procedures which should be applied during the lifetime of each clinical device. Several points should be especially fulfilled: close cooperation between clinical departments and biomedical engineering departments with available technicians, computer-based inventory of all devices, evaluation of specifications required before purchasing a new device, education of users on utilisation and maintenance, technical follow-up of devices and keeping maintenance and repair logs, ability to provide users with replacement devices, provision of check-lists before use, forging criteria to decide when device should be discarded. These principles are simple and should be considered as mandatory in order to improve medical device related security.

[Results of alginate and hypertonic solution in wound healing of head and neck cancers]. / Résultats de l'association de deux produits issus de la mer dans les troubles de la cicatrisation en cancérologie cervico-faciale.

INTRODUCTION: In head and neck cancers, complications such as pharyngostoma, orostoma, or fistula can present following surgery or surgery after irradiation. OBJECTIVE: To report the results of the association of two sea-derived products (Sinomarin and Algosteril) compared to normal saline for the management of healing. MATERIAL AND METHODS: This is retrospective study (1998-2000). Thirty patients were included in group 1 (Sinomarin-Algosteril) and 17 patients in group 2 (normal saline). The average age was respectively 60 and 56.2. Patients in both groups presented with advanced head and neck carcinoma (T3-T4) and healing complications. RESULTS: The delay of healing was respectively of 33.53 and 72.94 days. Results were statistically significant (Student T-test P < 0.05). CONCLUSION: Our results show the efficiency (p < 0.05) of the Sinomarin Algosteril association in head and neck cancer healing complications.

[Spontaneous cervical emphysema: a case report]. / Emphysème cervical spontané: à propos d'un cas.

Spontaneous cervical subcutaneous emphysema, without any aetiology found in the clinical history, is far less common than subcutaneous cervical emphysema following trauma, surgery, or infectious cervical processes. In this recent case report, the authors describe a young woman who developed a cervical subcutaneous emphysema. No responsible factor had been found. Radiological investigations revealed a pneumomediastinum, which is an uncommon but a serious complication of cervical emphysema. The CT-scan highlighted a rupture of the crico-thyroid membrane, from which the air had followed the fascial planes up to the neck and the mediastinum. The authors describe the treatment and clinical course. They put forward an embryological hypothesis regarding the spontaneous crico-thyroid membrane rupture. A congenital fragility of this area could exist which could explain its breach. The pathogenesis and management of spontaneous cervical emphysema are discussed in the light of diverses articles about this subject. The radiological or surgical explorations which may be used in this aetiological diagnosis and treatment are given.

Bench testing of pressure support ventilation with three different generations of ventilators.

OBJECTIVE: The new generations of intensive care ventilators tend to be more innovative and sophisticated than previous ones, but little is known about their respective performance for delivering pressure support ventilation (PSV) and how they compare to previous generations. DESIGN: Active lung model bench test. APPARATUS: Twenty-two commercially available ventilators classified into three categories: new generation ventilators (after 1993, n=7), previous generation (before 1993, n=6), and recent piston or turbine-based ventilators ( n=9). MEASUREMENTS AND RESULTS: During PSV, the unloading efficacy of the assistance depends on the ventilator's ability to meet inspiratory flow demand. Three levels of flow (0.1 l/s, 0.6 l/s, and 1.2 l/s) were used to simulate inspiratory demand and the net area of the inspiratory airway pressure-time trace was calculated over the first 0.3 s, 0.5 s, and 1 s (Area (0.3), Area (0.5), and Area (tot)) with three levels of PSV (5 cmH(2)O, 10 cmH(2)O, and 15 cmH(2)O). To assess the respective role of pressure support delivery and triggering function, triggering sensitivity was assessed independently by measuring the time delay ( TD (tg)) and the pressure fall (Delta Paw (tg)) with two levels of inspiratory drive. All the new generation ventilators exhibited significantly better results than most of the previous generation ventilators regarding Area (0.3) and TD (tg), indicating large improvements in terms of triggering and pressurisation. CONCLUSION: Regarding PSV and trigger performance, the new generation ventilators - but also some piston and turbine-based ventilators - outperform most of previous generation ventilators.

[Facial paralysis: treatment with an acyclovir-methylprednisolone combination, preliminary results]. / Paralysies faciales a frigore: traitement par l'association Aciclovir-Methylprednisolone, résultats préliminaires.

RATIONALE: Many actual data suspect a viral etiology to Bell's palsy. Herpes viridae are more and more incriminated. On these basis, we have studied the efficacity of parenteral association of 30 mg/Kg/j of Aciclovir and 1 mg/Kg/j of Methylprednisolone in the treatment of Bell's palsy with less than 12 days of evolution. METHOD: The evaluation concern 53 patients. We also evaluated the functional motor result (using House and Brackmann staging) and search prognostic factors in clinic and paraclinic data. A viral investigation have been made in most of the cases. RESULTS: Only one of our patients treated with Aciclovir keeps some sequeles (stage III of House and Brackmann classification). We didn't found any deleterious effect. Statistically, the electromyography is the only one test with a prognostic value. But we feel that delay between the starting and the treatment of the palsy is important. Viral tests show sometime abnormal Ig against the Herpes viridae group. CONCLUSIONS: These promising results are lightened with a review of the literature. A multicentric investigation is already in place for a stronger statistic effect.

[Perfusion instruments: analysis of product surveillance in 1998 and its on-the-job training. Subcommittee 4b for Product Surveillance]. / Matériels de perfusion: le bilan de la matériovigilance en 1998 et ses enseignements pour la pratique. Sous-commission 4b de matériovigilance.

OBJECTIVES: To analyze retrospectively the data base of the French national vigilance reporting system concerning infusion devices during the year 1998. METHODS: Each report has been reviewed and classified, except implantable catheter ports. RESULTS: The study included 309 reports. Among them, 28% concerned infusion pumps and 72% single use devices, i.e. catheters, infusion lines, taps, connectors, etc. We observed six deaths and 23 severe incidents. Only 25% of devices could be formally investigated by manufacturers. The origins of incidents were very different between infusion pumps and single use devices. The first showed simple failures, software errors, maintenance omissions or errors, and problems related to obsolescence of the device. The second revealed manufacturer quality insurance failures, design and utilization errors, and problems related to the technique itself rather than device. DISCUSSION: Our findings are similar to the few data available in international literature. They address the need to obtain an adequacy between the performances of devices which vary with generations of devices and the clinical risks: newest and safest devices should be preferred for the infusion of the most critical drugs.

Modulation detection by normal and hearing-impaired listeners.

In five normally hearing subjects and seven subjects with damaged cochleas, detection thresholds for sinusoidal frequency modulation (FM) and amplitude modulation (AM) were measured using 1 s stimuli with a 500 Hz carrier frequency (Fc) at a 'comfortable' loudness (given by subject-dependent SPLs and SLs). The modulation frequency (Fmod) was 2 Hz or 10 Hz. FM (but not AM) detection was poorer in the hearing-impaired group, especially when the hearing loss at Fc exceeded 50 dB. Fmod had a different effect on FM and AM detection. The corresponding interaction was essentially identical for the two groups of subjects. Previous studies strongly suggested that normal listeners use mainly neural phase-locking cues for the detection of FM when Fmod = 2 Hz, but mainly tonotopic cues when Fmod = 10 Hz. The present results suggest that cochlear damages reduce the usefulness of these two types of cues to an approximately equal degree.

[What equipment to be chosen, with what criteria, and what requirements?]. / Quel équipement choisir, sur quels critères, avec quelles exigences?

The increasing precision of exercise testing modalities has contributing to making it an excellent means of evaluating functional impairment in dyspnea patients. It has become an indispensable diagnostic tool. Interpretation of data acquired during an exercise test depends on the reliability of data collection and the accuracy of the different calculations. The wide variety of available measurement systems (different principles, different methods for measuring lung volumes and ventilatory flow, canalization systems and valves, analyzers) and data processing systems, and the presence of very simple or on the contrary very complicated systems emphasizes the importance of determining quality requirements used for selecting equipment.

[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).

[Hearing aids through the ages]. / La prothèse auditive acoustique à travers les âges.

Authors relate the history of acoustic hearing aids, from antiquity to our days, for air and bone conductions. It shows an evolution, more due to physical progress than medical progress, composed with deaf's psychology. The accession of electric amplification will make more than half-century to be imperative.

[Electric infusion devices: criteria of choice and comparative analysis of 45 models available in France]. / Appareils électriques de perfusion: critères de choix et analyse comparative de 45 modèles disponibles en France.

This study compared 45 electric infusion devices, either constant flow pumps or syringe pumps, available in France. These devices were tested for start-up delay, time to alarm following occlusion, bolus following occlusion, accuracy of flow rate and pressure output. Ergonomic, environmental and various technical criteria such as safety in continuous perfusion, correct positioning of infusion sets, air in line and end of perfusion detection were also considered. Users can compare these devices in easy to read tables. The newest devices include systems improving the quality of flow.

[Electric infusion devices]. / Les appareils électriques de perfusion.

Electrical infusion devices are specifically aimed to maintain an accurate and constant flow rate. The infused agents can be allocated into three categories of risk, according to their therapeutical index and their infusion rate. Each category requires infusion devices with the corresponding performances. Moreover the choice of a device depends also on ergonomical and environmental criteria as the area of use (e.g. ambulatory patient, transport, neonates, intravenous anaesthesia).

[A study of 11 ventilators for anesthesia: laboratory testing]. / Etude de 11 ventilateurs d'anesthésie: banc d'essai.

Eleven anaesthesia ventilators were instrumentally tested under various conditions. They included: Excel and Modulus II Plus (Ohmeda); 710 and Servo anaesthesia circle 985 (Siemens); Jollytronic (Soxil) and Elsa (Engström); SA2 and Cicero (Dräger); ABT 4,300 (Kontron); Monnal A and the prototype Alys (Taema). The test circuit comprised a two compartment model lung, a pneumotachograph, a pressure gauge in the "airway". The volume was calculated as the integral of flow rate. Each machine was calibrated by the firms' technicians. Before each test, the pneumotachograph was calibrated using a 11 air syringe and the pressure gauge with a 5 cm water column. Each machine ventilated the model lung for 30 min before starting the tests. There were five tests: 1) reliability of the machine's spirometer, 2) reliability of the ventilation rate, 3) reliability of pressure measurements, 4) effect of increasing fresh gas flow on spirometry, 5) effect of increasing downstream resistances. In usual simulated ventilatory conditions, all the machines accurately delivered the setted ventilation and spirometric measurements were with minimal error only. Several ventilators (SA2, Excel, 710, Elsa, ABT 4,300) did not succeed in maintaining their performances when compliance was strongly decreased or resistance of the test lung notably increased. Resistance in the circuit during simulated spontaneous ventilation was < 3.6 cmH2O.l-1.s-1. Increasing fresh gas flow raised the minute volume delivered in six ventilators. It is concluded that, during extreme ventilatory conditions, the inspired volume must be adjusted so as to maintain the inspired tidal volume. However, ventilators which increase inspiratory time in response to an increased mechanical load cannot be adjusted by this way.

Keratinocytes synthesize basal-lamina proteins in culture.

On histologic vertical sections of skin, the epidermis is separated from the dermis by an amorphous thin membrane, the basal lamina. Ultrastructurally, the basal lamina is composed of four areas, including the basal-cell plasma membrane and hemidesmosomes, the lamina lucida, the lamina densa, and the sub-lamina densa fibrillar region. In culture, epidermal keratinocytes are able to produce hemidesmosomes, lamina lucida, and lamina densa. There is no evidence that cultured keratinocytes can produce sub-lamina densa fibrils. Biochemically, the lamina lucida contains two major glycoproteins. One, the bullous pemphigoid antigen, is synthesized by epidermal keratinocytes in vitro. These cells also synthesize laminin, the other glycoprotein of lamina lucida. At the interface between lamina lucida and lamina densa there is probably a heparan sulfate proteoglycan. Whether this proteoglycan is produced by keratinocytes in culture is not known, but the possibility can be considered. Lamina densa contains collagen IV, and this collagen is synthesized by keratinocytes in culture. However, cultured keratinocytes may also synthesize collagen types I, III, and V. Type V is associated with the basal lamina, but its exact location is unknown. Types I and III (if they are produced in vivo) would be situated in the sub-basal lamina region. The problem of fibronectin remains unsolved. There is "some" fibronectin in the lamina lucida, but its origin is not clear.