Anesthesia Teleconsultation: Quality, Medicoeconomic Interest, and Patient Satisfaction of Preoperative Assessment-A Prospective Observational Study

Background: Telemedicine can be defined as the use of telecommunication technology for performing medical acts remotely by health professionals. Currently in anesthesia, teleconsultation (TC) is becoming widespread, although the benefit and quality have not been well evaluated. The objective of this study was to assess the quality, the patient satisfaction, as well as the ecological and medicoeconomic impacts of the preanesthesia TC. Methods: This prospective observational multicentric study was approved by the Société Française d'Anesthésie-Réanimation ethics committee. The study took place from October 2020 to March 2021, in eight French health care institutions. Every adult patient requiring TC before elective surgery could be included. Unavailability of videoconferencing for the patient was the main exclusion criteria. Five hundred three (n) patients, scheduled for surgery, were included. Their files were analyzed for quality, 375 were successfully interviewed for the second part of the study evaluating satisfaction and medicoeconomic impact. The study's evaluation criteria were the quality of the TeleMed-Cs, the satisfaction and comprehension for the patient, and the medicoeconomic impact of a remote evaluation compared with the face-to-face consultation with the surgeon. Results: Of the 503 files, 478 (95%) were reviewed and met all the high authority of health quality criteria. The electronic format of records was associated with higher completion rate. The median satisfaction was 10.0 (IQR 8.25-10.0). The cost of a TC in anesthesia was significantly lower than that of a face-to-face surgical consultation with a median cost of 1.49€ (IQR 0.8-1.99) versus 34.81€ (IQR 14.01-91.7) p < 0.001. Conclusions: TC in anesthesia seems to be a good alternative in terms of quality, patient satisfaction, and medicoeconomic gain for our patients. By facilitating access to preoperative evaluation, it could be adopted worldwide and thus reduce surgery-related morbidity and mortality in our patients.

Influence of gas law on ultrasonic behaviour of porous media under pressure

This paper deals with the influence of gas law on ultrasonic behaviour of porous media when the saturating fluid is high pressured. Previous works have demonstrated that ultrasonic transmission through a porous sample with variations of the static pressure (up to 18 bars) of the saturating fluid allows the characterization of high damping materials. In these studies, the perfect gas law was used to link static pressure and density, which is disputable for high pressures. This paper compares the effects of real and perfect gas laws on modeled transmission coefficient for porous foams at these pressures. Direct simulations and a mechanical parameters estimation from minimization show that results are very similar in both cases. The real gas law is thus not necessary to describe the acoustic behaviour of porous media at low ultrasonic frequencies (100 kHz) up to 20 bars.

Acoustic behaviour of high pressure air-filled porous media

This paper deals with the acoustic behaviour of porous media when the saturating fluid is high pressured. These observations are performed by ultrasonic transmission through a porous sample with variations of the static pressure of the saturating fluid. Previous works have experimentally demonstrated that a high frequency asymptotic equivalent fluid model allows to model the behaviour of such media for low pressure (between 0.2 and 6 bars). In this paper, in order to characterize high damping materials, measurements are performed for higher static pressure (up to 18 bars). It is shown that the behaviour of transmission coefficient and speed with pressure follows Biot's theory. Moreover, measurements are dependant on temperature variations. Temperature variations have been accounted for in this study, but this does not explain entirely the high sensitivity of the transmission coefficient with static pressure. It remains that the mechanical properties of the porous medium vary strongly with the thermodynamic variables.

Porous material characterization--ultrasonic method for estimation of tortuosity and characteristic length using a barometric chamber

An ultrasonic method of acoustic parameter evaluation for porous materials saturated by air (or any other gas) is discussed. The method is based on the evolution of speed of sound and the attenuation inside the material when the static pressure of the gas saturating the material is changed. Asymptotic development of the equivalent fluid model of Johnson-Allard is used for analytical description. The method allows an estimation of three essential parameters of the model: the tortuosity, and the viscous and thermal characteristic lengths. Both characteristic lengths are estimated individually by assuming a given ratio between them. Tests are performed with industrial plastic foams and granular substances (glass beads, sea sand) over a gas pressure range from 0.2 to 6 bars at the frequencies 30-600 kHz. The present technique has a number of distinct advantages over the conventional ultrasonic approach: operation at a single frequency, improved signal-to-noise ratio, possibility of saturation the porous media by different gases. In the case when scattering phenomena occur, the present method permits a separate analysis of scattering losses and viscothermal losses. An analytical description of the method is followed by a presentation of the set-up and the measurement procedure. Experimental results and perspectives are discussed.