Efficiency of passive activated carbon anaesthetic gas capturing systems during simulated ventilation.

Background: Interest in passive flow filter systems to remove sevoflurane from anaesthetic machine exhaust have increased recently to mitigate the environmental impact of volatile anaesthetics. These filter systems consist of chemically activated carbon, with limited evidence on their performance characteristics. We hypothesised that their efficiency depends on filter material.

Calculating intrinsic positive end-expiratory pressure from end-expiratory flow in mechanically ventilated children-A study in physical models of the pediatric respiratory system.

Rationale: The high resistance of pediatric endotracheal tubes (ETTs) exposes mechanically ventilated children to a particular risk of developing intrinsic positive end-expiratory pressure (iPEEP). To date, determining iPEEP at the bedside requires the execution of special maneuvers, interruption of ventilation, or additional invasive measurements. Outside such interventions, iPEEP may be unrecognized.

Establishment and validation of intravenous anesthesia with dexmedetomidine for pigs under assisted spontaneous breathing: A preclinical model of intensive care conditions.

Large animal models are frequently used to investigate new medical approaches. In most cases, animals are kept under general anesthesia and mandatory mechanical ventilation during the experiments. However, in some situations assisted spontaneous breathing is essential, e.

Lung area estimation using functional tidal electrical impedance variation images and active contouring.

Electrical impedance tomography is a valuable tool for monitoring global and regional lung mechanics. To evaluate the recorded data, an accurate estimate of the lung area is crucial.We present two novel methods for estimating the lung area using functional tidal images or active contouring methods.

Control of the expiratory flow in a lung model and in healthy volunteers with an adjustable flow regulator: a combined bench and randomized crossover study.

Background: Pursed-lips breathing (PLB) is a technique to attenuate small airway collapse by regulating the expiratory flow. During mandatory ventilation, flow-controlled expiration (FLEX), which mimics the expiratory flow course of PLB utilizing a digital system for measurement and control, was shown to exert lung protective effects. However, PLB requires a patient's participation and coordinated muscular effort and FLEX requires a complex technical setup.

Biosensor-Enabled Multiplexed On-Site Therapeutic Drug Monitoring of Antibiotics.

Personalized antibiotherapy ensures that the antibiotic concentration remains in the optimal therapeutic window to maximize efficacy, minimize side effects, and avoid the emergence of drug resistance due to insufficient dosing. However, such individualized schemes need frequent sampling to tailor the blood antibiotic concentrations. To optimally integrate therapeutic drug monitoring (TDM) into the clinical workflow, antibiotic levels can either be measured in blood using point-of-care testing (POCT), or can rely on noninvasive sampling.

Flow-controlled expiration (FLEX) homogenizes pressure distribution in a four compartment physical model of the respiratory system with chest wall compliance.

Flow-controlled expiration (FLEX) has been shown to attenuate ventilator-induced lung injury in animal models. It has also shown to homogenize compartmental pressure distribution in a physical model of the inhomogeneous respiratory system having independent compartments. We hypothesized that the homogenizing effects of FLEX are also effective in this regard when the independence of compartments is suspended by simulated chest wall compliance.

Prediction of expiratory desflurane and sevoflurane concentrations in lung-healthy patients utilizing cardiac output and alveolar ventilation matched pharmacokinetic models: A comparative observational study.

The Gas Man simulation software provides an opportunity to teach, understand and examine the pharmacokinetics of volatile anesthetics. The primary aim of this study was to investigate the accuracy of a cardiac output and alveolar ventilation matched Gas Man model and to compare its predictive performance with the standard pharmacokinetic model using patient data.Therefore, patient data from volatile anesthesia were successively compared to simulated administration of desflurane and sevoflurane for the standard and a parameter-matched simulation model with modified alveolar ventilation and cardiac output.

Mechanical ventilation restores blood gas homeostasis and diaphragm muscle strength in ketamine/medetomidine-anaesthetized rats.

New Findings: What is the central question of the study? Does respiratory support ensure blood gas homeostasis and the relevance of experimental outcomes? What is the main finding and its importance? Spontaneous breathing during surgical intervention under anaesthesia results in impaired gas exchange and loss of diaphragm muscle strength in rats. Subsequent short-term mechanical ventilation restored blood gas homeostasis and diaphragm muscle strength. Blood gas homeostasis interferes substantially with experimental conditions and may alter study results.

Sine ventilation in lung injury models: a new perspective for lung protective ventilation.

Mechanical ventilation is associated with the risk of ventilator induced lung injury. For reducing lung injury in mechanically ventilated patients, the application of small tidal volumes and positive end-expiratory pressures has become clinical standard. Recently, an approach based on linear airway pressure decline and decelerated expiratory flow during expiration implied lung protective capacities.

A linearized expiration flow homogenizes the compartmental pressure distribution in a physical model of the inhomogeneous respiratory system.

Objective: Flow-controlled expiration (FLEX) and flow-controlled ventilation (FCV) imply a linearized expiration, and were suggested as new approaches for lung-protective ventilation, especially in the case of an inhomogeneous lung. We hypothesized that a linearized expiration homogenizes the pressure distribution between compartments during expiration, compared to volume-controlled (VCV) and pressure-controlled (PCV) ventilation.

Approach: We investigated the expiratory pressure decays in a physical model of an inhomogeneous respiratory system.

Flow-Controlled Ventilation Attenuates Lung Injury in a Porcine Model of Acute Respiratory Distress Syndrome: A Preclinical Randomized Controlled Study.

Objectives: Lung-protective ventilation for acute respiratory distress syndrome aims for providing sufficient oxygenation and carbon dioxide clearance, while limiting the harmful effects of mechanical ventilation. "Flow-controlled ventilation", providing a constant expiratory flow, has been suggested as a new lung-protective ventilation strategy. The aim of this study was to test whether flow-controlled ventilation attenuates lung injury in an animal model of acute respiratory distress syndrome.

Glottic visibility for laryngeal surgery: Tritube vs. microlaryngeal tube: A randomised controlled trial.

Background: Good visibility is essential for successful laryngeal surgery. A Tritube with outer diameter 4.4 mm, combined with flow-controlled ventilation (FCV), enables ventilation by active expiration with a sealed trachea and may improve laryngeal visibility.

Improved lung recruitment and oxygenation during mandatory ventilation with a new expiratory ventilation assistance device: A controlled interventional trial in healthy pigs.

Background: In contrast to conventional mandatory ventilation, a new ventilation mode, expiratory ventilation assistance (EVA), linearises the expiratory tracheal pressure decline.

Objective: We hypothesised that due to a recruiting effect, linearised expiration oxygenates better than volume controlled ventilation (VCV). We compared the EVA with VCV mode with regard to gas exchange, ventilation volumes and pressures and lung aeration in a model of peri-operative mandatory ventilation in healthy pigs.

Pressure-flow characteristics of breathing systems and their components for pediatric and adult patients.

Background: Breathing circuits connect the ventilator to the patients' respiratory system. Breathing tubes, connectors, and sensors contribute to artificial airway resistance to a varying extent. We hypothesized that the flow-dependent resistance is higher in pediatric breathing systems and their components compared to respective types for adults.

Coaxial Tubing Systems Increase Artificial Airway Resistance and Work of Breathing.

Background: Tubing systems are an essential component of the ventilation circuit, connecting the ventilator to the patient's airways. Coaxial tubing systems incorporate the inspiratory tube within the lumen of the expiratory one. We hypothesized that by design, these tubing systems increase resistance to air flow compared with conventional ones.