Technology for noninvasive mechanical ventilation: looking into the black box

Current devices for providing noninvasive respiratory support contain sensors and built-in intelligence for automatically modifying ventilation according to the patient's needs. These devices, including automatic continuous positive airway pressure devices and noninvasive ventilators, are technologically complex and offer a considerable number of different modes of ventilation and setting options, the details of which are sometimes difficult to capture by the user. Therefore, better predicting and interpreting the actual performance of these ventilation devices in clinical application requires understanding their functioning principles and assessing their performance under well controlled bench test conditions with simulated patients. This concise review presents an updated perspective of the theoretical basis of intelligent continuous positive airway pressure and noninvasive ventilation devices, and of the tools available for assessing how these devices respond under specific ventilation phenotypes in patients requiring breathing support

Indications and practical approach to non-invasive ventilation in acute heart failure

In acute heart failure (AHF) syndromes significant respiratory failure (RF) is essentially seen in patients with acute cardiogenic pulmonary oedema (ACPE) or cardiogenic shock (CS). Non-invasive ventilation (NIV), the application of positive intrathoracic pressure through an interface, has shown to be useful in the treatment of moderate to severe RF in several scenarios. There are two main modalities of NIV: continuous positive airway pressure (CPAP) and pressure support ventilation (NIPSV) with positive end expiratory pressure. Appropriate equipment and experience is needed for NIPSV, whereas CPAP may be administered without a ventilator, not requiring special training. Both modalities have shown to be effective in ACPE, by a reduction of respiratory distress and the endotracheal intubation rate compared to conventional oxygen therapy, but the impact on mortality is less conclusive. Non-invasive ventilation is also indicated in patients with AHF associated to pulmonary disease and may be considered, after haemodynamic stabilization, in some patients with CS. There are no differences in the outcomes in the studies comparing both techniques, but CPAP is a simpler technique that may be preferred in low-equipped areas like the pre-hospital setting, while NIPSV may be preferable in patients with significant hypercapnia. The new modality 'high-flow nasal cannula' seems promising in cases of AHF with less severe RF. The correct selection of patients and interfaces, early application of the technique, the achievement of a good synchrony between patients and the ventilator avoiding excessive leakage, close monitoring, proactive management, and in some cases mild sedation, may warrant the success of the technique

Design of Ventilator with Gas Mixing, Tidal Volume, and Humidifier Parameters

On the ventilator, there are several important parameters, including gas mixing, which functions to mix oxygen with free air, the tidal volume serves to supply mixed air to the patient, respiratory rate is the frequency of breath given to the patient, and the humidifier functions to regulate the temperature of the air given to the patient. In this research, the author intends to design a ventilator device which uses a working system to open and close the valve to distribute air to the patient. This tool uses several sensors: oxygen sensor KE-25F3, flow sensor yf-s201, pressure sensor MPX 5700, and temperature sensor DS 12B20. The tidal volume (VT) has 3 setting values: 700 ml, 500 ml, and 300 ml. The test is carried out by opening and closing the valve. The respiratory rate has 2 settings of 15 and 20 breaths/minute. In addition, the humidifier has 3 setting modes 32, 35, and 40o C. From the test results, the highest error was obtained in the 300 ml tidal volume test, which was 7.20% and in the respiratory rate test, the highest error value was 0%. The test results with the oxygen concentration parameter obtained the largest error value of 0.1% at 100% oxygen concentration. In testing the temperature and humidity parameters, the largest average error was 2.40% at 40o C setting. So, it can be concluded that the tool is feasible to use because of the level of small error and still within the standard calibration tolerance of 15%

Year in review in Intensive Care Medicine, 2008: II. Experimental, acute respiratory failure and ARDS, mechanical ventilation and endotracheal intubation

SCOPUS: re.jinfo:eu-repo/semantics/publishe