A ventilator is a medical device designed to provide respiratory support by preserving lung functions associated with breathing. Indications for connecting the device are severe respiratory failure or complete cessation of breathing. With the help of the device, it is possible to preserve the functions of the lungs until they can function independently.
Operating principle
The modes of operation are related to the types of fixtures. There is invasive and non-invasive ventilation.
In invasive ventilation, tracheal intubation is preliminarily performed. Subsequently, after connecting the device, air enters the trachea, and then into the lungs through the tube. With such ventilation, a tracheostomy may be necessary.
Non-invasive ventilation does not require prior intubation. Here, air enters through a mask worn on the face, namely through the nose or mouth. A radiology technician, also known as a radiologic technologist, is a healthcare professional who uses imaging equipment, such as x-ray machines, to produce images of the body that are used by physicians to diagnose and treat injuries and illnesses. They are trained to operate the equipment, position patients correctly and ensure that the images produced are of high quality. They also need to maintain the equipment and keep accurate records of the images produced. Radiology technologist programs are available at many colleges and universities, and lead to a certificate or an associate’s degree. After completing their education, technologists must be licensed or certified in most states.
In the first and second cases, the device provides the phases of the respiratory cycle, which include:
- inhale;
- pause of inspiration;
- end of inspiration
- exhalation.
Basic ventilation modes
Among the many modes of ventilation, two categories stand out:
- forced mode;
- auxiliary mode.
The first mode (forced) is suitable for persons after a complete stop of breathing. Subsequently, ventilation takes place under the supervision of specialists. At this time, patients are under the influence of sedative drugs.
Forced ventilation modes include:
- volume-controlled – with it, the air entering the lungs at the time of inspiration is controlled, which allows you to fix the tidal volume. Exhalation occurs automatically after the parameter of the specified value has been set. This mode is not suitable for non-invasive ventilation;
- with controlled pressure – the mode allows you to determine the pressure of the air mass that enters at the moment of inspiration. Here you need to monitor spirometry.
The assisted modes are suitable for patients who are transitioning to non-device breathing and those with limited spontaneous breathing. The activity of respiratory movements is supported by pressure. In addition, synchronized intermittent forced ventilation is used, where control of the incoming air by volume is provided.
Basic settings
To set up different ventilation modes, it is important to pay attention to the parameters of pressure and volume.
The settings you need to configure include:
- DO – tidal volume;
- P – pressure, it includes the pressure on exhalation and inhalation;
- the inclusion of inspiration;
- the time it takes to inhale;
- frequency of respiratory movements;
- the ratio of inhalation and exhalation;
- switch from inhalation to exhalation.
Each ventilator must comply with the standard that applies to devices required for ventilation during intensive care.
Where are they mostly used?
Ventilators with their own parameters are used in various clinical situations where emergency medical care, intensive care, as well as some surgical interventions are required.
Requirements for ventilators:
- for emergency medical care – the device should be easily transported. This is especially true in situations where it is necessary to ventilate the lungs immediately in an ambulance before the patient is taken to the hospital department;
- in resuscitation, suitable for long-term treatment. Here, individual modes and parameters are selected for each patient;
- when performing operations, devices are used that are adapted to supply an oxygen mixture, anesthetic gases. As a rule, the devices are integrated into anesthesia stations.
Classification of ventilators
Classified according to the requirements of GOST 18856-81.
by connection method
- invasive – with an endotracheal tube;
- non-invasive – without an endotracheal tube. Fastening occurs due to the oxygen mask.
by drive type
The drive can be:
- manual;
- electric;
- pneumatic;
- combined.
by appointment
- general purpose devices – are used more often than others;
- special-purpose devices – are needed to solve specific problems.
according to the place and conditions of use
- stationary device – does not move outside the health facility;
- portable device – mobile, used, including in an ambulance.
by mode of operation
The mode of operation can be:
- forced – used if patients are not breathing on their own;
- auxiliary – the device works in conjunction with breathing;
- forced-auxiliary – is used when the patient breathes on his own, while the device controls this process.
by age of patients
Depending on the age of patients, the following groups of devices exist:
- Group 5 is intended for a patient from newborn to the end of 1 year of life;
- Group 4 is suitable for patients aged 1 to 6 years;
- Groups 1,2,3 apply to persons over 6 years of age.
Potential risks associated with the use of a ventilator
If the parameters are set incorrectly, then this may be accompanied by certain risks to the health of the patient. There is a possibility of asynchronous operation of the device and the patient’s breathing, as well as a change in tidal volume.
Excessive air volume leads to damage to the respiratory organs, and with a small respiratory volume – to the collapse of the alveoli, leading to hypoxemia.
With asynchrony, the functioning of the ventilator does not correspond to the patient’s respiratory movements. Thanks to the optimization of the parameters, it is possible to avoid errors in the operation of the device. New generation ventilators operate without asynchrony. If it manifests itself, then the ongoing monitoring reveals shortcomings that can be quickly and easily corrected.