e-Learning: Mechanical Ventilator System Concept

Mechanical ventilation is an advanced respiratory therapy that is increasingly popular around the world when applied properly. Mechanical ventilation is a very powerful and effective means of saving many lives because it maintains vital respiratory functions artificially. However, if applied inappropriately,

mechanical

ventilation can be equally powerful and effective in harming patients. Mechanical ventilation could be the most challenging of all clinical therapies not only because the therapy itself is complicated but because the tool therapy, the ventilation

system

, is equally complicated. This is a fact that is not usually recognized. The result of

mechanical

ventilation depends largely on the knowledge of the specialists of the doctors in charge of patient care.

It is generally the case that the more doctors know, the better the outcome. Increasingly aware of this situation, Hamilton Medical now offers a free e-

learning

program that focuses on teaching the basics of mechanical ventilation and ventilation

system

s, the course is easy and interesting in the training unit About natural and artificial lung ventilation, we learned that positive pressure artificial lung ventilation is achieved by intermittently alternating the airway opening pressure between the baseline pressure. and maximum pressure After studying this training unit, you should be able to explain how variable airway opening pressure or pa-o is generated the

concept

underlying a ventilation system the conditions required for a ventilation system to function as should be artificial lung ventilation or mechanical ventilation can be performed using one of three working principles: the graph above shows the pressure waveform of iPPV or intermittent positive pressure ventilation using this principle, a positive opening pressure is applied airway or pa-o intermittently above the baseline pressure shown here in red.

The positive pa-o pushes the inspiring gas into the lungs. The initial pressure is called positive end-expiratory pressure or peep and is generally higher than the local atmospheric pressure. The center graph shows the pressure waveform for In PV or intermittent negative pressure ventilation using this principle a negative alveolar pressure or PA LV is applied below the pressure baseline the negative PA LV draws air into the lungs the line base is usually the local atmospheric pressure 3 the lower graph shows the pressure waveform of h FV or high frequency ventilation using this principle the airway opening pressure PA o oscillates in a defined range around a baseline of defined pressure at a defined speed that is at least 150 cycles per minute of the three principles IP PV is the basis of most modern

ventilator

s, regardless of the brand and model from now on Whenever we say artificial lung ventilation or ventilation Mechanically we refer to ventilation according to the iPPV principle.

The main function of a ventilation system is to intermittently generate positive BP. Oh, how does it work? Let's start with a simple balloon inflation system as shown. Here, the system has four parts, a filled gas cylinder with a valve connecting tube in a blue balloon and a to control the flow of gas passing when the cylinder valve opens, the huge pressure gradient forces the gas to move towards the balloon, however, by pinching the two between your finger and thumb, it is easy to control if the balloon inflates and how quickly now let's add three more elements, the second tube shown in pink and peace and the second hand Controller, after modifying the balloon inflation system as shown, can you see that we have built a very simple system? but fully functional model of an IP PV

ventilator

system balloon inflation if hand A opens the blue tube and hand B closes the pink tube simultaneously, the tube pressure becomes higher than the balloon pressure, the pressure gradient It then pushes the gas into the balloon and it inflates the balloon. deflated if hand A closes the blue tube and hand B opens the pink tube simultaneously, the pressure of the tube becomes less than the pressure of the balloon due to the elastic recoil force of the balloon wall, the pressure gradient then pushes the gas out of the balloon and deflated with the With two hands, the balloon inflation and deflation process can be controlled quite well with respect to the magnitude of time and speed in a real ventilation system.

Hand A is replaced with an inspiratory valve and hand B with an expert or evaluates on this slide the circuit pressure is equivalent to airway opening pressure or PA oh and the balloon pressure to alveolar pressure or PA Inflation of the LV balloon when the inspiratory valve is opened and the expert or evaluator closes the circuit pressure becomes higher than the balloon pressure and as a result gas is pushed into the balloon. Balloon deflation increases when the inspiratory valve closes and the eval v' opens to the environment, the circuit pressure drops below the balloon pressure and gas is expelled from the balloon, as a result, the balloon deflates. contracts.

The valve control in a real ventilation system is greater. complicated than this, but the basic principle remains valid the balloon model is highly comparable to a real ventilation system one the cylinder in the model corresponds to the high pressure gas supply provided for the ventilation system in reality a ventilation system requires the supply of two high-pressure gases oxygen and high-pressure air to the hand a in the model corresponds to the inspiratory valve 3 the hand to be in the model corresponds to the expert or evaluator for the blue and pink tubes between the wipes and the two hands correspond to a respiratory circuit 5 the blue tube piece between the Y PS and the balloon corresponds to the airway 6 the balloon corresponds to the lungs of a ventilated patient a tool is defined as a device that is used to produce or achieve something but typical tools that we know well are not consumed in the process, they are a wrench, a hammer, a knife, scissors or even a bicycle, it is a ventilator, a tool for mechanical ventilation therapy, no, the therapeutic tool for Mechanical ventilation is a ventilation system that generally has six parts, a high-pressure air supply and a high-pressure air supply. -pressurized oxygen for AC power supply three ventilators for the respiratory circuit with all necessary accessories five artificial airways and interface six the lungs of a ventilated patient or a rubber balloon to act as a simulator, therefore the ventilator It is just one of the parts necessary for ventilation.

It can be attached to a bicycle wheel if not properly integrated into a system. A fan alone cannot do anything about mechanical ventilation. This may seem surprising or confusing, but it is. fundamental for everyone involved in the mechanical ventilation business To understand the

concept

of ventilation system, as we already know, the movement of gas is driven by the presence of a pressure gradient within a functioning ventilation system. There are invisible pressure cascades along the gas duct that begin at the air and oxygen supply outlets and end at the outlet. expert's port or evaluation the Galileo fan system serves as an example here one the gas supply pressure is between 2000 and 6000 centimeters of water the tank pressure is between 280 and 340 centimeters of water 3 the circuit pressure equivalent to the airway opening pressure is between 5 and 40 centimeters of water for the pulmonary pressure equivalent to alveolar pressure is also between 5 and 40 centimeters of water 5 the ambient pressure is 0 centimeters of water for a ventilation system to perform its intended function it is essential to have and to maintain its designed pressure ranges, it is a critical but rarely mentioned fact that the function of a ventilation system is conditioned by many factors;

In other words, the system can operate as specified only when all required conditions are satisfied. The required conditions are only one. of the required parts are present and functioning properly so that the entire system is configured correctly and safely 3 the supply of air and oxygen is continuous and stable within the pressure range specified for the AC power supply is continuous and stable within of the specified voltage range v the system does not have any noticeable gas leaks 6 the gas passage is not noticeably occluded 7 the patient's lungs are inflatable 8 the operator fully knows how to configure and operate the ventilation system correctly in design and development Fan engineers assume that all of these required conditions are met in the real world, however, this assumption may not always be correct.

This discrepancy could be the most important and common root cause of the problems we sometimes experience during mechanical ventilation, to summarize in the last pulmonary training unit. natural and artificial ventilation we learned that artificial lung ventilation is achieved by varying the airway opening pressure or pa-o in this unit we have modified a balloon inflation system into a simple but fully functional model of a ventilation system this model has helped us understand how a variable pa-o can be generated to intermittently inflate and deflate a balloon. Additionally, a critical ventilation system concept has been introduced. We now know that the tool for mechanical ventilation therapy is the ventilation system and that the ventilator is only one of the parts. required within the system we have finally discussed the conditions required for a ventilator system to function as designed if one of the conditions is not fully met the system will not function correctly or at all Hamilton medical now offers a free e-

learning

program that is focuses on teaching the basics of mechanical ventilation and ventilation systems.

The course is easy and interesting.