Instrument technology for UPV/High School (nurse)

Fan

• A technical device that fully or partially ensures the exchange of gases between the alveoli and the external environment
• The mixture is driven by the so-called supraatmospheric pressure (higher pressure than in the vicinity of the device)

Fan distribution

• Distribution by patient age

→ for a neonatal, children's ventilator.

→ universal - enables UPV to be performed in both children and adults.

→ ventilator for adults, where we also take into account the weight of the patient and the size of the cannula.

• Distribution according to use

→transport ventilator, portable, intended for patient transfer (e.g. Oxylog 3000 from the company Drager or oxygenator).

→ ventilators for performing domestic UPV.

→ anesthetic devices enabling the administration of inhalation anesthetics.

→ ICU ventilators, so-called servo ventilators, the ventilator is also able to monitor the parameters that are measured in the circuit.

• According to the design of the control unit:

→ electronic.

→ microprocessor.

→ mechanical.

• According to the provision of the inspiratory phase

→ pressure, flow, time, volume generators.

• Standard X high frequency.
• Semi-automatic X automatic.

Principle of operation

• For a ventilated patient, the inspiratory pressure is generated only by the device (i.e. Ppres) or it is created in combination with the pressure exerted by the respiratory muscles (i.e. Pmus).

• The amount of pressure required for inhalation is given by the sum

• The pressure required to overcome the resistance of the respiratory system (breathing circuit, lung tissue and chest wall).
• The pressure required to keep the DC open.
• The pressure required to overcome the end-expiratory alveolar pressure.

Construction - general scheme

• Drive source – compressed gas, electric power.
• Propulsion device – the conversion of energy from a source into the working pressure of a device that performs work.
• Control unit (CTU) – coordinates activities and controls the drive equipment, the fan generation is determined according to the design; hardware and software → generation of devices.

• I. Generation – only mechanical CT (Chirolog 1, Dräger Oxylog 1000).
• II. Generation – ŘJ partially electronic, there are already simple alarms (modern anesthesia devices, Dräger Oxylog 2000).
• III. Generation – a microprocessor enabling electronic feedback and regulation of control valves based on sensed data (Dräger Evita2, Puritan Bennett 7200).
• IV. Generation – multiprocessor ventilators enabling hybrid modes (Dräger Evita XL, high frequency ventilators).

• Control variables include pressure, volume, flow, time.
• Phase variables include trigger, limitation and cycling.
• Expiria modulation device - PEEP valve.
• Control elements – computer screen with a cursor or touch screen or using mechanical control elements (lever, rotary knobs, etc.).
• Pressure and flow measurement:

• The pressure transducer is located either on the Y coupling or in one of the arms of the circuit, by measuring the pressure the function of the device is checked, its activity is monitored, alarms are set, a breath can be initiated according to the pressure gradient.

• The volume is calculated according to pressure and flow over time, the device is called a pneumotachograph or anemometer

• Monitoring unit – an alarm system ensuring safety, displays current values ​​and their trends, triggers an alarm when the limit is exceeded.
• Safety features – backup power supply, backup ventilation mode, anti-asphyxiation valve, leakage compensation, etc.
• The design and layout of the ventilators vary, but regardless, they must meet the basic requirements for setting optimal ventilation for specific patients.

Fan circuit

• One-way X two-way system.
• Disposable circuits X reusable circuits.
• Heated circuits X circuits without heating X circuits with double wall hoses.

Basic parameters

• FiO2 = fraction of oxygen – percentage of O2 in the breathing mixture (21-100% = 0.21 - 1)
• MV = minute volume – amount of mixture inhaled in 1 min. (MV=Vt xf).
• Vt = volume inhaled in 1 breath (approx. 500 ml).
• PEEP = positive pressure value (in cm H2O).
• P-peak = airway pressure.
• Total frequency: spontaneous + "artificial" breaths.
• Type of ventilation.

Means of humidification and heating

• Active humidification – the mixture flows through the chamber system, where it is heated and moistened with sterile water.
• Passive humidification – a moisture and heat exchanger (HME filter) is included in the circuit.

Nebulizers

• Jet X Ultrasonic.
• The nebulizer can be connected either to the compressed gas end of the ventilator (aerosol application in synchronization with inspirium) or we include a nebulizer with a continuous flow from the oxygen distribution.
• Spacers.

Monitoring

• Oxymeters – used to measure oxygen saturation (0-100% SPo2) and pulse rate (20-250 beats/min.).
• Capnometers – used to measure exhaled CO2.
• Ventilometers – monitor ventilation parameters in the anesthesia equipment circuit (VENAR, ANEMAT, N8).

Suction device

• Central - central distribution.
• Mobile - mechanical X electric.

ECMO

• Extracorporeal membrane oxygenation used in cases where the lungs are unable to fulfill their function.
• It is a system similar to extracorporeal circulation, where blood is taken from the circulatory system using a catheter, which is then driven through an oxygenator and pumped back into the body.
• Continuous heparinization required.

Veno-venous

• Oxygenation of venous blood returned to the venous system.
• Gas exchange only, not circulatory support.
• The drainage cannula is in the right vena jugularis interna → blood is drawn into the pump → oxygenator → return to the circulation in the vena femoralis.

Veno-arterial

• Gas exchange and circulation support.
• Drainage cannula in the right internal jugular vein → blood drawn into the pump → oxygenator → return to the patient's circulation via the right common carotid artery.

Links

External links

• Artificial lung ventilation

References

• DOSTÁL, Pavel. Fundamentals of artificial pulmonary ventilation. 2. edition. Maxdorf, 2005. ISBN 80-7345-059-3.