Tidal volume (symbol V_T or TV) is the volume of air moved into or out of the lungs during a normal breath. In a healthy, young human adult, tidal volume is approximately 500 ml per inspiration or 7 ml/kg of body mass.

Mechanical ventilation

Tidal volume plays a significant role during

mechanical ventilation Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air ...

to ensure adequate ventilation without causing trauma to the lungs. Tidal volume is measured in milliliters and ventilation volumes are estimated based on a patient's ideal body mass. Measurement of tidal volume can be affected (usually overestimated) by leaks in the

breathing circuit A breathing system or breathing circuit is a medical device used to deliver oxygen, remove carbon dioxide, and deliver inhalational anaesthetic agents to a patient. Originally developed for use in anaesthesiology, many variants of breathing system ...

or the introduction of additional gas, for example during the introduction of nebulized drugs. Ventilator-induced lung injury such as

Acute lung injury Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...

(ALI) /

Acute Respiratory Distress Syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...

(ARDS) can be caused by ventilation with very large tidal volumes in normal lungs, as well as ventilation with moderate or small volumes in previously injured lungs, and research shows that the incidence of ALI increases with higher tidal volume settings in nonneurologically impaired patients. . Similarly A 2018 systematic review by

The Cochrane Collaboration Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health profess ...

provided evidence that low tidal volume ventilation reduced post operative pneumonia and reduced the requirement for both invasive and non invasive ventilation after surgery Initial settings of mechanical ventilation:

Patients without pre-existing lung disease

Protective lung ventilation strategies should be applied with V_T 6ml/kg to 8ml/kg with RR = 12 to 20 and an average starting target minute ventilation of 7 L/min.

Patients with chronic obstructive lung disease

Protective lung volumes apply 6ml/kg to 8ml/kg with a rate high enough for proper alveolar ventilation but does not create or aggravate intrinsic Positive End-Expiry Pressure (PEEP).

Acute respiratory distress syndrome

Protective lung ventilation strategies apply. V_T 6 to 8 ml/kg or as low as 5 ml/kg in severe cases. Permissive hypercapnia can be employed in an attempt to minimize aggressive ventilation leading to lung injury. Higher peeps are often required however not all ARDS patients require the same peep levels. Patient should be started on 6 ml/kg and peep increased until plateau pressure is 30 cm H₂0 in most severe cases.

References

External links

* {{DEFAULTSORT:Tidal Volume Respiratory physiology Respiration de:Atmung#Atemzugvolumen