Selective mechanical ventilation

Ventilación mecánica selectiva

Selective lung ventilation (SLV) is a procedure employed in chest surgery before opening the pleural cavity. It is done by ventilating only one lung (dependent lung), while the lung that is going to be operated (nondependent lung) collapses. The main goals of this technique are: lung protection, control of pulmonary ventilation, and improvement of surgical access. Surgical interventions are thus more easily feasible and operative times are reduced.

The authors reviewed the literature concerning the following topics: respiratory physiology during SLV in the lateral recumbent position, its absolute and relative indications, physiologic changes in the ventilatory mechanics of the compressed lung whose mobility is limited (especially hypoxic pulmonary vasoconstriction (HPV), different anesthetic agents and interventions used in order to
modulate HPV (such as halogenated anesthetics, vasoactive medications, levels of CO2, PEEP, epidural anesthesia, and hypothermia),
and other factors that are to be taken into account, such as liberation of vasoactive substances that can inhibit HPV, as well as its
important repercussions on blood gases, such as increased alveolar dead space. A review of the ventilatory parameters established
for SLV in each study was carried out. These parameters must be followed depending on the patient's previous pulmonary conditions,
in order to avoid intraoperative complications such as hypoxemia, air entrapment, and barotrauma.

The decision to use SLV must depend on the relative benefits offered by the technique, as well as on the tolerability of the individual
patient. As a general guideline, patients at risk for acute lung injury or acute respiratory distress syndrome following SLV should be
identified.