Mechanisms of atelectasis in the perioperative period
2010 (English)In: Best practice & research Clinical anaesthesiology, ISSN 1521-6896, Vol. 24, no 2, 157-169 p.Article in journal (Refereed) Published
Atelectasis appears in about 90% of all patients who are anaesthetised. Up to 15–20% ofthe lung is regularly collapsed at its base during uneventful anaesthesia prior to any surgery being carried out. Atelectasis can persist for several days inthe postoperative period. It is likely to be a focus of infection and may contribute to pulmonary complications. A major cause of anaesthesia-induced lung collapse is the use of high oxygen concentration during induction and maintenance of anaesthesia together with the use of anaesthetics that cause loss of muscle tone and fall in functional residual capacity (a common action of almost all anaesthetics). This causes absorption atelectasis behind closed airways. Compression of lung tissue and loss of surfactant or surfactant function are additional potential causes ofatelectasis. Ventilation ofthe lungs with pure oxygen after a vital capacity manoeuvre that had re-opened a previously collapsed lung tissue results in rapid reappearance ofatelectasis. If 40% O2in nitrogen is used for ventilation ofthe lungs, atelectasis reappears slowly. A post-oxygenation manoeuvre is regularly performed to reduce the risk of hypoxaemia during awakening. However, a combination of oxygenation and airway suctioning will most likely cause new atelectasis. Recruitment at the end ofthe anaesthesia followed by ventilation with 100% O2 causes new atelectasis before anaesthesia is terminated but not with ventilation with lower fraction of inspired oxygen (FIO2). Thus, recruitment must be followed by ventilation with moderate FIO2.
Place, publisher, year, edition, pages
2010. Vol. 24, no 2, 157-169 p.
IdentifiersURN: urn:nbn:se:uu:diva-125955DOI: 10.1016/j.bpa.2009.12.002PubMedID: 20608554OAI: oai:DiVA.org:uu-125955DiVA: diva2:321474