One-lung ventilation in a patient with an organizing empyema and severe idiopathic pulmonary fibrosis

Abstract

Fig 1 CT scan showing pulmonary fibrosis and organizing empyema. (A) At the level of aortic arch; (B) at the level of carina; (C) at the level of left ventricle, and showing extensive fibrotic changes and honeycombing effect in both lower lobes. Pig-tailed drain also shown.

The role of an ambient pressure oxygen source during one-lung ventilation for thoracoscopic surgery

“…But once the chest is opened and the lung has collapsed promptly and presumably to the point of small airways closure 5 , apnoeic oxygenation should, in theory, cease. However, it has subsequently been observed clinically that a varying degree of small airways patency does persist at ambient pressure in some patients, as supported by ongoing uptake of O 2 from the connected ambient pressure O 2 reservoir-bag system 4,7,21 . This is most marked in those patients where there is appreciable ongoing tidal gas movement after the chest is opened, such as those with pleural adhesions or pleural thickening 4,21 .…”

“…However, it has subsequently been observed clinically that a varying degree of small airways patency does persist at ambient pressure in some patients, as supported by ongoing uptake of O 2 from the connected ambient pressure O 2 reservoir-bag system 4,7,21 . This is most marked in those patients where there is appreciable ongoing tidal gas movement after the chest is opened, such as those with pleural adhesions or pleural thickening 4,21 . However, it is also seen in some patients where there is no observable ongoing tidal gas movement 7,22 .…”

“…This apparatus does not have the fundamental re-breathing distraction of the reservoir-bag apparatus, although the latter does have proposed clinical advantages. First, the cyclical distension and collapse of the connected reservoir bag serves as visual confirmation of the presence and magnitude of the tidal gas movement in a given patient 4,[21][22][23] . Second, its use enables the reliable and early identification of both small and larger volume gas leakage past the bronchial cuff, with a large leak resulting in a progressive expansion of the reservoir bag over a number of ventilations 4 , while a small gas leak can be identified by pressing an ear against the reservoir bag to hear the unmistakeable sound of gas escaping past a tight restriction 4,24 .…”

Evidence-based medicine: time to upend the pyramid for some clinical situations?

“…Is it sacrilege to say that the evidence might lie in a lowly 'level of evidence' such as a case report? One particularly persuasive and convincing case report of apnoeic oxygenation in one-lung ventilation was rejected as a case report by the BJA, but accepted and published as correspondence 8 with the necessary changes to the discussion, and with the removal of 'ambient pressure oxygenation' from the title, thus removing the main justification for and potential clinical value in reporting the case. I wonder whether the authors of the two recent editorials 1,2 might feel honour-bound to ask their thoracic anaesthesia colleagues how they would conduct onelung ventilation for the particular patient described in the letter.…”

“…I wonder whether the authors of the two recent editorials 1,2 might feel honour-bound to ask their thoracic anaesthesia colleagues how they would conduct onelung ventilation for the particular patient described in the letter. 8 Unavoidably high inflation pressures for this patient with severe pulmonary fibrosis would inevitably promote the diversion of pulmonary blood flow to the non-ventilated lung and, without utilising apnoeic oxygenation, one-lung ventilation would be initiated with 100% oxygen. Continuous positive airway pressure with oxygen to the non-ventilated lung 9 would almost certainly be required to maintain adequate oxygenation (which is in itself a form of apnoeic oxygenation).…”