• Anaesth Intensive Care · May 2011

    Intrabronchial airway pressures in intubated patients during bronchoscopy under volume controlled and pressure controlled ventilation.

    • E R Nakstad, H Opdahl, O H Skjønsberg, and F Borchsenius.
    • Department of Acute Medicine, The National Center for NBC Medicine, Oslo University Hospital, University of Oslo, Oslo, Norway. naes@uus.no
    • Anaesth Intensive Care. 2011 May 1;39(3):431-9.

    AbstractBronchoscope insertion through an endotracheal tube increases airflow resistance. Constant tidal volume (T(v)) ventilation can be maintained by augmenting the inspiratory pressure, but increased outflow resistance cannot be compensated for. Air trapping distal to the tube may lead to higher airway pressures in volume controlled (VC) mode and reduced T(v) in pressure controlled (PC) mode. Increased end-expiratory airway pressures will not be detected by ventilator pressure sensors. In mechanically ventilated and sedated patients, the effects of bronchoscope insertion on intrabronchial pressures were recorded by a pressure transducer distal to the endoscope. In half of the patients, the ventilator was set in VC mode prior to bronchoscope insertion, keeping the previous T(v) constant. In the other half the ventilator was set in PC mode, keeping previous peak inspiratory pressures constant. All patients underwent sequences of VC-PC-VC or PC-VC-PC ventilation with two-minute intervals between mode-changes. In VC mode, bronchoscope insertion increased peak airway pressure from 29 cmH2O (22 to 43) to 41 cmH2O (36 to 49) (P = 0.012) and end-expiratory airway pressure from 11 cmH2O (6 to 18) to 22.5 cmH2O (15 to 30) (P = 0.012). There were no significant changes in T(v), P(a)CO2 or P(a)O2 after two minutes. In PC mode, peak airway pressure was unchanged and end-expiratory airway pressure increased from 9.5 cmH2O (7 to 10) to 10.5 cmH2O (9 to 18) (P = 0.017). Median T(v) was reduced from 673 ml (585 to 800) to 450 ml (408 to 560) (P = 0.012); median P(a)CO2 increased from 5.7 kPa to 6.5 kPa (P = 0.012). Using distal measurement, positive end-expiratory airway pressure increased markedly in VC mode but only marginally in PC mode after bronchoscope insertion.

      Pubmed     Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…