Measurement of functional residual capacity during mechanical ventilation. Comparison of a computerized open nitrogen washout method with a closed helium dilution method

Ibañez, J.; Raurich, J. M.; Moris, S. García

doi:10.1007/bf01699264

Cited by 20 publications

(10 citation statements)

References 9 publications

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“…These methods have the advantage of being noninvasive, allowing bedside and repeated measurements. However, they are not always reproducible (1,2,5) and do not provide any measurement of the volume of nonaerated lung. Furthermore, there are some important limitations common to all these techniques when applied to patients with ALI: ( 1 ) the diseased lung is characterized by the presence of poorly aerated areas where the gas mixing is problematic, ( 2 ) distention of previously aerated regions cannot be distinguished from true alveolar recruitment when FRC increases after positive end-expiratory pressure (PEEP), and ( 3 ) regional distribution of aerated and nonaerated lung volumes and of PEEPinduced alveolar recruitment cannot be assessed.…”

mentioning

confidence: 97%

A Computed Tomography Scan Assessment of Regional Lung Volume in Acute Lung Injury

Puybasset

Cluzel²,

Nan³

et al. 1998

Am J Respir Crit Care Med

245

146

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The lobar and cephalocaudal distribution of aerated and nonaerated lung and of PEEP-induced alveolar recruitment is unknown in acute lung injury (ALI). Dimensions of the lungs and volumes of aerated and nonaerated parts of each pulmonary lobe were measured using a computerized tomographic quantitative analysis and compared between 21 patients with ALI and 10 healthy volunteers. Distribution of PEEP-induced alveolar recruitment along the anteroposterior and cephalocaudal axis and influence of the resting volume of nonaerated lower lobes were also assessed. Anteroposterior and transverse dimensions of the lungs of the patients were similar to those of healthy volunteers, whereas cephalocaudal dimensions were reduced by more than 15%. Total lung volume (aerated plus nonaerated lung) was reduced by 27%. Volumes of upper and lower lobes were 99 and 48% of normal values. In addition to an anteroposterior gradient in the distribution of aerated and nonaerated areas, a cephalocaudal gradient was also observed. Nonaerated areas were predominantly found in juxtadiaphragmatic regions. PEEP-induced alveolar recruitment was more pronounced in nondependent than in dependent regions and in cephalad than in caudal regions. A significant correlation between resting volume of nonaerated lower lobes and regional PEEP-induced alveolar recruitment was observed. In ALI, loss of lung volume involves predominantly lower lobes. The thorax shortens along its cephalocaudal axis. PEEP-induced alveolar recruitment predominates in nondependent and cephalad lung regions and is inversely correlated with the resting volume of nonaerated lung.

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mentioning

confidence: 97%

A Computed Tomography Scan Assessment of Regional Lung Volume in Acute Lung Injury

Puybasset

Cluzel²,

Nan³

et al. 1998

Am J Respir Crit Care Med

245

146

View full text Add to dashboard Cite

show abstract

“…Helium replaced hydrogen for safety reasons 40-50 yrs ago when clinicians started to use the test [1]. Since its description in 1940, the nitrogen washout method has been shown to give results equivalent to the helium dilution technique in patients and to body plethysmographic techniques in healthy subjects [2][3][4][5][6][7][8][9][10][11][12].…”

mentioning

confidence: 99%

Multiple breath helium dilution measurement of lung volumes in adults

Brown¹,

Leith²,

Enright³

1998

Eur Respir J

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“…The helium concentration in the balloon can be measured and FRC can be calculated. This system has been used in patients during controlled and assisted ventilation 54,56,57 but has never gained widespread acceptance, possibly due to the complex instrumentation required. A simplified helium‐dilution method has been used in ventilated patients but it requires disconnection of the ventilator 36,58 .…”

Section: Physiologymentioning

confidence: 99%

“…Nitrogen is most frequently used as the tracer gas in multiple breath wash‐out investigations. It was first described by Darling et al, 63 later modified and used mainly in research situations 8,9,19,57,64,65 …”

Section: Physiologymentioning

confidence: 99%

Measurements of functional residual capacity during intensive care treatment: the technical aspects and its possible clinical applications

Heinze

Eichler

2009

Acta Anaesthesiol Scand

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Direct measurement of lung volume, i.e. functional residual capacity (FRC) has been recommended for monitoring during mechanical ventilation. Mostly due to technical reasons, FRC measurements have not become a routine monitoring tool, but promising techniques have been presented. We performed a literature search of studies with the key words 'functional residual capacity' or 'end expiratory lung volume' and summarize the physiology and patho-physiology of FRC measurements in ventilated patients, describe the existing techniques for bedside measurement, and provide an overview of the clinical questions that can be addressed using an FRC assessment. The wash-in or wash-out of a tracer gas in a multiple breath maneuver seems to be best applicable at bedside, and promising techniques for nitrogen or oxygen wash-in/wash-out with reasonable accuracy and repeatability have been presented. Studies in ventilated patients demonstrate that FRC can easily be measured at bedside during various clinical settings, including positive end-expiratory pressure optimization, endotracheal suctioning, prone position, and the weaning from mechanical ventilation. Alveolar derecruitment can easily be monitored and improvements of FRC without changes of the ventilatory setting could indicate alveolar recruitment. FRC seems to be insensitive to over-inflation of already inflated alveoli. Growing evidence suggests that FRC measurements, in combination with other parameters such as arterial oxygenation and respiratory compliance, could provide important information on the pulmonary situation in critically ill patients. Further studies are needed to define the exact role of FRC in monitoring and perhaps guiding mechanical ventilation.

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Measurement of functional residual capacity during mechanical ventilation. Comparison of a computerized open nitrogen washout method with a closed helium dilution method

Cited by 20 publications

References 9 publications

A Computed Tomography Scan Assessment of Regional Lung Volume in Acute Lung Injury

A Computed Tomography Scan Assessment of Regional Lung Volume in Acute Lung Injury

Multiple breath helium dilution measurement of lung volumes in adults

Measurements of functional residual capacity during intensive care treatment: the technical aspects and its possible clinical applications

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