Estimation Of Lung Volume Research Articles

Fetal MRI for prediction of neonatal mortality following preterm premature rupture of the fetal membranes

Lung MRI volumetrics may be valuable for fetal assessment following early preterm premature rupture of the foetal membranes (pPROM). To evaluate the predictive value of MRI lung volumetrics after pPROM. Retrospective cohort study of 40 fetuses after pPROM in a large, tertiary, perinatal referral center. Fetuses underwent MRI lung volumetrics. Estimated lung volume was expressed as percentage of expected lung volume (our own normal references). Primary outcome was neonatal mortality due to respiratory distress before discharge from hospital. Gestational age range was 16-27 weeks. Estimated-to-expected lung volume was 73% in non-survivors and 102% in survivors (P < 0.05). There were no survivors with a lung volume less than 60% of expected. By logistic regression, mortality could be predicted with a sensitivity of 80%, specificity of 86% and accuracy of 85%. Fetal MR lung volumetrics may be useful for predicting mortality due to respiratory distress in children with early gestational pPROM.

Smallest detectable change in volume differs between mass flow sensor and pneumotachograph

BackgroundTo assess a pulmonary function change over time the mass flow sensor and the pneumotachograph are widely used in commercially available instruments. However, the smallest detectable change for both devices has never been compared. Therefore, the aim of this study is to determine the smallest detectable change in vital capacity (VC) and single-breath diffusion parameters measured by mass flow sensor and or pneumotachograph.MethodIn 28 healthy pulmonary function technicians VC, transfer factor for carbon monoxide (DLCO) and alveolar volume (VA) was repeatedly (10×) measured. The smallest detectable change was calculated by 1.96 x Standard Error of Measurement ×√2.FindingsThe mean (range) of the smallest detectable change measured by mass flow sensor and pneumotachograph respectively, were for VC (in Liter): 0.53 (0.46-0.65); 0.25 (0.17-0.36) (p = 0.04), DLCO (in mmol*kPa-1*min-1): 1.53 (1.26-1.7); 1.18 (0.84-1.39) (p = 0.07), VA (in Liter): 0.66. (0.53-0.82); 0.43 (0.34-0.53) (p = 0.04) and DLCO/VA (in mmol*kPa-1*min-1*L-1): 0.22 (0.19-0.28); 0.19 (0.14-0.22) (p = 0.79).ConclusionsSmallest detectable significant change in VC and VA as measured by pneumotachograph are smaller than by mass flow sensor. Therefore, the pneumotachograph is the preferred instrument to estimate lung volume change over time in individual patients.

Airway distensibility and volume recruitment with lung inflation in COPD

The effects of full lung inflation on respiratory conductance (Grs) and reactance (Xrs) were measured in 15 subjects with moderate to severe chronic obstructive pulmonary disease (COPD) and 11 matched healthy control subjects. Airway distensibility was estimated from the ratio of the difference of Grs between functional residual capacity and total lung capacity to the relevant changes in lung volume (ΔGrs/ΔVl) or transpulmonary pressure (ΔGrs/ΔPtp). Similar analysis was applied to Xrs to estimate lung volume recruitment (ΔXrs/ΔVl or ΔXrs/ΔPtp). The extent of emphysema in COPD subjects was estimated from the percentage of low attenuation area (LAA) at high-resolution computed tomography. At baseline, ΔGrs/ΔVl and ΔXrs/ΔVl were significantly less in COPD than control subjects, indicating less distensibility and volume recruitment in the former. In COPD, ΔGrs/ΔPtp and ΔXrs/ΔPtp were uncorrelated with LAA but correlated with 1-s forced expiratory volume and with each other. After albuterol, both ΔGrs/ΔPtp and ΔGrs/ΔVl became significantly and negatively correlated with LAA, while ΔXrs/ΔPtp and ΔXrs/ΔVl decreased significantly independently of LAA. Moreover, ΔGrs/ΔPtp and ΔXrs/ΔPtp with lung inflation were no longer correlated with each other, suggesting that airway distensibility and volume recruitment were affected differently by airway smooth muscle tone. Assuming that Grs mainly reflects airway caliber and Xrs the number of ventilated lung units, we conclude that airway smooth muscle contributes to airway stiffness and ventilation inhomogeneities in COPD subjects with prevailing bronchitis but only to the latter in those with more emphysema. We suggest that changes of airway distensibility and volume recruitment with a bronchodilator may be useful for disease phenotyping.

Effect of body position on respiratory system volumes in anesthetized red-tailed hawks (Buteo jamaicensis) as measured via computed tomography

To determine the effects of body position on lung and air-sac volumes in anesthetized and spontaneously breathing red-tailed hawks (Buteo jamaicensis). 6 adult red-tailed hawks (sex unknown). A crossover study design was used for quantitative estimation of lung and air-sac volumes in anesthetized hawks in 3 body positions: dorsal, right lateral, and sternal recumbency. Lung volume, lung density, and air-sac volume were calculated from helical computed tomographic (CT) images by use of software designed for volumetric analysis of CT data. Effects of body position were compared by use of repeated-measures ANOVA and a paired Student t test. Results for all pairs of body positions were significantly different from each other. Mean +/- SD lung density was lowest when hawks were in sternal recumbency (-677 +/- 28 CT units), followed by right lateral (-647 +/- 23 CT units) and dorsal (-630 +/- 19 CT units) recumbency. Mean lung volume was largest in sternal recumbency (28.6 +/- 1.5 mL), followed by right lateral (27.6 +/- 1.7 mL) and dorsal (27.0 +/- 1.5 mL) recumbency. Mean partial air-sac volume was largest in sternal recumbency (27.0 +/- 19.3 mL), followed by right lateral (21.9 +/- 16.1 mL) and dorsal (19.3 +/- 16.9 mL) recumbency. In anesthetized red-tailed hawks, positioning in sternal recumbency resulted in the greatest lung and air-sac volumes and lowest lung density, compared with positioning in right lateral and dorsal recumbency. Additional studies are necessary to determine the physiologic effects of body position on the avian respiratory system.

Postmortem fetal organ volumetry using magnetic resonance imaging and comparison to organ weights at conventional autopsy

Following perinatal death, organ weights at autopsy may provide evidence of growth restriction and pulmonary hypoplasia. Whilst postmortem magnetic resonance imaging (MRI) may provide comparable information to autopsy about structural abnormalities, its ability to provide reproducible data about organ size has yet to be determined. We examined the feasibility of using postmortem MRI to provide estimates of organ size and weight. Twenty-five fetuses of gestational age from 16 to 40 weeks underwent postmortem MRI prior to autopsy. Fetal lung, brain and liver volume estimations were performed by two observers using the stereology technique on postmortem MRI slices. Fetal lung, brain and liver weights were recorded at autopsy. Organ volume estimates and autopsy organ weights were compared using regression analysis, and estimates of fetal organ densities made. Interobserver variability was assessed using a Bland-Altman plot. Receiver-operating characteristics curve (ROC) analysis compared MRI brain : liver volume ratios to autopsy brain : liver weight ratios. A linear relationship between organ volume estimates and organ weight was observed. Estimated densities for the fetal brain, liver and lung were 1.08 g/cm(3), 1.15 g/cm(3) and 1.15 g/cm(3), respectively. Interobserver 5th and 95th percentile limits of agreement for fetal brain, liver and lung were - 5.4% to + 7.9%, - 11.8% to + 8.3% and - 14.3% to + 8.7%, respectively. For MRI organ volumes to detect a brain weight : liver weight ratio > or = 4, ROC analysis demonstrated an area under the curve of 0.61, with an optimal cut-off of 4.1. Postmortem MRI organ volumetry can be used to estimate weights of major fetal organs. This may increase the information obtained from a minimally-invasive perinatal autopsy, particularly in the context of pulmonary hypoplasia and intrauterine growth restriction, where differential organ growth plays a major part in assessment of the underlying pathology.

Fetal lung volume: three‐dimensional ultrasonography compared with magnetic resonance imaging

An accurate and reliable method for measuring fetal lung volumes would be helpful in predicting the outcome in cases with suspected impaired lung growth. Recent studies show that it is possible to obtain fetal lung volume estimations with magnetic resonance imaging (MRI) and three-dimensional (3D) ultrasonography. The purpose of this study was to assess the agreement of lung volumes measured with 3D ultrasonography and MRI in uncomplicated pregnancies. This was a prospective study in which MRI and 3D ultrasonography examinations were conducted on the same day to measure the fetal lung volumes of 10 women with uncomplicated pregnancies. Intraclass correlation was used to evaluate the agreement between fetal lung volume measurements obtained by MRI and 3D ultrasonography. A proportionate Bland-Altman plot was constructed. The intraclass correlation coefficient between MRI and 3D ultrasonography measurements for the right lung was 0.92 (95% CI 0.71-0.98) and for the left lung was 0.95 (95% CI 0.82-0.99). The proportionate limits of agreement between the methods were for the right lung -32.57% to 20.03% and for the left lung -21.26% to 17.13%. There is good agreement between lung volumes measured by MRI and those measured by 3D ultrasonography.

Sampling for stereology in lungs

The present article reviews the relevant stereological estimators for obtaining reliable quantitative structural data from the lungs. Stereological sampling achieves reliable, quantitative information either about the whole lung or complete lobes, whilst minimising the workload. Studies have used systematic random sampling, which has fixed and constant sampling probabilities on all blocks, sections and fields of view. For an estimation of total lung or lobe volume, the Cavalieri principle can be used, but it is not useful in estimating individual cell volume due to various effects from over- or underprojection. If the number of certain structures is required, two methods can be used: the disector and the fractionator. The disector method is a three-dimensional stereological probe for sampling objects according to their number. However, it may be affected on tissue deformation and, therefore, the fractionator method is often the preferred sampling principle. In this method, a known and predetermined fraction of an object is sampled in one or more steps, with the final step estimating the number. Both methods can be performed in a physical and optical manner, therefore enabling cells and larger lung structure numbers ( e.g. number of alveoli) to be estimated. Some estimators also require randomisation of orientation, so that all directions have an equal chance of being chosen. Using such isotropic sections, surface area, length, and diameter can be estimated on a Cavalieri set of sections. Stereology can also illustrate the potential for transport between two compartments by analysing the barrier width. Estimating the individual volume of cells can be achieved by local stereology using a two-step procedure that first samples lung cells using the disector and then introduces individual volume estimation of the sampled cells. The coefficient of error of most unbiased stereological estimators is a combination of variance from blocks, sections, fields of view, and noise due to random positioning of the probes. This can be decreased by increasing the number of units from the element causing the most variance. Overall, stereology provides lung scientists with efficient tools for estimating structural components correctly.

Computerized Estimation of the Lung Volume Removed During Lung Volume Reduction Surgery

This study was designed to develop an automated method for estimating lung volume removed during lung volume reduction surgery (LVRS) using computed tomography (CT). The CT examinations of six patients who underwent bilateral LVRS were analyzed in this study. The resected lung tissue (right and left) was weighed during pathologic examination. An automated computer scheme was developed to estimate the lung volume removed using the CT voxel values and lung specimen weight. The computed fraction of lung volume removed was evaluated across a range of simulated surgical planes (ie, other than parallel to the CT image plane) and CT reconstruction kernels, and it was compared with the surgeons' postsurgical estimates. The computed fraction of the lung volume removed during LVRS was linearly correlated with the resected lung tissue weight (Pearson correlation = 0.697, P = .012). The computed fraction of lung volume removed ranged from 12.9% to 51.7% of the total lung volume. The surgeons' postsurgical estimates of lung volume removed ranged from 30% to 33%. The percent difference between the surgeons' estimates and the computed lung volume removed as a percentage of the surgeons' estimates ranged from -72.3% to 57.0% with mean absolute difference of 29.7% (+/-20.7). The preliminary findings of this study suggest that the proposed quantitative model should provide an objective measure of lung volume removed during LVRS that may be used to investigate the relationship between lung volume removed and outcome.

The Effects of Conjugated Linoleic Acid Supplementation during Resistance Training

We determined the effects of conjugated linoleic acid (CLA) supplementation during resistance training. Seventy-six subjects were randomized to receive CLA (5 g.d(-1)) or placebo (PLA) for 7 wk while resistance training 3 d.wk(-1). Seventeen subjects crossed over to the opposite group for an additional 7 wk. Measurements at baseline, 7 wk, and 14 wk (for subjects in the crossover study) included body composition, muscle thickness of the elbow flexors and knee extensors, resting metabolic rate (RMR), bench and leg press strength, knee extension torque, and urinary markers of myofibrillar degradation (3-methylhistidine (3MH) and bone resorption (cross-linked N-telopeptides (Ntx)). After 7 wk the CLA group had greater increases in lean tissue mass (LTM) (+1.4 vs +0.2 kg; P < 0.05), greater losses of fat mass (-0.8 vs +0.4 kg; P < 0.05), and a smaller increase in 3MH (-0.1 vs + 1.3 micromol.kg LTM.d(-1); P < 0.05) compared with PLA. Changes between groups were similar for all other measurements, except for a greater increase in bench press strength for males on CLA (P < 0.05). In the crossover study subjects had minimal changes in body composition, but smaller increases in 3MH (-1.2 vs +2.2 micromol.kg LTM.d(-1); P < 0.01) and NTx (-4.8 vs +7.3 nmol.kg(-1) LTM.d(-1); P < 0.01) while on CLA versus PLA. Supplementation with CLA during resistance training results in relatively small changes in body composition accompanied by a lessening of the catabolic effect of training on muscle protein.

Respiratory inductive plethysmography accuracy at varying PEEP levels and degrees of acute lung injury

Background and objective: This study was performed to assess the accuracy of respiratory inductive plethysmographic (RIP) estimated lung volume changes at varying positive end-expiratory pressures (PEEP) during different degrees of acute respiratory failure.Methods: Measurements of inspiratory tidal volume were validated in eight piglets during constant volume ventilation at incremental and decremental PEEP levels and with increasing severity of pulmonary injury. RIP accuracy was assessed with calibration from the healthy state, from the disease state as the measurement error was assessed, and at various PEEP levels.Results: Best results (bias 3%, precision 7%) were obtained in healthy animals. RIP accuracy decreased with progressing degrees of acute respiratory failure and was PEEP dependent, unless RIP was calibrated again. When calibration was performed in the disease state as the measurement error was assessed, bias was reduced but precision did not improve (bias – 2%, precision 9%).Conclusions: RIP accuracy is within the accuracy range found in monitoring devices currently in clinical use. Most reliable results with RIP are obtained when measurements are preceded by calibration in pulmonary conditions that are comparable to the measurement period. When RIP calibration is not possible, fixed weighting of the RIP signals with species and subject size adequate factors is an alternative. Measurement errors should be taken into account with interpretation of small volume changes.

Accuracy of fetal lung volume assessed by three‐dimensional sonography

To determine the accuracy and precision of prenatal three-dimensional (3D) ultrasound in estimating fetal lung volume using the rotational multiplanar technique (VOCAL) by comparing it to postmortem volume measurements. Fetal lung volume was measured during 3D ultrasound examination using a rotational multiplanar technique in eight cases of congenital diaphragmatic hernia (CDH) (six left and two right-sided) and in 25 controls without pulmonary malformation, immediately before termination. Prenatal 3D sonographic estimates of fetal lung volume were compared with postmortem measurement of fetal lung volume achieved by water displacement. The intraclass correlation coefficient of fetal lung volume estimated by 3D ultrasound and measured at postmortem examination was 0.95 in CDH cases and 0.99 in controls. Based on Bland-Altman analysis, the bias, precision and limits of agreement were, respectively, 0.35 cm(3), 1.46 cm(3) and between -2.51 and + 3.21 cm(3) in cases with CDH and 0.08 cm(3), 2.80 cm(3) and between -5.41 and + 5.57 cm(3) in controls. The mean relative error of 3D ultrasound fetal lung volume measurement was -7.19% (from -42.70% to + 18.11%) in CDH cases and -0.72% (from -30.25% to + 19.22%) in controls, while the mean absolute error of 3D ultrasound fetal lung volume measurement was 1.40 (range, 0.71-2.52) cm(3) and 2.12 (range, 0.05-4.98) cm(3), respectively. Accuracy of 3D ultrasound for measuring fetal lung volumes was 84.86 (range, 57.30-99.48)% in cases with CDH and 91.38 (range, 69.75-99.45)% in controls. The mean intraobserver variability for lung volume estimated by 3D ultrasound was 0.28 cm(3) in controls and 0.17 cm(3) in CDH cases. Prenatal 3D ultrasound can estimate accurately fetal lung volume using the rotational multiplanar technique for volume measurements (VOCAL), even in fetuses with very small lungs, such as cases with isolated CDH.

SU-FF-J-22: Impact of Respiratory Motion On Dose Distributions and DVHs of Thoracic Structures - Evaluation Using 4DCT

Purpose: Respiratory motion may have effect on dose distributions and DVHs of thoracic organs and tumors themselves. The purposes of this work are to determine (1) changes of doses and DVHs with respiration; (2) actual doses delivered to these structures upon completion of one treatment fraction. Method and Materials: Ten non‐small‐cell lungcancer cases were selected, all had free‐breathing fast CT and 4DCT scans during normal breathing. These cases had acceptable breathing regularity and 4DCT image quality, sufficient motion of tumor and lung, and inclusion of entire lung. All cases were treated with 3D (8 cases) or IMRT (2 cases) techniques. Lung volumes were outlined on all respiratory phases consistently using a single CT‐number threshold. Dose distributions were re‐calculated for all phases, with DVHs obtained for each structure on all respiratory phases. For cases with significant changes of lung DVHs, deformable image registration was used to calculate total cumulative dose distribution combining all phases. Results: The overall dose distributions were rather insensitive to respiration for both 3D and IMRT beams except extreme cases with diaphragm moved in/out of beams. Thus, change of DVH for static structures (e.g. cord) was often insignificant. Large changes of lung DVHs were observed only for half of the cases, the degree of which was affected by tumor location and volume, and lung motion. Changes of PTV and heart DVHs were mainly caused by their translational movements. Use of free‐breathing CT was inadequate to represent moving anatomies and could cause spurious results, whiles mid‐inspiration CT provided the best estimate of average lung volume, mass, and dose distributions. Conclusion: Though dose distributions did not change significantly with breathing for photon treatments, variations of DVHs for thoracic structures were more complex and had to be assessed for individual patients and structures.

A parametric model of the relationship between EIT and total lung volume

Spirometry and electrical impedance tomography (EIT) data from 26 healthy subjects (14 males, 12 females) were used to develop a model linking contrast variations in EIT difference images to lung volume changes. Eight recordings, each 64 s long, were made for each subject in four postures (standing, sitting, reclining at 45°, supine) and two breathing modes (quiet tidal and deep breathing). Age, gender and five anthropometric variables were recorded. The database was divided into four subsets. The first subset, data from 22 subjects (12 males, 10 females) recorded in deep breathing mode, was used to create the model. Validation was done with the other subsets: data recorded during quiet tidal breathing in the same 22 subjects, and data recorded in both breathing modes for the other four subjects. A quadratic equation in ΔVP (lung volume changes recorded by the spirometer) provided a very good fit to total contrast changes in the EIT images. The model coefficients were found to depend on posture, gender, thoracic circumference and scapular skin fold. To validate the model, the quadratic equation was inverted to estimate lung volume changes from the EIT images. The estimated changes were then compared to the measured volume changes. Validations with each data subset yielded mean standard errors ranging from 9.3% to 12.4%. The proposed model is a first step in enabling inter individual comparisons of EIT images since: (1) it provides a framework for incorporating the effects of anthropometric variables, gender and posture, and (2) it references the images to a physical quantity (volume) verifiable by spirometry.

Comparison of lung area by chest radiograph, with estimation of lung volume by helium dilution during prone and supine positioning in mechanically ventilated preterm infants: A pilot study

Measurement of lung volume may be useful in determining the degree of lung disease and for optimizing an infant's mechanical ventilator settings. A chest radiograph (CXR) is often used to estimate lung volume, because direct measurement, e.g., functional residual capacity (FRC), is neither practical nor possible in the neonatal intensive care unit. In supinely positioned infants, good correlation was found between lung area determined by CXR and lung volume, e.g., functional residual capacity (FRC). Whether this is true for the prone position is unknown. Since positioning may affect oxygenation and pulmonary function, we studied the relationship between lung area measured from CXR and FRC during both supine and prone positioning in 14 mechanically ventilated preterm infants. Lung area was determined from CXRs using computed radiography and FRCs obtained by helium dilution at end-expiration in both supine and prone positions. Reproducibility of lung area measurements was demonstrated by high correlations between two observers (R2 = 0.92 and 0.99 for supine and prone, respectively). When supine, lung area was 15.4 +/- 3.1 cm2, and FRC was 19.5 +/- 7.3 ml. In prone position, lung area was 16.7 +/- 4.2 cm2, and FRC 23.0 +/- 9.4 ml. There was a moderate to strong positive correlation between lung area and FRC for both positions (supine: r = 0.57, P < 0.03; prone: r = 0.63, P < 0.02). Lung area measured by computed radiography is a reproducible and practical method for estimating lung volume from routine chest X-rays in both supine and prone positions in mechanically ventilated preterm infants.

A radiographic method to estimate lung volume and its use in small mammals

In this paper we develop a method to estimate lung volume using chest x-rays of small mammals. We applied this method to assess the lung volume of several rodents. We showed that a good estimator of the lung volume is: V*L = 0.496 x VRX approximately equal to 1/2 x VRX, where VRX is a measurement obtained from the x-ray that represents the volume of a rectangular box containing the lungs and mediastinum organs. The proposed formula may be interpreted as the volume of an ellipsoid formed by both lungs joined at their bases. When that relationship was used to estimate lung volume, values similar to those expected from allometric relationship were found in four rodents. In two others, M. musculus and R. norvegicus, lung volume was similar to reported data, although values were lower than expected.

Pre- and post-bronchodilator spirometric values and the degree of reversibility in patients with COPD

From the authors: H. Fehrenbach is perfectly correct to point out that the assessment of our data is based only on the measurement of mean chord length (Lm) and lung volume estimations, whereas “a whole range of stereological tools is available for more detailed anaysis”. However, the results were so dramatic that we felt that there was no need for these further, rather esoteric analyses, which would …

Accuracy of Respiratory Inductive Plethysmography in Estimating Lung Volume Changes: The authors reply

Albaiceta, Guillermo M. MD; Taboada, Francisco MD, PhD; Piacentini, Enrique MD; Villagrá, Ana MD; López-Aguilar, Josefina PhD; Blanch, Lluis MD, PhD Author Information

Fetal Lung Volume Estimated by 3‐Dimensional Ultrasonography and Magnetic Resonance Imaging in Cases With Isolated Congenital Diaphragmatic Hernia

To assess the agreement of 3-dimensional ultrasonography and magnetic resonance imaging in estimating fetal lung volume in cases with isolated congenital diaphragmatic hernia. Fetal lung volume was measured in 11 cases of congenital diaphragmatic hernia (10 left and 1 right) by 3-dimensional ultrasonography and magnetic resonance imaging. These examinations were performed during the same week. The operators were blinded to each other's results. Intraclass correlation was used to evaluate the agreement between 3-dimensional ultrasonography and magnetic resonance imaging estimations of the ipsilateral, contralateral, and total fetal lung volume. A Bland-Altman graph was plotted to detect possible discordant observations. The global intraclass correlation coefficient between magnetic resonance imaging and 3-dimensional ultrasonographic measurement of fetal lung volume was 0.94 (95% confidence interval, 0.78-0.98) with no outliers observed on the Bland-Altman plot. There is a good agreement between 3-dimensional ultrasonography and magnetic resonance imaging for fetal lung volume estimation in cases with congenital diaphragmatic hernia.

Dimensional Statistics for Estimation of Lung Volumes

The theory of dimension has been widely used in physics to check the validity of formulae. This theory has not been used more frequently in statistics as compared to physics for development of various prediction formulae/equations in applied physiology. An attempt has, therefore, been made in the present investigation to evolve formulae for estimation of lung volumes from cubic function of height based on dimensional considerations in boys and girls 8-13 and 16-21 years of age.

Early perfluorodecalin lung distension in infants with congenital diaphragmatic hernia

Background/Purpose: Pulmonary hypoplasia contributes to mortality in infants with severe congenital diaphragmatic hernia (CDH). Accelerated postnatal lung growth with perfluorocarbon lung distension has been demonstrated in animals. The authors present a study measuring perfluorodecalin distension in neonates with severe CDH on extracorporeal membrane oxygenation (ECMO) support. Methods: Six consecutive neonates with CDH requiring ECMO support were recruited. The lungs were filled with perfluorodecalin, and continuous positive airway pressure was applied for 6 to 10 days (mean, 7.7 days ± 0.7). The perfluorodecalin was exchanged 4 times a day. Radiographic lung projections were measured, and from 2-dimensional measurements an estimated lung volume was calculated using the ECMO cannula as reference. Results: Perfluorodecalin instillation started soon after starting ECMO support (mean, 13.5 ± 5.3 hours). The volume required to fill the lungs increased significantly (P <.02). The radiographic dimension of the affected lung increased significantly (mean percentage increase, 272%; P <.02). The contralateral lung dimension also increased (mean percentage increase 51%; P <.02). CDH repair was undertaken on ECMO in all cases. All patients survived (follow-up, 3 to 42 months). Conclusions: This protocol of early perfluorodecalin lung distension in infants with severe CDH on ECMO support resulted in significant radiographic lung enlargement. Clinical outcomes are encouraging. Possible mechanisms include alveolar recruitment, alveolar dilatation, and accelerated postnatal lung growth. J Pediatr Surg 38:17-20. Copyright 2003, Elsevier Science (USA). All rights reserved.