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PubMed2005

Static pressure volume curves and body posture in acute respiratory failure.

OBJECTIVE: In acute respiratory distress syndrome the body posture effects on pressure-volume (PV) curves are still unclear. We examined the effects of prone position on inflation PV curves and their potential relationships with postural alterations in gas exchange. DESIGN AND SETTING: Prospective study with patients serving as their own controls in a university-affiliated 30-bed intensive care unit. PATIENTS AND PARTICIPANTS: Thirteen anesthetized, paralyzed, semirecumbent, mechanically ventilated patients with early/severe/diffuse ARDS. INTERVENTIONS: Sequential body posture changes: preprone semirecumbent, prone, and postprone semirecumbent. MEASUREMENTS AND RESULTS: In each posture hemodynamics, gas exchange, and lung volumes were determined before/during removal and after restoration of positive end-expiratory pressure (PEEP=10.2+/-0.6 cmH2O). At zero PEEP PV curves of respiratory system, lung, and chest wall were constructed. Prone position vs. preprone semirecumbent resulted in significantly reduced pressure at lower inflection point of lung PV curve (2.2+/-0.2 vs. 3.7+/-0.5 cmH2O) and increased volume at upper inflection point (0.87+/-0.03 vs. 0.69+/-0.05 l). Postural reduction in lower inflection point pressure of lung PV curve was the sole independent predictor of pronation-induced increases in PaO2/FIO2 (R2=0.76). PaO2/FIO2 increases were also significantly related with increases in functional residual capacity (R2=0.60). CONCLUSIONS: In early/severe/diffuse ARDS prone position reduces lower inflection point pressure and increases upper inflection point UIP volume of the lung PV curve. Lower inflection point pressure reductions explain oxygenation improvements, which are also associated with a postural increase in functional residual capacity.

Adult↗

PubMed2002

Exercise-induced bronchodilation in natural and induced asthma: effects on ventilatory response and performance.

We studied whether bronchodilatation occurs with exercise during the late asthmatic reaction (LAR) to allergen (group 1, n = 13) or natural asthma (NA; group 2, n = 8) and whether this is sufficient to preserve maximum ventilation (VE(max)), oxygen consumption (VO(2 max)), and exercise performance (W(max)). In group 1, partial forced expiratory flow at 30% of resting forced vital capacity increased during exercise, both at control and LAR. W(max) was slightly reduced at LAR, whereas VE(max), tidal volume, breathing frequency, and VO(2 max) were preserved. Functional residual capacity and end-inspiratory lung volume were significantly larger at LAR than at control. In group 2, partial forced expiratory flow at 30% of resting forced vital capacity increased greatly with exercise during NA but did not attain control values after appropriate therapy. Compared with control, W(max) was slightly less during NA, whereas VO(2 max) and VE(max) were similar. Functional residual capacity, but not end-inspiratory lung volume at maximum load, was significantly greater than at control, whereas tidal volume decreased and breathing frequency increased. In conclusion, remarkable exercise bronchodilation occurs during either LAR or NA and allows VE(max) and VO(2 max) to be preserved with small changes in breathing pattern and a slight reduction in W(max).

Adult↗

PubMed1998

Aerosolized albuterol improves airway reactivity in infants with acute respiratory failure from respiratory syncytial virus.

The objective of this investigation was to measure the bronchodilator effect of aerosolized albuterol on infants with respiratory syncytial virus (RSV)-induced respiratory failure. Infants who required intubation and mechanical ventilator support for RSV disease were eligible for this prospective, nonrandomized study. Pulmonary function tests, including respiratory mechanics by least mean square analysis, small airway function by rapid thoraco-abdominal compression, and functional residual capacity by nitrogen washout were performed before and 20 min after inhalation of 20-40 breaths of undiluted (0.5%) albuterol solution via a small-volume nebulizer. Analysis of maximum expiratory flow at functional residual capacity (V'maxFRC) before and after albuterol administration was performed using a t-test for paired comparisons. A two-tailed P-value of less than 0.05 was considered statistically significant. Twenty-five infants (mean +/-SD postconceptional age = 45 +/- 5 weeks) were enrolled. Thirteen of the 25 infants had a prior history of prematurity and/or cardiorespiratory disease. After aerosolized albuterol, mean V'maxFRC increased significantly from 48 +/- 46 ml/sec to 65 +/- 59 ml/sec (P = 0.03); however, only three patients had an increase into the normal range. Three patients had a substantial (40-50%) decrease in V'maxFRC. These findings suggest that during the acute phase of severe RSV respiratory infection some of this group of very young infants had airway reactivity that improved in response to inhaled albuterol.

Acute Disease↗

PubMed1991

Initial airway function is a risk factor for recurrent wheezing respiratory illnesses during the first three years of life. Group Health Medical Associates.

We recently reported a significant relationship between lung function measured prior to any lower respiratory tract illness and subsequent wheezing illnesses during the first year of life (N Engl J Med 1988; 319:1112-7). Follow-up has continued for this group of infants during the second and third years of life. When compared with never wheezers, infants who wheezed during the first year of life and had at least one additional lower respiratory illness had 22% lower initial levels of an indirect index of airway conductance derived from the shape of tidal breathing curves (p less than or equal to 0.01), 22% lower respiratory conductance (p less than or equal to 0.05), 25% lower maximal flows at the end-expiratory point (p less than or equal to 0.01), and 10% lower functional residual capacity (p less than or equal to 0.05). Infants who wheezed only once during the first 3 yr of life or who started wheezing during the second year of life had normal tidal breathing curves but significantly lower maximal expiratory flows (p less than or equal to 0.05). Their functional residual capacity was also lower than that of never wheezers (p less than or equal to 0.05). We conclude that diminished initial airway function may be a predisposing factor for recurrent wheezing respiratory illnesses starting in the first year of life. Infants who will have only one wheezing respiratory illness or who will start wheezing after the first year of life seem to have lower levels for some but not for all lung function tests performed in this study.

Age Factors↗

PubMed2004

Diaphragm electromyogram root mean square response to hypercapnia and its intersubject and day-to-day variation.

Diaphragm activation can be quantified by measuring the root mean square of crural EMG (RMSdi) (Beck J, Sinderby C, Lindstrom L, and Grassino A, J Appl Physiol 85: 1123-1134, 1998). To examine intersubject and day-to-day variation in the RMSdi-Pco(2) relationship, end-tidal Pco(2), minute ventilation (Ve), respiratory frequency (f(B)), and RMSdi were measured in seven healthy subjects on two occasions during steady-state ventilation at seven levels of inspired O(2) fraction (Fi(CO(2))) from 0 to 0.08 in random order. RMSdi was measured with a multielectrode esophageal catheter and controlled for signal contamination and diaphragm position. RMSdi was normalized for values obtained during quiet breathing at functional residual capacity, at Fi(CO(2)) of 0.04, and during an inspiratory capacity maneuver (RMSdi%max) as well as ECG R-wave amplitude at functional residual capacity (RMSdi/ECG(R)), f(B), and thickness of the costal diaphragm measured by ultrasound. RMSdi increased linearly with Pco(2) (mean r(2) = 0.83 +/- 0.10); at the highest Fi(CO(2)), RMSdi%max was 40.2 +/- 11.6%. Relative to the intersubject variation in the Ve-Pco(2) relationship, intersubject variations in the slopes and intercepts of the RMSdi-Pco(2) relationships were 1.7 and 1.8 times, respectively, and RMSdi%max-Pco(2) relationships 0.9 and 1.3 times, respectively, and were unrelated to f(B) and diaphragm thickness. Relative to the day-to-day variation in the Ve-Pco(2) relationship, day-to-day variation in the slopes and intercepts of the RMSdi-Pco(2) relationships were 2.8 and 4.4 times, respectively, and RMSdi/ECG(R)-Pco(2) relationships 1.3 and 2.2 times, respectively. It was concluded that the RMSdi-Pco(2) relationship measures chemosensitivity and is best compared between subjects via RMSdi%max and on separate occasions in the same subject via RMSdi/ECG(R).

Adult↗

PubMed2001

Volume displaced by diaphragm motion in emphysema.

To examine the effect of hyperinflation on the volume displaced by diaphragm motion (DeltaVdi), we compared nine subjects with emphysema and severe hyperinflation [residual volume (RV)/total lung capacity (TLC) 0.65 +/- 0.08; mean +/- SD] with 10 healthy controls. Posteroanterior and lateral chest X rays at RV, functional residual capacity, one-half inspiratory capacity, and TLC were used to measure the length of diaphragm apposed to ribcage (Lap), cross-sectional area of the pulmonary ribcage, DeltaVdi, and volume beneath the lung-apposed dome of the diaphragm. Emphysema subjects, relative to controls, had increased Lap at comparable lung volumes (4.3 vs. 1.0 cm near predicted TLC, 95% confidence interval 3.4-5.2 vs. 0-2.1), pulmonary rib cage cross-sectional area (emphysema/controls 1.22 +/- 0.03, P < 0.001 at functional residual capacity), and DeltaVdi/DeltaLap (0.25 vs. 0.14 liters/cm, P < 0.05). During a vital capacity inspiration, relative to controls, DeltaVdi was normal in five (1.94 +/- 0.51 liters) and decreased in four (0.51 +/- 0.40 liters) emphysema subjects, and volume beneath the dome did not increase in emphysema (0 +/- 0.36 vs. 0.82 +/- 0.80 liters, P < 0.05). We conclude that DeltaVdi can be normal in emphysema because 1) hyperinflation is shared between ribcage and diaphragm, preserving Lap, and 2) the diaphragm remains flat during inspiration.

Abdomen↗

PubMedDate not supplied

Ventilatory function in cervical and high thoracic spinal cord injury. Relationship to level of injury and tone.

Weakness and spasticity of chest wall muscles are known to adversely affect pulmonary function in spinal cord-injured patients. To test the assertion that impaired strength and increased tone contribute to ventilation deficits, 52 patients with recent acute traumatic cervical and high thoracic spinal cord injury underwent complete pulmonary function testing. Regression analyses were performed to determine relationships between spinal cord injury level and pulmonary function test results and between Ashworth scale tone ratings and pulmonary function test results. Level of injury was found to be significantly correlated with expiratory reserve volume (and percent predicted expiratory reserve volume), residual volume/total lung capacity ratio, and negative inspiratory pressure but not with vital capacity, forced expiratory volume in one second, forced expiratory volume in one second/vital capacity ratio, inspiratory capacity, total lung capacity, functional residual capacity, residual volume, or positive expiratory pressure. There were significant correlations between Ashworth Scale tone ratings and negative inspiratory pressure but not between tone ratings and any of the other pulmonary function test results. It appears that muscle strength may be a more important factor than muscle tone in determining pulmonary function in spinal cord-injured patients and that both strength and tone are closely related to negative inspiratory pressure.

Adolescent↗

PubMed1995

Prenatal hormonal therapy improves pulmonary compliance in the nitrofen-induced CDH rat model.

Neonates with congenital diaphragmatic hernia (CDH) experience a high mortality despite intensive medical and surgical management. The associated pulmonary hypoplasia is accompanied by an underlying biochemical deficiency that bears similarity to respiratory distress syndrome (RDS) in the premature newborn. Using therapies extrapolated from those used to treat RDS, the authors have previously shown correction of the immature pulmonary biochemical indices in the nitrofen rat CDH model. This study investigates the functional and histological outcome of prenatal hormone therapy on CDH rats. Compared with saline-treated CDH controls, dexamethasone-treated CDH animals achieved significant increases in lung distensibility (P = .0006) and functional residual capacity (P = .004); CDH rats treated with combined dexamethasone and thyrotropin-releasing hormone (TRH) showed improved functional residual capacity (P = .043) and alveolar stability (P = .025); CDH animals treated with TRH alone (TRH-CDH) showed no improvement in any parameter tested. Histologically, the lungs from dexamethasone- and dexamethasone-TRH-treated CDH animals showed changes that included narrow septal walls, increased air saccule size, and thinning of the pulmonary interstitium compared with the lungs of saline or TRH-CDH rats, which were developmentally arrested at the canalicular stage. Lung weights and lung weight-body weights ratios were similar in all CDH rats, confirming that treatment did not impair pulmonary growth. These results support the potential clinical use of prenatal pharmacological therapies to treat human fetuses with prenatally diagnosed CDH.

Animals↗

PubMed1978

Alterations in pulmonary function of premature lambs due to positive end-expiratory pressure.

These studies compare lung mechanics and volumes of premature lambs delivered at 139 days of gestation by cesarean section and ventilated by either intermittent positive pressure (IPP) or positive end-expiratory pressure (PEEP). During the first few hours of life, sequential determinations of lung compliance, specific lung compliance; lung resistance, specific lung conductance and functional residual capacity were made at half-hour intervals. Measurements in 5 lambs ventilated with PEEP demonstrated that lung compliance (p less than 0.005), specific lung compliance (p less than 0.001) and specific lung conductance (p less than 0.005) decreased; while lung resistance (p less than 0.10) and functional residual capacity (p less than 0.02) increased as compared to 7 lambs ventilated with IPP.

Animals↗

PubMed2004

Pulmonary function abnormalities in children with sickle cell disease.

BACKGROUND: Adults with sickle cell disease (SCD) have restrictive lung function abnormalities which are thought to result from repeated lung damage caused by episodes of pulmonary vaso-occlusion; such episodes start in childhood. A study was therefore undertaken to determine whether children with SCD have restrictive lung function abnormalities and whether the severity of such abnormalities increases with age. METHODS: Sixty four children with SCD aged 5-16 years and 64 ethnic matched controls were recruited. Weight and sitting and standing height were measured, and lung function was assessed by measurement of lung volumes and forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) before and after bronchodilator. RESULTS: Compared with the control subjects, the children with SCD had lower mean (SD) sitting height (69 (6.3) cm v 73 (7.7) cm; p=0.004), sitting:standing height ratio (0.50 (0.02) v 0.51 (0.01); p<0.0001), weight (33 (10.9) kg v 41 (14.9) kg; p=0.001), functional residual capacity measured by a helium gas dilution technique (1.2 (0.3) l v 1.3 (0.4) l; p=0.04), FEV1 (1.5 (0.5) l v 1.9 (0.7) l; p=0.0008), FVC (1.7 (0.6) l v 2.1 (0.8) l; p=0.001), and PEF (3.9 (1.3) l/s v 4.8 (1.5) l/s; p=0.0004). The effect of age on lung function differed significantly between the children with SCD and the controls for total lung capacity and vital capacity measured by plethysmography and functional residual capacity measured by helium gas dilution. CONCLUSION: Lung function differs significantly in children with SCD compared with ethnic matched controls of a similar age. Our results suggest that restrictive abnormalities may become more prominent with increasing age.

Adolescent↗

PubMedDate not supplied

Classical conditioning of total respiratory resistance in humans.

A differential classical conditioning paradigm was used to investigate changes in total respiratory resistance in healthy adult female subjects. The conditioned stimuli were red and blue colors projected on a screen, and the unconditioned stimulus was an arithmetic task in which the subject mentally subtracted serial 17s from a number displayed on the screen. One of the two colors was paired with the arithmetic problem, and the other color was presented alone. Participants completed seven paired and seven unpaired trials. Both total respiratory resistance and functional residual capacity changes were measured before and during each conditioned stimulus. Total respiratory resistance was higher during the paired conditioned stimuli than it was during the unpaired conditioned stimuli. This result was not related to variations in functional residual capacity. It was concluded that elevated total respiratory resistance during the paired stimuli was a result of conditioning. The elevations were probably due to increases in bronchomotor tone. Conditioned changes in total respiratory resistance may be related to some respiratory behaviors both in healthy individuals and in patients with asthma.

Adolescent↗

PubMed1986

Response to bronchodilators assessed by lung mechanics.

Abnormalities of compliance and functional residual capacity were shown in eight young children aged 2-8 years with asthma during an acute attack. In a randomised, placebo controlled study treatment with bronchodilator (salbutamol) was associated with a significant improvement in compliance and lessening of hyperinflation as shown by a reduction in functional residual capacity.

Acute Disease↗

PubMed1998

Perfluorocarbon induced alterations in pulmonary mechanics.

Perfluorocarbon (PFC) compounds induce pulmonary hyperinflation and respiratory distress in some animals following intravenous administration. This study was designed to quantify the effects of two PFC emulsions on lung volumes and compliance and to identify the mechanism of pulmonary hyperinflation. New Zealand White rabbits received isotonic saline (3 ml/kg), Fluosol (15 ml/kg) or Oxygent (90% perfluorooctyl-bromide emulsion, 3 ml/kg). After seven days we measured functional residual capacity, vital capacity, lung compliance and thoracic gas volume. Gross and microscopic histologic examination of the lungs was performed. Functional residual capacity after Fluosol administration was 16.0 +/- 4.0 ml/kg, significantly greater than after saline (3.4 +/- 1.0 ml/kg) or Oxygent (4.0 +/- 1.4 ml/kg). Vital capacity was lower with Fluosol (30 +/- 5.0 ml/kg) than after saline (37 +/- 3.0 ml/kg) or Oxygent (37 +/- 2.0 ml/kg). Thoracic gas volume increased from 9 +/- 1.0 ml/kg (saline) to 16 +/- 13 ml/kg (Oxygent) and 33 +/- 7.0 ml/kg (Fluosol). Lung compliance was the same after saline (1.6 +/- 0.5 ml.cm H2O-1.kg-1) and Oxygent (1.5 +/- 0.3 ml.cm H2O-1.kg-1) but lower after Fluosol (0.9 +/- 0.1 ml.cm H2O-1.kg-1). Gross pathology demonstrated foam exudation from airways of animals receiving PFCs and intra-alveolar foam was identified by light microscopy. These results show intra-airway foam formation causes gas trapping and shifts tidal breathing to a less compliant region of the pressure-volume curve.

Animals↗

PubMed1998

Lung aeration and pulmonary gas exchange during lumbar epidural anaesthesia and in the lithotomy position in elderly patients.

We investigated a total of 36 subjects with a mean (SD) age of 65 (13) years, during baseline conditions (supine, before any anaesthesia), and then during one of the following protocols: (1) lithotomy positioning (n = 12), (2) epidural anaesthesia (n = 12), (3) general anaesthesia in the supine position (n = 12). Lung aeration, ventilation/perfusion matching, gas exchange and functional residual capacity were measured. Lung aeration was normal during baseline assessment with almost no regions with poor aeration and no substantial dependent densities. Shunt and perfusion of poorly ventilated regions were minor. Lithotomy positioning did not reduce functional residual capacity and did not affect aeration of the lung or ventilation/perfusion matching. Epidural anaesthesia, in general, had no effect on aeration, ventilation/perfusion matching or gas exchange, regardless of whether the patient was in the supine or lithotomy position. General anaesthesia, however, caused significant increases in poorly aerated lung regions and in dependent densities (interpreted as atelectasis). In conclusion, no or little impairment of lung aeration and ventilation/perfusion matching was caused by the lithotomy position and/or epidural anaesthesia, contrary to the effects seen during general anaesthesia. However, our findings also suggest that being overweight is a factor that may cause impairment of lung aeration.

Aged↗

PubMed2000

Lung function reference values in Chinese children and adolescents in Hong Kong. II. Prediction equations for plethysmographic lung volumes.

As part of a comprehensive evaluation of lung function in Hong Kong Chinese children and adolescents, over a thousand healthy subjects aged 7-19 yr from seven schools were recruited for lung function testing that included spirometry and, in many cases, lung subdivision measurements. Lung function tests were performed using SensorMedics Automated Body Plethysmograph according to published standards. Of these, 551 subjects (219 males), aged 8-19 yr, had satisfactory lung subdivision indices recorded. Analysis for the values of lung subdivisions including total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC) demonstrated that standing height and sitting height were the best predictors of lung volumes. After allowing for standing height or sitting height in the regression models for lung volumes, age at examination was the second best parameter, although its inclusion into the equations contributed to less than 1% of explained variance for boys and 3% for girls. These are the first reported data in international literature on reference values for lung subdivisions in Chinese children and adolescents.

Adolescent↗

PubMed1999

Combined effects of inhaled nitric oxide and hyperoxia on pulmonary vascular permeability and lung mechanics.

OBJECTIVE: To determine whether inhaled nitric oxide (NO) may alter pulmonary vascular permeability and respiratory function in an in vivo model. DESIGN: Prospective, randomized, controlled, experimental study. SETTING: University experimental pharmacology laboratory. SUBJECTS: Mechanically ventilated newborn piglets, 1 to 2 days old, exposed to 100% oxygen for 76 hrs. INTERVENTIONS: The piglets were randomly assigned either to a treatment group receiving 20 ppm inhaled NO from the onset of ventilation (n = 5) or to a control group (n = 6) receiving no treatment. MEASUREMENTS AND MAIN RESULTS: The main variables studied were gas exchange (PaO2/F(IO2) ratio, lung diffusing capacity), respiratory mechanics (static compliance of the respiratory system, stat, quasi-static hysteresis area, functional residual capacity), and pulmonary vascular permeability assessed by simultaneous intravenous administration of iodine-125-labeled albumin and chromium-51-labeled red blood cells. Extravascular albumin space of the lung and dry lung weight were significantly higher in the NO group vs. the control group (albumin space, 1.08+/-0.16 vs. 0.70+/-0.26 [SD] mL/kg body weight [p < .05]; dry lung weight, 3.20+/-0.34 vs. 2.66+/-0.14 g/kg body weight [p < .05]). Moreover, the hysteresis area was higher from 24 hrs of NO exposure. Conversely, NO inhalation altered neither the extravascular lung water content (12.98+/-2.79 mL/kg body weight in the NO group vs. 12.18+/-2.26 mL/kg body weight in the control group [not significant]) nor the main respiratory mechanical variables (static compliance, functional residual capacity) and gas exchange (lung diffusing capacity, PaO2/F(IO2) ratio). CONCLUSION: These results do not support the hypothesis that NO inhalation combined with hyperoxia can alter the main lung-function variables in neonates. However, it may induce an increase in lung vascular protein leakage. The pathophysiologic consequences of this finding remain to be elucidated.

Administration, Inhalation↗

PubMed1999

Pulmonary function for pectus excavatum at long-term follow-up.

PURPOSE: The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction. METHODS: A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR). RESULTS: TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases. CONCLUSIONS: Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

Adolescent↗

PubMed2000

Pulmonary function changes following surgical correction for pectus excavatum.

OBJECTIVE: To assess whether and to what extent pulmonary function returns to normal after surgical correction for pectus excavatum. METHODS: Twenty-seven patients who could be examined in person at the outpatient department of our hospital were included in this study. Of these patients, 24 were boys and 3 were girls, with age ranging from 3 to 16 years (mean: 8.67 years). The mean age at surgery was 4 years and mean years at follow-up was 6.8. Pulmonary function measurements included inspiratory vital capacity (IVC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV/TLC ratio, maximal voluntary ventilation (MVV), forced ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMEF), maximal expiratory flow at 75% vital capacity (V75), maximal expiratory flow at 50% vital capacity (V50), maximal expiratory flow at 25% vital capacity (V25) and breathing reserve ratio (BR). RESULTS: TLC, FRC, MVV, MMEF, V75 and V50 were not different from normal values. IVC, FVC, FEV1 and V25 were significantly decreased compared with normal values. RV and RV/TLC were high in 87.5% cases. CONCLUSIONS: Preoperative symptoms improved substantially after operation. Little airway obstruction was observed postoperatively, suggesting that patients with pectus excavatum should have surgery as early in life as possible, preferably by age 3.

Adolescent↗