Biomedical subjects

Anastassios C Koumbourlis

Publications and source records attributed to Anastassios C Koumbourlis.

6 recordsLinked to original sources

PubMed2006

Scoliosis and the respiratory system.

Scoliosis is caused by the lateral displacement and rotation of the vertebral bodies. It is most common during periods of rapid somatic growth. Scoliosis impedes on the movement of the ribs, places the respiratory muscles at a mechanical disadvantage and displaces the various organs of the thoracic cavity. Scoliosis decreases the chest wall compliance directly and the lung compliance indirectly (due to progressive atelectasis and air-trapping), causing a significant increase in the work of breathing that, because of the associated respiratory muscle weakness may lead to chronic respiratory failure. Progressive pulmonary hypertension also constitutes a leading cause for morbidity and mortality. Scoliosis is not reversible, but it can be controlled. Routine screening should start early and continue until the child reaches skeletal maturation. Pulmonary function testing can provide an easy and reliable means for the evaluation and follow-up of the condition.

Child↗

PubMed2006

Lung function in infants after repair of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is initially characterized by severe restrictive lung defect and low lung compliance, but survivors have relatively few abnormalities later in life. We studied the changes in lung growth and function in infants after the repair of CDH. METHODS: Retrospective analysis of pulmonary function tests was performed during the first 24 months of life in 56 infants (33 male and 23 female) after repair of CDH. Lung function (functional residual capacity [FRC], respiratory system compliance [C(rs)] and resistance [R(rs)], and maximum expiratory flow rate at FRC [V'(maxFRC)]) were compared among 4 different ages (0-3, 4-6, 7-12, and 13-24 months). RESULTS: All indices of lung function (mean +/- SD of z scores) were abnormal during the first 6 months of life but were almost normalized by 24 months (P < .0001): FRC, from -0.84 +/- 0.5 to 3.26 +/- 2.07; C(rs), from -0.87 +/- 0.4 to 1.84 +/- 1.75; R(rs), from 2.85 +/- 2.71 to -0.23 +/- 2.03, and V'(maxFRC), from -1.63 +/- 0.4 to -0.09 +/- 0.94. There was significant correlation (P < .001) between lung function and increase in age, height, and especially weight. CONCLUSIONS: Lung growth and function gradually normalize between 6 and 24 months of life after repair of CDH.

Airway Resistance↗

PubMed2004

Lower airway obstruction, bronchial hyperresponsiveness, and primary pulmonary hypertension in children.

We investigated the prevalence and reversibility of lower airway obstruction (LAO) and its correlation with pulmonary artery pressure in children with primary pulmonary hypertension (PPH). The analysis was performed retrospectively in a cohort of children with PPH between 5-18 years of age. PPH was defined as mean pulmonary artery pressure (PAPm) >25 mmHg at rest, or >30 mmHg during exercise, with normal pulmonary capillary wedge pressure in the absence of other causes. Lower airway function was assessed by spirometry and maximal expiratory flow-volume curves. Lung volumes were measured by body plethysmography. Patients were assigned according to their pattern of lung function into "normal," "obstructive," and "restrictive" groups. The reversibility of LAO was defined as an increase of > or = 15% from baseline in forced expiratory volume at 1 sec (FEV1) and/or > or =20% in forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%) in response to nebulized albuterol. An "obstructive" pattern was found in 23 children (59%), a "restrictive" pattern in 2 children (5%), and a "normal" pattern in 14 children (36%). Response to bronchodilator was documented in 78% of children with an "obstructive" pattern and in 22% of those with a "normal" pattern. The PAPm showed a significant positive correlation with the TLC, RV, and RV/TLC, but a negative one with the ratio FEV1/FVC. Our findings suggest that reversible LAO is the most common lung function abnormality among pediatric patients with PPH. Whether airway reactivity is a cause of or the result of PPH remains to be determined.

Adolescent↗

PubMed2004

Maximal expiratory flow at FRC (V'maxFRC): Methods of selection and differences in reported values.

We compared three methods of reporting maximal expiratory flow (V'maxFRC) measured in partial expiratory flow-volume curves (PEFVCs) at the point of functional residual capacity (FRC). PEFVCs were obtained with the rapid thoracoabdominal compression technique (RTC) on a total of 446 occasions in 281 HIV-negative, asymptomatic infants (4.8-28.1 months old). Three different expressions of V'maxFRC were recorded: 1) the highest measured flow (maxV'FRC), 2) the mean of the three highest flows (mean3V'FRC), and 3) the flow at FRC in a composite curve (compV'FRC) consisting of PEFVCs, obtained at different jacket pressures and superimposed at their distal limb. The numerical value of maxV'FRC was 7.4% (+/-5.6%) higher than the mean3V'FRC, and 11.9% (+/-17.7%) higher than the compV'FRC; the mean3V'FRC was 5% (+/-18.3%) higher than the compV'FRC. Bland-Altman analysis was used to evaluate the agreement between the three indices. The mean difference and 95% limits of agreement were: maxV'FRC -mean3V'FRC, 14 +/- 18 ml/sec; maxV'FRC - compV'(FRC), 23 +/- 58 ml/sec; and mean3V'(FRC) - compV'(FRC), 10 +/- 52 ml/sec. The differences between the slopes of the three indices (regressed against height) were statistically significant, although clinically unimportant. We conclude that despite their high correlation, the mean3V'FRC and maxV'FRC should not be used interchangeably, and that the composite analysis, although useful, does not improve the reproducibility of V'maxFRC, and thus it cannot be recommended for routine use in its current form.

Child, Preschool↗

PubMed2004

Lung growth and function in children and adolescents with idiopathic pectus excavatum.

Patterns of lung growth and function were studied retrospectively in 103 patients (73 male and 30 female) with idiopathic pectus excavatum in order to determine: 1) the prevalence of restrictive lung defect and/or other lung function abnormalities; 2) the possible association between type of lung function abnormalities and age of the patient; and 3) whether the type of lung function is associated with other clinical conditions. Forty-three patients (42%) were between 5-9 years of age; 36 (35%) were between 10-14 years; and 24 (23%) were between 15-19 years. Restrictive lung disease was detected only in 5 patients (5%), whereas 42 patients (41%) had evidence of obstructive pattern, and the remaining 56 patients (54%) had a normal pattern. The mean values for lung volume (total lung capacity (TLC) and/or forced vital capacity (FVC)) were lowest in the 10-14-year group, whereas the mean values of the indices of lower airway function (forced expiratory volume at 1 sec (FEV(1)), FEV(1)/FVC, forced expiratory flow at 25-75% of forced vital capacity (FEF(25-75)), and FEF(25-75)/FVC) were higher in the younger group. Residual volume (RV) and RV/TLC were elevated in all age groups, but they declined toward normalization with increasing age. There were no significant differences between groups (stratified either by pattern of lung function or by age) with regard to their demographics or clinical characteristics (scoliosis, direction of sternal rotation, history of asthma/reactive airways disease, or exercise intolerance). We conclude that idiopathic pectus excavatum may be associated with a variety of lung function abnormalities (in particular, lower airway obstruction) even in the absence of overt clinical symptoms. There was no evidence of significant worsening of lung function with increasing age.

Adolescent↗

PubMed2002

Electrical injuries.

Electrical injury is a relatively infrequent but potentially devastating form of multisystem injury with high morbidity and mortality. Most electrical injuries in adults occur in the work-place, whereas children are exposed primarily at home. In nature, electrical injury occurs due to lightning, which also carries the highest mortality. The severity of the injury depends on the intensity of the electrical current (determined by the voltage of the source and the resistance of the victim), the pathway it follows through the victim's body, and the duration of the contact with the source of the current. Immediate death may occur either from current-induced ventricular fibrillation or asystole or from respiratory arrest secondary to paralysis of the central respiratory control system or due to paralysis of the respiratory muscles. Presence of severe burns (common in high-voltage electrical injury), myocardial necrosis, the level of central nervous system injury, and the secondary multiple system organ failure determine the subsequent morbidity and long-term prognosis. There is no specific therapy for electrical injury, and the management is symptomatic. Although advances in the intensive care unit, and especially in burn care, have improved the outcome, prevention remains the best way to minimize the prevalence and severity of electrical injury.

Adult↗