PubMed Health⌕ Search

PubMed · 9368261

Lung function in infants with sickle cell disease.

Abstract

We performed pulmonary function testing in 20 infants (11 male and 9 female; ages 3-30 months) with sickle cell disease to assess whether abnormal lung function develops early in life. Respiratory system compliance (Crs) and resistance (Rrs) were measured by the passive occlusion technique, functional residual capacity (FRC) was measured by the nitrogen washout technique, and tidal flow-volume loops and partial expiratory flow-volume curves were obtained by the thoracoabdominal compression technique to detect airway obstruction. Patients with Hb SS (Group I, n = 12) had significantly lower hemoglobin levels and a higher (but not significant) incidence of acute chest syndrome (ACS), vasoocclusive crisis (VOC), splenic sequestration, transfusions, and history of intermittent bronchospasm compared to with patients with hemoglobinopathies Hb SC, Hb Sbt and Hb SF (Group II; n = 8). Both groups had elevated FRC, decreased maximum expiratory flows at FRC (V'max,FRC), and decreased time needed to reach peak expiratory flow (tme/tE), suggesting lower airway obstruction (LAO) and hyperinflation. Restrictive disease was found in only three patients of Group I. Our findings suggest that in sickle cell disease (especially among patients with Hb SS), abnormal lung function (predominantly LAO) may be present in early infancy. Airway reactivity may play a role in the pathogenesis, but the relation to VOC or ACS remains unclear.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A C Koumbourlis, A Hurlet-Jensen, M R Bye. 1997. Lung function in infants with sickle cell disease.. https://doi.org/10.1002/(sici)1099-0496(199710)24%3A4%3C277%3A%3Aaid-ppul6%3E3.0.co%3B2-h

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Correction of compliance and resistance altered by endotracheal tube leaks and non-linear pressure/volume-relationships.

Measurements of lung compliance (C) and resistance (R) are influenced by endotracheal tube leaks (ETTL) as well as non-linear pressure/volume relationships (P/V relationship). To keep C and R reliable, we developed an algorithm to mathematically correct inspiratory and expiratory volume (V) and flow. In this study, a ventilated lung model for non-linear P/V relationship with adjustment of an increasing ETTL was studied. In addition, the recordings (airway pressure, flow, and volume) of 21 infants (median weight: 1,220 g, range: 640-2,160 g, with a median leak size of 32%, range: 24-56%) were investigated. C and R were calculated continuously from the recordings of flow, volume, and airway pressure over time according to the changing volume. A method especially developed for the analysis of non-linear pressure-volume-relationship (APVNL) was employed. C and R affected by leaks were corrected applying the newly developed mathematical algorithm and compared with measurements without leakage. C could be corrected up to a leak of 80% and R up to 55% leak at half tidal V for the model with non-linear P/V-R. C and R without leak and after leak correction did not differ significantly in all infants where the APVNL method was applied (P > 0.05).

Airway Resistance↗

Parenchymal tethering, airway wall stiffness, and the dynamics of bronchoconstriction.

We do not yet have a good quantitative understanding of how the force-velocity properties of airway smooth muscle interact with the opposing loads of parenchymal tethering and airway wall stiffness to produce the dynamics of bronchoconstriction. We therefore developed a two-dimensional computational model of a dynamically narrowing airway embedded in uniformly elastic lung parenchyma and compared the predictions of the model to published measurements of airway resistance made in rats and rabbits during the development of bronchoconstriction following a bolus injection of methacholine. The model accurately reproduced the experimental time-courses of airway resistance as a function of both lung inflation pressure and tidal volume. The model also showed that the stiffness of the airway wall is similar in rats and rabbits, and significantly greater than that of the lung parenchyma. Our results indicate that the main features of the dynamical nature of bronchoconstriction in vivo can be understood in terms of the classic Hill force-velocity relationship operating against elastic loads provided by the surrounding lung parenchyma and an airway wall that is stiffer than the parenchyma.

Airway Resistance↗

Use of dynamic compliance for open lung positive end-expiratory pressure titration in an experimental study.

OBJECTIVE: We tested whether the continuous monitoring of dynamic compliance could become a useful bedside tool for detecting the beginning of collapse of a fully recruited lung. DESIGN: Prospective laboratory animal investigation. SETTING: Clinical physiology research laboratory, University of Uppsala, Sweden. SUBJECTS: Eight pigs submitted to repeated lung lavages. INTERVENTIONS: Lung recruitment maneuver, the effect of which was confirmed by predefined oxygenation, lung mechanics, and computed tomography scan criteria, was followed by a positive end-expiratory pressure (PEEP) reduction trial in a volume control mode with a tidal volume of 6 mL/kg. Every 10 mins, PEEP was reduced in steps of 2 cm H2O starting from 24 cm H2O. During PEEP reduction, lung collapse was defined by the maximum dynamic compliance value after which a first measurable decrease occurred. Open lung PEEP according to dynamic compliance was then defined as the level of PEEP before the point of collapse. This value was compared with oxygenation (Pao2) and CT scans. MEASUREMENTS AND MAIN RESULTS: Pao2 and dynamic compliance were monitored continuously, whereas computed tomography scans were obtained at the end of each pressure step. Collapse defined by dynamic compliance occurred at a PEEP of 14 cm H2O. This level coincided with the oxygenation-based collapse point when also shunt started to increase and occurred one step before the percentage of nonaerated tissue on the computed tomography exceeded 5%. Open lung PEEP was thus at 16 cm H2O, the level at which oxygenation and computed tomography scan confirmed a fully open, not yet collapsed lung condition. CONCLUSIONS: In this experimental model, the continuous monitoring of dynamic compliance identified the beginning of collapse after lung recruitment. These findings were confirmed by oxygenation and computed tomography scans. This method might become a valuable bedside tool for identifying the level of PEEP that prevents end-expiratory collapse.

Airway Resistance↗