Thoracoabdominal Compression and Respiratory System Compliance in HIV-infected Infants

Abstract

The thoracoabdominal compression technique (TAC) is used to measure expiratory flow in infants. We investigated whether TAC caused a change in total thoracic compliance (Crs), resistance (Rrs), and respiratory system time constant (Trs). We studied 41 infants (mean age, 12.4 mo; SD, 7.5) from five centers studying longitudinal lung and cardiovascular function of infants from HIV-infected mothers. We measured Crs, Rrs, and Trs before and after TAC. Changes in Crs, Rrs, and Trs after TAC were not dependent on the length of time since TAC. Crs and Trs were reduced after TAC, p = 0.013 and p = 0.003, respectively, whereas Rrs did not change. When compared with uninfected infants, HIV-infected infants had a larger post-pre TAC percent decline in Crs (p = 0.003) and a post-pre TAC rise in mean Rrs (p = 0.03). These differences remained significant after adjusting for sex and age. When performing infant pulmonary function testing, TAC itself produces a temporary decrease in Crs and Trs that is more significant in infants at risk for abnormal lung volume or compliance. Therefore, the sequence of performing the infant lung function parameters should be the same each time the testing is repeated with TAC as the last parameter tested at each testing session.

Changes in multiple breath washout measures after raised volume rapid thoracoabdominal compression maneuvers in infants

“…Previous studies examining the effects of thoracoabdominal compression maneuvers on tidal flow measures support our findings that tidal volume decreases after thoracoabdominal compressions. In a study by Platzker et al, tidal breathing compression technique decreased compliance and respiratory system time constants post tidal compression maneuvers. Furthermore, there was a differential effect of the disease status on the time constant with more severe lung disease being associated with a greater decrease in time constants.…”

Effect of raised lung volume technique on subsequent measures of V′maxFRC in infants

“…15 Additionally, although atelectasis is unlikely to occur in healthy full-term infants beyond the neonatal period, repeated compressions of the chest and upper abdomen with an inflatable jacket, as required during both full and partial forced expiratory maneuvers in infants, may induce changes in lung volume and mechanics. 43 In summary, in addition to the potential impact of any gastric distension, possible explanations for the observed variability in forced expiratory flow measurements after the raised volume technique include changes in airway smooth muscle properties, airway-parenchymal relationships, stretch receptor activity, lung volumes, or pressure volume characteristics of the lungs and airways, all of which may be influenced by developmental changes. Further, carefully designed studies to separate out the effects of lung inflations and chest compressions, wherein the magnitude and duration of lung inflations can be administered in a standardized fashion, ideally accompanied by repeated assessment of resting lung volume, airway and lung tissue mechanics, and airway caliber, all of which were beyond the scope of this study, will be necessary to determine which, if any, of these mechanisms are primarily responsible for the observed changes.…”

White Matter Development is Potentially Influenced in Adolescents with Vertically Transmitted HIV Infections: A Tract-Based Spatial Statistics Study

“…1 HIV is a neurotrophic virus affecting the cellular immune system through the infection and destruction of CD4 lymphocytes, which causes multiple organs, such as the respiratory system, 2 digestive system, 3 and CNS, to have relevant illnesses. 4 Cognitive impairment, HIV-associated dementia, and AIDS dementia complex are commonly observed.…”