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P A Tansey

Publications and source records attributed to P A Tansey.

5 recordsLinked to original sources
PubMed1989

Periodic breathing parameter values depend on specific pneumogram scoring criteria.

Periodic breathing (PB) has been related to both normal and pathologic respiratory system control in infants. However, comparison of the results of separate studies has been limited by the variability in procedures used by different investigators to quantify PB. In this study we scored 15 24-hr impedance pneumograms using the criteria of Parmelee et al. (Neuropediatrie 3:294-304, 1972), Christova-Gueorguieva (Biology of the Neonate 44:325-332, 1983), and Curzi-Dascalova, Kelly and Shannon (Pediatrics 63:355-360, 1979) and analyzed the resulting differences in several commonly used PB parameters. Scoring criteria consistently and significantly influenced three PB parameters: the %PB, number of episodes of PB/100 min recording time, and mean duration of PB episode length showed average changes of 74%, 179%, and 36%, respectively, when the methods with the most extreme differences were compared. In contrast, the duration of the longest episode of PB showed no significant change as a function of scoring criteria. Awareness of the particular method of PB scoring is therefore essential in interpreting PB parameter values.

Cardiography, Impedance↗
PubMed1989

Periodic breathing in preterm infants: influence of bronchopulmonary dysplasia and theophylline.

Periodic breathing (PB) has been studied extensively in both normal term infants and term infants presumed to be at high risk for sudden infant death syndrome (SIDS); however, little is known about the incidence and significance of PB in preterm infants. Twenty-four hour impedance pneumograms were obtained from 108 preterm infants prior to their discharge from the nursery and four PB parameters (%PB, No. of episodes of PB/100 min, mean duration of PB episode length, and duration of the longest episode of PB) were quantified in each recording. Control infants who were asymptomatic for apnea had the highest PB parameter values (%PB, 12.0; No. episodes/100 min, 8.6; mean duration, 1.2 min; and longest episode, 7.3 min); infants with bronchopulmonary dysplasia (BPD) showed dramatic decreases in all PB parameters, with a median %PB of 1/16 of the control population. Theophylline use was associated with a significant decrease in PB parameter values only in infants without BPD. Central apneas greater than 15 s did not vary significantly as a function of BPD, theophylline, or postconceptional age. We conclude that the clinical status of preterm infants significantly influences PB parameter values and must be taken into account in the interpretation of pneumograms, for decision-making about home cardiorespiratory monitoring, and in assigning risk for SIDS.

Acoustic Impedance Tests↗
PubMed1989

Periodic breathing cycle duration in preterm infants.

Periodic breathing cycle duration (PCD), the time interval from the beginning of one respiratory pause to the beginning of the next pause within an episode of periodic breathing (PB), was measured by examination of 24-h impedance pneumograms in 51 preterm infants. Calculations of the SD of PCD within a given PB episode (approximately 3 s) and comparison of PCD values between two PB episodes in each infant (r = 0.68) revealed considerable variability in PCD. This variability was not related to the number of cycles in the PB episode or to the amount of PB in the recording. Contrary to the decrease in PCD from 15.0 s at 1 wk to 12.4 s at 12 wk in term infants reported previously, PCD did not vary as a function of postconceptional, gestational, or postnatal age in our preterm population. PCD has limited value as an indicator of chemoreceptor maturation in the preterm infant, and most likely reflects transient adjustments in respiratory system control.

Aging↗
PubMed1989

Periodic breathing in preterm infants: incidence and characteristics.

The prevalence and characteristics of periodic breathing in preterm infants were measured by 24-hour impedance pneumograms in 66 preterm infants before discharge from the nursery. Four periodic breathing parameters (percentage of periodic breathing per quiet time, number of episodes of periodic breathing per 100 minutes of quiet time, mean duration of periodic breathing, and longest episode of periodic breathing) were compared to data available from healthy term infants and from term infants who subsequently died of sudden infant death syndrome (SIDS). Periodic breathing was found in all preterm infants studied and mean periodic breathing parameter values (12.0%, 8.6 episodes, 1.2 minutes, and 7.3 minutes, respectively) in our preterm population were substantially higher than values from healthy term infants and SIDS victims. Most periodic breathing parameters decreased significantly in infants studied at 39 to 41 weeks' postconceptional age compared with earlier postconceptional age groups. No relationship was found between central apneas of greater than or equal to 15 seconds' duration and postconceptional age or any periodic breathing parameter. Periodic breathing is a common respiratory pattern in preterm infants that is usually not of pathologic significance. Associations between elevated levels of periodic breathing and respiratory dysfunction or SIDS should be made with caution.

Apnea↗