Diaphragm Dimensions of the Healthy Term Infant

Aim: Human neonatal diaphragm development has not been extensively studied. Previous work in children and adults suggests that diaphragm thickness (tdi) is in scale with body size such that maximal transdiaphragmatic pressure (Pdimax) remains relatively constant. Such assessments have not been made in healthy term infants. This study was designed to evaluate the relationships among tdi, body dimensions and Pdimax healthy term infants. Methods: It was hypothesized that in healthy term infants 1) tdi is positively correlated with body size and 2) calculated Pdimax is independent of body weight and length. Fifteen clinically stable term infants (8 males and 7 females) were recruited [birthweight (BW), 3.3 ± 0.7 kg, (mean ± SD); head circumference (HC), 33.7 ± 2 cm; body length (BL) 50 ± 3 cm; gestational age (GA) 39 ± 1 wk; and postnatal age 1.7 ± 0.8 day]. Ultrasound was used to visualize the diaphragm at the level of the zone of apposition and measure tdi. Standard techniques were used to measure the anthropometric dimensions of the rib cage. Pdimax was calculated using the piston‐in‐cylinder model of diaphragm function. Results: Significant correlations were found among tdi and BW (R = 0.58), BL (R = 0.58) and HC (R = 0.65) but not between GA (R = 0.20). Larger infants tended to have thicker diaphragms and larger cross‐sectional areas of the lower rib cage (AZAP). For the group, calculated Pdimax was independent of either body weight or length and was greater than that calculated for adults.

[1]  P. Fayers,et al.  Exploring Longitudinal Data , 2002 .

[2]  V. Rehan,et al.  Effects of Continuous Positive Airway Pressure on Diaphragm Dimensions in Preterm Infants , 2001, Journal of Perinatology.

[3]  V. Rehan,et al.  Diaphragm dimensions of the healthy preterm infant. , 2001, Pediatrics.

[4]  V. Rehan,et al.  Effects of the supine and prone position on diaphragm thickness in healthy term infants , 2000, Archives of disease in childhood.

[5]  G. Sieck,et al.  Maximum specific force depends on myosin heavy chain content in rat diaphragm muscle fibers. , 2000, Journal of applied physiology.

[6]  V. Rehan,et al.  Effects of CPAP on Diaphragm Dimensions in the Neonate , 1999 .

[7]  J. Watchko,et al.  Ventilatory failure during resistive loaded breathing in the newborn primate , 1998, Pediatric pulmonology.

[8]  D. Chemla,et al.  Developmental changes in crossbridge properties and myosin isoforms in hamster diaphragm. , 1997, American journal of respiratory and critical care medicine.

[9]  S. Eveloff,et al.  Diaphragm thickening during inspiration. , 1997, Journal of applied physiology.

[10]  F. Mccool,et al.  Ultrasound evaluation of the paralyzed diaphragm. , 1997, American journal of respiratory and critical care medicine.

[11]  J. Benditt,et al.  Variability of diaphragm structure among healthy individuals. , 1997, American journal of respiratory and critical care medicine.

[12]  J. Benditt,et al.  Maximal inspiratory pressures and dimensions of the diaphragm. , 1997, American journal of respiratory and critical care medicine.

[13]  J. Watchko,et al.  Developmental transitions in the myosin heavy chain phenotype of human respiratory muscle. , 1996, Biology of the neonate.

[14]  M. Cohen,et al.  Lung volume specificity of inspiratory muscle training. , 1994, Journal of applied physiology.

[15]  D. E. Valentine,et al.  Effect of long-term undernutrition on male and female rat diaphragm contractility, fatigue, and fiber types. , 1994, Journal of applied physiology.

[16]  M Paiva,et al.  Three-dimensional reconstruction of the in vivo human diaphragm shape at different lung volumes. , 1994, Journal of applied physiology.

[17]  J. Watchko,et al.  Respiratory muscle fatigue resistance relates to myosin phenotype and SDH activity during development. , 1993, Journal of applied physiology.

[18]  G. Sieck,et al.  Effect of acute nutritional deprivation on diaphragm structure and function in adolescent rats. , 1992, Journal of applied physiology.

[19]  R Tojo,et al.  [The assessment of growth and development]. , 1991, Anales espanoles de pediatria.

[20]  A. Milner.  Basic Mechanisms of Pediatric Respiratory Disease: Cellular and Integrative , 1991 .

[21]  J. Khoury,et al.  New Ballard Score, expanded to include extremely premature infants. , 1991, The Journal of pediatrics.

[22]  D. Nichols.  Respiratory muscle performance in infants and children. , 1991, The Journal of pediatrics.

[23]  G. Sieck,et al.  Effect of acute nutritional deprivation on diaphragm structure and function. , 1990, Journal of applied physiology.

[24]  L. C. Maxwell,et al.  Regional distribution of fiber types in developing baboon diaphragm muscles , 1989, The Anatomical record.

[25]  A. C. Bryan,et al.  Comparison of diaphragmatic fatigue in newborn and older rabbits. , 1989, Journal of applied physiology.

[26]  A. C. Bryan,et al.  Comparison of diaphragmatic fatigue in newborn and older rabbits , 1988 .

[27]  A. Stark,et al.  Diaphragmatic movement in newborn infants. , 1988, The Journal of pediatrics.

[28]  W. LaFramboise,et al.  Developmental changes in the ventilatory response of the newborn to added airway resistance. , 1987, The American review of respiratory disease.

[29]  John K. Hall,et al.  Diaphragmatic Muscle Fiber Type Development in Swine , 1987, Pediatric Research.

[30]  J. Watchko,et al.  Response to Resistive Loading in the Newborn Piglet , 1987, Pediatric Research.

[31]  J. Mortola.  Dynamics of breathing in newborn mammals. , 1987, Physiological reviews.

[32]  J. Watchko,et al.  Postnatal Changes in Transdiaphragmatic Pressure in Piglets , 1986, Pediatric Research.

[33]  J. Leiter,et al.  A comparative analysis of contractile characteristics of the diaphragm and of respiratory system mechanics. , 1986, Respiration physiology.

[34]  R. McCARTER,et al.  Temporal changes after death in primate diaphragm muscle oxidative enzyme activity. , 1984, American Review of Respiratory Disease.

[35]  T. Shaffer,et al.  Effect of External Inspiratory Loading on Ventilation of Premature Infants , 1984, Pediatric Research.

[36]  R. McCARTER,et al.  Development of histochemical and functional properties of baboon respiratory muscles. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[37]  D. F. Rochester,et al.  Maximum contractile force of human diaphragm muscle, determined in vivo. , 1982, Transactions of the American Clinical and Climatological Association.

[38]  T. Clarke,et al.  Maximum inspiratory force in predicting successful neonate tracheal extubation. , 1979 .

[39]  A C Bryan,et al.  Diaphragmatic muscle fatigue in the newborn. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[40]  A. C. Bryan,et al.  Developmental pattern of muscle fiber types in human ventilatory muscles. , 1978, Journal of applied physiology: respiratory, environmental and exercise physiology.

[41]  D. Leith.  Comparative mammalian respiratory mechanics. , 1976, The Physiologist.

[42]  D. Leith,et al.  Ventilatory muscle strength and endurance training. , 1976, Journal of applied physiology.

[43]  H. Prechtl,et al.  The behavioural states of the newborn infant (a review). , 1974, Brain research.

[44]  L. C. Maxwell,et al.  Adaptation of guinea pig diaphragm muscle to aging and endurance training. , 1972, The American journal of physiology.

[45]  Davidson Mb.  The relationship between diaphragm and body weight in the rat. , 1968 .

[46]  Stahl Wr,et al.  Systematic allometry in five species of adult primates. (Systematic allometry in primates). , 1967 .

[47]  W. R. Stahl,et al.  Systematic allometry in five species of adult primates. (Systematic allometry in primates). , 1967, Growth.

[48]  F. Adams,et al.  Alteration of the infant's thorax during vaginal delivery. , 1963, Acta obstetricia et gynecologica Scandinavica.

[49]  Goyer Ra,et al.  The size of muscle fibers in infants and children. , 1960 .