Differences In Respiratory Patterns Research Articles

Respiratory patterns in neonates hospitalized with brief resolved unexplained events

Objective: The objective of this study is aimed at investigating and evaluating respiratory patterns between infants hospitalized with brief resolved unexplained event (BRUE) and the control group. Methods: A convenient sampling method was used to select 52 patients presented at an urban, tertiary, and teaching pediatric hospital fitting the American Academy of Pediatrics' criteria of a lower-risk BRUE from December 2019 to December 2020. A random probability sampling method was used to select 52 patients as a control group. A NINIX apnea monitoring device was used to record respiratory time patterns and analyzed with SPSS 25. Results: A total of 104 participants participated in the study. Our study found that inspiration time (0.31 ± 0.04), expiratory time (0.93 ± 0.14), respiratory rate (38.48 ± 4.38), body temperature (37.11 ± 0.20), and heart rate (137.90 ± 6.60) were not statistically different between both groups. Mean birth weight in the control group and BRUE were respectively (3.43 ± 0.39, 3.23 ± 0.35). Mean gestational age in the control and BRUE groups were respectively (38.94 ± 1.01, 39.0 ± 1.04). Mean postnatal age in the control and BRUE groups were respectively (17.19 ± 6.07, 17.32 ± 7.35). Birth weight (P = 0.08) was statistically significant between both groups. In one patient, we recorded breath arrest for more than 20 s. Conclusion: There were no significant differences in respiratory patterns between infants hospitalized with BRUE and the control group. Low birth weight and low APGAR score are possible risk factors for infants experiencing BRUE, and more investigations are required to establish underlying causes.

3D analysis of sexual dimorphism in size, shape and breathing kinematics of human lungs.

Sexual dimorphism in the human respiratory system has been previously reported at the skeletal (cranial and thoracic) level, but also at the pulmonary level. Regarding lungs, foregoing studies have yielded sex-related differences in pulmonary size as well as lung shape details, but different methodological approaches have led to discrepant results on differences in respiratory patterns between males and females. The purpose of this study is to analyse sexual dimorphism in human lungs during forced respiration using 3D geometric morphometrics. Eighty computed tomographies (19 males and 21 females) were taken in maximal forced inspiration (FI) and expiration (FE), and 415 (semi)landmarks were digitized on 80 virtual lung models for the 3D quantification of pulmonary size, shape and kinematic differences. We found that males showed larger lungs than females (P < 0.05), and significantly greater size and shape differences between FI and FE. Morphologically, males have pyramidal lung geometry, with greater lower lung width when comparing with the apices, in contrast to the prismatic lung shape and similar widths at upper and lower lungs of females. Multivariate regression analyses confirmed the effect of sex on lung size (36.26%; P < 0.05) and on lung shape (7.23%; P < 0.05), and yielded two kinematic vectors with a small but statistically significant angle between them (13.22°; P < 0.05) that confirms sex-related differences in the respiratory patterns. Our 3D approach shows sexual dimorphism in human lungs likely due to a greater diaphragmatic action in males and a predominant intercostal muscle action in females during breathing. These size and shape differences would lead to different respiratory patterns between sexes, whose physiological implications need to be studied in future research.

Main Taste Effects on Swallowing Apnea Duration in Healthy Adults

This study examined swallowing apnea duration (SAD) and respiratory phase patterns as a function of taste, tastes combined with barium, age, and genetic taste group. Prospective group design. University medical center. Eighty healthy adult women were identified as nontasters and supertasters and equally comprised 2 age groups: 18 to 35 years (n = 40) and 60+ years (n = 40). The KayPentax Swallowing Signals Lab was used to acquire SAD and respiratory phase patterns via nasal cannula during randomized 5-mL swallows of water, 1.0 M sucrose (sweet), 1.0 M sodium chloride (salty), and 0.032 M caffeine (bitter) alone and mixed with barium. The SAD and respiratory patterns were analyzed in a linear mixed model and a binary logistic regression generalized estimating equation model, respectively. A significant main effect of age was found (P = .007). Older women demonstrated longer SAD than younger women. There were no significant effects of taste or genetic taste group on SAD. There was a significant interaction between barium and supertaster status; SAD was shorter in supertasters when barium was included. There were no significant differences in respiratory patterns between age groups, genetic taste groups, or among taste stimuli. Advanced age elicited longer SAD, a robust finding in repeated investigations from multiple laboratories. Main tastes did not affect SAD or respiratory phase patterns. Genetic taste group altered SAD when barium was combined with the taste. That is, taste + barium shortened SAD in supertasters. This finding may affect clinical management of dysphagia patients and warrants further investigation.

Alternative and cytochrome pathway respiration during shoot bud formation in cultured Pinus radiata cotyledons

Respiration rates for excised cotyledons of Pinus radiata cultured in the presence (shoot‐forming) and absence (non‐shoot‐forming) of N6‐benzyladenine (BA) over a 21‐day period were measured using a Clark‐type oxygen electrode. The capacities and activities of cytochrome and alternative pathways of respiration were determined from titrations with KCN (1‐10 mM) and salicylhydroxamic acid (2–20 mM) individually and in combination. Respiration accounted for by alternative (AP) and cytochrome (CP) pathways varied with both culture treatment and age in culture. Rates of total respiration, CP respiration and AP activity rose concurrent with key developmental events of shoot bud formation. The greatest AP capacity was measured at day 3 in shoot‐forming tissue. In contrast, for cotyledons cultured under non‐shoot‐forming conditions, no AP activity was observed after day 3 despite relatively constant AP capacity throughout the culture period. Although initial increases in cotyledon respiration during the culture period may be related to wounding and introduction to a tissue culture environment, later differences in respiratory patterns between shoot‐forming and non‐shoot‐forming cotyledons appear to be associated with the cytokinin‐induced developmental changes which give rise to shoot primordia in cultured radiata pine cotyledons.

Differences in respiratory patterns after acute and chronic pulmonary denervation

The role of pulmonary vagal information in the control of respiratory patterns was assessed in awake and anaesthetised rats in which pulmonary denervation was effected by bilateral cervical vagotomy or by right cervical vagotomy combined with left pneumonectomy or left intrathoracic vagotomy. Acute denervation led to increases of tidal volume (V t), inspiratory duration (T i) and expiratory duration (T e) in both awake and halothane anaesthetised animals; in awake rats the increase of T e rapidly subsided. Chronic pulmonary denervation produced markedly smaller increases of V t and T i and no change of T e from control values. In hypercapnia, awake animals with combined pneumonectomy and vagotomy consistently increased respiratory frequency by reductions in T i and T e; awake animals with combined intrathoracic and cervical vagotomy showed no increase in f because decreases in T i offset increases in T e; in anaesthetised rats with acute bilateral cervical vagotomy there was a consistent fall in respiratory frequency due to an expiratory pause. The results demonstrate that (1) the role of vagal activity in the production of respiratory patterns is unlikely to be accounted for solely in terms of influences arising from pulmonary stretch receptors; (2) vagal influences of T e are transitory; (3) under halothane anaesthesia hypercapnia induces an expiratory pause; and (4) the combination of pneumonectomy with contralateral vagotomy makes possible studies in awake rats although pulmonary denervation is less complete than with bilateral intrathoracic vagotomy.

Sudden infant death syndrome: 1987 perspective

The pathophysiology of SIDS remains unknown. Although a multifactorial cause appears plausible on the basis of available data, new data are needed to determine which components of this multifactorial hypothesis are most important and whether other factors need to be added. We need to better understand control of breathing in the newborn infant and the manner in which maturation of cardiorespiratory control progresses during infancy. The unique period of vulnerability for SIDS, in which risk is less in the neonate than at 2 to 6 months of age, remains unexplained. Is there a worsening in some aspect of cardiorespiratory control in infants destined to die of SIDS? An improved understanding of the increased risk in black infants, preterm infants, and infants with intrauterine drug exposure, although only a small percentage of all SIDS deaths, should contribute substantially to our understanding. Appropriately designed and well-controlled prospective studies are needed in asymptomatic infants at risk, to determine the true contemporary nonintervention rate of SIDS and the extent to which any assessment or intervention lowers this rate. Prospective pneumogram screening studies have demonstrated significant group differences in respiratory patterns in normal infants compared with later SIDS victims, but have failed to achieve sufficient sensitivity and specificity to be useful for populationwide prospective screening. To assess aspects of brainstem cardiorespiratory control in addition to those assessed by a conventional pneumogram, future studies will need to be based on an expanded or modified technology. On the basis of both physiologic considerations and available technology, addition of an oxygen saturation channel offers the most promise for providing a more comprehensive assessment of cardiorespiratory control. If there is an underlying deficiency in asphyxic arousal responsiveness, for example, with or without other respiratory control deficits, continuous monitoring of oxygen saturation as part of a second-generation pneumogram system currently has the greatest promise for providing a modified pneumogram assessment of greater clinical use. The use of continuous oxygen saturation as a home monitoring technique should also be investigated. Power spectrum analysis of cardiorespiratory variability also appears to have potential advantages over conventional pneumogram analyses, and needs to be evaluated in prospective studies. The following statements summarize our current knowledge regarding SIDS, apnea, pneumograms, and home monitors: The cause(s) of SIDS remains unknown.(ABSTRACT TRUNCATED AT 400 WORDS)

Differences in respiratory patterns after acute and chronic pulmonary denervation

The role of pulmonary vagal information in the control of respiratory patterns was assessed in awake and anaesthetised rats in which pulmonary denervation was effected by bilateral cervical vagotomy or by right cervical vagotomy combined with left pneumonectomy or left intrathoracic vagotomy. Acute denervation led to increases of tidal volume (V t), inspiratory duration (T i) and expiratory duration (T e) in both awake and halothane anaesthetised animals; in awake rats the increase of T e rapidly subsided. Chronic pulmonary denervation produced markedly smaller increases of V t and T i and no change of T e from control values. In hypercapnia, awake animals with combined pneumonectomy and vagotomy consistently increased respiratory frequency by reductions in T i and T e; awake animals with combined intrathoracic and cervical vagotomy showed no increase in f because decreases in T e; in anaesthetised rats with acute bilateral cervical vagotomy there was a consistent fall in respiratory frequency due to an expiratory pause. The results demonstrate that (1) the role of vagal activity in the production of respiratory patterns is unlikely to be accounted for solely in terms of influences arising from pulmonary stretch receptors; (2) vagal influences of T e are transitory; (3) under halothane anaesthesia hypercapnia induces an expiratory pause; and (4) the combination of pneumonectomy with contralateral vagotomy makes possible studies in awake rats although pulmonary denervation is less complete than with bilateral intrathoracic vagotomy.