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De Benedetto F, Marinari S, De Blasio F. Phase angle in assessment and monitoring treatment of individuals with respiratory disease. Rev Endocr Metab Disord 2023; 24:491-502. [PMID: 36694055 DOI: 10.1007/s11154-023-09786-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/05/2023] [Indexed: 01/26/2023]
Abstract
Phase angle (PhA) represents a raw variable measured with bioelectrical impedance analysis (BIA) that is used to assess malnutrition in many diseases, including respiratory diseases, mainly chronic obstructive pulmonary disease (COPD). COPD patients with reduced PhA are older, more hypoxic and hypercapnic; patients with more severe COPD have reduced cell mass, evident skeletal muscle depletion, and worsening gas exchange. Malnourished patients with stable COPD in long-term oxygen therapy (LTOT) have more intense dyspnea at rest, greater weight loss over the past 12 months, and more exacerbations per year. Multiple regression analysis highlighted the significance of PhA° in the estimation of muscle strength: hand grip strength (HGS) and in that of respiratory muscles: maximal inspiratory pressure / max. expiratory pressure ratio (MIP/MEP). Furthermore, the relationship between PhA° and all-cause mortality in COPD patients was confirmed with the Cox regression model, Kaplan-Meier test, and log-rank tests. The role of malnutrition in idiopathic pulmonary fibrosis (IPF) is confirmed by the PhA° measurements which, regardless of body weight, is associated with the reduction in muscle mass of these patients, reduces their strength and exercise capacity, and greatly influences the prognosis. In conclusion PhA is a novel biomarker of morbidity and mortality in patients with severe respiratory diseases.
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Affiliation(s)
- Fernando De Benedetto
- Scientific Director FISAR Foundation (Fondazione Salute Ambiente e Respiro), Chieti, Italy.
| | | | - Francesco De Blasio
- Respiratory Medicine and Pulmonary Rehabilitation Unit - Clinic Center Private Hospital, Naples, Italy
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2
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Ryu G, Kim HY, Choi JH. Associations of respiratory mechanic instability with respiratory parameters in pediatric patients with obstructive sleep apnea syndrome. Int J Pediatr Otorhinolaryngol 2022; 159:111208. [PMID: 35728462 DOI: 10.1016/j.ijporl.2022.111208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/25/2022] [Accepted: 06/09/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This study aimed to identify the effectiveness of respiratory mechanic instability (RMI) in the diagnosis of pediatric obstructive sleep apnea syndrome (OSAS). We sought to evaluate the correlations of RMI with sleep-related parameters and determine the effectiveness of using RMI for diagnosing OSAS in children. METHODS Children who underwent polysomnography (PSG) for various reasons were enrolled in this study. Patients' clinical and PSG data at two university hospitals were reviewed retrospectively. During PSG, RMI parameters were automatically calculated according to the phase relationship between thoracic and abdominal movement signals. RESULTS Among 263 children who underwent PSG, 183 (70.4%) were diagnosed with OSAS (apnea-hypopnea index [AHI] ≥ 1). RMI parameters were higher in the OSAS group than in the control group. They also tended to increase with disease severity. RMI scores were well correlated with respiratory parameters, showing a stronger correlation in those with moderate or severe OSAS without central apnea. Areas under the receiver operating characteristics curves (AUROCs) of RMI indicators were over 0.65. The percentage of RMI in stage duration showed the highest value of the AUROCs. CONCLUSION Paradoxical thoraco-abdominal movement assessed by RMI provides additional information. It may be useful in diagnosing OSAS in children.
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Affiliation(s)
- Gwanghui Ryu
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
| | - Hyo Yeol Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
| | - Ji Ho Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon, Gyeonggi-do, Republic of Korea.
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3
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Passafiume JA, Glover NA, Crecelius AR, Chaudhari AMW. The influence of receiving real-time visual feedback on breathing during treadmill running to exhaustion. PLoS One 2022; 17:e0270335. [PMID: 35797373 PMCID: PMC9262203 DOI: 10.1371/journal.pone.0270335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/08/2022] [Indexed: 11/24/2022] Open
Abstract
Breathing plays a vital role in everyday life, and specifically during exercise it provides working muscles with the oxygen necessary for optimal performance. Respiratory inductance plethysmography (RIP) monitors breathing through elastic belts around the chest and abdomen, with efficient breathing defined by synchronous chest and abdomen movement. This study examined if providing runners with visual feedback through RIP could increase breathing efficiency and thereby time to exhaustion. Thirteen recreational runners (8F, 5M) ran to exhaustion on an inclined treadmill on two days, with visual feedback provided on one randomly chosen day. Phase angle was calculated as a measure of thoraco-abdominal coordination. Time to exhaustion was not significantly increased when visual feedback was provided (p = 1). Phase angle was not significantly predicted by visual feedback (p = 0.667). Six participants improved phase angle when visual feedback was provided, four of whom increased time to exhaustion. Four participants improved phase angle by 9° or more, three of whom increased time to exhaustion. Participants who improved phase angle with visual feedback highlight that improving phase angle could increase time to exhaustion. Greater familiarization with breathing techniques and visual feedback and a different paradigm to induce running fatigue are needed to support future studies of breathing in runners.
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Affiliation(s)
- Joseph A. Passafiume
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
| | - Nelson A. Glover
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio, United States of America
| | - Anne R. Crecelius
- Department of Health and Sport Science, University of Dayton, Dayton, Ohio, United States of America
| | - Ajit M. W. Chaudhari
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio, United States of America
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, Ohio, United States of America
- Sports Medicine Research Institute, The Ohio State University, Columbus, Ohio, United States of America
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Choi JH, Jung JY, Moon JE, Hwang SH. The Usefulness of Respiratory Mechanic Instability in Evaluating the Effect of Continuous Positive Airway Pressure for Obstructive Sleep Apnea. Ann Otol Rhinol Laryngol 2019; 129:388-393. [PMID: 31779483 DOI: 10.1177/0003489419889371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Respiratory mechanics instability (RMI) based on paradoxical movement is correlated with respiratory disturbance such as apnea-hypopnea index (AHI) and reflects the severity of obstructive sleep apnea (OSA). The purpose of this study was to identify RMI as a method for assessing the effectiveness of continuous positive airway pressure (CPAP) in the management for OSA. METHODS A total of 71 consecutive OSA patients with CPAP titration were included in this study. We compared sleep (sleep efficiency, arousal index, and sleep stages), respiratory (AHI, oxygen desaturation index ≥3% [ODI3], and lowest oxygen saturation), and RMI parameters (events, index, duration, and % of stage duration) between diagnostic polysomnography and CPAP titration data. RESULTS All RMI parameters (events [157.5 ± 80.9 vs 80.0 ± 47.1; P < .001], index [25.3 ± 12.4 vs 12.7 ± 7.0; P < .001], duration [182.6 ± 96.2 vs 79.8 ± 88.9; P < .001], and % of stage duration [49.0 ± 24.4 vs 20.5 ± 21.3; P < .001]) were significantly improved by the alleviation of obstructive respiratory disturbance parameters (AHI [45.1 ± 23.0 vs 4.2 ± 4.3; P < .001], ODI3 [44.9 ± 22.6 vs 4.8 ± 4.6; P < .001], and lowest oxygen saturation [77.7 ± 7.3 vs 89.3 ± 3.8; P < .001]) compared to diagnostic polysomnography and CPAP titration data. CONCLUSION RMI may be a useful method for evaluating the effect of CPAP in OSA patients.
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Affiliation(s)
- Ji Ho Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Soonchunhyang University, Bucheon Hospital, Bucheon, Korea
| | - Jae Yeup Jung
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Soonchunhyang University, Cheonan Hospital, Cheonan, Korea
| | - Ji Eun Moon
- Department of Biostatistics, Clinical Trial Center, Soonchunhyang University, Bucheon Hospital, Bucheon, Korea
| | - Se-Hwan Hwang
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Zaffanello M, Lippi G, Tenero L, Piazza M, Sacchetto L, Nosetti L, Gasperi E, Piacentini G. Childhood nasal obstruction and sleep-disordered breathing during clinical setting: Myth or reality? ACTA ACUST UNITED AC 2018. [DOI: 10.18621/eurj.410657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Flénet T, Fontecave-Jallon J, Guméry PY, Eynard C, Boucher F, Baconnier P, Tanguy S. High-resolution respiratory inductive plethysmography in rats: validation in anesthetized conditions. Physiol Meas 2017; 38:1362-1372. [PMID: 28301327 DOI: 10.1088/1361-6579/aa6737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Respiratory monitoring is often required in experimental physiological and pharmacological studies in rodents. Currently, the mostly used techniques are direct measurement of airflow on intubated animals and whole body plethysmography. OBJECTIVE Although the reliability of these methods has been broadly demonstrated, they also have several drawbacks such as invasiveness, high cost of use or confinement of the animals. Respiratory inductive plethysmography (RIP) is a non-invasive technique already used in medium-sized mammals that has not yet been evaluated in small rodents. The implementation of inductive plethysmography in rats represents an instrumental challenge because of the small inductances that are expected. APPROACH A rodent-specific RIP apparatus has been developed and compared to direct airflow measurement provided by a pneumotachograph (PNT) considered as the invasive gold standard for respiratory monitoring. The experiments were carried out on anesthetized rats artificially ventilated at different levels of tidal volumes (V T) covering the whole physiological range. MAIN RESULTS Based on the Euclidian distance between signals, this study shows that after calibration, signals from RIP fit at 93% with PNT values. The Bland and Altman plot evidences differences between RIP and PNT lower than 20% and the values obtained are highly correlated (R = 0.98, p < 0.001). SIGNIFICANCE This study demonstrates that it is possible to design RIP systems suitable for measurement of tidal volumes and airflow in anesthetized rats. Further studies will now be focused on the validation in extended physiological conditions.
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Affiliation(s)
- T Flénet
- Université Grenoble Alpes, CNRS, TIMC-IMAG Laboratory UMR 5525, PRETA team, F-38041 Grenoble, France
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Brennan C, Ulm L, Julian S, Hamvas A, Ferkol T, Hoffman J, Linneman L, Kemp J. Thoracoabdominal Asynchrony Is Not Associated with Oxyhemoglobin Saturation in Recovering Premature Infants. Neonatology 2017; 111:297-302. [PMID: 28013296 PMCID: PMC5443694 DOI: 10.1159/000452787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 10/22/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Recovering premature infants are at risk for hypoxemia and lack of synchrony between their rib cage and abdomen due to airflow obstruction and poor respiratory compliance. Thoracoabdominal asynchrony (TAA) is a useful marker of resistive and elastic lung properties. Whether TAA predicts oxygenation is unknown. OBJECTIVES We investigated oxyhemoglobin saturation (SpO2%) and TAA (phase angle, φ) in preterm infants with/without high-humidity nasal cannula (HHNC). METHODS A cross-sectional observational study was conducted in 92 infants at 32 weeks' postmenstrual age. We measured SpO2% with pulse oximetry and TAA with φ via respiratory inductance plethysmography in infants (mean gestational age: 26.4 + 1.3 weeks) who required room air (n = 18) or HHNC with/without supplemental oxygen (1-5 liters per minute, FiO2 0.21-0.33, n = 74). We calculated median SpO2% from 24.7 + 10.0 min of quiet sleep and median φ from up to 60 breaths. RESULTS Infants breathing room air alone had marked TAA (φ = 83.6 + 32.9°, range: 10.9-148.5) as did those receiving varying degrees of ventilatory and oxygen support via HHNC (range of group means, φ = 47.0-90.0°). Infants breathing room air had statically greater median SpO2% than those receiving support (96.3 + 0.6% vs. 91.3 + 0.6%; ANOVA p = 0.001). SpO2% was not associated with TAA in either group (r2 = 0.09). CONCLUSION Recovering premature infants exhibited TAA regardless of need for ventilatory support and supplemental oxygen. TAA was not associated with SpO2% in either group. Maintenance of SpO2% does not require correction of TAA.
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Affiliation(s)
- Colleen Brennan
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
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Liu X, Immanuel S, Pamula Y, Kennedy D, Martin J, Baumert M. Adenotonsillectomy for childhood obstructive sleep apnoea reduces thoraco-abdominal asynchrony but spontaneous apnoea−hypopnoea index normalisation does not. Eur Respir J 2016; 49:13993003.01177-2016. [DOI: 10.1183/13993003.01177-2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/14/2016] [Indexed: 11/05/2022]
Abstract
The efficacy of adenotonsillectomy for treating obstructive sleep apnoea syndrome (OSAS) in children has been established, but its precise effects on inspiratory effort are not well documented.In 353 children enrolled in the Childhood Adenotonsillectomy Trial, randomised to undergo either early adenotonsillectomy (n=182) or a strategy of watchful waiting with supportive care (WWSC) (n=171), thoraco-abdominal asynchrony (TAA) was analysed during quiet, non-apnoeic and non-hypopnoeic breathing during sleep at baseline and at 7 months using overnight polysomnography.Children who underwent early adenotonsillectomy demonstrated a reduction in TAA post-surgery while the WWSC arm showed no change. On assessing TAA with regard to normalisation of clinical polysomnography findings at follow-up, TAA was reduced in children who had surgical resolution of OSAS (based on apnoea–hypopnoea index), but not in children who displayed spontaneous normalisation of apnoea–hypopnoea index. In the latter group, TAA was inversely correlated with quality of life.We conclude that adenotonsillectomy reduces TAA during quiet sleep. Monitoring of instantaneous TAA may yield additional insight in the dynamic changes of inspiratory effort. In combination with traditional indices of obstruction, TAA may more accurately characterise the degree of sleep-disordered breathing in children.
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An Official American Thoracic Society/European Respiratory Society Workshop Report: Evaluation of Respiratory Mechanics and Function in the Pediatric and Neonatal Intensive Care Units. Ann Am Thorac Soc 2016; 13:S1-11. [PMID: 26848609 DOI: 10.1513/annalsats.201511-730st] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ready access to physiologic measures, including respiratory mechanics, lung volumes, and ventilation/perfusion inhomogeneity, could optimize the clinical management of the critically ill pediatric or neonatal patient and minimize lung injury. There are many techniques for measuring respiratory function in infants and children but very limited information on the technical ease and applicability of these tests in the pediatric and neonatal intensive care unit (PICU, NICU) environments. This report summarizes the proceedings of a 2011 American Thoracic Society Workshop critically reviewing techniques available for ventilated and spontaneously breathing infants and children in the ICU. It outlines for each test how readily it is performed at the bedside and how it may impact patient management as well as indicating future areas of potential research collaboration. From expert panel discussions and literature reviews, we conclude that many of the techniques can aid in optimizing respiratory support in the PICU and NICU, quantifying the effect of therapeutic interventions, and guiding ventilator weaning and extubation. Most techniques now have commercially available equipment for the PICU and NICU, and many can generate continuous data points to help with ventilator weaning and other interventions. Technical and validation studies in the PICU and NICU are published for the majority of techniques; some have been used as outcome measures in clinical trials, but few have been assessed specifically for their ability to improve clinical outcomes. Although they show considerable promise, these techniques still require further study in the PICU and NICU together with increased availability of commercial equipment before wider incorporation into daily clinical practice.
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10
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Khemani RG, Flink R, Hotz J, Ross PA, Ghuman A, Newth CJL. Respiratory inductance plethysmography calibration for pediatric upper airway obstruction: an animal model. Pediatr Res 2015; 77:75-83. [PMID: 25279987 PMCID: PMC4268304 DOI: 10.1038/pr.2014.144] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 08/05/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND We sought to determine optimal methods of respiratory inductance plethysmography (RIP) flow calibration for application to pediatric postextubation upper airway obstruction. METHODS We measured RIP, spirometry, and esophageal manometry in spontaneously breathing, intubated Rhesus monkeys with increasing inspiratory resistance. RIP calibration was based on: ΔµV(ao) ≈ M[ΔµV(RC) + K(ΔµV(AB))] where K establishes the relationship between the uncalibrated rib cage (ΔµV(RC)) and abdominal (ΔµV(AB)) RIP signals. We calculated K during (i) isovolume maneuvers during a negative inspiratory force (NIF), (ii) quantitative diagnostic calibration (QDC) during (a) tidal breathing, (b) continuous positive airway pressure (CPAP), and (c) increasing degrees of upper airway obstruction (UAO). We compared the calibrated RIP flow waveform to spirometry quantitatively and qualitatively. RESULTS Isovolume calibrated RIP flow tracings were more accurate (against spirometry) both quantitatively and qualitatively than those from QDC (P < 0.0001), with bigger differences as UAO worsened. Isovolume calibration yielded nearly identical clinical interpretation of inspiratory flow limitation as spirometry. CONCLUSION In an animal model of pediatric UAO, isovolume calibrated RIP flow tracings are accurate against spirometry. QDC during tidal breathing yields poor RIP flow calibration, particularly as UAO worsens. Routine use of a NIF maneuver before extubation affords the opportunity to use RIP to study postextubation UAO in children.
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Affiliation(s)
- Robinder G. Khemani
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA,Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Rutger Flink
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA,Department of Biomedical Engineering, University of Groningen, Groningen, Netherlands
| | - Justin Hotz
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA
| | - Patrick A. Ross
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA,Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Anoopindar Ghuman
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA,Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Christopher JL Newth
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital Los Angeles, Los Angeles, California, USA,Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, USA
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11
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Cardiorespiratory safety evaluation in non-human primates. J Pharmacol Toxicol Methods 2012; 66:114-24. [DOI: 10.1016/j.vascn.2012.04.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 03/30/2012] [Accepted: 04/04/2012] [Indexed: 11/19/2022]
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12
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A simple dynamic model of respiratory pump. Acta Biotheor 2010; 58:265-75. [PMID: 20652727 DOI: 10.1007/s10441-010-9108-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/28/2010] [Indexed: 10/19/2022]
Abstract
To study the interaction of forces that produce chest wall motion, we propose a model based on the lever system of Hillman and Finucane (J Appl Physiol 63(3):951-961, 1987) and introduce some dynamic properties of the respiratory system. The passive elements (rib cage and abdomen) are considered as elastic compartments linked to the open air via a resistive tube, an image of airways. The respiratory muscles (active) force is applied to both compartments. Parameters of the model are identified in using experimental data of airflow signal measured by pneumotachography and rib cage and abdomen signals measured by respiratory inductive plethysmography on eleven healthy volunteers in five conditions: at rest and with four level of added loads. A breath by breath analysis showed, whatever the individual and the condition are, that there are several breaths on which the airflow simulated by our model is well fitted to the airflow measured by pneumotachography as estimated by a determination coefficient R(2) > or = 0.70. This very simple model may well represent the behaviour of the chest wall and thus may be useful to interpret the relative motion of rib cage and abdomen during quiet breathing.
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13
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Ross PA, Hammer J, Khemani R, Klein M, Newth CJL. Pressure-rate product and phase angle as measures of acute inspiratory upper airway obstruction in rhesus monkeys. Pediatr Pulmonol 2010; 45:639-44. [PMID: 20575087 DOI: 10.1002/ppul.21212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
RATIONALE There are limited validated, objective, and minimally invasive techniques for the bedside evaluation of upper airway obstruction (UAO) in sick infants, despite its frequency in pediatric medicine. Prior techniques include pressure-rate product (PRP), a product of esophageal pressure and respiratory rate and phase angles (PAs), a measure of asynchrony between ribcage and abdominal respiratory movements in infants with UAO. The purpose of this study is to validate the PRP and compare it to a previously validated PA in rhesus monkeys. METHODS Calibrated resistors were applied to the inspiratory limb of 10 anesthetized, intubated, and spontaneously breathing rhesus monkeys (weight 8.7 +/- 2.5 kg). Airway pressure, respiratory rate, PAs, heart rate, and oxygen saturation were recorded. Obstruction was applied in random order as 0, 5, 20, 200, 500, and 1,000 cmH(2)O/L/sec for 2-min periods, the last 15 sec (10-20 breaths) were analyzed for each timeframe. RESULTS PA increased significantly at the 200 cmH(2)O/L/sec level but it reached a plateau above 500 cmH(2)O/L/sec. PRP rose progressively and was significantly different at all levels of obstruction. Esophageal pressure change was progressively and statistically significantly different from baseline and each other at 200, 500, and 1,000 cmH(2)O/L/sec (P < 0.001). CONCLUSIONS In this model of UAO, PRP tracks increasing inspiratory load better than PA. PRP continued to be linear up through the highest inspiratory resistance where the change in PA reached a plateau before the highest load. The assessment of esophageal pressure changes may offer the simplest objective measure of UAO.
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Affiliation(s)
- Patrick A Ross
- University of Southern California Keck School of Medicine, Los Angeles, CA, USA.
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14
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Abstract
Thoraco-abdominal asynchrony is often observed in many respiratory disorders and/or respiratory muscle dysfunctions and clinically assessed as a sign of respiratory distress and increased work of breathing. This review describes the assessment of thoraco-abdominal asynchrony by respiratory inductance plethysmography. Visual inspection of the Konno-Mead plot yields information about the relative contribution of the RC and the ABD to respiration and about respiratory muscle dysfunction in selected patients. The monitoring of thoraco-abdominal asynchrony is a useful, non-invasive indicator of respiratory muscle load or respiratory muscle dysfunction and can be used to determine response to therapy in individual patients. The technique is limited by the fact that it does not detect respiratory muscle fatigue and that the occurrence of TAA does not always correspond to a clinically relevant respiratory problem, especially in the neonatal period.
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Affiliation(s)
- J Hammer
- Division of Intensive Care and Pulmonology, University Children's Hospital Basel, Römergasse, Basel 8 4005, Switzerland.
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15
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Gappa M, Pillow JJ, Allen J, Mayer O, Stocks J. Lung function tests in neonates and infants with chronic lung disease: lung and chest-wall mechanics. Pediatr Pulmonol 2006; 41:291-317. [PMID: 16493664 DOI: 10.1002/ppul.20380] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This is the fifth paper in a review series that summarizes available data and critically discusses the potential role of lung function testing in infants and young children with acute neonatal respiratory disorders and chronic lung disease of infancy (CLDI). This review focuses on respiratory mechanics, including chest-wall and tissue mechanics, obtained in the intensive care setting and in infants during unassisted breathing. Following orientation of the reader to the subject area, we focused comments on areas of enquiry proposed in the introductory paper to this series. The quality of the published literature is reviewed critically with respect to relevant methods, equipment and study design, limitations and strengths of different techniques, and availability and appropriateness of reference data. Recommendations to guide future investigations in this field are provided. Numerous different methods have been used to assess respiratory mechanics with the aims of describing pulmonary status in preterm infants and assessing the effect of therapeutic interventions such as surfactant treatment, antenatal or postnatal steroids, or bronchodilator treatment. Interpretation of many of these studies is limited because lung volume was not measured simultaneously. In addition, populations are not comparable, and the number of infants studied has generally been small. Nevertheless, results appear to support the pathophysiological concept that immaturity of the lung leads to impaired lung function, which may improve with growth and development, irrespective of the diagnosis of chronic lung disease. To fully understand the impact of immaturity on the developing lung, it is unlikely that a single parameter such as respiratory compliance or resistance will accurately describe underlying changes. Assessment of respiratory mechanics will have to be supplemented by assessment of lung volume and airway function. New methods such as the low-frequency forced oscillation technique, which differentiate the tissue and airway components of respiratory mechanics, are likely to require further development before they can be of clinical significance.
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Affiliation(s)
- Monika Gappa
- Department of Pediatric Pulmonology and Neonatology, Medizinische Hochschule Hannover, Hannover, Germany.
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16
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Willis BC, Graham AS, Yoon E, Wetzel RC, Newth CJL. Pressure-rate products and phase angles in children on minimal support ventilation and after extubation. Intensive Care Med 2005; 31:1700-5. [PMID: 16228176 DOI: 10.1007/s00134-005-2821-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Accepted: 09/08/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To compare the pressure-rate products and phase angles of children during minimal support ventilation and after extubation. DESIGN AND SETTING Prospective, randomized single-center trial in a pediatric intensive care unit in a tertiary children's hospital. METHODS Seventeen endotracheally intubated, mechanically ventilated children were placed on T-piece, T-piece with heliox, continuous positive airway pressure, and pressure support in random order. Esophageal pressure swings, phase angles, respiratory mechanics, and physiological parameters were measured on these modes and after extubation. MEASUREMENTS AND RESULTS Pressure-rate product postextubation was significantly higher than on support modes. For each mode and after extubation they were: pressure support 198+/-31, continuous positive airway pressure 237+/-30, T-piece 323+/-47, T-piece/heliox 308+/-61, and extubation 378+/-43 cmH2O/min. Phase angles were significantly higher during T-piece ventilation than pressure support but not did not differ significantly from postextubation. CONCLUSIONS Assessment of effort of breathing during even minimal mechanical ventilation may underestimate postextubation effort in children. Postextubation pressure-rate product and hence "effort of breathing" in children is best approximated by T-piece ventilation.
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Affiliation(s)
- Brigham C Willis
- Division of Pediatric Critical Care, Department of Pediatrics, University of Texas Southwestern Medical School, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9063, USA.
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Riedel T, Richards T, Schibler A. The value of electrical impedance tomography in assessing the effect of body position and positive airway pressures on regional lung ventilation in spontaneously breathing subjects. Intensive Care Med 2005; 31:1522-8. [PMID: 16195908 DOI: 10.1007/s00134-005-2734-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Accepted: 09/15/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Functional electrical impedance tomography (EIT) measures relative impedance changes in lung tissue during tidal breathing and creates images of local ventilation distribution. A novel approach to analyse the effect of body position and positive pressure ventilation on intrapulmonary tidal volume distribution was evaluated in healthy adult subjects. DESIGN AND SETTING Prospective experimental study in healthy adult subjects in the intensive care unit at university hospital. SUBJECTS Ten healthy male adults. INTERVENTIONS Change in body position from supine to prone, left and right lateral during spontaneous breathing and positive pressure support ventilation. MEASUREMENTS AND RESULTS EIT measurements and multiple-breath sulphur hexafluoride (SF6) washout were performed. Profiles of average relative impedance change in regional lung areas were calculated. Relative impedance time course analysis and Lissajous figure loop analysis were used to calculate phase angles between dependent or independent lung and total lung (phi). EIT data were compared to SF6 data washout measuring the lung clearance index (LCI). Proposed EIT profiles allowed inter-individual comparison of EIT data and identified areas with reduced regional tidal volume using pressure support ventilation. Phase angle phi of dependent lung in supine position was 11.7+/-1.4 degrees, in prone 5.3+/-0.5 degrees, in right lateral 11.0+/-1.3 degrees and in left lateral position 10.8+/-1.0 degree. LCI increased in supine position from 5.63+/-0.43 to 7.13+/-0.64 in prone position. Measured phi showed inverse relationship to LCI in the four different body positions. CONCLUSIONS EIT profiles and phi of functional EIT are new methods to describe regional ventilation distribution with EIT allowing inter-individual comparison.
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Affiliation(s)
- Thomas Riedel
- Queensland Paediatric Intensive Care Service, Mater Children's Hospital, Mater Misericordiae Hospitals, 41010, South Brisbane, QLD, Australia
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Willis BC, Graham AS, Wetzel R, L Newth CJ. Respiratory inductance plethysmography used to diagnose bilateral diaphragmatic paralysis: a case report. Pediatr Crit Care Med 2004; 5:399-402. [PMID: 15215015 DOI: 10.1097/01.pcc.0000124019.99266.b6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To report the use of respiratory inductance plethysmography in the diagnosis and management for a case of bilateral diaphragmatic paralysis after repeated sternotomies in a 23-month-old child. DESIGN Case report. SETTING A 15-bed pediatric cardiothoracic intensive care unit in an academic children's hospital. INTERVENTIONS The patient could not be weaned from the ventilator after a repeat sternotomy for pulmonary artery reconstruction. Pulmonary function test results were within normal limits, and plain film radiography, ultrasonography, and fluoroscopy were unable to establish a definitive diagnosis. Evaluation of thoracoabdominal synchrony was undertaken using respiratory inductance plethysmography (RespiTrace). The work of breathing was assessed using esophageal manometry to obtain the pressure-rate product. RESULTS During spontaneous breathing, complete thoracoabdominal asynchrony was noted, with clockwise Konno-Mead loops and associated phase angles of nearly 180 degrees. The pressure-rate product was 120 cm H(2)O/min, indicating elevated work of breathing. The pressure-rate product decreased dramatically, as indicated by measurement and observation, in response to increased levels of continuous positive airway pressure. CONCLUSIONS The diagnosis of bilateral diaphragmatic paralysis can be confirmed by measurement of thoracoabdominal synchrony. Therapeutic and diagnostic application of continuous positive airway pressure may predict response to diaphragmatic plication. Controlled trials comparing measurement of thoracoabdominal synchrony with standard methods for the early diagnosis of diaphragmatic paralysis are needed.
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Affiliation(s)
- Brigham C Willis
- Department of Anesthesiology Critical Care Medicine, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA 90027, USA.
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Abstract
The evaluation of infants and children with upper airway obstruction always involves a history and physical examination, which in many cases allow a diagnosis to be made. Assessment of severity and response to treatment relies on subjective parameters. Flow-volume loop analysis is a rapid, simple and effective method of evaluating patients with upper airway obstruction non-invasively. Imaging studies are complementary to endoscopy, and include plain radiography as well as computed tomography and magnetic resonance imaging, with the latter two being increasingly used in the evaluation of the paediatric airway. The ultimate diagnostic test for evaluation of upper airway obstruction, however, is flexible endoscopy.
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Affiliation(s)
- Ernst Eber
- Respiratory and Allergic Disease Division, Paediatric Department, University of Graz, Austria.
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Mayer OH, Clayton RG, Jawad AF, McDonough JM, Allen JL. Respiratory Inductance Plethysmography in Healthy 3- to 5-Year-Old Children *. Chest 2003; 124:1812-9. [PMID: 14605053 DOI: 10.1378/chest.124.5.1812] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
STUDY OBJECTIVES Because of the challenges of using standard measurements such as spirometry to measure respiratory function in 3- to 5-year-old children, there may be a role for respiratory inductive plethysmography (RIP), which is noninvasive and requires minimal subject cooperation. In this study, we described normative values of thoracoabdominal motion and timing mechanics in 3- to 5-year-old children, and hypothesized positional dependence of these measurements in this age group. DESIGN We measured relative thoracoabdominal motion during tidal breathing using the phase angle (Phi), the labored breathing index, and the phase relation during the total breath and timing mechanics with the ratio of time to peak tidal expiratory flow to expiratory time (TPTEF/TE). SETTING Preschools within the greater Philadelphia area and the Pulmonary Office of The Children's Hospital of Philadelphia. PATIENTS OR PARTICIPANTS Fifty healthy children between 3 years and 5 years of age. INTERVENTIONS RIP. MEASUREMENTS AND RESULTS All measures varied with position. Thoracoabdominal motion was nearly synchronous in the sitting position and most asynchronous in the supine position (Phi, 15.7 +/- 4.0 degrees vs 56.1 +/- 4.3 degrees, respectively; p < 0.001). This also led to an increase in the TPTEF/TE from the sitting to the supine positions (30.3 +/- 1.4% vs 37.0 +/- 1.6%, respectively; p < 0.001). Measurements of thoracoabdominal motion and timing mechanics did not change with age, weight, height, or gender. CONCLUSIONS We conclude that the positional dependence of these measurements is due to the alteration in respiratory mechanics between the sitting, standing, and supine positions. We further conclude that if RIP is to be a useful longitudinal measure of respiratory function in this age range, comparison measurements should be made in the same position.
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Affiliation(s)
- Oscar H Mayer
- Division of Pulmonary Medicine, Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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21
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Reber A, Geiduschek JM, Bobbià SA, Bruppacher HR, Frei FJ. Effect of continuous positive airway pressure on the measurement of thoracoabdominal asynchrony and minute ventilation in children anesthetized with sevoflurane and nitrous oxide. Chest 2002; 122:473-8. [PMID: 12171819 DOI: 10.1378/chest.122.2.473] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVE s: To quantify thoracoabdominal asynchrony (TAA) in children during anesthesia, and to measure the effect of continuous positive airway pressure (CPAP) on TAA, tidal volume (VT), and minute ventilation (E). DESIGN Prospective, nonrandomized, controlled study. SETTING Operating room of a university children's hospital. PARTICIPANTS Ninety children aged 2 to 9 years scheduled for elective outpatient day surgery who were enrolled prospectively. METHODS Each subject was anesthetized with sevoflurane 3% in equal parts O2 and N2O while breathing spontaneously through a facemask. Respiratory impedance plethysmography was used to calculate TAA indexes (phase angle [PA], phase relation in inspiration [PhRIB], phase relation in expiration, phase relation in total breath [PhRTB], and ratio of the inspiratory time to the total duration of the respiratory cycle [TI/TTOT]), VT, and E. Tidal gas flows were measured with a dual-hotwire anemometer with the sensor inserted between the facemask and the Y-piece of the anesthetic breathing circuit. This enabled the volume calibration of the respiratory impedance plethysmography equipment. The following conditions were compared: (1) no CPAP, (2) CPAP of 5 cm H2O, and (3) CPAP of 10 cm H2O. RESULTS Eighty-one children completed the study protocol. All measurements of TAA with an inspiratory component (PA, PhRIB, PhRTB, and TI/TTOT) decreased significantly from baseline with the addition of CPAP to the circuit. Application of CPAP of 10 cm H2O decreased significantly mean VTs and Es compared with CPAP of 5 cm H2O and no CPAP. There were no differences in TAA for all conditions when comparing children scheduled for adenoidectomy with other surgical procedures. CONCLUSIONS With spontaneously breathing anesthetized children, TAA decreases with the application of CPAP. CPAP of 5 cm H2O was as effective as CPAP of 10 cm H2O in reducing PA, PhRIB, PhRTB, and TI/TTOT. However, CPAP of 10 cm H2O also caused a significant decrease in VT and E.
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Affiliation(s)
- Adrian Reber
- Division of Pediatric Anesthesia, University Children's Hospital of Basel, Basel, Switzerland.
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22
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Litman RS, Kottra JA, Gallagher PR, Ward DS. Diagnosis of anesthetic-induced upper airway obstruction in children using respiratory inductance plethysmography. J Clin Monit Comput 2002; 17:279-85. [PMID: 12546260 DOI: 10.1023/a:1021246119194] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Upper airway obstruction is the most rapid and clinically relevant cause of hypoxia during sedation and anesthesia. This study was designed to determine if respiratory inductance plethysmography (RIP) could quantify the degree of upper airway obstruction caused by induction of general anesthesia. METHODS RIP tracings were obtained during induction of general anesthesia in healthy children. Three sets of measurements were obtained during: (1) a 3 minute control period without anesthetics, (2) 3 minutes of 50% nitrous oxide, and (3) halothane administration to complete the induction of general anesthesia. Clinical impression of upper airway obstruction (none, partial, or complete) was correlated with two separate RIP analysis techniques. RESULTS Three hundred ninety-five breathing epochs from 20 children (ages 3-10 years) were analyzed by both phase shift and phase inversion techniques. Although both techniques had good general correlation with severity of airway obstruction, neither was sufficiently reliable for accurate prediction of severity of airway obstruction. CONCLUSIONS We investigated two methods for analyzing RIP tracings during varying degrees of upper airway obstruction in anesthetized children. We found that neither technique was sufficiently accurate for predicting the severity of upper airway obstruction and would not be useful as a predictor of upper airway obstruction in the clinical or research settings.
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Affiliation(s)
- Ronald S Litman
- Department of Anesthesiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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23
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Meier S, Geiduschek J, Paganoni R, Fuehrmeyer F, Reber A. The effect of chin lift, jaw thrust, and continuous positive airway pressure on the size of the glottic opening and on stridor score in anesthetized, spontaneously breathing children. Anesth Analg 2002; 94:494-9; table of contents. [PMID: 11867364 DOI: 10.1097/00000539-200203000-00004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Chin lift and jaw thrust are two common maneuvers used to improve the patency of the upper airway during general anesthesia. We investigated the effect of these maneuvers combined with continuous positive airway pressure (CPAP) on the size of glottic opening and on stridor score. Forty children, aged 2--9 yr, premedicated with midazolam and spontaneously breathing end-tidal 1% halothane and equal parts of nitrous oxide and oxygen, were studied. A flexible fiberoptic bronchoscope was placed via mask and one nostril to the level of the junction of the soft palate and oropharynx. Video recordings and simultaneous stridor scores were obtained during six conditions: 1) chin unsupported, 2) manual chin lift, 3) chin lift and CPAP 10 cm H(2)O, 4) repeat chin unsupported, 5) manual jaw thrust, and 6) jaw thrust and CPAP 10 cm H(2)O. Videos were analyzed to determine the percentage of glottic opening (POGO) score. POGO score increased (P < 0.05) in Conditions 2, 3, 5, and 6. With increasing POGO score there was a decrease in stridor score (P < 0.05). IMPLICATIONS Chin lift and jaw thrust maneuvers combined with continuous positive airway pressure improve the view of the glottic opening as viewed by flexible nasal laryngoscopy and decrease stridor in anesthetized, spontaneously breathing children.
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Affiliation(s)
- Sonja Meier
- Department of Anaesthesia, University Children's Hospital of Basel, Switzerland
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24
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Hoffman A, Kuehn H, Riedelberger K, Kupcinskas R, Miskovic MB. Flowmetric comparison of respiratory inductance plethysmography and pneumotachography in horses. J Appl Physiol (1985) 2001; 91:2767-75. [PMID: 11717245 DOI: 10.1152/jappl.2001.91.6.2767] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Respiratory inductance plethysmographic (RIP) and pneumotachographic (Pn) flows were compared dynamically in horses with bronchoconstriction. On a breath-by-breath basis, RIP was normalized to inspiratory volume from Pn, and peak [peak of subtracted final exhalation waveform (SFE(max))] and selected area [integral of subtracted final waveform during first 25% of exhaled volume (SFE(int))] differences between RIP and Pn flows during early expiration were measured in three settings: 1) healthy horses (n = 8) undergoing histamine bronchoprovocation; 2) horses with naturally occurring lower airway obstruction (AO) (n = 7); and 3) healthy horses (n = 6) given lobeline. HCl to induce hyperpnea. In setting 1, histamine challenge induced a dose-dependent increase in SFE(max) and SFE(int) differences. A test index of airway reactivity (interpolated histamine dose that increased SFE(max) by 35%) closely correlated (r(s) = 0.93, P = 0.001) with a conventional index (histamine dose that induced a 35% decrease in dynamic compliance). In setting 2, in horses with AO, SFE(max) and SFE(int) were markedly elevated, and their absolute values correlated significantly (P < 0.005) with pulmonary resistance and the maximum change in transpulmonary pressure. The effects of bronchodilator treatment on the SFE(max) and SFE(int) were also highly significant (P < 0.0001). In setting 3, hyperpnea, but not tachypnea, caused significant (P < 0.01) increases in SFE(max) but not in SFE(int). In conclusion, dynamic comparisons between RIP and Pn provide a defensible method for quantifying AO during tidal breathing, without the need for invasive instrumentation.
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Affiliation(s)
- A Hoffman
- Department of Clinical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA 01536, USA.
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25
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26
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Reber A, Bobbià SA, Hammer J, Frei FJ. Effect of airway opening manoeuvres on thoraco-abdominal asynchrony in anaesthetized children. Eur Respir J 2001; 17:1239-43. [PMID: 11491171 DOI: 10.1183/09031936.01.00047801] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Thoraco-abdominal asynchrony is frequently encountered during inhalation anaesthesia in children with adenotonsillar hypertrophy causing an upper airway obstruction. The study goal was to evaluate the impact of different airway opening manoeuvres on thoraco-abdominal asynchrony as a measure of airway obstruction. Thirty anaesthetized children (aged 2-8 yrs; sevoflurane 3% in 50% oxygen/nitrous oxide) were studied prior to elective adenotonsillectomy using respiratory inductance plethysmography to record ribeage and abdominal wave forms as a basis for calculation of the phase angle. Five airway situations were compared: 1) baseline (unsupported mandible); 2) chin lift; 3) chin lift combined with continuous positive airway pressure of 10 cmH2O; 4) jaw thrust; and 5) jaw thrust combined with continuous positive airway pressure of 10 cmH2O. Three children had complete upper airway obstruction at baseline and were excluded from the study. With chin lift, thoraco-abdominal asynchrony improved in three patients, worsened in three patients and was unchanged in 21 patients. Additional continuous positive airway pressure during chin lift did not markedly reduce thoraco-abdominal asynchrony (phase angle 89 +/- 43 , p = 0.33). Jaw thrust resulted in a significant decrease of the phase angle (from 106 +/- 53 at baseline to 65 +/- 49 , p < 0.01); when combined with continuous positive airway pressure, no further effect on thoraco-abdominal asynchrony was found (72 +/- 44). In anaesthetized children with adenotonsillar hypertrophy, airway opening manoeuvres have distinct effects on thoraco-abdominal asynchrony. Delivery of continuous positive airway pressure and jaw thrust can be the first airway opening manoeuvres to improve breathing patterns. Chin lift without additional continuous positive airway pressure should be used with caution in these patients because it may convert partial into almost complete airway obstruction.
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Affiliation(s)
- A Reber
- Dept of Anaesthesia, University Children's Hospital of Basel, Switzerland
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27
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Weese-Mayer DE, Corwin MJ, Peucker MR, Di Fiore JM, Hufford DR, Tinsley LR, Neuman MR, Martin RJ, Brooks LJ, Davidson Ward SL, Lister G, Willinger M. Comparison of apnea identified by respiratory inductance plethysmography with that detected by end-tidal CO(2) or thermistor. The CHIME Study Group. Am J Respir Crit Care Med 2000; 162:471-80. [PMID: 10934073 DOI: 10.1164/ajrccm.162.2.9904029] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
As part of the Collaborative Home Infant Monitoring Evaluation (CHIME) we compared apnea identified by a customized home monitor using respiratory inductance plethysmography (RIP) with simultaneously recorded polysomnography-acquired nasal end-tidal CO(2) (PET(CO(2))) and nasal/oral thermistor in 422 infants during overnight laboratory recordings to determine concordance between techniques, sources of disagreement, and capacity of RIP to detect obstructed breaths within an apnea. Among 233 episodes of apnea identified by at least one method as >/= 16 s, 120 were observed by the CHIME monitor, 219 by PET(CO(2)), and 163 by thermistor. The positive predictive value of the CHIME-identified apnea was 89.2% (95% CI 83, 95) and 73% (95% CI 65, 81) for PET(CO(2)) and thermistor, respectively. However, the sensitivity of the CHIME monitor in identifying events detected by the other methods was only approximately 50%. Among 87 apnea events identified by all three techniques, no two methods showed high agreement in measurement of apnea duration: RIP and PET(CO(2)) (ICC = 0.54), RIP and thermistor (ICC = 0.13), PET(CO(2)) and nasal thermistor (ICC = 0.41). Among the 179 breaths identified by RIP as obstructed, 79.9% were judged to be obstructed on the PET(CO(2)) and 80.4% were judged to be obstructed on the thermistor channel. Among 238 breaths identified on PET(CO(2)) as obstructed, 54.2% were determined to be obstructed by RIP. Among 204 breaths identified on thermistor as obstructed, 55. 4% were determined to be obstructed by RIP. Reasons for discrepancies in apnea detection among channels included body movement, partial airway obstruction, and obstructed breaths. Despite these limitations the CHIME monitor provides an opportunity to record physiological data previously unavailable in the home.
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Affiliation(s)
- D E Weese-Mayer
- Department of Pediatrics, Rush Children's Hospital at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA.
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28
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Miller C, Hoffman AM, Hunter J. Thoracoabdominal asynchrony failed to grade airway obstructions in foals. J Appl Physiol (1985) 2000; 88:2081-7. [PMID: 10846021 DOI: 10.1152/jappl.2000.88.6.2081] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Respiratory inductive plethysmography (RIP) can be used to obtain a valid measure of tidal volume in humans. This device also compares the contributions to ventilation of the thorax and abdomen. Although thoracoabdominal asynchrony is a prominent clinical feature for patients with airway obstruction, the accuracy of the RIP device to assess the severity of obstruction is unclear. This study analyzes how well RIP variables reflect the degree of a fixed external inspiratory plus expiratory resistive load in foals. Foals were employed because the species and age group are commonly afflicted with respiratory disease. Eight conscious, sedated (xylazine 1.25 mg/kg body wt) foals were subjected to randomly ordered resistive loads at the airway opening and, on a separate day, to histamine aerosol challenge. During resistive loading, phase angle changed significantly, as did phase relation (P < or = 0.05). However, no significant correlation was found between the degree of change in resistive load and the degree to which phase angle or relation was altered (r(s) = 0.41 and 0.25, respectively). In addition, neither phase angle nor relation changed significantly with histamine challenge. We conclude that, although RIP variables changed markedly with fixed upper airway resistive loading, the degree to which they changed was erratic and therefore not useful for grading these obstructions. Furthermore, RIP variables were insensitive measures of histamine-induced bronchoconstriction.
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Affiliation(s)
- C Miller
- Department of Veterinary Clinical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA 01536, USA
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29
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Strömberg NO, Nelson N. Thoracoabdominal asynchrony in small children with lung disease--methodological aspects and the relationship to lung mechanics. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1998; 18:447-56. [PMID: 9784941 DOI: 10.1046/j.1365-2281.1998.00118.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Thoracoabdominal asynchrony (TAA) has been regarded as a clinical sign of lung disease. A measure of TAA is the phase angle (phi) between ribcage (RC) and abdominal (ABD) respiratory motion. The aim of this study was to assess the effect of the points chosen for phi calculation. The influence of correct respiratory timing was assessed by calculating TAA indices using a pneumotachometer (PTM) as timing reference and using the calibrated respiratory inductive plethysmograph (RIP) signal for respiratory timing. The relationship between TAA and lung mechanics was studied in 15 young children 9 months to 2.5 years of age with a wide span of restrictive and/or obstructive lung disease. phi as calculated from mid-RC points was poorly related to phi as calculated from the top RC and ABD positions, indicating non-sinusoidal respiratory motions. The estimation of the TAA indices depended on correct respiratory timing, which in the case of severe asynchrony cannot be inferred from the RIP signals alone. An external source for respiratory timing, such as the airway flow measured by a PTM, is needed. The degree of asynchronous chest wall movement was only a weak indicator of pathological lung mechanics. We conclude that the usefulness of TAA indices as indicators of impaired lung mechanics is limited by the sensitivity to the points used for their calculation (phi) and the need of an external source for respiratory timing. It was therefore not surprising that a rather weak relationship was seen between TAA indices and lung mechanics.
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Affiliation(s)
- N O Strömberg
- Department of Clinical Physiology, Linköping University, Sweden
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30
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Steele DW, Santucci KA, Wright RO, Natarajan R, McQuillen KK, Jay GD. Pulsus paradoxus: an objective measure of severity in croup. Am J Respir Crit Care Med 1998; 157:331-4. [PMID: 9445317 DOI: 10.1164/ajrccm.157.1.9701071] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We used a noninvasive monitor of arterial pressure to determine the utility of pulsus paradoxus (PP) as an objective severity measure in croup. We performed a prospective, blinded comparison of PP in children with croup versus healthy control subjects, analyzed the relationship between PP and Westley croup score (WCS), and observed the effect of racemic epinephrine (RE) on PP and WCS in a subgroup of patients with severe croup. The PP and WCS were measured at presentation and in severe patients after treatment with RE. Mean PP was 6.1 +/- 1.8 (SD) mm Hg (n = 29) in control subjects compared with a mean of 17.8 +/- 11.2 (SD) mm Hg (n = 28) in patients with croup (p < 0.00001). There was significant concordance between baseline WCS and PP (Spearman's rho: 0.68; p = 0.0001). The mean decrease in PP after RE was 7.5 +/- 11.8 (SD) mm Hg (p = 0.05; n = 12). The magnitude of decrease in PP after RE has significant concordance with the concurrent decrease in WCS (Spearman's rho: 0.73; p < 0.007). PP is elevated in children with croup, and the magnitude of elevation correlates with severity as measured by the WCS. PP may have utility as a research tool to objectively measure the severity of upper airway obstruction in croup.
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Affiliation(s)
- D W Steele
- Brown University, Department of Pediatrics, Center for Statistical Sciences, Providence, Rhode Island
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31
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Hammer J, Sivan Y, Deakers TW, Newth CJ. Flow limitation in anesthetized rhesus monkeys: a comparison of rapid thoracoabdominal compression and forced deflation techniques. Pediatr Res 1996; 39:539-46. [PMID: 8929878 DOI: 10.1203/00006450-199603000-00025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Rapid thoracoabdominal compression (RTC) and forced deflation (FD) allow the examination of maximal expiratory flow-volume (MEFV) curves in animals and human infants unable to generate a voluntary maximal expiratory maneuver. We compared flows generated by these two techniques and by constructing isovolume pressure-flow (IVPF) curves examined each method's potential to produce flow limitation. RTC and FD were performed in seven intubated rhesus monkeys from +40 cm H2O inspiratory pressure with deflation pressures ranging from -20 to -100 cm H2O and jacket pressures from +20 to +100 cm H2O (arms outside jacket). We also performed RTC maneuvers in all monkeys with the arms inside the jacket at +100 cm H2O jacket pressure. Maximal expiratory flows achieved by FD and RTC were analyzed at isovolume points. Both techniques produced flow limitation conditions over the last 25% of the MEFV curve. Individual IVPF curves generated by the two techniques demonstrated remarkable differences in shape and flow rates. Maximal transpulmonary pressures achieved with FD were higher than those with RTC in this experiment. Negative effort dependence was observed with higher deflation pressures in the majority of the monkeys. Flows achieved by RTC with the arms in were lower than those achieved with the arms out when compared at identical pressure gradients. We conclude that the difference in expiratory flow rates at isovolume-pressure points is most likely related to different effects on the behavior of intrapulmonary airways and choke point characteristics by the two techniques.
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Affiliation(s)
- J Hammer
- Division of Pediatric Critical Care, Children's Hospital of Los Angeles, School of Medicine, California 90027, USA
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Hammer J, Newth CJ. Infant lung function testing in the intensive care unit. Intensive Care Med 1995; 21:744-52. [PMID: 8847430 PMCID: PMC7095417 DOI: 10.1007/bf01704742] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/1993] [Accepted: 08/30/1994] [Indexed: 02/02/2023]
Abstract
As a result of the previous shortage of tools to assess objectively the overall physiological status of the respiratory system in infants and young children, it has been difficult to measure the degree of physiological disorder or the response to therapy in respiratory diseases such as BPD, the pediatric version of ARDS, bronchiolitis, pneumonia, asthma and croup in this patient population. The newborn- four-year old child is particularly difficult to study because of their lack of cooperation and size. The recent progress in computer technology made pulmonary function testing available for this age range and opened up new possibilities for monitoring changes in disease processes affecting the respiratory system. This may improve medical management of infants and children with lung and heart diseases in particular. In 1989, Shannon [49] proposed in this Journal that the minimum physiological information needed for the intelligent use of mechanical ventilation (particularly if lower airway and/or pulmonary parenchymal disease was apparent) required the measurement of at least 4 variables: i) arterial partial pressure of carbon dioxide; ii) arterial oxygen saturation; iii) the mechanical time constant of the lung and iv) FRC. In many circumstances, arterial CO2 is approximated by alveolar (end-tidal) CO2 and the arterial oxygen saturation is obtained from pulse oximetry accurately if perfusion is adequate. The mechanical time constant and FRC are easily measured by the techniques described above and together provide important information concerning appropriate ventilator settings for a given disease. The described techniques bring new insights and awareness, but also new responsibilities in the management of infants and children with respiratory compromise. Not all of these techniques need to be applied to all infants in the ICU. Not all the assumptions upon which some of the techniques we have described are based will prove true. Any such methods which do not withstand solid scientific testing must be quickly discarded and replaced with better and (hopefully) easier methods.
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Affiliation(s)
- J Hammer
- Division of Pediatric Critical Care, Children's Hospital of Los Angeles, University of Southern California School of Medicine 90027, USA
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