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Yamada Y, Mitani Y, Yamamoto A, Miura K, Yamada K, Oki Y, Oki Y, Maejima Y, Kurumatani Y, Ishikawa A. Metabolic and ventilatory changes during postural change from the supine position to the reclining position in bedridden older patients. Medicine (Baltimore) 2023; 102:e33250. [PMID: 36897678 PMCID: PMC9997819 DOI: 10.1097/md.0000000000033250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/21/2023] [Indexed: 03/11/2023] Open
Abstract
The prevention of pneumonia in bedridden older patients is important, and its recurrence in these patients is a relevant issue. Patients who are bedridden and inactive, and have dysphagia are considered to be at risk for pneumonia. Efforts to reduce the bedridden state and low activity may be necessary to reduce the risk of developing pneumonia in bedridden older patients. This study aimed to clarify the effects of postural change from the supine position to the reclining position on metabolic and ventilatory parameters and on safety in bedridden older patients. Using a breath gas analyzer and other tools, we assessed the following 3 positions: lying on the back (supine), resting in the Fowler position (Fowler), and resting in an 80° recline wheelchair (80°). Measurements were oxygen uptake, carbon dioxide output, gas exchange ratio, tidal volume (VT), minute volume, respiratory rate, inspiratory time, expiratory time, total respiratory time, mean inspiratory flow, metabolic equivalents, end-expiratory oxygen, and end-expiratory carbon dioxide as well as various vital signs. The study analysis included 19 bedridden participants. The change in oxygen uptake driven by changing the posture from the supine position to the Fowler position was as small as 10.8 mL/minute. VT significantly increased from the supine position (398.4 ± 111.2 mL) to the Fowler position (426.9 ± 106.8 mL) (P = .037) and then showed a decreasing trend in the 80° position (416.8 ± 92.5 mL). For bedridden older patients, sitting in a wheelchair is a very low-impact physical activity, similar to that in normal people. The VT of bedridden older patients was maximal in the Fowler position, and the ventilatory volume did not increase with an increasing reclining angle, unlike that in normal people. These findings suggest that appropriate reclining postures in clinical situations can promote an increase in the ventilatory rate in bedridden older patients.
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Affiliation(s)
- Yoji Yamada
- Department of Rehabilitation, Isawa Kyoritsu Hospital, Fuefuki, Yamanashi, Japan
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Yuji Mitani
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Akio Yamamoto
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Kazumo Miura
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Kanji Yamada
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Yukari Oki
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Yutaro Oki
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Yasumichi Maejima
- Department of Rehabilitation, Kofu Kyoritsu Hospital, Kofu, Yamanashi, Japan
| | - Yoko Kurumatani
- Department of Cardiology, Kofu Kyoritsu Hospital, Kofu, Yamanashi 406-0035, Japan
| | - Akira Ishikawa
- Department of Public Health, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
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Rizzato A, Marcolin G, Paoli A. Non-exercise activity thermogenesis in the workplace: The office is on fire. Front Public Health 2022; 10:1024856. [PMID: 36388282 PMCID: PMC9650196 DOI: 10.3389/fpubh.2022.1024856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/05/2022] [Indexed: 01/28/2023] Open
Abstract
From the second half of the previous century, there has been a shift toward occupations largely composed of desk-based behaviors. This, inevitably, has led to a workload reduction and a consequent lower energy expenditure. On this point, small increments of the non-exercise activity thermogenesis (NEAT) could be the rationale to reach health benefits over a prolonged period. Different published researches suggest solutions to reverse sitting time and new alternative workstations have been thought to increase total physical activity. Therefore, the purpose of this narrative review is to summarize the current state of the research regarding the "NEAT approach" to weight-gain prevention in work environments. This review analyzes the main evidence regarding new alternative workstations such as standing, walking workstations, seated pedal, and gymnastic balls to replace a standard office chair.
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Stewart JM, Pianosi PT. Postural orthostatic tachycardia syndrome: A respiratory disorder? Curr Res Physiol 2021; 4:1-6. [PMID: 34746821 PMCID: PMC8562237 DOI: 10.1016/j.crphys.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 11/28/2022] Open
Abstract
Postural orthostatic tachycardia syndrome (POTS) is a disorder epitomized by the story of the blind men and the elephant. Patients may see primary care internists or pediatricians due to fatigue, be referred to neurologists for “spells”, to cardiologists for evaluation of pre-syncope or chest pain, to gastroenterologists for nausea or dyspepsia, and even pulmonologists for dyspnea. Adoption of a more systematic approach to their evaluation and better characterization of patients has led to greater understanding of comorbidities, hypotheses prompting mechanistic investigations, and pharmacologic trials. Recent work has implicated disordered sympathetic nervous system activation in response to central (thoracic) hypovolemia. It is this pathway that leads one zero in on a putative focal point from which many of the clinical manifestations can be explained – specifically the carotid body. Despite heterogeneity in etiopathogenesis of a POTS phenotype, we propose that aberrant activation and response of the carotid body represents one potential common pathway in evolution. To understand this postulate, one must jettison isolationist or reductionist ideas of chemoreceptor and baroreceptor functions of the carotid body or sinus, respectively, and consider their interaction and interdependence both locally and centrally where some of its efferents merge. Doing so enables one to connect the dots and appreciate origins of diverse manifestations of POTS, including dyspnea for which the concept of neuro-mechanical uncoupling is wanting, thereby expanding our construct of this symptom. This perspective expounds our premise that POTS has a prominent respiratory component. Dyspnea affects ~⅓ patients with postural orthostatic tachycardia syndrome (POTS). POTS is characterized by thoracic hypovolemia and compromised cephalad perfusion when upright. Carotid body and adjacent carotid sinus mediate chemo- and baro- reflexes, respectively. These are not independent and stimulation of either activates sympathetic discharge. We speculate that carotid body mediates hyperventilation and dyspnea in POTS.
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Affiliation(s)
- Julian M Stewart
- Department of Pediatrics, New York Medical College, Valhalla, NY, USA.,Department of Physiology, New York Medical College, Valhalla, NY, USA
| | - Paolo T Pianosi
- Department of Pediatrics, Division of Pulmonary & Sleep Medicine, University of Minnesota, VCRC, 401 E River Parkway Rm 413, Minneapolis, UK
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Comparison of inspiratory and expiratory lung and lobe volumes among supine, standing, and sitting positions using conventional and upright CT. Sci Rep 2020; 10:16203. [PMID: 33004894 PMCID: PMC7530723 DOI: 10.1038/s41598-020-73240-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
Currently, no clinical studies have compared the inspiratory and expiratory volumes of unilateral lung or of each lobe among supine, standing, and sitting positions. In this prospective study, 100 asymptomatic volunteers underwent both low-radiation-dose conventional (supine position, with arms raised) and upright computed tomography (CT) (standing and sitting positions, with arms down) during inspiration and expiration breath-holds and pulmonary function test (PFT) on the same day. We compared the inspiratory/expiratory lung/lobe volumes on CT in the three positions. The inspiratory and expiratory bilateral upper and lower lobe and lung volumes were significantly higher in the standing/sitting positions than in the supine position (5.3–14.7% increases, all P < 0.001). However, the inspiratory right middle lobe volume remained similar in the three positions (all P > 0.15); the expiratory right middle lobe volume was significantly lower in the standing/sitting positions (16.3/14.1% decrease) than in the supine position (both P < 0.0001). The Pearson’s correlation coefficients (r) used to compare the total lung volumes on inspiratory CT in the supine/standing/sitting positions and the total lung capacity on PFT were 0.83/0.93/0.95, respectively. The r values comparing the total lung volumes on expiratory CT in the supine/standing/sitting positions and the functional residual capacity on PFT were 0.83/0.85/0.82, respectively. The r values comparing the total lung volume changes from expiration to inspiration on CT in the supine/standing/sitting positions and the inspiratory capacity on PFT were 0.53/0.62/0.65, respectively. The study results could impact preoperative CT volumetry of the lung in lung cancer patients (before lobectomy) for the prediction of postoperative residual pulmonary function, and could be used as the basis for elucidating undetermined pathological mechanisms. Furthermore, in addition to morphological evaluation of the chest, inspiratory and expiratory upright CT may be used as an alternative tool to predict lung volumes such as total lung capacity, functional residual capacity, and inspiratory capacity in situation in which PFT cannot be performed such as during an infectious disease pandemic, with relatively more accurate predictability compared with conventional supine CT.
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Verbanck SAB, Polfliet M, Schuermans D, Ilsen B, de Mey J, Vanderhelst E, Vandemeulebroucke J. Ventilation heterogeneity in smokers: role of unequal lung expansion and peripheral lung structure. J Appl Physiol (1985) 2020; 129:583-590. [PMID: 32614688 DOI: 10.1152/japplphysiol.00105.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Smoking-induced ventilation heterogeneity measured at the mouth via established washout indices [lung clearance index (LCI) and alveolar mixing efficiency (AME)] potentially results from unequal expansion, which can be quantified by computer tomography (CT), and structural changes down to the lung periphery, characterized by CT parametric response mapping indices [percentage of lung affected by functional small airway disease (PRMfSAD) and emphysema (PRMEmph)]. By combining CT imaging and nitrogen (N2) washout tests in smokers, we specifically examined the roles of unequal lung expansion and peripheral structure. We first extracted three-dimensional maps of local lung expansion from registered inspiratory/expiratory CT images in 50 smokers (GOLD 0-IV) to compute for each smoker the theoretical N2 washout concentration curve solely attributable to unequal local expansion. By a head-on comparison with washout N2 concentrations measured at the mouth in the same smokers supine, we observed that 1) LCI increased from 4.8 ± 0.2 (SD) to 6.6 ± 0.8 (SD) due to unequal lung expansion alone and further increased to 9.0 ± 1.5 (SD) independent of local expansion and 2) AME decreased (from 100% by definition) to 95 ± 2 (SD)% due to unequal expansion alone and further decreased to 75 ± 7(SD)% independent of local expansion. In a multiple regression between the washout indices and CT-derived PRMfSAD and PRMEmph, LCI was related to PRMfSAD (r = +0.58; P < 0.001), whereas AME was related to both PRMfSAD (rpartial = -0.44; P = 0.002) and PRMEmph (rpartial = -0.31; P = 0.033), in line with AME being dominated by alterations in peripheral structure. We conclude that smokers showing an increased LCI without corresponding AME decrease are predominantly affected by unequal lung expansion, whereas an AME decrease with a commensurate LCI increase indicates a smoking-induced alteration of peripheral structure.NEW & NOTEWORTHY A head-on comparison between imaging and multiple breath washout in supine smokers shows that computer tomography-measured unequal local lung expansion accounts for 50% or less of smoking-induced increase in ventilation heterogeneity. The contributions from unequal lung expansion and peripheral structure to the two main washout indices also explain their respective association with parametric response mapping indices.
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Affiliation(s)
- Sylvia A B Verbanck
- Respiratory Division, University Hospital (UZ Brussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Mathias Polfliet
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Imec, Kapeldreef, Leuven, Belgium.,Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Daniel Schuermans
- Respiratory Division, University Hospital (UZ Brussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Bart Ilsen
- Department of Radiology, University Hospital (UZ Brussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Johan de Mey
- Department of Radiology, University Hospital (UZ Brussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Eef Vanderhelst
- Respiratory Division, University Hospital (UZ Brussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Jef Vandemeulebroucke
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Imec, Kapeldreef, Leuven, Belgium
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Dağar S, Çorbacıoğlu ŞK, Emektar E, Uzunosmanoğlu H, Çevik Y. Effects of spinal immobilization at 20° on end-tidal carbon dioxide. Am J Emerg Med 2020; 38:1180-1184. [PMID: 32122717 DOI: 10.1016/j.ajem.2020.02.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVE The aim was to determine the effect on end-tidal carbon dioxide (ETCO2) of spinal immobilization (SI) at a conventional 0° angle and to investigate the usefulness of immobilization at a 20° angle for preventing possible hypoventilation. METHODS The study included 80 healthy volunteers, randomly divided into two groups. Spinal backboards and cervical collars were applied in Group 1 using a 0° angle and in Group 2 using a 20° angle, with the head up. SI was continued for 1 h, and ETCO2 values were measured at the 0th, 30th and 60th minute. RESULTS There were no significant differences between the groups in 0th and 30th minute ETCO2. However, after 60th minute, results showed a statistically significant increase in ETCO2 in Group 1 (35.5 mmHg [IQR 25-75:35-38]) compared to Group 2 (34 mmHg [IQR 25-75:33-36]) (p < 0.001). During SI, there was a statistically significant increase in ETCO2 in Group 1 (35 mmHg [IQR 25-75:34-36], 35.5 mmHg [IQR 25-75:34-37] and 36 mmHg [IQR 25-75:35-38] respectively at the 0th, 30th and 60th minute after SI) (p < 0.001) and no change in Group 2. Also, we found statistically significant differences between ΔETCO2 levels in Groups 1 and 2 at all 3 time intervals. CONCLUSION Conventional SI with an angle of 0° led to an increase in ETCO2 while subjects immobilization at a 20° angle maintained their initial ETCO2 values. Immobilization at 20° may prevent decompensation in patients who have thoracic trauma or lung diseases or those who are elderly, pregnant, or obese.
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Affiliation(s)
- Seda Dağar
- Kecioren Training and Research Hospital, Department of Emergency Medicine, Ankara, Turkey.
| | | | - Emine Emektar
- Kecioren Training and Research Hospital, Department of Emergency Medicine, Ankara, Turkey
| | - Hüseyin Uzunosmanoğlu
- Kecioren Training and Research Hospital, Department of Emergency Medicine, Ankara, Turkey
| | - Yunsur Çevik
- Kecioren Training and Research Hospital, Department of Emergency Medicine, Ankara, Turkey
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Matić Z, Platiša MM, Kalauzi A, Bojić T. Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling. Front Physiol 2020; 11:24. [PMID: 32132926 PMCID: PMC7040454 DOI: 10.3389/fphys.2020.00024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 01/14/2020] [Indexed: 12/21/2022] Open
Abstract
Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, α1RRI, α2RRI, α1Resp, α2Resp), Multiple Scaling Entropy (MSERRI1-4, MSERRI5-10, MSEResp1-4, MSEResp5-10), spectral coherence (CohRRI-Resp), cross DFA (ρ1 and ρ2) and cross MSE (XMSE1-4 and XMSE5-10) indices in four physiological conditions: supine with spontaneous breathing, standing with spontaneous breathing, supine with 0.1 Hz breathing and standing with 0.1 Hz breathing. Main results: Standing is primarily characterized by the change of RRI parameters, insensitivity to change with respiratory parameters, decrease of CohRRI-Resp and insensitivity to change of in ρ1, ρ2, XMSE1-4, and XMSE5-10. Slow breathing in supine position was characterized by the change of the linear and non-linear parameters of both signals, reflecting the dominant vagal RRI modulation and the impact of slow 0.1 Hz breathing on Resp parameters. CohRRI-Resp did not change with respect to supine position, while ρ1 increased. Slow breathing in standing reflected the qualitatively specific state of autonomic regulation with striking impact on both cardiac and respiratory parameters, with specific patterns of cardiorespiratory coupling. Significance: Our results show that cardiac and respiratory short term and long term complexity parameters have different, state dependent patterns. Sympathovagal non-linear interactions are dependent on the pattern of their activation, having different scaling properties when individually activated with respect to the state of their joint activation. All investigated states induced a change of α1 vs. α2 relationship, which can be accurately expressed by the proposed measure-inter-fractal angle θ. Short scale (α1 vs. MSE1-4) and long scale (α2 vs. MSE5-10) complexity measures had reciprocal interrelation in standing with 0.1 Hz breathing, with specific cardiorespiratory coupling pattern (ρ1 vs. XMSE1-4). These results support the hypothesis of hierarchical organization of cardiorespiratory complexity mechanisms and their recruitment in ascendant manner with respect to the increase of behavioral challenge complexity. Specific and comprehensive cardiorespiratory regulation in standing with 0.1 Hz breathing suggests this state as the potentially most beneficial maneuver for cardiorespiratory conditioning.
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Affiliation(s)
- Zoran Matić
- Biomedical Engineering and Technology, University of Belgrade, Belgrade, Serbia
| | - Mirjana M. Platiša
- Faculty of Medicine, Institute of Biophysics, University of Belgrade, Belgrade, Serbia
| | - Aleksandar Kalauzi
- Department for Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
| | - Tijana Bojić
- Laboratory for Radiobiology and Molecular Genetics-080, Institute for Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
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Kuenzel A, Marshall B, Verges S, Anholm JD. Positional Changes in Arterial Oxygen Saturation and End-Tidal Carbon Dioxide at High Altitude: Medex 2015. High Alt Med Biol 2020; 21:144-151. [PMID: 31985275 DOI: 10.1089/ham.2019.0066] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background: Body position alters aspects of pulmonary function in health and disease. Although studies have assessed positional effects on the heart and lungs, little is known about positional changes in gas exchange parameters at high altitude. We hypothesized that following ascent, supine positioning would cause lower oxygen saturation than sitting, partially due to decreased ventilation and increased partial pressure of end-tidal carbon dioxide (Petco2). Materials and Methods: Twenty-eight healthy subjects were studied at sea level and following gradual ascent to 5150 m. After 10 minutes of sitting rest, subjects were studied for 5 minutes each in the sitting, supine, and prone positions with the order randomly assigned. Pulse oximeter oxygen saturation (SpO2), minute ventilation (VE), end-tidal O2 (Peto2) and Petco2, oxygen consumption, and CO2 production were continuously measured. Alveolar ventilation (VA) was calculated from the measured parameters. Results: At high altitude, VE was not affected by body position (12.96 ± 3.09 and 11.54 ± 3.45 L/min in the sitting and supine positions, respectively, p = 0.255). Petco2 increased from sitting to supine (22.8 ± 3.1 to 23.5 ± 3.3 mm Hg, p < 0.005), but VE and Petco2 were not different between the supine and prone positions. Calculated VA was not significantly affected by body position at either sea level or high altitude. SpO2 decreased from 81.3% ± 4.4% sitting to 78.8% ± 6.0% supine (p = 0.025), with a mean positional SpO2 difference of 2.5% ± 4.9% (95% confidence interval 0.6%-4.4%). SpO2 was not different between the supine and prone positions. Twenty-two of 28 subjects had lower SpO2 supine compared with sitting. Conclusions: These results extend earlier low-altitude studies and demonstrate the importance of postural regulation in different environments. As 79% of subjects had lower SpO2 while supine than sitting, control of body position is necessary for SpO2 comparisons at altitude to be meaningful.
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Affiliation(s)
- Arlena Kuenzel
- Department of Anaesthesia, Royal Infirmary of Edinburgh, NHS Lothian, Edinburgh, Scotland
| | - Ben Marshall
- Sheffield Teaching Hospitals, NHS Foundation Trust, Sheffield, United Kingdom
| | - Samuel Verges
- INSERM U1042 and HP2 Laboratory, Grenoble Alpes University, Grenoble, France
| | - James D Anholm
- Division of Pulmonary, Critical Care, Hyperbaric and Sleep Medicine, Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA
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Hazlett C, Edgell H. Chemoreflex function and brain blood flow during upright posture in men and women. Physiol Rep 2018; 6. [PMID: 29333725 PMCID: PMC5789659 DOI: 10.14814/phy2.13571] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/09/2017] [Indexed: 11/24/2022] Open
Abstract
Orthostatic intolerance is more common in women than men, and some studies have found that women in the early follicular (EF) phase of the menstrual cycle experience the greatest feelings of lightheadedness. Chemoreflex function while supine or upright was investigated to determine the potential contribution of ventilatory control to these phenomena. Men (n = 13) and women (n = 14) were tested while supine and 70° upright (head-up tilt [HUT]) and given: (1) normoxia or (2) hypercapnia (5% CO2 ). Women were tested during the EF phase (days 2-5) and the midluteal phase (ML; days 18-24). During HUT, all groups reduced cerebrovascular resistance index (men: 1.45 ± 0.08 to 1.42 ± 0.07 mmHg/(cm·sec), EF: 1.38 ± 0.11 to 1.26 ± 0.10 mmHg/(cm·sec), ML: 1.25 ± 0.07 to 1.09 ± 0.07 mmHg/(cm·sec); P ≤ 0.019); however, only men increased ventilation (men: 11.99 ± 0.65 to 13.24 ± 0.83 L/min; P < 0.01). In response to hypercapnia in the supine position, men had a smaller increase of diastolic middle cerebral artery velocity compared to women in the ML phase (men: +9.1 ± 2.0 cm/sec, ML: +15.7 ± 3.1 cm/sec, P = 0.039). During hypercapnia in HUT (compared to hypercapnia while supine), all groups had an augmented increase of ventilation (men: +7.46 ± 1.34 vs. +5.84 ± 1.09 L/min, EF: +6.71 ± 0.83 vs. +5.48 ± 0.66 L/min, ML: +7.99 ± 1.13 vs. +5.65 ± 0.81 L/min; P ≤ 0.028), suggesting that all groups experienced augmentation of the CO2 chemoreflex; however, only men had an augmented increase of mean arterial pressure (+0.10 ± 0.58 to +4.71 ± 0.87 mmHg; P ≤ 0.017). Our results indicate that men have different ventilatory responses to upright tilt compared to women, and that the CO2 chemoreflex response is enhanced in upright posture in both sexes. Furthermore, sexually dimorphic blood pressure responses to this chemoreflex enhancement are evident.
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Affiliation(s)
- Christopher Hazlett
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada
| | - Heather Edgell
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada.,Muscle Health Research Centre, York University, Toronto, Ontario, Canada
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Katz S, Arish N, Rokach A, Zaltzman Y, Marcus EL. The effect of body position on pulmonary function: a systematic review. BMC Pulm Med 2018; 18:159. [PMID: 30305051 PMCID: PMC6180369 DOI: 10.1186/s12890-018-0723-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 09/17/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Pulmonary function tests (PFTs) are routinely performed in the upright position due to measurement devices and patient comfort. This systematic review investigated the influence of body position on lung function in healthy persons and specific patient groups. METHODS A search to identify English-language papers published from 1/1998-12/2017 was conducted using MEDLINE and Google Scholar with key words: body position, lung function, lung mechanics, lung volume, position change, positioning, posture, pulmonary function testing, sitting, standing, supine, ventilation, and ventilatory change. Studies that were quasi-experimental, pre-post intervention; compared ≥2 positions, including sitting or standing; and assessed lung function in non-mechanically ventilated subjects aged ≥18 years were included. Primary outcome measures were forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC, FEV1/FVC), vital capacity (VC), functional residual capacity (FRC), maximal expiratory pressure (PEmax), maximal inspiratory pressure (PImax), peak expiratory flow (PEF), total lung capacity (TLC), residual volume (RV), and diffusing capacity of the lungs for carbon monoxide (DLCO). Standing, sitting, supine, and right- and left-side lying positions were studied. RESULTS Forty-three studies met inclusion criteria. The study populations included healthy subjects (29 studies), lung disease (nine), heart disease (four), spinal cord injury (SCI, seven), neuromuscular diseases (three), and obesity (four). In most studies involving healthy subjects or patients with lung, heart, neuromuscular disease, or obesity, FEV1, FVC, FRC, PEmax, PImax, and/or PEF values were higher in more erect positions. For subjects with tetraplegic SCI, FVC and FEV1 were higher in supine vs. sitting. In healthy subjects, DLCO was higher in the supine vs. sitting, and in sitting vs. side-lying positions. In patients with chronic heart failure, the effect of position on DLCO varied. CONCLUSIONS Body position influences the results of PFTs, but the optimal position and magnitude of the benefit varies between study populations. PFTs are routinely performed in the sitting position. We recommend the supine position should be considered in addition to sitting for PFTs in patients with SCI and neuromuscular disease. When treating patients with heart, lung, SCI, neuromuscular disease, or obesity, one should take into consideration that pulmonary physiology and function are influenced by body position.
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Affiliation(s)
- Shikma Katz
- Chronic Ventilator-Dependent Division, Herzog Medical Center, POB 3900, Jerusalem, Israel
- 0000 0004 1937 0511grid.7489.2Recanati School for Community Health Professions, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Nissim Arish
- Pulmonary Institute, Shaare Zedek Medical Center, POB 3235, Jerusalem, Israel
- 0000 0004 1937 0538grid.9619.7Hebrew University-Hadassah Faculty of Medicine, Jerusalem, Israel
| | - Ariel Rokach
- Pulmonary Institute, Shaare Zedek Medical Center, POB 3235, Jerusalem, Israel
- 0000 0004 1937 0538grid.9619.7Hebrew University-Hadassah Faculty of Medicine, Jerusalem, Israel
| | - Yacov Zaltzman
- Chronic Ventilator-Dependent Division, Herzog Medical Center, POB 3900, Jerusalem, Israel
| | - Esther-Lee Marcus
- Chronic Ventilator-Dependent Division, Herzog Medical Center, POB 3900, Jerusalem, Israel
- 0000 0004 1937 0538grid.9619.7Hebrew University-Hadassah Faculty of Medicine, Jerusalem, Israel
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Javorka M, El-Hamad F, Czippelova B, Turianikova Z, Krohova J, Lazarova Z, Baumert M. Role of respiration in the cardiovascular response to orthostatic and mental stress. Am J Physiol Regul Integr Comp Physiol 2018; 314:R761-R769. [PMID: 29443551 DOI: 10.1152/ajpregu.00430.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to determine the response of heart rate and blood pressure variability (respiratory sinus arrhythmia, baroreflex sensitivity) to orthostatic and mental stress, focusing on causality and the mediating effect of respiration. Seventy-seven healthy young volunteers (46 women, 31 men) aged 18.4 ± 2.7 yr underwent an experimental protocol comprising supine rest, 45° head-up tilt, recovery, and a mental arithmetic task. Heart rate variability and blood pressure variability were analyzed in the time and frequency domain and modeled as a multivariate autoregressive process where the respiratory volume signal acted as an external driver. During head-up tilt, tidal volume increased while respiratory rate decreased. During mental stress, breathing rate increased and tidal volume was elevated slightly. Respiratory sinus arrhythmia decreased during both interventions. Baroreflex function was preserved during orthostasis but was decreased during mental stress. While sex differences were not observed during baseline conditions, cardiovascular response to orthostatic stress and respiratory response to mental stress was more prominent in men compared with women. The respiratory response to the mental arithmetic tasks was more prominent in men despite a significantly higher subjectively perceived stress level in women. In conclusion, respiration shows a distinct response to orthostatic versus mental stress, mediating cardiovascular variability; it needs to be considered for correct interpretation of heart rate and blood pressure phenomena.
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Affiliation(s)
- Michal Javorka
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Fatima El-Hamad
- School of Electrical and Electronic Engineering, The University of Adelaide, South Australia, Australia
| | - Barbora Czippelova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Zuzana Turianikova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Jana Krohova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Zuzana Lazarova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Mathias Baumert
- School of Electrical and Electronic Engineering, The University of Adelaide, South Australia, Australia
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12
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Pesola AJ, Laukkanen A, Tikkanen O, Finni T. Heterogeneity of muscle activity during sedentary behavior. Appl Physiol Nutr Metab 2016; 41:1155-1162. [PMID: 27806635 DOI: 10.1139/apnm-2016-0170] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Replacing sitting by standing has been hypothesized to reduce the health risks of sitting, based on the assumption that muscles are passive during sitting and active during standing. Interventions have been more effective in overweight (OW) than in normal weight (NW) individuals, but subjects' muscle activities have not been quantified. This study compared quadriceps and hamstring muscle electromyographic (EMG) activity between 57 NW (body mass index (BMI) 22.5 ± 1.5 kg/m2, female n = 36) and 27 OW (BMI 28.4 ± 2.9 kg/m2, female n = 8) subjects during non-fatiguing standing (15 s, EMGstanding) and sitting (30 min). EMG amplitude was normalized to EMG measured during maximal isometric knee extension and flexion (% EMGMVC), and sitting muscle inactivity and bursts were determined using 4 thresholds (60% or 90% EMGstanding and 1% or 2% EMGMVC). Comparisons were adjusted for sex, age, knee extension strength, and the individual threshold. Standing EMG amplitude was 36% higher in OW (1.9% ± 1.5% EMGMVC) than in NW (1.4% ± 1.4% EMGMVC, P < 0.05) subjects. During sitting, muscles were inactive 89.8% ± 12.7% of the measurement time with 12.7 ± 14.2 bursts/min across all thresholds. On average, 6% more activity was recorded in NW than in OW individuals for 3 of the 4 thresholds (P < 0.05 for 60% or 90% EMGstanding and 1% EMGMVC). In conclusion, the OW group had higher muscle activity amplitude during standing but more muscle inactivity during sitting for 3/4 of the thresholds tested. Interventions should test whether the observed heterogeneity in muscle activity affects the potential to gain cardiometabolic benefits from replacing sitting with standing.
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Affiliation(s)
- Arto J Pesola
- a Neuromuscular Research Center, Department of Biology of Physical Activity, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
| | - Arto Laukkanen
- a Neuromuscular Research Center, Department of Biology of Physical Activity, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.,b Department of Sport Sciences, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
| | - Olli Tikkanen
- a Neuromuscular Research Center, Department of Biology of Physical Activity, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.,c Exercise Health and Technology Center, Department of Physical Education, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Minhang District, Shanghai 200240, China
| | - Taija Finni
- a Neuromuscular Research Center, Department of Biology of Physical Activity, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
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13
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Hellyer NJ, Andreas NM, Bernstetter AS, Cieslak KR, Donahue GF, Steiner EA, Hollman JH, Boon AJ. Comparison of Diaphragm Thickness Measurements Among Postures Via Ultrasound Imaging. PM R 2016; 9:21-25. [PMID: 27297447 DOI: 10.1016/j.pmrj.2016.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 05/31/2016] [Accepted: 06/04/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Assessment of diaphragm contraction may be useful for identifying impairments in patients with movement dysfunction involving trunk stabilization, respiration, or both. Real-time ultrasound imaging is a readily available technology that can be used to quickly assess this aspect of diaphragm activity. Although previous studies have examined diaphragm contraction in the supine posture, a comparison of measurements between supine and upright postures has not been made. OBJECTIVE To examine whether diaphragm thickness measurements differ among 3 different body postures in healthy subjects. DESIGN Descriptive repeated measures. SETTING Clinical laboratory. PATIENTS (OR PARTICIPANTS) Twenty-four healthy subjects (12 male and 12 female) aged 22-35 years old were recruited and completed the study. METHOD Diaphragm thickness was assessed in via B-mode ultrasound imaging in supine, seated, and standing postures. Measurements of diaphragm thickness were taken in the zone of apposition during maximal inspiration to total lung capacity (TLC) and end-tidal expiratory lung volume (EELV). A thickness ratio (inspiration thickness/expiration thickness) was calculated to compare relative diaphragm contraction during each condition. MAIN OUTCOME MEASUREMENTS The primary dependent variable was diaphragm thickness (mm). RESULTS Average diaphragm thickness at EELV and maximum TLC were more than 20% greater in the seated and standing postures than in supine (P < .05). Moreover, the diaphragm was approximately 205% thicker at TLC than at EELV (P < .05). Relative inspiratory to expiratory thickness ratios (TLC/EELV) did not differ among postures (P = .24). CONCLUSIONS The diaphragm is thicker when the body is in more upright postures (standing and sitting versus supine) perhaps due to greater vertical gravitational load on the muscle and associated change in the resting length of the muscle fibers. Thus it appears that ultrasound imaging may be a sensitive tool to examine changes in diaphragm contraction during varying postural tasks. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Nathan J Hellyer
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, 1107 Siebens Bldg, Rochester, MN 55905(∗).
| | - Nicholas M Andreas
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(†)
| | - Andrew S Bernstetter
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(‡)
| | - Kathryn R Cieslak
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(§)
| | - Gerad F Donahue
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(¶)
| | - Elizabeth A Steiner
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(#)
| | - John H Hollman
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN(∗∗)
| | - Andrea J Boon
- Departments of Physical Medicine and Rehabilitation and Neurology, Mayo Clinic, Rochester, MN(††)
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14
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Analysis of cardio-pulmonary and respiratory kinetics in different body positions: impact of venous return on pulmonary measurements. Eur J Appl Physiol 2016; 116:1343-53. [DOI: 10.1007/s00421-016-3386-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 04/30/2016] [Indexed: 11/27/2022]
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15
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Szczygieł E, Zielonka K, Mazur T, Mętel S, Golec J. Respiratory chest movement measurement as a chair quality indicator – preliminary observations. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2015; 21:207-12. [PMID: 26323780 PMCID: PMC4566904 DOI: 10.1080/10803548.2015.1028224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Regardless of the constantly increasing time man is spending in a sitting position, there is still a lack of objective chair quality assessment criteria. The aim of this paper is to find the answer to whether respiratory chest movement measurements can be a chair quality indicator. The study included 34 participants (mean 34.7 years ± 5.2). Their chest movements were assessed using respiratory inductive plethysmography while sitting on two subsequent chairs. Significant differences in chest movements depending on chair type were observed concerning the breathing duct (upper and lower) and breathing movement amplitude. The amplitude of the upper respiratory track in the first chair was higher (239.4 mV) compared with the second seat (207.3 mV) (p = .018). The analyzed parameters of respiratory chest movement may become a helpful indicator for design and selection of chairs which enable people to both work and relax in the most ergonomic conditions.
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Laubacher M, Perret C, Hunt KJ. Work-rate-guided exercise testing in patients with incomplete spinal cord injury using a robotics-assisted tilt-table. Disabil Rehabil Assist Technol 2014; 10:433-8. [DOI: 10.3109/17483107.2014.908246] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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17
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Son SM, Lee JH, Cha YJ. Comparison of the plantar pressure distributions at different degrees of tilting: a preliminary report. J Phys Ther Sci 2014; 26:401-3. [PMID: 24707092 PMCID: PMC3976011 DOI: 10.1589/jpts.26.401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/02/2013] [Indexed: 11/24/2022] Open
Abstract
[Purpose] The purpose of this study was to investigate the amount of plantar pressures on
the lower limb during tilt table standing and to indicate the ideal degree of tilting for
partial weight bearing. [Subjects and Methods] Fifteen healthy subjects between the ages
of 20 and 30 were recruited as volunteers for this study. All the measurements were taken
while standing on a tilt table according to different inclination angles. [Results] The
plantar pressures for 60° tilt table standing were lower by 7–9% of total body weight than
the pressures during tilt table standing at 90°, and the pressures for 30° tilt table
standing were lower by 18–20% of total body weight than the pressures for tilt table
standing at 90°. [Conclusion] Standing training on a 60° tilt table might be equivalent to
80% of full weight bearing training, and tilt table standing training at 30° might be
equivalent to 60% of full weight bearing training.
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Affiliation(s)
- Sung-Min Son
- Department of Physical Therapy, College of Rehabilitation Science, Daegu University, Republic of Korea
| | - Jun-Ho Lee
- Department of Emergency Medical Technology, College of Natural Science, Daejeon University, Republic of Korea
| | - Yong-Jun Cha
- Department of Physical Therapy, College of Natural Science, Daejeon University, Republic of Korea
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18
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Retrospective observations on the ability to diagnose and manage patients with asthma through the use of impulse oscillometry: comparison with spirometry and overview of the literature. Pulm Med 2014; 2014:376890. [PMID: 24665365 PMCID: PMC3934316 DOI: 10.1155/2014/376890] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 10/31/2013] [Accepted: 11/26/2013] [Indexed: 11/20/2022] Open
Abstract
Objective. Impulse oscillometry (IOS) is an evolving technology for the diagnosis and followup of patients with asthma. Our objective is to review the findings on patients who underwent both spirometry and IOS during clinical evaluations of their asthma. The goal was to retrospectively evaluate IOS during the initial diagnosis and followup of patients with asthma in comparison with spirometry. Methods. We routinely perform IOS and spirometry evaluation in patients with suspected asthma during baseline visits and at followup. We reviewed the data on 39 patients over the age of 13 with asthma at baseline and following treatment with inhaled corticosteroids. IOS and spirometry were both done at baseline, following short acting bronchodilator administration, and at followup after at least three months of inhaled corticosteroid treatment. Results. IOS showed improvement in airway function both initially, following short acting bronchodilator introduction, and later after initiation of long term inhaled corticosteroid treatment, even when the spirometry did not reveal improvement. We noted the IOS improvement in the reactance or AX as well as the resistance in smaller airways or R5. Conclusion. IOS may provide a useful measure towards identifying an asthma diagnosis and followup without inducing the extra respiratory effort spirometry requires.
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19
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Skow RJ, Tymko MM, MacKay CM, Steinback CD, Day TA. The effects of head-up and head-down tilt on central respiratory chemoreflex loop gain tested by hyperoxic rebreathing. PROGRESS IN BRAIN RESEARCH 2014; 212:149-72. [DOI: 10.1016/b978-0-444-63488-7.00009-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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20
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Abstract
Many articles in this section of Comprehensive Physiology are concerned with the development and function of a central pattern generator (CPG) for the control of breathing in vertebrate animals. The action of the respiratory CPG is extensively modified by cortical and other descending influences as well as by feedback from peripheral sensory systems. The central nervous system also incorporates other CPGs, which orchestrate a wide variety of discrete and repetitive, voluntary and involuntary movements. The coordination of breathing with these other activities requires interaction and coordination between the respiratory CPG and those governing the nonrespiratory activities. Most of these interactions are complex and poorly understood. They seem to involve both conventional synaptic crosstalk between groups of neurons and fluid identity of neurons as belonging to one CPG or another: neurons that normally participate in breathing may be temporarily borrowed or hijacked by a competing or interrupting activity. This review explores the control of breathing as it is influenced by many activities that are generally considered to be nonrespiratory. The mechanistic detail varies greatly among topics, reflecting the wide variety of pertinent experiments.
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Affiliation(s)
- Donald Bartlett
- Department of Physiology & Neurobiology, Dartmouth Medical School, Lebanon, New Hampshire, USA.
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21
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Rubini A, Paoli A, Parmagnani A. Body metabolic rate and electromyographic activities of antigravitational muscles in supine and standing postures. Eur J Appl Physiol 2011; 112:2045-50. [PMID: 21947455 DOI: 10.1007/s00421-011-2180-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 09/13/2011] [Indexed: 11/29/2022]
Abstract
We measured metabolic (oxygen uptake, carbon dioxide production, respiratory ratio), cardio-circulatory (heart rate, systolic and diastolic arterial blood pressure, rate-pressure product, an index of myocardial oxygen consumption calculated by multiplying heart rate by systolic pressure) and electromyographic (integrated electromyographic activities of two antigravitational muscles of the lower limb, soleus and gastrocnemius) variables on 12 young healthy subjects in supine and standing positions at rest. We found statistically significant increments of oxygen uptake, carbon dioxide production, heart rate and integrated electromyographic activities in standing versus supine position. Rate-pressure product increased but not significantly, and no other significant changes were detected. We conclude that postural changes influence metabolic rate, antigravitational muscle reflex activities, and heart rate. A significant positive correlation was found between oxygen uptake and carbon dioxide production and integrated electromyographic activities of antigravitational muscles, while the same was not found for cardio-circulatory variables. These results suggest that the increased metabolic rate in standing position is, at least in part, due to antigravitational muscle tone.
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Affiliation(s)
- Alessandro Rubini
- Department of Human Anatomy and Physiology, Section Physiology, University of Padova, 3 Via Marzolo, 35100 Padova, Italy.
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22
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Kabir MM, Saint DA, Nalivaiko E, Abbott D, Baumert M. Time delay correction of the synchrogram for optimized detection of cardiorespiratory coordination. Med Biol Eng Comput 2011; 49:1249-59. [PMID: 21830053 DOI: 10.1007/s11517-011-0822-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 07/02/2011] [Indexed: 10/17/2022]
Abstract
The cardiorespiratory synchrogram, a graphical tool based on the stroboscopic technique, is an established method for evaluating phase-locking between cardiac and respiratory oscillators. In the original method, the phase of the respiratory oscillator is observed at the instants of time when the phase of the cardiac oscillator attains a certain value. In this article, we introduced an additional adaptive delay in the cardiac oscillator based on the maximisation of the cross-correlation or symbolic coupling traces between the phases of respiration and the delayed R-R intervals. We then investigated phase coordination in thirteen normal subjects (five males, eight females; age: 19-24 years) for different body postures. Cardiorespiratory coordination was observed to be significantly reduced in the upright position (supine vs. upright: 11.9 ± 5.1 vs. 6.9 ± 3.6, P < 0.05). Compared to the original algorithm we observed an increase in the detection of average cardiorespiratory coordination (supine original vs. delay: 11.9 vs. 18.9%), together with a decrease in standard deviation of the percentage of coordination in all the subjects, after introducing the heart rate delay (supine original vs. delay: 5.1 vs. 4.4%). In conclusion, the performance of the synchrogram technique was improved by including an adaptive delay in the cardiac oscillator.
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Affiliation(s)
- Muammar M Kabir
- Centre for Heart Rhythm Disorders, The University of Adelaide, Adelaide, SA 5005, Australia.
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23
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Lee LJ, Chang AT, Coppieters MW, Hodges PW. Changes in sitting posture induce multiplanar changes in chest wall shape and motion with breathing. Respir Physiol Neurobiol 2010; 170:236-45. [DOI: 10.1016/j.resp.2010.01.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 01/06/2010] [Accepted: 01/06/2010] [Indexed: 11/24/2022]
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24
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Ogata H, Nakahara M, Sato T, Hoshikawa S, Ogata T, Nakazawa K. Hyperventilation during orthostatic challenge in spinal cord-injured humans. Clin Auton Res 2009; 19:327-34. [DOI: 10.1007/s10286-009-0023-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 06/22/2009] [Indexed: 10/20/2022]
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