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Pinna GD, Dacosto E, Maestri R, Crotti P, Montemartini S, Caporotondi A, Guazzotti G, Bruschi C. Postural changes in lung volumes in patients with heart failure and Cheyne-Stokes respiration: Relationship with sleep apnea severity. Sleep Med 2023; 101:154-161. [PMID: 36395720 DOI: 10.1016/j.sleep.2022.10.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND AIM It has been proposed that the increased severity of sleep apnea frequently observed in heart failure (HF) patients with Cheyne-Stokes respiration (CSR) when sleeping in the supine compared to the lateral position, may be caused by the concomitant reduction in functional residual capacity (FRC). We assessed positional changes in FRC in patients with CSR and investigated the relationship between these changes in the laboratory and corresponding changes in CSR severity during sleep. METHODS After a diagnostic polysomnography, 18 HF patients with dominant CSR and an apnea-hypopnea index (AHI)≥15 events/h underwent a standard pulmonary function test in the sitting position. Measurements were repeated in the supine, left lateral and right lateral. The latter two measurements were averaged to obtain a single lateral measurement. RESULTS The FRC in the seated position was 3.0 ± 0.5 L (85 ± 13% of predicted), decreased to 2.3 ± 0.3 L (-21 ± 8%, p < 0.0001) in the supine position, and increased to 2.8 ± 0.4 L (+21 ± 12%, p < 0.0001) from the supine to the lateral position (-5±8% vs seated, p = 0.013). During sleep, the AHI and the apnea index (AI) decreased from 47 ± 15 events/h to 26 ± 12 events/h (-46 ± 20%, p < 0.0001) and from 29 ± 21 events/h to 12 ± 10 events/h (-61 ± 40%, p < 0.001) from the supine to the lateral position. Changes in the AI were significantly correlated with corresponding changes in FRC (ρ = -0.55, p = 0.032). CONCLUSION In patients with HF and CSR, lying in the supine position causes a significant reduction in FRC in the context of a chronically reduced FRC. The negative correlation between postural changes in FRC and AI supports the hypothesis that the reduction in lung gas stores in the supine position may promote/exacerbate respiratory control instability.
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Affiliation(s)
- Gian Domenico Pinna
- Laboratory for the Study of Ventilatory Instability, Department of Biomedical Engineering, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy.
| | - Elena Dacosto
- Respiratory Physiopathology and Sleep Unit, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Roberto Maestri
- Laboratory for the Study of Ventilatory Instability, Department of Biomedical Engineering, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Paola Crotti
- Respiratory Physiopathology and Sleep Unit, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Silvia Montemartini
- Respiratory Physiopathology and Sleep Unit, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Angelo Caporotondi
- Department of Cardiology, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Giampaolo Guazzotti
- Department of Cardiology, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
| | - Claudio Bruschi
- Department of Pneumology, Istituti Clinici Scientifici Maugeri, Montescano Institute - IRCCS, Montescano, Italy
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Miyake K, Shiroyama T, Hirata H, Nagatomo I, Takeda Y, Kumanogoh A. Lateral Decubitus Position Enables Further Advancement of the Bronchoscope into the Lung Periphery. J Bronchology Interv Pulmonol 2022; 29:307-310. [PMID: 35876738 PMCID: PMC9488940 DOI: 10.1097/lbr.0000000000000875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Kotaro Miyake
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
| | - Takayuki Shiroyama
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
| | - Haruhiko Hirata
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
| | - Izumi Nagatomo
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
| | - Yoshito Takeda
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine
- Department of Immunopathology, WPI, Immunology Frontier Research Center (iFReC)
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI)
- Center for Infectious Diseases for Education and Research (CiDER), Osaka University, Suita, Osaka, Japan
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Niewinski P, Tubek S, Paleczny B, Banasiak W, Ponikowski P. Induction of Day-Time Periodic Breathing is Associated With Augmented Reflex Response From Peripheral Chemoreceptors in Male Patients With Systolic Heart Failure. Front Physiol 2022; 13:912056. [PMID: 35711301 PMCID: PMC9197443 DOI: 10.3389/fphys.2022.912056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/19/2022] [Indexed: 11/28/2022] Open
Abstract
Spontaneous day-time periodic breathing (sPB) constitutes a common phenomenon in systolic heart failure (HF). However, it is unclear whether PB during wakefulness could be easily induced and what are the physiological and clinical correlates of patients with HF in whom PB induction is possible. Fifty male HF patients (age 60.8 ± 9.8 years, left ventricle ejection fraction 28.0 ± 7.4%) were prospectively screened and 46 enrolled. After exclusion of patients with sPB the remaining underwent trial of PB induction using mild hypoxia (stepwise addition of nitrogen gas to breathing mixture) which resulted in identification of inducible (iPB) in 51%. All patients underwent assessment of hypoxic ventilatory response (HVR) using transient hypoxia and of hypercapnic ventilatory response (HCVR) employing Read’s rebreathing method. The induction trial did not result in any adverse events and minimal SpO2 during nitrogen administration was ∼85%. The iPB group (vs. non-inducible PB group, nPB) was characterized by greater HVR (0.90 ± 0.47 vs. 0.50 ± 0.26 L/min/%; p <0.05) but comparable HCVR (0.88 ± 0.54 vs. 0.67 ± 0.68 L/min/mmHg; p = NS) and by worse clinical and neurohormonal profile. Mean SpO2 which induced first cycle of PB was 88.9 ± 3.7%, while in sPB mean SpO2 preceding first spontaneous cycle of PB was 96.0 ± 2.5%. There was a reverse relationship between HVR and the relative variation of SpO2 during induced PB (r = −0.49, p = 0.04). In summary, PB induction is feasible and safe in HF population using simple and standardized protocol employing incremental, mild hypoxia. Pathophysiology of iPB differs from sPB, as it relies mostly on overactive peripheral chemoreceptors. At the same time enhanced HVR might play a protective role against profound hypoxia during iPB.
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Affiliation(s)
- Piotr Niewinski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
| | - Stanislaw Tubek
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
| | - Bartlomiej Paleczny
- Department of Physiology and Pathophysiology, Wroclaw Medical University, Wroclaw, Poland
| | | | - Piotr Ponikowski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
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Lagier D, Zeng C, Fernandez-Bustamante A, Melo MFV. Perioperative Pulmonary Atelectasis: Part II. Clinical Implications. Anesthesiology 2022; 136:206-236. [PMID: 34710217 PMCID: PMC9885487 DOI: 10.1097/aln.0000000000004009] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.
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Affiliation(s)
- David Lagier
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Congli Zeng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Marcos F. Vidal Melo
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Traversi E, Rossi D, Maestri R, Olmetti F, La Rovere MT, Pinna GD. The reduction of central sleep apnoea severity in the left lateral position is not due to an improvement in cardiac haemodynamics in patients with chronic heart failure. Sleep Med 2017; 34:30-32. [DOI: 10.1016/j.sleep.2017.02.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 01/30/2017] [Accepted: 02/22/2017] [Indexed: 12/28/2022]
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van der Wal HH, Cowie MR, van der Meer P. Sleep-disordered breathing and chronic heart failure: changing position may be important. Eur J Heart Fail 2015; 17:1219-22. [DOI: 10.1002/ejhf.441] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 01/04/2023] Open
Affiliation(s)
- Haye H. van der Wal
- Department of Cardiology; University Medical Centre Groningen, University of Groningen; Groningen the Netherlands
| | - Martin R. Cowie
- Imperial College London (Royal Brompton Hospital); London United Kingdom
| | - Peter van der Meer
- Department of Cardiology; University Medical Centre Groningen, University of Groningen; Groningen the Netherlands
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Pinna GD, Robbi E, La Rovere MT, Taurino AE, Bruschi C, Guazzotti G, Maestri R. Differential impact of body position on the severity of disordered breathing in heart failure patients with obstructive vs. central sleep apnoea. Eur J Heart Fail 2015; 17:1302-9. [DOI: 10.1002/ejhf.410] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/20/2015] [Accepted: 08/22/2015] [Indexed: 11/10/2022] Open
Affiliation(s)
- Gian Domenico Pinna
- Department of Biomedical Engineering; Fondazione S. Maugeri - IRCCS; 27040 Montescano (PV) Italy
| | - Elena Robbi
- Sleep Laboratory, Department of Pneumology; Fondazione S. Maugeri - IRCCS; Montescano Italy
- Department of Cardiology; Fondazione S. Maugeri - IRCCS; Montescano Italy
| | | | - Anna Eugenia Taurino
- Sleep Laboratory, Department of Pneumology; Fondazione S. Maugeri - IRCCS; Montescano Italy
| | - Claudio Bruschi
- Respiratory Function Laboratory, Department of Pneumology; Fondazione S. Maugeri - IRCCS; Montescano Italy
| | | | - Roberto Maestri
- Department of Biomedical Engineering; Fondazione S. Maugeri - IRCCS; 27040 Montescano (PV) Italy
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Verbanck S, Paiva M, Schuermans D, Hanon S, Vincken W, Van Muylem A. Relationships between the lung clearance index and conductive and acinar ventilation heterogeneity. J Appl Physiol (1985) 2011; 112:782-90. [PMID: 22162528 DOI: 10.1152/japplphysiol.01221.2011] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lung clearance index (LCI) derived from a multiple breath washout test has regained considerable popularity in recent years, alternatively being promoted as an early detection tool or a marker of small airways function. In this study, we systematically investigated the link between LCI and indexes of acinar and conductive airways ventilation heterogeneity (Sacin, Scond) to assess potential contributions from both lung zones. Relationships were examined in 55 normal subjects after provocation, where only Scond is known to be markedly increased, and in 55 asthma patients after bronchodilation, in whom both Scond and Sacin ranged between normal and abnormal. LCI was correlated to Scond in both groups (R = 0.37-0.43; P < 0.01 for both); in the asthma group, LCI was also tightly correlated to Sacin (R = 0.70; P < 0.001). Potential mechanisms operational at various levels of the bronchial tree were identified by considering washout curvilinearity in addition to LCI to distinguish specific ventilation and dead space effects (also illustrated by simple 2-compartment model simulations). Although the asthma data clearly demonstrate that LCI can reflect very peripheral ventilation heterogeneities, the normal provocation data also convincingly show that LCI increases may be the exclusive result of far more proximal ventilation heterogeneities. Because LCI potentially includes heterogeneities at all length scales, it is suggested that ventilation imaging in combination with LCI measurement at the mouth could identify the scale of relevant ventilation heterogeneities. In the meantime, interpretations of LCI results in the clinic based on washout curves collected at the mouth should be handled with caution.
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Affiliation(s)
- Sylvia Verbanck
- Respiratory Division, Univ. Hospital UZ Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium.
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Abstract
The pleural space separating the lung and chest wall of mammals contains a small amount of liquid that lubricates the pleural surfaces during breathing. Recent studies have pointed to a conceptual understanding of the pleural space that is different from the one advocated some 30 years ago in this journal. The fundamental concept is that pleural surface pressure, the result of the opposing recoils of the lung and chest wall, is the major determinant of the pressure in the pleural liquid. Pleural liquid is not in hydrostatic equilibrium because the vertical gradient in pleural liquid pressure, determined by the vertical gradient in pleural surface pressure, does not equal the hydrostatic gradient. As a result, a viscous flow of pleural liquid occurs in the pleural space. Ventilatory and cardiogenic motions serve to redistribute pleural liquid and minimize contact between the pleural surfaces. Pleural liquid is a microvascular filtrate from parietal pleural capillaries in the chest wall. Homeostasis in pleural liquid volume is achieved by an adjustment of the pleural liquid thickness to the filtration rate that is matched by an outflow via lymphatic stomata.
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Affiliation(s)
- Stephen J Lai-Fook
- Center for Biomedical Engineering, Wenner-Gren Research Laboratory, Univ. of Kentucky, Lexington, KY 40506-0070, USA.
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10
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Moens Y, Lagerweij E, Gootjes P, Poortman J. Distribution of inspired gas to each lung in the anaesthetised horse and influence of body shape. Equine Vet J 1995; 27:110-6. [PMID: 7607142 DOI: 10.1111/j.2042-3306.1995.tb03045.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The distribution of inspired gas to each lung, time constants of the lungs and parameters of gas exchange were studied in 2 groups of horses (mean bwt 606 kg), anaesthetised using thiopentone and chloral hydrate and breathing room air. One group (n = 4) had a downward curved abdominal contour (round-bellied) and the other group (n = 4) had an upward curved abdominal contour (flat-bellied). An equal distribution of inspired gas between the lungs existed in both groups in dorsal recumbency. Flat-bellied horses maintained this equal distribution in lateral recumbency whereas in round-bellied horses an uneven distribution of tidal volume (VT) developed. The percentage of (VT) distributed to the dependent lung was 23% and 38% for left and right lateral recumbency respectively. The distribution of VT agreed with the ratio of time constants of the lungs in flat-bellied horses but differed markedly from this ratio in round-bellied horses suggesting that, in the latter, factors other than compliance and resistance play a role in distribution of ventilation. Round-bellied horses had a lower PaO2 and a larger (A-a)PaO2 than flat-bellied horses in all body positions. The results are compatible with the known hypothesis that pressure exerted by abdominal contents on the dependent lung and diaphragm is an important factor in ventilation/perfusion mismatch of the anaesthetised horse.
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Affiliation(s)
- Y Moens
- Department of Veterinary Anaesthesiology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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Abstract
Little information has been published concerning the pattern of regional ventilation in children, yet many differences in lung and chest wall mechanics in childhood, supported by clinical observation, have led to the hypothesis that the pattern of regional ventilation seen in children may not be the same as in adults. Forty-three children and 16 adult volunteers underwent Krypton (Kr) 81m radionuclide ventilation lung scans in the supine and right and left decubitus postures. In children aged 2-10 years mean fractional ventilation to the right lung (VfR) was 46.1%. This fell to 36% when dependent and rose to 56.1% in the uppermost position. Redistribution of ventilation away from the dependent towards the uppermost lung was seen in all children. In children aged 10-18 years VfR was 57.2% (supine), 48.0% (dependent), and 62.9% (uppermost). An identical pattern was seen in children with normal or abnormal pulmonary function tests (peak expiratory flow rate, and FEV1: FVC ratio). In subjects over 18 years of age a different pattern was seen: mean VfR was 52.4% (supine), rising to 53.4% (dependent), and falling to 48.9% (uppermost). Postural redistribution of ventilation, as assessed by Kr81m ventilation imaging, changes late in the second decade of life. This will have clinical consequences in the management of children with unilateral lung disease.
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Affiliation(s)
- H Davies
- Department of Paediatrics, Central Middlesex Hospital, London, England
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12
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Gillespie DJ, Rehder K. Body position and ventilation-perfusion relationships in unilateral pulmonary disease. Chest 1987; 91:75-9. [PMID: 3792089 DOI: 10.1378/chest.91.1.75] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The effect of positional change (right vs left lateral decubitus) on the distribution of ventilation and perfusion ratios was determined in four patients with respiratory failure and chest roentgenographic findings of unilateral pulmonary disease. In these patients with a unilateral interstitial pattern, improvement in oxygenation which occurred when the "good" side was dependent (down) was associated with changes in the patterns of ventilation-perfusion distribution; two patients showed a predominant decrease in right-to-left intrapulmonary shunt, and two showed an improvement in ventilation-perfusion equality. Therefore, when unilateral interstitial pulmonary disease was present, positional change resulted in changes in right-to-left intrapulmonary shunt or low ventilation-perfusion ratios or both. Variability between patients can be explained by the nonhomogeneity of pulmonary disease in patients with respiratory failure.
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Rehder K, Marsh HM. Respiratory Mechanics During Anesthesia and Mechanical Ventilation. Compr Physiol 1986. [DOI: 10.1002/cphy.cp030343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rehder K. Anaesthesia and the respiratory system. CANADIAN ANAESTHETISTS' SOCIETY JOURNAL 1979; 26:451-62. [PMID: 393367 DOI: 10.1007/bf03006156] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pulmonary gas exchange is disturbed during general anaesthesia; both oxygenation and elimination of carbon dioxide are impaired. The shape of the chest wall alters after induction of anaesthesia-paralysis in recumbent subjects, and its motion during inspiration is also altered. The mechanical properties of lung and chest wall are also affected and FRC may be reduced. Inspired gas distribution changes after induction of anaesthesia-paralysis with mechanical ventilation of the lungs. Distribution of pulmonary blood flow is altered in subjects in the sitting and right lateral decubitus positions, but the distribution is not adjusted to the altered distribution of inspired gas. This results in an increased mismatching of ventilation to perfusion, with development of lung regions that have low and high ventilation-to-perfusion ratios. Some lung regions with low ventilation-to-perfusion ratios develop into right-to-left shunt on breathing 100 per cent oxygen. The following sequence of events probably occurs after induction of anaesthesia-paralysis. The initial effect of anaesthesia seems to be on the shape and motion of the chest wall. This may alter the mechanical properties of both the chest wall and the lung. Intrapulmonary gas distribution is altered secondarily. Pulmonary bloodflow distribution, which is primarily determined by gravity, does not seem to adjust to the altered distribution of inspired gas. Hence, an increased mismatching of ventilation to perfusion develops. This includes the development of lung regions with low ventilation-to-perfusion ratios. These regions may progress into right-to-left shung during 100 per cent oxygen breathing. The low ventilation-to-perfusion regions and the shunt may both impair oxygenation. The development of lung regions with high ventilation-to-perfusion ratios after induction of anaesthesia-paralysis contributes to the inefficient elimination of carbon dioxide.
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Purcell GR, Manners JM, Cockburn JS. Pulmonary arterio-venous fistula. A shunt equation exercise during thoracotomy. Anaesthesia 1977; 32:777-83. [PMID: 920920 DOI: 10.1111/j.1365-2044.1977.tb10081.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A report is given of a patient with multiple bilateral pulmonary arterio-venous fistulae who underwent right thoracotomy for this condition. Blood-gas studies before and during surgery showed that the arterio-venous oxygen content differences of 1-16-1-34 mmol/l were less than normal, and the calculated venous admixture during the procedure varied from 44 to 60% of cardiac output. The changes in venous admixture at various stages of the operation could not be predicted on the basis of evidence derived from normal lungs.
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Katz JD, Barash PG. Positional hypoxaemia following post-traumatic pulmonary insufficiency. CANADIAN ANAESTHETISTS' SOCIETY JOURNAL 1977; 24:346-52. [PMID: 326354 DOI: 10.1007/bf03005107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The effect of body position on ventilatory function was evaluated in a patient with unilateral lung disease. The patient's pulmonary dynamics were examined in the supine, right, and left decubitus positions under conditions of positive pressure ventilation with zero end-expiratory pressure (ZEEP) and 5 cm H2O (0.9 KPa) positive end expiratory pressure (PEEP). When the patient was positioned so that the "diseased" lung was dependent, there was a marked decrease in PaO2 and increase in venous admixture when compared to the values in the supine position. These changes were relatively greater in the ZEEP, than the PEEP situation. When the "diseased* lung was not dependent, there was an increase in PaO2 and a decrease in venous admixture. This was most pronounced when PEEP was applied. Changes in body position may result in clinically significant alterations in pulmonary gas exchange, especially in patients with pre-existing pulmonary dysfunction.
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Rehder K, Sessler AD. Intrapulmonary gas and blood flow distribution in awake and in anesthetized man. Surg Clin North Am 1973; 53:827-42. [PMID: 4717253 DOI: 10.1016/s0039-6109(16)40087-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
A case is reported of complete isolated occlusion of the right pulmonary artery resulting in underperfusion of the right lung; this was confirmed radiographically and at thoracotomy. Bronchospirometry showed that there was a reduction of ventilation to the right lung. When this lung alone was supplied with a carbon dioxide rich mixture there was a shift of ventilation towards the normal pattern with reversion to the initial distribution when air breathing was resumed. Ventilation of the right lung with a low oxygen mixture failed to cause any shift of ventilation. The results confirm that the effects of pulmonary artery occlusion on differential ventilation which have been shown in animals also occur in man and provide further evidence that carbon dioxide can have a bronchodilator action in man.
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Littlejohn A, Mitchell B. THE EFFECTS OF CHANGES OF POSTURE AND ANAESTHESIA ON CARDIOPULMONARY FUNCTION IN MAN AND HORSES. ACTA ACUST UNITED AC 1972. [DOI: 10.1111/j.1467-2995.1972.tb00209.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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