Lung and chest wall mechanical properties before and after cardiac surgery with cardiopulmonary bypass

1994 ◽  
Vol 76 (1) ◽  
pp. 166-175 ◽  
Author(s):  
G. M. Barnas ◽  
R. J. Watson ◽  
M. D. Green ◽  
A. J. Sequeira ◽  
T. B. Gilbert ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Tidal Volume ◽  
Chest Wall ◽  
Respiratory System ◽  
Supine Posture ◽  
Duration Of Surgery ◽  
Before And After ◽  
System Properties

From measurements of airway and esophageal pressures and flow, we calculated the elastance and resistance of the total respiratory system (Ers and Rrs), chest wall (Ecw and Rcw), and lungs (EL and RL) in 11 anesthetized-paralyzed patients immediately before cardiac surgery with cardiopulmonary bypass and immediately after chest closure at the end of surgery. Measurements were made during mechanical ventilation in the frequency and tidal volume ranges of normal breathing. Before surgery, frequency and tidal volume dependences of the elastances and resistances were similar to those previously measured in awake seated subjects (Am. Rev. Respir. Dis. 145: 110–113, 1992). After surgery, Ers and Rrs increased as a result of increases in EL and RL (P < 0.05), whereas Ecw and Rcw did not change (P > 0.05). EL and RL exhibited nonlinearities (i.e., decreases with increasing tidal volume) that were not seen before surgery, and RL showed a greater dependence on frequency than before surgery. The changes in RL or EL after surgery were not correlated with the duration of surgery or cardiopulmonary bypass time (P > 0.05). We conclude that 1) frequency and tidal volume dependences of respiratory system properties are not affected by anesthesia, paralysis, and the supine posture, 2) open-chest surgery with cardiopulmonary bypass does not affect the mechanical properties of the chest, and 3) cardiac surgery involving cardiopulmonary bypass causes changes in the mechanical behavior of the lung that are generally consistent with those caused by pulmonary edema induced by oleic acid (J. Appl. Physiol. 73: 1040–1046, 1992) and decreases in lung volume.

Effects of mean airway pressure and tidal volume on lung and chest wall mechanics in the dog

1993 ◽  
Vol 74 (5) ◽  
pp. 2286-2293 ◽  
Author(s):  
G. M. Barnas ◽  
J. Sprung
Keyword(s):  
Mechanical Properties ◽  
Tidal Volume ◽  
Chest Wall ◽  
Respiratory System ◽  
Lung Volume ◽  
Airway Pressure ◽  
Dynamic Mechanical Properties ◽  
Mean Airway Pressure ◽  
Residual Capacity ◽  
Normal Mean

Dependencies of the dynamic mechanical properties of the respiratory system on mean airway pressure (Paw) and the effects of tidal volume (VT) are not completely clear. We measured resistance and dynamic elastance of the total respiratory system (Rrs and Ers), lungs (RL and EL), and chest wall (Rcw and Ecw) in six healthy anesthetized paralyzed dogs during sinusoidal volume oscillations at the trachea (50–300 ml; 0.4 Hz) delivered at mean Paw from -9 to +23 cmH2O. Changes in end-expiratory lung volume, estimated with inductance plethysmographic belts, showed a typical sigmoidal relationship to mean Paw. Each dog showed the same dependencies of mechanical properties on mean Paw and VT. All elastances and resistances were minimal between 5 and 10 cmH2O mean Paw. All elastances, Rrs, and RL increased greatly with decreasing Paw below 5 cmH2O. Ers and EL increased above 10 cmH2O. Ecw, Ers, Rcw, and Rrs decreased slightly with increasing VT, but RL and EL were independent of VT. We conclude that 1) respiratory system impedance is minimal at the normal mean lung volume of supine anesthetized paralyzed dogs; 2) the dependency of RL on lung volume above functional residual capacity is dependent on VT and respiratory frequency; and 3) chest wall, but not lung, mechanical behavior is nonlinear (i.e., VT dependent) at any given lung volume.

CIRP Secretion during Cardiopulmonary Bypass Is Associated with Increased Risk of Postoperative Acute Kidney Injury

2021 ◽  
Author(s):  
Wenyan Liu ◽  
Yang Yan ◽  
Dan Han ◽  
Yongxin Li ◽  
Qian Wang ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Rna Binding ◽  
Multivariable Analysis ◽  
Kidney Injury ◽  
Proinflammatory Response ◽  
Increased Risk ◽  
Before And After ◽  
The Difference

Abstract Background Systemic inflammation contributes to cardiac surgery–associated acute kidney injury (AKI). Cardiomyocytes and other organs experience hypothermia and hypoxia during cardiopulmonary bypass (CPB), which induces the secretion of cold-inducible RNA-binding protein (CIRP). Extracellular CIRP may induce a proinflammatory response. Materials and Methods The serum CIRP levels in 76 patients before and after cardiac surgery were determined to analyze the correlation between CIRP levels and CPB time. The risk factors for AKI after cardiac surgery and the in-hospital outcomes were also analyzed. Results The difference in the levels of CIRP (ΔCIRP) after and before surgery in patients who experienced cardioplegic arrest (CA) was 26-fold higher than those who did not, and 2.7-fold of those who experienced CPB without CA. The ΔCIRP levels were positively correlated with CPB time (r = 0.574, p < 0.001) and cross-clamp time (r = 0.54, p < 0.001). Multivariable analysis indicated that ΔCIRP (odds ratio: 1.003; 95% confidence interval: 1.000–1.006; p = 0.027) was an independent risk factor for postoperative AKI. Patients who underwent aortic dissection surgery had higher levels of CIRP and higher incidence of AKI than other patients. The incidence of AKI and duration of mechanical ventilation in patients whose serum CIRP levels more than 405 pg/mL were significantly higher than those less than 405 pg/mL (65.8 vs. 42.1%, p = 0.038; 23.1 ± 18.2 vs. 13.8 ± 9.2 hours, p = 0.007). Conclusion A large amount of CIRP was released during cardiac surgery. The secreted CIRP was associated with the increased risk of AKI after cardiac surgery.

Level of agreement between laboratory and point-of-care prothrombin time before and after cardiopulmonary bypass in cardiac surgery

2014 ◽  
Vol 133 (6) ◽  
pp. 1141-1144 ◽  
Author(s):  
Michael I. Meesters ◽  
Alexander B.A. Vonk ◽  
Emma K. van de Weerdt ◽  
Suzanne Kamminga ◽  
Christa Boer
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Prothrombin Time ◽  
Point Of Care ◽  
Before And After ◽  
Level Of Agreement

Ontogeny of respiratory control and pulmonary mechanics in newborn rabbits

1985 ◽  
Vol 59 (5) ◽  
pp. 1477-1486 ◽  
Author(s):  
M. M. Grunstein ◽  
D. T. Tanaka
Keyword(s):  
Mechanical Properties ◽  
Tidal Volume ◽  
Respiratory System ◽  
Minute Ventilation ◽  
Work Of Breathing ◽  
Relative Volume ◽  
Respiratory Pattern ◽  
Pulmonary Mechanics ◽  
Volume Loss ◽  
Age Related

Maturation of the respiratory pattern and the active and passive mechanical properties of the respiratory system were assessed in 19 tracheotomized rabbits (postnatal age range: 1–26 days) placed in a body plethysmograph. With maturation both minute ventilation and tidal volume significantly increased, whereas respiratory frequency decreased. When normalized for body weight (kg) both the passive (Rrs X kg) and active (R'rs X kg) resistances of the respiratory system significantly increased with age, whereas the corresponding passive (Crs X kg-1) and active (C'rs X kg-1) compliances significantly decreased. At any given age R'rs X kg only slightly exceeded Rrs X kg, whereas C'rs X kg-1 was significantly lower than Crs X kg-1. Moreover, the maturational increases in Rrs X kg and R'rs X kg exceeded the corresponding decreases in Crs X kg-1 and C'rs X kg-1, resulting in significant age-related increases in both the passive (tau rs) and active (tau'rs) time constants of the respiratory system. Due to the age-related increases in tau'rs, producing a delayed volume response to any given inspiratory driving pressure, the relative volume loss obtained at any time during inspiration was greater in the maturing rabbit. On the other hand, because of concomitant compensatory changes in respiratory pattern, evidenced by increases in inspiratory duration with age, the end-inspiratory tidal volume loss in the maturing animal was maintained generally less than 10% at all postnatal ages. Thus maturational changes in respiratory pattern appear coupled to changes in the active mechanical properties of the respiratory system. The latter coupling serves to optimize the transduction of inspiratory pressure into volume change in a manner consistent with establishing the minimum inspiratory work of breathing during postnatal development.

The influence of supine posture on chest wall volume changes is higher in obese than in normal weight children

2015 ◽  
Vol 40 (2) ◽  
pp. 178-183
Author(s):  
Letícia Silva ◽  
Jacqueline de Melo Barcelar ◽  
Catarina Souza Rattes ◽  
Larissa Bouwman Sayão ◽  
Cyda Albuquerque Reinaux ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Tidal Volume ◽  
Chest Wall ◽  
Supine Position ◽  
Normal Weight ◽  
Obese Children ◽  
Rib Cage ◽  
Percentage Contribution ◽  
Supine Posture ◽  
And Control

The objective of this study was to analyze thoraco-abdominal kinematics in obese children in seated and supine positions during spontaneous quiet breathing. An observational study of pulmonary function and chest wall volume assessed by optoelectronic plethysmography was conducted on 35 children aged 8–12 years that were divided into 2 groups according to weight/height ratio percentiles: there were 18 obese children with percentiles greater than 95 and 17 normal weight children with percentiles of 5–85. Pulmonary function (forced expiratory volume in 1 s (FEV1); forced vital capacity (FVC); and FEV1/FVC ratio), ventilatory pattern, total and compartment chest wall volume variations, and thoraco-abdominal asynchronies were evaluated. Tidal volume was greater in seated position. Pulmonary and abdominal rib cage tidal volume and their percentage contribution to tidal volume were smaller in supine position in both obese and control children, while abdominal tidal volume and its percentage contribution was greater in the supine position only in obese children and not in controls. No statistically significant differences were found between obese and control children and between supine and seated positions regarding thoraco-abdominal asynchronies. We conclude that in obese children thoraco-abdominal kinematics is influenced by supine posture, with an increase of the abdominal and a decreased rib cage contribution to ventilation, suggesting that in this posture areas of hypoventilation can occur in the lung.

Effects of longitudinal laparotomy on respiratory system, lung, and chest wall mechanics

1992 ◽  
Vol 72 (5) ◽  
pp. 1985-1990 ◽  
Author(s):  
R. L. Santos ◽  
M. A. Santos ◽  
R. S. Sakae ◽  
P. H. Saldiva ◽  
W. A. Zin
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Guinea Pigs ◽  
Inspiratory Flow ◽  
Total Resistance ◽  
Abdominal Incision ◽  
Mechanically Ventilated ◽  
Flow Method ◽  
Chest Wall Mechanics ◽  
Before And After

In six sedated, anesthetized, paralyzed, and mechanically ventilated guinea pigs, total respiratory system (RT,rs), lung, and chest wall resistances and respiratory system (Est,rs), lung, and chest wall (Est,w) elastances were determined before and after longitudinal laparotomy. Furthermore the resistances were also split into their initial and difference components, with the former reflecting the Newtonian resistances and the latter representing the viscoelastic/inhomogeneous pressure dissipations in the system. For such purpose the end-inflation occlusion during constant inspiratory flow method was used. During laparotomy, a statistically significant increase in respiratory system difference resistance (from 0.086 to 0.101 cmH2O.ml-1.s) significantly augmented RT,rs (from 0.157 to 0.167 cmH2O.ml-1.s). The former was entirely secondary to a significant increase in chest wall difference resistance (0.019 to 0.034 cmH2O.ml-1.s), which naturally raised chest wall total resistance (from 0.030 to 0.047 cmH2O.ml-1.s). Est,rs and Est,w also increased (14.7 and 13.1%, respectively) after abdominal incision. It can be concluded that the midline xiphipubic laparotomy accompanied by the bilateral ventrodorsal infracostal incision increases RT,rs as a consequence of augmented chest wall difference resistance and Est,rs as a result of higher Est,w.

Effects of vagotomy on respiratory mechanics in newborn and adult pigs

1986 ◽  
Vol 60 (6) ◽  
pp. 1992-1999 ◽  
Author(s):  
M. G. Clement ◽  
J. P. Mortola ◽  
M. Albertini ◽  
G. Aguggini
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Respiratory Mechanics ◽  
Breathing Patterns ◽  
External Work ◽  
Vagal Control ◽  
Before And After ◽  
Wall Compliance ◽  
Bilateral Vagotomy ◽  
System Time

We have examined breathing patterns and respiratory mechanics in anesthetized tracheostomized newborn piglets and adult pigs and the changes determined by cervical bilateral vagotomy. Piglets had a respiratory system compliance and resistance, on a per kilogram basis, respectively, higher and smaller than the adults. After vagotomy neither variable changed in the newborn, but resistance dropped in the adult. This may suggest that efferent vagal control of bronchomotor tone is more pronounced in the adult. Respiratory system time constant was longer in newborns both before and after vagotomy. The distortion of the chest wall, examined as the ratio between the volume inhaled spontaneously and the passive volume for the same abdominal motion, was more marked in newborns, reflecting their higher chest wall compliance. The work per minute, computed from the pressure and volume changes, was larger in piglets. After vagotomy the external work per minute was not different; however, the larger tidal volumes were accompanied by a larger chest distortion. This may indicate that vagal control of the breathing pattern, by limiting the depth of inspiration and hence the amount of chest distortion, has implications on the energetics of breathing.

Pharmacokinetics of alfentanil before and after cardiopulmonary bypass in pediatric patients undergoing cardiac surgery: Part I

1992 ◽  
Vol 6 (3) ◽  
pp. 308-312 ◽  
Author(s):  
Jose M. den Hollander ◽  
Pim J. Hennis ◽  
Anton G.L. Burm ◽  
Arie A. Vletter ◽  
James G. Bovill
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Pediatric Patients ◽  
Before And After

Increased Plasma Adrenomedullin Concentrations during Cardiac Surgery

1998 ◽  
Vol 94 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Toshio Nishikimi ◽  
Yukio Hayashi ◽  
Gentaro Iribu ◽  
Shuichi Takishita ◽  
Yoshio Kosakai ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Pulmonary Vein ◽  
Coronary Sinus ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Elevated Plasma ◽  
Specific Radioimmunoassay ◽  
Duration Of Surgery ◽  
Severity Of The Disease

1. Adrenomedullin (AM), a potent hypotensive peptide, was originally isolated from human phaeochromocytoma. Plasma AM concentrations are elevated in hypertension, heart failure and renal failure in proportion to the severity of the disease. This study was performed to investigate the pathophysiological significance of AM during cardiac surgery. 2. Serial blood samples were obtained from patients undergoing cardiac surgery and plasma AM concentrations were determined by specific radioimmunoassay. 3. Plasma AM concentrations did not increase with anaesthesia or surgery (n = 9). Plasma AM concentrations gradually increased during cardiopulmonary bypass and after pulmonary reperfusion. After pulmonary reperfusion, plasma AM concentrations increased further. In addition, we measured plasma AM concentrations in the pulmonary vein (n = 8) and coronary sinus (n = 8) to examine the contribution of the lungs and heart to the increase in circulating AM concentrations after cardiopulmonary bypass. However, no significant differences were seen in plasma AM concentrations of the pulmonary vein or the coronary sinus and the aorta. Peak AM concentrations during cardiac surgery correlated with duration of surgery. Elevated plasma AM levels during and after surgery began to decline next day after surgery and returned to normal levels 7 days after surgery. 4. These results demonstrate that plasma AM concentrations increase during cardiac surgery and that the duration of surgery may be related to the changes in AM concentrations. Taken together with recent findings that vascular endothelial cells and vascular smooth muscle cells actively produce AM, these results suggest that plasma AM during cardiac surgery may act as a vasodilatory hormone.

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