Hering-Breuer reflex and respiratory system compliance in the first year of life: a longitudinal study

1994 ◽  
Vol 76 (2) ◽  
pp. 650-656 ◽  
Author(s):  
P. S. Rabbette ◽  
M. E. Fletcher ◽  
C. A. Dezateux ◽  
H. Soriano-Brucher ◽  
J. Stocks
Keyword(s):  
Respiratory System ◽  
Relative Strength ◽  
Reflex Response ◽  
Respiratory System Compliance ◽  
Lung Inflation ◽  
Airway Occlusion ◽  
Age Related ◽  
Healthy Infants ◽  
Occlusion Technique ◽  
Relative Change

The airway occlusion technique for measuring passive respiratory mechanics in infants relies on an ability to evoke the Hering-Breuer lung inflation reflex (HBR). However, there is conflicting evidence regarding the persistence of the HBR beyond the early newborn period. This study was designed to assess maturational changes in HBR activity and passive total respiratory system compliance (Crs) in healthy infants during the 1st yr of life. The strength of the HBR was assessed from the relative change in expiratory time (TE) after brief end-inspiratory airway occlusions compared with resting TE during spontaneous breathing. Crs was measured using the multiple-occlusion technique. Paired measurements of HBR activity and Crs were obtained during sedated sleep in 30 infants at 4–8 wk and at 1 yr of age. Significant HBR activity during tidal breathing persisted throughout the 1st yr of life, with TE increasing during occlusion by at least 26% in every infant. However, the relative strength of the reflex response decreased from a mean of 88.3% (range, 34–160%) at approximately 6 wk to 50.3% (range, 26–125%) by 1 yr of age (P < 0.001). All infants showed an increase in Crs with age, with mean Crs increasing from 60.1 +/- 8.9 (SD) to 149.0 +/- 20.6 ml/kPa between 6 wk and 1 yr. However, there was no apparent relationship between the magnitude of decline in HBR response and the age-related changes in Crs.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistence of the Hering-Breuer reflex beyond the neonatal period

1991 ◽  
Vol 71 (2) ◽  
pp. 474-480 ◽  
Author(s):  
P. S. Rabbette ◽  
K. L. Costeloe ◽  
J. Stocks
Keyword(s):  
Spontaneous Breathing ◽  
Neonatal Period ◽  
Tidal Breathing ◽  
Natural Sleep ◽  
Airway Occlusion ◽  
Conflicting Evidence ◽  
Healthy Infants ◽  
Occlusion Technique ◽  
Relative Change ◽  
Stimulation Of

There is conflicting evidence regarding the persistence of the Hering-Breuer reflex (HBR) beyond the 1st wk of life. This study was designed to assess the influence of postnatal age on the HBR. The airway occlusion technique was used to assess changes in respiratory timing during stimulation of the HBR in healthy full-term unsedated infants measured shortly after birth and at 6–8 wk of life. The strength of the HBR was assessed from the relative change in expiratory time (TE) after end-inspiratory occlusion compared with resting TE during spontaneous breathing. Paired studies were performed in 31 infants at approximately 2 days and 6 wk of age. There was a significant increase in TE during each occlusion in every infant irrespective of age at measurement. No maturational changes were observed. The increase in TE after end-inspiratory occlusion was 91.9 +/- 31.6% (SD) (range 38–158%) at approximately 2 days and 89.8 +/- 30.7% (range 44–175%) at approximately 6 wk. We conclude that the activity of the HBR during tidal breathing persists beyond the neonatal period and that there is no statistically significant change in its strength during the first 2 mo life in healthy infants during natural sleep.

scholarly journals Inhaled Nitric Oxide Counterbalances ET-1 Dependent Pulmonary Hypertension and Bronchoconstriction in the Pig

1994 ◽  
Vol 3 (2) ◽  
pp. 131-135 ◽  
Author(s):  
M. G. Clement ◽  
M. Dimori
Keyword(s):  
Nitric Oxide ◽  
Respiratory System ◽  
Inhaled Nitric Oxide ◽  
Respiratory Resistance ◽  
Respiratory Effects ◽  
Endothelin 1 ◽  
Airway Occlusion ◽  
Pulmonary Vasodilator ◽  
Additional Resistance ◽  
Occlusion Technique

In anaesthetized, paralysed, ventilated pigs the ability of inhaled nitric oxide (80 ppm in 02) to reduce the haemodynamic and respiratory effects of endothelin-1 administration (200 pmol/kg, i.v.) was evaluated. The mechanical properties of the respiratory system were evaluated by the rapid airway occlusion technique. The overall respiratory resistance, the interrupter resistance and the additional resistance that reflects the viscoelastic properties of tissues and the inequality of the time constant within the system were also evaluated. The results show that inhaled nitric oxide can act as a selective pulmonary vasodilator and as a bronchodilator to counteract the vasoconstrictor and bronchoconstrictor activity of endothelin-1. In the pig, nitric oxide inhaled at 80 ppm for 6 mitt reduced the changes in respiratory-, interrupter- and additional resistance due to endothelin-1 administration without significantly changing the static and dynamic elastance of the respiratory system.

Respiratory system compliance as seen from the cardiac fossa

1982 ◽  
Vol 53 (1) ◽  
pp. 57-62 ◽  
Author(s):  
T. C. Lloyd
Keyword(s):  
Left Ventricle ◽  
Chest Wall ◽  
Respiratory System ◽  
Shape Change ◽  
Left Ventricular ◽  
Respiratory System Compliance ◽  
Lung Volumes ◽  
Lung Inflation ◽  
Cardiac Filling ◽  
Different Levels

Changes in cardiac size and shape should impose stresses on the surrounding lung and chest wall. To examine pressure-volume relationships of the cardiac fossa we measured pressures required to increase the pericardial volume of freshly killed dogs at different levels of lung inflation, first by expanding the pericardium uniformly and then by expanding only the left ventricle. In both cases we obtained linear pressure-volume relationships, the slopes of which expressed an apparent compliance. Compliance decreased as lung volumes were increased by raising end-expiratory pressure, and compliance with symmetrical pericardial filling exceeded that with asymmetrical (left ventricular) distension. These compliances were compared with the total respiratory system compliance measured during tidal ventilation, and we found that the compliance of the cardiac fossa was significantly less than would be predicted from lung and chest wall compliances as classically measured. We concluded that the respiratory system imposes a finite compliance load on cardiac filling that raises local epicardial pressure above ambient pleural pressure. This respiratory system load depends upon lung volume and the cardiac shape change.

A method for the assessment of phasic vagal influence on tidal volume

1975 ◽  
Vol 38 (2) ◽  
pp. 335-343 ◽  
Author(s):  
M. Younes ◽  
S. Iscoe ◽  
J. Milic-Emili
Keyword(s):  
Tidal Volume ◽  
Respiratory System ◽  
Spontaneous Breathing ◽  
Volume Changes ◽  
Lung Volumes ◽  
Lung Inflation ◽  
Airway Occlusion ◽  
Tracheal Pressure ◽  
Vagal Cooling ◽  
Vagal Influence

Vagal influence related to lung volume changes results in reduction in tidal volume during spontaneous breathing due primarily to premature termination of inspiration. The strength of this vagal influence was traditionally assessed by the duration of apnea following lung inflation, a method recently shown to be inadequate and potentially misleading. An alternate method is described utilizing analysis of the volume tracing of spontaneous breaths and the tracheal pressure tracing during the first breath following airway occlusion at FRC. A formula was devised which, on the basis of previous observations, should predict the tidal volume to be obtained in the absence of phasic vagal influence. The formula was tested in four pentobarbital-anesthetized rabbits using a technique of vagal cooling which rapidly eliminated the vagal influence under study. It was found that the tidal volume obtained following vagal block could be accurately predicted provided allowances were made for the vagally mediated terminal inhibition during spontaneous breathing and the relative stiffness of the respiratory system at high lung volumes.

Thoracoabdominal Compression and Respiratory System Compliance in HIV-infected Infants

2000 ◽  
Vol 161 (5) ◽  
pp. 1567-1571 ◽  
Author(s):  
ARNOLD C. G. PLATZKER ◽  
ANDREW A. COLIN ◽  
XIN C. CHEN ◽  
PETER HIATT ◽  
JANICE HUNTER ◽  
...  
Keyword(s):  
Respiratory System ◽  
Respiratory System Compliance

scholarly journals Robustness of two different methods of monitoring respiratory system compliance during mechanical ventilation

2017 ◽  
Vol 55 (10) ◽  
pp. 1819-1828 ◽  
Author(s):  
Gaetano Perchiazzi ◽  
Christian Rylander ◽  
Mariangela Pellegrini ◽  
Anders Larsson ◽  
Göran Hedenstierna
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Respiratory System Compliance

Flow and volume dependence of expiratory resistance in anesthetized cats

1989 ◽  
Vol 67 (3) ◽  
pp. 1013-1019 ◽  
Author(s):  
M. Skaburskis ◽  
F. Shardonofsky ◽  
J. Milic-Emili
Keyword(s):  
Respiratory System ◽  
Volume Flow ◽  
Flow Profile ◽  
Pressure Flow ◽  
Lung Inflation ◽  
Mechanically Ventilated ◽  
Volume Dependence ◽  
Flow Dependence ◽  
Lung Deflation ◽  
Respiratory Muscle Activity

In five anesthetized paralyzed cats, mechanically ventilated with tidal volumes of 36–48 ml, the isovolume pressure-flow relationships of the lung and respiratory system were studied. The expiratory pressure was altered between 3 and -12 cmH2O for single tidal expirations. Isovolume pressure-flow plots for three lung volumes showed that the resistive pressure-flow relationships were curvilinear in all cases, fitting Rohrer's equation: P = K1V + K2V2, where P is the resistive pressure loss, K1 and K2 are Rohrer's coefficients, and V is flow. Values of K1 and K2 declined with lung inflation, consistent with the volume dependence of pulmonary (RL) and respiratory system resistances (Rrs). During lung deflation against atmospheric pressure, RL and Rrs tended to remain constant through most of expiration, resulting in a nearly linear volume-flow relationship. In the presence of a fixed respiratory system elastance, the shape of the volume-flow profile depended on the balance between the volume and the flow dependence of RL and Rrs. However, the flow dependence of RL and Rrs indicates that their measured values will be affected by all factors that modify expiratory flow, e.g., respiratory system elastance, equipment resistance, and the presence of respiratory muscle activity.

scholarly journals Thoracic sympathetic block reduces respiratory system compliance

2007 ◽  
Vol 125 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Fábio Ely Martins Benseñor ◽  
Joaquim Edson Vieira ◽  
José Otávio Costa Auler Júnior
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Lung Resection ◽  
Lung Compliance ◽  
Airway Hyperreactivity ◽  
Sympathetic Block ◽  
Respiratory System Compliance ◽  
Double Blind ◽  
Thoracic Epidural ◽  
Student’S T

CONTEXT AND OBJECTIVE: Thoracic epidural anesthesia (TEA) following thoracic surgery presents known analgesic and respiratory benefits. However, intraoperative thoracic sympathetic block may trigger airway hyperreactivity. This study weighed up these beneficial and undesirable effects on intraoperative respiratory mechanics. DESIGN AND SETTING: Randomized, double-blind clinical study at a tertiary public hospital. METHODS: Nineteen patients scheduled for partial lung resection were distributed using a random number table into groups receiving active TEA (15 ml 0.5% bupivacaine, n = 9) or placebo (15 ml 0.9% saline, n = 10) solutions that also contained 1:200,000 epinephrine and 2 mg morphine. Under general anesthesia, flows and airway and esophageal pressures were recorded. Pressure-volume curves, lower inflection points (LIP), resistance and compliance at 10 ml/kg tidal volume were established for respiratory system, chest wall and lungs. Student’s t test was performed, including confidence intervals (CI). RESULTS: Bupivacaine rose 5 ± 1 dermatomes upwards and 6 ± 1 downwards. LIP was higher in the bupivacaine group (6.2 ± 2.3 versus 3.6 ± 0.6 cmH2O, p = 0.016, CI = -3.4 to -1.8). Respiratory system and lung compliance were higher in the placebo group (respectively 73.3 ± 10.6 versus 51.9 ± 15.5, p = 0.003, CI = 19.1 to 23.7; 127.2 ± 31.7 versus 70.2 ± 23.1 ml/cmH2O, p < 0.001, CI = 61 to 53). Resistance and chest wall compliance showed no difference. CONCLUSION: TEA decreased respiratory system compliance by reducing its lung component. Resistance was unaffected. Under TEA, positive end-expiratory pressure and recruitment maneuvers are advisable.

Effect of lung inflation on pulmonary vascular resistance by arterial and venous occlusion

1982 ◽  
Vol 53 (5) ◽  
pp. 1110-1115 ◽  
Author(s):  
T. S. Hakim ◽  
R. P. Michel ◽  
H. K. Chang
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Venous Occlusion ◽  
Lung Inflation ◽  
Pressure Drops ◽  
Constant Flow Rate ◽  
Initial Decrease ◽  
Occlusion Technique ◽  
First Time

To explain the changes in pulmonary vascular resistance (PVR) with positive- and negative-pressure inflation (PPI and NPI, respectively), we studied their effects in isolated canine left lower lobes perfused at constant flow rate. The venous pressure was kept constant relative to atmospheric pressure during lung inflation. The total arteriovenous pressure drop (delta Pt) was partitioned with the arterial and venous occlusion technique into pressure drops across arterial and venous segments (large indistensible extra-alveolar vessels) and a middle segment (small distensible extra-alveolar and alveolar vessels). PPI caused a curvilinear increase in delta Pt due to a large Starling resistance effect in the alveolar vessels associated with a small volume-dependent increase in the resistance of alveolar and extra-alveolar vessels. NPI caused an initial decrease in delta Pt due to reduction in the resistance of extra-alveolar vessels followed by an increase in delta Pt due to a volume-dependent increase in the resistance of all vessels. In conclusion, we provided for the first time evidence that lung inflation results in a volume-dependent increase in the resistance of both alveolar and extra-alveolar vessels. The data suggest that while the volume-related changes in PVR are identical with PPI and NPI, there are pressure-related changes that can be different between the two modes of inflation.

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