Abdominal Respiratory Movements Research Articles

Determinants of oxygen desaturation in the course of ventilation during sleep in chronic obstructive pulmonary disease.

During sleep, none of 9 subjects with chronic obstructive pulmonary disease (COPD) were apneic. Despite ventilation, acute arterial oxygen desaturation of 11% or more occurred in 6 of them. The other 3 were nondesaturators (i.e., 3% or less desaturation) during sleep. The desaturation that occurred in the 6 subjects with COPD was associated with episodes of (1) esophageal pressure or abdominal respiratory movement that acutely decreased in amplitude during rapid-eye-movement (REM) sleep, or (2) esophageal pressure or abdominal respiratory movement that acutely increased in amplitude in association with snoring during non-REM and REM sleep. During daytime wakefulness, ventilatory responses to hypoxia and hypercapnia were markedly less in the 6 desaturators compared with the 3 nondesaturators and 5 healthy control subjects. The decreased ventilatory responses in the 6 desaturators appeared to result from both impaired respiratory mechanical effectiveness and impaired respiratory center responsiveness to chemoreceptor stimulation. We suggest that subjects with COPD with these respiratory impairments are predisposed to develop severe nonapneic oxygen desaturation during the added respiratory impairment of REM sleep or of what appears to be sleep-related partial upper airway obstruction.

Thoracico-abdominal respiratory correlations in infants: constancy and variability in different sleep states

28 polygraphic recordings were made in normal infants: 20 in full-term newborns and 8 in 2- to 10-wk-old babies. Data were analysed by 20-sec epochs. Relationships between thoracic (3rd-4th rib level) and abdominal respiratory movements were studied according to their maximum out-of-phase occurring (180° maximum) in every 20-sec period. The thoracico-abdominal phase relationships according to sleep states do not change during the first trimester of life. In quiet sleep, while in-phase thoracico-abdominal respiration was the most frequent pattern, the out-of-phase one was also a possible pattern. In active sleep, out-of-phase respiration is characteristic, in-phase relation being a rare exception. In transitional sleep, respiratory relationships could be those appropriate for the preceding or the following sleep state. Nasal air flow always occurred in phase with abdominal movements. Total flattening of thoracicorespiratory movements only were found in all sleep states; these thoracic flattenings must be differentiated from apnea. Transient fluctuations in the degree of phase relations are possible. There exists both interand intraindividual variability in normal infants. Variability of fusimotor system tonus is probably the neurological mechanism underling these phenomena.

Brain stem control of respiratory depth and rate in the cat ,2

A study was made on the roles of the Hering-Breuer reflex, the pneumotaxic center, the apneustic center, and the medullary respiratory center in the regulation of rate and depth of respiration in response to changes in blood concentration of carbon dioxide and oxygen. Integrated phrenic nerve discharge, abdominal respiratory movement, and intra-abdominal and intra-tracheal pressures were recorded in decerebrate cats as they breathed air, 5 % and 7% CO 2 in O 2,10% O 2 and, 100% O 2. Vagotomy abolished the rate increase but not the depth increase in response to CO 2 breathing. Pneumotaxic center ablation reduced the depth increase but exaggerated the rate increase in response to CO 2 breathing. Thus, the Hering-Breuer reflex normally controls the respiratory rate and, in the absence of the pneumotaxic center, maintains a relatively constant depth. The pneumotaxic center normally controls the respiratory depth and, in the absence of Hering-Breuer reflex, maintains a constant rate. During apneustic breathing, following vagotomy and pneumotaxic center ablation, both inspiratory depth and duration vary with the inspired CO 2 concentration. The apneustic center thus provides maximum depth and prolonged duration so that rate can be regulated by the Hering-Breuer reflex and depth by the pneumotaxic center. Following medullary respiratory center isolation, gasping rate was reduced by 100% O 2 but unaffected by 7% CO 2.

Studies on Respiratory Movements

The author studied the amplitudes of chest and abdominal respiratory movements in supine, sitting and standing positions at rest.The results obtained were as follows;1. The amplitude of abdominal movements was 2-5 times greater than that of chest movements. This fact was indifferent of sex and age.2. Chest movements became, in general, greater, when the subjects changed their posture from supine to sitting and standing.

A COMPARISON OF THE EFFECTS OF ANOXEMIA AND CARBON‐DIOXIDE SATURATION ON COSTAL AND ABDOMINAL BREATHING

The effects of lowered alveolar oxygen and of increased alveolar carbon dioxide on costal and abdominal breathing were recorded with six encircling bands.Lowered alveolar oxygen most commonly increased the circumference of the chest and abdomen at the end of expiration and decreased the intra‐thoracic pressure.This expansion of the chest and abdomen was tentatively attributed to an increased tension of the diaphragm and of the inspiratory muscles of the chest.Sometimes anoxemia increased the expiratory circumference of the abdomen and decreased that of the chest.This differential effect was tentatively attributed to a greater development of tension in the diaphragm which, through the lungs, exerted an inward traction on the chest.During recovery from anoxemia costal respiratory movements were inhibited more than abdominal respiratory movements. The upper costal segments were inhibited more than the lower costal segments. Upper costal apnea and abdominal hyperpnea were not uncommon. In one experiment upper costal apnea was accompanied by abdominal hyperpnea greater than the hyperpnea of the immediately preceding anoxemia.As abdominal respiratory movements diminished during recovery the costal movements increased. This unusual co‐ordination (?) of costal and abdominal breathing led to a smooth return to normal ventilation.The effects of carbon dioxide differed importantly from those of anoxemia. In most experiments there was a decrease in circumference of the chest and abdomen at the end of expiration and a corresponding rise in the intra‐thoracic pressures.It was tentatively suggested that carbon dioxide decreases the tonus of the inspiratory muscles by inhibiting prevailing reflexes which tend to increase lung volume, and that anoxemia increases the tonus of the inspiratory muscles by augmenting these same prevailing reflexes.

Costal and Abdominal Respiratory Movements in Relation to Nervous Control of Breathing

Changes in body circumference associated with respiratory movements were simultaneously recorded in the dog at 6 different levels—3 costal and 3 abdominal. (Fig. 1.) Continuous registration of respiratory movements with this method showed variations in type from time to time in the same individual. Some of these changes were spontaneous; others were elicited by deliberate introduction of new variables.Analysis of measurements on 31 female and 73 male dogs failed to show any relation between sex and mode of breathing. Comparing the magnitude of increased costal circumference with the magnitude of increased abdominal circumference 34.3% of 106 dogs were found to breathe more with the chest than with the abdomen. Using our new method of comparing costal and abdominal accommodation of air by grossly correcting for the greater costal circumference and greater length of chest 79% were found to be costal breathers. The mean ratio of costal to abdominal accommodation for all of the dogs studied was 2.15 indicatin...

CRITICAL THERMAL INCREMENTS FOR RHYTHMIC RESPIRATORY MOVEMENTS OF INSECTS

The rhythm of abdominal respiratory movements in various insects, aquatic and terrestrial, is shown to possess critical increments 11,500+/- or 16,500+/- calories (Libellula, Dixippus, Anax). These are characteristic of processes involved in respiration, and definitely differ from the increment 12,200 calories which is found in a number of instances of (non-respiratory) rhythmic neuromuscular activities of insects and other arthropods. With grasshoppers (Melanoplus), normal or freshly decapitated, the critical increment is 7,900, again a value encountered in connection with some phenomena of gaseous exchange and agreeing well with the value obtained for CO(2) output in Melanoplus. It is shown that by decapitation the temperature characteristic for abdominal rhythm, in Melanoplus, is changed to 16,500, then to 11,300-depending upon the time since decapitation; intermediate values do not appear. The frequency of the respiratory movements seems to be controlled by a metabolically distinct group of neurones. The bearing of these results upon the theory of functional analysis by means of temperature characteristics is discussed, and it is pointed out that a definite standpoint becomes available from which to attempt the specific control of vital processes.

The postural activity of the rectus abdominis muscle of the cat

If we accept Sherrington's view that a muscle may undergo changes in length without concomitant changes in tension as a means of preserving a certain posture or attitude of the body, we find that the rectus abdominis of the cat manifests this property in a high degree. The animals used for experiment were etherized and a tracheal cannula inserted. The skin was incised in the median line of the thorax. The pectoral muscles of one side were then severed close to their attachments to the sternum and sternal portions of the ribs and reflected outward. The tendinous insertions of the rectus abdominis on the ribs were divided and the free upper end lifted out. A thread was tied about the tendinous end of the muscle and led through a system of small pulleys to a muscle lever. The abdominal wall was kept intact. A rise of the writing point of the lever indicated a shortening of the muscle, while the writing point fell when the muscle relaxed. The thoracic and abdominal respiratory movements were recorded by Verdin tambours connected to Crile stethographs. Small changes in the length of the rectus abdominis occurred during ordinary respiration. But if fluid, usually an M/8 solution of sodium chloride, was introduced into the stomach through a stomach tube passed down the esophagus, or directly into the peritoneal cavity through a hypodermic needle, the muscle promptly relaxed, the amount of relaxation being proportional to the amount of fluid introduced, and continuing until the limit of distension of the abdominal cavity was reached. This limit of distension is determined by the muscular wall and not by the skin. The relaxation occurs when fluid flows in at pressures of only two or three centimeters of salt solution, and a contraction occurs when fluid is flowing out of the stomach.

Absence of Abdominal Respiratory Movement as an Indication of Pericarditis

Absence of Abdominal Respiratory Movement as an Indication of Pericarditis

SOLITARY ABSCESS OF THE LEFT LOBE OF THE LIVER SIMULATING ABSCESS IN THE ABDOMINAL WALL.

Thomas J., 44 years of age, had rheumatism ten years ago, from which he made a perfect recovery. He remained in perfect health and continued at active labor until the morning of April 24, 1901, when he complained of nausea and epigastric pain. He took salts and obtained a copious action of the bowels, which, however, did not afford relief. The next day there was a slight chill, some fever, pain and soreness in the epigastrium, anorexia and restlessness. On April 29 the symptoms were more pronounced. There were no subsequent chills, but the temperature had risen to 102.5 and the pulse to 100. Abdominal respiratory movements were free and equal on both sides. In the left epigastrium there was a tumor or bulging of the abdominal wall, circular in outline, hard, circumscribed and exquisitely tender to touch and percussion. The tenderness was very superficial, while deep pressure from below