The Effects of Abdominal Loading on Rib Cage Distortion in Premature Infants

PEDIATRICS ◽  
1979 ◽  
Vol 64 (4) ◽  
pp. 425-428
Author(s):  
Peter J. Fleming ◽  
Nestor L. Muller ◽  
M. Heather Bryan ◽  
A. Charles Bryan
Keyword(s):  
Premature Infants ◽  
Muscle Tone ◽  
Minute Ventilation ◽  
Newborn Infants ◽  
Intrathoracic Pressure ◽  
Abdominal Muscle ◽  
Abdominal Pressure ◽  
Intercostal Muscle ◽  
Rib Cage ◽  
Inflatable Cuff

The action of the diaphragm in inspiration is to decrease intrathoracic pressure and raise abdominal pressure, which elevates the rib cage. In the supine position, the rise in abdominal pressure is smaller because of the lack of abdominal muscle tone. In premature infants the inward pull of the diaphragm on the very compliant ribs causes inward movement on inspiration (ie, distortion) which is exacerbated by the lack of intercostal muscle activity during rapid eye movement (REM) sleep, their predominant state. We raised abdominal pressure by means of an inflatable cuff in 12 newborn infants (gestation 28 to 40 weeks) to try to improve inspiratory coupling of the rib cage and diaphragm. There was no significant change in minute ventilation, indicating no ventilatory impairment. In all studies in which there was distortion, abdominal loading produced a reduction or abolition of distortion (P <.01). Abdominal loading may be useful in reducing diaphragmatic activity in premature infants.

Effects of separate rib cage and abdominal restriction on exercise performance in normal humans

1985 ◽  
Vol 58 (6) ◽  
pp. 2020-2026 ◽  
Author(s):  
S. N. Hussain ◽  
B. Rabinovitch ◽  
P. T. Macklem ◽  
R. L. Pardy
Keyword(s):  
Minute Ventilation ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Abdominal Muscle ◽  
Work Rate ◽  
Abdominal Pressure ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Constant Work Rate ◽  
And Control

We assessed the effects of selective restriction of movements of the rib cage (Res,rc) and abdomen (Res,ab) on ventilatory pattern, transdiaphragmatic pressure (Pdi), and electrical activity of the diaphragm (Edi) in five normal subjects exercising at a constant work rate (80% of maximum power output) on a cycle ergometer till exhaustion. Restriction of movements was achieved by an inelastic corset applied tightly around the rib cage or abdomen. Edi was recorded by an esophageal electrode, rectified, and then integrated, and peak values during inspiration were measured. Each subject exercised at the same work rate on 3 days: with Res,rc, with Res,ab, and without restriction (control). Res,rc but not Res,ab reduced exercise time (tlim). Up to tlim, minute ventilation (VE) was similar in all three conditions. At any level of VE, however, Res,rc decreased tidal volume and inspiratory and expiratory time, whereas Res,ab had no effect on the pattern of breathing. Res,ab was associated with higher inspiratory Pdi swings at any level of VE, whereas peak Edi was similar to control. Inspiratory Pdi swings were the same with Res,rc as control, but the peak Edi for a given Pdi was greater with Res,rc (P less than 0.05). During Res,rc the abdominal pressure swings in expiration were greater than with Res,ab and control. We conclude that Res,rc altered the pattern of breathing in normal subjects in high-intensity exercise, decreased diaphragmatic contractility, increased abdominal muscle recruitment in expiration, and reduced tlim. On the other hand, Res,ab had no effect on breathing pattern or tlim but was associated with increased diaphragmatic contractility.

Human respiratory muscle actions and control during exercise

1997 ◽  
Vol 83 (4) ◽  
pp. 1256-1269 ◽  
Author(s):  
A. Aliverti ◽  
S. J. Cala ◽  
R. Duranti ◽  
G. Ferrigno ◽  
C. M. Kenyon ◽  
...  
Keyword(s):  
Lung Volume ◽  
Respiratory Muscle ◽  
Abdominal Muscle ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Velocity Of Shortening ◽  
And Control ◽  
Muscle Actions

Aliverti, A., S. J. Cala, R. Duranti, G. Ferrigno, C. M. Kenyon, A. Pedotti, G. Scano, P. Sliwinski, Peter T. Macklem, and S. Yan. Human respiratory muscle actions and control during exercise. J. Appl. Physiol. 83(4): 1256–1269, 1997.—We measured pressures and power of diaphragm, rib cage, and abdominal muscles during quiet breathing (QB) and exercise at 0, 30, 50, and 70% maximum workload (W˙max) in five men. By three-dimensional tracking of 86 chest wall markers, we calculated the volumes of lung- and diaphragm-apposed rib cage compartments (Vrc,p and Vrc,a, respectively) and the abdomen (Vab). End-inspiratory lung volume increased with percentage of W˙max as a result of an increase in Vrc,p and Vrc,a. End-expiratory lung volume decreased as a result of a decrease in Vab. ΔVrc,a/ΔVab was constant and independent ofW˙max. Thus we used ΔVab/time as an index of diaphragm velocity of shortening. From QB to 70%W˙max, diaphragmatic pressure (Pdi) increased ∼2-fold, diaphragm velocity of shortening 6.5-fold, and diaphragm workload 13-fold. Abdominal muscle pressure was ∼0 during QB but was equal to and 180° out of phase with rib cage muscle pressure at all percent W˙max. Rib cage muscle pressure and abdominal muscle pressure were greater than Pdi, but the ratios of these pressures were constant. There was a gradual inspiratory relaxation of abdominal muscles, causing abdominal pressure to fall, which minimized Pdi and decreased the expiratory action of the abdominal muscles on Vrc,a gradually, minimizing rib cage distortions. We conclude that from QB to 0% W˙max there is a switch in respiratory muscle control, with immediate recruitment of rib cage and abdominal muscles. Thereafter, a simple mechanism that increases drive equally to all three muscle groups, with drive to abdominal and rib cage muscles 180° out of phase, allows the diaphragm to contract quasi-isotonically and act as a flow generator, while rib cage and abdominal muscles develop the pressures to displace the rib cage and abdomen, respectively. This acts to equalize the pressures acting on both rib cage compartments, minimizing rib cage distortion .

First Aid for the Choking Child

PEDIATRICS ◽  
1993 ◽  
Vol 92 (3) ◽  
pp. 477-479 ◽  
Author(s):  
Keyword(s):  
Muscle Tone ◽  
Heart Association ◽  
Intrathoracic Pressure ◽  
The United States ◽  
First Aid ◽  
Red Cross ◽  
Abdominal Pressure ◽  
Permanent Disability ◽  
Foreign Objects ◽  
Local Agencies

There are more than 300 annual deaths of children in the United States due to choking.1 Prompt, effective first aid provided by a bystander may and often does prevent morbidity or death. Pediatricians should review the risk of choking with parents during routine health care visits and encourage families to obtain formal training from local agencies such as the American Red Cross and American Heart Association. Toys, food, or other foreign objects find their way into youngsters' airways. Any child who has choked on a foreign body and is coughing, crying, or speaking is best left to his/her own reflexes to relieve the obstruction. If the child or infant is unable to make sounds or if complete obstruction develops, without evidence of respiratory air movement, immediate first aid is required to avoid permanent disability or death. CURRENT TECHNIQUES Abdominal Thrust Technique Most experts agree that the abdominal thrust maneuver (Fig 1), as originally described by Henry Heimlich, MD, is the most effective method of relieving airway obstruction in children more than 1 year of age.2-8 This method utilizes the following concepts: (1) four fifths of normal respiration occurs using the diaphragm; (2) abdominal pressure compresses the diaphragm upward, thereby raising intrathoracic pressure; (3) rapid increase in intrathoracic pressure may expel the obstructing object; and (4) as a patient becomes hypoxic, muscle tone diminishes. Thus, repeated abdominal thrusts that may be ineffective initially become effective minutes later. Controversy exists concerning first aid management for a choking child less than 12 months of age: abdominal thrust technique versus back-blow and chest thrust technique.

Abdominal muscle and diaphragm activities and cavity pressures in pressure breathing

1963 ◽  
Vol 18 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Beverly Bishop
Keyword(s):  
Technical Assistance ◽  
Respiratory Activity ◽  
Silent Period ◽  
Intrathoracic Pressure ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Abdominal Pressure ◽  
Negative Pressure Breathing ◽  
External Oblique ◽  
Anesthetized Cat

The respiratory contribution of the diaphragm and external oblique abdominal muscle has been assessed by recording from the anesthetized cat the integrated electromyograms during continuous pressure breathing. As the intrapulmonary pressure is progressively reduced from 0 to -12 cm H2O, the diaphragm becomes increasingly active until it has no silent period during the respiratory cycle. Concomitantly, any respiratory activity in the abdominal muscle is completely silenced. A hyperactive diaphragm and relaxed abdominal wall can account for the constancy seen in the directly recorded intra-abdominal pressure even though the intrathoracic pressure falls. When the animal is subjected to pressures from 0 to +14 cm H2O, the diaphragm is initially inhibited and the abdominal muscle becomes increasingly active. In every animal, on positive pressure the abdominal muscle becomes active during expiration and in 20% of the animals it is also active during inspiration. Active expiration continues throughout the pressure breathing and is sufficient to reverse the breath by breath abdominal pressure variations. During negative pressure breathing, respiration is an inspiratory act and only the thorax is subjected to stress. During positive pressure breathing, respiration is an expiratory act and both the thorax and abdomen are subjected to the stress. Submitted on May 21, 1962 Note: (With the Technical Assistance of J. R. Blumstein and D. Pennec) Submitted on January 22, 1962

Effects of pursed-lips breathing and expiratory resistive loading in healthy subjects

1996 ◽  
Vol 80 (5) ◽  
pp. 1772-1784 ◽  
Author(s):  
J. A. Spahija ◽  
A. Grassino
Keyword(s):  
Tidal Volume ◽  
Lung Volume ◽  
Healthy Subjects ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Abdominal Muscle ◽  
Breathing Frequency ◽  
Muscle Recruitment ◽  
Rib Cage ◽  
Resistive Loading

To examine the effect of pursed-lips breathing (PLB) on breathing pattern and respiratory mechanics, we studied 11 healthy subjects breathing with and without PLB at rest and during steady-state bicycle exercise. Six of these subjects took part in a second study, which compared the effects of PLB to expiratory resistive loading (ERL). PLB was found to prolong expiratory and total breath durations and to promote a slower and deeper breathing pattern. During exercise, the compensatory increase that occurred in tidal volume was not sufficient to counter the reduction in breathing frequency, causing minute ventilation to be reduced. Although ERL similarly caused minute ventilation and breathing frequency to be decreased, unlike PLB, it produced no change in tidal volume and prolonged expiratory and total breath durations to a lesser extent. PLB and ERL increased the expiratory resistance to a comparable degree, also increasing the expiratory resistive work of breathing and promoting greater expiratory rib cage and abdominal muscle recruitment in response to the expiratory loads. End-expiratory lung volume, which was determined from inspiratory capacity maneuvers, was not altered by PLB; however, with ERL it was increased by 0.20 and 0.24 liter during rest and exercise, respectively. Inspiratory muscle recruitment patterns were not altered by PLB at rest, although small increases in the relative contribution of the rib cage/accessory muscles in conjunction with abdominal muscle relaxation occurred during exercise. Similar trends were observed with ERL. We conclude that, although ERL and PLB induce comparable respiratory muscle recruitment responses, they are not equivalent with respect to breathing pattern changes and effect on end-expiratory lung volume.

Effects of augmented respiratory muscle pressure production on locomotor limb venous return during calf contraction exercise

2005 ◽  
Vol 99 (5) ◽  
pp. 1802-1815 ◽  
Author(s):  
Jordan D. Miller ◽  
David F. Pegelow ◽  
Anthony J. Jacques ◽  
Jerome A. Dempsey
Keyword(s):  
Steady State ◽  
Venous Return ◽  
Vena Cava ◽  
Intrathoracic Pressure ◽  
Moderate Intensity ◽  
Abdominal Pressure ◽  
Venous Blood Flow ◽  
Diaphragmatic Breathing ◽  
Rib Cage ◽  
Gastric Pressure

We determined effects of augmented inspiratory and expiratory intrathoracic pressure or abdominal pressure (Pab) excursions on within-breath changes in steady-state femoral venous blood flow (Q̇fv) and net Q̇fv during tightly controlled (total breath time = 4 s, duty cycle = 0.5) accessory muscle/“rib cage” (ΔPab <2 cmH2O) or diaphragmatic (ΔPab >5 cmH2O) breathing. Selectively augmenting inspiratory intrathoracic pressure excursion during rib cage breathing augmented inspiratory facilitation of Q̇fv from the resting limb (69% and 89% of all flow occurred during nonloaded and loaded inspiration, respectively); however, net Q̇fv in the steady state was not altered because of slight reductions in femoral venous return during the ensuing expiratory phase of the breath. Selectively augmenting inspiratory esophageal pressure excursion during a predominantly diaphragmatic breath at rest did not alter within-breath changes in Q̇fv relative to nonloaded conditions (net retrograde flow = −9 ± 12% and −4 ± 9% during nonloaded and loaded inspiration, respectively), supporting the notion that the inferior vena cava is completely collapsed by relatively small increases in gastric pressure. Addition of inspiratory + expiratory loading to diaphragmatic breathing at rest resulted in reversal of within-breath changes in Q̇fv, such that >90% of all anterograde Q̇fv occurred during inspiration. Inspiratory + expiratory loading also reduced steady-state Q̇fv during mild- and moderate-intensity calf contractions compared with inspiratory loading alone. We conclude that 1) exaggerated inspiratory pressure excursions may augment within-breath changes in femoral venous return but do not increase net Q̇fv in the steady state and 2) active expiration during diaphragmatic breathing reduces the steady-state hyperemic response to dynamic exercise by mechanically impeding venous return from the locomotor limb, which may contribute to exercise limitation in health and disease.

Upper and lower rib cage deformation during breathing in quadriplegics

1986 ◽  
Vol 60 (2) ◽  
pp. 618-622 ◽  
Author(s):  
W. Urmey ◽  
S. Loring ◽  
J. Mead ◽  
A. S. Slutsky ◽  
M. Sarkarati ◽  
...  
Keyword(s):  
Abdominal Muscle ◽  
Abdominal Pressure ◽  
Costal Margin ◽  
Abdominal Compression ◽  
Muscle Paralysis ◽  
Lung Volumes ◽  
Rib Cage ◽  
Anteroposterior Diameter ◽  
Paradoxical Motion

In quadriplegia, the anteroposterior diameter of the rib cage (RC) decreases during inspiration. Our aim was to characterize this paradoxical motion further and to determine to what extent it was due to a diminished inspiratory effect of the diaphragm on the RC because of abdominal muscle paralysis. In six quadriplegics, upper and lower RC (URC, LRC) displacements were studied in various postures with and without extrinsic abdominal support. LRC was in its relaxed configuration at all lung volumes studied in three subjects before and four subjects during abdominal compression. URC distorted most and, despite improvement during abdominal compression, was never in the relaxed configuration during tidal inspiration. Thoracic distortability was further studied by noting the effect on URC and LRC of a cephalad force applied to the RC at the costal margin. This produced distortion similar to that observed during spontaneous inspiration. It was concluded that during spontaneous inspiration in quadriplegics lack of abdominal support does not entirely explain the RC distortion which occurs, and high abdominal pressure results in diminished RC distortion, an effect which we attribute to an increase in the area of diaphragmatic apposition to the RC.

Synergistic behavior of inspiratory muscles after diaphragmatic fatigue in the newborn

1981 ◽  
Vol 51 (3) ◽  
pp. 547-551 ◽  
Author(s):  
J. M. Lopes ◽  
N. L. Muller ◽  
M. H. Bryan ◽  
A. C. Bryan
Keyword(s):  
Muscle Fatigue ◽  
Frequency Spectrum ◽  
Muscle Activity ◽  
Newborn Infants ◽  
Intercostal Muscle ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Inspiratory Muscles ◽  
Diaphragmatic Fatigue ◽  
Synergistic Behavior

We studied diaphragmatic and intercostal muscle activity and the pattern of motion of rib cage and abdomen after diaphragmatic muscle fatigue in 15 newborn infants (birth wt 1,251 +/- 424 g, mean +/- SD). Rib cage and abdominal motion were monitored with magnetometers and intercostal and diaphragmatic electromyograms (EMG's) with surface electrodes. Twelve infants showed a total of 66 episodes of muscle fatigue identified by EMG frequency spectrum analysis. Two patterns of responses to fatigue were observed. In the first case, five infants consistently recruited their intercostal muscles; this was followed by a normalization of the diaphragmatic frequency spectrum. In these infants, recruitment of intercostal muscles successfully prevented any clinical deterioration. In the second, seven infants showed no change in their intercostal muscle activity, and diaphragmatic fatigue was followed by apnea. We conclude that in newborn infants the synergistic behavior of the diaphragm and intercostal muscles can maximize the performance of these muscles and, in some infants, seems to prevent development of apnea.

Rib cage and abdominal contributions to ventilatory response to CO2 in infants

1984 ◽  
Vol 56 (5) ◽  
pp. 1211-1216 ◽  
Author(s):  
Y. Honma ◽  
D. Wilkes ◽  
M. H. Bryan ◽  
A. C. Bryan
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Newborn Infants ◽  
Nrem Sleep ◽  
Sleep State ◽  
Co2 Response ◽  
Rib Cage ◽  
Ventilatory Responses ◽  
Significant Linear Correlation ◽  
Co2 Response Curve

We have measured the ventilatory response to inhaled CO2 of six newborn infants in rapid-eye-movement (REM) and non-REM (NREM) sleep. Ventilatory responses were measured using the Read rebreathing technique. The response was further partitioned into the volume contributions of the rib cage and abdominal compartment using the respiratory inductance plethysmograph. Sleep state was defined by electroencephalogram, electrooculogram, and behavioral criteria. In NREM sleep, there was a highly significant linear correlation between both tidal volume (VT) and instantaneous minute ventilation (VI) with CO2. Among infants, the slope of VT varied from 1.0 to 0.34 ml X Torr-1 X kg-1. However, these differences were largely due to differences in rib cage contribution, which varied from 0.56 to -0.08 ml X Torr-1 X kg-1. The abdominal contribution was similar among infants (0.41–0.56 ml X Torr-1 X kg-1). In REM, the slopes of VI were less steep than in NREM, with greater breath-to-breath variability. Slopes of VT also tended to be lower. The abdominal responses were similar to those in NREM, whereas the rib cage response was low and negative in three studies. We conclude that the slope of the CO2 response curve is primarily determined by the extent of rib cage recruitment.

Oral Vitamin E Supplementation for the Prevention of Anemia in Premature Infants: A Controlled Trial

PEDIATRICS ◽  
1987 ◽  
Vol 79 (1) ◽  
pp. 61-68 ◽  
Author(s):  
A. Zipursky ◽  
E. J. Brown ◽  
J. Watts ◽  
R. Milner ◽  
C. Rand ◽  
...  
Keyword(s):  
Vitamin E ◽  
Premature Infants ◽  
Controlled Trial ◽  
Newborn Infants ◽  
Serum Vitamin ◽  
Hemoglobin Concentration ◽  
Erythrocyte Morphology ◽  
Significant Difference ◽  
Vehicle Treatment ◽  
Vitamin E Supplementation

Serum vitamin E levels are reduced in newborn infants. It has been reported that this deficiency is responsible, in part, for the development of anemia in premature infants during the first 6 weeks of life. The efficacy of vitamin E supplementation for the prevention of anemia in premature infants has been studied in a randomized, controlled, and blinded trial. Premature infants whose birth weights were less than 1,500 g were given, by gavage, 25 IU of dl-α-tocopherol or a similar volume of the drug vehicle. Treatment was continued for the first 6 weeks of life. A total of 178 infants were studied. Vitamin E levels were significantly higher in a supplemented group by day 3 and for the remainder of the 6-week period. At 6 weeks of age, there was no significant difference between the supplemented and unsupplemented groups in hemoglobin concentration, reticulocyte and platelet counts, or erythrocyte morphology. It is concluded that there is no evidence to support a policy of administering vitamin E to premature infants to prevent the anemia of prematurity.

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