Determinants of diaphragm motion in unilateral diaphragmatic paralysis

2004 ◽  
Vol 96 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Pierre Scillia ◽  
Matteo Cappello ◽  
André De Troyer
Keyword(s):  
Clinical Practice ◽  
Muscle Contraction ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Diaphragmatic Paralysis ◽  
Phrenic Nerve Stimulation ◽  
Anesthetized Dogs ◽  
Diaphragm Motion ◽  
Cardinal Sign ◽  
Stimulation Of

Cranial displacement of a hemidiaphragm during sniffs is a cardinal sign of unilateral diaphragmatic paralysis in clinical practice. However, we have recently observed that isolated stimulation of one phrenic nerve in dogs causes the contralateral (inactive) hemidiaphragm to move caudally. In the present study, therefore, we tested the idea that, in unilateral diaphragmatic paralysis, the pattern of inspiratory muscle contraction plays a major role in determining the motion of the inactive hemidiaphragm. We induced a hemidiaphragmatic paralysis in six anesthetized dogs and assessed the contour of the diaphragm during isolated unilateral phrenic nerve stimulation and during spontaneous inspiratory efforts. Whereas the inactive hemidiaphragm moved caudally in the first instance, it moved cranially in the second. The parasternal intercostal muscles were then severed to reduce the contribution of the rib cage muscles to inspiratory efforts and to enhance the force generated by the intact hemidiaphragm. Although the change in pleural pressure (ΔPpl) was unaltered, the cranial displacement of the paralyzed hemidiaphragm was consistently reduced. A pneumothorax was finally induced to eliminate ΔPpl during unilateral phrenic nerve stimulation, and this enhanced the caudal displacement of the inactive hemidiaphragm. These observations indicate that, in unilateral diaphragmatic paralysis, the motion of the inactive hemidiaphragm is largely determined by the balance between the force related to ΔPpl and the force generated by the intact hemidiaphragm.

Effect of digitalis on the diaphragm in anesthetized dogs

1987 ◽  
Vol 63 (1) ◽  
pp. 277-284 ◽  
Author(s):  
Y. Kikuchi ◽  
W. Hida ◽  
C. Shindoh ◽  
T. Chonan ◽  
H. Miki ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Stimulus Frequency ◽  
Dependent Manner ◽  
Phrenic Nerve Stimulation ◽  
Transdiaphragmatic Pressure ◽  
Mechanically Ventilated ◽  
Before And After ◽  
Residual Capacity ◽  
Anesthetized Dogs

We examined the effect of digitalis on diaphragmatic contractility and fatigability in 19 anesthetized mechanically ventilated dogs. The diaphragmatic force was assessed from transdiaphragmatic pressure (Pdi) developed at functional residual capacity against an occluded airway during cervical phrenic nerve stimulation. In a first group of five dogs, Pdi-stimulus frequency relationships were compared before and after administration of ouabain in doses of 0.01, 0.02, and 0.04 mg/kg. In a second group, diaphragmatic fatigue was produced by bilateral phrenic nerve stimulation at 30 Hz. Ten seconds of stimulation and 15 s of mechanical ventilation were repeated for 30 min. The rates of decrease in Pdi were compared between two groups, one of 0.05 mg/kg deslanoside-treated dogs (n = 7) and one of nontreated dogs (n = 7). After ouabain administration Pdi was significantly greater at each frequency in a dose-dependent manner. On the other hand, the rate of decrease in Pdi in the deslanoside group was significantly smaller than that in the nontreated group, whereas deslanoside did not greatly change the Pdi-frequency curves in fresh diaphragm. We conclude that ouabain improves contractility of the fresh diaphragm and that deslanoside has a protective effect against fatigability.

scholarly journals Explorations of Unilateral Diaphragmatic Paralysis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Alexandre Quesnel ◽  
Françoise Beuret Blanquart ◽  
Jean Paul Marie ◽  
Eric Verin
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Esophageal Pressure ◽  
Diagnostic Value ◽  
Diaphragmatic Paralysis ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure ◽  
Phrenic Nerve Stimulation ◽  
Diaphragmatic Dysfunction ◽  
Chest X Ray

Objective. The aim of the present study was to evaluate sniff test, maximal inspiratory pressure, and presence of paradoxical inspiratory diaphragmatic movements and their diagnostic value in patients referred for suspicion of diaphragmatic dysfunction. Methods. Twenty-two patients (8 men and 14 women, 58±13 years) with suspected diaphragmatic dysfunction were included. Pulmonary function test was evaluated by spirometry. Diaphragm dysfunction was diagnosed with unilateral phrenic nerve stimulation. Esophageal pressure was recorded during sniff test and maximal static inspiratory movements. Detection of paradoxical diaphragmatic movement was performed with anteroposterior projection of chest X-ray fluoroscopic video. Results. Phrenic nerve stimulation enabled diagnosis of diaphragmatic paralysis in 15 of the 22 patients. The remaining 7 patients had normal explorations. Lung volumes were significantly lower in patients with diaphragmatic paralysis than in control subjects, as maximal inspiratory pressure. No patient with normal diaphragmatic exploration had paradoxical inspiratory movement. The combined diagnostic value of reduced esophageal pressure during sniff test, reduced esophageal pressure during maximal static inspiratory movements, and presence of paradoxical inspiratory movement had a sensitivity of 87% and a specificity of 71%. Conclusion. Our results suggest that, in most cases, a combination of sniff test, maximal inspiratory pressure, and paradoxical inspiratory movement could help to diagnose diaphragmatic dysfunction. Nevertheless, phrenic nerve stimulation remains the best test for assessing diaphragmatic dysfunction.

scholarly journals Comparison of magnetic and electrical phrenic nerve stimulation in assessment of phrenic nerve conduction time

1997 ◽  
Vol 82 (4) ◽  
pp. 1190-1199 ◽  
Author(s):  
Thomas Similowski ◽  
Selma Mehiri ◽  
Alexandre Duguet ◽  
Valérie Attali ◽  
Christian Straus ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Nerve Conduction ◽  
Clinical Implications ◽  
Conduction Time ◽  
Electromyographic Activity ◽  
Average Difference ◽  
Phrenic Nerve Stimulation ◽  
Stimulation Of

Similowski, Thomas, Selma Mehiri, Alexandre Duguet, Valérie Attali, Christian Straus, and Jean-Philippe Derenne.Comparison of magnetic and electrical phrenic nerve stimulation in assessment of phrenic nerve conduction time. J. Appl. Physiol. 82(4): 1190–1199, 1997.—Cervical magnetic stimulation (CMS), a nonvolitional test of diaphragm function, is an easy means for measuring the latency of the diaphragm motor response to phrenic nerve stimulation, namely, phrenic nerve conduction time (PNCT). In this application, CMS has some practical advantages over electrical stimulation of the phrenic nerve in the neck (ES). Although normal ES-PNCTs have been consistently reported between 7 and 8 ms, data are less homogeneous for CMS-PNCTs, with some reports suggesting lower values. This study systematically compares ES- and CMS-PNCTs for the same subjects. Surface recordings of diaphragmatic electromyographic activity were obtained for seven healthy volunteers during ES and CMS of varying intensities. On average, ES-PNCTs amounted to 6.41 ± 0.84 ms and were little influenced by stimulation intensity. With CMS, PNCTs were significantly lower (average difference 1.05 ms), showing a marked increase as CMS intensity lessened. ES and CMS values became comparable for a CMS intensity 65% of the maximal possible intensity of 2.5 Tesla. These findings may be the result of phrenic nerve depolarization occurring more distally than expected with CMS, which may have clinical implications regarding the diagnosis and follow-up of phrenic nerve lesions.

Diaphragmatic pressures: transvenous vs. direct phrenic nerve stimulation

1985 ◽  
Vol 59 (1) ◽  
pp. 269-273 ◽  
Author(s):  
R. F. Planas ◽  
R. H. McBrayer ◽  
P. A. Koen
Keyword(s):  
Analysis Of Variance ◽  
Respiratory System ◽  
Functional Residual Capacity ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Phrenic Nerve Stimulation ◽  
Transdiaphragmatic Pressure ◽  
Residual Capacity ◽  
Anesthetized Dogs

Diaphragmatic force, determined by stimulating the phrenic nerve while simultaneously measuring the pressures in a closed respiratory system, was assessed in five anesthetized dogs over a 5-h period to evaluate the inherent variability of this technique. Transdiaphragmatic pressure (Pdi) was measured at functional residual capacity during stimulation (120 Hz, 0.2-ms duration) of one phrenic nerve by either direct phrenic nerve stimulation (DPNS) or transvenous phrenic nerve stimulation (TPNS). An analysis of variance showed no significant (P greater than 0.50) change during the 5-h period. There was a significant correlation (r = 0.94, P less than 0.001) between Pdi obtained by TPNS and that obtained by DPNS. It is concluded that either DPNS or TPNS can be used to evaluate diaphragmatic strength over a 5-h period and that TPNS can be used in lieu of DPNS.

Assessment of neonatal diaphragmatic paralysis using magnetic phrenic nerve stimulation

1999 ◽  
Vol 27 (3) ◽  
pp. 224-226 ◽  
Author(s):  
G.F. Rafferty ◽  
A. Greenough ◽  
G. Dimitriou ◽  
M. I. Polkey ◽  
A. Long ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Diaphragmatic Paralysis ◽  
Phrenic Nerve Stimulation

Botzinger complex region role in phrenic-to-phrenic inhibitory reflex of cat

1989 ◽  
Vol 67 (4) ◽  
pp. 1364-1370 ◽  
Author(s):  
D. F. Speck
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Inhibitory Response ◽  
Phrenic Nerve Stimulation ◽  
Bötzinger Complex ◽  
Before And After ◽  
Pass Through ◽  
Bilateral Lesions ◽  
Decerebrate Cats ◽  
Inhibitory Reflex

Neuronal recordings, microstimulation, and electrolytic and chemical lesions were used to examine the involvement of the Botzinger Complex (BotC) in the bilateral phrenic-to-phrenic inhibitory reflex. Experiments were conducted in decerebrate cats that were paralyzed, ventilated, thoracotomized, and vagotomized. Microelectrode recordings within the BotC region revealed that some neurons were activated by phrenic nerve stimulation (15 of 69 expiratory units, 9 of 67 inspiratory units, and 19 nonrespiratory-modulated units) at average latencies similar to the onset latency of the phrenic-to-phrenic inhibition. In addition, microstimulation within the BotC caused a short latency transient inhibition of phrenic motor activity. In 17 cats phrenic neurogram responses to threshold and supramaximal (15 mA) stimulation of phrenic nerve afferents were recorded before and after electrolytic BotC lesions. In 15 animals the inhibitory reflex was attenuated by bilateral lesions. Because lesion of either BotC neurons or axons of passage could account for this attenuation, in eight experiments the phrenic-to-phrenic inhibitory responses were recorded before and after bilateral injections of 5 microM kainic acid (30–150 nl) into the BotC. After chemical lesions, the inhibitory response to phrenic nerve stimulation remained; however, neuronal activity typical of the BotC could not be located. These results suggest that axons important in producing the phrenic-to-phrenic reflex pass through the region of the BotC, but that BotC neurons themselves are not necessary for this reflex.

Mapping for Acute Transvenous Phrenic Nerve Stimulation Study (MAPS Study)

2017 ◽  
Vol 40 (3) ◽  
pp. 294-300
Author(s):  
LUKAS R.C. DEKKER ◽  
BART GERRITSE ◽  
AVRAM SCHEINER ◽  
LILIAN KORNET
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Phrenic Nerve Stimulation
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