Effects of lung volume and electrode position on the esophageal diaphragmatic EMG

Kim, M. J.; Druz, Walter S.; Danon, Joseph; Machnach, W.; Sharp, John T.

doi:10.1152/jappl.1978.45.3.392

Cited by 21 publications

(10 citation statements)

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“…Furthermore, these investigators noted that during more physiologic submaximal phrenic nerve stimulations, changes in muscle length had little effect on EMG activity. Corroborating this latter observation are other reports documenting that lung volume changes have little effect on directly recorded diaphragmatic EMG signals in vivo (14,17). Thus, we believe that our diaphragmatic EMG recordings are an acceptable index of central neural respiratory output.…”

Section: Discussionsupporting

confidence: 81%

Effect of Hypercapnia and Hypoxia on Costal and Crural Diaphragm Electromyograms in Piglets

et al. 1988

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ABSTRACT. We examined the separate effects of acute hypercapnia and acute hypoxia on the electromyographic activity (EMG) of the costal and crural diaphragm in 6 anesthetized spontaneously breathing piglets (age 12-23 days, weight 3.00-4.37 kg). Bipolar wire electrodes were inserted into the anterior paratendinous costal diaphragm and the midportion of the crural diaphragm. EMG activity was quantified in arbitrary units (au) of peak moving time average while the animals breathed 50% 02/50% N2 (baseline) and after 30 min of either hypercapnia (12% COz) or hypoxia (12% Oz) exposure. After 30 min of hypercapnia, the peak moving time average EMG increased in both parts of the diaphragm with the increase in crural diaphragm EMG activity (from baseline: 20 f 2 au to 30 min 12% C02: 83 f 20 au) not being significantly different from that observed in the costal diaphragm (from baseline: 21 f 2 au to 30 min 12% C02: 72 f 20 au, p = 0.17).Similarly, the peak moving time average EMG increased in both parts of the diaphragm after 30 min of hypoxia with the increase in the crural diaphragm EMG activity (from baseline: 21 f 2 au to 30 min 12% 02: 28 f 6 au) not being significantly different from that observed in the costal diaphragm (from baseline: 21 f 1 au to 30 min 12% 02: 26 f 7 au, p = 0.51). These data indicate that the inspiratory EMG activity of the diaphragm is not differentially distributed between its costal and crural components during chemically stimulated breathing in piglets. (Pediatr Res 23: 54-57,1987 Abbreviations EMG, electromyography PaOz, arterial oxygen partial pressure PaC02, arterial carbon dioxide partial pressure au, arbitrarity unit IRL, inspiratory resistive loaded breathing Experimental evidence from adult animal studies suggest that the costal and crural portions of the diaphragm may be two separate muscles (I -5). Specifically, differences in the mechanical actions (I), fiber composition (2), embryologic development (3), and segmental innervation (4,5) of the costal and crural segments have been documented. Furthermore, investigators have reported differential costal and crural diaphragm electromyographic activity during periods of heightened respiratory drive (6, 7) suggesting that the neural control of the two diaphragmatic segments may be different.In support of this concept, we have recently reported that the inspiratory EMG activity of the diaphragm is differentially distributed between its costal and crural components during inspiratory resistive loaded breathing in piglets (8). Specifically, we observed a greater augmentation in crural EMG activity when compared to its costal counterpart during the period of loaded breathing. The etiology of the greater augmentation in crural when compared with costal activity during inspiratory resistive loaded breathing is not known. However, investigators have reported that hypercapnia (6, 9) (a resultant condition of inspiratory resistive loaded breathing in our study) and hypoxia (9,10) will in and of themselves lead to a preferential augmentation...

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Section: Discussionsupporting

confidence: 81%

Effect of Hypercapnia and Hypoxia on Costal and Crural Diaphragm Electromyograms in Piglets

et al. 1988

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“…We thought this recording would be useful to eliminate some of the contamination by chest wall muscles on the surface electrodes. Pre vious observations in adult subjects have sug gested that the electrical activity of the dia phragm recorded by esophageal electrodes mimics that obtained by surface electrodes [10][11][12]. That is, the EMG of the vertebral or crural part of the diaphragm would be repre sentative of the anterior and lateral portions as well.…”

Section: Fig 2 Diagrammatic Changes In Vt 'Timing' Andmentioning

confidence: 89%

Diaphragmatic Activity and Ventilation in Preterm Infants

Reis

Cates²,

Landriault³

et al. 1994

Neonatology

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To determine the effects of sleep on diaphragmatic activity and ventilation we studied 10 preterm infants (birth weight 1,840 ± 50 g, gestational age 33 ± 0.6 weeks, and postnatal age 9.4 ± 1.4 days). We measured surface and esophageal diaphragmatic electromyograms (EMG_di). Ventilation was measured using a nasal flowmeter and a flow-through system. Diaphragmatic activity was analyzed for total phasic activity, expiratory phasic activity, the expiratory to total phasic activity ratio, and the presence of ‘tonic’activity. The latter was defined by the presence of electrical activity and the end of expiration. There was a decrease in the average total phasic activity (1.25 vs. 0.71 s, p = 0.001), expiratory phasic activity (0.67 vs. 0.21 s, p = 0.002), the expiratory to total phasic activity ratio (0.51:0.27 s, p = 0.001) and tonic activity (51 to 5%, p = 0.01) from quiet to REM sleep in the surface EMG_di. Similar changes were found in the esophageal EMG_di, except that tonic activity was rarely observed. In parallel with these changes in electrical activity of the diaphragm, minute ventilation and alveolar ventilation increased from quiet to REM sleep. This increase was primarily related to an increase in frequency with a negligible change in tidal volume. The increase in frequency was primarily due to shortening of inspiratory time. The findings that tonic activity recorded via surface electrodes decreased substantially from quiet to REM sleep and was not observed in the esophageal EMG_di suggests that this tonic activity may represent electrical activity of the postural muscles of the chest wall rather than the diaphragm.

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“…Many studies have addressed the effect of lung volume on the oesophageal diaphragm compound muscle action potential (CMAP). The studies performed in animals showed that change of lung volume had only a small effect on diaphragm CMAP amplitude [5,6]. In contrast, GANDEVIA and MCKENZIE [7] using a balloon stabilized oesophageal electrode to record the human diaphragm CMAP during supramaximal electrical stimulation (ES) at different lung volumes, reported that diaphragm CMAP amplitude systematically increased with increasing lung volume.…”

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confidence: 99%

Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

Luo¹,

Lyall²,

Harris³

et al. 2000

Eur Respir J

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To reassess the effect of lung volume on the oesophageal diaphragm CMAP, six normal subjects were studied using an oesophageal catheter incorporating seven electrodes (number one being proximal and seven distal) that were 1 cm in length and 1 cm apart. Electrode number three was positioned at the centre of the electrically active region of the diaphragm (EARdi) at functional residual capacity (FRC). The diaphragm CMAP elicited by bilateral magnetic stimulation of the phrenic nerves was simultaneously recorded from four electrode pairs. Pair one was created from electrodes one and three, pair two from electrodes two and four, pair three from electrodes three and five, and pair four from electrodes five and seven. Phrenic nerve stimulation was at residual volume (RV), FRC, FRC+1.0 L, FRC+2.0 L, and total lung capacity (TLC).The CMAP recorded from pair one was least influenced by changes in lung volume and the amplitude was 2.41 0.39 (mean SD), 2.60 0.27, 2.64 0.29, and 2.71 0.45 mV at RV, FRC, FRC+1.0 L and FRC+2.0 L, respectively. At TLC the CMAP was more variable. The CMAP amplitude recorded from pair two increased with increasing lung volume and at FRC+2.0 L was 3.7 times larger than that at FRC. Pair four usually recorded substantially smaller CMAPs at all lung volumes.This study shows that the diaphragm compound muscle action potential recorded from an oesophageal electrode just above the diaphragm is relatively stable over the lung volume range residual volume to functional residual capacity+2.0 L. Eur Respir J 2000; 15: 1033±1038.

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Effects of lung volume and electrode position on the esophageal diaphragmatic EMG

Cited by 21 publications

References 0 publications

Effect of Hypercapnia and Hypoxia on Costal and Crural Diaphragm Electromyograms in Piglets

Effect of Hypercapnia and Hypoxia on Costal and Crural Diaphragm Electromyograms in Piglets

Diaphragmatic Activity and Ventilation in Preterm Infants

Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

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