Transcutaneous Electromyography Research Articles

Transcutaneous electromyography associated with electric activity of the diaphragm allows differential diagnosis complex neuro-myopathy.

Transcutaneous electromyography associated with electric activity of the diaphragm allows differential diagnosis complex neuro-myopathy.

Simultaneous measurement of diaphragm activity, chest impedance, and ECG using three standard cardiorespiratory monitoring electrodes.

Current cardiorespiratory monitoring in neonates with electrocardiogram (ECG) and chest impedance (CI) has limitations. Adding transcutaneous electromyography of the diaphragm (dEMG) may improve respiratory monitoring, but requires additional hardware. We aimed to determine the feasibility of measuring dEMG and ECG/CI simultaneously using the standard ECG/CI hardware, with its three electrodes repositioned to dEMG electrode locations. Thirty infants (median postmenstrual age 30.4 weeks) were included. First, we assessed the feasibility of extracting dEMG from the ECG-signal. If successful, the agreement between dEMG-based respiratory rate (RR), using three different ECG-leads, and a respiratory reference signal was assessed using the Bland-Altman analysis and the intraclass correlation coefficient (ICC). Furthermore, we studied the agreement between CI-based RR and the reference signal with the electrodes placed at the standard and dEMG position. Finally, we explored the quality of the ECG-signal at the different electrode positions. In 15 infants, feasibility of measuring dEMG with the monitoring electrodes was confirmed. In the next 15 infants, comparing dEMG-based RR to the reference signal resulted in a mean difference and limits of agreement for ECG-lead I, II and III of 4.2 [-8.2 to 16.6], 4.3 [-10.7 to 19.3] and 5.0 [-14.2 to 24.2] breaths/min, respectively. ICC analysis showed a moderate agreement for all ECG-leads. CI-based RR agreement was similar at the standard and dEMG electrode position. An exploratory analysis suggested similar quality of the ECG-signal at both electrode positions. Measuring dEMG using the ECG/CI hardware with its electrodes on the diaphragm is feasible, leaving ECG/CI monitoring unaffected.

Multicentre paired non-inferiority study of the cardiorespiratory monitoring performance of the wireless and non-adhesive Bambi® belt measuring diaphragm activity in neonates: study protocol

IntroductionCardiorespiratory monitoring is used in the neonatal intensive care unit (NICU) to assess the clinical status of newborn infants and detect critical deteriorations in cardiorespiratory function. Currently, heart rate (HR)...

Feasibility of wireless cardiorespiratory monitoring with dry electrodes incorporated in a belt in preterm infants

Objective. Monitoring heart rate (HR) and respiratory rate (RR) is essential in preterm infants and is currently measured with ECG and chest impedance (CI), respectively. However, in current clinical practice these techniques use wired adhesive electrodes which can cause skin damage and hinder parent-infant interaction. Moreover, CI is not always reliable. We assessed the feasibility of a wireless dry electrode belt to measure HR and RR via transcutaneous diaphragmatic electromyography (dEMG). Approach. In this prospective, observational study, infants were monitored up to 72 h with the belt and standard CI. Feasibility of the belt was expressed by its ability to retrieve a respiratory waveform from dEMG, determining the percentage of time with stable respiration data without signal errors (‘lead-off’ and Bluetooth Loss Error, ‘BLE’), skin-friendliness of the belt (skin score) and by exploring the ability to monitor trends in HR and RR with the belt. Main results. In all 19 included infants (median gestational age 27.3 weeks) a respiratory waveform could be obtained. The amount of signal errors was low (lead-off 0.5% (IQR 0.1–1.6) and BLE 0.3% (IQR 0.1–0.9)) and 76.5% (IQR 69.3–80.0) of the respiration measurement was stable. No adverse skin effects were observed (median skin score of 3(3–4)). A similar HR and RR trend between the belt and CI was observed. Significance. Dry electrodes incorporated in a non-adhesive belt can measure dEMG in preterm infants. The belt provided a HR and RR trend similar to CI. Future studies are required to investigate the non-inferiority of the belt as a cardiorespiratory monitor compared to CI.

Diaphragmatic electromyography during a spontaneous breathing trial to predict extubation failure in preterm infants

BackgroundPremature attempts at extubation and prolonged episodes of ventilatory support in preterm infants have adverse outcomes. The aim of this study was to determine whether measuring the electrical activity of the diaphragm during a spontaneous breathing trial (SBT) could predict extubation failure in preterm infants.MethodsWhen infants were ready for extubation, the electrical activity of the diaphragm was measured by transcutaneous electromyography (EMG) before and during a SBT when the infants were on endotracheal continuous positive airway pressure.ResultsForty-eight infants were recruited (median (IQR) gestational age of 27.2 (25.6–30.4) weeks). Three infants did not pass the SBT and 13 failed extubation. The amplitude of the EMG increased during the SBT [2.3 (1.5–4.2) versus 3.5 (2.1–5.3) µV; p < 0.001]. In the whole cohort, postmenstrual age (PMA) was the strongest predictor for extubation failure (area under the curve (AUC) 0.77). In infants of gestational age <29 weeks, the percentage change of the EMG predicted extubation failure with an AUC of 0.74 while PMA was not associated with the outcome of extubation.ConclusionsIn all preterm infants, PMA was the strongest predictor of extubation failure; in those born <29 weeks of gestation, diaphragmatic electromyography during an SBT was the best predictor of extubation failure.ImpactComposite assessments of readiness for extubation may be beneficial in the preterm population.Diaphragmatic electromyography measured by surface electrodes is a non-invasive technique to assess the electrical activity of the diaphragm.Postmenstrual age was the strongest predictor of extubation outcome in preterm infants.The change in diaphragmatic activity during a spontaneous breathing trial in extremely prematurely born infants can predict subsequent extubation failure with moderate sensitivity and specificity.

Diaphragm Activity Pre and Post Extubation in Ventilated Critically Ill Infants and Children Measured With Transcutaneous Electromyography.

Swift extubation is important to prevent detrimental effects of invasive mechanical ventilation but carries the risk of extubation failure. Accurate tools to assess extubation readiness are lacking. This study aimed to describe the effect of extubation on diaphragm activity in ventilated infants and children. Our secondary aim was to compare diaphragm activity between failed and successfully extubated patients. Prospective, observational study. Single-center tertiary neonatal ICU and PICU. Infants and children receiving invasive mechanical ventilation longer than 24 hours. None. Diaphragm activity was measured with transcutaneous electromyography, from 15 minutes before extubation till 180 minutes thereafter. Peak and tonic activity, inspiratory amplitude, inspiratory area under the curve, and respiratory rate were calculated from the diaphragm activity waveform. One hundred forty-seven infants and children were included (median postnatal age, 1.9; interquartile range, 0.9-6.7 wk). Twenty patients (13.6%) failed extubation within 72 hours. Diaphragm activity increased rapidly after extubation and remained higher throughout the measurement period. Pre extubation, peak (end-inspiratory) diaphragm activity and tonic (end-inspiratory) diaphragm activity were significantly higher in failure, compared with success cases (5.6 vs 7.0 μV; p = 0.04 and 2.8 vs 4.1 μV; p = 0.04, respectively). Receiver operator curve analysis showed the highest area under the curve for tonic (end-inspiratory) diaphragm activity (0.65), with a tonic (end-inspiratory) diaphragm activity greater than 3.4 μV having a combined sensitivity and specificity of 55% and 77%, respectively, to predict extubation outcome. After extubation, diaphragm activity remained higher in patients failing extubation. Diaphragm activity rapidly increased after extubation. Patients failing extubation had a higher level of diaphragm activity, both pre and post extubation. The predictive value of the diaphragm activity variables alone was limited. Future studies are warranted to assess the additional value of electromyography of the diaphragm in combined extubation readiness assessment.

The Effect of Initial Oxygen Exposure on Diaphragm Activity in Preterm Infants at Birth.

Background: The initial FiO2 that should be used for the stabilization of preterm infants in the delivery room (DR) is still a matter of debate as both hypoxia and hyperoxia should be prevented. A recent randomized controlled trial showed that preterm infants [gestational age (GA) < 30 weeks] stabilized with an initial high FiO2 (1.0) had a significantly higher breathing effort than infants stabilized with a low FiO2 (0.3). As the diaphragm is the main respiratory muscle in these infants, we aimed to describe the effects of the initial FiO2 on diaphragm activity.Methods: In a subgroup of infants from the original bi-center randomized controlled trial diaphragm activity was measured with transcutaneous electromyography of the diaphragm (dEMG), using three skin electrodes that were placed directly after birth. Diaphragm activity was compared in the first 5 min after birth. From the dEMG respiratory waveform several outcome measures were determined for comparison of the groups: average peak- and tonic inspiratory activity (dEMGpeak and dEMGton, respectively), inspiratory amplitude (dEMGamp), area under the curve (dEMGAUC) and the respiratory rate (RR).Results: Thirty-one infants were included in this subgroup, of which 29 could be analyzed [n = 15 (median GA 28.4 weeks) and n = 14 (median GA 27.9 weeks) for the 100 and 30% oxygen group, respectively]. Tonic diaphragm activity was significantly higher in the high FiO2-group (4.3 ± 2.1 μV vs. 2.9 ± 1.1 μV; p = 0.047). The other dEMG-parameters (dEMGpeak, dEMGamp, dEMGAUC) showed consistently higher values in the high FiO2 group, but did not reach statistical significance. Average RR showed similar values in both groups (34 ± 9 vs. 32 ± 10 breaths/min for the high and low oxygen group, respectively).Conclusion: Preterm infants stabilized with an initial high FiO2 showed significantly more tonic diaphragm activity and an overall trend toward a higher level of diaphragm activity than those stabilized with an initial low FiO2. These results confirm that a high initial FiO2 after birth stimulates breathing effort, which can be objectified with dEMG.

Transcutaneous monitoring of diaphragm activity as a measure of work of breathing in preterm infants.

ObjectiveMonitoring work of breathing (WOB) is important to assess the pulmonary condition and adjust respiratory support in preterm infants. Conventional WOB measurement (esophageal pressure, tidal volume) is invasive and we hypothesized that monitoring diaphragm activity could be a noninvasive alternative to estimate WOB. The objective was to determine the correlation between conventional WOB measures and diaphragm activity, in preterm infants.MethodsWOB and diaphragm activity, measured with transcutaneous electromyography (dEMG), were simultaneously recorded at different nasal continuous positive airway pressure (nCPAP) levels. During a 30‐s recording at each nCPAP level, dEMG parameters, inspiratory WOB (WOBi), and pressure time product (PTPin) were calculated per breath. The correlation coefficient between WOB‐ and dEMG‐measures was calculated using single breaths and after aggregating all breaths into deciles of incremental WOBi.ResultsFifteen preterm infants were included (median gestational age, 28 weeks). Single‐breath analysis showed a poor median correlation of 0.27 (interquartile range [IQR], 0.03 to 0.33) and 0.08 (IQR, −0.03 to 0.28), respectively, for WOBi and PTPin with peak diaphragmatic activity (dEMGpeak). A modest median correlation coefficient of 0.65 (IQR, 0.13 to 0.79) and 0.43 (IQR, −0.33 to 0.69) was found for, respectively, WOBi and PTPin with dEMGpeak in the aggregated analysis.ConclusionDiaphragm activity showed a modest correlation with WOBi and PTPin in an aggregated analysis. This finding warrants further studies in infants with more significant lung disease.

Cardiorespiratory monitoring in the delivery room using transcutaneous electromyography

ObjectiveTo assess feasibility of transcutaneous electromyography of the diaphragm (dEMG) as a monitoring tool for vital signs and diaphragm activity in the delivery room (DR).DesignProspective observational study.SettingDelivery room.PatientsNewborn infants requiring...

The transcutaneous electromyography recording method for intraoperative neuromonitoring of recurrent laryngeal nerve during minimally invasive parathyroidectomy

Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) protection in thyroid and parathyroid surgeries. This study aimed to investigate a novel transcutaneous electromyography (EMG) recording method for IONM of the RLN during minimally invasive parathyroidectomy (MIP). Twenty patients with primary hyperparathyroidism undergoing MIP were enrolled. Two paired needle electrodes were percutaneously inserted into the bilateral laminas of thyroid cartilage for monitoring the vagus nerve and RLN. A standardized IONM procedure (V1-R1-R2-V2 signals) was strictly followed, and the RLN was routinely located and mapped. Pre- and postoperative laryngofiberoscopy was performed to confirm vocal cord function. The proposed technique was successfully used in all patients, and typical EMG signals were effectively detected. No significant change in EMG signals before and after tumor resection was noted, and a normal vocal cord movement was ensured in all patients with postoperative laryngofiberoscopy. IONM helped localize the position of the RLN and facilitated the safe resection of the parathyroid tumor during MIP. The novel transcutaneous EMG recording method proposed in this study was feasible, convenient, reliable, and inexpensive.

Nasal high flow in preterm infants: A dose-finding study.

To investigate the relationship between applied flows of nasal high flow (NHF) and physiological outcomes and work of breathing (WOB), to identify an optimal delivery flow which results in reduced WOB in preterm infants. A prospective observational clinical study with randomly applied NHF rates. Preterm infants within 72 hours of commencement of NHF respiratory support. Infants were initially placed on 8 L/min of NHF and flows of 2, 4, and 6 L/min were then applied in random order. WOB was measured using transcutaneous electromyography and respiratory inductance plethysmography. Physiological variables were also recorded. Measurements taken 10 minutes after each flow change were compared with 8 L/min. Sixteen infants with a median gestational age of 28 (range 24-31) weeks and postnatal age of 14 (2-55) days were included in the study. The median flow rate before the study was 6 (4-8) L/min and a fraction of inspired oxygen (FiO2 ) was 0.21 (0.21-0.26). Changes in flow resulted in changes in activity in the front diaphragm (P = .027) and intercostals (P = .034). The electrical activity of the front diaphragm at 8 L/min was significantly lower than that at 2 L/min (P = .016). Respiratory rate was lowest at 6 L/min (P = .002) and SpO2 /FiO2 was highest at 8 L/min (P < .04). In preterm infants, changes in WOB resulting from randomly applied levels of NHF can be demonstrated by measuring the electrical activity of the diaphragm and intercostal muscles with transcutaneous electromyography. In combination with physiological measurements, the similarities in electrical activity between 4, 6, and 8 L/min suggest that these three flows may be equally as effective.

Diaphragmatic electromyography in preterm infants: The influence of electrode positioning.

ObjectiveTo determine the effect of changing electrode positions on vital signs and respiratory effort parameters measured with transcutaneous electromyography of the diaphragm (dEMG) in preterm infants.MethodsIn this observational study, simultaneous dEMG measurements were performed at the standard position and at one alternative electrode position (randomly assigned to lateral, superior, medial, inferior to the standard placement, or dorsal). The activity of the diaphragm was measured for 1 hour at both positions. Main outcome measures were the agreement in heart rate (HR), respiratory rate (RR), and percentage difference in dEMG parameters of respiratory effort (peak and tonic activity, amplitude, area under the curve, and frequency content) between the standard and alternative electrode positions.ResultsThirty clinically stable preterm infants (gestational age 30.1 ± 3.0 weeks) with either no or noninvasive respiratory support were included. Agreement in HR was excellent at all positions (ICC > 0.95) while RR agreement showed more diversity (ICC range 0.40‐0.86). Mixed modeling of dEMG parameters revealed that medial and inferior placement measured the weakest signals (median 75.5% and 64.5% lower dEMG amplitude). Lateral electrode placement showed the highest similarity to standard positioning (median 23.5% lower amplitude).ConclusionMeasuring HR showed high similarity at all positions. However, registration of RR and respiratory effort is clearly influenced by the electrode position. Electrodes in the same transversal plane as the diaphragm, and at sufficient distance from each other, provide the best agreement with the standard positioning.

Diaphragm electromyography results at different high flow nasal cannula flow rates

Heated, humidified, high-flow nasal cannula (HHHFNC) is increasingly being used, but there is a paucity of evidence as to the optimum flow rates in prematurely born infants. We have determined the impact of three flow rates on the work of breathing (WOB) assessed by transcutaneous diaphragm electromyography (EMG) amplitude in infants with respiratory distress or bronchopulmonary dysplasia (BPD). Flow rates of 4, 6 and 8 L/min were delivered in random order. The mean amplitude of the EMG trace and mean area under the EMG curve (AEMGC) were calculated and the occurrence of bradycardias and desaturations recorded. Eighteen infants were studied with a median gestational age of 27.8 (range 23.9–33.5) weeks and postnatal age of 54 (range 3–122) days. The median flow rate prior to the study was 5 (range 3–8) L/min and the fraction of inspired oxygen (FiO2) was 0.29 (range 0.21–0.50). There were no significant differences between the mean amplitude of the diaphragm EMG and the AEGMC and the number of bradycardias or desaturations between the three flow rates.Conclusions: In infants with respiratory distress or BPD, there was no advantage of using high (8 L/min) compared with lower flow rates (4 or 6 L/min) during support by HHHFNC.What is known:• Humidified high flow nasal cannulae (HHHFNC) is increasingly being used as a non-invasive form of respiratory support for prematurely born infants.• There is a paucity of evidence regarding the optimum flow rate with 1 to 8 L/min being used.What is new:• We have assessed the work of breathing using the amplitude of the electromyogram of the diaphragm at three HHHFNC flow rates in infants with respiratory distress or BPD.• No significant differences were found in the EMG amplitude results or the numbers of bradycardias or desaturations at 4, 6 and 8 L/min.

Patient-ventilator asynchrony in preterm infants on nasal intermittent positive pressure ventilation

ObjectiveTo describe the incidence of patient-ventilator asynchrony and different types of asynchrony in preterm infants treated with non-synchronised nasal intermittent positive pressure ventilation (nIPPV).DesignAn observational study was conducted including preterm...

The Effect of Minimally Invasive Surfactant Therapy on Diaphragmatic Activity

Background: Minimally invasive surfactant therapy (MIST) is increasingly used to treat preterm infants with respiratory distress syndrome (RDS). However, the effect of MIST on breathing effort is poorly studied. Objectives: To describe the effect of MIST on neural breathing effort assessed with transcutaneous electromyography of the diaphragm (dEMG) in preterm infants with RDS. Methods: Preterm infants with a gestational age < 37 weeks treated with MIST for RDS were included. dEMG measurements were done from 15 min before to 1 h after MIST. The percentage change in dEMG activity after MIST and the clinical response were analyzed. Results: Twenty preterm infants (mean gestational age 29.3 [SD 2.1] weeks; mean birth weight 1,230 [SD 391] g) were included. Seventeen infants did complete the 1-h measurement. Eleven (65%) infants had a decrease in their peak_dEMG activity (median change –11.8% [IQR –26.8 to 5.8, p = 0.08]) 1 h after MIST. Tonic_dEMG activity decreased in 12 (71%) infants, with a median reduction of 6.3% (IQR –29.2 to 9.0, p = 0.07). FiO₂ showed a rapid decrease following MIST (before, 0.47 [IQR 0.38–0.84]; 1 h after, 0.25 [IQR 0.21–0.30], p < 0.001). Conclusion: In addition to improved oxygenation, MIST results in a decrease in neural breathing effort measured by dEMG activity in the majority of preterm infants with RDS.

Classifying Apnea of Prematurity by Transcutaneous Electromyography of the Diaphragm

Background: Treatment of apnea is highly dependent on the type of apnea. Chest impedance (CI) has inaccuracies in monitoring respiration, which compromises accurate apnea classification. Electrical activity of the diaphragm measured by transcutaneous electromyography (EMG) is feasible in preterm infants and might improve the accuracy of apnea classification. Objectives: To compare the accuracy of apnea classification based on diaphragmatic EMG (dEMG) and CI tracings in preterm infants. Methods: Fifteen cases of central apnea, 5 of obstructive apnea, and 10 of mixed apnea were selected from recordings containing synchronized continuous tracings of respiratory inductive plethysmography (RIP), airway flow, heart rate (HR), oxygen saturation (SpO₂), and breathing activity measured by dEMG and CI. Twenty-two assessors (neonatologists, pediatricians-in-training, and nurses) classified each apnea twice; once based on dEMG, HR, and SpO₂ tracings, and once based on CI, HR, and SpO₂. The assessors were blinded to the type of respiratory tracing (dEMG or CI) and to the RIP and flow tracings. Results: In total 1,320 assessments were performed, and in 71.1% the apnea was classified correctly. Subgroup analysis based on respiratory tracing showed that 74.8% of the dEMG tracings were classified correctly compared to 67.3% of the CI tracings (p < 0.001). This improved apnea classification based on dEMG was present for central (86.7 vs. 80.3%, p < 0.02) and obstructive (56.4 vs. 32.7%, p < 0.001) apnea. The improved apnea classification based on dEMG tracing was independent of the type of assessor. Conclusion: Transcutaneous dEMG improves the accuracy of apnea classification when compared to CI in preterm infants, making this technique a promising candidate for future monitoring systems.

Breath detection by transcutaneous electromyography of the diaphragm and the Graseby capsule in preterm infants.

To compare triggering, breath detection and delay time of the Graseby capsule (GC) and transcutaneous electromyography of the diaphragm (dEMG) in spontaneous breathing preterm infants. In this observational study, a 30 minutes respiration measurement was conducted by respiratory inductance plethysmography (RIP), the GC, and dEMG in stable preterm infants. Triggering was investigated with an in vitro set-up using the Infant Flow® SiPAPTM system. The possibility to optimize breath detection was tested by developing new algorithms with the abdominal RIP band (RIPAB ) as gold standard. In a subset of breaths, the delay time was calculated between the inspiratory onset in the RIPAB signal and in the GC and dEMG signal. Fifteen preterm infants with a mean gestational age of 28 ± 2 weeks and a mean birth weight of 1086 ± 317 g were included. In total, 14 773 breaths were analyzed. Based on the GC and dEMG signal, the Infant Flow® SiPAP™ system, respectively, triggered 67.8% and 62.6% of the breaths. Breath detection was improved to 99.9% for the GC and 113.4% for dEMG in new algorithms. In 1492 stable breaths, the median delay time of inspiratory onset detection was +154 ms (IQR +118 to +164) in the GC and -50 ms (IQR -90 to -22) in the dEMG signal. Breath detection using the GC can be improved by optimizing the algorithm. Transcutaneous dEMG provides similar breath detection but with the advantage of detecting the onset of inspiration earlier than the GC.

Electrical activity of the diaphragm during nCPAP and high flow nasal cannula

ObjectiveTo determine if the electrical activity of the diaphragm, as measure of neural respiratory drive and breathing effort, changes over time in preterm infants transitioned from nasal continuous positive airway...

Diaphragmatic activity during weaning from respiratory support in preterm infants

ObjectiveTo determine if weaning from nasal continuous positive airway pressure (nCPAP) to lesser supportive low flow nasal cannula (LFNC) results in a change in electrical activity of the diaphragm in...

The Effect of Caffeine on Diaphragmatic Activity and Tidal Volume in Preterm Infants

To determine the effect of caffeine on diaphragmatic activity, tidal volume (Vt), and end-expiratory lung volume (EELV) in preterm infants. Using transcutaneous electromyography of the diaphragm (dEMG), we measured diaphragmatic activity from 30 minutes before (baseline) to 3 hours after administration of an intravenous caffeine-base loading dose in 30 spontaneously breathing preterm infants (mean gestational age, 29.1 ± 1.3 weeks), most of whom were on noninvasive respiratory support. Diaphragmatic activity was expressed as the percentage change in dEMG amplitude, area under the curve, respiratory rate, and inspiratory and expiratory times. Using respiratory inductive plethysmography, we measured changes in Vt and EELV from baseline. These outcome variables were calculated at 8 fixed time points after caffeine administration (5, 15, 30, 60, 90, 120, 150, and 180 minutes) and compared with baseline. Caffeine administration resulted in rapid (within 5 minutes) increases in dEMG amplitude (median, 43%; IQR, 24%-63%; P < .001) and area under the curve (median, 28%; IQR, 14%-48%; P < .001). Vt also increased by a median of 30% (IQR, 7%-48%), and this change was significantly correlated with the change in dEMG amplitude (r = 0.67; P < .001). These effects were relatively stable until 120 minutes after caffeine administration. Caffeine did not consistently impact EELV, respiratory rate, or inspiratory and expiratory times. Caffeine treatment results in a rapid and sustained increase in diaphragmatic activity and Vt in preterm infants.