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

Introduction: 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. Methods: 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. Results: 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. Conclusion: Measuring dEMG using the ECG/CI hardware with its electrodes on the diaphragm is feasible, leaving ECG/CI monitoring unaffected

The Effects of a New Wireless Non-Adhesive Cardiorespiratory Monitoring Device on the Skin Conditions of Preterm Infants

Aim: The aim of our study was to investigate skin conditions when wearing and removing a novel wireless non-adhesive cardiorespiratory monitoring device for neonates (Bambi-Belt) compared to standard adhesive electrodes. Study Design: This was a prospective study including preterm neonates requiring cardiorespiratory monitoring. Besides standard electrodes, the infants wore a Bambi Belt for 10 consecutive days. Their skin conditions were assessed using Trans Epidermal Water Loss (TEWL) and the Neonatal Skin Condition Score (NSCS) after daily belt and standard electrode removal. The ∆TEWL was calculated as the difference between the TEWL at the device’s location (Bambi-Belt/standard electrode) and the adjacent control skin location, with a higher ∆TEWL indicating skin damage. Results: A total of 15 infants (gestational age (GA): 24.1–35.6 wk) were analyzed. The ΔTEWL significantly increased directly after electrode removal (10.95 ± 9.98 g/m2/h) compared to belt removal (5.18 ± 6.71 g/m2/h; F: 8.73, p = 0.004) and after the washout period (3.72 ± 5.46 g/m2/h vs. 1.86 ± 3.35 g/m2/h; F: 2.84, p = 0.09), although the latter did not reach statistical significance. The TEWL was not influenced by prolonged belt wearing. No significant differences in the NSCS score were found between the belt and electrode (OR: 0.69, 95% CI [0.17, 2.88], p = 0.6). Conclusion: A new wireless non-adhesive device for neonatal cardiorespiratory monitoring was well tolerated in preterm infants and may be less damaging during prolonged wearing

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

Background: The initial FiO 2 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 FiO 2 (1.0) had a significantly higher breathing effort than infants stabilized with a low FiO 2 (0.3). As the diaphragm is the main respiratory muscle in these infants, we aimed to describe the effects of the initial FiO 2 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 (dEMG peak and dEMG ton, respectively), inspiratory amplitude (dEMG amp), area under the curve (dEMG AUC) 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 FiO 2-group (4.3 ± 2.1 μV vs. 2.9 ± 1.1 μV; p = 0.047). The other dEMG-parameters (dEMG peak, dEMG amp, dEMG AUC) showed consistently higher values in the high FiO 2 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 FiO 2 showed significantly more tonic diaphragm activity and an overall trend toward a higher level of diaphragm activity than those stabilized with an initial low FiO 2. These results confirm that a high initial FiO 2 after birth stimulates breathing effort, which can be objectified with dEMG

Influence of neonatal endotracheal tube dimensions on oscillometry-acquired reactance: a bench study

Objective. To examine the influence of the endotracheal tube (ETT) on respiratory reactance (Xrs) measured with the forced oscillation technique (FOT) and develop a correction method for it. Approach. In a bench study, the reactance of ETTs (Xtube) with different dimensions was measured on a breathing test lung in various respiratory settings. Main results. Xtube can be accurately predicted by a fitted formula, with an R2 of 0.97, with negligible effects due to changes in respiratory pattern and lung volume. Significance. The developed formula offers the ability to measure ETT-independent Xrs values of patients, improving the potential of FOT for lung function testing in mechanically ventilated newborns

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

Introduction Cardiorespiratory 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) is monitored by electrocardiography (ECG) and respiration by chest impedance (CI). Disadvantages of current monitoring techniques are usage of wired adhesive electrodes which may damage the skin and hinder care. The Bambi® belt is a wireless and non-adhesive alternative that enables cardiorespiratory monitoring by measuring electrical activity of the diaphragm via transcutaneous electromyography. A previous study showed feasibility of the Bambi® belt and this study compares the belt performance to ECG and CI. Methods and analysis This multicentre non-inferiority paired study will be performed in the NICU of the Máxima Medical Center (MMC) in Veldhoven and the Emma Children's Hospital, Amsterdam University Medical Centre (AmsterdamUMC) in Amsterdam, The Netherlands. 39 infants in different postmenstrual age groups (minimally 10 infants32 weeks) will be recruited. These infants will be monitored with the Bambi® belt in addition to standard ECG and CI for 24 hours. The primary outcome is the HR, studied with three criteria: (1) the limits of agreement of the HR measurements in terms of the second-to-second difference in the HR between the belt and standard ECG, (2) the detection of cardiac events consisting of bradycardia and tachycardia and (3) the quality of HR-monitoring. The secondary outcome is the respiratory rate (RR), studied with the criteria (1) agreement in RR-trend monitoring, (2) apnoea and tachypnoea detection and (3) reliable registrations. Ethics and dissemination This protocol was approved by the Medical Ethical Committee of the MMC and the Central Committee for Human Research. The MMC started patient recruitment in July and the AmsterdamUMC in August 2021. The results will be presented at conferences and published in peer-reviewed journals

Cardiorespiratory monitoring with a wireless and nonadhesive belt measuring diaphragm activity in preterm and term infants:A multicenter non-inferiority study

Introduction: We determined if the heart rate (HR) monitoring performance of a wireless and nonadhesive belt is non-inferior compared to standard electrocardiography (ECG). Secondary objective was to explore the belt's respiratory rate (RR) monitoring performance compared to chest impedance (CI). Method: In this multicenter non-inferiority trial, preterm and term infants were simultaneously monitored with the belt and conventional ECG/CI for 24 h. HR monitoring performance was estimated with the HR difference and ability to detect cardiac events compared to the ECG, and the incidence of HR-data loss per second. These estimations were statistically compared to prespecified margins to confirm equivalence/non-inferiority. Exploratory RR analyses estimated the RR trend difference and ability to detect apnea/tachypnea compared to CI, and the incidence of RR-data loss per second. Results: Thirty-nine infants were included. HR monitoring with the belt was non-inferior to the ECG with a mean HR difference of 0.03 beats per minute (bpm) (standard error [SE] = 0.02) (95% limits of agreement [LoA]: [−5 to 5] bpm) (p &lt; 0.001). Second, sensitivity and positive predictive value (PPV) for cardiac event detection were 94.0% (SE = 0.5%) and 92.6% (SE = 0.6%), respectively (p ≤ 0.001). Third, the incidence of HR-data loss was 2.1% (SE = 0.4%) per second (p &lt; 0.05). The exploratory analyses of RR showed moderate trend agreement with a mean RR-difference of 3.7 breaths/min (SE = 0.8) (LoA: [−12 to 19] breaths/min), but low sensitivities and PPV's for apnea/tachypnea detection. The incidence of RR-data loss was 2.2% (SE = 0.4%) per second. Conclusion: The nonadhesive, wireless belt showed non-inferior HR monitoring and a moderate agreement in RR trend compared to ECG/CI. Future research on apnea/tachypnea detection is required.</p