Measurement of block thresholds in kiloHertz frequency alternating current peripheral nerve block

Roldan, Leah Marie; Eggers, Thomas E.; Kilgore, Kevin L.; Bhadra, Narendra; Vrabec, Tina; Bhadra, Niloy

doi:10.1016/j.jneumeth.2019.01.002

Cited by 13 publications

(11 citation statements)

References 54 publications

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“…Furthermore, maternal fever in labor decreases the sensitivity of the cervix and uterus to indomethacin, and weak contractions result in delayed cervical dilation, leading to a prolonged labor process or even obstructed labor [ 19 ]. Therefore, clinical attention to women with elevated body temperature and fever should be strengthened to minimize or avoid adverse maternal outcomes [ 20 ]. Here, the Apgar scores showed no significant differences between the two groups.…”

Section: Discussionmentioning

confidence: 99%

Impact of Intraspinal Nerve Block Anesthesia on Intrapartum Fever and the Neonate

Wang

Chang

Chen

2022

Evidence-Based Complementary and Alternative Medicine

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Objective. To evaluate the impact of intraspinal nerve block anesthesia on intrapartum fever and the neonate. Methods. In this prospective study, between October 2019 and December 2020, 90 eligible primiparous women enrolled in the obstetrics and gynecology department of our hospital for delivery were recruited and assigned via the random number table method at a ratio of 1 : 1 to either an analgesic group given intraspinal nerve block anesthesia for labor or a nonanalgesic group without anesthesia for labor. Outcome measures included intrapartum body temperature, cases of intrapartum fever, Apgar scores of neonates, visual analogue scale (VAS) scores, delivery mode, and indomethacin use. Results. Intraspinal nerve block anesthesia was associated with a higher body temperature at 4 h and 5 h after analgesia and more cases of intrapartum fever versus no anesthesia ( P < 0.05 ). There were no significant differences in the Apgar scores between the two groups ( P > 0.05 ). Participants given intraspinal nerve block anesthesia had lower VAS scores during labor versus those without anesthesia ( P < 0.05 ). The differences in the delivery mode between the two groups were not significant ( P > 0.05 ). Intraspinal nerve block anesthesia resulted in a significantly higher demand for indomethacin versus no anesthesia ( P < 0.05 ). Conclusion. Intraspinal nerve block anesthesia is clinically effective in labor analgesia but may cause increased body temperature or even overt clinical fever, so close clinical observation of maternal temperature changes is required to mitigate the effects of anesthesia on the mothers. No adverse consequences of intraspinal nerve block anesthesia on the newborns were reported in this study.

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Section: Discussionmentioning

confidence: 99%

Impact of Intraspinal Nerve Block Anesthesia on Intrapartum Fever and the Neonate

Wang

Chang

Chen

2022

Evidence-Based Complementary and Alternative Medicine

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“…We measured block threshold with each waveform using a binary search (Figure 1(e)) (Roldan et al 2019). During each search, we continuously applied 1 Hz stimulus pulses.…”

Section: Experimental Protocolmentioning

confidence: 99%

Quantitative comparisons of block thresholds and onset responses for charge-balanced kilohertz frequency waveforms

Peña

Pelot²,

Grill³

2020

J. Neural Eng.

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Objective: There is growing interest in delivering kilohertz frequency (KHF) electrical signals to block conduction in peripheral nerves for treatment of various diseases. Previous studies used different KHF waveforms to achieve block, and it remains unclear how waveform affects nerve block parameters. Approach:We quantified the effects of waveform on KHF block of the rat tibial nerve in vivo and in computational models. We compared block thresholds and onset responses across currentcontrolled sinusoids and charge-balanced rectangular waveforms with different asymmetries and duty cycles.Main Results: Sine waves had higher block thresholds than square waves, but used less power at block threshold. Block threshold had an inverse relationship with duty cycle of rectangular waveforms irrespective of waveform asymmetry. Computational model results were consistent with relationships measured in vivo, although the models underestimated the effect of duty cycle on increasing thresholds. The axonal membrane substantially filtered waveforms, the filter transfer function was strikingly similar across waveforms, and filtering resulted in post-filtered rms block thresholds that were approximately constant across waveforms in silico and in vivo. Onset response was not consistently affected by waveform shape, but onset was smaller at amplitudes well above block threshold. Therefore, waveforms with lower block thresholds (e.g., sine waves or square waves) could be more readily increased to higher amplitudes relative to block threshold to reduce onset response. We also observed a reduction in onset responses across consecutive trials after initial application of supra-block threshold amplitudes.

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“…Researchers believed that the run time for the block threshold determination was the shortest for the High-Low method and that method was recommended for most experimental situations. The amplitude was reduced in a step size of 1 V and the block threshold was determined to be the lowest value at which complete block was achieved [32]. However, this method has a significant deficiency.…”

Section: Discussionmentioning

confidence: 99%

Neural Signal Blocking Based on Spike Trapping Principle: Effect of Electrode and Pulse Parameters

et al. 2020

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Electrical stimulation of nerves to treat neurological disorders has been extensively studied. In this paper, a proactive blocking method, spike trapping, is introduced, which was previously referred to as the ''antimissile strategy''. Acute experiments on sciatic nerve-gastrocnemius muscle preparations of bullfrogs were performed to explore the parameters of this blocking method, including the size, spacing, and placement of the electrodes, as well as the widths of the cathodic triangular pulses used to trap the evoked neural signals. The block threshold voltage decreased with increasing electrode spacing and for larger diameter when the tripolar platinum wire electrodes were placed longitudinally on the same side of the sciatic nerve. However, there was no statistically significant difference between the minimum pulse widths which requires achieving nerve block with different electrode spacing or size. Placing bipolar electrodes of asymmetrical shape and size on the opposite sides across the nerve, the block threshold and the minimum pulse width both decreased first and then increased as a function of increasing anode width. Whether the electrodes is placed longitudinally along the nerve with tripolar configuration or transversely across the nerve with bipolar configuration, the nerve conduction can be instantaneously blocked without undesired excitation using the spike trapping strategy.

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Measurement of block thresholds in kiloHertz frequency alternating current peripheral nerve block

Cited by 13 publications

References 54 publications

Impact of Intraspinal Nerve Block Anesthesia on Intrapartum Fever and the Neonate

Impact of Intraspinal Nerve Block Anesthesia on Intrapartum Fever and the Neonate

Quantitative comparisons of block thresholds and onset responses for charge-balanced kilohertz frequency waveforms

Neural Signal Blocking Based on Spike Trapping Principle: Effect of Electrode and Pulse Parameters

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