Phrenic nerves stimulation

Electrical Stimulation Devices. Bioelectrodes that transmit electrical signals into the body are generally known as electrical stimulation devices, examples of which include cardiac pacemakers, transcutaneous electronic nerve stimulators (TENs) for pain suppression, and neural prostheses such as auditory stimulation systems for the deaf and phrenic nerve stimulators for artificial respiratory control. In these, and other similar devices, electrodes transmit current to appropriate areas of the body for direct control of, or indirect influence over, target cells. 

Phrenic nerve stimulation for respiration is backed up by more than 10 years of experience [34]. It is used for patients where a high lesion of the spinal cord causes chronic respiratory insufficiency. The Vienna phrenic pacemaker stimulates the two branches of the phrenic nerves with four electrodes each. The cyclic combination of the electrodes, called roundabout stimulation, changes over time to prevent fatigue of the diaphragm during the 24 hours of stimulation per day. 

Fig. (4 a). The structure-activity relationship of glycyrrhizin (GLR)-derivatives blended with (closed symbols) or without (open symbols) paeoniflorin (PF) on the phrenic nerve-stimulated twitch response in mouse diaphragm. Percentage inhibition of twitch responses is plotted against the log-concentration of the GLR-derivative. PF was combined with GLR or GLR-related compounds at the same molar ratio of concentrations. I deoxyglycyrrhetol dihemisuccinate disodium, 11 deoxyglycyrrhetol dihemiphthalate disodium, and III glycyrrhetinic acid hemiphthalate disodium. 

Glenn, W.W., Phelps, M.L., Elefteriades, J.A., Dentz, B., and Hogan, J.F. 1986. Twenty years of experience in phrenic nerve stimulation to pace the diaphragm pacing. Clin. Electrophysiol. 9 780. 

Subclavian artery puncture Venous thromboembolism Phrenic nerve stimulation Right ventricular perforation Pericardial effusion/tamponade Generator pocket hematoma CVA/TIA... 

The most complete European data on the use of HMV has been reported recently as the Eurovent study, a survey of long-term ventilator use conducted in 16 countries (15). In this survey, home ventilation was defined as ventilatory assistance for three months or more. Those receiving other forms of ventilation, such as rocking beds, negative-pressure ventilation, and phrenic nerve stimulation, were included. A total of 483 surveys were sent to the centers prescribing HMV in the 16 countries, with 329 centers (68%) responding. The numbers of patients and prevalence rates were estimated for each country. As noted in Table 3, there was a wide variation in the prevalence of HMV in Europe, ranging from 0.1/ 100,000 population in Poland to 17/100,000 in France. The survey identified a total of 21,526 VAIs and estimated the prevalence of HMV to be 6.6/100,000 population in Europe. 

Figure 7 Twitch transdiaphragmatic pressure elicited by phrenic nerve stimulation (upper panel) and FRC (lowerpanel) in a patient with severe emphysema before (left) and after (right) lung volume reduction surgery. The increase in transdiaphragmatic pressure after surgery was partly due to a decrease in the operating lung volume as demonstrated by the decrease in FRC. Abbreviation FRC, functional residual capacity. Source Data from Ref. 128.

Watson AC, Hughes PD, Louise HM, et al. Measurement of twitch transdiaphragmatic, esophageal, and endotracheal tube pressure with bilateral anterolateral magnetic phrenic nerve stimulation in patients in the intensive care unit Crit Care Med 2001 29(7) 1325-1331. Cattapan SE, Laghi F, Tobin MJ. Can diaphragmatic contractility be assessed by airway twitch pressure in mechanically ventilated patients Thorax 2003 58(l) 58-62. 

She had minimal maintenance issues for many years, with the exception of transmitter replacements. Her tidal volumes ranged from 450 to 700 cc on minimal amplitude settings (right 2.4 and left 2.5) and a respiratory rate of 12 bpm, to maintain blood gases within the normal range. Routine follow-up phrenic nerve studies showed that conduction time on both sides and the diaphragmatic response to phrenic nerve stimulation was normal. 

Wessler, I., Rashach, J., Scheuer, B., Hillen, U., Kilhinger, M. (1987h). Effects of rf-tuhocurarine on [ Hjacetylcholine release Irom the rat phrenic nerve at different stimulation frequencies and train lengths. Naunyn-Schmiedebergs Arch. Pharmacol. 335 496-501. 

Heffron, P. F., Hobbinger, F. (1979). Relationship between inhibition of acetylcholinesterase and response of the rat phrenic nerve-diaphragm preparation to indirect stimulation at higher frequencies. British Journal of Pharmacology, 66, 323—329. 

FIGURE 16.1 The effect of BoNT/A on muscle tension in isolated mouse phrenic nerve-hemidiaphragm preparations. Muscles were exposed to BoNT/A at concentrations ranging from 1 pM to 1 nM and the time to paralysis was monitored. Toxins were added to the muscle bath at 0 time from concentrated stock solutions each concentration was tested on a separate hemidiaphragm muscle. Twitch tensions were elicited by supramaximal stimulation of the phrenic nerve at 30 s intervals. Temperature, 37°C. 

During stimulation of cholinergic nerves (e.g., phrenic nerve diaphragm preparation) there is a 2-5 fold increase in released ACh (Krnjevic and Mitchell, 1961 Mitchell and Silver, 1963 Schmidt, Szilagyi, Alkon and Green, 1970, Szerb, 1971). 

Lis Balchin et al. [69] studied the action of S. sclarea oil on the rat isolated phrenic nerve diaphragm preparations and compared with activity on field- stimulated guinea-pig ileum preparations. The oil produced a contracture and inhibition on the skeletal muscle of the bi-phasic response to nerve stimulation, whilst only a contracture, with or without a decrease in response to field stimulation, was produced in smooth muscle. 

Tetanic contractions (Wedensky inhibition) induced by repetitive nerve stimulation in phrenic nerve-diaphragm preparations of mice was faded by 0.5-2 ijlM neostigmine (Chang ei al., 1986). The fade was brought about by failure to elicit muscle action potentials, which was due to end-plate depolarization and a decrease in transmitter release. Both effects were attributed to ACh accumulation as a result of ChE inhibition. 

Fig. (6 a). Influence of the position of the side-chains on the phenylene ring of bis(4-trimethylammoniobutyl)benzene (upper) and of the side-chain length of bis-trimethylammonium derivatives (lower) on neuromuscular blocking activity. The percentage inhibition of nerve-stimulated twitch response in mouse phrenic nerve-diaphragm muscle is plotted against the log concentration. The values represent means S.E.M. (n = 4-7). 

Respiration—Respiratory control systems involve a two-channel implantable stimulator with electrodes applied bilaterally to the phrenic nerve. Most of the devices in clinical use were developed by Avery Laboratories (Dobelle Institute) and employed discrete circuitry with epoxy encapsulation of the implant and a nerve cuff electrode. Approximately 1000 of these devices have been implanted in patients with respiratory disorders such as high-level tetraplegia (Glenn et al.. 

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