life and care pns 2015

Diaphragm pacingAnother way to breathe

SwissParaplegic CentreNottwilMichael Baumberger, Nottwil

• History• Current surgical techniques• Ventilator weaning options• Long-term results of functional electrical stimulation in restoring

respiratory function.

Functional electrical stimulation: restoration of respiratoryfunction.Onders RP.Handb Clin Neurol. 2012;109:275-82. doi: 10.1016/B978-0-444-52137-8.00017-6.

The need for tracheostomy mechanical ventilation significantly increases thecost of care, decreases the quality of life of the patient and decreases lifeexpectancy in spinal cord injury (SCI) because of pneumonias.

Phrenic nerve stimulation was initially developed in the 1960s and diaphragmpacing was developed in the 1990s

Animal Electricity ~ 1700Diaphragm Pacing

Animal Electricity ~ 1700

BenjaminFranklin

Diaphragm Pacing

First reports on diaphragm pacing by Cavallo (1746), Hufeland (1783), Caldinii (1784) andAndrew Ure (1819).

1964 first clinical application by Glenn (Electricalstimulation of excitable tissue by radiofrequencytransmission. Ann Surg 1964).

Diaphragm Pacing

Andrew Ure: An account of some experiments made on thebody of a hanged criminal immediately after execution, with physiological andpractical observations

Journal of Science and the Arts, 1819; 6:283-294

Human electricity - 1819

AndrewUre- 1819

Diaphragm Pacing - Synonyms

• Diaphragm Pacemaker• Phrenic Nerve Pacemaker• Electrophrenic Respiration• Breathing Pacemaker

Two approaches:Nerve stimulation or muscle stimulation

Phrenic nerve stimulation:

• Avery Biomedical: breathing pacermakersystem - Mark IV Transmitter

• Atrotech: Atrostim Phrenic Nerve Stimulator (PNS)

Direct diaphragm muscle stimulation• Synapse Biomedical: NeurRX DPS

Diaphragm Pacing - Indications

• High spinal cord injury, traumatic and non traumatic

• Central alveolar hypoventilation

• Decreased day or night ventilatory drive (i.e. sleep apnea, Ondine's Curse)

Diaphragm Pacing - Indications

• Brain stem injury or disease, includingcomorbidity of hiccups, diaphragm myoclonus, ALS and obstructive apnea (?)

• Damaged phrenic nerve(s)

Diaphragm pacing

• High Tetraplegia• C 2 Lesion• Ventilatory support

What do we need in order to stimulatethe phrenic nerve?

• Electrode

• Pulse generator

• Connection between the two

Avery Biomedical 2009

Electrode propertiesAvery Biomedical 2009

• Electrical conductor

• Biocompatible

• Tensile strength

• Fatigue resistant

• Insulated from other tissue

Where are the electrodes to be implanted ?

• Neck approach

• Thorax (Video-Assisted Thoracoscopic SurgeryVATS) approach

• Diaphragm (laparoscopic approach)

Advantages and disadvantages

Anatomy of the Phrenic Nerve

Cervical Approach – Avery Biomedical

Phrenic Nerve PacingDiaphragm Pacing

Avery Biomedical Atrotech

Diaphragm Pacing

Atrotech Finnland

• Atrostim Phrenic Nerve Stimulator

Diaphragm Pacing

Mark IV transmitterAvery Biomedical

Amplitude 0 -10 volts

Respiration rate 6 - 24 min

Inspiratory period 1.2 – 1.45 sec

Pulse interval 40 - 130 ms

Pulse width 150 - 300 ms

Adjustable post operative settings

Amplitude, pulse width, pulse frequency, ramp (slope), respiration rate and inspirationinterval.

Diaphragm Pacing - Electrodes

The Avery Model S-242 was the first commercially distributed diaphragm pacemaker

Non innervated versus normal DiaphragmSynapse Biomedical

Neurology of Breathing – Charles Bolton – BH 2004

ENG Nervus Phrenicus - Telegrafo

left right

Diaphragm pacing

Diaphragm Reconditioning

• Patients should be allowed to pace until indications ofdiaphragm fatigue occur. This can be observed by a 50%decrease in tidal volume, decreasing oxygen saturation, orincreasing CO2 retention.

• Pacing should be resumed daily until 24 hour pacing, ordesired amount, is achieved.

• When patients use the pacer while eating or drinking, theymust learn to swallow between inspiration to avoidaspiration of food or liquid.

Diaphragm pacing – Synapse Biomedical

Alternative techniques

• Intercostal muscle stimulation

• Electrophrenic respiration after intercostal to phrenic nerve anastomosis

• Diaphragm Pacing with Endovascular Electrodes

Alternative techniquesphrenic nerves

subclavian veins

superior venacava

Diaphragm Pacing with Endovascular Electrodes

Lungpacer Medical Inc. 2010

2013Emerging Rocket LifeScienceCompany,SanDiegoUSA

• Intravenously inserted Lungpacer™ electrodesrhythmically activate the diaphragm.

• In critically ill patients who would typically fail towean and become ventilator-dependent, the pacingtherapy is expected to prevent diaphragm muscle-disuse atrophy and maintain diaphragmaticendurance, thus facilitating weaning of patientsfrom MV.

Hoffer JA, Tran BD, Tang JK, Saunders JTW, Francis CA, Sandoval RA, Meyyappan R, Seru S, Wang HDY, Nolette MA, Tanner AC. "Diaphragm Pacing with Endovascular Electrodes". IFESS 2010 - Int’l. Functional Electrical Stimulation Soc., 15th Ann. Conf., Vienna, Austria, pp 40-42, 2010.

Meyyappan R, Sandoval RA, Francis CA, Nolette MA, Tang J, Tindale L, Tran B, Afram BB, Coquinco B, Reynolds S, Hoffer JA. "Diaphragm pacing during controlled mechanical ventilation: pre-clinical observations reveal a substantial improvement in respiratory mechanics.17th Biennial Canadian Biomechanics Society Meeting, Burnaby, BC, June 6-9, 2012

Diaphragm Pacing

• Electrophrenic RespirationafterIntercostaltoPhrenicNerveAnastomosisinaPatientwithAnteriorSpinalArterySyndrome:TechnicalCaseReport

AbbottJ.Krieger,M.D.;MitchellR.Gropper,M.D.;RobertaJ.Adler,R.N.(Neurosurgery35:760-763,1994)

Nervus intercostalis to phrenic nerve anastomosisKrieger 2000

Diaphragm Pacing

Advantages

• Improved mobility• Improved sense of smell• Improved verbal communication• Improved health• Ease of eating and drinking• Improved quality of life• Diminished need of nursing• Significant reduction in upper airway infections• Reduced anxiety and embarrassment associated with

ventilator tubing and noiseHirschfeld et al. - Spinal Cord 2008

Long Term Follow-up of Diaphragm Pacing in Tetraplegia - Avery

• More than 2000 patients world-wide• 5 > 30 years pacing• Dozens > 20 years pacing• Hundreds > 10 years pacing

5th International Workshop on Breathing Pacemakers and Disorders of the Diaphragm – 2008

Long Term Follow-up of Diaphragm Pacing in Tetraplegia - 2010

• All patients demostrated normal tidal volumes and arterial blood gaseswhile pacing full time

• No patient lost the ability to pace the phrenic nerve

• Thresholds currents and maximal currents did not increase with time

• Histologic studies of the phrenic nerves of the patient who had diedhaving paced for ten years showed overall good preservation of myelinand no significant axonal loss

• In the same patient specimens from both hemi diaphragms wereessentially normal

Mechanical ventilation or phrenic nerve stimulation for treatment of spinal cord injury-induced respiratory insufficiencyHirschfeld S, Exner G, Luukkaala T, Baer GASpinal Cord. 2008 Nov;46(11):738-42.

STUDY DESIGN: Prospective clinical study of two treatments

OBJECTIVE: To compare mechanical ventilation (MV) with phrenic nerve stimulation (PNS) for treatment of respiratory device-dependent (RDD) spinal cord-injured (SCI) patients.

.

METHODS: Prospective data collection of treatment-related data over 20 years.

RESULTS: In total, 64 SCI-RDD patients were treated during the study period.

CONCLUSIONS: PNS instead of MV for treatment of SCI-RDD reduces Respiratory Infections, running costs of respiratory treatment and obviously improves patients' quality of life.Hirschfeld SSpinal Cord. 2008 Nov;46(11):738-42

• Failure of the diaphragm pacer could lead to respiratoryarrest.

• An apnea alarm should be provided to summon helpshould diaphragm pacer failure occur.

• Diaphragm pacing systems should not be used aboardcommercial aircraft without prior clearance with the pilotor airline.

General cautions regarding Diaphragm Pacing


• Change in atmospheric pressure (for example, a changein altitude above sea level) may diminish the performanceof the breathing pacemaker.

• Failure of the diaphragm pacing system can occur due tobattery failure, broken battery connector wire, orintermittent antenna cable or connector, or componentfailure in the receiver, electrode wire, or externaltransmitter.

• A device for providing artificial ventilation by mask,mouth piece, or tracheal tube should be available forthose patients who are continually dependent on thephrenic pacemaker as an alternative to mechanicalventilation.

• Use of antispasmodic drugs (Baclofen and others) maydiminish the performance of the breathing pacemakeror prevent it from working.


• Magnetic Resonance Imaging, shock wave lithotripsy, and diathermy are contraindicated in phrenic nerve pacing but not in direct diaphragm muscle pacing.

• If the use of a defibrillator is necessary, the implanted receiver and the phrenic nerve could be damaged (only in phrenic nerve pacing).

• A permanent tracheostomy may be required to obtain adequate ventilation. Diaphragm pacing can induce or worsen upper airway obstruction. Augmentation of the force of inspiration and laryngeal and pharyngeal musculature is the probable cause.


Diaphragmpacing- monitoring

• eTCO2• SaO2

life and care pns 2015

Documents