Final Flashcards
Deck Objective: Pass
What are the two types of electrodes used for ENG
nerve cuff electrodes
intrafascicular electodes
what type of neuromuscular interface is used for amputated nerves?
EMG, as the amputated axons that terminate in neuroma survive.
voluntary motor nerve signals would be unavailable for prosthetics, therefore EMG is the way to go and not ENG
Targetted reinnvervation requires EMG, as the emg signals can be recorded and can innervate other muscles
what are the best electrodes for human prosthetic use
nerve cuff electrodes as they are the most stable
what is nerve-muscle grafting
signal enhancement method
severed nerves of interest are grafted to neighboring regions of muscle, which would be denervated to provide appropriate target for cross-reinnervation
also allows for recording of emg signals directly from cross-reinnervated muscles (targetted reinnervation)
how is targetted muscle reinnervation used to treat phantom limb pain
targetted muscle reinnervation lowers phantom pain, if nerve-muscle grafting is also done
WHat is a RPNI
regenerative peripheral nerve interface
transected nerve that is implanted into a free muscle graft to create a stable peripheral nerve bioamplifier to produce high EMG signals
what muscle fibres comprise the diaphragm
type 1 fatigue resistant and type 2a fast twitch
highly active muscle, susceptible to inactivity or disuse
what are central causes for loss of control of one or both hemidiaphragms
brain/brainstem stroke, ALS
spinal cord injury, polio
autoimmune disease (MS)
what are peripheral causes for loss of control of one or both hemidiaphragms
phrenic nerve trauma from surgery, radiation, or tumor
phrenic neuropathy or infections
what patients require temporary assisted ventilation
critically ill patients in ICU
surgeries with pt under general anesthesia
what patients require lifelong assisted ventilation
those with a high cervical SCI
brain injury
ALS
Central apnea
What is the negative pressure mechanical ventilation machine?
aka iron lung and cuirass ventilators
makes pressure negative around the body, causing the air to funnel into lungs due to pressure difference
what is positive pressure mechanical ventilation
opposite of negative pressure machines, utilize positive pressure instead
air is forced in, ventilator helps providing a mandatory breath, assist a pt who can initiate a breath, or combo of both
pts can vary between being comatose to alert
what are the harms of positive pressure ventilation
ventilator-induced lung injury - VILI or VALI
Ventilator-induced pneumonia -VAP
ventilator induced diaphragmatic dysfunction - VIDD
what is ventilator-induced lung injury
causes:
biotrauma/volutrauma - high end inspiratory volume, causing direct damage/inflammation leading to fluid filtration into alveoli (pulmonary edema)
atelectotrauma - complete or partial collapse of lung or lobe that develops when alveoli become deflated. pressure yields inhomogeneous pressure distribution and parts of lung collapse due to extrinsic weight
barotrauma - high positive airway pressure causing lung overdistension , resulting in pneumothorax
all examples of acute respiratory distress syndrome
what is lung protective ventilation
limits on volume and pressure to ensure that acute respiratory distress syndrome does not occur
cannot eliminate VILI, as overinflation or atelectasis will occur regardless
What is ventilator associated pneumonia
pneumonia exogenously occuring from hands of healthcare worker, the ventilator circuit, or the biofilm of the endotracheal tube.
endogenously occurring due to impared natural protection of nasopharynx, colonized oropharynx, and colonized tracheal secretions. usually this bacteria is multidrug resistant
develops 48hrs after ventilator starts, and it increases ICU stays
what is ventilator induced diaphragmatic dysfunction
loss of diaphragmatic force generation due to mechanical ventilation
causes rapid atrophy of the diaphragm thickness, causing a decrease in force generation potential
prevented by encouraging voluntary ventilation as soon as possible, no clinically way to prevent
What are the possible diaphragm activation methods
transcutaneous stimulation
surgical implantation
laparoscopically implantation
what is transcutaneous stimulation of the diaphragm
electrical or magnetic stim
hard to apply and maintain longterm positioning
not selective enough to stimulate phrenic nerves without recruiting brachial plexus
suitable for assessment of function, but not for therapeutic stimulation
what is surgically implanted diaphragm activation
avery breathing pacemaker system
implanted reciever and electrode (monopolar) with bipolar configuration to work with cardiac pacemakers
atrostim - electrode is fixed to phrenic nerve below clavicle as electrodes above acnnot stimulate fibers from c6
lower risk of VAP and tracheal complications while having negative pressure breathing and increased freedom
however is an invasive surgery with nerve damage risk and high cost. also very few pts are even elegible
what is laparoscopically implantation for diaphragm activation
no thoracotomy and less nerve damage risk, alongside lower complication risk and faster recovery.
lengthy and costly surgery needing full anaesthesia, with percutaneous wires connecting to external control unit. critically ill pts are not eligible
What is the synapse NeuRx
type of laparoscopic implantation
uses diaphragmatic pacing to slow respiratory failure and decrease in FVC decline in pts w ALS
may be as harmful as ALS, as pts treated with it had more than a double increased risk of death than those who only had noninvasive ventilation, also has increased infection risk due to exposed wires and high cost
how can pacing phrenic nerves in ICU prevent VIDD
maintains diaphragmatic endurance
provides exercise to strengthen weakened diaphragm
provides a negative pressure ventilation, replicating normal respiration
can be done by using an intravenous catheter to pace nearby nerves, and this can be adjusted in strength of electric fields to isolate nerves (minimally invasive nerve stimulation aka MINS)
