Clinical Agents Midterm and Practical

What are the 2 theories of pain modulation?

1. gate control theory

-theory that alpha and beta fibers (distractive stimulus) have a higher conduction velocity than C and delta fibers (noxious stimulus)

2. endorphin release theory

-theory that natural opiates are released from the body when sensory nerves are stimulated

Gate control TENS is also known as...

1. conventional TENS

2. high-rate TENS

3. sensory level TENS

Endorphin theory TENS is also known as...

1. burst TENS

2. low rate TENS

3. motor level TENS

How is pain relief from Gate control TENS described?

-immediate relief with short carryover due to partial breaking of pain cycle mechanism

What is the frequency and pulse width used in gate theory TENS?

frequency = 80-150 pps

pulse width = < 100 microseconds

What is the amplitude used in gate theory TENS?

max sensory

What is the average clinical treatment time for gate theory TENS?

5-60 mins, dependent of patient pain

At what stages may gate control TENS and endorphin theory TENS be used?

gate control: acute or subacute

endorphin theory: subacute or chronic

How is pain relief from Endorphin theory TENS described?

not immediate relief, but longer carryover (2-4 hrs), if TENS is applied for minimum of 20-30 secs

What is the frequency and pulse width used in endorphin theory TENS?

frequency = 1-10 pps

pulse width = >100 microseconds

What is the amplitude used in endorphin theory TENS?

mild motor reponse

What is the average clinical treatment time for endorphin theory TENS?

minimum 20-30 mins or 30-60 mins for multiple times per day

What type of waveform is used in TENS?

symmetrical or asymmetrical biphasic waveform

What feature may be used if the patient experiences accommodation to the TENS stimulus?

modulation mode: changes TENS response w/o increase of intensity

What are the two electrode arrangements used in TENS?

bipolar and bilateral bipolar

What are indications for TENS?

1. acute and subacute pain

2. chronic pain

3. referred pain

4. arthritis

5. neuropathy

6. phantom limb

7. labor and delivery

What are precautions and contraindications for TENS?

1. cognitive impairments

2. epilepsy or seizure disorder

3. hypersensitivity or asensitivity

4. open wounds

5. pacemaker

6. active infection

7. transcranially/ transthoracically

8. areas of recent hemorrhage

9. areas of thrombophlebitis/thrombosis

10. areas of healing tissue

11. carotid sinus

12. in water

13. pregnancy (except for in acute labor)

14. areas of malignancy (except in hospice care)

What is the therapeutic frequency for IFC?

1-150 pps

Describe the impact of skin and subcutaneous fat with therapeutic currents?

acts as resistor and reduces the amount of current reaching the underlying tissue

-may cause patient discomfort/skin irritation if intensity is increased too high

What is the relationship between frequency and resistance?

increasing frequency decreases resistance of skin/subcutaneous fat

What is the minimum number of Hz delivered by each independent IFC channel?

4000 Hz

What is the resultant/beat frequency?

difference between two crossing currents that create interference (observed in IFC)

When should IFC with quadripolar placement and sweep be used?

1. general painful site

2. large tissue treatment area

3. electrode placement is less than optimal

When should IFC with quadripolar with target be used?

-patient is able to identify specific location

What is Wedensky inhibition?

formation of "physiological block" of pain impulses after application of medium-frequency currents (IFC) creates subsequent action potential failures

What is the difference when dosing IFC for gate control theory and endorphin theory?

-rates are same as TENS

-pulse duration is dictated already

-treatment durations are similar

What are precautions for IFC?

1. cardiomyopathies

2. excessive hair

3. adverse effects of fainting, nausea, burns/rashes and swelling

What are contraindications for IFC?

1. pacemakers

2. cancer/active infections

3. pregnancy

4. transcranially/transthoracically

5. areas of recent hemorrhage

6. areas of thrombophlebitis/thrombosis

7. carotid sinus

8. over healing tissue

According to the Grabianska et al. (2015) study, what is more effective in pain relief between IFC and TENS?

Both have equal analgesic efficacy

What type of current is used in NMES?

alternating current

-current produces increased comfort and decreased chance of burns at higher intensities

True or False

NMES stimulates contractions similar to voluntary contractions, so it may completely replace therapeutic exercise during the early phases of recovery.

False; contractions are different and NMES must always be used adjunct to therapeutic exercise

What is the frequency of electrically activied contractions?

35-50 pps

-higher fatigue rate with fast twitch activation

What is the frequency of voluntary contractions from the CNS?

5-25 pps

-fatigue resistant with slow twitch to fast twitch glycolytic contractions

When would NMES be used?

1. re-education/facilitation

2. strengthening augmentation

3. build endurance in postural muscles/extremities

4. relaxing muscle spasms

5. edema reduction

6. decreasing venous thrombosis risk

7. reducing atrophy/fibrosis

When is duty cycle (on/off cycle) not used in NMES treatments?

when used for spasm reduction

What type of waveform is used in NMES?

symmetric and asymmetric biphasic

What is RAMP time?

easing and releasing time from max stimulation

-usually 2 secs in NMES treatments

How is amplitude measured in NMES?

milliamps (mA)

-intensity is synonym for amplitude

What level of contraction would be desired for endurance goals?

mild

What level of contraction would be desired for neuromuscular re-education and edema reduction goals?

moderate

What level of contraction would be desired for strength and spasm reduction goals>

maximal

True or False

Electrical stimulation is more metabolically fatiguing than a normal active contraction.

True

What are the frequencies used in NMES treatments

35-50 pps for endurance, edema, neuromuscular re-education and strength

80-150 pps for spasm reduction

What is the pulse duration for most NMES protocals?

200-300 microseconds

-lower pulse duration is used to higher amplitudes used in NMES

When should an asymmetric biphasic waveform in NMES be used?

used for smaller muscle groups

When should a symmetric biphasic waveform in NMES be used?

used for larger muscle groups

What are the benefits and drawbacks of using a higher RAMP time in NMES treatments?

benefit: more comfortable for patient

drawback: treatment may lose its efficiency

What duty cycle should be used for a strength NMES program?

1:5

What duty cycle should be used for a neuromuscular re-education NMES program?

1:2

What duty cycle should be used for an endurance NMES program?

1:3

What duty cycle should be used for a spasm reduction NMES program?

5:1 or 1:1

What is the typical treatment time for a strength NMES session?

10 mins (10 contractions w/ a 1:5 duty cycle)

What is the typical treatment time for a neuromuscular re-education NMES session?

10-15 mins (short, frequent sessions)

What are the 2 placement patterns for the electrodes in NMES?

bipolar or bipolar biphasic

What are the 3 stimulation options for NMES?

synchronous: both channels on at the same time

alternating: one channel on; one channel off at given point of treatment

sequential: one channel on and then second channel comes on before channel one turns off

What are precautions for NMES?

1. heart disease

2. epilepsy

3. 1 meter within microwave

4. obesity

What are contraindications for NMES?

1. pacemakers

2. carotid sinus

3. transthoracically or transcerebrally

4. anterior neck structures

5. infected/compromised skin

6. cancer

7. patients connected to medical monitoring devices

8. water immersion

9. pregnancy

10. active hemorrhages

11. fractures

12. post-surgical use

13. sensory nerve damage

What are the 3 claims made by Kotz regarding Russian stimulation?

1. Russian stimulation does not cause discomfort (unproven)

2. Russian stimulation generates 30% more force than maximum voluntary contraction (unproven)

3. Claims of lasting gains after training (proven)

What waveform is used for Russian stimulation?

sinusoidal AC current

What frequency is used for Russian stimulation?

2500 Hz at bursts of 50 bps

What is the protocol recommended by Kotz for Russian stimulation?

10 contractions for 10 second hold with 50 second rest

-70% maximum voluntary contraction to start

What is the difference between NMES and FES?

same modality with FES applying functional movement with each stimulation

When would FES be used?

stimulating weak muscle that are typically supported with an orthotic

What are the typical parameters for FES?

-same parameters as neuromuscular re-education

35-50 pps frequency

moderate motor intensity

200 microseconds duration

1:2 duty cycle

When should FES not be used in patient post-CVA?

in the presence of total spasticity

According to the ANPT, the evidence supports the use of FES for...

1. improving QOL

2. improving gait speed

3. improving other mobility

4. improving dynamic balance

5. improving walking endurance

6. improving plantar flexor spasticity

7. improving muscle activation

8. improving gait kinematics

What type of current is used in inotophoresis?

continuous direct current

What is the principle behind iontophoresis?

electrically charged electrode will repel a similarly charged ion causing the driving of medication into the skin

What property must a drug have in order be used in iontophoresis?

ionized

What are the two types of electrodes used in iontophoresis?

1. treatment pad: pushes medication

2. dispersive pad: closes circuit

What are the usual concentrations for ionized medications used in iontophoresis?

2-5%

How long does it take for medications deposited with iontophoresis to reach their full benefit?

12-24 hrs

What are the electrode properties for the cathode and anode?

cathode: black negatively charged electrode

anode: red positively charged electrode

What is the skin prep used in iontophoresis?

1. test skin sensation

2. use alcohol wipe to clean skin of oils and dry skin

3. do not shave hair

What electrode properties may help reduce the risk of burns in iontophoresis?

1. buffered and pH balanced electrodes

2. Reduce dry spots on treatment electrode

Where should the dispersive electrode be placed?

4-6 inches proximally from treatment electrode

What is the formula for medication delivery or dosage in iontophoresis?

dosage (mA per min) = current (mA) x time (min)

Describe the relationship between current and time in iontophoresis.

greater amount of current requires less time

-may cause burns

What is the most common dosage for iontophoresis?

40 mA-min

What are the dosage parameters concerning depth and current synchronization?

depth of penetration = 1.7 cm

-current is continuous but patient should only feel mild-moderate tingling sensation

How many treatments should be used with iontophoresis?

improvements should be noticed during first 2-3 treatments

-max amount of 6-8 treatments

True or False

Leaving on the treatment patch after iontophoresis treatment is effective in delivering medication through passive diffusion.

True

How may cathodes cause burns and chemical irritation?

accumulation of positive ions resulting in formation of sodium hydroxide

How may anodes cause burns and chemical irritation?

accumulation of negative ions resulting in formation of hydrochloric acid

How may burns be prevented in iontophoresis?

decrease intensity and increase electrode size

What are indications for iontophoresis?

1. bursitis

2. tendonitis

3. carpal tunnel syndrome

4. plantar fasciitis

5. arthritis

6. painful conditions

What are precautions for iontophoresis?

1. elderly skin

2. area of extreme edema/adipose tissue

What are contraindications for iontophoresis?

1. broken, damaged skin

2. electro-sensitive patients

3. pacemakers/electrical devices

4. drug contraindications

5. transcranially

6. orbital region

7. pregnancy

8. diabetes with sensory loss

What is skin tolerance for continuous direct current?

density < 1 mA/sq.cm

If a histamine reaction were to occur, how would you treat it?

treat with moisturizing skin cream to neutralize the area

What are some procedures that should not be combined with iontophoresis?

1. binding or taping the electrodes to skin

2. no ultrasound/phonophoresis before treatment

3. stop treatment if patient reports burning sensation

What are advantages of iontophoresis?

1. localized, low systemic effects

2. avoids fear of needles

3. non-invasive

What are disadvantages of iontophoresis?

1. drugs must be ionized

2. risk of burns, blisters and skin irritation

What must be documented after an iontophoresis treatment?

1. type of medication

2. skin condition pre and post-testing

3. time of delivery (dosage = mA x time)

4. amount of medication used

5. prescription from MD on file

What organizations was responsible for the approval of non-thermal low laser devices for medical treatment?

FDA

How are wavelength and frequency related in phototherapy laser light?

inversely proportional

What is the difference between higher and lower frequencies of phototherapy?

higher = x-rays and gamma rays, which are ionizing and potential harmful to the body

lower = SWD, MWD, IR and UV, which are non-ionizing and considered therapeutic and safe

What is the optical window for phototherapy?

the range of wavelengths considered to be therapeutic and provide photo-chemical effects (600-900 nm)

What does LASER stand for?

light amplification by stimulated emission of radiation

What is the wavelength used in laser treatments?

coherent, monochromatic and directional