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Haemodynamic performance of neuromuscular electrical stimulation (NMES) during recovery from total hip arthroplasty.

Broderick BJ, Breathnach O, Condon F, Masterson E, Ólaighin G - J Orthop Surg Res (2013)

Bottom Line: The effect of calf muscle NMES on peak venous velocity, mean venous velocity and volume flow were compared to resting values.Mean velocity increased by 178% compared to resting and volume flow increased by 159% compared to resting.In the un-operated limb, peak venous velocity increased by 288%, mean velocity increased by 354% and volume flow increased by 614% compared to basal flow (p<0.05 in all cases).

View Article: PubMed Central - HTML - PubMed

Affiliation: Electrical & Electronic Engineering, School of Engineering & Informatics, NUI Galway, University Road, Galway, Ireland. barry.broderick@nuigalway.ie

ABSTRACT

Background: Patients post total hip arthroplasty (THA) remain at high risk of developing Deep Vein Thrombosis (DVT) during the recovery period following surgery despite the availability of effective pharmacological and mechanical prophylactic methods. The use of calf muscle neuromuscular electrical stimulation (NMES) during the hospitalised recovery period on this patient group may be effective at preventing DVT. However, the haemodynamic effectiveness and comfort characteristics of NMES in post-THA patients immediately following surgery have yet to be established.

Methods: The popliteal veins of 11 patients, who had undergone unilateral total hip replacement surgery on the day previous to the study, were measured using Doppler ultrasound during a 4 hour neuromuscular electrical stimulation (NMES) session of the calf muscles. The effect of calf muscle NMES on peak venous velocity, mean venous velocity and volume flow were compared to resting values. Comfort was assessed using a 100mm non-hatched visual analogue scale taken before application of NMES, once NMES was initiated and before NMES was withdrawn.

Results: In the operated limb NMES produced increases in peak venous velocity of 99% compared to resting. Mean velocity increased by 178% compared to resting and volume flow increased by 159% compared to resting. In the un-operated limb, peak venous velocity increased by 288%, mean velocity increased by 354% and volume flow increased by 614% compared to basal flow (p<0.05 in all cases). There were no significant differences observed between the VAS scores taken before the application of NMES, once NMES was initiated and before NMES was withdrawn (p=.211).

Conclusions: NMES produces a beneficial hemodynamic response in patients in the early post-operative period following orthopaedic surgery. This patient group found extended periods of calf-muscle NMES tolerable.

Trial registration: ClinicalTrials.gov NCT01785251.

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Related in: MedlinePlus

An illustration of the posterior aspect of the legs showing the position of the two NMES electrodes placed over the soleus muscles of both legs.
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Figure 1: An illustration of the posterior aspect of the legs showing the position of the two NMES electrodes placed over the soleus muscles of both legs.

Mentions: Two surface electrodes measuring 5 cm × 5 cm (PALS UltraStim, Axelgaard Manufacturing Co., Ltd., CA, USA) were placed over the motor points of the soleus muscles of both legs of consenting patients as shown in Figure 1. NMES was applied using a custom-built, two-channel stimulator (Duo-STIM, Bioelectronics Research Cluster, NUI Galway [20]). The stimulator was programmed to apply a biphasic square-wave with a 350 μs pulse width, an inter-pulse interval of 100 μs and a frequency of 36 Hz. A comfortable calf muscle contraction was produced using a contraction time of 1s, a ramp up time of 500 ms and ramp down time of 500 ms which resulted in a slight plantar flexion. A series of test pulses were applied initially at a very low intensity to ensure correct electrode placement and to establish that the patient was comfortable with the sensation of electrical stimulation. The stimulus intensity was then gradually increased until a noticeable contraction was observed for both legs, as indicated by a visible tightening of the soleus muscle or a slight plantar flexion. Once the patient was comfortable with the chosen stimulation amplitude, the Duo-STIM was set to run for 4 hours. Stimulation parameters were set so that stimulation was applied alternatively to each leg every 30 seconds. Both legs were stimulated despite the patient having only a single operated limb so as to compare the haemodynamic performance in the operated limb versus the un-operated limb. Moreover, both legs are susceptible to DVT during unilateral THA [21].


Haemodynamic performance of neuromuscular electrical stimulation (NMES) during recovery from total hip arthroplasty.

Broderick BJ, Breathnach O, Condon F, Masterson E, Ólaighin G - J Orthop Surg Res (2013)

An illustration of the posterior aspect of the legs showing the position of the two NMES electrodes placed over the soleus muscles of both legs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643860&req=5

Figure 1: An illustration of the posterior aspect of the legs showing the position of the two NMES electrodes placed over the soleus muscles of both legs.
Mentions: Two surface electrodes measuring 5 cm × 5 cm (PALS UltraStim, Axelgaard Manufacturing Co., Ltd., CA, USA) were placed over the motor points of the soleus muscles of both legs of consenting patients as shown in Figure 1. NMES was applied using a custom-built, two-channel stimulator (Duo-STIM, Bioelectronics Research Cluster, NUI Galway [20]). The stimulator was programmed to apply a biphasic square-wave with a 350 μs pulse width, an inter-pulse interval of 100 μs and a frequency of 36 Hz. A comfortable calf muscle contraction was produced using a contraction time of 1s, a ramp up time of 500 ms and ramp down time of 500 ms which resulted in a slight plantar flexion. A series of test pulses were applied initially at a very low intensity to ensure correct electrode placement and to establish that the patient was comfortable with the sensation of electrical stimulation. The stimulus intensity was then gradually increased until a noticeable contraction was observed for both legs, as indicated by a visible tightening of the soleus muscle or a slight plantar flexion. Once the patient was comfortable with the chosen stimulation amplitude, the Duo-STIM was set to run for 4 hours. Stimulation parameters were set so that stimulation was applied alternatively to each leg every 30 seconds. Both legs were stimulated despite the patient having only a single operated limb so as to compare the haemodynamic performance in the operated limb versus the un-operated limb. Moreover, both legs are susceptible to DVT during unilateral THA [21].

Bottom Line: The effect of calf muscle NMES on peak venous velocity, mean venous velocity and volume flow were compared to resting values.Mean velocity increased by 178% compared to resting and volume flow increased by 159% compared to resting.In the un-operated limb, peak venous velocity increased by 288%, mean velocity increased by 354% and volume flow increased by 614% compared to basal flow (p<0.05 in all cases).

View Article: PubMed Central - HTML - PubMed

Affiliation: Electrical & Electronic Engineering, School of Engineering & Informatics, NUI Galway, University Road, Galway, Ireland. barry.broderick@nuigalway.ie

ABSTRACT

Background: Patients post total hip arthroplasty (THA) remain at high risk of developing Deep Vein Thrombosis (DVT) during the recovery period following surgery despite the availability of effective pharmacological and mechanical prophylactic methods. The use of calf muscle neuromuscular electrical stimulation (NMES) during the hospitalised recovery period on this patient group may be effective at preventing DVT. However, the haemodynamic effectiveness and comfort characteristics of NMES in post-THA patients immediately following surgery have yet to be established.

Methods: The popliteal veins of 11 patients, who had undergone unilateral total hip replacement surgery on the day previous to the study, were measured using Doppler ultrasound during a 4 hour neuromuscular electrical stimulation (NMES) session of the calf muscles. The effect of calf muscle NMES on peak venous velocity, mean venous velocity and volume flow were compared to resting values. Comfort was assessed using a 100mm non-hatched visual analogue scale taken before application of NMES, once NMES was initiated and before NMES was withdrawn.

Results: In the operated limb NMES produced increases in peak venous velocity of 99% compared to resting. Mean velocity increased by 178% compared to resting and volume flow increased by 159% compared to resting. In the un-operated limb, peak venous velocity increased by 288%, mean velocity increased by 354% and volume flow increased by 614% compared to basal flow (p<0.05 in all cases). There were no significant differences observed between the VAS scores taken before the application of NMES, once NMES was initiated and before NMES was withdrawn (p=.211).

Conclusions: NMES produces a beneficial hemodynamic response in patients in the early post-operative period following orthopaedic surgery. This patient group found extended periods of calf-muscle NMES tolerable.

Trial registration: ClinicalTrials.gov NCT01785251.

Show MeSH
Related in: MedlinePlus