Fluidized Therapy (Fluidotherapy)

Number: 0450


Aetna considers fluidized therapy medically necessary for the treatment of acute or subacute traumatic or non-traumatic musculoskeletal disorders of the extremities.

Aetna considers fluidized therapy experimental and investigational for all other indications (e.g., carpal tunnel syndrome, limb edema after stroke, re-warming hypothermic subjects, and rheumatoid arthritis) because of insufficient evidence in the peer-reviewed literature for indications other than the ones listed above.

Notes: Fluidized therapy is considered to be a physical therapy modality subject to the physical therapy guidelines and any applicable plan benefit limits for physical therapy.

Aetna will cover only the professional charges of a physical therapist or other recognized, licensed providers for fluidized therapy and other physical therapy modalities that require direct, one-on-one, patient contact.  Please check benefit plan descriptions.


Fluidized therapy (Fluidotherapy) is a high-intensity heat modality consisting of a dry whirlpool of finely divided solid particles suspended in a heated air stream, the mixture having the properties of a liquid. In addition to the superficial heat, it provides tactile stimulation while also allowing for active range of motion.

Studies comparing its effective heating with that of a paraffin bath and whirlpool have found them to be similar. The indications for fluidized therapy are similar to paraffin baths and whirlpool.  Use of fluidized therapy dry heat is an acceptable alternative to other heat therapy modalities in reducing pain, edema, and muscle spasm from acute or subacute traumatic or non-traumatic musculoskeletal disorders of the extremities.  Fluidized therapy is contraindicated in patients with local sensory loss, open lesions, severe circulatory obstruction disorders (eg, arterial, lymphatic or venous disorders) or systemic infectious diseases.

The maximum duration of treatment is generally four weeks.

The Work Loss Data Institute's clinical practice guideline on "Carpal tunnel syndrome (acute & chronic)" (2011) listed fluidotherapy as one of the interventions/procedures that were considered, but are not currently recommended.

The Work Loss Data Institute's clinical practice guideline on "Forearm, wrist, & hand (acute & chronic), not including carpal tunnel syndrome" (2013) listed fluidotherapy as one of the interventions/procedures that were considered, but are not currently recommended.

Mild Hypothermia Re-Warming

Kumar and colleagues (2015) examined the effectiveness of fluidotherapy re-warming through the distal extremities for mildly hypothermic, vigorously shivering subjects. A total of 7 subjects (2 females) were cooled on 3 occasions in 8˚C water for 60 minutes, or to a core temperature of 35°C.  They were then dried and re-warmed in a seated position by
  1. shivering only;
  2. fluidotherapy applied to the distal extremities (46 ± 1°C, mean ± SD); or
  3. water immersion of the distal extremities (44 ± 1°C). 
The order of re-warming followed a balanced design.  Esophageal temperature, skin temperature, heart rate, oxygen consumption, and heat flux were measured.  The warm water produced the highest re-warming rate, 6.1°C/hour, 95 % confidence interval [CI]: 5.3 to 6.9, compared with fluidotherapy, 2.2°C/hour, 95 % CI: 1.4 to 3.0, and shivering only, 2.0°C/hour, 95 % CI: 1.2 to 2.8.  The fluidotherapy and warm water conditions increased skin temperature and inhibited shivering heat production, thus reducing metabolic heat production (166 ± 42 W and 181 ± 45 W, respectively), compared with shivering only (322 ± 142 W).  Warm water provided a significantly higher net heat gain (398.0 ± 52 W) than shivering only (288.4 ± 115 W).  The authors concluded that fluidotherapy was not as effective as warm water for re-warming mildly hypothermic subjects.  They stated that although fluidotherapy was more portable and technically simpler, it provided a lower rate of re-warming that was similar to shivering only.

Limb Edema after Stroke

Han and Lee (2017) examined the effect of fluidotherapy on hand's dexterity and activities of daily living (ADL) for stroke patients with upper limb edema.  The objective of the present study was to treat 30 stroke patients with a 3-week course of fluidotherapy to investigate the efficacy of such therapy for reduction of edema.  For accurate baseline and post-intervention assessment of edema volume, hand edema was measured in the morning using a forearm volumeter.  Mean edematous volume in the affected side measured 600.53 ± 29.94 ml prior to intervention, significantly decreasing to 533.53 ± 27.85 ml after 3 weeks of fluidotherapy.  To examine how such reduction may have enhanced the ability to perform ADL, Korean Version of Modified Barthel Index assessment was performed.  The results showed 46.10 ± 4.27 points at baseline and significantly improved to a mean score of 49.96 ± 4.34 points at the time of re-assessment.  Furthermore, Box and Block Test was performed to examine hand dexterity.  Before fluidotherapy, affected patients transferred 21.13 ± 3.63 blocks in 1 min, increasing to 23.20 ± 3.42 blocks transferred in 1 min following 3 weeks of treatment.  Although the number of blocks transferred did increase slightly, the difference was not statistically significant.  The authors concluded that the findings of this study suggested that using fluidotherapy could reduce edema, and such a reduction may have a positive effect on ADL.  Based on the current findings, these researchers hypothesized that long-term fluidotherapy treatment may be more effective in reducing edema.

The authors stated that a major drawback of this study was that it did not compare the experimental group with the control group.  Also, the number of subjects was insufficient and various evaluation tools related to the function of the hand were not used.  These investigators stated that future studies should be performed to prove the effect of reducing the edema and improving the hand function by using the control design and more various evaluation tools.

Rheumatoid Arthritis

In a prospective, randomized controlled trial (RCT), Erdinc and colleagues (2019) examined the efficacy of dry heat treatment (fluidotherapy) in improving hand function in patients with rheumatoid arthritis (RA).  All patients were randomly divided into 2 groups: Group 1 underwent fluidotherapy; and group 2 was a control group.  Patients in both groups participated in a joint protection and exercise program.  Primary outcome measures were Health Assessment Questionnaire and Duruoz Hand Index; secondary outcome measures were pain and stiffness, Grip Ability Test, Disease Activity Score-28, and grip strength.  These assessments were performed at the hospital at baseline, week 3, and week 12.  A total of 93 subjects were allocated to Group 1 (n = 47) and Group 2 (n = 46).  The mean age of these groups was 54.19 ± 11.15 years and 53.00 ± 10.15 years, respectively (p = 0.592).  At baseline, there were no significant differences between the groups in any parameter except significantly poorer Health Assessment Questionnaire score in Group 1 (p = 0.007).  At week 3, there were no significant differences between the groups in any of the parameters (p > 0.005).  At week 12, Duruoz Hand Index scores were significantly better in Group 2 (p = 0.039).  The authors concluded that fluidotherapy was not effective in improving hand function in patients with RA.  Moreover, no positive effect on any other clinical parameters was observed.

Table: CPT Codes / HCPCS Codes / ICD-10 Codes
Code Code Description

Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":

There is no specific code for fluidized therapy (fluidotherapy):

Other CPT codes related to the CPB:

97036 Application of a modality to one or more areas; Hubbard tank, each 15 minutes
97113 Therapeutic prodecure, one or more areas, each 15 minutes; aquatic therapy with therapeutic exercises

ICD-10 codes covered for indications listed in the CPB :

Too many to list

ICD-10 codes not covered for indications listed in the CPB (not all-inclusive):

G56.00 - G56.03 Carpal tunnel syndrome
I69.398 Other sequelae of cerebral infarction [limb edema]
M05.00 - M05.9 Rheumatoid arthritis with rheumatoid factor
M06.00 - M06.9 Other rheumatoid arthritis
R22.30 - R22.43 Localized swelling, limbs [limb edema after stroke]
R60.0 Localized edema [limb edema after stroke]
T68.xxxA - T68.xxxS Hypothermia

The above policy is based on the following references:

  1. Borrell RM, Henley EJ, Ho P, et al. Fluidotherapy: Evaluation of a new heat modality. Arch Phys Med Rehab. 1977;58(2):69-71.
  2. Borrell RM, Parker R, Henley EJ, et al. Comparison of in vivo temperatures produced by hydrotherapy, paraffin wax treatment, and Fluidotherapy. Phys Ther. 1980;60(10):1273-1276.
  3. Dorf E, Blue C, Smith BP, Koman LA. Therapy after injury to the hand. J Am Acad Orthop Surg. 2010;18(8):464-473.
  4. Erdinc Günduz N, Erdem D, Kızıl R, et al. Is dry heat treatment (fluidotherapy) effective in improving hand function in patients with rheumatoid arthritis? A randomized controlled trial. Clin Rehabil. 2019;33(3):485-493.
  5. Ganz SB, Harris LL. General overview of rehabilitation of the rheumatoid patient. Rheum Dis North Am. 1998;24(1):181-201.
  6. Gloth JM, Matesi AM. Physical therapy and exercise in pain management. Clin Geriatr Med. 2001;17(3):525-535, vii.
  7. Han SW, Lee MS. The effect of fluidotherapy on hand dexterity and activities of daily living in patients with edema on stroke. J Phys Ther Sci. 2017;29(12):2180-2183.
  8. Herrick RT, Herrick S. Fluidotherapy. Clinical applications and techniques. Ala Med. 1992;61(12):20-25.
  9. Klein MJ. Superficial heat and cold. eMedicine Physical Medicine and Rehabilitation Topic 201. Omaha, NE: eMedicine.com; updated December 16, 2004. Available at: http://www.emedicine.com/pmr/topic201.htm. Accessed July 10, 2005.
  10. Kumar P, McDonald GK, Chitkara R, et al. Comparison of distal limb warming with fluidotherapy and warm water immersion for mild hypothermia rewarming. Wilderness Environ Med. 2015;26(3):406-411.
  11. U.S. Department of Health and Human Services, Center for Medicare & Medicaid Services (CMS). Fluidized therapy dry heat for certain musculoskeletal disorders. Medicare Coverage Issues Manual Section 35-56. Baltimore, MD: CMS; 2002.
  12. Work Loss Data Institute. Carpal tunnel syndrome (acute & chronic). Encinitas, CA: Work Loss Data Institute; May 7, 2013.
  13. Work Loss Data Institute. Forearm, wrist, & hand (acute & chronic), not including carpal tunnel syndrome. Encinitas, CA: Work Loss Data Institute; May 8, 2013.