Cryotherapy

Cryotherapy, sometimes known as cold therapy, is the local or general use of low temperatures in medical therapy. Cryotherapy can be used in many ways, including whole body exposure for therapeutic health benefits or may be used locally to treat a variety of tissue lesions.

Cryotherapy is often used in an effort to prevent or relieve muscle pain, sprains and swelling after soft tissue damage or surgery. When a musculoskeletal injury occurs, the body sends signals to the inflammatory cells, macrophages, which release IGF-1. IGF-1 is a hormone-insulin-like growth factor which initiates the termination of damaged tissue. In some cases, this inflammatory response can be aggravated and cause increased swelling and edema, which can actually prolong the recovery process.

For decades, it has been commonly used to accelerate recovery in athletes after exercise. Cryotherapy decreases the temperature of tissue surfaces to minimize hypoxic cell death, edema accumulation, and muscle spasms. Minimising each or all of these ultimately alleviates discomfort and inflammation. It can involve a range of treatments, from the application of ice packs or immersion in ice baths (generally known as cold therapy), to the use of cold chambers.

Cryotherapy chamber

Electric cryotherapy chambers are fully enclosed, walk-in rooms designed to expose the human body to ultra low temperatures for 2–3 minutes resulting in various therapeutic and health benefits.

The purpose of cryotherapy is to trigger the body’s natural response to the extreme cold. Upon entering the cryo chamber, the extreme cold temperatures elicit a fight or flight response, causing increased levels of dopamine and Norepinephrine resulting in the feeling of extreme focus and sense of euphoria. The process of thermoregulation occurs to protect vital organs from the cold temperatures, promoting increased blood flow and delivery of nutrients throughout the body via vasoconstriction and vasodilation of the blood vessels.

Electric cryo chambers use refrigeration as a cooling agent providing a safe, breathable environment, not exposing the client to any dangerous gases such as nitrogen.

Cryotherapy is a specific type of low-temperature treatment used to reduce inflammation and its associated pain.

Cryotherapy was developed in the 1970s by Japanese rheumatologist Toshima Yamaguchi and introduced to Europe, US and Australia in the 1980s and 1990s.

Mechanism of action

When the body is subjected to extreme cooling, the blood vessels are narrowed which reduces blood flow to the areas of swelling. Once outside the cryogenic chamber, the vessels expand, and an increased presence of anti-inflammatory proteins (IL-10) is established in the blood. The treatment typically involves exposing the individual to freezing, dry temperatures (at −40 °C) for 2 to 4 minutes in one of these chambers. While in the cryotherapy chamber, blood flow is reduced in that injured area. This will reduce muscle spasms and soreness. This is important to activate the circulatory system to encourage healing and regenerate muscle fibers.

Main uses

Proponents say that cryotherapy may reduce pain and inflammation, help with mental disorders, support exercise recovery and improve joint function. Cryotherapy chambers belong to the group of equipment associated with sports rehabilitation and wellness.

* Reducing the symptoms of eczema

Cryosurgery

Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The application of ultra-cold liquid causes damage to the treated tissue due to intracellular ice formation. The degree of damage depends upon the minimum temperature achieved and the rate of cooling. Cryosurgery is used to treat a number of diseases and disorders, most especially skin conditions like warts, moles, skin tags and solar keratoses. Liquid nitrogen is usually used to freeze the tissues at the cellular level. The procedure is used often as it is relatively easy and quick, can be done in the doctor's office, and is deemed quite low risk. If a cancerous lesion is suspected then excision rather than cryosurgery may be deemed more appropriate. Contraindications to the use of cryosurgery include but are not limited to; using it over a neoplasm, someone with conditions that are worsened by exposure to cold (i.e. Raynaud's, urticaria), and poor circulation or no sensation in the area. There are some precautions to using cryosurgery. They include someone with collagen vascular disease, dark-skinned individuals (due to high risk of hypopigmentation), and impaired sensation at the area being treated.

Ice pack therapy

Ice pack therapy is a treatment of cold temperatures to an injured area of the body. Though the therapy is extensively used, and it is agreed that it alleviates symptoms, testing has produced conflicting results about its efficacy and possibility of producing undesirable results.

An ice pack is placed over an injured area and is intended to absorb heat of a closed traumatic or Edematous injury by using conduction to transfer thermal energy. The physiologic effects of cold application include immediate vasoconstriction with reflexive vasodilation, decreased local metabolism and enzymatic activity, and decreased oxygen demand. Cold decreases muscle spindle fiber activity and slows nerve conduction velocity; therefore, it is often used to decrease spasticity and muscle guarding. It is commonly used to alleviate the pain of minor injuries, as well as decrease muscle soreness. The use of ice packs in treatment decreases the blood flow most rapidly at the beginning of the cooling period, this occurs as a result of vasoconstriction, the initial reflex sympathetic activity. Although the use of cryotherapy has been shown to aid in muscle recovery, some studies have highlighted that the degree of muscle cooling in humans is not significant enough to produce a considerable effect on muscle recovery. Based on previous research comparing human and animal models, the insufficient degree of cooling is due to larger limb size, more adipose tissue, and a higher muscle diameter in humans.

Ice is not commonly used prior to rehabilitation or performance because of its known adverse effects to performance such as decreased myotatic reflex and force production, as well as a decrease in balance immediately following ice pack therapy for 20 minutes. However, if ice pack therapy is applied for less than 10 minutes, performance can occur without detrimental effects. If the ice pack is removed at this time, athletes are sent back to training or competition directly with no decrease in performance. Ice has also been shown to possibly slow and impair muscle protein synthesis and repair in recreational athletes. This is especially true for cold water immersion, but equivalent controlled studies have not been done to see if the same effects hold true for ice packs. Regardless, ice has been shown in studies to inhibit the uptake of dietary protein post-muscle conditioning exercise.

Although there are many positive effects of cryotherapy in athletes' short-term recovery, in recent years, there has been much controversy regarding whether cryotherapy is actually beneficial or may be causing the opposite effect. While inflammation that occurs post-injury or from a damaging exercise may be detrimental to secondary tissue, it is beneficial for the structural and functional repair of the damaged tissue. Therefore, some researchers are now recommending that ice not be used so as not to delay the natural healing process following an injury. The original RICE (rest, ice, compression, elevation) method was rescinded because the inflammatory response is necessary for the healing process, and this practice may delay healing instead of facilitating it. Animal studies also show that a disrupted inflammatory stage of healing may lead to impaired tissue repair and redundant collagen synthesis.

There is a study that concludes that cryotherapy has a positive impact on the short-term recovery of athletes. Cryotherapy helped manage muscle soreness and facilitate recovery within the first 24 hours following a sport-related activity. Athletes who use cryotherapy within the first 24 hours to alleviate pain recovered at a faster rate than athletes who did not use cryotherapy after their sport-related activity.

Cryotherapy following total knee replacement

Cryotherapy may be associated with reducing inflammation and pain reduction. However, the effectiveness of cryotherapy on total knee arthroplasty (TKA) is still unclear. A systemic review found that six out of eight randomized controlled trails indicate that there is no significant benefit of using cryotherapy. The result may depend on several factors such as application time per session, duration and frequency of application of cryotherapy

Post-surgical management following total knee replacement surgery may include cryotherapy with the goal of helping with pain management and blood loss following surgery. Cryotherapy is applied using ice, cold water, or gel packs, sometimes in specialized devices that surround the skin and surgical site (but keeps the surgical site clean). Evidence from clinical trials regarding the effectiveness of cryotherapy is weak and because of this, the use of cryotherapy may not be justified. Weak evidence indicates that cryotherapy used postoperatively may be associated with a small decrease in blood loss and pain following the surgery. No clinically significant improvements in range of motion have been reported. There are not many side effects or adverse effects reported with this intervention. Some studies suggest that cryotherapy may offer minor reductions in swelling and pain after total knee arthroplasty, but systematic reviews indicate that its overall effectiveness remains inconclusive. The application methods vary, with durations ranging from brief ice pack sessions to continuous cooling for up to 48 hours using automated devices. Further study is needed to assess any potential harms or adverse effects associated with cryotherapy after total knee arthroplasty.

Traditional vs continuous cryotherapy after total knee arthroplasty

Cryotherapy, the withdrawal of heat from an individual's body via the application of cold modalities to reduce tissue temperature, has been known as a treatment intervention for the overall management of musculoskeletal injuries, especially when it comes to relieving pain and improving functional outcomes after total knee arthroplasty. Over the years, new cryotherapy devices that aim to maintain a fixed temperature for a prolonged time have become more apparent, thereby questioning both the efficacy and therapeutic outcomes of continuous cryotherapy with the ones of traditional cryotherapy.

The most concurrent systematic review and meta-analysis aimed to compare continuous and traditional applications of cryotherapy on patients who have undergone total knee arthroplasty, specifically in pain intensity, analgesics consumption, swelling, blood loss, postoperative range of motion (PROM), and length of hospital stay. According to the study's findings, there were no statistically significant differences in pain intensity, analgesic consumption, swelling, blood loss, PROM, and length of hospital stay between the continuous and traditional cryotherapy groups. At the same time, the study acknowledges its limitations, including lack of blinding, substantial heterogeneity, and modest sample sizes in eligible trials.

In addition to such findings, the study compared the financial implications of both continuous cryotherapy and traditional cryotherapy. They found that continuous cryotherapy may be subject to additional costs not covered by insurance. In contrast, the cost of traditional cryotherapy is nearly negligible.

With that in mind, continuous cryotherapy was shown to have produced similar clinical effects to traditional cryotherapy; the only difference being the additional costs that insurance companies do not cover with continuous cryotherapy. Therefore, the researchers state the current evidence isn’t substantial enough to support the theoretical cost-effectiveness of continuous cryotherapy after total knee arthroplasty.

Cold spray anesthetics

In addition to their use in cryosurgery, several types of cold aerosol sprays are used for short-term pain relief. Unlike other cold modalities, it does not produce similar physiological effects due to the fact it decreases skin temperature, not muscle temperature. It reflexively inhibits underling muscle by using evaporation to cool the area. Ordinary spray cans containing tetrafluoroethane