What is Acute Compartment Syndrome?
Acute compartment syndrome is a condition where pressure inside a closed area of the body, wrapped by a layer of tissue known as fascia, becomes too high. This increased pressure can disrupt local blood flow. If left untreated, this condition can cause tissue damage due to lack of oxygen (ischemia) and eventually, tissue death (necrosis). It’s important to deal with this issue right away as it is considered a surgical emergency. Though doctors usually diagnose this condition based on symptoms, they might also measure the pressure inside the affected compartment. A reading above 30 mmHg can be a strong clue of the problem, but even a single normal reading doesn’t rule out the condition.
The body’s fascia, a kind of thin, stiff connective tissue, wraps around muscle compartments and restricts sudden swelling. The leg, for example, has four muscle compartments – the front (anterior), side (lateral), deep back (deep posterior), and surface back (superficial posterior). The most common place for compartment syndrome to occur is in the front compartment of the leg, which houses the toe-extending muscles, the tibialis anterior muscle, a major nerve, and a key artery.
While acute compartment syndrome can occur in different parts of the body like the forearm, thighs, buttocks, shoulder, hand, and foot, it is more typically found in the limbs. It’s possible for it to occur in the abdomen, but this is less common.
Special care should be provided to patients suffering from open fractures, as recent studies suggest that even an open wound doesn’t relieve the pressure inside the muscle compartments. So, it’s still possible to have acute compartment syndrome. This is particularly relevant for certain types of severe fractures in the upper part of the bone of the lower leg (proximal intra-articular tibia fractures).
What Causes Acute Compartment Syndrome?
Acute compartment syndrome is a medical condition that can happen when there’s limited space or increased fluid amount inside a certain section of the body. This condition can happen even without an injury, but it most often happens after a fracture of a long bone. The most common bone fracture leading to this condition is the tibia (shinbone), followed by the distal radius (a bone in the forearm). In fact, approximately 75% of acute compartment syndrome cases are connected to fractures.
After fractures, the next most common cause is injuries to soft tissue. Other causes can include burns, injuries to the blood vessels, crush injuries, drug overdoses, blood flow returning after being blocked, blood clotting, bleeding disorders, infections, casts or splints wrongly placed, tight bandages, penetrating injuries, intense sports activity, and incorrect body positioning during surgery.
In children, fractures above the elbow, or to the lower arm bones (the ulna and the radius), can be linked to compartment syndrome.
Risk Factors and Frequency for Acute Compartment Syndrome
Acute compartment syndrome is a condition that primarily affects males, particularly those under 35 years old. It is commonly caused by a type of leg bone injury called a tibial shaft fracture. Other risk factors also exist, such as having bleeding disorders like hemophilia or conditions such as pediatric leukemia. Cases can occur even without a triggering injury, but in these situations, the likelihood of complications and delays in treatment increases.
- The rate of acute compartment syndrome is estimated to be 7.3 in every 100,000 males and 0.7 in every 100,000 females.
- Most cases occur after some form of trauma.
- Tibial (leg) shaft fractures are the most common cause, linking to 1 to 10 percent of cases.
- This condition usually affects males under 35, possibly due to more muscle mass in the same space and higher chances of experiencing high-energy trauma.
- People with bleeding disorders like hemophilia have a higher risk of getting acute compartment syndrome.
- There have been reports of cases in children with leukemia, without any related injury.
- When acute compartment syndrome occurs without any fracture, the chance of complications and treatment delays increases.
Signs and Symptoms of Acute Compartment Syndrome
Acute compartment syndrome usually happens within a few hours of an injury, but it can happen up to two days later. The condition often starts with a “wood-like” stiffness in the area of pain. At first, the pain might only be noticeable when the area is stretched, but it may become continuous as the condition progresses. It’s often intense and may feel like a burning sensation or a deep, painful ache. Also, there might be weakening or loss of feeling in the affected area.
Doctors sometimes remember the symptoms of this condition with “The Five P’s”: pain, pulselessness (no pulse), paresthesia (abnormal sensation like tingling), paralysis (loss of muscle function), and pallor (pale skin). However, of these, only paresthesia usually occurs early. The other symptoms usually appear later, if they appear at all. For example, even if this condition is severe, you may still have a pulse in the affected body part.
A physical examination for this condition would evaluate the sensitive and motor function in the area of pain:
- Is there any visible damage to the skin, any swelling, or changes in color?
- Is the area warm, stiff, or tender?
- Is there a pulse?
- Is there any abnormality in the sensation or loss of sensation?
- Is there any muscle weakness or loss of function?
While these symptoms can be helpful in diagnosing acute compartment syndrome, they are not always present. The best way to confirm the diagnosis often involves measuring pressure in the affected area with specific medical equipment. Doctors must monitor patients with suspected compartment syndrome closely, as the condition can worsen rapidly.
Testing for Acute Compartment Syndrome
Acute compartment syndrome is a medical condition that requires urgent treatment. This diagnosis is commonly based on symptoms and physical examination, but there are additional tests that doctors can use to confirm their suspicions and further understand the condition.
If a broken bone is suspected, your doctor might want to take an X-ray. Additionally, measuring the pressure within your compromised compartment (a section of your arm or leg) can be helpful in confirming the diagnosis if there’s any doubt. This can be done using a device known as a manometer. It works by injecting saline into the affected area and then measuring the resistance encountered. An alternative method is to use a slit catheter, where a catheter is inserted in the compartment, and an arterial line transducer is used to measure the pressure. This method is more precise and allows for ongoing monitoring. It is recommended for assessing all the areas around the compartment. Normal pressure within these compartments is usually between 0 and 8 mmHg.
If your intra-compartmental pressure exceeds 30 mmHg, it’s an indicator of compartment syndrome and shows a need for a surgical procedure known as a fasciotomy. Also, if this pressure gets within 10 to 30 mmHg of your diastolic blood pressure (the bottom number in a blood pressure reading), it suggests the blood supply to your limbs is inadequate, signifying relative ischemia. Doctors often refer to the difference between your diastolic blood pressure and the intra-compartmental pressure as the delta pressure. If your delta pressure is 30 mmHg or less, this may indicate that you need a fasciotomy.
An ultrasound with Doppler can be used to check for blockages or blood clots. Raised levels of a muscle enzyme called creatine phosphokinase (CPK) may suggest that your muscles are breaking down due to insufficient blood supply, injury, or a condition called rhabdomyolysis.
If rhabdomyolysis is a concern, tests of your kidney function, urine myoglobin (a protein found in your muscles), and a urine test may be needed. If you’re diagnosed with rhabdomyolysis, your doctor will want to carry out a full chemistry panel.
Lastly, if surgery is likely, preoperative tests should be done. At a minimum, these should include a complete blood count to check the health of your blood cells and coagulation studies to ensure your blood can clot properly.
Treatment Options for Acute Compartment Syndrome
Acute compartment syndrome is a condition that requires immediate medical attention. Any delay in treatment might lead towards the loss of a limb. The course of action typically includes:
- Contacting a surgeon right away
- Administering additional oxygen to the patient
- Removing any tight casts, bandages, or dressings to lessen the pressure
- Keeping the affected limb at heart’s level to prevent slow blood perfusion
- Preventing low blood pressure and providing support to patients with low blood pressure
- Performing fasciotomy, which is a surgical procedure that relieves tension or pressure, if the intra-compartmental pressure (ICP) is equal to or more than 30 mmHg or the difference in pressure is equal to or below 30 mmHg.
Patients who show signs of being at high risk for this condition, despite not meeting the diagnostic criteria, or have ICPs ranging from 15 to 20 mmHg, should have their intra-compartmental pressure regularly monitored. If the ICP is between 20-30 mmHg, these patients should be hospitalized and evaluated by surgeons. For those with ICPs of more than 30 mmHg or difference in pressures of below 30 mmHg, fasciotomy should be done.
Acute compartment syndrome is critical, and its quick identification and treatment are vital. As soon as the condition is confirmed, right away fasciotomy is essential to lower the intra-compartmental pressure. Ideally, this procedure is carried out within six hours of the injury and not recommended 36 hours after the injury. If the pressure lingers for too long, irreversible damage might occur and fasciotomy won’t be helpful in such cases.
If the tissue has died before performing fasciotomy, there’s a high chance of infection that could even lead to amputation. In case infection occurs, debridement, the removal of damaged tissue or foreign objects from a wound, is crucial for preventing the spread of the infection and other complications.
After performing fasciotomy and subsidence of swelling, a skin graft is usually used to close the incision. Close monitoring of patients for complications like infection, acute renal failure, and severe muscle damage is mandatory.
What else can Acute Compartment Syndrome be?
- Blood clot in a deep vein (Deep Vein Thrombosis)
- Skin infection (Cellulitis)
- A severe type of skin and muscle infection (Gas Gangrene)
- A serious condition with painful blue discoloration of the legs (Phlegmasia Cerulean Dolens)
- A condition that involves the breakdown of muscle tissue (Rhabdomyolysis)
- Sting or bite from a sea creature (Cnidaria Envenomation)
- Injuries to the blood vessels (Peripheral Vascular Injuries)
What to expect with Acute Compartment Syndrome
The treatment outcome for compartment syndrome, a severe condition affecting the muscles, mostly depends on how soon it is noticed and treated. If the treatment, a procedure called fasciotomy, is done within the first 6 hours, it tends to result in nearly complete recovery of that affected limb. Beyond this timeframe, there might be lingering nerve damage. For instance, research indicates that patients who undergo fasciotomy within 12 hours have only a two-thirds chance of their limb returning to normal function. For very late cases, there might be a need to amputate the affected limb.
It is important to note that treatment outcomes for compartment syndrome occurring in the back portion of the leg are generally poorer than for the front section of the leg. This is primarily due to the difficulty in adequately relieving the pressure in the posterior compartment.
Long-term studies on people who have gone through this experience often highlight ongoing pain, a condition called Volkmann’s contracture where the hand become claw-like, minor neurological issues and noticeable cosmetic changes in the affected limb. Athletes sometimes experience recurrent compartment syndrome caused by scar tissue.
In some severe cases, compartment syndrome may cause death, usually when an infection from the condition triggers sepsis, a severe body-wide response to infection leading to the failure of multiple organs.
Possible Complications When Diagnosed with Acute Compartment Syndrome
Compartment syndrome can lead to various complications. These complications include:
- Pain
- Shortening and hardening of muscle tissue, also known as contractures
- Rhabdomyolysis, a condition where damaged skeletal muscle breaks down rapidly
- Nerve damage, often leading to numbness and/or weakness
- Infections
- Renal failure, a condition in which the kidneys stop functioning properly
- Potential death
Recovery from Acute Compartment Syndrome
Physical therapy is important to regain strength and prevent the condition known as contractures, which is when muscles or joints become stiff. Additionally, taking care of cuts and scrapes and keeping an eye out for any signs of limited blood flow, infection, or a condition known as gangrene, which involves the death of body tissue, is critical.
If an infection is present, antibiotic medication may be necessary. Also, medication for pain relief will be provided. During their recovery period, individuals will need to use walking aids, such as crutches, until they are fully healed.
To make their day-to-day activities easier, it is recommended that the individual gets advice from an occupational therapist. This professional can teach them new ways to do everyday tasks.
Preventing Acute Compartment Syndrome
Patients should be advised to get medical attention following a serious injury or if they notice any pain or swelling in their limbs. If they have undergone a procedure called a fasciotomy, it’s crucial to take good care of the wound. Proper wound care is essential for proper healing.
