**Abstract**

**Considerable number of new amputations** yearly in the United States and internationally represent considerable population experiencing pain that is not just acutely from surgical insult but chronically that is related to phantom limb pain and residual limb pain. This chronic pain can last from weeks to years in these patients and lead to other debilitation such as depression, anxiety and even opioid addiction. Early interventions help lessen long-term pain for these patients. These interventions include nerve blockade as well as multi-modal therapy. Understanding the pathophysiology of the pain experienced by these patients will better allow any provider to care for these patients effectively and help alleviate chronic pain in the long term.

**Keywords:** amputation, phantom pain, neuropathic pain

### **1. Introduction**

Patients with amputations can be found living fulfilled lives. We have all seen them running marathons, in the Olympics, surfing, climbing Mount Everest and even as an MLB pitcher. However, most just want to lead normal lives and be the best parents, siblings, friends, or co-workers they can be. They want to return to their job and function in their daily lives as they did before. Recovery from an amputation is not immediate and takes significant time. Recovery time from amputation is usually prolonged. Wound healing is done in 4–8 weeks, but the prolonged mental, emotional, and physical recovery afterwards takes much longer and will be different for everyone. One of the limiting factors for recovery from an amputation is pain.

In looking at data from the Amputee Coalition, there are 185,000 in the United States every year. This means that an average of two million people is living with an amputated extremity in the United States alone [1–3]. Other data to consider is just as alarming; globally, there are 1 million amputations annually. This is an estimated 1–2 amputation per minute. Lower limb amputations are the most common, with most being due to vascular disease. 85% of lower limb amputations are preceded by a foot ulcer. About half of the people with diabetes who get a lower limb amputation will receive a second amputation [4]. African American populations are four times more likely to get an amputation than Caucasian [5]. Around a third of these patients have persistent depression and anxiety after their amputation [6]. Financially, it is noted that amputees have higher healthcare costs and if the amputation was related to vascular disease higher mortality [7].

All these factors can lead to an unknown fear for a patient undergoing an amputation. Understanding the cause of an amputation first is paramount. This can help guide a plan for better pain control in the perioperative period. The main causes of amputation are progression of disease processes such as peripheral vascular disease (82%) including ischemia and thrombosis. Diabetes and infections such as osteomyelitis and gangrene that is unresponsive to antibiotic treatment. The second major cause is trauma (16.4%). This has a high predominance in upper extremity amputations. Lower extremity amputations with trauma can also be seen with severe fractures that do not heal and frost bites as other causes. Finally, surgical removal of malignancies (0.9%) can result in amputations in upper or lower extremities depending on the location and type of the tumor and growth. Congenital malformations (0.8%) make up the final list for amputation categories [1, 2].

It is important as we consider the cause of the amputation and perioperative pain control, we also factor in the amount of time each patient had before surgery for their amputation decision. A diabetic patient that had a long time to make a decision for an amputation may have had considerable time to go through the stages of grief and accept the amputation as opposed to a trauma that did not have this time. Other things to consider are support system that the patient has at home. As discussed, wound healing is brief, but psychological healing will take longer in most and require repeated support and reminders to the patient to keep moving in a positive direction [8]. In addition to medical management, these patients will need pain-coping strategies and too many these may be a new technique for them in a life altering situation.

### **2. Pain classification with an emphasis on amputees**

Amputation patients have a variety of different pain to consider when treating them in the perioperative setting. The broad classification of this pain is postamputation pain. However, further classifying it in four categories helps to better understand each pain and how it originates. They are acute post-operative pain, phantom sensations, residual limb pain and phantom limb pain [2, 3].

Acute post-operative pain is the pain that most surgical patients experience after any surgery. It is the pain at the surgical incision site related to surgical trauma, swelling and tissue damage. This is usually reported as sharp and stabbing by patients due to nociceptive afferent nerve supply at the surgical site. Patient can also report muscle spasms related to the immobility of the limb or the compression dressing or brace applies to the amputation site after surgery [2, 9, 10].

Phantom sensations are the non-painful sensations arising from the amputated extremity. This is reported by 75% of patients 4 days after the amputations and higher at 6 months. This can be perceived as movement of the prior extremity or portion of the extremity (i.e. toe or finger). The patient can also note temperature changes or position changes or the missing limb. This has also been noted in mastectomies, dental extractions, and enucleations as well, and can also be seen in spinal cord injuries. Many of the phantom sensations are mild and decline but some patients have some degree persistent sensations indefinitely. There are a few patients in whom these sensations progress to severe pain and become problematic, leading to residual limb pain or phantom limb pain. There are reports of phantom sensations that do fade away and they appear to do this in a progressive fashion called telescoping. This is most common in upper extremity amputations where the phantom sensations continue to decrease such that eventually the patient is left with a sensation of the hand on the stump alone instead of distal [2].

Residual limb pain (stump pain) is the pain localized to the remained affected body segment and can be present for years. Residual limb pain can be of many

**35**

**Table 1.**

*Amputation Pain Management*

occurrence as well [2, 3, 12].

found in **Table 1** [1–3, 12, 13].

2. Elevated pre-amputation pain

1. Female gender

3. Upper extremity 4. Increasing age 5. Bilateral amputation 6. Traumatic amputation 7. Stump healing

9. Poor social support 10. High expectations 11. Poor coping strategies

*Risk factors for developing or prolonged phantom limb pain.*

*DOI: http://dx.doi.org/10.5772/intechopen.93846*

different modalities as it can be described as deep tissue pain, superficial incision pain and neuropathic in nature. 75% of patients will experience a component of this chronically after surgery [11]. Neuropathic pain will be described as burning and electric in nature. Some patient may even become hyperalgesia or have allodynia on the stump site. This may lead to difficulty with prosthetic fitting for the patient. This pain is usually noted early in recovery. There are causes of increased stump pain: infection, stump neuroma, heterotopic ossification [9]. These should be assessed with prolonged or increased stump pain as these are easily treatable. Infection is not uncommon in these patients due to high prevalence of diabetes and peripheral vascular disease. This should be assessed and treated with antibiotics accordingly to prevent sepsis and wound dehiscence. Stump neuromas occur when the severed nerve at the amputation site have an inflammatory mediated immune reaction. This can cause pain, but it can also cause unmyelinated A and C fibers to form around the nerve. Neuromas develop over time and usually are characterized by point pain on the stump and sensory changes. Heterotopic ossifications usually occur later after amputation as well. These are calcium deposits that occur in the soft tissue of the stump. These ossifications occur much higher in traumatic amputations. There is some association with traumatic brain injury and the risk of this

Phantom limb pain was first described in 1462 by French Surgeon, Ambrose Pare' [13]. However, it was not until 1871 that Silas Weir Mitchell, a Civil War surgeon, called this phenomenon "phantom limb" [2, 13]. Phantom limb pain is an unpleasant or painful feeling in the amputated extremity. 45–85% of patients from amputations can suffer from phantom limb pain [9]. This can have neuropathic components with burning and electrical shooting pain and nociceptive components of dull, aching, crushing and cramping pain [13]. There are two times of onset for this pain. One is usually early after amputation in the first month and the second can occur a year after amputation. The further out a patient is from amputation the less likely they will experience this. However, if a patient does begin to experience this, it can last for years. Phantom limb pain does not always have to occur alone and usually occurs with residual limb pain. While residual limb pain may be bothersome early on, phantom limb pain persists and become more bothersome later and tends to last longer. Risk factors for development or prolonging phantom limb pain are

8. Disease states such as fibromyalgia, migraines, Raynaud's, IBS, irritable bladder, depression, and anxiety

#### *Amputation Pain Management DOI: http://dx.doi.org/10.5772/intechopen.93846*

*Pain Management - Practices, Novel Therapies and Bioactives*

**2. Pain classification with an emphasis on amputees**

categories [1, 2].

altering situation.

causes of amputation are progression of disease processes such as peripheral vascular disease (82%) including ischemia and thrombosis. Diabetes and infections such as osteomyelitis and gangrene that is unresponsive to antibiotic treatment. The second major cause is trauma (16.4%). This has a high predominance in upper extremity amputations. Lower extremity amputations with trauma can also be seen with severe fractures that do not heal and frost bites as other causes. Finally, surgical removal of malignancies (0.9%) can result in amputations in upper or lower extremities depending on the location and type of the tumor and growth. Congenital malformations (0.8%) make up the final list for amputation

It is important as we consider the cause of the amputation and perioperative pain control, we also factor in the amount of time each patient had before surgery for their amputation decision. A diabetic patient that had a long time to make a decision for an amputation may have had considerable time to go through the stages of grief and accept the amputation as opposed to a trauma that did not have this time. Other things to consider are support system that the patient has at home. As discussed, wound healing is brief, but psychological healing will take longer in most and require repeated support and reminders to the patient to keep moving in a positive direction [8]. In addition to medical management, these patients will need pain-coping strategies and too many these may be a new technique for them in a life

Amputation patients have a variety of different pain to consider when treating

Acute post-operative pain is the pain that most surgical patients experience after

Phantom sensations are the non-painful sensations arising from the amputated extremity. This is reported by 75% of patients 4 days after the amputations and higher at 6 months. This can be perceived as movement of the prior extremity or portion of the extremity (i.e. toe or finger). The patient can also note temperature changes or position changes or the missing limb. This has also been noted in mastectomies, dental extractions, and enucleations as well, and can also be seen in spinal cord injuries. Many of the phantom sensations are mild and decline but some patients have some degree persistent sensations indefinitely. There are a few patients in whom these sensations progress to severe pain and become problematic, leading to residual limb pain or phantom limb pain. There are reports of phantom sensations that do fade away and they appear to do this in a progressive fashion called telescoping. This is most common in upper extremity amputations where the phantom sensations continue to decrease such that eventually the patient is left with

Residual limb pain (stump pain) is the pain localized to the remained affected body segment and can be present for years. Residual limb pain can be of many

them in the perioperative setting. The broad classification of this pain is postamputation pain. However, further classifying it in four categories helps to better understand each pain and how it originates. They are acute post-operative pain,

any surgery. It is the pain at the surgical incision site related to surgical trauma, swelling and tissue damage. This is usually reported as sharp and stabbing by patients due to nociceptive afferent nerve supply at the surgical site. Patient can also report muscle spasms related to the immobility of the limb or the compression

phantom sensations, residual limb pain and phantom limb pain [2, 3].

dressing or brace applies to the amputation site after surgery [2, 9, 10].

a sensation of the hand on the stump alone instead of distal [2].

**34**

different modalities as it can be described as deep tissue pain, superficial incision pain and neuropathic in nature. 75% of patients will experience a component of this chronically after surgery [11]. Neuropathic pain will be described as burning and electric in nature. Some patient may even become hyperalgesia or have allodynia on the stump site. This may lead to difficulty with prosthetic fitting for the patient. This pain is usually noted early in recovery. There are causes of increased stump pain: infection, stump neuroma, heterotopic ossification [9]. These should be assessed with prolonged or increased stump pain as these are easily treatable. Infection is not uncommon in these patients due to high prevalence of diabetes and peripheral vascular disease. This should be assessed and treated with antibiotics accordingly to prevent sepsis and wound dehiscence. Stump neuromas occur when the severed nerve at the amputation site have an inflammatory mediated immune reaction. This can cause pain, but it can also cause unmyelinated A and C fibers to form around the nerve. Neuromas develop over time and usually are characterized by point pain on the stump and sensory changes. Heterotopic ossifications usually occur later after amputation as well. These are calcium deposits that occur in the soft tissue of the stump. These ossifications occur much higher in traumatic amputations. There is some association with traumatic brain injury and the risk of this occurrence as well [2, 3, 12].

Phantom limb pain was first described in 1462 by French Surgeon, Ambrose Pare' [13]. However, it was not until 1871 that Silas Weir Mitchell, a Civil War surgeon, called this phenomenon "phantom limb" [2, 13]. Phantom limb pain is an unpleasant or painful feeling in the amputated extremity. 45–85% of patients from amputations can suffer from phantom limb pain [9]. This can have neuropathic components with burning and electrical shooting pain and nociceptive components of dull, aching, crushing and cramping pain [13]. There are two times of onset for this pain. One is usually early after amputation in the first month and the second can occur a year after amputation. The further out a patient is from amputation the less likely they will experience this. However, if a patient does begin to experience this, it can last for years. Phantom limb pain does not always have to occur alone and usually occurs with residual limb pain. While residual limb pain may be bothersome early on, phantom limb pain persists and become more bothersome later and tends to last longer. Risk factors for development or prolonging phantom limb pain are found in **Table 1** [1–3, 12, 13].


#### **Table 1.**

*Risk factors for developing or prolonged phantom limb pain.*
