Osteomyelitis in the Diabetic Patient Management OF OSTEOMYELITIS IN THE DIABETIC PATIENT

Osteomyelitis is an infection of the bone or bone marrow which is typically categorized as acute, subacute or chronic.1 It is characteristically defined according to the basis of the causative organism (pyogenic bacteria or mycobacteria) and the route, duration and physical location of the infection site.2 Infection modes usually take one of three forms: direct bone contamination from an open fracture, puncture wound, bone surgery, total joint replacement, or traumatic injury; extension of a soft tissue infection such as a vascular ulcer; or hematogenous (blood borne) spread from other infected areas of the body such as the tonsils, teeth or the upper respiratory system.2(p807) Bacteria such as Staphylococcus aureus, Pseudomonas, Klebsiella, Salmonella, and Escherichia coli are the most common causative agents of the disease, although viruses, parasites and fungi may also lead to the development of osteomyelitis.3

Patients most at risk are the elderly, obese, and malnourished, as well as those suffering from impaired immune systems or chronic illness such as rheumatoid arthritis.3(p348) Other risk factors include long-term skin infections, arteriosclerosis, high blood pressure, cigarette smoking, and high cholesterol, intravenous drug use, sickle cell anemia and cancer. 4 The disease is very common in diabetic patients.5

This case study examines osteomyelitis in the diabetic patient and includes an in-depth look at a diabetic patient that has obtained a foot wound. Over time, the foot wound stalled, became chronic and resisted healing. Eventually, this led to infection which reached the bone, resulting in osteomyelitis. This hypothetical study illustrates that an effective nursing management plan can help diabetic patients facing this condition avoid complications and painful, expensive and intrusive surgeries.6 In extreme cases, the disease can even lead to amputation. The occurrence of osteomyelitis in diabetics can be avoided with routine medical attention and simple and proper patient education.

Osteomyelitis in the Diabetic Patient

There are roughly 14 million diabetics in the United States.5(p1019) Foot complications are among the most serious and costly complications of diabetes.6(p236) 15-25% of diabetics will have a foot ulcer in their lifetime.7 For 14-24%, this will lead to amputation of all or part of a lower extremity.2(p806)

Diabetic foot lesions frequently result from two or more risk factors occurring together. In the majority of patients, diabetic peripheral neuropathy plays a central role: up to 50% of people with Type 2 diabetes have neuropathy and at-risk feet.2(p810) Neuropathy leads to insensitive and sometimes deformed foot and bony prominences, often resulting in an abnormal walking pattern and foot loading. In people with neuropathy, minor trauma - caused for example by ill-fitting shoes, walking barefoot or an acute injury - can precipitate a chronic foot ulcer.8 Loss of sensation and limited joint mobility can also result in the abnormal biomechanical loading of the foot and the formation of calluses. Calluses further contribute to the patient's discomfort and increase abnormal weight loading which often results in subcutaneous hemorrhage.7(p17) Whatever the primary causes, should a patient continue walking on an insensitive foot, healing will be impaired. The breakdown of skin often leads to a deep foot infection with osteomyelitis.3(p349)

Symptoms and Complications

The onset of osteomyelitis can be sudden. Clinical manifestations include chills, high fever, rapid pulse, and general malaise.9 Osteomyelitis can be difficult to treat, especially if it is undetected at its onset. Systemic symptoms are often more prevalent than local symptoms. As the infection spreads through the cortex of the bone it involves the periosteum and soft tissue.2(p811) This often results in swelling, pain and tenderness for the patient. Many patients describe a "continuous, throbbing pain" that may intensify with movement due to collecting pus.4(pS20) Once bone has become infected, pus is produced within the bone creating an abscess that deprives the bone of its blood supply.

Infection in a diabetic foot presents a direct threat to the affected limb, and should be treated promptly and actively.4(pS21) Signs and/or symptoms of infection, such as fever, pain or increased white blood counts, are often absent. However, if infection is present, substantial tissue damage and risk of osteomyelitis is likely.

Diagnosis

The diagnosis of osteomyelitis is based primarily on clinical findings, with data from personal history, physical examination and laboratory tests also being considered in treatment plans.9(p886) Leukocytosis and elevations in the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level may be noted. Blood cultures or bone biopsies are also used to inform diagnosis.

Many diabetic patients complain of sensory loss. Healthcare practitioners can assess neuropathy...

When patients fail to protectively respond to two out of three applications of any method, the patient is considered at high risk of ulceration and perhaps osteomyelitis, particularly if this is in combination with other risk factors.3(p349)
Radiographic evidence often provides the clearest diagnostic evidence of the disease, highlighting bone destruction by osteomyelitis.11(p38) However, indications may not appear until roughly two weeks after the start of infection. The radiographs may reveal osteolysis or periosteal reaction.4(pS21) In severe cases, sequestra can occur -- a condition in which segments of necrotic bone separate from living bone creating an opportunistic environment for microorganism growth.10 This can lead to chronic osteomyelitis. A bone abscess uncovered during the subacute or chronic stage of hematogenous osteomyelitis is known as a Brodie's abscess which can require drainage.7(p18)

Treatment

The primary objective of treatment is to eliminate the infection and prevent escalation and recurrence.9(p901) Prompt treatment prevents further bone deformity and injury and restores comfort to the patient. It can also circumvent the complications of impaired mobility. Treatment of osteomyelitis is dependent upon the severity of the clinical manifestations -- how the infection has spread to the bone and how deeply it has penetrated. In less severe cases and with early diagnosis, treatment with oral antibiotic medications in high doses proves quite effective.2(p808) Fine needle aspirations of the area surrounding infected bones may be taken for lab cultures to aid physicians in making an official diagnosis and selecting the appropriate antibiotic. Antiviral and antifungal treatment plans may be needed if the causative agent is determined not to be bacterial. Regardless, timely therapy is essential to recovery. Once the bone's blood supply has been compromised, re-infection can occur which decreases the likelihood of success with any non-surgical treatment.9(p902)

In dangerous cases, patients may begin initial treatment with intravenous antibiotics and then switch to oral antibiotic pills once the infection has subsided.2(p812) In addition, the buildup of pus may need to be drained by surgery or needle aspiration, and any surrounding soft tissue that has been impacted may require surgical removal. Resulting tissue voids are then filled with healthy bone, muscle, or skin grafts before antibiotics are administered. Infected artificial joints may require surgical removal and replacement. Antibiotics are usually given before and after surgery. When the infection cannot be cured, the infected limb may need to be amputated or the joint fused with surgery. The duration of treatment plans can range from 4 to 6 weeks.6(p227) Exceptions include infections of the spinal vertebrae, which necessitate a 6- to 8-week treatment.

In diabetic patients, foot ulcers can spread to the bones of the feet and result in infections that are difficult to cure with antibiotics alone.5(p1020) Diabetic patients with advanced cases of osteomyelitis may face the surgical removal of the infected extremity. This is the chief reason diabetic patients should engage in proper foot care and follow all diet and treatment plans to control blood sugar levels, stabilizing them within normal ranges.4(pS22) Ulcers and osteomyelitis may not be successfully treated when uncontrolled diabetes is a factor.

Case Study -- Patient B

Patient B. is an African-American male from Chicago, Illinois suffering for diabetes. He is 65 years of age. He lives alone and is retired from the Burlington Northern Railroad where he served as a Railroad Safety Inspector for more than 25 years. He has a history of metabolic syndrome including Type 2 diabetes mellitus (T2DM), which he has been living with for over 10 years. He also has hypertension and is overweight. His family history indicates susceptibility to T2DM with the disease occurring in both the maternal and paternal families. A combination high calorie diet and sedentary lifestyle due to a back injury prior to his retirement have contributed to his weight gain in recent years. He also complains of occasional bouts of insomnia and general fatigue. His diabetes is managed with oral medication taken daily, as well as a recommended diet and exercise plan - although the management plan is rarely followed.

Patient B. was recently admitted for medical care due to sudden swelling in the left lower leg and complaints of a tingling sensation in the left foot. Six months prior to admission, he stepped on a small piece of broken glass and sustained a small puncture wound on the bottom of his left foot.…