Care plans for native and prosthetic joint septic arthritis , and acute hematogenous and chronic osteomyelitis

*Mr Luc Bergeron, Centre hospitalier universitaire de Québec, Ste-Foy, Québec; Dr Ross Pennie, McMaster University Medical Centre, Hamilton, Ontario; Ms Alison Alleyne, Mount Sinai Hospital, Toronto, Ontario; Mr Jim Oxsley, Moose Jaw Union Hospital, Moose Jaw, Saskatoon; Dr John Gill, Southern Alberta Human Immunodeficiency Virus Clinic, Calgary, Alberta; Dr Christopher Wong, Royal Columbian Hospital, New Westminster, British Columbia; Ms Carol DeLorme, Hôpital Charles Lemoyne, Greenfield Park, Québec; Ms Kristi Hallett, Foothills Hospital, Calgary, Alberta; Mr Don Hamilton, British Columbia Children’s Hospital, Vancouver, British Columbia; Dr Andy Pattullo, Kelona General Hospital, Winnipeg, Manitoba; Ms Leilani Todorovic, Burnaby General Hospital, Burnaby, British Columbia; Ms Maria Lazaruk, St Boniface General Hospital, Winnipeg, Manitoba; Ms Carolyn Doroshuk, Misericordia Hospital, Edmonton, Alberta Correspondence: Dr Stephen D Shafran, Division of Infectious Diseases, Department of Medicine, University of Alberta, H-Site, 10240-112 Street NW, Edmonton, Alberta T6G 2B7. Telephone 780-407-7137, fax 780-407-8077, e-mail sshafran@ualberta.ca S Shafran and The Septic Arthritis/Osteomyelitis Outpatient Intravenous Antibiotic Therapy Working Group. Care plans for native and prosthetic joint septic arthritis, and acute hematogenous and chronic osteomyelitis. Can J Infect Dis 2000;11(Suppl D):34D-40D.


SEPTIC ARTHRITIS OF A NATIVE JOINT
Septic arthritis of a native joint is the prevalent form of septic arthritis (1).The most common predisposing condition of this infection in adults is rheumatoid arthritis (2), and any monoarticular exacerbation of arthritis in a patient with rheumatoid arthritis must be investigated for infection.The care plan for this septic arthritis of a native joint is outlined in Figure 1.The most common pathogens are methicillinsusceptible Staphylococcus aureus followed by streptococci (2); therefore, the usual empirical therapy is cloxacillin Can J Infect Dis Vol 11 Suppl D November/December 2000 35D Septic arthritis and osteomyelitis care plans or cefazolin.Pending culture results, some clinicians add gentamicin in selected cases to eradicate Enterobacteriaceae, such as Escherichia coli, Klebsiella species and Enterobacter species (3).However, de novo Gram-negative rod infections are not common in the immunocompetent host.In penicillinallergic patients, vancomycin or clindamycin are the agents of choice.The usual duration of therapy is three to four weeks (4).
In addition to antibiotics, joint drainage should be performed in all cases.Usually this can be accomplished by aspirations, but sometimes open surgical drainage must be employed if pus is too thick or if the infection involves the hip joint.In children, initial parenteral antibiotic therapy is usually stepped down to oral therapy if there is a known susceptible organism and if the infection is resolving well clinically.The care pathway (Figure 1) does not apply to gonococcal arthritis, which presents differently and is easy to distinguish clinically from septic arthritis due to other pathogens.Gonococcal arthritis usually requires only three days of intravenous antibiotics (usually ceftriaxone) followed by seven days of oral antibiotics.

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Figure 2) Care plan for septic arthritis of a prosthetic joint

SEPTIC ARTHRITIS OF A PROSTHETIC JOINT
The clinical signs and symptoms for the patient with an infected prosthetic joint may be insidious; for example, the patient may have pain as the major complaint, instead of fever or other features of sepsis.Figure 2 depicts the steps to follow when caring for a patient with an infected prosthetic joint.The most important diagnostic procedure is aspiration of the involved joint.Empirical therapy should be avoided if at all possible so that reliable cultures can be taken and susceptibility testing can be performed on any isolates.The most common pathogen is coagulase-negative staphylococcus (5).The minimum duration of therapy is six weeks, which usually Can J Infect Dis Vol 11 Suppl D November/December 2000 37D Septic arthritis and osteomyelitis care plans Figure 3) Care plan for hematogenous osteomyelitis includes a short hospital stay and outpatient intravenous antibiotic therapy using a peripherally inserted central catheter.
A two-stage exchange arthroplasty is the usual surgical strategy (6).Medical therapy alone almost always fails.If the erythrocyte sedimentation rate and the C-reactive protein levels are high to begin with, further monitoring these parameters may be used as a rough index of response of the infection, because reculturing the joint by reaspiration is not usually conducted until just before the second-stage arthroplasty.

HEMATOGENOUS OSTEOMYELITIS
Hematogenous osteomyelitis may present either in the acute stage, as is usual for small children, or in the chronic stage.The care plan for hematogenous arthritis is presented in Figure 3.For a patient in the acute stage, it is important to remember that plain x-rays do not exclude the diagnosis of osteomyelitis.A technetium-labelled bone scan is much more sensitive in the early stages.The best microbiological diagnostic test for children is blood culture, and S aureus is by far the most common isolate (7,8).Cloxacillin, therefore, is the usual agent of choice, but cefazolin can also be used.In children with staphylococcal or streptococcal osteomyelitis, oral step-down therapy is usually preferred once the acute stage of the infection is under control (9).The usual duration of therapy for children is four weeks, while the usual duration of intravenous therapy for adults is six weeks with a peripherally inserted central catheter.In adults with infection caused by Gram-negative rods, an oral fluoroquinolone such as ciprofloxacin, 500 to 750 mg bid, is usually preferred.

CHRONIC OSTEOMYELITIS
The care plan for chronic osteomyelitis can be found in Figure 4.In chronic osteomyelitis, blood culture is usually negative; empirical therapy should be avoided.The most important diagnostic test is a bone biopsy with histology, and aerobic and anaerobic culture.Normal x-rays usually show changes, but a normal x-ray does not rule out osteomyelitis.If a draining sinus is present, surface swab cultures should be avoided because they may pick up colonizing bacteria and lead to treatment with unnecessary antibiotics.Sinus tract swabs that grow S aureus often predict that the pathogen is in bone, but sinus tract swabs that grow Gram-negative rods do not (10).Although orthopedic hardware should be removed whenever possible, in the case of a patient with infection of a fracture with internal fixation, the aim of therapy is only to suppress the infection to a low level that will allow bone union to occur.Once this is achieved and the patient can bear weight, the hardware can be removed, any sequestrum can be debrided, and a second course of antibiotics can be started to eradicate the infection.The minimum duration of therapy is six weeks, usually completed in an outpatient intravenous antibiotic program with a peripherally inserted central catheter.In the case of susceptible Gram-negative osteomyelitis, the full course of treatment may be accomplished with an oral fluoroquinolone, such as ciprofloxacin, 500 to 750 mg bid, if adherence to the oral regimen can be assured.The sedimentation rate and C-reactive protein levels may be useful surrogate markers of the progress of the infection.

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Figure 4) Care plan for chronic osteomyelitis

NURSING CARE PLAN FOR SEPTIC ARTHRITIS OR OSTEOMYELITIS
Patients often receive a portion (usually the majority) of intravenous therapy in an outpatient program.In these cases, home care nurses clinically monitor the patients and the intravenous devices, often every day or every other day.A nursing care plan is presented in Table 1.The physician should follow the progress of these patients approximately every week during the intravenous treatment.

PATHOGEN-SPECIFIC THERAPY FOR COMMON PATHOGENS
Variability exists in the therapy of septic arthritis and osteomyelitis.Therapy depends on the pathogen isolated and patient-related specifics that dictate a regimen (eg, known allergies or drug intolerance).Tables 2 and 3 list the antibiotics of choice for the paediatric and adult age groups for some of the most common pathogens, with alternative regimens for patients with penicillin allergy.
Can J Infect Dis Vol 11 Suppl D November/December 2000 39D Septic arthritis and osteomyelitis care plans

Figure 1 )
Figure 1) Care plan for septic arthritis of a native joint

TABLE 2 Pathogen-specific therapy: Antibiotics of choice for common Gram-positive cocci Organism Antibiotic treatment* Adult dose Paediatric dose
May need to adjust doses based on renal function or size in adults.†It is usually possible to switch from intravenous to oral antibiotics in children in the first week of therapy for streptococcal infections and methicillin-susceptible staphylococcal infections.Some clinicians prefer to measure serum bactericidal concentrations when switching to oral therapy.‡ Can use penicillin G instead of ampicillin if synergistic with aminoglycosides.§ Substitute streptomycin for gentamicin if synergistic and gentamicin-resistant. Consider fluoroquinolone for synergy if resistant to both gentamicin and streptomycin.**More data exist on conventional dosing than on the once daily dosing of aminoglycosides for enterococcal infections *

TABLE 3 Pathogen-specific therapy: Antibiotics of choice for common Gram-negative cocci Organism Antibiotic treatment* Adult dose Paediatric dose
May need to adjust doses based on renal function or size in adults.† If possible, avoid these cephalosporins if pathogen is Serratia species, Enterobacter species, Providencia species, Morganella species or Citrobacter freundii, due to the possibility of derepressing latent cephalosporinase *