Kembara Xtra - Medicine - Osteomyelitis

Kembara Xtra - Medicine - Osteomyelitis 
​​An inflammation-related acute or chronic bone infection that can be brought on by hematogenous seeding, contiguous infection transmission, or direct inoculation into intact bone (due to trauma or surgery). There are two main classification schemes:
- Waldvogel and Lew
 Grouped by duration (acute or chronic) and source (hematogenous or contiguous) of infection - Classification using Cierny-Mader-
Depending on the area of the bone afflicted, the host's physiology, and risk factors 


Special circumstances:
Vertebral osteomyelitis is caused by contiguous spread, direct inoculation, or the most frequent cause, hematogenous seeding. The most frequent initial symptom is back pain.
The lumbar spine is most frequently affected, then the thoracic spine. One third of individuals experience neurological problems.
Surgery is advised when neurological symptoms or spinal implant infection are present.
Antibiotics should be taken for six weeks to treat uncomplicated acute hematogenous vertebral osteomyelitis.
- Infections in prosthetic joints
• Three-phase bone scan and X-ray. MRI/CT is not very useful when using prosthetics.
 Rifampin (4–6 weeks) may be added to pathogen-directed antibiotic therapy for a better rate of success.
—drills into biofilm - Infections caused by trauma
Risk factors include contamination and fracture type and severity.
The most frequent place is in Tibia.

Epidemiology 
Predominant age: more prevalent in elderly people Hematogenous osteomyelitis - Adults (usually >50 years of age): vertebral - Children: long bones - Predominant sex: male > female
Contiguous osteomyelitis is linked to decubitus ulcers, infected total joint arthroplasties, and diabetic foot infections (DFIs) in older persons; surgery and trauma in younger adults. Vertebral osteomyelitis is most frequently caused by Mycobacterium tuberculosis worldwide. It is more likely to affect several vertebral bodies, especially those in the thoracic spine, and it is linked to the development of paraspinal abscesses.
Incidence
In general low; healthy bone is infection-resistant.
Prevalence
Approximately 66% of diabetics get foot ulcers.

Pathophysiology and Etiology 
Hematogenous osteomyelitis (usually monomicrobial) is a type of acute osteomyelitis that causes suppurative bone infection, edema, and vascular compromise that results in sequestrum (segments of necrotic bone that may include pus). - Staphylococcus aureus, the most prevalent
- Aerobic gram-negative bacteria and coagulase-negative staphylococci
- Pseudomonas aeruginosa (a user of intravenous drugs) - Salmonella species (Sickle Cell Anemia)
Contiguous focal osteomyelitis (polymicrobial) - M. tuberculosis and fungal (rare; in endemic locations or in immunocompromised hosts) - Coagulase-positive and coagulase-negative staphylococci Diabetes or vascular insufficiency
Pressure-related skin ulceration and necrosis; Streptococci, gram-negative bacilli, anaerobes (Peptostreptococcus sp.); débridement to healthy bone and/or soft tissue coverage/surgical flap operation; puncture wound through shoe; P. aeruginosa
Coagulase-negative staphylococci and S. aureus in prosthetic devices

Risk factors include: immunosuppression (including dialysis), recent trauma or surgery, recent diabetes (especially diabetic foot ulcer), foreign bodies (such as prosthetic implants), neuropathy, and vascular insufficiency. Sickle cell anemia
Drug injection history, osteomyelitis in the past, and bacteremia

Basic Prevention 

 Comprehensive foot examinations each year for diabetes patients  Examine your peripheral arteries for disease.
Improve diabetes glycemic control.
 Preventative antibiotic use for posttraumatic infection - Bone-cleansing surgery
Give IV antibiotics within an hour of making a skin incision, maintain their therapeutic dose throughout surgery, and give them for at least 24 hours after the procedure.
Closing of fractures
Cefazolin, cefuroxime, clindamycin, or vancomycin (for MRSA infection or -lactam allergy) - Open fractures
First-generation cephalosporins are favored in individuals who can take antibiotics within three hours of injury with prompt surgical therapy (clindamycin or vancomycin if allergic). Ceftriaxone for fractures of type III. If contamination of the soil or feces is present, add metronidazole.


History – Particularly in cases of acute osteomyelitis, fever, chills, discomfort, swelling, and erythema. These characteristics might not exist in chronic osteomyelitis.
Ask the patient about any bacteremia-predisposing illnesses they may have had in the past, such as diabetes, hemodialysis, invasive procedures, IV medication use, and immunosuppression.
- Recent trauma or surgery within the previous 1 to 2 months - The presence of a prosthetic device - A history of diabetes or DFI
Chronic osteomyelitis, acute osteomyelitis in the past, and a sinus drainage tract

clinical assessment 

 Fever, limited motion, discomfort, and indications of localized inflammation Probe to bone test in DFI had high pooled sensitivity and specificity for osteomyelitis of 0.87 (95% CI 0.75-0.93) and 0.83 (95% CI 0.65-0.93), respectively. Motor and sensory impairments (vertebral infection).
 Exposed bone in a DFI setup
Osteomyelitis risk is increased in DFI by ulcers that are more than 2 cm in width and 2 cm in depth.
Classic signs and symptoms of infection may be hidden in diabetics because to vascular dysfunction and neuropathy. Physical exam findings that best support osteomyelitis in the setting of DFI include a positive probe to bone test and an ulcer area >2 cm2.

Multiple Diagnoses 

A Brodie abscess (subacute osteomyelitis) is a systemic infection from another source, aseptic bone infarction, localized inflammation or infection of the soft tissues just beneath the skin (like gout), and aseptic bone infarction. (Charcot foot) Neuropathic joint disease
 Trauma/fractures Tumor

Laboratory Results 

Initial examinations (lab, imaging)
(1)[A] WBC is unreliable (may be normal).
Usually high and nonspecific CRP.
ESR is typically elevated:
- ESR >70 mm/hr multiplies the chance by almost ten.
Procalcitonin levels might also be increased.
 Giving antibiotics before a culture could change the outcome.
Immunosuppression (including diabetes), chronic inflammatory diseases, and various infection sites are additional conditions that can affect lab results. Routine radiography is the initial imaging step: Demineralization, periosteal response, and bone disintegration are the traditional osteomyelitis symptoms: Plain films don't show bone loss until 10 to 21 days after infection.
- After a normal x-ray, a bone scan is the first test used to assess infection linked to prosthetic devices.
 Radionuclide scanning (e.g., technetium, indium, or gallium) is beneficial if the extent of the disease cannot be determined at the time of diagnosis or if the scan has a poor sensitivity/specificity.  MRI - Best for seeing DFI, spinal infection, and septic arthritis 
- Low signal intensity in the T1-weighted image
- High signal intensity in the T2-weighted picture
- In diabetic foot ulcers, MRI has a sensitivity of 90% and a specificity of 80% for osteomyelitis. 
- MRI does not help evaluate the response to therapy due to the persistence of bone edema. - Not as accurate for diagnosing osteomyelitis with the presence of Charcot neuroarthropathy joint condition or after recent surgery.
To measure bony fragments and sequestration, CT is superior to normal radiography; to assess soft tissues and bone marrow, MRI is superior. 

Tests in the Future & Special Considerations

 Osteomyelitis can be accompanied by a consistently increased CRP for 4 to 6 weeks, but this association is nonspecific. ESR declines following therapy is a favorable prognostic indicator, even though CRP declines more quickly.
Utilize weekly lab tests to keep an eye on individuals getting prolonged antibiotic medication.

Diagnostic Techniques/Other Bone biopsies and blood cultures
Vertebral disc aspiration or blood culture are used to determine the cause of vertebral/hematogenous osteomyelitis.
Patients who have radiographic indications of osteomyelitis and positive blood cultures (with a pathogen likely to induce vertebral/hematogenous osteomyelitis) do not require bone biopsy.
A bone biopsy for histology and culture is used to make a conclusive diagnosis of contiguous osteomyelitis.
 Decubitus ulcers and DFI should not be treated with wound swabs or needle aspiration because these procedures do not correlate well with bone biopsy culture.
 Bone biopsy is possible concurrently with surgical débridement. Test interpretation is based on the pathology of the bone, which reveals an inflammatory process with pyogenic bacteria and necrosis.

Management Adequate diet, quitting smoking, controlling blood sugar, taking care of one's feet, and quitting IV drug usage

Medication 
Delay the start of empiric antibiotics in clinically stable individuals until a biopsy and/or blood cultures have been taken.
 Target the likely organism with empiric therapy and adjust it in accordance with culture findings.
 The ideal antibiotic concentration at the affected location is crucial (take vascular perfusion into consideration).
 Change antibiotic dosage based on renal function.
For the majority of acute osteomyelitis cases, 4 to 6 weeks of treatment are sufficient. A two-week course of pathogen-directed antibiotics may be sufficient in cases when an amputation is necessary or the contaminated bone must be completely removed.
A prolonged 6-week treatment of parenteral antibiotics is recommended if a prosthetic joint or other orthopedic hardware cannot be thoroughly débrided or removed. Later, some individuals could need long-term oral antibacterial suppression.
 Take into account longer (8 week minimum) treatment regimens for MRSA infections or persistent osteomyelitis.
Empiric therapy for vertebral/hematogenous osteomyelitis should cover gram-negative and MRSA infections.
- For DFI/contiguous osteomyelitis, IV vancomycin with 3rd- or 4th-generation cephalosporin +/ metronidazole Initial Line
 Coagulase-negative staphylococci or S. aureus For MSSA, use lactam at a high dose (nafcillin or oxacillin 2 g IV every four hours) or cefazolin 1 to 2 g IV every eight hours (use 2 g for patients above 80 kg). Vancomycin 15 to 20 mg/kg IV every 8 to 12 hours (use every 8 hours if CrCl >70 mL/min) with a target trough of 15 to 20 g/mL, not to exceed 2 g/dose for Streptococcus species; Ceftriaxone 2 g IV every 24 hours; Cefazolin 2 g IV every 8 hours; Ciprofloxacin 750 mg PO every 12 hours (or 400 mg IV

S. aureus - Ceftriaxone 2 g IV every 24 hours - MRSA: Linezolid 600 mg PO/IV every 12 hours or daptomycin 6 mg/kg IV every 24 hours - Streptococcus sp. - Penicillin G 4 million U every 6 hours - Enterobacter sp. (quinolone-resistant, including extendedspectrum -lactamase-producing Escherichia coli) - C

Caution 

The risk of acute renal failure can increase when vancomycin and piperacillintazobactam are combined (number needed to harm is 11).


Further Therapies 

There is currently no evidence to support the use of topical negative pressure, maggots, growth factors, or hyperbaric oxygen therapy for diabetic foot osteomyelitis.

Surgical Techniques 
Surgical drainage, reducing dead space, ensuring enough soft tissue coverage, reestablishing blood flow, and removing necrotic tissues all contribute to higher cure rates.
Débridement of necrotic bone was traditionally considered to be the cornerstone of therapy, but current research indicates that antibiotics alone may be sufficient for DFI.
On this subject, there is still a lot of research to be done.
In order to minimize dead space and aid in infection control in patients with vascular insufficiency, antibiotic-loaded cement has been used successfully for decades during surgery.

Discharge criteria: clinical and laboratory evidence of an infection's resolution and suitable outpatient therapy

Patient Follow-Up Monitoring
Antimicrobial blood levels, CRP, ESR, and repeat plain radiography, as needed by the clinical course. Compared to ESR, CRP has a stronger correlation with clinical response to medication.

Diet, glycemic management for diabetics, and proper nourishment for individuals who are malnourished

Modifying one's lifestyle; managing one's blood sugar levels; and taking care of one's feet are all necessary.


Prognosis: Antimicrobial and surgical therapy have a 90–100% response rate for treating superficial and medullary osteomyelitis.
 The recurrence rate in diabetics might reach 36%.  Enhanced mortality following amputation


Complications include the development of abscesses, bacteremia, fractures and nonunions, loosening of prosthetic implants, postoperative infections, and the possibility of sinus tract formation being linked to neoplasms (such as Marjolin ulcers), especially in cases where there has been a history of protracted infection.

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