Chapter 9: Infection: Prevention, Diagnosis, and Management

INTRODUCTION

Prevention of infection in patients undergoing interventional procedures remains a top priority of the interventional pain physician. Proper techniques and standard precautions must be strictly adhered to prevent infectious complications in patients receiving interventional procedures ranging from peripheral joint injections to the implantation of devices such as spinal cord stimulators and intrathecal medication delivery systems. Infectious complications include, but are not limited to, epidural, spinal, or subdural abscess; paravertebral, paraspinous, or psoas abscess; meningitis; encephalitis; sepsis; bacteremia; viremia; fungemia; osteomyelitis; local subcutaneous infection; hardware infections causing removal of expensive equipment; or discitis. The risk of infection may be reduced by identifying patients who are at increased risk for infection, adhering to the standard of care for reducing the risks, and considering prompt interventions to improve outcomes after infectious complications.

HISTORY AND PHYSICAL EXAMINATION

A focused history and physical examination of the patient receiving an interventional procedure or implantable device can be helpful in identifying patients at risk for developing infectious complications.

• Coexisting medical conditions can impair the immune system and increase the risks of infections such as cancer, chemotherapy, radiation, AIDS, and diabetes.

• Preexisting infection, pancreatitis, drug, or alcohol abuse may be associated with a higher incidence of infectious complications.

• Bacteremia and septicemia are contraindications; however, distal localized infection without any indication of systemic disease are not contraindications.

• Close postoperative follow-up and a high index of suspicion for infection in the high-risk patients.

• Review of current lab values such as CBC to assess for leukocytosis can be helpful, although routine preprocedure measurement is not recommended.

IMPACT OF SURGICAL SITE INFECTIONS

The procedures that involve implantable devices are done in the operating rooms and follow the strict intraoperative discipline to prevent the infection to reduce the financial burden.

• In United States, more than 40 million inpatient surgical procedures each year; 2% to 5% complicated by surgical site infections (SSIs).

• The infection rate varies from 3% to 6%.

• SSIs are second most common nosocomial infection (24% of all nosocomial infections).

• Infection is responsible for prolonged hospital stay by 7.4 days.

• It costs $400 to $2600 per infection depending on the surgical site and type of device.

• The cost of treatment of infection from neurosurgic implants to vascular shunts can be as high as 50,000 per case.

INFECTION WITH IMPLANTABLE DEVICES

• It varies from 2.5% (clean cases) to 9% (immunocompromised patients).

Most Common Organisms

• Staphylococcus aureus: coagulase positive

• Staphylococcus epidermidis: coagulase negative

• Methicillin-resistant S aureus (MRSA)

• Vancomycin-resistant enterococci (VRE)

• Vancomycin-resistant S aureus (VRSA)

• Multidrug-resistant organisms (MDRO)

MRSA Infection

• Usually staphylococci are sensitive to β-lactam antibiotics (ampicillin, methicillin, and cephalosporin).

• Two strains exist: Less-resistant community-acquired MRSA (CA-MRSA) and highly resistant hospital-acquired MRSA (HA-MRSA).

• It carries high risk ...