Cardiac catheterization lab/EP lab

What elements of the cardiac catheterization lab/EP lab are necessary for infection prevention and control?

Discussion of infection control in the cardiac catheterization lab/ EP lab will be limited to non-valvular cardiovascular devices and procedures.

Current guidelines regarding infection control were last published by the Society for Cardiovascular Angiography and Interventions in 2006. The spectrum of sterile procedures can vary depending on the type of procedure. Regardless if the procedure is placing animplantable cardiac device versus angiography, current practice should reflect those of the many disciplines of infection control.

Application of the principles of infection control in the setting of the cardiac catherization/EP lab can be broken down into the following:

• Hand hygiene, surgical scrubbing and gloving

• Prepping the patient

• Preoperative antibiotic administration

• Catheterization technique

• Wound care and closure devices

• Personal protective equipment

• Anti-infective impregnated devices

How do the clinical trials or meta-analyses on cardiac catheterization lab/EP lab guide infection control practices?

1) Hand hygiene, surgical scrubbing and gloving

Fingernails should be short and devoid of polish. Artificial nails pose as an infection hazard. All jewelry should be removed. Remove fingernail debris using a nail cleaner and water prior to scrubbing.

Perform preoperative scrubbing with an antiseptic agent rather than a non-antimicrobial soap as this has shown to reduce surgical site infection rates. Anti-septic agents that have immediate and persistent activity are the most important factors in choosing a product. Chlorhexidine gluconate appears to be the most effective in reducing hand flora. Scrub time should be between 2-5 minutes depending on the manufacturer of the antiseptic. Using a sponge/brush combination is equally effective as scrubbing with a brush. Scrubbing with a brush can damage the skin and result in increased shedding of bacteria from the hands, thus is not recommended more than once per day. For subsequent scrubs, prior to the procedure, antiseptic hand foam/wash or brushless sponge can be used. Alternatively, waterless preparations of 1% chlorhexidine /61% ethanol may be used. This preparation is superior or equal to standard 4% chlorhexidine scrub in antimicrobial reduction.

Gloves should be donned in a sterile fashion. Double gloves should be considered. In a study to evaluate gloves specifically for cardiac catheterization; 38 of 200 gloves had punctures generally at the index or thumb position, most likely from stopcock manipulation.

2) Prepping the patient

Remove hair preoperatively with clippers or a depilatory cream, only if it will interfere with the surgical site. Hair removal should not be done the night/day before as it can be associated with dermal abrasions and a portal of entry for infection. Avoid shaving the operative site with razors as it causes micro-abrasions increasing the risk of infection. Have the patient shower or bathe with an antiseptic agent at least the night before the procedure.

Thoroughly wash and clean the incision site and surrounding area to remove gross contamination prior to antiseptic skin preparation. Preparations containing 2% chlorhexidine are superior to iodine based preparations for both reductions in microorganism colony counts and residual antimicrobial effect. Fever can be considered a relative contraindication to elective cardiac catheterization. Infections remote to surgical site should be treated; it may be prudent to postpone elective procedures until Infection has resolved.

Maximum sterile barrier precautions should be used. Large sterile sheet should cover the entire patient and equipment that may be contacted by catheters.

3) Preoperative antibiotic administration

Antibiotic prophylaxis is not routinely indicated for cardiac catheterization. Antibiotic prophylaxis should be considered for any immunocompromised patient or for any patient with probable or definite wound contamination during the procedure. Antibiotics are indicated for placement of non valvular cardiovascular implantable devices, or other prosthesis. Administration of appropriate antibiotics should be directed towards skin flora. Staph species (S. aureus, coagulase negative staph) account for most cardiovascular implantable electronic device infections. Prevalence of methicillin resistant S. aureus in the institution of practice should be considered when choosing which antibiotic prophylaxis. Initial dose should be given in time so the bactericidal concentrations of the antibiotic are established in serum and tissues when incision is made. Antibiotics of choice are generally a cephalosporin such as cefazolin, given 30 minutes prior to incision. If vancomycin is used, it should be given within 2 hours prior to the procedure.

4) Catheterization technique

Hematomas can serve as a nidus of infection. Thus, great care should be taken to prevent large hematomas. Pressure dressings 12-24 hours after skin closure may decrease the risk of hematoma formation. Low molecular weight heparin predisposes formation of hematoma in chest wall pockets. Infection at the puncture site is more likely when repeat catheterization is done at the same femoral site. Consideration should be given to using the contralateral femoral site for access for subsequent procedures. Brachial artery cut down has been demonstrated to have 10 times the infection site rate compared to femoral approach. Single use devices should not be reused unless permitted by federal regulations.

5) Wound care and closure devices

Incisions should be closed using monofilament suture. Vascular access sheaths should be removed following diagnostic/interventional procedures as soon as it appropriate to do so. Sterile semi-permeable dressing should be used or sterile gauze dressing if there bleeding at the incision site. The incision site should be protected 24-48 hours post-procedure. Non permeable dressings increase infection risk, as does re-application of topical antibiotic ointments after the initial application.

Pre-operative antibiotics are recommended for diabetics if use of a vascular closure device is planned. Vascular closure devices may carry a higher risk of infection approximately 0.3%, compared to manual compression.

6) Personal protective equipment

Aseptic technique, use of sterile gown and gloves, hat mask, eye protection are recommended for any surgical procedure. Maximum sterile barrier precautions are required for from during catheter insertion and throughout the duration of implantable cardiovascular electronic device procedures.

7) Anti-infective impregnated devices

Recently published results of a retrospective multi-center study by Bloom et al. of the AIGIS Rx antibacterial envelope system, is promising. This a polymer mesh implanted in the generator pocket with the cardiac implantable electronic device (CIED) that releases rifampin and minocycline to reduce biofilm formation. Almost half of the enrolled patients had 3 or more risk factors for CIED infections. The study reports less than 0.5% rate of infection. However, the authors comment average follow up was 1.9+/-2.4 months, which may be a limitation of the study.

What are the consequences of ignoring the key principles of the cardiac catheterization lab/EP lab?

In general, infection rates related to cardiac catheterization and electrophysiology procedures are low. There are few, if any prospective trials regarding infection rates or post procedure infections to guide change in current infection control guidelines. Reported incidences of all related infections in relation to cardiac catheterization was less than 1%, but low numbers have been attributed to low tracking of events as generally there is a 5-10 day delay from procedure to symptoms of infection.

Cardiac implantable electronic device infections (CIED) are rising disproportionately to the rate of implantation. Recent guidelines published January 2010 by the American Heart Association regarding management of CIED infections, site several studies showing an increase of CIED infections from 0.94 to 2.11 per 1000 beneficiaries. CIED infection rates vary in reporting anywhere from 1 to 7%. The National Hospital Discharge Survey (2004-2006) demonstrated a 3.1 fold increase in CIED (4.1% infection in 2004 vs. 5.8% in 2006). These findings underscore the need to continued practice of current infection control guidelines to lower rates CIED infections, percutaneous access infections, endocarditis, sepsis and other infectious complications related to cardiovascular procedures.

Risk factors for CIED infection:

• Immunosuppression

• Oral anticoagulation use

• Patient coexisting illnesses

• Periprocedural factors including failure to administer pre-operative antimicrobial prophylaxis

• Device revision/replacement

• Amount of indwelling hardware

• Operator experience

• The microbiology of bloodstream infection in patients with indwelling CIED

Device Factors for CIED infection:

Type of plastic polymer, irregularity of surface, shape, hydrophobicity

Factors that may influence surgical site infections likely applicable to CIED patients:

Patient related:

Age, nutritional status, diabetes, smoking, obesity, co-existing infection at remote body site, altered immune response, colonization with micro-organism (S. aureus), length of preoperative hospital stay.

Procedural related:

Duration of surgical scrub, skin antisepsis, preoperative shaving, duration of operation, antimicrobial prophylaxis, inadequate sterilization of surgical instruments, foreign material in the surgical site, surgical drains, poor hemostasis, failure to obliterate dead space, tissue trauma.

What other information supports the use of cardiac catheterization lab/EP lab for infection control?

One prospective trial demonstrated the importance of following infection control guidelines. Borer, et al. demonstrated lower device associated infections after implementation of an empiric comprehensive infection control program for implantation of CIED at a tertiary care center in Israel. Observed CIED infection rates decreased from (14 cases during first 9 months of 2001) 4.2% to 0 cases during 24 month of follow up.

Interventions included: staff education, preoperative modification of patient risk factors, intraoperative control of strict aseptic technique, surgical scrubbing and attire, control of environmental risk factors, optimization of antibiotic prophylaxis, postoperative wound care and active surveillance.

Patient Risk Factors:

• Preoperative Optimization of glucose levels of patients with DM

• Elective implantation procedures avoided within 30 days after antibiotic therapy for other infections.

• Hair depilation was avoided the night before procedure

• Patients were required to wash their entire body with an antiseptic solution (triclosan 1%) the evening prior to the procedure

Aseptic Technique:

The skin of the surgical site was rigorously prepared by circular application of 4% chlorhexidine for 2 minutes followed by circular application of 0.5% chlorhexidine combined with 70% ethyl alcohol for 3 minutes, with special emphasis on the axillary and neck regions.

Surgical Scrubbing and Attire:

Members of the surgical staff were prohibited from wearing artificial fingernails or jewelry. Operating room personnel had to thoroughly scrub their hands with 4% chlorhexidine for 2 minutes and then 0.5% chlorhexidine combined with 70% ethyl alcohol for 3 minutes. Standard operating room attire included facemasks, caps, and sterile gowns and gloves.

Environmental Risk Factors:

Implantation procedures were performed in a facility with controllable optimal ventilation including positive-pressure ventilation and maintenance of a minimum of 15 air changes per hour, of which at least three were fresh air. Additional practices implemented included quality control of reusable equipment, high-level disinfection, strict environmental cleansing, and disinfection of visibly soiled surfaces.

Prophylaxis:

A dose of 1.5 g of cefuroxime intravenously was administered 30 minutes prior to skin incision. A second dose was indicated only for procedures lasting more than 3 hours. Doses of 750 mg of cefuroxime intravenously were given every 8 hours until 24 hours following surgery.

Wound Care:

Sterile, dry gauze pads were used to cover surgical incisions for 24 hours. Hand washing was performed and sterile gloves were applied prior to changing dressings and caring for wounds.

Education:

All operating room staff, including cardiology, nursing, and anesthesia personnel was educated regarding the importance and magnitude of surgical asepsis and recommended aseptic techniques.

Surveillance:

Active surveillance was performed for all surgical procedures throughout the intervention period both among inpatients and among patients who had been discharged for 28 days post-procedure. Thereafter, patients were observed as outpatients by a cardiologist.

Summary of current controversies.

Reuse of single use electrophysiology and cardiac catheterizations is common practice in limited resource countries. Reprocessing of single use devices could have significant economic savings making life saving procedures possible that otherwise would not be available. The practice of reprocessing single use devices is controversial in the United States. Both ethical and economic issues need to be taken into consideration along with the risk of re-using a single use device before instituting this practice. At present no standardized quality controls exist to guide reprocessing.

Overview of important clinical trials, meta-analyses, case control studies, case series, and individual case reports related to infection control and cardiac catheterization lab/EP lab.

See Table I for the clinical trials, meta-analyses, case control studies, case series, and individual case reports related in cardiac catheterization lab/EP lab and infection control.