Risk Factors Identified for Post-Surgery Patients with Clostridium Difficile Colitis

Patawut Bovonratwet, BS, Department of Orthopaedics and Rehabilitation, Yale School of Medicine

Patawut Bovonratwet, BS

A study from researchers at the Yale School of Medicine and Rush University Medical Center in Chicago, utilized data for 39,617 patients who underwent primary Total Hip Arthroplasty (THA) or Total Knee Arthroplasty (TKA) and determined several factors that put THA and TKA patients at risk for development of Clostridium difficile associated with Clostridium difficile infection (CDI) post-surgery.

Among these risks are age, dependent functional status, anemia, hypertension, and postoperative risk factors such as UTI and sepsis. Researchers also found that THA versus TKA was associated with higher risk factors of CDI for patients.

Using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database for 2015, lead author Patawut Bovonratwet, BS, Department of Orthopaedics and Rehabilitation, Yale School of Medicine, and colleagues performed a retrospective cohort study to collect post-discharge and patient population data for patients who underwent primary THA or TKA in order to determine the incidence, timing, risk factors and clinical implications of CDI in THA and TKA patients.

Patient demographics data collected on the study's 39,617 patients included age, gender, height, weight, body mass index, American Society of Anesthesiologists classifications for patient health and length of hospital stay. Pre-surgical data on lifestyle factors such as smoking, comorbidities and medications, as well as patient pre-operative laboratory values including hematocrit levels and serum albumin levels were also collected.

Bovonratwet and colleagues followed patients in the 2015 NSQIP for the progress of C. difficile colitis and other infections like urinary tract infection [UTI], pneumonia, wound infection, and sepsis through postoperative day 30, regardless of discharge status.

Bovonratwet and colleagues report a total of 38 patients developed C. difficile colitis yielding an incidence of 0.10% (95% CI 0.07- 0.13). Of these 38 patients developing CDI, 21% were diagnosed prior to hospital discharge, while 79% occurred post-discharge, and only 6 (16%) patients diagnosed with CDI had a prior infection.

Using a multivariate analysis the researchers assessed the risk factors for postoperative CDI and determined the greatest risk factor was age (>80 years) with a relative risk [RR] of 5.28. Other risk factors included dependent functional status, or "frailty," (RR 5.28), anemia (RR 2.52) and hypertension (RR 2.51).

The data showed that those patients receiving THA versus TKA were at a higher relative risk factor (RR 2.25). Postoperative relative risk factors were higher for patients with UTI (RR 10.66), sepsis (RR 17.80) and any infection (RR 6.60), but Bovonratwet notes "development of C. difficile colitis was not associated with postoperative pneumonia or wound infection." Risk was also higher for those patients with longer hospital stays. Patients hospitalized for 6.6 versus 2.6 days saw a RR of 2.65-5.63 (95% CI, P < .001).

Bovonratwet and colleagues state that the rate of CDI colitis "in orthopedic surgery depends considerably on the type of procedure and subspecialty" but that the overall risk of 0.10% with THA and TKA are relatively low in comparison to risk rates of other surgical procedures.

Their findings, according to the study, are in line with previous studies in different patient populations, and they hope the data on increased risk factors will reinforce the need for special considerations for those patients at heightened risk for CDI development.

Bovonratwet and colleagues state that easy steps to take to reduce risk for those most at-risk patients include preventing placement of those high-risk patients in the same rooms as CDI positive patients, practicing diligent hygiene when working with high-risk patients, and to selecting appropriate antibiotics with lower risk of CDI infection for high-risk patients.

"Incidence, Risk Factors, and Impact of Clostridium difficile Colitis Following Primary Total Hip and Knee Arthroplasty" appears in the January 2018 issue of Journal of Arthoplasty.