Postdischarge Test Results, Acute Renal Failure, Diagnosing PE

The Hospitalist. 2005 November;2005(11):

November 1, 2005 | The Hospitalist

Methods: One academic medical center prospectively studied the rate of catheter-related bloodstream infection in PICC lines used exclusively in hospitalized patients as part of two trials assessing efficacy of different skin antiseptics. PICC-related bloodstream infection was confirmed when organisms isolated from positive blood cultures matched (by DNA subtyping) organisms isolated from culturing the PICC line at the time of removal. The authors also performed a systematic review of the literature to provide overall estimates of PICC-related bloodstream infection in hospitalized patients.

Acute renal failure in the ICU setting is relatively uncommon, is most often caused by septic shock, and typically does require renal replacement therapy.

Results: A total of 115 patients received 251 PICC lines during the study period and the mean duration of catheterization was 11.3 days. More than 40% of the patients were in the intensive care unit (ICU) and most had risk factors for the development of bloodstream infection, including urinary catheterization, mechanical ventilation, prior antibiotic use, and low albumin. Six cases (2.4%) of PICC-related bloodstream infection were confirmed, four with coagulase-negative staphylococcus, one with S. aureus, and one with Klebsiella pneumoniae, a rate of 2.1 per 1,000 catheter-days. In their systematic review, the authors identified 14 studies evaluating the rate of PICC-related bloodstream infection in hospitalized patients; the pooled rate was 1.9 per 1,000 catheter-days.

Discussion: In a small but methodologically sound prospective study and systematic review, Safdar and Maki found a surprisingly high rate of PICC-related bloodstream infection in hospitalized patients. Their calculated rate of 2.1 cases per 1,000 catheter-days is five times the rate seen in PICCs used exclusively in outpatients (0.4 per 1,000 catheter-days). More strikingly, 2.1 cases per 1,000 catheter-days is similar to the rate of catheter-related bloodstream infection in conventional central venous catheters placed in the subclavian or internal jugular veins (two to five per 1,000 catheter-days). Unfortunately, the study didn’t assess the rate of mechanical complications associated with PICC lines or correlate the risk of infection with duration of catheterization.

In the Literature Take-Home Points

In patients with low or moderate pre-test probability for pulmonary embolism, CT angiography must be combined with lower extremity dopplers to adequately exclude PE.
PICC lines in hospitalized patients have the same infection risk as subclavian or internal jugular central lines.
The development of acute renal failure in the intensive care unit carries a high mortality but those that survive to discharge are unlikely to require long-term hemodialysis.
Up to half of discharged patients have test results pending and as much as 10% of these require immediate action.
Mandatory infectious disease consultation for all patients scheduled to receive outpatient parenteral intravenous antibiotics may reduce costs without affecting outcomes.

Hospitalists should be aware that PICC lines likely have the same infection risk as subclavian and internal jugular lines in hospitalized patients and a much higher rate of infection than PICC lines in outpatients. The higher-than-expected rates are likely related to the increased prevalence of risk factors for bloodstream infection in hospitalized patients. Thus, the decision to use PICC lines in hospitalized patients should be made based on factors other than presumed lower infection risk.

Uchino S, Kellum JA, Bellomo R, et al. Acute renal failure in critically ill patients. A multinational, multicenter study. JAMA. 2005;294:813.

Background: Acute renal failure in critically ill patients is believed common and is associated with a high mortality. The exact prevalence and the calculated risk of death have not been clearly defined across populations.

Methods: A multinational group of investigators conducted a massive prospective observational study of ICU patients who developed renal failure after ICU admission. The study encompassed 54 hospitals in 23 countries with a total of 29,269 admissions over the 14-month study period. Note, acute renal failure was defined as either oliguria (urine output <200cc/12 hours) or BUN >84mg/dL.