Is this A-line infected? We spend a lot of time worrying about central lines and wonder often, is this line the cause of something bad? Should we worry about the a-line too? Increasingly, the wide-spread belief that arterial lines don't cause infection is being questioned. Despite lore to the contrary, multiple well conducted randomized clinical controlled trials and one large review have shown the arterial lines are just as likely as central lines be colonized and cause CR-BSI. The misconception likely comes from huge, retrospective papers assessing the safety of arterial lines that report very low rates of line-associated sepsis, even though those studies were not designed to look at CR-BSI. Finally, remember the large biopatch trial that caused biopatches to suddenly appear overnight in hospitals around the country looked at both arterial and venous lines, finding a clear benefit for placing them on both.
Although it defies common practice at UVa, I believe a preponderance of evidence argues for using a more careful sterile technique and biopatches for lines that could possibly be in place for more than 48 hours. I challenge the defenders of the lazy, dirty technique to find meaningful evidence that a careful sterile technique is not justified.
Lucet JC, Timsit JF Infectious risk associated with arterial catheters compared with central venous catheters Crit Care Med. 2010 Apr;38(4):1030-5.
Timsit, JF. Chlorhexidine-Impregnated Sponges and Less Frequent Dressing Changes for Prevention of Catheter-Related Infections in Critically Ill Adults: A Randomized Controlled Trial. JAMA. 2009;301(12):1231-1241.
Traore O, Liotier J, Souweine B: Prospective study of arterial and central venous catheter colonization and of arterial- and central venous catheter-related bacteremia in intensive care units. Crit Care Med 33. 1276-1280.2005;
Koh DB, Gowardman JR, Rickard CM, et al: Prospective study of peripheral arterial catheter infection and comparison with concurrently sited central venous catheters. Crit Care Med 36. 397-402.2008;
Khalifa R, Dahyot-Fizelier C, Laksiri L, et al: Indwelling time and risk of colonization of peripheral arterial catheters in critically ill patients. Intensive Care Med 34. 1820-1826.2008;
Maki DG, Kluger DM, Crnich CJ: The risk of bloodstream infection in adults with different intravascular devices: A systematic review of 200 published prospective studies. Mayo Clin Proc 81. 1159-1171.2006;
BIS Monitors. The BiSpectral Index was developed in the early 1990's as a measure of consciousness. The machine monitors EEG information and processes it using a propriety algorithm into a single number, 0 - 100. One hundred implies full consciousness, where 0 represents no EEG activity ('burst suppression'). General anesthesia is 40-60. Conscious sedation is 65-80. I don't know what 61-64 is. Someplace magical, I suppose. Originally validated for patients undergoing OR anesthesia with propofol, its use has expanded to anesthetics with other agents and monitoring sedation in the ICU. Numbers below 60 are associated with a very low risk of recall and are the usual OR target. For the ICU, I think below 70 is an appropriate target.
How well does it work? The original, industry funded trial done in over 2400 patients in Australia in patients under general anesthesia with volatile anesthetics, found that the BIS could reduce awareness by 80%, with a estimated cost of $2200 to prevent one case of awareness. Four years later, a similar trial done with private funding here in the US found no benefit to using the BIS. Nevertheless, it still is commonly used and likely has an evolving role in monitoring sedatives and anesthetics.
For ICU monitoring, many small trials have been done which show mixed results. Overall, commonly used sedation scales (such as RASS) appear to be better when they can be used. For paralyzed patients, BIS is often the only practical monitor available and is therefore recommend by many authors, despite the mixed results. It appears that in paralyzed patients use of the BIS can limit drug accumulation and may reduce ICU length of stay. Several recent software updates have been made, reportedly to address ICU concerns.
Avidan MS. Anesthesia awareness and the bispectral index. N Engl J Med. 2008 Mar 13;358(11):1097-108.
Myles PS. Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. Lancet. 2004 May 29;363(9423):1757-63.
S.A. Nasraway, The bispectral index: expanded performance for everyday use in the intensive care unit?, Critical Care Medicine 33 (2005), pp. 685–687.
Alvimopan. Postoperative ileus (POI) after abdominal surgery (e.g. bowel resection) causes significant patient discomfort, morbidity, and prolongs length of stay in the hospital. One contributing factor to POI is the use of narcotics for post-operative pain. Opiods bind to mu-receptors in the GI tract and may exacerbate POI. Alvimopan (Entereg, Adolor) is a oral, peripherally acting mu-receptor antagonist approved for accelerating GI recovery after abdominal surgery. It was approved in May 2008.
To date, four randomized, double-blind, placebo-controlled, parallel-group, phase 3 trials conducted in the U.S. and Canada and a single phase 3 trial conducted in Europe have shown some benefit to the use of Alvimopan post-operatively. Delaney et. al, 2005, found that in patients undergoing total abdominal hysterectomy and partial colectomy with primary anastomosis time to stool or tolerance of solid foods was reduced. Wolff et. al,2004, in a similar study population, found similar results with mean time difference to be 15-22 hours. Most trials as of now have differing results regarding whether or not patient length of stay in the hospital is changed or if there is benefit to patient outcomes beyond time to GI recovery.
Delaney et. al. 2005. "Phase III Trial of Alvimopan, a Novel, Peripherally Acting, Mu Opioid Antagonist, for Postoperative Ileus After Major Abdominal Surgery."Diseases of the Colon and Rectum. 1114-1130.
Wolff, et. al. 2004. "Results of a Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase III Trial of Major Abdominal Surgery and Postoperative Ileus." Ann Surg. 240:728-735
Need more Rounds Reports? Back issues here.