Prevention of Hospital-Acquired Infections

Prevention of Surgical Site Infections

When we examine the prevention of SSI, we again see that a bundle approach is necessary and that many single interventions, although demonstrated effective in prospective trials, do not achieve the benefits we are seeking. Indeed, it has become popular lately to write articles claiming that the elements of the Centers for Medicare Services (CMS)'s Surgical Care Improvement Project (SCIP) are not effective, because when SCIP compliance increased, SSI rates did not decrease in tandem [5,6]. What is not always appreciated is that no single element of the multi-process preventive measures is enough, and no single bundle is the final word [7].

Prevention of SSI should start with the initial visit between the surgeon and the patient. One idea is to take the concept of the surgical safety checklist, which has improved safety in the operating room (OR), and bring the completed checklist to the surgeon's office [8]. Such a checklist, including inquiries regarding medication use, diabetes risk, nutrition, and smoking, is featured on the Web site Strong for Surgery [8]. As part of the thorough history, the surgeon should gather information regarding nutritional status, including unintended weight loss, and consider obtaining a serum albumin measurement for patients having major elective operations. Recent weight loss and low albumin are both associated with a greater risk of complications, including SSI [9,10]. If the operation is not urgent, nutritional referral and improvement can reduce SSI risk. Smoking increases the risk of various complications, and patients having non-urgent operations should be encouraged to quit beforehand [11].

Warming patients before entry into the OR [12] and aggressive warming in the OR [13] both reduce infection risk. Much has been written about skin preparation in the OR, but a consensus is lacking regarding the superiority of one preparation solution over another [14–16]. Appropriate use of parenteral antibiotic prophylaxis, with a choice of effective agent(s), weight-based dosing during the hour before the incision, and repeat dosing during long cases, is well established; and a recent comprehensive guideline reflecting the agreement of the American Society of Hospital Pharmacists, the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, and the Surgical Infection Society is available as a reference for all of the details on this topic [17].

A topic that been subject to a considerable amount of misunderstanding in recent years is the role of oral antibiotics the day before the operation for patients having colorectal operations. Although data from Europe, where oral antibiotics often are not used, show that a mechanical bowel preparation has no benefit for patients who have not received oral antibiotics, a growing body of literature demonstrates a reduction of colorectal SSI rates in the neighborhood of 50% when both oral antibiotics and appropriate parenteral prophylactic antibiotics are given to these patients compared with the use of either route alone [18–23].

All surgeons understand that diabetic patients have a greater risk of SSI, and most realize that adequate control of the peri-operative blood glucose concentration can reduce this risk. Because SCIP requires prevention of hyperglycemia only for cardiac patients, some surgeons have been under the mistaken notion that this concern is important only for cardiac surgery patients. However, multiple convincing papers demonstrate that peri-operative hyperglycemia increases the risk of all complications, including SSI, and that this influence appears to extend for as long as two days after the operation for cardiac, general, colorectal, breast, vascular, hepatic, orthopedic, and trauma surgery. What also is not always appreciated is that the risk of hyperglycemia and the accompanying increase in SSI risk is not limited to diabetic patients. Several references demonstrate that a significant number of patients with peri-operative hyperglycemia are not diabetic and that these patients also are at greater risk of SSI [24–26]. In fact, some recent evidence shows that nondiabetics who experience peri-operative hyperglycemia are less likely to be treated and actually have a greater risk of surgery-related infections than do diabetics with the same degree of hyperglycemia [27]. Finally, the use of a checklist and the teamwork and communication that must go along with it to reduce complications also reduces SSI [28–32].

Prevention of VAP

Prevention of VAP is difficult because only high-risk patients are maintained on a ventilator in the intensive care unit (ICU), and the need for the ventilator and the endotracheal tube (ETT) is the greatest single risk factor in these fragile patients. Nevertheless, for patients on the borderline of needing ventilation, noninvasive ventilator support can save some of these patients from intubation. When intubation is necessary, daily sedation vacations and institution of trials of spontaneous breathing can minimize the time on the ventilator and lower the risk of VAP. In addition to these items, standardized practices for maintenance of respiratory equipment, antiseptic oral care, elevation of the head of the bed, subglottic suctioning, adherence to hand hygiene standards, and use of a checklist to confirm that all bundle items are being followed are all beneficial [33–36].

Prevention of Urinary Infections

Although CAUTI cost much less than most other HAIs, they still are associated with additional morbidity and deaths and an increase in the use of antimicrobial agents, which expose the patient to the risk of resistant infections and C. difficile colitis, as well as stressing the hospital environment. The single best preventive for CAUTI is to avoid urinary catheter insertion when possible and to get any catheter out as soon as possible. An important informational note for surgeons is that most patients with a post-operative thoracic epidural catheter can void without a urinary catheter unless there is some other factor preventing spontaneous voiding [37,38]. When a catheter does need to be inserted, proper preparation and insertion techniques combined with a closed system are of course necessary. If a catheter is inserted in the OR, there should be a discussion in the debriefing section of the checklist regarding whether the catheter needs to remain in place after the operation is over, and, if so, when it can be expected to be removed. Helpful practices include prominent documentation of time of placement of a catheter and its reason for being in place, along with a checklist that encourages a daily inquiry into the necessity for a urinary catheter [39]. Some medical institutions place prominent posters with the query “W.T.F?” (“Where's the Foley?”) to call attention to this issue.

Prevention of C. difficile Infections

Prevention of C. difficile infections is an issue assuming more and more importance with the recent reports of greater lethality of some of the common strains now infecting our patients [40,41] and data showing that in some locations, HAI caused by C. difficile is more common than HAI caused by methicillin-resistant Staphylococcus aureus [42]. Probably one of the most effective preventive measures we can provide to our surgical patients is to reduce the amount of antibiotics we give [43]. All available data show that prophylactic antibiotics given after a surgical incision is closed do not improve the prevention of SSI [44], yet many surgeons continue antibiotics in the post-operative period. Most SSIs can be treated with opening of the surgical incision without giving systemic antibiotics [45], yet many patients receive these antibiotics. Most fevers in the first four post-operative days are not the signal of any infectious complication [46,47], but many of these patients nevertheless are given antibiotics. The paper by Magill et al. cited at the beginning of this paper showed that 50% of all hospitalized patients are receiving an antibiotic although only 4% of them have an HAI [2]. In that paper, 71% of all GI-related HAIs were caused by C. difficile.

When C. difficile is present in the hospital, the most important way to prevent its transmission among patients is good contact precautions; hand washing with soap and water rather than alcohol-based agents, which do not kill C. difficile spores; and special cleaning for hospital rooms and equipment after discharge of a patient with C. difficile infection [48]. For a patient who has more than one recurrence of the infection after appropriate treatment with metronidazole, vancomycin, or both, consideration should be given to an infectious disease consult on the desirability of fecal transplantation [49,50].

Can We Achiever Zero HAIs?

So with all of these HAIs and the multiple strategies we have to reduce their risk, can we achieve zero HAIs? Should zero HAIs be our target? Although it is not reasonable to state any figure above zero HAI that would make us completely happy, it is important to realize that the only foolproof way to ensure zero HAIs is not to admit any patients to a hospital. Having eliminated this tactic, what would be a practical target? I propose that we work toward zero “potentially preventable” HAIs. What we all need to do is to define the preventive measures for each HAI that we believe are achievable and agreed on by the medical and nursing and other ancillary staff in the hospital. These protocols should be widely distributed and supported by administration and executive leadership. All medical staff should hold one another accountable for following the policies and using the bundles.

When surveillance detects any HAI, there should be an investigation. If every agreed on measure for prevention was followed, this is an “apparently unpreventable” infection, but if any elements were omitted or missed, it is a potentially preventable infection. This concept was promoted by James Lee, a pioneering surgeon with a mission for infection control in an article published in 1992 regarding the prevention of SSI [51]. At first, in any such effort, the rate of potentially preventable infections will be measurable and greater than anyone wants, but if this is followed up in a systematic manner and the defects are found and corrected, the rate of potentially preventable infections will drop. When it gets low enough, that is the time to add another element to the prevention bundle and widen the definition of “potentially preventable.” The rate of potentially preventable infections will increase, but the rate of overall infections will fall. Using this approach for SSI in my own institution, beginning more than ten years ago, we began with the simple definition of giving the right antibiotic at the right time before an operation and avoiding shaving of the operative site. When we had gotten our rate of potentially preventable SSIs down, we increased the definition, adding redosing of the prophylactic antibiotic for long cases. When we had conquered that metric, we added the rule that the patient had to reach the recovery room with a temperature above 36°C. Our most recent effort is to ensure good intra-operative glucose control for all of our patients, both diabetic and nondiabetic. Using this approach, we moved our clean-incision SSI rate from 0.83 at the beginning of this journey to 0.24 after years of work [52]. We hope to continue strengthening our definition and lowering our rate further. Subsequent efforts may involve nutritional intervention, cessation of smoking, and control of intra-operative FiO₂, but these are decided by our multidisciplinary Surgical Infection Prevention Subcommittee of the hospital Infection Prevention Committee and involve everyone associated with the care of the surgical patient.