The Efficacy of an Enteral Access Protocol for Feeding Trauma Patients
* Clinical Nutrition/Pharmacy and the Trauma
Program and Correspondence: J. Wooley, MS, RD, CNSD, St. Joseph Mercy Hospital, Clinical Nutrition/Pharmacy, 5301 East Huron River Dr, PO Box 995, Ann Arbor, MI 48106. Electronic mail may be sent to wooleyj{at}trinity-health.org. Background: Proper enteral access to deliver specialized nutrition support in critically injured patients can be difficult, time consuming, and costly. We designed a protocol with interdisciplinary input to facilitate early enteral access in our trauma patients. Our primary objective was to determine if the protocol improved our ability to obtain small-bowel access in patients within 48 hours of their admission to the surgical intensive care unit (SICU). Secondary objectives were to examine the efficacy of the protocol by evaluating parenteral nutrition (PN) use, adequacy of enteral caloric delivery, and clinical outcomes including pneumonia and sepsis rates, SICU length of stay (LOS), hospital LOS, and mortality before and after its implementation. Methods: The medical records of 51 trauma patients admitted to the SICU, who met inclusion criteria, were reviewed retrospectively and divided into 2 groups. Patients in group 1 were admitted before protocol implementation (1997–1998, n = 17). Patients in group 2 were admitted after protocol implementation (1998–2000, n = 34). Results: Small-bowel access was achieved earlier in group 2 compared with group 1 [2.2 ± 2 days vs 5.4 ± 8 days, respectively (p = .04)]. PN was used less frequently in group 2 at 41.2% (14/34) as opposed to 64.7% (11/17) in group 1 (p = .05). There was a reduction in the number of days to reach caloric goal from 4.9 days in group 1 to 3.9 days in group 2 (n.s.). Clinical outcomes were similar in both groups. Conclusions: The use of a protocol was effective in the achievement of prompt small bowel access. The number of days to reach caloric goal decreased after protocol implementation, but not to a statistically significant degree. However, we were able to detect a significant reduction in the use of PN. Nutrition support is an important component of the routine care provided to critically ill trauma patients. A strong body of evidence has shown that enteral nutrition is superior to parenteral nutrition (PN) because it is associated with fewer infectious complications and better clinical outcomes.1–5 The data are so compelling that the American Society for Parenteral and Enteral Nutrition and the Eastern Association for the Surgery of Trauma Practice Management Workgroup have published guidelines regarding the role of nutrition support in trauma, concluding that those with blunt and penetrating abdominal injuries sustain fewer septic complications when fed enterally as opposed to the parenteral route.6,7 Early introduction of enteral nutrition, within 48 hours of admission, appears to benefit patients by preserving the gut barrier and blunting the catabolic response to injury.8–10 A meta-analysis by Marik and Zaloga11 concluded that patients receiving early enteral nutrition support experienced fewer infectious complications and had shorter lengths of stay compared with those fed later. However, poor tolerance of gastric feedings secondary to stress-induced gastric atony can delay the achievement of caloric goal.12 Consequently, intolerance of gastric feedings can result in the overuse of PN, which undermines the proposed benefits of enteral nutrition.13 Recent studies have shown that it is possible to take advantage of ongoing small bowel activity in the presence of stress-induced gastroparesis by feeding postpylorically into the small intestine.13,14 The successful placement of a nasoenteric tube at the bedside into the small bowel can be difficult, time consuming, and costly. We recognized the need for a simple approach to the achievement of small-bowel access in a timely fashion with minimal risk and expense to the patient. We developed an early enteral access protocol to standardize our approach to proper feeding tube placement in the care of severely injured trauma patients. Our primary objective was to determine if the protocol improved our ability to obtain small-bowel access in patients within 48 hours of their admission to the surgical intensive care unit (SICU). Secondary objectives were to examine the efficacy of the protocol by evaluating PN use, adequacy of caloric delivery, and clinical outcomes before and after its implementation.
St. Joseph Mercy Hospital is a 500-bed teaching hospital in Ann Arbor, Michigan, that meets the criteria of the American College of Surgeons for a Level II trauma center. We queried hospital's trauma registry to identify severely injured adult trauma patients consecutively admitted to the trauma service between the time periods of January 1997 and December 2000 who met the following inclusion criteria: Injury Severity Score (ISS)  20, adult
(18 years of age), and admitted to the SICU with an acuity level
warranting nutrition intervention. Exclusion criteria included patients <18
years of age and those with an ISS <20. Upon approval from St. Joseph Mercy Hospital institutional review board, a retrospective analysis was conducted comparing patients in group 1 who were admitted before protocol implementation (1997–1998, n = 17) with patients in group 2 who were admitted after protocol implementation (1998–2000, n = 34). Data were retrieved from the medical record on the following patient demographics: age, sex, mechanism of injury, and ISS. The nutrition outcomes that were studied included number of days to small-bowel access, number of days to caloric goal, and use of PN. Clinical outcomes included pneumonia and sepsis rates, SICU length of stay (LOS), hospital LOS, and mortality.
Sample size determination was performed with n-Query Advisor (Saugas, MA).
A 2-group An early enteral access protocol (Fig. 1) was designed with interdisciplinary input to expedite early small-bowel access through the cooperation of surgeon, nurse at the bedside, interventional radiologist, and registered dietitian. According to the protocol, critically ill trauma patients requiring exploratory laparotomy were evaluated for intraoperative feeding tube placement. If intraoperative enteral access was not feasible, the first line of intervention began at the bedside where the SICU nurse placed a nasoenteric tube (43-inch, 10-French, weighted tip) within 48 hours of admission. The SICU nurses were required to complete a competency program before being qualified to place feeding tubes.15 The method of estimating placement used by the nursing staff was the air bolus method (Table 1), also described by Salasidis et al.16 Proper final placement of the feeding tube was confirmed by abdominal x-ray.
If small-bowel access was not initially achieved, the nurse attempted repositioning the tube into the small bowel at the bedside for a total of 2 bedside attempts. If this was unsuccessful and the patient was stable enough for transport to the radiology department, an interventional radiologist repositioned the tube into the small intestine under fluoroscopy. Prokinetic agents could be administered on an individualized basis at the discretion of the physician. The Trauma Service selected an enteral formula and entered the tube-feeding order, including a progression to caloric goal according to the registered dietitian's nutrition assessment, into a computerized ordering system. If enteral nutrition was anticipated to be necessary for >4 weeks, a percutaneous gastrojejunostomy feeding tube was a consideration.
We identified 51 severely injured adult trauma patients who met inclusion criteria. Group 1 represents those managed before (n = 17), whereas group 2 represents those managed after (n = 34), protocol implementation. Both groups were well matched regarding age, gender, ISS, and mechanism of injury (Table 2).
The average number of days to achieve small-bowel enteral access after admission to the SICU was 2.24 ± 2 days in group 2 compared with 5.4 ± 8 days in group 1 (p = .04). Small-bowel cannulation within 2 attempts at the bedside was achieved more often in group 2 (53%, 18/34) compared with group 1 (35%, 6/17). Furthermore, the number of trips to fluoroscopy to reposition gastric feeding tubes into the small bowel decreased from 29% in group 1 to 18% in group 2 after protocol implementation. PN use was decreased from 64.7% (11/17) in group 1 to 41.2% (14/34) in group 2 (p = .05) (Table 3). Presence of abdominal or pelvic injuries decreased the number of days to small-bowel access (p = .005), presumably secondary to intraoperative jejunostomy tube placement. Although the number of days to reach caloric goal was lower in group 2 compared with group 1 (3.9 ± 3.8 vs 4.9 ± 2.9 days), this did not reach statistical significance (p = .18) (Table 3). Long-term enteral access was pursued if patients were predicted to require enteral nutrition support for at least 4 weeks. Sixty-six percent (34/51) of patients required long-term enteral access. No direct correlation was observed between early enteral nutrition and the clinical outcomes of pneumonia, sepsis, SICU LOS, hospital LOS, or mortality (Table 4).
Enteral nutrition is preferred over PN in critically ill trauma patients requiring specialized nutrition support. Numerous prospective randomized trials have shown the beneficial effects of small-bowel vs gastric access on clinical outcomes in this population13,17–20; therefore, we chose to focus our attention on the translation of this evidence into clinical practice. The development of an early enteral access protocol with interdisciplinary input served as the catalyst to improve the nutrition support of our trauma patients. We significantly reduced the number of days to achieve small-bowel enteral access and decreased PN use after protocol implementation. The prevention of PN overuse has cost-saving implications as the cost of PN is approximately 4 times the cost of enteral therapy.13,21 Evidence is becoming incontrovertible that early use of the gut for nutrition support is beneficial, but the answer to the question, "How early is early?" remains elusive.10 If provided within 48 hours of critical injury or illness, enteral nutrition may have a significant effect on patient outcome by curtailing the hypermetabolism associated with stress.22,23 According to this evidence, we designed our protocol to facilitate proper enteral access within 48 hours of admission, and our data suggest that the protocol was successful in the achievement of this objective. The practice of allowing up to 48 hours to obtain enteral access facilitates early intervention while promoting resuscitation and restoration of hemodynamic stability before feeding initiation. Although uncommon, enteral feeding-associated bowel necrosis in hemodynamically underresuscitated patients can be lethal.24 unstable, For this reason, critically ill patients undergoing enteral feeding should be monitored for signs of gut failure such as nausea, vomiting, abdominal pain, distention, high gastric output, and ileus.24,25 firmness, The presence of any of these signs or symptoms warrants temporary interruption of enteral nutrition until the cause can be determined and corrected. There is great debate in the critical care literature as to whether small-bowel access is protective against pulmonary aspiration compared with gastric access. Although a number of studies have shown that gastric access increases gastroesophageal regurgitation and microaspiration in critically ill patients compared with small-bowel feedings,26–28 others have reported that postpyloric enteral access may not always translate into the prevention of ventilator-associated pneumonia.29 However, the trauma literature has emphasized that the target should be the small bowel for feeding critically injured patients in order to minimize aspiration risk.30 We consider any protection small-bowel access may offer our patients against aspiration risk an additional benefit of our protocol, but this specific parameter was not evaluated in our study. Small-bowel access can improve the nutrition status of critically ill trauma patients by decreasing the time required to achieve caloric goal.20,29,30 Our protocol was designed to facilitate the achievement of caloric goal within 72 hours of feeding initiation. We were able to reduce the number of days to caloric goal after protocol implementation but not to a statistically significant degree. Studies have looked at what percentage of feeding prescription patients actually receive and found that a critical threshold to maintain gut integrity may be as high as 50%– 60% of caloric goal.22 Our goal was to feed patients at 100% of their caloric goal, but the assessment of day-to-day enteral feeding tolerance was not included in our data collection, so it is impossible to determine if this critical threshold was maintained throughout each patient's clinical course. Injury severity can influence tolerance of nutrition despite route and location within the gastrointestinal tract and must be taken into consideration when interpreting outcomes.31 The high acuity level of our patients, as evidenced by their mean ISS levels (Table 2), may have been a factor in the longer-than-expected time to reach caloric goal with enteral nutrition and may also explain the fact that our use of PN remained relatively high (41%) despite improvements in the attainment of proper enteral access after protocol implementation. Nevertheless, whereas many clinical interventions become less effective in high-acuity populations, research has shown that the most acute and severely injured patients benefit the most from early enteral nutrition intervention.3 A variety of strategies for achieving small-bowel access exist. These include the use of protocols, various bedside placement techniques, weighted vs unweighted nasoenteric tubes, prokinetic agents, magnets, or pH sensor tubes. Many institutions have used a dedicated service specializing in the placement of feeding tubes, or used a radiologist with fluoroscopic skills or gastroenterologist with endoscopic skills to improve enteral access.14,16,32–39 With a protocol in place, our findings suggest that a dedicated member or specialized service is not necessary to achieve proper enteral access as long as all members of the healthcare team remain vigilant to the nutrition needs of patients. We significantly increased the number of patients fed into the small bowel without the need to increase staffing or routinely administer prokinetic agents. This was accomplished through the empowerment of SICU staff nurses with education and training to place nasoenteric tubes at the bedside using the air bolus method, followed by abdominal x-ray verification of placement.20,40 At the time of this study, we were using a weighted tube. Since the completion of this research, we have switched to an unweighted tube according to evidence that unweighted tubes pass through the pylorus more efficiently at the bedside.31 Successful bedside placement of nasoenteric tubes into the small bowel can minimize the need for fluoroscopic placement, which is invasive, expensive, and typically requires patient transport, unless a portable C-arm to perform this function at the bedside is available. Another reason to minimize transporting a critically ill patient, besides risk to the patient, is that it puts a burden on nursing and respiratory staff.40–43 Despite a substantial body of clinical evidence documenting a decrease in infectious complications, LOS, and mortality related to early enteral nutrition in critically injured trauma patients,1–5 we were not able to detect significant improvements in any of these endpoints (Table 4). This may be partly due to the limitations of this study in terms of its retrospective design, small sample size, and lack of power to detect differences in these outcomes. In conclusion, we have provided evidence that the use of a protocol focused on proper placement of enteral access is effective in a critical care unit when a specialized tube insertion team was not feasible. We achieved our goal of prompt small-bowel enteral access after admission to the SICU and we significantly reduced the use of PN after protocol implementation. This research was funded through a grant from the St. Joseph Mercy Hospital Research Advisory Committee. We are indebted to all of the nurses who work in the SICU at St. Joseph Mercy Hospital for their commitment and dedication to placing nasoenteric tubes at the bedside.
Nutrition in Clinical Practice, Vol. 20, No. 3,
348-353 (2005)
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Materials and Methods
Results
.05. 