Introduction
Nutrition support is an essential component in the recovery of rehabilitation patients. If a patient is unable to eat orally and the gut is functional, the use of enteral nutrition (EN) support is preferred (Nelms & Sucher, 2015). The gastrointestinal tract runs from the mouth to the anus and is responsible for the breakdown and absorption of food. In a healthy individual, digestion of food begins in the mouth and continues into the intestines. In the case of a tube-fed patient, the digestive process starts in the stomach or the jejunum, depending on where the tube is placed. For these patients, postpyloric feeding is sometimes preferred due to delayed stomach emptying or gastric outlet obstruction (Nelms & Sucher, 2015). Nasointestinal feeds also minimize the possibility of aspiration (Doley & Phillips, 2017).
Recent research has shown that most critical care patients do not usually receive their calculated nutrition requirements and may suffer from malnutrition and/or underfeeding during their hospitalization (Binnekade, Tepaske, Bruynzeel, Mathus-Vliegen, & de Hann, 2005; Friesecke, Schwabe, Stecher, & Abel, 2014; Haskins et al., 2017; Stewart, 2014a; Wilson et al., 2016). Underfeeding may result in longer hospital stays, more complications, and greater mortality (James et al., 2005). In 2016, the American Society for Parenteral and Enteral Nutrition (ASPEN) and the Society of Critical Care Medicine offered "Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient" (McClave et al., 2015). These guidelines recommend that EN be initiated within 24-48 hours if a patient is unable "to maintain volitional intake" (McClave et al., 2015, p. 105). According to the ASPEN Adult Nutrition Support Core Curriculum, EN is indicated for patients with impaired swallowing ability, including those who have experienced strokes and other neurological disorders (Doley & Phillips, 2017). These types of conditions are commonly seen in rehabilitation patients.
According to the chapter "Neurologic Impairment" in the ASPEN Adult Nutrition Support Curriculum, nutrition support therapies provided during the acute rehabilitation phase of injury are "equally important" as the initial therapies provided in the intensive care unit (Woodward, Ruf, & Kolpek, 2017, p. 437). In fact, many rehabilitation patients were formerly critical care patients, and as such, these patients may experience eating limitations due to "dysphagia, cognitive impairment, limited mobility and movement" (James et al., 2005, p. S82). EN provides rehabilitation patients with adequate nutrition and the energy necessary to undertake intensive therapy sessions required for recovery (James et al., 2005). Therefore, if a rehabilitation patient is unable to eat orally, EN should be initiated to prevent nutritional decline.
Enteral nutrition may be administered by a continuous, intermittent, or bolus method. The feeding modality may change as the patient transitions across the continuum of care (Doley & Phillips, 2017). Patients on EN are usually fed using an hourly rate calculated to meet their total daily caloric needs. These needs are based on body weight and height, food/nutrient intake, health history and clinical diagnoses, dietary history and preferences, and presence or absence of muscle wasting and body fat stores (Lehman, 2015). Most patients receive only about 60% of their energy and protein needs due to both scheduled and unscheduled interruptions (Stewart, 2014a). EN may be disrupted for a variety of reasons, including procedures, positioning, technical issues with feeding accesses, and/or gastric intolerance (Stewart, 2014a).
To increase the likelihood of reaching calculated caloric intake for critical care patients, volume-based tube feeding (VBTF) has been proposed. With VBTF, feeding rates are recalculated by nursing staff and adjusted throughout the day to meet patients' daily nutrition goals. Currently, most enteral feeds are calculated using hourly rates (i.e., 70 ml/hour) to be delivered over a specified period of time, often 20-24 hours, or as bolus volumes, which are written for a set milliliter amount of formula to be given at specific times (Doley & Phillips, 2017). VBTF over bolus tube feedings was chosen for the study intervention because boluses may be missed while patients are receiving therapy or are absent for other procedures. Bolus feeding orders provide no flexibility to give the feeding at another time. Alternatively, VBTF provides nurses and other medical staff with patients' total daily volumes, and when feedings are interrupted, they are restarted using a greater rate or more concentrated formula to make up for the caloric loss experienced during the stoppage (Friesecke et al., 2014; McClave et al., 2015).
VBTF is an uncommon practice, and research describing the use of VBTF has only been found in the critical care literature. One of the first studies describing the use of VBTF in intensive care units was a multicenter study in Canada using the Enhanced Protein-Energy Provision via the Enteral Route Feeding Protocol (PEP uP protocol) (Heyland, Dhaliwal, Lemieux, Wang, & Day, 2015). In this study, a volume-based feeding rate was calculated, and feeds were given as necessary to meet the 24-hour volume goal. The patients on VBTF at the PEP uP protocol sites received significantly greater amounts of protein and calories than those at the control sites (Heyland et al., 2015). A single-site study found that volume-based feeding in the critically ill patient is safe, leads to increased caloric intake, and may improve patient outcomes (McClave et al., 2015).
To date, there are no studies on the use of VBTF in rehabilitation patients, but further research is warranted. Nutrition support is critical for these individuals as rehabilitation patients have increased energy needs (James et al., 2005). Enteral nutrition has been recommended as an important intervention in the rehabilitation of stroke (James et al., 2005) and traumatic brain injury (TBI) patients (Horn et al., 2015). Malnourishment in stroke patients may result in reduced energy, stamina, strength, and mental focus, which may lead to poorer outcomes (James et al., 2005).
The current study analyzed caloric intake of rate-based versus volume-based tube-fed patients in an inpatient medical rehabilitation (IMR) unit setting to determine whether VBTF increased caloric intake, and if so, whether the increased caloric intake resulted in improved nutrition-related outcomes including reduced length of stays and fewer readmissions for rehabilitation patients.
Methods
Study Design
A cohort study with a prospective group and a historical control group was used as the study design. The intervention was VBTF, a change from hourly rate-based EN, which is more commonly used in hospitalized patients. Data were identified through retrospective chart review of rate-based tube-fed patients and information collected prospectively after implementation of VBTF were compared to determine whether the implementation of VBTF in the IMR unit at the University of Utah Health resulted in increased calorie intake. In addition, the study compared preintervention and postintervention patients' length of stays and readmission rates to ascertain whether increased caloric intake improved these outcomes.
Ethics
The proposed study design was submitted to the University of Utah Institutional Review Board and deemed exempt (IRB 00099667).
Sample
Thirty-five patients over the age of 18 years sequentially admitted to the University of Utah Health IMR unit from September 1, 2017, through January 1, 2018, who required EN support were included in the prospective data set. For the retrospective data, information on 35 patients admitted to the rehabilitation unit between August 1, 2016, through January 1, 2017, who required EN during their stay were sequentially pulled from the University of Utah Health Enterprise Data Warehouse. The total number of patients included in the study was 70. Patients who were less than 18 years of age and those who did not require EN were excluded. The study was a quality improvement project, and 35 patients from each group were deemed an acceptable number to provide enough information to learn about the effectiveness of the change.
Intervention
The nursing staff was primarily responsible for the implementation of VBTF in the prospective study population. To assist the nursing staff in making the change from rate-based tube feeding (RBTF) to VBTF, training was provided on the protocol through in-services, staff meetings, and one-on-one follow-up meetings. In roundtable discussions with clinical providers regarding setting parameters for the study, 150 mL/hour was chosen as the maximum infusion rate. The selection of this rate was based on the PEP uP study (Heyland et al., 2010). In addition, an article by McClave et al. (2015) suggested that this amount could be safely fed into the small intestine. VBTF orders were written as milliliters to be infused daily. In general, patients on the IMR unit are fed enterally after having received a J-tube placement on a previous hospital unit. VBTF versus straight bolus feeding was selected as the intervention to give the nursing staff the autonomy to make up for the time patients were disconnected from their feeding tubes. The use of VBTF in this study did not exclude bolus feedings, but the rate of formula and flush was limited to 150 ml/hour because of the prevalence of jejunal feeding. Checking gastric residual volumes is not common practice on this unit, and therefore, this information was not included in data collection. In the spectrum of order writing for EN, VBTF is written as total milliliters to be provided daily, and the amount could be given as either an hourly rate not to exceed 150 ml/hour or as a bolus if the patient had a gastrostomy tube placement.
To assist the nurses in executing VBTF, a written protocol (see Figure 1) and a volume-based feeding schedule (see Figure 2) were located at each nurses' station. Patients on EN in the prospective group received the tube feeding formula they were prescribed on a prior unit, or if they were admitted from a location outside the University of Utah Health, they received the University Health's formulary equivalent. The IMR dietitian determined patients' target volumes, and the VBTF order was written by the resident or physician on duty. The majority of tube-fed patients on this unit are admitted after having jejunal enteral feeding tolerance established on a previous hospital unit. The IMR unit nursing staff then determined the hourly rate to be administered based on the volume tube feed order. If the patient was disconnected from the tube feed, when the patient was reconnected, nursing staff recalculated the rate based on the amount already given and the remaining amount required and adjusted the rate to make up for the time lost. All patients on EN were checked for feeding tolerance. If a patient was distressed, such as experiencing nausea or fullness, the rate was reduced. If the patient continued to experience intolerance after the rate reduction, the dietitian was contacted to assess the formula recommendation.
Data Collection and Statistical Analysis
Data about admission diagnosis, volume received, length of stay, and 30-day readmission rates were recorded for the patients in the control group using retrospective chart analysis and prospectively for patients on EN entering the rehabilitation unit. No data on gastrointestinal (GI) reflux were collected, as the protocol clearly stated that "[i]f patient is distressed (nausea, fullness, etc.), reduce rate" and "if intolerance persists, contact dietitian to assess formula recommendation" (see Figure 1). The same dietitian calculated needs for both the prospective and retrospective study periods.
Data were analyzed using a combination of descriptive and analytical techniques. The primary analysis was proportion of recommended caloric intake preimplementation versus postimplementation of VBTF per length of stay for each patient. This percentage was calculated by dividing the total amount of EN received by the total prescribed at admission to the rehabilitation unit (Stewart, 2014b). An independent t test was used to determine if the proportion of recommended volume differed significantly between the two groups. A secondary analysis using linear regression was done to determine if increased caloric intake impacted the length of stays and/or readmission rates while controlling for gender and admit diagnosis. Data were analyzed using the Statistical Package for the Social Sciences (SPSS, Version 24, 2016).
Results
Three outliers were removed before statistical analysis was performed. These outliers were flagged after a careful review of patient data using boxplots and an analysis for skewness. No significant demographic differences were found between the retrospective and prospective cohorts (see Table 1). The retrospective group received 66.48% +/- 23.98% of their prescribed tube feeding, whereas the prospective group received 80.92% +/- 13.53% (see Table 2). The t test comparing the mean percentage difference in percentage caloric intake between the retrospective and prospective groups showed that there was a significant difference (p = .004) between the means of the RBTF and VBTF groups. No significant differences were found between the length of stays (p = .820) and readmission rates between the two groups (p = .787). The average length of stay for the VBTF group was 22.6, whereas the average length of stay for the RBTF cohort was 21.7. The readmission rates for the two groups were also similar with the prospective group having six readmissions and the retrospective group having five.
Discussion
In searching the literature, no studies on the use of VBTF in a rehabilitation setting were found. Giving nurses the ability to adjust feeding rates using VBTF appears to increase the amount of nutrition IMR patients receive. This increase provides the energy and protein needed for the intensive therapy sessions these patients must undergo. Length of stays and readmission rates were similar between both groups. The nonsignificant differences in length of stays and readmission rates between the VBTF and RBTF cohorts may have been due to the small sample size or because both groups received adequate nutrition during their rehabilitation stays. In addition, many patients in the study were able to advance to oral intake prior to discharge, which may have decreased readmits secondary to tube feeding complications.
Limitations
The time frame from which patients in the retrospective and prospective groups in this study were chosen was quite different. The groups were selected a year apart, and factors, such as staffing or procedures, may have changed, possibly biasing the study results. This study also depended heavily on the nurses correctly administering and documenting the amount of nutrition received by each patient on VBTF (Morphet, Clarke, & Bloomer, 2016). Although staff training was completed to avoid errors, it is possible the amount of formula a patient received may have been administered or recorded incorrectly, resulting in measurement bias. Finally, if there were more patients who were sicker in either the historical or prospective group, the results may have been skewed. These patients may have experienced more gastrointestinal distress or required more tests and/or procedures resulting in their being disconnected from their feeding tubes for longer periods. These sicker patients may have had reduced calorie intake and possibly poorer outcomes, which may have potentially affected the study results. Although this may be a possibility, an analysis of the demographic data in Table 1 shows that patients in both the retrospective and prospective groups had a similar distribution of disease severity. Finally, no information on the number of patients who may have experienced GI reflux was collected.
Implications
Rehabilitation patients participate in many activities throughout the day, that are designed to facilitate their independence once they leave the facility. At a minimum, these patients are required to undergo at least 3 hours of therapy per day in the areas of physical therapy, occupational therapy, speech therapy, recreational therapy, specialized skill training, and rehabilitation psychology sessions. In addition, showers are taken in a different location, not in patients' rooms, and for some patients, bowel care may take a significant amount of time. Rehabilitation patients may also have to leave the unit for additional tests, such as swallow studies. All of these "interruptions" reduce the amount of time a patient is connected to EN, which may limit the volume received if on traditional RBTF.
The protocol for VBTF in this study has only been in place in the IMR since October 2017. Lichtenberg, Guay-Berry, Pipitone, Bondy, & Rotello, (2010) noted that a new protocol can take up to 2 or 3 years to fully implement. Although the protocol is located at each nursing station, some nurses may be unaware that this document exists. This possible lack of awareness of the VBTF protocol is compounded by the fact that the hospital in which this study was conducted is a teaching hospital, which means there is continual turnover of doctors and nurses. For this reason, education about what VBTF is and how to implement it must be ongoing. Although most doctors, nurses, and new residents are familiar with RBTF, they may be unacquainted with the concept of VBTF and how it is administered. For these reasons, it would be beneficial to conduct a similar retrospective/prospective cohort study after the protocol has been in place for at least 2 years.
Finally, the use of VBTF gives nurses more autonomy and control in overseeing their patients' nutritional needs. For nurses, VBTF allows them to function at the top of their licensure using the full extent of their education and training.
Conclusion
The purpose of this study was to demonstrate whether or not a change to VBTF would be beneficial in helping patients reach their prescribed caloric needs. This study found that a small cohort of rehabilitation patients on VBTF received more nutrition than patients on RBTF. The VBTF group received 82% of their prescribed feed, whereas rate-based patients received 70%. Because rehabilitation patients participate in a variety of activities throughout the day, adequate energy is needed. A switch to VBTF may be beneficial in helping these patients reach their prescribed caloric goals. The applicability of our study results is limited due to the small number of patients. However, more research on the use of VBTF in rehabilitation units should be undertaken, as many patients in this setting may already be malnourished, especially those who have suffered a stroke (James et al., 2005). Further research should be conducted with a larger cohort of IMR patients, and additional demographic data (gender, age, weight, body mass index, and admission diagnosis) and outcome data (pressure injury, length of stay, discharge disposition, readmission rates, and tube feeding as sole source of nutrition) should be collected. An increased sample size will provide the power needed to determine what effect increased nutrition may have on important patient outcomes.
Key Practice Points
* Volume-based tube fed patients receive significantlymore (p=0.004) of their prescribed tube feeding than rate-based tube fed patients.
* Patients in rehabilitation units undergo at least 3 hours of therapy each day and increased caloric intake is important in meeting their energy needs.
* Nurses are a critical component in the implementation of a volume-based tube feed protocol.
* More research on the use of volume-based tube feeding in rehabilitation units is needed.
Conflict of Interest
The authors declare no conflict of interest.
Acknowledgments
The authors would like to acknowledge Julie Metos for serving as faculty advisor for this study, Caran Graves for completing the institutional review board for the project, John Speed for providing physician oversight, and Alissa Brown and Carissa Christensen for supporting the project and helping edit the final manuscript.
References