Despite the high occurrence and negative impact of malnutrition on clinical outcomes and hospitalization costs, the nutritional status of patients remains poorly identified and documented (Waitzberg et al. 2001; Singh et al. 2006; Gout et al. 2009). This highlights the need for a continuing education program in clinical nutrition for health-care providers, which should begin in medical and nursing schools (Acuna et al. 2008) and extend into residency and nursing training curricula.

Medical societies and quality improvement organizations have proposed structured guidelines to screen, identify, and treat malnutrition. Crucial to the successful implementation of these guidelines is the formation of nutrition support teams (Nehme 1980; Schneider 2006). The NST represents a model of transdisciplinary management where specialists from multiple disciplines combine their knowledge and expertise to achieve management decisions and outcomes superior to those obtained in isolation. An effective NST is a physician-led team of doctors, nurses, dieticians, and pharmacists who actively manage patients through daily clinical rounds using evidence-based protocols (Gales and Gales 1994). These teams are expected to interact closely with referring physicians, promote awareness, and improve the education of health-care providers in all aspects of nutrition care. The exact composition and roles of team members should be adapted to fit local demands and resources.

Successful NST practice has led to an increase in the appropriate use of PN and reduction in catheter-related complications and metabolic derangements (Nehme 1980; Gales and Gales 1994; Sriram et al. 2010). The implementation of an NST and nutritional clinical practice guidelines in a set of patients undergoing elective surgery for colorectal cancer resulted in a significant reduction in postoperative complications and hospital length of stay (Planas et al. 2007). It is important for each NST to determine performance goals or aims in terms of clinical nutrition outcomes of their patients. Regular audit of performance indicators will identify areas which require improvement or a change in clinical practice (Schneider 2006).

Nutrition screening is a simple process to identify patients at risk of malnutrition who will require a more thorough and detailed nutrition assessment to determine nutritional status (Kondrup et al. 2003). Many guidelines recommend screening in all cancer patients during the initial preoperation evaluation, either in the inpatient or outpatient setting. It is often challenging, however, to accurately measure nutritional status. Several markers have been explored as an indicator of nutritional status including albumin, prealbumin, and total lymphocyte counts (Elia 2000), but no single clinical or laboratory marker can be recommended as a comprehensive indicator of nutritional status. Levels of laboratory markers may be lowered during the acute phase response in inflammatory conditions making them unreliable in patients presenting with an acute colorectal problem (Fuhrman 2002).

In the 1990s, The Joint Commission mandated nutrition screening within 24 hours of admission, followed by a full nutrition assessment if found to be at nutritional risk. This guideline has since been widely adopted; however, colorectal patients who are undergoing elective procedures on the day of admission ought to be screened preoperatively in the outpatient clinic (Kudsk et al. 2003a). Nutrition screening tools should be easy to use, cost-effective, valid, reliable, and sensitive. Several nutrition screening tools have been described including the Mini Nutritional Assessment (MNA) (Vellas et al. 1999), the Malnutrition Universal Screening Tool (MUST) (Ferguson et al. 1999), and the Nutritional Risk Screening (Kondrup et al. 2003). The main limitations of these tools are the dependency on subjective parameters and clinical judgment and the variable evidence of their accuracy and reliability.

After nutrition screening, patients who are identified to be at risk of malnutrition should receive a more detailed nutritional assessment by a nutrition expert. This is a complete and systematic examination of the metabolic, nutritional, or functional variables which allows the NST to create an appropriate nutritional plan for each patient (Kondrup et al. 2003). ASPEN recommends using the Subjective Global Assessment (SGA), which is an assessment tool that consists of both the patient’s history and physical assessment (Fig. 4.2). Patients are subjectively classified as A (well nourished), B (moderate malnutrition), or C (severe malnutrition) (Detsky et al. 1987). The SGA is a validated and simple assessment that predicts postoperative complications with high accuracy (Baker et al. 1982).

Patients assessed to be malnourished will require a nutrition therapy care plan, which should be delivered by a transdisciplinary team of nutrition experts, especially for those requiring PN. Regular reassessments of nutritional status must be conducted throughout the hospital stay to identify any changes in clinical or nutritional status, which may impact current nutrition status and therapy (Fig. 4.3).

The crucial element in designing a nutrition therapy care plan is the calculation of a patient’s daily energy requirement. The daily requirement depends on resting energy rate, diet-induced thermogenesis, and physical activity (Manchanda 2003). The resting energy expenditure of patients after major colorectal surgery increased by 13 % compared to those in healthy volunteers, with no difference in urinary nitrogen losses (Soop et al. 2004). The change in the energy expenditure of cancer patients is variable and is dependent on body composition and tumor type and stage (Elia 2005).

Indirect calorimetry represents the gold standard for measuring energy expenditure in the clinical setting. This machine, however, is often unavailable due to its high cost. Most nutrition therapists use predictive equations to estimate energy expenditure; the components of these equations usually include characteristics which influence the amount of fat-free mass including body weight, height, age, and gender. Many equations have been developed for healthy individuals (Table 4.1) and can be adjusted for sick patients using stress factors (Frankenfield et al. 2004).

ESPEN recommends the use of 25 kcal/kg ideal body weight as an approximate estimation of daily energy requirements and 30 kcal/kg ideal body weight during severe stress. ESPEN guidelines also recommend 1.2–1.5 g/kg ideal body weight/day of protein to limit nitrogen losses in surgical patients (Braga et al. 2009).

In addition to calorie and protein requirements, patients should receive daily recommended amounts of fluids, electrolytes, trace elements, and vitamins (Tables 4.2, 4.3, and 4.4) (Langley 2007; Clark 2007).