Malnutrition and Chemotherapy-Induced Nausea and Vomiting
Chemotherapy ambulatory care units have rarely been evaluated in isolation for the prevalence of malnutrition and CINV that limits dietary intake because many studies have surveyed mixed inpatient and outpatient populations. The reported prevalence of cancer-related malnutrition has ranged from 11%–80% in the literature (Bauer et al., 2002; Creaser, 2010; Laviano, Meguid, & Rossi-Fanelli, 2003; Read, Choy, Beale, & Clarke, 2006b; Segura et al., 2005); the wide variation is attributed to tumor site and likely influenced by tumor type and stage, chemotherapy agent, the setting where patients were surveyed, and the definition of malnutrition used (Vandebroek & Schrijvers, 2008). The current study found that 26% of patients in the chemotherapy ambulatory care unit were malnourished, a figure consistent with that reported by Isenring, Cross, Daniels, Kellett, and Koczwara (2006) in their validation of the Malnutrition Screening Tool (MST) in the ambulatory chemotherapy setting. In a study of patients with cancer undertaken in a medical outpatient facility, Read et al. (2006a) reported a higher prevalence, with about 66% of the sample identified as malnourished. However, this could be because of a higher proportion of high nutritional risk diagnoses and minimal exposure to dietetic services as the patient group surveyed were new to the clinic and had no prior chemotherapy or radiotherapy treatment. This highlights a high prevalence of pretreatment malnutrition, which may not be identified on presentation to ambulatory care units in the absence of formal nutrition screening.
The current analysis demonstrates that malnutrition is associated with CINV that limits dietary intake, with nausea being one of the most common and distressing symptoms experienced by patients undergoing chemotherapy (Hesketh, 2008; Tipton et al., 2007; Tong et al., 2009). Nausea has been found to adversely affect the dietary intake of 21%–35% of patients receiving chemotherapy from one month to one year of treatment (Tong et al., 2009). In the current study, intake-limiting CINV likely was minimized by the effect of the high dietetic involvement in patient care and cross-sectional nature of the data collection, which captured patients at all times throughout treatment. Although patients experiencing vomiting that limited dietary intake reported prior dietetic input, 33% of those experiencing intake-limiting nausea in the absence of vomiting reported no prior dietetic input despite its association with malnutrition. Forty percent of those in critical need of improved symptom management experienced nausea that impaired dietary intake. Vomiting is an overt symptom that is identified easily; however, poorly-controlled chemotherapy-related nausea impairs functional capacity, increasing the risk of malnutrition (Hesketh, 2008; Ravasco et al., 2007; Tipton et al., 2007) and poorer treatment outcomes. Despite the increasing availability of pharmacologic agents for managing CINV, the effective management of those symptoms remains a challenge for clinicians. Evidence-based practice recommends that, in addition to pharmaceuticals, dietary interventions are likely to minimize the symptoms (Tipton et al., 2007).
Bozzetti (2009) found that 40% of patients undergoing chemotherapy experienced weight loss. In the current study, significant weight loss is defined as 5% or greater in one month or 10% or greater in six months, resulting in a prevalence of 18%; however, Bozzetti (2009) determined weight loss to be significant at a 10% or greater loss from usual weight, irrespective of time frame. Weight loss is associated with malnutrition and is a component of many screening tools used to assess nutritional risk. In the ambulatory setting, weight loss can be monitored easily by patients and nurses as patients are advised to monitor their weight in addition to regular weighing at the ambulatory clinic.
Malnutrition is a major cause of morbidity and mortality in cancer (Dewys et al., 1980). It reduces the response to treatment, has a negative impact on quality of life (Ravasco et al., 2007), and burdens healthcare facilities by increasing costs through lengthened therapies, longer hospital stays, and increased clinician consultation times for therapeutic interventions and treatment-related toxicities (Alexandre et al., 2003). It may have been difficult for staff to identify malnutrition in this group because 52% were overweight or obese and only 8% were underweight. Although low BMI and malnutrition are associated, 23 patients in the normal or overweight or obese ranges were malnourished. The high proportion of patients in nonunderweight BMI categories highlights the increasing difficulty in identifing those in need of dietetic interventions. The authors found that six patients with malnutrition, seven with significant weight loss, and four critically in need of improved nutrition symptom management in the higher BMI categories reported no prior dietetic input. Overweight and obese patients may be pleased with inadvertent weight loss during treatment and, therefore, may be less inclined to report it as a concern. Clinicians and patients need to be aware of the effects malnutrition may have on patient outcomes (Watterson et al., 2009), particularly in those receiving chemotherapy, as changes in nutritional status have been associated with changes in the absorption, metabolism, and elimination of chemotherapy drugs (Vandebroek & Schrijvers, 2008).
During the audit, a dietetic presence was in the ambulatory care unit, which may have influenced the number of referrals to the dietitian. Therefore, it is of clinical concern that 35% of the patients who had signs or symptoms indicating a need for dietetic referral reported no prior dietetic involvement. With no formal nutrition screening processes in place, patients were referred ad hoc, and many who were malnourished or required improved nutrition-related symptom management were missed. Relying on BMI and patient self-reporting symptoms is inadequate for identifying all patients at risk for malnutrition or with poor nutritional status. The multidisciplinary team must correctly identify, refer, and support patients with poor nutritional status or who are at risk of malnutrition; a process made more difficult in the absence of formal screening.
Patients undergoing chemotherapy experience many symptoms that negatively affect their dietary intake. In this audit, only intake-limiting CINV was evaluated for prior dietetic involvement, supporting the implementation of formal nutrition screening tools. As such, the findings of patients with symptoms who needed dietetic involvement but were missed are likely an underestimate. In addition to intake-limiting CINV and BMI, other variables such as taste may be associated with malnutrition. However, those variables were not evaluated because of the small sample size.
Discussion
Chemotherapy ambulatory care units have rarely been evaluated in isolation for the prevalence of malnutrition and CINV that limits dietary intake because many studies have surveyed mixed inpatient and outpatient populations. The reported prevalence of cancer-related malnutrition has ranged from 11%–80% in the literature (Bauer et al., 2002; Creaser, 2010; Laviano, Meguid, & Rossi-Fanelli, 2003; Read, Choy, Beale, & Clarke, 2006b; Segura et al., 2005); the wide variation is attributed to tumor site and likely influenced by tumor type and stage, chemotherapy agent, the setting where patients were surveyed, and the definition of malnutrition used (Vandebroek & Schrijvers, 2008). The current study found that 26% of patients in the chemotherapy ambulatory care unit were malnourished, a figure consistent with that reported by Isenring, Cross, Daniels, Kellett, and Koczwara (2006) in their validation of the Malnutrition Screening Tool (MST) in the ambulatory chemotherapy setting. In a study of patients with cancer undertaken in a medical outpatient facility, Read et al. (2006a) reported a higher prevalence, with about 66% of the sample identified as malnourished. However, this could be because of a higher proportion of high nutritional risk diagnoses and minimal exposure to dietetic services as the patient group surveyed were new to the clinic and had no prior chemotherapy or radiotherapy treatment. This highlights a high prevalence of pretreatment malnutrition, which may not be identified on presentation to ambulatory care units in the absence of formal nutrition screening.
The current analysis demonstrates that malnutrition is associated with CINV that limits dietary intake, with nausea being one of the most common and distressing symptoms experienced by patients undergoing chemotherapy (Hesketh, 2008; Tipton et al., 2007; Tong et al., 2009). Nausea has been found to adversely affect the dietary intake of 21%–35% of patients receiving chemotherapy from one month to one year of treatment (Tong et al., 2009). In the current study, intake-limiting CINV likely was minimized by the effect of the high dietetic involvement in patient care and cross-sectional nature of the data collection, which captured patients at all times throughout treatment. Although patients experiencing vomiting that limited dietary intake reported prior dietetic input, 33% of those experiencing intake-limiting nausea in the absence of vomiting reported no prior dietetic input despite its association with malnutrition. Forty percent of those in critical need of improved symptom management experienced nausea that impaired dietary intake. Vomiting is an overt symptom that is identified easily; however, poorly-controlled chemotherapy-related nausea impairs functional capacity, increasing the risk of malnutrition (Hesketh, 2008; Ravasco et al., 2007; Tipton et al., 2007) and poorer treatment outcomes. Despite the increasing availability of pharmacologic agents for managing CINV, the effective management of those symptoms remains a challenge for clinicians. Evidence-based practice recommends that, in addition to pharmaceuticals, dietary interventions are likely to minimize the symptoms (Tipton et al., 2007).
Bozzetti (2009) found that 40% of patients undergoing chemotherapy experienced weight loss. In the current study, significant weight loss is defined as 5% or greater in one month or 10% or greater in six months, resulting in a prevalence of 18%; however, Bozzetti (2009) determined weight loss to be significant at a 10% or greater loss from usual weight, irrespective of time frame. Weight loss is associated with malnutrition and is a component of many screening tools used to assess nutritional risk. In the ambulatory setting, weight loss can be monitored easily by patients and nurses as patients are advised to monitor their weight in addition to regular weighing at the ambulatory clinic.
Malnutrition is a major cause of morbidity and mortality in cancer (Dewys et al., 1980). It reduces the response to treatment, has a negative impact on quality of life (Ravasco et al., 2007), and burdens healthcare facilities by increasing costs through lengthened therapies, longer hospital stays, and increased clinician consultation times for therapeutic interventions and treatment-related toxicities (Alexandre et al., 2003). It may have been difficult for staff to identify malnutrition in this group because 52% were overweight or obese and only 8% were underweight. Although low BMI and malnutrition are associated, 23 patients in the normal or overweight or obese ranges were malnourished. The high proportion of patients in nonunderweight BMI categories highlights the increasing difficulty in identifing those in need of dietetic interventions. The authors found that six patients with malnutrition, seven with significant weight loss, and four critically in need of improved nutrition symptom management in the higher BMI categories reported no prior dietetic input. Overweight and obese patients may be pleased with inadvertent weight loss during treatment and, therefore, may be less inclined to report it as a concern. Clinicians and patients need to be aware of the effects malnutrition may have on patient outcomes (Watterson et al., 2009), particularly in those receiving chemotherapy, as changes in nutritional status have been associated with changes in the absorption, metabolism, and elimination of chemotherapy drugs (Vandebroek & Schrijvers, 2008).
During the audit, a dietetic presence was in the ambulatory care unit, which may have influenced the number of referrals to the dietitian. Therefore, it is of clinical concern that 35% of the patients who had signs or symptoms indicating a need for dietetic referral reported no prior dietetic involvement. With no formal nutrition screening processes in place, patients were referred ad hoc, and many who were malnourished or required improved nutrition-related symptom management were missed. Relying on BMI and patient self-reporting symptoms is inadequate for identifying all patients at risk for malnutrition or with poor nutritional status. The multidisciplinary team must correctly identify, refer, and support patients with poor nutritional status or who are at risk of malnutrition; a process made more difficult in the absence of formal screening.
Limitations
Patients undergoing chemotherapy experience many symptoms that negatively affect their dietary intake. In this audit, only intake-limiting CINV was evaluated for prior dietetic involvement, supporting the implementation of formal nutrition screening tools. As such, the findings of patients with symptoms who needed dietetic involvement but were missed are likely an underestimate. In addition to intake-limiting CINV and BMI, other variables such as taste may be associated with malnutrition. However, those variables were not evaluated because of the small sample size.