PhilSPEN Online Journal of Parenteral and Enteral Nutrition

(Article 7 | POJ_0012) January 2010 - January 2012

Original Clinical Investigation

Predicting Post-operative Complications Based on Surgical Nutritional Risk Level using the SNRAF in Colon Cancer Patients: A Chinese General Hospital & Medical Center Experience

Abstract | Introduction | Methodology | Results | Discussion | Conclusion | References | Back to Total Names Codes

Submitted: October 1, 2010 | Posted: December 2, 2011


Rommel B. Ocampo, M.D.; Yemen Kadatuan, M.D.; Maila Rose Torillo, M.D.; Catherine M. Camarse, M.D.

Advisers: Ray B. Malilay, M.D.,FPCS; George K. Cheu, M.D., FPCS; Luisito Llido, M.D., FPCS; Amiel A. Gilbuena, M.D., DPBS


Department of Surgery, Chinese General Hospital and Medical Center



Objective: To evaluate the preoperative nutritional status, using the Philippine College of Surgeon Surgical Nutrition Risk Assessment Form (SNRAF) and to identify nutrition related complications in colorectal cancer patients who underwent resection with anastomosis.

Methodology: This is a prospective observational study evaluating the preoperative nutritional status of colorectal cancer patients who underwent resection with anastomosis using the nutrition assessment and risk leveling form by the Philippine College of Surgeons. The patients were classified as low, moderate, and high risk for nutrition related complications and monitored during their entire hospital stay and followed up to 30 days from date of discharge. The outcomes determined were: major and minor complication(s), mortality, and length of hospital stay..

Results: Forty three subjects were included with a malnutrition prevalence of 46.5%. 53.4% (23/43) were well nourished with low risk for complications; 21% (9/43) had moderate risk and 25.6% (11/43) had high risk. Only 2 out of 23 patients with low risk developed minor complications; the group had no major complications and no mortality. In the group with moderate nutritional risk, the number of patients who developed minor complications was 2 (22.2%); the number who developed major morbidities was also 2 (22.2%); there was no mortality in the group. In the group with high nutritional risk, 5 patients (45.5%) developed minor complications, 4 (36.4%) of which also developed major complications. Two (18.2%) patients died of complications in the high risk group.

Conclusion: The SNRAF showed significant correlation between nutritional risk and development of complications. Moderate to high risk patients developed minor and major complications with the high risk patients showing the highest rate and mortality.


KEYWORDS: Nutrition risk level, assessment, surgical complications, colon cancer



Malnutrition is defined as abnormal body composition with impairment of organ function due to chronic or acute, absolute or relative reduction of calorie and protein intake which would adversely affect clinical outcome. A study abroad revealed that 51% of 9348 hospitalized patients in Latin America were malnourished (1) while a local study in St. Luke’s Medical Center in 1995 (2) showed a 52% malnutrition rate specifically among surgical patients. Clinical examination, body mass index and albumin were used to assess for the nutritional status.

Cancer patients are of special interest because a high percentage of them may present with preoperative malnutrition (3). Cancer cachexia syndrome further subjects this population to severe malnutrition with the following manifestations: weight loss, anorexia, skeletal muscle and visceral organ atrophy and dysfunction (4). The commonly associated biochemical changes are hypoalbuminemia, hypoglycemia, lacticidemia, hyperlipidemia and glucose intolerance (5). The syndrome is prevalent in greater than 50% of oncologic patients and responsible for approximately to two thirds of cancer related mortality (6). The severity of cachexia appears to be an important prognostic index of survival in patients with malignant disease.

Many studies have established the association between malnutrition and post operative complication(s) (7). The consequences of malnutrition are severe and include impairment of immune function with increased susceptibility to infection and perhaps tumor growth, increased perioperative morbidity and ultimately death. Wound infection, enteric fistula, intra-abdominal abscess, delayed wound healing, and wound dehiscence are some of the surgical problems that fall under nutrition related complications (8). Respiratory tract infection, urinary tract infection, bacteremia, sepsis and shock are medical dilemmas that may arise after surgery which can be also be explained by malnutrition. Major anastomotic leaks requiring reoperation however, are usually due to technical errors, but could also be associated to poor nutrition because of delayed wound healing. These have been reported by Sitges-Serra in their paper who concluded that excessive post operative morbidity and mortality have been found in severely malnourished patients whenever they undergo major surgery (9).

The challenge to the surgeon therefore is to prevent or correct the malnutrition induced by malignancy in the preoperative phase, which may in turn lead to lower complication rates after surgery. Before any intervention can be done, the surgeon must first identify malnutrition among his patients. The Subjective Global Assessment (SGA) is a tried and tested method of evaluating nutrition based on medical history and physical signs (10) and was used as a tool in predicting complications in a number of different groups of patients, including cancer patients: (11) Ottery 1996, (12) Ek et al, 1996, and (13) Jones. It has also been correlated with a number of objective parameters such as anthropometric (body mass index or BMI), biochemical (albumin), immunological (total lymphocyte count or TLC), morbidities (infection rate, use of antibiotics), quality of life and health care costs (14) Detsky et al, (15) Capra et al).

In 2006, the Philippine College of Surgeons through the Committee on Surgical Nutrition developed its own version of a scored SGA called Surgical Nutrition Risk Assessment Form (SNRAF). In 2007, the committee on nutrition started its campaign in educating health professionals, specifically surgeons regarding the importance and the mechanics on how to use the SNRAF. The authors of this study decided to be part of the initiative by using and testing this new nutritional assessment tool in recording the prevalence of malnutrition in cancer patients, specifically colorectal patients in Chinese General Hospital and Medical Center. The objectives of this study were: a) To determine the prevalence of preoperative malnutrition in admitted colorectal cancer patients in this institution and to classify their nutritional risk levels, b) To determine major and minor complication rates in low risk, moderate risk & high risk patients, and c) To correlate malnutrition in each nutritional risk level with the complications.



All patients diagnosed to have colorectal malignancy who underwent elective surgical resection with anastomosis from January 2007 to September 2007 at Chinese General Hospital and Medical Center were included in the study. Preoperatively, each patient was evaluated using the Surgical Nutrition Risk Assessment Form (SNRAF) produced by the Philippine College of Surgeons, Committee on Nutrition (Figure 1). The Surgical Nutrition Risk Assessment Form consisted of: the patient profile (name, age, sex, height, and weight), the Subjective Global Assessment criteria (weight loss, food intake, gastrointestinal symptoms > 2 weeks, functional capacity, disease and relation to nutritional requirements and physical examination) and objective assessment of nutrition (muscle status using the mid-arm circumference and fat status using the triceps skin fold thickness measurements).


The SGA classification had their own score and added parameters with scores were included like BMI, albumin & Total Lymphocyte Count (TLC). The total scores had corresponding risk levels which were: no risk/low risk, moderate risk, and high risk (See Figure 1) SGA grade, BMI, albumin and TLC were individually classified under normal/mild, moderate and severe malnutrition and were given a corresponding score of 0, 1 and 2, respectively. Nutritional Risk Level for each patient was then obtained by adding up all the scores from the subjective & objective assessments. Patients with a score of 0-1 were classified as No Risk/Low Risk, 2-3 as Moderate Risk and 4 as High Risk. It also included computations for initial nutritional requirements and a daily monitoring form to optimize the nutritional support for all cancer patients from the time of admission until the patient is discharged. In addition, it was designed so that the components of the medical history can easily be completed by the user using a checkbox format.

All patients underwent the same bowel preparation. They all had resection with anastomosis without diverting colostomy/ileostomy. Antibiotics given post-op were cefuroxime and metronidazole. After surgery, the post-operative course was strictly monitored documenting morbidity and mortality from day one post-operative to discharge from the hospital for the next thirty (30) days. These data constitute the minor complications: surgical site infection small wound dehiscence, infections like urinary tract or pulmonary infection. The major complications were the following: sepsis, large wound dehiscence, anastomotic leak, re-operation, medical complications requiring prolonged hospital stay (sepsis, pneumonia, ICU stay, and readmission) within 30 days from date of discharge. Length of hospital stay was likewise recorded.

One Way Analysis of Variance (ANOVA) and Chi Square were used to assess the relationship between the nutritional risk levels and their respective post operative outcome. Linear regression was used to determine the correlation between nutrition risk versus the other outcome data. The software used was the NCSS/PASS and the level of significance was set at P < 0.05 (16).


Patient Profile (Tables 1 and 2):

A total of 43 admitted patients diagnosed to have colorectal cancer and who underwent resection with anastomosis from January to September 2007 at Chinese General Hospital and Medical Center were included in the study (male to female ratio = 1.5:1). The mean weight of the patients was 57 kg (SD: 9.69) with the males being the heavier sex (males: 63.3 kg [SD: 8.19] versus females: 52.9 kg [SD: 8.39]). Out of the total population, 23/43 (53.4%) patients were classified as no nutritional risk or low risk, 9/43 (20.9%) patients were considered moderate risk, and 11/43 (25.6%) patients were considered high risk. The prevalence rate of malnutrition in this population was 46.5% (20/43).


Based on the nutrition risk level classifications significant difference was seen in the following areas: age in years (P = 0.01, one way ANOVA), presence of complications (P < 0.001, Chi Square), mortality (P = 0.04, Chi Square), and hospital stay (P = 0.003, one way ANOVA).There was none seen in cancer stage (P = 0.87, chi square), site of the tumor (P = 0.18, chi square), and sex of the patient (P = 0.15, chi square).


No or low nutritional risk (N = 23; Table 2, Figure 2):

For the patients classified under no nutritional risk or low risk, the median age was 56 year old with a male to female ratio of 1.09 to 1. Most of the patients were Cancer Stage 2 (39%) and Stage 3 (44%). There were 2/23 (8.7%) patients who developed minor morbidities and no major complication or mortality occurred. Ninety one percent (91%) had no complications. The median hospital stay, from the date of the operation until date of discharge for this group, was 5.9 days.

Moderate nutritional risk (N = 9; Table 2, Figure 2):

For the patients classified under moderate risk, the median age was 70 years old with a male to female ratio of 1 to 2. The majority of patients were in Cancer Stage 2 (33%) and Stage 3 (56%). Two (2) out of nine patients (22%) developed minor complications and two (2) now had major complications (22%). There was no mortality. The median hospital stay for this group was 9 days.

High nutritional risk (N = 11; Table 2, Figure 2):

For the patients classified as high risk, the median age was 64 years old (P = 0.01, one way ANOVA) with a male to female ratio of 1 to 4.5. Two thirds of the patients were in Cancer Stage 3 (7/11 or 64%). Four patients (4/11 or 36.4%) had no complications, one had minor complications (1/11 or 9%), and four (4/11 or 36.4%) showed both major and minor complications (P < 0.001, chi square). Two fatalities (2/11 or 18.2%; P = 0.047, chi-square) occurred in this group. Median hospital stay for this group was 10.8 days (P = 0.003; one way ANOVA).


Canonical Correlations of the Nutrition Risk Level and patient outcome:

Moderate correlations were seen with hospital stay (r = 0.50) and complication rate (r = 0.55); fair correlations were seen with age in years (r = 0.32), mortality (r = 0.33), and sex (r = 0.29);and little or no correlation with cancer staging (r = 0.13). A negative correlation was seen with site (r = - 0.17).

Subjective Global Assessment Criteria (Table 3):

The top five signs and symptoms shown by the patients were: GI symptoms such as nausea & vomiting (58%), suboptimal food intake (53%), <10% weight loss (49%) suboptimal work capacity (49%), and symptoms of moderate stress (48%). A weight loss of more than 10% was seen in 28% of patients.




The Surgical Nutrition Assessment Form showed the prevalence of malnutrition in this institution to be 46.6% which was similar to the reported malnutrition rates locally and worldwide (17-20). When the patients were classified according to nutrition risk levels there was a significant difference in the patient outcome values like complication rate, hospital stay, age in years, and mortality (from the highest to the lowest) showing this form’s value as a nutritional assessment tool. The resulting nutrition risk level also correlated positively with the above values including the cancer stage. Focusing on the complications, the patients who were classified as high risk had the major and minor complications including death (18%). These data showed the value of the SNRAF in alerting the attending physician to potential problems which may arise if the nutritional status of the patient was not properly addressed. It would also pave the way to better patient management by providing the information which would optimize the patient’s condition before and after surgery.

The minor complications encountered in this study were superficial surgical site infections (SSI) which were lowest (8.7%) in the low risk group and highest (45.5%) in the high risk group. These showed the primary factor of malnutrition as the main difference in patient management outcome in as much the surgeries were similar in both technique and aseptic environment. The major complications were 22% in the moderate risk group and 36.4% in the high risk group, with the mortalities occurring in the high risk group. The two mortalities (18%) were due to sepsis, which was a reflection of the immunosuppression effect of surgery (21) with the added impact of the malnourished state. The first, a 55 year old female who died on the 12th  post-operative day developed medical conditions such as bipedal edema, pulmonary edema, pneumonia, electrolyte imbalance and ileus which lead to prolonged hospital stay. She ultimately developed septic shock. The second, a 66 year old male, also developed hospital acquired pneumonia, renal failure, and ultimately multi-organ failure. These complications can be attributed to malnutrition and its associated increase in the inflammatory response secondary to prolonged surgery, decreased immune competence (22), and massive fluid shifts due to not so strict fluid control (23). Extracellular water expansion manifested by edema has been associated with undesirable effects such as increased lung water, diminished perfusion to the whole body and ultimately poor wound healing in the operative site (23). Muscular function, which had been deteriorating due to a reduction in muscle protein content from the tumor and reduced food intake, further contributed to the higher complication rate (e.g. sepsis and wound dehiscence).

The non-fatal complications that occurred were the following: respiratory, encephalopathy, refeeding side effects, and anastomotic dehiscence. The respiratory problems were delayed extubation, secondary to decreased respiratory muscle strength, and pulmonary edema. Some patients showed deterioration in incentive spirometry, which was indicative of a malnourished state. The encephalopathy may be secondary to the biochemical alterations and fluid dislocation secondary to the malnutrition, surgery, and fluid management. Refeeding secondary to high volume parenteral nutrition may also be a factor leading to hypophosphatemia and osmolarity changes (24). The hyperammonemia that came up may be due to the inadequate antibiotic coverage. The two (2) reoperations due to anastomotic dehiscence may be mainly technical in nature, however, the anastomotic site may have been poorly perfused due to the malnutrition associated local inflammatory and coagulation status. The main co-morbidities were hypertension (10/43 or 23%) and diabetes mellitus which further contributed to the poor wound healing and decreased immunocompetence in 4 patients (4/43 or 9.3%). The two patients who died had these co-morbidities.

In the final context the SNRAF was able to focus on and identify the patient’s malnourished status and thus provide a way to avoid potential complications secondary to this state and the subsequent injury caused by the surgical procedure.


The Surgical Nutrition Risk Assessment Form (SNRAF) showed a significant relationship and correlation between nutritional risk and the development of complications in colorectal cancer patients who underwent resection with anastomosis. It was also able to predict complications, major, minor or combined, and mortality to occur in the moderate to high risk patient.

We therefore recommend using this tool as part of the pre-operative assessment of all patients scheduled for surgery.



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Abstract | Introduction | Methodology | Results | Discussion | References | Back to Total Names Codes