Analysis of heart rate variability and accelerometry in patients following surgery for the treatment of gastrointestinal cancer

Background: Gastrointestinal cancer is the most prevalent form of cancer worldwide. Surgical treatment interferes with functionality and increases the length of hospital stay. However, studies have shown that early mobilization reduces the length of hospital stay. Aim: To determine the cardiovascular safety and intensity of an adapted protocol for early mobilization in patients following surgery for the treatment of gastrointestinal cancer. Methods: An observational, cross-sectional study was conducted with 24 individuals: 15 in the case group (cancer patients in the post-operative period) and nine in the control group (hospitalized patients without cancer). All participants were submitted to a standardized early mobilization physiotherapeutic protocol. A portable heart rate monitor and accelerometer were used to obtain data on heart rate variability (HRV), analyzing the variables ‘interval between consecutive beats’ (RR), ‘mean heart rate’ (HR), ‘standard deviation from mean of all normal RR intervals’ (SDNN), ‘square root of mean of square of differences between consecutive RR intervals’ (RMSSD), ‘number of RR intervals’ (NN50) and ‘percentage of adjacent RR intervals with difference in duration greater than 50 ms’ (pNN50), and the intensity of physical activity (IPA), analyzing metabolic equivalents (METS), before and after the intervention. Data analysis involved the Student’s t-test for the comparison of data with parametric distribution and the Mann-Whitney U test for variables with non-parametric distribution. Results: No statistically significant differences in energy expenditure or IPA percentages were found between groups. Moreover, no significant difference in HRV occurred in the case group, whereas differences in RR, HR and pNN50 variables were found in the control group. Conclusions: Early mobilization for patients following surgery for the treatment of gastrointestinal cancer can be performed without increasing HRV and with energy expenditure and IPA similar to those found in patients without cancer.