Propofol doses differ in total intravenous anaesthesia (TIVA) for cancer and no cancer surgery - observational cohort study

OBJECTIVE: Propofol (2,6-diiso-propylphenol) is a broadly used anaesthetic in total intravenous anaesthesia (TIVA) that might alter course of disease in patients who underwent oncology surgery. High inter-individual variability of the propofol dose needed for the same level of consciousness during surgical tumour removal is influenced by many factors. PATIENTS AND METHODS: This is a retrospective observational cohort study of prospectively collected patients data over 20 month's period. The main endpoint of the study was to compare propofol consumption needed for cancer and no cancer surgical interventions. The secondary endpoints were to find out whether there is a difference in recovery time between the two groups of patients and to reveal potential correlations between propofol consumption and age, duration of anaesthesia, body weight and Charlson co-morbidity index (CCI) in cancer and no cancer surgery. RESULTS: There were 103 patients with cancer (mean age 59.3 yr +/- 10.7) and 109 patients operated due to other reasons (mean age 47.6 yr +/- 17.52). Female sex predominated in both groups (70.9% in cancer and 67.9% in no cancer patients). They differed regarding CCI, 4.48 (+/- 2.1) in cancer in contrast to 1.49 (+/- 1.83) in no cancer patients, and anaesthesia time, 92.67 minutes +/- 46.15 vs. 75.24 +/- 37.28, respectively (p = 0.0012). Propofol induction dose did not differ significantly between the two groups (p = 0.193), while total propofol consumption was 85.86 mcg/kgBW/min (+/- 25.98) in cancer and 95.77 (+/- 31.48) in no cancer patients (p = 0.01). Propofol consumption negatively correlated with duration of anaesthesia and body weight in cancer group. However, in no cancer patients there was very strong negative association with age, duration of anaesthesia and CCI, and significant but weaker negative association with body weight. The time to awakening did not differ significantly between the groups (p = 0.219). CONCLUSIONS: Propofol dose differed in cancer comparing to no cancer patients under general anaesthesia. There was no need for dose adjustment regarding the age and sex in patients with cancer in contrast to no cancer surgery.