Definition, prevalence and characteristics of sudden exhaustion: a possible syndrome of fatigue in cancer?

PURPOSE: Although sudden fatigue/exhaustion is a symptom expression that oncology clinicians frequently hear from their patients, empirical information about this phenomenon is limited. This study investigated the occurrence and characteristics of sudden fatigue in patients treated for breast cancer.
METHODS: This cross-sectional descriptive study enrolled 114 breast cancer chemotherapy outpatients from a cancer clinic and an urban teaching hospital in the Midwestern United States. Subjects were screened for sudden fatigue and completed an investigator-developed Sudden Onset of Fatigue Questionnaire on the day of their chemotherapy treatment. Descriptive statistics were used to examine prevalence and clinical characteristics.
RESULTS: Approximately half (46 %) of the patients (age 31-67, 62 % Black, and 70 % unemployed) experienced sudden fatigue. The majority (81 %) reported more than one (median = 3) episode per day; 67 % of episodes lasted 60 min or less. The sudden fatigue was most likely (77 %) to occur between 10 a.m. and 5 p.m., while individuals were active (94 %). When it occurred, individuals stopped activities and sought immediate rest. It was described as abrupt exhaustion/weakness often (66 %) accompanied by other symptoms. Fatigue intensity before, during, and after a specific episode were 5, 9, and 5, respectively, on 0-10 (highest) scale.
CONCLUSIONS: To better characterize sudden fatigue, a new descriptor, sudden exhaustion syndrome, which encompasses observed abrupt onset, transitory exhaustion/paralysis, and multiple symptoms, is proposed. Individuals may experience multiple occurrences of sudden exhaustion across a day, especially during activities. The syndrome needs to be recognized by oncology professionals. Patients should be educated about the syndrome to enhance sense of control and prevent harm.