Frailty in perioperative patients in three South African academic hospitals

Abstract

Background. Frailty is a state characterised by diminished physiological reserve that leaves an individual vulnerable to external stressors and delays recovery. Frailty assessments are proving to be more valuable in predicting poor perioperative outcomes than other well-known perioperative risk assessment tools. Very few studies using validated frailty assessment tools have been done to assess the prevalence of frailty in South Africa (SA), and none have assessed the intraoperative implications of frailty in a surgical population.

Objectives. To determine the demographics and frailty levels of patients presenting for surgery at three academic hospitals in Johannesburg, compare intraoperative complications between the frail and non-frail patients, and compare the association between frailty scores and American Society of Anesthesiologists Physical Status (ASA-PS) scores.

Methods. We prospectively enrolled 299 patients aged 18 - 90 years undergoing various types of elective surgery between mid-November 2016 and mid-March 2017 in three SA academic hospitals. Frailty was assessed using the nine-point Clinical Frailty Scale (CFS) and defined as a score of ≥5. The CFS and demographic and clinical data were documented by the anaesthetists assigned to the respective elective lists. The primary outcome measure was intraoperative complications (hypotension, desaturation, and need for vasopressors and blood transfusion). We also compared associations between the patients’ comorbidities and frailty and those between the CFS and ASA-PS scores.

Results. Of a total of 299 patients included in the study (mean age (standard deviation) 50.6 (15.8) years), 156 (52%) were women and 67 (22%) were classified as frail. Compared with patients who were not classified as frail, the frail group had significantly higher incidences of hypotension (odds ratio (OR) 1.87, 95% confidence interval (CI) 1.083 - 3.259; p=0.02) and desaturation (OR 3.79, 95% CI 1.367 - 10.54; p=0.01), and were more likely to need vasopressors (OR 2.81, 95% CI 1.607 - 4.912; p=0.00) and blood transfusion (OR 3.26, 95% CI 1.138 - 9.368; p=0.02). On multivariable logistic regression analysis, adjusting for factors related to frailty such as age, gender and comorbidities, desaturation was significantly associated with frailty (adjusted OR (aOR) 4.21, 95% CI 1.31 - 13.53; p=0.01), and the frail were more likely to require blood transfusion (aOR 5.36, 95% CI 1.50 - 19.16; p=0.01) and were older and had more comorbidities. Higher ASA-PS scores were also strongly associated with frailty.

Conclusions. The prevalence of frailty was high among surgical patients. Consistent with other studies, frailty was associated with older age and multiple comorbidities. The association between frailty and intraoperative complications found in this study may indicate and help inform areas of further research.