BACKGROUND: Impaired cognition is a major risk factor for perioperative delirium. It is essential to provide good pain control in patients with hip fractures and especially important in patients with severely impaired cognitive status, as they receive less pain medication, have poorer mobility, poorer quality of life and higher mortality than patients with intact cognition. The purpose of this study was to examine the association between preoperative pain management with nerve blocks and cognitive status in patients with hip fractures during the perioperative period.

METHODS: One hundred and twenty-seven patients with hip fractures participating in a double-blind, randomised, controlled trial were included in this study. At hospital admission, a low-dose fascia iliaca compartment block (FICB) was administered as a supplement to regular analgesia. Cognitive status was registered on arrival at hospital before FICB and on the first postoperative day using the Short Portable Mental Status Questionnaire.

RESULTS: Changes in cognitive status from arrival at hospital to the first postoperative day showed a positive, albeit not significant, trend in favour of the intervention group. The results also showed that patients with no or a moderate cognitive impairment received 50% more prehospital pain medication than patients with a severe cognitive impairment. FICB was well tolerated in patients with hip fractures.

CONCLUSION: Fascia iliaca compartment block given to patients with hip fractures did not affect cognitive status in this study. Patients with a cognitive impairment may receive inadequate pain relief after hip fracture and this discrimination needs to be addressed in further studies.

TRIAL REGISTRATION: EudraCT number 2008-004303-59 date of registration: 2008-10-24.