A Dose Finding Study for Pain Relief of a Broken Hip

Overview

Studies have suggested a link with effective pain relief and reduced illness and death in high risk patients. Ultrasound guided nerve blocks have been associated with an increased success rate and allow visualization of all the anatomical structures and the distribution of the local anesthetic on injection. The hospital mortality for patients admitted to hospital from home in the UK in 2006 with a fractured hip is 14.3% (Bottle and Aylin 947-51). The aim of this clinical trial is to determine the effective dose of local anesthetic to provide pain relief to patients with a broken hip using ultrasound to guide needle insertion. The hospital mortality for patients admitted to hospital from home in the UK in 2006 with a fractured hip was 14.3%. Patients for emergency surgical fixation or replacement of broken hip will be recruited prior to surgical fixation. All patients recruited to this study will receive standard anesthesia and surgical fixation of their broken hip. The trial can be divided into two sequential parts; the results of part A will be an amount of local anesthetic which will relieve pain of a broken hip in 95% of all patients. Part B will determine the duration of pain relief provided by the amount of local anaesthetic from part A and blood levels of local anesthetic. In parts A and B a standard pain relieving nerve block to numb the nerves supplying the hip joint will be administered using ultrasound to guide the injection of local anesthetic. The patient will then be observed for 30 minutes during which time the feeling in the upper leg and pain scores will be recorded. Patients with ineffective nerve blocks will be given immediate pain relief and withdrawn from further participation in the study. In part A the amount of local anesthetic for the next patient will be increased or decreased if the nerve block is ineffective or effective respectively. In part B the dose will be the same (calculated from the results of part A). In order to determine the duration of pain relief pain scores will be recorded hourly for up to 24 hours. Blood samples will be taken before the pain relieving nerve block and at 5, 10, 20, 30 and 60 minutes afterwards.