BACKGROUND Hip fractures occur frequently and are usually very painful. Pain itself is an
indicator for increased risk of complications. A significant complication is delirium,
occurring in up to 25% of all elderly patients with hip fractures. For a large proportion,
triggers for development of delirium reaches back to the preoperative phase, where
polypharmacy (including opioid use) and inadequately treated pain are major risk factors.
Delirium is associated with negative health consequences, increased hospital stay, falls,
higher mortality, decreased physical and cognitive function, re-hospitalization, increased
risk of dementia and increased societal costs. Therefore, pain should be optimally treated as
soon as possible, however the elderly patient poses a challenge in good pain treatment,
because of physiological age-related changes, different drug effects, distribution,
metabolism and elimination. Opioids frequently lead to respiratory depression, hypotension,
nausea/vomiting and sedation in this vulnerable patient group. As a consequence, these drugs
are often under dosed and pain treated insufficiently. Besides, drugs as opioids and NSAIDs
have been associated with an increased delirium risk. A nerve block could alleviate these
clinical issues.
An example of a nerve block frequently utilized in the Emergency Department (ED) is a Fascia
Iliaca Compartment Block (FICB), in which local anesthetics are injected underneath the
pelvic iliac fascia in order to block femoral, obturator and lateral cutaneous nerves to
provide anesthesia of hip, thigh and knee. Case-series and historically controlled cohort
studies show a single-shot FICB is a rapid, safe and easy procedure providing excellent
analgesia, decreased opioid need and little risk of complications. Delirium as outcome was
reported in one RCT; a decreased delirium incidence after using repetitive, blind,
single-shot FICBs (not in the acute setting) with pethidine (with increased intrinsic risk of
developing delirium) as comparison. In order to prevent the need for repetitive insertions,
leaving a catheter would create a route in order to provide continuous analgesia with local
anesthetics. Two case series describe this continuous FICB in hip fractures and reported good
pain control and decreased length of hospital stay without any infectious complications. No
comparison studies have been done with a continuous FICB.
The objective of the current study is to investigate whether the use of a continuous FICB,
started early (in the ED) and continued throughout the complete clinical course of a hip
fracture, will decrease occurrence of delirium in elderly patients with hip fractures.
METHODS This study is designed as a prospective, open, multi-center, randomized
interventional trial. Patients will be allocated to continuous FICB or care as usual
(according to national guidelines) in a 1:1 ratio and followed up until three months after
hospital discharge.
SAMPLE SIZE AND DATA ANALYSIS The primary outcome (occurrence of delirium) is expected to be
distributed normally. Although evidence to prevent delirium is scarce, an absolute reduction
of 13% incidence has been reported previously after an intervention. The estimated delirium
incidence according to literature is 25%. The hypothesis is that by using a continuous FICB
administered very early in the clinical course in the ED, the incidence can be decreased from
25 to 12%. Superiority of the FICB versus usual care will be tested using the Chi Square
Test. In order to detect a clinically relevant between-group-difference of 13% decrease in
incidence, a significance level of 0.05 and 80% power will be used. For this analysis, each
group will have 154 patients. When accounting for 10% loss to follow-up after three months, a
total study population of 340 will be needed.
The primary analysis will be based on the intention to treat principle. Per protocol analysis
will be performed to check robustness of results. Baseline characteristics will be presented
using descriptive statistics. Ordinal data will be analyzed using Chi Square Test or Fisher
exact test. Continuous data will be assessed by a Student's t-test if normally distributed or
Mann Whitney U test if otherwise. Missing data will be corrected by multiple imputation.
An economic evaluation will be performed focusing on possible gained benefits of pain
management with a continuous FICB compared to care as usual and the related health care
costs. The economic evaluation will be performed from a societal perspective with a time
horizon of three months and capturing the value of all resources utilized. The economic
evaluation will be set up as a Cost-Effectiveness Analysis (CEA). Besides a CEA, a Budget
Impact Analysis (BIA) will be performed according to the ISPOR Task Force principles.
