The effects of early femoral nerve block intervention on preoperative pain management and incidence of postoperative delirium geriatric patients undergoing trochanteric femur fracture surgery: A randomized controlled trial.

BACKGROUND: Hip fracture is a common clinical problem which causes severe pain in geriatric patients. However, severe pain following fracture may bring on mental disorders and delirium. A neuroinflammatory response with IL-6 and IL-8 has been shown to be associated with the pathophysiology of delirium. In this study, our primary hypothesis is that preoperative femoral nerve block (FNB) intervention in geriatric patients will more effectively attenuate pain following trochanteric femur fracture than the preoperative paracetamol application. Our secondary hypothesis is that interleukin levels (IL-6, IL-8) in cerebrospinal fluid (CSF) will be lower in the femoral nerve block group than the paracetamol group. Our tertiary hypothesis is that the incidence of postoperative delirium will be lower in the femoral nerve block group. METHODS: The patients over 65 years of age with ASA status II-IV and admitted to the Emergency Service for femur fracture were included in this study. Recommendations of the 'delirium prevention table' were applied to all of the patients at arrival. In the first group, 15 mg/kg paracetamol was administered intravenously every eight hours. In the second group, femoral nerve blockage was performed, and a catheter was placed. Then, 0.5 mL/kg bupivacaine 0.25% was applied every eight hours. In both groups, pain scores four hours after interventions were recorded. All patients were operated within 48 hours under spinal anesthesia. During spinal anesthesia, 2 mL of CSF samples were taken from all patients for analysis of IL-6 and IL-8 cytokines, and pain scores during positioning were recorded. RESULTS: VAS scores four hours after the first preoperative pain treatment and during the positioning for regional anesthesia were significantly lower in the femoral nerve block group. IL-8 levels are significantly lower in the femoral nerve block group but not in IL-6 levels. The incidence of delirium was less in the femoral nerve block group, but the difference was not statistically significant. CONCLUSION: The femoral nerve block was more effective in preoperative pain management of trochanteric femur fracture and preventing pain during regional anesthesia application. The mean IL-8 level was lower in the femoral nerve block group when compared to the paracetamol group. There is no difference in the postoperative delirium incidence between groups.

Assessment of Distal Motor Latency of the Femoral Nerve in Clinically Healthy Adult Dogs.

This study aimed to evaluate femoral nerve latency time recorded from both vastus lateralis and vastus medialis muscles, in clinically healthy dogs. Eighteen adult dogs were distributed into 2 distinct body mass ranges (Group 1: 1-4.1 kg, n= 9; Group 2: 4.2-13 kg, n= 8), according to the median body mass (4.1 kg). Distal motor latencies for the femoral nerve were obtained in right- and left hind limbs. Platinum surface electrodes were used to record the latency of femoral nerve from the vastus lateralis muscle, whereas coaxial needle electrodes were used to record the latency from the vastus medialis muscle. The distal motor nerve latencies were 1.52 ± .23 milliseconds and 1.69 ± .42 milliseconds, respectively, for vastus lateralis and vastus medialis muscles. There were no significant differences of distal motor nerve latencies between vastus lateralis and vastus medialis muscles. Hind limb length of Group 1 was significant shorter than Group 2. There were no significant differences of latencies between Groups 1 and 2. No significant correlations were observed between latency and body mass, and between latency and hind limb length for dogs of both groups. In conclusion, the femoral motor latency measurement was easy to obtain and may supply additional data in the examination of diseases that affect the hind limbs. Latency values of vastus lateralis longer than 1.52 ± .23 milliseconds in small/medium-sized breeds may be considered as suggestive of a femoral neuropathy.

Assessment of quadriceps muscle inactivation with a new electrical stimulation paradigm.

INTRODUCTION: In this study we evaluated the validity of garment-based quadriceps stimulation (GQS) for assessment of muscle inactivation in comparison with femoral nerve stimulation (FNS). METHODS: Inactivation estimates (superimposed doublet torque), self-reported discomfort, and twitch and doublet contractile properties were compared between GQS and FNS in 15 healthy subjects. RESULTS: Superimposed doublet torque was significantly lower for GQS than for FNS at 20% and 40% maximum voluntary contraction (MVC) (P < 0.01), but not at 60%, 80%, and 100% MVC. Discomfort scores were systematically lower for GQS than for FNS (P < 0.05). Resting twitch and doublet peak torque were lower for GQS, and time to peak torque was shorter for GQS than for FNS (P < 0.01). CONCLUSIONS: GQS can be used with confidence for straightforward evaluation of quadriceps muscle inactivation, whereas its validity for assessment of contractile properties remains to be determined.

Nonvolitional assessment of muscle endurance in idiopathic inflammatory myopathies: there is no relationship between patient-reported fatigue and muscle fatigability.

INTRODUCTION: We investigated whether muscle endurance differs between IIM patients and controls and if a relationship exists between perceived fatigue and poor muscle endurance. METHODS: Quadriceps contractility, measured using femoral nerve stimulation (TwQ), and strength, measured using maximal voluntary contraction (MVCQ), were assessed in 20 IIM patients and matched controls. Quadriceps endurance was assessed using repetitive electrical stimulation (3 minutes). Time for force to fall to 70% initial force was determined (T70). Reported fatigue was measured using the FACIT-F/Fatigue Severity Scales. RESULTS: TwQ and MVCQ were lower and perceived fatigue greater for patients. There was no difference in T70 between groups. No relationships were observed between perceived fatigue and endurance (T70). CONCLUSIONS: IIM patients reported more fatigue and were weaker than controls, but there was no difference in muscle endurance. Endurance and strength were unrelated to reported fatigue measures. Mechanisms driving perceived IIM fatigue are likely to be multifactorial.

Quadriceps function assessment using an incremental test and magnetic neurostimulation: a reliability study.

We investigated the reliability of a test assessing quadriceps strength, endurance and fatigability in a single session. We used femoral nerve magnetic stimulation (FMNS) to distinguish central and peripheral factors of neuromuscular fatigue. We used a progressive incremental loading with multiple assessments to limit the influence of subject's cooperation and motivation. Twenty healthy subjects (10 men and 10 women) performed the test on two different days. Maximal voluntary strength and evoked quadriceps responses via FMNS were measured before, after each set of 10 submaximal isometric contractions (5-s on/5-s off; starting at 10% of maximal voluntary strength with 10% increments), immediately and 30min after task failure. The test induced progressive peripheral (41±13% reduction in single twitch at task failure) and central fatigue (3±7% reduction in voluntary activation at task failure). Good inter-day reliability was found for the total number of submaximal contractions achieved (i.e. endurance index: ICC=0.83), for reductions in maximal voluntary strength (ICC>0.81) and evoked muscular responses (i.e. fatigue index: ICC>0.85). Significant sex-differences were also detected. This test shows good reliability for strength, endurance and fatigability assessments. Further studies should be conducted to evaluate its feasibility and reliability in patients.

Muscle inactivation: assessment of interpolated twitch technique.

The validity, reliability, and protocol for the interpolated twitch technique (ITT) were investigated with isometric plantar flexor and leg extension contractions. Estimates of muscle inactivation were attempted by comparing a variety of superimposed with potentiated evoked torques with submaximal and maximal voluntary contraction (MVC) torques or forces. The use of nerve and surface stimulation to elicit ITT was reliable, except for problems in maintaining maximal stimulation with nerve stimulation at 20 degrees plantar flexion and during leg extension. The interpolated twitch ratio-force relationship was best described by a shallow hyperbolic curve resulting in insignificant MVC prediction errors with second-order polynomials (1.1-6.9%). The prediction error under 40% MVC was approximately double that over 60% MVC, contributing to poor estimations of MVC in non-weight-bearing postimmobilized ankle fracture patients. There was no significant difference in the ITT sensitivity when twitches, doublets, or quintuplets were used. The ITT was valid and reliable when high-intensity contractions were analyzed with a second-order polynomial.