The Role of Precision Anesthesia Strategy on Perioperative Organ Protection in Hip Surgery [PASPOP]

The goal of this clinical trial is to investigate the effect of three anesthetic strategies on organ protection in elderly patients undergoing hip fracture surgery.

The main questions it aims to answer are: 1.Does the nerve block anesthesia group have a protective effect on the incidence of postoperative delirium in elderly patients undergoing hip surgery? 2.Does the nerve block anesthesia group also provide protective effects on other organs for elderly patients undergoing hip surgery? 3.What effects will these anesthetic strategies have on short-term and long-term prognosis of elderly patients undergoing hip surgery?

The investigators will compare it with the spinal anesthesia group and the general anesthesia group to see which has a better protective effect on organs.

Participants will undergo preoperative interviews and will be interviewed twice daily, in the morning and evening, from postoperative day 1 to 7 or until discharge, to assess the occurrence of delirium and cognitive levels, pain intensity, and sleep status.

Interventions:

1. Nerve block anesthesia group (NA group): Combined Lumbar and Sacral Plexus Block + sedation or laryngeal mask anesthesia
2. General anesthesia group (GA group): General anesthesia (Endotracheal intubation) + iliac fascial block
3. Spinal anesthesia group (SA group): Spinal anesthesia without any nerve blockade

Background: Over 10 million hip fractures happen per year globally, which lead to a burden on patients, their families, and healthcare systems.98% hip fracture patients require orthopedic surgery. Hip fracture patients are typically elderly and often have multiple comorbidities, decreased organ function, poor physical tolerance, high anesthesia risks, and slow postoperative recovery. Perioperative blood loss is considerable during hip surgery, and the stress response is significant, often leading to severe postoperative pain, which can result in organ damage and complications. These patients pose challenges to anesthesia management, but at the same time, making the anesthetic care episode a major opportunity to impact outcomes.In clinical practice, general anesthesia and spinal anesthesia are the two most commonly used anesthesia strategies. However, current domestic and international studies believe that there is no difference in outcomes for patients undergoing hip surgery under these two strategies. With the advancement of medical science, nerve blocks, due to precise action on the surgical area and effective suppression of postoperative pain, are increasingly applied in clinical settings. When combined with light general anesthesia, nerve blocks can meet surgical requirements. Nerve blocks can reduce quadriceps spasms, decrease stress responses, help maintain hemodynamic stability, and thus might have potential organ-protective effects. Due to the inconsistent clinical research outcomes regarding nerve blocks, coupled with a lack of high-quality study results, the investigators plan to conduct this study to explore the anesthetic strategy with the most prognostic improvement value for patients undergoing hip surgery. So, it will fill critical evidence gaps to inform policy and practice.

Purpose: The purpose of this study is to explore, in the real world, which anesthesia strategy has more organ-protective effects and accelerates postoperative recovery for patients undergoing hip surgery.

Research Design: A prospective randomized three-arm parallel-group double-center exploratory trial with blinded end point evaluation.

Primary hypothesis is that participantis who receive combined lumbar plexus and sacral plexus block + sedation or laryngeal mask anaesthesia will demonstrate improved recovery after randomisation compared with participants who receive general anaesthesia or spinal anesthesia.

Research population: Elderly patients with acute hip fractures requiring surgical treatment.

Interventions:

Participants randomly assigned to NA or GA or SA group in a 1:1:1 ratio.

1. Nerve block anesthesia group (NA group): Combined Lumbar Plexus and Sacral Plexus Block + sedation or laryngeal mask anesthesia. Participants assigned to the NA group will receive lumbar-sacral plexus block combined with laryngeal mask anesthesia. The lumbar-sacral plexus block (0.33% ropivacaine 30ml+20ml) will be performed under the guidance of an ultrasound or nerve stimulator, and the effectiveness of the block will be assessed 20 minutes after the nerve block. Subsequently, participants will undergo sedation or laryngeal mask anesthesia.
2. General anesthesia group (GA group): General anesthesia + iliac fascial block .Participants assigned to the GA group will receive iliac fascial block combined with endotracheal intubation general anesthesia. The iliac fascial block (0.33% ropivacaine 30ml) will be performed under the guidance of an ultrasound or nerve stimulator, and the effectiveness of the block will be assessed 20 minutes after the nerve block. Subsequently, participants will undergo endotracheal intubation general anesthesia.
3. Spinal anesthesia group (SA group):Spinal anesthesia without any nerve blockade. Participants assigned to the SA group will receive spinal anesthesia with or without sedation. Spinal anesthesia is The spinal puncture site is at L2-3 or L3-4. After the puncture needle reaches the subarachnoid space, 1% ropivacaine 0.8-2 ml, totaling 8-20mg, is injected. Depending on the center's practice, it may be replaced with an equivalent dose of bupivacaine .

Statistical analysis:

This study employed R Studio software version 4.3.3 (R Project for Statistical Computing) for data analysis. The specific methodologies are detailed below:

Analysis Principles Primary analysis set: Intent-to-treat (ITT) analysis Randomization method: Stratified randomization by study center

Data Distribution Assessment Normality of continuous variables was evaluated using the Shapiro-Wilk test Normally distributed data: Presented as mean ± standard deviation (Mean ± SD) Non-normally distributed data: Presented as median (interquartile range, Median \[IQR\])

Intergroup comparison methods Continuous variables

For normally distributed data:

Intergroup comparisons among three groups were performed using one-way analysis of variance (ANOVA).

When ANOVA showed significant differences (P \< 0.05), pairwise comparisons were conducted using Student's t-test with Bonferroni correction.

For non-normally distributed data:

Intergroup comparisons were performed using the Kruskal-Wallis nonparametric test.

When significant differences were detected, pairwise comparisons were conducted using the Mann-Whitney U test.

Median differences were calculated using Hodges-Lehmann estimators with 95% confidence intervals (95% CI).

Categorical variables were presented as frequency (percentage, n (%)), Intergroup comparisons were performed using chi-square test (χ² test) or Fisher's exact test (for small sample sizes).

Statistical Significance Criteria:

All tests were two-sided, Significance threshold: P \< 0.05.

Multiple comparison adjustment: When performing multiple pairwise comparisons, the significance level (α) was adjusted to 0.05/number of comparisons (Bonferroni method)

Study end points will be assessed via in-person interview (during hospitalisation), medical record review, telephone interview(after hospital discharge).

This study is designed as a Pilot study to provide data reference for future large-sample studies. The study plans to include 30 patients per group, totaling 90 patients across three groups.

Statistical Analysis: The statistical analysis software used was SAS 9.4. ① For the primary outcome measures, continuous variables were analyzed and expressed using standard deviation mean or interquartile range median, and the distribution type of the data was assessed for normality. Categorical variables were represented by counts and percentages. A modified intention-to-treat (ITT) analysis was employed. Randomization was stratified by hospital. The risk of the primary outcome was compared within each group. Additionally, the primary outcome measures could also be analyzed using a generalized linear model to adjust for potential confounding factors, Risk Ratio (crude, adjusted), and their 95% CI. The model was adjusted for the type of surgery and sensitivity analysis was performed to clarify the impact of data missingness on the robustness of the model. ② For the analysis of secondary outcome measures, depending on the variable situation, different types of variables were analyzed using generalized linear models, generalized estimating equations, Winratio, and COX regression, respectively.

Analysis of Data: All analyses were two-tailed tests, with a statistically significant difference set at P\<0.05.

Expected test progress: 30 days

Eligibility Criteria:
Inclusion Criteria:

1. Aged 65 years and older
2. American Society of Anesthesiologists (ASA) physical status 1 to 3
3. Scheduled for unilateral hip surgery

Exclusion Criteria:

1. Have psychiatric disorders or cognitive impairments, or are unable to understand the scale
2. Have a heart failure history (EF \< 40) or a history of AMI in 3 months
3. Complex injuries: multiple fractures, chest, abdomen, pelvic and sacral trauma, head trauma, etc.
4. Combined with respiratory failure or hepatic failure (Child-Pugh C) or renal failure (rely on dialysis treatment)
5. Nerve block contraindication: puncture site infection, peripheral neuropathy, regional anesthetic allergy, etc.
6. Contraindications of intraspinal anesthesia: coagulation dysfunction, thrombocytopenia, intraspinal space occupying, infection of puncture site, etc.
7. Relative contraindications of general anesthesia: known difficult airway, malignant hyperthermia, etc.
8. Enrolled in another randomized clinical trial