The application of iliac fascia space block combined with esketamine intravenous general anesthesia in PFNA surgery of the elderly: A prospective, single-center, controlled trial

Abstract To observe the effect of iliac fascia space block combined with esketamine intravenous general anesthesia in proximal femoral nail antirotation (PFNA) of the elderly. Eighty elderly patients who underwent PFNA were randomly divided into experimental group and control group. In the experimental group, iliac fascial block combined with esketamine and propofol intravenous general anesthesia was used to keep spontaneous breathing. The control group used iliac fascia block combined with remifentanil and propofol intravenous general anesthesia to maintain spontaneous breathing. Record important indexes such as heart rate (HR), mean arterial pressure (MAP), pulse oxygen saturation (SpO2), visual analogue score (VAS) scores, etc. at different moment during the operation. Trial data showed that there were significant differences in HR, MAP, and SpO2 between the two groups at the beginning of operation, and there was no significant difference in VAS scores between the two groups at each moment after surgery, and there were significant differences in the number of vasopressor applications, length of hospital stay, and QoR-15 scores between the two groups, and there were significant differences in the incidence of total adverse reactions and the incidence of hypotension. The trial indicated that patients in the experimental group have more stable hemodynamics and lower stress response, which is conducive to rapid recovery after surgery.


Introduction
Intertrochanteric fractures of the femur occur more often in the elderly and are often treated with proximal femoral nail antirotation (PFNA) internal fixation [1,2].At present, this procedure mostly uses neuraxial anesthesia or general anesthesia.Previous studies have shown that the above two anesthesia methods have good anesthesia effects on elderly patients with intertrochanteric fractures, and there are no obvious differences [3], but neuraxial anesthesia has problems such as difficult control of anesthesia plane, difficult operation, and easy to cause secondary injury in position [4].General anesthesia alone interferes greatly with the patient's physiology and easily increases the risk of postoperative complications [5].The choice of the best anesthesia modality remains controversial, and safe and reliable anesthesia methods remain one of the key factors in the success of PFNA, as well as the use of new drugs, new anesthesia techniques, or combinations.Therefore, this article studies the application of fascia iliac block combined with esketamine intravenous general anesthesia in elderly patients with PFNA, so as to provide a reference for further improving the management of perioperative anesthesia.

General information
A total of 80 elderly patients who underwent elective PFNA internal fixation from November 2021 to August 2022 were randomly divided into experimental group (S group) and control group (C group), with 40 cases in each group.In the experimental group, fascial iliac block was used combined with esketamine and propofol intravenous general anesthesia to preserve the patient's spontaneous breathing.The control group used fascial iliac block combined with refentanil, propofol, and laryngeal mask to assist spontaneous breathing.Inclusion criteria: elective surgery patients who can actively cooperate, have normal heart, liver, kidney and lung function before surgery, and are not allergic to the drugs used in this study.Age > 65 years old, regardless of gender, body mass index (BMI) 18-28 kg/m 2 , American society of anesthesiologists (ASA) score II-III.Exclusion criteria: patients with neurological, psychiatric diseases, hematologic, immune system, respiratory system and other major diseases, history of allergy or addiction to esketamine and propofol, and contraindications to surgery.Approved by the ethics committee of our hospital, the patient signed the informed consent form before surgery.

Anesthesia method
Both groups routinely fasted from eating and drinking.All patients were given intravenous access, nasal cannula for 2 L/min of oxygen, and routine monitoring of blood pressure (BP), heart rate (HR), and pulse oxygen saturation (SpO 2 ).Under the guidance of ultrasound, the iliac fascia space block (modified high iliac fascia space block-subvascular method) was performed, and the specific process could be described as follows.First, placed the sterilesheathed ultrasound probe on the position, which was on the line connecting the navel and the anterior superior iliac spine on the side of the anterior superior iliac spine.Once the iliacus muscle and anterior superior iliac spine were identified, the outer end of the probe was adjusted to approximately 15°inward rotation.Then, using the inplane technique, the tip of the ultrasonic probe was placed under the deep circumflex iliac artery and 30 mL of 0.375% ropivacaine hydrochloride and 0.5 µg/kg dexmedetomidine were injected into that area.After injection, the deep circumflex iliac artery moved upwards and the iliacus muscle moved downwards, followed by invasive arterial monitoring and Bis monitoring.
After the successful block, the patients in S group were maintained with the dose of 0.3 mg/kg/h of esketamine and the dose of 2-4 mg/kg/h of propofol under micropump anesthesia, and 0.3-0.5 mg/kg of esketamine was slowly injected intravenously at the beginning of surgery (before skin incision).During the operation, if the patient had a body movement reaction, the anesthesiologist could add 0.25 mg/kg of esketamine in a single dose according to the patient's condition.The C group pumped refentanil and propofol, in target-controlled infusion mode, the Minto model and Marsh model were selected, respectively, and 2.5-4.5 ng/mL of refentanil and 2-3 μg/mL of propofol were loaded first, the eyelash reflex of the patient to be observed disappeared, and when the Bis value of the anesthesia depth was below 60, the target concentration of refentanil and 1-2 μg/mL propofol was maintained, and a laryngeal mask was inserted, and spontaneous breathing was retained (spontaneous breathing mode of the anesthesia machine).After receiving a load dose of remifentanil and propofol, patients in C group might experience temporary respiratory depression as the blood concentration increased.At this moment, it was necessary to change to controlled breathing mode and observe the waveform of end-tidal carbon dioxide.After the patient had spontaneous breathing, the anesthesia machine was adjusted to spontaneous breathing mode, and the Bis value was maintained at 40-60 during the operation.When the patient's BP was below 20% of the preoperative basal value, the vasoactive drug ephedrine or metahydroxylamine was given.After the operation, if the visual analogue score (VAS) of patients in both groups was greater than 5, both groups were given 15-30 mg of ketorolone for pain relief.

Observation index
HR, mean arterial pressure (MAP), and SpO 2 at the time of admission (T0), at the beginning of surgery (T1), 15 min from the beginning of surgery (T2), and at the end of surgery (T3); VAS scores of 2 h (T4), 6 h (T5), 12 h (T6), 24 h (T7), and 48 h (T8) were recorded postoperatively.The number of intraoperative vasopressor doses, the quality of recovery at 24 h after surgery, and the length of hospital stay were recorded.Assessment of postoperative 24 h recovery quality (QoR-15) score (15 quality of recovery questionnaire 15 (QoR-15), a total score of 150 points, each score is scored by 0-10 points, the sum is taken as the final evaluation result, the higher the total score, the better the patient's recovery quality [6]).Adverse effects such as nausea and vomiting, hypotension, hyperalgesia, and delirium were recorded.

Statistical analysis
The statistical data are analyzed using SPSS 22.0.The measurement data were expressed by ( ± x s ¯), and the t-test was used for comparison.The counting data are represented by cases or percent (%), and the χ 2 test was used for comparison.P < 0.05 was statistically significant.

Results
There were no significant differences in age, BMI, and ASA scores between the two groups (P > 0.05) (Table 1).
The distribution and mean value of HR, MAP, and SpO 2 of the two groups at T0, T1, T2, and T3 are shown in Figures 1-3.Taking the distribution of the measured values of HR of the S group at T0 as an example, the box diagram contains the upper adjacent, lower adjacent, and median of the distribution of the measured values.The box part represents the interval of most measured values.
At the T1 time, the differences in HR, MAP, and SpO 2 between the two groups are statistically significant (P < 0.05), while the differences between the two groups at other times are not statistically significant (P > 0.05) (Table 2).
The distribution and mean value of VAS scores of patients in the two groups after operation are shown in Figure 4.There is no significant difference in VAS scores between the two groups at each moment after surgery (P > 0.05) (Table 3).
There are significant differences in the number of vasopressor applications, length of hospital stay, and QoR-15 scores between the two groups (P < 0.05) (Table 4).
There is no significant difference in the incidence of intraoperative nausea and vomiting, hyperalgesia, and delirium between the two groups (P > 0.05).There are significant differences in the incidence of total adverse reactions and the incidence of hypotension (P < 0.05) (Table 5).

Discussion
Due to the advanced age, organ function, and compensatory function of elderly patients, often accompanied by cardiovascular and cerebrovascular diseases, they are more sensitive to anesthesia drugs, and are high-risk groups of anesthesia, and need to complete the operation under a safe and reliable anesthesia program.Nerve block has the advantages of small impact on circulatory, respiratory, and physiological functions, and has been widely reported in elderly hip surgery and lower limb surgery, especially for elderly patients with many comorbidities, but nerve block alone can easily lead to block insufficiency and cannot meet the needs of surgery [7].Ultrasound-guided fascia iliac space block can effectively block the innervated femoral nerve and lateral femoral cutaneous nerve in the PFNA surgical area, and has the advantages of accurate  A prospective, single-center, controlled trial  3 positioning, fast onset, long duration of blockade, and hemodynamic stability [8].Esketamine has sedative, analgesic, and anesthetic effects and has a positive effect on the patient's postoperative mood [9].Therefore, the combination of ultrasound-guided fascia iliac space block and esketamine in elderly PFNA should have obvious advantages.
Both anesthesia regimens were found to be effective, patients completed surgery as planned, and VAS scores indicated that postoperative analgesia was accurate in all patients.Comparing the vital signs at each moment, it was found that the HR, MAP, and SpO 2 indicators in the experimental group were stable at each moment, the HR, MAP,  and SpO 2 in the control group at the T1 moment decreased significantly, and the T2 and T3 gradually recovered, which should be related to the control group's use of opioids combined with propofol to maintain anesthesia.Literature [10,11] studies have shown that ultrasound-guided fascia iliac space block accurately and safely delivers anesthetics to the vicinity of the peripheral nerve trunk in the PFNA surgery area, which can effectively block the impulse conduction of nerves, and basically does not affect the patient's intraoperative BP, HR and pulse, and other vital signs, while in this study, both groups of patients used fascial iliac block, and the blocking method and medication were completely consistent; therefore, the impact of nerve block on the hemodynamics of the two groups of patients could be excluded.Refentanil is a powerful anesthetic analgesic drug, while propofol is a short-acting alkylphenol intravenous anesthetic drug, both have the advantages of fast onset, short maintenance time, rapid postoperative  recovery, etc. Clinically, the two drugs are used in combination, but these two drugs have a certain inhibitory effect on the patient's breathing, circulatory system, etc., and the degree of inhibition is obviously positively correlated with the dose of anesthetic drugs [12].Thus, after the control group was given a loading dose of refentanil and propofol, the inhibitory effect of the two produced a synergistic effect, resulting in a transient decrease in BP and pulse oxygen.The above results also show that the experimental group can better maintain the hemodynamic stability of patients, because esketamine has sympathetic excitatory effect, which can neutralize the inhibitory effect caused by propofol drugs, stabilize circulation, control BP, and maintain stable vital signs [13,14].
Relevant studies have shown that opioids, while effectively exerting analgesic effects, inevitably bring adverse reactions such as nausea and vomiting, hypotension, hyperalgesia, and delirium due to dose dependence [15].The results showed that the experimental group significantly reduced the incidence of adverse reactions, especially the absence of hypotension, hyperalgesia, and delirium, suggesting that it was safe and reliable.The clinical adverse reactions of esketamine are similar to ketamine, such as easily inducing mental reactions, and are dose related.
Although the incidence rate of the clinical adverse reactions of esketamine is significantly lower than that of ketamine, it also limits the application of esketamine [16].Two possible reasons are analyzed for the absence of hallucinations, delirium, and other psychological reactions in the experimental group.On the one hand, it is related to the combined application of propofol.Due to the activation of γ-aminobutyric acid receptors by propofol, the mental reactions such as hallucinations and delirium could be effectively suppressed [17].On the other hand, the dose of esketamine used in this study is lower than the recommended dose of the drug (0.5 mg/kg).Literature [18] studies the effect of esketamine on the early postoperative cognitive function of elderly patients undergoing knee arthroplasty.The patient's intravenous dose before skin incision is 0.5 mg/kg and the maintenance dose is 0.4 mg/kg/h, which is greater than that in our research.The conclusion in literature [18] is that no obvious adverse reactions are found.
Literature [19] shows that hypotension is an independent risk factor for postoperative delirium, but delirium did not occur in the experimental group, and the number of cases of hypotension in the intraoperative use of vasopressors and adverse reactions was significantly lower  than that in the control group, which further verified that esketamine combined with fascia iliac block can maintain hemodynamic stability in patients.For the experimental group did not appear hyperalgesia and the control group had one patient, because esketamine can block the activity of spinal NMDA receptor and effectively inhibit central pain sensitization [20], remifentanil can enhance spinal NMDA receptor activity and induce central pain sensitization, especially continuous infusion during the anesthesia maintenance phase is a high-risk factor for refentanilinduced hyperalgesia [20,21].The literature [22,23] also suggests that esketamine is effective in preventing hyperalgesia caused by refentanil.From the fact that the hospitalization time of patients in the experimental group was significantly less than of the control group, and the QoR-15 score was significantly better than that of the control group, it can also be directly seen that the quality of recovery of patients in the experimental group is better, which is more conducive to the rapid recovery of patients.In summary, fascial iliac block combined with esketamine intravenous general anesthesia in elderly patients can provide safe and reliable anesthesia effect for elderly patients, simple and easy operation, more stable intraoperative hemodynamics, and does not increase the incidence of adverse reactions, shortens the hospital stay, is conducive to the postoperative rehabilitation of elderly patients, and provides a safe and effective anesthesia method for elderly patients to undergo PFNA surgery.

Figure 1 :
Figure 1: Distribution and mean value of HR of the two groups.

Figure 3 :
Figure 3: Distribution and value of SpO 2 of two groups.

Figure 2 :
Figure 2: Distribution and value of MAP of the two

Figure 4 :
Figure 4: Distribution and mean value of VAS of the two groups.

Table 1 :
Comparison of the general condition of the two groups

Table 2 :
Comparison of HR, MAP, and SpO 2 at different time points between the two groups ( ± Indicates that the T0 moment is compared with each point in the group, and P < 0.05; b indicates P < 0.05 compared with each time point between the groups.

Table 3 :
Comparison of VAS scores at different postoperative moments between the two groups ( ±

Table 4 :
Comparison of vasopressor doses, length of hospital stay, and QoR-15 scores between the two groups (n = 40, ±

Table 5 :
Comparison of the incidence of adverse reactions between the two groups (n (%))