The fascia iliaca block was originally described in children and involved the detection of a double pop sensation as the needle transverses the fascia lata and fascia iliaca of the thigh. 14 The fascia iliaca block, also called the fascia iliaca compartment block, is a well-established alternative to lumbar plexus or femoral nerve blocks to provide analgesia for hip procedures [1]. The analgesic efficacy of this technique assumes that injection of local anesthetic beneath the fascia iliaca spreads underneath the fascia and reaches the femoral nerve, lateral femoral cutaneous nerve of the thigh, and the obturator nerve [2]. This block has been performed by landmark and loss of resistance techniques previously, but with the advent of ultrasound, it became apparent that many of these blind techniques result in improper deposition of local anesthetic [1].  The ultrasound-guided fascia iliaca block has evolved from the classic infra-inguinal approach to a supra-inguinal approach to spread local anesthetic cranially, more consistently reaching the lumbar plexus, and resulting in greater analgesic efficacy [3].  The fascia iliaca compartment block is a widely used method of postoperative analgesia along with opioids for hip surgeries, and it can be performed either by the conventional approach or the modified proximal supra-inguinal approach. 5 Pain control after THA is a debatable topic since there are no strong recommendations or uniform guidelines. Uncontrolled pain is associated with delayed physical therapy, which prolongs the patients’ rehabilitation period, increases the length and cost of hospital stay, and decreases patient satisfaction with the operation [4]. Opioids are established as the best treatment for postoperative pain; however, their serious side effects, such as respiratory depression and risk of dependence, have increased the need to search for safer alternatives.8 Ropivacaine is another amide local anesthetic structurally similar to bupivacaine, which has emerged as a potential alternative to bupivacaine. It is structurally similar to bupivacaine but exhibits a lower potential for cardiotoxicity and CNS toxicity and improves the relative sensory to motor profiles. The pharmacological profile makes ropivacaine an alternative option [5]. With this background, we in the current study tried to compare the efficacy of ultrasound-guided supra inguinal fascia illiaca block and the infra inguinal fascia illiaca block for postoperative analgesia in patients undergoing hip surgeries in our tertiary care hospital.

It is a comparative study with a duration of 2 years, conducted on 100 patients, in the Department of Anesthesiology, Osmania General Hospital Hyderabad, Telangana. Institutional Ethical approval was obtained for the study. Written consent was obtained from all the participants of the study after explaining the nature of the study in vernacular language.

Inclusion criteria

1. Age 18 – 70 years
2. Males and Females
3. ASA grades I, II, III, and IV
4. Those giving informed consent
5. Voluntarily willing to participate in the study

Exclusion criteria

1. Presence of local skin infection near the injection site
2. INR (INR) > 1.4.
3. Platelet count is < 100,000.
4. Patients who are unable to comprehend the pain scale.
5. Patients who are not willing to give informed consent forms

The study population was divided into 2 study groups according to the technique received by each group. Each study group includes 50 patients. The patients were explained about the study, the procedure, and the complications, and the informed consent form was collected from all participating patients before the commencement of the study. The informed consent form was distributed before the commencement of the study.

Group allocation

Group A- Ultrasound-guided Supra inguinal fascia illiaca block (US-SIFIB) (n=50). They were given the Supra inguinal fascia illiaca block technique.

Group B- Ultrasound-guided Infra inguinal fascia illiaca block (US-IIFIB) (n=50). They were given the Infra inguinal fascia illiaca block technique.

Methodology: During the preoperative anesthetic assessment of patients, a visual analog scale (VAS) for pain assessment from 0 to 10 with 0 refers no pain and 10 refers the worst pain imaginable was explained to patients. All routine investigations were carried out, and fitness was confirmed. On a preoperative night, each patient received a ranitidine tablet of 150 mg orally. All cases were done at Osmania General Hospital and after taking informed and written consent. Patients were randomly assigned to one of two groups; each group was composed of 30 patients according to the type of block given:

Anesthetic technique:

Preoperative preparation: Fasting hours were 6 hours for solid foods and 2 hours for clear fluids. No premedication as benzodiazepines or Opioids was given so as not to interfere with our results.

Intraoperative: Patients in all groups received a standard anesthetic technique. An intravenous cannula was inserted after alcohol sterilization and routine administration of Ondansetron (0.1 -0.2mg/kg body weight, maximum 8mg) was done. Standard ASA monitors were connected (ECG, NIBP, pulse oximeter) and continuously displayed and recorded every 5 minutes till the end of surgery. No sedatives, Opioids, or analgesics were given intraoperatively. Then the patient was put in either the sitting or left lateral position, with flexed hips and knees. After complete sterilization, a lumbar puncture was done at the L3-L4 intervertebral space. Subarachnoid block was performed using a 25G Quincke Babcock needle. After negative aspiration to ensure no intravascular injection, 0.5% Bupivacaine was injected. The dose was varied according to body weight. After a successful injection, the patient was placed in the supine position. The level of the block was fixed at the T4-T6 level. Intraoperatively vitals were monitored and fluids were given accordingly.

Post-operative block: The skin at the site of injection was sterilized and the block was given according to the group into which the patient was randomly allocated

.

Group A: In SIFICB, an ultrasound probe was placed on the inguinal ligament perpendicular to it towards the umbilicus. The probe was tilted as necessary in the cephalad or caudal direction until a clear optimized image AIIS was visualized, the deep circumflex artery was identified, and Sartorius and internal oblique muscles convergence was identified as a bow tie or hourglass horizontally over fascia iliaca identified and, A 23G needle tip was then targeted to deposit local anesthetic below fascia iliaca, and the 0.2% plain Ropivacaine 20 -30 ml was administered.

Group B: The probe was placed parallel to the inguinal ligament and psoas muscle and femoral artery and femoral vein were identified fascia iliaca identified 23G QBN needle tip was targeted in the plane and 0.2% plain Ropivacaine 20-30 ml deposited below the fascia iliaca in-plane technique. After the administration of the block, patients were transferred to the recovery room with continuous monitoring of vital data.

Postoperative Assessment: A standard postoperative analgesia regimen was used in the 24-hour immediate postoperative period. Supplemental analgesia was provided using Paracetamol infusion 1 gram intravenously every 8 hours in both groups. Patients with VAS >4 were given Tramadol 2mg/kg intravenously. The patients were interviewed at 2, 4, 6, 12, 24, and 48 hours after surgery for the following parameters:

1. VAS scores at rest.
2. VAS score at movement

Statistical analysis: All the available data was refined, segregated, and uploaded to an MS Excel spreadsheet and analyzed by SPSS version 23 in Windows format. The categorical variables were represented as mean, standard deviation, frequency, and percentages. The means of the two groups were compared with the student's t-test. The categorical variables were calculated between the two groups using the Mann-Whitney-Wilcoxon (MWW) test. The values of p (<0.05) were considered as significant.

A total of 100 cases were included in the study. The distribution of cases and their baseline characteristics is depicted in Table 1. The mean age did not significantly differ between the groups (p=0.885). There was also a similarity between groups in terms of sex distribution and ASA physical status groups, which provided well-matched cohorts. The prevalence of male patients was high in the two groups, although the values did not reach statistical significance. ASA Grades I and II were distributed evenly, and there was no statistical difference (p=0.422), which implies that the variations in postoperative results could not be expected to be influenced by the baseline demographic or health status variables.

Table 2 shows the visual analog scale (VAS) scores in the postoperative period. A critical analysis of the table shows that up to 6 h post-surgery, both groups showed similar levels of pain, as shown in the table by non-significant p values. However, in the time duration between 12 and 36 h, patients who received the suprainguinal block reported significantly lower pain than those who received the infrainguinal block. This shows that the suprainguinal block demonstrated better analgesia.  At the end of 48 h, the infra-inguinal group cases reported lower resting pain, as demonstrated by significant p values showing a reversal in efficacy. Thus, the supra-inguinal block provided superior analgesia between 12 and 36 hours postoperatively. This shows that it has an advantage in controlling intermediate postoperative pain at rest.

                            *Significant

Table 3 shows the outcome measurements of pain scores within 48 hours of movement. Supra-inguinal block offered much better analgesia at 2-, 6-, 12- and 36-hour follow-ups (p<0.05). An early benefit was reported at 2 h, as the patients did not experience any pain. Pain perceptions differed with infra-inguinal reporting greater pain at various instances, that is, at 36 h. Interestingly, pain related to movement trended higher in the supra-inguinal patients at 48 hours (p< 0.001), indicating time-specific efficacy differences. In general, the supra-inguinal block was more effective in managing dynamic pain at the critical early and intermediate stages of post-surgery.

                                           *Significant

Table 4 depicts the analgesia and clinical outcomes of rescue analgesia. Patients undergoing supra-inguinal block also took considerably longer to receive rescue analgesia (mean 13.10 vs. 9.30 hours, p<0.001) indicating that its action lasts longer. At rest pain scores were higher in the infra-inguinal group at 12-36 hours and higher scores during movement occurred in the 6, 12, and 36 hours. On the other hand, the supra-inguinal group recorded improved and stable analgesia. These results support the advantage of the supra-inguinal approach in the aspect of reduced delayed analgesia requirement and improved control of pain in the intermediate postoperative period.

            *Significant

Table 5 presents a comparison of the efficacy of analgesia between the two blocks. Early pain (0-6h) relief was similar, although the supra-inguinal block demonstrated a benefit only at 2 h when the patients were in motion. The supra-inguinal block was significantly better during the mid-phase (12-36h) with significantly reduced pain scores. The infra-inguinal block was marginally effective at 48 h in controlling restorative pain, but the supra-inguinal block was much more effective in pain control during movement. In the infra-inguinal group, rescue analgesia was required approximately 4 hours prior. Overall, the suprainguinal fascia iliaca block provided greater, long-lasting, and effective postoperative analgesia, especially during the risky intermediate stage.

This study was done to compare the efficacy of supra-inguinal fascia iliaca block (SIFIB) and infra-inguinal fascia iliaca block (IIFIB) in patients undergoing hip surgery. The aim was to identify a better technique for postoperative pain control. The pain following hip surgeries is mostly intense due to the involvement of deep tissue and because of the manipulation of the joint capsule. The management often requires regional analgesia techniques. The results of this study showed that both groups were comparable in baseline demographic characteristics such as age, sex, and ASA grade, thus eliminating such confounding factors or preoperative status. The homogeneity of both groups ensures the reliability of outcome interpretation [6]. The results of this study showed that the early postoperative pain scores (up to 6 hours) were comparable between the groups. However, the SIFIB group started to show significantly lower VAS scores at rest from the duration of 12 to 36 hours postoperatively. Similarly, during the movement, the VAS scores were lower in SIFIB groups at 6, 12, and 36 hours. These findings show that the supra-inguinal approach provides an anatomical advantage as compared to the infra-inguinal approach. Similar studies in this field have shown that the supra-inguinal technique ensures a better spread of local anesthetic to femoral, obturator, and lateral femoral cutaneous nerves because of the placement of anesthetic above the inguinal ligament and closer to the iliac crest [7-9].

The infra-inguinal approach has advantages because of ease of technique and is also practiced widely however; there are disadvantages such as the placement of local anesthetic more distally and inconsistent spread of anesthetic [10]. These limitations could be the explanation for the higher pain scores observed during the critical intermediate postoperative period in the IIFIB group of cases of our study. Another important finding of this study was the occurrence of a significantly prolonged duration of analgesia in the SIFIB group. The first rescue analgesia needed in this group was after an average duration of 13.1 hours compared to 9.3 hours of the IIFIB group. The results of our study are consistent with existing literature which emphasizes that SIFIB provides a longer duration of sensory blockade due to its closer proximity to the lumbar plexus [11, 12]. Since there was a delay in the need for rescue analgesia it reduces the overall opioid use, fewer side effects, and potentially faster mobilization and rehabilitation of the cases [13]. We found that at 48 hours the IIFIB showed slightly lower VAS scores at rest whereas the SIFIB had marginally better control of pain on movement. Although the differences were statistically significant their clinical relevance could be limited because of the waning effects of both blocks by this time and the potential of systemic analgesics used postoperatively. Apart from the pain scores, movement-related analgesia is crucial in orthopedic surgeries because it can impact early ambulation and physiotherapy activities. SIFIB's superiority in this field during the first 24 hours shows that it could be more effective for functional recovery [14]. Clinically, the findings are strongly inclined to the use of SIFIB, especially during hip surgeries aiming at achieving the enhanced recovery after surgery (ERAS) technique. Its high mid-phase analgesia, rescue analgesia, and superior management of dynamic pain make it superior to others as far as long-lasting pain management is concerned in the early postoperative surgical condition. Since complications are rare and anatomically SIFIB is reliable, it is now promoted as a platform of choice over more technically difficult blocks such as lumbar plexus block [15]. Though both methods require the use of ultrasound guidance due to their high accuracy and safety, the SIFIB learning curve is within the envelope, and its advantages might compensate for its integration into the clinical setting. In the end, we can say that SIFIB provides superior postoperative analgesia as compared to IIFIB in hip surgeries. It must be considered as the preferred technique for optimal pain management and functional outcomes.

In this study, the supra-inguinal fascia iliaca block (SIFIB) administered to patients undergoing hip surgery was proven to be better for postoperative analgesia than the infra-inguinal block. SIFIB was associated with considerably lower pain scores in the mid-postoperative segment, better dynamic pain management, and delayed use of rescue analgesia. Both approaches were equivalent in terms of initial pain control, but SIFIB provided long-term and more proficient pain relief and was associated with increased patient comfort and the possibility of earlier rehabilitation. Given their effectiveness and side effect profile, SIFIB should be considered the most preferable method for performing regional analgesia during hip surgery under an enhanced recovery program.

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