Comparison of Pre-Operative Ultrasound Guided Fascia Iliaca Block and Quadratus Lumborum Block for Reduction of Pain During Positioning for Spinal Anaesthesia and Post-Operative Analgesia in Patients with Femoral Neck Fracture

Introduction

Hip fractures are painful in preoperative period and is associated with morbidity especially in the elderly, due to underlying osteoporosis and presence of other coexisting diseases.¹ Subarachnoid block is the choice of anaesthesia for fracture femur surgeries,² but pain can interfere with optimal positioning for administration of spinal anaesthesia. Current methods of providing pre-and post-operative analgesia include non-steroidal anti-inflammatory drugs (NSAIDS), oral or parenteral opioids, and regional anaesthesia techniques.³ Systemic analgesia including both opioids and non-steroidal analgesia can have significant adverse effects especially in the elderly population due to age related changes in pharmacokinetics and pharmacodynamics.

Regional anaesthesia is very effective in alleviating pain due to trauma. It has the advantage of producing localized but complete pain relief, while avoiding the side effects of systemic analgesics. Different types of regional nerve blocks have been tried to address the pain of hip fractures like traditional femoral nerve block (FNB), 3 in 1 femoral nerve block, fascia iliaca block (FIB) and quadratus lumborum block (QLB), but FIB and QLB have the advantage of greater spread and better analgesia compared to others.

The fascia iliaca block is an easier method to provide perioperative analgesia in patients with painful conditions affecting the thigh, the hip joint and the femur. FIB blocks the femoral, lateral cutaneous nerve of thigh and obturator nerves, hence provides perioperative analgesia for hip and femur surgeries; however sacral branches to hip joint may be spared. Authors have successfully demonstrated the analgesic effect of fascia iliaca block for fractures of femur in pre hospital care setting.⁴

The quadratus lumborum block, is a deep fascial plane block involving T7 – L4 nerves by administration of local anaesthetic to the anterior aspect of the quadratus lumborum muscle. Quadratus lumborum block has been proved to be effective in providing post-operative analgesia mostly in abdominal surgeries, myocutaneous flap surgery and in hip fractures.⁵

Many studies have compared efficacy of FNB with FIB, FNB with QLB in post-operative analgesia of femur neck fracture. But, there is no study comparing the efficacy of FIB with QLB in pre- and post-operative analgesia for femur neck fracture. Hence, present study was designed to compare the efficacy of FIB with QLB for positioning and for post-operative analgesia in patients with femur neck fractures. The primary objective was to compare effect of FIB with QLB on pain (reduction of VAS score) during positioning of patient with femur facture for spinal anaesthesia. Duration of post-operative analgesia, 24 hour analgesic consumption were secondary objectives.

Methods

After approval from institutional ethical committee, this prospective randomized comparative study was conducted in a tertiary teaching hospital from March 2019 to October 2019 in patients undergoing elective femoral fracture surgeries under spinal anaesthesia (CTRI/2019/02/017744). Fifty-two patients of either sex aged between 20 – 70 years belonging to American Society of Anaesthesiologists physical status I and II, who gave written informed consent were included in the study. Patients with known allergy to local anaesthetics, mental disability that preclude comprehension of Visual analogue pain scale (VAS), peripheral neuropathy, coagulation disorder, local site infection, multiple trauma, and femoral graft in the affected limb and patients with heart disease, head injury, peripheral vascular disease, contraindication to spinal anaesthesia and Body mass index >30 were excluded from the study.

After taking written informed consent, patients were allocated into two groups based on computer generated randomized sequence (www.ramdom.org). All patients underwent pre anaesthetic evaluation and were explained in detail about the blocks, anaesthetic procedure and were made familiar with use of VAS scale. Patients were premedicated with pantoprazole 40 mg intravenous on the day of surgery and kept nil per oral for 6 hours before surgery. Group A received FIB before spinal anaesthesia, whereas in Group B, QLB was administered before spinal anaesthesia. Allocation concealment was done using sealed envelope method which was opened just before administration of the block. All the patients were monitored (NIBP, ECG and pulse oximetry) and intravenous peripheral access was placed. None received analgesic premedication before administration of block. Patients were asked to mark on VAS scoring system before giving block. Both the blocks were administered by an experienced anaesthesiologist who had done more than 25 blocks of each type and was not involved in further management of the patient, and patient assessment was done by anaesthesiologist not aware of group allocation.

In FIB, with patient in supine position, with limb kept in resting position, the suprainguinal anatomy was ascertained with probe placement in the suprainguinal region. Using high frequency linear probe (7 – 15 Hz) (Sonosite M-Turbo®ultrasound machine), the fascia iliaca compartment was approached below as well as above the inguinal ligament. The femoral artery and the iliacus muscle lateral to it, covered by the fascia iliaca were identified. If the division of the femoral artery was visualized, the probe was moved more cranially. The needle was inserted in plane of the ultrasound beam. The needle was advanced until the tip was placed underneath the fascia iliaca (appreciating the pop sensation as the fascia was perforated) and negative aspiration was confirmed, then 30 mL of 0.125% bupivacaine was injected.

In the group-B, patient was kept in supine position, moved to edge of the bed and a small bolster was kept under the buttock, so that the affected side could be easily accessed for placement of probe and needle insertion. Thirty mL of 0.125% bupivacaine was administered in the anterolateral aspect of the quadratus lumborum muscle. Placing the low frequency convex transducer (3 – 8 Hz) (SonositeM-Turbo®ultrasound machine) on the midaxillary line, between the 12th rib and the iliac crest, the abdominal muscles (external oblique, internal oblique and transversus abdominis) were identified, and the quadratus lumborum muscle, posterior to them. The needle was inserted in plane approach so as to place the tip anterior to the quadratus lumborum muscle and local anaesthetic solution was injected after negative aspiration for blood.

The success of both blocks was confirmed by checking for decreased or loss of cold sensation to alcohol swab in upper medial, anterior and lateral aspect of thigh, and upper and lower outer quadrants of gluteal region. The block was considered successful if there was loss/ decrease in sensation in at least two areas of thigh and one area in gluteal region, partial if only two areas were affected, and failure if none of the areas were affected.

Both the blocks were administered in the preoperative room and the patient was shifted to operation theatre 20 minutes after administration of the block. Patient was asked to mark severity of pain on VAS scoring system. The anaesthesiologist recording the VAS score and managing the case intraoperatively and post-operatively was not aware of the type of block given. Following this, spinal anaesthesia was administered at L2-3/ L3-4 level with 10 mg of 0.5% hyperbaric bupivacaíne (2 mL) in sitting posture. Haemodynamics (heart rate, blood pressures, SpO2 ) were continuously monitored and recorded every 5 minutes till end of surgery. Patient was kept supine for 5 minutes after spinal anaesthesia and then position altered as per requirement for surgery. Highest level of sensory block was assessed by pin prick method 30 min after spinal anaesthesia.

After surgery, patient was transferred to the PostAnaesthesia Care Unit (PACU), pain was assessed in post-operative period at regular intervals and rescue analgesia with inj. Paracetamol (PCT) 1 gm IV infusion was given once the VAS score was more than or equal to 4. Time from administration of block to demand for first rescue analgesia was considered as duration of analgesia. Inj Tramadol 50 mg was administered slowly by intravenous route if pain did not subside 20 minutes after PCT infusion. Maximum of 4 g paracetamol and 200 mg of tramadol was allowed for 24 hours; if there was additional requirement, diclofenac 75 mg was used. The rescue analgesics were repeated as per the patients demands and the amount of paracetamol and tramadol consumed over first 24 hours was noted. A minimum of 4 hours’ difference was maintained between two doses of PCT or tramadol. Side effects such as blood aspiration during block administration, swelling/ haematoma at block site, pain in abdomen, prolonged motor blockade (more than 6 hours post operatively), local anaesthetic toxicity, haemodynamic disturbances if any, nausea and vomiting, neuropathy, paraesthesias were observed for and recorded.

The outcome measures included VAS scores before and 20 minutes after block, and during positioning for spinal anaesthesia and post operatively every hour till 6 hours and then at 12, 18, and 24 hours, amount of rescue analgesics required in first 24 hours, intraoperative and early post-operative haemodynamics and adverse effects if any.

Sample size estimation was done based on reduction in VAS from the previous study.4 We hypothesized that QLB would result in better reduction pain scores during positioning compared to FIB. Keeping power of study at 80%, α error at 0.05, assuming standard deviation of 0.2 and normal distribution of values, a minimum of 23 patients were required in each group to detect a difference of at least 1 in magnitude of post block VAS score reduction between the groups during positioning for SAB. Twenty-six patients were included in each group to compensate for drop outs. Sample size estimation was done using online software www.openepi.com.

Statistical evaluation of data or parameters was done using IBM SPSS version 22 software. Data was presented in numbers/ percentages for categorical data and as mean and standard deviation or median with interquartile range for continuous data. Quantitative data was assessed for normality of distribution by Shapiro Wilk test. Chi-square/ Fisher Exact test was used to find the significance of study parameters on categorical scale between two groups. Student t test/ Mann Whitney U test was used for quantitative data, paired t test for intra group comparison. p value < 0.05 was considered as statistically significant.

Results

A total of 58 patients were assessed for eligibility and 52 of them were enrolled for the study. One patient in each group had a failed block and were excluded from statistical analysis. So finally 25 patients in each group were analyzed (Figure 1). Patient demographic characteristics were comparable in both the groups (Table 1A). Level of sensory block and duration of surgery were also comparable in both the groups (Table 1B).

The pain score assessed by VAS score before giving block, 20 minutes after block and during positioning of the patient for spinal anaesthesia were comparable in both the groups. The reduction in VAS score after 20 minutes from baseline was also comparable in both the groups. But reduction in VAS score at the time of positioning for SAB was higher in group-B [Group-A 5.66 ± 0.86 (95% CI 5.33 to 5.99), Group-B 6.55±1.13 (95% CI 5.72 to 6.58), p=0.003] (Table 2). 

The duration of analgesia (p=0.33), post-operative requirement of paracetamol (p=0.22) and tramadol (p=0.34) was comparable in both the groups (Table 3). The time for onset of motor blockade (Group A - , Group B - , p - ) and recovery from motor blockade (Group A - , Group B - , p - ) was comparable between the two groups. The mean post-operative VAS scores were comparable between the two groups. (Figure 2) The baseline heart rate and blood pressure were comparable (p – 0.6). There was decrease in heart rate and blood pressure following block in both the groups and the magnitude of decrease was comparable between the groups. (p – 0.78). The intraoperative heart rate and mean arterial pressures were comparable between the two groups (Figure 3). Four patients in group A and six patients in group B had hypotension in intraoperative period (p – 0.47). None of the patients had any adverse haemodynamic effects following blocks in the preoperative room or any other side effects pertaining to blocks in the post-operative period. Post-operative haemodynamic parameters were comparable.

Discussion

Anterior section of the hip joint capsule is innervated by femoral nerve and obturator nerve, and posterior section is innervated by the nerve to quadratus femoris muscle and occasionally by the superior gluteal (posterolateral region) and sciatic nerve (posterosuperior region).⁶ Regional anesthesia has been commonly used for procedures around the hip, most frequently in hip fracture surgery and arthroplasty. One of the regional anesthesia options for hip surgery is the fascia iliaca compartment block (FIB) that affects nerves important for hip innervation and sensory innervation of the thigh - femoral, obturator and lateral femoral cutaneous nerves. FIB can be easily performed and is often a good solution for the management of hip fractures in emergency departments. Quadratus lumborum block (QLB) is a block of the posterior abdominal wall performed exclusively under ultrasound guidance, with still unclarified mechanism of action.6 When considering hip surgery and postoperative management, the anterior QLB has shown to improve perioperative analgesia in patients undergoing hip and proximal femoral surgery compared to standard intravenous analgesia regimen, provides early and rapid pain relief and allows early ambulation, thus preventing deep vein thrombosis and thromboembolic complications etc. Hence, QLB has shown potential for use in hip surgery and its perioperative pain management. However, this technique still needs to be validated as a reliable treatment approach, as some experimental models show that nerve branches responsible for innervation of the hip joint are not affected by QLB, which must be taken into consideration.⁷

A recent comparative study showed that length of hospital stay following total hip arthroplasty was found to be significantly decreased in patients receiving QLB compared with no block.⁸ Kukreja et al.,^9,10 found in two separate studies that both the anterior and posterior QLB are effective at decreasing opioid requirements following hip arthroplasty in the first 48 hours postoperatively. The results of these preliminary studies provide a promising outlook for research into the QLB for femur neck fracture surgeries.

In the present study, it was observed that VAS before giving block, 20 minutes after the block and during positioning of the patient for spinal anaesthesia were comparable in both the groups. The reduction in VAS after 20 minutes from baseline was also comparable in both the groups. QLB was associated with marginally better reduction in VAS compared to FIB during positioning for spinal anaesthesia. Though it was statistically significant, the clinical significance of pain score reduction was minimal. The duration of analgesia and the requirement of rescue analgesia like PCT and tramadol were comparable in both the group.

In a study conducted by Ryan E et al., (2020)¹¹ to evaluate the effect of the single-shot QLB versus femoral nerve and fascia iliacus blocks in patients undergoing hip arthroscopy under general anesthesia, they observed that patients receiving a QLB required significantly lower total morphine equivalents (63.1 vs 87.0, p < .001). They also observed that patients receiving QLB had shorter PACU stays (116 vs 148 minutes, p < .001) and lower subjective pain scores at the time of discharge (3.27 vs 4.98, p < .001) compared with the FNB/FIB group. There was also significant decrease in the number of intraoperative opioids (42.1 vs 58.4, p < .001) and PACU opioids (20.7 vs 28.7, p= .03). Hence, they concluded that the QLB required lesser opioids, shorter PACU stay, and lower pain scores at discharge than FNB/FIB blocks with no reported adverse events. Similarly, Green M S et al., (2018)⁸ conducted a study evaluating the effect of transmuscular QLB in reducing the length of stay in hospital in patients undergoing total hip arthroplasty under general anaesthesia. They observed that length of stay was shorter in patients receiving QLB (2.9 days) versus patients not receiving QLB (5.1 days) (p= 0.01). Intra-operative use of fentanyl was lower in patients receiving QLB (183.5 mcg) versus patients not receiving QLB (240 mcg) (p=0.03). Hence, they concluded that QLB significantly reduced the length of stay and intraoperative fentanyl use. Parras T and Blanco R¹² (2015) compared efficacy of USG guided QLB with FNB for post-operative analgesia in femoral neck fracture in 104 patients undergoing hemiarthroplasty, and they found that VAS score and the opioid consumption was reduced by 50% for the first 24 hours postoperatively in QLB group. The sensory and motor blockade, satisfaction, and adverse effects, were similar in both the groups. In contrast to above studies, in our study reduction in VAS at the time of SAB was higher in Group B, but duration of post-operative analgesia and requirement of analgesics were comparable in both the groups, which may be attributed to amount of drug used in our study.

This study had few limitations like comparing one approach of QLB with FIB, as it may differ from different approaches. Hence results of this study cannot be generalised and patient blinding could not be done due to obvious differences in the point of insertion of needle, which may not totally eliminate bias.

Conclusion

QLB was not associated with better reduction in preoperative pain compared to FIB during positioning for spinal anesthesia, and also did not prolong duration of post-operative analgesia or decrease the analgesia requirement in patients with femoral neck fracture.

Conflict of interest

None.