DOI: https://doi.org/10.21203/rs.3.rs-2605855/v1
The purpose of the study is to evaluate and compare the effectiveness of two different anesthesia techniques, PENG block and fascia iliaca compartment block (FICB), in managing pain and minimizing side effects for patients undergoing hip fracture surgery. Due to increasing numbers of patients with comorbidities, anesthesia for hip fractures has become a significant challenge.
From the initiation of the study until April 26, 2022, a comprehensive search was conducted across several electronic databases, including PubMed, Embase, Cochrane Library, CNKI, and WanFang Data, to identify relevant studies. The focus of the search was randomized controlled trials (RCTs) that compared the clinical efficacy of PENG block and FICB in hip fracture surgery. To ensure the validity of the study, two independent reviewers applied the standards of the Cochrane systematic review to evaluate and index all the papers. In case of heterogeneity between studies, a random-effects model was utilized, and a fixed-effects model was employed otherwise.
According to the combined data, PENG block can decrease 24-hour postoperative opioid consumption (P༜0.05), but its 48-hour postoperative opioid consumption is not significantly different from control group (CI [-12.27, 2.79], P = 0.22). There are also no differences in side effects (CI [0.13,4.57], P = 0.76) and dynamic or static pain scores (P༞0.05) .
The results of the meta-analysis indicate that PENG blocks are effective in reducing opioid consumption for 24 hours post-hip fracture surgery. This implies that PENG blocks may be a promising alternative for reducing pain and minimizing the risk of substance abuse in patients. However, to establish this with certainty, more research with larger sample sizes and longer-term follow-up in the form of prospective randomized controlled trials is necessary.
Hip surgery is a common procedure in orthopedics, with an average of 131 hip replacements per 100,000 people and over 959,000 primary and revision surgeries performed annually[1]. By 2050, population growth and aging are predicted to push the number up to 7–21 million[2]. During the perioperative period, hip surgery can cause considerable pain [3]and result in a number of complications (e.g., delirium, dementia) [4–6] that not only increase the perioperative risk but are also detrimental to the prognosis of patients[7, 8]. Effective anesthesia and pain management during and after surgery are crucial for patients' postoperative recovery and ability to perform rehabilitation exercises.
Regional anesthesia, such as femoral nerve block (FNB) and FICB, is frequently used in hip surgery to improve postoperative analgesia [9]. It has been demonstrated that appropriate pain management reduces complications and promotes postoperative activity[4]. The time for patients who use FNB to take analgesics for the first time after surgery can be postponed[10], FNB can also reduce patients’ need for systemic analgesics within 24 hours after surgery, and help patients be discharged from the hospital earlier[11]. Although FNB can delay the time of first postoperative analgesic use and the dosage of analgesic drugs, it can affect the recovery of quadriceps muscle strength after surgery[12]. FICB is commonly used to relieve perioperative pain in patients[13–15] which uses fewer opioids for postoperative analgesia[16–18]and has good effects in decreasing static and dynamic pain scores[19]. A study by Short et al. found that the anterior capsule of the hip has a high density of sensory nerves, and in most cases, the femoral nerve has sensory branches that run above the inguinal ligament, making it challenging to block using subinguinal techniques like the FICB or femoral nerve block[20]. Therefore, numerous studies and past clinical researches indicate that FICB is associated with risk of neurovascular impairment, quadriceps weakness, and a longer time to recover[21, 22]. The PENG block, introduced by Gilón-Arango et al. in 2018, is a regional anesthesia technique aimed at reducing hip pain by blocking the obturator nerve (ON), the accessory obturator nerve (AON), and the femoral nerve[13]. In the 5 patients reported in the case studies, the effectiveness of the PENG block was evaluated by measuring dynamic and static pain scores 30 minutes after the block was administered. The results showed a significant decrease in pain scores in all patients, with no observed clinical signs of quadriceps muscle weakness[13].
The PENG block is a relatively new technique and the majority of studies on it have limited sample sizes. Further systematic research is needed to validate its effectiveness and compare it with the frequently used FICB method in clinical practice. The aim is to determine which technique provides better analgesia and has a lower incidence of side effects.
Search strategy
This meta-analysisis based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines[23]. The study was conducted by searching various electronic databases, including PubMed, Embase, Cochrane Library, CNKI, and WanFang Data, without language or other restrictions, from the start of the study until April 26, 2022. The search was carried out using various terms such as "Pericapsular nerve group block", "PENG block", "fascia liaca compartment block", "Hip Fractures", "Femoral Neck Fractures", "Dynamic hip screw", and "Hip Replacement", along with corresponding medical subject headings and entry terms. The authors were also contacted to obtain additional data information. The selection of research articles and data extraction was performed independently by two researchers (Miao and Niu).
Inclusion criteria and exclusion criteria
The identification of studies was carried out independently by two researchers (Miao and Niu) to minimize bias in article selection. The following conditions must be met for studies to be eligible: (1) Corresponds to diagnostic standards for hip fracture in 2014 [24]; (2) Study design: RCTs and prospective controlled studies; (3) Population: age > 18 years with hip fractures requires surgical treatment; (4) Intervention: PENG block is used to control pain; (5) Comparison: FICB; (6) At least one of the following outcomes was reported: opioid consumption, the rate of side effects and postoperative pain score. The exclusion criteria were as follows: (1) reviews, letters, cohort studies, observational studies, retrospective studies, conference abstracts, and case reports; (2) repeated literature; (3) studies weren't finished; (4) included comparisons with other anesthesia protocols; (5) employed cadaveric evaluation; (6) lacked data for extraction; and (7) failed to report results. In Table 1, study characteristics are described in more detail.
| Table 1. Characteristics of the included studies. | oncomitant pain | PCA with morphine | PCA with sufentanil | PCA with morphine | PCA with fentanyl | PCA with fentanyl | |
| Drug dose of block | FICB group | 3 mL/kg (a maximum of 40 mL) of ropivacaine 0. 5% | 30mL of ropivacaine hydrochloride 0. 4% | 40 mL of levobupivacaine 0. 25% | 30 mL of Levobupivacaine 0. 25% | 30 mL of ropivacaine 0. 2% | |
| PENG block | 3 mL/kg ropivacaine 0. 5% | 20mL of ropivacaine 0. 4% | 20 mL of levobupivacaine 0. 5% | 30 mL of levobupivacaine 0. 25% | 20 mL of ropivacaine 0. 2% | ||
| Surgery type | Gamma nail Screws dynamic hip screw | hip arthroplasty | total hip arthroplasty | dynamic hip screw fixation proximal femur nailing | total hip arthroplasty | ||
| Female (n) | FICB group | 6' | 11' | 13' | 8' | 11' | |
| PENG group | 8 | 10 | 13 | 10 | 13 | ||
| Age(years, Mean ± SD) | FICB group | 50 ± 13.63 | 74 ± 8 | 59.6 ± 9.2 | 52.5 ± 9.8 | 63.0 ± 4.85 | |
| PENG group | 53 ± 16.46 | 74 ± 7 | 56.8 ± 13 | 53. 9 ± 9.9 | 61.0 ± 5.875 | ||
| Author | Faramarz Mosaffa 2022 | Hao Hua 2022 | Julián Aliste 2021 | K.S. Senthil 2022 | Yong Seon Choi 2021 | ||
| Data extraction | |||||||
The following items were included in the data extraction form: author and year of publication; study design; geographic location; total population (i.e., sample size, gender, and age); intervention measures; control measures; and outcomes (i.e., pain intensity rating form, pain intervention, side effects) .
The pain assessment was conducted using the Numerical Rating Scale (NRS) and Visual Analog Scale (VAS). In the NRS scale, patients were asked to rate the intensity of their pain on a scale from 0 (no pain) to 10 (worst imaginable pain). In the VAS scale, patients were asked to choose an image corresponding to their degree of pain on a 100 mm line. The consumption of various postoperative opioids was converted into oral morphine equivalents.[25].
The extraction form was created in advance by two calibrated reviewers (Miao and Niu). The reviewers screened the titles and abstracts of articles that matched the items listed on the extraction form independently, and they received duplicates of the form. If there was disagreement at any stage, it was resolved through discussion, and a third reviewer (Wang) was involved if necessary. The full text versions of all eligible studies were collected, as well as those with insufficient information in the title or abstract, which required a full text review to determine their eligibility. If data for quantitative analysis was missing, attempts were made to contact the corresponding authors for the information. Indicators with incomplete information were excluded if the effort was unsuccessful.
Quality assessment
This meta-analysis is a randomized controlled trial (RCT) and it evaluates the risk of bias using the Cochrane Risk of Bias Tool. This tool assesses factors such as randomization method, allocation concealment, blinding, incomplete outcome data, selective reporting, and other sources of bias. Two reviewers evaluated each study independently, and in case of any disagreements, a third reviewer was consulted to resolve the issue. All studies were included in the risk of bias assessment and the data was analyzed using RevMan software.
Risk of bias
Figure 1 and Fig. 2 show the summary and graph of the risk of bias, respectively. According to the analysis, three articles had a high risk of performance bias due to the requirement for patients to sign informed consent forms. On the other hand, two publications did not have any high-risk factors identified.
All data analysis was performed using Review Manager 5. 4. 1 software. For continuous variable data, each result was calculated using mean different (MD) and a 95% confidence interval (CI). The risk ratio (RR) was used for dichotomous outcomes. Low heterogeneity means that I2is less than 50%, moderate heterogeneity means that I2is between 50% and 75%, and high heterogeneity means I2 is between 75% and 100%. A random-effects model was used if there was significant heterogeneity between studies; otherwise, a fixed-effects model was considered acceptable. Forest plots were drawn using the Review Manager.
Study selection
From the study's start to April 26, 2022, a literature search was conducted following PRISMA criteria, resulting in 190 potential articles from sources such as PubMed, Embase, the Cochrane Library, CNKI, and WanFang Data. After removing 29 duplicates using EndNote, 161 articles were selected for further review. 70 articles were analyzed as full-text publications after title and abstract screening, while 65 articles were rejected due to insufficient data. The review process was conducted by two independent researchers (Miao and Niu) and agreement was reached through discussion. The screening process is summarized in the flow chart shown in Fig. 3.
Study design and sample characteristics
The five studies included in the research were published from 2020 to 2022 and originated from five different countries. The sample size ranged from 20 to 30. The main characteristics of the studies are summarized as follows: measuring 24-hour and 48-hour opioid consumption after surgery, evaluating perioperative side effects, and assessing dynamic and static pain scores at various time intervals after block. All studies used ultrasound for localization and only one study used general anesthesia while the rest used spinal anesthesia. Patient-controlled analgesia (PCA) was used postoperatively.
Opioid consumption in 24 hours
Five studies examined the 24-hour postoperative opioid consumption of the PENG block and the FICB and the consumption of various opioids was translated into morphine equivalents administered orally[25]. Since there was heterogeneity, a random effect model was adopted (P = 0. 01, I 2 = 69%). Based on the findings of all of these investigations, it appears that PENG block could reduce the consumption of opioids in 24 hours (MD = -7.26, 95% CI [-14.32, -0.19], P = 0.04, Fig. 4) .
Opioid consumption in 48 hours
A total of three RCTs involving 142 patients showed opioid consumption in 48 hours after hip surgery. The different types of opioids used after surgery were turned into oral morphine equivalents[25]. We utilized a fixed effects model to pool the relevant data because the heterogeneity between the three studies was not significant (I 2 = 34%, P = 0.22). PENG failed to identify a significant association with changes in opioid consumption in 48 hours(MD = -4.74, 95% CI [-12.27, 2.79], P = 0.22, Fig. 5) .
Perioperative Side effects
Four trials with a total of 194 patients provided information on perioperative side effects. Since there was some heterogeneity, we used a random effect model (P = 0. 06, I2 = 59%). Our meta-analysis showed no statistically significant differences existed between the groups (MD = 0.76, 95% CI [0.13,4.57], P = 0.76, Fig. 6) .
Dynamic pain score at 6 hour after surgery
Three studies, a total of 134 participants reported the NRS at 6 hour after surgery. Because there was no significant heterogeneity (P = 0.37, I 2 = 0%), a fixed effect model was used. Based on the results of all of these studies, we made conclusion that the NRS at 6 hour after surgery of PENG block and FICB block was not significantly different (MD = -0.63, 95% CI [-1.46,0.19], P = 0.13, Fig. 7) .
Static pain score at 6 hour after surgery
Three RCTs have assessed the static pain score at 6 hour after hip surgery. When the fixed effect model was used, there was some heterogeneity, so a random effect model was used (P = 0.14, I 2 = 50%). According to the current meta-analysis, the results of the PENG block had no significant effect compared to the FICB block group (SMD = -0.36, 95% CI [-0.83,0.11], P = 0.13, Fig. 8) .
Dynamic pain score at 24 hour after surgery
Three trials, a total of 134 patients provided data on NRS at 24 hour. According to all three studies, there was no significant difference in NRS scores after 24 hour of block. There is one paper which not only measured the pain levels of the patients between PENG block and FICB using NRS score but also using VAS (VAS data was not extracted) [26]. Compared with the control group, PENG block had no benefit on NRS at 24 hour with moderate heterogeneity (MD = -0.07, 95% CI [-0.86,0.72], P = 0.86; P = 0.08, I 2 = 61%, Fig. 9) .
The PENG block technique is a novel and efficient method for providing relief from hip pain. It utilizes an anatomic approach and has been shown to effectively alleviate pain without increased negative side effects. Previous research supports its efficacy in providing adequate pain control[27]. The FICB technique is a more simplified and efficient method for pain management in patients undergoing hip surgery compared to traditional methods such as intravenous fentanyl and non-steroidal analgesics alone. It has been proven to provide superior pain relief in these patients[28]. FICB can also reduce the pain in the perioperative period[16, 29, 30, 31], but the spread of local anesthesia with FICB could neither block the obturation nor completely relieve hip pain[32]. Our research shows that the PENG block results in a reduced use of opioids within 24 hours post-operation. However, there was no statistically significant difference in pain reduction or side effects between the PENG and FICB groups.
Based on the work of Hao Hua, Julián Aliste, and Yong Seon Choi[33–35], we conducted a meta-analysis of high-quality randomized controlled trials and found that the PENG block can effectively reduce opioid consumption within 24 hours after surgery. This results in improved pain relief and may decrease the incidence of opioid-related adverse effects such as constipation, dizziness, nausea, and physical dependence.[36]. However, the research found no significant difference between the PENG and FICB techniques in terms of 48-hour opioid consumption. The three studies included in the analysis indicate that the cumulative use of opioids at 48 hours post-surgery was comparable in both block groups[33–35]. In a study of femoral neck fracture surgeries, Allard et al. found no significant difference in median consumption of morphine equivalents between the PENG block group (20 mg, range 0–50 mg) and the FNB group (10 mg, range 0–20 mg)[37]. We converted the administered dose to the amount of oral morphine and came to the above conclusions by a comparison of standardized analgesic effects. After analyzing the reasons we believe that, in terms of patients, some who took part in the study had a history of chronic opioid use, local anesthetics may be effective till 24 hours after surgery[38], so morphine use decreases within 24 hours after surgery. We hope that there will be more high-quality experiments in the future to expand our sample size and further confirm our conclusions.
Additionally, our meta-analysis suggests that there is no appreciable difference in side effects between the two blocking techniques[33, 34, 35, 39]. Some researchers believed that PENG block improved postoperative functional recovery and range of hip mobility[37, 40]. Although it may not be statistically analyzable in our article, it’s worth mentioning that one RCT demonstrated no patients with PENG block had symptoms of quadriceps weakness which occurred in 29% of the FICB patients[33]. In Choi's report, participants in the PENG block had nausea and urine retention 11% more frequently than those in the FICB group, however, Zheng argued that PENG block is able to reduce the incidence of vomiting[41], in the prior study, FICB also showed that it might guard patients from delirium[15, 42]. Hao also evaluated patient delirium performance in the article that was included, there was nothing more that could be done to investigate in aspects of cognition because the article demonstrated that neither group of patients had delirium.
Next, we analyzed patients' pain scores at various points after surgery. The results show that there was no clear difference between the scores of the PENG block and the scores of the control group. Although there is no statistical significance, in terms of dynamic pain 6 hours after surgery, the PENG block group's scores were lower than those of the control group by K. S. Senthil [26]and Yong Seon Choi[35]. According to Faramarz Mosaffa's article[39], while the static pain scores were similar in both groups at 6 hours after surgery, the PENG block group had significantly lower VAS scores at 15 minutes and 12 hours after surgery, demonstrating the PENG block's ability to provide pain relief in a specific time frame. There was also a trend towards reduced pain scores in the PENG block group, but it is worth noting that the use of patient-controlled analgesia may have impacted the solidity of this trend, as patients could adjust their dose and frequency of injections based on their level of pain.
The studies included in the analysis were all randomized controlled trials (RCTs) due to the limitations of observational and retrospective studies. However, the PENG block is a relatively new technique, so the sample size is limited. Further high-quality studies are needed to provide stronger support for the conclusions. Additionally, variables such as the type of hip surgery, length of surgery, type of anesthesia, and varying doses of anesthetics may impact pain and side effects, and require further investigation to optimize the use of both PENG and FICB blocks.
Based on this meta-analysis, PENG blocks have a good effect in reducing 24-hour opioid consumption after hip fracture surgery, which may reduce opioid-related adverse effects such as constipation, dizziness, nausea, and physical dependence. This suggests that PENG block may be a better alternative to reduce patients’ pain and reduce the risk of substance abuse. However, this requires further validation and investigation in prospective and randomized studies with larger sample sizes and long-term follow-up which can help us find a better anesthetic and analgesia methods that are helpful for postoperative functional exercises of patients and help patients be discharged from the hospital earlier.
Fascia iliaca compartment block = FICB; Randomized controlled trials = RCTs; total hip arthroplasty = THA; femoral nerve block = FNB; obturator nerve = ON; accessory obturator nerve = AON; Preferred Reporting Items for Systematic Reviews and Meta-Analyses = PRISMA; Numerical Rating Scale = NRS; Visual Analog Scale = VAS; mean different = MD; confidence interval = CI; risk ratio = RR; patient-controlled analgesia = PCA.
Ethics approval and consent to participate:
Not applicable.
Consent for publication:
Not applicable.
Availability of data and materials:
All data generated or analysed during this study are included in these published articles.
26. Senthil KS, Kumar P, Ramakrishnan L. Comparison of Pericapsular Nerve Group Block versus Fascia Iliaca Compartment Block as Postoperative Pain Management in Hip Fracture Surgeries. Anesth Essays Res. 2022; 15(4): 352-356.
33. HuaH, XuY, JiangML, et al. Evaluation of Pericapsular Nerve Group (PENG) Block for Analgesic Effect in Elderly Patients with Femoral Neck Fracture Undergoing Hip Arthroplasty. J Healthc Eng. 2022; 2022: 7452716.
34. AlisteJ, LayeraS, BravoD, et al. Randomized comparison between pericapsular nerve group (PENG) block and suprainguinal fascia iliaca block for total hip arthroplasty. Reg Anesth Pain Med. 2021; 46(10): 874-878.
35. ChoiY, ParkK, LeeB, et al. Pericapsular Nerve Group (PENG) Block versus Supra-Inguinal Fascia Iliaca Compartment Block for Total Hip Arthroplasty: A Randomized Clinical Trial. J Pers Med. 2022; 12(3): 408.
39. MosaffaF, TaheriM, RasiA, et al. Comparison of pericapsular nerve group (PENG) block with fascia iliaca compartment block (FICB) for pain control in hip fractures: A double-blind prospective randomized controlled clinical trial. Orthop Traumatol Surg Res. 2022; 108(1): 103135.
Competing interests:
The authors declare no conflicts of interest.
Funding:
The study was funded by the "Clinical Medicine + X" Project of the Affiliated Hospital of Qingdao University.
Acknowledgements:
Thanks to Dr. Niu for the inspiration of our project.
Authors' contributions:
Each author has played a crucial role in the creation and completion of the reported work, contributing from the study's inception to its design, implementation, data collection, analysis, and interpretation. Specifically, Yuxin Miao, Zejun Niu, and Xiaoyu Wang were primarily responsible for screening articles and extracting data. Meanwhile, Zongxiao Li and Xiaoxu Zhang took charge of article retrieval. Miao led the writing of the article and produced pictures 1-6, while Wang created picture 7. Li completed picture 8, and Zhang was responsible for picture 9. All authors unanimously agree on the submission of the article to the chosen journal and take full responsibility for all aspects of the work.