Abstract
Objective
This study aimed to explore the spectrum of analgesic regimens, their effectiveness, and related adverse events following cesarean sections (CS) in Hubei Province, China, to provide an evidence base for refining post-CS pain management.
Methods
This facility-based cross-sectional study used aggregate institutional data submitted by department heads through the Hubei Anesthesia Quality Control and Service Cloud Platform. The analgesic practice (the utilization of intravenous analgesia and epidural analgesia and corresponding medication regimens), their effects (the incidence of inadequate analgesia), and safety profiles (the incidence of adverse reactions) of different pain management strategy following CS were collected for analyses. The primary outcome was the incidence of inadequate analgesia, which was defined as a Visual Analog Scale (VAS) score of ≥4 points within 48 hours. Unadjusted comparisons between groups were performed using chi-square tests and Spearman’s rank correlation; multivariable logistic regression was additionally applied to adjust for institutional-level covariates.
Results
36,620 CS cases were included in our analysis. Intravenous analgesia was the most common strategy (21,142 cases, 57.7%), followed by epidural analgesia (8569 cases, 23.4%). Despite its widespread use, our unadjusted comparison indicated that intravenous analgesia had significantly higher rates of inadequate pain control (VAS ≥4) than epidural analgesia (3.94% vs. 2.21%, p<0.001). Measurable disparities in analgesic practices and pain control outcomes across hospitals of different tiers and cities with different levels of economic development in Hubei Province were also observed.
Conclusion
In this large aggregate institutional dataset, intravenous analgesia was the predominant strategy. Unadjusted comparisons suggest a higher rate of inadequate analgesia in the intravenous group relative to the epidural group. Future studies with patient-level data and validated adverse event capture are needed to confirm these patterns. Better resource allocation and anesthesiologist training would be beneficial to promote equitable post-CS pain management.
Keywords: obstetric analgesia, postsurgical pain, intravenous analgesia, epidural analgesia, adverse effects
Introduction
Cesarean section (CS) is one of the most common surgical procedures among women of reproductive age. By 2030, the global CS rate is projected to reach 28.5%.1 Data showed that the rate of CS in China remained above 40% from 2016 to 2020 and by 2024, the national CS rate had reached 48.6%.2,3 Nevertheless, post-CS pain management remains a major challenge. At least 20% of women experience inadequate analgesia after CS in China.4,5 Owing to persistent postoperative pain, postpartum women are compelled to endure prolonged bed rest, thereby impinging upon the postoperative convalescence and potentially extending hospitalization periods.6 In addition, postoperative pain can also affect breastfeeding and diminish the scope for intimate maternal-newborn interactions.6,7 More seriously, unmitigated acute postoperative pain may precipitate chronic postoperative pain,8 even lead to postpartum depression.6,9,10
The American College of Obstetricians and Gynecologists (ACOG) proposes that, in the absence of medical contraindications, a maternal request alone constitutes sufficient justification for labor and post-CS analgesia.11 Despite being standard practice in developed nations, post-CS analgesia remains underutilized in many developing countries. This stems from persistent unfounded concerns, including widespread beliefs about the technical complexity of epidural procedures, postpartum back pain, and fears of permanent neurological damage.12,13 Disparities between urban and rural areas also persist in healthcare resource allocation and the access to postoperative pain management.14,15 Besides, hospitals are organized into a three-tier hierarchical system in China. Post-CS analgesic practices and resource availability also differ substantially across these tiers.16
Neuraxial opioids is considered the most effective form of postoperative analgesia. Although they provide excellent pain control, their use may be tempered by side effects including hypotension and pruritus.17–19 When administered at an appropriate dosage, clinically significant respiratory depression is extremely rare.20 However, adequate analgesia following CS has not been fully utilized.21 ACOG’s guidelines also advocate for personalized multimodal analgesic protocols to curtail superfluous reliance on opioid analgesics following elective CS. Parallel recommendations have been articulated by the PROSPECT Working Group of the European Society of Regional Anesthesia and Pain Therapy and Enhanced Recovery After Surgery (ERAS) Society.22 Nevertheless, clinical practice in China differs markedly from international guidelines. According to a single-center report, intravenous patient-controlled analgesia was the most widely used modality for analgesic delivery, owing to its ease of operation and nursing management, rapid drug administration, and reliable efficacy.4
Moreover, there appears to be a significant gap in understanding the inadequate rate of pain relief and the adverse effects associated with postpartum analgesia, which has led to inconsistencies in pain management practices. We conducted a cross-sectional survey in 215 Hubei Province hospitals to map current post-CS analgesic practices. Based on the official data platform of Anesthesia Quality Control Center of Hubei, we accessed the current patterns of pump based intravenous and epidural analgesia for post caesarean section pain management in Hubei Province, China, and to explore factors associated with their use.
Methods
Study Design and Population
This cross-sectional study was reported in accordance to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines (Appendix Table 1). This was a facility-based study using aggregate-level data submitted by the heads of the department of anesthesiology. Data on anesthesia modalities used during CS, postoperative analgesia techniques, efficacy of analgesic interventions, and occurrences of analgesia-related adverse events were systematically extracted from the Hubei Anesthesia Quality Control and Service Cloud Platform (https://www.medqc.com), which was established in 2009 as the official data repository of the Hubei Anesthesia Quality Control Center and routinely collected anesthesia and analgesia-related data on a monthly basis from 323 hospitals across Hubei Province. Appendix Table 2 present the item checklist used for data collection in this study. The study covered the period from March to June 2023. The inclusion and exclusion criteria of the study were as follows: (1) Inclusion Criteria: All women who had undergone CS; Patients with complete records of their postoperative analgesia regimen. (2) Exclusion Criteria: Women who had undergone CS but did not have complete records of their postoperative analgesia regimen; Patients with incomplete or missing data regarding their analgesic regimen.
Ethics Approval
The study was conducted in accordance with the Declaration of Helsinki and was registered for clinical observation study on February 3rd, 2023 (ChiCTR2300068021). Ethical approval (20230004) was obtained from the ethical committee at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. The committee did not require written informed consent since only aggregated data that was not personally identifiable to the patient was used.
Outcomes
We focused on the post-cesarean section analgesia, including analgesia efficacy and analgesia-related adverse events. The primary outcome was the incidence of inadequate analgesia, which was defined as a Visual Analog Scale (VAS) score of ≥4 points within 48 hours post-surgery.23 The secondary outcomes included the determinants of inadequate analgesia and the adverse events related to postoperative analgesia. Adverse effects encompassed phenomena such as blood pressure drop, respiratory depression, nausea, vomiting, urinary retention, skin itching, limb numbness or weakness, and muscle pain.
For the routine of clinical practice in Hubei Province, the epidural catheter was placed before surgery as part of the combined spinal-epidural anaesthesia technique. For the intravenous group, the catheter was removed after surgery and replaced with a PCIA pump. For the epidural group, the catheter was retained and connected to a PCEA pump, typically left in place for 24–48 hours. Pain assessments and adverse effect assessments were performed by anesthesiologists (with 2–3 years of clinical experience) as part of routine clinical care at 24 hours and 48 hours postoperatively. For patients discharged before the 48-hour window, follow-up was conducted via telephone. And the number of inadequate analgesia would be upload to the website of the Hubei Anesthesia Quality Control and Service Cloud Platform, where we extracted the data.
Subgroup Analyses
When evaluating the effects of different pain management strategies, we compared the incidence of inadequate analgesia between the intravenous analgesia pump group and the epidural analgesia group. Similar comparisons have also been conducted among the tertiary hospital group with the non-tertiary hospital group, the specialized hospital group with the non-specialized hospital group, and even the cities with a population greater than 3 million and less than three million, and the cities with a per capita GDP greater than 70000 and less than 70000. In addition, we compared the incidence of several common adverse reactions (such as skin itching, nausea and vomiting, respiratory depression, hypotension, and gastrointestinal dysfunction) between the intravenous analgesia pump group and the epidural analgesia group.
Statistical Analysis
A data analysis and statistical plan had been developed before data were accessed. We mainly collected categorical data, which were described as number (percentage). For polytomous variables, categories accounting for a percentage of <1% were combined with other categories.
The association between each variable and the primary outcome was first described by univariable logistic regression and then by multivariable logistic regression, in which the event was inadequate analgesia. Enter method was applied in multivariable logistic regression. Chi-square analysis was used to evaluate the differences in analgesic efficacy among different analgesic methods, medication plan, hospital level, hospital category, urban population and economic development level. The Spearman correlation analysis was employed to evaluate the association between insufficient analgesic rate of intravenous/epidural pump analgesia and several variables, including the composition ratio of anesthesia method (general anesthesia and epidural anesthesia) and delivery technique (CS and conversion from spontaneous delivery to CS). A value of 2-sided P<0.05 was considered statistically significant. The statistical analysis was performed using SPSS and R studio.
Results
This province-wide survey encompassed all 215 hospitals in Hubei Province, China. Non-participating institutions were predominantly specialty hospitals without obstetric services (including pulmonary and traditional Chinese medicine hospitals). Totally, the study covered 36,620 CS cases documented between March to June, 2023.
Analysis of Analgesic Methods Distribution Following CS
Among all the hospitals analyzed, intravenous analgesia (21,142 (57.7%)) emerged as the predominant method following CS, with epidural analgesia (8569 (23.4%)) as the second primary method. Firstly, we delve into the distribution of various analgesic modalities employed post-CS, to assess the prevalence and utilization of different pain management across hospitals of varying tiers and categories (Table 1). Across various hospital levels (tertiary and non-tertiary) and categories (specialized and non-specialized), the predominant method is the utilization of intravenous analgesia, exceeding half of the cases. When comparing tertiary hospitals to non-tertiary facilities, it is notable that the former exhibit a higher tendency to use epidural analgesia after CS and a lower tendency to use intravenous pumps (5122 (26.2%) vs 3447 (20.2%) and 11,021 (56.4%) vs 10,121 (59.2%), both p<0.001). When contrasting specialized and non-specialized hospitals, the former exhibit a higher proportion of utilizing epidural analgesia after CS (4400 (32.9%) vs 4169 (18.0%), p<0.001). Use of alternative analgesic modalities remains limited and shows only minor differences across hospital tiers.
Table 1.
Comparison of Postoperative Analgesia Methods for CS in Different Levels/Categories Hospitals
| Hospital Levels | p value | Hospital Categories | p value | |||
|---|---|---|---|---|---|---|
| Tertiary Hospitals (n=78) |
Non-Tertiary Hospitals (n=137) |
Specialized Hospitals (n=45) |
Non-Specialized Hospitals (n=170) |
|||
| Total cases of cesarean section | 19524 | 17,096 | 13,404 | 23,216 | ||
| Epidural analgesia | 5122 (26.2%) | 3447 (20.2%) | <0.001a | 4400 (32.9%) | 4169 (18.0%) | <0.001a |
| Intravenous analgesia | 11021 (56.4%) | 10,121 (59.2%) | <0.001a | 7796 (58.2%) | 13,346 (57.5%) | 0.211 |
| Other analgesic methods | 463 (2.4%) | 359 (2.1%) | 0.083 | 515 (3.8%) | 307 (1.3%) | <0.001a |
Notes: %: cases of corresponding analgesic methods/total cases of cesarean section; a: statistical significance, p<0.05; chi-squared test was used to compare proportions. Specialized hospitals refer to maternal and child health hospitals, obstetrics and gynecology hospitals, or other officially designated obstetric hospitals; non-specialized hospitals refer to general hospitals that provide obstetric services.
Evaluation of the Efficacy of Varied Analgesic Approaches in CS
Subsequently, we conducted a comparative analysis of the efficacy of epidural analgesia and intravenous analgesia across surveyed hospitals in the province and its 17 cities. Notably, despite intravenous analgesia currently being the primary method employed, the incidence of insufficient analgesia of intravenous analgesia were higher than those of epidural analgesia (829 (3.94%) vs 185 (2.21%), p<0.001). The spatial distribution of the incidence of insufficient epidural/intravenous analgesia is displayed in the Figure 1.
Figure 1.
Geographic distribution of insufficient analgesia rates across hospitals in 17 surveyed cities, shown separately for (A) intravenous analgesia and (B) epidural analgesia pumps. The figure was generated by the authors using ArcGIS software (v10.8). The authors have the rights to reproduce this figure with the permission of ArcGIS software.
The findings from our results revealed that the efficacy of analgesia was also related to the hospital and city characteristics (Table 2). The insufficient analgesic rates were higher in non-tertiary hospitals as opposed to tertiary hospitals (for intravenous pump analgesia: 572 (5.72%) vs 257 (2.33%), p<0.05; for epidural pump analgesia: 122 (3.75%) vs 63 (1.23%), p<0.05). Notably, the effectiveness of intravenous pump analgesia was less robust in specialized hospitals than in non-specialized ones (356 (4.57%) vs 473 (3.58%), p<0.05), while the inadequate analgesia rates for epidural analgesia were lower (63 (1.43%) vs 122 (3.07%), p<0.05). We also found that cities with larger populations have a lower incidence of insufficient intravenous analgesia (491 (3.35%) vs 338 (5.30%), p<0.05), but there is no difference in epidural analgesia (143 (2.24%) vs 42 (2.11%), p=0.792). Additionally, cities with higher economic development demonstrated a lower incidence of insufficient epidural analgesia (99 (1.93%) vs 86 (2.64%), p<0.05), while no significant difference was observed in intravenous analgesia (406 (4.17%) vs 423 (3.75%), p=0.134). These variables emerged as crucial determinants in pain management success, while the composition ratio of anesthesia method (general anesthesia and epidural anesthesia) and delivery technique (CS and conversion from spontaneous delivery to CS) in the surveyed area demonstrated no significant impact, as evidenced by Spearman correlation analyses (Figure 2).
Table 2.
Comparison of the Incidence of Insufficient Postoperative Analgesia in Different Cities or Hospitals Subgroups After CS Surgery
| The Incidence of Insufficient Intravenous Pump Analgesia |
The Incidence of Insufficient Epidural Pump Analgesia |
|
|---|---|---|
| All hospitals | 829 (3.94%)b | 185 (2.21%)b |
| Tertiary hospitals | 257 (2.33%)a | 63 (1.23%)a |
| Non-tertiary hospitals | 572 (5.72%) | 122 (3.75%) |
| Specialized hospitals | 356 (4.57%)a | 63 (1.43%)a |
| Non-specialized hospitals | 473 (3.58%) | 122 (3.07%) |
| Cities with a population greater than 3 million | 491 (3.35%)a | 143 (2.24%) |
| Cities with a population of less than 3 million | 338 (5.30%) | 42 (2.11%) |
| Cities with per capita GDP greater than 70000 | 406 (4.17%) | 99 (1.93%)a |
| Cities with per capita GDP less than 70000 | 423 (3.75%) | 86 (2.64%) |
Notes: a: The differences between subgroups in different cities or hospitals are statistically significant, p<0.05; b The differences between intravenous and epidural pump groups are statistically significant, p<0.05.
Figure 2.
Spearman correlation analyses of the insufficient analgesia rate of (A) intravenous analgesia and (B) epidural analgesia with the composition ratios of anesthesia method (general anesthesia, epidural/spinal/combined spinal‑epidural anesthesia) and delivery technique (cesarean sections and conversions from spontaneous delivery to cesarean section) in the surveyed area.
We examined the impact of different medication regimens on the incidence of insufficient analgesia. In the case of intravenous analgesia, insufficient analgesia was notably less frequent when employing opioid receptor partial agonists (661 (3.78%) vs 168 (4.78%), p<0.05) and nonsteroidal anti-inflammatory drugs (NSAIDs) (257 (3.26%) vs 572 (4.35%), p<0.05). However, the utilization of different drug types and multiclass drug regimens did not demonstrate a mitigating effect on the risk of inadequate pain relief, as indicated by the absence of a statistically significant β value in regression analysis (Table 3). Conversely, for epidural analgesia, the use of opioid receptor agonists exhibited a more effective analgesic outcome, significantly reducing the incidence of insufficient analgesia (β = −19.5, p=0.024). Medication plan for intravenous and epidural analgesia in different levels/categories hospitals was displayed in Appendix Table 3 and 4. Comparison of analgesic effects of different medication plans for intravenous and epidural analgesia was displayed in Appendix Table 5 and 6.
Table 3.
Analysis of the Effectiveness of Different Medication Plans for Different Analgesic Methods
| Insufficient Analgesia Occurred with the Use of this Medication |
β | p value | |
|---|---|---|---|
| Intravenous analgesia | |||
| Pure opioid receptor agonists | 804/17,667 (4.55%) | 5.7 | 0.144 |
| Opioid receptor partial agonists | 661/17,505 (3.78%) | −2.9 | 0.221 |
| NSAIDs | 257/7885 (3.26%) | −0.7 | 0.742 |
| Multiclass Drug Regimen | 654/15,831 (4.13%) | −2.3 | 0.324 |
| Epidural analgesia | |||
| Local anesthetic | 185/8221 (2.25%) | 6.3 | 0.310 |
| Opioid drugs | 173/8280 (2.09%) | −19.5 | 0.024 |
| Multiclass drug regimen | 173/8124 (2.12%) | −2.5 | 0.631 |
Notes: logistic regression used to analysis the association between each medication and the occurrence of insufficient analgesia.
Abbreviation: NSAIDs, nonsteroidal anti-inflammatory drugs.
Examination of the Adverse Events Associated with Different Analgesic Methods After CS
Lastly, we explored the occurrence of adverse events related to various analgesic methods implemented after CS, to identify and assess the safety profile of different techniques (Table 4). The adverse effects of different analgesic methods varied across different analgesic methods. To evaluate safety comprehensively, we compared common adverse effects such as skin itching, nausea and vomiting, respiratory depression, hypotension, and gastrointestinal dysfunction. Notably, there were no significant differences in the incidence of nausea and vomiting, respiratory depression, and gastrointestinal dysfunction between intravenous analgesia and epidural analgesia. However, when contrasted with epidural analgesia, intravenous analgesia exhibited a lower incidence of skin itching (48 (0.23%) vs 37 (0.43%), p<0.05) and hypotension (20 (0.09%) vs 19 (0.22%), p<0.05).
Table 4.
Comparison of Adverse Effects of Intravenous Analgesia and Epidural Analgesia After Cesarean Section
| Intravenous analgesia | Epidural Analgesia | P value | |
|---|---|---|---|
| Total cases of analgesia | 21142 | 8569 | |
| Skin itching | 48 (0.23%) | 37 (0.43%) | 0.004a |
| Nausea | 143 (0.68%) | 53 (0.62%) | 0.582 |
| Respiratory depression | 18 (0.09%) | 5 (0.06%) | 0.503 |
| Hypotension | 20 (0.09%) | 19 (0.22%) | 0.008a |
| Gastrointestinal dysfunction | 45 (0.21%) | 21 (0.25%) | 0.684 |
Notes: %: Total cases of adverse effects relative to cases of pain relief. a: statistical significance (p<0.05). chi-squared test was used to compare proportions. Adverse event data were derived from aggregate reports provided by the head of the anesthesia department at each participating hospital, rather than from individual patient records.
Discussion
This study is the first provincial-level observational study in China to investigate the analgesic regimens and effects of post-CS pain management. It indicated that both the proportion of use and the inadequate-analgesia rate were higher for intravenous than for epidural techniques in the investigated hospitals. Despite the higher efficacy of epidural analgesia, it was associated with a higher incidence of hypotension and skin itching. Additionally, the inadequate analgesia rates of both methods correlated with specific hospital and city characteristics. The correlation between analgesic efficacy and hospital and city characteristics underscores the complexity of pain management.
Evaluation of the Distribution and Efficacy of Varied Analgesic Approaches
Previous studies showed that epidural analgesia is widely applied in the remission of labor pain and post-CS pain, and intravenous opioid-analgesics or nonmedical pain relief ways can offer an alternative in specific situations.24–26 However, in our study, the dominance of intravenous analgesia, representing over half of the cases, underscores their widespread use. The widespread use of intravenous analgesia may be related to its simple operation and higher safety of drug infusion. A survey of post-CS analgesia within 24 h in one of the largest hospitals in Africa likewise identified intravenous analgesia as the predominant method.27 In our study, tertiary hospitals exhibit a distinct pattern with a higher preference for epidural analgesia and a lower inclination towards intravenous analgesia compared to non-tertiary hospitals. Specialized hospitals, regardless of their tier, display a higher utilization of both epidural and intravenous analgesia. These observations emphasize the nuanced nature of analgesic preferences based on hospital characteristics.
Epidural analgesia has been shown to better improve early postoperative analgesia during mastectomy,28 prostatectomy,29 spinal fusion surgery30 and laparoscopic surgery.31 While some labor analgesia studies have reported comparable efficacy between intravenous and epidural techniques for pain relief during vaginal delivery,32,33 our post-CS findings reveal a clear superiority of epidural analgesia over intravenous analgesia. This divergence may reflect anatomical and physiological differences between peripartum and postoperative pain pathways. A meta-analysis of five trials found comparable efficacy between intravenous remifentanil and epidural analgesia in labor,34 yet direct comparisons of these modalities for post-CS pain management remain scarce. Another meta-analysis indicates that intravenous ketamine enhances post-operative analgesia after CS under epidural analgesia.35 Despite intravenous analgesia being the primary method in our study area, the higher incidence of inadequate analgesia signals the need for a more nuanced approach. In addition, ultrasound-guided transverse abdominal muscle plane block or ilioinguinal/iliopsoas nerve block, although rarely used in clinical practice, have also been proven to provide effective analgesia and were alternative options for post-CS pain management.36,37 Multimodal analgesia based on neuroaxial anaesthesia, gives the best post-CS analgesia outcome, and allows anaesthesiologists to reserve intravenous analgesia (opioids, corticoids, or ketamine) for situations where neuroaxial anaesthesia cannot be performed, for high-risk patients, or when pain is difficult to control.26
Factors Affecting the Analgesic Efficacy
Most investigations have focused on barriers to implementing post-CS analgesia, whereas far fewer have examined the determinants of its effectiveness. Our exploration extended to factors influencing the insufficient analgesic rate, encompassing analgesic methods, medication plans, hospital level, hospital category, urban population, and economic development level. Non-tertiary hospitals face higher rates of insufficient analgesia, emphasizing the need for tailored strategies. The analgesic effects of intravenous analgesia and epidural analgesia in tertiary hospitals were better than those in non-tertiary hospitals, while compared with non-specialized hospitals, specialized hospitals did not show any advantage in the intravenous analgesia after CS. This may because tertiary hospitals tend to have more professional and experienced medical teams, including obstetricians, anesthesiologists, and nurses. In addition, tertiary hospitals have more advanced equipment and sufficient resources to provide higher-quality postoperative analgesia services. Third, tertiary hospitals usually have stricter quality management systems to ensure timely updating of medical concepts and strict implementation of the latest clinical guidelines. Notably, anesthesia method and delivery technique showed no relationship with postoperative analgesia in our survey. A cross-sectional survey in Poland compared pain management across hospitals of different levels and fielded similar findings: Women who delivered in higher-level hospitals had better control of labor pain and received more adequate postpartum analgesia.38 This may be attributable to the greater availability of anesthesia professionals and more standardized pain management protocols in higher-level hospitals.
In our survey, the impact of city population and economic development on analgesic outcomes further highlights the intricate interplay of socio-economic factors in pain management success. Our analysis revealed distinct socio-economic patterns in analgesic efficacy (Table 2). For intravenous analgesia, larger cities (>3 million population) showed significantly better pain control than smaller cities (<3 million population), with lower rates of inadequate analgesia (3.35% vs 5.30%). This urban advantage may reflect: (1) greater availability of acute pain service teams, and (2) more frequent analgesic medication protocol updates. Economic development showed complementary effects, primarily benefiting epidural analgesia outcomes. High-GDP cities demonstrated superior epidural efficacy (1.93% vs 2.64% inadequate pain relief), likely due to: (1) higher ratios of anesthesiologists per CS delivery, and (2) advanced monitoring equipment availability. A systematic review indicated that in low-income countries, limited drug availability, healthcare costs, and shortages of regional anesthesia professionals constituted barriers to the widespread implementation of post-cesarean analgesia.39 Beyond these macro-level barriers, individual-level factors—household income, insurance status, and education—were also closely associated with the risk of inadequate pain assessment and insufficient pain management.40 Therefore, socioeconomic factors are closely linked to the quality of post-cesarean analgesia, necessitating targeted measures to rationally allocate healthcare resources and promote equitable access to effective postpartum analgesia.
We found that the effectiveness of epidural analgesia may be significantly enhanced with opioid receptor agonists (Table 3). Pain after CS may be accompanied by multiple pain mechanisms such as incision pain, visceral traction pain, and inflammatory reactions. Pure opioids may mainly produce analgesia through the central nervous system. For epidural analgesia, the use of opioids will achieve better analgesic effects, but the incidence of insufficient analgesia is higher when using local anesthetics. This may be because the action time of local anesthetics is limited.41,42
Adverse Events Associated with Analgesic Methods After CS
While common adverse effects such as nausea/vomiting, respiratory depression, and gastrointestinal dysfunction show no significant differences between intravenous analgesia and epidural analgesia, notable distinctions emerge in skin itching and hypotension. The lower incidence of skin itching and hypotension with intravenous analgesia suggests potential advantages in terms of tolerability and safety. However, some studies have shown that there is no difference in the incidence of postoperative skin itching between the two analgesia methods.43 This may be due to the more flexible dosing of opioids in clinical practice compared with randomized controlled trials where opioid dosing is strictly controlled.
This study has several limitations. Firstly, the cross-sectional study design and the unadjusted statistical analyses was susceptible to the influence of confounding factors. More prospective cohort studies are needed to further clarify the impact of various factors on analgesic effect. Besides, our data was obtained from the Quality Control and Service Cloud Platform, which was filled by directors or deputy directors of the anesthesiology department rather than patients. This may introduce measurement error and reporting bias—particularly for adverse events. Thirdly, oral analgesics (eg, NSAIDs, paracetamol) were not captured, meaning our findings only reflect pump-based intravenous and epidural strategies and do not represent the full landscape of post-CS pain management. Fourthly, while our study included the majority of hospitals in Hubei province, we acknowledged the potential for bias due to missing data from non-responding hospitals. We could not formally compare respondents versus non-respondents, so the generalization of the findings was limited. However, it is noteworthy that the non-respondents were primarily hospitals that do not offer obstetric medical services, such as pulmonary hospitals, community hospitals, and traditional Chinese medicine hospitals. Given that these institutions are not equipped to provide obstetric care, their absence from our study is considered to have a minimal impact on the generalizability of our research findings. Besides, We acknowledge that no formal power calculation was conducted for subgroup analyses. These findings should be interpreted as exploratory and hypothesis-generating, and they require confirmation in future adequately powered studies. Moreover, due to the limitation of data source, our study may not adequately assess the impact of post-CS analgesia methods on variables such as breastfeeding, maternal fever, neonatal acid-base status, and cognitive development, limiting the comprehensiveness of the evaluation dimensions. Finally, the study’s geographical scope is confined to one province in China, warranting larger datasets to assess the potential influence of geographical location and cultural disparities between the northern and southern regions on post-CS analgesia.
Conclusion
Our comprehensive analysis revealed significant variation in post-CS pain management practices. Intravenous analgesia, used in 57.7% of cases, was the most common strategy, yet it had a higher rate of inadequate pain relief (3.94%) compared to epidural analgesia (2.21%). While epidural analgesia provided better pain control, it carried higher risks of skin itching and hypotension. These findings underscore the need for further research and evidence-based refinement of post-CS pain management. However, because of the non-patient-level, observational, and self-reported nature of the data, these findings should be interpreted as descriptive associations rather than causal evidence of comparative effectiveness. Future prospective studies with patient-level data and validated adverse event capture are needed to confirm these patterns. Notably, the substantial and measurable disparity in analgesic practice across hospital tiers in Hubei Province underscores the need for better policies for allocating analgesia resources and providing technical training to anesthesiologists, thereby promoting equitable access to post-CS pain management.
Acknowledgments
The authors express their gratitude to the Hubei Anesthesia Quality Control Center for their support and assistance.
Funding Statement
This work was supported by National Natural Science Foundation of China (grant No.81772131) and the China International Medical Foundation (Z-2017-24-2421).
Data Sharing Statement
All data can be requested from the corresponding author via Email (drjingwu@hust.edu.cn).
Ethical Statement
The study was conducted in accordance with the Declaration of Helsinki and ethical approval (20230004) was obtained from the ethical committee at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.
Consent to Participate
The ethical committee did not require written informed consent since only aggregated data that was not personally identifiable to the patient was used.
Author Contributions
All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.
Disclosure
The authors declare no conflicts of interest in this work.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
All data can be requested from the corresponding author via Email (drjingwu@hust.edu.cn).