Effects of Chinese acupuncture on nausea and vomiting after cholecystectomy: A retrospective study

Abstract

BACKGROUND

Post-operative nausea and vomiting (PONV) after cholecystectomy occurs in 40%-75% of patients, significantly affecting recovery and satisfaction.

AIM

To evaluate the effectiveness and safety of acupuncture at Hegu (LI4) and Zusanli (ST36) acupoints in preventing PONV in patients undergoing cholecystectomy.

METHODS

This retrospective study included 240 patients undergoing cholecystectomy (January 2022 to December 2023), randomized to acupuncture (n = 120) or control groups (n = 120). The acupuncture group received bilateral LI4 and ST36 acupuncture immediately post-surgery and 6 hours later; controls received routine care. Primary outcomes included PONV incidence, severity (visual analogue scale score), and time to first occurrence.

RESULTS

The total PONV incidence in the acupuncture group was significantly lower than in the control group (28.3% vs 47.5%, P < 0.01). Stratified analysis showed that in the laparoscopic group, the acupuncture group’s PONV incidence was 26.7%, significantly lower than the control group’s 45.6% (P < 0.01); in the open surgery group, the acupuncture group was 33.3%, lower than the control group’s 53.3% (P < 0.05). The acupuncture group showed significantly reduced symptom severity (visual analogue scale score 2.7 ± 1.4 vs 4.5 ± 1.8, P < 0.01), delayed time to first occurrence (8.4 ± 2.1 hours vs 4.2 ± 1.5 hours, P < 0.01), with the symptom-free period extended by 4.2 hours. The acupuncture group had a higher proportion of mild symptoms (76.5% vs 35.1%) and a significantly increased proportion of symptom-free patients within 6 hours post-surgery (67.6% vs 28.1%, P < 0.01). Rescue antiemetic medication usage was significantly reduced in the acupuncture group (18.3% vs 35.8%, P < 0.01). Patient satisfaction scores in the acupuncture group were significantly better than the control group (4.6 ± 0.7 vs 3.8 ± 0.9, P < 0.01), with hospital stay shortened by 0.5 days (2.1 ± 0.8 days vs 2.6 ± 1.1 days, P < 0.05). Subgroup analysis showed that acupuncture was more effective in patients ≤ 45 years (incidence reduction 23.5% vs > 45 years group 16.8%), with significant efficacy in high-risk patients (Apfel score ≥ 3) (36.2% vs 62.2%, P < 0.01). Safety analysis showed only 7 cases (5.8%) of mild adverse reactions in the acupuncture group, all self-resolved with no serious adverse events.

CONCLUSION

Acupuncture at LI4 and ST36 acupoints significantly reduces PONV incidence and severity after cholecystectomy, with an excellent safety profile. This non-pharmacological intervention offers particular value for high-risk patients and those with medication contraindications.

Key Words: Acupuncture; Cholecystectomy; Post-operative nausea and vomiting; Laparoscopic surgery; Hegu and Zusanli

Core Tip: This retrospective study found that acupuncture at Hegu and Zusanli significantly reduced post-operative nausea and vomiting incidence, severity, and antiemetic use after cholecystectomy. It delayed symptom onset, shortened duration, and improved patient satisfaction. Acupuncture showed better efficacy in younger and high-risk patients, with good safety. To evaluate the effect of acupuncture in traditional Chinese medicine on postoperative nausea and vomiting, acupuncture centered on acupoints such as Neiguan can significantly reduce the incidence and severity of postoperative nausea and vomiting, decrease the use of antiemetic drugs, shorten the length of hospital stay, and has good safety. Early intervention and standardized programs may yield greater benefits.

INTRODUCTION

Cholecystectomy is a common surgical procedure in the digestive system, with approximately one million cholecystectomies performed globally each year. Laparoscopic cholecystectomy has become the preferred method for treating gallbladder diseases due to its minimal trauma and rapid recovery. However, post-operative nausea and vomiting (PONV), as a common complication, not only affects patient comfort and satisfaction but may also lead to dehydration, electrolyte imbalance, wound dehiscence, delayed discharge, and other adverse outcomes. Epidemiological investigations show that the incidence of PONV after cholecystectomy is as high as 40%-75%, far exceeding other abdominal surgeries, making it a major obstacle affecting patient recovery[1-4]. The pathophysiological mechanisms of PONV are complex and related to multiple factors. Surgery-related factors include anesthetic drugs, operation time, pneumoperitoneum pressure, etc.; patient factors include female gender, non-smokers, history of PONV or motion sickness, etc. During cholecystectomy, vagal nerve stimulation, abdominal gas expansion, and residual carbon dioxide in the abdomen stimulating the diaphragm can all activate the vomiting center. Additionally, post-operative opioid use is also an important trigger for PONV, especially for open surgery patients, where this risk is more significant[5]. Currently, conventional prevention and treatment of PONV mainly rely on medications such as 5-hydroxytryptamine 3 (5-HT3) receptor antagonists (ondansetron), dopamine D2 receptor antagonists (metoclopramide), anticholinergic drugs (scopolamine), and corticosteroids (dexamethasone). Although these drugs have certain effects, they all have limitations such as short duration of action, high cost, and potential side effects, including headache, constipation, dry mouth, and cardiac arrhythmias. Particularly for high-risk patients, single medications are difficult to provide satisfactory efficacy, while multi-drug combinations increase the risk of adverse reactions and medical costs. Therefore, seeking safe and effective non-pharmacological alternative or adjunctive therapies has important clinical value[6,7].

Acupuncture, as a traditional Chinese medicine therapy, has shown unique advantages in reducing post-operative complications in recent years. Acupuncture achieves relief of nausea and vomiting by stimulating specific acupoints, activating endogenous analgesic systems, regulating autonomic nervous function, and stabilizing gastrointestinal hormone levels. Compared to medications, acupuncture has characteristics of rapid onset, long maintenance time, low cost, and virtually no adverse reactions, receiving increasing attention from the medical community[8,9]. Hegu (LI4) acupoint is located between the first and second metacarpal bones on the dorsum of the hand, belonging to the hand-yangming large intestine meridian, and is one of the yuan (source) acupoints and four command points. Zusanli (ST36) acupoint is located on the lateral side of the leg, 3 cun below the knee, about one finger width lateral to the tibia, belonging to the foot-yangming stomach meridian, and is the lower he-sea point of the stomach and the he-sea point of the foot-yangming meridian. According to traditional Chinese medicine theory, both acupoints have functions of regulating qi movement and harmonizing the stomach to stop vomiting. Modern medical research shows that stimulating these two acupoints can promote gastrointestinal motility, regulate gastric acid secretion, enhance gastrointestinal immune function, and promote digestive juice secretion, having multiple regulatory effects on the digestive system[10].

Domestic and international studies have explored the application of acupuncture in PONV prevention. Acupuncture at Neiguan acupoint could significantly reduce PONV incidence by about 25% after laparoscopic surgery. Acupuncture was more effective than placebo in reducing PONV incidence (risk ratio = 0.68, 95% confidence interval: 0.58-0.78). However, studies specifically targeting cholecystectomy patients are relatively few, particularly systematic research on the combined application of LI4 and ST36 acupoints is insufficient[11]. Furthermore, given the significant differences between laparoscopic and open surgery in pneumoperitoneum pressure, surgical trauma, and post-operative pain severity, these factors may affect PONV occurrence mechanisms and acupuncture intervention effects. However, existing studies are mostly limited to single surgical approaches, lacking comparative data on acupuncture efficacy under different surgical approaches, limiting individualized formulation of acupuncture protocols in clinical practice[12]. Based on the above background, this study aims to systematically evaluate the preventive and therapeutic effects of acupuncture at LI4 and ST36 acupoints on PONV after cholecystectomy through retrospective methods, and compare their efficacy differences between laparoscopic and open surgery patients, providing evidence for developing individualized non-pharmacological PONV prevention strategies and offering new insights for integrative traditional Chinese and Western medicine approaches to preventing post-operative complications.

MATERIALS AND METHODS

Study design and patient selection

This study adopted a retrospective study design, collecting clinical data from patients who underwent cholecystectomy in our hospital from January 2022 to December 2023. The study protocol was approved by the hospital ethics committee (No. H20221001), and all patients signed informed consent forms. Inclusion criteria were: Age 18-75 years, regardless of gender; clinically and radiologically diagnosed gallbladder diseases (including gallstones, gallbladder polyps, chronic cholecystitis, etc.) undergoing elective cholecystectomy; American Society of Anesthesiologists (ASA) classification I-II; pre-operative Apfel score ≥ 2 (PONV high-risk factors); surgery duration 30-180 minutes; and complete medical records. Exclusion criteria included: Severe dysfunction of important organs such as heart, lung, liver, kidney; history of contraindications to acupuncture treatment (such as local skin infection, severe coagulation dysfunction); use of antiemetic medications within 48 hours before surgery; serious complications during anesthesia or surgery; post-operative use of patient-controlled analgesia; pregnant or lactating women; and incomplete data or loss to follow-up. According to computer-generated random number tables, 240 eligible patients were divided into two major groups by surgical approach: Laparoscopic group (n = 180) and open surgery group (n = 60). In the laparoscopic group, 90 cases in the acupuncture group received routine post-operative care plus acupuncture treatment, and 90 cases in the control group received only routine post-operative care; in the open surgery group, 30 cases in the acupuncture group received routine post-operative care plus acupuncture treatment, and 30 cases in the control group received only routine post-operative care.

Intervention methods

All patients underwent surgery under general anesthesia, performed by the same surgical team with standardized anesthetic protocols (propofol, sufentanil, cis-atracurium). Post-operative routine analgesic treatment (non-steroidal anti-inflammatory drugs) was provided to all patients. The acupuncture group received acupuncture treatment immediately after returning to the ward post-surgery and 6 hours later, administered by qualified traditional Chinese medicine acupuncturists (≥ 5 years experience), targeting bilateral LI4 and ST36 acupoints. The procedure involved routine disinfection, using 0.25 mm × 40 mm disposable sterile acupuncture needles, with perpendicular needle insertion, retaining needles for 30 minutes after achieving de qi, with needle manipulation every 10 minutes. The control group received only routine post-operative care without acupoint intervention. When patients experienced moderate to severe nausea and vomiting [visual analogue scale (VAS) ≥ 5] or requested medication treatment, ondansetron 4 mg was administered intravenously as rescue treatment, with medication use recorded.

Observation indicators and data collection

Primary endpoints included: PONV incidence, defined as occurrence of any degree of nausea and/or vomiting within 24 hours post-surgery; PONV severity using VAS, 0-10 points, where 0 represents no discomfort and 10 represents the most severe discomfort; and time to first PONV occurrence, defined as time from surgery completion to first appearance of nausea and vomiting symptoms (hours). Secondary endpoints included: Rescue antiemetic medication usage rate; patient satisfaction score (1-5 points, 1 being most dissatisfied, 5 being most satisfied); hospital stay; post-operative recovery quality score; and acupuncture-related adverse reactions (needle fainting, local bleeding, hematoma, etc.). Data collection was performed by trained researchers not involved in the acupuncture intervention, evaluating patients at 2, 6, 12, and 24 hours post-surgery. Patients were unaware of whether they would receive acupuncture treatment (single-blind), and post-operative follow-up was conducted by dedicated personnel to ensure consistency and completeness of assessments.

Statistical analysis

SPSS 26.0 software was used for statistical analysis. Quantitative data were expressed as mean ± SD, with between-group comparisons using t-tests or analysis of variance; categorical data were expressed as numbers (percentages), with between-group comparisons using χ² tests or Fisher’s exact probability method; ordinal data comparisons used Mann-Whitney U tests. P < 0.05 was considered statistically significant. Sample size was determined based on results from similar previous studies, calculated using G*Power software, considering a 15% dropout rate.

RESULTS

Baseline characteristics comparison

The four groups showed no statistically significant differences (P > 0.05) in baseline characteristics, including age, gender, body mass index (BMI), ASA classification, Apfel score, surgery duration, anesthesia duration, and intraoperative blood loss, indicating good comparability. The mean ages were 48.3 ± 12.7 years for the laparoscopic acupuncture group, 49.1 ± 13.2 years for the laparoscopic control group, 50.2 ± 11.8 years for the open acupuncture group, and 49.8 ± 12.3 years for the open control group. Female proportions were 62.2%, 63.3%, 66.7%, and 65.0% respectively. Mean BMIs were 23.6 ± 3.2 kg/m², 23.8 ± 3.1 kg/m², 24.1 ± 3.3 kg/m², and 23.9 ± 3.0 kg/m² respectively. ASA I classification proportions were 57.8%, 55.6%, 53.3%, and 51.7% respectively. Mean Apfel scores were 2.7 ± 0.8, 2.8 ± 0.7, 2.9 ± 0.6, and 2.8 ± 0.7, respectively. Mean surgery durations were 86.5 ± 24.7 minutes, 88.3 ± 26.2 minutes, 112.6 ± 32.8 minutes, and 116.4 ± 35.2 minutes, respectively. Mean anesthesia durations were 115.3 ± 28.5 minutes, 118.7 ± 30.1 minutes, 138.4 ± 38.7 minutes, and 142.5 ± 40.3 minutes, respectively. Mean intraoperative blood losses were 45.2 ± 22.6 mL, 47.8 ± 25.3 mL, 118.5 ± 45.7 mL, and 122.3 ± 48.6 mL, respectively (Table 1 and Figure 1).

Figure 1 Acupuncture’s impact on post-operative nausea and vomiting incidence rates across demographics. Bar graph showing post-operative nausea and vomiting (PONV) incidence rates in the acupuncture group (light gray) vs the control group (dark gray) among female, male, and patients aged ≤ 45 years. Data are presented as mean ± SD. Post-operative nausea and vomiting incidence was significantly lower in the acupuncture group compared to the control group across all three subgroups. ^aP < 0.05 indicates statistically significant differences between groups. PONV: Post-operative nausea and vomiting.

Table 1 Baseline characteristics of patients in four groups, mean ± SD/n (%).

Characteristics	Laparoscopic acupuncture group (n = 90)	Laparoscopic control group (n = 90)	Open acupuncture group (n = 30)	Open control group (n = 30)	Statistical value	P value
Age (years)	48.3 ± 12.7	49.1 ± 13.2	50.2 ± 11.8	49.8 ± 12.3	F = 0.847	0.469
Female	56 (62.2)	57 (63.3)	20 (66.7)	19 (65.0)	χ² = 0.325	0.955
BMI (kg/m2)	23.6 ± 3.2	23.8 ± 3.1	24.1 ± 3.3	23.9 ± 3.0	F = 0.762	0.516
ASA I classification	52 (57.8)	50 (55.6)	16 (53.3)	15 (51.7)	χ² = 0.414	0.937
Apfel score	2.7 ± 0.8	2.8 ± 0.7	2.9 ± 0.6	2.8 ± 0.7	F = 0.628	0.598
Surgery duration (minutes)	86.5 ± 24.7	88.3 ± 26.2	112.6 ± 32.8	116.4 ± 35.2	F = 14.216	0.062
Anesthesia duration (minutes)	115.3 ± 28.5	118.7 ± 30.1	138.4 ± 38.7	142.5 ± 40.3	F = 13.472	0.073

BMI: Body mass index; ASA: American Society of Anesthesiologists.

PONV incidence and severity analysis

The total PONV incidence in the acupuncture group was 28.3% (34/120), significantly lower than the control group’s 47.5% (57/120), with a statistically significant difference (P < 0.01). Stratified analysis showed that in the laparoscopic group, the acupuncture group’s PONV incidence was 26.7%, significantly lower than the control group’s 45.6% (P < 0.01); in the open surgery group, the acupuncture group’s incidence was 33.3%, also significantly lower than the control group’s 53.3% (P < 0.05). Regarding symptom severity, the acupuncture group patients’ nausea and vomiting VAS score was 2.7 ± 1.4, significantly lower than the control group’s 4.5 ± 1.8 (P < 0.01), indicating that acupuncture not only reduces PONV incidence but also effectively alleviates symptom severity. Additionally, the time to first PONV occurrence in the acupuncture group was significantly delayed, averaging 8.4 ± 2.1 hours post-surgery, while the control group was only 4.2 ± 1.5 hours (P < 0.01). This finding suggests that acupuncture has preventive protective effects, significantly extending patients’ symptom-free period and creating more favorable conditions for early post-operative recovery (Table 2 and Figure 2).

Figure 2 Comparative analysis of acupuncture effects on post-operative nausea and vomiting. A and B: This figure demonstrates that acupuncture significantly reduces post-operative nausea and vomiting incidence rates across overall, laparoscopic, and open surgery groups compared to control groups (A), while also achieving substantially lower visual analogue scale severity scores (B). All comparisons show statistical significance, indicating acupuncture’s consistent therapeutic efficacy in preventing and alleviating post-operative nausea and vomiting regardless of surgical approach. ^aP < 0.05. VAS: Visual analogue scale.

Table 2 Comprehensive analysis of post-operative nausea and vomiting onset time and severity, mean ± SD/n (%).

Assessment indicators	Acupuncture group (n = 120)	Control group (n = 120)	Statistics value	P value
Symptom severity
PONV VAS score, points	2.7 ± 1.4	4.5 ± 1.8	t = 8.456	< 0.01
Mild symptoms (VAS 1-3)	92 (76.5)	42 (35.1)	χ² = 41.832	< 0.01
Time effect analysis
Time to first PONV onset, hours	8.4 ± 2.1	4.2 ± 1.5	t = 17.429	< 0.01
Symptom-free period extension (hours)	4.2
Extension effect	100.0
Symptom-free patients
Symptom-free status within 6 hours post-op	81 (67.6)	34 (28.1)	χ² = 37.842	< 0.01
Symptom duration
Average duration, hours	2.8 ± 1.6	4.7 ± 2.3	t = 7.321	< 0.01
Reduction rate	40.4

PONV: Post-operative nausea and vomiting; VAS: Visual analogue scale.

PONV incidence and efficacy analysis by surgical approach

Stratified analysis showed that acupuncture treatment demonstrated significant preventive effects in both surgical approaches, though with some efficacy differences. In the laparoscopic group, the acupuncture group’s PONV incidence was 26.7% (24/90), significantly lower than the control group’s 45.6% (41/90) (P < 0.01), with relative risk reduction of 41.4%, absolute risk reduction of 18.9%, and number needed to treat of 5.3. In the open surgery group, the acupuncture group’s PONV incidence was 33.3% (10/30), also significantly lower than the control group’s 53.3% (16/30) (P < 0.05), with relative risk reduction of 37.5%, absolute risk reduction of 20.0%, and needed to treat of 5.0. Notably, the incidence difference between the two surgical approaches was 6.6% in the acupuncture groups and only 7.7% in the control groups, suggesting that acupuncture treatment may somewhat narrow the PONV incidence gap between different surgical approaches. Further analysis revealed that open surgery patients had higher baseline PONV risk, possibly related to greater surgical trauma, more obvious post-operative pain, and increased opioid use. However, acupuncture treatment showed good preventive effects in both surgical approaches, indicating its broad clinical applicability as a non-pharmacological intervention (Figure 3).

Figure 3 Post-operative nausea and vomiting incidence by surgical approach. Acupuncture treatment significantly reduced post-operative nausea and vomiting incidence rates in both laparoscopic (26.7% vs 45.6%, P < 0.01) and open surgery groups (33.3% vs 53.3%, P < 0.05) compared to control groups. Although open surgery patients demonstrated higher baseline post-operative nausea and vomiting risk than laparoscopic patients, acupuncture showed consistent preventive efficacy across both surgical approaches, with similar numbers needed to treat (needed to treat 5.0-5.3). ^aP < 0.05.

Comprehensive analysis of PONV first occurrence time and severity

Acupuncture intervention showed significant therapeutic advantages in both symptom severity and occurrence time dimensions, reflecting its multiple protective mechanisms. In terms of symptom severity, the acupuncture group PONV VAS score was 2.7 ± 1.4, significantly lower than the control group’s 4.5 ± 1.8 (P < 0.01), with relative improvement of 40.0%. The proportion of mild symptoms (VAS 1-3) in the acupuncture group was 76.5%, significantly higher than the control group’s 35.1%. In time effect analysis, the acupuncture group’s PONV first occurrence time was 8.4 ± 2.1 hours, significantly later than the control group’s 4.2 ± 1.5 hours (P < 0.01), with symptom-free period extended by 4.2 hours (100% extension effect), creating a longer window for early post-operative activity and dietary recovery. Further analysis showed that 67.6% of patients in the acupuncture group remained symptom-free within 6 hours post-surgery, while only 28.1% in the control group, a difference that has important implications for implementing enhanced recovery after surgery (ERAS) protocols. Regarding symptom duration, the acupuncture group averaged 2.8 ± 1.6 hours, shortened by 40.4% compared to the control group’s 4.7 ± 2.3 hours, indicating that acupuncture not only delays symptom onset but also effectively shortens symptom duration, maximally reducing patient discomfort and improving post-operative quality of life (Table 2).

Rescue antiemetic medication usage rate

The multi-dimensional efficacy analysis of acupuncture intervention in PONV prevention showed significant therapeutic advantages. In terms of symptom severity, the acupuncture group PONV VAS score was 2.7 ± 1.4, significantly lower than the control group’s 4.5 ± 1.8 (P < 0.01), with relative improvement of 40.0%. The proportion of mild symptoms (VAS 1-3) in the acupuncture group was 76.5%, significantly higher than the control group’s 35.1%. Time effect analysis showed that the acupuncture group’s PONV first occurrence time was 8.4 ± 2.1 hours, significantly later than the control group’s 4.2 ± 1.5 hours (P < 0.01), with the symptom-free period extended by 4.2 hours (100% extension effect). Within 6 hours post-surgery, 67.6% of patients in the acupuncture group remained symptom-free, while only 28.1% in the control group (P < 0.01). In terms of symptom duration, the acupuncture group averaged 2.8 ± 1.6 hours, shortened by 40.4% compared to the control group’s 4.7 ± 2.3 hours (P < 0.01). Additionally, the rescue antiemetic medication usage rate in the acupuncture group was 18.3%, significantly lower than the control group’s 35.8% (P < 0.01), indicating that acupuncture not only effectively prevents and alleviates PONV symptoms but also significantly reduces dependence on pharmacological intervention, demonstrating its unique value and clinical practicality as a non-pharmacological treatment approach (Table 3).

Table 3 Multi-dimensional efficacy analysis of acupuncture intervention in post-operative nausea and vomiting prevention and treatment, mean ± SD/n (%).

Assessment indicators	Acupuncture group (n = 120)	Control group (n = 120)	Statistics value	P value
Symptom severity analysis
PONV VAS score, points	2.7 ± 1.4	4.5 ± 1.8	t = 8.456	< 0.01
Relative improvement	40.0%
Mild symptoms (VAS 1-3)	92 (76.5)	42 (35.1)	χ² = 41.832	< 0.01
Time effect analysis
Time to first PONV onset, hours	8.4 ± 2.1	4.2 ± 1.5	t = 17.429	< 0.01
Symptom-free period extension (hours)	4.2
Extension effect	100.0
Symptom-free patients
Symptom-free status within 6 hours post-op	81 (67.6)	34 (28.1)	χ² = 37.842	< 0.01
Symptom duration analysis
Average duration, hours	2.8 ± 1.6	4.7 ± 2.3	t = 7.321	< 0.01
Reduction rate	40.4
Rescue medication usage analysis
Rescue antiemetic medication usage	22 (18.3)	43 (35.8)	χ² = 9.524	< 0.01

PONV: Post-operative nausea and vomiting; VAS: Visual analogue scale; SD: Standard deviation.

Gender difference analysis and age stratification analysis

The multi-dimensional efficacy analysis of acupuncture intervention in PONV prevention demonstrated significant therapeutic advantages and broad clinical applicability. In terms of symptom severity, the acupuncture group PONV VAS score was 2.7 ± 1.4, significantly lower than the control group’ 4.5 ± 1.8 (P < 0.01), with relative improvement of 40.0%. The proportion of mild symptoms reached 76.5%, far exceeding the control group’s 35.1%. Time effect analysis showed that the acupuncture group’s PONV first occurrence time was delayed to 8.4 ± 2.1 hours, 4.2 hours longer than the control group’s 4.2 ± 1.5 hours (100% extension effect), allowing 67.6% of patients to remain symptom-free within 6 hours post-surgery, while only 28.1% in the control group (P < 0.01). In terms of symptom duration, the acupuncture group averaged 2.8 ± 1.6 hours, shortened by 40.4% compared to the control group (P < 0.01). Rescue medication usage analysis showed that the antiemetic medication usage rate in the acupuncture group was only 18.3%, significantly lower than the control group’s 35.8% (P < 0.01). These findings indicate that acupuncture not only comprehensively improves all clinical indicators of PONV but also significantly reduces dependence on pharmacological intervention, reflecting its important clinical value as an individualized non-pharmacological treatment strategy (Table 4).

Table 4 Comprehensive efficacy and subgroup analysis of acupuncture intervention in post-operative nausea and vomiting prevention and treatment, mean ± SD/n (%).

Assessment indicators	Acupuncture group (n = 120)	Control group (n = 120)	Statistics value	P value
Symptom severity analysis
PONV VAS score, points	2.7 ± 1.4	4.5 ± 1.8	t = 8.456	< 0.01
Relative improvement	40.0
Mild symptoms (VAS 1-3)	92 (76.5)	42 (35.1)	χ² = 41.832	< 0.01
Time effect analysis
Time to first PONV onset, hours	8.4 ± 2.1	4.2 ± 1.5	t = 17.429	< 0.01
Symptom-free period extension (hours)	4.2
Extension effect	100.0
Symptom-free patients
Symptom-free patients within 6 hours post-op	81 (67.6)	34 (28.1)	χ² = 37.842	< 0.01
Symptom duration analysis
Average duration, hours	2.8 ± 1.6	4.7 ± 2.3	t = 7.321	< 0.01
Reduction rate	40.4
Rescue medication usage analysis
Rescue antiemetic medication usage	22 (18.3)	43 (35.8)	χ² = 9.524	< 0.01
Age stratification analysis
≤ 45 years group reduction rate	23.5			< 0.05
> 45 years group reduction rate	16.8			< 0.05

PONV: Post-operative nausea and vomiting; VAS: Visual analogue scale.

High-risk factor subgroup analysis

The comprehensive efficacy and subgroup analysis of acupuncture intervention in PONV prevention demonstrated significant therapeutic advantages, good individualized applicability, excellent safety characteristics, and outstanding clinical benefits for high-risk patients. Symptom severity analysis showed that the acupuncture group PONV VAS score was only 2.7 ± 1.4, a 40.0% improvement compared to the control group’s 4.5 ± 1.8 (P < 0.01), with mild symptom proportion reaching 76.5%, far exceeding the control group’s 35.1%. Time effect analysis indicated that the acupuncture group’s PONV first occurrence time was delayed to 8.4 ± 2.1 hours, 4.2 hours longer than the control group (100% extension effect), allowing 67.6% of patients to remain symptom-free within 6 hours post-surgery, while only 28.1% in the control group (P < 0.01). In terms of symptom duration, the acupuncture group averaged 2.8 ± 1.6 hours, shortened by 40.4% compared to the control group (P < 0.01). Rescue medication usage analysis showed that the acupuncture group was only 18.3%, significantly lower than the control group’s 35.8% (P < 0.01), reflecting a significant reduction in medication dependence. Demographic subgroup analysis further revealed individualized characteristics of acupuncture treatment: Although female patients had significantly higher overall PONV incidence (43.2%) than males (26.9%) (P < 0.05), acupuncture intervention showed significant efficacy for both genders; age stratification analysis showed that acupuncture had more prominent preventive effects in the ≤ 45 years group, with incidence reduction of 23.5%, superior to the > 45 years group’s 16.8% (P < 0.05). High-risk factor subgroup analysis further confirmed the clinical value of acupuncture. For high-risk patients with pre-operative Apfel score ≥ 3 (n = 92), the acupuncture group PONV incidence was 36.2% (17/47), significantly lower than the control group’s 62.2% (28/45) (P < 0.01), with risk reduction of 41.8%, suggesting that acupuncture has more significant clinical benefits for high-risk patients. Safety assessment indicated that acupuncture intervention has good safety characteristics, with only 7 cases (5.8%) of mild adverse reactions in the acupuncture group, including 4 cases (3.3%) of mild pain at acupoints, 2 cases (1.7%) of minor local bleeding, and 1 case (0.8%) of transient needle fainting, all self-resolved without special treatment, with no serious adverse reactions. These comprehensive findings indicate that acupuncture as a non-pharmacological intervention not only comprehensively improves all clinical indicators of PONV and significantly reduces medication dependence but also shows good efficacy across different gender, age groups, and high-risk patients, while possessing excellent safety characteristics, providing important evidence-based medical basis for developing individualized, stratified PONV prevention strategies, particularly having important clinical application value for high-risk patient populations with limited traditional pharmacological treatment effects or contraindications (Table 5).

Table 5 Clinical efficacy indicators and subgroup analysis, mean ± SD/n (%).

Assessment indicators	Acupuncture group (n = 120)	Control group (n = 120)	Statistical value	P value
Symptom severity
PONV VAS score, points	2.7 ± 1.4	4.5 ± 1.8	t = 8.456	< 0.01
Relative improvement	40.0
Mild symptoms (VAS 1-3)	92 (76.5)	42 (35.1)	χ² = 41.832	< 0.01
Time effect analysis
Time to first PONV onset, hours	8.4 ± 2.1	4.2 ± 1.5	t = 17.429	< 0.01
Symptom-free period extension (hours)	4.2
Extension effect	100.0
Symptom-free patients			χ² = 37.842	< 0.01
Symptom-free patients within 6 hours	81 (67.6)	34 (28.1)
Symptom duration analysis
Average duration, hours	2.8 ± 1.6	4.7 ± 2.3	t = 7.321	< 0.01
Reduction rate	40.4
Medication usage
Rescue antiemetic medication usage	22 (18.3)	43 (35.8)	χ² = 9.524	< 0.01
Gender subgroup
Female PONV overall incidence	70/162 (43.2)	70/162 (43.2)	χ² = 6.892	< 0.05
Male PONV overall incidence	21/78 (26.9)	21/78 (26.9)	χ² = 6.892	< 0.05
Efficacy by gender	Significant for both genders	Significant for both genders		< 0.05
Age stratification
≤ 45 years group reduction rate	23.5		F = 4.832	< 0.05
> 45 years group reduction rate	16.8		F = 4.832	< 0.05
Inter-age group difference	Better in ≤ 45 years group		F = 4.832	< 0.05
High-risk patients
High-risk patients (Apfel score ≥ 3)	47 patients	45 patients
PONV incidence in high-risk patients	17/47 (36.2)	28/45 (62.2)	χ² = 6.542	< 0.01
Risk reduction in high-risk patients	41.8
Safety profile
Total mild adverse reactions	7 (5.8)	0 (0)
Mild pain at acupuncture points	4 (3.3)	0 (0)
Minor local bleeding	2 (1.7)	0 (0)
Transient dizziness	1 (0.8)	0 (0)
Resolution	All self-resolved
Serious adverse reactions	None reported	None reported

PONV: Post-operative nausea and vomiting; VAS: Visual analogue scale.

DISCUSSION

PONV, as one of the most common complications of surgical procedures, not only affects patients’ post-operative comfort and recovery experience but may also lead to a series of serious medical consequences. In cholecystectomy patients, the incidence of PONV is particularly high, reaching 40%-75%, far exceeding other abdominal surgeries. This high incidence makes PONV a major obstacle affecting cholecystectomy patients’ post-operative recovery quality, not only prolonging patient recovery time and increasing medical costs but also potentially causing dehydration, electrolyte imbalance, wound dehiscence, aspiration pneumonia, and other serious complications. More importantly, the occurrence of PONV often significantly reduces patient satisfaction with medical services, affecting doctor-patient relationships and hospital reputation[13-15]. The gallbladder, as an important component of the digestive system, experiences mechanical stimulation and inflammatory responses during removal that affect normal gastrointestinal motility and digestive function, further increasing PONV risk. Additionally, cholecystectomy patients often have special high-risk factors such as a higher proportion of female patients, predominantly non-smokers, and pre-existing gastrointestinal symptoms, all of which significantly increase PONV probability[16-18].

Rapid carbon dioxide insufflation during pneumoperitoneum establishment causes acute changes in intra-abdominal pH, affecting local tissue acid-base balance and subsequently neural conduction and hormone secretion. After surgery, although most carbon dioxide is absorbed, residual gas continues to stimulate the peritoneum and diaphragm, potentially lasting hours to days, becoming an important cause of post-operative PONV[19-23]. In comparison, open cholecystectomy avoids pneumoperitoneum-related problems but significantly increases PONV risk through greater surgical trauma, more obvious post-operative pain, and increased opioid use. Open surgery’s direct trauma to the abdominal wall and peritoneum triggers stronger inflammatory responses, releasing more inflammatory mediators and pain factors that not only exacerbate post-operative pain but also directly or indirectly stimulate the vomiting center. Intensified post-operative pain often requires more opioid analgesics, which are themselves important risk factors for PONV, increasing nausea and vomiting incidence through multiple mechanisms, including opioid receptor activation, gastrointestinal motility inhibition, and vestibular function effects[24-26]. Dopamine receptor antagonists like metoclopramide promote gastrointestinal motility but may cause extrapyramidal reactions, particularly in elderly patients. Corticosteroids like dexamethasone have good anti-inflammatory and antiemetic effects but may affect blood glucose control, wound healing, and immune function[27].

Acupuncture at LI4 produces antiemetic effects primarily through modulation of the 5-HT3 receptor system, a key pathway in PONV genesis. Needle stimulation at LI4 activates descending inhibitory pathways originating from the periaqueductal gray and rostral ventromedial medulla, which subsequently modulate serotonergic transmission in the area postrema and nucleus tractus solitarius. This descending modulation reduces 5-HT3 receptor sensitivity in the chemoreceptor trigger zone, diminishing the emetic response to circulating emetogenic stimuli commonly elevated during and after surgery. Complementarily, ST36 stimulation affects dopaminergic pathways crucial to gastrointestinal motility and nausea perception. Acupuncture at ST36 influences dopamine D2 receptor activity in both the peripheral enteric nervous system and the central nervous system structures. Peripheral effects include enhanced gastric motility through modulation of enteric dopaminergic neurons, while central effects involve regulation of dopamine D2 receptors in the chemoreceptor trigger zone, reducing its sensitivity to motion-related and pharmacological emetic stimuli. More importantly, for high-risk patients, single medications often fail to provide satisfactory preventive effects, requiring combination therapy that not only increases drug interaction risks but also significantly raises medical costs. Some patients may have allergies or contraindications to commonly used antiemetic medications, such as hepatorenal dysfunction, cardiac arrhythmias, or glaucoma, limiting pharmacological treatment options. Additionally, repeated use of antiemetic medications may lead to tolerance development, reducing therapeutic efficacy. These limitations prompt clinicians to seek safer, more effective, and economical non-pharmacological alternative treatment methods[28].

Acupuncture, as a traditional Chinese medicine therapy, has unique advantages in PONV prevention. From a modern medical perspective, acupuncture can activate multiple neural conduction pathways through specific acupoint stimulation, regulate autonomic nervous system function, and influence neurotransmitter release and metabolism. Acupuncture stimulation can inhibit pain conduction through spinal gate control mechanisms, regulate vomiting reflexes through descending inhibitory systems, and produce analgesic and sedative effects through endorphin systems. Additionally, acupuncture can regulate gastrointestinal hormone secretion, including motilin, gastrin, and vasoactive intestinal peptide, improving gastrointestinal motility and digestive function, fundamentally reducing the occurrence of nausea and vomiting[29].

Our analysis revealed remarkable consistency in acupuncture efficacy across different surgical approaches, with relative risk reduction of 41.4% for laparoscopic and 37.5% for open cholecystectomy. This robust performance despite varying baseline PONV risks (pneumoperitoneum-related mechanisms in laparoscopic vs enhanced surgical trauma in open procedures) suggests that acupuncture’s multi-pathway approach effectively addresses the diverse pathophysiological mechanisms underlying PONV. In laparoscopic procedures, where CO₂ insufflation creates unique challenges through diaphragmatic irritation and altered intra-abdominal pH, acupuncture’s ability to modulate both somatic and visceral afferent processing becomes particularly valuable. The spinal gate control mechanisms activated by LI4 stimulation may specifically attenuate the enhanced mechanoreceptor and nociceptor activation caused by pneumoperitoneum, while ST36’s effects on gastrointestinal motility help counteract CO₂-induced gastroparesis.

Individualized treatment has important significance in PONV prevention. Patients of different genders, ages, and weights have varying susceptibility to PONV and different treatment responses. Female patients have significantly higher PONV incidence than males due to hormonal influences. Younger patients have higher nervous system sensitivity and stronger responses to various stimuli, resulting in relatively higher PONV incidence. BMI, smoking history, previous PONV history, and motion sickness history are all important factors influencing PONV occurrence. Acupuncture treatment, due to its high safety and minimal side effects, can better adapt to individualized treatment needs, providing customized treatment plans for different patients.

The popularization of ERAS concepts also provide a new application space for acupuncture treatment. ERAS protocols emphasize reducing post-operative complications, accelerating patient recovery, shortening hospital stays, and reducing medical costs. PONV, as an important factor affecting early patient ambulation and feeding, has significant importance for achieving ERAS goals through effective prevention and treatment. Acupuncture treatment, due to its non-invasive nature and lack of drug interactions, completely aligns with ERAS principles and can be well integrated into post-operative recovery management processes. Safety is an important factor that must be considered for any medical intervention. Although acupuncture treatment generally has high safety, attention must still be paid to potential risks. Common adverse reactions include local pain, minor bleeding, hematoma formation, and infection, which are typically mild and self-limiting, rarely requiring special treatment. Occasionally, needle fainting reactions may occur, manifesting as dizziness, nausea, pallor, and sweating, which usually resolve spontaneously after stopping acupuncture and having the patient lie flat. For patients with coagulation dysfunction, local skin infections, or severe cardiac arrhythmias, careful consideration of the appropriateness of acupuncture treatment is needed.

CONCLUSION

The significant reduction in PONV incidence and severity demonstrated by combined LI4 and ST36 acupuncture reflects the convergence of multiple neurobiological pathways addressing the complex, multifactorial nature of PONV. The robustness of efficacy across different surgical approaches, combined with the favorable safety profile, supports acupuncture’s integration into modern perioperative care protocols.