Postoperative nausea and vomiting (PONV) remains one of the most frequent and distressing complications following surgical procedures performed under general anesthesia. Despite improvements in anesthetic techniques, perioperative monitoring, and pharmacological prophylaxis, PONV continues to affect approximately 20–30% of surgical patients, with substantially higher rates among susceptible individuals. It contributes to patient discomfort, delayed oral intake, prolonged post-anesthesia care unit (PACU) stay, increased healthcare expenditure, and reduced postoperative satisfaction. Severe episodes may result in dehydration, electrolyte disturbances, aspiration, wound complications, and unplanned hospital admissions. Laparoscopic surgeries are particularly associated with increased PONV because of carbon dioxide pneumoperitoneum, peritoneal stretching, visceral manipulation, and the emetogenic effects of anesthetic agents and postoperative opioids. Prakash et al. highlighted the persistent challenge of preventing PONV in patients undergoing laparoscopic procedures despite prophylactic antiemetic interventions [1]. The pathophysiology of PONV involves complex interactions among the chemoreceptor trigger zone, vomiting center, vestibular apparatus, and gastrointestinal tract. Several neurotransmitters, particularly serotonin (5-hydroxytryptamine), dopamine, histamine, acetylcholine, and substance P, contribute to the emetic response. Among these, serotonin acting through 5-HT3 receptors plays an important role in triggering postoperative nausea and vomiting. Consequently, 5-HT3 receptor antagonists have become essential components of perioperative antiemetic prophylaxis. Ondansetron, a first-generation selective 5-HT3 receptor antagonist, is widely employed because of its established efficacy, accessibility, and favorable tolerability. However, its relatively short elimination half-life of approximately 3–6 hours may limit sustained protection during the later postoperative period. Balyan et al. demonstrated the clinical importance of comparing ondansetron with newer antiemetic agents in high-risk patients undergoing laparoscopic gynecological surgery [2]. Palonosetron is a second-generation 5-HT3 receptor antagonist characterized by high receptor-binding affinity, distinctive receptor interactions, and a prolonged elimination half-life of approximately 40 hours. These pharmacological properties provide a rationale for extended antiemetic protection following a single intravenous dose. Dey et al. reported a lower overall incidence of PONV with palonosetron compared with ondansetron combined with dexamethasone in laparoscopic gynecological surgery [3]. Kim et al., through an updated systematic review, further demonstrated the potential effectiveness of palonosetron in preventing late postoperative vomiting compared with another 5-HT3 antagonist, ramosetron [4]. Recent clinical investigations have evaluated different pharmacological strategies for PONV prevention. Sadhoo et al. examined palonosetron, dexamethasone, and their combination in laparoscopic procedures, reporting no statistically significant reduction in overall PONV with combination therapy [5]. Moraitis et al. investigated palonosetron for post-discharge nausea and vomiting, emphasizing the clinical relevance of sustained antiemetic protection following ambulatory surgery [6]. Davolos et al. conducted a randomized non-inferiority trial comparing palonosetron and repeated-dose ondansetron following laparoscopic cholecystectomy, demonstrating the importance of administration schedules when interpreting comparative efficacy [7]. Krishnan et al. subsequently reported comparable prophylactic efficacy between intravenous palonosetron and ondansetron combined with dexamethasone following laparoscopic procedures, although numerically fewer patients developed PONV in the palonosetron group [8]. A systematic review and meta-analysis by Kumar et al. involving laparoscopic surgical patients demonstrated superior overall antiemetic efficacy of palonosetron, particularly regarding postoperative nausea, vomiting, and rescue medication requirements [9]. Lal et al. also identified improved late postoperative protection with palonosetron in non-laparoscopic surgical populations [10]. Despite these investigations, clinically relevant uncertainties remain regarding the comparative effectiveness of single-dose intravenous ondansetron and palonosetron across different postoperative intervals, particularly when anesthetic techniques, surgical characteristics, and patient risk factors vary. Differences in drug dosage, administration timing, adjunctive antiemetic use, and outcome assessment complicate the interpretation of existing evidence. Contemporary consensus recommendations emphasize individualized risk assessment and multimodal PONV prevention, reinforcing the need to evaluate individual antiemetic agents within standardized perioperative protocols [11]. Therefore, the present study aims to compare the efficacy of intravenous ondansetron and palonosetron in preventing postoperative nausea and vomiting among patients undergoing laparoscopic surgeries under general anesthesia, with particular emphasis on the incidence and severity of PONV, timing of emetic episodes, requirement for rescue antiemetic medication, complete response, and associated adverse effects.

The present study was designed as a prospective, randomized, comparative clinical study to evaluate the efficacy of intravenous ondansetron and palonosetron in preventing postoperative nausea and vomiting (PONV) among patients undergoing laparoscopic surgeries under general anesthesia. The study was conducted in the Department of Anaesthesiology, DR VRK Women’s Medical College, Hyderabad. A total of 50 patients undergoing elective laparoscopic surgical procedures under general anesthesia were included in the study. Patients were divided into two groups of 25 each to compare the efficacy, safety, and duration of antiemetic action of the two drugs. The study was planned to assess the incidence and severity of PONV, requirement for rescue antiemetic medication, and drug-related adverse effects during the first 24 hours following surgery. Study Population and Sample Size The study population comprised 50 adult patients scheduled for elective laparoscopic surgeries under general anesthesia. Patients meeting the eligibility criteria were selected and allocated equally into two study groups using a computer-generated randomization sequence. Group O (n = 25) received intravenous ondansetron 4 mg, whereas Group P (n = 25) received intravenous palonosetron 0.075 mg. Both drugs were administered approximately 30 minutes before completion of surgery. All patients were managed using a standardized general anesthesia protocol to minimize variations in anesthetic management and postoperative outcomes. Inclusion Criteria • Patients aged between 18 and 60 years. • Patients undergoing elective laparoscopic surgeries under general anesthesia. • Patients belonging to American Society of Anesthesiologists (ASA) physical status I or II. • Patients of either sex who fulfilled the study eligibility criteria. • Patients willing to participate and provide written informed consent. • Patients with an anticipated surgical duration of 30–180 minutes. Exclusion Criteria 1. Patients unwilling to participate in the study. 2. Patients with ASA physical status III or above. 3. Patients with known hypersensitivity to ondansetron, palonosetron, or other 5-HT3 receptor antagonists. 4. Patients with a history of severe motion sickness or recurrent postoperative nausea and vomiting. 5. Patients who received antiemetic medication within 24 hours before surgery. 6. Patients with significant hepatic, renal, cardiovascular, or neurological disorders. 7. Pregnant or lactating women. 8. Patients with pre-existing nausea, vomiting, or gastrointestinal disorders likely to influence postoperative outcomes. 9. Patients with known QT prolongation or clinically significant cardiac arrhythmias. Study Tool The following tools and parameters were used for data collection and assessment: 1. Patient information proforma: Used to record demographic characteristics, including age, sex, body mass index (BMI), ASA physical status, medical history, and type of laparoscopic procedure. 2. Preoperative assessment checklist: Used to document relevant medical history, comorbidities, previous anesthetic exposure, and factors associated with PONV. 3. Numerical Rating Scale (NRS): Used to assess nausea severity on a scale of 0–10, where 0 indicated no nausea and 10 indicated the worst imaginable nausea. 4. PONV assessment chart: Used to record the occurrence of nausea, retching, and vomiting during predefined postoperative intervals. 5. Rescue antiemetic record: Used to document the requirement, timing, and frequency of rescue antiemetic administration. 6. Adverse drug reaction checklist: Used to identify headache, dizziness, constipation, cardiac symptoms, and other treatment-related adverse effects. 7. Postoperative monitoring chart: Used to record heart rate, blood pressure, oxygen saturation, and other relevant clinical observations. Study Procedure and Data Collection 1. Preoperative evaluation: All eligible patients underwent detailed pre-anesthetic evaluation, including history taking, general examination, systemic examination, and routine investigations. Demographic details, ASA classification, surgical diagnosis, and relevant PONV risk factors were documented. 2. Informed consent: Written informed consent was obtained from all participants after explaining the study objectives, procedures, and potential adverse effects. 3. Randomization and group allocation: The 50 participants were randomly allocated into two equal groups. Group O received intravenous ondansetron 4 mg, and Group P received intravenous palonosetron 0.075 mg. 4. Anesthetic management: Standard monitoring was established, including electrocardiography, non-invasive blood pressure, and pulse oximetry. General anesthesia was induced and maintained according to a standardized institutional protocol. Endotracheal intubation, mechanical ventilation, intraoperative analgesia, and neuromuscular blockade were provided as clinically indicated. 5. Administration of study medication: The allocated antiemetic drug was administered intravenously approximately 30 minutes before completion of surgery. The dose, administration time, and any immediate adverse reactions were documented. 6. Postoperative assessment: Following extubation, patients were monitored in the post-anesthesia care unit and subsequently in the postoperative ward. The incidence and severity of nausea, retching, and vomiting were assessed during the intervals of 0–2 hours, 2–6 hours, 6–12 hours, and 12–24 hours after surgery. 7. Assessment of nausea and vomiting: Nausea severity was evaluated using the NRS. Vomiting episodes were recorded separately, and the overall incidence of PONV was calculated for each study group. 8. Rescue antiemetic medication: Patients experiencing significant nausea or vomiting received rescue antiemetic treatment according to the institutional postoperative protocol. The number of patients requiring rescue therapy and the timing of administration were recorded. 9. Complete response assessment: Complete response was defined as the absence of vomiting or retching and no requirement for rescue antiemetic medication during the 24-hour postoperative observation period. 10. Adverse effects: Patients were monitored for headache, dizziness, constipation, and other suspected drug-related adverse reactions during the observation period. 11. Data documentation: All observations were entered into a structured data collection proforma and subsequently transferred to a computerized database for statistical analysis. Outcome Measures The primary outcome was the incidence of postoperative nausea and vomiting during the first 24 hours following laparoscopic surgery. Secondary outcomes included the severity of nausea, incidence of vomiting at different postoperative intervals, requirement for rescue antiemetic medication, complete response rate, and adverse effects associated with ondansetron and palonosetron. Statistical Analysis The collected data were entered into Microsoft Excel and analyzed using IBM SPSS Statistics. Continuous variables were expressed as mean ± standard deviation, whereas categorical variables were presented as frequencies and percentages. The independent-samples Student's t-test or Mann–Whitney U test, as appropriate, was used to compare continuous variables between the two groups. The Chi-square test or Fisher's exact test was applied to compare categorical variables, including the incidence of PONV, complete response rates, and rescue antiemetic requirements. A two-tailed p-value of less than 0.05 was considered statistically significant. Relative risks with 95% confidence intervals were calculated for the primary outcome where appropriate.

Table 1. Comparison of Baseline Demographic and Clinical Characteristics Between the Ondansetron and Palonosetron Groups Parameter Group O (n = 25) Group P (n = 25) p-value Age (years), mean ± SD 38.9 ± 8.3 34.8 ± 9.2 0.106 Sex: male 8 (32%) 10 (40%) 0.769 Sex: female 17 (68%) 15 (60%) BMI (kg/m²), mean ± SD 25.1 ± 3.5 26.4 ± 3.0 0.155 ASA I 13 (52%) 15 (60%) 0.776 ASA II 12 (48%) 10 (40%) Current smokers 0 (0%) 3 (12%) 0.235 Laparoscopic cholecystectomy 10 (40%) 10 (40%) 0.910* Laparoscopic appendectomy 4 (16%) 5 (20%) Laparoscopic gynecological surgery 8 (32%) 6 (24%) Other laparoscopic procedures 3 (12%) 4 (16%) The present study included 50 patients divided equally between the two treatment groups. The mean age was 38.9 ± 8.3 years in Group O and 34.8 ± 9.2 years in Group P, without a statistically significant difference (p = 0.106). Female patients constituted 68% and 60% of the respective groups. Mean BMI and ASA physical status distributions were also comparable. Laparoscopic cholecystectomy accounted for 40% of procedures in both groups. Overall, the baseline characteristics did not demonstrate statistically significant between-group differences, supporting comparability on the measured characteristics. Table 2. Comparison of Intraoperative and Anesthetic Characteristics Between the Study Groups Parameter Group O (n = 25), mean ± SD Group P (n = 25), mean ± SD p-value Duration of surgery (min) 90.2 ± 22.3 97.3 ± 23.3 0.278 Duration of anesthesia (min) 112.2 ± 21.2 120.1 ± 23.9 0.224 Intraoperative fentanyl (µg) 138.8 ± 47.1 147.3 ± 39.5 0.490 Baseline heart rate (beats/min) 76.5 ± 10.3 78.0 ± 9.0 0.591 Baseline systolic BP (mmHg) 123.8 ± 8.7 120.8 ± 12.9 0.341 Baseline diastolic BP (mmHg) 75.3 ± 8.9 75.8 ± 7.4 0.850 Intraoperative fluids (mL) 778.0 ± 163.4 852.0 ± 153.1 0.105 The present perioperative characteristics were broadly comparable between the ondansetron and palonosetron groups. Mean surgical duration was 90.2 minutes in Group O and 97.3 minutes in Group P (p = 0.278). Mean anesthesia duration was slightly longer in Group P, although the difference was not statistically significant (p = 0.224). Intraoperative fentanyl consumption also showed no significant difference between groups (p = 0.490). Baseline heart rate and blood pressure measurements were similar. These findings suggest that the measured intraoperative variables were unlikely to explain major differences in postoperative outcomes, although residual confounding cannot be excluded. Table 3. Comparison of Postoperative Nausea and Vomiting Incidence at Different Time Intervals Postoperative interval Group O (n = 25), n (%) Group P (n = 25), n (%) p-value Nausea at 0–2 hours 7 (28%) 4 (16%) 0.496 Nausea at 2–6 hours 7 (28%) 4 (16%) 0.496 Nausea at 6–12 hours 5 (20%) 2 (8%) 0.417 Nausea at 12–24 hours 5 (20%) 1 (4%) 0.189 Vomiting at 0–2 hours 3 (12%) 1 (4%) 0.609 Vomiting at 2–6 hours 3 (12%) 1 (4%) 0.609 Vomiting at 6–12 hours 2 (8%) 0 (0%) 0.490 Vomiting at 12–24 hours 2 (8%) 0 (0%) 0.490 Overall PONV (0–24 hours) 15 (60%) 9 (36%) 0.156 The table 3 results demonstrated a consistently lower incidence of postoperative nausea and vomiting among patients receiving palonosetron. During the first two postoperative hours, nausea occurred in 28% of Group O compared with 16% of Group P. Late postoperative nausea during 12–24 hours was observed in 20% and 4%, respectively. No vomiting episodes were recorded in Group P beyond six hours, whereas Group O continued to experience vomiting. The cumulative 24-hour PONV incidence was 60% with ondansetron and 36% with palonosetron, corresponding to a 24-percentage-point absolute difference. However, the primary comparison was not statistically significant (p = 0.156), so superiority cannot be established from this simulated sample. Table 4. Comparison of Postoperative Nausea Severity Scores Between the Study Groups Postoperative interval Group O, median (IQR) Group P, median (IQR) p-value 0–2 hours 0 (0–3) 0 (0–0) 0.370 2–6 hours 0 (0–3) 0 (0–0) 0.284 6–12 hours 0 (0–0) 0 (0–0) 0.234 12–24 hours 0 (0–0) 0 (0–0) 0.102 Maximum nausea score during 24 hours 3 (0–7) 0 (0–5) 0.186 Nausea severity was generally lower in the palonosetron group across the postoperative observation intervals. The median nausea score was zero in both groups at each individual interval because most patients reported no nausea during those periods. Nevertheless, the upper quartile of nausea severity was higher in Group O during the early postoperative intervals. The maximum 24-hour nausea score had a median of 3 in Group O compared with 0 in Group P. Although the results numerically favored palonosetron, the difference in maximum nausea severity did not reach statistical significance (p = 0.186). These simulated findings illustrate why both symptom incidence and severity should be reported when evaluating antiemetic efficacy. Table 5. Comparison of Rescue Antiemetic Requirements and Complete Response Rates Between the Study Groups Outcome Group O (n = 25), n (%) Group P (n = 25), n (%) p-value Patients requiring rescue antiemetics 9 (36%) 3 (12%) 0.095 Rescue antiemetic during 0–6 hours 6 (24%) 2 (8%) 0.247 Rescue antiemetic during 6–24 hours 3 (12%) 1 (4%) 0.609 Patients requiring repeated rescue doses 2 (8%) 1 (4%) 1.000 Complete response during 0–24 hours 14 (56%) 21 (84%) 0.062 Patients without nausea or vomiting 10 (40%) 16 (64%) 0.156 Rescue antiemetic use was numerically greater in the ondansetron group than in the palonosetron group. Nine patients (36%) receiving ondansetron required rescue medication, compared with three patients (12%) receiving palonosetron (p = 0.095). The greatest difference in rescue medication use occurred during the first six postoperative hours. Complete response was achieved in 56% of Group O and 84% of Group P, a difference of 28 percentage points. Similarly, the proportion of patients remaining free from nausea and vomiting was higher in Group P. Table 6. Comparison of Adverse Drug Effects Between the Ondansetron and Palonosetron Groups Adverse effect Group O (n = 25), n (%) Group P (n = 25), n (%) p-value Headache 4 (16%) 2 (8%) 0.667 Dizziness 3 (12%) 0 (0%) 0.235 Constipation 2 (8%) 1 (4%) 1.000 Palpitations 0 (0%) 0 (0%) 1.000 Other adverse effects 1 (4%) 0 (0%) 1.000 Any recorded adverse effect 8 (32%) 3 (12%) 0.171 The present study demonstrated generally low frequencies of adverse effects in both treatment groups. Headache was reported by four patients receiving ondansetron and two patients receiving palonosetron. Dizziness occurred in three patients in Group O and none in Group P. Constipation was uncommon, and no palpitations were recorded in either group. At least one adverse effect was reported in 32% of Group O and 12% of Group P, although this difference was not statistically significant (p = 0.171). Table 7. Correlation Between Demographic and Perioperative Characteristics and Maximum Postoperative Nausea Severity Correlation parameter Spearman's correlation coefficient (ρ) p-value Age versus maximum nausea score 0.068 0.636 BMI versus maximum nausea score 0.260 0.069 Duration of surgery versus maximum nausea score 0.277 0.052 Duration of anesthesia versus maximum nausea score 0.226 0.115 Intraoperative fentanyl dose versus maximum nausea score 0.170 0.237 The simulated correlation analysis identified weak positive associations between several perioperative parameters and maximum postoperative nausea severity. Duration of surgery demonstrated the strongest association (ρ = 0.277, p = 0.052), although it did not reach statistical significance. BMI also showed a weak positive correlation with nausea severity (ρ = 0.260, p = 0.069). Duration of anesthesia and fentanyl dose exhibited weaker, statistically nonsignificant positive associations. Age demonstrated almost no relationship with maximum nausea severity. Table 8. Association of Treatment Allocation and Selected Clinical Risk Factors With Overall Postoperative Nausea and Vomiting Predictor variable PONV present, n (%) PONV absent, n (%) p-value Ondansetron (n = 25) 15 (60.0%) 10 (40.0%) Palonosetron (n = 25) 9 (36.0%) 16 (64.0%) 0.156 Age ≤40 years (n = 35) 16 (45.7%) 19 (54.3%) Age >40 years (n = 15) 8 (53.3%) 7 (46.7%) 0.760 BMI 90 min (n = 31) 17 (54.8%) 14 (45.2%) 0.255 The simulated association analysis indicated that palonosetron recipients had a lower risk of overall PONV compared with ondansetron recipients (RR = 0.60, 95% CI: 0.33–1.11). This corresponded to an estimated 40% relative reduction in PONV risk, although the confidence interval included 1 and the difference was not statistically significant. Patients with BMI ≥25 kg/m² demonstrated a numerically higher risk of PONV than those with lower BMI (RR = 1.62). Longer surgical duration was also associated with a numerically increased risk (RR = 1.49). Age above 40 years showed only a small difference in PONV risk. None of the evaluated predictors demonstrated a statistically significant association, and the results should be regarded as exploratory.

Postoperative nausea and vomiting (PONV) remains an important concern in patients undergoing laparoscopic surgeries under general anesthesia because of its adverse effects on postoperative recovery, patient comfort, and hospital discharge. Effective prophylaxis is essential to minimize complications and improve patient satisfaction. The present analysis compares intravenous ondansetron 4 mg and palonosetron 0.075 mg in 50 patients, divided equally into two groups. The findings described below are based on the previously generated simulated dataset and should be replaced with verified patient observations before clinical publication. The demographic characteristics of both groups were comparable, with mean ages of 38.9 ± 8.3 years in the ondansetron group and 34.8 ± 9.2 years in the palonosetron group (p = 0.106). The distribution of sex, body mass index, ASA physical status, and surgical procedures showed no statistically significant differences. Similarly, the duration of surgery, duration of anesthesia, intraoperative fentanyl consumption, and baseline hemodynamic parameters were comparable. This baseline similarity is relevant because several patient-related and perioperative factors influence the development of PONV. Khan et al. (2021), in a randomized study involving 100 female patients undergoing laparoscopic cholecystectomy, evaluated palonosetron against dexamethasone and observed comparable antiemetic efficacy, with complete response rates of 90% and 88%, respectively [12]. Their findings established the clinical usefulness of palonosetron as a prophylactic antiemetic during laparoscopic surgery. The overall incidence of PONV in the present analysis was 60% among patients receiving ondansetron compared with 36% among those receiving palonosetron. Although the absolute difference was 24 percentage points, statistical significance was not achieved (p = 0.156). The relative risk of PONV with palonosetron was 0.60 (95% CI: 0.33–1.11), indicating a numerical reduction in risk. This finding is pharmacologically plausible because palonosetron possesses a longer elimination half-life and greater receptor-binding affinity than ondansetron. Chu (2022), in a systematic review and meta-analysis evaluating palonosetron in surgical patients, examined its effectiveness in reducing postoperative symptoms and supported its potential role in PONV prevention [13]. However, the limited sample size in the present analysis prevents a definitive conclusion regarding comparative superiority. Assessment of PONV across different postoperative intervals showed a consistently lower incidence of nausea among patients receiving palonosetron. During the initial 0–2 hours, nausea occurred in 28% of ondansetron recipients compared with 16% of palonosetron recipients. At 12–24 hours, nausea was recorded in 20% and 4%, respectively. Vomiting was absent in the palonosetron group beyond six postoperative hours, whereas episodes continued in the ondansetron group. These differences were not individually statistically significant. Kumar et al. (2022) investigated palonosetron alone and in combination with dexamethasone among patients undergoing middle ear surgery. They observed a substantially lower incidence of early PONV with combination therapy, demonstrating that antiemetic effectiveness may be influenced by treatment strategy and postoperative observation period [14]. Although their intervention differed from the present comparison, their findings emphasize the importance of evaluating early and delayed emetic episodes separately. The maximum postoperative nausea severity score also favored palonosetron, with median scores of 0 and 3 in the palonosetron and ondansetron groups, respectively (p = 0.186). However, the difference was not statistically significant. Bhargava et al. (2024), in a randomized trial involving 112 renal transplantation recipients, reported significantly lower PONV incidence with palonosetron at six hours (12.5% versus 32.1%; p = 0.013) and 72 hours (1.8% versus 33.9%; p < 0.001). At 24 hours, the difference was not statistically significant [15]. These findings support the potential benefit of palonosetron over an extended postoperative period. Nevertheless, differences in surgical population, drug administration, and clinical risk profile should be considered when comparing results. Another important outcome was the requirement for rescue antiemetic medication. In the present analysis, 36% of patients receiving ondansetron required rescue medication compared with 12% receiving palonosetron (p = 0.095). The complete response rate was 56% in the ondansetron group and 84% in the palonosetron group (p = 0.062). Although these numerical differences suggest a possible clinical advantage, neither comparison reached statistical significance. Worravitudomsuk et al. (2025) conducted a randomized controlled trial involving patients undergoing cesarean delivery with intrathecal morphine. They reported PONV incidences of 26.3% with palonosetron, 34.7% with ondansetron, and 50.0% with placebo. However, the difference between palonosetron and ondansetron was not statistically significant [16]. These observations are consistent with the uncertainty surrounding the magnitude of the comparative treatment effect in smaller studies. The safety analysis demonstrated headache, dizziness, and constipation as the principal recorded adverse effects. At least one adverse effect occurred in 32% of ondansetron recipients and 12% of palonosetron recipients (p = 0.171). No palpitations were recorded in either group. Thus, both medications appeared tolerable within the simulated 24-hour observation period, although the small sample was inadequate for detecting uncommon adverse reactions. Correlation analysis demonstrated weak positive associations between maximum nausea severity and surgical duration (ρ = 0.277; p = 0.052), BMI (ρ = 0.260; p = 0.069), and anesthesia duration (ρ = 0.226; p = 0.115). None reached statistical significance. Similarly, patients with BMI ≥25 kg/m² and those undergoing procedures lasting more than 90 minutes showed numerically higher PONV risks. Xu et al. (2025), in a systematic review and network meta-analysis of 5-HT3 receptor antagonists following gynecological surgery, reported superior efficacy of palonosetron compared with ondansetron for several outcomes, including overall nausea, late vomiting, overall PONV, and rescue medication requirements [17]. These findings reinforce the clinical rationale for evaluating palonosetron in laparoscopic surgical populations. The principal limitations of the present analysis include the small sample size, the 24-hour observation period, and the inclusion of different laparoscopic procedures. Moreover, individual PONV risk scores, postoperative opioid consumption, and anesthetic maintenance techniques require comprehensive evaluation. Larger randomized studies incorporating standardized risk assessment, extended follow-up, and clinically important outcomes are necessary to establish whether palonosetron offers a meaningful advantage over ondansetron.

The present study results demonstrated a lower overall incidence of postoperative nausea and vomiting with intravenous palonosetron (36%) compared with ondansetron (60%) following laparoscopic surgeries under general anesthesia. Palonosetron was also associated with numerically lower postoperative nausea severity, reduced rescue antiemetic requirements, and higher complete response rates. However, these differences did not achieve statistical significance, and no definitive superiority can be established. Both medications demonstrated generally acceptable tolerability during the 24-hour observation period. Palonosetron may offer an advantage in sustained postoperative antiemetic protection, but this requires confirmation using actual clinical data from adequately powered randomized controlled studies.

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