The pharmacokinetics of ropivacaine after intraperitoneal administration: instillation versus nebulization

Intraperitoneal nebulization versus intraperitoneal instillation of ropivacaine for postoperative pain management following laparoscopic donor nephrectomy

BACKGROUND

Laparoscopic donor nephrectomy is considered less painful than open nephrectomy but is still associated with significant postoperative pain. Studies reported that intraperitoneal instillation of local anesthetics provides uncertain pain relief after laparoscopic surgery. This randomized, double-blind study evaluated the effect of intraperitoneal nebulization of ropivacaine on postoperative pain relief after laparoscopic donor nephrectomy.

METHODS

Sixty patients undergoing elective laparoscopic donor nephrectomy were randomly assigned to receive either an instillation of 20 ml 0.5% ropivacaine after the induction of pneumoperitoneum or nebulization of 5 ml 1% ropivacaine before and after surgery. The primary outcome was the degree of pain relief (static and dynamic) after surgery. The secondary outcomes were postoperative fentanyl consumption, incidence of shoulder pain, unassisted walking and postoperative nausea and vomiting (PONV). Data were collected in the postanesthesia care unit (PACU) and at 6, 24, and 48 h after surgery.

RESULTS

Compared to patients in the instillation group, those in the nebulization group showed significant reductions in postoperative pain and fentanyl consumption, and none complained of significant shoulder pain (visual analog scale score ≥ 30 mm). Within 20 h of surgery, 13.3% of patients in the instillation group and 93.3% in the nebulization group started unassisted walking (absolute risk reduction, 38%; P = 0.001). In the nebulization group, PONV was significantly reduced in the PACU and at 6 h.

CONCLUSIONS

Intraperitoneal nebulization of ropivacaine reduced postoperative pain, fentanyl consumption, referred shoulder pain, and PONV while enabling earlier mobility without any difference in the length of hospital stay.

Nebulized analgesia during laparoscopic appendectomy (NALA): A randomized triple-blind placebo controlled trial

PURPOSE

Postoperative pain remains a considerable concern for patients and families. We assessed whether nebulized ropivacaine reduces morphine consumption and pain after laparoscopic appendectomy for uncomplicated appendicitis in children.

METHODS

Patients 7-17 years old with uncomplicated appendicitis were randomized to ropivacaine (intervention arm) or saline nebulization (placebo arm) at the onset of laparoscopy. Nonconsenting individuals were treated with standard care and invited to provide clinical data (baseline arm). The primary outcome was in-patient morphine utilization. Secondary outcomes included pain scores at multiple time-points, markers of recovery, operative times, and surgeon satisfaction. The trial was registered (NCT02624089).

RESULTS

Study enrollment was 116 patients over a 1-year period: Intervention (n = 43), Placebo (n = 39), Baseline (n = 34). No differences in baseline characteristics were noted between groups. No difference was noted in overall in-patient morphine consumption between randomized groups (0.31 vs. 0.35 mg/kg, p = 0.42) or between ropivacaine and baseline (0.31 vs. 0.277 mg/kg, p = 0.62). Although operative times were comparable between groups, 63% of surgeon respondents felt that nebulization obscured visualization.

CONCLUSION

Nebulized ropivacaine did not reduce postoperative morphine consumption or pain scores after laparoscopic appendectomy for simple appendicitis in children. Given that it decreases visualization and likely increases costs, nebulized administration of intraperitoneal analgesia does not appear warranted in this context.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level I.

Effects of Intraperitoneal Local Anaesthetics Bupivacaine and Ropivacaine versus Placebo on Postoperative Pain after Laparoscopic Cholecystectomy: A Randomised Double Blind Study

INTRODUCTION

Laparoscopic Cholecystectomy (LC) is the most frequently performed elective daycare surgery and provision of postoperative pain relief is of importance. After laparoscopic cholecystectomy shoulder and abdominal pain causes considerable distress. Visceral pain during coughing, respiration and mobilization increases morbidity, hospital stay and costs.

AIM

To compare the analgesic efficacy of intraperitoneally instilled equipotent concentrations of bupivacaine and ropivacaine versus placebo in relieving postoperative pain after laparoscopic cholecystectomy when used as a part of multimodal analgesia.

MATERIALS AND METHODS

In this randomised, prospective, double blind, placebo controlled study, 90 ASA Class I or II patients were randomly divided into three groups of 30 each. Group S received intraperitoneal infiltration with 35 ml of 0.9% normal saline, Group B with 35 ml of 0.25% bupivacaine and Group R with 35 ml of 0.375% ropivacaine. All groups received standard general endotracheal anaesthesia and analgesia with IV paracetamol 15 mg/kg and diclofenac 1.5 mg/kg. Numerical Rating Scale (NRS) score of analgesia at rest and on cough/movement, duration of analgesia, haemodynamic parameters, need for a rescue analgesic (IV tramadol 1 mg/kg) was recorded and adverse effects of procedure and drugs if any were monitored. Data was analysed with SPSS statistical software version 21.0. One way ANOVA or the Kruskal-Wallis test was used to compare continuous data across all three groups as appropriate. Subsequent analysis of continuous data between two groups was achieved by Tukey's post hoc test. Significance was accepted as p<0.05.

RESULTS

The mean NRS was <5 till only four hours in Group S, till eight hours in Group B and till 16 hours in Group R. The duration of analgesia was 13.47±1.38 hours in Group R, 7.93±1.44 hours in Group B and 4.47±0.86 hours in Group S.

CONCLUSION

Intraperitoneal infiltration of LA significantly reduces pain intensity scores in the early postoperative period after LC surgery and helps in improving the postoperative recovery profile and outcome. This makes LC surgery more amenable to day care surgical setup. Ropivacaine (0.375%) is more efficacious, longer acting with a higher intensity of postoperative analgesia than bupivacaine (0.25%).

Peritoneal Nebulization of Ropivacaine during Laparoscopic Cholecystectomy: Dose Finding and Pharmacokinetic Study

Background. Intraperitoneal nebulization of ropivacaine reduces postoperative pain and morphine consumption after laparoscopic surgery. The aim of this multicenter double-blind randomized controlled trial was to assess the efficacy of different doses and dose-related absorption of ropivacaine when nebulized in the peritoneal cavity during laparoscopic cholecystectomy. Methods. Patients were randomized to receive 50, 100, or 150 mg of ropivacaine 1% by peritoneal nebulization through a nebulizer. Morphine consumption, pain intensity in the abdomen, wound and shoulder, time to unassisted ambulation, discharge time, and adverse effects were collected during the first 48 hours after surgery. The pharmacokinetics of ropivacaine was evaluated using high performance liquid chromatography. Results. Nebulization of 50 mg of ropivacaine had the same effect of 100 or 150 mg in terms of postoperative morphine consumption, shoulder pain, postoperative nausea and vomiting, activity resumption, and hospital discharge timing (>0.05). Plasma concentrations did not reach toxic levels in any patient, and no significant differences were observed between groups (P > 0.05). Conclusions. There is no enhancement in analgesic efficacy with higher doses of nebulized ropivacaine during laparoscopic cholecystectomy. When administered with a microvibration-based aerosol humidification system, the pharmacokinetics of ropivacaine is constant and maintains an adequate safety profile for each dosage tested.

Intraperitoneal Levobupivacaine with or without Clonidine for Pain Relief after Laparoscopic Cholecystectomy: A Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND

Irrigation of local anesthetic intraperitoneally in combination with opioids and non-opioids agents has been used to provide pain relief with varying success in laparoscopic surgeries. This randomized double blind placebo controlled study is designed to study the effect of intraperitoneal instillation of levo-bupivacaine along with clonidine for pain relief after laparascopic cholecystectomy.

METHODS

75 patients were randomized to receive 20 ml of 0.9% normal saline as placebo (group I), 20 ml of 0.5% levo bupivacaine (group II) and 20 ml of 0.5% levo bupivacaine with 1mcg/kg clonidine (group III) intraperitoneally. The degree of postoperative pain was assessed using the VAS and VRS on the immediate arrival in the recovery room after surgery and thereafter at 2, 4, 8, 12 and 24 hours, postoperatively. Statistical analysis was performed with ANOVA, the Kruskal-Wallis test followed by the Wilcoxon matched pairs rank test was used and P < 0.05 were considered significant.

RESULTS

VAS was maximum in placebo (group I) than in levobupivacaine alone (group II) and was minimum in levobupivacaine with clonidine (group III) at all time intervals. The difference between group I and II is statistically significant at immediate and at 2 hours postoperatively but no difference were found between group I and II after 2 hour. However, there is statistically significant difference (P < 0.05) between group I and III and group II and III at all time intervals.

CONCLUSION

Intraperitoneal instillation of levobupivacaine along with clonidine in a dose of 1mcg/kg is superior to levobupivacaine alone without having any significant adverse effects.

A Novel Proliposomal Ropivacaine Oil: Pharmacokinetic-Pharmacodynamic Studies After Subcutaneous Administration in Pigs

BACKGROUND

Liposomal local anesthetics are limited by a short liposomal shelf-life, even when under refrigeration. We describe a novel proliposomal ropivacaine that produces liposomes in situ, only after exposure to aqueous media.

METHODS

In vitro: Nanoparticles were assessed (particle size distribution analyzer, cryo-transmission electron microscopy) at baseline and after exposure to saline/plasma.

TOXICITY

In porcine wound healing study (n = 12), healing was assessed by photography, clinical assessment, and histology. Pharmacodynamics: Seventeen young piglets were randomly assigned to plain 0.5% ropivacaine (n = 5), proliposomal 4% ropivacaine (n = 6), or sham (n = 6). Tactile threshold was assessed using von Frey filaments applied to the surgical wound; the nonoperated skin was used as a control. Tactile threshold over time was determined using area under the curve (AUC) and assessed by 1-way analysis of variance.

PHARMACOKINETICS

8 young piglets were randomly assigned to plain 0.5% (25 mg, n = 4) or proliposomal 4% (200 mg, n = 4) ropivacaine. Plasma ropivacaine was assessed by high-performance liquid chromatography at baseline and at intervals over 36 hours. Paired ropivacaine concentration (from wound exudate and plasma) was obtained at 96 hours. Data were analyzed using noncompartmental and compartmental models.

RESULTS

In vitro: On exposure to saline and plasma, the study drug was transformed from a homogenous oil to an emulsion containing liposomes of approximately 1.4-μm diameter; this effect was dilution dependent and stable over time.

TOXICITY

All wounds healed well; no effect of drug group was observed. Pharmacodynamics: Plain and proliposomal ropivacaine provided sensory anesthesia for approximately 6 and 30 hours, respectively. There was an approximately 7-fold increase in the AUC of anesthesia for proliposomal ropivacaine compared with plain ropivacaine (mean difference, 1010; 95% confidence interval [CI], 625-1396 g·h/mm; P < 0.0001).

PHARMACOKINETICS

There was no difference in Cmax (2.31 ± 0.74 vs 2.32 ± 0.46 mg/L), despite an approximately 8-fold difference in dose. However, proliposomal ropivacaine was associated with a marked prolongation of Tmax (6.50 ± 6.35 vs 0.5 ± 0.0 hours), terminal half-life (16.07 ± 5.38 vs 3.46 ± 0.88 hours; P = 0.0036), and ropivacaine-time AUC (47.72 ± 7.16 vs 6.36 ± 2.07 h·mg/L; P < 0.0001), when compared with plain ropivacaine. The proliposomal formulation provided an approximately 250-fold higher ropivacaine concentration in the surgical wound (mean difference, 3783 ng/mL; 95% CI, 1708-5858; P = 0.001) and an approximately 25-fold higher wound:plasma ropivacaine concentration ratio (mean difference, 126; 95% CI 38-213; P = 0.011).

CONCLUSIONS

Proliposomal ropivacaine exerted prolonged anesthesia with delayed elimination, typical for liposomal drugs. The advantage of this novel proliposomal ropivacaine is its ease of preparation and its extended shelf-stability (>2 years) at room temperature.

Aerosolized intraperitoneal local anesthetic for laparoscopic surgery: a randomized, double-blinded, placebo-controlled trial

BACKGROUND

Postoperative pain remains a significant challenge following laparoscopy. Aerosolized intraperitoneal local anesthetic (AILA) is a novel method to deliver local anesthetic. The aim was to evaluate aerosolized ropivacaine in pain management following laparoscopic Nissen fundoplication (LNF) and cholecystectomy (LC).

METHODS

This prospective randomized double-blinded placebo-controlled trial enrolled consecutive patients undergoing LNF and LC. The treatment group (TG) received intraperitoneal ropivacaine (5 mL 1 % Naropin(®)) at CO2 insufflation via the AeroSurge(®) aerosolizer device through the camera port. The control group (CG) received 5 mL of saline in the same manner. Postoperative shoulder tip pain at rest 6 h postoperatively was the primary study endpoint, with secondary endpoints of shoulder and abdominal pain within the first 24 h, recovery room stay, hospital stay, and postoperative analgesia use. Pain scores were collected using the Verbal Rating Score.

RESULTS

Eighty-seven patients were included in the final analysis (TG n = 40, CG n = 47). There was no significant difference between CG and TG at the primary endpoint. In the LC group, AILA significantly reduced shoulder tip pain at rest at 10 (p = 0.030) and 30 min (p = 0.040) and shoulder tip pain on movement at 10 (p = 0.030) and 30 min (p = 0.037). In the LNF group, AILA significantly reduced postoperative abdominal pain at rest at 6 h (p = 0.009). AILA reduced overall incidence of shoulder tip pain in the LC group (11.8 vs. 57.9 %, p = 0.004).

CONCLUSION

This study did not demonstrate a significant difference between TG and CG in the primary endpoint, pain at 6 h postoperatively.

Postoperative Analgesia after Laparoscopic Ovarian Cyst Resection: Double-blind Multicenter Randomized Control Trial Comparing Intraperitoneal Nebulization and Peritoneal Instillation of Ropivacaine

STUDY OBJECTIVE

To compare the effects of local anesthetic intraperitoneal nebulization with intraperitoneal instillation during laparoscopic ovarian cystectomy on postoperative morphine consumption and pain.

DESIGN

Multicenter, randomized, case-control trial.

DESIGN CLASSIFICATION

Canadian Task Force Classification I.

SETTING

University hospitals in Italy.

PATIENTS

One hundred forty patients scheduled for laparoscopic ovarian cystectomy.

INTERVENTIONS

Patients were randomized to receive either nebulization of ropivacaine 150 mg before surgery or instillation of ropivacaine 150 mg before surgery. Nebulization was performed using the Aeroneb Pro device (Aerogen, Galway, Ireland).

MEASUREMENTS AND MAIN RESULTS

One hundred forty patients were enrolled, and 123 completed the study. There was no difference between the 2 groups in average morphine consumption (7.3 ± 7.5 mg in the nebulization group vs 9.2 ± 7.2 mg in the instillation group; p = .17). Eighty-two percent of patients in the nebulization group required morphine compared with 96% in the instillation group (p < .05). Patients receiving nebulization had a lower dynamic Numeric Ranking Scale compared with those in the instillation group in the postanesthesia care unit postanesthesia care unit and 4 hours after surgery (p < .05). Ten patients (15%) in the nebulization group experienced shivering in the postanesthesia care unit compared with 2 patients (4%) in the instillation group (p = .035).

CONCLUSION

Nebulization of ropivacaine prevents the use of morphine in a significant proportion of patients, reduced postoperative pain during the first hours after surgery, and was associated with a higher incidence of postoperative shivering when compared with instillation.

Assessing the feasibility of a randomised, double-blinded, placebo-controlled trial to investigate the role of intraperitoneal ropivacaine in gastric bypass surgery: a protocol

INTRODUCTION

Postoperative pain control remains a major challenge for surgical procedures, including laparoscopic gastric bypass. Pain management is particularly relevant in obese patients who experience a higher number of cardiovascular and pulmonary events. Effective pain management may reduce their risk of serious postoperative complication, such as deep vein thrombosis and pulmonary emboli. The objective of this study is to evaluate the efficacy of intraperitoneal local anaesthetic, ropivacaine, to reduce postoperative pain in patients undergoing laparoscopic Roux-en-Y gastric bypass.

METHODS AND ANALYSIS

A randomised controlled trial will be conducted to compare intraperitoneal ropivacaine (intervention) versus normal saline (placebo) in 120 adult patients undergoing bariatric bypass surgery. Ropivacaine will be infused over the oesophageal hiatus and throughout the abdomen. Patients in the control arm will undergo the same treatment with normal saline. The primary end point will be postoperative pain at 1, 2 and 4 h postoperatively. Pain measurements will then occur every 4 h for 24 h and every 8 h until discharge. Secondary end points will include opioid use, peak expiratory flow, 6 min walk distance and quality of life assessed in the immediate postoperative period. Intention-to-treat analysis will be used and repeated measures will be analysed using mixed modelling approach. Post-hoc pairwise comparison of the treatment groups at different time points will be carried out using multiple comparisons with adjustment to the type 1 error. Results of the study will inform the feasibility of recruitment and inform sample size of a larger definitive randomised trial to evaluate the effectiveness of intraperitoneal ropivacaine.

ETHICS AND DISSEMINATION

This study has been approved by the Ottawa Health Science Network Research Ethics Board and Health Canada in April 2014. The findings of the study will be disseminated through national and international conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Clinicaltrial.gov NCT02154763.

Effects of peritoneal ropivacaine nebulization for pain control after laparoscopic gynecologic surgery

STUDY OBJECTIVE

To evaluate the effects of peritoneal cold nebulization of ropivacaine on pain control after gynecologic laparoscopy.

DESIGN

Evidence obtained from a properly designed, randomized, double-blind, placebo-controlled trial (Canadian Task Force classification I).

SETTING

Tertiary care center.

PATIENTS

One hundred thirty-five women with American Society of Anesthesiologists disease classified as ASA I-III who were scheduled to undergo operative laparoscopy.

INTERVENTION

Patients were randomized to receive either nebulization of 30 mg ropivacaine before surgery (preoperative group), nebulization of 30 mg ropivacaine after surgery (postoperative group), instillation of 100 mg ropivacaine before surgery (instillation group), or instillation of saline solution (control group). Nebulization was performed using the Aeroneb Pro device.

MEASUREMENT AND MAIN RESULTS

Pain scores, morphine consumption, and ambulation time were collected in the post-anesthesia care unit and at 4, 6, and 24 hours postoperatively. One hundred eighteen patients completed the study. Patients in the preoperative group reported lower pain Numeric Ranking Scale values compared with those in the control group (net difference 2 points; 95% confidence interval [CI], 0.3-3.1 at 4 hours, 1-3 at 6 hours, and 0.7-3 at 24 hours; p = .01) Patients in the preoperative group consumed significantly less morphine than did those in the control group (net difference 7 mg; 95% CI, 0.7-13; p = .02). More patients who received nebulization walked without assistance within 12 hours after awakening than did those in the instillation and control groups (net difference 15%; 95% CI, 6%-24%; p = .001).

CONCLUSIONS

Cold nebulization of ropivacaine before surgery reduced postoperative pain and morphine consumption and was associated with earlier walking without assistance.

Total systemic ropivacaine concentrations following aerosolized intraperitoneal delivery using the AeroSurge

STUDY OBJECTIVE

To evaluate intraperitoneal ropivacaine delivery with the AeroSurge device in the clinical setting and to evaluate the total systemic ropivacaine levels achieved following delivery of 50 mg of aerosolized ropivacaine.

DESIGN

Preliminary, prospective, nonrandomized study.

SETTING

Operating room of a university hospital.

PATIENTS

5 consecutive ASA physical status 1 and 2 patients undergoing elective laparoscopic Nissen fundoplication or cholecystectomy.

INTERVENTION

Five mL of 1% ropivacaine was delivered through the 10 mm port using the AeroSurge device at peritoneal insufflation.

MEASUREMENTS

Venous blood samples were collected and total ropivacaine concentration was determined using liquid chromatography-mass spectrometry.

MAIN RESULTS

The AeroSurge device delivered ropivacaine, visible as mist within the peritoneal cavity. Peak concentration (Cmax) was attained between 10 and 30 minutes following the end of aerosolized ropivacaine delivery. At no stage did any level approach toxic levels.

CONCLUSIONS

This preliminary study confirms that aerosolized intraperitoneal local anesthetic is feasible, with ropivacaine concentrations remaining within safe levels.

Intraperitoneal nebulization of ropivacaine for pain control after laparoscopic cholecystectomy: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Intraperitoneal local anaesthetic nebulization is a relatively novel approach to pain management after laparoscopic surgery. This randomized, double-blind, placebo-controlled trial evaluated the effects of intraperitoneal ropivacaine nebulization on pain control after laparoscopic cholecystectomy.

METHODS

Patients undergoing laparoscopic cholecystectomy were randomized to receive intraperitoneal nebulization of ropivacaine 1% (3 ml) before surgical dissection and normal saline 3 ml at the end of surgery (preoperative nebulization group); intraperitoneal nebulization of normal saline 3 ml before surgical dissection and ropivacaine 1% (3 ml) at the end of surgery (postoperative nebulization group); or intraperitoneal nebulization of normal saline 3 ml before surgical dissection and at the end of surgery (placebo group). Intraperitoneal nebulization of ropivacaine or saline was performed using the Aeroneb Pro(®) device. Anaesthetic and surgical techniques were standardized. The degree of pain on deep breath or movement, incidence of shoulder pain, morphine consumption, and postoperative nausea and vomiting were collected in the post-anaesthesia care unit and at 6, 24, and 48 h after surgery.

RESULTS

Compared with placebo, ropivacaine nebulization significantly reduced postoperative pain (-33%; Cohen's d 0.64), referred shoulder pain (absolute reduction -98%), morphine requirements (-41% to -56% Cohen's d 1.16), and time to unassisted walking (up to -44% Cohen's d 0.9) (P<0.01). There were no differences in pain scores between ropivacaine nebulization groups.

CONCLUSIONS

Ropivacaine nebulization before or after surgery reduced postoperative pain and referred shoulder pain after laparoscopic cholecystectomy. Furthermore, ropivacaine nebulization reduced morphine requirements and allowed earlier mobility.

Description of a novel approach for intraperitoneal drug delivery and the related device

BACKGROUND

Two significant limitations of intraperitoneal drug therapy are limited drug distribution and poor penetration into peritoneal nodules. A possible solution is the application of the so-called "therapeutic pneumoperitoneum," taking advantage of the gaseous nature and the pressure of capnoperitoneum during laparoscopy. Our objective was to develop a device able to apply such therapeutic pneumoperitoneum.

METHODS

The technology presented here is a spraying device and can be introduced through a trocar. It is driven by mechanical pressure and consists of an injector, a line, and a nozzle. An in vivo experimental study was performed in five pigs. A transvaginal cholecystectomy was performed. At the end of the procedure, a standard dose of methylene blue was sprayed/infused into the abdominal cavity for 30 min (4 test animals w/therapeutic pneumoperitoneum (12 mmHg CO(2)) and 1 control animal w/conventional lavage (2 l intra-abdominal volume with extracorporeal circulation)). At the end of the procedure, all animals were autopsied and the peritoneum was analyzed. Outcome criteria were: (1) drug distribution (as assessed by the stained peritoneal surface at autopsy), and (2) diffusion into the peritoneum (presence or not of macroscopic staining of the outer aspect of the peritoneum immediately after surgery).

RESULTS

Stained peritoneal surface was larger after aerosol application compared with peritoneal lavage, and staining more intense. Hidden peritoneal surfaces and the anterior abdominal wall were stained only in the aerosol group. In contrast to peritoneal lavage, the outer aspect of peritoneal membrane was immediately stained after pressurized spraying.

CONCLUSIONS

This device and the related approach significantly improve both distribution and penetration of a test substance into the peritoneal cavity in a large animal model. This might be a significant progress in treating intraperitoneal disease, in particular peritoneal carcinomatosis.

Intraperitoneal ropivacaine nebulization for pain management after laparoscopic cholecystectomy: a comparison with intraperitoneal instillation

BACKGROUND

Studies evaluating intraperitoneal local anesthetic instillation for pain relief after laparoscopic procedures have reported conflicting results. In this randomized, double-blind study we assessed the effects of intraperitoneal local anesthetic nebulization on pain relief after laparoscopic cholecystectomy.

METHODS

Patients undergoing elective laparoscopic cholecystectomy were randomly assigned to receive either instillation of ropivacaine 0.5%, 20 mL after induction of the pneumoperitoneum, or nebulization of ropivacaine 1%, 3 mL before and after surgery. Anesthetic and surgical techniques were standardized. Degree of pain at rest and on deep breathing, incidence of shoulder pain, morphine consumption, unassisted walking time, and postoperative nausea and vomiting were evaluated at 6, 24, and 48 hours after surgery.

RESULTS

Of the 60 patients included, 3 exclusions occurred for conversion to open surgery. There were no differences between groups in pain scores or in morphine consumption. No patients in the nebulization group presented significant shoulder pain in comparison with 83% of patients in the instillation group (absolute risk reduction -83, 95% CI -97 to -70, P<0.001). Nineteen (70%) patients receiving nebulization walked without assistance within 12 hours after surgery in comparison with 14 (47%) patients receiving instillation (absolute risk reduction -24, 95% CI -48 to 1, P=0.04). One (3%) patient in the instillation group vomited in comparison with 6 (22%) patients in the nebulization group (absolute risk reduction -19%, 95% CI -36 to -2, P=0.03).

CONCLUSIONS

Intraperitoneal ropivacaine nebulization was associated with reduced shoulder pain and unassisted walking time but with an increased incidence of postoperative vomiting after laparoscopic cholecystectomy.