|Year : 2017 | Volume
| Issue : 1 | Page : 272-278
Comparative study between ultrasound-guided thoracic paravertebral nerve block and intraperitoneal instillation of local anesthetic as pre-emptive analgesia in laparoscopic cholecystectomy surgery
Asmaa S Abdellah1, Fatma H Ashour2, Enas M.A Elshanawany2
1 Department of Anesthesia and Intensive Care, Al-Zahr University, Cairo, Egypt
2 Department of Anesthesia, Intensive Care and Pain Management, Al-Zahr University, Cairo, Egypt
|Date of Web Publication||3-Aug-2018|
Asmaa S Abdellah
Department of Anesthesia and Intensive Care, Al Azhar University HospitalAbbassia, Cairo
Source of Support: None, Conflict of Interest: None
Background Thoracic paravertebral block (TPVB) is an effective technique in controlling pain after lower thoracic and upper abdominal surgery, and ultrasound guidance is a recent technique that may offer several advantages. Intraperitoneal injections of local anesthetics have been proposed to minimize postoperative pain after laparoscopic surgery.
Patients and methods A total of 60 patients with American Society of Anesthesiologists status I and II aged 30–50 years undergoing elective laparoscopic cholecystectomy were divided into three equal groups (20 patients each): ultrasound-guided thoracic paravertebral block (UG-TPVB group) with 20 ml 0.25% bupivacaine bilaterally, intraperitoneal instillation of local anesthetics with 50 ml 0.25% bupivacaine after inflation of the abdomen with gas (IP group), and general anesthesia alone without any local anesthetics (GA group) (control group). General anesthesia was induced for all patients. Intraoperative and postoperative hemodynamic data (mean arterial blood pressure and heart rate) were recorded. Intraoperative anesthetic and analgesic consumption, pain intensity using visual analog scale, pethidine consumption, serum cortisol, blood glucose level, and complications were estimated.
Results Hemodynamic data were significantly lower in IP and UG-TPVB groups compared with GA group (P<0.05), and on comparing UG-TPVB group with IP group, with no significant difference was seen regarding postanaesthesia care unit admission and discharge (P1>0.05). End-tidal sevoflurane % (UG-TPVB: 1.1±0.21, IP: 1.8±0.22, GA: 2±0.23) and volume of consumption (UG-TPVB: 12.0±0.9, IP: 15.1±0.7, GA: 18.2±2) showed significant decrease when comparing UG-TPVB and IP groups with GA group (P<0.05). The mean dose of intraoperative fentanyl, mean dose of postoperative pethidine consumption, and the number of patients who received pethidine were significantly lower in IP and UG-TPVB groups compared with GA group (P<0.05). Postoperative serum cortisol and blood glucose level showed significant decrease in UG-TPVB and IP groups compared with GA group at 6 and 24 h postoperative (P<0.05). Pain score using visual analog scale and number of patients who experienced postoperative nausea and vomiting were significantly decreased in both groups in comparison with GA group.
Conclusion UG-TPVB and IP bupivacaine instillation as pre-emptive analgesia in laparoscopic cholecystectomy provided good intraoperative and postoperative analgesia and decreased the dose of anesthetics used with great safety, and the incidence of complications was less.
Keywords: intraperitoneal instillation, laparoscopic cholecystectomy, pre-emptive analgesia, thoracic paravertebral nerve block, ultrasound-guided nerve block
|How to cite this article:|
Abdellah AS, Ashour FH, Elshanawany EM. Comparative study between ultrasound-guided thoracic paravertebral nerve block and intraperitoneal instillation of local anesthetic as pre-emptive analgesia in laparoscopic cholecystectomy surgery. Ain-Shams J Anaesthesiol 2017;10:272-8
|How to cite this URL:|
Abdellah AS, Ashour FH, Elshanawany EM. Comparative study between ultrasound-guided thoracic paravertebral nerve block and intraperitoneal instillation of local anesthetic as pre-emptive analgesia in laparoscopic cholecystectomy surgery. Ain-Shams J Anaesthesiol [serial online] 2017 [cited 2018 Nov 20];10:272-8. Available from: http://www.asja.eg.net/text.asp?2017/10/1/272/238447
| Introduction|| |
Laparoscopic operative procedures have revolutionized surgery, with many advantages such as a smaller and more cosmetic incision, reduced blood loss, reduced postoperative stay, and reduced pain, which cut down hospital cost. However, patients undergoing laparoscopic procedures do experience postoperative pain, especially in the upper and lower abdomen, back, and shoulder region . Pain intensity usually peaks during the first postoperative day and usually declines over the following 2–3 days. Pain after laparoscopy results from the stretching of the intra-abdominal cavity, peritoneal inflammation, and phrenic nerve irritation caused by residual carbon dioxide in the peritoneal cavity .
Thoracic paravertebral block (TPVB) is an effective technique in controlling pain after lower thoracic and upper abdominal surgeries. Ultrasound guidance for regional anesthesia has further increased the block’s popularity [ultrasound-guided thoracic paravertebral block (UG-TPVB)], in part because of the ability to visualize the pleura, decrease complications, and increase success rate . Intraperitoneal instillation of local anesthetics such as bupivacaine, levobupivacaine, lidocaine, and ropivacaine has been suggested as a way of reduction of abdominal and shoulder pain in laparoscopic cholecystectomy . The instillation can be performed either before or after initiation of the pneumoperitoneum  or toward the end of the surgery. The instillation could be by washing the gall bladder bed of the liver with local anesthetics , instillation under the diaphragm, or as an aerolised spray in the general peritoneum, and it can be as a bolus or as a continuous infusion .
| Patients and methods|| |
After approval of the hospital ethical committee, informed consent was obtained from all the patients. A total of 60 patients with American Society of Anesthesiologists status I or II of both sex, aged 30–50 years, scheduled to undergo elective laparoscopic cholecystectomy surgery were included in the study. This study was carried out in Alzahraa University hospital in the period from June 2015 to December 2015 in the Operative Room and Surgical Department. Exclusion criteria included patient refusal, severe cardiovascular disease, and coagulation defect, infection at the site of TPVB placement, anatomic deformities, morbid obesity, and history of allergy to local anesthetics. Using a single-blinded method, the patients were randomly allocated into three groups (20 patients in each group) after enrollment into the study by opening sealed opaque envelopes that had been done by computer-generated random allocation.
- Group I (n=20) underwent bilateral UG-TPVB using 20-ml bupivacaine 0.25%, in epinephrine 1 : 200 000.
- Group II (n=20) underwent IP instillation of 50 ml bupivacaine 0.25% in epinephrine 1 : 200 000.
- Group III (n=20): GA alone (control group).
During the preoperative visit, patients were assessed and the study protocol was explained to each patient. On arrival to the operating room, all patients were monitored, and a 20-G venous cannula was inserted on the dorsum of the hand and sample for cortisol and glucose level obtained (baseline). Lactated ringer’s solution 6–8 ml/kg was given to replenish the overnight fasting hours. After that, all patients were premedicated with fentanyl 25–50 µg (fentanyl; Jansen, Oberict, Switzerland) and midazolam 1–3 mg (dormicum; Roche, Basle, Switzerland) intravenously.
For those randomized to receive UG-TPVB block, the patients were placed in the sitting position, and under aseptic condition at level of T7, using Touhy needle G18, the technique was performed bilaterally as described in ultrasound-guided TPVB (http://www.Ssra on line Cme.com). After 10 min, the block is assessed by pin prick.
After preoxygenation with 100% O2 for 5 min, patients in the three groups received GA, by a bolus dose of fentanyl (1 µg/kg) and then propofol 1–2 mg/kg (propofol; Fresenius, Munich Germany) injected over 60 s. This was followed by an intubation dose of cisatracurium 0.15 mg/kg (nimbex; Elaxo, Verona, Italy) to facilitate endotracheal intubation, and ventilator was controlled to maintain end-tidal CO2 at 30–35 mmHg. Maintenance was by sevoflurane in 100% O2 and incremental doses of cisatracurium (2 mg) and fentanyl (0.5 µg/kg) (when hemodynamic data increased 20% of preoperative values).
In group randomized to receive IP, after inflation of the abdominal cavity with gas, 50 ml bupivacaine 0.25% in epinephrine (1 : 200 000) solution was instilled intraperitoneally, as the surgeon requested to instill 20 ml of the local anesthetic solution into the hepatodiaphragmatic space, 10 ml in the area of gall bladder, and 20 ml into the space between liver and kidney.
ECG, noninvasive blood pressure (BP), pulse oximetry, and end-tidal carbon dioxide and end-tidal sevoflurane concentration (measured by gas monitor, AS/3 TM; Datex, Helsinki, Finland) were monitored throughout surgery. At the end of surgery, neuromuscular block was antagonized in all patients with neostigmine 0.04 mg/kg and atropine 0.02 mg/kg.
At postanaesthesia care unit (PACU), visual analog scale (VAS), and hemodynamic data were recorded. During the first 24 h postoperatively, all patients received ketrolac tromethamine 30 mg intravenously/8 h (ketolac; Amriya Pharma Inc., Cairo, Egypt) intravenous infusion every 8 h. When the patients’ experienced pain (VAS ≥4), pethidine was given intravenously (30–50 mg). Nurses in the PACU and ward (collecting the data) were blinded about the patient groups.
The following parameters were evaluated in all groups:
- Patient characteristics.
- Hemodynamic parameters [heart rate (HR) and mean arterial BP] were monitored preoperatively, on admission, and on discharge from PACU, at 6 and 12 h postoperatively.
- Average end-tidal sevoflurane concentration and volume consumed (ml/h).
- Cortisol and blood glucose levels were estimated on the following:
- Preoperatively (baseline).
- Postoperatively at sixth hour and 24th hour.
- Total dose of intraoperative fentanyl consumption, and postoperative analgesic requirement (pethidine) during the first 24 hours.
- Clinical evaluation of pain severity using VAS assessed on early postoperatively and then every 4 h during first 24 h postoperative.
Sample size was calculated using power analysis (α=0.05, β=0.8) and was found to require at least 18 patients per group to detect efficacy of analgesia, so 20 patients in each group were considered. Data were collected, revised, coded, and entered to the statistical package for social science IBM SPSS Inc. (version 20, IBM Corp., Armonk, NY, USA). Qualitative data were presented as number and percentages whereas quantitative data with parametric distribution were presented as mean, SD, and ranges. The comparison between the two groups with qualitative data was done by using χ2-test. Comparison between more than two groups with quantitative data was done by one-way analysis of variance followed by post-hoc analysis (least significant difference test). The confidence interval was set to 95% and the margin of error accepted was set to 5%. So, the P value was considered significant at the level of less than 0.05.
| Results|| |
A total of 60 patients were enrolled and randomized into three groups, with their demographic data shown in [Table 1]. Among the three groups, there were no significant difference regarding age, sex, height, American Society of Anesthesiologists physical status, and duration of surgery (P>0.05).
Hemodynamic data (heart rate and mean arterial blood pressure)
Mean intraoperative hemodynamic data significantly decreased in UG-TPVB and IP groups compared with GA group. Moreover, it was significantly higher in IP group compared with UG-TPVB (P<0.05), but there was no significant difference between both groups at PACU admission and discharge (P1>0.05; [Table 2] and [Table 3]).
|Table 2 Comparison among the three groups regarding heart rate (beats/min)|
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|Table 3 Comparison among the three groups regarding mean arterial blood pressure (mmHg)|
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Anesthetic and analgesic requirements
End-tidal sevoflurane % (UG-TPVB: 1.1±0.21, IP: 1.8±0.22, and GA: 2±0.23) and sevoflurane consumption ml/h (UG-TPVB: 12.0±0.9, IP: 15.1±0.7, and GA: 18.2±2) were significantly higher in GA group compared with UG-TPVB and IP groups, and it was significantly higher in IP group compared with UG-TPVB group (P<0.001) ([Table 4]). The mean dose of intraoperative fentanyl and mean dose of postoperative pethidine were significantly higher in GA group (24±32.25 and 65±52.35, respectively) compared with UG-TPVB (2.5±11.20 and 20±14.1, respectively) and IP (7.5±18.32 and35.5±18.32, respectively) groups. The number of patients needed to take pethidine showed significant reduction in UG-TPVB (two patients) and IP (five patients) groups compared with GA (12 patients) group ([Table 4]).
|Table 4 Comparison among three groups regarding anesthetic and analgesic requirements|
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Blood glucose and plasma cortisol levels (mg/dl)
Blood glucose and plasma cortisol levels showed significant increase in GA group compared with UG-TPVB and IP groups (P<0.05), with no significant difference between UG-TPVB and IP groups (P1>0.05) at sixth and 24th hour postoperatively ([Table 5] and [Table 6]).
|Table 5 Comparison among the three groups regarding blood glucose level (mg/dl)|
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|Table 6 Comparison among three groups regarding plasma cortisol level (mg/dl)|
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Visual analog scale (0–10)
In all groups, VAS decreased significantly at all measured times. The mean VAS was significantly higher in group GA compared with IP and TPVB groups at all measured times and it was significantly higher in group IP compared with UG-TPVB group at PACU admission and discharge and 4 h postoperatively (P<0.05) ([Table 7] and [Figure 1] and [Figure 2]).
|Table 7 Comparison among the three groups regarding mean visual analog score|
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|Figure 1 Visual analog scale difference among the three groups at postanaesthesia care unit admission and discharge. PACU, postanaesthesia care unit.|
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|Figure 2 Visual analog scale difference among the three groups at postoperative periods. PACU, postanaesthesia care unit.|
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Nausea and vomiting (numbers of patients)
Nausea occurred significantly more in GA group (10 patients) compared with UG-TPVB (two patients) and IP group (four patients) (P<0.05). Moreover, vomiting had occurred significantly more in GA group (six patients) compared with UG-TPVB (one patient) and IP (two patients) groups (P>0.05). Moreover, a significant increase was seen in the number of patients who experienced nausea and vomiting in GA group compared with UG-TPVB group (P=0.001 and 0.037, respectively; [Table 8]).
|Table 8 Comparison among groups regarding postoperative nausea and vomiting|
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| Discussion|| |
In laparoscopic cholecystectomy, overall pain consists of three different and clinically separate components: incisional pain (somatic pain), visceral pain (deep intra-abdominal pain), and shoulder pain (presumably referred visceral pain). So, several analgesic interventions, with varying targets and mechanisms, have been investigated for their influence on early pain after laparoscopic cholecystectomy . Local anesthetic techniques are part of the multimodal approach to postoperative pain management. Ultrasound guidance for regional anesthesia has further increased the block’s popularity .
In this study, we tried two different techniques of pre-emptive analgesic as an adjunct to GA in patients undergoing laparoscopic cholecystectomy to evaluate and compare their efficacy in reducing intraoperative and postoperative pain and stress: UG-TPVB and IP of local anesthetics. In our study, we found that HR and BP were significantly higher in GA group compared with IP and US-TPVB groups and were higher in IP compared with US-TPVB. There was less consumption of sevoflurane in IP and US-TPVB groups compared with GA group. Decreased stress response in UG-TPVB and IP groups was also observed. Pain score assessment using VAS showed that it was significantly higher in GA group compared with other groups at all measured times and it was significantly higher in IP compared with US-TPVB with significant decrease of intraoperative fentanyl and postoperative pethidine consumption in US-TPVB and IP groups compared with GA group.
Moussa and Bambherz  and Pasqualucci et al.  demonstrated a significant reduction in circulatory (HR and BP) and hormonal response to stress in patients receiving TPVB undergoing laparoscopic cholecystectomy under GA. In disagreement with the findings was the study by Paleczny et al.  about the efficacy of TPVB as an adjuvant to GA in open cholecystectomy, which found no significant differences in HR and BP between the two groups.
Observation by Pasqualucci and colleagues ,, showed a significant reduction in stress hormones during laparoscopic cholecystectomy after intraperitoneal installation of bupivacaine.
Omar and Aboushanab  concluded that intravenous lidocaine administration, during GA can decrease BIS-guided sevoflurane requirements. Jie et al.  evaluated combined general and epidural anesthesia with different concentrations of ropivacaine, and they found a decrease in end-tidal sevoflurane concentration as compared with placebo group (epidural with saline). Atsuka et al.  showed a significant reduction in end-tidal sevoflurane concentration in patients who received GA with epidural lidocaine 1%. On the contrary, Paleczny et al.  in a study about TPVB in open cholecystectomy found no significant reduction in mean consumption of sevoflurane.
Paleczny et al. , Naja et al. , Jaques et al , and Oofuvong et al.  supported our results, as they noted that postoperative pain score was significantly lower in TPVB group and there was significantly lower average consumption of fentanyl and decreased postoperative analgesic requirements for 36 h compared with GA group alone in open cholecystectomy surgeries. Culp et al.  have used TPVB for severe pain following radiofrequency ablation of liver mass; they found VAS has decreased from 10 to 0 in 30 min.
Kucuk et al.  in a placebo controlled comparison of bupivacaine and ropivacaine intraperitoneal instillation in laparoscopic cholecystectomy found a significant decrease in opioid analgesic consumption during 24 h postoperatively compared with GA group alone. Barczynski et al. , Alam et al. , and Maestroni et al.  using instillation and incisional infiltration of local anesthetics found that reduced overall pain and shoulder pain and reduction in analgesic requirements up to 12 h postoperatively with significantly reduced supplementary postoperative analgesic and antiemetic medications. Gupta et al.  in a study using intraperitoneal installation of bupivacaine with fentanyl found significant decrease in pain score and decreased postoperative analgesic requirement.
In contrast to our study, Ahmed et al.  found that IP bupivacaine did not attenuate pain following laparoscopic surgeries. Radmaker et al.  and Joris et al.  failed to demonstrate any reduction of postoperative pain after intraperitoneal instillation of 20 ml 0.25% bupivacaine or 0.5% lidocaine and 80 ml of 0.125% bupivacaine, respectively.Regarding the incidence of postoperative nausea and vomiting, it was significantly higher in GA group compared with IP and UG-TPVB groups. Pasqualucci et al.  in their study about intraperitoneal bupivacaine in laparoscopic cholecystectomy as a pre-emptive analgesia found a significant reduction in the incidence of nausea and vomiting compared with other groups. Moreover, Michaloliakou et al.  showed that the incidence of nausea and vomiting in the PACU and in the ward was lower in group that received intraperitoneal bupivacaine around the gall bladder than the control group (received saline).
In agreement with our study, Naja et al.  in their prospective, randomized clinical trial comparing the efficacy of bilateral TPVB combined with GA versus GA alone in reducing postoperative pain laparoscopic cholecystectomy found decreased number of patients who had nausea at 6 and 12 h postoperatively. Moussa and Bambherz , showed lower incidence of vomiting in patients who received bilateral TPVB with bupivacaine 0.25% in epinephrine 1 : 200 000 compared with those who received saline in hepatectomy. Moreover, Paleczny et al.  found a higher incidence of nausea and vomiting in patients who received GA alone compared with those who received TPVB in open cholecystectomy.
| Conclusion|| |
Use of ultrasound-guided paravertebral nerve block and intraperitoneal bupivacaine instillation as a pre-emptive analgesia in laparoscopic cholecystectomy provided good intraoperative and postoperative analgesia and decreased the dose of anesthetics and analgesics used, with great safety and less complications, mainly UG TPVB.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Sulekha IN. The effect of intraperitoneal bupivacaine for post-operative pain management in patients undergoing laparoscopic cholecystectomy – a prospective double-blind randomized control study. OSR J Dent Med Sci 2013; 4:64–69.
Hilvering B, Draaisma WA, van der Bilt JD, Valk RM, Kofman KE. Randomized clinical trial of combined preincisional infiltration and intraperitoneal instillation of levobupivacaine for postoperative pain after laparoscopic cholecystectomy. Br J Surg 2011; 98:784–789.
Kumar T, Rajendran SR. Comparative evaluation of thoracic epidural versus thoracic paravertebral block for post thoracotomy pain relief with 0.25% bupivacaine. Indian J Anaesth 2003; 47:269–274.
Alkhamesi NA, Peck DH, Lomax D, Darzi AW. Intraperitoneal aerosolization of bupivacaine reduces postoperative pain in laparoscopic surgery: a randomizedprospective controlled double-blinded clinical trial. Surg Endosc 2007; 21:602–606.
Barczynski M, Konturek A, Herman RM. Superiority of preemptive analgesia with intraperitoneal instillation of bupivacaine before rather than after the creation of pneumoperitoneum for laparoscopic cholecystectomy: a randomized, double-blind, placebo-controlled study. Surg Endosc 2006; 20:1088–1093.
Abdel-Raouf M, Amer H. Postoperative analgesic effects of intraperitoneal NMDA receptor antagonists (ketamine and magnesium) in patients undergoing laparoscopic cholecystectomy. Egypt J Anaesth 2004; 20:107–111.
Bisgard T. Analgesic treatment after laparoscopic cholecystectomy: a critical assessment of evidence. Anesthesiology 2006; 104:845–846.
Moussa A, Bambherz F. Bilateral thoracic paravertebral block versus intraperitoneal bupivacaine for pain management after laparoscopic cholecystectomy. Saudi J Anaesth 2007; 1:62–67. [Full text]
Pasqualucci A, Verna D, Ricco C. Preemptive analgesia: intraperitoneal local anesthetic in laparoscopic cholecystectomy. A randomized double-blind placebo-controlled study. Anesthesiology 1996; 85:11–20.
Paleczny J, Ziper P, Pysz M. Paravertebral nerve blockade for open cholecystectomy. Aestezjol Intens Ter 2009; 41:89–90.
Desai N, Richardson J, Lonnqist PA, Naja Z. Bilateral paravertebral block for post-procedure analgesia. BJA 2004; 106:164–171.
Aristomens K, Donald J, Denis C. Can anesthetic technique for primary breast cancer surgery affect recurrence or metastasis. Anaesthesiology 2006; 105:660–664.
Omar AM, Aboushanab OH. Effect of intravenous lidocaine infusion on evoflurane requirement as monitored by bispectral index: a randomized double-blinded controlled study. Egypt J Anaesth 2013; 29:235–239.
Jie Z, Wei Z, Bin L. The effect of epidural anesthesia with different concentrations of ropivacaine on sevoflurane requirements. Anesth Analg 2007; 104:984–986.
Atsuko S, Yoji S, Shinichi S. Sevoflurane requirements to suppress response to transcutaneous electrical stimulation during epidural anesthesia with 0.5% and 1% lidocaine. Anesth Analg 2003; 97:1168–1172.
Naja MZ, Ziade MF, Rajab M, El Tayar K, Lonnqvist PA. Somatic paravertebral nerve blockade. Incidence of failed blockade and complications effect on spread solution and nerve blockade. Anaesthesia 2004; 59:459–463.
Jaques EC, Taras P, Feng D, Joel BN. Multimodal analgesic approach incorporating paravertebral blocks for open radical retropubic prostatectomy: a randomized double-blind placebo controlled study. Can J Anaesth 2011; 58:371–378.
Oofuvong M, Asampinawat T, Uakritdathkarn T. Predictive factors of perioperative fentanyl consumption during urologic surgery in children. Songkla Med J 2010; 28:6.
Culp WC, Payne MN, Montgomry MI. Thoracic paravertebral block for analgesia following liver mass radiofrequency ablation. Br J Radiol 2008; 81:23–25.
Kucuk C, Kadiogullari N, Canoler O, Savli S. Placebo-controlled comparison of bupivacaine and ropivacaine instillation for preventing postoperative pain after laparoscopic cholecystectomy. Surg Today 2007; 37:396–400.
Alam MS, Hoque HW, Saifullah M, Ali MO. Port site and intraperitoneal instillation of local anesthetics in reduction of postoperative pain after laparoscopic cholecystectomy. Med Today 2009; 22:01.
Maestroni U, Sarli D, Devito C, Anania G, Brunaldi F. A new method of preemptive analgesia in laparoscopic cholecystectomy. Surg Endosc 2002; 16:1336–1340.
Gupta R, Bogra J, Kothari N, Kohli M. Postoperative analgesia with intraperitoneal fentanyl and bupivacaine: a randomized control trial. Can J Med 2010; 1:1–9.
Ahmed BH, Ahmed A, Tan D, Awad ZT. Post-laparoscopic cholecystectomy pain; effect of intraperitoneal local anesthetics on pain control – a randomized prospective double blinded placebo-controlled trial. Am Surg 2008; 74:201–209.
Radmaker MP, Kalkman CJ, Odoom JA. Intraperitoneal local anesthetic after laparoscopic cholecystectomy: effect on postoperative pain, metabolic response and lung function. Br J Anaesth 1994; 72:263–266.
Joris J, Thirty E, Paris P, Weerts J. Pain after laparoscopic cholecystectomy characteristics and effect of intraperitoneal bupivacaine. Anesth Analg 1995; 81:379–384.
Michaloliakou C, Chung F, Shama S. Preemptive multimodal analgesia facilitate recovery after ambulatory laparoscopic cholecystectomy. Anesth Analg 1996; 82:44–51.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]