Randomized, prospective comparison of postoperative pain in low- versus high-pressure pneumoperitoneum. Randomized comparison between low-pressure laparoscopic cholecystectomy and gasless laparoscopic cholecystectomy. Prospective randomized trial on low-pressure versus standard-pressure pneumoperitoneum in outpatient laparoscopic cholecystectomy. Randomized trial of low-pressure carbon dioxide-elicited pneumoperitoneum versus abdominal wall lifting for laparoscopic cholecystectomy. Lactate and acid base changes during laparoscopic cholecystectomy. Randomized comparison between different insufflation pressures for laparoscopic cholecystectomy. Laparoscopic cholecystectomy using abdominal wall retraction. Hemodynamics and gas exchange, a comparison with conventional pneumoperitoneum. Conventional pneumoperitoneum compared with abdominal wall lift for laparoscopic cholecystectomy. Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method.
Reduced postoperative pain after laparoscopic cholecystectomy (LC) compared to open cholecystectomy (OC) may be able to be further optimized. To reduce pain, focus should be directed on the effects of individual components of pain.
                A double-blind, randomized, controlled trial was carried out in a tertiary care hospital. Fifty-three elective patients with symptomatic gallstones were enrolled into the study. Patients were randomized to low- or high-pressure pneumoperitoneum groups. In all patients, gas pressure was set to 15 mmHg during placement of ports. Later on, in the low-pressure group, the rest of the procedure was performed at 10 mmHg pressure. At 6 and 24 h postoperatively, a short-form McGill Questionnaire (MPQ) was obtained from all patients. Patients were then asked to complete a 10-cm visual analogue scale (VAS) for abdominal pain.
                Pain scores were generally low for both groups. Statistical comparisons of mean cumulative McGill score and VAS abdominal pain scores in both groups did not reach statistical significance at 6 and 24 h after operation.
                There was no correlation between high- and low-pressure laparoscopy and postoperative pain after LC. Peritoneal stretching may be more responsible for shoulder pain but has less effect on intensity of abdominal pain or incisional pain. On the basis of these negative findings, routine use of low-pressure pneumoperitoneum for alleviation of postoperative pain following LC is not recommended. Laparoscopic cholecystectomy using low-pressure pneumoperitoneum (8 mmHg) minimizes adverse hemodynamic effects, reduces postoperative pain, and accelerates recovery. Similar claims are made for gasless laparoscopy using abdominal wall lifting. The aim of this study was to compare gasless laparoscopic cholecystectomy to low-pressure cholecystectomy with respect to postoperative pain and recovery.
                Thirty-six patients were randomized to low-pressure or gasless laparoscopic cholecystectomy using a subcutaneous lifting system (Laparotenser).
                The characteristics of the patients were similar in the two groups. The procedure was completed in all patients in the low-pressure group, but two patients in the gasless group were converted to pneumoperitoneum. There were no significant differences in postoperative pain and analgesic consumption, but patients in the gasless group developed shoulder pain more frequently (50% vs 11%, p < 0.05). Gasless operation took longer to perform (95 vs 72.5 min, p = 0.01).
                Gasless and low-pressure laparoscopic cholecystectomy were similar with respect to postoperative pain and recovery. The gasless technique provided inferior exposure and the operation took longer, but the technique may still have value in high-risk patients with cardiorespiratory disease. Inpatient low-pressure pneumoperitoneum laparoscopic cholecystectomy (LPLC) has been shown to have less postoperative pain (especially shoulder-tip pain). No report so far has documented the use of lower-pressure pneumoperitoneum in outpatient laparoscopic cholecystectomy (LC). A prospective randomized trial was conducted in Tung Wah Hospital, Day Surgery Centre from January 2004 to December 2004. A total of 40 patients were recruited and 20 of whom were allocated to each arm. Outcome measures included operation time, treatment-related morbidity, mortality, postoperative pain (eg, shoulder-tip pain), consumption of analgesics, and level of satisfaction. All patients in both groups could be discharged on the same day. Patients' demographics and operation time were comparable in both groups. There were no treatment-related morbidity and mortality, nor was there any significant difference in postoperative pain. Less shoulder-tip pain was observed in the LPLC group though without significant difference (5% vs. 20%; P=0.151). Three patients in the LPLC group needed higher insufflation pressure (12 mm Hg) because of inadequate exposure and adhesions, and the operations were successful in all of them. Otherwise, no conversion to open procedure was noted in both groups. The consumption of analgesics was minimal and a high level of satisfaction was achieved in both groups of patients. The present study demonstrated no difference in LPLC and standard-pressure pneumoperitoneum laparoscopic cholecystectomy in the outcomes of outpatient LC. Routine use of lower-pressure pneumoperitoneum in outpatient LC would not be recommended unless in selected straightforward cases. Two alternative surgical techniques for elective laparoscopic cholecystectomy (LC), low-pressure insufflation of the peritoneal cavity and abdominal wall lifting (AWL), have been developed over time to minimize the disadvantages associated with CO2-elicited pneumoperitoneum. To the best of our knowledge, the 2 methods have seldom been compared as regards their relative advantages and disadvantages.
                Eighty patients scheduled for elective LC were randomized into either a low-pressure (8 mmHg) CO2 insufflation method (LPLC) group, or a gasless technique using a subcutaneous abdominal wall lifting device (GLC group). The duration of the surgical procedure, the surgical results including level of postoperative pain, and perioperative cardiopulmonary function changes experienced by the members of both groups were compared.
                Laparoscopic surgery was completed for all but 1 patient from each group due to an inadequate surgical-site exposure. There was no mortality for study participants, and no major complications were noted for members of either group. The LPLC group evidenced a shorter surgical duration as compared to the GLC group (77 +/- 28 minutes vs. 98 +/- 27 minutes, respectively; p < 0.01) and a lower incidence of postoperative shoulder pain (2/38 vs. 8/39, respectively; p < 0.05), although significant differences in intraoperative pulmonary function were noted (an increased PaCO2, Pet CO2 and peak-airway pressure and decreased arterial blood pH; p < 0.01) for the LPLC group compared to the GLC group.
                Both alternative methods for this type of surgery appeared feasible and safe for LC. Low-pressure CO2 pneumoperitoneum had a shorter surgical duration and less postoperative shoulder pain compared to the GLC technique, but did not feature any other advantage over the AWL technique with regard to impact on cardiopulmonary function. The observation of hemodynamic and metabolic impairment related to CO2 pneumoperitoneum and postoperative mesenteric ischemia reports following laparoscopic procedures have raised concern about local and systemic effects of increase intraabdominal pressure during laparoscopic procedures. The present study aims to evaluate the metabolic and acid base responses of using high pressure versus low pressure pneumoperitonium in patients undergoing laparoscopic cholecystectomy in a prospective randomized clinical trial.
                20 ASA I-II patients scheduled for elective laparoscopic cholecystectomy were randomly allocated to one of two study groups; high pressure pneumoperitoneum 12-14mmHg (HPP, n=10) versus low pressure pneumoperitoneum 6-8mmHg (LPP, n=10) undergoing laparoscopic cholecystectomy. Arterial blood gases and lactate levels were determined after induction of anesthesia (before pneumoperitonium), then after 10 min, then 30 min after insufflations and at the end of surgery and 1 hour postoperatively. Nurses in recovery unit reported pain assessment starting postoperatively until 3 hours on a 10mm VAS (0-10). Statistical significant was established at P<0.05.
                Bicarbonate was significantly (P>0.0412) lower in high pressure group at 30 min and 60 min after insufflations. In high pressure group lactate levels increased significantly as compared to low pressure group, (at 30 minutes after the establishment of abdominal pneumatic inflation P<0.006 and remained significantly increased (P<0.001) until the end of surgery and one hour thereafter) (P<0.001). The mean postoperative pain score during second hour (VAS) at HPP group was 7.4 +/- 1.17 which is significantly (P < or = 0.006) higher than pain score in LPP group 5.0 +/- 1.886. Shoulder tip pain was reported in 3 patients in the high pressure group and only one patient in the lower pressure group.
                High-pressure pneumoperitonium causes statistically significant elevation in the arterial lactate level intraoperatively until one hour post operatively. It also causes higher pain score and shoulder tip pain. Laparoscopy using carbon dioxide insufflation induces adverse effects in both the cardiovascular and the respiratory function. The use of low pressure pneumoperitoneum has been shown to reduce adverse hemodynamic effects. However, its effect on tissue trauma and postoperative pain and recovery remains controversial. The aim of this study was to compare tissue trauma, postoperative pain, and recovery in two groups of patients undergoing laparoscopic cholecystectomy, one at insufflation pressure of 8 (LC8) and the other at 15 mm Hg (LC15). Forty patients were randomized, 20 in each group. The characteristics of the patients were similar in the two groups. The procedure was completed in all patients in the LC15 group, but in 2 patients in the LC8 group the pressure was increased to 15 mm Hg to complete the operation. There were no significant differences in postoperative pain scores, analgesic consumption, and the incidence of nausea, vomiting, and shoulder pain between the two groups. C-reactive protein concentrations and white blood cell count rose significantly after surgery, but the increase was similar in the two groups. The median duration of surgery was similar, 23 minutes (range 15-65) in the LC8 group and 25 minutes (range 15-80) in the LC15 group. Using our technique of laparoscopic cholecystectomy, there were no advantages to tissue damage, postoperative pain, and recovery when a low pressure pneumoperitoneum was used. Disadvantages related to CO2 pneumoperitoneum have led to development of the abdominal wall retractor (AWR), a device designed to facilitate laparoscopic surgery without conventional pneumoperitoneum (15 mmHg CO2). We investigated the effects of the AWR on hemodynamics and gas exchange in humans. We also investigated whether the use of an AWR imposed extra technical difficulties for the surgeon. A pilot study revealed that cholecystectomy without low-pressure pneumoperitoneum was technically impossible.
                A prospective randomized controlled trial: Twenty patients undergoing laparoscopic cholecystectomy were randomly allocated into group 1: AWR with low-pressure pneumoperitoneum (5 mmHg), or group 2: conventional pneumoperitoneum (15 mmHg).
                Surgery using the AWR lasted longer, 72 +/- 16 min (mean +/- SD) vs 50 +/- 18 min compared with standard laparoscopic cholecystectomy. There were no differences between the groups with respect to hemodynamic parameters, although a small reduction of the cardiac output was observed using conventional pneumoperitoneum (from 3.9 +/- 0.7 to 3. 2 +/- 1.1 l/min) and an increase during AWR (from 4.2 +/- 0.9 to 5.2 +/- 1.5 l/min). Peak inspiratory pressures were significantly higher during conventional pneumoperitoneum compared to AWR. A slight decrease in pH accompanied by an increase in CO2 developed during pneumoperitoneum and during the use of the AWR. In both groups arterial PO2 decreased.
                The results indicate that the view was impaired during use of the AWR and therefore its use was difficult and time-consuming. Possible advantages of this devices' effects on hemodynamics and ventilatory parameters could not be confirmed in this study. We have compared, in a randomized study, conventional carbon dioxide pneumoperitoneum with abdominal wall lift in 25 patients undergoing laparoscopic cholecystectomy. Intra-abdominal pressure (IAP) (11 (SD 2) mm Hg vs 2.7 (9) mm Hg) (P < 0.01) and total amount of carbon dioxide used (40 (23) litre vs 9 (7) litre) (P < 0.001) were significantly less with abdominal wall lift. Pulmonary compliance was significantly greater (P < 0.01) in the abdominal wall lift group throughout operation. During the first 15 min of insufflation, arterial pressures were lower with abdominal wall lift (P < 0.05). In the conventional pneumoperitoneum group, femoral vein pressure increased (P < 0.01) and remained elevated for 3 h in the recovery room. Postoperative drowsiness was of significantly longer duration in the conventional pneumoperitoneum group than in the abdominal wall lift group (98 (46) min vs 13 (34) min) (P < 0.01). Postoperative nausea and vomiting and right shoulder pain occurred more often in patients with conventional pneumoperitoneum (P < 0.05). We conclude that the benefits of abdominal wall lift may be attributed to avoiding excessive carbon dioxide and high IAP. Carbon dioxide (CO2) pneumoperitoneum together with an increased intraabdominal pressure (IAP) induces a hemodynamic stress response, diminishes urine output, and may compromise splanchnic perfusion. A new retractor method may be less traumatic. Accordingly, 30 ASA physical status I or II patients undergoing laparoscopic cholecystectomy were randomly allocated to a CO2 pneumoperitoneum (IAP 12-13 mm Hg) (control) or to a gasless abdominal wall lift method (retractor) group. Anesthesia and intravascular fluids were standardized. Direct mean arterial pressure (MAP), urine output, urine-N-acetyl-beta-D-glucosaminidase (U-NAG), arterial blood gases, gastric mucosal PCO2, and intramucosal pH (pHi) were measured. Normoventilation was instituted in all patients. MAP increased (P < 0.001) only with CO2 pneumoperitoneum. Minute volume of ventilation had to be increased by 35% with CO2 insufflation. PaCO2 was significantly higher (P < 0.05) for 3 h postoperatively in the control group. Diuresis was less (P < 0.01) and U-NAG levels (P < 0.01) higher in the control group. The pHi decreased after induction of pneumoperitoneum up to three hours postoperatively and remained intact in the retractor group. We conclude that the retractor method for laparoscopic cholecystectomy ensures stable hemodynamics, prevents respiratory acidosis, and provides protection against biochemical effects, which reveal the renal and splanchic ischemia caused by CO2 insufflation. Implications: A mechanical retractor method (gasless) was compared with conventional CO2 pneumoperitoneum for laparoscopic cholestectomy. The gasless method ensured stable hemodynamics, prevented respiratory acidosis, and provided protection against the renal and splanchnic ischemia seen with CO2 pneumoperitoneum.
Low pressure pneumoperitoneum appears effective in decreasing pain after laparoscopic cholecystectomy. The safety of low pressure pneumoperitoneum has to be established.