Utilization of deep neuromuscular blockade combined with reduced abdominal pressure in laparoscopic radical gastrectomy for gastric cancer: An academic perspective.

BACKGROUND: Few studies have examined the specific efficacy of deep neuromuscular blockade (NMB) combined with pneumoperitoneal pressure reduction in laparoscopic radical gastrectomy (LRG) in the elderly. AIM: To investigate the application effect of deep neuromuscular blockade (NMB) combined with reduced pneumoperitoneum pressure in LRG for gastric cancer (GC) in elderly patients and its influence on inflammation. METHODS: Totally 103 elderly patients with GC treated in our hospital between January 2020 and January 2022 were retrospectively analyzed. Among them, 45 patients treated with surgery based on deep NMB and conventional pneumoperitoneum pressure were assigned to the control group, while the rest of the 58 patients who underwent surgery based on deep NMB and reduced pneumoperitoneum pressure were assigned to the observation group. The two groups were compared in the changes of the Leiden-surgical rating scale score, serum tumor necrosis fact-α (TNF-α) and interleukin 6 (IL-6) before and after therapy. The visual analogue scale (VAS) was adopted for evaluating the shoulder pain of patients at 8 h, 24 h and 48 h after the operation. The driving pressure of the two groups at different time points was also compared. Additionally, the operation time, pneumoperitoneum time, infusion volume, blood loss, extubation time after surgery, residence time in the resuscitation room, TOF% = 90% time and post-anesthetic recovery room (PACU) stay time were all recorded, and adverse PACU-associated respiratory events were also recorded. The postoperative hospitalization time and postoperative expenses of the two groups were counted and compared. RESULTS: No significant difference was found between the two groups at the time of skin incision, 60 minutes since the operation and abdominal closure after surgery (P > 0.05). The observation group exhibited significantly lower VAS scores than the control group at 24 and 48h after surgery (P < 0.05). Additionally, the observation group had significantly lower driving pressure than the control group at 5 min and 60 min after the establishment of pneumoperitoneum (P < 0.05). Additionally, the two groups were similar in terms of the operation time, pneumoperitoneum time, infusion volume, blood loss, extubation time after surgery, residence time in the resuscitation room and TOF% = 90% time (P > 0.05), and the observation group showed significantly lower TNF-α and IL-6 Levels than the control group at 24 h after therapy (P < 0.05). Moreover, the incidence of adverse events was not significantly different between the two groups (P > 0.05), and the observation group experienced significantly less hospitalization time and postoperative expenses than the control group (P < 0.05). CONCLUSION: Deep NMB combined with reduced pneumoperitoneum pressure can decrease the VAS score of shoulder pain and inflammatory reaction, without hindering the surgical vision and increasing adverse PACU-associated respiratory events, and can thus shorten the hospitalization time and treatment cost for patient.

Low-Pressure Pneumoperitoneum During Laparoscopic Sleeve Gastrectomy: a Safety and Feasibility Analysis.

PURPOSE: Laparoscopy is advised under the lowest possible intra-peritoneal pressure. The aim of this study is to analyze the safety/feasibility of low pneumoperitoneum pressure (LPP) during laparoscopic sleeve gastrectomy (LSG). MATERIALS AND METHODS: All primary LSGs who completed a 3-month follow-up were included. Re-do operations and LSGs performed with concomitant procedures were excluded. All LSGs were performed by the senior author. Upon trocar insertions, pressure was set to 10 mmHg, and the procedure was started. The pressure was increased step-wise, according to the senior author's assessment of the quality of exposure. Doing so, three pressure groups were formed: groups 1 (10 mmHg), 2 (11-13 mmHg), and 3 (14 mmHg). All data was retrieved from our database. Statistical analysis was performed using one-way ANOVA/Tukey's HSD test/Chi-square test. P values < 0.05 were regarded as significant. RESULTS: Between February 2018 and October 2022, 708 consecutive/primary LSGs were studied. No mortality/conversion/thromboembolic event was observed. Groups 1, 2, and 3 comprised 376 (53.1%), 243 (34.3%), and 89 (12.6%) patients, respectively. Demographics, initial weight, duration of surgery, history for abdominoplasty, drain output, length of stay, and %total weight loss were evenly distributed among groups. Among 16 bleeding episodes, 14 occurred in the LPP group (p = 0.019). Including the only leak and stenosis, 8/9 of Clavien-Dindo 3b + 4 complications were observed in the LPP group (p = 0.092). CONCLUSIONS: LSG with LPP is feasible in about half of the patients. However, almost all potentially life-threatening complications occurred in the LPP group where a significantly higher rate of bleeding was observed. Our findings suggest caution for routinely using LPP during LSG.

Conjunctival congestion after laparoscopic operation in children: A retrospective case series in a single-centre children's medical centre.

Objective: In the present study, we report a retrospective analysis of 23 cases of conjunctival congestion after laparoscopic operation in children and try to explore the causes and intervention measures. Methods and Results: This is a retrospective, single-centre and observational study, and all patients with conjunctival congestion after laparoscopic operation admitted to our institution between August 2021 and December 2021 were included in this study. Records of 23 patients including 16 male patients and 7 female patients were retrospectively analysed. These patients were in the age group of 2-12 years. Their primary symptom was different degrees of conjunctival congestion, and the symptom onset was between 2 and 7 days after laparoscopic operation, including laparoscopic inguinal hernia repair, laparoscopic appendectomies, laparoscopic Meckel's diverticulectomy, laparoscopic removal of foreign body ingestions and laparoscopic choledochal cystectomy, and the duration of operations varies from 20 min to 255 min. The symptom disappeared from 5 to 21 days after the operation, and the duration of the symptom ranged from 2 to 14 days. A total of 1718 operations were performed, of which 461 were laparoscopic and 1257 were general operations, the incidence of conjunctival congestion after laparoscopic surgery was 23/461, and compared with 0/1257 after ordinary surgery, there was a significant difference between them. Of these 23 patients, 5 patients received no treatment and the other 18 patients were intervened with steroid-containing eye drops. Although eye drops containing steroids can significantly relieve eye discomfort, the duration of conjunctival congestion between the two groups (i.e. steroid-containing eye drop treated vs. non-steroid-containing eye drop treated) did not differ significantly. All patients recovered well. In the follow-up till the end of February 2022, no serious complications had occurred. Conclusion: Conjunctival congestion after laparoscopic operation is extremely rare in children, and the underlying causes are still unclear. We speculate that the pressure of pneumoperitoneum may be the main cause of this phenomenon. Symptoms may be self-limiting, and steroid-containing eye drops can relieve effectively the discomfort.

Laparoscopic surgery: A randomised controlled trial comparing intraoperative hemodynamic parameters and arterial-blood gas changes at two different pneumoperitoneal pressure values.

Background: The benefits of laparoscopic surgery are well known. However, clinic and metabolic consequences of pneumoperitoneum, achieved by insufflation of gas carbon dioxide, are still debated. Cardiovascular system suffering due to the compression of intra-abdominal venous structures can cause life-threatening complications. Increased partial pressure of carbon dioxide induces metabolic acidosis with further vascular suffering. Pneumoperitoneum reduces the pulmonary exchange volumes and bring renal suffering. Methods: The aim of this study is to evaluate the alterations in hemodynamic and hemogasanalysis parameters during the laparoscopic surgery at different pressure settings of pneumoperitoneum in order to assess the best pressure value.We evaluated and compared intraoperative hemodynamic and hemogasanalytic alterations in two groups of patients respectively subdue to laparoscopic cholecystectomy at a pneumoperitoneum pressure of 12 mmHg (group A) and at a pressure of 8 mmHg (group B). Results: In both groups, after the induction of anesthesia we observed a flexion in the heart rate, with no significant difference between the two groups. During the intervention, group A showed a significantly higher respiratory rate than the group B. The average blood pressure decreased mostly in group B. The oxygen saturation increased at the end of the procedure in group A, more than in the group B. The pH value was higher in group B. The hydrogen carbonate ion settled at lower levels in group A. Conclusion: Although significant differences between the two groups were appreciated on several parameters, they were never of such magnitude to prefer the induction of pneumoperitoneum at 8 mmHg.

Hemocoagulative Modifications after Laparoscopic Surgery at Different Pneumoperitoneum Pressure Settings.

Background: Many of the effects of pneumoperitoneum on cardiovascular, respiratory and metabolic systems have been discussed in Literature, but very little is known about the variations of the hemocoagulative parameters in patients undergoing laparoscopic surgery. The purpose of this study is to analyze the variations of the hemocoagulative parameters in patients undergoing elective laparoscopic cholecystectomy for symptomatic gallbladder stones. An eventual statistically significant difference linked to different pressure settings of pneumoperitoneum will allow selecting a specific intrabdominal pressure for a more adequate treatment with a lower incidence of pneumoperitoneum related complications. Materials and Methods: The clinical trial was conducted on 43 patients assigned in two groups based on the intra-abdominal pressure: group A, 27 patients, 12 mmHg, and group B, 16 patients, 8 mmHg. Hemoglobin, hematocrit, platelets count, PT ratio, aPTT, Fibrinogen, D-dimer, Von Willebrand factor, Factor II, Lupus Anticoagulant, Antithrombin III, Protein C, Protein S, Anticardiolipin IgG and IgM, anti-beta 2-Glicoprotein IgG and IgM were evaluated. Results: For group A, patient's variations were observed for D-dimer, Factor II, von Willembrand factor and protein C reactive, while for patients belonging to group B the parameters most affected were PT ratio, anti-thrombin III and protein C reactive.D-dimer values increased significantly in group A, a statistically significant decrease in anti-thrombin III levels was detected in group B, and a statistically significant difference in PT ratio in patients belonging to group B was observed. Conclusion: The statistical analysis showed no significant difference in the post-operative parameters when comparing the two groups of patients. Alterations of the coagulation parameters were present between pre- and post-operative data within the same group, namely a higher abdominal pressure is linked to a prothrombotic state. The question is worthy of further studies. Highlights: - Variations of the hemocoagulative parameters in patients undergoing laparoscopy are still a matter of study;- Pneumoperitoneum seems to cause alterations in the hemocoagulative parameters, which could be influenced by the pneumoperitoneum pressure;- An eventual statistically significant difference linked to different pressure settings of pneumoperitoneum will allow selecting a specific intrabdominal pressure for a more adequate surgical treatment with a lower incidence of pneumoperitoneum related complications.

Gas embolism under standard versus low pneumoperitoneum pressure during laparoscopic liver resection (GASES): study protocol for a randomized controlled trial.

BACKGROUND: Gas embolism induced by CO2 pneumoperitoneum is commonly identified as a risk factor for morbidity, especially cardiopulmonary morbidity, after laparoscopic liver resection (LLR) in adults. Increasing pneumoperitoneum pressure (PP) contributes to gas accumulation following laparoscopy. However, few studies have examined the effects of PP in the context of LLR. In LLR, the PP-central venous pressure (CVP) gradient is increased due to hepatic vein rupture, hepatic sinusoid exposure, and low CVP management, which together increase the risk of CO2 embolization. The aim of this study is to primarily determine the role of low PP (10 mmHg) on the incidence of severe gas embolism. METHODS: Adult participants (n = 140) undergoing elective LLR will be allocated to either a standard (15 mmHg) or low (10 mmHg) PP group. Anesthesia management, postoperative care, and other processes will be performed similarly in both groups. The occurrence of severe gas embolism, which is defined as gas embolism ≥ grade 3 according to the Schmandra microbubble method, will be detected by transesophageal echocardiography (TEE) and recorded as the primary outcome. The subjects will be followed up until discharge and followed up by telephone 1 and 3 months after surgery. Postoperative outcomes, such as the Post-Operative Quality of Recovery Scale, pain severity, and adverse events, will be assessed. Serum cardiac markers and inflammatory factors will also be assessed during the study period. The correlation between intraoperative inferior vena cava-collapsibility index (IVC-CI) under TEE and central venous pressure (CVP) will also be explored. DISCUSSION: This study is the first prospective randomized clinical trial to determine the effect of low versus standard PP on gas embolism using TEE during elective LLR. These findings will provide scientific and clinical evidence of the role of PP. TRIAL STATUS: Protocol version: version 1 of 21-08-2020 TRIAL REGISTRATION: ChiCTR2000036396 ( http://www.chictr.org.cn ). Registered on 22 August 2020.

Deep Neuromuscular Blockade Combined with Low Pneumoperitoneum Pressure for Nociceptive Recovery After Major Laparoscopic Gastrointestinal Surgery: Study Protocol for a Randomized Controlled Trial.

PURPOSE: Patients undergoing major laparoscopic surgery often experience significant pain and postoperative nausea and vomiting (PONV). Deep neuromuscular block (NMB) improves surgical conditions and facilitates the application of low intra-abdominal pressure (IAP), which may be beneficial for these patients. This study is designed to determine the effects of deep NMB combined with low IAP, as compared to moderate NMB combined with standard IAP, on patients' nociceptive recovery after major laparoscopic gastrointestinal surgery. STUDY DESIGN AND METHODS: This single-center randomized controlled trial will include 220 patients scheduled for major laparoscopic gastrointestinal surgery (lasts for ≥ 90 minutes). Patients will be randomly assigned, with a 1:1 ratio, into a deep NMB + low IAP group (train of four = 0, post-tetanic count = 1-3, IAP = 8 mmHg) and a moderate NMB + standard IAP group (train of four = 1-3, IAP = 12 mmHg). If the surgical workspace is inadequate, the surgeons can request a step increase of 1 mmHg in IAP during 3-min intervals. The upper limit of IAP will be set at 15 mmHg. Postoperative recovery will be assessed using the postoperative quality recovery scale (PQRS). The primary outcome of this trial is the PQRS nociceptive recovery (including pain and PONV) at postoperative day (POD) 1. The secondary outcomes include recovery in other PQRS domains at POD 1, and recovery in all PQRS domains in a post-anesthesia care unit, at POD 3 in the surgical wards, at hospital discharge, and at postoperative 30 days. For the sample size estimation, 110 patients in each group (220 in total) would be needed to detect an absolute increase rate of 20% in the PQRS nociceptive domain in the deep NMB + low IAP group at POD 1. DISCUSSION: This study investigates the effects of deep NMB combined with low IAP on postoperative PQRS nociceptive recovery in patients undergoing major laparoscopic gastrointestinal surgery. We expect that this deep NMB + low IAP strategy would improve postoperative pain and PONV following major laparoscopic gastrointestinal surgery.

A narrative review on the potential benefits and limitations of deep neuromuscular blockade.

BACKGROUND: Neuromuscular blockade was shown to improve surgical conditions. However, the risk of residual neuromuscular blockade upon extubation prevents anaesthesiologists from maintaining complete paralysis. For this reason, deep NMB is still underused in anaesthesia. This review focused on answering six questions revolving around the use of deep NMB versus moderate NMB. METHODS: This was a non-exhaustive narrative review based on 6 selected relevant questions: does deep NMB 1) improve surgical conditions? 2) reduce surgical complications? 3) facilitate a reduction in intraoperative pneumoperitoneum pressure (PnP)? 4) does a reduction in intraoperative PnP impact clinical outcomes? 5) does the combination of deep NMB and lower PnP improve respiratory parameters? 6) improve OR efficiency or readmission rates? RESULTS: This review highlights some of the key studies that have demonstrated potential benefits of deep NMB, but it also included reports showing no benefit, highlighting that the evidence is not unequivocal. Deep NMB does in fact improve surgical conditions, but whether this improvement translates into improved clinical outcomes is far from concluded. Indeed, there is an increased risk or residual curarisation, especially if patients are not monitored and reversed appropriately. The most important benefit of deep NMB may be the prevention of unacceptable surgical working conditions. The other potential major benefits are the reduction in PnP and reduction in pain. Deep NMB must be used with appropriate monitoring. CONCLUSION: Deep NMB was associated with an improvement in surgical conditions, reduction in PnP, pain, and complications; but further research is needed to definitively prove this relationship.

Serum cytokine levels as markers of paralytic ileus following robotic radical prostatectomy at different pneumoperitoneum pressures.

BACKGROUND: To evaluate intraoperative and postoperative cytokines in patients who underwent robotic prostatectomy (RP) at a pressure of 12 or 15 mm Hg, and the risk of postoperative ileus. MATERIALS AND METHODS: We presented the first series evaluating intraoperative and postoperative cytokines in patients undergoing RP at a pressure of 12 or 15 mm Hg by a single surgeon. Changes in cytokine concentrations were shown to correlate with surgical outcomes and pathological states. The study investigated the changes in cytokine concentrations (interferon-γ, tumor necrosis factor-α, interleukin-1ß [IL-1ß], IL-2, IL-4, IL-6, IL-12, and IL-17) at different pneumoperitoneum pressures and their potential role in the development of postoperative ileus. RESULTS: The data on 10 consecutive patients confirmed that a lower pneumoperitoneum pressure was associated with lower cytokine levels and a lower risk of ileus. There were increased levels of postoperative interferon-γ, tumor necrosis factor-α, IL-12p70, IL-1ß, IL-2, IL-4, and IL-17a at 15 mm Hg when compared to 12 mm Hg. CONCLUSIONS: The data indicated that lower pressure RP reduced intra-/postoperative cytokine levels confirming our hypothesis. Larger patient numbers are required to further validate this but the implications of this data will benefit not only urological patients but also other speciality patients undergoing minimally invasive surgery.

Randomized Controlled Comparison of Valveless Trocar (AirSeal) vs Standard Insufflator with Ultralow Pneuomoperitoneum During Robotic Prostatectomy.

Objective: To compare valveless insufflation (AirSeal®) with a conventional insufflation system (CIS) during robotic prostatectomy (RP) and the ability to use ultralow pneumoperitoneum at 6 mm Hg with each system as well as comparison of physiologic outcomes and pain scores. Patients and Methods: We conducted a prospective study of 100 patients randomized to AirSeal or CIS during RP. The frequency of need for increasing pneumoperitoneum was assessed as well as arterial blood gases, respiratory/hemodynamic parameters, pain scores, and analgesic requirements. Quality of smoke evacuation and scope cleaning frequency were also measured. Results: All procedures were completed at 6 mm Hg without needing to increase pressures with either insufflator. There were no statistically significant differences in partial pressure of carbon dioxide (PaCO2), partial pressure of oxygen (PaO2), HCO3, pH, carbon dioxide (CO2) elimination, or end-tidal carbon dioxide pressure (EtCO2) between groups. The AirSeal group had a lower maximum peritoneal pressure (7.9 vs 9.9 mm Hg, p < 0.001) but without differences in pain scores or analgesics. Surgeon-assessed smoke evacuation was poorer using CIS with more laparoscope cleanings in nonobese patients than with AirSeal (2.1 vs 3.0, p = 0.026). Conclusion: Valveless-trocar insufflation provided more stable pressure but without benefits in physiologic or pain parameters. Previously identified benefits may have been negated by being able to complete all procedures at ultralow pressure with either insufflator, although an expert bedside assistant moderating suction may have contributed to feasibility of maintaining low pressure with CIS. A randomized trial of 6 vs 15 mm Hg is currently underway. The ClinicalTrials.gov Identifier: NCT02114164.

Effect of pneumoperitoneum pressure and the depth of neuromuscular block on renal function in patients with diabetes undergoing laparoscopic pelvic surgery: study protocol for a double-blinded 2 × 2 factorial randomized controlled trial.

BACKGROUND: Patients with diabetes mellitus are at a high risk of developing postoperative acute kidney injury. For patients receiving laparoscopic surgery, standard-pressure pneumoperitoneum (SPP) currently applied in clinical practice also undermines renal perfusion. Several studies have shown that low-pressure pneumoperitoneum (LPP) might reduce pressure-related ischemic renal injury. However, LPP may compromise the view of the surgical field. Previous studies have indicated that deep neuromuscular blockade (NMB) can ameliorate this issue. However, the conclusion is still uncertain. The hypothesis of this study is that the joint use of LPP and deep NMB can reduce perioperative renal injury in diabetic patients undergoing laparoscopic pelvic surgery without impeding the view of the surgical field. METHODS: This is a double-blinded, randomized controlled trial using a 2 × 2 factorial trial design. A total of 648 diabetes patients scheduled for major laparoscopic pelvic surgeries at Peking Union Medical College Hospital will be randomized into the following four groups: SPP (12-15 mmHg) + deep-NMB (post-tetanic count of 1-2) group, LPP (7-10 mmHg) + deep-NMB group, SPP + moderate-NMB (train-of-four of 1-2) group, and LPP + moderate-NMB group. The primary outcome is serum cystatin C level measured before insufflation, after deflation, 24 h postoperatively, and 72 h postoperatively. The secondary outcomes are serum creatinine level, intraoperative urine output, erythrocytes in urinary sediment, renal tissue oxygen saturation, Leiden's surgical condition rating scale, surgery duration, and occurrence of bucking or body movement. DISCUSSION: This study will provide evidence for the effect of LPP on renal function protection in patients with diabetes undergoing laparoscopic pelvic surgery. The trial can also help us to understand whether deep NMB can improve surgical conditions. TRIAL REGISTRATION: ClinicalTrials.gov : NCT04259112 . Prospectively registered on 5 February 2020.

An individualised versus a conventional pneumoperitoneum pressure strategy during colorectal laparoscopic surgery: rationale and study protocol for a multicentre randomised clinical study.

BACKGROUND: A recent study shows that a multifaceted strategy using an individualised intra-abdominal pressure titration strategy during colorectal laparoscopic surgery results in an acceptable workspace at low intra-abdominal pressure in most patients. The multifaceted strategy, focused on lower to individualised intra-abdominal pressures, includes prestretching the abdominal wall during initial insufflation, deep neuromuscular blockade, low tidal volume ventilation settings and a modified lithotomy position. The study presented here tests the hypothesis that this strategy improves outcomes of patients scheduled for colorectal laparoscopic surgery. METHODS: The Individualized Pneumoperitoneum Pressure in Colorectal Laparoscopic Surgery versus Standard Therapy (IPPCollapse-II) study is a multicentre, two-arm, parallel-group, single-blinded randomised 1:1 clinical study that runs in four academic hospitals in Spain. Patients scheduled for colorectal laparoscopic surgery with American Society of Anesthesiologists classification I to III who are aged > 18 years and are without cognitive deficits are randomised to an individualised pneumoperitoneum pressure strategy (the intervention group) or to a conventional pneumoperitoneum pressure strategy (the control group). The primary outcome is recovery assessed with the Post-operative Quality of Recovery Scale (PQRS) at postoperative day 1. Secondary outcomes include PQRS score in the post anaesthesia care unit and at postoperative day 3, postoperative complications until postoperative day 28, hospital length of stay and process-related outcomes. DISCUSSION: The IPPCollapse-II study will be the first randomised clinical study that assesses the impact of an individualised pneumoperitoneum pressure strategy focused on working with the lowest intra-abdominal pressure during colorectal laparoscopic surgery on relevant patient-centred outcomes. The results of this large study, to be disseminated through conference presentations and publications in international peer-reviewed journals, are of ultimate importance for optimising the care and safety of laparoscopic abdominal surgery. Selection of patient-reported outcomes as the primary outcome of this study facilitates the translation into clinical practice. Access to source data will be made available through anonymised datasets upon request and after agreement of the Steering Committee of the IPPCollapse-II study. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02773173 . Registered on 16 May 2016. EudraCT, 2016-001693-15. Registered on 8 August 2016.

Oxidative damage and mitochondrial injuries differ following pneumoperitoneum pressure in rabbit models of varying degrees of hydronephrosis.

The influence of intraabdominal pressure which is necessary to maintain the operating area during the surgery cannot be ignored especially on the kidneys. Many articles have reported the effect of intraabdominal pressure on normal kidneys. However, the influence of intraabdominal pressure on hydronephrosis kidneys is rarely studied. The aim of the present study was to clarify whether intraabdominal pressure tolerance is modified in various degrees of kidney hydronephrosis by evaluating oxidative damage and mitochondrial injuries. A total of 72 rabbits were randomly divided into three groups (groups N, M and S, which represented rabbits with no, mild and severe hydronephrosis, respectively). Rabbits in groups M (n=24) and S (n=24) underwent a surgical procedure inducing mild or severe hydronephrosis, respectively. Subsequently, rabbits in all groups were allocated to 4 subgroups (N0­N3, M0­M3 and S0­S3) consisting of 6 rabbits each. Groups 0 to 3 were, respectively, subjected to intraabdominal pressures of 0, 5, 10 and 15 mmHg. Oxidative damage was assessed by analyzing levels of reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH­Px), catalase (CAT) and lactate (LD). Mitochondrial injuries were assessed based on mitochondrial membrane potential (MMP) alterations, mitochondrial structure and cytochrome c (cytc) protein expression, as measured by JC­1 staining, electron microscopy and western blotting, respectively. Oxidative damage and mitochondrial injuries were noticeably exacerbated in group N and M with increased levels of ROS, MDA and LD, decreased levels of SOD, GSH­Px, CAT and MMP, mitochondrial vacuolization and higher expression of cytc when the intraabdominal pressure reached 15 mmHg. In group S, these alterations occurred at pressures of 10 and 15 mmHg. Therefore, it was concluded that in rabbits exposed to pneumoperitoneal pressure, kidneys with severe hydronephrosis were more likely to suffer from oxidative damage and mitochondrial injuries compared with kidneys with mild hydronephrosis and normal kidneys.

Low vs standard pneumoperitoneum pressure during laparoscopic hysterectomy: prospective randomized trial.

STUDY OBJECTIVE: To compare the use of low pneumoperitoneum pressure (LPP; 8 mm Hg) vs standard pneumoperitoneum pressure (SPP; 12 mm Hg) during mini-laparoscopic hysterectomy (MLH). DESIGN: Randomized controlled trial (Canadian Task Force classification I). SETTING: Tertiary care center. PATIENTS: Forty-two consecutive women scheduled to undergo MLH to treat benign uterine disease. INTERVENTIONS: Women were randomly selected to undergo MLH using LPP (n = 20) or SPP (n = 22). MLH was performed via 3-mm ancillary ports. MEASUREMENTS AND MAIN RESULTS: The primary outcome was to evaluate changes in abdominal and shoulder-tip pain via a 100-mm visual analog scale at 1, 3, and 24 hours postoperatively. All procedures were completed via mini-laparoscopy without the need to increase intra-abdominal pressure or convert to conventional laparoscopy or open surgery. Intraoperatively, 1 episode of severe bradycardia occurred in the LPP group, whereas no intraoperative complications were recorded in the SPP group (p = .47). No postoperative complications were recorded (p > .99). Abdominal pain was similar between groups at each time point. Incidence and intensity of shoulder-tip pain at 1 and 3 hours postoperatively was lower in the LPP group than in the SPP group (p < .05), whereas no between-group differences were observed at 24 hours (p > .05). Rescue analgesic requirement did not differ statistically between the LPP and SPP groups (20% vs 41%, respectively; p = .19; odds ratio, 2.7; 95% confidence interval, 0.69-11.08). CONCLUSION: In experienced hands, use of LPP is safe and feasible. During performance of MLH, compared with SPP, LPP is a simple method that offers advantages of less shoulder-tip pain.