Estimation of the difference between peritoneal microenvironment and core body temperature during laparoscopic surgery - a prospective observational study.

Maintaining patients' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th-75th percentile: 0.2-0.8] °C at the beginning to 2.3 [2.1-2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects.Trial registration: Clinicaltrials.gov: NCT04294758.

[The role of magnesium sulfate in providing hemodynamic stability in patients undergoing laparoscopic surgery: a prospective randomized controlled study]. / Intérêt du sulfate de magnésium pour la stabilitée hémodynamique en cœliochirurgie: étude prospective contrôlée randomisée.

Introduction: during laparoscopic surgery, carbon dioxide (CO2) insufflation to create pneumoperitoneum increases blood pressure, heart rate and systemic vascular resistance. The purpose of our study was to investigate the efficacy of magnesium sulfate in preventing adverse hemodynamic reactions associated with pneumoperitoneum in patients undergoing laparoscopic cholecystectomy. Methods: we conducted a prospective, randomized, double-blind, controlled clinical study of patients scheduled for laparoscopic cholecystectomy and divided into two equal groups: the Mg2+ group received slow intravenous magnesium sulfate 50 mg/kg injection prior to pneumoperitoneum insufflation while the S group received the same volume of 0.9 % saline. Our primary endpoint was intraoperative changes in systolic blood pressure (SBP) related to pneumoperitoneum, in particular at 1 minute after insufflation. The secondary endpoints were the haemodynamic effects of pneumoperitoneum in terms of systolic blood pressure (SP), diastolic blood pressure (DP), mean arterial pressure (MAP) and heart rate (HR) from 2 minutes after insufflation to extubation and postoperatively, and the presence of possible adverse reactions related to the administration of magnesium sulphate. Results: we included 70 patients divided into two groups of 35. SP was significantly higher in the S group at insufflation (T0), 3 min, 4 min and 5 min post-operative, and at 60 min after surgery. HR was significantly higher in patients in the S group compared to the Mg2+ group at 7 min and 8 min after insufflation. No significant differences in DP and MAP measurements were observed between the 2 groups. No adverse reactions related to magnesium administration were reported. Conclusion: magnesium sulfate administered prior to pneumoperitoneum insufflation provided improved intraoperative hemodynamic stability during laparoscopic surgery.

A systematic review and meta-analysis compared the safety and effectiveness of the AirSeal system with traditional pneumoperitoneum systems in robot-assisted laparoscopic urologic surgery.

This study aimed to analyze perioperative results in robot-assisted laparoscopic urological surgeries, comparing the AirSeal system with traditional pneumoperitoneum systems. This study adhered to the PRISMA guidelines for conducting systematic reviews and meta-analyses. Extensive searches were conducted in PubMed, EMBASE, and Google Scholar, including randomized controlled trials (RCTs) and cohort studies up to June 15, 2024. A combined examination of the studies found that the AirSeal system had superior results in terms of surgery duration, end-tidal carbon dioxide levels, and tidal volume compared to the traditional pneumoperitoneum system. During robotic-assisted partial nephrectomy, the AirSeal team experienced a notable decrease in surgical time, ETCO2, and VT. In addition, the occurrence of SCE was lower in the AirSeal group. However, there were no significant differences observed between the groups regarding EBL, LOHS, overall complications, and major complications. Compared to conventional pneumoperitoneum systems, the AirSeal system offers several advantages in robot-assisted laparoscopic urological surgery: reduced operative time, lower end-tidal CO2 pressure, and decreased tidal volume. Furthermore, implementing the AirSeal system does not lead to higher rates of complications, estimated blood loss, or lengthier hospital stays.

Evaluation of surgical condition during laparoscopic gynaecological surgery in patients with moderate vs. deep neuromuscular block in low-pressure pneumoperitoneum.

INTRODUCTION: The significant effect of deep neuromuscular block (NMB) in laparoscopic surgery is still controversial, especially in lower-pressure pneumoperitoneum. This study investigates the effect of deep neuromuscular block on intraabdominal pressure (IAP), surgical space quality, post-operative abdominal pain, and shoulder tip pain in laparoscopic gynaecological surgery. MATERIAL AND METHODS: This is a randomised, double-blinded control trial which randomised samples to moderate NMB (train-of-four count [TOF] of 1 or 2) or deep NMB (post-tetanic count [PTC] of 1 or 2). Surgery began with IAP 8 mmHg but was allowed to increase the pressure if the surgical condition was unfavourable. The surgical condition was rated on a 4-point scale. Post-operative abdominal pain and shoulder tip pain was assessed using a numerical rating scale for pain, with 0 defined as no pain and 10 severe pain at recovery area (time 0), 30 minutes, and 24 hours post-operation. RESULTS: Seventy patients completed the study. The rate of increasing IAP between the 2 groups ( P = 0.172) is not significant, but deep NMB requires less pressure - mean highest IAP of 10.31 (± 1.39) mmHg, moderate NMB 11.54 (± 1.69) mmHg. The mean surgical space condition score was significantly better in the deep NMB group at 2.4 (± 0.7) compared to moderate NMB at 3.2 (± 0.66), P < 0.005. There was a significantly lower post-operative abdominal pain score in deep NMB but no significant difference in shoulder tip pain score between the 2 groups. CONCLUSIONS: Deep NMB enables the usage of lower IAP in laparoscopic surgery without interfering with surgical space condition, and it reduces the post-operative abdominal pain score in 24 hours compared to moderate NMB.

Recruitment-to-inflation ratio to assess response to PEEP during laparoscopic surgery: A physiologic study.

STUDY OBJECTIVE: During laparoscopic surgery, the role of PEEP to improve outcome is controversial. Mechanistically, PEEP benefits depend on the extent of alveolar recruitment, which prevents ventilator-induced lung injury by reducing lung dynamic strain. The hypotheses of this study were that pneumoperitoneum-induced aeration loss and PEEP-induced recruitment are inter-individually variable, and that the recruitment-to-inflation ratio (R/I) can identify patients who benefit from PEEP in terms of strain reduction. DESIGN: Sequential study. SETTING: Operating room. PATIENTS: Seventeen ASA I-III patients receiving robot-assisted prostatectomy during Trendelenburg pneumoperitoneum. INTERVENTIONS AND MEASUREMENTS: Patients underwent end-expiratory lung volume (EELV) and respiratory/lung/chest wall mechanics (esophageal manometry and inspiratory/expiratory occlusions) assessment at PEEP = 0 cmH2O before and after pneumoperitoneum, at PEEP = 4 and 12 cmH2O during pneumoperitoneum. Pneumoperitoneum-induced derecruitment and PEEP-induced recruitment were assessed through a simplified method based on multiple pressure-volume curve. Dynamic and static strain changes were evaluated. R/I between 12 and 4 cmH2O was assessed from EELV. Inter-individual variability was rated with the ratio of standard deviation to mean (CoV). MAIN RESULTS: Pneumoperitoneum reduced EELV by (median [IqR]) 410 mL [80-770] (p < 0.001) and increased dynamic strain by 0.04 [0.01-0.07] (p < 0.001), with high inter-individual variability (CoV = 70% and 88%, respectively). Compared to PEEP = 4 cmH2O, PEEP = 12 cmH2O yielded variable amount of recruitment (139 mL [96-366] CoV = 101%), causing different extent of dynamic strain reduction (median decrease 0.02 [0.01-0.04], p = 0.002; CoV = 86%) and static strain increases (median increase 0.05 [0.04-0.07], p = 0.01, CoV = 33%). R/I (1.73 [0.58-3.35]) estimated the decrease in dynamic strain (p ≤0.001, r = -0.90) and the increase in static strain (p = 0.009, r = -0.73) induced by PEEP, while PEEP-induced changes in respiratory and lung mechanics did not. CONCLUSIONS: Trendelenburg pneumoperitoneum yields variable derecruitment: PEEP capability to revert these phenomena varies significantly among individuals. High R/I identifies patients in whom higher PEEP mostly reduces dynamic strain with limited static strain increases, potentially allowing individualized settings.

Comparison of inflammatory markers in low-pressure pneumoperitoneum with deep neuromuscular block versus standard pressure pneumoperitoneum among patients undergoing laparoscopic cholecystectomy for gallstone disease: a randomized control trial.

BACKGROUND: Low-pressure pneumoperitoneum (LPP) is an attempt to improve laparoscopic surgery. Lower pressure causes lesser inflammation and better hemodynamics. There is a lack of literature comparing inflammatory markers in LPP with deep NMB to standard pressure pneumoperitoneum (SPP) with moderate NMB in laparoscopic cholecystectomy. METHODOLOGY: This was a single institutional prospective randomized control trial. Participants included all patients undergoing laparoscopic cholecystectomy for symptomatic gall stone disease. Participants were divided into 2 groups group A and B. Group A-Low-pressure group in which pneumoperitoneum pressure was kept low (8-10 mmHg) with deep Neuromuscular blockade (NMB) and Group B-Normal pressure group (12-14 mmHg) with moderate NMB. A convenience sample size of 80 with 40 in each group was selected. Lab investigations like CBC, LFT, RFT and serum IL-1, IL-6, IL-17, TNF alpha levels were measured at base line and 24 h after surgery and compared using appropriate statistical tests. Other parameters like length of hospital stay, post-operative pain score, conversion rate (low-pressure to standard pressure), and complications were also compared. RESULTS: Eighty participants were analysed with 40 in each group. Baseline characteristics and investigations were statistically similar. Difference (post-operative-pre-operative) of inflammatory markers were compared between both groups. Numerically there was a slightly higher rise in most of the inflammatory markers (TLC, ESR, CRP, IL-6, TNFα) in Group B compared to Group A but not statistically significant. Albumin showed significant fall (p < 0.001) in Group B compared to Group A. Post-operative pain was also significantly less (p < 0.001) in Group A compared to Group B at 6 h and 24 h. There were no differences in length of hospital stay and incidence of complications. There was no conversion from low-pressure to standard pressure. CONCLUSION: Laparoscopic cholecystectomy performed under low-pressure pneumoperitoneum with deep NMB may have lesser inflammation and lesser post-operative pain compared to standard pressure pneumoperitoneum with moderate NMB. Future studies with larger sample size need to be designed to support these findings.

Effect of cuff inflation with lidocaine, saline, and air on tracheal tube cuff pressure during laparoscopic resection of colorectal neoplasms: a randomized clinical trial.

BACKGROUND: Tracheal tube cuff pressure will increase after pneumoperitoneum when the cuff is inflated with air, high pressure can cause tracheal mucosal damage. This prospective trial aimed to assess if inflating with normal saline or lidocaine can prevent increase of tracheal tube cuff pressure and tracheal mucosal damage in laparoscopic surgeries with general anesthesia. Whether changes of tracheal tube cuff transverse diameter (CD) can predict changes of tracheal tube cuff pressure. METHODS: Ninety patients scheduled for laparoscopic resection of colorectal neoplasms under general anesthesia were randomly assigned to groups air (A), saline (S) or lidocaine (L). Endotracheal tube cuff was inflated with room-temperature air in group A (n = 30), normal saline in group S (n = 30), 2% lidocaine hydrochloride injection in group L (n = 30). After intubation, tracheal tube cuff pressure was monitored by a calibrated pressure transducers, cuff pressure was adjusted to 25 cmH2O (T0.5). Tracheal tube cuff pressure at 15 min after pneumoperitoneum (T1) and 15 min after exsufflation (T2) were accessed. CD were measured by ultrasound at T0.5 and T1, the ability of ΔCD (T1-0.5) to predict cuff pressure was accessed. Tracheal mucous injury at the end of surgery were also recorded. RESULTS: Tracheal tube cuff pressure had no significant difference among the three groups at T1 and T2. ΔCD had prediction value (AUC: 0.92 [95% CI: 0.81-1.02]; sensitivity: 0.99; specificity: 0.82) for cuff pressure. Tracheal mucous injury at the end of surgery were 0 (0, 1.0) in group A, 0 (0, 1.0) in group S, 0 (0, 0) in group L (p = 0.02, group L was lower than group A and S, p = 0.03 and p = 0.04). CONCLUSIONS: Compared to inflation with air, normal saline and 2% lidocaine cannot ameliorate the increase of tracheal tube cuff pressure during the pneumoperitoneum period under general anesthesia, but lidocaine can decrease postoperative tracheal mucosa injury. ΔCD measured by ultrasound is a predictor for changes of tracheal tube cuff pressure. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100054089, Date: 08/12/2021.

Anesthesiological and surgical perspectives on using 8 mmHg versus 12 mmHg pneumoperitoneum pressures during robotic radical prostatectomy: Results of a prospective randomized study.

BACKGROUND: This study aims to compare the effects of 8 mmHg and 12 mmHg pneumoperitoneum (PNP) pressures on operative, postoperative, and anesthesiological parameters in robot-assisted laparoscopic radical prostatectomy (RARP). METHODS: In this prospective study, 43 patients undergoing RARP performed by a single experienced surgeon were randomly assigned to either the low-pressure group (8 mmHg - Group I) or the standard-pressure group (12 mmHg - Group II). We evaluated the operative and postoperative parameters from both urological and anesthesiological perspectives. All patients were treated using the AirSeal® insufflation system. RESULTS: No statistically significant differences were observed between the groups in terms of console time, estimated blood loss, time to first flatus, or hospital length of stay. PNP was increased due to bleeding in six patients in the 8 mmHg group and two patients in the 12 mmHg group. Except for the heart rate measured five minutes after the initial incision, there were no observed differences between the groups in terms of blood pressure, ventilation, and administered medications. The heart rate was significantly lower in Group I (54.4 vs. 68.8, p=0.006). Additionally, during the surgery, the number of manipulations performed by the anesthesiologists, including drug administrations and ventilator management, was significantly lower in Group I (6.1 vs. 9.6, p=0.041). CONCLUSION: In RARP, while the 8 mmHg PNP pressure does not demonstrate differences in operative parameters compared to the 12 mmHg pressure, it offers the advantage of requiring fewer anesthetic interventions, thus minimizing the impact on cardiovascular and respiratory systems.

Low Pressure versus Standard Pressure Pneumoperitoneum in Laparoscopic Appendectomy: A Randomized Controlled Trial.

BACKGROUND: The creation of pneumoperitoneum using higher pressure is believed to be associated with increased postoperative abdominal pain. AIM: This study aimed to compare postoperative abdominal pain following low pressure laparoscopic appendectomy and standard pressure laparoscopic appendectomy. METHODS: This was a prospective, double-blind, randomized controlled trial of 54 patients aged between 18 and 56 years with clinical and/or radiologic diagnosis of acute appendicitis. The patients were randomly allocated to two groups: low pressure laparoscopic appendectomy (n = 26) and standard pressure laparoscopic appendectomy (n = 28). The intra-abdominal pressure was kept in either low pressure (9 mm Hg) or standard pressure (13 mm Hg). Abdominal and shoulder pain scores were assessed using the visual analog scale at 6 hours and 3 days post procedure. Postoperative analgesia requirement, duration of surgery, complications, and hospital stay were recorded. RESULTS: Both groups match for the demographic parameters. Three patients required conversion from low to standard pressure. There was no difference between the two groups in terms of abdominal pain (P = 0.86) and shoulder pain (P = 0.33), duration of surgery (P = 0.51), complications (P = 0.17), and length of hospital stay (P = 0.83). CONCLUSION: The use of low pressure pneumoperitoneum did not reduce the incidence of abdominal pain in patients who had laparoscopic appendectomy. Patients with acute appendicitis can be treated with either low or normal pressure pneumoperitoneum depending on the experience of the surgeon.

The impact of low pressure pneumoperitoneum in robotic assisted radical prostatectomy II: a prospective, randomized, double blinded trial.

OBJECTIVE: To analyze postoperative ileus rates and postoperative complications between the different pneumoperitoneum settings. The secondary objective was to evaluate narcotic use and intraoperative blood loss between the different pneumoperitoneum settings. METHODS: A prospective, randomized, double blinded study was conducted at pneumoperitoneum pressures of either 12 mmHg or 15 mmHg for patients undergoing robotic assisted radical prostatectomy with bilateral pelvic lymph node dissection by a single high volume surgeon. RESULTS: The risk of ileus in the 12 mmHg group was 1.9% (2/105) compared to 3.2% (3/93) in the 15 mmHg group (OR 0.58, 95%CI 0.1-3.6). There was no difference in the risk of any complication with a complication rate of 4.8% (5/105) in the 12 mmHg arm compared to 4.3% (4/93) in the 15 mmHg arm (OR 1.1, 95% CI 0.3 - 4.3). CONCLUSION: Pneumoperitoneum pressure setting of 12 mmHg has no significant difference to 15 mmHg in the rate of postoperative complications, narcotic use, and intraoperative bleeding. Additional research is warranted to understand the optimal.

Recovery and immune function after low pressure pneumoperitoneum during robot-assisted radical prostatectomy: a randomised controlled trial.

OBJECTIVE: To compare the effectiveness of low intra-abdominal pressure (IAP) facilitated by deep neuromuscular block (NMB) to standard practice in improving the quality of recovery, preserving immune function, and enhancing parietal perfusion during robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS: In this blinded, randomised controlled trial, 96 patients were randomised to the experimental group with low IAP (8 mmHg) facilitated by deep NMB (post-tetanic count 1-2) or the control group with standard IAP (14 mmHg) and moderate NMB (train-of-four 1-2). Recovery was measured using the 40-item Quality of Recovery questionnaire and 36-item Short-Form Health survey. Immune function was evaluated by plasma damage-associated molecular patterns, cytokines, and ex vivo lipopolysaccharide-stimulated cytokine production. Parietal peritoneum perfusion was measured by analysing the recordings of indocyanine-green injection. RESULTS: Quality of recovery was not superior in the experimental group (n = 46) compared to the control group (n = 50). All clinical outcomes, including pain scores, postoperative nausea and vomiting, and hospital stay were similar. There were no significant differences in postoperative plasma concentrations of damage-associated molecular patterns, cytokines, and ex vivo cytokine production capacity. The use of low IAP resulted in better parietal peritoneum perfusion. CONCLUSION: Despite better perfusion of the parietal peritoneum, low IAP facilitated by deep NMB did not improve the quality of recovery or preserve immune function compared to standard practice in patients undergoing RARP.

Use of mixed gas pneumoperitoneum during minimally invasive surgery: a systematic review of human and mouse modelled laparoscopic interventions.

The formation of pneumoperitoneum involves the process of inflating the peritoneal cavity during laparoscopic and typically uses CO2 as the insufflation gas. This review aims to identify ideal gas mixtures for establishing the pneumoperitoneum with animal and human studies undertaken up to the writing of this review. A systematic search of PubMed, OVID, and clinicaltrials.gov was performed to identify studies on the utilisation of mixed gases in laparoscopic surgery, including non-randomised/randomised trials, animal and human studies, and studies with inflating pressures between 12 and 16 mmHg. ROBINS-I and RoB2 tool was used to assess the risk of bias. A narrative synthesis of results was performed due to the heterogeneity of the studies. 5 studies from the database search and 5 studies from citation search comprising 128 animal subjects and 61 human patients were found. These studies collated results based on adhesion formation (6 studies), pain scores (2 studies) and other outcomes, with results favouring the use of carbon dioxide + 10% nitrous oxide + 4% oxygen. This has shown a significant reduction in adhesion formation, pain scores and inflammation. The use of this gas mixture provides promising results for future practice. Several of the studies available require larger sample sizes to develop a more definitive answer on the effects of different gas mixtures. Furthermore, the number of confounding factors in randomised trials should be reduced so that each component of the current suggested gas mixture can be tested for safety and efficacy.

Toxina botulínica y neumoperitoneo secuencial en el manejo de hernia inguinoescrotal gigante: Reporte de caso / Botulinum toxin and sequential pneumoperitoneum in the management of giant inguinoscrotal hernia: Case report

Introducción. Las hernias gigantes con pérdida de domicilio son aquellas cuyo saco herniario alcanza el punto medio del muslo en bipedestación y su contenido excede el volumen de la cavidad abdominal. Estas hernias son un reto quirúrgico dada la difícil reducción de su contenido y del cierre primario de la fascia. Tienen mayor riesgo de complicaciones asociadas al síndrome compartimental abdominal, así como mayor tasa de recurrencia y morbilidad en los pacientes. Caso clínico. Paciente masculino de 81 años, reconsultante por hernia inguinoescrotal derecha gigante, de dos años de evolución, sintomática, con índice de Tanaka de 24 %. Se decidió aplicar el protocolo de neumoperitoneo secuencial (hasta 11.000 ml en total en cavidad) además de toxina botulínica en pared abdominal (dos sesiones). Resultados. Se logró la corrección exitosa de la hernia inguinoescrotal gigante, sin recaídas de su patología abdomino-inguinal. El paciente manifestó satisfacción con el tratamiento un año después del procedimiento. Conclusiones. El protocolo de neumoperitoneo secuencial es una alternativa en casos de hernias complejas, con alto riesgo de complicaciones, que requieren técnicas reconstructivas adicionales. La aplicación previa de toxina botulínica es un adyuvante considerable para aumentar la probabilidad de resultados favorables. Sin embargo, debe incentivarse la investigación en esta área para evaluar su efectividad.

Introduction. Giant hernias with loss of domain are those whose hernial sac reaches the midpoint of the thigh in standing position and whose content exceeds the volume of the abdominal cavity. These hernias are a surgical challenge given the difficult reduction of their contents and the primary fascial closure, with a higher risk of complications associated with abdominal compartment syndrome, as well as a higher rate of recurrence and morbidity in patients. Clinical case. A 81-year-old male patient with comorbidity, reconsulting due to a symptomatic giant right inguinoscrotal hernia of two years of evolution, with a Tanaka index of 24%, eligible for a sequential pneumoperitoneum protocol (up to a total of 11,000 cc in cavity) plus application of botulinum toxin (two sessions) in the abdominal wall. Results. Successful correction of the patient's giant inguinoscrotal hernia was achieved using this protocol, without recurrence of his abdomino-inguinal pathology and satisfaction with the procedure after one year. Conclusion. The sequential pneumoperitoneum protocol continues to be an important alternative in cases with a high risk of complications that require additional reconstructive techniques, while the previous application of botulinum toxin is a considerable adjuvant to further increase the rate of favorable results. However, research in the area should be encouraged to reaffirm its effectiveness.

Low Pneumoperitoneum Pressure Reduces Gas Embolism During Laparoscopic Liver Resection: A Randomized Controlled Trial.

OBJECTIVE: To compare the effect of low and standard pneumoperitoneal pressure (PP) on the occurrence of gas embolism during laparoscopic liver resection (LLR). BACKGROUND: LLR has an increased risk of gas embolism. Although animal studies have shown that low PP reduces the occurrence of gas embolism, clinical evidence is lacking. METHODS: This parallel, dual-arm, double-blind, randomized controlled trial included 141 patients undergoing elective LLR. Patients were randomized into standard ("S," 15 mm Hg; n = 70) or low ("L," 10 mm Hg; n = 71) PP groups. Severe gas embolism (≥ grade 3, based on the Schmandra microbubble method) was detected using transesophageal echocardiography and recorded as the primary outcome. Intraoperative vital signs and postoperative recovery profiles were also evaluated. RESULTS: Fewer severe gas embolism cases (n = 29, 40.8% vs n = 47, 67.1%, P = 0.003), fewer abrupt decreases in end-tidal carbon dioxide partial pressure, shorter severe gas embolism duration, less peripheral oxygen saturation reduction, and fewer increases in heart rate and lactate during gas embolization episodes was found in group L than in group S. Moreover, a higher arterial partial pressure of oxygen and peripheral oxygen saturation were observed, and fewer fluids and vasoactive drugs were administered in group L than in group S. In both groups, the distensibility index of the inferior vena cava negatively correlated with central venous pressure throughout LLR, and a comparable quality of recovery was observed. CONCLUSIONS: Low PP reduced the incidence and duration of severe gas embolism and achieved steadier hemodynamics and vital signs during LLR. Therefore, a low PP strategy can be considered a valuable choice for the future LLR.

Intraoperative effects of an alveolar recruitment manoeuvre in patients undergoing laparoscopic colon surgery.

INTRODUCTION: Pulmonary atelectasis is common in patients undergoing laparoscopic abdominal surgery under general anaesthesia, which increases the risk of perioperative respiratory complications. Alveolar recruitment manoeuvres (ARM) are used to open up the lung parenchyma with atelectasis, although the duration of their benefit has not been clearly established. The aim of this study was to determine the effectiveness of an ARM in laparoscopic colon surgery, the duration of response over time, and its haemodynamic impact. METHODS: Twenty-five patients undergoing laparoscopic colon surgery were included. After anaesthetic induction and initiation of surgery with pneumoperitoneum, an ARM was performed, and then optimal PEEP determined. Respiratory mechanics and gas exchange variables, and haemodynamic parameters, were analysed before the manoeuvre and periodically over the following 90 min. RESULTS: Three patients were excluded for surgical reasons. The alveolar arterial oxygen gradient went from 94.3 (62.3-117.8) mmHg before to 60.7 (29.6-91.0) mmHg after the manoeuvre (P < .05). This difference was maintained during the 90 min of the study. Dynamic compliance of the respiratory system went from 31.3 ml/cmH2O (26.1-39.2) before the manoeuvre to 46.1 ml/cmH2O (37.5-53.5) after the manoeuvre (P < .05). This difference was maintained for 60 min. No significant changes were identified in any of the haemodynamic variables studied. CONCLUSION: In patients undergoing laparoscopic colon surgery, performing an intraoperative ARM improves the mechanics of the respiratory system and oxygenation, without associated haemodynamic compromise. The benefit of these manoeuvres lasts for at least one hour.

Impact of the combination of abdominal peripheral nerve block and neuromuscular blockade on the surgical space during robot-assisted laparoscopic surgery: a prospective randomized controlled study.

PURPOSE: The impact of the combination of abdominal peripheral nerve block (PNB) and the depth of neuromuscular blockade on the surgical field were assessed. METHODS: Thirty-eight patients undergoing elective robot-assisted laparoscopic radical prostatectomy (RARP) were randomized into two groups: a PNB group (moderate neuromuscular block [train-of-four 1-3 twitches] with abdominal PNB) and a non-PNB group (deep neuromuscular block [post-tetanic count 0-2 twitches] without abdominal PNB). The primary outcome was the change in the depth of the abdominal cavity relaxation assessed by the change in the distance (Δdistance) between the umbilicus port and peritoneum upon pneumoperitoneal pressure increase from 8 to 12 mmHg. The secondary outcomes were the CO2 usage for the pneumoperitoneal pressure increase and the subjective differences in the Surgical Rating Score (SRS) during surgery. RESULTS: The Δdistance and the CO2 usage from 8 to 12 mmHg did not differ significantly between the non-PNB and PNB groups (1.34 ± 0.65 vs. 1.28 ± 0.61 cm, p = 0.763 and 3.64 ± 1.68 vs. 4.34 ± 1.44 L, p = 0.180, respectively). There was also no significant difference in SRS. Comparisons of the Δdistance values for pressure increases from 6 to 8 mmHg, 6 to 10 mmHg and 6 to 12 mmHg between the non-PNB and PNB groups also showed no between-group differences, despite significant intra-group differences (p < 0.001) by pressure increment. CONCLUSIONS: Our findings indicate that moderate neuromuscular block with abdominal PNB maintained an adequate surgical space for RARP, with no significant difference from the space achieved by deep neuromuscular block.

Prospective, randomized, clinical trial on the effects of laparoscopic insufflation pressures on portal pressures in dogs.

OBJECTIVE: The adverse effects of intra-abdominal pressure from capnoperitoneum on cardiovascular and pulmonary systems have been well documented, but the effects on portal pressures in dogs with various insufflation pressures is poorly defined. The aim of the present study was to measure the effect of a range of insufflation pressures on the portal pressure, using direct pressure measurements in patients undergoing laparoscopy. STUDY DESIGN: Clinical randomized prospective study. ANIMALS: Nine client-owned dogs undergoing routine laparoscopy. METHODS: Two rounds of direct portal pressure assessments were performed, at insufflation pressures of 0, 6, 10, and 14 mmHg in a predetermined randomized sequence. The data were analyzed for effects of insufflation pressure, hemodynamic alterations, and round. A best-fit exponential model of the relationship between portal pressure and insufflation pressure was created. RESULTS: Portal pressure increased by 38% at 6 mmHg, 95% at 10 mmHg, and 175% at 14 mmHg compared to baseline. Portal pressure increased at an average rate of 7.45% per mmHg of insufflation pressure. Effects of weight, weight/insufflation pressure interaction, and round of insufflation were not statistically significant. No systemic hemodynamic adverse events were observed. CONCLUSION: Portal pressure increased as insufflation pressure increased. There was no clinically significant difference in baseline portal pressure between rounds of insufflation. CLINICAL SIGNIFICANCE: This exponential model of portal pressure supports the use of the minimum insufflation pressure to allow visualization during laparoscopy. The return of portal pressure to baseline following desufflation supports the comparison of portal pressure measurements before and after laparoscopic shunt attenuation.

Comparison of a Valveless Trocar System and Conventional Insufflation in Pediatric Urologic Surgery.

Background: Conventional operative insufflation uses a one-way trocar to handle instruments while maintaining pneumoperitoneum. In 2007, the AirSeal® valveless trocar insufflation system was introduced, which maintains stable pneumoperitoneum while continuously evacuating smoke. Although this device has been validated in adult patients, it has not been extensively validated in the pediatric population. Materials and Methods: A retrospective cohort study of pediatric urology patients aged 0 to 21 who underwent laparoscopic pyeloplasty between March 2016 and October 2021 was performed. Intraoperative physiologic parameters, procedure characteristics, postoperative outcomes, and demographics of each patient in whom either AirSeal insufflation system (AIS) or conventional insufflation system (CIS) was utilized were obtained from hospital records. Data were compared across the AIS and CIS cohorts. The primary outcomes were intraoperative anesthetic and physiologic parameters, including end tidal carbon dioxide, oxygen saturation, body temperature, positive inspiratory pressure, systolic blood pressure, and heart rate. Results: There were no significant differences in the anesthetic and physiologic parameters in the AIS and CIS groups. In addition, no differences in demographics, procedural characteristics, or complication rates were found between the cohorts. Conclusion: The AirSeal valveless trocar insufflation system demonstrates comparable intraoperative anesthetic and physiologic outcomes compared to conventional one-way valve insufflation in pediatric laparoscopic pyeloplasty. Certain surgeon-related qualitative metrics are underappreciated in this study, however, including improved visualization with vigorous suctioning and pressure maintenance with frequent instrument exchanges. Surgeon experience may mask the benefits of these characteristics as it pertains to quantitative surgical outcomes such as estimated blood loss, operative time, and perioperative complications.

Impact of Standard Versus Low Pneumoperitoneum Pressure on Peritoneal Environment in Laparoscopic Cholecystectomy. Randomized Clinical Trial.

BACKGROUND: High CO 2 pneumoperitoneum pressure during laparoscopy adversely affects the peritoneal environment. This study hypothesized that low pneumoperitoneum pressure may be linked to less peritoneal damage and possibly to better clinical outcomes. MATERIALS AND METHODS: One hundred patients undergoing scheduled laparoscopic cholecystectomy were randomized 1:1 to low or to standard pneumoperitoneum pressure. Peritoneal biopsies were performed at baseline time and 1 hour after peritoneum insufflation in all patients. The primary outcome was peritoneal remodeling biomarkers and apoptotic index. Secondary outcomes included biomarker differences at the studied times and some clinical variables such as length of hospital stay, and quality and safety issues related to the procedure. RESULTS: Peritoneal IL6 after 1 hour of surgery was significantly higher in the standard than in the low-pressure group (4.26±1.34 vs. 3.24±1.21; P =0.001). On the contrary, levels of connective tissue growth factor and plasminogen activator inhibitor-I were higher in the low-pressure group (0.89±0.61 vs. 0.61±0.84; P =0.025, and 0.74±0.89 vs. 0.24±1.15; P =0.028, respectively). Regarding apoptotic index, similar levels were found in both groups and were 44.0±10.9 and 42.5±17.8 in low and standard pressure groups, respectively. None of the secondary outcomes showed differences between the 2 groups. CONCLUSIONS: Peritoneal inflammation after laparoscopic cholecystectomy is higher when surgery is performed under standard pressure. Adhesion formation seems to be less in this group. The majority of patients undergoing surgery under low pressure were operated under optimal workspace conditions, regardless of the surgeon's expertise.