Objective To evaluate the influence on the estimation of respiratory mechanics with dynamic signal analysis approach during noninvasive positive pressure ventilation (NPPV) under different inspiratory effort conditions. Methods The Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in healthy adults with body weight from 65 to 70 kg, and patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress (ARDS). Each lung models was subjected to 4 different muscle pressures (Pmus): 0, 5.0, 10.0, and 15.0 cm H2O. Inspiratory pressure support level was adjusted to maintain tidal volume (VT) achieving 7.0 mL/kg outputted by ventilator respectively. Positive end expiratory pressure was set at 5.0 cm H2O and back-up rate was 10 beats per minute. Measurements were conducted at system leaks with 25 to 28 L/min. The respiratory system compliance (Crs), inspiratory and expiratory resistance (Rinsp and Rexp) were estimated by special equations, which was derived from the exhaled VT, flow rate and airway pressure. Results The driving pressure (DP) was decreased with Pmus increasing, and was 1.0 cm H2O after Pmus exceeding 10.0 cm H2O and the VT was larger than 7.0 mL/kg in normal adult model. The estimated value of Crs was affected by the changes of Pmus in all three lung models. The significant underestimation of Raw and the overestimation of Crs were observed when Pmus level exceed 10.0 cm H2O. The measured errors of Crs and Rexp were within 10% in COPD and ARDS model when Pmus was at 5.0 cm H2O. The underestimation of Rinsp was always existed in all Pmus level (P<0.01). Conclusions Using dynamic signal analysis approach, the real-time estimation of respiratory mechanics (Crs and Raw) is no need to interrupt the spontaneous breathing during NPPV. Excessive effort will increase the patient’s inspiratory workload, which is not benefit to accurate estimation of respiratory mechanics.
ObjectivesTo systematically review the efficacy and safety of 3D laparoscopic in the treatment of colorectal cancer.MethodsPubMed, EMbase, The Cochrane Library, CBM, VIP, WanFang Data and CNKI databases were electronically searched online to collect clinical trials of 3D laparoscopic in the treatment of colorectal cancer from inception to September 1st, 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 software.ResultsA total of 26 trials, including 4 randomized controlled trials and 22 cohort studies were included. The results of meta-analysis showed that: compared with 2D laparoscopic, 3D laparoscopic had shorter operative time (MD=–16.32, 95%CI –22.61 to –10.03, P<0.000 01), less amount of blood transfusion in operation (MD=–10.80, 95%CI –19.93 to –1.66, P=0.02), more lymph node dissection (MD=0.88, 95%CI 0.30 to 1.45, P=0.003), shorter recovery time of gastrointestinal function (MD=–0.18, 95%CI –0.31 to –0.04, P=0.01), lower incidence of postoperative complication (OR=0.63, 95%CI 0.44 to 0.89, P=0.009), and fewer days in hospital (MD=–0.84, 95%CI –1.40 to –0.28, P=0.003). Additionally, there was no significant difference in hospitalization costs (MD=–0.01, 95%CI –0.23 to 0.21, P=0.94).ConclusionsCurrent evidence shows that, compared with 2D laparoscopy, 3D laparoscopy assisted colorectal cancer surgery has obvious advantages such as less bleeding during operation, shorter operation time, lower incidence of complications after operation, shorter hospitalization time and no increase in hospitalization expenses. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.