Surgery In Trendelenburg Position Research Articles

Effect of analgesia nociception index monitor-based nociception control on perioperative stress responses during laparoscopic surgery in Trendelenburg position: a randomized controlled trial.

The analgesia nociception index (ANI) monitor is a nociception monitoring device based on heart rate variability. We aimed to determine the effect of ANI monitor-based intraoperative nociception control on the perioperative stress response during laparoscopic surgery in the Trendelenburg position. Altogether, 72 female patients who underwent total laparoscopic hysterectomy were randomized to either the control or ANI group. Intraoperative nociception was controlled by remifentanil administration in a conventional manner (based on blood pressure and heart rate) in the control group and by ANI monitoring in the ANI group. Perioperative stress responses were estimated by measuring the levels of serum catecholamines and catabolic stress hormones at three timepoints: after loss of consciousness, at the end of surgery, and 1 h after the end of surgery. The serum cortisol level at the end of surgery was significantly higher in the ANI group than in the control group (p < 0.001), although more remifentanil was administered in the ANI group than in the control group (p < 0.001). Changes in the other estimators' levels were comparable between groups during the perioperative period. The hemodynamic profiles during surgery were also significantly different between the two groups. Phenylephrine use to treat hypotension was more common in the ANI group than in the control group (p = 0.005). However, postoperative clinical outcomes such as pain and nausea/vomiting did not differ between groups. ANI monitor-based nociception control in laparoscopic surgery in the Trendelenburg position did not improve perioperative stress responses, intraoperative opioid consumption, or postoperative clinical outcomes.Clinical trial registration: ClinicalTrials.gov (NCT04343638).

Effects of pneumoperitoneum and Trendelenburg position on intracranial pressure and cerebral blood flow assessed using transcranial doppler: A prospective observational study.

Laparoscopic lower abdominal surgeries involve carbon dioxide (CO2) insufflation and Trendelenburg position. The raised intra-abdominal pressure can increase intracranial pressure (ICP) and alter cerebral blood flow. This study was conducted to determine the effect of pneumoperitoneum and Trendelenburg position on ICP and cerebral perfusion pressure (CPP) measured using transcranial Doppler (TCD). A prospective observational study was conducted in 43 patients of either sex, aged between 18 and 60 years with American Society of Anesthesiologists physical status I and II, undergoing elective laparoscopic surgery in Trendelenburg position. After standard anesthesia induction, pneumoperitoneum was created to facilitate surgery, maintaining an intra-abdominal pressure of 10-15 mmHg and Trendelenburg position of 25°-30°. End-tidal carbon dioxide (EtCO2) was maintained between 30 and 35 mmHg. The ICP was assessed non-invasively using TCD-based diastolic flow velocities (FVd) and pulsatility index (PI) of middle cerebral artery. Data was represented as mean ± standard deviation and compared using paired t test. A P value of < 0.05 was considered significant. Mean ICPPI at baseline was 14.02 ± 0.89 mmHg which increased to 14.54 ± 1.21 mmHg at pneumoperitoneum and Trendelenburg position (P = 0.005). Mean ICPFVd at baseline was 6.25 ± 2.47 mmHg which increased to 8.64 ± 3.79 mmHg at pneumoperitoneum and Trendelenburg position (P < 0.001). There was no statistically significant change in the CPP or mean arterial pressure values intraoperatively. Laparoscopic procedures with CO2 pneumoperitoneum in Trendelenburg position increase ICP as measured using TCD ultrasonography. The CPP was not significantly altered when EtCO2 was maintained in the range of 30-35 mmHg.

Lung mechanics during video-assisted abdominal surgery in Trendelenburg position: a cross-sectional propensity-matched comparison between classic laparoscopy and robotic-assisted surgery

BackgroundVideo-assisted surgery has become an increasingly used surgical technique in patients undergoing major thoracic and abdominal surgery and is associated with significant perioperative respiratory and cardiovascular changes. The aim of this study was to investigate the effect of intraoperative pneumoperitoneum during video-assisted surgery on respiratory physiology in patients undergoing robotic-assisted surgery compared to patients undergoing classic laparoscopy in Trendelenburg position.MethodsTwenty-five patients undergoing robotic-assisted surgery (RAS) were compared with twenty patients undergoing classic laparoscopy (LAS). Intraoperative ventilatory parameters (lung compliance and plateau airway pressure) were recorded at five specific timepoints: after induction of anesthesia, after carbon dioxide (CO2) insufflation, one-hour, and two-hours into surgery and at the end of surgery. At the same time, arterial and end-tidal CO2 values were noted and arterial to end-tidal CO2 gradient was calculated.ResultsWe observed a statistically significant difference in plateau pressure between RAS and LAS at one-hour (26.2 ± 4.5 cmH2O vs. 20.2 ± 3.5 cmH2O, p = 0.05) and two-hour intervals (25.2 ± 5.7 cmH2O vs. 17.9 ± 3.1 cmH2O, p = 0.01) during surgery and at the end of surgery (19.9 ± 5.0 cmH2O vs. 17.0 ± 2.7 cmH2O, p = 0.02). Significant changes in lung compliance were also observed between groups at one-hour (28.2 ± 8.5 mL/cmH2O vs. 40.5 ± 13.9 mL/cmH2O, p = 0.01) and two-hour intervals (26.2 ± 7.8 mL/cmH2O vs. 54.6 ± 16.9 mL/cmH2O, p = 0.01) and at the end of surgery (36.3 ± 9.9 mL/cmH2O vs. 58.2 ± 21.3 mL/cmH2O, p = 0.01). At the end of surgery, plateau pressures remained higher than preoperative values in both groups, but lung compliance remained significantly lower than preoperative values only in patients undergoing RAS with a mean 24% change compared to 1.7% change in the LAS group (p = 0.01). We also noted a more significant arterial to end-tidal CO2 gradient in the RAS group compared to LAS group at one-hour (12.9 ± 4.5 mmHg vs. 7.4 ± 4.4 mmHg, p = 0.02) and two-hours interval (15.2 ± 4.5 mmHg vs. 7.7 ± 4.9 mmHg, p = 0.02), as well as at the end of surgery (11.0 ± 6.6 mmHg vs. 7.0 ± 4.6 mmHg, p = 0.03).ConclusionVideo-assisted surgery is associated with significant changes in lung mechanics after induction of pneumoperitoneum. The observed changes are more severe and longer-lasting in patients undergoing robotic-assisted surgery compared to classic laparoscopy.

Optimal Insertion Depth of Gastric Decompression Tube with a Thermistor for Patients Undergoing Laparoscopic Surgery in Trendelenburg Position.

Monitoring core temperature is crucial for maintaining normothermia during general anesthesia. Insertion of a gastric decompression tube (GDT) may be required during laparoscopic surgery. Recently, a newly designed GDT with a thermistor for monitoring esophageal temperature has been introduced. The purpose of the present study was to evaluate the optimal insertion depth of a GDT with a thermistor. Forty-eight patients undergoing elective laparoscopic surgery in the Trendelenburg position were included in the study. The GDT was inserted to a depth of nose-earlobe-xiphoid distance (NEX) + 12 cm and withdrawn sequentially, 2 cm at a time, at 5-min intervals. Temperatures of the GDT thermistor were compared with the core temperature of the tympanic membrane (TM) using Bland and Altman analysis. The correlation between optimal insertion depth of the GDT and anatomical distance (cricoid cartilage to the carina, CCD; carina to the left hemidiaphragm, CLHD) was evaluated, and a mathematical model to predict the optimal insertion depth of the GDT with a thermistor was calculated. Temperatures of TM and GDT thermistor at NEX + 4 cm showed good agreement and strong correlation, but better agreement and stronger correlation were seen at the actual location with the most minor temperature differences. The optimal insertion depth of the GDT was estimated as -15.524 + 0.414 × CCD - 0.145 × CLHD and showed a strong correlation with the actual GDT insertion depth (correlation coefficient 0.797, adjusted R2 = 0.636). The mathematical formula using CCD and CLHD would be helpful in determining the optimal insertion depth of a GDT with a thermistor.

Recruitable alveolar collapse and overdistension during laparoscopic gynecological surgery and mechanical ventilation: a prospective clinical study

BackgroundLaparoscopic surgery in Trendelenburg position may impede mechanical ventilation (MV) due to positioning and high intra-abdominal pressure. We sought to identify the positive end-expiratory pressure (PEEP) levels necessary to counteract atelectasis formation (“Open-Lung-PEEP”) and to provide an equal balance between overdistension and alveolar collapse (“Best-Compromise-PEEP”).MethodsIn 30 patients undergoing laparoscopic gynecological surgery, relative overdistension and alveolar collapse were assessed with electrical impedance tomography (EIT) during a decremental PEEP trial ranging from 20 to 4 cmH2O in supine position without capnoperitoneum and in Trendelenburg position with capnoperitoneum.ResultsIn supine position, the median Open-Lung-PEEP was 12 (8–14) cmH2O with 8.7 (4.7–15.5)% of overdistension and 1.7 (0.4–2.2)% of collapse. Best-Compromise-PEEP was 8 (6.5–10) cmH2O with 4.2 (2.4–7.2)% of overdistension and 5.1 (3.9–6.5)% of collapse. In Trendelenburg position with capnoperitoneum, Open-Lung-PEEP was 18 (18–20) cmH 2 O (p < 0.0001 vs supine position) with 1.8 (0.5–3.9)% of overdistension and 0 (0–1.2)% of collapse and Best-Compromise-PEEP was 18 (16–20) cmH2O (p < 0.0001 vs supine position) with 1.5 (0.7–3.0)% of overdistension and 0.2 (0–2.7)% of collapse. Open-Lung-PEEP and Best-Compromise-PEEP were positively correlated with body mass index during MV in supine position but not in Trendelenburg position.ConclusionThe PEEP levels required for preventing alveolar collapse and for balancing collapse and overdistension in Trendelenburg position with capnoperitoneum were significantly higher than those required for achieving the same goals in supine position without capnoperitoneum. Even with high PEEP levels, alveolar overdistension was negligible during MV in Trendelenburg position with capnoperitoneum.Trial registrationThis study was prospectively registered at German Clinical Trials registry (DRKS00016974).

Frequency of Positive Cuff Leak Test Before Extubation in Robotic Surgeries Done in Steep Trendelenburg Position.

Anaesthesia for robotic surgeries done in steep trendelenburgposition are associated with risks such as facial oedema, conjunctival chemosis, raised intraocular pressure, laryngeal oedema, and delayed awakening. We proposed the use of the cuff leak test in them to record the frequency of laryngeal oedema at the end of surgery and attempted to find its correlation with probable risk factors. We conducted a prospective observational study of 100 patients aiming primarily to assess the frequency of positive cuff leak test in robotic abdominal surgeries performed in trendelenburg position. The secondary outcomes were to check its correlation with intravenous fluid administration, duration of pneumoperitoneum, and angle of trendelenburg position. We also recorded the frequency of chemosis, the frequency of post-extubation stridor in 24h post-operatively, and the frequency of reintubation. Out of 100 participants undergoing elective abdominal robotic surgery in trendelenburg position, ninety were analysed. Total 31.6% (n = 30) participants showed positive cuff leak test. Chemosis was observed in 31 (32.6%) participants. No patient experienced post-extubation stridor or required reintubation during post-operative follow up. There was a no correlation between cuff leak test and intravenous fluid, duration of pneumo-peritoneum, or with angle of trendelenburg. The frequency of positive cuff leak test was high in patients at the end of robotic surgery but none of these patients had post-extubation stridor or required reintubations. There was no correlation with the fluid, angle, or duration of surgery. Clinical Trials Registry of India (CTRI/2017/04/008289), ctri.nic.in.

Safety and Efficacy of the Baska Mask Versus Endotracheal Intubation in 64 Women Undergoing Elective Laparoscopic Gynecological Surgery Under General Anesthesia: A Prospective Single-Center Study.

BackgroundThe Baska mask is a supraglottic airway device that has a continuous non-inflatable flexible cuff that mimics an airway, reducing the risk of overinflation and aspiration of gastric contents. This prospective study from a single center aimed to compare the safety and efficacy of the Baska mask vs endotracheal intubation (ET) in 64 women undergoing elective laparoscopic gynecological surgery in Trendelenburg position under general anesthesia.Material/MethodsThis was a prospective randomized study conducted on 64 adult female patients, 32 in each group, undergoing gynecologic surgery under general anesthesia. The study population was divided into 2 groups: the Baska group and the ET group. The respiratory and haemodynamic variables, the degree of gastric distension, and postoperative pharyngolaryngeal symptoms were compared between groups.ResultsAfter 2 patients dropped out of the study, data from 62 patients were analyzed. The Baska group showed significantly shorter device insertion time (28.4±10.7 vs 46.6±19.8, P=0.001), a significantly lower oropharyngeal leak pressure at all studied time points, and a higher leak fraction at 1 min after the completion of pneumoperitoneum (5.6% vs 2.1%, P=0.031) compared to the ET group. Respiratory and haemodynamic variables, the gastric antrum size, and postoperative pharyngolaryngeal symptoms showed no significant difference.ConclusionsThis study supports the findings from previous studies in patients undergoing general surgery. The Baska mask was as effective as ET in ventilation during general anesthesia in women undergoing elective laparoscopic gynecological surgery. Respiratory and hemodynamic responses were similar to ET, and no complications were associated with the Baska mask in this study.

Comparison of arterial to end-tidal carbon dioxide gradient P (a-ET)CO2 in volume versus pressure controlled ventilation in patients undergoing robotic abdominal surgery in the Trendelenburg position. A randomised controlled study.

Background and Aims:Robotic surgery is increasingly prevalent as an advancement in care. Steep head-down positions in pelvic surgery can increase the ventilation-perfusion mismatch and increase ventilatory requirements to offset carbon dioxide (CO2) increases consequent to pneumoperitoneum. The primary objective was to assess the impact of two ventilatory strategies, volume versus pressure-controlled ventilation on the arterial to end-tidal carbon dioxide gradient P (a-ET)CO2 in patients undergoing robotic surgery in the Trendelenburg position. The effects on alveolar to arterial oxygen gradient P (A-a)O2, peak airway pressure (Paw), dynamic compliance (Cdyn) and haemodynamics were also assessed.Methods:Fifty-one patients, 18-75 y, American Society of Anesthesiologists I-III undergoing robotic surgery in Trendelenburg position were randomised to volume-controlled ventilation (Group VCV) or pressure-controlled ventilation (Group PCV). The P (a-ET)CO2 was measured at baseline T0, 10 min after Trendelenburg position T1, 2 h of surgery T2, 4 h T3 and at Te, 10 min after deflation. The P (A-a) O2, Paw, Cdyn, heart rate and blood pressure were also measured at the same time.Results:The P (a-ET)CO2 at T1, T2, T3 and at Te was lower in Group PCV versus Group VCV. The Paw was lower at T1, T2, and T3 and Cdyn higher at T3 and Te in Group PCV at comparable minute ventilation. Haemodynamics and P (A-a)O2 were comparable between the groups.Conclusion:Pressure-controlled ventilation reduces P (a-ET)CO2 gradient, Paw and improves Cdyn but does not affect P (A-a) O2 or haemodynamics in comparison to volume-controlled ventilation in robotic surgeries in the Trendelenburg position.

Effect of pressure-controlled ventilation-volume guaranteed mode combined with individualized positive end-expiratory pressure on respiratory mechanics, oxygenation and lung injury in patients undergoing laparoscopic surgery in Trendelenburg position

The study aimed to investigate the efficacy of PCV-VG combined with individual PEEP during laparoscopic surgery in the Trendelenburg position. 120 patients were randomly divided into four groups: VF group (VCV plus 5cmH2O PEEP), PF group (PCV-VG plus 5cmH2O PEEP), VI group (VCV plus individual PEEP), and PI group (PCV-VG plus individual PEEP). Pmean, Ppeak, Cdyn, PaO2/FiO2, VD/VT, A-aDO2 and Qs/Qt were recorded at T1 (15 min after the induction of anesthesia), T2 (60 min after pneumoperitoneum), and T3 (5 min at the end of anesthesia). The CC16 and IL-6 were measured at T1 and T3. Our results showed that the Pmean was increased in VI and PI group, and the Ppeak was lower in PI group at T2. At T2 and T3, the Cdyn of PI group was higher than that in other groups, and PaO2/FiO2 was increased in PI group compared with VF and VI group. At T2 and T3, A-aDO2 of PI and PF group was reduced than that in other groups. The Qs/Qt was decreased in PI group compared with VF and VI group at T2 and T3. At T2, VD/VT in PI group was decreased than other groups. At T3, the concentration of CC16 in PI group was lower compared with other groups, and IL-6 level of PI group was decreased than that in VF and VI group. In conclusion, the patients who underwent laparoscopic surgery, PCV-VG combined with individual PEEP produced favorable lung mechanics and oxygenation, and thus reducing inflammatory response and lung injury.Clinical Trial registry: chictr.org. identifier: ChiCTR-2100044928

Comparison of endotracheal tube cuff pressures inflated with saline or air in gynecological laparoscopic surgery

Objective: We compared the air or saline insufflated endotracheal tube (ETT) cuff pressures and their effects on postoperative respiratory complications in gynecological laparoscopic surgeries in the Trendelenburg position (TP). Patients and Methods: This prospective study was carried out on a total of 60 patients, whose ages ranged from 18 to 65 years and who were classified by the American Society of Anesthesiologists (ASA) as I-III. They were scheduled for gynecological laparoscopic surgery in TP. Patients included in the study were randomly divided into two groups as the saline (Group S, n=30) and air (Group A, n=30) groups. ETT cuff pressures and peak airway pressures were recorded immediately after intubation and at 10-minute intervals during the intraoperative period. Results: The cuff pressure and maximum cuff pressure values in the saline group were significantly lower than in the air group in the 50-minute (p&amp;lt;0.05). The sore throat and analgesic consumption were significantly lower in Group S in postoperative 24 hours (p&amp;lt;0.001, for all). Conclusion: The intraoperative cuff pressures, postoperative sore throat, and analgesic consumption were lower in the salineinsufflated group than in the air-insufflated group in gynecological laparoscopic surgery in TP.

Renal injury after open versus laparoscopic non-cardiac surgery: a retrospective cohort analysis

BackgroundLaparoscopic surgical approaches enhance recovery, reduce postoperative pain, and shorten hospital length-of-stay. Nevertheless, increased intra-abdominal pressure is associated with decreased renal blood flow, renal hypoxia and acute kidney injury. When combined with Trendelenburg positioning, renal function may further deteriorate. We tested the primary hypothesis that the combination of laparoscopic surgical approach and Trendelenburg position is associated with larger reductions in estimated Glomerular Filtration Rate (eGFR) within the initial 48 postoperative hours compared to open surgery without Trendelenburg positioning. Secondarily, we tested, if laparoscopic procedures are associated with greater incidence of postoperative acute kidney injury. MethodsAdults who had laparoscopic colorectal surgery in Trendelenburg position at the Cleveland Clinic Main Campus from 2009 to 2016 were propensity-matched to patients who had comparable open procedures. Patients with pre-existing renal impairment were excluded. ResultsAmong 7,357 eligible patients, 1,846 laparoscopic cases with Trendelenburg were matched to 1,846 open cases. No association was found between laparoscopic approach and postoperative eGFR. A significant protective effect of the laparoscopic procedure on the odds of having AKI was found. Patients who had laparoscopic surgeries were an estimated 0.70 (95% CI 0.55, 0.90, pHolm-adj = 0.006) times as likely to have AKI as open surgical patients. ConclusionDespite compelling potential mechanisms, laparoscopic approach with Trendelenburg position in adult colorectal surgeries did not worsen postoperative eGFR, and actually reduced postoperative acute kidney injury. Given the other advantages of laparoscopic surgery, the approach should not be avoided for concerns about renal injury.

The impact of laparoscopic surgery in Trendelenburg position on intraocular pressure

Background Patients′ intraocular pressure (IOP) significantly increase during laparoscopic surgery in Trendelenburg position, and the resulting intraoperative intraocular hypertension may be related to postoperative visual loss (POVL). Objective To review the impact of laparoscopic surgery in Trendelenburg position on IOP to let the practitioners aware of the association between intraocular hypertension and POVL. Content One of the major causes for POVL is ischemia in optic nerve following reduction of ocular perfusion pressure (OPP) because of the increase of IOP. Animal studies prove that persistently increased IOP leads to damages in the retina. Patients often receive the laparoscopic surgery in Trendelenburg position, and low OPP and high IOP are commonly seen in this situation. In addition to the body position, the increase of IOP can also be a consequence of hypercapnia following CO2 inflation in the abdominal cavity, and may be affected by anesthetics, duration of the surgery, blood pressure, obesity and gender, etc. Several procedures have been performed to alleviate the increase of IOP, such as, intermittent shift the Trendelenburg position into supine position and intraoperative pharmacological intervention. Trend POVL is rarely seen in laparoscopic surgery, but severely compromises patient′s life quality if happens. Cautions should be taken to carefully monitor IOP in the patients with risk factors for POVL during laparoscopic surgery in the Trendelenburg position. Key words: Intraocular pressure; Laparoscopic surgery; Trendelenburg position

Intraocular pressure changes during laparoscopic surgery in Trendelenburg position in patients anesthetized with propofol-based total intravenous anesthesia compared to sevoflurane anesthesia: A comparative study

Background:Intraocular pressure (IOP) is increased during laparoscopic surgery with Trendelenburg position and may contribute to deleterious effects on optic nerve in susceptible patients.Aims:The primary objective of this study is to compare the effects of propofol-based total intravenous anesthesia (TIVA) with those of sevoflurane anesthesia on IOP in patients undergoing lower abdominal laparoscopic surgery in Trendelenburg position. Secondary objectives are to compare hemodynamic changes, mean arterial pressure (MAP), end-tidal CO2, and peak inspiratory pressure changes.Materials and Methods:Sixty patients with physical status American Society of Anesthesiologists classes I and II were randomly allocated in two groups: Group A (propofol) and Group B (sevoflurane). IOP along with other parameters was measured at seven points including baseline (T0), 5 min after induction (T1), 5 min after CO2 pneumoperitoneum in supine position (T2), 30 min after CO2 pneumoperitoneum with Trendelenburg position (T3), 5 min after returning to supine position (T4), 5 min after CO2 desufflation (T5), and 5 min after extubation (T6).Results:The change in IOP was different between the two groups. Maximum rise in IOP was seen at T3, and mean ± standard deviation IOP was 15.5 ± 0.9 mmHg and 19.8 ± 1.2 mmHg in Group A and Group B, respectively (P < 0.01). In Group A (propofol), IOP remained almost equal to the baseline value at T3 and the IOP difference was 0.3 ± 0.9 mmHg less than baseline (statistically insignificant, P > 0.05), while in Group B (sevoflurane), IOP increased significantly at T3 and the difference was 4.0 ± 1.2 mmHg (P < 0.001). The IOP was significantly greater (P < 0.01) from T2 to T6 in sevoflurane group than propofol group.Conclusion:Propofol-based TIVA is more effective than inhalational anesthesia with sevoflurane in attenuating the increase in IOP during laparoscopic surgery requiring CO2 pneumoperitoneum with Trendelenburg position.

Comparison of volume-controlled ventilation and pressure-controlled ventilation volume guaranteed during laparoscopic surgery in Trendelenburg position

Study objectiveTo analyze the effects of pressure-controlled ventilation-volume guaranteed (PCV-VG) and volume controlled ventilation (VCV) on airway pressures and respiratory and circulatory indicators during laparoscopic surgery in Trendelenburg position. DesignProspective randomized comparative clinical study. SettingTertiary hospital. PatientsForty ASA physical status 1 and 2 patients who underwent elective laparoscopic surgery in Trendelenburg position. InterventionsPatients were randomly allocated to either VCV group (n=20) or the PCV-VG group (n=20). After induction of anesthesia, for both modes of ventilation, the target tidal volume (VT) was 8mL/kg and the respiratory rate was adjusted to avoid hypercarbia. MeasurementsThe peak and mean inspiratory pressures, dynamic compliance, exhaled VT, oxygenation index and physiological dead space were calculated and recorded at T1, 5minutes after induction of anesthesia in supine position, T2, 5minutes after stabilization of pneumoperitoneum, T3 and T4, 15 and 60minutes after 30° Trendelenburg position with pneumoperitoneum respectively. Main resultsPCV-VG group had significantly lower peak inspiratory pressure and greater dynamic compliance than VCV group (P<.001). ConclusionsIn patients who underwent laparoscopic surgery in Trendelenburg position, PCV-VG was superior to VCV in its ability to provide ventilation with lower peak inspiratory pressure and greater dynamic compliance.

Prevalence and impact of incompetence of internal jugular valve on postoperative cognitive dysfunction in elderly patients undergoing robot-assisted laparoscopic radical prostatectomy

Internal jugular vein (IJV) is the main pathway of cerebral venous drainage and its valves prevent regurgitation of blood to the brain. IJV valve incompetence (IJVVI) is known to be associated with cerebral dysfunctions. It occurs more often in male over 50 years old, conditions elevating intra-abdominal or intra-thoracic pressure. In robot-assisted laparoscopic radical prostatectomy (RALRP), elderly male undergoes surgery in Trendelenburg position with pneumoperitoneum applied. Therefore, we assessed the IJVVI during RALRP and its influence on postoperative cognitive function. 57 patients undergoing RALRP were enrolled. Neurocognitive tests including Mini-Mental State Examination (MMSE), Auditory Verbal Learning Test, Digit Symbol Substitution Test, Color Word Stroop Test, digit span test, and grooved pegboard test were performed the day before and 2 days after surgery. During surgery, IJVVI was assessed with ultrasonography in supine position with and without pneumoperitoneum, and Trendelenburg position with pneumoperitoneum. 50 patients underwent sonographic assessment and 41 patients completed neurocognitive examination. A total of 27 patients presented IJVVI, 19 patients in supine position without pneumoperitoneum, 7 patients in supine position with pneumoperitoneum and 1 patient in Trendelenburg position with pneumoperitoneum. In neurocognitive tests, patients with IJVVI showed statistically significant decline of score in MMSE postoperatively (p<0.05). IJVVI occurred in 38% in supine position but the incidence was increased to 54% after Trendelenburg position and pneumoperitoneum. Patients with IJVVI did not show significant differences in cognitive function tests except MMSE. Clinical and neurological significance of physiologic changes associated RALRP should be studied further.

Safety and Effectiveness of SAF-R, a Novel Patient Positioning Device for Robot-Assisted Pelvic Surgery in Trendelenburg Position

We found current robotic positioning devices to be inadequate and cumbersome. Furthermore, we realized there were no premarket well-designed studies to prove their safety and efficacy. In this prospective pilot study, we aimed to investigate the safety and effectiveness of a novel patient-positioning device (SAF-R) to secure the patient in Trendelenburg (T-burg) position for robot-assisted pelvic surgery. Sixteen patients undergoing robot-assisted pelvic operation in T-burg position were enrolled. Patients were positioned using SAF-R board. Pressure sensor mats were used for real-time monitoring of the contact pressures and contact area on the shoulders and calves throughout the surgery. Data collection included patients' body mass index (BMI), time needed for positioning, total time in the T-burg position, contact pressure and contact area readings from the sensor mats, and the patient shifting distance on the table. Patients were also followed for 1-month postoperatively for any position-related adverse event. The median age of the patients was 56.5 years with median BMI of 27.3. The median positioning time was 6 minutes, duration of T-burg position was 3.5 hours, and patient shift on the table was 1 cm. The contact pressure over the shoulders was in the safe range (< 80 mm Hg) before and at the end of the surgery in all cases (right: 13.12 ± 1.12 vs 20.25 ± 1.56 mm Hg, left: 12.84 ± 1.05 vs 19.60 ± 1.09 mm Hg, p = 0.001). The changes in the mean contact pressure over the calves and the mean contact area for the shoulders and calves during the T-burg position were not significantly different. No significant position-related complication was detected during follow-up. SAF-R surgical board is a safe, reliable, and timesaving positioning device for patients undergoing robotic pelvic surgery in the T-burg position.

Effects of Recruitment Maneuver and Positive End-expiratory Pressure on Respiratory Mechanics and Transpulmonary Pressure during Laparoscopic Surgery

The authors tested the hypothesis that during laparoscopic surgery, Trendelenburg position and pneumoperitoneum may worsen chest wall elastance, concomitantly decreasing transpulmonary pressure, and that a protective ventilator strategy applied after pneumoperitoneum induction, by increasing transpulmonary pressure, would result in alveolar recruitment and improvement in respiratory mechanics and gas exchange. In 29 consecutive patients, a recruiting maneuver followed by positive end-expiratory pressure 5 cm H(2)O maintained until the end of surgery was applied after pneumoperitoneum induction. Respiratory mechanics, gas exchange, blood pressure, and cardiac index were measured before (T(BSL)) and after pneumoperitoneum with zero positive end-expiratory pressure (T(preOLS)), after recruitment with positive end-expiratory pressure (T(postOLS)), and after peritoneum desufflation with positive end-expiratory pressure (T(end)). Esophageal pressure was used for partitioning respiratory mechanics between lung and chest wall (data are mean ± SD): on T(preOLS), chest wall elastance (E(cw)) and elastance of the lung (E(L)) increased (8.2 ± 0.9 vs. 6.2 ± 1.2 cm H(2)O/L, respectively, on T(BSL); P = 0.00016; and 11.69 ± 1.68 vs. 9.61 ± 1.52 cm H(2)O/L on T(BSL); P = 0.0007). On T(postOLS), both chest wall elastance and E(L) decreased (5.2 ± 1.2 and 8.62 ± 1.03 cm H(2)O/L, respectively; P = 0.00015 vs. T(preOLS)), and Pao(2)/inspiratory oxygen fraction improved (491 ± 107 vs. 425 ± 97 on T(preOLS); P = 0.008) remaining stable thereafter. Recruited volume (the difference in lung volume for the same static airway pressure) was 194 ± 80 ml. Pplat(RS) remained stable while inspiratory transpulmonary pressure increased (11.65 + 1.37 cm H(2)O vs. 9.21 + 2.03 on T(preOLS); P = 0.007). All respiratory mechanics parameters remained stable after abdominal desufflation. Hemodynamic parameters remained stable throughout the study. In patients submitted to laparoscopic surgery in Trendelenburg position, an open lung strategy applied after pneumoperitoneum induction increased transpulmonary pressure and led to alveolar recruitment and improvement of E(cw) and gas exchange.

Adaptive support ventilation for gynaecological laparoscopic surgery in Trendelenburg position: bringing ICU modes of mechanical ventilation to the operating room

The aim of the present study was to test the efficacy of adaptive support ventilation (ASV) to automatically adapt the ventilatory settings to the changes in the respiratory mechanics that occur during pneumoperitoneum and Trendelenburg position in gynaecological surgeries. We prospectively studied 22 ASA I women scheduled for gynaecological laparoscopic surgery in the Trendelenburg position. After intravenous induction of general anaesthesia, patients were ventilated with ASV, a closed-loop mode of mechanical ventilation based on the Otis formula, designed to automatically adapt the ventilatory settings to changes in the patient's respiratory system mechanics, while maintaining preset minute ventilation. Respiratory mechanics variables, ventilatory setting parameters and analysis of blood gases were recorded at three time points: 5 min after induction (baseline), 15 min after pneumoperitoneum and Trendelenburg positioning (Pneumo-Trend) and 15 min after pneumoperitoneum withdrawal (final). A reduction of 44.4% in respiratory compliance and an increase of 29.1% in airway resistance were observed during the Pneumo-Trend period. Despite these changes in respiratory mechanics, minute ventilation was kept constant. ASV adapted the ventilatory settings by automatically increasing inspiratory pressure by 3.2 +/- 0.9 cmH(2)O (+19%), P < 0.01, respiratory rate by 1.3 +/- 0.5 breaths per minute (+9%) and the inspiratory to total time ratio (T(i)/T(tot)) by 43.3%. At final time, these parameters returned towards their baseline values. Adequate gas exchange was maintained throughout all periods. PaCO(2) increased moderately (+13%) from 4.4 +/- 0.6 (baseline) to 5.0 +/- 0.9 kPa (Pneumo-Trend), P < 0.01; and decreased slightly at final time (4.7 +/- 0.8 kPa), P < 0.05. Clinician's intervention was needed in only one patient who showed a moderate hypercapnia (PaCO(2) 6.9 kPa) during pneumoperitoneum. In healthy women undergoing gynaecologic laparoscopy, ASV automatically adapted the ventilatory settings to the changes in the respiratory mechanics, keeping constant the preset minute ventilation, providing an adequate exchange of respiratory gases and obviating clinician's interventions.