Positional asphyxia: accidental death due to head-down position in a badger sett.

Death from positional asphyxia occurs when the victim is found in a position that interferes with adequate breathing. We present an unusual case of a 67-yearold man who was found deceased trapped in a badger sett. The autopsy revealed marked congestion, cyanosis and a multitude of pinpoint hemorrhages in the face, neck and upper chest. Confluent scleral and conjunctival hemorrhage were observed and numerous petechial bleedings were found in the oral mucosa and within the reflected scalp. Death was attributed to positional asphyxia due to head-down position in a badger sett.

Doppler-Derived Renal Functional Reserve in the Prediction of Postoperative Acute Kidney Injury in Patients Undergoing Robotic Surgery.

BACKGROUND: Postoperative acute kidney injury (PO-AKI) is a frequent complication after surgery. Various tools have been proposed to identify patients at high risk for AKI, including preoperative serum creatinine or estimated glomerular filtration rate (eGFR), urinary cell cycle arrest, and tubular damage biomarkers; however, none of these can appropriately assess AKI risk before surgery. Renal functional reserve (RFR) screened by the Doppler-derived intraparenchymal renal resistive index variation (IRRIV) test has been proposed to identify patients at risk for AKI before a kidney insult. IRRIV test has been developed in healthy individuals and previously investigated in cardiac surgery patients. This study aims to evaluate the value of the IRRIV test in identifying PO-AKI among patients undergoing robotic abdominal surgery in the Trendelenburg position for pelvic oncological disease. METHODS: We performed a prospective, double-blinded, observational study. Preoperative baseline renal function and RFR were assessed in 53 patients with baseline eGFR >60 mL/min/1.73 m2, undergoing robotic surgery in the Trendelenburg position for pelvic oncological disease. The capability of Doppler-derived RFR in predicting PO-AKI was investigated with the area under the receiver operating characteristic curve (ROC-AUC). RESULTS: Approximately 15.1% of patients developed AKI within the first 3 postoperative days. Thirty-one (58.5%) patients had a physiologic delta-RRI (ie, ≥0.05), while 22 (41.5%) patients did not. The ROC-AUC for PO-AKI was 0.85 (95% confidence interval [CI], 0.74-0.97; P = .007) for serum creatinine, 0.84 (95% CI, 0.71-0.96; P = .006) for eGFR, and 0.84 (95% CI, 0.78-0.91; P = .017) for delta-RRI. When combined with eGFR, the ROC-AUC for delta-RRI was 0.95 (95% CI, 0.9-1). CONCLUSIONS: Our findings show that the preoperative assessment of Doppler-derived RFR combined with baseline renal function improves the capability of identifying patients at high risk for PO-AKI with eGFR >60 mL/min/1.73 m2 after robotic abdominal surgery in Trendelenburg position for pelvic oncological disease.

Factors related to clearance of the small pelvic cavity during gynecologic laparoscopic surgery.

AIM: To identify factors influencing the Trendelenburg angle required during laparoscopic gynecological surgery. METHODS: Patients who underwent laparoscopic surgery at a single university hospital between May 1, 2019, and March 31, 2021 were enrolled. Data were extracted from the medical records, while magnetic resonance imaging scans and all laparoscopic surgery videos were retrospectively reviewed to assess the presence of the small intestine in the pelvic cavity as well as the adhesions at each site. Groups with and without the small intestine in the pelvic cavity, and those requiring a Trendelenburg angle above or below 13° were compared. RESULTS: In total, 219 patients were examined. The Trendelenburg angle was significantly higher (p = 0.004), while a significant increase in ovarian adhesions was observed (p = 0.033; odds ratio [OR], 2.30; 95% confidence interval [CI], 1.05-5.01) in the group without the presence of the small intestine in the pelvic cavity. Furthermore, the group requiring a Trendelenburg angle of ≥13° had significantly thicker subcutaneous fat (p = 0.044) and more ileal adhesions (p = 0.040, OR, 1.82; 95% CI, 1.03-3.23) than the group with an angle of <13°. CONCLUSION: Cases of ileal adhesions or thick subcutaneous fat are more likely to require a Trendelenburg angle of ≥13°. Therefore, Trendelenburg complications should be considered in this group. In addition, ovarian adhesions make it more difficult to exclude the small intestine from the small pelvic cavity, and may be associated with endometriosis.

Does salivary pH affect postoperative sore throat in the head-down position of general anesthesia?

BACKGROUND: Tracheal intubation sometimes causes postoperative sore throat (POST) due to laryngeal damage. However, clinical observations suggest that the environment of the oral cavity may also affect POST. OBJECTIVE: The purpose of this study was to investigate whether salivary pH in the oral cavity affects POST. METHODS: After obtaining ethical approval, informed consent was obtained from all patients. Patients who underwent surgery in the supine position were enrolled as the control group. Patients who underwent laparoscopic surgery in the head-down position were enrolled as the intervention group. Immediately before both groups of patients were anaesthetised, expelled saliva was collected, and salivary pH was measured. Immediately postoperatively, the same measurement was carried out before the patient regained consciousness. The primary outcome was the change in salivary pH. The secondary outcome was POST. In our study, POST was defined as pharyngeal and swallowing pain in the glossopharyngeal and superior laryngeal nerves. The normal distribution of pH was tested using the Shapiro-Wilk test followed by analysis using repeated-measurements and one-way analysis of variance. Statistical significance was set at p < .05. RESULTS: A total of 62 patients were enrolled, of whom two were excluded based on the exclusion criteria. Salivary pH in the intervention group was significantly lower than that in the control group. Five patients had POST in the intervention group, whereas none had POST in the control group had POST. CONCLUSION: Acidotic-shifted saliva is considered one of the causes of POST.

Association Between Acute Kidney Injury and the Trendelenburg Position Angle During Robot-assisted Radical Prostatectomy.

BACKGROUND/AIM: Robot-assisted radical prostatectomy (RARP) has been widely adopted as the standard treatment for localized prostate cancer. RARP is safer and results in better oncological control than conventional open total prostatectomy. However, it has also been reported that acute kidney injury (AKI) can be caused by the use of carbon dioxide pneumoperitoneum and a steep Trendelenburg position. We investigated the incidence of AKI after RARP and its relationship with the Trendelenburg position angle. PATIENTS AND METHODS: Seventy-seven patients underwent RARP at our institution. They were divided into two groups: Those in which a Trendelenburg position with the head down at 20 degrees was employed (group A) and those in which a Trendelenburg position with the head down at 25 degrees was used (group B). To detect AKI, the serum creatinine concentration was measured at the following four points: Prior to surgery, on postoperative day 0 (immediately after RARP), and on postoperative days 1 and 6 after RARP. RESULTS: The incidence of AKI on POD 0 was lower in group B than in group A (p=0.0408). On POD 6, the renal function of all patients had improved to preoperative levels. Hypertension was a predictor of the incidence of AKI immediately after RARP. CONCLUSION: Although there was a significant Trendelenburg position angle-dependent difference in the incidence of AKI immediately after RARP, it was temporary. Hypertension is a predictor of AKI immediately after RARP. It is recommended that a 25-degree Trendelenburg position angle should be employed during RARP.

High-intensity exercise does not protect against orthostatic intolerance following bedrest in 55- to 65-yr-old men and women.

Prolonged bedrest provokes orthostatic hypotension and intolerance of upright posture. Limited data are available on the cardiovascular responses of older adults to head-up tilt following bedrest, with no studies examining the potential benefits of exercise to mitigate intolerance in this age group. This randomized controlled trial of head-down bedrest (HDBR) in 55- to 65-yr-old men and women investigated if exercise could avert post-HDBR orthostatic intolerance. Twenty-two healthy older adults (11 female) underwent a strict 14-day HDBR and were assigned to either an exercise (EX) or control (CON) group. The exercise intervention included high-intensity, aerobic, and resistance exercises. Head-up tilt-testing to a maximum of 15 minutes was performed at baseline (Pre-Bedrest) and immediately after HDBR (R1), as well as 6 days (R6) and 4 weeks (R4wk) later. At Pre-Bedrest, three participants did not complete the full 15 minutes of tilt. At R1, 18 did not finish, with no difference in tilt end time between CON (422 ± 287 s) and EX (409 ± 346 s). No differences between CON and EX were observed at R6 or R4wk. At R1, just 1 participant self-terminated the test with symptoms, while 12 others reported symptoms only after physiological test termination criteria were reached. Finishers on R1 protected arterial pressure with higher total peripheral resistance relative to Pre-Bedrest. Cerebral blood velocity decreased linearly with reductions in arterial pressure, end-tidal CO2, and cardiac output. High-intensity interval exercise did not benefit post-HDBR orthostatic tolerance in older adults. Multiple factors were associated with the reduction in cerebral blood velocity leading to intolerance.

Prediction of blood pressure changes associated with abdominal pressure changes during robotic laparoscopic low abdominal surgery using deep learning.

BACKGROUND: Intraoperative hypertension and blood pressure (BP) fluctuation are known to be associated with negative patient outcomes. During robotic lower abdominal surgery, the patient's abdominal cavity is filled with CO2, and the patient's head is steeply positioned toward the floor (Trendelenburg position). Pneumoperitoneum and the Trendelenburg position together with physiological alterations during anesthesia, interfere with predicting BP changes. Recently, deep learning using recurrent neural networks (RNN) was shown to be effective in predicting intraoperative BP. A model for predicting BP rise was designed using RNN under special scenarios during robotic laparoscopic surgery and its accuracy was tested. METHODS: Databases that included adult patients (over 19 years old) undergoing low abdominal da Vinci robotic surgery (ovarian cystectomy, hysterectomy, myomectomy, prostatectomy, and salpingo-oophorectomy) at Soonchunhyang University Bucheon Hospital from October 2018 to March 2021 were used. An RNN-based model was designed using Python3 language with the PyTorch packages. The model was trained to predict whether hypertension (20% increase in the mean BP from baseline) would develop within 10 minutes after pneumoperitoneum. RESULTS: Eight distinct datasets were generated and the predictive power was compared. The macro-average F1 scores of the datasets ranged from 68.18% to 72.33%. It took only 3.472 milliseconds to obtain 39 prediction outputs. CONCLUSIONS: A prediction model using the RNN may predict BP rises during robotic laparoscopic surgery.

Influence of steep Trendelenburg position on postoperative complications: a systematic review and meta-analysis.

Intraoperative physiologic changes related to the steep Trendelenburg position have been investigated with the widespread adoption of robot-assisted pelvic surgery (RAPS). However, the impact of the steep Trendelenburg position on postoperative complications remains unclear. We conducted a meta-analysis to compare RAPS to laparoscopic/open pelvic surgery with regards to the rates of venous thromboembolism (VTE), cardiac, and cerebrovascular complications. Meta-regression was performed to evaluate the influence of confounding risk factors. Ten randomized controlled trials (RCTs) and 47 non-randomized controlled studies (NRSs), with a total of 380,125 patients, were included. Although RAPS was associated with a decreased risk of VTE and cardiac complications compared to laparoscopic/open pelvic surgery in NRSs [risk ratio (RR), 0.59; 95% CI 0.51-0.72, p < 0.001 and RR 0.93; 95% CI 0.58-1.50, p = 0.78, respectively], these differences were not confirmed in RCTs (RR 0.92; 95% CI 0.52-1.62, p = 0.77 and RR 0.93; 95% CI 0.58-1.50, p = 0.78, respectively). In subgroup analyses of laparoscopic surgery, there was no significant difference in the risk of VTE and cardiac complications in both RCTs and NRSs. In the meta-regression, none of the risk factors were found to be associated with heterogeneity. Furthermore, no significant difference was observed in cerebrovascular complications between RAPS and laparoscopic/open pelvic surgery. Our meta-analysis suggests that the steep Trendelenburg position does not seem to affect postoperative complications and, therefore, can be considered safe with regard to the risk of VTE, cardiac, and cerebrovascular complications. However, proper individualized preventive measures should still be implemented during all surgeries including RAPS to warrant patient safety.

Optic disc edema and chorioretinal folds develop during strict 6° head-down tilt bed rest with or without artificial gravity.

Spaceflight associated neuro-ocular syndrome (SANS) is hypothesized to develop as a consequence of the chronic headward fluid shift that occurs in sustained weightlessness. We exposed healthy subjects (n = 24) to strict 6° head-down tilt bed rest (HDTBR), an analog of weightlessness that generates a sustained headward fluid shift, and we monitored for ocular changes similar to findings that develop in SANS. Two-thirds of the subjects received a daily 30-min exposure to artificial gravity (AG, 1 g at center of mass, ~0.3 g at eye level) during HDTBR by either continuous (cAG, n = 8) or intermittent (iAG, n = 8) short-arm centrifugation to investigate whether this intervention would attenuate headward fluid shift-induced ocular changes. Optical coherence tomography images were acquired to quantify changes in peripapillary total retinal thickness (TRT), retinal nerve fiber layer thickness, and choroidal thickness, and to detect chorioretinal folds. Intraocular pressure (IOP), optical biometry, and standard automated perimetry data were collected. TRT increased by 35.9 µm (95% CI, 19.9-51.9 µm, p < 0.0001), 36.5 µm (95% CI, 4.7-68.2 µm, p = 0.01), and 27.6 µm (95% CI, 8.8-46.3 µm, p = 0.0005) at HDTBR day 58 in the control, cAG, and iAG groups, respectively. Chorioretinal folds developed in six subjects across the groups, despite small increases in IOP. Visual function outcomes did not change. These findings validate strict HDTBR without elevated ambient CO2 as a model for investigating SANS and suggest that a fluid shift reversal of longer duration and/or greater magnitude at the eye may be required to prevent or mitigate SANS.

Diaphragm Thickening Fraction as a Prognostic Imaging Marker for Postoperative Pulmonary Complications in Robot-Assisted Laparoscopic Prostatectomy Requiring the Trendelenburg Position and Pneumoperitoneum.

BACKGROUND: Robot-assisted laparoscopic prostatectomy (RALP) frequently entails postoperative pulmonary complications (PPCs) due to the Trendelenburg position and pneumoperitoneum. Diaphragm thickening fraction (TF) as an imaging marker can offer the advantage of predicting respiratory outcomes. Therefore, we evaluated the effect of diaphragm TF on the occurrence of PPCs in RALP. METHODS: We measured the preoperative thickness of the diaphragm at peak inspiration (T pi) and end expiration (T ee) using ultrasonography. Diaphragm TF was calculated as TF = (T pi-T ee)/T ee. A receiver operating characteristic (ROC) curve analysis of TF was performed. After dividing patients into two groups according to the optimal TF cut-off value, we compared the occurrence of PPCs between the groups. The predictivity of diaphragm TF for the occurrence of PPCs was evaluated. RESULTS: Of 145 patients, 40 patients (27.6%) developed PPCs. Patients with PPCs had a significantly lower TF than those without PPCs (0.31 ± 0.09 vs. 0.39 ± 0.11, P < 0.001). In the ROC curve analysis, the optimal TF cut-off value was 0.28. The patients were divided into TF ≥ 0.28 group (n = 114) and TF < 0.28 group (n = 31). The incidence of PPCs was significantly higher in the TF < 0.28 group than in the TF ≥ 0.28 group (51.6% vs. 21.1%, P = 0.001). Diaphragm TF < 0.28 was associated with a higher incidence of PPCs than diaphragm TF ≥ 0.28 (odds ratio = 4.534, 95% confidence interval [1.763-11.658], P = 0.002). CONCLUSION: Preoperative diaphragm TF < 0.28 was associated with an increased incidence of PPCs, suggesting that diaphragm TF as a prognostic imaging marker provides useful information on PPCs in RALP requiring the Trendelenburg position and pneumoperitoneum. Trial Registry Number. This trial is registered with KCT0005028.

Comparison of airway management without neuromuscular blockers in laparoscopic gynecological surgery.

ABSTRACT: New generation supraglottic airway devices are suitable for airway management in many laparoscopic surgeries. In this study, we evaluated and compared the ventilation parameters of the laryngeal mask airway-supreme (LM-S) and endotracheal tube (ETT) when a neuromuscular blocker (NMB) agent was not used during laparoscopic gynecological surgery. The second outcome was based on the evaluation of the surgical view because it may affect the surgical procedure.This was a randomized study that enrolled 100 patients between 18 and 65 years old with an ASA I-II classification. Patients were divided into 2 groups: Group ETT and Group LM-S. Standard anesthesia and ventilation protocols were administered to patients in each group. Ventilation parameters [airway peak pressure (Ppeak), mean airway pressure (Pmean), total volume, and oropharyngeal leak pressure] were recorded before, after, and during peritoneal insufflation and before desufflation, as well as after the removal of the airway device. Perioperative surgical view quality and the adequacy of the pneumoperitoneum were also recorded.The data of 100 patients were included in the statistical analysis. The Ppeak values in Group ETT were significantly higher in the second minute after airway device insertion. The Ppeak and Pmean values in Group ETT were significantly higher before desufflation and after removal of the airway device. No significant differences were found between the groups in terms of adequacy of the pneumoperitoneum or quality of the surgical view.The results of this study showed that gynecological laparoscopies can be performed without using a NMB. Satisfactory conditions for ventilation and surgery can be achieved while sparing the use of muscle relaxants in both groups despite the Trendelenburg position and the pneumoperitoneum of the patients, which are typical for laparoscopic gynecological surgery. The results are of clinical significance because they show that the use of a muscle relaxant is unnecessary when supraglottic airways are used for these surgical procedures.

Time-series analysis of heart rate and blood pressure in response to changes in work rate before and after 60 days of 6° head down tilt bed rest.

PURPOSE: Cardiovascular regulation during exercise, described using time series analysis, is expected to be attenuated after bed rest (BR) and this effect will be dampened by a reactive jumps countermeasure. METHODS: Twenty subjects (29 ± 6 years, 23.6 ± 1.7 kg m-2) were tested on a cycle ergometer 9 days (BDC-9) before the beginning of BR as well as 2 (R + 2) and 13 days (R + 13) after the end of BR, applying moderate pseudo-random binary (PRBS) work rate changes. Heart rate (HR) and mean arterial blood pressure (mBP) were measured beat-to-beat and interpolated to 1 s intervals. HR and mBP were cross-correlated [CCF(HR-mBP)] during the PRBS. Eleven subjects participated in a reactive jump countermeasure (JUMP) during the BR period, the other part of the group served as control group (CTRL). RESULTS: In the CTRL group, significantly lower CCF(HR-mBP) values during BDC-9 were observed compared to R + 2 during the lags 20-25 s and significantly higher values during the lags - 39 s to - 35 s. In the JUMP group, significantly lower CCFs were only observed at R + 2 compared with BDC-9 during the lags 23 s and 24 s, whereas the CCFs for BDC-9 were significantly higher at several lags compared with R + 13. CONCLUSION: Attenuations in the regulation of the cardiovascular system during cycling exercise after BR were found in the CTRL group of the RSL study. Cardiovascular regulation in the JUMP group was improved compared to values before the beginning of BR, suggesting the effectiveness of the reactive jumps countermeasure to mitigate the deleterious effects of prolonged BR.

Sixty days of head-down tilt bed rest with or without artificial gravity do not affect the neuromuscular secretome.

Artificial gravity is a potential countermeasure to attenuate effects of weightlessness during long-term spaceflight, including losses of muscle mass and function, possibly to some extent attributable to disturbed neuromuscular interaction. The 60-day AGBRESA bed-rest study was conducted with 24 participants (16 men, 8 women; 33 ± 9 years; 175 ± 9 cm; 74 ± 10 kg; 8 control group, 8 continuous (cAG) and 8 intermittent (iAG) centrifugation) to assess the impact of bed rest with or without daily 30-min continuous/intermittent centrifugation with 1G at the centre of mass. Fasting blood samples were collected before and on day 6, 20, 40 and 57 during 6° head-down tilt bed rest. Concentrations of circulating markers of muscle wasting (GDF-8/myostatin; slow skeletal muscle troponin T; prostaglandin E2), neurotrophic factors (BDNF; GDNF) and C-terminal Agrin Fragment (CAF) were determined by ELISAs. Creatine kinase activity was assessed by colorimetric enzyme assay. Repeated-measures ANOVAs were conducted with TIME as within-subject, and INTERVENTION and SEX as between-subject factors. The analyses revealed no significant effect of bed rest or sex on any of the parameters. Continuous or intermittent artificial gravity is a safe intervention that does not have a negative impact of the neuromuscular secretome.

Comparison of different end-tidal carbon dioxide levels in preventing postoperative nausea and vomiting in gynaecological patients undergoing laparoscopic surgery.

The aim of this study was to compare different end-tidal carbon dioxide (EtCO2) levels to prevent postoperative nausea and vomiting (PONV) caused by increased intracranial pressure due to pneumoperitoneum and Trendelenburg position in gynaecological laparoscopic surgery. A total of 60 female patients aged 25-50 years who would undergo laparoscopic gynaecological surgery under general anaesthesia were randomised into two groups: group A (EtCO2: 26 - 35 mmHg, n = 30) and group B (EtCO2: 36 - 45 mmHg, n = 30). In both groups, ONSD and EtCO2 of the patients were measured at baseline after anaesthesia induction (Tb), at 5 min after pneumoperitoneum (TPP5), and at 10 min intervals after Trendelenburg position (TPP10, TPP20, TPP30). At 5 (TD5) and 10 min (TD10) after deflation, ONSD measurements were repeated. The incidence and severity of PONV of the patients, and antiemetic drugs used in both groups were assessed in the postoperative period. In the intraoperative follow-up periods, TPP5 and subsequent EtCO2 values, as well as TPP10 and subsequent ONSD values, were significantly higher in group B and the incidence of nausea, the PONV scores and the incidence of rescue antiemetic use significantly lower in group A than in group B (p<.001 for all). This result indicates that low EtCO2 levels have beneficial effects on ICP and PONV in laparoscopic gynaecological operations.Impact statementWhat is already known on this subject? Laparoscopic gynaecologic surgery has been a more preferred technique. The incidence of postoperative nausea and vomiting (PONV) after laparoscopic gynaecologic surgery is remarkably high. In the prevention of PONV after gynaecologic laparoscopic surgery, single and multiple drug therapies and methods have been used.What the results of this study add? Postoperative nausea and vomiting caused by intracranial pressure (ICP) increase due to carbon dioxide pneumoperitoneum and Trendelenburg position in gynaecologic laparoscopic surgeries were decreased in the early postoperative period by low end-tidal carbon dioxide levels in the intraoperative period. It was shown that low end-tidal carbon dioxide levels have beneficial effects on ICP and PONV in laparoscopic gynaecologic operations.What the implications are of these findings for clinical practice and/or further research? This result indicates that low end-tidal carbon dioxide levels have beneficial effects on ICP and PONV in laparoscopic gynaecologic operations.

Gravity and Mastoid Effusion.

BACKGROUND: Asymptomatic mastoid effusions have recently been observed in astronauts returning from long-term spaceflight. In hospitalized patients, mastoid effusion increases the risks for bacterial otitis and mastoiditis. We reasoned that cephalad fluid shifts during strict -6° head down tilt bed rest could reproduce space-flight associated mastoid effusion and that artificial gravity may reverse the response. METHODS: The recent Artificial Gravity Bed Rest Study-European Space Agency study (AGBRESA) tested influences of artificial gravity during 60 days head down bed rest on a short-arm human centrifuge in healthy participants. The two intervention groups received daily artificial gravity with 30 minutes continuous artificial gravity or intermittent artificial gravity. A third group served as a control group and received no artificial gravity. We assessed cranial magnetic resonance images for mastoid effusions 1 day before bed rest, at days 14 and 52 of bed rest, and 3 days after bed rest. RESULTS: None of the participants exhibited mastoid effusions before bed rest. Six participants showed mastoid effusions at bed rest day 14 (4 continuous, 2 intermittent, 0 control). Fifteen participants showed mastoid effusions at bed rest day 52 and 3 days after bed rest (7 continuous, 3 intermittent, 5 control). CONCLUSIONS: Mastoid effusions commonly occur during strict head down tilt bed rest. The model can be applied to study the mechanisms and potential countermeasures for space flight-associated mastoid effusions. Formation of mastoid effusions during head down tilt bed rest is not prevented by daily 30 minutes short-arm intermittent or continuous centrifugation.

The effects of a spaceflight analog with elevated CO2 on sensorimotor adaptation.

Aboard the International Space Station (ISS), astronauts must adapt to altered vestibular and somatosensory inputs due to microgravity. Sensorimotor adaptation on Earth is often studied with a task that introduces visuomotor conflict. Retention of the adaptation process, known as savings, can be measured when subjects are exposed to the same adaptive task multiple times. It is unclear how adaptation demands found on the ISS might interfere with the ability to adapt to other sensory conflict at the same time. In the present study, we investigated the impact of 30 days' head-down tilt bed rest combined with elevated carbon dioxide (HDBR + CO2) as a spaceflight analog on sensorimotor adaptation. Eleven subjects used a joystick to move a cursor to targets presented on a computer screen under veridical cursor feedback and 45° rotated feedback. During this NASA campaign, five individuals presented with optic disk edema, a sign of spaceflight-associated neuro-ocular syndrome (SANS). Thus, we also performed post hoc exploratory analyses between subgroups who did and did not show signs of SANS. HDBR + CO2 had some impact on sensorimotor adaptation, with a lack of savings across the whole group. SANS individuals showed larger, more persistent after-effects, suggesting a shift from relying on cognitive to more implicit processing of adaptive behaviors. Overall, these findings suggest that HDBR + CO2 alters the way in which individuals engage in sensorimotor processing. These findings have important implications for missions and mission training, which require individuals to adapt to altered sensory inputs over long periods in space.NEW & NOTEWORTHY This is the first bed rest campaign examining sensorimotor adaptation and savings in response to the combined effect of HDBR + CO2 and to observe signs of spaceflight-associated neuro-ocular syndrome (SANS) in HDBR participants. Our findings suggest that HDBR + CO2 alters the way that individuals engage in sensorimotor processing. Individuals who developed signs of SANS seem to rely more on implicit rather than cognitive processing of adaptive behaviors than subjects who did not present signs of SANS.

Efeitos da PEEP na ventilação controlada a volume sobre parâmetros hemodinâmicos em suínos submetidos ao pneumoperitônio associado ao cefalodeclive / Effects of PEEP on hemodynamic variables in pigs submitted to volume-controlled ventilation under pneumoperitoneum associated to cephalodeclive

Videolaparoscopic procedures have gained prominence due to their low invasiveness, causing less surgical trauma and better post-surgical recovery. However, the increase in intra-abdominal pressure due to the institution of pneumoperitoneum can alter the patient's homeostasis. Therefore, volume-controlled ventilation, associated with positive end-expiratory pressure (PEEP), improves arterial oxygenation and prevents pulmonary collapse, but it can lead to important hemodynamic changes. The aim of this study was to evaluate, comparatively, the effects of positive end expiratorypressure (PEEP) on hemodynamic variables of pigs submitted to volume-controlled ventilation, during pneumoperitoneum and maintained in head-down tilt and determine which PEEP value promotes greater stability on hemodynamic variables. Twenty-four pigs were used, between 55 and 65-day-old, weighing between 15 and 25 kg, randomly divided into 3 distinct groups differentiated by positive end-expiratory pressure: PEEP 0 (volume-controlled ventilation and PEEP of 0 cmH2O), PEEP 5 (volume-controlled ventilation and PEEP of 5 cmH2O) and PEEP 10 (volume-controlled ventilation and PEEP of 10 cmH2O). Volume-controlled ventilation was adjusted to 8 mL/kg of tidal volume and a respiratory rate of 25 movements per min. Anesthesia was maintained with continuous infusion of propofol (0.2 mg/kg/min) and midazolam (1 mg/kg/h). Pneumoperitoneum was performed with carbon dioxide (CO2), keeping the intraabdominal pressure at 15 mmHg and the animals were positioned on a 30° head-down tilt. The evaluations of hemodynamic variables started 30 min after induction of anesthesia (M0), followed by measurements at 15-min intervals (from M15 to M90), completing a total of 7 evaluations. The variables of interest were collected over 90 min and submitted to analysis of variance followed by Tukey's post-hoc test, with P < 0.05. The PEEP 10 group had higher values of CVP and mCPP, while the PEEP 5 group, mPAP and PVR were higher. The PEEP 0 group, on the other hand, had higher means of CI. Regarding the moments, there were differences in HR, SAP, DAP, MAP, CO, IC and TPR. According to the literature, important hemodynamic effects due to pneumoperitoneum are reported, which can be caused by the pressure used in abdominal insufflation, CO2 accumulation, duration of the surgical procedure, hydration status and patient positioning. Mechanical ventilation associated with PEEP can also cause an increase in intrathoracic pressure and, therefore, reduce cardiac output. Cardiovascular changes are proportional to the PEEP used. Central venous pressure (PVC) measure the patient's preload, and intrathoracic pressure can interfere with this parameter. The peak pressure values in the PEEP 10 group were higher than the other groups, demonstrating that the increase in intrathoracic pressure results in higher PVC values. Regarding PAPm and PCPm, these variables can be influenced according to the PEEP values and the patient's position. In relation to CI, the increase in PEEP may reflect on intrathoracic pressure, resulting in greater compression of the heart, with a consequent reduction in cardiac output and cardiac index. Therefore, it is concluded that the PEEP effects of 0 cmH2O and 5 cmH2O on hemodynamics are discrete, under the proposed conditions.(AU)

S100B level and cognitive dysfunction after robotic-assisted laparoscopic radical prostatectomy procedures: a prospective observational study / Nível de S100B e disfunção cognitiva após prostatectomia radical laparoscópica assistida por robô: estudo observacional prospectivo

Abstract Background: The present study investigated the association between Postoperative Cognitive Dysfunction (POCD) and increased serum S100B level after Robotic-Assisted Laparoscopic Radical Prostatectomy (RALRP). Methods: The study included 82 consecutive patients who underwent RALRP. Serum S100B levels were determined preoperatively, after anesthesia induction, and at 30 minutes and 24 hours postoperatively. Cognitive function was assessed using neuropsychological testing preoperatively, and at 7 days and 3 months postoperatively. Results: Twenty four patients (29%) exhibited POCD 7 days after surgery, and 9 (11%) at 3 months after surgery. Serum S100B levels were significantly increased at postoperative 30 minutes and 24 hours in patients displaying POCD at postoperative 7 days (p = 0.0001 for both) and 3 months (p = 0.001 for both) compared to patients without POCD. Duration of anesthesia was also significantly longer in patients with POCD at 7 days and 3 months after surgery compared with patients without POCD (p = 0.012, p = 0.001, respectively), as was duration of Trendelenburg (p = 0.025, p = 0.002, respectively). Composite Z score in tests performed on day 7 were significantly correlated with duration of Trendelenburg and duration of anesthesia (p = 0.0001 for both). Conclusions: S100B increases after RALRP and this increase is associated with POCD development. Duration of Trendelenburg position and anesthesia contribute to the development of POCD. Trial Registry Number: Clinicaltrials.gov (N° NCT03018522).

Resumo Introdução: O presente estudo investigou a associação entre Disfunção Cognitiva Pós-Operatória (DCPO) e aumento do nível sérico de S100B após Prostatectomia Radical Laparoscópica Assistida por Robô (PRLAR). Métodos: O estudo incluiu 82 pacientes consecutivos submetidos à PRLAR. Os níveis séricos de S100B foram determinados: no pré-operatório, após indução anestésica, e aos 30 minutos e 24 horas do pós-operatório. A função cognitiva foi avaliada com testes neuropsicológicos no pré-operatório, no 7° dia pós-operatório (7 DPO) e aos 3 meses após a cirurgia (3 MPO). Resultados: Observamos 24 pacientes (29%) com DCPO no 7 DPO e 9 pacientes com DCPO (11%) após 3 meses da cirurgia. Quando comparados com os pacientes sem DCPO, os níveis séricos de S100B estavam significantemente aumentados aos 30 minutos e às 24 horas do pós-operatório nos pacientes que apresentaram DCPO no 7 DPO (p= 0,0001 para os dois momentos) e 3 meses após a cirurgia (p= 0,001 para os dois momentos) A duração anestésica também foi significantemente maior em pacientes com DCPO no 7 DPO e 3 MPO em comparação com pacientes sem DCPO (p= 0,012, p= 0,001, respectivamente), assim como a duração da posição de Trendelenburg (p= 0,025, p= 0,002, respectivamente). O escore Z composto nos testes realizados no 7 DPO foi significantemente correlacionado com a duração da posição de Trendelenburg e a duração da anestesia (p= 0,0001 para ambos). Conclusão: S100B aumenta após PRLAR e o aumento está associado ao desenvolvimento de DCPO. A duração anestésica e o tempo decorrido em posição de Trendelenburg contribuem para o desenvolvimento de DCPO. Número de registro do estudo: Clinicaltrials.gov (n° NCT03018522)

[S100B level and cognitive dysfunction after robotic-assisted laparoscopic radical prostatectomy procedures: a prospective observational study]. / Nível de S100B e disfunção cognitiva após prostatectomia radical laparoscópica assistida por robô: estudo observacional prospectivo.

BACKGROUND: The present study investigated the association between Postoperative Cognitive Dysfunction (POCD) and increased serum S100B level after Robotic-Assisted Laparoscopic Radical Prostatectomy (RALRP). METHODS: The study included 82 consecutive patients who underwent RALRP. Serum S100B levels were determined preoperatively, after anesthesia induction, and at 30 minutes and 24 hours postoperatively. Cognitive function was assessed using neuropsychological testing preoperatively and at 7 days and 3 months postoperatively. RESULTS: Twenty-four patients (29%) exhibited POCD 7 days after surgery, and 9 (11%) at 3 months after surgery. Serum S100B levels were significantly increased at postoperative 30minutes and 24 hours in patients displaying POCD at postoperative 7 days (p = 0.0001 for both) and 3 months (p = 0.001 for both) compared to patients without POCD. Duration of anesthesia was also significantly longer in patients with POCD at 7 days and 3 months after surgery compared with patients without POCD (p = 0.012, p = 0.001, respectively), as was duration of Trendelenburg (p = 0.025, p = 0.002, respectively). Composite Z score in tests performed on day 7 were significantly correlated with duration of Trendelenburg and duration of anesthesia (p = 0.0001 for both). CONCLUSIONS: S100B increases after RALRP and this increase is associated with POCD development. Duration of Trendelenburg position and anesthesia contribute to the development of POCD. TRIAL REGISTRY NUMBER: Clinicaltrials.gov (N° NCT03018522).

Postmortem Otorrhagia in Positional Asphyxia.

Otorrhagia is generally associated with basilar skull fractures or diving accidents. In routine forensic medical practice, an accurate knowledge of the etiology of otorrhagia may have a key role to distinguish between traumatic and atraumatic causes and accidental, homicidal, or suicidal manners. The authors present the case of an unusual cause of atraumatic otorrhagia occurred in an elderly farmer found dead in a barn. He remained entrapped in a narrow tunnel created by some hay bales. The autopsy findings revealed only an intense polyvisceral congestion and subpleural petechiae, with no signs of traumatic injuries and no fractures of skull base or temporal pyramid. The cause of death was determined to be positional asphyxia, and the manner of death was deemed accidental. In fact, the head-down position resulted in diaphragm compression causing respiratory failure in combination with the stasis of the upper venous circle districts. Mechanical and gravitational forces related to upside-down position and increased vascular pressure also caused postmortem otorrhagia. In this case, the death scene investigation and circumstantial information allowed for reconstruction of the unique dynamics of the death. At the death scene, the position of the corpse must be accurately investigated because it can explain some cadaveric findings such as the ear bleeding or other markers of increased cephalic venous pressure like pink teeth, facial and conjunctival petechiae, or Tardieu spots. Therefore, forensic pathologists should consider that ear bleeding in dead bodies is not always the evidence of severe head blunt trauma or diving accidents, but it might be a postmortem phenomenon mostly related to body position.