Assessment of dynamic variables of fluid responsiveness to predict desufflation-induced hypotension during paediatric laparoscopic surgery

Abstract

Background: During laparoscopic surgery in paediatric patients, sudden hypotension may occur following peritoneal desufflation due to hypovolaemia or an acute increase in gastrointestinal venous capacitance by the release of intra-abdominal pressure. This study examined whether dynamic variables of fluid responsiveness during pneumoperitoneum can predict the occurrence of hypotension following desufflation.Methods: A total of 120 paediatric subjects were prospectively enrolled. A predictor was derived from the initial 83 subjects and validated thereafter in 37 high-risk subjects. The pleth variability index, respiratory variation in the pulse oximetry plethysmographic waveform (ΔPOP), systolic pressure variation and pulse pressure variation during pneumoperitoneum were obtained 1 min before desufflation. Predictors of desufflation-induced hypotension were investigated using the multivariable logistic regression analysis. Predictability was assessed using the area under the receiver-operating characteristic curve (AUC).Results: In the derivation cohort, 27% (n=23) of subjects developed hypotension. Only ΔPOP was found to be a predictor, and showed high predictability of desufflation-induced hypotension [AUC 0.87, P<0.0001, 95% confidence interval (CI): 0.78–0.93]. A ΔPOP cut-off point of 38% predicted hypotension with a sensitivity of 83% and a specificity of 90%. In the validation cohort, 43% (n=16) of subjects developed hypotension, and ΔPOP was verified to be highly predictive of the occurrence of hypotension (AUC 0.90, P<0.0001, 95% CI: 0.76–0.98). The sensitivity and specificity of a ΔPOP cut-off point of 38% to predict hypotension was 88% and 90%, respectively.Conclusions: The ΔPOP during pneumoperitoneum is useful in predicting desufflation-induced hypotension during paediatric laparoscopic surgery.Clinical trial registration: NCT02536521.

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Assessment of dynamic variables of fluid responsiveness to predict desufflation-induced hypotension during paediatric laparoscopic surgery

Abstract

Background: During laparoscopic surgery in paediatric patients, sudden hypotension may occur following peritoneal desufflation due to hypovolaemia or an acute increase in gastrointestinal venous capacitance by the release of intra-abdominal pressure. This study examined whether dynamic variables of fluid responsiveness during pneumoperitoneum can predict the occurrence of hypotension following desufflation.Methods: A total of 120 paediatric subjects were prospectively enrolled. A predictor was derived from the initial 83 subjects and validated thereafter in 37 high-risk subjects. The pleth variability index, respiratory variation in the pulse oximetry plethysmographic waveform (ΔPOP), systolic pressure variation and pulse pressure variation during pneumoperitoneum were obtained 1 min before desufflation. Predictors of desufflation-induced hypotension were investigated using the multivariable logistic regression analysis. Predictability was assessed using the area under the receiver-operating characteristic curve (AUC).Results: In the derivation cohort, 27% (n=23) of subjects developed hypotension. Only ΔPOP was found to be a predictor, and showed high predictability of desufflation-induced hypotension [AUC 0.87, P<0.0001, 95% confidence interval (CI): 0.78–0.93]. A ΔPOP cut-off point of 38% predicted hypotension with a sensitivity of 83% and a specificity of 90%. In the validation cohort, 43% (n=16) of subjects developed hypotension, and ΔPOP was verified to be highly predictive of the occurrence of hypotension (AUC 0.90, P<0.0001, 95% CI: 0.76–0.98). The sensitivity and specificity of a ΔPOP cut-off point of 38% to predict hypotension was 88% and 90%, respectively.Conclusions: The ΔPOP during pneumoperitoneum is useful in predicting desufflation-induced hypotension during paediatric laparoscopic surgery.Clinical trial registration: NCT02536521.

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Cortical Processing of Vocal and Nonvocal Sounds in Cochlear-Implanted Children: An Electrophysiological Study.

Objectives: For prelingually deaf children, cochlear implants (CIs) can restore auditory input to the auditory cortex and the ability to acquire spoken language. Language development is strongly intertwined with voice perception. The aim of this electrophysiological study was to investigate human voice processing using measures of cortical auditory evoked potentials (AEPs) in pediatric CI users. Design: Cortical AEPs were measured in 8 CI children (4 to 12 years old) with good auditory and language performance and 8 normal-hearing (NH) age-matched controls. The auditory stimuli were nonspeech vocal sounds (laughing, sighing, coughing) and environmental sounds (e.g., telephones, alarms, cars, bells, water, wind). Independent component analysis was used to minimize the CI artifact in cortical AEPs. Results: Fronto-temporal positivity to vocal sounds was found in NH children, with a significant effect in the 140 to 240 msec latency range. In CI children, there was a positive response to vocal sounds in the 170 to 250 msec latency range, with a more diffuse and anterior distribution than in the NH children. Conclusions: Cortical responses to vocal sounds were recorded in CI children. The topography and latency of response to voice differed from that of NH children. The results suggest that cortical reorganization for processing vocal sounds may occur in congenitally deaf children fitted with a CI. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Auditory and Audiovisual Close Shadowing in Post-Lingually Deaf Cochlear-Implanted Patients and Normal-Hearing Elderly Adults.

Objectives: The goal of this study was to determine the effect of auditory deprivation and age-related speech decline on perceptuo-motor abilities during speech processing in post-lingually deaf cochlear-implanted participants and in normal-hearing elderly (NHE) participants. Design: A close-shadowing experiment was carried out on 10 cochlear-implanted patients and on 10 NHE participants, with two groups of normal-hearing young participants as controls. To this end, participants had to categorize auditory and audiovisual syllables as quickly as possible, either manually or orally. Reaction times and percentages of correct responses were compared depending on response modes, stimulus modalities, and syllables. Results: Responses of cochlear-implanted subjects were globally slower and less accurate than those of both young and elderly normal-hearing people. Adding the visual modality was found to enhance performance for cochlear-implanted patients, whereas no significant effect was obtained for the NHE group. Critically, oral responses were faster than manual ones for all groups. In addition, for NHE participants, manual responses were more accurate than oral responses, as was the case for normal-hearing young participants when presented with noisy speech stimuli. Conclusions: Faster reaction times were observed for oral than for manual responses in all groups, suggesting that perceptuo-motor relationships were somewhat successfully functional after cochlear implantation and remain efficient in the NHE group. These results are in agreement with recent perceptuo-motor theories of speech perception. They are also supported by the theoretical assumption that implicit motor knowledge and motor representations partly constrain auditory speech processing. In this framework, oral responses would have been generated at an earlier stage of a sensorimotor loop, whereas manual responses would appear late, leading to slower but more accurate responses. The difference between oral and manual responses suggests that the perceptuo-motor loop is still effective for NHE subjects and also for cochlear-implanted participants, despite degraded global performance. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Radiological Evaluation of Maxillary Sinus Anatomy: A cross-sectional study of 300 Patients

Publication date: Available online 29 July 2017
Source:Annals of Anatomy - Anatomischer Anzeiger
Author(s): Naroa Lozano-Carrascal, Oscar Salomó-Coll, Sergio Alexandre Gehrke, José Luis Calvo-Guirado, Federico Hernández-Alfaro, Jordi Gargallo-Albiol
ObjectiveThe aim of the present study was to evaluate the principal anatomical characteristics of the maxillary sinus using Cone Beam Computed Tomography (CBCT) in order to facilitate prevention of intra- and post-operative complications.Materials and methodsThree hundred CBCT scans from patients undergoing implant surgery were analysed. The following anatomical structures were evaluated: (1) Residual ridge height (RRH) and width (RRW); (2) Ridge bone density (BD); (3) Maxillary sinus angle (MSA); (4) Maxillary sinus lateral wall thickness (LWT); (5) Schneiderian membrane thickness (MT); (6) Maxillary sinus septa (SS); (7) Posterior superior alveolar artery (PSAA).ResultsMean patient age was 59.5±13.6. Mean RRH at upper second premolar (2PM) was 8.66±3.95mm, 4.90±2.28mm at first molar (1M), and 5.26±2.13mm at second molar (2M). Mean RRW was 6.72±2.69mm at 2PM, 6.87±2.65mm at 1M and 7.09±2.80mm at 2M. Bone Density was 330.93±211.02 Hounsfield Units (HU) at first molar position and MSA was 73.39±15.23°. LWT was 1.95±0.98mm. Mean Schneider Membrane thickness (MT) was 1.82±1.59mm; MT was≤3mm in 72.9% of patients and >3mm in 27.10%. 20.56% of patients presented bucco-palatal oriented septa with a mean height of 13.11±3.82mm. PSAA was observed in 48.60% and mean distance to the top of the ridge was 13.15±3.71mm, and was mostly observed inside the sinus (53.85%).ConclusionsCBCT scanning has been shown to be a useful tool for evaluating maxillary sinus anatomical variations. CBCT should be considered the gold standard when evaluating the maxillary sinus area.



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Online Embryology teaching using learning management systems appears to be a successful additional learning tool among Egyptian medical students

Publication date: Available online 29 July 2017
Source:Annals of Anatomy - Anatomischer Anzeiger
Author(s): Ahmed Farid Al-Neklawy
Although the traditional didactic lecture is considered to be efficient for presenting information and providing explanations, it usually does not provide adequate time for deeper learning activities. So, traditional lecture is one of the most widely criticized educational methods.Virtual learning environment (VLE) is a specially designed environment that facilitates teachers' management of educational courses for their students, using computer hardware and software, which involves distance learning.In this study, we evaluated the experiment of online teaching of General Embryology for Egyptian undergraduate medical students using WizIQ learning management system.A total of 100 students were invited to submit an online survey at the end of the course to evaluate delivery of instruction, creation of an environment that supported learning, and administrative issues.Most of the students reported that they were strongly satisfied with the efficacy of the instructional methods and were strongly satisfied with the degree of clarity of the course material. They strongly accepted the page format and design of the virtual classroom and strongly agreed that the learning environment supported the learning procedure. The item of easy logging into the virtual classroom had aberrant variable responses; it recorded the lowest mean response; this variation in responses was due to technical factors as the students used different devices with different speeds of internet connections.Ninety percent of students have strongly recommended the course attendance for their fellow students.These results demonstrate that online Anatomy teaching using learning management systems appears to be a successful additional learning tool among Egyptian medical students.



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Mechanistic insight into pyrene removal by natural sepiolites

Abstract

This paper investigates the sorption characteristics and mechanisms of pyrene onto two types of natural sepiolite-brown (B-Sep) and white (W-Sep). The effects of relevant properties such as clay content, surface area, pore diameter and volume, divalent cations, and organic carbon content were investigated by single component batch adsorption systems. The results suggest that pyrene has high affinity for both sepiolite and its sorption behavior could be mainly affected by exchangeable strongly hydrated cations such as Ca²⁺ and H₂O in the zeolite-like channels and by open channel defects (OCD) structures but no so much by the large number of Si-OH groups located on the sepiolite's basal surfaces. Mesoporosity rather than surface area largely controls the sorption capacity and intensity of both sepiolites. This is shown by the increase in pore volume that exhibited the greatest increase in BET surface area. Particle size and morphological changes of both sepiolites following pyrene adsorption determined by FE-SEM showed that the sepiolite fibers are much longer than their widths, which are only several laths (several nanometers). This is a result of growth, mostly along the c-axis, at the expense of the diffusion of pyrene molecules through aqueous solution. As a consequence, a significant fibrous morphology is produced following the adsorption of pyrene by both sepiolites.

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