Reciprocal Inhibition and Coactivation of Ankle Muscles in Low- and High-Velocity Forward and Backward Perturbations.

Reciprocal inhibition and coactivation are strategies of the central nervous system used to perform various daily tasks. In automatic postural responses (APR), coactivation is widely investigated in the ankle joint muscles, however reciprocal inhibition, although clear in manipulative motor actions, has not been investigated in the context of APRs. The aim was to identify whether reciprocal inhibition can be observed as a strategy in the recruitment of gastrocnemius Medialis (GM), Soleus (So) and Tibialis Anterior (TA) muscles in low- and high-velocity forward and backward perturbations. We applied two balance perturbations with a low and a high velocity of displacement of the movable platform in forward and backward conditions and we evaluated the magnitude and latency time of TA, GM and So activation latency, measured by electromyography (EMG). In forward perturbations, coactivation of the three muscles was observed, with greater activation amplitude of the GM and lesser amplitude of the So and TA muscles. For backward, the pattern of response observed was activation of the TA muscle, a decrease in the EMG signal, which characterizes reciprocal inhibition of the GM muscle and maintenance of the basal state of the So muscle. This result indicates that backward perturbations are more challenging.

Placental and Neonatal Serum Leptin Levels in Premature Infants After Phototherapy: Are They Determining Factors for the Safe Indication of Passive Exercises?

Purpose: To analyze leptin levels in placental tissue and premature infants undergoing phototherapy and to evaluate the potential for prescribing passive exercise after phototherapy in this population. Patients and Methods: This analytical, longitudinal, prospective cohort study included 108 parturients and their respective premature infants. Variables examined included weight, gestational age, body mass index, sex, serum leptin levels in placental tissue, serum bilirubin levels, and reticulocyte count. Results: When comparing each group to a leptin threshold, statistically significant differences were observed at all evaluated time points for placental leptin levels (p < 0.001). Additionally, reticulocyte count decreased in relation to rebound time (p < 0.004). No correlations were found between leptin/bilirubin levels, leptin/reticulocytes, onset of nutrition, and BMI/leptin levels. Conclusion: The findings regarding leptin levels suggest that prescribing passive exercises to premature infants undergoing phototherapy may be feasible because this intervention did not increase leptin levels.

Correlation between nasal anatomical characteristics in newborns and short binasal prong dimensions

Abstract Objective: To correlate the nasal anatomical characteristics of newborns with the dimensions of short binasal prongs. Method: Observational, cross-sectional study carried out in two hospitals in southern Brazil. The authors evaluated 1620 newborns with neonatal data and nasal dimensions. To measure the dimensions of the nasal region, the authors considered the width of the medial columella, the right nostril diameter, and the left nostril diameter. These data were correlated with the dimensions of two models of short binasal prongs. Results: Of the total newborns evaluated, 807 were female (49.8%), and 813 were male (50.2%). The majority were white (96.2%). The mean gestational age was 37.4 ± 2.9 weeks, ranging from 22 to 42 weeks. The birth weight was 2946.8 ± 699.3 g, ranging from 490.0 to 4740.0 g. Most of the nasal measures were significantly larger than both prong model measurements. Conclusion: The sizes of short binasal prongs available on the Brazilian market do not match the nasal anatomical characteristics of newborns.

Satisfaction of Health Professionals Regarding the Short Binasal Prong Used as a Non-Invasive Ventilation Interface in Neonatology.

Purpose: To evaluate the health professionals' satisfaction regarding the short binasal prong used in Neonatal Intensive Care Units (NICU), evaluate the difficulties related to its use, and present possible improvements in the design of this device. Patients and Methods: Observational, cross-sectional study with prospective data collection carried out in the NICU of a public hospital in southern Brazil. This research was presented into two stages. In the first stage, the Quebec User Evaluation of Satisfaction with Assistive Technology was applied with 90 health professionals to evaluate the satisfaction regarding the short binasal prong. In the second stage, the health professional's experiences and difficulties in using the binasal prongs in 14 newborns (NBs) that required non-invasive ventilation was collected. The short binasal prongs used was the Fanem® brand and the CPAP circuit was Gabisa Medical International (GMI®). Finally, improvements and recommendations were presented to optimize the device's design. Results: The mean score of the health professionals' satisfaction with short binasal prongs was 3.8 ± 0.6. Ease of adjustment (3.27) and dimensions (3.62) variables had the worst scores. The main difficulties pointed out by health professionals were: circuit disconnection (57.1%), the size of the prong did not correspond to NBs' anatomical characteristics (35.7%), air leakage (21.4%), and difficulty in fixing and positioning the prong in the NB (14.28%). The improvements suggested were: appropriate prong sizes based on the anatomical characteristics of the NBs; adjustable distance between insertion and base catheters; manufactured with malleable material, however not easily foldable; curved and adjustable insertion catheters and functional system of tracheas' connection. Conclusion: The dissatisfaction of health professionals with the dimensions and prongs adjustments and the difficulties faced in clinical practice indicate the need for improvements in these interfaces. The recommendations presented in this study may contribute to optimizing the design of the binasal prong in the future.

Investigation of the Use of Hollow Elastic Biomodels Produced by Additive Manufacturing for Clip Choice and Surgical Simulation in Microsurgery for Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) are dilatations of the cerebral arteries, whose treatment is commonly based on the implant of a metallic clip on the aneurysm neck. Despite the dissection and understanding of the surgical anatomy of the IA when often only parts of it are visible, the choice of the ideal clip to be used is one of the surgical difficulties. Although current imaging tests guarantee IA visualization, currently there is no planning method that allows for a real three-dimensional (3D) visualization for optimal choice of clip prior to surgery. The aim of this study is to evaluate whether IA biomodels generated by additive manufacturing methods are useful for surgical clip selection in microsurgeries for IA. METHODS: Three-dimensional (3D) IA biomodels of 10 patients with IA were evaluated using computerized tomography, surgical microscope, and 3D printer. The research was divided into 4 phases as follows: development of the 3D biomodels, evaluation of the biomodel dimensional characteristics, surgical planning evaluation with the biomodel and its clipping effectiveness, and evaluation of the actual surgical simulation process within the models. RESULTS: Ten 3D biomodels were obtained, made of a malleable and hollow part, formed by the IA and related arteries, and another rigid part, mimicking the skull and other arteries of the skull base. Based on these 3D models, 10 clips were chosen during the surgical planning, and all exactly matched the clip characteristics used during the actual surgeries. The surgical simulation with the biomodels performed by 2 neurosurgeons still in training obtained 100% accuracy in the identification of the clips that were eventually used during the actual surgeries. CONCLUSIONS: 3D biomodels generated by additive manufacturing methods were effective for surgical clip selection in microsurgeries for IA, reducing surgical time, increasing cerebral angioarchitecture understanding, and providing more safety in this type of surgery.

Thermal changes in the sacral region with different mattresses used in the prevention of pressure injuries.

BACKGROUND: Pressure Injury (PI) is a severe health problem that affects millions of people. As a preventive strategy for high-risk ICU patients, the appropriate selection of a support surface is essential for preventing PI, along with risk assessment and repositioning. Increasing skin temperature has been associated with a higher susceptibility to PI development. OBJECTIVE: This study aimed to evaluate thermal variations related to skin pressure in the sacral area of healthy individuals lying on three different mattresses models (standard, inflatable air, and egg crate). DESIGN: Experimental study. MAIN OUTCOMES: Initially, a survey was performed to identify the mattresses models most used in four public university hospitals and preventive strategies adopted. And then, an experimental study was conducted with a non-probabilistic sample involving 28 individuals of both sexes, aged 18-35 years old. The volunteers were immobilized for 2 h, and temperature variations in the sacral region were obtained by acquiring thermal images. RESULTS: A significant difference was not found in the temperature recorded on the three mattresses models before the experiment. However, there were significant differences at the 1st and 31st minute (p < 0.001). The lowest temperature values were identified in the air inflatable mattress. Post-hoc comparisons revealed a significant difference between standard or egg crate mattresses and the inflatable air model. CONCLUSION: The inflatable air mattress should be considered for preventing pressure injury in ICU patients since the temperature had returned to the initial value (pre-test) after the 31st min. In addition to the appropriate selection surface, risk assessment and positioning are essential to PI prevention strategies.

More than a feeling: Scalp EEG and eye signals in conscious tactile perception.

Understanding the neural basis of consciousness is a fundamental goal of neuroscience, and sensory perception is often used as a proxy for consciousness in empirical studies. However, most studies rely on reported perception of visual stimuli. Here we present behavior, high density scalp EEG and eye metric recordings collected simultaneously during a novel tactile threshold perception task. We found significant N80, N140 and P300 event related potentials in perceived trials and in perceived versus not perceived trials. Significance was limited to a P100 and P300 in not perceived trials. We also found an increase in pupil diameter and blink rate and a decrease in microsaccade rate following perceived relative to not perceived tactile stimuli. These findings support the use of eye metrics as a measure of physiological arousal associated with conscious perception. Eye metrics may also represent a novel path toward the creation of tactile no-report tasks in the future.

Detecting bone lesions in the emergency room with medical infrared thermography.

INTRODUCTION: Low- to high-energy impact trauma may cause from small fissures up to extended bone losses, which can be classified as closed or opened injuries (when they are visible at a naked eye). OBJECTIVE: The aim of this study was to investigate the feasibility of clinical diagnosis of bone trauma through medical infrared thermography, in a hospital emergency room. METHODS: Forty-five patients with suspected diagnosis of bone fracture were evaluated by means of medical infrared images, and the data correlated with the gold standard radiographic images, in the anteroposterior, lateral, and oblique views, at the orthopedic emergency department. The control group consisted of thermal images of the contralateral reference limb of the volunteers themselves. Data were acquired with a medical grade infrared camera in the regions of interest (ROIs) of leg, hand, forearm, clavicle, foot, and ankle. RESULTS: In all patients evaluated with a diagnosis of bone fracture, the mean temperature of the affected limb showed a positive difference greater than 0.9 °C (towards the contralateral), indicating the exact location of the bone trauma according, while the areas diagnosed with reduced blood supply, showed a mean temperature with a negative variation. CONCLUSION: Clinical evaluation using infrared imaging indicates a high applicability potential as a tool to support quick diagnosis of bone fractures in patients with acute orthopedic trauma in an emergency medical setting. The thermal results showed important physiological data related to vascularization of the bone fracture and areas adjacent to the trauma well correlated to radiographic examinations.

Effects of hydrotherapy and tactile-kinesthetic stimulation on weight gain of preterm infants admitted in the Neonatal Intensive Care Unit

Abstract Objective: The present study aimed to evaluate the effects of hydrotherapy and tactile-kinesthetic stimulation on the birth weight of preterm infants admitted in the Neonatal Intensive Care Unit. Method: It was a randomized controlled trial, without blinding, in which 44 preterm infants of both sexes with gestational age between 32 and 34 weeks were included into two groups: hydrotherapy group (n = = 22) and tactile-kinesthetic stimulation group (n = 22). Weight gain was the parameter assessed daily. Results: In the tactile-kinesthetic stimulation group there was a variation in weight gain, but without significant difference (p = 0,43). However, in the hydrotherapy group, it was observed that increased weight gain started from the 2nd day (p < 0,001). Conclusions: Hydrotherapy group presented significantly increased weight after the interventions, indicating that this technique can interfere with weight gain in preterm infants.

Forehead, Temple and Wrist Temperature Assessment of Ethnic Groups using Infrared Technology.

Non-contact infrared sensors are widely used as a diagnostic tool for elevated body temperature during initial screening for coronaviruses. The aim of this study was to investigate the thermal differences at three anatomical points: temple, forehead, and wrist, in the initial screening for temperature indicative of febrile and non-febrile states in skin pigmentation variations in Black, Half-Black and Caucasian skins, correlated with height and weight variables. Temperatures were obtained by means of an infrared thermometer in 289 volunteers with mean age of 18.30 ± 0.76, in a controlled environment according to Singapore Standard, SS582 part 1 and 2, normative standard IEC 80601-2-59, with standard technical protocols established by the International Organization for Standardization, ISO / TR 13154. The data were processed in MATLAB® R2021a, and data normality verified by Kolmogorov-Smirnov test, non-parametric data paired between temple / forehead / wrist were compared using the Wilcoxon signed-rank test. The results show different median temperatures in these anatomical regions, 37.2°C at the temple, 36.8°C at the forehead and 36.4°C at the wrist. As the temple region presents a temperature higher than the other investigated regions and, therefore, close to the core temperature, it should be considered for the initial screening of SARS-CoV-2 when using non-contact infrared thermometers. Furthermore, no significant changes were found due to variation in skin tone, height, or weight.

Effects of hydrotherapy and tactile-kinesthetic stimulation on weight gain of preterm infants admitted in the Neonatal Intensive Care Unit.

OBJECTIVE: The present study aimed to evaluate the effects of hydrotherapy and tactile-kinesthetic stimulation on the birth weight of preterm infants admitted in the Neonatal Intensive Care Unit. METHOD: It was a randomized controlled trial, without blinding, in which 44 preterm infants of both sexes with gestational age between 32 and 34 weeks were included into two groups: hydrotherapy group (n = = 22) and tactile-kinesthetic stimulation group (n = 22). Weight gain was the parameter assessed daily. RESULTS: In the tactile-kinesthetic stimulation group there was a variation in weight gain, but without significant difference (p = 0,43). However, in the hydrotherapy group, it was observed that increased weight gain started from the 2nd day (p < 0,001). CONCLUSIONS: Hydrotherapy group presented significantly increased weight after the interventions, indicating that this technique can interfere with weight gain in preterm infants.

Ergonomics of anatomical bra models for breastfeeding: a contribution of nursing / Ergonomía de modelos anatómicos de sostén para lactancia materna: una contribución de la enfermería / Ergonomia de modelos anatômicos de sutiã para amamentação: uma contribuição da enfermagem

ABSTRACT Objectives: to analyze the ergonomics of two models of breastfeeding bras. Methods: descriptive study carried out with 152 infants in a Brazilian university hospital. The prototypes were separated into two groups (A and B). To compare the two bra models, the Odds Ratio (OR) was used as a measure of the strength of the association. In subjective perceptions, the Modified Borg Scale, and the chi-square test of independence (χ2) were used. To compare the two prototypes, the Z test and logistic regression analysis were performed. A significance level of 5% was considered. Results: the bra in group B was more suitable for ergonomics of physical and psycho-aesthetic comfort than the bra in group A (p < 0.0001), according to the logistic regression tests. Conclusions: modeling B was ergonomically adequate, with usability and evaluation criteria centered on breastfeeding women.

RESUMEN Objetivos: analizar la ergonomía de dos modelados de sostén para lactancia materna. Métodos: estudio descriptivo realizado con 152 lactantes en un hospital universitario brasileño. Los prototipos fueron separados en dos grupos (A y B). Para comparar los dos modelados de sostén, fue utilizado la Odds Ratio (OR) como una medida de intensidad de la asociación. En las percepciones subjetivas, se utilizaron la Escala de Borg Modificada y el test chi-cuadrado de independencia (χ2). Para comparar los dos prototipos, se realizó el test Z y análisis de regresión logística. Se consideró un nivel de significación de 5%. Resultados: el sostén del grupo B fue el más adecuado para ergonomía de conforto físico y psicoestético del que el del grupo A (p < 0,0001), segundo los testes de regresión logística. Conclusiones: el modelado B fue ergonómicamente adecuado, con criterios de usabilidad y evaluación centrada en las lactantes.

RESUMO Objetivos: analisar a ergonomia de duas modelagens de sutiãs para amamentação. Métodos: estudo descritivo realizado com 152 lactantes em um hospital universitário brasileiro. Os protótipos foram separados em dois grupos (A e B). Para comparar as duas modelagens de sutiãs, foi utilizado a Odds Ratio (OR) como uma medida de intensidade da associação. Nas percepções subjetivas, utilizaramse a Escala de Borg Modificada e o teste qui-quadrado de independência (χ2). Para comparar os dois protótipos, realizou-se o teste Z e análise de regressão logística. Considerou-se um nível de significância de 5%. Resultados: o sutiã do grupo B foi o mais adequado para ergonomia de conforto físico e psicoestético do que o do grupo A (p < 0,0001), segundo os testes de regressão logística. Conclusões: a modelagem B foi ergonomicamente adequada, com critérios de usabilidade e avaliação centrada nas lactantes.

Clinical Applications of Additive Manufacturing Models in Neurosurgery: a Systematic Review

Introduction Three-dimensional (3D) printing technologies provide a practical and anatomical way to reproduce precise tailored-made models of the patients and of the diseases. Those models can allow surgical planning, besides training and surgical simulation in the treatment of neurosurgical diseases. Objective The aim of the present article is to review the scenario of the development of different types of available 3D printing technologies, the processes involved in the creation of biomodels, and the application of those advances in the neurosurgical field. Methods We searched for papers that addressed the clinical application of 3D printing in neurosurgery on the PubMed, Ebsco, Web of Science, Scopus, and Science Direct databases. All papers related to the use of any additivemanufacturing technique were included in the present study. Results Studies involving 3D printing in neurosurgery are concentrated on threemain areas: (1) creation of anatomical tailored-made models for planning and training; (2) development of devices and materials for the treatment of neurosurgical diseases, and (3) biological implants for tissues engineering. Biomodels are extremely useful in several branches of neurosurgery, and their use in spinal, cerebrovascular, endovascular, neuro-oncological, neuropediatric, and functional surgeries can be highlighted. Conclusions Three-dimensional printing technologies are an exclusive way for direct replication of specific pathologies of the patient. It can identify the anatomical variation and provide a way for rapid construction of training models, allowing the medical resident and the experienced neurosurgeon to practice the surgical steps before the operation.

Ergonomics of anatomical bra models for breastfeeding: a contribution of nursing.

OBJECTIVES: to analyze the ergonomics of two models of breastfeeding bras. METHODS: descriptive study carried out with 152 infants in a Brazilian university hospital. The prototypes were separated into two groups (A and B). To compare the two bra models, the Odds Ratio (OR) was used as a measure of the strength of the association. In subjective perceptions, the Modified Borg Scale, and the chi-square test of independence (χ2) were used. To compare the two prototypes, the Z test and logistic regression analysis were performed. A significance level of 5% was considered. RESULTS: the bra in group B was more suitable for ergonomics of physical and psycho-aesthetic comfort than the bra in group A (p < 0.0001), according to the logistic regression tests. CONCLUSIONS: modeling B was ergonomically adequate, with usability and evaluation criteria centered on breastfeeding women.

Evaluation of Tibia Bone Healing by Infrared Thermography: A Case Study.

BACKGROUND: Thermal imaging has been used as a clinical follow-up technique in several medical specialties. PURPOSE: The aim of this study was to investigate the feasibility of using medical thermography in the diagnosis and follow-up assessment of a severe orthopedic trauma that requires the use of an external circular fixator. PATIENTS AND METHODS: Twenty clinical follow-ups of thermal imaging correlated with X-ray images were performed in a male volunteer, diagnosed with bone nonunion, during 11 months of treatment, in the hospital trauma and reconstruction department. Data were acquired in the regions of interest of the proximal tibia, diaphysis and distal, with a Flir T530 medical grade infrared camera from Flir Systems®, and the data processed by the Matlab® 2019 custom made software. RESULTS: Statistical analysis was performed by Wilcoxon signed-rank test. The results showed a median temperature of 22.2°C, and thus some periods of interruption in the healing process between the third and twentieth clinical follow-up, and a significant increase of the temperature to 34.6°C synchronous with a diagnosis of bone infection by the eleventh clinical follow-up. The thermal images acquired during the 20 clinical follow-ups allow a correlation with the data from the X-ray exams and also with the contralateral limb of the evaluated patient, showing thermal alterations greater than 0.3°C, which are significant of physiological abnormality. CONCLUSION: The thermography exam can be a useful tool for applying on the follow-up of patients after trauma or bone fracture. The results showed important physiological data related to the vascularization necessary for bone repairing, being therefore a good indicator of the healing process. In addition, as infrared thermography does not use ionizing radiation, it can be used countlessly, in complement to the traditional X-ray exams that focus on anatomical data analysis.

Correlation of End-Tidal Carbon Dioxide with Arterial Carbon Dioxide in Mechanically Ventilated Neonates: A Scoping Review.

Monitoring CO2 levels in intubated neonates is highly relevant in the face of complications associated with altered CO2 levels. Thus, this review aims to present the scientific evidence in the literature regarding the correlation between arterial carbon dioxide measured by non-invasive methods in newborns submitted to invasive mechanical ventilation. The search was carried out from January 2020 to January 2021, in the Scopus, Medline, The Cochrane Library, Web of Science, CINAHL and Embase databases. Also, a manual search of the references of included studies was performed. The main descriptors used were: "capnography," "premature infant," "blood gas analysis," and "mechanical ventilation." As a result, 221 articles were identified, and 18 were included in this review. A total of 789 newborns were evaluated, with gestational age between 22.8 and 42.2 weeks and birth weight between 332 and 4790 g. Capnometry was the most widely used non-invasive method. In general, the correlation and agreement between the methods evaluated in the studies were strong/high. The birth weight did not influence the results. The gestational age of fewer than 37 weeks implied, in its majority, a moderate correlation and agreement. Therefore, we can conclude that there was a predominance of a strong correlation between arterial blood gases and non-invasive methods, although there are variations found in the literature. Even so, the results were promising and may provide valuable data for future studies, which are necessary to consolidate non-invasive methods as a reliable and viable alternative to arterial blood gasometry.

Influence of sensor mass and adipose tissue on the mechanomyography signal of elbow flexor muscles.

Mechanomyography (MMG) is a non-invasive technique that records muscle contraction using sensors positioned on the skin's surface. Therefore, it can have its signal attenuated due to the adipose tissue, directly influencing the results. This study evaluates the influence of different mass added to a sensor's assembly and the adipose tissue on MMG signals of elbow flexor muscles. Test protocol consisted of skinfold thickness measurement of 22 volunteers, followed by applying 2-3 s electrical stimulation for muscle contraction during the acquisition of MMG signals. MMG signals were processed in the time domain, using the average of the absolute amplitude, and expressed in gravity values (G), termed here as MMG(G). Tests occurred four times with different sensor masses. MMG data were processed and analyzed statistically using Friedman and Kruskal-Wallis tests to determine the differences between the MMG signals measured with different sensor masses. The Mann-Whitney analysis indicated differences in the MMG signals between groups with different skinfold thickness. MMG(G) signals suffered attenuation with increasing sensor mass (0.4416 G to 0.94 g; 0.3902 G to 2.64 g; 0.3762 G to 5.44 g; 0.3762 G to 7.14 g) and adipose tissue.

Incidence and Severity of Nasal Injuries in Preterm Infants Associated to Non-Invasive Ventilation Using Short Binasal Prong.

Short binasal prongs can cause skin and mucosal damage in the nostrils of preterm infants. The objective of this study was to investigate the incidence and severity of nasal injuries in preterm infants during the use of short binasal prongs as non-invasive ventilation (NIV) interfaces. A prospective observational study was carried out in the public hospital in a Southern Brazil. The incidence and severity of internal and external nasal injuries were evaluated in 28 preterm infants who required NIV using short binasal prongs for more than 24 hours. In order to identify possible causes of those nasal injuries, the expertise researcher physiotherapist has been carried empirical observations, analyzed the collected data, and correlated them to the literature data. A cause and effect diagram was prepared to present the main causes of the nasal injury occurred in the preterm infants assessed. The incidence of external nasal injuries was 67.86%, and internal ones 71.43%. The external nasal injuries were classified as Stage I (68.42%) and Stage II (31.58%). All the internal injuries had Stage II. The cause and effect diagram was organized into 5 categories containing 17 secondary causes of nasal injuries. There was a high incidence of Stage II-internal nasal injury and Stage I-external nasal injury in preterm infants submitted to NIV using prongs. The injuries genesis can be related to intrinsic characteristics of materials, health care, neonatal conditions, professional competence, and equipment issues.

Pupil Reactions to Tactile Stimulation: A Systematic Review.

Pupil dynamics can represent an indirect measure of perception; thus, it has been broadly explored in the auditory and visual fields. Although it is crucial for experiencing the outside world, tactile perception is not well-explored. Considering that, we sought to answer the following question via a systematic review: does normal tactile perception processing modulate pupil dilation in mammals (human or not)? The review process was conducted according to PRISMA Statement. We searched on Periódicos CAPES (Brazil) for the following terms: [(touch) OR (cutaneous stimulation) OR (tactile perception) OR (somatosensory) AND (pupil OR pupillary) NOT blind NOT reflex NOT pain NOT fear NOT noxious NOT autism NOT nerve NOT (pupillary block) NOT glaucoma NOT cataract NOT aneurysm NOT syndrome NOT treatment NOT special education]. From the 6,488 papers found, 4,568 were duplicates, and nine fulfilled the inclusion criteria. All papers found a positive relationship between pupil diameter and tactile perception. We found that the pupil is a reliable indirect measure of brain states and can evaluate norepinephrine (NE)/locus coeruleus (LC) action, stimulus inhibition, arousal, cognitive processes, and affection independently of the stimuli category (visual, auditory, or tactile). We also found that the perceptual tactile processing occurs in similar ways as the other perceptual modalities. We verified that more studies should be done, mostly avoiding low sampling rate recording systems, confounders as cue signs, not automated stimulation, and concurrent stimulus and using more reliable equipment.

Impact of Spontaneous Breathing Trials in Cardiorespiratory Stability of Preterm Infants.

BACKGROUND: A spontaneous breathing trial (SBT) is commonly used to determine extubation readiness in patients receiving mechanical ventilation. However, the physiological impact of such a trial in preterm infants has not been well described. This study aimed to investigate the effects of a 3-min SBT on the cardiorespiratory stability of these infants. METHODS: A retrospective analysis of prospectively collected data was done for infants < 37 weeks gestational age who were extubated after a successful 3-min SBT. Heart rate, [Formula: see text], breathing frequency, exhaled tidal volume, and Silverman Andersen Respiratory Severity Score (SA-RSS) to assess work of breathing, before and at the end of the SBT, were recorded and compared using nonparametric paired Mann-Whitney tests. A secondary analysis was done between extubation success (ie, 72 h without the need for re-intubation) and failure groups. Differences were considered statistically significant if P < .05. RESULTS: A total of 90 SBTs were performed in 70 premature infants; 65 had a successful SBT, and 5 failed the SBT. Of the 65 infants who had a successful SBT and were extubated, 6 failed extubation (9.2%). Subjects had a median (interquartile range [IQR]) gestational age of 30 (27-33) weeks at birth, a birthweight of 1,240 (860-1,790) g, and weight at extubation of 1,790 (1,440-2,500) g. Cardiorespiratory stability was noted by a significant decrease in median (IQR) exhaled tidal volume (6.4 [4.9-8.4] mL/kg vs 5.2 (3.8-6.6] mL/kg, P < .001), a significant increase in mean ± SD breathing frequency (45.1 ± 11.4 vs 52.6 ± 14.4 breaths/min, P < .001), and a significant median (IQR) increase in work of breathing (SA-RSS of 1 [1-2] vs 2 [1-3], P < .001) at the end of the SBT. Respiratory instability was more remarkable in the success group. CONCLUSIONS: In preterm infants receiving prolonged mechanical ventilation, the performance of a 3-min SBT was associated with increased respiratory instability while still leading to a 10% extubation failure rate. Therefore, the routine use of SBTs to assess extubation readiness in this population is not recommended until there are clear standards and definitions, as well as good accuracy to identify failures.