Head Elevation Research Articles

Transperineal ultrasound assessment of fetal head elevation by maneuvers used for managing umbilical cord prolapse.

To assess objectively the degree of fetal head elevation achieved by different maneuvers commonly used for managing umbilical cord prolapse. This was a prospective observational study of pregnant women at term before elective Cesarean delivery. A baseline assessment of fetal head station was performed with the woman in the supine position, using transperineal ultrasound for measuring the parasagittal angle of progression (psAOP), head-symphysis distance (HSD) and head-perineum distance (HPD). The ultrasonographic measurements of fetal head station were repeated during different maneuvers, including elevation of the maternal buttocks using a wedge, knee-chest position, Trendelenburg position with a 15° tilt and filling the maternal urinary bladder with 100 mL, 300 mL and 500 mL of normal saline. The measurements obtained during the maneuvers were compared with the baseline measurements. Twenty pregnant women scheduled for elective Cesarean section at term were included in the study. When compared with baseline (median psAOP, 103.6°), the knee-chest position gave the strongest elevation effect, with the greatest reduction in psAOP (psAOP, 80.7°; P < 0.001), followed by filling the bladder with 500 mL (psAOP, 89.9°; P < 0.001) and 300 mL (psAOP, 94.4°; P < 0.001) of normal saline. Filling the maternal bladder with 100 mL of normal saline (psAOP, 96.1°; P = 0.001), the Trendelenburg position (psAOP, 96.8°; P = 0.014) and elevating the maternal buttocks (psAOP, 98.3°; P = 0.033) gave modest elevation effects. Similar findings were reported for HSD and HPD. The fetal head elevation effects of the knee-chest position, Trendelenburg position and elevation of the maternal buttocks were independent of the initial fetal head station, but that of bladder filling was greater when the initial head station was low. To elevate the fetal presenting part, the knee-chest position provides the best effect, followed by filling the maternal urinary bladder with 500 mL then 300 mL of fluid, respectively. Filling the bladder with 100 mL of fluid, the Trendelenburg position and elevation of the maternal buttocks have modest effects. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Safe sleep after 1 year of age.

Safe sleep after 1 year of age.

Shortening effect influence of Distal Minimally Invasive Metatarsal Osteotomy in primary metatarsalgia

In primary metatarsalgia, Distal Minimally invasive Metatarsal Osteotomy (DMMO) achieves a correct load distribution which is a factor in pain relief, but contrary to the elevation of the metatarsal head, shortening the metatarsal length has no influence on plantar-loading parameters, while the increased metatarsal length is a factor in the development of metatarsalgia. Thus, we hypothesized that metatarsalgia could be partly related to a functional imbalance between bone structure and soft tissues and pain relief after DMMO results from soft tissue relaxation. Many authors have highlighted the correlation between joint pressure and periarticular soft tissue tension. To test our hypothesis, we measured intra-operatively the MTPJ pressure of 19 patients suffering from primary metatarsalgia, before and after DMMO. This pressure is being analyzed as a reflection of joint decompression and forefoot soft tissue release. Many authors have highlighted the correlation between joint pressure and periarticular soft tissue tension. Lower metatarsals presenting metatarsalgia show a significantly lower MTPJ pressure compared to asymptomatic rays, and DMMO induces a significant increase of MTPJ pressure. Those variations reflect the functional imbalance between bone structure and soft tissue in primary metatarsalgia. The biomechanical rationale of the shortening effect of DMMO could therefore be explained by the release of forefoot soft tissue, which could take part in the pain relief by restoring this balance.

Evaluating optic nerve head elevation

Evaluating optic nerve head elevation

Unilateral Optic Nerve Sheath Fenestration in Idiopathic Intracranial Hypertension: A 6-Month Follow-Up Study on Visual Outcome and Prognostic Markers.

Loss of vision is a feared consequence of idiopathic intracranial hypertension (IIH). Optic nerve sheath fenestration (ONSF) may be an effective surgical approach to protect visual function in medically refractory IIH. In this study, we evaluate the impact of unilateral superomedial transconjunctival ONSF on bilateral visual outcome using a comprehensive follow-up program. A retrospective chart review of IIH patients who underwent unilateral ONSF between January 2016 and March 2021 was conducted. Patients fulfilling the revised Friedman criteria for IIH and who had exclusively received ONSF as a surgical treatment were included. Main outcomes were visual acuity (VA); perimetric mean deviation (PMD); papilledema grade; and optic nerve head elevation (maxONHE) 1 week, 2 weeks, and 1, 3, and 6 months after surgery. VA (p < 0.05), PMD (p < 0.05), papilledema grade (p < 0.01), and maxOHNE (p < 0.001) were improved after 6 months on both the operated and non-operated eye. Prolonged surgical delay impedes PMD improvement (r = −0.78, p < 0.01), and an increasing opening pressure initiates a greater ganglion cell loss (r = −0.79, p < 0.01). In this small case series, we demonstrate that unilateral superonasal transconjunctival ONSF is a safe procedure with an effect on both eyes. Optic nerve head elevation and PMD are feasible biomarkers for assessing early treatment efficacy after ONSF.

Digestion-Specific Acupuncture Effect on Feeding Intolerance in Critically Ill Post-Operative Oral and Hypopharyngeal Cancer Patients: A Single-Blind Randomized Control Trial.

Malnourishment is prevalent in patients suffering from head and neck cancer. The postoperative period is crucial in terms of nutritional support, especially after composite resection and reconstruction surgery. These patients present with a number of risk factors that aggravate feeding intolerance, including postoperative status, prolonged immobility, decreased head elevation, mechanical ventilation, and applied sedative agents. Routine management protocols for feeding intolerance include prokinetic drug use and post-pyloric tube insertion, which could be both limited and accompanied by detrimental adverse events. This single-blind clinical trial aimed to investigate the effects of acupuncture in postoperative feeding intolerance in critically ill oral and hypopharyngeal cancer patients. Twenty-eight patients were randomized into two groups: Intervention group and Control group. Interventions were administered daily over three consecutive postoperative days. The primary outcome revealed that the intervention group reached 70% and 80% of target energy expenditure (EE) significantly earlier than the control group (4.00 ± 1.22 versus 6.69 ± 3.50 days, p = 0.012), accompanied by higher total calorie intake within the first postoperative week (10263.62 ± 1086.11 kcals versus 8384.69 ± 2120.05 kcals, p = 0.004). Furthermore, the intervention group also needed less of the prokinetic drug (Metoclopramide, 20.77 ± 48.73 mg versus 68.46 ± 66.56 mg, p = 0.010). In conclusion, digestion-specific acupuncture facilitated reduced postoperative feeding intolerance in oral and hypopharyngeal cancer patients.

What Is the Risk of Intraoperative Cerebral Oxygen Desaturation in Patients Undergoing Shoulder Surgery in the Beach Chair Position?

Previous studies have shown that intraoperative cerebral desaturation in patients undergoing shoulder surgery in the beach chair position varies widely, from 0% to 80%. To our knowledge, the risk of intraoperative cerebral desaturation is not known after all identified intraoperative modifiable physiologic parameters that influence cerebral blood flow have been controlled for. (1) What is the risk of intraoperative cerebral desaturation during shoulder surgery with the patient in the beach chair position when patients received combined general anesthesia and an interscalene block, and what other factors associated with intraoperative cerebral desaturation can be identified? (2) Is intraoperative cerebral desaturation associated with 24-hour cognitive decline? (3) What factors are associated with intraoperative hypotension? Between April and December 2020, 51 patients underwent elective shoulder surgery in the beach chair position at one center. Nine patients were excluded: four patients refused to participate, two patients were unable to receive an interscalene brachial plexus block, and three patients were operated on in less than 70° upright position. A total of 42 patients (aged 63 ± 10 years, of whom 52% [22 of 42] were female) were prospectively recruited into this study. Each patient was diagnosed with a rotator cuff tear and underwent arthroscopic repair in the beach chair position, which was performed in an upright position of 70° to 80°. Near-infrared spectroscopy was used to monitor regional cerebral oxygen saturation. The mean arterial pressure was monitored and controlled so that it was more than 70 mmHg in patients without hypertension and within 20% from the baseline mean arterial pressure in patients with hypertension. All patients received the standardized anesthesia protocol, which consisted of an interscalene brachial plexus block and general anesthesia. Intraoperative cerebral desaturation was defined as a decrease in the regional cerebral oxygen saturation level of more than 20% from the baseline value that lasted longer than 15 seconds after induction of anesthesia. Patients' clinical characteristics such as age, sex, BMI, preoperative hemoglobin level, preexisting medical conditions, and continuing antihypertensive medications on the morning of surgery were analyzed to identify the association with intraoperative cerebral desaturation. We used the Montreal Cognitive Assessment to assess cognitive function at preoperative and 24 hours postoperative. Episodes of hypotension and its treatment after maximum head elevation were recorded. The patients' clinical characteristics were analyzed to determine their association with hypotensive events. In this study, intraoperative cerebral desaturation occurred in 43% (18 of 42) of patients, and female sex was identified as an associated risk (odds ratio 4.3 [95% confidence interval 1.2 to 16.2]; p = 0.03). The median (interquartile range) duration of intraoperative cerebral desaturation was 19 minutes (5 to 38). There was no association between intraoperative cerebral desaturation and 24-hour postoperative cognitive decline (OR 0.6 [95% CI 0.1 to 2.4]; p = 0.44). Risk factors for intraoperative hypotension were a history of hypertension, regardless of whether or not the patient took antihypertensive drugs on the morning of surgery (OR 4.9 [95% CI 1.3 to 18.1]; p = 0.02), and dyslipidemia (OR 4.3 [95% CI 1.2 to 16.3]; p = 0.03). The intraoperative cerebral desaturation risk in the beach chair position was high. Female sex was an intraoperative cerebral desaturation risk factor. However, there was no association between intraoperative cerebral desaturation and postoperative cognitive decline. Patients with hypertension and dyslipidemia are at risk of intraoperative hypotension after positioning. Further large-scale studies are required to identify intraoperative cerebral desaturation-associated adverse neurologic outcome. Level II, therapeutic study.

A Review of the Tolerance and Adequacy of Enteral Nutrition Administered in the Prone Position in Critically Ill Patients Receiving Mechanical Ventilation

ObjectivesDuring the coronavirus 2019 (COVID-19) pandemic, more patients require enteral nutrition (EN) while mechanically ventilated in the prone position (PP). Prone positioning may improve oxygenation in patients receiving mechanical ventilation; however, it is unclear how it affects EN adequacy and tolerance. This review explored how EN delivered in the PP impacts EN tolerance (vomiting, diarrhea, abdominal distention, or aspiration pneumonia) and adequacy (meeting estimated energy and protein requirements) in critically ill adults receiving mechanical ventilation.MethodsA literature search was conducted in PubMed, CINAHL, Academic Search Premier, and Cochrane Library for English-language studies exploring EN administered in the PP published between 2000–2020. Studies that met inclusion criteria enrolled adult patients inintensive care units with acute respiratory distress syndrome or other respiratory conditions requiring mechanical ventilation, were cohort studies with ≥5 patients per study group, and had a dropout rate <20%. Studies were excluded if patients received only parenteral nutrition.ResultsOf 45 studies, 4 met inclusion criteria. Three were prospective cohorts and 1 was a before-after study. When comparing EN tolerance in the PP and supine positions, 1 study found no difference in diarrhea occurrence, 2 studies found no difference in the rate of vomiting, and 1 study found significantly higher rates of vomiting while in the PP. For feeding adequacy, 2 studies found no difference in the % of calories received when administered in prone or supine positions, while 1 study found patients in the PP received significantly less EN volume than patients in the supine position. One study concluded that prophylactic prokinetic agent use and head elevation while prone resulted in larger EN volumes delivered with reduced vomiting risk.ConclusionsThese results suggest the adequacy of EN delivered in the PP is comparable to the supine position and PP does not substantially increase vomiting or diarrhea risk. Prone positioning should not be considered an immediate contraindication to EN for adults receiving mechanical ventilation. These findings may apply to the nutritional management of critically ill mechanically ventilated adults with COVID-19.Funding SourcesNone

The Differences of Left Lateral and Head Elevation Position toward Heart Rate of Newborns with Asphyxia in the Perinatology Room RSUD Dr. Soediran Mangun Sumarso Wonogiri

BACKGROUND: Asphyxia delivery results in hypoxic-ischemic encephalopathy and multiorgan failure. The organ most affected by hypoxia is the cardiovascular system. Newborns with asphyxia have a lack of oxygen (hypoxia) and have an increased heart rate (tachycardia). Giving baby positions, such as supination position, pronation, right lateral, left lateral, and head elevation, are expected to improve the hemodynamic of newborns with asphyxia. AIM: This study was to determine the difference in effect between left lateral position and the head elevation position on the heart rate of newborns with asphyxia in the perinatology room of RSUD Dr. Soediran Mangun Sumarso Wonogiri. METHODS: This research is a quasi-experimental quantitative study with a pre- and post-test non-equivalent control group design. Sampling using non-probability sampling technique with consecutive sampling. The sample was divided into two groups, namely, the intervention group with 30 respondents who got the left lateral position and the control group with 30 respondents who got the head elevation position. Data analysis was performed using the Statistical Package for the Social Sciences parametric test with paired t-test and independent t-test. RESULTS: The results of paired t-test analysis in the intervention group obtained p = 0.003 (p &lt; 0.05) and in the control group obtained p &lt; 0.001 (p &lt; 0.05), which means that both have a significantly on changes in the heart rate of newborns with asphyxia. The results of the independent t-test analysis obtained p = 0.191 (p &lt; 0.05), which means that there is no significant difference in the heart rate of newborns with asphyxia in the intervention and control groups. CONCLUSION: Both interventions, giving the left lateral position and the head elevation position, have a significantly effect on changes in the heart rate of newborns with asphyxia.

ROLE OF MAGNETIC RESONANCE IMAGING IN DIAGNOSIS OF IDIOPATHIC INTRACRANIAL HYPERTENSION

Idiopathic intracranial hypertension (IIH) is a disorder of unknown cause that results in increased intracranial pressure without localizing neurologic findings .Brain imaging using MRI is important to exclude any mass occupying lesion or dural sinus thrombosis.MRI features of IIH include elevation of the optic nerve head, empty sellaturcica ,distention of the peri-optic subarachnoid space, tortuosity of the optic nerves, flattening of the posterior sclera of the globe, and dural venous sinus stenosis.AIM OF THE WORK:This study was conducted to study the role of MRI in diagnosis of benign intracranial hypertension.PATIENTS AND METHODSPATIENTS:This study was carried out on 20 patients with symptoms of intracranial hypertension referred to the Radio-diagnosis Department, Main University Hospital, Alexandria University from November 2019 to November 2020.METHODS:The studied patients were subjected to the following:Detailed history taking and thorough clinical examination.Imaging evaluation of the brain including :Routine magnetic resonance imaging sequences including 3D T1, axial, sagittal and coronal T2, axial FLAIR.T1 Weighted post contrast axial images if needed.MRV if needed to visualize dural venous stenosis or thrombosis

40 Dietary Saccharomyces cerevisiae fermentate affects mucosal immunity in young stress-challenged horses in training

Competition horses are under pressure from a wide range of stressors putting them at higher risk of infectious disease. Ingestion of Saccharomyces cerevisiae fermentate (SCF) products have been shown to improve immunocompetence in humans and other species, and we hypothesized it would provide similar benefits for horses. Yeast fermentate contains cellular components that can bind to pathogens and stimulate host immune cells, as well as bioactive fermentation byproducts (e.g., short chain fatty acids, vitamins, antioxidants) that can augment gut and other mucosal defenses. This study aimed to evaluate the effect of SCF on mucosal immunity in young horses in training. Two-year-old Quarter Horses (mean ± SEM; initial age 22 ± 0.3 mo and BW 439 ± 3 kg) were paired by age and sex and randomly assigned to receive SCF (Diamond V, Cedar Rapids, IA; 21 g/d; n = 10) or no supplement (CON; n = 10) added to their diet (60% hay, 40% concentrate) for 60 d. Horses were exercised 4 d/wk for 30–45 min/d at light to moderate intensity. On d 57, horses were placed in individual stalls and tethered with their heads elevated 35 cm above wither height for 12 h to induce mild upper respiratory tract inflammation. Feces, whole blood, and nasopharyngeal flush (NPF) samples were obtained at study initiation and before and up to 72 h after stress induction to evaluate immune responses. Data were compared using mixed model ANOVA with time as a repeated measure. Prolonged head elevation resulted in greater ( P < 0.0001) serum cortisol and increases ( P < 0.05) in mucus, total leukocytes, neutrophils, lymphocytes, monocytes, and ratio of neutrophils to lymphocytes in NPF, indicative of an inflammatory response that was mostly resolved by h 72. A similar leukogram was observed in whole blood, though it was delayed 12 h compared with NPF. Neutrophils and lymphocytes were lower ( P < 0.05) and monocytes greater ( P < 0.05) in NPF from horses fed SCF than CON. Immunoglobulin (Ig) A in NPF exhibited a time × treatment effect ( P = 0.05) with an increased response to head elevation in SCF horses but no change in CON. Head elevation increased ( P < 0.05) IgA, IgG and IgM in feces, and fecal concentrations of IgA and IgG were greater ( P < 0.05) for CON than SCF. Serum IgA, IgG, and IgM were not affected by head elevation nor treatment. Changes in leukocytes and IgG in mucosal secretions suggest a stronger inflammatory response to head elevation in CON horses. Higher IgA in NPF from SCF horses may have helped attenuate local inflammation. Further study is needed to determine if SCF could improve other markers of disease resistance.

Utility of Ultrasound and Optical Coherence Tomography in Differentiating Between Papilledema and Pseudopapilledema in Children.

Differentiating between papilledema and pseudopapilledema in children presenting with mild-to-moderate optic nerve head elevation is challenging. This study sought to determine which B-scan ultrasonography (BSUS) and optical coherence tomography (OCT) features, individually or in combination, are best able to differentiate between papilledema and pseudopapilledema in children. Children presenting with optic nerve head elevation of unknown etiology were eligible if they underwent BSUS and OCT performed by the same investigator. The absolute optic nerve sheath diameter (in millimeter) along with the presence/absence of a hyperreflective nodule(s) at the optic nerve head (indicative of druse) from BSUS was determined. The average circumpapillary retinal nerve fiber layer (cpRNFL), diameter of Bruch membrane opening, maximum papillary height, and the presence/absence of hyper-/hyporeflective lesions at the optic nerve head were calculated. Sensitivity and specificity were calculated to evaluate which BSUS and OCT imaging features, individually and in combination, accurately classified children as having papilledema vs pseudopapilledema. One hundred eighty-one eyes from 94 children (mean age, 11.0 years; range, 3.2-17.9) were included; 36 eyes with papilledema and 145 eyes with pseudopapilledema. Among BSUS features, optic nerve sheath widening (>4.5 mm) demonstrated the best sensitivity (86%; 95% confidence interval [CI], 64%-96%) and specificity (88%; 95% CI, 79%-94%) for papilledema. Among OCT measures, cpRNFL thickness of ≥140 µm demonstrated the best sensitivity (83%; 95% CI, 66%-93%) and specificity (76%; 95% CI, 66%-84%) to identify papilledema. The presence of both optic nerve sheath widening (>4.5 mm) and cpRNFL thickness of ≥140 µm reduced the sensitivity (72%; 95% CI, 52%-86%) but increased specificity (95%; 95% CI, 88%-98%). BSUS (optic nerve sheath widening [>4.5 mm]) and OCT (cpRNFL thickness ≥140 µm), individually and collectively, have good diagnostic accuracy for differentiating between papilledema and pseudopapilledema. The presence of druse does not exclude the diagnosis of papilledema.

The glenoid-intramedullary humeral angle: a measurement of compensatory scapular abduction in advanced rotator cuff arthropathy and its potential effects on implant choice.

BackgroundThis study establishes measurements to evaluate pathologic compensation in rotator cuff tear arthropathy and resultant considerations for reverse shoulder arthroplasty.MethodsRadiographs of patients with intact rotator cuffs were measured establishing interobserver and intraobserver reliability. Reverse shoulder arthroplasty cases performed by a single surgeon were then retrospectively reviewed. One year of follow-up radiographs were required for inclusion. Preoperative radiographs were analyzed for relative humeral head elevation ratio and humeral abduction relative to the glenoid face, termed the glenoid-intramedullary humeral angle. Statistical analyses assessed associations for radiographic measurements with presence and severity of scapular notching based on the Nerot-Sirveaux classification system.ResultsA total of 221 patients met inclusion criteria. At the 1-year follow-up, 61 (27.6%) shoulders had radiographic notching. There was a moderately strong (r = -0.56) negative correlation between glenoid-intramedullary humeral angle and humeral head elevation ratio. Patients with humeral head elevation ratio ≥ 20% were significantly (P = .024) and 9.2 times more likely to have notching of any grade. Patients with glenoid-intramedullary humeral angle ≤ 5 degrees were significant (P < .0001) and 6.7 times more likely to have notching of any grade and significantly (P = .00018) and 145 times more likely to have high-grade (3 and 4) notching.ConclusionsPreoperative humeral head elevation and compensatory scapular rotation with relative adduction of the humerus have significant associations with high-grade notching. These radiographic findings have potential to help surgeons in preoperative decision-making regarding implant choice and patient education.

#52: Role of Good Oral Hygiene in Reducing and Preventing Ventilator-associated Pneumonia (VAP) in the Intensive Care Unit (ICU) in a Tertiary Care Hospital

Abstract Background Ventilator-associated pneumonia (VAP) is when a patient who received mechanical ventilation for at least 48 hours develops pneumonia. According to the literature, the prevalence rate of VAP in patients experiencing mechanical ventilation is 9%–68%, its resulting mortality is 30%–70%, it also extends hospital and ICU stay by 6–7 days, raises healthcare costs by $40,000 per patient. VAP is a serious complication in the critically ill one factor causing VAP is an aspiration of oral colonization which may result from poor oral hygiene care. Oral hygiene care using either a mouth rinse or with help of forceps and gauze or combination together with the aspiration of secretion can reduce the risk of VAP in these critically ill patients. Method The main aim of this study was to evaluate the effect of strengthening oral hygiene practices and develop cost-effective and easy to use protocols of oral hygiene for ventilator-dependent patients. This study is an observational study conducted in all intensive care unit at tertiary care hospital, 41 bedded inpatient critical care area including high dependency unit (HDU)/coronary care unit (CCU), medical intensive care unit (MICU), surgical intensive care unit (SICU), neonate intensive care unit (NICU) and pediatric intensive care unit (PICU). Approximately 500 patients were admitted monthly to the intensive care unit. All ventilated patients admitted to the intensive care unit are included. Intervention is done in three phases: firstly, VAP device-associated infection (DAI’s) surveillance initiated according to the CDC guideline. HAI’s surveillance was done on daily basis. Secondly, educate staff regarding DAI’s surveillance, VAP bundle, Oral care and suction technique of ventilated patient). Ongoing training and hands-on practice on mannequin and also perform sign-off on the patient first under supervision of Nurse instructor and infection control officers. Finally, VAP bundle was initiated which include elevation of head, daily sedation vacation, and assessment of readiness to extubate, daily oral hygiene care, and assessment of stress ulcer and deep venous thrombosis prophylaxis. Result Before implementation, we just calculate all pneumonia rates together not using proper guidelines. But after we follow CDC guideline for DAI’s surveillance, we trained more than 50% of critical care staff out of 93 staffs, and 90% to 95% compliance of using chlorhexidine gluconate for oral care at least per shift and also as per patient needed observed in ventilated patients. Conclusion The implementation of these changes in practices along with using chlorhexidine gluconate products has made it possible to achieve goal and staff perform work according to the best practice guideline. Oral care hygiene using chlorhexidine gluconate (CHG) as an element of the ventilator bundle is supposed to decontaminate the mouth, avoid aspiration of contaminated secretion into the respiratory tract and prevent VAP.

An Analytical Model to Study the Behavior of Non-connected Piled Rafts with Granular Cushion Subjected to Vertical Load

Understanding the load transfer mechanism and the load settlement behavior of non-connected piled raft foundations with cushion is so complicated. In the present research, based on the assumption of an axisymmetric cylindrical unit cell including pile, subsoil, cushion, and raft, an analytical model is developed and introduced. This model is capable of estimating the transferred vertical stress from raft to piles head and subsoil, compression of cushion, and differential settlement between pile head and subsoil. Also, an experimental test program has been introduced to investigate the behavior of non-connected piled raft foundations and to validate the proposed model. To represent the effectiveness of using non-connected piled raft with different cushion thickness, number, and length of piles measure with the unpiled raft, the load improvement ratio and the settlement efficiency ratio are used. According to the results, the minimum increase in the bearing capacity and the reduction in the settlement of non-connected piled raft to the unpiled raft are 42% and 38% respectively. Also, increasing the cushion thickness increases the differential settlement at the pile head elevation, and for a given number and length of pile, reduced the bearing capacity of the piled raft by 30%. The good agreement of model predictions with the experimental results is verified. The difference between the experimental and analytical values of the cushion compression above the pile head is within an acceptable range.

The Impact of Hydrogeological Features on the Performance of Underground Pumped-Storage Hydropower (UPSH)

Underground pumped storage hydropower (UPSH) is an attractive opportunity to manage the production of electricity from renewable energy sources in flat regions, which will contribute to the expansion of their use and, thus, to mitigating the emissions of greenhouse gasses (GHGs) in the atmosphere. A logical option to construct future UPSH plants consists of taking advantage of existing underground cavities excavated with mining purposes. However, mines are not waterproofed, and there will be an underground water exchange between the surrounding geological medium and the UPSH plants, which can impact their efficiency and the quality of nearby water bodies. Underground water exchanges depend on hydrogeological features, such as the hydrogeological properties and the groundwater characteristics and behavior. In this paper, we numerically investigated how the hydraulic conductivity (K) of the surrounding underground medium and the elevation of the piezometric head determined the underground water exchanges and their associated consequences. The results indicated that the efficiency and environmental impacts on surface water bodies became worse in transmissive geological media with a high elevation of the piezometric head. However, the expected environmental impacts on the underground medium increased as the piezometric head became deeper. This assessment complements previous ones developed in the same field and contributes to the definition of (1) screening strategies for selecting the best places to construct future UPSH plants and (2) design criteria to improve their efficiency and minimize their impacts.

Body pressure prediction for pressure ulcer prevention in a bed head elevation operation

ABSTRACT Pressure ulcers are caused by tissue damage, which occurs when the blood supply to an area of skin is diminished because of sustained or concentrated pressure on a patient from the mattresses of a bed. One action that concentrates the pressure is a bed head elevation operation. Recently, a control system known as the alternative pressure mattress has been proposed to prevent the concentration of pressure. However, the challenge with this controlled system is that it has a slow response because it uses air cells. The slow response causes controlling the air cells to lag behind the change in pressure during the bed head elevation operation. Therefore, this system cannot adequately prevent the concentration of pressure on a patient. To address this issue, we need to predict the change in pressure during the bed head elevation operation and control the pressure based on this prediction. In the current work, we focus on predicting the pressure distribution. This prediction is high-dimensional. We regarded the pressure distribution as an image and predicted the change in pressure by applying a deep neural network. To the best of our knowledge, this paper is the first to propose the body pressure predictive model.

Updates on ophthalmic imaging features of optic disc drusen, papilledema, and optic disc edema.

Purpose of reviewOptic nerve head elevation can be associated with vision loss. This review provides an update regarding key features of optic disc drusen (ODD) compared with papilledema from increased intracranial pressure and optic disc edema from other causes.Recent findingsClinical history and funduscopic examination are not sufficient to correctly diagnose different causes of optic nerve head elevation. Multimodal ophthalmic imaging is noninvasive and should be used as first-line diagnostic testing to distinguish optic disc edema or papilledema from pseudoedema. Advanced ophthalmic imaging, including enhanced depth imaging optical coherence tomography (EDI-OCT) and autofluorescence imaging, can visualize ODD at high resolution and determine whether there is optic disc edema. OCT angiography does not require contrast and can rapidly visualize papillary, peripapillary, and macular microvasculature and identify important vascular biomarker of ischemia and, potentially, visual prognosis.SummaryMultimodal ophthalmic imaging can help in the diagnosis of ODD and optic disc edema and identify patients at high risk of vision loss and neurological issues in order to ensure appropriate diagnosis and treatment.

Should the Impact of Postural Change of Intracranial Pressure After Surgical Repair of Skull Base Cerebrospinal Fluid Leaks Be Considered? A Preliminary Survey.

Managing skull base cerebrospinal fluid (CSF) leaks is often challenging. Postoperative care, especially regarding postural restrictions and bedrest recommendations, is variable and continues to be based on empirical habits. An electronic survey was submitted to French experts in skull base surgery to evaluate current practice of postoperative postural recommendations in patients treated for skull base CSF leaks. Thirty-nine experts completed the survey. Postoperative recommendations were heterogenous. They depended on the size of defects: half of the surgeons did not recommend any constraints of posture for small defects; 84% recommended bed rest for large defects. The most preferred bed-rest modality was Fowler's position (20°-30° tilt). Standing/walking during short periods was allowed in up to 73%. From a physiological viewpoint, head elevation decreases ICP and thus limits the risk of recurrence of CSF leak. However, ICP can fall below 0 in the standing position, favouring pneumocephalus. These results confirmed that postural recommendations for patients surgically treated for skull base CSF leaks remain variable. Recommendations should take into consideration the postural change in ICP. Fowler's position may represent the best compromise between risk of recurrence of CSF leak and the risk of pneumocephalus in large CSF leaks.

Improving post-cardiac arrest cerebral perfusion pressure by elevating the head and thorax

AimThe optimal head and thorax position after return of spontaneous circulation (ROSC) following cardiac arrest (CA) is unknown. This study examined whether head and thorax elevation post-ROSC is beneficial, in a porcine model. MethodsProtocol A: 40 kg anesthetized pigs were positioned flat, after 7.75 min of untreated CA the heart and head were elevated 8 and 12 cm, respectively, above the horizontal plane, automated active compression decompression (ACD) plus impedance threshold device (ITD) CPR was started, and 2 min later the heart and head were elevated 10 and 22 cm, respectively, over 2 min to the highest head up position (HUP). After 30 min of CPR pigs were defibrillated and randomized 10 min later to four 5-min epochs of HUP or flat position. Multiple physiological parameters were measured. In Protocol B, after 6 min of untreated VF, pigs received 6 min of conventional CPR flat, and after ROSC were randomized HUP versus Flat as in Protocol A. The primary endpoint was cerebral perfusion pressure (CerPP). Multivariate analysis-of-variance (MANOVA) for repeated measures was used. Data were reported as mean ± SD. ResultsIn Protocol A, intracranial pressure (ICP) (mmHg) was significantly lower post-ROSC with HUP (9.1 ± 5.5) versus Flat (18.5 ± 5.1) (p < 0.001). Conversely, CerPP was higher with HUP (62.5 ± 19.9) versus Flat (53.2 ± 19.1) (p = 0.004), respectively. Protocol A and B results comparing HUP versus Flat were similar. ConclusionPost-ROSC head and thorax elevation in a porcine model of cardiac arrest resulted in higher CerPP and lower ICP values, regardless of VF duration or CPR method. IACUC Protocol Number19-09.