Sudden Deterioration Research Articles

Cardiac arrest and ventricular tachycardia in a newborn with carnitine–Acylcarnitine translocase deficiency

We report a female infant who was diagnosed to have carnitine–acylcarnitine translocate deficiency (CACTD) and developed ventricular tachycardia followed by cardiac arrest. Following full feeding, the infant developed significant bradycardia, hypothermia, hypotonia, hypoglycemia, metabolic acidosis, and hyperammonemia. The hyperammonemia was successfully treated with continuous renal replacement therapy (CRRT). One day after the CRRT, she developed ventricular tachycardia that was refractory to medical treatment and synchronized cardioversion. She had cardiac arrest that was unresponsive to full cardiopulmonary resuscitation and died. Raising high index of suspicion of CACTD in the deferential diagnosis of infants present with sudden deterioration, hypoglycemia or hyperammonemia is crucial for early recognition and providing appropriate treatment in this highly lethal disorder.

Cystic Vestibular Schwannomas and Post–Gamma Knife Radiosurgery-Induced Necrosis of Vestibular Schwannomas: Report of Two Cases and Review of Literature

AbstractCystic vestibular schwannomas (VS) form a rare subgroup that differs from the solid variant clinically and radiologically. Certain unique features reported in cystic VS are larger size, presentation with atypical initial symptoms such as dysgeusia, vertigo, facial pain and gait unsteadiness, short duration of symptoms, rapid progression of symptoms or sudden deterioration and frequent involvement of facial nerve. Gamma Knife radiosurgery (GKRS) is a safe and effective treatment for VS, achieving tumor control and resulting in a very low morbidity rate. Here, we described two cases of cystic vestibular schwannomas prior to GKRS and their radiological appearances post-GKRS.

Post-Traumatic Gallbladder Injury in Children: Case Rapport

Post-traumatic injuries of the gall bladder are rare. We report through a clinical description of its physio-pathological and evolutionary aspects. A 14-year-old boy was received 48 hours after a stabbing attack. After initial haemorrhage, the patient presented clinical improvement; then a sudden deterioration with vague symptoms and disturbance of the hepatic balance. The abdominal CT scan revealed a perivesicular hematoma with a focus on hepatic contusion. Laparoscopy showed a penetrating sore of the liver, but the exploration was limited by an important inflammation of the digestive tract. The diagnosis of gall bladder perforation was made during the operation. We performed a cholecystectomy by laparotomy. Postoperative evolution was simple, removal of the slides at D + 4 and discharged at D + 7 postoperative after improvement. At the 6th month, he presented an acute intestinal obstruction on bridles, managed at emergency by open surgery. After one year of follow up, the patient has no symptoms. We note that the vague clinical presentation and the limit of imaging examinations made the early diagnosis of a vesicular perforation a real challenge for the clinician. Cholecystectomy remains the optimal treatment.

Machine Learning Predicts Acute Pulmonary Exacerbations in Cystic Fibrosis

Background: Sudden deteriorations in lung health, termed acute pulmonary exacerbations (APEs), are a major driver of mortality and morbidity in Cystic Fibrosis (CF). Accurate prediction of impending APEs would permit pre-emptive interventions and allow home monitoring to safely replace hospital-based physician consultations. Methods: We enrolled 147 adults with CF into a six-month study of home monitoring based at seven UK specialist CF Centers. Subjects were asked to undertake daily measurements of lung function, oximetry, pulse rate, weight, and activity (using sensors Bluetooth-linked to mobile phones), and provide daily self-reported symptom scores of cough frequency, general wellness, and sleep quality. Linked-anonymised data were then analysed using machine learning (ML) methods to define the profile of APEs and predict their onset. Findings: End of study questionnaires revealed that 92% of participants found home monitoring easy to use and 76% found it helpful or very helpful in tracking their health over time. Unsupervised machine learning analysis uncovered the typical signal profile of an APE and revealed three distinct classes of exacerbation. We developed a ML predictive classifier that can detect an impending APE on average 10 days earlier that current clinical practice. Interpretation: High frequency home monitoring in CF is feasible, reveals distinct types of APEs, and permits accurate prediction of future exacerbations. Trial Registration Number: NCT02416375 (ClinicalTrials.gov). Funding Statement: This study was funded through research grants from the UK Cystic Fibrosis Trust, Royal Papworth Hospital, the Wellcome Trust (Investigator Award RAF; 107032/Z/15/Z), and Microsoft Research/EPSRC (PhD scholarship DES). Declaration of Interests: Thomas Daniels has accepted speaker fees from Vertex pharmaceuticals, and consultancy fees from Chiesi Pharmaceuticals, none of which were involved in anyway at all with the submitted manuscript, nor had any influence at any stage of the work. The remaining authors have no competing interests to declare. Ethics Approval Statement: The study received National Ethical approval from the NRES Committee East of England-Norfolk (REC 14/EE/1244) and site-specific approval and monitoring from each participating Hospital R&D Department. All participants provided written informed consent before enrolment into the study.

P631 A misleading EKG and the saviour echo

Abstract Introduction Floating right heart thrombi (in transit from the legs to the pulmonary arteries) are a severe form of venous thromboembolism, with a high early mortality rate without treatment. Evidence-based recommendations do not adequately address the treatment of right heart thrombi in patients who present with acute symptomatic pulmonary embolism. Case Report Woman, 76 years old. Previous medical history of hypertension, dyslipidaemia, mitral valve repair and hypothyroidism. Recent admission in our cardiology department with de diagnosis of NSTEMI. She performed an echocardiogram that revealed only an enlarged left atrium, with no other changes. EKG only revealed inversion of T waves in V2-V4 with posterior normalization during hospital stay. She underwent to coronary angiography and right dominance without any coronary lesions was showed. The presence of a fistula, with a badly defined route, was also pointed in the coronary angio. One month after this episode she was admitted again in our emergency department due to onset of dyspnoea and productive cough. The physical examination showed SatO2: 90%; BP: 95/53 mmHg; HR: 100 bpm; Respiratory rate: 27 cpm; Apyretic (36,9ºC). Normal pulmonary and cardiac auscultation, without any other pathological findings on physical examination. EKG revealed a sinus tachycardia, HR 122 bpm, with ST elevation in aVR and ST depression in DI, DII, aVL and V2-V6. Presence of S wave in DI and Q wave in DIII. While the EKG was being performed the patient presented a sudden cardiovascular deterioration (with blood pressure (BP: 67/35mmHg) drop and appearance of chest pain). We performed an arterial-blood gas test that revealed: pH7,16; pCO2 26,5; pO78,7; Potassium 4; Sodium 138; lactates 8,8. With these findings we decided to perform an echocardiogram to identify a possible cause for the shock. The echo showed right dilated chambers (with D-shape in parasternal short axis) with dilated IVC. We also point out the presence of a mobile intra-cardiac mass at the level of right atrium, suggestive of thrombus. We assumed the presence of obstructive shock in the context of pulmonary embolism. Thrombolysis was performed with clinical improvement of the patient. Medical therapy was optimized and heparin was initiated after the patient finished alteplase perfusion. During hospital stay the patients didn’t have any other cardiovascular complication and went home after 7 days in hospital. A venous doppler was performed before hospital discharge and it revealed the presence of a deep venous thrombosis at the level of right femoral vein. Conclusion The authors presented a didactic clinical case where the EKG mislead us to a possible Acute Coronary Syndrome involving the left main artery. Although there is no clear consensus for the management of right heart thrombus associated with pulmonary embolism, thrombolysis is readily available and can be effective in carefully selected patients.

P845 Deep vein thrombosis, pulmonary embolism and patent foramen ovale: a lethal mix

Abstract A 50-year-old woman without remarkable medical history was admitted at the Emergency Department for acute dyspnoea. The patient had been recently submitted to C5-C6 microdiscectomy. She was tachypneic and oxygen saturation was 88%. CT angiography showed bilateral pulmonary embolism (PE) (Figure 1A, yellow arrowheads) with signs of right ventricle overload. Bilateral deep vein thrombosis was also confirmed. The patient was admitted at the Intensive Care Unit, clinically stable. Few hours later, she presented sudden hemodynamic and respiratory deterioration, requiring invasive mechanical ventilation and vasopressors. Due to recent cervical surgery, systemic fibrinolysis was ruled out. Decision for percutaneous thrombectomy and inferior vena cava filter placement was made. Nevertheless, percutaneous thrombectomy was unsuccessful due to the impossibility to catheterize pulmonary artery. Contrast injection demonstrated that the guiding catheter was located in the left atrium (Figure 1B), suggesting a patent foramen ovale (PFO). Transoesophageal echocardiogram confirmed the presence of a 5x6 mm PFO with right-to-left shunt (Figures 1C – yellow arrows, and 1D). In addition, a 4 cm mobile mass attached to the aortic valve and protruding throughout the left ventricle outflow tract was visualized, suggesting paradoxical embolism (Figure 1E – white arrows). Accordingly, open surgical approach with pulmonary thrombectomy, PFO closure and removal of the left-sided thrombus was decided. Unfortunately, despite careful cannulation, thrombus was not found when aortic valve was inspected. Worst suspicions were confirmed, when the patient presented non-reactive mydriatic pupils. A brain CT showed signs of an extensive bihemisferic ischemic stroke (Figure 1F) presumably related to cerebral embolization of aortic thrombus. The patient finally died. Autopsy study was not consented. PFO has been associated with paradoxical embolisms and risk of stroke in PE. This case strikingly illustrates that treatment of these patients may be challenging in spite of an adequate diagnosis and management. Abstract P845 Figure.

Posterior cerebral artery ischemic stroke in a patient with hypoplastic P1 segment of the posterior cerebral artery

Posterior circulation stroke usually presents with clinical challenges, and symptoms may include blindness. Hypoplastic or atretic cerebral artery may be a risk factor for future ischemic stroke. We present a 75-year-old male patient with posterior cerebral artery ischemic stroke who presented with sudden visual deterioration, and brain magnetic resonance angiography showed hypoplastic right P1.

A new cumulative damage model for time-dependent reliability analysis of deteriorating structures

Performance and reliability of structures will deteriorate with the effects of loads, environment, and interior factors of materials. In this article, a novel cumulative damage model is developed for time-dependent reliability analysis of deteriorating structures. The deterioration is a combination of three stochastic processes: the gradual deterioration posed by aging effects, the sudden deterioration caused by transient loads, and the additional deterioration introduced by sustained loads. The aging effect is modeled as a gamma process, while the transient load is described by a Poisson process. The sustained load is modeled by a stationary binomial process and a Poisson square wave process, respectively. The load threshold for three different scenarios are all considered and applied to not only the transient loads but also the sustained loads. The time-dependent reliability of deteriorating structures is then evaluated based on this model via semi-analytical methods or numerical simulation methods. Three numerical examples and an example involving a natural gas pipeline are used to validate the effectiveness of the proposed model for computing the time-dependent reliability.

Performance of the Afferent Limb of Rapid Response Systems in Managing Deteriorating Patients: A Systematic Review.

Introduction The clinical components of the rapid response system (RRS) are the afferent limb, to ensure identification of in-hospital patients who deteriorate and activation of a response, and the efferent limb, to provide the response. This review aims to evaluate the factors that influence the performance of the afferent limb in managing deteriorating ward patients and their effects on patient outcomes. Methods A systematic review was performed for the years 1995–2017 by employing five electronic databases. Articles were included assessing the ability of the ward staffs to monitor, recognize, and escalate care to patient deterioration. The findings were summarized using a narrative approach. Results Thirty-one studies met the inclusion criteria. The analysis revealed major themes enclosing several factors affecting management of patients having sudden deterioration. The monitoring and recognition process was conditioned by the lack of recording of physiological parameters, the influence of facilitators, including staff education and training, and barriers, including human and environmental factors, and poor compliance with the calling criteria. The escalation of care process highlighted the influence of cultural barriers and personal judgment on RRS activation. Mainly, delayed team calls were factors strongly associated with the increased risk of unplanned admissions to the intensive care unit and length of stay, hospital length of stay and mortality, and 30-day mortality. Conclusions A combination of factors affects the timely identification and response to sudden deterioration by general ward staffs, leading to suboptimal care of patients, delayed or failed activation of RRS teams, and increased risks of worsening outcomes. The research efforts and clinical involvement to improve the governance of the factors limiting the performance of the afferent limb may ensure proper management of hospitalized patients showing physiological deterioration.

SACRIFICIAL OFFERING КУЯСЬКОН IN THE UDMURT FOLK MEDICINE

The article aims to systematize and analyze contemporary ethnographic data on an Udmurt healing ritual known as куяськон , that is making a sacrificial offering of symbolic presents (for example, coins, a heel of bread, en egg, salt, etc.) to the evil spirits or the undead. The ritual is believed to help to cure such disorders as skin diseases (abscesses, boils, rashes), pains in the lower extremities, sharp and persistent pain in any part of the body or sudden health deterioration, which are supposed to occur as the result of breaking ritual and cultural norms and space and time requirements. I pay particular attention to the structural components of the ritual, analyze its personal, verbal, spatial, temporal, attributive, and action codes, and trace its evolution.

Using Score for Neonatal Acute Physiology Perinatal Extension II (SNAPPE II) in Neonates with Acute Kidney Injury.

BACKGROUND:Acute kidney injury is a severe clinical condition. It is common in neonates in intensive care unit. It is defined as a sudden deterioration in kidney function resulting in derangements in fluid balance, electrolytes, and waste products. The score for neonatal acute physiology perinatal extension in critically sick neonates with kidney injury is a useful tool for assessing the severity of the disease.AIM:This study aimed to determine the incidence of AKI and the role of SNAPPE 2 score in predicting mortality and morbidity of kidney injury in neonates.METHODS:The study was designed as a prospective clinical investigation performed in the period of three years, which included 100 neonates (50 with AKI and 50 without AKI) hospitalised in intensive care unit of University Clinic of Children Diseases in Skopje. The severity of the illness of hospitalised newborn infants was estimated with SNAPPE 2 score realised in the first 12 hours of admission to NICU. Medical data records of admitted neonates with AKI were analysed. The material was statistically processed using methods of descriptive statistics.RESULTS:During the study period, 770 new born’s were hospitalised in the intensive care unit due to various pathological conditions and 50 new born’s were selected with AKI. The control group consisted of 50 neonates with comparable associated pathological conditions, but without kidney injury. The calculated prevalence of AKI in neonates was 6.4%. Most of the involved neonates in the study in both groups (AKI and non-AKI) were born at term (64% and 54%) with a predominance of male neonates (68% and 60%). The mortality rate was significantly higher in newborns with AKI than in the control group (36% vs 24%) (p < 0.01). The mean SNAPPE 2 score value in neonates with AKI was higher than in the control group (58.72 vs 40.0), and the difference was significant (p = 0.00001). Difficult score level predominated in half (50%) of newborn infants with AKI, while median score level predominated in control group (42%). There was a significant difference between the mean score value in neonates with AKI and lethal outcome compared to neonates with AKI without lethal outcome (70.73 ± 18.6 vs 40.2 ± 16.6) (p < 0.0001).CONCLUSION:Acute kidney injury is a life-threatening condition with still high mortality rate. The severity of the illness of hospitalised neonates in an intensive care unit is estimated by SNAPPE 2 score. Also, the risk of mortality is estimated too, taking into consideration the fact that higher values of the score are associated with higher mortality. Appropriate treatment of neonates with severe kidney injury improves the outcome and reduces the mortality of the disease.

P: 23 Prospective Study on Mortality of Acute on Chronic Liver Failure and Its Predictors

BACKGROUND: Acute on chronic liver failure (ACLF) is a well recognized entity, characterized by an acute liver insult in patients with underlying chronic liver disease leading to sudden deterioration of liver function and a high mortality. We aimed to determine hospital, 28 days and 12 weeks mortality of ACLF, its predictors and precipitating factors METHODS: We conducted a prospective descriptive study at AIMS (Asian institute of medical sciences, Hyderabad, Pak.) from January 2018 to December 2018. We enrolled patients of ACLF as defined by Asian Pacific Association for the Study of Liver (APASL, 2014) and collected data to determine cause, precipitating acute insult, organ failure, ACLF grade MELD, and CTP scores. Patients were followed to determine hospital, 28 days and 12 weeks mortality and its predictors. RESULTS: Total patients were 117 with mean age of 40.9 +- 13.9 years (range 12–85). Majority were males 86 (73.5%) and 31 (26.5%) were females. Majority of patients 55 (47%) were Hepatitis B Virus (HBV) positive, among them 24 (43.6%) were with HDV co-infection. The most common precipitating acute insult was SEPSIS 65 (55.6). Others were drug induce liver injury (DILI) 8 (6.8%), HEV acute hepatitis 7 (5.9), HDV superinfection 5 (4.3%), HBV flair 4 (3.4%), alcohol binge drinking 4 (3.4%), surgery 2 (1.7%), acute PVT 2 (1.7%), Upper GI Bleed 1 (0.9%) and 20 (17.1%) were unknown. Hospital mortality was 49 (41.9%), 28 days 71 (60.7%) and 12 weeks mortality was 103 (88.0%). Organ failure (P = 0.002), ACLF grade (P = 0.002), encephalopathy (P = 0.001), MELD (P = 0.01) and AKI (P = 0.02) were found to be predictors of mortality. CONCLUSIONS: Acute-on-chronic liver failure (ACLF) is an acute deterioration of liver function superimposed on Chronic Liver Disease with a high mortality. In our study HBV infection was the commonest cuase of CLD, and sepsis was the commonest acute insult. We found high hospital, 28 days and 12 weeks mortality. Organ failure, ACLF grade, encephalopathy, MELD score and AKI were found to be predictors of mortality of ACLF.

Study of combined flow control strategies based on a quantitative analysis in a high-load compressor cascade

Micro-vortex generator and a jet flow control technique are combined to improve the flow performance of a high-load compressor cascade, and the injection position is further investigated. The calculated results showed that the reverse flow region of baseline grows with the increment of incidence, and an unstable flow phenomenon rapidly occurs near the leading edge when the incidence rises to +7.9°. Meanwhile, two critical points occur on the end-wall, that is considered to be the main reason for occurring stall. When an injection tube is applied to remove the low energy fluid, the total pressure loss appears drastic reduction, and the occurrence of stall shows a slight delay from +7.9° to +8.7° incidence compared with the baseline. With the micro-vortex generator is introduced in the baseline, the occurrence of stall is delayed from +7.9° to +10.0° incidence due to the mixture of low energy fluid and main flow. The combined application shows an excellent effect in delaying the occurrence of stall and reducing the total pressure loss, and the sudden deterioration of the cascade performance occurs at +9.8° incidence. A quantitative analysis of total pressure loss shows that the secondary flow loss and wake loss contribute to the reduction of total pressure loss, the former is reduced by 31.0% and the latter is decreased by 24.1% at the near stall condition. Moreover, the spanwise injection position can affect both the total pressure loss and stall incidence, and the wider operating range is accompanied by the increment of total pressure loss.

Acute presentations of intradural lipomas: case reports and a review of the literature

BackgroundLumbosacral lipomas (LLs) may remain asymptomatic or lead to progressive neurological deterioration. However, sudden neurological deterioration is a rare and severe event. Herein, we report rare occurrences of sudden clinical deterioration in two previously asymptomatic children harbouring intradural LLs without dermal sinus tracts or signs of occult dysraphism. A review of the pertinent literature is also included.Case presentationOne child exhibited acute deterioration because of an epidural abscess associated with a filar lipoma without a sinus tract (probably caused by haematogenous spreading from a respiratory tract multiple infection), and the other child exhibited acute deterioration because of a very large, holocord syringomyelia-like cyst associated with a small conus lipoma. Both patients were 4 years old. In case #2, a previously undetected, severe tethered cord (conus at the S3-S4 level) was also present. A complete recovery was attained after an urgent surgical operation in both cases (in addition to targeted antibiotic therapy in case #1). All cases of deterioration in the literature were caused by abscess formation in dermal sinus tracts.ConclusionsProphylactic surgery may be indicated even in asymptomatic children that have tethered cord and surgically favourable LLs (small dorsal and filar LLs), especially if the conditions are associated with progressive syringomyelia. Similarly, intradural dermal sinus tracts should be regarded as surgery-indicated, even if the conus is in its normal position and the patient is asymptomatic because there is a consistent risk of severe, infection-related complications. Finally, asymptomatic patients with filar LLs and a normally located conus can be candidates for surgery or an accurate clinical and radiological follow-up.

Çocuklarda Böbrek Hastalıklarında Tıbbi Beslenme Tedavisi

Çeşitli hastalıklar nedeniyle böbrek işlevleri ani olarak bozulabilir (akut böbrek yetmezliği) ya da geri dönüşümsüz olarak kaybedilebilir (kronik böbrek yetmezliği). Böbrek hastalıklarına sahip bebek ve çocuklar tedavileri süresince diyetlerinde birçok değişikliklere maruz kalmaktadırlar. Böbrek hastalıklarının tüm evrelerinde büyüme ve gelişmeyi sağlamak için çocukların besin alımı önemlidir. Tıbbi beslenme tedavisi (TBT), tüm yaş gruplarında çocuğun gelişimsel durumu, büyüme potansiyeli ve böbrek işlev kısıtlılıkları göz önüne alınarak bireye özgü olmalıdır. Çocuk hastalarda tedavide amaç, hastalığın progresyonunu yavaşlatmak, komplikasyonları önlemek ve tedavi etmek, büyüme/gelişmeyi ve yaşam kalitesini sağlamaktır. Bu hedeflere ulaşmada tıbbi beslenme tedavisi kritik rol oynamaktadır. Bu derleme makalede, çocukluk çağı böbrek hastalıklarındaki son gelişmeler gözden geçirilerek, güncel beslenme tedavileri uygulamalarına odaklanılacaktır.

An exploratory study of patients' sudden losses during outpatient CBT and therapists' experience of difficulties.

Patients' sudden deterioration in symptomatology, also called sudden losses, is a rarely explored phenomenon. Psychological distress of 1,763 patients treated by 140 therapists was monitored after every therapy session. Patient-reported outcome measures and patients' therapy satisfaction was assessed. Therapists rated their experience of difficulties for every patient repeatedly over the course of therapy. More than one-quarter of patients (26.5%) experienced at least one sudden loss during therapy. Patients with sudden losses did not differ significantly in psychotherapy outcome and therapy satisfaction from patients without sudden shifts. Therapists did not experience professional self-doubt more often when working with sudden loss patients. Sudden losses were not necessarily harmful for the outcome of psychotherapy and patients' global therapy satisfaction. The results suggest that sudden losses can be compensated over the course of treatment.

Post Arthrotomy Prevotella bivia Septic Arthritis and Secondary Osteomyelitis

Prevotella is a common gram-negative anaerobic rod that is frequently associated with female genitourinary tract infections, pelvic inflammatory disease, aspiration pneumonia, lung abscess and pleural empyema. Osteomyelitis in association with septic arthritis is rare with only a handful of cases reported worldwide. In this case study, we report a patient who presented with a clinical picture of septic arthritis complicated by the presence of a sinus tract at the site of a previous arthroscopic surgery. Initial sinus pus cultures demonstrated Streptococcus agalactiae , which were confirmed with intra-operative joint fluid cultures. After a brief period of clinical improvement following arthrotomy, a sudden clinical deterioration prompted re-cultures demonstrating heavy growth of Provetella bivia . Repeat MRI demonstrated new signs of osseous involvement. The patient was managed with a redo arthrotomy, extensive debridement of osteomyelitic tissue, washout and an extended antibiotic therapy regimen. This association is first of its kind in Saudi Arabia. J Microbiol Infect Dis 2019; 9(2):100-103.

Is Bilateral Facial Paralysis an Indicator of Respiratory Outcome in Guillain-Barré Syndrome?

Background and objectives: Bilateral facial paralysis is a rare and specific clinical manifestation of various neurological disorders. Bilateral facial paralysis has been reported as an essential feature of Guillain–Barré syndrome (GBS) for many years. We aim to describe the incidence of bilateral facial paralysis and prognosis in our GBS patients. Materials and Methods: A retrospective chart review of all patients with GBS and bilateral facial paralysis who were treated at the Inönü University Medical Faculty was performed. Results: A total of 45 cases of GBS were reviewed. Four out of 45 patients (8.8%) had associated bilateral facial paralysis. Only one of the patients also had acute multiple cranial neuropathies. All patients experienced sudden deterioration and respiratory distress. In one of our patients who had multiple cranial neuropathies, serum antiganglioside antibody assay was performed, and anti-GQ1b IgG antibody positivity was observed. The cerebrospinal fluid had albuminocytological dissociation in all patients, and axonal involvement was present in nerve conduction studies (NCS). Three patients improved with immunotherapy; one patient died due to cardiac arrest after resistant hypotension. Conclusion: Bilateral facial paralysis is a rare condition in children. We wanted to emphasize bilateral facial involvement and poor prognosis in our GBS patients.

Insuficiencia renal aguda (I)

Acute renal failure (ARF) is a clinical syndrome characterized by a sudden deterioration in renal function, caused by an impairment of diuretic function and resulting in a rise of nitrogenous waste products in blood and in homeostasis impairment. ARF may result from several causes resulting in renal hypoperfusion (prerenal origin), damage in renal parenchyma (parenchymatous origin) or urinary tract obstruction (obstructive origin). Sometimes etiology is multifactorial. Depending on the etiology, clinical features vary. ARF affects both outpatients and inpatients, mainly to critically ill patient. Severe ARF is related to high mobility and mortality rates, which are associated with high healthcare costs. Most of the survivor patients recover renal function, although some of them will require renal-replacement therapy or will evolve to chronic renal insufficiency which will progress to end-stage renal disease. Because ARF prognosis is poor, early diagnosis is mandatory.

A combined application of micro-vortex generator and boundary layer suction in a high-load compressor cascade

In the current study, the effects of a combined application between micro-vortex generator and boundary layer suction on the flow characteristics of a high-load compressor cascade are investigated. The micro-vortex generator with a special configuration and the longitudinal suction slot are adopted. The calculated results show that a reverse flow region, which is considered the main reason for occurring stall at 7.9° incidence, grows and collapses rapidly near the leading edge and leads to two critical points occurring on the end-wall with the increasing incidence in the baseline. As the micro-vortex generator is introduced in the baseline cascade, the corner separation is switched to a trailing edge separation by the thrust from the induced vortex. Meanwhile, the occurrence of failure is delayed due to the mixed low energy fluid and main flow. The synergistic effects between the micro-vortex generator and the boundary layer suction on the performance of the cascade are superior to the baseline at all the incidence conditions before the occurrence of failure, and the sudden deterioration of the cascade occurs at 10.3° incidence. The optimal results show that the farther upstream suction position, the lower total pressure loss of the cascade with vortex generator at the near stall condition. Moreover, the induced vortex with a leg can migrate the accumulated low energy fluid backward to delay the occurrence of stall.