bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity of lung ultrasound FALLS-protocol in differentiating types of shock in critically ill patients
Authors: Mawla Tamer S.A. , Elhameed Aliaa A. , Abdallah Areeg A.Y. , Momtaz Osama M.
Published: September 2024

Background

Acute circulatory collapse is one of the most familiar challenges in ICUs. It is considered that artefacts generated by lung ultrasound (LUS) can help in diagnosis and management. FALLS-protocol using LUS is a tool proposed for the management of unexplained shock.

Objectives

To investigate the role of LUS FALLS-protocol in differentiating types of shock in critically ill patients.

Patients and methods

A total of 50 patients presented with undiagnosed shock. Fast bedside echocardiography and LUS FALLS-protocol were applied along with inferior vena cava diameter and collapsibility measurement.

Results

A total of 19 patients with septic shock on presentation had A profile in all of them and AB profile in three of them, and after resuscitation, they were transformed to B profile with 100% sensitivity, 90.5% specificity, 90.5% positive predictive value (PPV), and 100% negative predictive value (NPV). Overall, 16 patients with hypovolemic shock had A profile in all of them on presentation and after resuscitation, with 100% sensitivity, 94.1% specificity, 88.9% PPV, and 100% NPV. Moreover, eight patients with cardiogenic shock had B profile in all of them on presentation with 100% sensitivity, 95.2% specificity, 80% PPV, and 100% NPV; three patients with obstructive shock had A profile in all of them on presentation, with 100% sensitivity, 25.5% specificity, 7.9% PPV, and 100% NPV; and two patients with anaphylactic shock had A profile in all of them on presentation and transformed to B profile after resuscitation with 100% sensitivity, 50% specificity, 9.5% PPV, and 100% NPV. Our findings showed preference of FALLS-protocol than inferior vena cava diameter and collapsibility in directing fluid therapy.

Conclusion

Bedside chest ultrasound FALLS-protocol should be considered in the resuscitation pathways with a possible significant effect on patient management.
Serum copeptin level as a prognostic marker for acute ischemic cerebrovascular stroke and cerebral hemorrhage
Authors: Sabry Sherif , Samer Nael , Ibrahim Khaled F. , Mahmoud Mohammed
Published: September 2024

Objective

To assess the predictive utility of serum copeptin concerning the 30-day mortality among patients presenting with ischemic stroke (IS) or hemorrhagic stroke (HS) acute cerebrovascular stroke. Besides, we aimed to evaluate whether serum copeptin has a role in discriminating between HS and IS.

Background

Since its discovery in early 1970s, copeptin has emerged as an effective predictive marker with high potentials of wide clinical applications due to its stability and robust measure. Serum copeptin can reflect the vasopressogenics in a practical way.

Patients and methods

We performed this prospective study on patients with either IS or HS, as indicated by clinical signs and computed tomography. The serum copeptin level was assessed by sandwich immunoassay at admission. All patients were followed up for 30 days after admission.

Results

Nonsurvivors with acute cerebrovascular stroke exhibited a significantly higher copeptin level than the survivors’ group (P=0.038). Besides, patients with HS exhibited a significantly higher copeptin level than the patients with IS (P=0.042). Copeptin showed good sensitivity (70.6%) and specificity (56.5%) at a cutoff value of 48.8 pmol/l to predict mortality in the whole studied population.

Conclusions

Serum copeptin is a promising prognostic tool for the prediction of short-term mortality in patients with acute cerebrovascular stroke. Besides, the serum copeptin has a fair diagnostic accuracy for the differentiation of IS and HS.
Bupivacaine–lidocaine versus bupivacaine–lidocaine plus dexamethasone in supraclavicular brachial plexus block
Authors: Abdelrazik Amr N. , Ali Ashraf H.I. , Youssef Ibrahim A. , Megalla Sohair A.
Published: September 2024

Background

To evaluate whether dexamethasone as an adjuvant to bupivacaine–lidocaine mixture in supraclavicular brachial plexus block can enhance the block, prolong the duration of action, and improve postoperative analgesia than a mixture of bupivacaine–lidocaine only.

Patients and methods

In all, 60 patients were posted for elective and emergent upper limb orthopedic surgery (below shoulder joint), under supraclavicular brachial plexus block guided by a nerve stimulator. Patients were randomly divided into two equal groups: group C (the control group, n=30) received 40 ml solution containing local anesthetics only. Group D (the dexamethasone group, n=30) received a 40 ml solution containing local anesthetics plus 4 mg dexamethasone. Primary outcomes were onset time of sensory and motor block, and duration of sensory and motor block, which were assessed in minutes. Secondary outcomes were pain assessment using a scoring system based on the visual analog scale, time to first analgesic requirement, and total analgesic consumption.

Results

Duration of sensory and motor block in the dexamethasone group were significantly longer than the control group (753±68.04 vs. 565±30.85 min and 733.66±69.77 vs. 547.16±29.38 min, respectively). For visual analog scale, while comparing the two groups, the differences were significant at 9, 12, and 18 h after surgery in favor of the dexamethasone group. The time to first analgesic request was significantly longer in the dexamethasone group in comparison to the control group. The total analgesic requirement was also significantly lower in the dexamethasone group in comparison to the control group.

Conclusion

The use of dexamethasone at a dose of 4 mg as an adjuvant to local anesthetics provided effective prolongation in the duration of sensory and motor block, prolonged time to first analgesic request, and reduced the total analgesic consumption.
Prevalence and risk factors for depressive symptoms in physicians working in the icus in alexandria main university hospital
Authors: Zaytoun Tayseer M. , Hamdy Haitham M. , Siaf Moaz
Published: September 2024

Introduction

Depression can lead to significant emotional distress or impairment in social life, home life, and work. Both depression and substance disorders have been identified as major risk factors for the high rate of suicides among physicians, with more than 90% of those physicians who suicide having a history of mood disorder and/or substance abuse. Therefore, interest in the psychological well-being of physicians has increased recently, warranting further research regarding factors that influence the mental health of physicians. Worldwide prevalence of depression among physicians is around 28.8% (20–40%). Both developing and developed countries were high in the prevalence of depression in physicians. The percentage was more marked in a study from Egypt (73.8%) and USA (41%). Fewer studies are found in Asian countries. But the rate was high eventually (30.1%).

Objective

The aim of the study was to estimate the prevalence of depressive symptoms among critical care residents in Alexandria Main University Hospital and to identify the risk factors among them.

Patients and methods

This study implemented a cross-sectional survey. We present a questionnaire to each doctor, which includes three sections: sociodemographic information, lifestyle- and work-related characteristics, and Patient Health Questionnaire-9 survey.

Results

Three quarter of the surveyed ICU physicians reported moderate to severe depressive symptoms. In women, the level of stress is significantly higher than in men. In people working in the 12 and 24-h system and taking overtime hours, the stress level was the highest. Poor patient outcome and decisions with do-not-resuscitate are contributing with more depressive symptoms. Physically active physicians have less depressive symptoms.

Conclusion

Prevalence of depressive symptoms was high among Alexandria Main University Hospital residents. Lack of support and large number of patients along with poor patient outcome and long working hours were the most relevant risk factors.
Preoperative topical lidocaine in pediatric squint surgeries
Authors: Salem Abeer S. , Mohamed Dina Moustafa , Aboul Fetouh Iman S. , Khattab Rehab S. , Mahmoud Sara R.
Published: September 2024

Aims

To assess the safety and efficacy of lidocaine gel 2% used in pediatric squint surgeries to prevent the oculocardiac reflex intraoperatively and reduce postoperative pain and agitation.

Settings and design

This single-blinded, randomized trial was carried out at the Research Institute of Ophthalmology, Egypt.

Patients and methods

Forty-eight children (2–13 years old) of both sexes scheduled for squint surgeries were randomly allocated into two groups (24 patients each): the lidocaine gel group and the control group. In the experimental group, we applied lidocaine gel 2% abundantly below both eyelids of the surgical eye for at least 3 min before surgical incision, while nothing was applied to patients in the control group. Patients were monitored intraoperatively and postoperatively, and the outcomes were recorded.

Results

There was a lower median postoperative face, leg, activity, cry, and consolability scale in the lidocaine gel group (3.0, interquartile range=2.5–5.0) than in the control group (4.0, interquartile range=1.5–7.0) with no significant difference (P=0.770). The incidence of bradycardia was lower with lidocaine gel 2% use (16.7%) compared with the control group (41.7%), but this difference was not statistically significant (P=0.057). We found no complications except for two patients in the control group who had fever and flushing due to atropine administration.

Conclusion

Application of lidocaine gel 2% below both lids of the surgical eye in pediatric squint surgery under general anesthesia is safe with no observed systemic side effects. However, it has no adjuvant effects in reducing postoperative pain and agitation or preventing intraoperative oculocardiac reflex.
Diagnostic accuracy of lung ultrasound in acute heart failure
Authors: Yahia Mohamed , Soliman Mahmoud , Fawzy Mohamed , Sultan Hatem
Published: September 2024

Background and objective

Although acute heart failure (AHF) is a common cause of dyspnea, its diagnosis still represents a challenge. Lung ultrasound is an emerging point-of-care diagnostic tool, but its diagnostic performance for AHF is still under evaluation. We evaluated the accuracy and clinical usefulness of combining lung ultrasound with clinical assessment compared with the use of chest radiography, echocardiography, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in conjunction with clinical evaluation for diagnosing AHF in the emergency department.

Patients and methods

A total of 47 patients presenting with dyspnea and symptoms suggestive of AHF were evaluated by NT-proBNP, echocardiography, and chest radiography. Lung ultrasound was done to look for the presence of diffuse B-lines.

Results

Lung ultrasound showed a sensitivity of 91.9% and a specificity of 100% in diagnosing AHF comparable to plasma NT-proBNP, which had a sensitivity of 100% and a specificity of 60%. It was also superior to other methods of diagnosing AHF namely chest radiograph. Lung ultrasound showed a significant correlation with the echocardiography findings (P=0.001).

Conclusion

The implementation of lung ultrasound with the clinical evaluation improves accuracy of diagnosis of AHF in the emergency department.
Postoperative analgesic effect of hyaluronidase versus dexamethasone as additives to bupivacaine in transversus abdominis plane block for inguinal hernia repair: prospective, randomized, and double-blinded controlled study
Authors: Elsayed Hitham M. , Badawy Fawzy Abbas , Raheem Mohammed A.
Published: September 2024

Background

Inguinal hernia repair is associated with severe postoperative pain. Transversus abdominus plain block has been proved to provide effective analgesia for somatic lower abdominal pain. Several adjuvants have been added to local anesthetic to improve the quality of analgesia. This study compares the additive effect of hyaluronidase versus dexamethasone to improve the quality of analgesia of transversus abdominus plain block for inguinal hernia repair.

Patients and methods

This prospective, randomized, controlled, and double-blind study was carried out in Sohag University Hospital between November 2020 and February 2021. Seventy-five participants scheduled for inguinal hernia repair were included and randomly assigned into control, hyaluronidase, and dexamethasone groups. Exclusion criteria were neurological, psychiatric, neuromuscular, cardiovascular, pulmonary, renal, hepatic disease, alcoholism or drug abuse, pregnancy or lactating women, and patients receiving adrenoceptor agonist or antagonist therapy or chronic analgesic therapy, patients with morbid obesity, coagulopathy, and known allergy to study medications, and sepsis surgical scar at the site to be operated upon and those who refuse.

We targeted from this study to assess time to first analgesia, consumption of morphine, and visual analog scale at rest and during physical activity.

Also, we targeted to assess heart rate, noninvasive blood pressure, SpO2%, and adverse effects (nausea and vomiting, respiratory depression).

Results

Our study showed comparable analgesic efficacy for hyaluronidase versus dexamethasone with longer time to the first request of analgesia, less morphine consumption, and less side effects compared with these two groups to the control group.

Conclusion

Adding hyaluronidase or dexamethasone to bupivacaine not only prolonged the duration of analgesia and decreased the consumption of opioids but also decreased the incidence of adverse effects.
Validation of lung sonography in the implementation of open lung strategy as a recruitment maneuver versus traditional sustained inflation in acute respiratory distress syndrome patients
Authors: Mohamed Mohamed S. , El Maraghi Sameh , Saber Hamdy , Abu Hamela Mohamed F. , Abdalal Ahmed A.
Published: September 2024

Introduction

Acute respiratory distress syndrome (ARDS) is a serious problem in critically ill patients with high mortality rates. Lung recruitment maneuvers (RM) are important in the treatment of ARDS with an aim to improve oxygenation. There are many approved methods for lung recruitment like the traditional sustained inflation technique and the stepladder positive end-expiratory pressure (PEEP) titration technique. The traditional methods to evaluate RM like computed tomography and pressure–volume curves showed some limitation and disadvantages. Thus, bedside ultrasonography (US) could be a safe bedside tool to evaluate lung aeration and the effectiveness of RM defining the optimum PEEP needed and preventing lung overdistension.

Aim

To evaluate the usefulness of lung US as a guide to follow up RM by PEEP titration technique in comparison to sustained inflation technique.

Patients and methods

In all, 40 ARDS patients were segregated into two groups: group 1 included 20 patients who were subjected to traditional sustained inflation RM and group 2 included 20 patients were subjected to sonar-guided lung recruitment. US scoring, PO2, PO2/FiO2, and lung compliance were used to evaluate the pulmonary recruitment end point defining the best PEEP.

Results

Lung compliance, PO2, and PO2/FiO2 were significantly increased after RM in both groups (P<0.05); however, there was no statistically significant difference between the two groups. The best PEEP in group 1 and group 2 were 20.60±3.485 and 15.90±5.340, respectively, with a significant difference between the two groups (P=0.002). There was no statically significant difference between the two groups regarding complication, vent days and ICU days.

Conclusion

Bedside US can be very useful in the evaluation and management of mechanically ventilated patients in ICUs and to guide the RM in ARDS patients. There is no significant difference between the sustained inflation RM and the sonar-guided stepwise PEEP titration RM regarding oxygenation and compliance except for the level of PEEP reached, which is lower in the stepwise PEEP titration group giving less potentiality for complications.
Assessment of risk stratification scoring systems in upper gastrointestinal bleeding patients in the emergency department
Authors: ElBarragah Kesmat Abdelhamid , Elrewiny Mohamed Tawfiq , Ahmed Ezzat Ali , Sabry Ahmed Abdelfattah
Published: September 2024

Background

Acute upper gastrointestinal bleeding (UGIB) is a common medical emergency presented to the emergency department that requires early assessment and management. Many risk stratification scores have been developed to predict the clinical outcomes in patients with UGIB. The commonly used risk scores the Rockall scoring systems (PRS and FRS), Glasgow–Blatchford score (GBS) and AIMS65 score.

Aim

The aim of the present study was to assess and compare the ability of the wildly used risk scores the RS, GBS, and AIMS65 to predict the clinical outcomes in UGIB patients Patients and methods

One hundred patients (age >18 years) with acute UGIB in the emergency department of Alexandria Main University Hospital were prospectively studied. All the study scores were calculated and compared using the area under the receiver operating characteristic curve (AUC) method to evaluate the performance of each score to predict the mortality, blood transfusion, endoscopic intervention, ICU admission, rebleeding, and length of hospital stay.

Results

Among the one hundred patients included in the study, 65% were males with a median of age 58 years. 56% had esophageal varices and 63% with liver disease. All the used scores were statistically significant in predicting all clinical outcomes. GBS had the best AUC among the AIMS65, PRS, and FRS scores in predicting mortality with (AUC= 0.80 vs. 0.76, 0.69), blood transfusion need with (AUC= 0.92 vs. 0.88, 0.87), ICU admission with (AUC= 0.86 vs. 0.83, 0.81), rebleeding with (AUC= 0.81 vs. 0.77, 0.69), and length of hospital stay with (AUC= 0.81 vs. 0.75. 0.79).

Conclusion

All the study scores (GBS, AIMS65, PRS, and FRS) were able to predict the clinical outcomes in the UGIB patients. GBS was the best performing risk score among the four scores for predicting all the clinical outcomes (mortality, blood transfusion, rebleeding, ICU admission, and length of hospital stay) except the prediction of endoscopic intervention in our study population.
Efficacy of combined thoracic paravertebral block and intravenous dexmedetomidine in medical thoracoscopy
Authors: Maaly Ayman M. , Abdelhady Ahmed M. , Abdelaziz Rehab A.
Published: September 2024

Background

Medical thoracoscopy has become the gold standard for evaluation of intrapleural space. Thoracic paravertebral block is instillation of local anesthetic drug in the thoracic paravertebral space and can be used in several procedures such as medical thoracoscopy. Dexmedetomidine is a potent α-2 agonist with a higher potency and short duration of action. It has a rapid onset and offset. It produces an ‘interactive’ form of sedation and does not induce respiratory depression. This study was conducted to evaluate the efficacy of paravertebral block with intravenous (i.v.) infusion of dexmedetomidine compared with standardized general anesthesia method in medical thoracoscopy.

Patients and methods

A randomized controlled trial was conducted in the Department of Chest Diseases at Alexandria Main University Hospital, on patients indicated for medical thoracoscopy.

Patients were randomized into two groups (30 patients each). Group A received general anesthesia. Group B received paravertebral block at the level of medical thoracotomy covering three levels: at, above, and below thoracotomy level plus i.v. dexmedetomidine. Demographic data, hemodynamics, patient-rated procedural pain, and operator-rated overall procedure satisfaction scores were recorded.

Results

A significantly lower means of heart rate and blood pressure were found in group B after thoracotomy and immediately postoperative. Patient-rated procedural pain score in group A ranged from 2 to 5 with a mean of 3.90±0.85, while in group B, it ranged from 0 to 3 with a mean of 1.40±0.68. This difference was statistically significant (P<0.001). A significantly higher operator-rated overall procedure satisfaction score was found in group B (95.77±1.74) compared with group A (90.03±2.33) (P<0.001).

Conclusion

Use of thoracic paravertebral block plus use of i.v. dexmedetomidine in medical thoracoscopy is comparable to general anesthesia as it is comfortable to the patient and the operator without dealing with airway and its difficulties.
The challenge of aspiration prevention in a pediatric patient having proximal esophageal diverticulum
Authors: Sinha Chandni , Deepshikha  , Kumar Amarjeet , Kumar Ajeet , Vamshi Chethan , Sagdeo Gayatri D.
Published: September 2024

Diverticular pouch in the esophagus poses unique anesthetic challenges. Presence of a diverticular pouch in the pharynx poses high risk of aspiration, despite adequate hours of fasting. Herein, we describe a case of a child with proximal esophageal diverticulum in which the anesthesia team faced the challenge of aspiration prevention during the perioperative period. Proper preoperative history, preparation, and intraoperative and postoperative management are imperative to prevent aspiration. Manual compression of the pouch by the caregiver might be exercised in the pediatric age group during and after feeds.
Bilateral ultrasound-guided upper cervical erector spinae-plane block in posterior atlantoaxial fusion surgery
Authors: Kumar Amarjeet , Sinha Chandni , Kumar Ajeet , Agrawal Prabhat , Vamshi Chethan , Sagdeo Gayatri D.
Published: September 2024

Posterior atlantoaxial fusion surgeries are used to treat various pathologies involving the joint between the first and second cervical vertebrae. Anesthetic goals during spine surgeries include hemodynamic stability with no interference in neuromonitoring and optimal pain control. Ultrasound-guided erector spinae-plane blocks can be used to provide perioperative analgesia in spinal surgeries of cervical, thoracic, and lumbar-spine region. In this case report, bilateral upper cervical erector spinae-plane block was given to provide perioperative analgesia as part of a multimodal opioid-sparing regimen in a 36-year-old male patient scheduled for posterior atlantoaxial fusion surgery.
Predictive value of chest ultrasound in differentiation between cardiogenic and noncardiogenic pulmonary edema
Authors: Kasem Sohier M. , Soliman Mona M. , Sadek Samiaa H. , Thabet Ahmed A. , Tawfeek Samir El-Hadidy , Elhefny Noor Eldeen A.M.
Published: September 2024

Background

Adult respiratory distress syndrome (ARDS) and acute cardiogenic pulmonary edema (CPE) are common clinical issues. Based on clinical data, it is a big challenge to differentiate between both. Secondary to many limitations of computed tomography, chest ultrasound (CUS) provides pleuropulmonary signs that help in differentiation.

Objective

The current work aimed to assess the accuracy of CUS in differentiating CPE from ARDS.

Patients and methods

This is a cross-sectional study conducted on patients admitted to different ICUs with pulmonary edema, comprising 25 patients with CPE and 35 patients with ARDS. CUS, ECG, echocardiography, and chest radiograph were done for all patients.

Results

The mean age of patients with ARDS was 48.90±11.23 years, whereas the mean age of patients with CPE was 49.10±10.10 years. The majority of both groups were males. Systolic dysfunction and pneumonia were the most frequent etiology in CPE and ARDS, respectively. All patients in both groups had alveolar-interstitial syndrome. Pleural line, absence of lung sliding, and the spared area were presented in all cases with ARDS and absent in those with CPE. Moreover, none of those with CPE had lung pulse, but this finding was presented in 18 (51.4%) patients with ARDS.

Conclusion

CUS can help in differentiating ARDS from CPE in clinical practice. Based on CUS findings, absent or reduced lung sliding, pleural line abnormalities, and spared areas are diagnostic of ARDS.
Ultrasound-guided rectus-sheath block compared with thoracic epidural analgesia for major abdominal cancer surgeries with a midline incision
Authors: Gad Mona , Abdelkhalek Mohamed , Gaballa Khaled , Elbalka Saleh S. , Hegazy Mohammed A.
Published: September 2024

Background

The thoracic epidural analgesia (TEA) is considered as a standard technique for postoperative pain relief in major abdominal surgeries, but sometimes, it is contraindicated or complicated. Rectus-sheath block (RSB) bilaterally has developed recently to offer analgesia in these operations. This study was designed to evaluate the promising RSB as a suitable alternative to TEA in major operations for abdominal cancers through a midline incision.

Patients and methods

The current clinical trial that had been performed on American Society of Anesthesiologists I, II, and III patients underwent major operations for abdominal cancers through a midline incision, and randomly allocated into either the TEA group: received TEA with bupivacaine+fentanyl or RSB group: received RSB with bupivacaine+fentanyl bilaterally. The primary outcome was the cumulative intravenous (IV) fentanyl doses consumed through the postoperative 24 h. The secondary outcomes were the patients’ number who needed analgesia, the duration spent till the first analgesic request, visual analog score with rest and cough, and any complications related to either the block techniques or drugs.

Results

Cumulative IV fentanyl consumed and the titration doses of IV fentanyl during the postoperative 24 h, the time to the first request of fentanyl, number of patients who needed analgesia, and visual analog score with rest and cough at the time points of the study, all did not show any statistical significant difference between both groups. The RSB group recorded significant shorter time to ambulation compared with the TEA group. Sedation scores were comparable in both groups at all time points of the trial. Both groups were comparable regarding the incidence of fentanyl-associated side effects, time to passing flatus, and patient-satisfaction score.

Conclusion

RSB could be used as an efficient alternative to TEA, especially whenever the latter is contraindicated in patients subjected to major abdominal surgeries with midline incision.
A comparative study between 1 and 3 mg of granisetron in the prevention of postoperative nausea and vomiting in strabismus ophthalmic surgeries during general anesthesia
Authors: Khair Tamer M. , Ahmed Mohamed Y.M. , Mohamed Ahmed A. , Sayed Islam M. , Saafan Tamer F.H.
Published: September 2024

Aims

To compare the safety and efficacy of 1 and 3 mg of granisetron in the prevention of postoperative nausea and vomiting (PONV) in strabismus surgeries under general anesthesia.

Settings and design

This single-blinded, randomized, controlled trial was conducted at the ophthalmology operating theater of Kasr Al-Ainy Hospitals.

Patients and methods

We recruited 210 patients and allocated them randomly to receive either granisetron 1 mg (n=105) or 3 mg (n=105). The two groups were compared regarding demographic data, hemodynamic parameters, and percentage of patients with no complaints of PONV during the first 24 h.

Results

There was no statistically significant difference upon comparison of the two groups regarding PONV (P>0.05). The two doses (1 and 3 mg) provided total control of nausea and vomiting in 46.7 and 43.8% of patients during the first 24 h postoperatively, respectively. Moreover, we found no significant difference between the two groups regarding mean values of the heart rate or mean arterial pressure both preoperatively and intraoperatively (P>0.05). However, during the postoperative 24 h, both groups had significant differences regarding mean values of heart rate and mean arterial pressure at 2–4 h, 8–12 h, and 12–24 h postoperatively.

Conclusions

The comparison between two doses of granisetron (1 and 3 mg) showed no statistical difference regarding the total control of nausea and vomiting for 24 h postoperatively but showed a statistical difference regarding some postoperative vital sign readings.
Piston and Guide-Pin Rattle Noise Mitigation in Electro-Mechanical Brake Caliper
Authors: Yoon Boram , Jeon Kyeong Hun , Boo Sangpil , Shin Choongsik , Kim Tae Hoon
Published: September 2024

Brake caliper commonly utilizes rubber or spring components to maintain specific clearance range for sliding characteristics, rendering them susceptible to rattle noise. The Electro-Mechanical Brake (EMB) caliper has attracted attention for its advantageous features such as reduced brake drag, optimized vehicle layout, and precise brake control. However, the inclusion of additional components related to the dry-type pressurizing system results in increased caliper weight and susceptibility to rattle noise. This study thoroughly examines rattle noise characteristics in our prototype EMB caliper, identifying primary noise sources on the piston and guide-pin sides. Implementing piston seals and guide-pin boots tightening force proves the effectiveness in improving rattle noise characteristics. Collisions between the piston and ball-screw head can be mitigated by piston inner seal, significantly reducing rattle noise. The effectiveness of the piston outer seal is limited and can be sufficiently substituted through improved tightening force in the piston boot. Additionally, the guide-pin side is identified as significant source of rattle noise, with enhancements in guide-pin boot tightening force showing improved rattle noise characteristics, particularly under new pad conditions. These findings provide valuable insights for developing EMB calipers to minimize rattle noise, contributing to quieter and more efficient future braking systems.
Analysis of Stick-slip Phenomenon During Creep Groan Using Acoustic Emission Sensing
Authors: Toyoda Hajime , Yazawa Yusuke , Arai Shinichi , Ono Manabu , Hara Yasuhiro , Hase Alan
Published: September 2024

When the brakes are released and the vehicle starts, the brakes and suspensions vibrate and the car body resonates at 10 to 300 Hz, which is called brake creep groan. This low-frequency noise is more likely to occur in high-humidity environments. As vehicles become quieter with the introduction of EVs, improving this low-frequency noise has become an important issue. It is known that the excitation force is the stick-slip between the brake rotor and pads, but there are few studies that directly analyze stick-slip occurring in a vehicle. Acoustic emission (AE) is a phenomenon in which strain energy stored inside a material is released as elastic stress waves, and AE sensing can be used to elucidate the friction phenomena. In this study, the AE sensing is used to analyze changes in the stick-slip occurrence interval and generated energy when creep groan occurs. As a result, it was confirmed that the AE signal increased with high humidity. Furthermore, the friction phenomena during creep groan and their changes with humidity were also analyzed by frequency analysis of the AE signal waveforms, in-situ observations of the friction interface and their digital image correlation (DIC), ultimately determining the cause of creep groan.
Analysis of Disc-Brake Squeal Considering Lining Wear
Authors: Ikegami Tokunosuke , Millsap Tom , Yamaguchi Yoshiyuki
Published: September 2024

Brake squeal is a phenomenon caused by various factors such as stiffness of brake components, mode coupling, friction coefficient, friction force variation, pressure, temperature and humidity. FEA simulation is effective at predicting and investigating the cause of brake squeal, and is widely used. However, in many FEA simulations, models of brake lining are mostly a brand-new shaper, so that the change of pressure distribution or pad shape, which can occur due to the lining wear, are not taken account. In this research, brake squeal analysis was conducted with consideration of lining wear, applying Fortran codes for Abaqus user subroutine. The brake assembly model for the analysis is created by using a 3D scanner and has a close shape to the real one. The wear patterns calculated by the analysis are similar to those of brake pads after a noise test. The complex eigenvalue analysis shows two unstable modes at the frequency of squeal occurred in the noise test. One is out-of-plane vibration mode of the rotor and another is in-plane vibration mode of the rotor. These modes do not come out in the case of analysis with a brand-new lining shape. The results of parameter studies on physical properties and geometries of brake lining show the analysis model in this research is effective in reducing squeal of the brake system.
Investigation on Brake-Drag-Optimization on Vehicle-Level
Authors: Huchtkoetter Philipp , Neubeck Jens , Wagner Andreas
Published: September 2024

Brake drag in disc brakes occurs during the off-brake-phase, when the brake is not applied but friction contacts between brake disc and pads persist. First and foremost, the resulting drag torque increases energy consumption, where a few Newton meters can have a significant impact on the crucial factor – range – of battery-electric-vehicles. Moreover, brake wear is accelerated in conjunction with enlarged taper-wear of the pads. Additional wear can also imply increased brake particle emissions which are going to be limited by upcoming regulations due to their potential health risk.

In this light different countermeasures aim to create and maintain a sufficient air gap between brake disc and pads when the brake is released to avoid residual friction contacts. Among others these include optimization of piston retraction by adjusting the seal-grooves and integrating pad springs into the caliper to push the pads back. State of the art to analyze the effectiveness of countermeasures are component-level tests on brake dynamometers. As they provide high repeatability and the necessary accuracy to develop brakes with drag near zero. Though the laboratory conditions usually exclude influencing factors that are present on vehicle-level and can have a significant impact on brake drag, for example lateral acceleration. Therefore, this work uses a prototypical drag torque measurement system based on piezo-electric sensors to analyze, whether countermeasures that have been proven to be effective on component level also reduce brake drag on vehicle-level. A default brake setup with relatively high brake drag is compared to an optimized setup during chassis dynamometer tests, certain driving maneuvers on proving grounds and a real-driving cycle on the road.
Time for a Model Change - Inorganic Friction Materials
Authors: Milczarek Roman Paul , Wittig Niels
Published: September 2024

This paper’s aim is to explain alternative friction lining formulations based on inorganic polymer binders for the production of new, future-proof brake friction materials. The aspects of high-temperature stability in the fading tests of the AKM- and AMS tests, as well as the reduction in PM10 emissions compared to classic organic friction materials, make these materials particularly fascinating for future use. Additionally, the energy savings potential of this type of friction lining could be of particular importance when sustainability considerations further influence our development activities in friction brake related applications.
Initial Corrosion and Wear Behavior of Brake Rotors Treated with Plasma Electrolytic Aluminating or Ferritic Nitrocarburizing Process
Authors: Liu Yinting , Nie Xueyuan
Published: September 2024

To combat corrosion and wear issues of automotive brake discs, many manufacturers have introduced various surface treatment technologies, such as thermal spraying, laser cladding, and ferritic nitrocarburizing (FNC). Besides those surface treatment technologies, a plasma electrolytic aluminating (PEA) process has also shown to be effective in producing alumina-based ceramic coatings on cast iron substrates, providing an enhanced corrosion resistance. In this study, the PEA-coated brake rotor and FNC-treated brake rotor were comparatively tested in various corrosion conditions, including an electrochemical corrosion test and simulative corrosion experiment, before and after a road driving test. A scanning electron microscope (SEM) and an energy-dispersive X-ray (EDX) were used to observe and analyze morphology and chemical compositions of the surfaces and cross-sections of the tested rotors. The results showed that the new PEA-coated brake rotor demonstrated the best corrosion resistance in the electrochemical corrosion test among all given tested cases. After the vehicle test, the PEA-coated rotor surface had an obvious materials transfer layer which can protect the rotor from abrasive wear. The transfer layer materials sourcing from the low-met brake pads however contained metallic elements, leading to appearance of a lower corrosion resistance during the electrochemical corrosion test. In duration of the vehicle road test (1000 braking events at 0.3-0.4 g), the FNC brake rotor showed some loss of its white layer but maintained its nitrogen diffusion layer, which still showed protection to the brake rotor base material from corrosion. It was also found that some surface areas where the graphite flakes were located on FNC-treated cast iron brake disc surface were exposed to the ambient environment, which may be a reason why the localized corrosion appeared on the FNC-treated rotor in the late stage of the vehicle road test.
Enhancing Brake Performance: FNC-Smart-ONC® Technology to Address Corrosion Challenges and Extend the Durability of GCI Rotors
Authors: Nousir Saadia , Winter Karl-Michael
Published: September 2024

The most used rotor material is gray cast iron (GCI), known for its susceptibility to corrosion. The impact of corrosion on the braking system is paramount, affecting both braking performance and the emission of particulate matter. The issue becomes more severe, especially when the brakes are left stationary or unused for extended durations in humid conditions, as seen with electric vehicles (EVs). Brake disc corrosion amplifies the risk of corrosion adhesion between contacting surfaces, leading to substantial damage, increased quantity and mass of non-exhaust particulate emissions, and decreased braking effectiveness. In addition, brake pads' friction material plays a crucial role in generating the necessary stopping force, creating friction that transforms kinetic energy into heat. However, heightened pressure during braking elevates rotor temperatures, contributing to the degradation of the friction material. This degradation manifests in decreased mechanical strength, heightened pad-to-rotor force, wear, and reduced braking efficiency. To address all these challenges and meet the stringent Euro7 particulate emission standards, we have developed controlled wear-resistant nitrocarburized layers on cast iron surfaces with customizable thicknesses, compositions, and porosity coupled with a new generation of post-oxidized layers referred to as Smart-ONC®. These layers, known for their remarkable "self-healing" capabilities, are formed through a controlled, in-situ post-oxidation process by incorporating additional metals into the oxide layer to enhance corrosion resistance and fortify the surface against damage and potential failures. the dyno tests validated the integrity of the FNC-Smart ONC (Ferritic nitrocarburizing-Smart oxidation of the nitrocarburized layer) layers, affirming their ability to preserve mechanical properties without experiencing wear, delamination, or cracking. Notably, FNC-Smart ONC discs demonstrate pad material accumulation, effectively sustaining braking performance as an additional protective interface between pads and discs.
A Study on the Countermeasure to EURO7 Brake Dust Regulation Phase 1
Authors: Kim Yoon Cheol , Kim Jwa Kyum
Published: September 2024

This is a case study to cope with the brake dust regulation of EURO7, countermeasures were listed, and evaluation and verification studies using C segment sports utility vehicle were conducted on them. Through this phase1 study, it was most reasonable to apply hard metal cladding disks and metallic friction material to front brake and apply friction materials as NAO with less dust generation to rear brake. This was because it is possible to satisfy new regulations without deteriorating the required performance in Europe. However, it is necessary to develop detailed specifications of discs and friction materials to satisfy our braking development goals for European models in the Phase 2.
Low-Speed Stop and Near Zero-Speed Start-to-Move Brake Noise: Effect of Moisture Adsorption, Prior Braking and Deceleration Rate
Authors: Sriwiboon Meechai , Rhee Seong Kwan , Sukultanasorn Jittrathep , Kunthong Jitpanu
Published: September 2024

The influence of moisture adsorption, prior braking, and deceleration rate on the low-speed braking noise has been investigated, using copper-free disc pads on a passenger car. With increasing moisture adsorption time, decreasing severity of prior braking or increasing deceleration rate, the noise sound level increases for the air-borne exterior noise as well as for the structure-borne interior noise. The near-end stop noise and the zero-speed start-to-move noise show a good correlation. Also, a good correlation is found between the noise measured on a noise dynamometer and on a vehicle for the air-borne noise. All the variables need to be precisely controlled to achieve repeatable and reliable results for dynamometer and vehicle braking groan noise tests. It appears that the zero-speed start-to-move vehicle interior noise is caused by the pre-slip vibration of the brake: further research is needed.
Aluminum Alloy, Extrusions, 1.0Mg - 0.60Si - 0.28Cu - 0.20Cr (6061-T4511 or T4510), Solution Heat Treated and Stress Relieved by Stretching
Authors:   AMS D Nonferrous Alloys Committee
Published: September 2024

This specification covers an aluminum alloy in the form of extruded bars, rods, wire, profiles, and tubing (see 8.6).
Balancing Machines - Description and Selection Horizontal, Two-Plane, Hard-Bearing Type for Gas Turbine Rotors
Authors:   EG-1A Balancing Committee
Published: September 2024

This document provides the specifications of horizontal hard-bearing balancing machines, which make such machines suitable for gas turbine rotor balancing.
Onboard System Requirements for LTE-V2X V2V Safety Communications
Authors:   C-V2X Technical Committee
Published: September 2024

This SAE Standard specifies system requirements for an onboard vehicle-to-vehicle (V2V) safety communications system for vehicle classes of 2, 3, 4, and 51, including standards profiles, functional requirements, and performance requirements. The system is capable of transmitting and receiving the SAE J2735-defined basic safety message (BSM) over a PC5 Sidelink V2X (mode 4) communications link as defined in ETSI Release 142,3. The system uses Institute of Electrical and Electronics Engineers (IEEE) 1609 standards for network and transport layer communciations, as well as security.
Implementation of an Evidence-based Hospital Acquired Pressure Injury Strategy in the Intensive Care Unit
Authors:   , Brigman Tonya
Published: September 2024

Practice Problem: Hospital-acquired pressure injuries (HAPI) are a significant concern in healthcare with the most vulnerable group being the adult patients in ICUs leading to increased morbidity, longer hospital stays, and higher healthcare costs. PICOT: In adult ICU patients (P) does the implementation of daily chlorhexidine gluconate (CHG) baths with post bath barrier cream combined with intentional turning every 2-hours (I) compared to standard skin care practices and nonintentional turning (C) reduce the incidence of hospital-acquired pressure injuries (HAPI) (O) within 10-weeks (T)? Evidence: The project was based on the analysis of the literature published in the last five years and concerned with the assessment of chlorhexidine gluconate baths, barrier creams, and repositioning. These interventions were noted to have the potential of reducing the occurrence of HAPIs in ICU environments as pointed out in the evidence presented. Intervention: The intervention included the use of chlorhexidine gluconate baths and then applying barrier cream and intentional turning of the patient every two hours. Outcome: The results of the Fisher exact test were not significant based on an alpha value of .05, p = .118, suggesting that Post bath barrier cream application and Acquired HAPI were not related. The results were clinically significant with the reduction in pressure injury incidences. Conclusion: This project implemented an evidence-based practice to reduce the incidence of HAPIs in the ICU environment as a recurring problem. By implementing measures such as chlorhexidine gluconate bath, application of barrier creams and repositioning of patients, the initiative was able to reduce the risk and incidence of pressure injuries hence enhancing the quality and safety of patient care in critical care settings.
Wind speed prediction in some major cities in Africa using Linear Regression and Random Forest algorithms
Authors: Samson Timothy Kayode , Aweda Francis Olatunbosun
Published: September 2024

Globally, wind energy if properly harnessed, could serve as a source of energy generation in Africa. This study compared the performance of two Machine Learning (ML) algorithms (Linear regression and Random Forest) in predicting wind speed in five major cities in Africa (Yaoundé, Pretoria, Nairobi, Cairo and Abuja). Wind data were collected between January 1, 2000, and December 31, 2022, using the Solar Radiation Data Archive. The data preprocessing was carried out with 80% of the data used for training and 20% for validation. The performance of these ML algorithms was evaluated using Mean Square Error (MSE), Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and coefficient of determination (R2). The result shows that Nairobi (3.814795 m/s) closely followed by Cairo (3.606453 m/s) has the highest mean wind speed while Yaoundé (1.090512 m/s) has the lowest. Based on the performance metrics used, the two Machine Learning algorithms were competitive. Still, the Linear Regression (LR) algorithm outperformed the Random Forest Algorithm in predicting wind speed in all the selected major African cities. In Yaoundé (RMSE = 0.3892, MAE= 0.3001, MAPE =0.5030), Pretoria (RMSE=1.2339, MAE=0.9480, MAPE=0.7450) Nairobi (RMSE= 0.4223, MAE =0.6499, MAPE =0.1872), Nairobi (RMSE=0.6499, MAE=0.5171, MAPE =0.1872), Cairo (RMSE =1.0909, MAE =0.8544, MAPE =0.3541) and Abuja (RMSE = 0.70245, MAE =0.5441, MAPE= 0.4515) the Linear regression algorithms was found to outperformed Random Forest Regression. Therefore, the Linear regression algorithm is more reliable in predicting wind speed compared with the Random Forest regression.
Evaluation of rational drug use in primary healthcare centres of Probolinggo District, Indonesia
Authors: Rokayah  , Puspitasari Hanni Prihhastuti , Nita Yunita
Published: September 2024

Background: The Indonesian government has been working on optimising drug use in primary healthcare centres (puskesmas) of the Probolinggo District Health Office (dinkes).    Objective: This study aimed to evaluate the rationality of drug use (RDU) using indicators set by the Indonesian Ministry of Health.
Method: A retrospective descriptive study was conducted using data from 33 Puskesmas in Probolinggo Dinkes during the year 2022. Data on patients diagnosed with Acute Respiratory Infection (ARI) non-pneumonia (n = 36,378), non-specific diarrhoea (n = 4,291), and myalgia injection cases (n = 9,641) were collected.
Result: The study's findings showed that the percentage of antibiotics for ARI was 17.11%, meeting the standard. Of the 33 Puskesmas, 67% met the standard, while 33% did not. Meanwhile, the antibiotic used for non-specific diarrhoea was 9.58%, exceeding the tolerance limit, with 55% of Puskesmas meeting the standard and 45% not. The percentage for injectable drugs in myalgia cases was 0.43%, in line with the standard, with 82% of Puskesmas meeting the standard and 18% not.
Conclusion: The study found that antibiotic usage for ARI and injections for myalgia met the standards, but for non-specific diarrhoea cases did not.