Design and Additive Manufacturing of a Medical Face Shield for Healthcare Workers Battling Coronavirus (COVID-19)

During the coronavirus disease-19 pandemic, the demand for specific medical equipment such as personal protective equipment has rapidly exceeded the available supply around the world. Specifically, simple medical equipment such as medical gloves, aprons, goggles, surgery masks, and medical face shields have become highly in demand in the health-care sector in the face of this rapidly developing pandemic. This difficult period strengthens the social solidarity to an extent parallel to the escalation of this pandemic. Education and government institutions, commercial and noncommercial organizations and individual homemakers have produced specific medical equipment by means of additive manufacturing (AM) technology, which is the fastest way to create a product, providing their support for urgent demands within the health-care services. Medical face shields have become a popular item to produce, and many design variations and prototypes have been forthcoming. Although AM technology can be used to produce several types of noncommercial equipment, this rapid manufacturing approach is limited by its longer production time as compared to conventional serial/mass production and the high demand. However, most of the individual designer/maker-based face shields are designed with little appreciation of clinical needs and nonergonomic. They also lack of professional product design and are not designed according to AM (Design for AM [DfAM]) principles. Consequently, the production time of up to 4 – 5 h for some products of these designs is needed. Therefore, a lighter, more ergonomic, single frame medical face shield without extra components to assemble would be useful, especially for individual designers/makers and noncommercial producers to increase productivity in a shorter timeframe. In this study, a medical face shield that is competitively lighter, relatively more ergonomic, easy to use, and can be assembled without extra components (such as elastic bands, softening materials, and clips) was designed. The face shield was produced by AM with a relatively shorter production time. Subsequently, finite element analysis-based structural design verification was performed, and a three-dimensional (3D) prototype was produced by an original equipment manufacturer 3D printer (Fused Deposition Modeling). This study demonstrated that an original face shield design with <10 g material usage per single frame was produced in under 45 min of fabrication time. This research also provides a useful product DfAM of simple medical equipment such as face shields through advanced engineering design, simulation, and AM applications as an essential approach to battling coronavirus-like viral pandemics

Gastric intramucosal pH is stable during titration of positive end-expiratory pressure to improve oxygenation in acute respiratory distress syndrome

BACKGROUND: Optimal positive end-expiratory pressure (PEEP) is an important component of adequate mechanical ventilation in acute lung injury and acute respiratory distress syndrome (ARDS). In the present study we tested the effect on gastric intramucosal pH of incremental increases in PEEP level (i.e. PEEP titration) to improve oxygenation in ARDS. Seventeen consecutive patients with ARDS, as defined by consensus criteria, were included in this clinical, prospective study. All patients were haemodynamically stable, and were not receiving vasopressors. From an initial level of 5 cmH(2)O, PEEP was titrated at 2 cmH(2)O increments until the partial arterial oxygen tension was 300 mmHg or greater, peak airway pressure was 45 cmH(2)O or greater, or mean arterial blood pressure decreased by 20% or more of the baseline value. Optimal PEEP was defined as the level of PEEP that achieved the best oxygenation. The maximum PEEP was the highest PEEP level reached during titration in each patient. RESULTS: Gastric mucosal pH was measured using gastric tonometry at all levels of PEEP. The thermodilution technique was used for measurement of cardiac index. Gastric mucosal pH was similar at baseline and at optimal PEEP levels, but it was slightly reduced at maximum PEEP. Cardiac index and oxygen delivery remained stable at all PEEP levels. CONCLUSION: Incremental titration of PEEP based on improvement in oxygenation does not decrease gastric intramucosal perfusion when cardiac output is preserved in patients with ARDS

The Effects of Atropine and Aminophylline Premedication on Respiratory Problems After Electroconvulsive Therapy: A Prospective, Randomized, Crossover Trial

Objective: Electroconvulsive therapy (ECT) is a safe treatment for psychiatric disorders. As shown after epileptic seizure, mild to moderate respiratory problems could be observed after ECT. We investigated the effects of atropine and aminophylline premedication on respiratory problems that occur after ECT under general anesthesia

Comparison of ability of pulse pressure variation to predict fluid responsiveness in prone and supine position: an observational study

We aimed to compare the ability of pulse pressure variation (PPV) to predict fluid responsiveness in prone and supine positions and investigate effect of body mass index (BMI), intraabdominal pressure (IAP) and static respiratory compliance (CS) on PPV. A total of 88 patients undergoing neurosurgery were included. After standardized anesthesia induction, patients' PPV, stroke volume index (SVI), CS and IAP values were recorded in supine (T1) and prone (T2) positions and after fluid loading (T3). Also, PPV change percentage (PPV%) between T2 and T1 times was calculated. Patients whose SVI increased more than 15% after the fluid loading were defined as volume responders. In 10 patients, PPV% was -20%. All of these patients had CST230kg/m(2), and two had IAP(T2)>15mmHg. In 16 patients, PPV% was 20%. In these patients, 10 had CST230kg/m(2), and 12 had IAP(T2)>15mmHg. Thirty-nine patients were volume responder. When all patients were examined for predicting fluid responsiveness, area under curves (AUC) of PPVT2 (0.790, 95%CI 0.690-0.870) was significantly lower than AUC of PPVT1 (0.937, 95%CI 0.878-0.997) with ROC analysis (p=0.002). When patients whose CST2 was 30kg/m(2) were excluded from analysis separately, AUC of PPVT2 became similar to PPVT1. PPV in the prone can predict fluid responsiveness as good as PPV in the supine, only if BMI is 31ml/cmH(2)O

Evaluation of risk factors and development of acute kidney injury in aneurysmal subarachnoid hemorrhage, head injury, and severe sepsis/septic shock patients during ICU treatment.

BACKGROUND: There are few studies examining development of acute kidney injury (AKI) in the various types of patients in intensive care units (ICUs). Presently described is evaluation of risk factors and development of AKI in different groups of ICU patients

Effects of Prone and Jackknife Positioning on Lumbar Disc Herniation Surgery

Background: Intra-abdominal hypertension due to surgical position increases bleeding at the surgical site. In this study, we evaluated the impact of prone and jackknife position on intra-abdominal pressure (IAP), lung mechanics, blood loss at the surgical site, and duration of the surgical procedure on lumbar disc operations

A challenge with 5 cmH2O of positive end-expiratory pressure predicts fluid responsiveness in neurosurgery patients with protective ventilation: an observational study.

BACKGROUND: Positive end-expiratory pressure (PEEP) increment induces a decrease in Stroke Volume Index (SVI). We hypothesized that the magnitude of SVI reduction due to a 5 cmH(2)O increase in PEEP could predict fluid responsiveness during low tidal volume ventilation

A Comparison of the Effects of 20% Mannitol and 3% NaCl on Coagulation Parameters &lt;i&gt;In Vitro&lt;/i&gt; using ROTEM: A Prospective Randomized Crossover Study.

Objective: The aim of the present study is to compare the effect of 20% mannitol and 3% NaCl on blood coagulation in vitro using rotational thromboelastometry (ROTEM)