Oxygen Flowmeter Research Articles

Feasibility and acceptability of bubble continuous positive airway pressure oxygen therapy for the treatment of childhood severe pneumonia and hypoxaemia in Bangladeshi children

Effective management of hypoxaemia is key to reducing pneumonia deaths in children. In an intensive care setting within a tertiary hospital in Bangladesh, bubble continuous positive airway pressure (bCPAP) oxygen therapy was beneficial in reducing deaths in this population. To inform a future trial, we investigated the feasibility of introducing bCPAP in this population in non-tertiary/district hospitals in Bangladesh. We conducted a qualitative assessment using a descriptive phenomenological approach to understand the structural and functional capacity of the non-tertiary hospitals (Institute of Child and Mother Health and Kushtia General Hospital) for the clinical use of bCPAP. We conducted interviews and focus group discussions (23 nurses, seven physicians, 14 parents). We retrospectively (12 months) and prospectively (three months) measured the prevalence of severe pneumonia and hypoxaemia in children attending the two study sites. For the feasibility phase, we enrolled 20 patients with severe pneumonia (age two to 24 months) to receive bCPAP, putting in place safeguards to identify risk. Retrospectively, while 747 of 3012 (24.8%) children had a diagnosis of severe pneumonia, no pulse oxygen saturation information was available. Of 3008 children prospectively assessed with pulse oximetry when attending the two sites, 81 (3.7%) had severe pneumonia and hypoxaemia. The main structural challenges to implementation were the inadequate number of pulse oximeters, lack of power generator backup, high patient load with an inadequate number of hospital staff, and inadequate and non-functioning oxygen flow meters. Functional challenges were the rapid turnover of trained clinicians in the hospitals, limited post-admission routine care for in-patients by hospital clinicians due to their extreme workload (particularly after official hours). The study implemented a minimum of four hourly clinical reviews and provided oxygen concentrators (with backup oxygen cylinders), and automatic power generator backup. Twenty children with a mean age of 6.7 (standard deviation (SD) = 5.0)) months with severe pneumonia and hypoxaemia (median (md) SpO2 = 87% in room air, interquartile range (IQR) = 85-88)) with cough (100%) and severe respiratory difficulties (100%) received bCPAP oxygen therapy for a median of 16 hours (IQR = 6-16). There were no treatment failures or deaths. Implementation of low-cost bCPAP oxygen therapy is feasible in non-tertiary/district hospitals when additional training and resources are allocated.

Curious case of a spurious medical gas cylinder.

INTRODUCTION Anaesthesia machines are supplied through a central medical gas pipeline system (MGPS) or cylinders. Type E cylinders are used as backup when the pipeline system fails.[1,2] Ensuring a filled type E oxygen cylinder attached to the anaesthesia machine is an element of the pre-use daily equipment checklist in the operating rooms (ORs).[3] Various safety features ensure that correct gas is delivered to the patient through the cylinders, namely colour coding and label, pin index system, etc. Pin index is unique to each gas and prevents connection of wrong cylinder to the anaesthesia machine.[4] We report our recent encounter with a cylinder, colour coded (black body and white shoulder) and labelled for oxygen but with a pin index and label on valve for nitrous oxide (N2O). CASE REPORT In an OR, the backup oxygen cylinder was empty. Hence, another oxygen cylinder (as identified by ‘O2’ marking and colour coding) was attempted to attach to the hanger yoke assembly. However, it could not be attached. Upon close inspection of the cylinder, the holes on the cylinder corresponded to pin index of N2O, (3,5) and N2O was engraved on the valve [Figure 1a and b]. This cylinder could be successfully attached to the nitrous oxide hanger yoke assembly without any leak [Figure 1c]. Also, there was doubt regarding the actual contents of the cylinder. The anaesthetic gas monitor (AGM) of the anaesthesia workstation (Datex Ohmeda 9100c NXT, GE Healthcare, United Kingdom) was utilized after disconnecting the N2O and air pipelines. The oxygen pipeline was not disconnected since N2O cannot be turned on without oxygen. A test lung was connected to the breathing circuit, and gas flow was turned on (O2:N2O 50:50; 5 L/min each). The N2O flowmeter was supplied by the spurious cylinder and oxygen flowmeter by the pipeline. As depicted by the AGM, both the inspiratory and expiratory gases had just oxygen and no N2O, indicating that the actual content of the cylinder in question was oxygen. The faulty oxygen cylinder was labelled appropriately for caution and segregated, and another oxygen cylinder was attached as backup for the day. The event was reported to the hospital authorities for suitable action towards the supplier/manufacturer.Figure 1: (a) Cylinder, colour coded for oxygen (black body and white shoulders) with N2O engraved over the valve (black arrow); (b) Pin holes corresponding to pin index of nitrous oxide (white arrow); and (c) The spurious cylinder attached to nitrous oxide hanger yoke, since it could not be attached to the oxygen hanger yokeDISCUSSION Despite the technical advances and incorporation of safety features, potentially catastrophic events continue to happen every now and then. Pauling and Ball reviewed case reports pertaining to the delivery of anoxic gas mixtures to the patients, both prior to and after the obligatory safety checklist.[5] The safety features are prone to disregard which may arise out of unawareness, disinterest or accident. This can occur at any point in the process, manufacturer, supplier or end user. Pin index system has been instrumental in preventing erroneous connection of cylinder. The pin index system is also used to fill the correct gas in the cylinder.[6] However, this system is not infallible. It can be bypassed by using an adapter while filling the gas or using multiple washers (Bodok seal) while attaching to the hanger yoke assembly of anaesthesia machine. The same seemed to have happened in our case as well, where oxygen was filled in the cylinder through a N2O valve. Had it been the other way around with N2O filled in an oxygen cylinder, the outcome could have been catastrophic. Ours was a clear instance of threading a N2O valve onto a shoulder and body which was colour coded and labelled for oxygen. This could have been the result of amateurish work in an unsupervised environment at the point of manufacturing. Sensitization, upskilling, training and reeducating at this level of the supply chain are mandatory to avoid such mishaps. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Monitoring the Stability of Oxygen Flow Analyzer on Oxygen Station in the Hospital

Oxygen therapy besides having benefits also has certain dangers and side effects. For this reason, oxygen therapy must be given at the proper dose by monitoring the patient regularly and adjusting the oxygen flowmeter. The accuracy of flowmeter under standard conditions is guaranteed by manufacturer. With time and use the precision may change and the flow accuracy given in a hospital setting may differ from the original value. Thepurpose of this research is to conduct further research on Oxygen flow analyzer which focuses on discussing the accuracy and stability of the oxygen flow sensor against the gold standard. Contribution of this study is to increase the range of oxygen flowrate measurement to 15 liters per minute (LPM). This research uses Arduino Mega while the gas flow sensor used is legris flow sensor. The measurement results are displayed on TFT LCD equipped with SD Card data storage. The gas flowrate is regulated using a flowmeter (GEA). Meanwhile the comparison tools using Oxygen Analyzer and 1 m3 oxygen gas cylinder. At the testing stage, the sensor reading value on the module that appears on the TFT LCD is compared with the resultsf a comparison tool with a measurement range of 1 LPM to 15 LPM 6 times at each point. The conclusion from these results is that the calibrator module has a relative error is still within the allowable tolerance limit of ±10%.
 INDEX TERMS Calibration, Oxygen Flow Analyzer, Flowmeter, TFT Display

SG-APSIC1065: The effectiveness of an ultraviolet-C device for terminal room disinfection in an intensive care unit

Objectives: Medical devices and the hospital environment can be contaminated easily by multidrug-resistant bacteria. The effectiveness of cleaning practices is often suboptimal because environmental cleaning in hospitals is complex and depends on human factors, the physical and chemical characteristics of environment, and the viability of the microorganisms. Ultraviolet-C (UV-C) lamps can be used to reduce the spread of microorganisms. We evaluated the effectiveness of an ultraviolet-C (UV-C) device on terminal room cleaning and disinfection. Methods: The study was conducted at an ICU of a medical center in Taiwan. We performed a 3-stage evaluation for the effectiveness of UV-C radiation, including pre–UV-C radiation, UV-C radiation, and a bleaching procedure. The 3 stages of evaluation were implemented in the ICU rooms from which a patient had been discharged or transferred. We collected the data from adenosine triphosphate (ATP) bioluminescence testing, colonized strains, and their corresponding colony counts by sampling from the environmental surfaces and air. We tested 8 high-touch surfaces, including 2 sides of bed rails, headboards, footboards, bedside tables, monitors, pumping devices, IV stands, and oxygen flow meters. Results: In total, 1,696 environmental surfaces and 72 air samples were analyzed. The levels of ATP bioluminescence and colony counts of isolated bacteria decreased significantly after UV-C radiation and bleaching disinfection for both the environmental and air samples (P < .001). Resistant bacteria (vancomycin-resistant Enterococcus, VRE) were commonly isolated on the hard-to-clean surfaces of monitors, oxygen flow meters, and IV pumps. However, they were also eradicated (P < .001). Conclusions: UV-C can significantly reduce environmental contamination by multidrug-resistant microorganisms. UV-C is an effective device to assist staff in cleaning the hospital environment.

An optimisation approach for determining the efficiency of vital medical devices in intensive care units with COVID-19 patients using Apriori algorithm

Improving the process of strategic management in hospitals preparation and equipping the intensive care units (ICUs) and the availability of medical devices plays an important role for knowing consumer behaviour and need. This cross-sectional study was performed in the ICU of Farhikhtegan Hospital, Tehran, Iran for a period of six months. During these months, ten medical devices have been used 5,497 times. These devices include: ventilator, oxygen cylinder, infusion pump, electrocardiography machine, vital signs monitor, oxygen flowmeter, wavy mattress, ultrasound sonography machine, ultrasound echocardiography machine, and dialysis machine. The Apriori algorithm showed that four devices: ventilator, oxygen cylinder, vital signs monitoring device, oxygen flowmeter are the most used ones by patients. These devices are positively correlated with each other and their confidence is over 80% and their support is 73%. For validating the results, we have used equivalence class clustering and bottom-up lattice traversal (ECLAT) algorithm in our dataset.

COVID-19 is a Global Threat, But Why Mucormycosis upsurged in India Alone?

Abstract: A fatal problem associated with SARS-CoV-2 called mucormycosis or black fungus was observed in COVID-19 patients worldwide, in particular from India. The rare infection rose more rapidly during the second wave of COVID in India. Upswing in mucormycosis is a public health concern as the fatality rate is pretty high, upto 90%. These realities demanded a search for the reason for upsurging cases of mucormycosis in India alone. The probable explanations for COVID patients developing mucormycosis include injudicious use of steroids, uncontrolled diabetes with or without diabetic ketoacidosis (DKA), absurd use of immuno-modulants with steroids, and extensive use of antimicrobials. Besides, overuse of zinc and iron supplements, features of B.1.617 variant of SARS-CoV-2 that suppress immunity, along with several other risk factors including long intensive care unit (ICU) stays with or without mechanical ventilators might have contributed to the increased prevalence of mucormycosis in patients with COVID-19. India is regarded as the “mucor capital of the world”, having 70 times higher pre-COVID incidence than the global data. Therefore, it is vital to rectify the aggravating factors and curb the spread of mucormycosis. If this isn’t brought under control, there are chances of other deadly infections to remain in the background. Rational glycemic control in COVID patients should be ensured. Use of steroids and immuno-modulants along with steroids should be reserved. Also, use of immunity boosters like zinc and iron should be limited. Furthermore, a holistic approach to improve the use of selfmedication through public education should be introduced. Government should make sure that the oxygen cylinders are hygienic and rightly maintained. Sterile normal saline or distilled water should be used in humidifiers and oxygen flow meters has to be changed periodically. Negligence of all these imparts a huge mess not only on individuals but also on government. If the tribulations of overuse of drugs and insufficient hygiene persist, chances of outbreak of secondary infections alongside epidemics and pandemics should be expected in future. Key words: Mucormycosis, Blackfungus, COVID-19, India, Infection.

Use of Bubble Continuous Positive Airway Pressure (BCPAP) in Management of Neonatal Respiratory Distress Syndrome in Resource Limited Settings

Aim: To determine the efficacy of use of bubble continuous positive airway pressure in management of neonatal respiratory distress syndrome. Study design: Prospective study. Place and duration of study: Paediatric Medicine, Abbas Institute of Medical Sciences (AIMS) Muzafarabad, AJ Kashmir from 01-02-2022 to 31-07-2022. Methodology: Fifty new born who were admitted with respiratory distress syndrome was enrolled. On clinical examination their shake test was found positive for respiratory distress syndrome or in other cases the chest x-ray imaging was suggestive towards respiratory distress syndrome symptoms. Oxygen flow-meter was prepared and nasal-pong were closed for bubble prior attachment with neonate. Appearance, pulse, grimace, activity and respiration scoring at five min, primigravida, child temperature, vital signs, oxygen saturation rate, complications, post and pre-bubble continuous positive airway pressure were recorded. Results: The mean age of the neonates was 2.7±1.1 days. There were more male children than female new born who were suffering from respiratory distress syndrome. The mean maternal age was 32.3±3.5 years with 70% of the births to be in singleton Antenatal steroids were received by 66.7% of new born and the 5 minutes appearance, pulse, grimace, activity and respiration score presented 64% new born within a range of 8-10 points. There were 76.2% respiratory distress syndromes new born who were successfully weaned off from bubble continuous positive airway pressure. Conclusion: Bubble continuous positive airway pressure is a cost-effective technique in resource limited regions for reducing and treating respiratory distress syndrome cases and decreasing mortality. Keywords: Management, Respiratory distress syndrome, Management

Design of an automated oxygen flow control system for hypoxemic patients

Hypoxemia is a condition for which there is a lack of sufficient oxygen in the blood. Which might range from minor issues like dizziness and shortness of breath to more severe problems like interfering with heart and brain functions. The amount of oxygen in a person’s blood indicates how efficiently the body transports oxygen from the lungs to the cells. The present research aims to design continuously monitor the blood oxygen level and to regulate the opening and closing of the oxygen flow meter valve using a servo motor. If the blood oxygen level is normal, the valve remains closed. If the blood oxygen level falls below the normal range, the valve is opened. The system employs a SpO2 sensor for monitoring the heart rate and oxygen saturation. The output of the sensor is sent to the microcontroller that comes up with an in-built analog to digital converter. Servo motor is utilized to control the flow meter valve to deliver the required oxygen to the patient during abnormal detection of blood oxygen saturation level. When the blood oxygen level falls below 94%, the oxygen valve is opened to allowing for oxygen flow. The blood oxygen level detected as normal that is 97% and hence the oxygen flow is at off state. The output is sent to an LCD unit, which keeps track of the SpO2 level. This microcontroller-based oxygen supply control device can prevent the adverse effects of hypoxemia. The present research reduces the time and a caretaker requirement to oxygenate the patient by providing controlled delivery system.

Medical gas pipeline system as a limiting factor for hospital oxygen supply during COVID-19 outbreak.

Medical gas pipeline system as a limiting factor for hospital oxygen supply during COVID-19 outbreak.

Bacteriological Surveillance of Ambulance Vehicles from a Tertiary Care Hospital of North India.

Objective An ambulance is a medically equipped vehicle which is used in case of any medical emergency for the transport of patients to treatment facilities. The ambulances help in the transportation of thousands of patients per year, and such patients may carry infectious microorganisms which pose a major threat to the treatment of such patients. In this study, we analyzed the extent of bacterial contamination in our ambulance vehicles and measured the degree of antimicrobial resistance among isolated pathogens. Material and Method This study included five ambulances of our tertiary care hospital and different random sites were swabbed in each vehicle. These were selected based on their well-known high frequency of contact by emergency personnel and patients. Swabs were inserted into sterile test tubes containing normal saline and immediately transferred to our microbiology laboratory to identify bacterial contaminants utilizing standard microbiological procedures. Result A total of 198 swab samples were collected from all the five ambulances, out of which 170 (85.8%) swabs were sterile and 28 (14.2%) swabs yielded potentially pathogenic bacterial isolates. The highest contamination rate with pathogenic bacteria was detected in the oxygen flow meter knob (60%), suction machine tubing (60%), and stethoscope (40%). Staphylococcus aureus (32%) was the most frequently detected microorganism. Conclusion Our study showed low prevalence of bacterial contamination in ambulances because of good infection control policy of our hospital, however, some areas still need improvement and require proper standard operating procedures of disinfection policies of these emergency vehicles.

Sustainable veterinary anaesthesia: single centre audit of oxygen and inhaled anaesthetic consumption and comparisons to a hypothetical model.

Single centre carbon footprint audit of oxygen and inhaled anaesthetic agent consumption. Retrospective audit with hypothetical intervention. Records of 100 consecutive anaesthetics were examined. Consumption of oxygen and inhaled anaesthetic agent were estimated from oxygen flowmeter and vaporiser settings. Carbon dioxide equivalents (kg CO2 e) were calculated. Records were reassessed to identify potential reductions in oxygen flow. Animals >5kg were assigned to use circle systems set at a maintenance flow of 1L/min following a short transitional period of higher flow. Animals <5kg were assigned to Mapleson-A breathing systems at a flow of 1L/min. Potential reductions in oxygen and inhaled anaesthetic agent consumption and CO2 e were calculated. A total of 14,370 minutes of anaesthesia were audited. Median bodyweight of the animals was 12.1 (interquartile range 5 to 25.8) kg. Median anaesthetic time was 110 (interquartile range 73.8 to 205) minutes. It was estimated 43,132 L of oxygen were used to vaporise 2605 mL of liquid sevoflurane and 1654 mL of liquid isoflurane. Potential oxygen consumption was 16,798 L, lowering sevoflurane consumption to 1123 mL and isoflurane to 589 mL. Using the suggested technique, oxygen and inhaled anaesthetic agent could have been reduced in 97% of anaesthetics with a median inhaled anaesthetic agent reduction of 59% (interquartile range 43 to 71%). Carbon footprint of the inhaled anaesthetic agent used was calculated as 1.82 metric tonnes of CO2 e. This could have been lowered to 0.67 metric tonnes (63% reduction). Large reductions in oxygen and inhaled anaesthetic agent consumption and therefore greenhouse gas emission and financial expenditure can be made if we audit and adapt our practices.

A recurring case of ‘no trace, right place’ during emergency tracheal intubations in the critical care setting

We wish to highlight a safety issue concerning the use of the Mapleson C circuit along with high fresh gas flows and the potential impact this could have on capnography. The authors have encountered a situation where despite successful tracheal intubation, there can be continued failure to detect carbon dioxide. This issue became apparent during the undertaking of a large number of emergency tracheal intubations in the current COVID-19 pandemic. The cases involved patients with uneventful airway management and clear placement of a tracheal tube between the vocal cords using videolaryngoscopy. This was followed in all cases by the clinical confirmation of successful tracheal intubation but the absence of a capnographic trace. A commonly identified feature in all events was very high fresh gas flow to the Mapleson C circuit. This high flow was unintentional and frequently had been commenced by a clinician assisting with the tracheal intubation, before the arrival of the intubator. Furthermore, the high flow was initially unrecognised due to the urgent nature of the situation and the impact of personal protective equipment. The standard oxygen flowmeter present in most wards or resuscitation bays displays flow graduations of up to 15 l.min-1. The authors found that while often the last graduation marked is 15 l.min-1, these devices are not flow-limited and when the valve is opened fully can generate flows much higher than this. Further investigation of the technical data supplied by the manufactures of several flowmeters reveals that the high flows produced when the valve is opened fully are referred to as ‘flush’ or ‘flood’ flows and can be as high as 90 l.min-1 [1]. The authors confirmed this by testing the flows generated from oxygen flowmeters encountered throughout their hospital including the auxiliary oxygen outlet present on the anaesthetic machine which produced 84 l.min-1 oxygen while a standard ward oxygen flowmeter achieved 75 l.min-1. When the situation was encountered again and the high flows identified, a capnographic trace could be produced by turning down the oxygen flow to the Mapleson C circuit. The exact cause of this phenomenon is yet to be determined but correspondence with the manufacturer of the Mapleson C circuit suggests that carbon dioxide washout is the likely cause. However, a number of confounders may also contribute and they include the flowmeters flush rate, the composition of the circuit, the type of heat and moisture exchange filter, the behaviour of the adjustable pressure limiting (APL) valve, the adequacy of the tracheal tube cuff and the patient's pulmonary compliance. A review of the technical data provided by the manufacturers of the Mapleson C circuit, revealed that with the APL valve set in the semi-closed position, a fresh gas flow of 50 l.min-1 will generate a resistance of 32 cmH2O (Technical document, Armstrong Medical, Coleraine). The authors will explore these concepts further in a laboratory setting. The current pandemic has seen oxygen capacity in hospitals come under strain due to the large number of COVID-19 patients [2, 3]. It is, therefore, imperative that we reduce the wastage of oxygen wherever possible.

A comparison of cannula insufflation device performance for emergency front of neck airway.

Pediatric emergency front of neck airway guidelines recommend oxygenation via cannula cricothyroidotomy or tracheotomy. The primary aim was to measure test lung pressures and volumes generated by cannula insufflation devices recommended for emergency front of neck airway compared with a pressure limit of 50cm H2 O and volume limit of 20ml/kg. The secondary aim was to calculate pressure and volume variability. The primary end point was test lung expansion. Adult, child, and infant airway models, each with three degrees of upper airway obstruction, were oxygenated using six cannula insufflation devices: 3-way stopcock, Rapid-O2 , Manujet, Enk oxygen flow modulator, Ventrain, and self-inflating bags. Test lung pressures and volumes were recorded. Pressures and volumes from all devices were highly variable, despite oxygen flow calibration and strict adherence to oxygen insufflation protocols. With upper airway occlusion, pressures >50cm H2 0 were produced by Rapid-O2 and Enk oxygen flow meter in adult and infant lungs, 3-way stopcock in adult and child lungs, and Manujet in all lung sizes. Ventrain produced acceptable pressures <35cm H2 O in all models. Test lung volumes >20ml/kg were recorded in airway models with fully obstructed proximal airways using Rapid-O2 and Enk oxygen flow meter in infant lungs, and Manujet in all lung sizes. Rapid-O2 produced lung volumes >20ml/kg in the infant model with partially obstructed and open upper airways. Test lung volumes >20ml/kg were produced by the 3-way stopcock in adult, child, and infant models. Insufflation was unsuccessful with the self-inflating bag. Ventrain produced acceptable volumes <7ml/kg in all airway models. Rapid-O2 , Enkoxygen flow meter, Manujet, and 3-way stopcock oxygenation devices produced highly variable and excessive airway pressures and volumes in models with obstructed upper airways. Self-inflating bag insufflation was unsuccessful. Ventrain was the only device that insufflated oxygen with acceptable pressures and volumes in adult, child, and infant airway models with any degree of airway obstruction.

A Simple Approach for Gas Blender on Extracorporeal Membrane Oxygenation in Resource Shortage Context.

With the massive influx of patients during COVID-19 pandemic into intensive care unit, resources have quickly been stretched to the limit, including extracorporeal membrane oxygenation (ECMO). Gas blender attached to ECMO is used to allow precise adjustment of characteristics of fresh gas flow, that is, blood oxygen delivery and carbon dioxide removal. To cope with the gas blender shortage, we describe a back-up system set up in our French tertiary referral ECMO center using air and oxygen flowmeters. A table has been created to facilitate medical prescription but also nurse monitoring. This extraordinary situation forces physicians to adapt medical devices, and that could be useful in future viral pandemics.

Assessment of Air-Oxygen Blender and Flow Meter Setup in Neonatal Intensive Care Units.

Oxygen therapy is provided in neonatal intensive care units to prevent and treat neonatal hypoxia. This treatment is essential for the physiological development and survival of neonates with respiratory dysfunctions. One method of providing oxygen therapy involves the use of a simple face mask to deliver oxygen-enriched medical air. In these systems, a flow meter is used to adjust the volumetric flow rate of the gas between 5 to 15 L/min. If the flow rate falls below 5 L/min, there is a risk for exhaled carbon dioxide to accumulate in the mask and cause hypercapnia. Several potential hazards have been identified in the configuration of these oxygen therapy systems in neonatal intensive care units that can result in a decrease of flow rate measurement accuracy: the use of an oxygen flow meter to deliver a mixed gas, the orientation of how the flow meter is installed, and a decrease in pressure due to the use of junctions and medical gas hoses. With reduced measurement accuracy at low flow rate settings, clinical users may not be aware that flow rate may drop below 5 L/min. Furthermore, inconsistencies in physical set-up and labelling may result in the wrong gas being delivered to a neonatal patient. To ensure that patient safety is maintained in neonatal intensive care units, a best practice recommendation is provided to address these potential hazards.

Noise Level and Comfort in Healthy Subjects Undergoing High-Flow Helmet Continuous Positive Airway Pressure.

The aim of this study was to assess the noisiness levels produced by different gas source systems, breathing circuits setup, and gas flow rates during continuous positive airway pressure (CPAP) delivered through helmet. This was a crossover design study. Ten healthy subjects received helmet CPAP at 5 cm H2O in random order with different gas flow rates (60 and 80 L/min), 3 diverse gas source systems (A: Venturi system, B: oxygen and air flowmeters, C: electronic Venturi system), and 3 different breathing circuit configurations. During every step of this study, a heat and moisture exchanger (HME) was placed on the helmet inlet gas port to measure the effects on noise production. Noise intensity level was recorded through a sound-level meter. Participants scored their noisiness perception on a visual analog scale. The noise level inside the helmet ranged between 76 ± 4 and 117 ± 1 Decibel A. The gas source and the gas flow rate always affected the noise level inside and outside the helmet (P < .001). The different "breathing circuit setup" did not change the noise levels inside the helmet (P = .244), but affected the noise level outside, especially when a Venturi system was used (P < .001). An HME filter placed at the junction between the inspiratory limb of the breathing circuit and the helmet significantly decreased the noise intensity inside the helmet (mean dBA without HME, 99.56 ± 13.30 vs 92.26 ± 10.72 with HME; P < .001) and outside (mean dBA without HME, 68.16 ± 12.05 vs 64.97 ± 12.17 with HME; P < .001). The perception of noise inside the helmet was lower when an HME filter was placed on the inspiratory inlet gas port (median, 6 [interquartile range, 4-7] vs 7 [5-8]; P < .001). When helmet CPAP is delivered through gas flow rates up to 50 L/min, an HME placed on the helmet inlet gas port should be used to reduce noise inside the helmet and to improve patients' comfort.

79 Do Medical Students Understand the Ward Environment? A Survey of Penultimate Year Medical Students Exploring How Well Healthcare Of Older People Placements Prepare Them for Working on Hospital Wards

Abstract Medical students are expected to know how to function on hospital wards; i.e. where to find things, other Health Care Professionals’ (HCPs’) roles, and how to use certain items of equipment (GMC, 2018). This ward-based knowledge indicates that a student is ‘ward smart’.1 Whilst being ‘ward smart’ is key for many aspects of medicine, it is particularly important for students learning geriatric medicine: older patients (who make up around 42% of all inpatients)2 are more likely to have communication difficulties and to require assistance. However, formal teaching in this area seems to be somewhat neglected, with students being left to ‘pick up’ this knowledge as they go along.3,4 In our sample of 41 students in their penultimate year (most of whom were undertaking their Healthcare of Older People placement), 98% did not know how to turn on a hearing aid and only 24% knew what a Waterlow score was. Furthermore, 88% did not know how to read an oxygen flowmeter, and only 59% knew where the CPR lever on the bed was situated. This is a significant gap in knowledge: Students may not be as prepared to work in a ward environment as expected. Students felt that their understanding would be improved by teaching sessions, more time on wards, formal ward inductions, and shadowing other HCPs: only 41.5% had had a ward induction or introduction, and less than 20% had shadowed a nurse. We propose specific teaching/practical sessions for students during their Healthcare of Older People placement centred around patient communication and understanding the ward environment.

Design of linear capillary measuring transducers for low gas flow rates

The performed analysis of known capillary flowmeters for low gas flows reveals the prospect of constructing the primary measuring transducers of flowmeters with a linear output signal. Owing to the stability of dimensions of the pass-through channels in glass capillaries channels such flowmeters can demonstrate high metrological characteristics. In this regard, we have investigated the capillary as a sensing element in the primary transducers of flowmeters for low gas flows.Different circuits of capillary primary transducers for the measuring instruments of low gas flow rate have been examined. Our study makes it possible to select the optimal circuit of a primary measuring transducer based on the measurement range, as well as the number and size of the pass-through channels in capillaries. For example, the flow meter based on a package of capillaries demonstrates a wider measurement range compared to other schemes.We have derived analytical dependences that enable the design of single- capillary, package, and bridge transducers. Comparative characteristics of the specified primary measuring transducers are provided. We have constructed algorithms for calculating dimensions of channels in the capillaries of transducers with a linear output signal.The influence of temperature and barometric pressure on a deviation in the static characteristic of the transducer has been estimated. It was established that the bridge circuit, unlike others, ensures partial compensation for the influence of external factors.We have designed and investigated a capillary oxygen flowmeter, constructed using the bridge measurement circuit with a linear conversion function, intended for an automated system of the manufacturing process of workpieces for fiber light guides. The upper limit of measurement by the flowmeter is at the level of 54 l/h, its basic relative error is 0.8 %

Evaluation of Knowledge of Oxygen Therapy and Reading of Flowmeter among the Health Workers in the Pediatric Unit of the Hospital Universitario San Ignacio, Bogotá, Colombia

Introduction: Supplemental oxygen is considered a pharmaceutical drug; therefore, it can produce adverse effects. Lack of consensus regarding the reading of oxygen flowmeters and the peripheral oxygen saturation (SpO2) goals can influence clinical and paraclinical decisions and hospital stay length. Objective: To assess knowledge on oxygen therapy, adverse effects, SpO2 goals and reading of oxygen flowmeters among personnel in the Pediatric Unit at Hospital Universitario San Ignacio, Bogotá, Colombia. Methodology: Cross-sectional study derived from convenience sampling through a self-applied survey between December 2016 and January 2017. The poll evaluated topics on supplemental oxygen therapy fundamentals and adverse effects, SpO2 goals and flowmeter readings through flowmeters photographs indicating a specific fraction of inspired oxygen (FiO2). Results: The response rate was 77% from 259 subjects. 22% considered that the oxygen saturation either increases or remains the same during sleep periods in children. 78% of participants knew at least one complication associated to prolonged oxygen therapy and 67% due to supplemental oxygen concentration greater than required. In neonatal population, 10% considered oxygen saturation goals equal to or greater than 96%. In the flowmeter’s reading evaluation, incorrect answers ranged from 9 to 19%. Conclusion: It is imperative to reinforce updated concepts on oxygen therapy, with emphasis in SpO2 goals, adverse effects and appropriate flowmeter’s readings through periodic educational campaigns.

Oxygen therapy of two patients from single oxygen flow meter

Oxygen therapy of two patients from single oxygen flow meter