Anesthesia Machine Research Articles

Intraoperative Anesthesia-Related Critical Events in Low-Resource Hospitals During Short-Term Surgical Missions in Tanzania and Democratic Republic of the Congo: An Observational Study.

Critical incidents and mortality related to anesthesia are more frequently observed in low- and middle-income countries in comparison to high-income countries. The difficulties linked to anesthesia in rural areas of the Democratic Republic of the Congo (DRC) and Tanzania have limited documentation. The aim of this study was to comprehensively document anesthesia-related critical events that occurred during surgical missions organized by the nongovernmental organization 2nd Chance in hospitals in DRC and Tanzania. Data were collected during 6 surgical missions in 3 hospitals in the DRC and 1 in Tanzania. All scheduled surgery patients were included. Anesthesia was administered by a local Non-Physician Anesthesia Provider (NPAP), using local resources, under the supervision of an anesthesiologist from the association. The anesthesiologist reported critical events and collected data. Local teams managed critical events initially, with intervention by the anesthesiologist from 2nd Chance on the local team's request, according to preestablished protocol or if the situation was considered dangerous. Critical incidents associated with anesthesia, including bradycardia, hypoxemia, airway management failure, and equipment problems, were documented from induction of anesthesia until discharge from the recovery room. We recruited 201 patients, of whom 192 were evaluated, with 9 patients dropping out due to protocol noncompliance. All patients were American Society of Anesthesiologists (ASA) I (62%; n = 120) or ASA II (38%; n = 72). Among them, 104 individuals (54%) experienced at least 1 critical event, totaling 202 critical events. Hypoxemia emerged as the most common event, affecting 29% of the patients (n = 55) with at least 1 episode. Equipment problems (oxygen supply and/or anesthesia machine failure) occurred in 24% of cases (n = 46), airway management issues in 23% (n = 44), and bradycardia in 6% (n = 12). Hypotension and hypertension were not documented due to the lack of monitoring. The majority of these events (over 60%) required intervention by the anesthesiologist. The occurrence of critical events related to anesthesia appears to be high in this study. Due to numerous limitations, these results cannot be generalized to all hospitals in Tanzania and the DRC. However, this study underscores the challenges faced by anesthesia teams, encompassing inadequate resources, equipment deficiencies, and varying levels of expertise among anesthesia personnel. The research further stresses the significance of addressing these challenges to enhance patient safety.

Use of esketamine for tracheoscopic drug injection: a randomized controlled trial.

Sufentanil may induce hypotensive bradycardia and other adverse reactions in elderly patients during anesthesia, while esketamine exhibits sedative and analgesic effects with minimal impact on respiration and circulation. The objective of this study was to investigate the impact of these two anesthetics on vital signs in patients undergoing bronchoscopy and lavage under general anesthesia. This study was a randomized controlled trial with a parallel design. A total of 100 patients aged ≥60 years with ASAI or II who were undergoing bronchoscopy and lavage were randomly assigned to two groups: group A (esketamine, n = 50) and group B (sufentanil, n = 50). During anesthesia induction, both groups received intravenous infusion of propofol at a dose of 1.5 mL/kg and atracurium. In group A, esketamine at a dose of 0.3 mg/kg was injected; in group B, sufentanil at a dose of 0.2 μg/kg was injected intravenously. Subsequently, a laryngeal mask was inserted and connected to an anesthesia machine for mechanical ventilation. Anesthesia maintenance involved continuous intravenous infusion of propofol at a dose of 3 mL/kg. The mean arterial pressure (MAP), heart rate (HR), and blood oxygen saturation (SpO2) were recorded at various time points: before anesthesia injection (T0), after laryngeal mask insertion (T1), 5 min after the operation started (T2), 15 min after the operation started (T3), and before the end of the operation (T4). Additionally, the recovery time was recorded. The blood pressure of patients in the esketamine group exhibited higher levels compared to those in the sufentanil group at multiple time points during the operation, while maintaining a more stable intraoperative blood pressure and shorter postoperative recovery time than that observed in the sufentanil group. The blood pressure and heart rate of patients in the esketamine group exhibited significant fluctuations after laryngeal mask implantation compared to pre-anesthesia induction, with a statistically significant increase observed. Conversely, no significant changes were observed in the sufentanil group. The heart rate and oxygen saturation showed no significant differences between the two groups, nor did the amount of propofol administered during the procedure. The utilization of esketamine during the induction phase of bronchoscopy and lavage under general anesthesia can enhance hemodynamic stability and reduce the occurrence of hypotension, thereby facilitating postoperative anesthetic recovery.

Jonathan GE Hinkle, Alkaform, and Dental Anesthesia Apparatus: A New Discovery, and Perhaps the First Practitioner of Conscious Sedation?

Jonathan GE Hinkle, Alkaform, and Dental Anesthesia Apparatus: A New Discovery, and Perhaps the First Practitioner of Conscious Sedation?

Implementation of the WHO surgical safety checklist in resource-limited Somalia: a new standard in surgical safety

BackgroundSurgical safety remains a critical global health concern, with complications from surgical procedures resulting in significant morbidity and mortality, particularly in low- and middle-income countries. The World Health Organization (WHO) Surgical Safety Checklist (SSC) has been shown to reduce surgical complications and mortality rates. However, its implementation and impact in resource-limited settings like Somalia remain understudied. This study aimed to evaluate the implementation of the WHO SSC in selected hospitals in Mogadishu, Somalia, and assess its impact on surgical safety practices.MethodsA pre- and post-intervention study was conducted in 15 randomly selected hospitals in Mogadishu, Somalia. The intervention involved a comprehensive training program on the WHO SSC for surgical teams. Data on hospital characteristics, surgical details, and adherence to the SSC were collected over two periods: pre-intervention (April 12th to May 4th, 2024) and post-intervention (May 12th to June 3rd, 2024). The primary outcome was the adherence to the SSC, categorized as good (> 60%) or poor (≤ 60%). Descriptive statistics, McNemar’s test, and binary logistic regression were used for data analysis.ResultsAdherence to the WHO SSC significantly improved post-intervention, with 98.8% of surgical cases demonstrating good adherence compared to 37% pre-intervention (p < 0.001). The mean adherence score increased from 51.6% (SD = 29.6) to 94.1% (SD = 8.2). Significant improvements were observed for most individual checklist items, including patient identity confirmation, surgical site marking, anesthesia machine checks, and pulse oximeter use (p < 0.001). Team dynamics and communication also improved significantly post-intervention. Hospital type, size, years of service, funding source, surgical department, surgery type, urgency, and staff numbers were associated with checklist adherence pre-intervention.ConclusionThe implementation of a comprehensive training intervention significantly improved adherence to the WHO Surgical Safety Checklist in resource-limited hospitals in Mogadishu, Somalia. The findings highlight the feasibility and effectiveness of the SSC in enhancing surgical safety practices, team communication, and patient outcomes in challenging healthcare environments. Tailored implementation strategies, ongoing training, and cultural adaptation are crucial for the successful adoption of the SSC in resource-constrained settings.

Conscious Sedation Using Nitrous Oxide and Midazolam for Dental Procedures in Pediatric Patients in Armed Forces Hospital – Our Experience

Abstract Background and Aim: Management of pain and anxiety associated with dental procedures in pediatric age group is a big challenge. In this part of the world, counselling has been the main modality for managing such patients. It is associated with mixed outcome. We share our experience of managing 23 patients using a combination of inhalational nitrous oxide- oxygen and intravenous midazolam with satisfactory outcomes. Material and Methods: Patients aged more than six years, American society of anaesthesiologists classification (ASA) I or II, procedure that could be finished within one hour like pulpectomies, root canal treatments, extraction and multiple restorations were accepted for conscious sedation. Complete blood count was done and pre-anaesthetic checkup (PAC) with written informed consent from the parent was taken for the dental procedure under conscious sedation. We placed the nasal mask of the Conscious sedation anesthesia machine and made the child inhale Oxygen/Nitrous oxide mixture. After inhaling variable concentration of nitrous oxide/ oxygen mixture in proportion increasing from 30:70 to 70:30, procedure was done. After completion of the procedure, the patient was administered hundred percent oxygen for five minutes. Results: We have done a total of twenty-three cases till now with ages between five to seventeen years. The duration of procedures ranged from 30 min to one and half hour. Two patients less than six years were found to be uncooperative for the procedure. Conclusion: Minimum age group that was suitable for conscious sedation was six years and above. Frequent meetings and counselling by the same team should be facilitated prior to taking up for the procedure.

Intraoperative Lung Mechanics In Post-Covid Healthy Pregnants Who Required Cesarean Section: A Randomized Controlled Trial

Objective: This study aimed to investigate whether lung mechanics were affected in patients recovering from Covid-19 without ARDS who did not undergo lung imaging during the active infection period. Methods: The study included pregnant patients undergoing cesarean section operations. Participants were divided into two groups: those who had recovered from Covid-19 within the past year (group 1, n=50) and those who had never been infected with Covid-19 (group 2, n=50). The study included 100 patients divided into two groups: those who had recovered from Covid-19 within the last year (group 1, n=50) and those who had never experienced Covid-19 infection (group 2, n=50). Peak pressure (Ppeak), plateau pressure (Pplato), dynamic compliance (Cdyn), and positive end-expiratory pressure (PEEP) values, measured by the anesthesia machine, were recorded at specified time intervals following intubation. Results: Comparisons of Ppeak, Pplato, ΔP, Cdyn, and R data at specified times (1 min, 5 min, 10 min, 20 min, 30 min, and 40 min) showed no significant differences between the groups (p&gt;0.05). Conclusion: No significant differences in lung mechanics were found between the Covid-19-recovered patient group and the control group. Differences observed in SpO2, MAP, and Cdyn values in both groups are considered to be expected changes associated with routine procedures of general anesthesia

Green endoscopy, one step toward a sustainable future: Literature review.

Rapid climate change or climate crisis is one of the most serious emergencies of the 21st century, accounting for highly impactful and irreversible changes worldwide. Climate crisis can also affect the epidemiology and disease burden of gastrointestinal diseases because they have a connection with environmental factors and nutrition. Gastrointestinal endoscopy is a highly intensive procedure with a significant contribution to greenhouse gas (GHG) emissions. Moreover, endoscopy is the third highest generator of waste in healthcare facilities with significant contributions to carbon footprint. The main sources of direct carbon emission in endoscopy are use of high-powered consumption devices (e.g. computers, anesthesia machines, wash machines for reprocessing, scope processors, and lighting) and waste production derived mainly from use of disposable devices. Indirect sources of emissions are those derived from heating and cooling of facilities, processing of histological samples, and transportation of patients and materials. Consequently, sustainable endoscopy and climate change have been the focus of discussions between endoscopy providers and professional societies with the aim of taking action to reduce environmental impact. The term "green endoscopy" refers to the practice of gastroenterology that aims to raise awareness, assess, and reduce endoscopy´s environmental impact. Nevertheless, while awareness has been growing, guidance about practical interventions to reduce the carbon footprint of gastrointestinal endoscopy are lacking. This review aims to summarize current data regarding the impact of endoscopy on GHG emissions and possible strategies to mitigate this phenomenon. Further, we aim to promote the evolution of a more sustainable "green endoscopy".

Sedaconda ACD-S for Sedation with Volatile Anaesthetics in Intensive Care: A NICE Medical Technologies Guidance.

Intensive care unit (ICU) patients receive highly complex care and often require sedation as part of their management. ICU sedation has traditionally been delivered using intravenous (IV) agents due to the impractical use of anaesthetic machines in this setting, which are used to deliver volatile sedation. Sedaconda anaesthetic conserving device (ACD)-S (previously known as AnaConDa-S) is a device which allows for the delivery of volatile sedation via the majority of mechanical ventilators by being inserted in the breathing circuit where the heat and moisture exchanger is normally placed. The National Institute of Health and Care Excellence (NICE), as part of the Medical Technologies Evaluation Programme, considered the potential benefits of using Sedaconda ACD-S compared to standard IV sedation in ICU patients. Here we describe the evidence evaluation undertaken by NICE on this technology, supported by CEDAR. CEDAR considered the evidence present in 21 publications that compared the clinical outcomes of patients receiving Sedaconda ACD-S-delivered sedation and IV sedation, and critiqued the economic model provided by the manufacturer. Clinical expert input during the evaluation process was used extensively to ensure that the relevant clinical evidence was captured and that the economic model was suitable for the UK setting. Due to the uncertainty of the evidence, sensitivity analysis was carried out on the key economic inputs to ensure the reliability of the results. Economic modelling has shown that Sedaconda ACD-S-delivered isoflurane sedation is cost saving on a 30-day horizon compared to IV sedation by £3833.76 per adult patient and by £2837.41 per paediatric patient. Clinical evidence indicated that Sedaconda ACD-S-delivered isoflurane sedation is associated with faster patient wake-up times than standard of care. Consequently, NICE recommended Sedaconda ACD-S as an option for delivering sedation in the ICU setting, but noted that further research should inform whether Sedaconda ACD-S-delivered sedation is of benefit to any particular subgroup of patients.

Extrinsic Positive End-Expiratory Pressure due to Failure of the Positive-Pressure Relief Valve Within the Scavenging System: A Case Report.

The anesthesia gas scavenging system (AGSS) removes waste gases from the anesthesia machine. Within the AGSS, safety features prevent excessive pressures from affecting ventilation. Although the literature contains reports describing failures of the AGSS, we found no reports of positive-pressure relief valve (PPRV) malfunctions. We encountered 2 cases of extrinsic positive end-expiratory pressure (PEEP) resulting from a malfunctioning PPRV. Both cases suffered delayed identification intraoperatively but patients did not experience postoperative complications. These cases highlight the importance of daily scavenger system prechecks, the potential physiologic implications of AGSS malfunctions, and the importance of preplanned contingencies for machine failure.

End-Tidal Control Versus Manual Control of Inhalational Anesthesia Delivery: A Randomized Controlled Noninferiority Trial.

Precise anesthesia delivery helps ensure amnesia, analgesia, and immobility. Conventionally, the end-tidal anesthetic concentration is maintained through manual adjustment of the fresh gas flow and anesthetic vaporizer output. Some anesthesia delivery systems can deliver and maintain clinician-selected end-tidal anesthetic agent (EtAA) concentration using a modified closed-loop system. We evaluated the performance of an End-tidal Control (EtC) system on the Aisys CS 2 anesthesia machine (GE HealthCare). We hypothesized EtC anesthetic delivery would be noninferior to manually controlled anesthetic delivery. The Multi-site Anesthesia randomized controlled STudy of End-tidal control compared to conventional Results (MASTER) Trial evaluated anesthetic delivery in 210 adult patients receiving inhaled anesthesia. Patients were randomized to either EtC or manual control (MC) anesthetic delivery. The primary objective was to determine whether, compared to conventional anesthesia practice, EtC achieves and maintains clinician-specified EtAA and end-tidal oxygen (Et o2 ) concentrations within defined noninferiority limits. Noninferiority was concluded if the lower limit of the 95% confidence interval (CI) of the difference between the percent duration within the acceptable range (5% of steady state or a margin of ~10% of each agent's minimum alveolar concentration) for EtC and MC was ≥ -5% for both EtAA and Et o2 . Secondary objectives included performance measures: response time: time required to attain 90% of the first desired EtAA, overshoot: amount the controller (or vaporizer delivery) exceeded the desired EtAA, and accuracy: average deviation from the desired EtAA. EtC achieved and sustained targeted EtAA and Et o2 concentrations within the noninferiority threshold. The EtAA was within 5% of the desired value 98% ± 2.05% of the time with EtC compared to 45.7% ± 31.7% of the time with MC (difference 52.3% [95% CI, 45.9%-58.6%], P < .0001). For Et o2 , EtC was within the noninferiority limit 86.3% ± 22.8% of the time compared with MC at 41% ± 33.3% ( P < .0001, difference 45.3% [95% CI, 36.1%-54.5%]). The median response time for achieving 90% of the initial EtAA desired value was 75 seconds with EtC and 158 seconds with MC ( P = .0013). EtC exhibited a median overshoot of 6.64% of the selected EtAA concentration, whereas MC often failed to reach the clinician's desired value. The difference in median percent deviation from desired EtAA value was 15.7% ([95% CI, 13.5%-19.0%], P < 0001). EtC achieves and maintains the EtAA and Et o2 concentration in a manner that is noninferior to manually controlled anesthesia delivery.

Surgical outreach for the Americas: a self-sustainable model for partnership and education.

It is estimated that up to 28% of global disease burden is surgical with hernias representing a unique challenge as the only definitive treatment is surgery. Surgical Outreach for the Americas (SOfA) is a nongovernmental organization focused primarily on alleviating the disease burden of inguinal and umbilical hernias in Central America. We present the experience of SOfA, a model focused on partnership and education. SOfA was established in 2009 to help individuals recover from ailments that are obstacles to working and independent living. Over the past 15years, SOfA has partnered with local healthcare providers in the Dominican Republic, El Salvador, Honduras, and Belize. The SOfA team consists of surgeons, surgery residents, triage physicians, an anesthesiologist, anesthetists, operating room nurses, recovery nurses, a pediatric critical care physician, sterile processing technicians, interpreters, and a team coordinator. Critical partnerships required include the CMO, internal medicine, general surgery, nursing, rural health coordinators and surgical training programs at public hospitals. SOfA has completed 24 trips, performing 2074 procedures on 1792 patients. 71.4% of procedures were hernia repairs. To enhance sustainability of healthcare delivery, SOfA has partnered with the local facilities through capital improvements to include OR tables, OR lights, anesthesia machines, monitors, hospital beds, stretchers, sterilizers, air conditioning units, and electrosurgical generators. A lecture series and curriculum on perioperative care, anesthesia, anatomy, and operative technique is delivered. Local surgery residents and medical students participated in patient care, learning alongside SOfA teammates. Recently, SOfA has partnered with SAGES Global Affairs Committee to implement a virtual Global Laparoscopic Advancement Program, a simulation-based laparoscopic training curriculum for surgeons in El Salvador. A sustainable partnership to facilitate surgical care in low resource settings requires longitudinal, collaborative relationships, and investments in capital improvements, education, and partnership with local healthcare providers, institutions, and training programs.

Inhalational Agent Dosing Behaviors of Anesthesia Practitioners Cause Variability in End-Tidal Concentrations at the End of Surgery and Prolonged Times to Tracheal Extubation.

Prolonged times to tracheal extubation are intervals from the end ofsurgery to extubation ≥15 minutes. We examined why there are associations with the end-tidal inhalational agent concentration as a proportion of the age‑adjusted minimum alveolar concentration (MAC fraction) at the end of surgery. The retrospective cohort study used 11.7 years of data from one hospital. All p‑values were adjusted for multiple comparisons. There was a greater odds ofprolonged time to extubation if the anesthesia practitioner was a trainee (odds ratio 1.68) or had finished fewer than five cases with the surgeon during the preceding three years (odds ratio 1.12) (both P<0.0001). There was a greater risk of prolonged time to extubation if the MAC fraction was >0.4 at the end of surgery (odds ratio 2.66, P<0.0001). Anesthesia practitioners who were trainees and all practitioners who had finished fewer than five cases with the surgeon had greater mean MAC fractions atthe end of surgery and had greater relative risks of the MAC fraction >0.4 at the end of surgery (all P<0.0001). The source for greater MAC fractions at the end of surgery was not greater MAC fractions throughout the anesthetic because the means during the case did not differ among groups. Rather, there was substantial variability ofMAC fractions at the end of surgery among cases ofthe same anesthesia practitioner, with the mean (standard deviation) among practitioners of each practitioner's standard deviation being 0.35 (0.05) and the coefficient ofvariation being 71% (13%). More prolonged extubations were associated with greater MAC fractions at the end ofsurgery. The cause of the large MAC fractions was the substantial variability of MAC fractions among cases of each practitioner at the end ofsurgery. That variability matches what was expected from earlier studies, both from variability among practitioners in their goals for the MAC fraction given at the start ofsurgical closure and from inadequate dynamic forecasting of the timing of when surgery would end. Future studies should examine how best to reduce prolonged extubations by using anesthesia machines' display of MAC fraction and feedback control of end-tidal agent concentration.

Multidisciplinary Cancer Treatment Capacity in Ukraine During the War

PURPOSE Assessment of cancer diagnostic and treatment capacity is crucial to optimizing cancer care, especially in the setting of limited resources, including as a result of war. We assessed personnel, equipment, and treatment availability during Russia's full-scale invasion of Ukraine to define gaps that could then be addressed with tailored strategies. METHODS An online survey designed in collaboration with oncology specialists from the National Cancer Institute in Ukraine was distributed to oncologists in Ukraine through oncology-related social media. Data were analysed using descriptive statistics. RESULTS 192 physicians from all regions of Ukraine, including 53 (23.6%) medical oncologists, 89 (46.4%) surgical oncologists, and 32 (16.7%) radiation oncologists completed the survey. The average number of medical oncologists per regional cancer centre was 4.7 compared to 2.5 seen as the optimal number. The average number of nurses trained in chemotherapy administration was 6.4 compared to the desired number of 8.6. The average number of chemotherapy infusion machines was 8.2 compared to 17.7 desired. On average, 5.7 ports were put in per month compared to 22.1 desired. Average number of infusion chairs was 6.4 compared to 16.3 desired, while the number of inpatient chemotherapy beds was 26.8 compared to 34.0 perceived as the optimal number. The reported average number of surgical oncologists was 12.1 with an optimal average of 6.0. The average number of surgical beds was 52.8 v 60.7 desired. The average and optimal numbers of the following were fairly close: surgical oncology trainees (2.1 v 2.6), operating room nurses (4.1 v 4.3), anesthesiologists (4.4 v 4.2), operating rooms (3.6 v 3.4), anaesthesia machines (4.4 v 4.0), average surgeries per week (21.5 v 21.8). The average number of radiation oncologists was 7.9 compared to 8.5 optimal numbers. For other metrics, average and optimal numbers were somewhat close: number of radiation therapy laboratory technicians (7.9 v 8.5), medical physicists (3.8 v 4.8), dosimetrists (1.5 v 2.1), Cobalt 60 machines (0.9 v 1.1), brachytherapy machines (1.1 v 1.7). CONCLUSION We identified important equipment and personnel gaps in oncology care in Ukraine. Results are limited by the decreased number of respondents from areas directly affected by active hostilities.

Effect of static lung expansion on pulmonary function following cardiopulmonary bypass in children

ObjectiveTo observe the effect of the lung-protective ventilation strategy, static lung expansion, during cardiopulmonary bypass (CPB) on pulmonary function and tracheal intubation time following cardiac surgery in children. MethodsA total of 48 child patients (aged 1–3) with ventricular septal defect (VSD) were enrolled, and all underwent CPB cardiac surgery for the first time. The patients were divided into two groups using the random number table method: the experimental group (Group A, n = 30) and the control group (Group B, n = 18). After terminating the mechanical ventilation during CPB, the adjustable pressure limiting valve of the anesthesia machine was adjusted in the experimental group to maintain the pressure of the breathing circuit at 5 cmH2O, such that both lungs remained in a static expansion state. In the control group, routine mechanical ventilation was terminated as usual. ResultsWhen static lung expansion with a continuous positive airway pressure of 5 cmH2O was employed in the VSD children during CPB, compared with termination of mechanical ventilation, the partial pressure of oxygen in the arterial blood increased, while the respiratory index decreased and the oxygenation index increased following the surgery. ConclusionIn child patients undergoing VSD reparation under CPB, lung injury occurs following the procedure, and the pulmonary oxygenation function and pulmonary oxygen diffusion function decrease. When static lung expansion of 5 cmH2O is performed during CPB, the improvement in lung function is better than that of apnea without lung expansion pressure.

A novel, cassette-based nitric oxide delivery system with an advanced feedback control algorithm accurately delivers nitric oxide via the anesthesia machine independent of fresh gas flow rate and volatile anesthetic agent

Nitric oxide (NO), a selective pulmonary vasodilator, can be delivered via conventional ICU and anesthesia machine ventilators. Anesthesia machines are designed for rebreathing of circulating gases, reducing volatile anesthetic agent quantity used. Current cylinder- and ionizing-based NO delivery technologies use breathing circuit flow to determine NO delivery and do not account for recirculated gases; therefore, they cannot accurately dose NO at FGF below patient minute ventilation (MV). A novel, cassette-based NO delivery system (GENOSYL® DS, Vero Biotech Inc.) uses measured NO concentration in the breathing circuit as an input to an advanced feedback control algorithm, providing accurate NO delivery regardless of FGF and recirculation of gases. This study evaluated GENOSYL® DS accuracy with different anesthesia machines, ventilation parameters, FGFs, and volatile anesthetics. GENOSYL® DS was tested with GE Aisys and Dräger Fabius anesthesia machines to determine NO dose accuracy with FGF < patient MV, and with a Getinge Flow-i anesthesia machine to determine NO dose accuracy when delivering various volatile anesthetic agents. Neonatal and adult mechanical ventilation parameters and circuits were used. GENOSYL® DS maintained accurate NO delivery with all three anesthesia machines, at low FGF with recirculation of gases, and with all volatile anesthetic agents at different concentrations. Measured NO2 levels remained acceptable at ≤ 1 ppm with set NO dose ≤ 40 ppm. GENOSYL® DS, with its advanced feedback control algorithm, is the only NO delivery system capable of accurately dosing NO with anesthesia machines with rebreathing ventilation parameters (FGF < MV) regardless of anesthetic agent.

Smart materials for sustainable energy

In the new era of technologies, different smart or responsive materials are used which can respond to external stimuli, such as a specific amount of mechanical stress, pressure, temperature, pH, or sunlight radiations, by modifying their shape or dimensions or mechanical properties. As global temperatures rise and weather patterns become more erratic and severe. The risk to communities with energy-passive structures is growing, smart materials such as smart rooftops, thermoelectrics, photovoltaics, pyroelectrics, chromoactive, photoluminescent, as well as other innovations, help to conserve renewable energy smartly and sustainably. This review paper reflects on the applications of different smart materials as renewable smart resources. Intelligent quantum dot solar cells, Schottky solar cells, organic thin-film photovoltaic cells, dye-sensitized solar cells (DSSCs), and organic-inorganic heterojunction solar cells have high conversion efficiency, low cost, and possess wide absorption spectra that reach the near-infrared range. Biomechanical energy can be transformed into green energy using triboelectric and piezoelectric-based smart nanogenerators such as zinc oxide nanowires. Shape memory materials such as Nitinol (NiTi) have been embedded in the wind turbine blades to enhance aerodynamic efficiency. Piezoelectric nanogenerators can convert mechanical energy directly into electrical energy by using wireless sensors to harvest energy from moving water in hydroelectric power plants. Thermoelectric materials such as silver antimony telluride (AgSbTe2) offer a sustainable energy option, which employs industrial waste heat to produce power. Smart materials like graphene are more reliable and effective than carbon nanotubes for storing green hydrogen. Smart non-enzymatic biofuel cells are used in biomedical gadgets such as anesthesia machines and pacemakers, which are self-powered and have great sensitivity. Shape memory materials (SMM) are introduced in natural gas and oil reservoirs because they offer exceptional qualities such as the shape memory effect (SME), lightweight, corrosion resistance, and superelasticity, which enhance the performance and robustness of offshore industries. These new advancements, challenges, and applications of smart materials for renewable energy are covered in this review paper.

Hypoxaemia risk in pediatric flexible bronchoscopy for foreign body removal: a retrospective study

BackgroundHypoxemia represents the most prevalent adverse event during flexible bronchoscopy procedures aimed at foreign body retrieval in pediatric patients; if not expeditiously managed, it carries the potential for cardiac or respiratory arrest. The specific risk factors contributing to the occurrence of hypoxemia during foreign body FB removal via bronchoscopy have yet to be definitively established.MethodsThis retrospective study included a cohort of 266 pediatric subjects from January 1, 2015, to December 31, 2022, who underwent flexible bronchoscopy for the purpose of FB extraction. In this cohort, the supraglottic airway was used to connect the anesthesia apparatus during the removal procedure.ResultsIn total, 45 of the pediatric patients (16.9%) experienced episodes of hypoxemia during the FB removal procedure. Multivariate analysis revealed that the following factors were significantly associated with the occurrence of hypoxemia: an operation time exceeding 60 min (odds ratio [OR] 8.55; 95% confidence interval [CI] 3.82–19.13), a maximum diameter exceeding 7 mm (OR 5.03; 95% CI, 2.24–11.29), and the presence of radiological evidence indicating pneumonia (OR 2.69; 95% CI, 1.27–5.69).ConclusionDuring flexible bronchoscopy procedures aimed at FB removal in pediatric patients, there is an increased susceptibility to hypoxemia. Factors including extended operation duration, larger FB dimensions, and radiographic evidence suggestive of pneumonia significantly contribute to a heightened risk of hypoxemia.

Effect of different lung recruitment strategies and airway device on oscillatory mechanics in children under general anaesthesia.

Atelectasis has been reported in 68 to 100% of children undergoing general anaesthesia, a phenomenon that persists into the recovery period. Children receiving recruitment manoeuvres have less atelectasis and fewer episodes of oxygen desaturation during emergence. The optimal type of recruitment manoeuvre is unclear and may be influenced by the airway device chosen. We aimed to investigate the different effects on lung mechanics as assessed by the forced oscillation technique (FOT) utilising different recruitment strategies: repeated inflations vs. one sustained inflation and different airway devices, a supraglottic airway device vs. a cuffed tracheal tube. Pragmatic enrolment with randomisation to the recruitment strategy. We conducted this single-centre trial between February 2020 and March 2022. Seventy healthy patients (53 boys) aged between 2 and 16 years undergoing general anaesthesia were included. Forced oscillations (5 Hz) were superimposed on the ventilator waveform using a customised system connected to the anaesthesia machine. Pressure and flow were measured at the inlet of the airway device and used to compute respiratory system resistance and reactance. Measurements were taken before and after recruitment, and again at the end of surgery. The primary endpoint measured is the change in respiratory reactance. Statistical analysis (linear model with recruitment strategy and airway device as factors) did not show any significant difference in resistance and reactance between before and after recruitment. Baseline reactance was the strongest predictor for a change in reactance after recruitment: prerecruitment Xrs decreased by mean (standard error) of 0.25 (0.068) cmH 2 O s l -1 per 1 cmH 2 O -1 s l -1 increase in baseline Xrs ( P < 0.001). After correcting for baseline reactance, the change in reactance after recruitment was significantly lower for sustained inflation compared with repeated inflation by mean (standard error) 0.25 (0.101) cmH 2 O ( P = 0.0166). Although there was no significant difference between airway devices, this study demonstrated more effective recruitment via repeated inflations than sustained inflation in anaesthetised children. Australian New Zealand Clinical Trials Registry: ACTRN12619001434189.

Bridging the mismatch: observing the introduction of new anesthesia technology for a low-resource environment.

The objective of this study was to examine the impact of the introduction of the Universal Anaesthesia Machine (UAM), a device designed for use in clinical environments with limited clinical perioperative resources, on the choice of general anesthesia technique and safe anesthesia practice in a tertiary-care hospital in Sierra Leone. We introduced an anesthesia machine (UAM) into Connaught Hospital, Freetown, Sierra Leone. We conducted a prospective observational study of anesthesia practice and an examination of perioperative clinical parameters among surgical patients at the hospital to determine the usability of the device, its impact on anesthesia capacity, and changes in general anesthesia technique. We observed a shift from the use of ketamine total intravenous anesthesia to inhalational anesthesia. This shift was most demonstrable in anesthesia care for appendectomies and surgical wound management. In 10 of 17 power outages that occurred during inhalational general anesthesia, anesthesia delivery was uninterrupted because inhalational anesthesia was being delivered with the UAM. Anesthesia technologies tailored to overcome austere environmental conditions can support the delivery of safe anesthesia care while maintaining fidelity to recommended international anesthesia practice standards.

Comparison of automated and manual control methods in minimal flow anesthesia.

New-generation anesthesia machines administer inhalation anesthetics and automatically control the fresh gas flow (FGF) rate. This study compared the administration of minimal flow anesthesia (MFA) using the automatically controlled anesthesia (ACA) module of the Mindray A9 (Shenzhen, China) anesthesia machine versus manual control by an anesthesiologist. We randomly divided 76 patients undergoing gynecological surgery into an ACA group (Group ACA) and a manually controlled anesthesia group (Group MCA). In Group MCA, induction was performed with a mixture of 40-60% O2 and air with a 4L/min FGF until the minimum alveolar concentration (MAC) reached 1. Next, MFA was initiated with 0.5L/min FGF. The target fraction of inspired oxygen (FiO2) value was 35-40%. In Group ACA, the MAC was defined as 1, and the FiO2 was adjusted to 35%. Depth of anesthesia, anesthetic agent (AA) consumption, time to achieve target end-tidal AA concentration, awakening times, and number of ventilator adjustments were analyzed. The two groups showed no statistically significant differences in depth of anesthesia or AA consumption (Group ACA: 19.1 ± 4.9ml; Group MCA: 17.2 ± 4.5; p-value = 0.076). The ACA mode achieved the MAC target of 1 significantly faster (Group ACA: 218 ± 51s; Group MCA: 314 ± 169s). The number of vaporizer adjustments was 15 in the ACA group and 217 in the MCA group. The ACA mode was more advantageous than the MCA mode, reaching target AA concentrations faster and requiring fewer adjustments to achieve a constant depth of anesthesia.