The Global Anesthesia Workforce Survey: Updates and Trends in the Anesthesia Workforce.

BACKGROUND: There is a large global deficit of anesthesia providers. In 2016, the World Federation of Societies of Anaesthesiologists (WFSA) conducted a survey to count the number of anesthesia providers worldwide. Much work has taken place since then to strengthen the anesthesia health workforce. This study updates the global count of anesthesia providers. METHODS: Between 2021 and 2023, an electronic survey was sent to national professional societies of physician anesthesia providers (PAPs), nurse anesthetists, and other nonphysician anesthesia providers (NPAPs). Data included number of providers and trainees, proportion of females, and limited intensive care unit (ICU) capacity data. Descriptive statistics were calculated by country, World Bank income group, and World Health Organization (WHO) region. Provider density is reported as the number of providers per 100,000 population. RESULTS: Responses were obtained for 172 of 193 United Nations (UN) member countries. The global provider density was 8.8 (PAP 6.6 NPAP 2.3). Seventy-six countries had a PAP density <5, whereas 66 countries had a total provider density <5. PAP density increased everywhere except for high- and low-income countries and the African region. CONCLUSIONS: The overall size of the global anesthesia workforce has increased over time, although some countries have experienced a decrease. Population growth and differences in which provider types that are counted can have an important impact on provider density. More work is needed to define appropriate metrics for measuring changes in density, to describe anesthesia cadres, and to improve workforce data collection processes. Effort to scale up anesthesia provider training must urgently continue.

Capnography-An Essential Monitor, Everywhere: A Narrative Review.

Capnography is now recognized as an indispensable patient safety monitor. Evidence suggests that its use improves outcomes in operating rooms, intensive care units, and emergency departments, as well as in sedation suites, in postanesthesia recovery units, and on general postsurgical wards. Capnography can accurately and rapidly detect respiratory, circulatory, and metabolic derangements. In addition to being useful for diagnosing and managing esophageal intubation, capnography provides crucial information when used for monitoring airway patency and hypoventilation in patients without instrumented airways. Despite its ubiquitous use in high-income-country operating rooms, deaths from esophageal intubations continue to occur in these contexts due to incorrect use or interpretation of capnography. National and international society guidelines on airway management mandate capnography's use during intubations across all hospital areas, and recommend it when ventilation may be impaired, such as during procedural sedation. Nevertheless, capnography's use across high-income-country intensive care units, emergency departments, and postanesthesia recovery units remains inconsistent. While capnography is universally used in high-income-country operating rooms, it remains largely unavailable to anesthesia providers in low- and middle-income countries. This lack of access to capnography likely contributes to more frequent and serious airway events and higher rates of perioperative mortality in low- and middle-income countries. New capnography equipment, which overcomes cost and context barriers, has recently been developed. Increasing access to capnography in low- and middle-income countries must occur to improve patient outcomes and expand universal health care. It is time to extend capnography's safety benefits to all patients, everywhere.

A Cross-Sectional Survey of Anesthetic Airway Equipment and Airway Management Practices in Uganda.

BACKGROUND: Anesthesia-related causes contribute to a significant proportion of perioperative deaths, especially in low and middle-income countries (LMICs). There is evidence that complications related to failed airway management are a significant contributor to perioperative morbidity and mortality. While existing data have highlighted the magnitude of airway management complications in LMICs, there are inadequate data to understand their root causes. This study aimed to pilot an airway management capacity tool that evaluates airway management resources, provider practices, and experiences with difficult airways in an attempt to better understand potential contributing factors to airway management challenges. METHODS: We developed a novel airway management capacity assessment tool through a nonsystematic review of existing literature on anesthesia and airway management in LMICs, internationally recognized difficult airway algorithms, minimum standards for equipment, the safe practice of anesthesia, and the essential medicines and health supplies list of Uganda. We distributed the survey tool during conferences and workshops, to anesthesia care providers from across the spectrum of surgical care facilities in Uganda. The data were analyzed using descriptive methods. RESULTS: Between May 2017 and May 2018, 89 of 93 surveys were returned (17% of anesthesia providers in the country) from all levels of health facilities that provide surgical services in Uganda. Equipment for routine airway management was available to all anesthesia providers surveyed, but with a limited range of sizes. Pediatric airway equipment was always available 54% of the time. There was limited availability of capnography (15%), video laryngoscopes (4%), cricothyroidotomy kits (6%), and fiber-optic bronchoscopes (7%). Twenty-one percent (18/87) of respondents reported experiencing a "can't intubate, can't ventilate" (CICV) scenario in the 12 months preceding the survey, while 63% (54/86) reported experiencing at least 1 CICV during their career. Eighty-five percent (74/87) of respondents reported witnessing a severe airway management complication during their career, with 21% (19/89) witnessing a death as a result of a CICV scenario. CONCLUSIONS: We have developed and implemented an airway management capacity tool that describes airway management practices in Uganda. Using this tool, we have identified significant gaps in access to airway management resources. Gaps identified by the survey, along with advocacy by the Association of Anesthesiologists of Uganda, in partnership with the Ugandan Ministry of Health, have led to some progress in closing these gaps. Expanding the availability of airway management resources further, providing more airway management training, and identifying opportunities to support skilled workforce expansion have the potential to improve perioperative safety in Uganda.

Quantifying pulse oximeter accuracy during hypoxemia and severe anemia using an in vitro circulation system.

Anemia and hypoxemia are common clinical conditions that are difficult to study and may impact pulse oximeter performance. Utilizing an in vitro circulation system, we studied performance of three pulse oximeters during hypoxemia and severe anemia. Three oximeters including one benchtop, one handheld, and one fingertip device were selected to reflect a range of cost and device types. Human blood was diluted to generate four hematocrit levels (40%, 30%, 20%, and 10%). Oxygen and nitrogen were bubbled through the blood to generate a range of oxygen saturations (O2Hb) and the blood was cycled through the in vitro circulation system. Pulse oximeter saturations (SpO2) were paired with simultaneously-measured O2Hb readings from a reference CO-oximeter. Data for each hematocrit level and each device were least-squares fit to a 2nd-order equation with quality of each curve fit evaluated using standard error of the estimate. Bias and average root mean square error were calculated after correcting for the calibration difference between human and in vitro circulation system calibration. The benchtop oximeter maintained good accuracy at all but the most extreme level of anemia. The handheld device was not as accurate as the benchtop, and inaccuracies increased at lower hematocrit levels. The fingertip device was the least accurate of the three oximeters. Pulse oximeter performance is impacted by severe anemia in vitro. The use of in vitro calibration systems may play an important role in augmenting in vivo performance studies evaluating pulse oximeter performance in challenging conditions.

Global surgery, obstetric, and anaesthesia indicator definitions and reporting: An Utstein consensus report.

BACKGROUND: Indicators to evaluate progress towards timely access to safe surgical, anaesthesia, and obstetric (SAO) care were proposed in 2015 by the Lancet Commission on Global Surgery. These aimed to capture access to surgery, surgical workforce, surgical volume, perioperative mortality rate, and catastrophic and impoverishing financial consequences of surgery. Despite being rapidly taken up by practitioners, data points from which to derive the indicators were not defined, limiting comparability across time or settings. We convened global experts to evaluate and explicitly define-for the first time-the indicators to improve comparability and support achievement of 2030 goals to improve access to safe affordable surgical and anaesthesia care globally. METHODS AND FINDINGS: The Utstein process for developing and reporting guidelines through a consensus building process was followed. In-person discussions at a 2-day meeting were followed by an iterative process conducted by email and virtual group meetings until consensus was reached. The meeting was held between June 16 to 18, 2019; discussions continued until August 2020. Participants consisted of experts in surgery, anaesthesia, and obstetric care, data science, and health indicators from high-, middle-, and low-income countries. Considering each of the 6 indicators in turn, we refined overarching descriptions and agreed upon data points needed for construction of each indicator at current time (basic data points), and as each evolves over 2 to 5 (intermediate) and >5 year (full) time frames. We removed one of the original 6 indicators (one of 2 financial risk protection indicators was eliminated) and refined descriptions and defined data points required to construct the 5 remaining indicators: geospatial access, workforce, surgical volume, perioperative mortality, and catastrophic expenditure. A strength of the process was the number of people from global institutes and multilateral agencies involved in the collection and reporting of global health metrics; a limitation was the limited number of participants from low- or middle-income countries-who only made up 21% of the total attendees. CONCLUSIONS: To track global progress towards timely access to quality SAO care, these indicators-at the basic level-should be implemented universally as soon as possible. Intermediate and full indicator sets should be achieved by all countries over time. Meanwhile, these evolutions can assist in the short term in developing national surgical plans and collecting more detailed data for research studies.

Assessment of Anesthesia Capacity in Public Surgical Hospitals in Guatemala.

BACKGROUND: International standards for safe anesthetic care have been developed by the World Federation of Societies of Anaesthesiologists (WFSA) and the World Health Organization (WHO). Whether these standards are met is unknown in many nations, including Guatemala, a country with universal health coverage. We aimed to establish an overview of anesthesia care capacity in public surgical hospitals in Guatemala to help guide public sector health care development. METHODS: In partnership with the Guatemalan Ministry of Public Health and Social Assistance (MSPAS), a national survey of all public hospitals providing surgical care was conducted using the WFSA anesthesia facility assessment tool (AFAT) in 2018. Each facility was assessed for infrastructure, service delivery, workforce, medications, equipment, and monitoring practices. Descriptive statistics were calculated and presented. RESULTS: Of the 46 public hospitals in Guatemala in 2018, 36 (78%) were found to provide surgical care, including 20 district, 14 regional, and 2 national referral hospitals. We identified 573 full-time physician surgeons, anesthesiologists, and obstetricians (SAO) in the public sector, with an estimated SAO density of 3.3/100,000 population. There were 300 full-time anesthesia providers working at public hospitals. Physician anesthesiologists made up 47% of these providers, with an estimated physician anesthesiologist density of 0.8/100,000 population. Only 10% of district hospitals reported having an anesthesia provider continuously present intraoperatively during general or neuraxial anesthesia cases. No hospitals reported assessing pain in the immediate postoperative period. While the availability of some medications such as benzodiazepines and local anesthetics was robust (100% availability across all hospitals), not all hospitals had essential medications such as ketamine, epinephrine, or atropine. There were deficiencies in the availability of essential equipment and basic intraoperative monitors, such as end-tidal carbon dioxide detectors (17% availability across all hospitals). Postoperative care and access to resuscitative equipment, such as defibrillators, were also lacking. CONCLUSIONS: This first countrywide, MSPAS-led assessment of anesthesia capacity at public facilities in Guatemala revealed a lack of essential materials and personnel to provide safe anesthesia and surgery. Hospitals surveyed often did not have resources regardless of hospital size or level, which may suggest multiple factors preventing availability and use. Local and national policy initiatives are needed to address these deficiencies.

Factors affecting job choice among physician anesthesia providers in Uganda: a survey of income composition, discrete choice experiment, and implications for the decision to work rurally.

BACKGROUND: One of the biggest barriers to accessing safe surgical and anesthetic care is lack of trained providers. Uganda has one of the largest deficits in anesthesia providers in the world, and though they are increasing in number, they remain concentrated in the capital city. Salary is an oft-cited barrier to rural job choice, yet the size and sources of anesthesia provider incomes are unclear, and so the potential income loss from taking a rural job is unknown. Additionally, while salary augmentation is a common policy proposal to increase rural job uptake, the relative importance of non-monetary job factors in job choice is also unknown. METHODS: A survey on income sources and magnitude, and a Discrete Choice Experiment examining the relative importance of monetary and non-monetary factors in job choice, was administered to 37 and 47 physician anesthesiologists in Uganda, between May-June 2019. RESULTS: No providers worked only at government jobs. Providers earned most of their total income from a non-government job (50% of income, 23% of working hours), but worked more hours at their government job (36% of income, and 44% of working hours). Providers felt the most important job attributes were the quality of the facility and scope of practice they could provide, and the presence of a colleague (33% and 32% overall relative importance). These were more important than salary and living conditions (14% and 12% importance). CONCLUSIONS: No providers accepted the salary from a government job alone, which was always augmented by other work. However, few providers worked only nongovernment jobs. Non-monetary incentives are powerful influencers of job preference, and may be leveraged as policy options to attract providers. Salary continues to be an important driver of job choice, and jobs with fewer income generating opportunities (e.g. private work in rural areas) are likely to need salary augmentation to attract providers.

Diagnosis and Acute Management of COVID-19 and Multisystem Inflammatory Syndrome in Children.

ABSTRACT: Most children with coronavirus disease 2019 (COVID-19) infection are asymptomatic or have mild disease. About 5% of infected children will develop severe or critical disease. Rapid identification and treatment are essential for children who are critically ill with signs and symptoms of respiratory failure, septic shock, and multisystem inflammatory syndrome in children. This article is intended for pediatricians, pediatric emergency physicians, and individuals involved in the emergency care of children. It reviews the current epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children, summarizes key aspects of clinical assessment including identification of high-risk patients and manifestations of severe disease, and provides an overview of COVID-19 management in the emergency department based on clinical severity.

Impact of capnography on patient safety in high- and low-income settings: a scoping review.

BACKGROUND: Capnography is universally accepted as an essential patient safety monitor in high-income countries (HICs) yet is often unavailable in low and middle-income countries (LMICs). Increasing capnography availability has been proposed as one of many potential approaches to improving perioperative outcomes in LMICs. This scoping review summarises the existing literature on the effect of capnography on patient outcomes to help prioritise interventions and guide expansion of capnography in LMICs. METHODS: We searched MEDLINE and EMBASE databases for articles published between 1980 and March 2019. Studies that assessed the impact of capnography on morbidity, mortality, or the use of airway interventions both inside and outside the operating room were included. RESULTS: The search resulted in 7445 unique papers, and 31 were included for analysis. Retrospective and non-randomised data suggest capnography use may improve outcomes in the operating room, ICU, and emergency department, and during resuscitation. Prospective data on capnography use for procedural sedation suggest earlier detection of hypoventilation and a reduction in haemoglobin desaturation events. No randomised studies exist that assess the impact of capnography on patient outcomes. CONCLUSION: Despite widespread endorsement of capnography as a mandatory perioperative monitor, rigorous data demonstrating its impact on patient outcomes are limited, especially in LMICs. The association between capnography use and a reduction in serious airway complications suggests that closing the capnography gap in LMICs may represent a significant opportunity to improve patient safety. Additional data are needed to quantify the global capnography gap and better understand the barriers to capnography scale-up in LMICs.

Anesthesia Provider Training and Practice Models: A Survey of Africa.

BACKGROUND: In Africa, most countries have fewer than 1 physician anesthesiologist (PA) per 100,000 population. Nonphysician anesthesia providers (NPAPs) play a large role in the workforce of many low- and middle-income countries (LMICs), but little information has been systematically collected to describe existing human resources for anesthesia care models. An understanding of existing PA and NPAP training pathways and roles is needed to inform anesthesia workforce planning, especially for critically underresourced countries. METHODS: Between 2016 and 2018, we conducted electronic, phone, and in-person surveys of anesthesia providers in Africa. The surveys focused on the presence of anesthesia training programs, training program characteristics, and clinical scope of practice after graduation. RESULTS: One hundred thirty-one respondents completed surveys representing data for 51 of 55 countries in Africa. Most countries had both PA and NPAP training programs (57%; mean, 1.6 pathways per country). Thirty distinct training pathways to become an anesthesia provider could be discriminated on the basis of entry qualification, duration, and qualification gained. Of these 30 distinct pathways, 22 (73%) were for NPAPs. Physician and NPAP program durations were a median of 48 and 24 months (ranges: 36-72, 9-48), respectively. Sixty percent of NPAP pathways required a nursing background for entry, and 60% conferred a technical (eg, diploma/license) qualification after training. Physicians and NPAPs were trained to perform most anesthesia tasks independently, though few had subspecialty training (such as regional or cardiac anesthesia). CONCLUSIONS: Despite profound anesthesia provider shortages throughout Africa, most countries have both NPAP and PA training programs. NPAP training pathways, in particular, show significant heterogeneity despite relatively similar scopes of clinical practice for NPAPs after graduation. Such heterogeneity may reflect the varied needs and resources for different settings, though may also suggest lack of consensus on how to train the anesthesia workforce. Lack of consistent terminology to describe the anesthesia workforce is a significant challenge that must be addressed to accelerate workforce research and planning efforts.

Evidence Against Use of Nitrogen for the Death Penalty.

This Viewpoint discusses the recent use of forced nitrogen inhalation as capital punishment in Alabama and describes the body of evidence indicating that forced nitrogen inhalation is an inhumane practice.

Comparison of Transcranial Doppler and Ultrasound-Tagged Near Infrared Spectroscopy for Measuring Relative Changes in Cerebral Blood Flow in Human Subjects.

BACKGROUND: Currently, no reliable method exists for continuous, noninvasive measurements of absolute cerebral blood flow (CBF). We sought to determine how changes measured by ultrasound-tagged near-infrared spectroscopy (UT-NIRS) compare with changes in CBF as measured by transcranial Doppler (TCD) in healthy volunteers during profound hypocapnia and hypercapnia. METHODS: Ten healthy volunteers were monitored with a combination of TCD, UT-NIRS (c-FLOW, Ornim Medical), as well as heart rate, blood pressure, end-tidal PCO2 (PEtCO2), end-tidal O2, and inspired O2. Inspired CO2 and minute ventilation were controlled to achieve 5 stable plateau goals of EtCO2 at 15-20, 25-30, 35-40, 45-50, and 55-60 mm Hg, for a total of 7 measurements per subject. CBF was assessed at a steady state, with the TCD designated as the reference standard. The primary analysis was a linear mixed-effect model of TCD and UT-NIRS flow with PEtCO2, which accounts for repeated measures. Receiver operating characteristic curves were determined for detection of changes in CBF. RESULTS: Hyperventilation (nadir PEtCO2 17.1 ± 2.4) resulted in significantly decreased mean flow velocity of the middle cerebral artery from baseline (to 79% ± 22%), but not a consistent decrease in UT-NIRS cerebral flow velocity index (n = 10; 101% ± 6% of baseline). Hypercapnia (peak PEtCO2 59.3 ± 3.3) resulted in a significant increase from baseline in both mean flow velocity of the middle cerebral artery (153% ± 25%) and UT-NIRS (119% ± 11%). Comparing slopes versus PEtCO2 as a percent of baseline for the TCD (1.7% [1.5%-2%]) and UT-NIRS (0.4% [0.3%-0.5%]) shows that the UT-NIRS slope is significantly flatter, P < .0001. Area under the receiver operating characteristic curve was significantly higher for the TCD than for UT-NIRS, 0.97 (95% confidence interval, 0.92-0.99) versus 0.75 (95% confidence interval, 0.66-0.82). CONCLUSIONS: Our data indicate that UT-NIRS cerebral flow velocity index detects changes in CBF only during hypercarbia but not hypocarbia in healthy subjects and with much less sensitivity than TCD. Additional refinement and validation are needed before widespread clinical utilization of UT-NIRS.

Effects of Acute, Profound Hypoxia on Healthy Humans: Implications for Safety of Tests Evaluating Pulse Oximetry or Tissue Oximetry Performance.

Extended periods of oxygen deprivation can produce acidosis, inflammation, energy failure, cell stress, or cell death. However, brief profound hypoxia (here defined as SaO2 50%-70% for approximately 10 minutes) is not associated with cardiovascular compromise and is tolerated by healthy humans without apparent ill effects. In contrast, chronic hypoxia induces a suite of adaptations and stresses that can result in either increased tolerance of hypoxia or disease, as in adaptation to altitude or in the syndrome of chronic mountain sickness. In healthy humans, brief profound hypoxia produces increased minute ventilation and increased cardiac output, but little or no alteration in blood chemistry. Central nervous system effects of acute profound hypoxia include transiently decreased cognitive performance, based on alterations in attention brought about by interruptions of frontal/central cerebral connectivity. However, provided there is no decrease in cardiac output or ischemia, brief profound hypoxemia in healthy humans is well tolerated without evidence of acidosis or lasting cognitive impairment.

Feasibility of the modified sequential organ function assessment score in a resource-constrained setting: a prospective observational study.

BACKGROUND: Sub-Saharan Africa has a great burden of critical illness with limited health care resources. We evaluated the feasibility and utility of the modified Sequential Organ Function Assessment (mSOFA) score in assessing morbidity and mortality in the National Referral Hospital's intensive care unit (ICU) for one year. METHODS: We conducted a prospective, observational cohort study on patients above 12 years of age admitted to the ICU at Mulago Hospital (Kampala, Uganda). All SOFA scores were determined at admission and at 48 h. We modified the SOFA score by replacing the PaO2/FiO2 ratio with SPO2/FiO2. The primary outcome was ICU mortality. RESULTS: This ICU cohort of 118 patients had a mean age of 37 years and an ICU mortality rate of 46.6%. Non-survivors had higher initial (7.7 SD 3.8 vs. 5.5 SD 3.3; p = 0.007), mean (8.1 SD 3.9 vs 4.7 SD 2.6; p < 0.001) and highest mSOFA scores (9.4 SD 4.2 vs. 5.8 SD 3.2; p < 0.001), with an increase of 1.0 (SD 3.1) mSOFA on average after 48 h when compared to survivors (p < 0.001). The area under the receiver operating characteristic curves for each mSOFA category was: initial-0.68, mean-0.76, highest-0.76 and delta mSOFA-0.74. Multivariate logistic regression analysis showed no significant association between mSOFA scores and mortality. CONCLUSION: Our results confirm that calculation of the mSOFA score is feasible for an ICU population in a resource-limited country. More data are needed to test for an association between mSOFA and mortality.

The Accuracy of 6 Inexpensive Pulse Oximeters Not Cleared by the Food and Drug Administration: The Possible Global Public Health Implications.

BACKGROUND: Universal access to pulse oximetry worldwide is often limited by cost and has substantial public health consequences. Low-cost pulse oximeters have become increasingly available with limited regulatory agency oversight. The accuracy of these devices often has not been validated, raising questions about performance. METHODS: The accuracy of 6 low-cost finger pulse oximeters during stable arterial oxygen saturations (SaO2) between 70% and 100% was evaluated in 22 healthy subjects. Oximeters tested were the Contec CMS50DL, Beijing Choice C20, Beijing Choice MD300C23, Starhealth SH-A3, Jumper FPD-500A, and Atlantean SB100 II. Inspired oxygen, nitrogen, and carbon dioxide partial pressures were monitored and adjusted via a partial rebreathing circuit to achieve 10 to 12 stable target SaO2 plateaus between 70% and 100% and PaCO2 values of 35 to 45 mm Hg. Comparisons of pulse oximeter readings (SpO2) with arterial SaO2 (by Radiometer ABL90 and OSM3) were used to calculate bias (SpO2 - SaO2) mean, precision (SD of the bias), and root mean square error (ARMS). RESULTS: Pulse oximeter readings corresponding to 536 blood samples were analyzed. Four of the 6 oximeters tested showed large errors (up to -6.30% mean bias, precision 4.30%, 7.53 ARMS) in estimating saturation when SaO2 was reduced <80%, and half of the oximeters demonstrated large errors when estimating saturations between 80% and 90%. Two of the pulse oximeters tested (Contec CMS50DL and Beijing Choice C20) demonstrated ARMS of <3% at SaO2 between 70% and 100%, thereby meeting International Organization for Standardization (ISO) criteria for accuracy. CONCLUSIONS: Many low-cost pulse oximeters sold to consumers demonstrate highly inaccurate readings. Unexpectedly, the accuracy of some low-cost pulse oximeters tested here performed similarly to more expensive, ISO-cleared units when measuring hypoxia in healthy subjects. None of those tested here met World Federation of Societies of Anaesthesiologists standards, and the ideal testing conditions do not necessarily translate these findings to the clinical setting. Nonetheless, further development of accurate, low-cost oximeters for use in clinical practice is feasible and, if pursued, could improve access to safe care, especially in low-income countries.

Effect of temperature acclimation on red blood cell oxygen affinity in Pacific bluefin tuna (Thunnus orientalis) and yellowfin tuna (Thunnus albacares).

Hemoglobin-oxygen (Hb-O2) binding properties are central to aerobic physiology, and must be optimized for an animal's aerobic requirements and environmental conditions, both of which can vary widely with seasonal changes or acutely with diving. In the case of tunas, the matter is further complicated by large regional temperature differences between tissues within the same animal. This study investigates the effects of thermal acclimation on red blood cell Hb-O2 binding in Pacific bluefin tuna (T. orientalis) and yellowfin tuna (T. albacares) maintained in captive tanks at acclimation temperatures of 17°, 20° and 24 °C. Oxygen binding properties of acclimated tuna isolated red blood cells were examined under varying experimental temperatures (15°-35 °C) and CO2 levels (0%, 0.5% and 1.5%). Results for Pacific bluefin tuna produced temperature-independence at 17 °C- and 20 °C-acclimation temperatures and significant reverse temperature-dependence at 24 °C-acclimation in the absence of CO2, with instances of reverse temperature-dependence in 17 °C- and 24 °C-acclimations at 0.5% and 1.5% CO2. In contrast, yellowfin tuna produced normal temperature-dependence at each acclimation temperature at 0% CO2, temperature-independence at 0.5% and 1.5% CO2, and significant reverse temperature-dependence at 17 °C-acclimation and 0.5% CO2. Thermal acclimation of Pacific bluefin tuna increased O2 binding affinity of the 17 °C-acclimation group, and produced a significantly steeper oxygen equilibrium curve slope (nH) at 24 °C-acclimation compared to the other acclimation temperatures. We discuss the potential implications of these findings below.

Pressure Control Surrogate Formula for Estimating Mechanical Power in ARDS is Associated with Mortality.

BACKGROUND: Mechanical power applied to the respiratory system (MPRS) is associated with ventilator-induced lung injury (VILI) and ARDS mortality. Absent automated ventilator MPRS measurements, the alternative is clinically unwieldy equations. However, simplified surrogate formulas are now available and accurately reflect values produced by airway pressure-volume curves. This retrospective, observational study examined whether the surrogate pressure-control equation alone could accurately assess mortality risk in ARDS subjects managed almost exclusively with volume-control ventilation.METHODS: 948 subjects were studied in whom invasive mechanical ventilation and implementation of ARDSNet ventilator protocols commenced ≤ 24hr after ARDS onset, and who survived > 24hr. MPRS was calculated as 0.098 x respiratory frequency x VT x (PEEP + driving pressure [PDR]). MPRS was assessed as a risk factor for hospital mortality, and compared between non-survivors and survivors across Berlin Definition classifications. In addition, mortality was compared across 4 MPRS thresholds associated with VILI or mortality (ie. 15, 20, 25 and 30 J/m).RESULTS: MPRS was associated with increased mortality risk: Odds Ratio (95% CI) of 1.06 (1.04-1.07) per J/m, P<0.001). Median MPRS differentiated non-survivors from survivors in Mild (24.7 vs. 18.5 J/m, respectively, P==0.034); Moderate (25.7 vs. 21.3 J/m, P<0.001); and Severe ARDS (28.7 vs. 23.5 J/m, P<0.001). Across 4 MPRS thresholds mortality increased from 23-29% when MPRS was < threshold vs. 38-51% when MPRS was > threshold (P<0.001). In the > cohort the Odds Ratio (95%CI) increased from 2.03 (1.34-3.12) to 2.51 (1.87-3.33).CONCLUSION: The pressure control surrogate formula is sufficiently accurate to assess mortality in ARDS, even when using volume control ventilation. In our subjects when MPRS exceeds established cut-off values for VILI or mortality risk, we found mortality risk consistently increased by a factor of > 2.0.

Open Access Data Repository and Common Data Model for Pulse Oximeter Performance Data.

The OpenOximetry Repository is a structured database storing clinical and lab pulse oximetry data, serving as a centralized repository and data model for pulse oximetry initiatives. It supports measurements of arterial oxygen saturation (SaO2) by arterial blood gas co-oximetry and pulse oximetry (SpO2), alongside processed and unprocessed photoplethysmography (PPG) data and other metadata. This includes skin color measurements, finger diameter, vital signs (e.g., arterial blood pressure, end-tidal carbon dioxide), and arterial blood gas parameters (e.g., acid-base balance, hemoglobin concentration). Data contributions are encouraged. All data, from desaturation studies to clinical trials, are collected prospectively to ensure accuracy. A common data model and standardized protocols for consistent archival and interpretation ensure consistent data archival and interpretation. The dataset aims to facilitate research on pulse oximeter performance across diverse human characteristics, addressing performance issues and promoting accurate pulse oximeters. The initial release includes controlled lab desaturation studies (CLDS), with ongoing updates planned as further data from clinical trials and CLDS become available.