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Context 1
... 8.7.1 Oxygen saturation target range for most patients i40 8.7.2 Oxygen requirements of specifi c groups of patients i40 8.8 Importance of blood gas measurements in guiding oxygen therapy i40 8.9 What should be the initial choice of oxygen delivery system in hospital settings? i40 8.9.1 Devices used in emergency oxygen therapy in hospitals i40 8.10 Recommended oxygen therapy for major medical emergencies and critical illness i40 8. 10 Section 9: Emergency use of oxygen in ambulances, community and prehospital settings i60 9.1 Pulse oximetry and availability of oxygen i60 9.2 Clinical assessment by fi rst responder(s) (GP, nurse or ambulance staff ) i60 9.3 Immediate management of hypoxaemic patients i60 9.4 Patients with known COPD i61 9.5 Patients who should be assumed to have COPD i61 9.6 Other patients at risk of hypercapnic respiratory failure with respiratory acidosis i61 9.7 Oxygen alert care and 24% or 28% Venturi masks in patients with COPD (and others at risk of respiratory acidosis) who have had an episode of hypercapnic respiratory failure i62 9.8 Choice of devices in prehospital care i62 9.9 Emergency use of oxygen in patient's home i62 9.10 Use of oxygen by rescue services and other non-NHS fi rst responders i63 9.11 Use of nitrous oxide/oxygen mixtures (eg, Entonox) i63 9.12 Use of oxygen in prehospital care for pregnant women i62 Figure 8 Example of oxygen alert card Section 10: Practical aspects of oxygen therapy i63 Table 12 Examples of common oxygen cylinder sizes and capacities i65 Table 13 Total gas fl ow rate from Venturi masks i64 Figure 9 High-concentration reservoir mask i64 Figure 10 Simple face mask i65 Figure Section 11: Prescription, administration and monitoring of oxygen therapy i74 11.1 Safe prescription and administration of oxygen i74 11.1.1 Legal status of medical oxygen: Does it need a prescription? ...
Context 2
... ambulance staff are often not informed at present of a diagnosis of COPD and may not be aware of the presence of other high-risk conditions such as kyphoscoliosis or respiratory failure due to neuromuscular con- ditions. 447 These patients should be issued with an oxygen alert card (example shown in figure 8) and a 24% or 28% Venturi mask based on previous blood gas results. The recommended oxygen saturation will be based on the clinical scenario for each individual patient but will usually be 88-92%, occasionally 85- 88% or 85-90% based on previous blood gas results. ...
Context 3
... humidifying systems are really 'giant nebulisers' with a 1 L reservoir of saline or sterile water and an adjust- able Venturi device ( figure 18). These systems are attached directly to the oxygen flow meter and connected to an aerosol mask via Flex tube. ...
Context 4
... not allow hypoxaemia to occur while administering nebu- lised treatments: ✓ For hypoxaemic patients, oxygen therapy should continue during nebulised treatments. Figure 18 Large volume nebulisation-based humidifier. Driving gas for nebulised treatment in ambulances: ✓ During treatment by ambulance staff oxygen-driven nebuli- sers should be used for patients with asthma and may be used for patients with COPD in the absence of an air-driven compressor system. ...
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Presenting potential compensatory movement strategies in patients with COPD
Citations
... The remaining 93 undecided items were re-rated in round three, where a further 35 indicators of risk reached consensus for inclusion. Details of the 50 indicators of risk that reached consensus for inclusion in the final risk assessment tool by the end of the Delphi process, as well as the 28 that Moving from bed to chair 1 (20) Walking 3 (60) were excluded and the 36 left undecided are found in Additional File 1: Supplementary Tables 9-11. Eleven of the undecided indicators were then included because the sum of ratings for 'agree' plus 'strongly agree' (for higher risk) plus 'contraindicated' were ≥ 70% and they are found in Additional File 1: Supplementary Table 12. ...
... The adverse event tool moves away from using specific thresholds previously used to define unsafe changes in physiological variables [7,8] and instead opts for individualised patient-specific target ranges or specific events such as causing rehabilitation to stop or requiring a new treatment. This avoids the problem of one threshold not being appropriate for all patient groups [60] and therefore, means the events captured are more meaningful. ...
Background
Physical rehabilitation of critically ill patients is implemented to improve physical outcomes from an intensive care stay. However, before rehabilitation is implemented, a risk assessment is essential, based on robust safety data. To develop this information, a uniform definition of relevant adverse events is required. The assessment of cardiovascular stability is particularly relevant before physical activity as there is uncertainty over when it is safe to start rehabilitation with patients receiving vasoactive drugs.
Methods
A three-stage Delphi study was carried out to (a) define adverse events for a general ICU cohort, and (b) to define which risks should be assessed before physical rehabilitation of patients receiving vasoactive drugs. An international group of intensive care clinicians and clinician researchers took part. Former ICU patients and their family members/carers were involved in generating consensus for the definition of adverse events. Round one was an open round where participants gave their suggestions of what to include. In round two, participants rated their agreements with these suggestions using a five-point Likert scale; a 70% consensus agreement threshold was used. Round three was used to re-rate suggestions that had not reached consensus, whilst viewing anonymous feedback of participant ratings from round two.
Results
Twenty-four multi-professional ICU clinicians and clinician researchers from 10 countries across five continents were recruited. Average duration of ICU experience was 18 years (standard deviation 8) and 61% had publications related to ICU rehabilitation. For the adverse event definition, five former ICU patients and one patient relative were recruited. The Delphi process had a 97% response rate. Firstly, 54 adverse events reached consensus; an adverse event tool was created and informed by these events. Secondly, 50 risk factors requiring assessment before physical rehabilitation of patients receiving vasoactive drugs reached consensus. A second tool was created, informed by these suggestions.
Conclusions
The adverse event tool can be used in studies of physical rehabilitation to ensure uniform measurement of safety. The risk assessment tool can be used to inform clinical practise when risk assessing when to start rehabilitation with patients receiving vasoactive drugs.
Trial registration This study protocol was retrospectively registered on https://www.researchregistry.com/ (researchregistry2991).
... However, such findings were not supported by subsequent studies, which yielded conflicting results with a similar setup [13][14][15][16][17][18][19][20][21][22][23][24]. Despite recommendations for oxygenation targets [25,26], the clinical efficacy of oxygenation strategies in critically ill patients remains uncertain. ...
... It is reasonable to assume that the patients in medical ICUs may have had more severe gas-exchange impairments and refractory hypoxemia, requiring more oxygen. It may also be worth noting that the COT strategy avoids hyperoxemia but exposes patients to a higher risk of hypoxia, especially in these patients with more comorbidities [26]. Clinical trials comparing different oxygenation groups for these specific patient groups are needed; if possible, such studies should also incorporate stratification of important baseline risk factors (e.g., comorbidities). ...
Background
It remains unclear whether conservative oxygen therapy (COT) or liberal oxygen therapy (LOT) is more beneficial to the clinical outcomes of intensive care unit (ICU) patients. We systematically reviewed the efficacy and safety of conservative versus liberal oxygen therapy for ICU patients.
Methods
We systematically searched PubMed, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, MedRxiv, and BioRxiv for reports on randomized controlled trials (RCTs) that compared the effects of COT versus LOT on the clinical outcomes of ICU patients published in English before April 2024. The primary outcome was the mortality rate, secondary outcomes included ICU and hospital length of stay, days free from mechanical ventilation support (MVF), vasopressor-free time (VFT), and adverse events.
Results
In all, 13 RCTs involving 10,632 patients were included in analyses. Meta-analysis showed COT did not reduce mortality at 30-day (risk ratio [RR] = 1.01, 95% confidence interval [CI] 0.94 to 1.09, I ² = 42%, P = 0.78), 90-day (RR = 1.01, 95% CI 0.95 to 1.08, I ² = 9%, P = 0.69), or longest follow-up (RR = 1.00, 95% CI 0.95 to 1.06, I ² = 22%, P = 0.95) compared to LOT in ICU patients. In subgroup analyses, no significant difference was observed between the two groups in terms of the different ICU, baseline P/F, and actual PaO 2 . In addition, COT did not affect ICU length of stay, hospital length of stay, or VFT, it only affected MVF days.
Conclusions
COT did not reduce all-cause mortality in ICU patients. Further RCTs are urgently needed to confirm the impact of COT strategy on specific populations.
... The primary application requirements are as follows: (1) high O 2 purity, as only O 2 with a purity exceeding 99.5% meets the standards for medical O 2 ; (2) high energy efficiency, to ensure low energy consumption of the O 2 production equipment; (3) a high rate of O 2 production, which needs to reach at least 1 L min −1 to satisfy practical application requirements. 29,30 To meet the above criteria, it is essential to concurrently focus on optimizations and designs in terms of the catalytic mechanism, catalyst, and reactor structure. In a previous report, 10 Zhang et al. designed a coupled ORR and OER electrocatalytic system to construct a high-performance electrochemical O 2 generator (EOG) for in situ medical O 2 production. ...
Over the years, electrochemical reactors have evolved significantly, with modern reactors now able to achieve a high current density and power output in compact sizes. This leap in performance has not only greatly accelerated the rate of electrochemical reactions but also had a broader impact on the environment. Traditional research perspectives, focused primarily on the internal working systems of reactors, possibly overlook the potential of electrochemical systems in regulating their surrounding environment. A novel research perspective considering the interaction between electrochemical processes and their environmental context as a unified subject of study has gradually emerged alongside the dramatic development of electrochemical techniques. This viewpoint introduces a paradigm shift: electrochemical reactors are not isolated entities but rather are integral parts that interact with their surroundings. Correspondingly, this calls for an innovative research methodology that goes beyond studying the electrochemical processes in isolation. Rather, it integrates the design of the electrochemical system with its specific application environment, ensuring seamless integration for optimal performance under various practical conditions. Therefore, performance metrics should include not only the basic parameters of the electrochemical reactions but also the adaptability of the electrochemical system in real-world scenarios beyond the laboratory. By focusing on environmental integration and application-driven design, the applications of electrochemical technology can be more effectively leveraged. This perspective is exemplified by an electrochemical system based on coupled cathodic oxygen reduction and anodic oxygen evolution reactions. By adopting this new research paradigm, the applications of this electrochemical system can be extended to fields like medical treatment, food science, and microbial fermentation, with an emphasis on tailored designs for these specific application fields. This comprehensive and systematic new research approach aims to fully explore the potential applications of electrochemical technology and foster interdisciplinary collaboration in the electrochemical field.
... By adhering to these recommendations, physicians can provide patients with personalized, appropriate, and evidence-based O 2 therapy. Clinical professionals need to be aware of these guidelines, as adhering to these recommendations contributes to more efficient and safe medical practice, resulting in better clinical outcomes for patients (Pneumonia 2005;Siemieniuk et al. 2018;Beasley et al. 2015;O'Driscoll et al. 2017). ...
Oxygen (O2) supplementation is commonly used to treat hypoxia in patients with respiratory failure. However, indiscriminate use can lead to hyperoxia, a condition detrimental to living tissues, particularly the brain. The brain is sensitive to reactive oxygen species (ROS) and inflammation caused by high concentrations of O2, which can result in brain damage and mitochondrial dysfunction, common features of neurodegenerative disorders. Hyperoxia leads to increased production of ROS, causing oxidative stress, an imbalance between oxidants and antioxidants, which can damage tissues. The brain is particularly vulnerable to oxidative stress due to its lipid composition, high O2 consumption rate, and low levels of antioxidant enzymes. Moreover, hyperoxia can cause vasoconstriction and decreased O2 supply to the brain, posing a challenge to redox balance and neurodegenerative processes. Studies have shown that the severity of hyperoxia-induced brain damage varies with inspired O2 concentration and duration of exposure. Therefore, careful evaluation of the balance between benefits and risks of O2 supplementation, especially in clinical settings, is crucial.
... 27,28 While the avoidance of hypoxia is widely practised, a growing amount of evidence has shown the potentially deleterious effects of hyperoxia. [29][30][31] In AHF patients, changes in SpO 2 levels may be a precursor to the disease deterioration, and hyperoxia might decrease vigilance and delay recognition of deteriorating patients. 32 A study in the ICU reported that conservative oxygen therapy (SpO 2 = 94-98%) had lower ICU mortality than usual care (SpO 2 ≥ 97%). ...
Aims
Both hypercapnia and hypocapnia are common in patients with acute heart failure (AHF), but the association between partial pressure of arterial carbon dioxide (PaCO 2 ) and AHF prognosis remains unclear. The objective of this study was to investigate the connection between PaCO 2 within 24 h after admission to the intensive care unit (ICU) and mortality during hospitalization and at 1 year in AHF patients.
Methods and results
AHF patients were enrolled from the Medical Information Mart for Intensive Care IV database. The patients were divided into three groups by PaCO 2 values of <35, 35–45, and >45 mmHg. The primary outcome was to investigate the connection between PaCO 2 and in‐hospital mortality and 1 year mortality in AHF patients. The secondary outcome was to assess the prediction value of PaCO 2 in predicting in‐hospital mortality and 1 year mortality in AHF patients. A total of 2374 patients were included in this study, including 457 patients in the PaCO 2 < 35 mmHg group, 1072 patients in the PaCO 2 = 35–45 mmHg group, and 845 patients in the PaCO 2 > 45 mmHg group. The in‐hospital mortality was 19.5%, and the 1 year mortality was 23.9% in the PaCO 2 < 35 mmHg group. Multivariate logistic regression analysis showed that the PaCO 2 < 35 mmHg group was associated with an increased risk of in‐hospital mortality [hazard ratio (HR) 1.398, 95% confidence interval (CI) 1.039–1.882, P = 0.027] and 1 year mortality (HR 1.327, 95% CI 1.020–1.728, P = 0.035) than the PaCO 2 = 35–45 mmHg group. The PaCO 2 > 45 mmHg group was associated with an increased risk of in‐hospital mortality (HR 1.387, 95% CI 1.050–1.832, P = 0.021); the 1 year mortality showed no significant difference (HR 1.286, 95% CI 0.995–1.662, P = 0.055) compared with the PaCO 2 = 35–45 mmHg group. The Kaplan–Meier survival curves showed that the PaCO 2 < 35 mmHg group had a significantly lower 1 year survival rate. The area under the receiver operating characteristic curve for predicting in‐hospital mortality was 0.591 (95% CI 0.526–0.656), and the 1 year mortality was 0.566 (95% CI 0.505–0.627) in the PaCO 2 < 35 mmHg group.
Conclusions
In AHF patients, hypocapnia within 24 h after admission to the ICU was associated with increased in‐hospital mortality and 1 year mortality. However, the increase in 1 year mortality may be influenced by hospitalization mortality. Hypercapnia was associated with increased in‐hospital mortality.
... Reduced oxygen saturation results in inadequate tissue supply, particularly when oxygen demand is increased, as occurs during exercise [3]. Hypoxaemia is regarded as a low partial pressure of oxygen (PaO 2 ) less than 8.0 kPa (60 mmHg) or peripheral arterial oxygen saturation (S P O 2 ) less than 95% when measured by pulse oximetry [4,5]. The (SaO 2 ) of less than or equal to 95% is called hypoxaemia and it predicts a partial pressure of oxygen (PaO 2 ) of less than 70 mm Hg based on a normal oxyhaemoglobin curve [6]. ...
Objectives
Hypoxia is a known feature of sickle cell anaemia (SCA) which results from chronic anaemia and recurrent vaso-occlusive crisis (VOC) which can cause tissue ischaemia that leads to an end organ damage. The hallmark of SCA is chronic anaemia and recurrent vaso-occlusive crisis. The aim of this study is to compare the oxygen saturation of sickle cell anaemic individuals with the normal haemoglobin type (Hb AA) control and also to determine the prevalence of hypoxemia among SCA.
Results
Two-hundred and twenty-two (136 Hb SS and 86 Hb AA) participated in the study. The mean ± SD of age (years), oxygen saturation (%) and pulse rate (bpm) of participants with sickle cell anaemia and Hb AA control were 21.85 ± 3.04 and 22.14 ± 3.18 (t = 0.701, p = 0.436), 95.21 ± 3.02 and 98.07 ± 0.81 (t=-8.598, p < 0.0001) and 77.10 ± 9.28 and 73.16 ± 8.52 (t = 3.173, p = 0.002) respectively. The prevalence of hypoxemia among SCA participants was 47.1%. Prevalence of hypoxemia in males with SCA was 60.9% while 39.1% of the females had hypoxemia.
... In addition to hypoxemia, postoperative hyperoxemia occurred in this study, with the highest values of 4.4% in the control group at 2 h after patients returned to the cardiac ICU and 3.6% in the observation group immediately after surgery ( Table 2), indicating that there is still a gap in the understanding and management of PaO 2 , SpO 2 , and FiO 2 by the doctor and nurse teams, and that clear target ranges should be established. SpO 2 levels between 94% and 98% are often recommended for patients without hypercapnia, while SpO 2 levels between 88% and 92% are recommended for patients at risk of hypercapnic respiratory failure [28]. ...
Objective
In this study, we investigated the effect of various oxygen therapy regimens on oxygenation in patients with acute type A aortic dissection (AAD).
Methods
A quasi-randomized controlled trial was conducted, in which patients with AAD hospitalized for surgery from June to September 2021 were assigned to the control group (patients received conventional oxygen therapy after postoperative mechanical ventilation, weaning, and extubation) and those who were admitted from October to December 2021 were assigned to the observation group [patients underwent optimally adjusted therapy based on the treatment of the control group, which mainly included prioritized elevation of positive end-expiratory pressure (PEEP) and restricted use of the fraction of inspired oxygen (FiO2)].The postoperative oxygenation index, blood gas analysis, and duration of mechanical ventilation were compared between the two groups.
Results
There were significant differences in oxygenation observed at 2 h postoperatively between the groups. 12, 24, and 72 h postoperatively, the oxygenation index varied significantly between the two groups. There were statistically significant differences in the time effects of the oxygenation index and PaO2 between the two groups, as well as significant differences in the length of stay in the intensive care unit.
Conclusion
For the postoperative care of patients with AAD, it is suggested that the minimum FiO2 required for oxygenation of patients be maintained. In addition, it is possible to enhance PEEP as a priority when PaO2 is low.
... An oxygen saturation (SpO 2 ) of 94-98% is a valid target range to prescribe or to be given by an expert with recording of inspired oxygen, the oxygen delivery system, oxygen flow rate, and oxygen saturation, all linked to a track-and-trigger early warning system [45]. ...
During pregnancy and in the post-partum period, several diseases may arise or become exacerbated. Acute pancreatitis is an inflammatory disease with an increasing incidence in Western countries. The incidence of acute pancreatitis during pregnancy is not different with respect to the general population, but this incidence increases in the first 2 years after delivery. Biliary sludge and stones are the most frequent aetiologies, followed by hypertriglyceridemia. Taking care of the mother and foetus through a potentially severe disease requires a team consisting of an obstetrician, a gastroenterologist, an anaesthesiologist, and a surgeon. It is necessary to monitor the health of the foetus/child and the mother during pregnancy, childbirth, and puerperium. The management of this care depends on the systemic and local complications, the severity of the acute pancreatitis, and the trimester of pregnancy. Some diagnostic tools and many drugs are not safe for foetuses, while interventional endoscopy and surgery have limitations and can only be used after an accurate evaluation of benefit/risk ratios. Despite these limitations, maternal mortality due to acute pancreatitis is low during pregnancy, mainly thanks to multidisciplinary approaches for these patients. A careful diet to prevent obesity, alcohol abstinence, routine serum triglyceride control, and breastfeeding for at least three months may prevent acute pancreatitis during and after pregnancy.
... Apart of lactate no further parameters of acid-base status were associated with SpO2, HR, crSO2 or cFTOE, neither in preterm neonates with respiratory support nor in stable term neonates. SpO 2 represents the percentage of hemoglobin saturated with oxygen in peripheral arterial blood (17). Our findings regarding SpO 2 values in term neonates 5 min after birth are consistent with those of Rabi et al. (18), who described median SpO 2 values of 81% (75-83). ...
Objective
Aim was to investigate whether acid-base and metabolic parameters obtained from arterial umbilical cord blood affect cerebral oxygenation after birth in preterm neonates with respiratory support and in term neonates without respiratory support.
Study design
This was a post-hoc analysis of secondary outcome parameters of a prospective observational study including preterm neonates with and term neonates without respiratory support. Non-asphyxiated neonates with cerebral oxygenation measured with near-infrared spectroscopy during the first 15 min and with blood gas analyses from arterial umbilical cord blood were included. Arterial oxygen saturation (SpO2) and heart rate (HR) were monitored with pulse oximetry. Potential correlations were investigated between acid-base and metabolic parameters (pH-value, bicarbonate, base-excess, and lactate) and crSO2/cFTOE 5 min after birth.
Results
Seventy-seven neonates were included: 14 preterm neonates with respiratory support (mean gestational age [GA] 31.4 ± 4.1 weeks; mean birth weight [BW] 1,690 ± 640 g) and 63 term neonates without respiratory support (GA 38.7 ± 0.8 weeks; BW 3,258 ± 443 g). Mean crSO2 5 min after birth was 44.0% ± 24.2% in preterm and 62.2% ± 20.01% in term neonates. Mean cFTOE 5 min after birth was 0.46 ± 0.06 in preterm and 0.27 ± 0.19 in term neonates. In preterm neonates with respiratory support higher lactate was significantly associated with lower crSO2 and SpO2 and tended to be associated with higher cFTOE. In term neonates without respiratory support no significant correlations were found.
Conclusion
In non-asphyxiated preterm neonates with respiratory support, lactate levels were negatively associated with crSO2 and SpO2, whereas in term neonates without respiratory support no associations were observed.
... Alongside this development, the Centers for Disease Control and Prevention (CDC) issued a guideline supporting the use of high FiO 2 in intubated surgical patients, 29 whilst other groups, including the British Thoracic Society and the World Federation of Societies of Anaesthesiologists, have continued to advocate a more conservative approach (with the latter also considering the unnecessary added acquisition costs of both oxygen and delivery systems). 30,31 Consequently, guidelines for perioperative oxygen supplementation remain conflicting with no certainty on the approach anaesthetists are choosing to follow in their routine practice (see Fig. 2). ...
... Currently though they recommend a target SpO 2 of 94e96% for most acutely ill patients not at risk of hypercapnic respiratory failure. 30,42 The Thoracic Society of Australia and New Zealand (in guidelines issued more recently) are slightly more conservative, recommending an SpO 2 of 92e96% for most acute medical conditions, and 88e92% for patients with chronic obstructive pulmonary disease (COPD) and other conditions associated with chronic respiratory failure, with supplemental oxygen only to be administered when the SpO 2 is below the lower limit of the appropriate range. 43 Throughout their training, clinicians are repeatedly taught to reach for the oxygen first in situations of uncertainty or in emergencies, and with good reason; brain tissue may have a hypoxia tolerance of <3 min. ...
Oxygen is the most used drug in anaesthesia. Despite such widespread use, optimal perioperative oxygen administration remains highly controversial because of concerns about the competing harms of both hyperoxia and hypoxia.
Notwithstanding a Cochrane review concluding that routinely administering a fractional inspired oxygen concentration (FiO2) >0.6 intraoperatively might increase postoperative morbidity and mortality, the World Health Organization (WHO) currently recommends all anaesthetised patients receive 0.8 FiO2 during and immediately after surgery to reduce surgical site infections. Results from the largest trial available at the time of these two reviews (suggesting long-term survival may be worse with high FiO2, particularly in patients with malignant disease) were considered ‘biologically implausible’ by the WHO's Guideline Development Group. In addition, the integrity of some perioperative oxygen studies has been challenged. Resolving these controversies is of fundamental importance to all perioperative clinicians.
This narrative review is based on the inaugural BJA William Mapleson lecture delivered by the senior author (AC) at the 2023 annual meeting of the Royal College of Anaesthetists in Birmingham. We present the current evidence for perioperative oxygen administration and contrast this with how oxygen therapy is targeted in other specialties (e.g. intensive care medicine). We will explore whether anaesthetists follow the WHO recommendations and consider how oxygen administration affects the stress response to surgery. We reason that novel clinical trial designs in combination with targeted experimental medicine studies will be required to improve our understanding of how best to optimise individualised perioperative oxygenation—a cornerstone of anaesthesia.
