scholarly journals Determining a target SpO2 to maintain PaO2 within a physiological range

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250740
Author(s):  
Jantine G. Röttgering ◽  
Angelique M. E. de Man ◽  
Thomas C. Schuurs ◽  
Evert-Jan Wils ◽  
Johannes M. Daniels ◽  
...  
Keyword(s):  
Supplemental Oxygen ◽  
Arterial Oxygen ◽  
Ongoing Debate ◽  
Peripheral Oxygen Saturation ◽  
Arterial Hypoxemia ◽  
Physiological Range ◽  
Increased Risk ◽  
Potential Risks ◽  
Oxygenation Status ◽  
Function Testing

Objective In the context of an ongoing debate on the potential risks of hypoxemia and hyperoxemia, it seems prudent to maintain the partial arterial oxygen pressure (PaO2) in a physiological range during administration of supplemental oxygen. The PaO2 and peripheral oxygen saturation (SpO2) are closely related and both are used to monitor oxygenation status. However, SpO2 values cannot be used as an exact substitute for PaO2. The aim of this study in acutely ill and stable patients was to determine at which SpO2 level PaO2 is more or less certain to be in the physiological range. Methods This is an observational study prospectively collecting data pairs of PaO2 and SpO2 values in patients admitted to the emergency room or intensive care unit (Prospective Inpatient Acutely ill cohort; PIA cohort). A second cohort of retrospective data of patients who underwent pulmonary function testing was also included (Retrospective Outpatient Pulmonary cohort; ROP cohort). Arterial hypoxemia was defined as PaO2 < 60 mmHg and hyperoxemia as PaO2 > 125 mmHg. The SpO2 cut-off values with the lowest risk of hypoxemia and hyperoxemia were determined as the 95th percentile of the observed SpO2 values corresponding with the observed hypoxemic and hyperoxemic PaO2 values. Results 220 data pairs were collected in the PIA cohort. 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 94%, and 95% of hyperoxemic PaO2 measurements occurred in patients with an SpO2 above 96%. Additionally in the 1379 data pairs of the ROP cohort, 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 93%. Conclusion The SpO2 level marking an increased risk of arterial hypoxemia is not substantially different in acutely ill versus stable patients. In acutely ill patients receiving supplemental oxygen an SpO2 target of 95% maximizes the likelihood of maintaining PaO2 in the physiological range.

scholarly journals Predicting the Need for Supplemental Oxygen During Airline Flight in Patients with Chronic Pulmonary Disease: A Comparison of Predictive Equations and Altitude Simulation

2009 ◽  
Vol 16 (4) ◽  
pp. 119-124 ◽  
Author(s):  
Ana C Bradi ◽  
Marie E Faughnan ◽  
Matthew B Stanbrook ◽  
Eva Deschenes-Leek ◽  
Kenneth R Chapman
Keyword(s):  
Predictive Value ◽  
Ground Level ◽  
Supplemental Oxygen ◽  
Forced Expiratory Volume ◽  
Arterial Oxygen ◽  
British Thoracic Society ◽  
Predictive Equations ◽  
Screening Guidelines ◽  
Specificity And Sensitivity ◽  
Increased Risk

BACKGROUND: Patients with chronic pulmonary diseases are at increased risk of hypoxemia when travelling by air. Screening guidelines, predictive equations based on ground level measurements and altitude simulation laboratory procedures have been recommended for determining risk but have not been rigorously evaluated and compared.OBJECTIVES: To determine the adequacy of screening recommendations that identify patients at risk of hypoxemia at altitude, to evaluate the specificity and sensitivity of published predictive equations, and to analyze other possible predictors of the need for in-flight oxygen.METHODS: The charts of 27 consecutive eligible patients referred for hypoxia altitude simulation testing before flight were reviewed. Patients breathed a fraction of inspired oxygen of 0.15 for 20 min. This patient population was compared with the screening recommendations made by six official bodies and compared the partial pressure of arterial oxygen (PaO2) obtained during altitude simulation with the PaO2predicted by 16 published predictive equations.RESULTS: Of the 27 subjects, 25% to 33% who were predicted to maintain adequate oxygenation in flight by the British Thoracic Society, Aerospace Medical Association or American Thoracic Society guidelines became hypoxemic during altitude simulation. The 16 predictive equations were markedly inaccurate in predicting the PaO2measured during altitude simulation; only one had a positive predictive value of greater than 30%. Regression analysis identified PaO2at ground level (r=0.50; P=0.009), diffusion capacity (r=0.56; P=0.05) and per cent forced expiratory volume in 1 s (r=0.57; P=0.009) as having predictive value for hypoxia at altitude.CONCLUSIONS: Current screening recommendations for determining which patients require formal assessment of oxygen during flight are inadequate. Predictive equations based on sea level variables provide poor estimates of PaO2measured during altitude simulation.

scholarly journals Highs and lows of hyperoxia: physiological, performance, and clinical aspects

2018 ◽  
Vol 315 (1) ◽  
pp. R1-R27 ◽  
Author(s):  
Julien Vincent Brugniaux ◽  
Geoff B. Coombs ◽  
Otto F. Barak ◽  
Zeljko Dujic ◽  
Mypinder S. Sekhon ◽  
...  
Keyword(s):  
Carbon Monoxide Poisoning ◽  
Barometric Pressure ◽  
Supplemental Oxygen ◽  
Arterial Oxygen ◽  
Future Research ◽  
Clinical Aspects ◽  
Comprehensive Overview ◽  
Diverse Range ◽  
Arterial Oxygen Content ◽  
Increased Risk

Molecular oxygen (O2) is a vital element in human survival and plays a major role in a diverse range of biological and physiological processes. Although normobaric hyperoxia can increase arterial oxygen content ([Formula: see text]), it also causes vasoconstriction and hence reduces O2 delivery in various vascular beds, including the heart, skeletal muscle, and brain. Thus, a seemingly paradoxical situation exists in which the administration of oxygen may place tissues at increased risk of hypoxic stress. Nevertheless, with various degrees of effectiveness, and not without consequences, supplemental oxygen is used clinically in an attempt to correct tissue hypoxia (e.g., brain ischemia, traumatic brain injury, carbon monoxide poisoning, etc.) and chronic hypoxemia (e.g., severe COPD, etc.) and to help with wound healing, necrosis, or reperfusion injuries (e.g., compromised grafts). Hyperoxia has also been used liberally by athletes in a belief that it offers performance-enhancing benefits; such benefits also extend to hypoxemic patients both at rest and during rehabilitation. This review aims to provide a comprehensive overview of the effects of hyperoxia in humans from the “bench to bedside.” The first section will focus on the basic physiological principles of partial pressure of arterial O2, [Formula: see text], and barometric pressure and how these changes lead to variation in regional O2 delivery. This review provides an overview of the evidence for and against the use of hyperoxia as an aid to enhance physical performance. The final section addresses pathophysiological concepts, clinical studies, and implications for therapy. The potential of O2 toxicity and future research directions are also considered.

scholarly journals The Effect of Supplemental Oxygen on the Incidence of Hypoxaemia after Premedication in Patients Undergoing Cardiac Surgery

1997 ◽  
Vol 25 (4) ◽  
pp. 347-349 ◽  
Author(s):  
C. F. Royse ◽  
R. J. B. Tiernan ◽  
S. M. Portelli ◽  
S. Davies ◽  
R. Arblaster ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Arterial Oxygen Saturation ◽  
Supplemental Oxygen ◽  
Arterial Oxygen ◽  
Patient Demographics ◽  
Routine Administration ◽  
High Incidence ◽  
Patient Groups ◽  
To Receive ◽  
Elective Patients

Opiate premedication may cause significant respiratory depression, particularly when other sedative agents such as scopolamine or benzodiazepines are added. This can cause hypoxaemia with potential for worsening myocardial ischaemia in cardiac surgery patients. The aim of this study was to investigate the incidence of hypoxaemia (SpO2 <90%) in elective patients undergoing cardiac surgery and to assess the efficacy of supplemental oxygen in preventing it. One hundred elective patients without significant respiratory disease or cardiac failure, who received both an opiate and a sedative premedication, were prospectively randomized to receive either oxygen via a facemask at 4 l/min or no oxygen. Continuous arterial oxygen saturation was recorded using a pulse oximeter from the time of premedication until the patient arrived in theatre. An SpO2 <90% was recorded as a significant event and oxygen was administered to the patients. Six patients were excluded because of equipment failure or protocol violations. The patient groups were comparable with respect to patient demographics, premedication type and dose or the duration of monitoring. In patients receiving oxygen (n=48) there were no episodes of hypoxaemia (0%). In patients not receiving oxygen (n=46) there were 14 episodes of hypoxaemia (30%, P<0.0001). We conclude that there is a significantly high incidence of hypoxaemia in cardiac surgery patients following combined opiate and sedative premedication and that it can be reduced by the routine administration of supplemental oxygen.

Antiplatelet drugs in patients with enhanced platelet turnover: biomarkers versus platelet function testing

2015 ◽  
Vol 114 (09) ◽  
pp. 459-468 ◽  
Author(s):  
Susanne Gruber ◽  
Erik Grove ◽  
Thomas Weiss ◽  
Johann Wojta ◽  
Kurt Huber ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Platelet Reactivity ◽  
Platelet Inhibition ◽  
Antiplatelet Drugs ◽  
P2y12 Inhibitors ◽  
Reticulated Platelets ◽  
Increased Risk ◽  
Key Factor ◽  
Coronary Syndromes ◽  
Function Testing

SummaryPlatelets are key players in atherothrombosis. Antiplatelet therapy comprising aspirin alone or with P2Y12-inhibitors are effective for prevention of atherothrombotic complications. However, there is interindividual variability in the response to antiplatelet drugs, leaving some patients at increased risk of recurrent atherothrombotic events. Several risk factors associated with high on-treatment platelet reactivity (HTPR), including elevated platelet turnover, have been identified. Platelet turnover is adequately estimated from the fraction of reticulated platelets. Reticulated platelets are young platelets, characterised by residual messenger RNA. They are larger, haemostatically more active and there is evidence that platelet turnover is a causal and prognostic factor in atherothrombotic disease. Whether platelet turnover per se represents a key factor in pathogenesis, progression and prognosis of atherothrombotic diseases (with focus on acute coronary syndromes) or whether it merely facilitates insufficient platelet inhibition will be discussed in this state-of-the art review.

Acute hypoxia in a simulated high-altitude airdrop scenario due to oxygen system failure

2017 ◽  
Vol 123 (6) ◽  
pp. 1443-1450 ◽  
Author(s):  
William Ottestad ◽  
Tor Are Hansen ◽  
Gaurav Pradhan ◽  
Jan Stepanek ◽  
Lars Øivind Høiseth ◽  
...  
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Supplemental Oxygen ◽  
Cerebral Oximetry ◽  
Arterial Oxygen ◽  
Hypoxic Exposure ◽  
System Failure ◽  
Oxygen System ◽  
Simulated High Altitude ◽  
Oxygen Tensions

High-Altitude High Opening (HAHO) is a military operational procedure in which parachute jumps are performed at high altitude requiring supplemental oxygen, putting personnel at risk of acute hypoxia in the event of oxygen equipment failure. This study was initiated by the Norwegian Army to evaluate potential outcomes during failure of oxygen supply, and to explore physiology during acute severe hypobaric hypoxia. A simulated HAHO without supplemental oxygen was carried out in a hypobaric chamber with decompression to 30,000 ft (9,144 m) and then recompression to ground level with a descent rate of 1,000 ft/min (305 m/min). Nine subjects were studied. Repeated arterial blood gas samples were drawn throughout the entire hypoxic exposure. Additionally, pulse oximetry, cerebral oximetry, and hemodynamic variables were monitored. Desaturation evolved rapidly and the arterial oxygen tensions are among the lowest ever reported in volunteers during acute hypoxia. PaO2 decreased from baseline 18.4 (17.3–19.1) kPa, 138.0 (133.5–143.3) mmHg, to a minimum value of 3.3 (2.9–3.7) kPa, 24.8 (21.6–27.8) mmHg, after 180 (60–210) s, [median (range)], N = 9. Hyperventilation with ensuing hypocapnia was associated with both increased arterial oxygen saturation and cerebral oximetry values, and potentially improved tolerance to severe hypoxia. One subject had a sharp drop in heart rate and cardiac index and lost consciousness 4 min into the hypoxic exposure. A simulated high-altitude airdrop scenario without supplemental oxygen results in extreme hypoxemia and may result in loss of consciousness in some individuals. NEW & NOTEWORTHY This is the first study to investigate physiology and clinical outcome of oxygen system failure in a simulated HAHO scenario. The acquired knowledge is of great value to make valid risk-benefit analyses during HAHO training or operations. The arterial oxygen tensions reported in this hypobaric chamber study are among the lowest ever reported during acute hypoxia.

scholarly journals 834. Characterization of Heavily Treatment Experienced HIV-1 Infected Clinical Trial Participants Infected with SARS-CoV-2 COVID 19: Fostemsavir BRIGHTE Phase 3 Clinical Trial

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S509-S509
Author(s):  
Shiven Chabria ◽  
Stephane De Wit ◽  
Amy Pierce ◽  
Bronagh M Shepherd ◽  
Michael Warwick-Sanders ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Supplemental Oxygen ◽  
Multidrug Resistant ◽  
Cd4 Count ◽  
People Living With Hiv ◽  
Research Support ◽  
Increased Risk ◽  
Living With Hiv ◽  
Hiv 1

Abstract Background BRIGHTE is an ongoing global study evaluating the gp120 attachment inhibitor fostemsavir (FTR) in heavily treatment-experienced (HTE) adults with multidrug resistant (MDR) HIV-1 unable to form a viable antiretroviral (ARV) regimen. An estimated 2 million people living with HIV-1 have been infected with SARS-CoV-2. Those with HIV viremia and/or low CD4+ counts are at increased risk of serious adverse outcome. We describe the reported COVID cases in a clinical trial population of people living with MDR HIV and immune suppression. Methods At the start of the COVID pandemic, all ongoing BRIGHTE subjects had achieved ≥ 192 weeks on FTR and optimized background ARVs; results through Week 96 were presented previously. Investigators used WHO guidelines for COVID diagnosis and reported exposure, testing results and symptom presence. Figure 1. BRIGHTE Study Design Results 371 subjects [272 Randomized Cohort (RC), 99 Non-Randomized Cohort (NC)] were enrolled; 44% were ≥ 50 years of age and 86% had an AIDS history. Median CD4+ count at study start of was 80 cells/mm3 (IQR 11–202); 30% with ≤ 20 cells/mm3. 250 subjects remained in BRIGHTE at pandemic start. By April 2021, 17 subjects (14 RC, 3 NC) had confirmed COVID infection (positive PCR test). Severity was Grade 1-3, all cases resolved with no deaths. Six subjects were hospitalized (Table 1); most recent CD4+ count prior to COVID were 293-1641 cells/mm3 and 5/6 subjects were virologically suppressed. Treatments often included prophylactic anticoagulants and supplemental oxygen; no cART changes were made. The remaining 11/17 confirmed cases were managed outpatient. Five more subjects had suspect COVID not confirmed by PCR and 2 subjects had negative PCR tests. Table 1. Characterization of Participants with Serious AEs of Confirmed COVID-19 Infections – All Hospitalizations Conclusion A total of 22/250 COVID-19 cases (17 confirmed, 5 unconfirmed) have been reported in BRIGHTE. Outcomes were reassuring with no deaths or known persistent sequelae, despite having advanced HIV and comorbid diseases at baseline associated with poorer COVID outcomes. Outcomes may have benefitted from immunologic improvement during the trial. Disclosures Shiven Chabria, MD, Viiv Healthcare (Employee) Stephane De Wit, MD, Gilead (Grant/Research Support)Janssen (Grant/Research Support)Merck Sharpe & Dohme (Grant/Research Support)ViiV Healthcare (Grant/Research Support) Amy Pierce, BS, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Bronagh M. Shepherd, PhD, GlaxoSmithKline (Employee, Shareholder) Michael Warwick-Sanders, BM BSc DPM MFPM, GSK (Employee) Marcia Wang, PhD, GlaxoSmithKline (Employee, Shareholder) Andrew Clark, MD, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Peter Ackerman, MD, GSK/ViiV Healthcare (Employee, Shareholder)

The use of oral contraceptives in women over age 35 years

1995 ◽  
Vol 4 (2) ◽  
pp. 115-120
Author(s):  
Robert F Casper ◽  
Selim Senoz ◽  
Avraham Ben-Chetrit
Keyword(s):  
Cardiovascular Disease ◽  
Oral Contraceptive ◽  
Oral Contraceptives ◽  
Contraceptive Use ◽  
Older Woman ◽  
Oral Contraceptive Use ◽  
Increased Risk ◽  
Potential Risks ◽  
Europe Today ◽  
The Impact

Oral contraceptives remain the most widely used form of contraception in North America and Europe today. In spite of the concerns of many women relating to the potential risks of these preparations, recent data have demonstrated that currently available oral contraceptives are safe, with no increased risk of cardiovascular disease or cancer in nonsmoking women. The present review will focus on the impact of oral contraceptive use in the older woman, including a discussion of the noncontraceptive health benefits of oral contraceptives.

843 Paradoxical Waking Hypoxemia that Improves with Sleep

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A328-A328
Author(s):  
Jessica Cho ◽  
David Dai ◽  
Constance Fung
Keyword(s):  
Pulmonary Hypertension ◽  
Case Reports ◽  
Supplemental Oxygen ◽  
Nocturnal Hypoxemia ◽  
Cpap Titration ◽  
Obstructive Sleep ◽  
Paradoxical Worsening ◽  
Chronic Hypoxemia ◽  
Function Testing ◽  
Titration Study

Abstract Introduction We present a case of paradoxically worsened hypoxia during wake phase of polysomnography while undergoing a CPAP titration study. Nighttime hypoxemia is a common feature in obstructive sleep apnea, due to obstructive events that manifest while sleeping. Excluding OSA, there remains an extensive differential for disease processes that cause hypoxemia while asleep; however, none of these processes can explain waking hypoxemia that improves upon sleeping. Report of case(s) A 70 year old male with severe OSA diagnosed by home sleep test (REI 46.5, nadir O2=76%) underwent polysomnography with PAP titration and demonstrated several hours of interrupted sleep without hypoxia and minimal obstructive events on CPAP 9–13 cmH2O. During the study, while awake at CPAP of 14 cmH2O, he developed hypoxia to mid-high 80s and supplemental oxygen bleed in was added starting at 3L and increased to 5L during a prolonged period of wakefulness. On CPAP 15 cmmH2O with 5L bleed-in, the patient fell asleep and oxygen saturation again increased to low 90s. He underwent an extensive workup for other cardiopulmonary causes of hypoxemia, with pulmonary function testing showing moderate obstructive ventilatory defect and mild DLCO impairment. An echocardiogram with saline contrast bubble study was relatively unremarkable, without evidence of right to left shunting. He underwent a chest CTA which was negative for pulmonary embolism, though it did reveal an enlarged pulmonary artery consistent with pulmonary hypertension. His chronic hypoxemia was treated with 2L supplemental oxygen during the day and bleed-in with CPAP at night. Conclusion Though nocturnal hypoxemia is common with OSA, polysomnography with paradoxical hypoxemia during wake phase has not been reported. Notably, the patient was without prolonged hypoxia during his sleep phase while on CPAP treatment with minimal apneic/hypopneic events. Pulmonary hypertension can also present as nocturnal hypoxemia, but it should worsen with sleep, rather than improve. There are case reports of right to left shunting worsened by PAP, though his hypoxemia persisted despite PAP. His paradoxical worsening hypoxemia with wakefulness is still unexplained. Support (if any):

Hypoxic Arousal Responses in Normal Infants

PEDIATRICS ◽  
1992 ◽  
Vol 89 (5) ◽  
pp. 860-864 ◽  
Author(s):  
Sally L. Davidson Ward ◽  
Daisy B. Bautista ◽  
Thomas C. Keens
Keyword(s):  
Ventilatory Response ◽  
Arterial Oxygen Saturation ◽  
Periodic Breathing ◽  
High Risk Group ◽  
Arterial Oxygen ◽  
Sudden Infant ◽  
Hypoxic Ventilatory Response ◽  
Quiet Sleep ◽  
Term Infants ◽  
Increased Risk

Failure to arouse in response to hypoxia has been described in infants at increased risk for sudden infant death syndrome (SIDS) and has been suggested as a possible mechanism for SIDS. However, most SIDS victims are not in a high-risk group before death. Thus, if a hypoxic arousal disorder is an important contributor to SIDS, normal infants might fail to arouse from sleep in response to hypoxia. To test this hypothesis, the authors studied hypoxic arousal responses in 18 healthy term infants younger than 7 months of age (age 12.1 ± 1.7 [SEM] weeks; 56% girls). Hypoxic arousal challenges were performed during quiet sleep by rapidly decreasing inspired oxygen tension (Pio2) to 80 mm Hg for 3 minutes or until arousal (eye opening, agitation, and crying) occurred. Tests were performed in duplicate when possible. Only 8 infants (44%) aroused in response to one or more hypoxic challenges; arousal occurred during 8 (32%) of 25 trials. There were no significant differences in lowest Pio2 or arterial oxygen saturation during hypoxia between those infants who aroused and those who failed to arouse. All 18 infants had a fall in their end-tidal carbon dioxide tension during hypoxia, suggesting that each had a hypoxic ventilatory response despite failure to arouse in the majority. Periodic breathing occurred following hypoxia in only 1 (13%) of the 8 trials that resulted in arousal, compared with 16 (94%) of 17 trials without arousal (P &lt; .005). It is concluded that the majority of normal infants younger than 7 months of age fail to arouse from quiet sleep in response to hypoxia, despite the apparent presence of a hypoxic ventilatory response.

Prescription opioid use during pregnancy and risk for preterm birth or term low birthweight

2021 ◽  
Vol 17 (3) ◽  
pp. 215-225
Author(s):  
Julia D. Interrante, MPH ◽  
Stacey L. P. Scroggs, PhD ◽  
Carol J. Hogue, PhD ◽  
Jan M. Friedman, MD ◽  
Jennita Reefhuis, PhD ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Gestational Age ◽  
Low Birthweight ◽  
Opioid Analgesic ◽  
Population Based ◽  
Prescription Opioid ◽  
Opioid Use ◽  
Increased Risk ◽  
Potential Risks ◽  
Prescription Opioid Use

Objective: Examine the relationship between prescription opioid analgesic use during pregnancy and preterm birth or term low birthweight.Design, setting, and participants: We analyzed data from the National Birth Defects Prevention Study, a US multisite, population-based study, for births from 1997 to 2011. We defined exposure as self-reported prescription opioid use between one month before conception and the end of pregnancy, and we dichotomized opioid use duration by ≤7 days and 7 days.Main outcome measures: We examined the association between opioid use and preterm birth (defined as gestational age 37 weeks) and term low birthweight (defined as 2500 g at gestational age ≥37 weeks).Results: Among 10,491 singleton mother/infant pairs, 470 (4.5 percent) reported opioid use. Among women reporting opioid use, 236 (50 percent) used opioids for 7 days; codeine (170, 36 percent) and hydrocodone (163, 35 percent) were the most commonly reported opioids. Opioid use was associated with slightly increased risk for preterm birth [adjusted odds ratio, 1.4; 95 percent confidence interval, 1.0, 1.9], particularly with hydrocodone [1.6; 1.0, 2.6], meperidine [2.5; 1.2, 5.2], or morphine [3.0; 1.5, 6.1] use for any duration; however, opioid use was not significantly associated with term low birthweight.Conclusions: Preterm birth occurred more frequently among infants of women reporting prescription opioid use during pregnancy. However, we could not determine if these risks relate to the drug or to indications for use. Patients who use opioids during pregnancy should be counseled by their practitioners about this and other potential risks associated with opioid use in pregnancy. 

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