Acute Hypoxemic Respiratory Failure Research Articles

Oxygen therapy in acute hypoxemic respiratory failure: guidelines from the SRLF-SFMU consensus conference

IntroductionAlthough largely used, the place of oxygen therapy and its devices in patients with acute hypoxemic respiratory failure (ARF) deserves to be clarified. The French Intensive Care Society (Société de Réanimation de Langue Française, SRLF) and the French Emergency Medicine Society (Société Française de Médecine d’Urgence, SFMU) organized a consensus conference on oxygen therapy in ARF (excluding acute cardiogenic pulmonary oedema and hypercapnic exacerbation of chronic obstructive diseases) in December 2023.MethodsA committee without any conflict of interest (CoI) with the subject defined 7 generic questions and drew up a list of sub questions according to the population, intervention, comparison and outcomes (PICO) model. An independent work group reviewed the literature using predefined keywords. The quality of the data was assessed using the GRADE methodology. Fifteen experts in the field from both societies proposed their own answers in a public session and answered questions from the jury (a panel of 16 critical-care and emergency medicine physicians, nurses and physiotherapists without any CoI) and the public. The jury then met alone for 48 h to write its recommendations.ResultsThe jury provided 22 statements answering 11 questions: in patients with ARF (1) What are the criteria for initiating oxygen therapy? (2) What are the targets of oxygen saturation? (3) What is the role of blood gas analysis? (4) When should an arterial catheter be inserted? (5) Should standard oxygen therapy, high-flow nasal cannula oxygen therapy (HFNC) or continuous positive airway pressure (CPAP) be preferred? (6) What are the indications for non-invasive ventilation (NIV)? (7) What are the indications for invasive mechanical ventilation? (8) Should awake prone position be used? (9) What is the role of physiotherapy? (10) Which criteria necessarily lead to ICU admission? (11) Which oxygenation device should be preferred for patients for whom a do-not-intubate decision has been made?ConclusionThese recommendations should optimize the use of oxygen during ARF.

Epidemiology of acute hypoxaemic respiratory failure in Australian and New Zealand intensive care units during 2005–2022. A binational, registry-based study

PurposeAcute hypoxaemic respiratory failure (AHRF) is a common reason for intensive care unit (ICU) admission. However, patient characteristics, outcomes, and trends over time are unclear. We describe the epidemiology and outcomes of patients with AHRF over time.MethodsIn this binational, registry-based study from 2005 to 2022, we included all adults admitted to an Australian or New Zealand ICU with an arterial blood gas within the first 24 h of ICU stay. AHRF was defined as a partial pressure of oxygen/inspired oxygen ratio (PaO2/FiO2) ≤ 300. The primary outcome was adjusted in-hospital mortality, categorised based on PaO2/FiO2 (mild: 200–300, moderate: 100–200, and severe < 100, and non-linearly). We investigated how adjusted mortality evolved based on temporal trends (by year of admission), sex, age, admission diagnosis and the receipt of mechanical ventilation.ResultsOf 1,560,221 patients, 826,106 (52.9%) were admitted with or developed AHRF within the first 24 h of ICU stay. Of these 826,106 patients, 51.4% had mild, 39.3% had moderate, and 9.3% had severe AHRF. Compared to patients without AHRF (5.3%), patients with mild (8%), moderate (14.2%) and severe (29.9%) AHRF had higher in-hospital mortality rates. As PaO2/FiO2 ratio decreased, adjusted in-hospital mortality progressively increased, particularly below an inflection point at a PaO2/FiO2 ratio of 200. The adjusted in-hospital mortality for all patients decreased over time (13.3% in 2005 to 8.2% in 2022), and this trend was similar in patients with and without AHRF.ConclusionThe healthcare burden due to AHRF may be larger than expected, and mortality rates remain high in severe AHRF. Although mortality has decreased over time, this may reflect improvements in ICU care in general, rather than specifically in AHRF. More research is required to earlier identify AHRF and stratify these patients at risk of deterioration early, and to validate our findings.

Non-Invasive Ventilation in Patients with Acute Hypoxemic Respiratory Failure

Non-Invasive Ventilation in Patients with Acute Hypoxemic Respiratory Failure

Monitoring and modulation of respiratory drive in patients with acute hypoxemic respiratory failure in spontaneous breathing.

Non-invasive respiratory support, namely, non-invasive ventilation, continuous positive airway pressure, and high-flow nasal cannula, has been increasingly used worldwide to treat acute hypoxemic respiratory failure, giving the benefits of keeping spontaneous breathing preserved. In this scenario, monitoring and controlling respiratory drive could be helpful to avoid patient self-inflicted lung injury and promptly identify those patients that require an upgrade to invasive mechanical ventilation. In this review, we first describe the physiological components affecting respiratory drive to outline the risks associated with its hyperactivation. Further, we analyze and compare the leading strategies implemented for respiratory drive monitoring and discuss the sedative drugs and the non-pharmacological approaches used to modulate respiratory drive during non-invasive respiratory support. Refining the available techniques and rethinking our therapeutic and monitoring targets can help critical care physicians develop a personalized and minimally invasive approach.

Expert perspectives on ECCO2R for acute hypoxemic respiratory failure: consensus of a 2022 European roundtable meeting

BackgroundBy controlling hypercapnia, respiratory acidosis, and associated consequences, extracorporeal CO2 removal (ECCO2R) has the potential to facilitate ultra-protective lung ventilation (UPLV) strategies and to decrease injury from mechanical ventilation. We convened a meeting of European intensivists and nephrologists and used a modified Delphi process to provide updated insights into the role of ECCO2R in acute respiratory distress syndrome (ARDS) and to identify recommendations for a future randomized controlled trial.ResultsThe group agreed that lung protective ventilation and UPLV should have distinct definitions, with UPLV primarily defined by a tidal volume (VT) of 4–6 mL/kg predicted body weight with a driving pressure (ΔP) ≤ 14–15 cmH2O. Fourteen (93%) participants agreed that ECCO2R would be needed in the majority of patients to implement UPLV. Furthermore, 10 participants (majority, 63%) would select patients with PaO2:FiO2 > 100 mmHg (> 13.3 kPa) and 14 (consensus, 88%) would select patients with a ventilatory ratio of > 2.5–3. A minimum CO2 removal rate of 80 mL/min delivered by continuous renal support machines was suggested (11/14 participants, 79%) for this objective, using a short, double-lumen catheter inserted into the right internal jugular vein as the preferred vascular access. Of the participants, 14/15 (93%, consensus) stated that a new randomized trial of ECCO2R is needed in patients with ARDS. A ΔP of ≥ 14–15 cmH2O was suggested by 12/14 participants (86%) as the primary inclusion criterion.ConclusionsECCO2R may facilitate UPLV with lower volume and pressures provided by the ventilator, while controlling respiratory acidosis. Since recent European Society of Intensive Care Medicine guidelines on ARDS recommended against the use of ECCO2R for the treatment of ARDS outside of randomized controlled trials, new trials of ECCO2R are urgently needed, with a ΔP of ≥ 14–15 cmH2O suggested as the primary inclusion criterion.

Characterization of anisotropic pore structure and dense selective layer of capillary membranes for long-term ECMO by cross-sectional ion-milling method.

Since the COVID-19 pandemic of 2020-2023, extracorporeal membrane oxygenator (ECMO) has attracted considerable attention worldwide. It is expected that ECMO with long-term durability is put into practical use in order to prepare for next emerging infectious diseases and to facilitate manufacturing for novel medical devices. Polypropylene (PP) and polymethylpentene (PMP) capillary membranes are currently the mainstream for gas exchange membrane for ECMO. ECMO support days for COVID-19-related acute hypoxemic respiratory failure have been reported to be on average for 14 or 24days. It is necessary to improve opposing functions such that promoting the permeation of oxygen and carbon dioxide and inhibiting the permeation of water vapor or plasma to develop sufficient durability for long-term use. For this purpose, accurately controlling the anisotropy of the pore structure of the entire cross section and functions of capillary membrane is significant. In this study, we focused on the cross-sectional ion-milling (CSIM) method, to precisely clarify the pore structure of the entire cross section of capillary membrane for ECMO, because there is less physical stress on the porous structure applied during the preparation of cross-sectional samples of porous capillary membranes. We attempted to observe the cross sections of commercially available PMP membranes using the CSIM method. As a result, we succeeded in fabricating fine-scale flat cross-sectional samples of PMP capillary membranes. The pore structures and the degree of anisotropy of the cross sections are quantitatively clarified. The achievements and the approaches of this study are being applied to the development of next-generation gas exchange membranes.

Longitudinal transcriptomic analysis reveals persistent enrichment of iron homeostasis and erythrocyte function pathways in severe COVID-19 ARDS.

The acute respiratory distress syndrome (ARDS) is a common complication of severe COVID-19 and contributes to patient morbidity and mortality. ARDS is a heterogeneous syndrome caused by various insults, and results in acute hypoxemic respiratory failure. Patients with ARDS from COVID-19 may represent a subgroup of ARDS patients with distinct molecular profiles that drive disease outcomes. Here, we hypothesized that longitudinal transcriptomic analysis may identify distinct dynamic pathobiological pathways during COVID-19 ARDS. We identified a patient cohort from an existing ICU biorepository and established three groups for comparison: 1) patients with COVID-19 ARDS that survived hospitalization (COVID survivors, n = 4), 2) patients with COVID-19 ARDS that did not survive hospitalization (COVID non-survivors, n = 5), and 3) patients with ARDS from other causes as a control group (ARDS controls, n = 4). RNA was isolated from peripheral blood mononuclear cells (PBMCs) at 4 time points (Days 1, 3, 7, and 10 following ICU admission) and analyzed by bulk RNA sequencing. We first compared transcriptomes between groups at individual timepoints and observed significant heterogeneity in differentially expressed genes (DEGs). Next, we utilized the likelihood ratio test to identify genes that exhibit different patterns of change over time between the 3 groups and identified 341 DEGs across time, including hemoglobin subunit alpha 2 (HBA1, HBA2), hemoglobin subunit beta (HBB), von Willebrand factor C and EGF domains (VWCE), and carbonic anhydrase 1 (CA1), which all demonstrated persistent upregulation in the COVID non-survivors compared to COVID survivors. Of the 341 DEGs, 314 demonstrated a similar pattern of persistent increased gene expression in COVID non-survivors compared to survivors, associated with canonical pathways of iron homeostasis signaling, erythrocyte interaction with oxygen and carbon dioxide, erythropoietin signaling, heme biosynthesis, metabolism of porphyrins, and iron uptake and transport. These findings describe significant differences in gene regulation during patient ICU course between survivors and non-survivors of COVID-19 ARDS. We identified multiple pathways that suggest heme and red blood cell metabolism contribute to disease outcomes. This approach is generalizable to larger cohorts and supports an approach of longitudinal sampling in ARDS molecular profiling studies, which may identify novel targetable pathways of injury and resolution.

Prolonged vs shorter awake prone positioning for COVID-19 patients with acute respiratory failure: a multicenter, randomised controlled trial

PurposeAwake prone positioning has been reported to reduce endotracheal intubation in patients with coronavirus disease 2019 (COVID-19)-related acute hypoxemic respiratory failure (AHRF). However, it is still unclear whether using the awake prone positioning for longer periods can further improve outcomes.MethodsIn this randomized, open-label clinical trial conducted at 12 hospitals in China, non-intubated patients with COVID-19-related AHRF were randomly assigned to prolonged awake prone positioning (target > 12 h daily for 7 days) or standard care with a shorter period of awake prone positioning. The primary outcome was endotracheal intubation within 28 days after randomization. The key secondary outcomes included mortality and adverse events.ResultsIn total, 409 patients were enrolled and randomly assigned to prolonged awake prone positioning (n = 205) or standard care (n = 204). In the first 7 days after randomization, the median duration of prone positioning was 12 h/d (interquartile range [IQR] 12–14 h/d) in the prolonged awake prone positioning group vs. 5 h/d (IQR 2–8 h/d) in the standard care group. In the intention-to-treat analysis, intubation occurred in 35 (17%) patients assigned to prolonged awake prone positioning and in 56 (27%) patients assigned to standard care (relative risk 0.62 [95% confidence interval (CI) 0.42–0.9]). The hazard ratio (HR) for intubation was 0.56 (0.37–0.86), and for mortality was 0.63 (0.42–0.96) for prolonged awake prone positioning versus standard care, within 28 days. The incidence of pre-specified adverse events was low and similar in both groups.ConclusionProlonged awake prone positioning of patients with COVID-19-related AHRF reduces the intubation rate without significant harm. These results support prolonged awake prone positioning of patients with COVID-19-related AHRF.

Efficacy of high-flow nasal oxygen therapy started in the emergency room versus conventional oxygen therapy in patients with acute hypoxaemic respiratory distress: protocol for a French multicentric, prospective, open and randomised superiority study protocol (HIFLOWED)

IntroductionAcute respiratory failure is a life-threatening condition frequently found in the emergency department. High-flow nasal oxygen (HFNO) is increasingly used in emergency departments for patients with hypoxaemic acute respiratory failure....

Positioning therapy for intensive care patients

The current S3 guideline, "Positioning Therapy and Mobilization of Critically Ill Patients in Intensive Care Units", introduces methodological changes and substantive updates compared to the previous version. Additionally, new evidence-based insights with specified PICO questions have been integrated, aiming for a more precise application of recommendations in clinical practice and thus enhancing the care of critically ill patients.A notable aspect is the more nuanced approach to early mobilization, which is recommended to commence within the first 72 hours of ICU admission. A staged concept and score-based mobilization schema facilitate improved patient rehabilitation. Mobilization should be standard of care, i.e., immobilization should be ordered by the physician. The guideline provides suggestions for the duration and additional mobilization measures to ensure patients stand, transfer actively from bed to chair, or walk as frequently as possible. These recommendations apply even during ECMO therapy, highlighting the importance of early mobilization.Further updates include semi-recumbent positions of at least 40° in intubated patients, with careful consideration of potential side effects. Continuous lateral rotation therapy (CLRT) is not advised due to the progress in intensive care therapy, shifting from deep sedation toward responsive patient management.Prone positioning (PP) involves rotating the patient 180° onto the ventral side. It is recommended as a therapeutic option for invasively ventilated patients with ARDS and impaired arterial oxygenation (PaO2/FiO2 <150mmHg), with a recommended minimum duration of 12 hours, ideally 16 hours. Special recommendations apply, for example, to COVID-19 patients with acute hypoxemic respiratory failure, where awake proning should be considered.Additionally, new chapters have been introduced focusing on assistive devices and neuromuscular electrical stimulation.

Pulmonary benign metastasizing leiomyoma presenting as acute hypoxemic respiratory failure: a case report

Pulmonary benign metastasizing leiomyoma is an uncommon condition, predominantly affecting women of childbearing age with a history of uterine smooth muscle tumors and uterine leiomyoma surgery for uterine leiomyoma. The progression of PBML is often unpredictable and depends on the extent of lung involvement. Generally, most patients remain asymptomatic, but a minority may experience coughing, wheezing, or shortness of breath, which are frequently misdiagnosed as pneumonia. consequently, this presents significant challenges in both treatment and nursing care before diagnosis. This paper reports the case of a 35-year-old woman primarily diagnosed with acute hypoxic respiratory failure who was transferred from the emergency room to the intensive care unit. The initial computed tomography scan of the patient’s lungs indicated diffuse interstitial pneumonia, but the sequencing of the alveolar lavage fluid pathogen macro did not detect any bacteria, fungi, or viruses. Moreover, the patient remained in a persistent hypoxic state before the definitive diagnosis. Therefore, our focus was on maintaining the airway patency of the patient, using prone ventilation, inhaling nitric oxide, monitoring electrical impedance tomography, and preventing ventilator-associated pneumonia to improve oxygenation, while awaiting immunohistochemical staining of the patient’s biopsied lung tissue. This would help us clarify the diagnosis and treat it based on etiology. After meticulous treatment and nursing care, the patient was weaned off the ventilator after 26 days and transferred to the respiratory ward after 40 days. This case study may serve as a reference for clinical practice and assist patients suffering from PBML.

Optimizing Positive End-Expiratory Pressure Based on Intra-Abdominal Pressure in Patients with Acute Respiratory Failure.

Positive end-expiratory pressure (PEEP) is a crucial component of mechanical ventilation to improve oxygenation in critically ill patients with respiratory failure. The interaction between abdominal and thoracic compartment pressures is known well. Especially in intra-abdominal hypertension, lower PEEP may cause atelectotrauma by repetitive opening and closing of alveoli. In this study, it was aimed to investigate the effect of PEEP adjustment according to the intra-abdominal pressure (IAP) on oxygenation and clarify possible harms. Patients older than 18 were mechanically ventilated due to hypoxemic respiratory failure and had normal IAP (<15 mmHg) included in the study. Patients with severe cardiovascular dysfunction were excluded. The following PEEP levels were applied: PEEPzero of 0 cmH2O, PEEPIAP/2 = 50% of IAP, and PEEPIAP = 100% of IAP. After a 30-minute equilibration period, arterial blood gases and mean arterial pressures were measured. One hundred thirty-eight patients (mean age 66.5 ± 15.9, 56.5% male) enrolled on the study. The mean IAP was 9.8 ± 3.4. Seventy-nine percent of the patients' PaO2/FiO2 ratio was under 300 mmHg. Figure 1 shows the change in PaO2/FiO2 ratio, PaCO2, PPlato, and MAP of the patients according to the PEEP levels. Overall increases were detected in the PaO2/FiO2 ratio (P < 0.001) and Pplato (P < 0.001), while PaCO2 and MAP did not change after increasing PEEP gradually. Pairwise analyses revealed differences in PaO2/FiO2 between PEEPzero (186.4 [85.7-265.8]) and PEEPIAP/2 (207.7 [101.7-292.9]) (t = -0.77, P < 0.001), between baseline and PEEPIAP (236.1 [121.4-351.0]) (t = -1.7, P < 0.001), and between PEEPIAP/2 and PEEPIAP (t = -1.0, P < 0.001). Plato pressures were in the safe range (<30 cmH2O) at all three PEEP levels (PEEPzero = 12 [10-15], PEEPIAP/2 = 15 [13-18], PEEPIAP = 17 [14-22]). In patients with acute hypoxemic respiratory failure and mechanically ventilated, PEEP adjustment according to the IAB improves oxygenation, especially in the settings of the limited source where other PEEP titration methods are absent.

Cambios longitudinales en el índice de ROX y el puntaje de HACOR en pacientes críticos con insuficiencia respiratoria aguda por COVID-19 que requirieron cánula nasal de alto flujo: estudio de cohorte retrospectivo

ObjectivesValidate the IROX and HACOR scores, including their deltas, in determining their success, defined as survival and the need for intubation. DesignRetrospective cohort study involving 115 patients admitted to intensive care for acute hypoxemic respiratory failure (AHRF) and treated with high-flow nasal cannula (HFNC). Materials and methodsIROX and HACOR scores were evaluated at the initiation of HFNC use and at 24hours (delta). BackgroundIn patients with AHRF due to SARS-CoV-2, the study aimed to determine the success of HFNC by evaluating this index and score and their respective deltas at 24hours. ResultsAt 24hours, the IROX was higher in the success group (6.53 [4.80-10.44] vs. 4.76 [4.11-5.90]) and the HACOR was lower (4 [2-6] vs. 6 [5-6.75]), both results being significant (p=<0.001). The D-ROX was positively associated with survival (47.37 [-1.89-136.11] vs. 5.06 [-16.85-34.25]; p=0.002), contrary to the D-HACOR (-25 [-66.67-0] vs. 0 [-16.67-16.67]; p=<0.001). Multivariate analysis of D-IROX (HR=0.99, 95%CI [0.99-1], p=0.001) and D-HACOR (HR=1.01, 95%CI [1-1.01], p=0.001) indicated that both are valid predictors of survival and failure. ConclusionThe IROX and HACOR scores at 24hours, along with their deltas, are good predictors of success.

Outcome of Early Initiation of High-flow Nasal Oxygen Therapy among Pneumonia Patients Presenting with Acute Hypoxemic Respiratory Failure.

High-flow nasal oxygen (HFNO) therapy is an upcoming and beneficial modality for patients with acute hypoxemic respiratory failure (AHRF). To evaluate whether early use of HFNO in pneumonia patients with AHRF can reduce the need for invasive ventilation. In this prospective, randomized controlled trial, 160 patients who fulfilled the criteria were included. The patient's characteristics, sequential organ failure assessment score, and simplified acute physiology score were recorded. Respiratory rate (RR), and oxygenation parameters (PaO2/FiO2), and RR-oxygenation index at selected time intervals were collected and analyzed. The primary outcome was the number of patients who needed intubation. Secondary outcomes included length of intensive care unit (ICU) and hospital stay and mortality at day 28. The rate of intubation was not statistically significant between the two groups 15 vs 18.7%; difference 3.7% [(95% confidence interval (CI): 2.5-5.7%]. In 48-hour time periods, the mean PaO2/FiO2 ratio was significantly increased in the HFNO group compared with the non-invasive ventilation (NIV) group. The RRs and heart rate (HR) showed a significant decrease in the HFNO group.The length of ICU and hospital stays was not different between both groups. No significant differences were found in mortality rates between the HFNO and NIV groups 9 (11.2%) and 10 (12.5%), with 1.3% (95% CI: 0.7-3.8%) (p = 0.21). Multivariate analysis demonstrated that low baseline PaO2/FiO2, Respiratory rate-oxygenation index (ROX index) ≤ 5.4 measured at 12 hour and high severity scores were independent risk factors for intubation. Treatment with HFNO did not reduce the need for intubation among patients with pneumonia-induced AHRF, despite the improved PaO2/FiO2 observed with HFNO compared with NIV. NCT05809089. Magdy DM. Outcome of Early Initiation of High-flow Nasal Oxygen Therapy among Pneumonia Patients Presenting with Acute Hypoxemic Respiratory Failure. Indian J Crit Care Med 2024;28(8):753-759.

Noninvasive ventilation on reintubation in patients with obesity and hypoxemic respiratory failure following abdominal surgery: a post hoc analysis of a randomized clinical trial.

Although noninvasive ventilation (NIV) may reduce reintubation in patients with acute hypoxemic respiratory failure following abdominal surgery, this strategy has not been specifically assessed in patients with obesity. We conducted a post hoc analysis of a multicenter randomized controlled trial comparing NIV delivered via facial mask to standard oxygen therapy among patients with obesity and acute hypoxemic respiratory failure within 7 days after abdominal surgery. The primary outcome was reintubation within 7 days. Secondary outcomes were invasive ventilation-free days at day 30, intensive care unit (ICU)-acquired pneumonia and 30-day survival. Among 293 patients with hypoxemic respiratory failure following abdominal surgery, 76 (26%) patients had obesity and were included in the intention-to-treat analysis. Reintubation rate was significantly lower with NIV (13/42, 31%) than with standard oxygen therapy (19/34, 56%) within 7 days (absolute difference: - 25%, 95% confidence interval (CI) - 49 to - 1%, p = 0.03). NIV was associated with significantly more invasive ventilation-free days compared with standard oxygen therapy (27.1 ± 8.6 vs 22.7 ± 11.1days; p = 0.02), while fewer patients developed ICU-acquired pneumonia (1/42, 2% vs 6/34, 18%; p = 0.04). The 30-day survival was 98% in the NIV group (41/42) versus 85% in the standard oxygen therapy (p = 0.08). In patients with body mass index (BMI) < 30kg/m2, no significant difference was observed between NIV (36/105, 34%) and standard oxygen therapy (47/109, 43%, p = 0.03). An interaction test showed no statistically significant difference between the two subsets (BMI ≥ 30kg/m2 and BMI < 30kg/m2). Among patients with obesity and hypoxemic respiratory failure following abdominal surgery, use of NIV compared with standard oxygen therapy reduced the risk of reintubation within 7 days, contrary to patients without obesity. However, no interaction was found according to the presence of obesity or not, suggesting either a lack of power to conclude in the non-obese subgroup despite existing differences, or that the statistical difference found in the overall sample was driven by a large effect in the obese subsets.

Lower or higher oxygenation targets in the intensive care unit: an individual patient data meta-analysis

PurposeOptimal oxygenation targets for patients with acute hypoxemic respiratory failure in the intensive care unit (ICU) are not clearly defined due to substantial variability in design of previous trials. This study aimed to perform a pre-specified individual patient data meta-analysis of the Handling Oxygenation Targets in the ICU (HOT-ICU) and the Handling Oxygenation Targets in coronavirus disease 2019 (COVID-19) (HOT-COVID) trials to compare targeting a partial pressure of arterial oxygen (PaO2) of 8–12 kPa in adult ICU patients, assessing both benefits and harms.MethodsWe assessed 90-day all-cause mortality and days alive without life support in 90 days using a generalised mixed model. Heterogeneity of treatment effects (HTE) was evaluated in 14 subgroups, and results graded using the Instrument to assess the Credibility of Effect Modification Analyses (ICEMAN).ResultsAt 90 days, mortality was 40.4% (724/1792) in the 8 kPa group and 40.9% (733/1793) in the 12 kPa group (risk ratio, 0.99; 95% confidence interval [CI] 0.92–1.07; P = 0.80). No difference was observed in number of days alive without life support. Subgroup analyses indicated more days alive without life support in COVID-19 patients targeting 8 kPa (P = 0.04) (moderate credibility), and lower mortality (P = 0.03) and more days alive without life support (P = 0.02) in cancer-patients targeting 12 kPa (low credibility).ConclusionThis study reported no overall differences comparing a PaO2 target of 8–12 kPa on mortality or days alive without life support in 90 days. Subgroup analyses suggested HTE in patients with COVID-19 (moderate credibility) and cancer (low credibility).

High-flow nasal cannula oxygen therapy for mild-moderate acute respiratory failure in patients with blunt chest trauma: An exploratory descriptive study

ObjectiveThe use of high-flow nasal cannula (HFNC) oxygen therapy is gaining popularity for the treatment of acute respiratory failure (ARF). However, limited evidence exists regarding the effectiveness of HFNC for hypoxemic ARF in patients with blunt chest trauma (BCT). MethodsThis retrospective analysis focused on BCT patients with mild-moderate hypoxemic ARF who were treated with either HFNC or non-invasive ventilation (NIV) in the emergency medicine department from January 2021 to December 2022. The primary endpoint was treatment failure, defined as either invasive ventilation, or a switch to the other study treatment (NIV for patients in the NFNC group, and vice-versa). ResultsA total of 157 patients with BCT (72 in the HFNC group and 85 in the NIV group) were included in this study. The treatment failure rate in the HFNC group was 11.1% and 16.5% in the NIV group - risk difference of 5.36% (95% CI, −5.94–16.10%; P = 0.366). The most common cause of failure in the HFNC group was aggravation of respiratory distress. While in the NIV group, the most common reason for failure was treatment intolerance. Treatment intolerance in the HFNC group was significantly lower than that in the NIV group (1.4% vs 9.4%, 95% CI 0.40–16.18; P = 0.039). Univariate logistic regression analysis showed that chronic respiratory disease, abbreviated injury scale score (chest) (≥3), Acute Physiology and Chronic Health Evaluation II score (≥15), partial arterial oxygen tension /fraction of inspired oxygen (≤200) at 1 h of treatment and respiratory rate (≥32 /min) at 1 h of treatment were risk factors associated with HFNC failure. ConclusionIn BCT patients with mild-moderate hypoxemic ARF, the usage of HFNC did not lead to higher rate of treatment failure when compared to NIV. HFNC was found to offer better comfort and tolerance than NIV, suggesting it may be a promising new respiratory support therapy for BCT patients with mild-moderate ARF.

Factor for Predicting Non-Invasive Ventilation Failure in Very Old Patients with Hypoxemic Respiratory Failure in Intensive Care Unit

Aims: This study aimed to investigate the efficacy of NIV in patients with pneumonia-associated acute hypoxemic respiratory failure (AHRF) and to identify factors that predict NIV failure. Methods: A total of 50 very elderly patients (aged 85 and older) with pneumonia-associated AHRF were retrospectively evaluated from January 2021 to August 2022. Failure of NIV was defined was characterized by a transition to mechanical ventilation (either through tracheal intubation or tracheostomy), discharge under "hopeless" conditions while still on NIV, or death during NIV. Results: The mean age of the patients was 87.4±2.4 years, median SOFA score was 5, median duration of NIV was 4 days, and median length of stay in the ICU for the patients was 7 days. It was determined that 48% of the patients experienced NIV failure due to worsening clinical conditions. The SOFA score, levels of procalcitonin, CRP, heart rate, and respiratory rate were higher in the NIV failure group compared to the NIV successful group. An increased SOFA score (OR= 1.51, 95% CI= 1.11-2.06, p= 0.009), elevated CRP levels (OR= 1.03, 95% CI= 1.01-1.05, p= 0.003), and increased respiratory rate (OR= 1.18, 95% CI= 1.01-1.38, p= 0.039) were identified as independent predictors of NIV failure. Conclusion: In very elderly patients with AHRF due to pneumonia, the use of NIV may offer a significant survival benefit if patients are closely monitored and potential risk factors such as systemic inflammation parameters, SOFA score, and respiratory rate are considered.

Oxygenation Index and Oxygen Saturation Index for Predicting Postoperative Outcome in Patients Undergoing Emergency Surgery: A Prospective Cohort Study.

The OI was originally evaluated as a prognostic tool for acute hypoxemic respiratory failure in children and was an independent predictor for mortality in adult patients with acute respiratory distress syndrome (ARDS). Oxygenation index and OSI of 201 adult patients undergoing emergency surgery were evaluated at different time points. The primary objective of this study was to find the correlation between OI and OSI. The secondary objectives were to find the prognostic utility of OI and OSI for postoperative mechanical ventilation and mortality. Significant statistical correlation was found between OI and OSI both at the beginning (r 2 = 0.61; p < 0.001) and immediately after surgery (r 2 = 0.47; p < 0.001). Oxygen saturation index at the beginning [area under the receiver operating characteristics curve (AUROC) (95% CI) 0.76 (0.62-0.89); best cutoff 3.9, sensitivity 64% and specificity 45%] and immediately after surgery [AUROC (95% CI) 0.82 (0.72-0.92); best cutoff 3.57, sensitivity 79%, and specificity 62%] were reasonable predictors of the requirement of invasive ventilatory support. Exploratory analysis reported that older age (p = 0.02), higher total leukocyte count (p = 0.002), higher arterial lactate (p = 0.02), and higher driving pressure (p < 0.001) were independently associated with hospital mortality. In adult patients undergoing emergency laparotomy under general anesthesia, OI and OSI were found to be correlated. Both metrics demonstrated reasonable accuracy in predicting the need for invasive ventilatory support beyond 24 hours and hospital mortality. Thakuria R, Ernest EE, Chowdhury AR, Pangasa N, Kayina CA, Bhattacharjee S, et al. Oxygenation Index and Oxygen Saturation Index for Predicting Postoperative Outcome in Patients Undergoing Emergency Surgery: A Prospective Cohort Study. Indian J Crit Care Med 2024;28(7):645-649.

Hypoxaemic respiratory failure and awake prone ventilation (HYPER-AP) - Protocol for randomized, controlled clinical trial

BackgroundAwake prone positioning is studied extensively during Covid-19 pandemic, but there is very limited evidence on its utility in acute hypoxic respiratory failure caused by bacterial infections or other causes. The aim of our research is to evaluate the impact of awake prone positioning on outcomes in non-intubated adult patients with acute non-Covid19 hypoxemic respiratory failure. MethodsThis is a multi-center randomized controlled trial (RCT) with a parallel-group design and a 1:1 allocation ratio. Adult patients, admitted to ICU and diagnosed with hypoxemic respiratory failure will be randomly allocated into intervention (awake prone position (APP)) or control group. Our hypothesis is that addition of awake prone positioning to standard oxygen, high flow oxygen therapy and non-invasive ventilation may reduce the need for mechanical ventilation in adult patients diagnosed with acute hypoxemic respiratory failure. Primary outcome is rate of endotracheal intubation; secondary outcomes include intensive care and hospital mortality, duration of mechanical ventilation, length of intensive care and hospital stay and health related quality of life post hospital discharge. Primary and secondary outcomes will be assessed at hospital discharge, 30, 90 days and 1 year following randomisation. ConclusionThe Hyper-AP study will assess the superiority of awake prone positioning versus standard treatment in spontaneously breathing ICU patients diagnosed with hypoxaemic respiratory failure.