Oxygen Therapy Group Research Articles

The relationship between oxygen therapy, drug therapy, and COVID-19 mortality.

Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19). We conducted a retrospective study of COVID-19 inpatients in Wuhan Pulmonary Hospital (Wuhan, China) from January 1 to February 29, 2020. The subjects were divided into four groups due to different treatment regimes. We used the Kaplan-Meier method to determine the cumulative rates of in-hospital death and the Cox proportional hazard model to calculate the risk factors and corresponding hazard ratios. A total of 185 patients were included in this study. The median age of the patients was 62 years, including 94 men and 91 women. Kaplan-Meier analysis demonstrated that mortality was higher in older patients, higher in men, and lower in the low-flow oxygen therapy group. Body mass index (BMI) had no influence on mortality, as well as high flow oxygen therapy, Lopinavir-ritonavir (LPV/r) therapy, and the interferon-alpha add LPV/r therapy. Cox proportional hazard regression confirmed that the low flow oxygen therapy was independent protective factor for in-hospital death after adjusting for age, gender, and BMI. In conclusion, the mortality was higher in older patients, higher in men, and lower in the low-flow oxygen therapy group. BMI had no influence on mortality, as well as high flow oxygen therapy, LPV/r therapy, and interferon-alpha add LPV/r therapy.

Role of modified nasopharyngeal oxygen therapy in apnoeic oxygenation under general anaesthesia: a single-centre, randomized controlled clinical study

Apnoeic oxygenation is not only important for patients who cannot be intubated/ventilated, but also can be routinely employed when planning to secure the airway.We aimed to compare safe apnoea times between patients receiving modified nasopharyngeal oxygen therapy and those receiving high-flow nasal oxygen therapy (HFNO) following the induction of general anaesthesia.This was a single-centre, randomized controlled clinical study. Eighty-four female patients undergoing elective laparoscopic gynaecological surgery under general anaesthesia were randomly assigned to the high-flow nasal oxygen therapy group (Group HFNO) or the modified nasopharyngeal oxygen therapy group (Group Naso). A Kaplan–Meier survival curve was used to describe the apnoeic oxygenation time.The safe apnoea time of the patients in the Group Naso was higher than that of the patients in the Group HFNO (20 (19.3 to 20.0) vs. 16.5 (12.9 to 20) minutes, P < 0.05). The incidence of SpO2 < 95% in the Group Naso was lower than that in the Group HFNO; hazard ratio 0.3 (95% confidence interval 0.2 to 0.6, P < 0.0001). Modified nasopharyngeal oxygen therapy which uses far less oxygen than HFNO is a convenient and effective method of apnoeic oxygenation in normal female patients.Trial registration: https://www.chictr.org.cn, ChiCTR2000039433; date of registration: 28/10/2020.

The prospective screening for SARS-CoV-2 S1/S2 antibodies delineates the factual incidence of COVID-19 and shows a sustained serological response post COVID-19 in kidney transplant recipients

ABSTRACT Background The impact of immunosuppression on the occurrence of Coronavirus Disease 2019 (COVID-19) remains unclear. Methods We conducted a prospective screening of anti-S1/S2 IgGs against SARS-CoV-2 Spike protein from March, 1 2020 to May, 15 2021 (prior to the vaccination campaign) in a cohort of 713 kidney transplant recipients (KTRs). In a first phase, the factual incidence and seroprevalence of COVID-19 was established in this cohort: cases diagnosed by serology were added to RT-PCR-based diagnoses to obtain the overall incidence of COVID-19 in both symptomatic and asymptomatic KTRs. In the second phase, the kinetics of the post-COVID-19 humoral response were studied, taking into account the severity of the disease defined by the need for oxygen therapy (group S, ”severe”) or not (group nS, ”not severe”). Results The combined diagnostic approaches identified 138 COVID-19 cases (19.2%), with 37 diagnoses by serology (26.8%). The rate of asymptomatic KTRs reached 20.3% (28/138). Thirteen patients (9.4%) died from COVID-19. The seroconversion rate was 91.7% (99/108). The peak anti-S1/S2 IgG level was 85 [30-150] AU/ml and was similar between the S and nS groups (117 [38; 186] AU/ml versus 73 [23; 140] AU/ml). A high probability of persistence of anti-S1/S2 IgG post-COVID-19 was observed, with only 10.1% (7/69) of the patients having negated their serology during the 9-month follow-up. Conclusion Our pragmatic serological screening combined with RT-PCR tests provides a better estimation of the real incidence of COVID-19 in KTRs. A significant proportion of KTRs develop humoral immunity post COVID-19, which most often persists beyond 9 months.

Hyperbaric oxygen therapy as adjuvant treatment for surgical site infections after male-to-female gender affirmation surgery: A 10-year experience.

IntroductionSeveral urological conditions that share an impairment of tissue oxygenation can benefit from hyperbaric oxygen therapy; limited evidence is available of its impact on patients undergoing male‐to‐female gender affirmation surgery.AimTo evaluate the efficacy and safety of hyperbaric oxygen therapy as adjuvant treatment for surgical site infections in patients undergoing male‐to‐female gender affirmation surgery.MethodsThis research was conducted as an observational retrospective study. Patients undergoing male‐to‐female gender affirmation surgery at the principal investigators’ institution from January 2009 to September 2019, with a discharge diagnosis of complicated superficial or deep wound infections, were included. All patients underwent standard management of wound infection. Subjects received/not‐received hyperbaric oxygen therapy at the surgeon's discretion and were assigned to the hyperbaric oxygen therapy versus non‐hyperbaric oxygen therapy group accordingly. Complete wound healing rate (primary outcome), duration of antibiotic therapy, perineal drain time, bladder catheter time, and hospital stay were recorded. All adverse events that occurred during the study period were described.ResultsA total of 156 patients underwent male‐to‐female gender affirmation surgery in the study period. Thirty‐three patients were enrolled. Fifteen subjects belonged to the hyperbaric oxygen therapy group, the other 18 to the non‐hyperbaric oxygen therapy group. No statistically significant differences were found between the two groups at baseline. Penile inversion vaginoplasty and intestinal vaginoplasty were performed in nine (60%) and six (40%) patients of the hyperbaric oxygen therapy group. Only penile inversion vaginoplasty was performed in subjects of the non‐hyperbaric oxygen therapy group. Complete wound healing was obtained in 15 patients (100%) of the hyperbaric oxygen therapy group and 17 patients (94.4%) of the non‐hyperbaric oxygen therapy group (p = 0.35). Duration of antibiotic therapy, perineal drain time, bladder catheter time, and hospital stay were significantly lower in the hyperbaric oxygen therapy group (p < 0.05).ConclusionOur preliminary data suggest a role of hyperbaric oxygen therapy as adjuvant treatment for surgical site infection in patients undergoing male‐to‐female gender affirmation surgery. Randomized controlled trials properly powered are needed to confirm our findings.

Usefulness of monocyte distribution width and presepsin for early assessment of disease severity in COVID-19 patients.

Early predictors of severe coronavirus disease 2019 (COVID-19) would identify patients requiring intensive care. Recently, the monocyte distribution width (MDW) and presepsin level have been used for the early diagnosis of sepsis. Here, we assessed the utility of MDW and presepsin for the early assessment of COVID-19 severity.Eighty-seven inpatients with confirmed COVID-19 were enrolled and divided into 3 groups by the type of respiratory support: (1) mechanical ventilation or high-flow nasal cannula oxygen therapy (MVHF-OT), (2) conventional oxygen therapy, and (3) no oxygen therapy. We measured the complete blood count; MDW; erythrocyte sedimentation rate; and the levels of presepsin, C-reactive protein, procalcitonin, lactate dehydrogenase, ferritin, Krebs von den Lungen-6 (KL-6), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibody.Thirteen (14.9%) patients on MVHF-OT exhibited a significantly higher mortality and a longer hospital stay than did the others. The MDW and presepsin levels were significantly elevated on admission, and correlated with COVID-19 severity (both P < .001). Notably, only the MDW correlated significantly with symptoms in the no oxygen therapy group (P < .012). In the first week after admission, the MDW fell and no longer differed among the groups. The KL-6 level did not differ by disease severity at any time. Neutralizing antibodies were detected in 74 patients (91.4%) and the level of neutralization correlated significantly with COVID-19 severity (P < .001).The MDW and presepsin are useful indicators for early assessment of disease severity in COVID-19 patients.

Streamlining Patient Management of Suspected COVID-19 Patients in the Emergency Department: Incorporation of Pulmonary CT Angiography into the Triaging Algorithm.

Purpose: To evaluate the use of pulmonary computed tomography (CT) angiography during initial admission at an emergency department (ED), to identify COVID-19 patients with accompanying pulmonary embolism (PE) and its impact on clinical management. Methods: We performed a retrospective analysis of COVID-19 patients that underwent pulmonary CT angiography at the ED. CT scans were evaluated for the presence and extent of PE and for imaging changes suspicious of COVID-19. Patients were subdivided into two groups: (1) Group A consisted of patients with proven COVID-19 based on real-time polymerase chain reaction (RT-PCR), and (2) Group B of patients suspected for COVID-19, comprising patients positive on RT-PCR and/or COVID-19-suspicious CT findings. To assess the differences between patients with and without pulmonary embolism, Fisher’s exact test was used. Results: A total of 308 patients were admitted to the ED for diagnostic work-up of dyspnea and suspected COVID-19, and 95 patients underwent pulmonary CT angiography. PE was detected in 13.6% (3/22) of patients in Group A and 20.7% (6/29) in Group B. No significant differences were observed between patients with and without PE concerning hospitalization (Group B: 100% (6/6) vs. 91.3% (21/23)), the necessity of oxygen therapy (Group B: 66% (4/6) vs. 43.5% (10/23)), and death (Group B: 33% (2/6) vs. 4.3% (1/23) p > 0.05, respectively). Conclusions: In 20.7% of COVID-19 patients, PE was detected upon admission to the ED. Although the incorporation of early pulmonary CT angiography in patients suspicious of COVID-19 may be beneficial to identify concomitant PE, further studies are necessary to corroborate these findings.

Poor prognosis of patients with severe COVID-19 admitted to an infectious disease intensive care unit during the pandemic caused by the Delta variant in Japan.

During the surge of coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) delta variant, our institution operated an intensive care unit (ICU) for patients with severe COVID-19. The study aim was to determine the survival rate and treatment outcomes of patients with severe COVID-19 treated in the ICU during the surge. A total of 23 consecutive patients with severe COVID-19 were admitted to the ICU between August 5 and October 6, 2021. Patients received multidrug therapy consisting of remdesivir, tocilizumab, heparin, and methylprednisolone. The patients were divided into two groups based on the ordinal scale (OS): a non-invasive oxygen therapy (OS-6) group, and an invasive oxygen therapy (OS-7) group. There were 13 (57%) and 10 (43%) patients in the OS-7 and OS-6 groups, respectively. All patients were unvaccinated. Sixteen patients (70%) were male. The median age was 53 years; the median body mass index (BMI) was 30.3 kg/m2; and the median P/F ratio on admission was 96. The 30-day survival rate was 69% and was significantly poorer in the OS-7 group (54%) than in the OS-6 group (89%; p = 0.05). The prevalence of obesity (p = 0.05) and the Sequential Organ Failure Assessment (SOFA) score on admission (p < 0.01) were significantly higher in the OS-7 group. Seven patients in the OS-7 group (54%) developed bacteremia. A low P/F ratio on admission was a significant unfavorable prognostic factor (hazard ratio: 10.9; p = 0.03). The survival rate was poor, especially in patients requiring invasive oxygen therapy. More measures are needed to improve the treatment outcomes of patients with severe COVID 19.

High-flow nasal cannula versus conventional oxygen therapy in acute COPD exacerbation with mild hypercapnia: a multicenter randomized controlled trial

BackgroundHigh-flow nasal cannula (HFNC) can improve ventilatory function in patients with acute COPD exacerbation. However, its effect on clinical outcomes remains uncertain.MethodsThis randomized controlled trial was conducted from July 2017 to December 2020 in 16 tertiary hospitals in China. Patients with acute COPD exacerbation with mild hypercapnia (pH ≥ 7.35 and arterial partial pressure of carbon dioxide > 45 mmHg) were randomly assigned to either HFNC or conventional oxygen therapy. The primary outcome was the proportion of patients who met the criteria for intubation during hospitalization. Secondary outcomes included treatment failure (intolerance and need for non-invasive or invasive ventilation), length of hospital stay, hospital cost, mortality, and readmission at day 90.ResultsAmong 337 randomized patients (median age, 70.0 years; 280 men [83.1%]; median pH 7.399; arterial partial pressure of carbon dioxide 51 mmHg), 330 completed the trial. 4/158 patients on HFNC and 1/172 patient on conventional oxygen therapy met the criteria for intubation (P = 0.198). Patients progressed to NPPV in both groups were comparable (15 [9.5%] in the HFNC group vs. 22 [12.8%] in the conventional oxygen therapy group; P = 0.343). Compared with conventional oxygen therapy, HFNC yielded a significantly longer median length of hospital stay (9.0 [interquartile range, 7.0–13.0] vs. 8.0 [interquartile range, 7.0–11.0] days) and a higher median hospital cost (approximately $2298 [interquartile range, $1613–$3782] vs. $2005 [interquartile range, $1439–$2968]). There were no significant differences in other secondary outcomes between groups.ConclusionsIn this multi-center randomized controlled study, HFNC compared to conventional oxygen therapy did not reduce need for intubation among acute COPD exacerbation patients with mild hypercapnia. The future studies should focus on patients with acute COPD exacerbation with respiratory acidosis (pH < 7.35). However, because the primary outcome rate was well below expected, the study was underpowered to show a meaningful difference between the two treatment groups.Trial registration: NCT03003559. Registered on December 28, 2016.

The Clinical Effect of High-Flow Oxygen Therapy through the Nose on Patients with Acute Left Heart Failure and Hypoxemia.

Objective To evaluate the clinical efficacy of nasal high-flow oxygen therapy in patients with acute left heart failure and hypoxemia. Methods From July 2016 to November 2018, patients with acute left heart failure complicated with hypoxemia treated in the Department of Critical Medicine of Yantai Affiliated Hospital of Binzhou Medical University were retrospectively observed (a total of 140 cases met the inclusion criteria). They were randomly divided into two groups, with 70 cases in each group. Patients were given continuous ECG monitoring, improved blood gas analysis test, and recorded HR, RR, map, SaO2, pH, PaO2, PaCO2, and Lac, perfect examination and color Doppler echocardiography, and record NT-proBNP and EF before and 24 hours after treatment. The effective rates of the two groups before and after oxygen therapy were detected. Results There were 67 patients with high-flow oxygen therapy group improvement, 95.7% improvement rate, and 55 patients with general oxygen therapy group improvement rate. The treatment improvement rate was 78.6%. A total of 67 patients were treated with high-flow oxygen therapy. After high-flow oxygen therapy, HR (t = 18.8, P ≤ 0.05), RR (t = 19.7, P ≤ 0.05), MAP (t = 12.1, P ≤ 0.05), PaCO2 (t = 9.53, P ≤ 0.05), Lac (t = 8.69, P ≤ 0.05), and NT-proBNP (t = 7.03, P ≤ 0.05) were significantly lower than before. SaO2 (t = −12.4, P ≤ 0.05), pH (t = −12.2, P ≤ 0.05), PaO2 (t = −17.7, P ≤ 0.05), and EF (t = −13.4, P ≤ 0.05) were significantly higher than before. A total of 55 patients were in the general oxygen therapy group. After administration of ordinary oxygen therapy, HR (t = 18.2, P ≤ 0.05), RR (t = 10.8, P ≤ 0.05), MAP (t = 13.1, P ≤ 0.05), PaCO2 (t = 15.8, P ≤ 0.05), Lac (t = 7.1, P ≤ 0.05), and NT-proBNP (t = 10, P ≤ 0.05) were significantly lower than before. SaO2 (t = −15.5, P ≤ 0.05), pH (t = −4.5, P ≤ 0.05), PaO2 (t = −20, P ≤ 0.05), and EF value (t = −7.7, P ≤ 0.05) were significantly higher than before. Conclusion High-flow oxygen therapy and general oxygen therapy have an obvious curative effect on patients with acute left heart failure and hypoxemia. Compared with the two, high-flow oxygen therapy is more effective. After high-flow oxygen therapy and general oxygen therapy in patients with acute left heart failure and hypoxia, HR, RR, MAP, SaO2, pH, PaO2, PaCO2, Lac, EF, and NT-proBNP value all improved, and the improvement of high-flow oxygen therapy was greater.

How to treat patients with acute respiratory failure? Conventional oxygen therapy versus high‐flow nasal cannula in the emergency department

Objective:To investigate whether high‐flow nasal cannula oxygen therapy could reduce the rate of endotracheal intubation and improve arterial blood gas values, vital signs, and clinical outcomes of patients with hypoxemic acute respiratory failure as compared with conventional oxygen therapy alone.Methods:This retrospective, observational study was performed in the 15‐month study period and included adult patients with tachypnea and hypoxemia, whose vital signs and arterial blood gas were monitored. The high‐flow nasal cannula oxygen group consisted of patients admitted to the emergency department with acute respiratory failure when high‐flow nasal cannula oxygen treatment was available in the hospital, while the conventional oxygen therapy group consisted of patients who have presented to the emergency department with acute respiratory failure in the absence of high‐flow nasal cannula oxygen device in the hospital. The primary outcome of the study was improvement in vital signs and arterial blood gas values within first and fourth hours of the treatment. The second outcome was the need for intubation in the emergency department, length of hospital stay, and hospital mortality.Results:The decrease in the pulse and respiratory rate of high‐flow nasal cannula oxygen–treated group was significantly greater than the conventional oxygen therapy group on the first and fourth hours of treatment (p &lt; 0.001). PaO2 values were significantly higher in the high‐flow nasal cannula oxygen group at the first and fourth hours of treatment (p ⩽ 0.001). Likewise, mean SaO2 levels of patients receiving high‐flow nasal cannula oxygen treatment was significantly higher than those of patients in the conventional oxygen therapy group (p = 0.006 at 1 h and p &lt; 0.001 at 4 h). In the hypercapnic patients, the decrease in PaCO2 and increase in pH and PaO2 values were significantly greater in high‐flow nasal cannula oxygen group (p &lt; 0.001). The difference between the groups regarding the need for invasive mechanical ventilation was not statistically significant (p = 0.179).Conclusion:High‐flow nasal cannula oxygen treatment has been associated with favorable effects in vital signs and arterial blood gas values in patients with acute respiratory failure. High‐flow nasal cannula oxygen might be considered as the first‐line therapy for patients with hypoxemic and/or hypercapnic acute respiratory failure.

Effect of Noninvasive Respiratory Strategies on Intubation or Mortality Among Patients With Acute Hypoxemic Respiratory Failure and COVID-19

Continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) have been recommended for acute hypoxemic respiratory failure in patients with COVID-19. Uncertainty exists regarding the effectiveness and safety of these noninvasive respiratory strategies. To determine whether either CPAP or HFNO, compared with conventional oxygen therapy, improves clinical outcomes in hospitalized patients with COVID-19-related acute hypoxemic respiratory failure. A parallel group, adaptive, randomized clinical trial of 1273 hospitalized adults with COVID-19-related acute hypoxemic respiratory failure. The trial was conducted between April 6, 2020, and May 3, 2021, across 48 acute care hospitals in the UK and Jersey. Final follow-up occurred on June 20, 2021. Adult patients were randomized to receive CPAP (n = 380), HFNO (n = 418), or conventional oxygen therapy (n = 475). The primary outcome was a composite of tracheal intubation or mortality within 30 days. The trial was stopped prematurely due to declining COVID-19 case numbers in the UK and the end of the funded recruitment period. Of the 1273 randomized patients (mean age, 57.4 [95% CI, 56.7 to 58.1] years; 66% male; 65% White race), primary outcome data were available for 1260. Crossover between interventions occurred in 17.1% of participants (15.3% in the CPAP group, 11.5% in the HFNO group, and 23.6% in the conventional oxygen therapy group). The requirement for tracheal intubation or mortality within 30 days was significantly lower with CPAP (36.3%; 137 of 377 participants) vs conventional oxygen therapy (44.4%; 158 of 356 participants) (absolute difference, -8% [95% CI, -15% to -1%], P = .03), but was not significantly different with HFNO (44.3%; 184 of 415 participants) vs conventional oxygen therapy (45.1%; 166 of 368 participants) (absolute difference, -1% [95% CI, -8% to 6%], P = .83). Adverse events occurred in 34.2% (130/380) of participants in the CPAP group, 20.6% (86/418) in the HFNO group, and 13.9% (66/475) in the conventional oxygen therapy group. Among patients with acute hypoxemic respiratory failure due to COVID-19, an initial strategy of CPAP significantly reduced the risk of tracheal intubation or mortality compared with conventional oxygen therapy, but there was no significant difference between an initial strategy of HFNO compared with conventional oxygen therapy. The study may have been underpowered for the comparison of HFNO vs conventional oxygen therapy, and early study termination and crossover among the groups should be considered when interpreting the findings. isrctn.org Identifier: ISRCTN16912075.

High Flow Nasal Cannula Decreased Pulmonary Complications in Neurologically Critically Ill Patients.

Objective: Pulmonary complications could badly affect the recovery of neurological function and neurological prognosis of neurological critically ill patients. This study evaluated the effect of high-flow nasal cannula (HFNC) therapy on decreasing pulmonary complications in neurologically critically ill patients.Patients and Methods: The patients admitted to the intensive care unit (ICU) with serious neurological disease and receiving oxygen therapy were retrospectively reviewed (Ethical No. IRB2021-YX-001). Patients were divided into the HFNC group and the conventional oxygen therapy (COT) group. We analyzed the data within these two groups, including patients’ baseline data, short-term outcomes of respiratory complications, general outcomes including hospital stay, ICU stay and mortality, and neurological functions. To analyze the relevant factors, we performed multivariable logistic regression analysis.Results: A total of 283 patients met the criteria, including 164 cases in the HFNC group and 119 cases in the COT group. The HFNC group had remarkably less mechanical ventilation requirement with lower phlegm viscosity. Even more, ICU stay and total hospital stay were significantly shortened in the HNFC group.Conclusion: HFNC decreased pulmonary complications in neurologically critically ill patients and improved recovery of neurological function and neurological prognosis.

Non-invasive ventilation versus oxygen therapy after extubation in patients with obesity in intensive care units: the multicentre randomised EXTUB-OBESE study protocol

IntroductionPatients with obesity are considered to be at high risk of acute respiratory failure (ARF) after extubation in intensive care unit (ICU). Compared with oxygen therapy, non-invasive ventilation (NIV) may...

Effects of Oxygen Therapies in Experimental Acute Acoustic Trauma.

Background: Acute acoustic trauma is defined as a sudden sensorineural hearing loss that occurs after an exposure to acoustic overstimulation. Increasing the oxygen in perilymph can be a treatment modality. Our study aims to investigate the influence of normobaric oxygen therapy on the recovery of acute acoustic trauma and to compare it with the hyperbaric oxygen therapy.Methods:Three groups of rats (5 rats each) were exposed to white noise for 1 hour. Sensorineural hearing loss was identified using distortion product otoacoustic emission. Subsequently, the first group was treated with hyperbaric oxygen therapy, the second group was treated with normobaric oxygen therapy, and the third group did not receive any treatment and was used as a control group.Results:There was a statistically significant difference within time for frequencies of 1, 1.5, and 2 kHz, but there was no statistically significant difference between groups. For frequencies of 3, 4, 5, and 6 kHz, there was a statistically significant difference within time and between groups. Between groups, recovery of distortion product otoacoustic emission values in all frequencies was better in the control group by the third, fifth, and seventh days. Comparing the values of hyperbaric oxygen therapy and normobaric oxygen therapy groups, it was observed that by the third day, the hyperbaric oxygen therapy values were better than those of the normobaric oxygen therapy values. However, by the fifth and seventh days, the normobaric oxygen therapy values were better (except at a frequency of 1 kHz).Conclusion:Because there is a high rate of spontaneous recovery, physicians should be more selective to treat patients with oxygen therapies.

High-flow nasal cannula for reducing hypoxemic events in patients undergoing bronchoscopy: A systematic review and meta-analysis of randomized trials.

Patients undergoing bronchoscopic procedures may develop hypoxemia and severe complications. High-flow nasal cannula (HFNC) may prevent hypoxemic events during bronchoscopy. We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of HFNC in these patients. We conducted a search in PubMed, Embase, and the Cochrane Library for RCTs published before November 2021. Individual effect sizes were standardized, and a meta-analysis was performed to calculate the pooled effect size using random-effects models. The primary outcome was the incidence of hypoxemic events (oxygen saturation [SpO2] < 90%) during bronchoscopy. Secondary outcomes included the incidence of interrupted bronchoscopy due to desaturation, lowest SpO2 during bronchoscopy, partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), end-tidal CO2 (EtCO2) at the end of bronchoscopy, and the incidence of intubation after the procedure. Five trials involving 257 patients were reviewed. The incidence of hypoxemic events was lower in the HFNC group than in the conventional oxygen therapy group (risk ratio, 0.25; 95% confidence interval [CI], 0.14-0.42). The lowest SpO2 during the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (weighted mean difference [WMD], 7.12; 95% CI, 5.39-8.84). PaO2 at the end of the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (WMD, 20.36; 95% CI, 0.30-40.42). The incidence of interrupted bronchoscopy due to desaturation, PaCO2 and EtCO2 at the end of the procedure, and the incidence of intubation after the procedure were not significantly different between groups. HFNC may reduce the incidence of hypoxemic events and improve oxygenation in patients undergoing bronchoscopy.

High-flow nasal oxygenation reduces the risk of desaturation in adults receiving procedural sedation: a meta-analysis of randomized controlled trials

BackgroundProcedural sedation reduces patients’ discomfort and anxiety, facilitating performance of the examination and intervention. However, it may also cause adverse events, including airway obstruction and hypoxia. We conducted this systematic review and meta-analysis to evaluate the efficacy of high-flow nasal oxygenation (HFNO) compared with that of standard oxygen therapy in adult patients undergoing procedural sedation.MethodsWe identified randomized controlled trials published before November 2020 based on PubMed, Embase, and Cochrane Library databases and ClinicalTrials.gov registry. Intraprocedural desaturation [peripheral oxygen saturation (SpO2) < 90%] was evaluated as the primary outcome. The secondary outcomes were the lowest SpO2, need for airway intervention, oxygen therapy-related complications, and patient, operator, and anesthetist’s satisfaction.ResultsSix trials with a total of 2633 patients were reviewed. Patients using HFNO compared with standard oxygen therapy had a significantly lower risk of intraprocedural desaturation [risk ratio 0.18, 95% confidence interval (CI) 0.04-0.87]. The lowest intraprocedural SpO2 in HFNO group was significantly higher than that in standard oxygen therapy group (mean difference 4.19%, 95% CI 1.74-6.65).ConclusionsCompared with standard oxygen therapy, HFNO may reduce the risk of desaturation and increase the lowest SpO2 in adult patients undergoing sedation for medical procedures.

Modified high-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients undergoing bronchoscopy: a randomized clinical trial

BackgroundHypoxemia frequently occurs during bronchoscopy. High-flow nasal cannula (HFNC) oxygen therapy may be a feasible alternative to prevent the deterioration of gas exchange during bronchoscopy. With the convenience of clinical use in mind, we modified an HFNC using a single cannula. This clinical trial was designed to test the hypothesis that a modified HFNC would decrease the proportion of patients with a single moment of peripheral arterial oxygen saturation (SpO2) < 90% during bronchoscopy.MethodsIn this single-center, prospective randomized controlled trial, hospitalized patients in the respiratory department in need of diagnostic bronchoscopy were randomly assigned to a modified HFNC oxygen therapy group or a conventional oxygen therapy (COT) group. The primary outcome was the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy.ResultsEight hundred and twelve patients were randomized to the modified HFNC (n = 406) or COT (n = 406) group. Twenty-four patients were unable to cooperate or comply with bronchoscopy. Thus, 788 patients were included in the analysis. The proportion of patients with a single moment of SpO2 < 90% during bronchoscopy in the modified HFNC group was significantly lower than that in the COT group (12.5% vs. 28.8%, p < 0.001). There were no significant differences in the fraction of inspired oxygen between the two groups. The lowest SpO2 during bronchoscopy and 5 min after bronchoscopy in the modified HFNC group was significantly higher than that in the COT group. Multivariate analysis showed that a baseline forced vital capacity (FVC) < 2.7 L (OR, 0.276; 95% CI, 0.083–0.919, p = 0.036) and a volume of fluid instilled > 60 ml (OR, 1.034; 95% CI, 1.002–1.067, p = 0.036) were independent risk factors for hypoxemia during bronchoscopy in the modified HFNC group.ConclusionsA modified HFNC could decrease the proportion of patients with a single moment of SpO2 < 90% during bronchoscopy. A lower baseline FVC and large-volume bronchoalveolar lavage may predict desaturation during bronchoscopy when using a modified HFNC.Trial registration ClinicalTrials. Gov: NCT02606188. Registered 17 November 2015.

Evaluation of predictive factors related to the presence or absence of supplemental oxygen therapy and comparison of physical functions after video-assisted thoracic surgery.

ABSTRACTWe performed a retrospective study of 102 individuals to evaluate predictive factors for needing supplemental oxygen therapy following video-assisted thoracic surgery (VATS) and to compare patients’ physical functions before and after surgery. Prior to surgery, we evaluated quadriceps torque, 6-minute walk distance (6MWD), timed up and go test, and grip strength. During the 6MWD, patients’ oxygen saturation was recorded every minute. Quadriceps torque and 6MWD were evaluated again following surgery. The indication for supplemental oxygen therapy was determined based on desaturation (<85%) during the 6MWD in room air. A total of 14 patients needed oxygen therapy at discharge (group A), while 88 patients did not need oxygen therapy (group B). In group A, the postoperative 6MWD was repeated with supplemental oxygen. Compared with the same parameters in group B, in group A the percentage diffusing capacity for carbon monoxide was significantly lower (p=0.011), while a history of smoking (p=0.016), exercise-induced hypoxemia (EIH, p<0.001), chronic obstructive pulmonary disease (p<0.001), and interstitial pneumonia (p=0.008) were significantly higher. Logistic regression analysis showed that EIH was an independent risk factor for requiring supplemental oxygen therapy following surgery (odds ratio: 46.2, 95% CI: 9–237.1; p<0.001). In group A, patients’ minimum oxygen saturation was significantly improved by oxygen administration (83.4±3.4 vs. 87.7±3.3, p=0.002), but there was no difference in walking distance (359.5±64.2 vs. 353.6±41.6, p=0.482). Our data indicate that patients should be preoperatively evaluated to predict postoperative hypoxemia and that this evaluation could complement the prediction of postoperative need for oxygen therapy.

Are there any long-term cardio-pulmonary limitations of hospitalized Covid-19 patients?

Abstract Background The Covid-19 pandemic has affected our lives for over a year and almost 500.000 people in Austria have been infected. Although many of them only had low or mild symptoms some had to be treated in the hospital. Even months after their infection some patients complain about fatigue, exercise intolerance and dyspnoea. The aim of this study was to perform a follow-up cardiopulmonary exercise test (CPET) on those patients, at 6 months after their hospitalization to find out if there are long-term cardio-pulmonary limitations (CPL) of Covid-19. We also wanted to check if there is any difference in outcome and CPL between patients who received oxygen therapy vs. without oxygen therapy. Methods 40 patients were included into this study (16 women = 40%; 24 men = 60%). All patients were hospitalized during their infection with Covid-19 (5 patients at ICU) and underwent CPET 6±2 month after discharge. 20 patients (50%) received oxygen therapy or ventilation during their hospitalization. CPET data were assessed at rest, during exercise and at recovery. Blood parameters including NT-pro BNP were collected and an interview and examination were performed. CPL was defined as VO2% of Predicted ≤84%, VE/CO2 Slope ≥34 and RER at peak of exercise ≥1.1. Results Median age of all patients was 46 years [interquartile range (IQR): 35.3–55.8], median BMI was 26.0 m2/kg [IQR: 23.0–29.0] and the median NTproBNP was 53.1 pg/mL [IQR: 24.0–95.6]. When comparing the two groups, we found higher percentage of CPL in patients who received oxygen therapy during their hospitalization (10% with oxygen vs. 5% without oxygen). Notably, the number of patients with a BMI ≥25 m2/kg was higher in the oxygen therapy group than in those without oxygen (80% vs. 45%). The median BMI without oxygen therapy was 24.0 [IQR: 20.3–26.8] vs. 29.0 [IQR: 25.0–31.0] with oxygen therapy (p=0.004). There were no significant differences in NT-proBNP levels (p=0.545). The median VO2% of predicted was 88.0% [72.5–98.0] without oxygen therapy vs. 84.5% [IQR: 70.8–91.8] with oxygen therapy (p=0.289), the median HR percentage of predicted was 92.5% [IQR: 85.5–97.8] without oxygen therapy vs. 94.5% [IQR: 88.3–103.5] with oxygen therapy (p=0.478), the median physical performance in watt in patients without oxygen therapy was 130.0 [IQR: 108.5–197.5] vs. 135.0 [IQR: 97.0–188.3] with oxygen therapy (p=0.820). Conclusion The findings of our study did not show any statistically significant difference in long-term CPL between patients who received oxygen therapy vs. those who didn't. Therefore, other causes of the exercise intolerance and dyspnoea have to be discussed multidisciplinary. Subclinical CPL in the absence of significant clinical symptoms represent a concern after a Covid-19 infection. Overall, 7.5% of our patients showed CPL although those patients didn't have any clinical symptoms. Therefore, CPET is a good method to discover asymptomatic patients with CPL. Funding Acknowledgement Type of funding sources: None.

Observation of the curative effect of conservative oxygen therapy in mechanical ventilation of patients with severe pneumonia

To compare the effects of conservative oxygen therapy and conventional oxygen therapy on the efficacy and prognosis of mechanical ventilation support in patients with severe pneumonia. A prospective randomized controlled study were conducted, 110 patients with severe pneumonia requiring mechanical ventilation in intensive care unit (ICU) of Hefei First People's Hospital from May 2019 to May 2021 were selected and divided into conventional oxygen therapy group (51 cases) and conservative oxygen therapy group (55 cases) according to random number table method. Patients in both groups were treated with invasive to non-invasive sequential mechanical ventilation strategy, and the target of oxygen therapy in the conventional oxygen therapy group was set as the arterial partial pressure of oxygen (PaO2) > 150 mmHg (1 mmHg = 0.133 kPa) or pulse oxygen saturation (SpO2) > 0.96. In the conservative oxygen therapy group, PaO2 was set at 70-100 mmHg or SpO2 at 0.90-0.92. The changes of blood gas analysis, mechanical ventilation time, ICU stay time, ICU mortality, new organ dysfunction and infection more than 48 hours after admission were observed in two groups before and after treatment. Kaplan-Meier method was used to analyze the difference in cumulative survival rate between the two groups. After treatment, pH value, PaO2 and oxygenation index (PaO2/FiO2) in both groups were significantly higher than before treatment, and arterial partial pressure of carbon dioxide (PaCO2) was significantly lower than before treatment. pH value in the conservative oxygen therapy group was significantly higher than that in the conventional oxygen therapy group (7.4±0.1 vs. 7.3±0.3). PaO2, PaCO2 and PaO2/FiO2 were significantly lower than those in conventional oxygen therapy group [PaO2 (mmHg): 68.9±4.7 vs. 75.2±6.0, PaCO2 (mmHg): 42.1±5.6 vs. 50.5±7.5, PaO2/FiO2 (mmHg): 329±126 vs. 365±108, all P < 0.05]. The mechanical ventilation time in the conservative oxygen therapy group was significantly longer than that in the conventional oxygen therapy group (days: 19.7±3.5 vs. 13.9±4.5, P < 0.05), but there was no significant difference in ICU hospitalization time between the conservative oxygen therapy group and the conventional oxygen therapy group (days: 26.5±5.0 vs. 25.5±4.6, P > 0.05). Compared with the conventional oxygen therapy group, the ICU mortality, the incidence of nosocomial bloodstream infection, and the incidence of liver insufficiency, shock, and ICU acquired weakness (ICUAW) were decreased significantly in the conservative oxygen therapy group [ICU mortality: 27.3% (15/55) vs. 45.1% (23/51), liver insufficiency: 1.8% (1/55) vs. 7.8% (4/51), shock: 3.6% (2/55) vs. 9.8% (5/51), ICUAW: 5.5% (3/55) vs. 11.8% (6/51), the incidence of new bloodstream infection: 5.5% (3/55) vs. 11.8% (6/51), all P < 0.05]. Kaplan-Meier analysis showed that the cumulative survival rate of the conservative oxygen therapy group was significantly higher than that of the conventional oxygen therapy group (72.7% vs. 54.9%; Log-Rank test: χ2 = 4.244, P = 0.039). Conservative oxygen therapy can reduce ICU mortality, the incidence of shock, liver insufficiency, ICUAW, and bloodstream infection in patients with severe pneumonia, but prolong mechanical ventilation time.