BACKGROUND: We evaluated the influence of different partial carbon dioxide pressure (PaCO2) levels on organ perfusion in patients with respiratory failure receiving pressure-support ventilation with veno-venous extracorporeal membrane oxygenation (V-V ECMO).
METHODS: In this twelve patients prospective study, ECMO gas-flow was decreased from baseline (PaCO2 < 40 mmHg) until PaCO2 increased by 5-10 mmHg (High-CO2 phase). Resistance indices of gut, spleen, and snuffbox artery, the peripheral perfusion index (PPI), and heart rate variability were measured at baseline and High-CO2 phase.
RESULTS: When PaCO2 increased from 36 (36-37) mmHg at baseline to 42 (41-43) mmHg in the High-CO2 phase (p < 0.001), PPI decreased significantly (p = 0.026). The snuffbox artery (p = 0.022), superior mesenteric artery (p = 0.042), and spleen (p = 0.012) resistance indices increased significantly. The root mean square of successive differences (RMSSD) decreased from 19.5(18.1-22.7) to 15.9(14.4-18.6) ms (p = 0.034), and the ratio of low-frequency to high-frequency components(LF/HF) increased from 0.47 ± 0.23 to 0.70 ± 0.38 (p = 0.013).
CONCLUSIONS: High PaCO2 might cause decreased peripheral tissue and visceral organ perfusion through autonomic nervous system in patients with respiratory failure undergoing PSV with V-V ECMO.

Objective: To summarize the effects of disease-modifying drugs for spinal muscular atrophy (SMA) on the ventilation support of type 1 children after acute respiratory failure. Methods: A case-control study was conducted, including the data of clinical characteristics, medication and ventilation supports of 38 SMA patients of type 1 with pneumonia and acute respiratory failure hospitalized in Children\'s Hospital Affiliated to Capital Institute of Pediatrics from January 2020 to July 2023. Children were divided into the treatment group and the untreated group based on whether they started and persisted in using Nusinersen or Risdiplam or not before hospitalization. The differences of ventilation support between the 2 groups were analyzed. The children of the treatment group were divided into the improved group and the unimproved group based on whether they could be avoid of prolonged dependence on continuous mechanical ventilation in the next six months after discharge. The differences in clinical characteristics between the two groups were analyzed. T-test and χ2 test were used for comparison. Results: Among the enrolled children, 19 were male and 19 were female. The age was 1.3 (0.6, 2.0) years at the time of hospitalization due to pneumonia. There were 26 cases in the treatment group and 12 cases in the untreated group. The treatment group had a higher proportion of patients without prolonged dependence on continuous mechanical ventilation in the next six months after discharge (69% (18/26) vs. 2/12, χ2=9.10, P<0.05). Eighteen children were improved among the treated group, while 8 children were not. The improved group had a larger age of first onset of acute respiratory failure (1.6 (0.4, 3.4) vs. 0.5 (0.3, 0.7) years, Z=2.07, P<0.05), a longer duration of medication taken before hospitalization (3.6 (2.4, 8.7) vs. 1.2 (1.2, 2.4) months, t=2.74, P<0.05), and a smaller proportion with underlying diseases (1/18 vs. 6/8, χ2=13.58, P<0.05). Conclusions: SMA disease-modifying drugs are useful for type 1 children to avoid of prolonged dependence on continuous mechanical ventilation after acute respiratory failure. The patients who take medication longer, or have acute respiratory failure for the first-time at an older age, or without underlying diseases are more likely to avoid of.
目的： 总结脊髓性肌萎缩（SMA）疾病修正药物对1型患儿在急性呼吸衰竭后通气支持需求的影响。 方法： 病例对照研究，纳入2020年1月至2023年7月于首都儿科研究所附属儿童医院呼吸内科因肺炎并急性呼吸衰竭住院的38例1型SMA患儿的临床特征、用药及通气支持需求情况。根据住院前是否开始并坚持使用诺西那生或利司扑兰分为治疗组和未治疗组；根据治疗组患儿出院后半年能否脱离长期持续依赖机械通气分为改善组与未改善组。组间比较采用独立样本t检验、χ2检验。 结果： 38例患儿中男女各19例，因肺炎住院年龄1.3（0.6，2.0）岁。治疗组26例、未治疗组12例，治疗组出院半年后无需长期持续依赖机械通气者比例高于未治疗组［69%（18/26）比2/12，χ2=9.10，P<0.05］。改善组18例、未改善组8例，改善组首次发生急性呼吸衰竭的年龄更大［1.6（0.4，3.4）比0.5（0.3，0.7）岁，Z=2.07，P<0.05］，用药时间更长［3.6（2.4，8.7）比1.2（1.2，2.4）月，t=2.74，P<0.05］，合并基础疾病比例更小（1/18比6/8，χ2=13.58，P<0.05）。 结论： SMA疾病修正药物有助于1型患儿在急性呼吸衰竭后避免长期持续依赖机械通气，坚持更长时间用药、首次发生急性呼吸衰竭年龄更大、无基础疾病者更有可能避免。.

BACKGROUND: The ratio (E/Ea) of mitral Doppler inflow velocity to annular tissue Doppler wave velocity by transthoracic echocardiography and diaphragmatic excursion (DE) by diaphragm ultrasound have been confirmed to predict extubation outcomes. However, few studies focused on the predicting value of E/Ea and DE at different positions during a spontaneous breathing trial (SBT), as well as the effects of △E/Ea and △DE (changes in E/Ea and DE during a SBT).
METHODS: This study was a reanalysis of the data of 60 difficult-to-wean patients in a previous study published in 2017. All eligible participants were organized into respiratory failure (RF) group and extubation success (ES) group within 48 h after extubation, or re-intubation (RI) group and non-intubation (NI) group within 1 week after extubation. The risk factors for respiratory failure and re-intubation including E/Ea and △E/Ea, DE and △DE at different positions were analyzed by multivariate logistic regression, respectively. The receiver operating characteristic (ROC) curves of E/Ea (septal, lateral, average) and DE (right, left, average) were compared with each other, respectively.
RESULTS: Of the 60 patients, 29 cases developed respiratory failure within 48 h, and 14 of those cases required re-intubation within 1 week. Multivariate logistic regression showed that E/Ea were all associated with respiratory failure, while only DE (right) and DE (average) after SBT were related to re-intubation. There were no statistic differences among the ROC curves of E/Ea at different positions, nor between the ROC curves of DE. No statistical differences were shown in △E/Ea between RF and ES groups, while △DE (average) was remarkably higher in NI group than that in RI group. However, multivariate logistic regression analysis showed that △DE (average) was not associated with re-intubation.
CONCLUSIONS: E/Ea at different positions during a SBT could predict postextubation respiratory failure with no statistical differences among them. Likewise, only DE (right) and DE (average) after SBT might predict re-intubation with no statistical differences between each other.

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.

OBJECTIVE: Awake 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.
METHODS: In 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.
RESULTS: In 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.
CONCLUSIONS: Prolonged 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.

UNASSIGNED: Compared with Human Immunodeficiency Virus (HIV) patients, non-HIV patients with Pneumocystis pneumonia (PCP) have more rapid onset, more rapid progression, and higher mortality.
UNASSIGNED: To investigate the predictive value of variables obtained upon hospital admission for in-hospital death and 90-day outcomes in non-HIV-PCP patients with respiratory failure (RF).
UNASSIGNED: This was a single center retrospective study in a tertiary care institution over 15 years. It included all adults inpatients (≥18 years old) with laboratory confirmed non-HIV-PCP with RF who were discharged or died from Peking University First Hospital between April 1st, 2007 and November 1st, 2022. Epidemiological, clinical, laboratory, imaging and outcome data were collected from patient records.
UNASSIGNED: In this study, a total of 146 non-HIV-PCP patients with RF were included. There were 57 patients (39%) died during hospitalization, 44 patients (53%) died in Intensive care unit (ICU). A total of 137 patients completed 90 days of follow-up, of which 58 (42.3%) died. The multivariable regression analysis revealed that a CD8+ T cell count <115/μl (P=0.009), bronchoalveolar lavage fluid (BALF)-neutrophil percentage ≥50% (P=0.047), the time from corticosteroids withdrawal to symptom onset ≤5 days (P=0.012), and the time from visit to initiation of sulfonamides ≥2 days (P=0.011) were independent risk factors for in-hospital death. Furthermore, a CD8+ T cell count < 115/μl (P=0.001) and the time from visit to initiation of sulfonamides therapy ≥2 days (P=0.033) was independently associated with 90-day all-cause death.
UNASSIGNED: A low CD8+ T cell count in peripheral blood, a high percentage of BALF-neutrophils, a short time from corticosteroids withdrawal to symptom onset, and a long time from visit to initiation of sulfonamides are associated with poor prognosis in non-HIV-PCP patients with RF.

Opioids exert analgesic effects by agonizing opioid receptors and activating signaling pathways coupled to receptors such as G-protein and/or β-arrestin. Concomitant respiratory depression (RD) is a common clinical problem, and improvement of RD is usually achieved with specific antagonists such as naloxone; however, naloxone antagonizes opioid analgesia and may produce more unknown adverse effects. In recent years, researchers have used various methods to isolate opioid receptor-mediated analgesia and RD, with the aim of preserving opioid analgesia while attenuating RD. At present, the focus is mainly on the development of new opioids with weak respiratory inhibition or the use of non-opioid drugs to stimulate breathing. This review reports recent advances in novel opioid agents, such as mixed opioid receptor agonists, peripheral selective opioid receptor agonists, opioid receptor splice variant agonists, biased opioid receptor agonists, and allosteric modulators of opioid receptors, as well as in non-opioid agents, such as AMPA receptor modulators, 5-hydroxytryptamine receptor agonists, phosphodiesterase-4 inhibitors, and nicotinic acetylcholine receptor agonists.

BACKGROUND: Although cumulative studies have demonstrated a beneficial effect of high-flow nasal cannula oxygen (HFNC) in acute hypercapnic respiratory failure, randomized trials to compare HFNC with non-invasive ventilation (NIV) as initial treatment in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) patients with acute-moderate hypercapnic respiratory failure are limited. The aim of this randomized, open label, non-inferiority trial was to compare treatment failure rates between HFNC and NIV in such patients.
METHODS: Patients diagnosed with AECOPD with a baseline arterial blood gas pH between 7.25 and 7.35 and PaCO2 ≥ 50 mmHg admitted to two intensive care units (ICUs) at a large tertiary academic teaching hospital between March 2018 and December 2022 were randomly assigned to HFNC or NIV. The primary endpoint was the rate of treatment failure, defined as endotracheal intubation or a switch to the other study treatment modality. Secondary endpoints were rates of intubation or treatment change, blood gas values, vital signs at one, 12, and 48 h, 28-day mortality, as well as ICU and hospital lengths of stay.
RESULTS: 225 total patients (113 in the HFNC group and 112 in the NIV group) were included in the intention-to-treat analysis. The failure rate of the HFNC group was 25.7%, while the NIV group was 14.3%. The failure rate risk difference between the two groups was 11.38% (95% CI 0.25-21.20, P = 0.033), which was higher than the non-inferiority cut-off of 9%. In the per-protocol analysis, treatment failure occurred in 28 of 110 patients (25.5%) in the HFNC group and 15 of 109 patients (13.8%) in the NIV group (risk difference, 11.69%; 95% CI 0.48-22.60). The intubation rate in the HFNC group was higher than in the NIV group (14.2% vs 5.4%, P = 0.026). The treatment switch rate, ICU and hospital length of stay or 28-day mortality in the HFNC group were not statistically different from the NIV group (all P > 0.05).
CONCLUSIONS: HFNC was not shown to be non-inferior to NIV and resulted in a higher incidence of treatment failure than NIV when used as the initial respiratory support for AECOPD patients with acute-moderate hypercapnic respiratory failure.
BACKGROUND: chictr.org (ChiCTR1800014553). Registered 21 January 2018, http://www.chictr.org.cn.

Peripheral intravenous central catheter (PICC) is a common tool for intravenous infusion for children who need central venous access. Although it is safe for physicians and nurses to place, complications like infection, occlusion, phlebitis, and bleeding can occur. We report a 5-month-old infant who suffered respiratory failure caused by catheter malposition resulting in massive fluid infusion into the thoracic cavity. Point-of-care ultrasound (POCUS) was utilized to identify a massive pleural effusion that prompted urgent drainage. Complications related to PICC in pediatric patients are not common but difficult to immediately identify sometimes. Therefore, careful attention should be paid by physicians to identify and reduce the risk of complications associated with PICC. Thus, visual tools are strongly advised to enhance the safety of invasive procedures.

OBJECTIVE: The 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).
METHODS: This 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).
RESULTS: A 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.
CONCLUSIONS: In 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.