Risk factors for COVID-19 associated pulmonary aspergillosis and outcomes in patients with acute respiratory failure in a respiratory sub-intensive care unit.

BACKGROUND: COVID-19-associated pulmonary aspergillosis (CAPA) is burdened by high mortality. Data are lacking about non-ICU patients. Aims of this study were to: (i) assess the incidence and prevalence of CAPA in a respiratory sub-intensive care unit, (ii) evaluate its risk factors and (iii) impact on in-hospital mortality. Secondary aims were to: (i) assess factors associated to mortality, and (ii) evaluate significant features in hematological patients. MATERIALS AND METHODS: This was a single-center, retrospective study of COVID-19 patients with acute respiratory failure. A cohort of CAPA patients was compared to a non-CAPA cohort. Among patients with CAPA, a cohort of hematological patients was further compared to another of non-hematological patients. RESULTS: Three hundred fifty patients were included in the study. Median P/F ratio at the admission to sub-intensive unit was 225 mmHg (IQR 155-314). 55 (15.7%) developed CAPA (incidence of 5.5%). Eighteen had probable CAPA (37.3%), 37 (67.3%) possible CAPA and none proven CAPA. Diagnosis of CAPA occurred at a median of 17 days (IQR 12-31) from SARS-CoV-2 infection. Independent risk factors for CAPA were hematological malignancy [OR 1.74 (95%CI 0.75-4.37), p = 0.0003], lymphocytopenia [OR 2.29 (95%CI 1.12-4.86), p = 0.02], and COPD [OR 2.74 (95%CI 1.19-5.08), p = 0.014]. Mortality rate was higher in CAPA cohort (61.8% vs 22.7%, p < 0.0001). CAPA resulted an independent risk factor for in-hospital mortality [OR 2.92 (95%CI 1.47-5.89), p = 0.0024]. Among CAPA patients, age > 65 years resulted a predictor of mortality [OR 5.09 (95% CI 1.20-26.92), p = 0.035]. No differences were observed in hematological cohort. CONCLUSION: CAPA is a life-threatening condition with high mortality rates. It should be promptly suspected, especially in case of hematological malignancy, COPD and lymphocytopenia.

Physiologically based modeling reveals different risk of respiratory depression after fentanyl overdose between adults and children.

Despite a rapid increase in pediatric mortality rate from prescription and illicit opioids, there is limited research on the dose-dependent impact of opioids on respiratory depression in children, the leading cause of opioid-associated death. In this article, we extend a previously developed translational model to cover pediatric populations by incorporating age-dependent pharmacokinetic, pharmacodynamic, and physiological changes compared to adults. Our model reproduced previous perioperative clinical findings that adults and children have similar risk of respiratory depression at the same plasma fentanyl concentration when specific endpoints (minute ventilation, CO2 tension in the blood) were used. However, our model points to a potential caveat that, in a perioperative setting, routine use of mechanical ventilation and supplemental oxygen maintained the blood and tissue oxygen partial pressures in patients and prevented the use of oxygen-related endpoints to evaluate the consequences of respiratory depression. In a community setting when such oxygenation procedures are not immediately available, our model suggests that the higher oxygen demand and reduced cerebrovascular reactivity could make children more susceptible to severe hypoxemia and brain hypoxia, even with the same plasma fentanyl concentration as adults. Our work indicates that when developing intervention strategies to protect children from opioid overdose in a community setting, these pediatric-specific factors may need to be considered.

Pro-Con Debate: Universal Versus Selective Continuous Monitoring of Postoperative Patients.

In this Pro-Con commentary article, we discuss use of continuous physiologic monitoring for clinical deterioration, specifically respiratory depression in the postoperative population. The Pro position advocates for 24/7 continuous surveillance monitoring of all patients starting in the postanesthesia care unit until discharge from the hospital. The strongest arguments for universal monitoring relate to inadequate assessment and algorithms for patient risk. We argue that the need for hospitalization in and of itself is a sufficient predictor of an individual's risk for unexpected respiratory deterioration. In addition, general care units carry the added risk that even the most severe respiratory events will not be recognized in a timely fashion, largely due to higher patient to nurse staffing ratios and limited intermittent vital signs assessments (e.g., every 4 hours). Continuous monitoring configured properly using a "surveillance model" can adequately detect patients' respiratory deterioration while minimizing alarm fatigue and the costs of the surveillance systems. The Con position advocates for a mixed approach of time-limited continuous pulse oximetry monitoring for all patients receiving opioids, with additional remote pulse oximetry monitoring for patients identified as having a high risk of respiratory depression. Alarm fatigue, clinical resource limitations, and cost are the strongest arguments for selective monitoring, which is a more targeted approach. The proponents of the con position acknowledge that postoperative respiratory monitoring is certainly indicated for all patients, but not all patients need the same level of monitoring. The analysis and discussion of each point of view describes who, when, where, and how continuous monitoring should be implemented. Consideration of various system-level factors are addressed, including clinical resource availability, alarm design, system costs, patient and staff acceptance, risk-assessment algorithms, and respiratory event detection. Literature is reviewed, findings are described, and recommendations for design of monitoring systems and implementation of monitoring are described for the pro and con positions.

Successful Recovery of a Catatonic Patient with Severe Pneumonia and Respiratory Failure: Modified Electroconvulsive Therapy Following Tracheotomy.

BACKGROUD: Catatonia encompasses a group of severe psychomotor syndromes affecting patients' motor, speech, and complex behaviors. Common features include rigidity, reduced mobility, speech, sputum production, defecation, and eating. Risks associated with catatonia, such as increased muscle tension and reduced swallowing and coughing reflexes, along with risks from therapeutic approaches like prolonged bed rest and sedative drugs, can elevate the risk of aspiration pneumonia, severe pneumonia, and acute respiratory failure. These complications significantly impede catatonia treatment, leading to poor prognosis and jeopardizing patient safety. CASE DESCRIPTION: In this report, we present a case of catatonia complicated by severe pneumonia and respiratory failure, successfully managed with modified electroconvulsive therapy alongside tracheotomy. We hope this case provides valuable insights for psychiatrists encountering similar scenarios, facilitating the development of rational therapeutic strategies for prompt improvement of patient condition.

Comparison of Remimazolam and Propofol on Postoperative Delirium in Elderly Patients Undergoing Radical Resection of Colon Cancer: A Single-Center Prospective Randomized Controlled Study.

BACKGROUND We compared the effect of remimazolam and propofol intravenous anesthesia on postoperative delirium in elderly patients undergoing laparoscopic radical resection of colon cancer. MATERIAL AND METHODS One hundred patients undergoing elective radical operation of colon cancer under general anesthesia were divided into a remimazolam group (group R) and propofol group (group P) by a random number table method. During anesthesia induction and maintenance, group R was intravenously injected with remimazolam to exert sedation; however, in group P, propofol was injected instead of remimazolam. The occurrence of postoperative delirium was assessed with the Confusion Assessment Method for the Intensive Care Unit scale and postoperative pain was assessed with the visual analogue score (VAS). The primary outcome measures were the incidence and duration of delirium within 7 days following surgery. Secondary outcome measures included postoperative VAS scores, intraoperative anesthetic drug dosage, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression. RESULTS There was no significant difference in baseline data between the 2 groups (P>0.05). There was no statistically significant difference in the incidence and duration of postoperative delirium between the 2 groups (P>0.05). There were no significant differences in VAS scores, remifentanil consumption, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression between the 2 groups (P>0.05). CONCLUSIONS In elderly patients undergoing radical colon cancer surgery, remimazolam administration did not improve or aggravate the incidence and duration of delirium, compared with propofol.

Home-based respiratory support.

This review provides an overview of home-based respiratory support modalities for patients with chronic lung diseases. It discusses the increasing use of long-term high-flow nasal cannula (LT-HFNC) and long-term non-invasive ventilation (LT-NIV) and their potential to enhance patient quality of life. This review addresses various types of respiratory failure and their respective treatments, emphasising the significance of monitoring and telemedicine in home care. This comprehensive review underscores the clinical relevance of these interventions in the management of chronic lung diseases.

Outcomes of coronary artery bypass grafting (CABG) in patients with OSA-COPD overlap syndrome versus COPD alone: an analysis of US Nationwide Inpatient Sample.

BACKGROUND: Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are associated with unfavorable outcomes following coronary artery bypass grafting (CABG). The purpose of this study was to compare in-hospital outcomes of patients with COPD alone versus OSA-COPD overlap after CABG. METHODS: Data of adults ≥ 18 years old with COPD who received elective CABG between 2005 and 2018 were extracted from the US Nationwide Inpatient Sample (NIS). Patients were divided into two groups: with OSA-COPD overlap and COPD alone. Propensity score matching (PSM) was employed to balance the between-group characteristics. Logistic and linear regression analyses determined the associations between study variables and inpatient outcomes. RESULTS: After PSM, data of 2,439 patients with OSA-COPD overlap and 9,756 with COPD alone were analyzed. After adjustment, OSA-COPD overlap was associated with a significantly increased risk of overall postoperative complications (adjusted odd ratio [aOR] = 1.12, 95% confidence interval [CI]: 95% CI: 1.01-1.24), respiratory failure/prolonged mechanical ventilation (aOR = 1.27, 95%CI: 1.14-1.41), and non-routine discharge (aOR = 1.16, 95%CI: 1.03-1.29), and AKI (aOR = 1.14, 95% CI: 1.00-1.29). Patients with OSA-COPD overlap had a lower risk of in-hospital mortality (adjusted odd ratio [aOR] = 0.53, 95% CI: 0.35-0.81) than those with COPD only. Pneumonia or postoperative atrial fibrillation (AF) risks were not significantly different between the 2 groups. Stratified analyses revealed that, compared to COPD alone, OSA-COPD overlap was associated with increased respiratory failure/prolonged mechanical ventilation risks among patients ≥ 60 years, and both obese and non-obese subgroups. In addition, OSA-COPD overlap was associated with increased risk of AKI among the older and obese subgroups. CONCLUSION: In US adults who undergo CABG, compared to COPD alone, those with OSA-COPD are at higher risks of non-routine discharge, AKI, and respiratory failure/prolonged mechanical ventilation, but a lower in-hospital mortality. No increased risk of AF was noted.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT.

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in patients at very high risk for extubating failure: A systematic review of randomized controlled trials.

BACKGROUND: Mechanical ventilation is commonly used for managing respiratory failure in chronic obstructive pulmonary disease (COPD) patients, but weaning patients off ventilator support can be challenging and associated with complications. While many patients respond well to Non-invasive ventilation (NIV), a significant proportion may not respond as favourably. We aimed to assess whether high-flow nasal cannula (HFNC) is equally effective as NIV in reducing extubation failure among previously intubated COPD patients. METHODS: This systematic review was carried out in line with PRISMA guidelines We searched PubMed, Scopus, Web of Science, and Cochrane library from inception until February 15, 2023. Randomized Clinical Trials (RCTs) of adults at high risk for extubating failure were included. We examined the use of HFNC as the intervention and NIV as the comparator. Our outcome of interest included, reintubation rate, length of hospital or intensive care unit (ICU) stay, adverse events, and time to reintubation. The Cochrane risk-of-bias tool was used for randomized trials to assess risk of bias. RESULTS: We identified 348 citations, 11 of which were included, representing 2,666 patients. The trials indicate that HFNC is comparable to NIV in preventing reintubation after extubating in COPD patients. In comparison to NIV, HFNC also produced improved tolerance, comfort, and less complications such as airway care interventions. NIV with active humification may be more effective that HFNC in avoiding reintubation in patients who are at extremely high risk for extubating failure. CONCLUSION: The inconclusive nature of emerging evidence highlights the need for additional studies to establish the efficacy and suitability of HFNC as an alternative to NIV for previously intubated COPD patients. Clinicians should consider the available options and individualize their approach based on patient characteristics. Future research should focus on addressing these gaps in knowledge to guide clinical decision-making and optimize outcomes for this patient population.

[Veno-venous extracorporeal membrane oxygenation for capillary leak syndrome during induction chemotherapy in acute myeloid leukemia].

A 44-year-old woman was diagnosed with acute myeloid leukemia (RUNX1::RUNX1T1 translocation) and received induction chemotherapy with idarubicin hydrochloride and cytosine arabinoside. The pneumonia that had been present since admission worsened, and a drug-induced skin rash appeared. On day 17, she presented with respiratory failure and shock, complicated by hemoconcentration and hypoalbuminemia. This was considered capillary leak syndrome due to pneumonia and drug allergy, so she was started on pulse steroid therapy and IVIG, and was intubated on the same day. On day 18, venovenous-extracorporeal membrane oxygenation (VV-ECMO) was started due to worsening blood gas parameters despite ventilatory management. Bronchoalveolar lavage fluid was serous, and both blood and sputum cultures yielded negative. The patient was weaned from VV-ECMO on day 26 as the pneumonia improved with recovery of hematopoiesis. She was disoriented, and a CT scan on day 28 revealed cerebral hemorrhage. Her strength recovered with rehabilitation. After induction chemotherapy, RUNX1::RUNX1T1 mRNA was not detected in bone marrow. The patient received consolidation chemotherapy, and has maintained complete remission. Severe respiratory failure during induction chemotherapy for acute leukemia can be fatal, but VV-ECMO may be lifesaving.

Associations between respiratory function, balance, postural control, and fatigue in persons with multiple sclerosis: an observational study.

Introduction: Fatigue, postural control impairments, and reduced respiratory capacities are common symptoms in persons diagnosed with Multiple Sclerosis (MS). However, there is a paucity of evidence establishing correlations among these factors. The aim of this study is to analyze respiratory function in persons with MS compared to the control group as well as to analyze the relationship between fatigue, respiratory function and postural control in persons with MS. Materials and methods: A total of 17 persons with MS and 17 healthy individuals were enrolled for this cross-sectional study. The evaluated parameters included fatigue assessed using the Visual Analog Scale-fatigue (VAS-F) and the Borg Dyspnea Scale, postural control assessed through the Mini Balance Evaluation System Test (Mini-BESTest), Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and Trunk Impairment Scale (TIS); and respiratory capacities measured by Maximum Inspiratory Pressure (MIP), Maximum Expiratory Pressure (MEP), Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), FEV1/FVC ratio, Diaphragmatic excursion and diaphragmatic thickness. Results: A very high correlation was observed between the Borg Dyspnoea Scale and the BBS (r = -0.768), TUG (0.867), and Mini-BESTest (r = -0.775). The VAS-F exhibited an almost perfect correlation solely with the TUG (0.927). However, none of the variables related to fatigue exhibited any correlation with the respiratory variables under study. Balance-related variables such as BBS and Mini-BESTest demonstrated a very high and high correlation. Respectively, with respiratory function variables MEP (r = 0.783; r = 0.686), FVC (r = 0.709; r = 0.596), FEV1 (r = 0.615; r = 0.518). BBS exhibited a high correlation with diaphragmatic excursion (r = 0.591). Statistically significant differences were noted between the persons with MS group and the control group in all respiratory and ultrasound parameters except for diaphragmatic thickness. Conclusion: The findings suggest that decreased postural control and balance are associated with both respiratory capacity impairments and the presence of fatigue in persons with MS. However, it is important to note that the alterations in respiratory capacities and fatigue are not mutually related, as indicated by the data obtained in this study. Discrepancies were identified in abdominal wall thickness, diaphragmatic excursion, and respiratory capacities between persons with MS and their healthy counterparts.

The effect of antifibrotic agents on acute respiratory failure in COVID-19 patients: a retrospective cohort study from TriNetX US collaborative networks.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on global health and economies, resulting in millions of infections and deaths. This retrospective cohort study aimed to investigate the effect of antifibrotic agents (nintedanib and pirfenidone) on 1-year mortality in COVID-19 patients with acute respiratory failure. METHODS: Data from 61 healthcare organizations in the TriNetX database were analyzed. Adult patients with COVID-19 and acute respiratory failure were included. Patients with a pre-existing diagnosis of idiopathic pulmonary fibrosis before their COVID-19 diagnosis were excluded. The study population was divided into an antifibrotic group and a control group. Propensity score matching was used to compare outcomes, and hazard ratios (HR) for 1-year mortality were calculated. RESULTS: The antifibrotic group exhibited a significantly lower 1-year mortality rate compared to the control group. The survival probability at the end of the study was 84.42% in the antifibrotic group and 69.87% in the control group. The Log-Rank test yielded a p-value of less than 0.001. The hazard ratio was 0.434 (95% CI: 0.264-0.712), indicating a significant reduction in 1-year mortality in the antifibrotic group. Subgroup analysis demonstrated significantly improved 1-year survival in patients receiving nintedanib treatment and during periods when the Wuhan strain was predominant. DISCUSSION: This study is the first to demonstrate a survival benefit of antifibrotic agents in COVID-19 patients with acute respiratory failure. Further research and clinical trials are needed to confirm the efficacy of these antifibrotic agents in the context of COVID-19 and acute respiratory failure.

Clinical characteristics and prognosis of patients with COVID-19 on mechanical ventilation undergoing continuous renal replacement therapy.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has significantly strained global healthcare, particularly in the management of patients requiring mechanical ventilation (MV) and continuous renal replacement therapy (CRRT). This study investigated the characteristics and prognoses of these patients. METHODS: This multicenter retrospective cohort study gathered data from patients with COVID-19 across 26 medical centers. Logistic analysis was used to identify the factors associated with CRRT implementation. RESULTS: Of the 640 patients with COVID-19 who required MV, 123 (19.2%) underwent CRRT. Compared to the non-CRRT group, the CRRT group was older and exhibited higher sequential organ failure assessment scores. The incidence of hypertension, diabetes, cardiovascular disease, chronic neurological disease, and chronic kidney disease was also higher in the CRRT group. Moreover, the CRRT group had higher intensive care unit (ICU) (75.6% vs. 26.9%, p < 0.001) and in-hospital (79.7% vs. 29.6%, p < 0.001) mortality rates. CRRT implementation was identified as an independent risk factor for both ICU mortality (hazard ratio [HR]:1.833, 95% confidence interval [CI]:1.342-2.505, p < 0.001) and in-hospital mortality (HR: 2.228, 95% CI: 1.648-3.014, p < 0.001). Refractory respiratory failure (n = 99, 19.1%) was the most common cause of death in the non-CRRT death group, and shock with multi-organ failure (n = 50, 40.7%) was the most common cause of death in the CRRT death group. Shock with multi-organ failure and cardiac death were significantly more common in the CRRT death group, compared to non-CRRT death group. CONCLUSION: This study indicates that CRRT is associated with higher ICU and in-hospital mortality rates in patients with COVID-19 who require MV. Notably, the primary cause of death in the CRRT group was shock with multi-organ failure, emphasizing the severe clinical course for these patients, while refractory respiratory failure was most common in non-CRRT patients.

Opioid-induced respiratory depression suspected of drug interaction in a prostate cancer patient: a case report.

BACKGROUND: Many of the drugs used for the treatment and alleviation of symptoms in cancer patients are known to inhibit or induce cytochrome P450 (CYP). Therefore, it is important to pay attention to the drug interactions of opioid analgesics that are metabolized by CYPs, because for example when using oxycodone metabolized by CYP3A4, it is possible that the effect will be attenuated or enhanced by the concomitant use of drugs that induce or inhibit CYP3A4. Aprepitant, an antiemetic drug used in many patients receiving anticancer drugs, is known as a moderate competitive inhibitor of CYP3A4. We experienced a case of respiratory depression caused by opioids, which was suspected to be caused by a drug interaction with antiemetics especially aprepitant. CASE DESCRIPTION: The patient was a 72-year-old man. He had been treated with continuous oxycodone infusion for perianal pain associated with the rectal invasion of prostate cancer. No comorbidities other than renal dysfunction were observed. Oxycodone treatment was started at 48 mg/day, and was increased to 108 mg/day, and then the pain decreased. Once the pain was controlled, chemotherapy was planned. Antiemetics (dexamethasone, palonosetron, and aprepitant) were administered before anticancer drug administration. Approximately 3 hours after antiemetics administration and before the administration of the anticancer drugs, a ward nurse noticed that oversedation and respiratory depression had occurred. When the patient was called, he immediately woke up and was able to talk normally, so the anticancer drugs were administered as scheduled. About 2 hours after the nurse noticed oversedation, the attending physician reduced the dose of oxycodone infusion to 48 mg/day. After that, his drowsiness persisted, but his respiratory condition improved. Despite reducing the dose of oxycodone to less than half, the pain remained stable at numeric rating scale (NRS) 0-1, without the use of a rescue dose. The patient was discharged from the hospital 36 days after the administration of anticancer drugs, without any problems. CONCLUSIONS: The cause of respiratory depression in this case was thought to be a combination of factors, including drug interactions between oxycodone and antiemetics, and oxycodone accumulation due to renal dysfunction.

The Safety and Efficacy of Remimazolam Compared to Dexmedetomidine for Awake Tracheal Intubation by Flexible Bronchoscopy: A Randomized, Double-Blind, Controlled Trial.

Background: Remimazolam is a novel ultra-short-acting benzodiazepine sedative that has the potential to be an alternative for procedural sedation due to its rapid sedation and recovery, no accumulation effect, stable hemodynamics, minimal respiratory depression, anterograde amnesia effect, and specific antagonist. Here, we aimed to compare the safety and efficacy of remimazolam with dexmedetomidine for awake tracheal intubation by flexible bronchoscopy (ATI-FB). Methods: Ninety patients scheduled for ATI-FB were randomly divided into three groups, each consisting of 30 cases: dexmedetomidine 0.6 µg/kg + sufentanil (group DS), remimazolam 0.073 mg/kg + sufentanil (group R1S), or remimazolam 0.093 mg/kg + sufentanil (group R2S). The primary outcome was the success rate of sedation. Secondary outcomes were MOAA/S scores, hemodynamic and respiratory parameters, intubation conditions, intubation time, tracheal intubation amnesia, and adverse events. Results: The success rates of sedation in groups R2S and DS were higher than that in group R1S (93.3%, 86.7%, respectively, vs 58.6%; P = 0.002), and intubation conditions were better than those in group R1S (P < 0.05). Group R2S had shorter intubation times than groups R1S and DS (P = 0.003), and a higher incidence of tracheal intubation amnesia than group DS (P = 0.006). No patient in the three groups developed hypoxemia or hypotension, and there were no significant differences in oligopnea, PetCO2, or bradycardia (P > 0.05). Conclusion: In conclusion, both DS and R2S had higher success rates of sedation, better intubation conditions, and minor respiratory depression, but R2S, with its shorter intubation time, higher incidence of anterograde amnesia, and ability to be antagonized by specific antagonists, may be a good alternative sedation regimen for patients undergoing ATI-FB.

The relationship between red cell distribution width, serum calcium ratio, and in-hospital mortality among patients with acute respiratory failure: A retrospective cohort study of the MIMIC-IV database.

To investigate the impact of RDW/CA (the ratio of red cell distribution width to calcium) on in-hospital mortality in patients with acute respiratory failure (ARF). This retrospective cohort study analyzed the data of 6981 ARF patients from the Medical Information Mart for Intensive Care (MIMIC-IV) database 2.0. Critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston. The primary outcome of interest was in-hospital mortality. A Cox proportional hazards regression model was used to determine whether the RDW/CA ratio independently correlated with in-hospital mortality. The Kaplan-Meier method was used to plot the survival curves of the RDW/CA. Subgroup analyses were performed to measure the mortality across various subgroups. After adjusting for potential covariates, we found that a higher RDW/CA was associated with an increased risk of in-hospital mortality (HR = 1.17, 95% CI: 1.01-1.35, P = .0365) in ARF patients. A nonlinear relationship was observed between RDW/CA and in-hospital mortality, with an inflection point of 1.97. When RDW/CA ≥ 1.97 was positively correlated with in-hospital mortality in patients with ARF (HR = 1.554, 95% CI: 1.183-2.042, P = .0015). The Kaplan-Meier curve indicated the higher survival rates for RDW/CA < 1.97 and the lower for RDW/CA ≥ 1.97 after adjustment for age, gender, body mass index, and ethnicity. RDW/CA is an independent predictor of in-hospital mortality in patients with ARF. Furthermore, a nonlinear relationship was observed between RDW/CA and in-hospital mortality in patients with ARF.

Respiratory failure as first presentation of myasthenia gravis: a case report.

Myasthenia gravis (MG) is often complicated by respiratory failure, an exacerbation known as myasthenic crisis. However, most patients with MG develop respiratory symptoms during the late course of the disease. Respiratory failure as an exclusive initial and primary complaint in patients with MG is rare and seldom reported. We herein describe a woman in her late 50s who presented with respiratory failure and was diagnosed with obesity hypoventilation syndrome at a local hospital. Her condition gradually worsened during the next 4 months and became accompanied by dysphagia. After 1 year of medical investigation, she was diagnosed in our hospital. A high level of anti-muscle-specific receptor tyrosine kinase antibody was found in her serum, and stimulation and electromyography results suggested MG. The patient's symptoms were improved by intravenous immunoglobulin and hormone therapy. This case reminds physicians to consider MG when encountering a patient who initially presents with respiratory failure.