Ventilatory Failure Research Articles

Respiratory Trajectories and Correlation with Serum Biochemical Indices in Spinal and Bulbar Muscular Atrophy

Background/Objectives: The primary life-threatening complication in spinal–bulbar muscular atrophy (SBMA) is ventilatory failure. The present study analyzes the longitudinal patterns of respiratory function tests over a follow-up of 11 years. Methods: We collected data from 9 genetically confirmed SBMA patients. Spirometric measurements [maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and forced vital capacity (FVC)], serum biochemical indices and SBMA functional rating scale (SBMAFRS) were collected every 6 months for 11 years. An average time curve was utilized to assess the changes in both pulmonary tests and serum biochemical indices of the patients. One-way repeated-measures ANOVA was applied to assess statistical differences. The Spearman’s rank correlation coefficient was utilized to evaluate the correlations between the respiratory function tests and serum biochemical and clinical indices. Results: A progressive decrease was observed in the respiratory function tests; the slope of the linear regression was significantly non-zero (p < 0.0001) for all three time curves. A major decrease was observed for MEP (52%) and MIP (42%), while this was minor for FVC (25%). SBMAFRS score correlated with FVC (r = 0.27), MIP (r = 0.53) and MEP (r = 0.51). MIP and MEP correlated with creatine phosphokinase (r = 0.3, r = 0.25, respectively) and MIP with creatinine levels (r = 0.31). Conclusions: This longitudinal study shows a progressive decline of spirometric data throughout life in SBMA patients. The decline appears to be related to clinical deterioration and muscle denervation. Spirometric measures relative to maximal strength of the respiratory muscles (MIP and MEP) may have a better predictive value for pulmonary and muscular decline than FVC.

Role of Heart Rate, Acidosis, Consciousness, Oxygenation, and Respiratory Rate Score in Predicting Outcomes of Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease Patients.

In patients with chronic obstructive pulmonary disease (COPD), early detection of noninvasive ventilation (NIV) failure is a promising technique for decreasing mortality. The objective of this study was to evaluate the efficacy of heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) score in predicting NIV outcome in COPD-associated respiratory failure. A prospective observational study was conducted on 100 COPD patients with acute respiratory failure who were initiated on NIV. HACOR score was calculated at the start of NIV and after 1-2, 12, and 24 hours. NIV failure was defined as progression to invasive mechanical ventilation or death. NIV success was defined as liberation from NIV prior to hospital day seven and not meeting criteria for failure. In this study, 100 patients with COPD and respiratory failure were enrolled. Their mean age was 65.34 years [standard deviation (SD) 8.19]. Male patients were predominant (n = 81). Eighty-nine percent of patients were smokers, and the remaining had exposure to biomass fuel. At the initiation of NIV, the median HACOR score was 3 (interquartile: 2, 4). In 13% of patients, there was NIV failure. There were 17 (17%) patients whose HACOR score at initiation was ≥5. In patients with a HACOR score ≥5, the NIV failure rate was 76.4% and mortality was 41.1%. The area under the curve (AUC) for prediction of NIV failure by HACOR score at initiation was 0.980 (p-value < 0.05). The HACOR score had high sensitivity as well as specificity at initiation in the prediction of NIV failure. A higher HACOR score predicts a high chance of NIV failure. Obtaining the HACOR score at the bedside makes it convenient for assessing the efficacy of NIV in patients with COPD.

Extravascular lung water assessment by lung ultrasound in infants following pediatric cardiac surgery.

Lung edema is a significant factor in prolonged mechanical ventilation and extubation failure after cardiac surgery. This study assessed the predictive capability of point-of-care Lung Ultrasound (LUS) for the duration of mechanical ventilation and extubation failure in infants following cardiac procedures. We conducted a prospective observational trial on infants under 1 year, excluding those with pre-existing conditions or requiring extracorporeal membrane oxygenation. LUS was performed upon intensive care unit (ICU) admission and prior to extubation attempts. B-line density was scored by two independent observers. The primary outcomes included the duration of mechanical ventilation and extubation failure, the latter defined as the need for reintubation or non-invasive ventilation within 48 h post-extubation. The study included 42 infants, with findings indicating no correlation between initial LUS scores and extubation timing. Extubation failure occurred in 21% of the patients, with higher LUS scores observed in these cases (p = 0.046). However, interobserver variability was high, impacting the reliability of LUS scores to predict extubation readiness. LUS was ineffective in determining the length of postoperative ventilation and extubation readiness, highlighting the need for further research and enhanced training in LUS interpretation.

A nationwide survey on the management of neonatal respiratory distress syndrome: insights from the MUNICH survey in 394 Chinese hospitals

BackgroundAt present, preterm infants with respiratory distress syndrome (RDS) in China present higher mortality and morbidity rates than those in high-income countries. The aim of this nationwide survey was to assess the clinical management of RDS in China.MethodsA nationwide cross-sectional survey to assess adherence to RDS management recommendations was performed. One neonatologist per hospital was randomly selected. The primary outcome was the key care of RDS management.ResultsAmong the 394 participating hospitals, 88·3% were birthing centres. The number of doctors and nurses per bed were 0·27 and 0·72, respectively. Antenatal corticosteroids (any dose) were administered to 90% of the women at risk of preterm birth at < 34 weeks of gestation (90·0% inborn vs. 50·0% outborn, p < 0·001). The median fraction of inspired oxygen (FiO2) for initial resuscitation was 0·30 for babies born at ≤ 32 weeks of gestation and 0·25 for those born at > 32 weeks. T-piece resuscitators were available in 77·8% of delivery rooms (DRs) (tertiary hospitals: 82·5% vs. secondary hospitals: 63·0%, p < 0·001). Surfactant was used in 51·6% of the DRs. Less invasive surfactant administration (LISA) was used in 49·7% of the hospitals (tertiary hospitals: 55·3% vs. secondary hospitals: 31·5%, p < 0·001). Primary non-invasive ventilation was initiated in approximately 80·0% of the patients. High-frequency oscillation ventilation was primarily reserved for rescue after conventional mechanical ventilation (MV) failure. Caffeine was routinely used during MV in 59·1% of the hospitals. Bedside lung ultrasonography was performed in 54·3% of the health facilities (tertiary hospitals: 61·6% vs. secondary hospitals: 30·4%, p < 0·001). Qualified breast milk banks and Family Integrated Care (FICare) were present in 30·2% and 63·7% of the hospitals, respectively.ConclusionsSignificant disparities in resource availability and guidelines adherence were evident across hospitals. Future strategies should address DR facilities and medication access, technical training, staff allocation, and ancillary facility development for a better management of RDS patients in China.

Effects of electrical and percussive stunning on neural, ventilatory and cardiac responses of rainbow trout

From an ethical standpoint, it is imperative that rainbow trout (Oncorhynchus mykiss) are humanely slaughtered, which entails that they are rendered unconscious immediately by a stunning method and remain so until death. The efficacy of electrical stunning following dewatering (i.e., in-air electrical stunning at intensities of 50 to 920 mA and durations of 5 to 30 s) and percussive stunning, both advocated as humane stunning and/or killing methods, are evaluated here for this species via the presence or absence of visually evoked responses (VERs). In addition, ventilatory and cardiac responses were evaluated to elucidate the physiological basis for the lethality of both methods. While the present study was unable to determine the capability of in-air electrical stunning to induce immediate unconsciousness, our findings revealed that irreversible stuns were induced by both in-air electrical stunning (i.e., ∼25 to 70% of individuals did not recover VERs across the various combinations of stunning intensities and/or durations) and percussive stunning (i.e., ∼100% of individuals did not recover VERs). The efficacy of in-air electrical stunning for permanently abolishing VERs was marginally, but significantly, impacted by stun intensity (i.e., explained 8% of the variation). Furthermore, due to substantial inter-specific variability and a limited sample size, significant impacts of stun intensity and/or duration on the recovery of VERs in reversibly stunned individuals were not detected in the present study (i.e., VERs recovered between <0.5 to 28.8 min). Further investigation is therefore necessary before in-air electrical stunning can be endorsed as a standalone humane slaughter method for rainbow trout. This includes determining its capacity to induce immediate unconsciousness, as well as to identify additional factors that could be modified or enhanced to improve its efficacy. Furthermore, since death following in-air electrical stunning likely entails a prolonged process involving ventilatory failure, hypoxemia, and subsequent vital organ malfunction, rather than immediate cardiac arrest or central nervous system failure, the sequential use of methods such as percussive stunning is recommended to safeguard the welfare of rainbow trout during slaughter.

Development and validation of a predictive model for pulmonary infection risk in patients with traumatic brain injury in the ICU: a retrospective cohort study based on MIMIC-IV

ObjectiveTo develop a nomogram for predicting occurrence of secondary pulmonary infection in patients with critically traumatic brain injury (TBI) during their stay in the intensive care unit, to further optimise...

Frequency of side effects experienced in two different NIM-EMG tubes used in thyroid and parathyroid surgery; a prospective observational study

BackgroundIn this study, we observed the frequency of side effects encountered when the neural integrity monitor electromyogram endotracheal tube (NIM-EMG-ETT) was used in thyroidectomy and parathyroidectomy surgeries.MethodsAfter obtaining hospital ethics committee approval, 239 cases affiliated with the American Society of Anesthesiologists (ASA II-IV) who used NIM EMG tubes in thyroid and parathyroid surgery were included in the prospective observational study. Tube and patient-related complications encountered with two different NIM EMG-ETT (silicone and polyvinyl chloride-PVC) were recorded.ResultsThe average age of the patients is 49.50 ± 13.44 years, the average BMI is 28.25 ± 4.91 kg/m2, the median surgery time is 115 (32–475) minutes, 75.7% are women, 97.5% are ASA II. Additional diseases other than thyroid and parathyroid problems were present in 77.3%. Thyroidectomy was performed in 73.2% of the patients. In our study, only 0.8% of patients with transient recurrent laryngeal nerve RLN paralysis were observed in thyroid and parathyroid surgeries performed using NIM-EMG tubes, 3 patient already had nerve involvement in the preoperative period. The most common complication was loss of stimulation response related to tubes and patient-related ventilation failure. There was no difference between the complications of silicone and PVC tubes except for irregular EMG response.ConclusionsThere was no significant difference in side effects other than irregular EMG response in the two different tubes we used in our study. It was observed that prolonging the surgical time increased the risk of irregular EMG response. It should not be forgotten that no matter which NIM-EMG tube is used, additional risks are encountered during the intubation and extubation process. In order to avoid negative consequences, it is necessary to follow the usage rules recommended by the manufacturer when using NIM-EMG tubes.

New noninvasive modalities in long-term pediatric ventilation: a scoping review.

Long-term noninvasive ventilation modalities for the pediatric population have undergone a continuous evolution. Hybrid noninvasive ventilation modalities have been recently introduced in clinical practice. Combining the advantages of conventional ventilation, hybrid modes use algorithms that automatically adjust the ventilator's settings to achieve a predefined ventilation target. Most of the recommendations on the use and settings of hybrid noninvasive ventilation modalities in children are derived from adult experience. Therefore, there is a lack of evidence on its implementation in pediatric chronic respiratory diseases. This scoping review aims to map the existing information regarding the use of hybrid ventilation modalities in the pediatric population and identify knowledge or research gaps. We performed a literature search using MEDLINE and Pubmed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. We included 13 studies (ten studies on average volume-assured pressure-support ventilation; two studies on intelligent volume-assured pressure-support ventilation; and one study on adaptive servoventilation). The use of new noninvasive ventilation modes in the pediatric population has been applied for the treatment of neuromuscular and hypoventilation syndromes as an alternative therapeutic option in the case of the failure of conventional noninvasive ventilation. Their widespread use has been hampered by the limited evidence available. Longitudinal studies on a larger number of patients are needed to confirm their effectiveness and evaluate their long-term clinical and functional outcomes.

Effect of Renin-Angiotensin-Aldosterone System Blockers on Adverse Outcomes in COVID-19 Patients.

Angiotensin-converting enzyme 2 (ACE2) of the renin-angiotensin-aldosterone system (RAAS) serves as a functional receptor to gain entry into the cells for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19). The interaction between SARS-CoV-2 and ACE2 is a potential virulent factor in infectivity. Our study aimed to ascertain the association of RAAS inhibitors with adverse cardiovascular and other outcomes in hospitalized COVID-19 patients. This is a retrospective study of medical records of ≥18-year-old patients hospitalized for COVID-19 from March 2020 to October 2020. Primary outcomes were acute cardiovascular events (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction type 1, acute congestive heart failure, acute stroke) and mortality. Secondary outcomes were respiratory failure, need for and duration of mechanical ventilation, acute deep vein thrombosis or pulmonary embolism (DVT/PE), and readmission rate. Among 376 hospitalized COVID-19 patients, 149 were on RAAS inhibitors. No statistically significant differences were found between RAAS inhibitor and non-RAAS inhibitor groups with respect to acute cardiovascular events (6% vs. 6.2%, p = 0.94), acute DVT/PE (4.7% vs. 4.8%, p = 0.97), hypoxia (62.4% vs. 58.6%, p = 0.46), need for mechanical ventilation (18.1% vs. 16.7%, p = 0.72), mortality (19.5% vs. 22%, p = 0.56), and readmission rate (11.4% vs. 14.1%, p = 0.45). Some nuances discovered were a higher rate of hospitalizations among Native Americans receiving RAAS inhibitors (30.2% vs. 19.8%) and significantly lower levels of procalcitonin in patients on RAAS inhibitors. Among hospitalized patients with COVID-19, those on RAAS inhibitors showed no significant differences in acute cardiovascular events, acute DVT/PE, hypoxia, need for mechanical ventilation, readmission, or mortality rate compared to those not on them. However, further large-scale studies are needed to validate these findings.

Establishment and Validation of a Risk Prediction Model for Non-Invasive Ventilation Failure After Birth in Premature Infants with Gestational Age < 32 Weeks.

This study was performed to construct and validate a risk prediction model for non-invasive ventilation (NIV) failure after birth in premature infants with gestational age < 32weeks. The data were derived from the multicenter retrospective study program - Jiangsu Provincial Neonatal Respiratory Failure Collaboration Network from Jan 2019 to Dec 2021. The subjects finally included were preterm infants using NIV after birth with gestational age less than 32weeks and admission age within 72h. After screening by inclusion and exclusion criteria, 1436 babies were subsequently recruited in the study, including 1235 infants in the successful NIV group and 201 infants in the failed NIV group. (1) Gestational age, 5min Apgar, Max FiO2 during NIV, and FiO2 fluctuation value during NIV were selected by univariate and multivariate analysis. (2) The area under the curve of the prediction model was 0.807 (95% CI: 0.767-0.847) in the training set and 0.825 (95% CI: 0.766-0.883) in the test set. The calibration curve showed good agreement between the predicted probability and the actual observed probability (Mean absolute error = 0.008 for the training set; Mean absolute error = 0.012 for the test set). Decision curve analysis showed good clinical validity of the risk model in the training and test cohorts. This model performed well on dimensions of discrimination, calibration, and clinical validity. This model can serve as a useful tool for neonatologists to predict whether premature infants will experience NIV failure after birth.

The burden of major complications on failure to rescue after surgery for acute type A aortic dissection: Analysis of more than 19,000 patients

BackgroundThe relationship between the number and type of postoperative complications and mortality in the setting for surgery for acute type A aortic dissection (ATAAD) remains underexplored despite its critical role in the failure-to-rescue (FTR) metric. MethodsThis retrospective study used data from the Society of Thoracic Surgeons Adult Cardiac Surgical Database on ATAAD surgeries performed between January 2018 and December 2022. Patients were categorized based on their number of major complications. The primary outcome was FTR. We used multilevel regression and classification and regression tree models. ResultsWe included 19,243 patients (33% females), with a median age of 61 years. Regarding complications, 47.7% of patients had 0, 20.2% had 1, 12.7% had 2, and 19.4% experienced 3 or more. The most frequently reported complications were prolonged mechanical ventilation (30.3%), unplanned reoperation (19.5%), and renal failure (17.2%). Cardiac arrest occurred in 7.1% of cases. FTR increased from 13% in patients with 1 complication to >30% in those with 4 or more complications. Cardiac arrest (adjusted odds ratio [aOR], 10.9) and renal failure (aOR, 5.3) had the highest odds for mortality, followed by limb ischemia (aOR, 2.7), stroke (aOR, 2.6), and gastrointestinal complications (aOR, 2.4). Hospitals in the top performance quartile consistently showed lower FTR rates across all levels of complication. ConclusionsThe study validates a dose–response association between postoperative complications and mortality in patients undergoing surgery for ATAAD. Top-performing hospitals consistently show lower FTR rates independent of the number of complications. Future research should focus on the timing of complications and interventions to reduce the burden of complications.

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.

Gene replacement therapy for spinal muscular atrophy: safety and preliminary efficacy in a Brazilian cohort.

Spinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness, ventilatory failure, and reduced survival. Onasemnogene abeparvovec is the first gene replacement therapy (GT) approved to treat this condition. An observational retrospective study was conducted to assess adverse events and efficacy of GT in SMA patients. Forty-one patients with SMA (58.5% females and 80.1% SMA type 1) were included. The mean age at GT dosing was 18 (±6.4) months. Thirty-six patients (87.8%) were under previous treatment with nusinersen, and 10 (24.4%) continued nusinersen after GT. Mean CHOP-INTEND increased 13 points after 6 months and this finding did not differ between groups according to nusinersen maintenance after GT (p = 0.949). Among SMA type 1 patients, 14 (46.6%) reached the ability to sit alone. Liver transaminases elevation at least two times higher than the upper limit of normal value occurred in 29 (70.7%) patients. Thrombocytopenia occurred in 13 (31.7%) patients, and one presented thrombotic microangiopathy. Older age (>2 years) was associated with more prolonged use of corticosteroids (p = 0.021). GT is effective in SMA patients, combined nusinersen after GT did not appear to add gain in motor function and older age is associated with prolonged corticosteroid use.

Clinical outcomes, demographics and associative analysis of lung cancer patients with Lambert-Eaton myasthenic syndrome: Insights from the National Inpatient Sample (NIS) database.

e20134 Background: Lambert-Eaton myasthenic syndrome (LEMS) is a rare neuromuscular junction disorder that may present as a paraneoplastic syndrome or a primary autoimmune disorder. Approximately 60% of LEMS patients have an underlying tumor, with the paraneoplastic form predominantly associated with small cell lung cancer (SCLC). Understanding the clinical outcomes and risks associated in lung cancer patients with LEMS is crucial in effective management of such patients. Methods: This retrospective study utilized inpatient hospitalization data from the National Inpatient Sample (NIS) between January 1, 2016, and December 31, 2019. Data of patients with a primary or secondary discharge diagnosis of lung cancer (ICD10-CM codes C34, C78.0, C46.5, D02.2) were obtained. Then, out of this population, we identified Lambert-Eaton myasthenic syndrome with ICD-10 codes (G70.80, G70.81, G73.1). The objective was to run a descriptive analysis of clinical outcomes, risks, demographics and associations of LEMS in patients with lung cancer. Results: A total of 204 cases of lung cancer hospitalizations with LEMS were analyzed. The mean age was 68.23 years, with a slight female (51.72%) preponderance as compared to male (48.28%). Race distribution revealed increased prevalence in White Caucasians (83%), followed by Black (7%), Hispanic (4.5%), Asian or Pacific Islander (3%), Native American (0.5%), and Other (2%). The majority were covered by Medicare (66.33%), followed by private insurance (26.13%). The mortality rate was 8.9%, with a mean length of stay of 10.35 days and mean hospital charges of $118,676. Clinical outcomes and risks were analyzed, with sepsis occurring in 17.6% of cases, pneumonia in 22.5%, and acute respiratory failure in 26.9%. Intubation/mechanical ventilation was necessary in 18.1% of cases. The incidence of urinary tract infection (UTI) was 16.7%, acute kidney injury (AKI) was 17.2%, and venous thromboembolism (VTE) was 6.4%. Additionally, interventions such as intravenous immunoglobulin (IVIG) therapy and blood transfusions were also noted. Conclusions: This study provides insights into the demographic characteristics and clinical outcomes of lung cancer patients with Lambert-Eaton myasthenic syndrome (LEMS). The findings highlight the need for comprehensive management strategies targeting associated complications like acute respiratory failure, intubation and need for mechanical ventilation, pneumonia, UTI, AKI, and VTE to improve patient outcomes, quality of care and effective patient education with regards to their diagnosis of LEMS in lung cancer.

Incidence and Risk Factors for Acute Kidney Injury in PICU of Dr. Mohammad Hoesin Hospital Palembang

Introduction. Acute kidney injury (AKI) is a heterogeneous group of conditions characterized by a sudden decrease in the glomerular filtration rate, manifested by an increase in serum creatinine or oliguria. In the Pediatric Intensive Care Unit (PICU), AKI is one of the most common conditions found. Several factors, including age, infection, sepsis, shock, heart disease, mechanical ventilation, and multiple organ failure cause the increase in the incidence of AKI in children. This study aimed to determine the incidence and risk factors for AKI in critically ill children in the PICU of Dr. Mohammad Hoesin Hospital Palembang. Methods. This study was an observational analytic with a cross-sectional design. This study used secondary data based on the medical records of patients treated at the PICU. Critically ill children aged 1-18 years who were treated at the PICU of Dr. Mohammad Hoesin Hospital Palembang in the period of 1 January 2020 to 31 December 2021 were included while existing kidney dysfunction before being admitted to PICU and not fulfilled medical records were excluded to the study. Results. AKI incidence in PICU was 46.7%. There were significant risk factors for AKI which are age (p 0.025), sepsis (p 0.019), shock (p 0.002), mechanical ventilation used (p 0.043), nephrotoxic drugs (p 0.039), and fluid overload (p 0.039). Conclusion. This study found that age, sepsis, shock, mechanical ventilation, nephrotoxic drugs, and fluid overload, were significant risk factors for the incidence of AKI in critically ill children in PICU.

FOT Technique Applied for Monitoring of COVID-19 Pneumonia Reveals Small Airways Involvement.

The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional character of hypoxia. We hypothesize that such effects could be explained by the closure of small airways. To prove the hypothesis, we evaluated the patency of small airways in 30 oxygen-dependent, spontaneously breathing patients with SARS-CoV-2 pneumonia during their hospital stay using the FOT method and then compared the results with data obtained three months later. During the acute period, total resistance (R5) and peripheral resistance (R5-20) rose above the upper limit of normal (ULN) in 28% and 50% of all patients, respectively. Reactance indices X5, AX and Fres exceeded ULN in 55%, 68% and 66% of cases. Significant correlations were observed between PaO2/FiO2, the time spent in the hospital and R5, X5, AX and Fres. After 3 months, 18 patients were re-examined. During the hospital stay, 11 of them had risen above the upper limit of normal (ULN), for both resistance (R5-20) and reactance (X5, AX) values. Three months later, ULN for R5-20 was exceeded in only four individuals, but ULN for X5 and AX was exceeded in five individuals. Lung function examination revealed a combined restrictive/obstructive ventilatory failure and reduced CO transfer factor. We interpret these changes as lung tissue remodeling due to the process of fibrosis. We conclude that during acute period of SARS-CoV-2 pneumonia, dilated pulmonary blood vessels and parenchymal oedema induce functional closure of small airways, which in turn induce atelectasis with pulmonary right-to-left shunting, followed by the resulting hypoxemia.

Digital Twins of Acute Hypoxemic Respiratory Failure Patients Suggest a Mechanistic Basis for Success and Failure of Noninvasive Ventilation.

To clarify the mechanistic basis for the success or failure of noninvasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF). We created digital twins based on mechanistic computational models of individual patients with AHRF. Interdisciplinary Collaboration in Systems Medicine Research Network. We used individual patient data from 30 moderate-to-severe AHRF patients who had failed high-flow nasal cannula (HFNC) therapy and subsequently underwent a trial of NIV. Using the digital twins, we evaluated lung mechanics, quantified the separate contributions of external support and patient respiratory effort to lung injury indices, and investigated their relative impact on NIV success or failure. In digital twins of patients who successfully completed/failed NIV, after 2 hours of the trial the mean (sd) of the change in total lung stress was -10.9 (6.2)/-0.35 (3.38) cm H2O, mechanical power -13.4 (12.2)/-1.0 (5.4) J/min, and total lung strain 0.02 (0.24)/0.16 (0.30). In the digital twins, positive end-expiratory pressure (PEEP) produced by HFNC was similar to that set during NIV. In digital twins of patients who failed NIV vs. those who succeeded, intrinsic PEEP was 3.5 (0.6) vs. 2.3 (0.8) cm H2O, inspiratory pressure support was 8.3 (5.9) vs. 22.3 (7.2) cm H2O, and tidal volume was 10.9 (1.2) vs. 9.4 (1.8) mL/kg. In digital twins, successful NIV increased respiratory system compliance +25.0 (16.4) mL/cm H2O, lowered inspiratory muscle pressure -9.7 (9.6) cm H2O, and reduced the contribution of patient spontaneous breathing to total driving pressure by 57.0%. In digital twins of AHRF patients, successful NIV improved lung mechanics, lowering respiratory effort and indices associated with lung injury. NIV failed in patients for whom only low levels of positive inspiratory pressure support could be applied without risking patient self-inflicted lung injury due to excessive tidal volumes.

Factors related to mortality of patients with COVID-19 who are admitted to the ICU: Prognostic mortality factors of COVID-19 patients.

During the severe acute respiratory syndrome coronavirus 2 pandemic, hospital resources, particularly critical care units, were overburdened and this had a significant impact on both the therapies and the prognosis of these patients. This study aimed to identify factors and therapies that may improve prognosis and other factors associated with increased mortality. A secondary objective was to evaluate the impact that obesity had on these patients. An observational study was conducted on 482 patients aged 18 years or older who were diagnosed with SARS-CoV-2 pneumonia and admitted to the Intensive Care Units of 3 national hospitals registered in the CIBERESUCICOVID database between September 2020 and March 2021. After identifying the sample profile, risk factors were analyzed, the predictive model was constructed, and crude odd ratios were calculated for each factor. Additionally, logistic regression was used to build the multivariate model adjusting for potential confounders. The final model included only the variables selected using the Backward method. A sample of 335 men (69.5%) and 145 women (30.08%) aged 61.94 ± 12.75 years with a body mass index (BMI) of 28.05 (25.7; 31.2) was obtained. A total of 113 patients received noninvasive mechanical ventilation. The most common comorbidities were: high blood pressure (51.04%), obesity (28%), diabetes mellitus (23.44%), other metabolic diseases (21.16%), chronic heart failure (18.05%), chronic obstructive pulmonary disease (11.62%), and chronic kidney disease (10.16%). In-hospital, 3-month and 6-month post-discharge mortality in patients with BMI > 30 (n = 135) versus BMI ≤ 30 (n = 347) was significantly different (P = .06). Noninvasive mechanical ventilation failed in 42.4% of patients with BMI > 30 compared to 55% of patients with BMI ≤ 30. This study identified the factors associated with failure of mechanical ventilation. The most common comorbidities were congestive heart failure, high blood pressure, chronic kidney disease, severe liver disease, diabetes mellitus, and solid organ transplantation. In terms of ventilatory support, patients who received high-flow nasal oxygen therapy on admission had lower mortality rates. The use of renal replacement therapy was also significantly associated with higher mortality.

HACOR score to predict NIV failure in patients with COVID-related hypoxemic respiratory failure managed in the ordinary ward and in the critical care setting.

We evaluated the prevalence of non-invasive ventilation (NIV) failure among patients with COVID-19-related pneumonia, managed in the ordinary ward and in the HDU/ICU and we tested the prognostic role of the HACOR score in those different settings. This is a retrospective study, conducted in the University-Hospital Careggi. We included all subjects with COVID-19 and ARF requiring NIV between March 2020 and May 2021, respectively managed in the ordinary ward (G1) and in the critical care setting (G2). Clinical parameters, HACOR and SOFA score were evaluated at Day 0 and after 1, 2 and 5days of treatment. The primary outcome was NIV failure. 13% G1 patients and 40% G2 patients underwent endotracheal intubation (ETI). NIV was successful in 60% G1 AND 43% G2 patients (p < 0.001). In G1, compared to those with successful NIV, patients who underwent ETI, had a higher HACOR since the baseline evaluation (T0: 6 [5-6] vs 5 [3-6]; T1: 6 [5-6] vs 5 [3-6], all p < 0.05). An HACOR score > 5 was associated with an increased prevalence of ETI independent to an advanced age and a SOFA score > 5 both in G1 (T1: RR 4.87, 95% CI 1.462-16.275; T5: 3.630, 95% CI 0.979-13.462) and G2 (T0: 1.76, 95% CI 0.906-3.422; T1: 3.38, 95% CI 1.386-8.265). Among patients with COVID-related-ARF, NIV could be managed in the ordinary ward in a consistent proportion of patients and, among them, an HACOR score > 5 was independently associated with increased NIV failure from the earliest evaluations.

PaCO2 is nonlinearly associated with NIV failure in patients with hypoxemic respiratory failure

ObjectiveTo explore the association between PaCO2 and noninvasive ventilation (NIV) failure in patients with hypoxemic respiratory failure.MethodsA retrospective study was performed in a respiratory ICU of a teaching hospital. Patients admitted to ICU between 2011 and 2019 were screened. We enrolled the patients with hypoxemic respiratory failure. However, patients who used NIV due to acute-on-chronic respiratory failure or heart failure were excluded. Data before the use of NIV were collected. Requirement of intubation was defined as NIV failure.ResultsA total of 1029 patients were enrolled in final analysis. The rate of NIV failure was 45% (461/1029). A nonlinear relationship between PaCO2 and NIV failure was found by restricted cubic splines (p = 0.03). The inflection point was 32 mmHg. The rate of NIV failure was 42% (224/535) in patients with PaCO2 >32 mmHg. However, it increased to 48% (237/494) in those with PaCO2 ≤ 32 mmHg. The crude and adjusted hazard ratio (HR) for NIV failure was 1.36 (95%CI:1.13–1.64) and 1.23(1.01–1.49), respectively, if the patients with PaCO2 >32 mmHg were set as reference. In patients with PaCO2 ≤ 32 mmHg, one unit increment of PaCO2 was associated with 5% reduction of NIV failure. However, it did not associate with NIV failure in patients with PaCO2 >32 mmHg.ConclusionsPaCO2 and NIV failure was nonlinear relationship. The inflection point was 32 mmHg. Below the inflection point, lower PaCO2 was associated with higher NIV failure. However, it did not associate with NIV failure above this point.