Mechanical Ventilation Research Articles

A Computational Study of Hospital Isolation Room Environment to Assess the Spread of Airborne Contaminants

The safety of healthcare workers and patients in hospitals is a matter of paramount importance. Therefore, the significance of adequate ventilation in hospital rooms towards controlling airborne infections cannot be ignored. Although several reports discuss natural and mechanical ventilation in hospital isolation rooms, conflicting opinions recommend one ventilation method. There is also a paucity of information that relates engineering evaluation of hospital room ventilation to the design standards laid down by established public health agencies in the United States. This research aims to study hospital isolation room ventilation performance using natural and mechanical ventilation methods and assess certain guidelines on hospital room ventilation. Computational Fluid Dynamics is used to evaluate the concentration of contaminated air following a coughing event within a hospital isolation room using natural and mechanical ventilation. A novel technique employing a mechanical exhaust tube is proposed that may substantially reduce contaminant concentration. Within the same hospital isolation room, the normalized maximum concentration of contaminated air is much lower with two different mechanical ventilation methods (0.2% and 0.25%) than with the natural ventilation method (0.6%), suggesting that mechanical ventilation methods are more effective in reducing the concentration of contaminated air. In addition to established design parameters such as Air Change per Hour (ACH) and ventilation volume per patient, closer proximity to the vent from the contaminant source may also play a critical role in reducing contaminant concentration.

Critical Care Approach to Severe Tetanus with Septic Shock: A Case Report

Introduction: Tetanus, caused by Clostridium tetani neurotoxin, remains a life-threatening condition, particularly in regions with suboptimal vaccination coverage. Severe tetanus often necessitates intensive care unit (ICU) admission due to profound muscle spasms, respiratory failure, and autonomic nervous system dysfunction. Concomitant septic shock further complicates management and worsens prognosis. This report details the critical care management of a patient presenting with severe tetanus complicated by septic shock. Case presentation: A 41-year-old male presented with generalized muscle rigidity, trismus, and recurrent severe spasms following a puncture wound from bamboo 10 days prior. He had no prior tetanus immunization history. Upon admission, he exhibited signs of respiratory distress (Sp90% on a 15L non-rebreather mask) and septic shock (tachycardia, hypotension requiring vasopressors, SOFA score 7). Diagnosis of severe tetanus (Ablett Grade III) with respiratory failure and septic shock was made. Management involved immediate intubation, mechanical ventilation, administration of human tetanus immunoglobulin (HTIG), intravenous metronidazole, aggressive sedation with benzodiazepines (diazepam infusion) and neuromuscular blockade (vecuronium infusion), hemodynamic support with intravenous fluids and noradrenaline infusion, early tracheostomy, and comprehensive supportive care including nutritional support and VTE prophylaxis. His ICU stay was complicated by autonomic instability and ventilator-associated pneumonia (VAP). Conclusion: Managing severe tetanus complicated by septic shock requires a prompt, multidisciplinary critical care approach. Key elements include securing the airway, controlling spasms and rigidity, neutralizing toxins, eradicating the source, managing autonomic instability, aggressive sepsis management according to current guidelines, and providing meticulous supportive care. Despite significant challenges, a favorable outcome is possible with comprehensive ICU management.

Maintaining ventilation with very low tidal volume and positive-end expiratory pressure versus no ventilation during cardiopulmonary bypass for cardiac surgery in adults: a randomized clinical trial.

Cardiopulmonary bypass (CPB) during cardiac surgery mechanically circulates and oxygenates the blood, bypassing the heart and lungs. Despite limited evidence, maintaining mechanical ventilation (MV) during CPB is recommended, as ventilator strategies during surgery may reduce the occurrence of postoperative infections. We aimed to determine whether maintaining MV for cardiac surgery would decrease postoperative infections compared with stopping MV during CPB. We conducted a multicenter, single-blind, randomized trial among adult patients undergoing scheduled cardiac surgery with CPB in six hospitals in France. During CPB, the tracheal tube was disconnected from the ventilator in the control group (MV- group). In the MV + group, ventilation was maintained during CPB with very low tidal volume ventilation, using a tidal volume of 2.5mL/kg of predicted body weight, with 5-7cmH2O positive end expiratory pressure. The primary outcome was the occurrence of all types of postoperative infections within the first 28days after surgery. There were six secondary evaluation criteria including the number of days of exposure to antibiotics. A total of 1362 patients were enrolled in the study. Postoperative infection occurred in 74 out of 680 patients (10.9%) in the MV- group, compared to 68 out of 682 patients (10.0%) in the MV + group (relative risk, 0.92; 95% confidence interval [CI] 0.67-1.25; p = 0.58). Antibiotic use was higher in the MV + group than in the MV- group (incidence risk ratio, 1.08; 95% CI 1.02-1.15; p = 0.02). There were no significant differences between the groups for all other secondary outcomes or for the incidence of adverse events. Maintaining very low tidal volume ventilation with positive end-expiratory pressure during CPB did not reduce postoperative infections at 28days compared to when mechanical ventilation was stopped during CPB. An unexpectedly higher use of antibiotics was observed when ventilation was maintained. ClinicalTrials.gov (NCT03372174).

Respiratory dysbiosis as prognostic biomarker of disease severity for adults with community-acquired pneumonia requiring mechanical ventilation

ObjetivesTo ascertain the role of the lung microbiome in the development of severe pneumonia and its potential as a biomarker for disease progression.MethodsBAL samples from 34 adults with severe community-acquired pneumonia (CAP) (17 viral, 8 viral coinfected with bacteria and 9 bacterial) admitted to the ICU for acute respiratory failure between 2019 and 2021 were collected within the first 48 h of admission to the ICU. The microbiome was characterized via the Ion 16S Metagenomics Kit and the Ion Torrent sequencing platform. Clinical factors, including survival, mechanical ventilation duration, blood biomarkers and organ failure in terms of acute respiratory distress syndrome (ARDS), shock or acute renal failure, were correlated with microbiome characteristics.ResultsThe microbiome diversity in patients with viral pneumonia was significantly greater than that in patients with bacterial or coinfected pneumonia: the Shannon diversity index was 3.75 (Q1–Q3: 2.5–4.1) versus 0.4 (Q1–Q3: 0.2–1.3) and 0.48 (Q1–Q3: 0.3–1.1), respectively (p < 0.05). The microbiome diversity index was associated with severity-of-illness (APACHE II), independent of the etiology of pneumonia (B coefficient -1.845; p < 0.01). Patients with severe viral CAP who developed ARDS had a lower presence of Proteobacteria, and those who were complicated with ventilator-associated pneumonia had a higher prevalence of Acinetobacter at admission. The mortality of patients with bacterial or coinfected pneumonia was 35%. In coinfected patients, the diversity index was associated with the development of shock.ConclusionPatients with severe CAP have low respiratory microbiome diversity, indicating that respiratory microbiome diversity is a potential biomarker of disease severity.

Terminal Hospitalizations in Liver Transplant Recipients: Reducing Costs and High-Intensity Care Through Palliative Care.

IntroductionEnd-of-life care for liver transplant recipients is often characterized by high utilization of invasive procedures, prolonged hospital stays, and elevated health care costs. Despite evidence demonstrating that palliative care can reduce aggressive interventions, improve patient-centered outcomes, and lower costs, its integration into transplant care remains inconsistent.MethodsA retrospective analysis was conducted using the National Inpatient Sample database (2016-2021). Hospitalizations ending in death for liver transplant recipients were compared to non-recipients regarding invasive procedures, health care costs, and the impact of palliative care consultations. Assessed procedures included: mechanical ventilation, tracheostomy, enteral and parenteral nutrition support, red blood cell transfusion, renal replacement therapy, central line placement, and cardiopulmonary resuscitation. Multivariable regression models adjusted for demographic and clinical covariates were utilized.ResultsAmong 4,582,658 terminal hospitalizations, liver transplant recipients (n = 5995) were younger (mean age: 66.0 vs 70.9years, P < 0.001), had higher comorbidity burdens, and were more likely to have undergone one or more of the assessed procedures (74.7% vs 58.4%, P < .001) compared to non-recipients. Hospitalization costs were increased in transplant recipients ($62,630 vs $46,930, P < .001). Palliative care consultations were associated with reduced procedure utilization (69.9% vs 83.7%, P < .001), shorter hospital stays, and lower costs ($46,930 vs $62,630, P < .001).DiscussionLiver transplant recipients face unique end-of-life care challenges, including greater reliance on high-intensity interventions and associated costs. Palliative care is associated with less invasive procedures and lower costs, highlighting the need for its integration into transplant care pathways.

The impact of magnesium sulfate administration on the prognosis of septic patients with hypomagnesemia: a retrospective propensity score-matched cohort study based on MIMIC-IV

IntroductionThis study aimed to provide a basis for optimizing clinical treatment by retrospectively analyzing the clinical characteristics of hypomagnesemia in sepsis patients and the impact of magnesium sulfate administration on their prognosis.Material and methodsBased on inclusion and exclusion criteria, we included adult individuals diagnosed with sepsis and concurrent hypomagnesemia. Exposure was defined as administration of magnesium sulfate on the first day of ICU admission. The primary outcome assessed was the 28-day mortality rate. Secondary outcomes encompassed mortality rates at 90 and 365 days, the duration of mechanical ventilation, requirement for continuous renal replacement therapy (CRRT), hospital stay duration, intensive care unit (ICU) stay duration, hospital mortality, and ICU mortality. A multivariable Cox regression analysis was conducted to evaluate the relationship between sepsis with hypomagnesemia and 28-day mortality. Propensity score matching (PSM) was performed at a 1 : 1 ratio. Multivariable analysis was used to adjust for confounding factors.ResultsIn the PSM analysis, the 28-day mortality rate appeared reduced in the magnesium sulfate treatment group relative to the untreated group (10.15% [33/3192] vs. 16.31% [53/347]). Magnesium sulfate use correlated with a decreased 28-day mortality rate (hazard ratio [HR] = 0.61; 95% CI: 0.39–0.94; p = 0.026). Magnesium sulfate administration also reduced the 90-day mortality rate (p = 0.039). Statistical analysis revealed no significant differences between magnesium sulfate administration and the use of CRRT, mechanical ventilation duration, hospital and ICU lengths of stay, or mortality rates at 365 days.ConclusionsThe administration of magnesium sulfate is associated with a reduced mortality rate in individuals diagnosed with sepsis and hypomagnesemia, providing theoretical support for clinical practice.

UTERINE ARTERY EMBOLIZATION FOR FIBROIDS AN ALTERNATIVE TO HYSTERECTOMY

Background: Uterine fibroids, or leiomyomas, are common benign tumors affecting women of reproductive age and often present with symptoms such as heavy menstrual bleeding, pelvic pain, and pressure effects. Hysterectomy has long been the definitive treatment; however, uterine artery embolization (UAE) has emerged as a minimally invasive alternative aimed at preserving the uterus. Evaluating the comparative safety and effectiveness of UAE versus hysterectomy can guide treatment decisions for symptomatic fibroid uterus. Objective: To determine the effectiveness of uterine artery embolization in the treatment of symptomatic uterine fibroids compared to hysterectomy. Methods: This prospective observational study was conducted at the Armed Forces Institute of Radiology and Imaging, Rawalpindi, from March 2023 to September 2023. A total of 60 women diagnosed with uterine fibroids were enrolled using non-probability convenience sampling. Participants were equally allocated into two groups: Group A underwent uterine artery embolization, and Group B underwent hysterectomy. Post-treatment outcomes assessed included bleeding from the surgical site, postoperative pain, hospital discharge within 24 hours, mechanical ventilation requirement, HDU admission, and mortality. Data were analyzed using SPSS version 26.0, with the chi-square test applied to compare outcomes (p&lt;0.05 considered significant). Results: Group A showed lower rates of bleeding from the surgical site (16.6%) compared to Group B (46.6%). Postoperative pain was reported in 26.6% of UAE patients versus 70% in the hysterectomy group. Early discharge within 24 hours was achieved in 80% of UAE cases versus 16.6% in the hysterectomy group. Mechanical ventilation was required in 6.6% and 40% of patients, respectively. Mortality was nil in both groups. Conclusion: Uterine artery embolization demonstrated fewer complications, faster recovery, and comparable clinical outcomes, suggesting it may serve as a viable alternative to hysterectomy for the treatment of symptomatic uterine fibroids.

Liberation and discharge status of older patients after invasive mechanical ventilation: a retrospective cohort study

BackgroundData on the proportion of patients liberated from invasive mechanical ventilation (IMV) and the prognosis of those who have undergone IMV are limited. Objective data on prognosis are important when discussing preference for IMV. Therefore, this study explored both the proportion of liberation and prognosis after IMV in older patients in Japan.MethodsWe conducted a retrospective cohort study using claim data from April 2014 to March 2019 from the National Health Insurance, Late Elders' Health Insurance, and Long-Term Care Insurance in Tsukuba City, Japan. Patients aged ≥ 65 years who underwent IMV were included, and patients who died within 3 days after intubation were excluded. A descriptive analysis of the liberation and the discharge status on day 180 was conducted including a stratification by age categories and care level (CL) < 3 or ≥ 3. The chi-square or Fisher’s exact test was conducted to assess whether liberation and discharge status differed among age categories or CLs.ResultsIn total, 272 patients were included in the study, and the median age was 78 years (interquartile range: 73–84). The median duration of mechanical ventilation was 9.0 days. Pneumonia was the most frequent main diagnosis (12.5%). In total, 73.5% achieved liberation and 42.6% were discharged alive until day 180, while 19.9% were hospitalized and 37.5% were deceased on day 180. The proportion of liberation did not differ among age categories and CLs. However, the IMV duration for those requiring CL ≥ 3 was longer, and the proportion of hospitalized patients on day 180 among patients requiring CL ≥ 3 was significantly higher than that in patients requiring CL < 3 (35.1% vs 17.4%, p = 0.012).ConclusionsThis study shows that many older patients can be successfully liberated from IMV. However, one third of patients died in the hospital and one fifth of patients required prolonged hospitalization. IMV and hospitalization were likely to be longer among patients requiring CL ≥ 3. Therefore, it may be important to discuss not only the potential difficulty of liberation, but also to convey the risks of undesired outcomes and physical function decline when considering IMV.

A Case of Tracheal Flap Impeding Weaning from Mechanical Ventilation

A Case of Tracheal Flap Impeding Weaning from Mechanical Ventilation

Technological integration in predicting hypoxemia risk for improved surgical outcomes in Type A aortic dissection.

BackgroundPostoperative hypoxemia is a severe complication in patients undergoing surgery for acute Type A aortic dissection (AAD), with significant impacts on recovery and clinical outcomes. Technological advancements in risk assessment models offer opportunities for early intervention and optimized care.ObjectiveTo develop and validate a technology-driven predictive model for hypoxemia based on clinical and intraoperative risk factors, enhancing postoperative management strategies.MethodsA retrospective cohort of 242 patients was analyzed, including 77 with hypoxemia (PaO2/FiO2 ≤ 200 mmHg) and 165 without. Key clinical variables, intraoperative factors, and postoperative outcomes were examined. Spearman correlation analysis and receiver operating characteristic (ROC) curve analysis were conducted to identify and validate predictive markers.ResultsProlonged time from symptom onset to surgery (>48 h), aortic cross-clamp time, and deep hypothermic circulatory arrest time (DHCA) emerged as the most significant predictors (all p < 0.001). DHCA time demonstrated the highest sensitivity (0.961) and area under the curve (AUC = 0.891). Additional significant predictors included intraoperative blood product use and prolonged mechanical ventilation, with cumulative predictive value for hypoxemia risk.ConclusionThe integration of clinical variables into a technology-enhanced prediction model provides robust early warnings of postoperative hypoxemia risk. Implementing timely surgical interventions and refined intraoperative management can minimize adverse respiratory outcomes, improving recovery in AAD patients.

Corticosteroids for adult patients hospitalised with non-viral community-acquired pneumonia: a systematic review and meta-analysis.

International clinical practice guidelines addressing corticosteroid treatment for patients hospitalised with non-viral community-acquired pneumonia (CAP) are inconsistent. We conducted a systematic review of randomized controlled trials (RCTs) evaluating the use of corticosteroids in hospitalised adult patients with suspected or probable CAP. We performed random effects pairwise, Bayesian, and dose-response meta-analyses using the restricted maximum likelihood (REML) heterogeneity estimator. We assessed certainty of evidence using GRADE methodology. We identified 30 eligible RCTs, including a total of 7519 patients. The prednisone-equivalent doses ranged between 29mg/day and 100mg/day. Corticosteroids probably reduced short-term (28-30days) mortality (RR 0.82 [95% CI 0.74-0.91]; moderate certainty) while the reduction in longer term (60-90day) mortality is less certain (RR 0.89 [95% CI 0.76-1.03]; low certainty). Corticosteroids reduced the need for invasive mechanical ventilation (IMV) (RR 0.63 [95% CI 0.48-0.82]; high certainty) and may reduce duration of ICU stay (MD 1.53days fewer [95% CI 0.31-2.75days fewer]; low certainty), and hospital stay (MD 2.30days fewer [95% CI 0.81-3.81days fewer]; low certainty). Corticosteroids probably increased hyperglycaemia requiring intervention (RR 1.32 [95% CI 1.12-1.56]; moderate certainty) but probably have no effect on secondary infections (RR 0.97 [95% CI 0.85-1.11]; moderate certainty). Corticosteroids probably reduced short-term mortality and reduce the need for invasive mechanical ventilation in hospitalised patients with CAP. CRD42024521536.

Nebulized Heparin for Inhalation Injury in Burn Patients: An Updated Systematic Review and Meta-Analysis of Efficacy and Safety Outcomes

Background: Inhalation injury significantly increases morbidity and mortality in burn patients, primarily through airway obstruction, inflammation, and impaired gas exchange. Nebulized heparin has been investigated as a potential therapy to counteract local pulmonary coagulopathy and fibrin cast formation. However, evidence regarding its clinical efficacy and safety remains conflicting. This systematic review and meta-analysis aimed to synthesize updated evidence on the efficacy and safety outcomes of nebulized heparin in burn patients with inhalation injury. Methods: A systematic literature search was conducted in PubMed, EMBASE, Cochrane Library, and Web of Science for studies published between January 2014 and December 2024. We included randomized controlled trials (RCTs) and comparative cohort studies evaluating nebulized heparin versus placebo or standard care in adult and pediatric burn patients with inhalation injury. Primary efficacy outcomes included mortality and ventilator-free days (VFDs) at 28 days. Secondary outcomes included duration of mechanical ventilation (DoMV), hospital length of stay (LOS), changes in PaO2/FiO2 ratio, incidence of pneumonia, and safety outcomes (bleeding events). Data were synthesized, and a random-effects meta-analysis was planned to estimate pooled effect sizes (Risk Ratios [RR] or Standardized Mean Differences [SMD]). Study quality was assessed using appropriate tools. Results: The search strategy yielded seven studies (3 RCTs, 4 cohort studies) meeting the inclusion criteria, encompassing a total of 950 patients. Study quality varied. The meta-analysis suggested a potential reduction in mortality associated with nebulized heparin compared to control groups (Risk Ratio [RR]: 0.79; 95% CI: 0.64-0.97, P=0.02; I²=45%). A trend towards increased VFDs (Standardized Mean Difference [SMD]: 0.35; 95% CI: -0.05 to 0.75, P=0.08; I²=60%) and reduced DoMV (SMD: -0.50; 95% CI: -0.85 to -0.15, P=0.005; I²=55%) was observed. Effects on hospital LOS and PaO2/FiO2 ratio were less consistent across studies. There was no significant difference in the incidence of pneumonia (RR: 0.95; 95% CI: 0.80-1.13, P=0.55; I²=20%). Safety analysis indicated no significant increase in major bleeding events (RR: 1.15; 95% CI: 0.88-1.50, P=0.30; I²=10%), although minor bleeding, like blood-stained sputum, was noted in some studies. Substantial heterogeneity was present for some outcomes. Conclusion: Based on this updated systematic review and meta-analysis, nebulized heparin may be associated with reduced mortality and duration of mechanical ventilation in burn patients with inhalation injury, without a significantly increased risk of major bleeding. However, considerable uncertainty remains due to study heterogeneity and methodological limitations in the available literature. Its effect on pneumonia incidence appears negligible. Large-scale, high-quality RCTs are still needed to confirm these findings and establish optimal treatment protocols.

Study of Psychomotor Agitation Constraint Method: A Systematic Review.

Psychomotor agitation is a common psychiatric disorder that often requires physical restraint, consuming significant healthcare resources. Assessing the clinical importance of the correct method of physical restraint for patients with psychomotor agitation presents a challenge for physicians and researchers. This review aims to assess the use of physical restraints in Intensive Care Units (ICUs) and other departments, identifying potential factors influencing their use. Two independent researchers conducted a computerized search of PubMed, Embase, Web of Science, and Cochrane databases for literature related to methods of psychomotor agitation restraint. The review focused on the methods of inhibiting psychomotor agitation in the ICU. A total of seven papers met the inclusion criteria for this systematic review. The restraint rates among patients ranged from 8.7% to 59.07%. Factors influencing patient restraint included gender, marital status, mental and behavioral disorders, emergency referrals, and the use of mechanical ventilation. Restraint is frequently used among patients, particularly among the elderly, males, and those with disorders of consciousness or social relationship issues. This review identifies several factors influencing restraint rates in patients with psychomotor agitation, highlighting the need for further research to develop targeted interventions aimed at reducing the necessity for physical restraints.

Predicting prolonged hospitalization in asthma patients: model development and external validation

Purpose This study aims to develop and validate a machine learning (ML) model to predict prolonged hospitalization in asthma patients. Patients and methods This retrospective cohort study included patients with asthma as the primary diagnosis. We randomly divided 2820 asthma patients from Beth Israel Deaconess Medical Center into a training set and an internal validation set (in an 8:2 ratio), and used 1714 asthma patients from 208 other hospitals in the United States as an external validation cohort. Prolonged hospitalization was the primary outcome. Feature selection was conducted using LASSO regression, univariate logistic regression, and multivariate logistic regression analyses. Nine ML algorithms were employed to develop predictive models. Results Based on discrimination, calibration, and clinical utility, the Extreme Gradient Boosting (XGBoost) model demonstrated the best overall performance. The nine most important predictors in the model were age, oxygen saturation (SpO2), red blood cell count, hemoglobin count, comorbid pneumonia, chronic obstructive pulmonary disease (COPD), congestive heart failure, anxiety, and use of invasive mechanical ventilation. The XGBoost model achieved an area under the receiver operating characteristic curve (AUC) of 0.829 and a Cohen’s Kappa value of 0.439 in the internal validation set, and an AUC of 0.745 and a Cohen’s Kappa value of 0.315 in the external validation set. The decision curve analysis indicated good clinical utility of the model. Conclusions The XGBoost model can effectively predict prolonged hospitalization in asthma patients.

Personalized Therapies For Chronic Obstructive Pulmonary Disease (Copd) And Acute Respiratory Failure In Mechanically Ventilated Patients.

Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disease associated with high morbidity and mortality, especially in acute exacerbations that require admission to the Intensive Care Unit (ICU) and invasive ventilatory support. Considering the pathophysiological complexity of COPD, standardized therapies are not always effective and individualized management is necessary. This study aimed to critically analyze the available evidence on personalized therapies in COPD patients under mechanical ventilation. Specifically, it sought to identify ventilatory adjustments and individualized pharmacological interventions, as well as to assess their impact on clinical outcomes.This is a systematic review of the literature carried out in five databases, including studies published between 2013 and 2024 that addressed personalized therapies in COPD under invasive mechanical ventilation. Studies focusing exclusively on non-invasive ventilation or case reports were excluded. The results show that detailed physiological assessment, using tools such as electrical impedance tomography and esophageal catheter, allows for personalized titration of parameters such as PEEP and ΔP. In addition, pharmacotherapy adjusted to inflammatory phenotypes and clinical condition showed a reduction in ventilation time, a higher rate of successful weaning and lower hospital mortality. It is concluded that personalization of ventilatory and pharmacological therapy in COPD patients in the ICU contributes to more favourable outcomes, reinforcing the need to incorporate strategies based on physiology and individual variability into intensive care practice. Keywords : Chronic Obstructive Pulmonary Disease; Mechanical Ventilation; Intensive Care Unit; Ventilatory Weaning.

Investigating the effectiveness of combining high-frequency chest wall oscillation with bilevel positive airway pressure in pneumonia patients: a retrospective cohort study

BackgroundPneumonia represents a significant global health burden with high morbidity and mortality rates, despite advances in therapeutic and preventive strategies. Airway clearance techniques (ACT), including High-Frequency Chest Wall Oscillation (HFCWO) and bilevel positive airway pressure (BiPAP), are critical in managing respiratory conditions. However, the combined effectiveness of BiPAP and HFCWO in treating adult pneumonia remains underexplored.MethodsA retrospective cohort study was conducted at a college hospital in southern Taiwan, enrolling patients aged ≥ 18 years, admitted for pneumonia from January 2020 to December 2022, who received HFCWO therapy for ≥ 5 days in the ordinary ward. Exclusion criteria included prior mechanical ventilation before HFCWO initiation. Univariate and multivariable logistic regression models were used to assess the effectiveness of the combined use of BiPAP and HFCWO.ResultsA total of 271 patients received HFCWO and were enrolled for analysis, including 163 patients who received both BiPAP and HFCWO. Patients receiving both BiPAP and HFCWO were associated with decreased frequency of sputum suction (OR: 2.91, 95% CI: 1.46–5.78, P = 0.002), and reduced oxygen need post-HFCWO (OR: 0.55, 95% CI: 0.33–0.91, P = 0.021). However, there was no difference in hospital stay, respiratory failure, ICU admission, or hospital death between the groups. Additionally, there was no difference in these outcomes for patients who received HFCWO twice daily compared to those who received it once daily.ConclusionsCombining BiPAP and HFCWO reduces the need for sputum suction and improves oxygen demand for patients but does not change hospital days, respiratory failure, or mortality. Further large prospective cohort studies are necessary to confirm the efficacy of this management approach.

Nationwide assessment of COVID-19 ventilator and non-invasive respiratory support burden during the early pandemic in the United States

In this nationwide cross-sectional study of 4,055,462 hospital admissions with a diagnosis of coronavirus disease 2019 (COVID-19) from April 2020 to December 2021 identified in the Agency of Healthcare Research and Quality’s Healthcare Cost and Utilization Project National Inpatient Sample in the United States, a total of 489,390 (12.1%) patients experienced endotracheal intubation and mechanical ventilation, with the highest peak in August 2021 (48,735 endotracheal intubations and mechanical ventilation), followed by January 2021 (47,100 endotracheal intubations and mechanical ventilation) and December 2021 (43,835 endotracheal intubations and mechanical ventilation). During the 3-month long large surge from November 2020 to January 2021, a total of 104,750 endotracheal intubations and mechanical ventilation occurred among 1,069,874 COVID-19 admissions. Shock (adjusted-odds ratio 24.21, 95% confidence interval 23.93–24.49) and respiratory failure (adjusted-odds ratio 14.09, 95% confidence interval 13.80–14.38) were the two strongest factors associated with endotracheal intubation and mechanical ventilation. A total of 266,585 (6.6%) patients received non-invasive respiratory support alone without endotracheal intubation and mechanical ventilation during the study period with the highest peak in August 2021 (30,725 cases), followed by January 2021 (28,035 cases), and December 2021 (26,200 cases). The utilization of non-invasive respiratory support without endotracheal intubation and mechanical ventilation increased by nearly three-fold during the 21-month study period (adjusted-odds ratio for the fourth year-quarter of 2021 compared to the second year-quarter of 2020 2.94, 95% confidence interval 2.88–3.00). A total of 515,800 (12.7%) deaths occurred during COVID-19 hospitalization, with highest in the peak of multi-month lasting largest surge (January 2021, 56,775 deaths), followed by August 2021 (47,535 deaths) and December 2021 (46,880 deaths). Among those who deceased following endotracheal intubation and mechanical ventilation, the median time from admission to death was 14 days (interquartile range 7–21). COVID-19 admissions, respiratory intervention approach, and COVID-19 case fatality differed across the nine U.S. census divisions during the study period. In conclusion, these statistics may be useful to inform the national-level preparedness of global pandemic from respiratory illness in the future, possibly exceeding 48,000 endotracheal intubations and mechanical ventilation across the country in a month and 100,000 endotracheal intubations and mechanical ventilation in three months when encountering long-lasting surge with one-million admissions.

Thermal performance of transmissive solar concentrating window for building integration

As temperatures rise, the efficiency of concentrating photovoltaic modules decreases significantly. This study investigated optimal mechanical and natural ventilation strategies for integrated concentrating building skins to minimise component temperatures, thereby enhancing electrical performance and improving indoor thermal conditions. Using ANSYS-CFX simulations, the thermal behaviour of the concentrator module under various ventilation methods was analysed. Results indicated that active ventilation significantly lowers photovoltaic cells temperatures. Under 5 m/s wind speed, the concentrating cells’ temperature under different ventilation forms was decreased by up to 35.12°C. When wind speed was below 3 m/s, the temperature of each component in the concentrating module was decreased rapidly with increasing wind speed, regardless of the ventilation method. However, beyond 3 m/s, the rate of temperature reduction declined gradually. For example, with bottom inlet ventilation, the average temperature of the concentrating cell was decreased by 30.09°C under 3 m/s wind speed. However, when the wind speed was increased from 3 m/s to 5 m/s, the average temperature was decreased by only 2.20°C. Comparing different ventilation forms, mechanical ventilation with bottom inlet airflow achieved better heat dissipation than top or side inlets, while natural ventilation in the external open type outperformed the fully open type.

Beta-Lactam Antibiotic Concentrations and the Acquisition of Multi-Drug Resistant Bacteria in Critically Ill Patients

Antimicrobial resistance (AMR) is a worldwide healthcare emergency. Whether insufficient beta-lactam antibiotic concentrations can be associated with AMR emergence remains controversial. This is a retrospective single-center cohort study including patients admitted to the intensive care unit of a tertiary university hospital from 2009 to 2014, who required a broad-spectrum beta-lactam antibiotic and had at least one therapeutic drug monitoring (TDM). Patients were categorized as having inadequate drug levels if the trough concentration (Cmin) fell below the clinical breakpoint for Pseudomonas aeruginosa. AMR was defined according to breakpoints recommended by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) using the disk diffusion method. A total of 444 patients (male sex, n = 313, 71%; female sex, n = 131, 29%; mean age 58 ± 15 years) were enrolled in the study. Patients received piperacillin/tazobactam (n = 168), ceftazidime/cefepime (n = 58) or meropenem (n = 218); among them, 65 (15%) had insufficient drug levels. Nine of these 65 (13.8%) patients with insufficient antibiotic levels acquired at least one pathogen with AMR within 15 days of TDM, when compared to 84/379 (22%) in the other group (OR 0.56 [95%CI 0.27–1.19]; p = 0.13). In a multivariable competing-risk analysis including male gender, APACHE score on admission, previous colonization by other MDR bacteria, urinary catheter, central venous catheter, mechanical ventilation, previous hospitalization and previous surgery, insufficient antibiotic levels were not associated with AMR acquisition (sHR 0.84 [95% CI 0.42–1.68]). Similar results were found when a higher threshold was used to define insufficient drug levels (Cmin &lt; 4 times the clinical breakpoint). In conclusion, insufficient beta-lactam levels were not independently associated with AMR acquisition. Future prospective studies are needed to evaluate better the relationship between low drug levels and antibiotic resistance acquisition.

Improving weaning and liberation from mechanical ventilation for tracheostomy patients: a quality improvement initiative.

For patients in the intensive care unit (ICU), prolonged mechanical ventilation is associated with poor outcomes. A quality improvement (QI) initiative with the aim of reducing median time on the ventilator for tracheostomy patients was undertaken at a tertiary care ICU in Toronto, Canada. A QI team was formed, and using QI methodology, a deep understanding of our local process was achieved. Based on this information and on the latest evidence on weaning, a standard tracheostomy weaning protocol was designed. The protocol was refined through three developmental and two testing plan-do-study-act cycles. This study was a prospective time series showing the effect of the implementation of our intervention on tracheotomy patients' time on the ventilator. The baseline median number of days on the ventilator after tracheostomy insertion was 17. Within 12 months of the introduction of the intervention, a shift in the data showing a reduction in the median time on the ventilator to 10.6 days had developed. Length of stay in the ICU was reduced by 4.3 days. Adherence and compliance to the protocol also improved over time. A standard tracheostomy weaning protocol was successfully developed, tested and implemented in a tertiary care ICU. Using strategies such as frequent communication with key stakeholders and incorporating a tracheostomy weaning progress sheet to document and track tracheostomy patients and their outcomes, this QI intervention has become engrained in the local culture at our centre. This weaning protocol has successfully reduced the median time on the ventilator for tracheostomy patients by over 6 days.