Mechanical Ventilation In Adults Research Articles

A novel, cassette-based nitric oxide delivery system with an advanced feedback control algorithm accurately delivers nitric oxide via the anesthesia machine independent of fresh gas flow rate and volatile anesthetic agent

Nitric oxide (NO), a selective pulmonary vasodilator, can be delivered via conventional ICU and anesthesia machine ventilators. Anesthesia machines are designed for rebreathing of circulating gases, reducing volatile anesthetic agent quantity used. Current cylinder- and ionizing-based NO delivery technologies use breathing circuit flow to determine NO delivery and do not account for recirculated gases; therefore, they cannot accurately dose NO at FGF below patient minute ventilation (MV). A novel, cassette-based NO delivery system (GENOSYL® DS, Vero Biotech Inc.) uses measured NO concentration in the breathing circuit as an input to an advanced feedback control algorithm, providing accurate NO delivery regardless of FGF and recirculation of gases. This study evaluated GENOSYL® DS accuracy with different anesthesia machines, ventilation parameters, FGFs, and volatile anesthetics. GENOSYL® DS was tested with GE Aisys and Dräger Fabius anesthesia machines to determine NO dose accuracy with FGF < patient MV, and with a Getinge Flow-i anesthesia machine to determine NO dose accuracy when delivering various volatile anesthetic agents. Neonatal and adult mechanical ventilation parameters and circuits were used. GENOSYL® DS maintained accurate NO delivery with all three anesthesia machines, at low FGF with recirculation of gases, and with all volatile anesthetic agents at different concentrations. Measured NO2 levels remained acceptable at ≤ 1 ppm with set NO dose ≤ 40 ppm. GENOSYL® DS, with its advanced feedback control algorithm, is the only NO delivery system capable of accurately dosing NO with anesthesia machines with rebreathing ventilation parameters (FGF < MV) regardless of anesthetic agent.

Mechanical ventilation: Beyond the basics.

Mechanical ventilation is rarely a simple matter. Skill and knowledge are required to operate the ventilator modes, choose the optimal settings, and understand many monitored variables. Supporting the patient safely and effectively is the top priority in providing mechanical ventilation. This article discusses mechanical ventilation in adults.

Tracheal Intubation and Mechanical Ventilation in Adults with Severe Salicylate Poisoning

BackgroundSalicylate poisoning may lead to critical acid–base disturbances. Tracheal intubation and mechanical ventilation for patients with severe salicylism has been strongly discouraged. Study ObjectiveThis study aims to describe pH trends, complications, and outcomes in a cohort of salicylate-poisoned patients who were intubated. MethodsThis retrospective observational study included adults presenting to the emergency department (ED) with severe salicylate poisoning (serum salicylate concentration >40 mg/dL and admission to an intensive care unit) over a 14-year period (2007–2021). The primary and secondary outcomes were the change in serum pH and the occurrence of severe complications (systolic blood pressure <80 mm Hg, oxygen saturation <80%, or cardiac arrest), respectively, in the 6 h after presentation. ResultsAmong 32 adults with severe salicylate poisoning (median serum salicylate level 64.2, interquartile range 52.5–70.7), 11 (34%) underwent tracheal intubation. The initial mean pH (±SD) in the no intubation group was 7.48 ± 0.07 and was 7.36 ± 0.04 in the intubation group. The mean absolute difference in pH measured before and after intubation was -0.02 (95% confidence interval −0.11 to 0.07). No severe complications were observed during or up to 6 h after tracheal intubation and mechanical ventilation. ConclusionIn our single-center experience managing adults with severe salicylate poisoning, tracheal intubation and mechanical ventilation were not associated with substantial perturbation of serum pH or severe complications. These findings challenge the current paradigm that these interventions should be avoided in salicylate-poisoned patients.

AARC Clinical Practice Guideline: Spontaneous Breathing Trials for Liberation From Adult Mechanical Ventilation.

Despite prior publications of clinical practice guidelines related to ventilator liberation, some questions remain unanswered. Many of these questions relate to the details of bedside implementation. We, therefore, formed a guidelines committee of individuals with experience and knowledge of ventilator liberation as well as a medical librarian. Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we make the following recommendations: (1) We suggest that calculation of a rapid shallow breathing index is not needed to determine readiness for a spontaneous breathing trial (SBT) (conditional recommendation; moderate certainty); (2) We suggest that SBTs can be conducted with or without pressure support ventilation (conditional recommendation, moderate certainty); (3) We suggest a standardized approach to assessment and, if appropriate, completion of an SBT before noon each day (conditional recommendation, very low certainty); and (4) We suggest that FIO2 should not be increased during an SBT (conditional recommendation, very low certainty). These recommendations are intended to assist bedside clinicians to liberate adult critically ill patients more rapidly from mechanical ventilation.

Nursing care to prevent ventilator-associated pneumonias in adult patients

INTRODUCTION: Pneumonia associated with mechanical ventilation is a serious complication in patients with artificial airway in intensive care units, increasing morbidity and mortality. It increases the use of antibiotics, oropharyngeal microbial resistance increasing the risk, driving the need for preventive strategies. METHODS: A review of scientific articles published between (2018-2023) in PubMed was conducted. Key terms: nursing prevention, Pneumonia associated with mechanical ventilation in adults. Fourteen relevant studies were selected for analysis, looking for preventive measures of mechanical ventilation-associated pneumonia. RESULTS: Fifteen articles analyzed in the last 5 years (2018-2023), focused on prevention of mechanical ventilation-associated pneumonia. The most effective preventive measures included head-of-bed elevation, oral hygiene with chlorhexidine, subglottic suctioning, and endotracheal tube pressure control. Implementation of these strategies decreased the incidence of ventilator-associated pneumonia and improved the recovery of patients on mechanical ventilation. CONCLUSION: Ventilator-associated pneumonia represents a challenge in intensive care units, with high mortality. Preventive measures, such as bundles of care, can reduce infections and improve patient health. Nursing staff collaboration is essential for the successful implementation of preventive strategies in older patients to reduce the risks associated with mechanical ventilation and improve care in the intensive care unit.

Predictive value of extubation failure by decrease in central venous oxygen saturation: A systematic review and meta-analysis

BackgroundThe predictive power of extubation failure diagnosed by decrease in central venous oxygen saturation (ΔScvO2) varies by studies. Here we summarized the diagnostic value of extubation failure tested by ΔScvO2. MethodsA comprehensive online search was performed to select potentially eligible studies that evaluated the predictive power of extubation failure tested by ΔScvO2. A manual search was also performed to identify additional studies. Data were extracted to calculate the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) to evaluate the predictive power of extubation failure. ResultsOverall, five studies including 353 patients were included in this review, of whom 105 (30%) were extubation failure. The cutoff values of ΔScvO2 varied across studies, ranging from 3.8% to 5.4%. Heterogeneity between studies was assessed with an overall Q = 0.007, I2 = 0%, and P = 0.498. The pooled sensitivity and specificity for the overall population were 0.83 (95% CI: 0.74–0.90) and 0.88 (95% CI: 0.83–0.92), respectively. The pooled positive LR and negative LR were 7.2 (95%CI: 4.6–11.2) and 0.19 (95%CI: 0.12–0.31), respectively. The DOR was 38 (95% CI: 17–86). Overall, the pooled AUROC was 0.92 (95% CI: 0.90–0.94). ConclusionsThe ΔScvO2 performed well in predicting extubation failure in adult mechanical ventilation patients. Further studies with a larger data set and well-designed models are required to confirm the diagnostic accuracy and utility of ScvO2 in predicting extubation outcomes in mechanical ventilation patients.

277-LB: Weight Cycling Is Associated with ICU Admission and Mechanical Ventilation in Adults with Diabetes Hospitalized with COVID-19

Weight variability in diabetes is an emerging risk factor for macrovascular complications and mortality, potentially via increased inflammation. We examined the impact of pre-admission weight cycling (WC) on COVID-19-related outcomes, including in-hospital mortality, ICU admission, and mechanical ventilation (MV), using a large multicenter cohort. This study included 277 adults with diabetes hospitalized with COVID-19 (March 2020-February 2021) at 5 university hospitals in the eastern US (COVIDEastDM Consortium) with body weight measurements at 0, 6, and 12 months before admission. Weight change was considered significant if it exceeded 5% in each 6-month interval. The cohort was grouped into four weight categories: unchanged (n=57; reference group), weight loss (WL; n=88), weight gain (WG; n=50) and WC (n=32), and was 54.6% male, 58.6% White, 24.2% Black, 18.5% Hispanic, with mean (SD) age 65.1 (12.6) years and HbA1c 7.7 (2.0)%. During hospitalization, 41.9% subjects were admitted to the ICU, 25.1% received MV, and 15.0% died. Age was the strongest risk factor for mortality (OR = 1.08 [95% CI: 1.03-1.13), and the presence of pre-existing comorbidity for both ICU admission (OR = 2.58 [1.13-5.90]) and MV (OR = 3.89 [1.30-11.64]). In an adjusted model, WC, but not WL or WG, was associated with ICU admission (OR = 3.09 [1.11-8.59]) and MV ((OR = 4.59 [1.48-14.19]), but not with mortality (OR = 3.19 [0.76-13.32]). The glycemic gap, shown previously to be associated with increased MV and mortality, did not change the relationship between WC and outcomes. The WC group trended toward higher peak ESR (94.3±23.1 ml/h vs. 62.2±33.5 ml/h, P=0.044) and hsCRP levels (150.0±133.9 mg/L vs. 104.1±105.3 mg/L, P=0.142). Conclusion: Weight cycling is associated with ICU admission and mechanical ventilation in adults with diabetes and COVID-19. Our findings identify a unique vulnerability of individuals with diabetes and recent weight cycling. Disclosure Y. Kang: None. R. S. Weinstock: Consultant; Jaeb Center for Health Research, Other Relationship; Wolters Kluwer Health, Research Support; Insulet Corporation, Medtronic, Eli Lilly and Company, Novo Nordisk, Boehringer Ingelheim Inc., Hemsley Charitable Trust, National Institute of Diabetes and Digestive and Kidney Diseases, Tandem Diabetes Care, Inc., Kowa Pharmaceuticals America, Inc. M. E. Mcdonnell: None. D. C. Simonson: Stock/Shareholder; Phase V Technologies, Inc., GI Windows. A. S. Chaugule: None. R. K. Garg: None. G. Gopalakrishnan: Research Support; Spruce Biosciences, Sparrow Pharmaceuticals Inc, Medtronic. K. Howard: None. J. Lebastchi: None. J. Mitri: Other Relationship; Novo Nordisk, Research Support; Kowa Company, Ltd. N. E. Palermo: Research Support; Dexcom, Inc.

The basics of mechanical ventilation in adults

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1034. Risk Score for the Need of Mechanical Ventilation in Adults Presenting with Encephalitis.

Abstract Background The purpose of this study was to stratify risk subgroups for mechanical ventilation in adults presenting with encephalitis. Methods A retrospective observational study of 271 adults ( &amp;gt; 18 years old) admitted with an encephalitis diagnosis according to International Encephalitis Consortium guidelines were enrolled from sixteen hospitals in Houston, Texas between the years of 2005 and 2015. Results Mechanical ventilation (MV) was utilized in 91/271 (33.6%) adults with encephalitis and it was associated in hospital mortality (24.2% vs 3.9%, P&amp;lt; 0.001). There were no significant differences in age, race, gender, underlying comorbidities or immunosuppressive conditions, fever, symptoms on presentation, focal neurological deficits, Glasgow coma scale, CSF profile, and abnormal cranial imaging including cerebral edema between patients with or without MV (P &amp;gt;0.05). Risk factors associated with the need for MV included seizures, serum white blood cell (WBC) counts &amp;gt;11,000/mm3, a Sequential Organ Failure Assessment (SOFA) score &amp;gt;3 and abnormal Electroencephalogram (EEG) (P&amp;lt; 0.05). A risk model was created using 3 baseline variables independently associated with MV (P&amp;lt; 0.05): serum WBC count &amp;gt;11,000/mm3, a SOFA &amp;gt;3 and abnormal EEG. The risk score classified patients into 3 subgroups for the need for MV: low risk [none of the three variables, 1/32 (3.1%)], intermediate risk [1 of the 3 variables, 19/106 (17.9%], and high risk [2 or 3 of the 3 variables, 71/136 (52.2%)]. Risk Classification for Mechanical Ventilation in Patients with Encephalitis. a Predictors include white blood cell count &amp;gt; 11, Sequential Organ Failure Assessment (SOFA) scores &amp;gt; 3 or abnormal Electroencephalogram (EEG) Receiver Operating Characteristic (ROC) curve of risk score (Low =0 variables seen in the patients, Intermediate = 1 variable seen, and High = 2 or 3 variables seen). Area under the curve = 0.728. Conclusion This risk score can be utilized by clinicians to assess the need for MV in adults presenting with encephalitis to help stratify patients that require intensive care unit admissions. Disclosures Rodrigo Hasbun, MD MPH FIDSA, Biofire: Grant/Research Support|Biofire: Honoraria.

Position of different nebulizer types for aerosol delivery in an adult model of mechanical ventilation.

BackgroundThe optimal positions of different types of nebulizer for aerosol delivery remain unclear.MethodsThree ICU ventilators employing three types of nebulizer were separately connected to a simulated lung to simulate nebulization during invasive ventilation. Assist/control-pressure control (A/C-PC) mode was utilized, with inspiratory pressure (Pi) set to 12 cmH2O and positive end expiratory pressure (PEEP) set to 5 cmH2O, and with a target Vt of 500 ml. The bias flow of all the ventilators was set to 2 L/min. The three nebulizers were the continuous jet nebulizer (c-JN), the inspiratory synchronized jet nebulizer (i-JN), and the vibrating mesh nebulizer (VMN). The five nebulizer positions were as follows: at the Y-piece (position 1) and 15 cm from the Y-piece (position 2) between the endotracheal tube and the Y-piece, at the Y-piece (position 3) and 15 cm from the Y-piece (position 4) in the inspiratory limb; and at the humidifier inlet (position 5). Aerosols were collected with a disposable filter placed at the simulated lung outlet (n = 3) and were measured by UV spectrophotometry (276 nm). The measurements were compared under different experimental conditions.ResultsThe aerosol delivery of c-JN, i-JN, and VMN was 5.33 ± 0.49~11.12 ± 0.36%, 7.73 ± 0.76~13.75 ± 0.46% and 11.13 ± 56–30.2 ± 1.63%, respectively. The higher aerosol delivery: for c-JN~Positions 2 (10.95 ± 0.15%), fori-JN~Positions 1 or 2 (12.91 ± 0.88% or 13.45 ± 0.42%), for VMN~Positions 4(29.03 ± 1.08%); the lower aerosol delivery: for c-JN~Positions 1, 3 or 5, fori-JN~Positions 4 or 5, for VMN~Positions 5.The highest aerosol delivery:For c-JN at Position 2 (10.95 ± .15%), for i-JN at Position 1 or 2 (12.91 ± .88% or 13.45 ± .42%), for VMN at Positions 4 (29. 03 ± 1.08%); the lower aerosol delivery: for c-JN at Positions 1, 3 or 5, for i-JN at Positions 4 or 5, for VMN at Positions 5. The highest aerosol deliveryof c-JN was lower than that of i-JN while the VMN was the highest (all P < .05). However, no differences were observed between the highest aerosol delivery with c-JN and the lowest aerosol delivery with i-JN. Similar results were found between the lowest aerosol delivery with VMN and the highest aerosol delivery with c-JN /i-JN in the Avea ventilator. There were no differences in the highest aerosol delivery of each nebulizer among the different ventilators (all p > 0.05).ConclusionDuring adult mechanical ventilation, the type and position of nebulizer influences aerosol delivery efficiency, with no differences between ventilators.

Performance Characteristics of a Novel 3D-Printed Bubble Intermittent Mandatory Ventilator (B-IMV) for Adult Pulmonary Support.

The COVID-19 pandemic has brought attention to the need for developing effective respiratory support that can be rapidly implemented during critical surge capacity scenarios in healthcare settings. Lung support with bubble continuous positive airway pressure (B-CPAP) is a well-established therapeutic approach for supporting neonatal patients. However, the effectiveness of B-CPAP in larger pediatric and adult patients has not been addressed. Using similar principles of B-CPAP pressure generation, application of intermittent positive pressure inflations above CPAP could support gas exchange and high work of breathing levels in larger patients experiencing more severe forms of respiratory failure. This report describes the design and performance characteristics of the BubbleVent, a novel 3D-printed valve system that combined with commonly found tubes, hoses, and connectors can provide intermittent mandatory ventilation (IMV) suitable for adult mechanical ventilation without direct electrification. Testing of the BubbleVent was performed on a passive adult test lung model and compared with a critical care ventilator commonly used in tertiary care centers. The BubbleVent was shown to deliver stable PIP and PEEP levels, as well as timing control of breath delivery that was comparable with a critical care ventilator.

Comparison of advanced closed-loop ventilation modes with pressure support ventilation for weaning from mechanical ventilation in adults: A systematic review and meta-analysis.

To compare neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV), adaptive support ventilation (ASV) and Smartcare pressure support (Smartcare/PS) with standard pressure support ventilation (PSV) regarding their effectiveness for weaning critically ill adults from invasive mechanical ventilation (IMV). Electronic databases were searched to identify parallel-group randomized controlled trials (RCTs) comparing NAVA, PAV, ASV, or Smartcare/PS with PSV, in adult patients under IMV through July 28, 2021. Primary outcome was weaning success. Secondary outcomes included weaning time, total MV duration, reintubation or use of non-invasive MV (NIMV) within 48h after extubation, in-hospital and intensive care unit (ICU) mortality, in-hospital and ICU length of stay (LOS) (PROSPERO registration No:CRD42021270299). Twenty RCTs were finally included. Compared to PSV, NAVA was associated with significantly lower risk for in-hospital and ICU death and lower requirements for post-extubation NIMV. Moreover, PAV showed significant advantage over PSV in terms of weaning rates, MV duration and ICU LOS. No significant differences were found between ASV or Smart care/PS and PSV. Moderate certainty evidence suggest that PAV increases weaning success rates, shortens MV duration and ICU LOS compared to PSV. It is also noteworthy that NAVA seems to improve in-hospital and ICU survival.

Practical Review of Mechanical Ventilation in Adults and Children in the Operating Room and Emergency Department

During general anesthesia, mechanical ventilation can cause pulmonary damage through mechanism of ventilator-induced lung injury, which is a major cause of post-operative pulmonary complications, which varies between 5 and 33% and increases the 30-day mortality of the surgical patient significantly. The aim of this review is to analyze different variables which played a key role in the safe application of mechanical ventilation in the operating room and emergency setting. Also, we wanted to analyze different types of the population that underwent intraoperative mechanical ventilation like obese patients, pediatric and adult population and different strategies such as one lung ventilation and ventilation in trendelemburg position. The peer-reviewed articles analyzed were selected according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) from Pubmed/Medline, Ovid/Wiley and Cochrane Library, combining key terms such as: "pulmonary post-operative complications", "protective ventilation", "alveolar recruitment maneuvers", "respiratory compliance", "intraoperative paediatric ventilation", "best peep", "types of ventilation". Among the 230 papers identified, 150 articles were selected, after title - abstract examination and removing the duplicates, resulting in 94 articles related to mechanical ventilation in operating room and emergency setting that were analyzed. Careful preoperative patient's evaluation and protective ventilation (i.e., use of low tidal volumes, adequate PEEP and alveolar recruitment maneuvers) has been shown to be effective not only in limiting alveolar de-recruitment, alveolar overdistension and lung damage, but also in reducing the onset of Pulmonary Post-operative Complications (PPCs). Mechanical ventilation is like "Janus Bi-front" because it is essential for surgical procedures, for the care of critical care patients and in life-threatening conditions, but it can be harmful to the patient if continued for a long time and where an excessive dose of oxygen is administered into the lungs. Low tidal volume is associated with a minor rate of PPCs and other complications and every complication can increase the length of Stay, adding cost to NHS between 1580 € and 1650 € per day in Europe and currently the prevention of PPCS is the only weapon that we possess.

Evaluation of Aerosol Drug Delivery Options during Adult Mechanical Ventilation in the COVID-19 Era.

Drug delivery devices used for aerosol therapy during mechanical ventilation to ease the symptoms of respiratory diseases provide beneficial treatment but can also pose challenges. Reflecting the significant changes in global guidance around aerosol usage and lung-protective ventilation strategies, seen in response to the COVID-19 pandemic, for the first time, we describe the drug delivery performance of commonly used devices under these conditions. Here, vibrating mesh nebuliser (VMN), jet nebuliser (JN) and pressurised metered-dose inhaler (pMDI) performance was assessed during simulated adult mechanical ventilation. Both standard test breathing patterns and those representatives of low tidal volume (LTV) ventilation with concurrent active and passive humidification were investigated. Drug delivery using a VMN was significantly greater than that with a JN and pMDI for both standard and LTV ventilation. Humidification type did not affect the delivered dose across all device types for standard ventilation. Significant variability in the pMDI dosing was evident, depending on the timing of actuation and the adapter type used. pMDI actuation synchronised with inspiration resulted in a higher delivered drug dose. The type of adapter used for pMDI actuation influenced drug delivery, with the highest dose observed using the CombiHaler.

Biomarkers for oxidative stress and organ injury during Transnasal Humidified Rapid‐Insufflation Ventilatory Exchange compared to mechanical ventilation in adults undergoing microlaryngoscopy: A randomised controlled study

Apnoeic oxygenation using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) during general anaesthesia prolongs the safe apnoeic period. However, there is a gap of knowledge how THRIVE-induced hyperoxia and hypercapnia impact vital organs. The primary aim of this randomised controlled trial was to characterise oxidative stress and, secondary, vital organ function biomarkers during THRIVE compared to mechanical ventilation (MV). Thirty adult patients, American Society of Anesthesiologists (ASA) 1-2, undergoing short laryngeal surgery under general anaesthesia were randomised to THRIVE, FI O2 1.0, 70Lmin-1 during apnoea or MV. Blood biomarkers for oxidative stress, malondialdehyde and TAC and vital organ function were collected (A) preoperatively, (B) at procedure completion and (C) at PACU discharge. Mean apnoea time was 17.9 (4.8)min and intubation to end-of-surgery time was 28.1 (12.8)min in the THRIVE and MV group, respectively. Malondialdehyde increased from 11.2 (3.1) to 12.7 (3.1)µM (P=.02) and from 9.5 (2.2) to 11.6 (2.6)µM (P=.003) (A to C) in the THRIVE and MV group, respectively. S100B increased from 0.05 (0.02) to 0.06 (0.02)µgL-1 (P=.005) (A to C) in the THRIVE group. No increase in TAC, CRP, leukocyte count, troponin-T, NTproBNP, creatinine, eGFRcrea or NSE was demonstrated during THRIVE. While THRIVE and MV was associated with increased oxidative stress, we found no change in cardiac, inflammation or kidney biomarkers during THRIVE. Further evaluation of stress and inflammatory response and cerebral and cardiac function during THRIVE is needed.

A parallel-group, multicenter randomized, double-blinded, placebo-controlled, phase 2/3, clinical trial to test the efficacy of pyridostigmine bromide at low doses to reduce mortality or invasive mechanical ventilation in adults with severe SARS-CoV-2 infection: the Pyridostigmine In Severe COvid-19 (PISCO) trial protocol

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the causative agent of coronavirus disease 2019 (COVID-19), may lead to severe systemic inflammatory response, pulmonary damage, and even acute respiratory distress syndrome (ARDS). This in turn may result in respiratory failure and in death. Experimentally, acetylcholine (ACh) modulates the acute inflammatory response, a neuro-immune mechanism known as the inflammatory reflex. Recent clinical evidence suggest that electrical and chemical stimulation of the inflammatory reflex may reduce the burden of inflammation in chronic inflammatory diseases. Pyridostigmine (PDG), an ACh-esterase inhibitor (i-ACh-e), increases the half-life of endogenous ACh, therefore mimicking the inflammatory reflex. This clinical trial is aimed at evaluating if add-on of PDG leads to a decrease of invasive mechanical ventilation and death among patients with severe COVID-19.MethodsA parallel-group, multicenter, randomized, double-blinded, placebo-controlled, phase 2/3 clinical trial to test the efficacy of pyridostigmine bromide 60 mg/day P.O. to reduce the need for invasive mechanical ventilation and mortality in hospitalized patients with severe COVID-19.DiscussionThis study will provide preliminary evidence of whether or not -by decreasing systemic inflammation- add-on PDG can improve clinical outcomes in patients with severe COVID-19.Trial registrationClinicalTrials.gov NCT04343963 (registered on April 14, 2020).

Factors Determining Continuous Infusion Aerosol Delivery During Mechanical Ventilation.

Continuous nebulization of prostacyclins and albuterol by infusion pump during mechanical ventilation evolved as a popular off-label treatment for severe hypoxemic respiratory failure and asthma. Most institutions use a vibrating mesh nebulizer. A new breath-enhanced jet nebulizer is a potential alternative. This study was designed to compare these devices to better define factors influencing continuous infusion aerosol delivery. Device function, ventilator settings, and infusion pump flow were studied invitro. Using a bench model of adult mechanical ventilation, radiolabeled saline was infused at6 flows (1.5-12mL/h) into test nebulizers; 4 examples of each were used in rotation to test device reproducibility. Four breathing patterns with duty cycles (percentage of inspiratory time) ranging from0.13 to0.34 were tested. The vibrating mesh nebulizer was installed on the "dry" side of the heated humidifier (37°C). The breath-enhanced jet nebulizer, installed on the "wet" side, was powered by air at3.5L/min and50psi. Infusion time was1h. Inhaled mass of aerosol was collected on a filter at the airway opening. Inhaled mass was expressed as the percentage of the initial syringe radioactivity delivered per hour. Radioactivity deposited in the circuit was measured with a gamma camera. Data were analyzed with multiple linear regression. Variation in inhaled mass was significantly explained by pump flow and duty cycle (R20.92) and not by nebulizer technology. Duty cycle effects were more apparent at higher pump flow. Vibrating mesh nebulizers failed to nebulize completely in 20% of the test runs. Mass balance indicated that vibrating mesh nebulizers deposited 15.3% in the humidifier versus 0.2% for breath-enhanced jet nebulizer. Aerosol delivery was determined by infusion pump flow and ventilator settings with comparable aerosol delivery between devices. The breath-enhanced jet nebulizer was more reliable than the vibrating mesh nebulizer;10-12mL/h was the maximum infusion flow for both nebulizer technologies.

Proportional assist ventilation versus pressure support ventilation for weaning from mechanical ventilation in adults: a meta-analysis and trial sequential analysis

BackgroundPressure support ventilation (PSV) is the prevalent weaning method. Proportional assist ventilation (PAV) is an assisted ventilation mode, which is recently being applied to wean the patients from mechanical ventilation. Whether PAV or PSV is superior for weaning remains unclear.MethodsEligible randomized controlled trials published before April 2020 were retrieved from databases. We calculated the risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CIs).ResultsSeven articles, involving 634 patients, met the selection criteria. Compared to PSV, PAV was associated with a significantly higher rate of weaning success (fixed-effect RR 1.16; 95% CI 1.07–1.26; I2 = 0.0%; trial sequential analysis-adjusted CI 1.03–1.30), and the trial sequential monitoring boundary for benefit was crossed. Compared to PSV, PAV was associated with a lower proportion of patients requiring reintubation (RR 0.49; 95% CI 0.28–0.87; I2 = 0%), a shorter ICU length of stay (MD − 1.58 (days), 95% CI − 2.68 to − 0.47; I2 = 0%), and a shorter mechanical ventilation duration (MD − 40.26 (hours); 95% CI − 66.67 to − 13.84; I2 = 0%). There was no significant difference between PAV and PSV with regard to mortality (RR 0.66; 95% CI 0.42–1.06; I2 = 0%) or weaning duration (MD − 0.01 (hours); 95% CI − 1.30–1.28; I2 = 0%).ConclusionThe results of the meta-analysis suggest that PAV is superior to PSV in terms of weaning success, and the statistical power is confirmed using trial sequential analysis.Graphical abstract

Lung volume changes in Apnoeic Oxygenation using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) compared to mechanical ventilation in adults undergoing laryngeal surgery.

BackgroundTransnasal Humidified Rapid‐Insufflation Ventilatory Exchange (THRIVE) using high‐flow 100% oxygen during apnoea has gained increased use during difficult airway management and laryngeal surgery due to a slower carbon dioxide rise compared to traditional apnoeic oxygenation. We have previously demonstrated high arterial oxygen partial pressures and an increasing arterial‐alveolar carbon dioxide difference during THRIVE. Primary aim of this study was to characterise lung volume changes measured with electrical impedance tomography during THRIVE compared to mechanical ventilation.MethodsThirty adult patients undergoing laryngeal surgery under general anaesthesia were randomised to THRIVE or mechanical ventilation. Subjects were monitored with electrical impedance tomography and repeated blood gas measurement perioperatively. The THRIVE group received 100% oxygen at 70 l min−1 during apnoea. The mechanical ventilation group was intubated and normoventilated with an FiO2 of 0.4.ResultsMean age were 48.2 (19.9) and 51.3 (12.3) years, and BMI 26.0 (4.5) and 26.0 (3.9) in the THRIVE and mechanical ventilation group respectively. Mean apnoea time in the THRIVE group was 17.9 (4.8) min. Mean apnoea to end‐of‐surgery time was 28.1 (12.8) min in the mechanical ventilation group. No difference in delta End Expiratory Lung Impedance was seen between groups over time. In the THRIVE group all but three subjects were well oxygenated during apnoea. THRIVE was discontinued for the three patients who desaturated.ConclusionsNo difference in lung volume change over time, measured by electrical impedance tomography, was detected when using THRIVE compared to mechanical ventilation during laryngeal surgery.

Prone Positioning for Acute Respiratory Distress Syndrome in Adults.

Prone Positioning for Acute Respiratory Distress Syndrome in Adults.