Expiratory flow limitation during mechanical ventilation: real-time detection and physiological subtypes.

BACKGROUND: Tidal expiratory flow limitation (EFLT) complicates the delivery of mechanical ventilation but is only diagnosed by performing specific manoeuvres. Instantaneous analysis of expiratory resistance (Rex) can be an alternative way to detect EFLT without changing ventilatory settings. This study aimed to determine the agreement of EFLT detection by Rex analysis and the PEEP reduction manoeuvre using contingency table and agreement coefficient. The patterns of Rex were explored. METHODS: Medical patients ≥ 15-year-old receiving mechanical ventilation underwent a PEEP reduction manoeuvre from 5 cmH2O to zero for EFLT detection. Waveforms were recorded and analyzed off-line. The instantaneous Rex was calculated and was plotted against the volume axis, overlapped by the flow-volume loop for inspection. Lung mechanics, characteristics of the patients, and clinical outcomes were collected. The result of the Rex method was validated using a separate independent dataset. RESULTS: 339 patients initially enrolled and underwent a PEEP reduction. The prevalence of EFLT was 16.5%. EFLT patients had higher adjusted hospital mortality than non-EFLT cases. The Rex method showed 20% prevalence of EFLT and the result was 90.3% in agreement with PEEP reduction manoeuvre. In the validation dataset, the Rex method had resulted in 91.4% agreement. Three patterns of Rex were identified: no EFLT, early EFLT, associated with airway disease, and late EFLT, associated with non-airway diseases, including obesity. In early EFLT, external PEEP was less likely to eliminate EFLT. CONCLUSIONS: The Rex method shows an excellent agreement with the PEEP reduction manoeuvre and allows real-time detection of EFLT. Two subtypes of EFLT are identified by Rex analysis. TRIAL REGISTRATION: Clinical trial registered with www.thaiclinicaltrials.org (TCTR20190318003). The registration date was on 18 March 2019, and the first subject enrollment was performed on 26 March 2019.

The ratio of respiratory rate to diaphragm thickening fraction for predicting extubation success.

BACKGROUND: Several parameters are used to predict successful extubation but their accuracy varies among studies. We hypothesized that combining conventional and diaphragmatic parameters would be more effective than using just one. Our primary objective was to evaluate the performance of the respiratory rate in relation to the diaphragm thickening fraction (RR/DTF) ratio to predict the success of extubation. METHODS: We enrolled 130 adult patients who required invasive mechanical ventilation, planned to be extubated, and used a spontaneous breathing trial (SBT) in the intensive care unit from July 2020 to April 2022. We measured the conventional parameters and the diaphragmatic parameters 2 h after SBT. The RR/DTF was calculated by dividing the respiratory rate (RR) by the diaphragm thickening fraction (DTF). The definition of weaning success is successful extubation within 48 h. RESULTS: Of 130 patients, 8 patients (6.2%) were reintubated within 48 h. The RR/DTF was significantly lower in the successful extubation group than in the extubation failure group (right hemidiaphragm; 0.47 (0.33-0.64) vs 1.1 (0.6-2.32), p < 0.001 and left hemidiaphragm; 0.45 (0.31-0.65) vs 0.78 (0.48-1.75), p < 0.001). The right RR/DTF using a cut-off point at ≤ 0.81 had a sensitivity of 87.7%, a specificity of 75%, and areas under the receiver operating characteristic curve (AUROC) of 0.762 for predicting successful extubation (p = 0.013). The sensitivity, specificity, and AUROC for predicting extubation success of right DTF at a cut-off point of ≥ 26.2% were 84.3%, 62.5%, and 0.775, respectively (p = 0.009). CONCLUSION: The RR/DTF ratio is a promising tool for predicting extubation outcome. Additionally, using RR/DTF was more reliable than conventional or diaphragmatic parameters alone in predicting extubation success.

Relationship between lung ultrasound and electrical impedance tomography as regional assessment tools during PEEP titration in acute respiratory distress syndrome caused by multi-lobar pneumonia: a pilot study.

Acute respiratory distress syndrome (ARDS) caused by multilobar pneumonia (MLP) is markedly different from typical ARDS in pathology, imaging characteristics, and lung mechanics. Regional lung assessment is required. We aimed to analyze the relationship between two regional assessment tools, lung ultrasound (LUS) and electrical impedance tomography (EIT) during positive end-expiratory pressure (PEEP) titration, and determine an appropriate PEEP level. We conducted a prospective study of patients with ARDS caused by MLP with PaO2/FiO2 < 150 mmHg. All subjects were equipped with two EIT belts connected with a single EIT machine to measure upper and lower hemithorax impedance change alternatingly at each PEEP level. LUS score was simultaneously determined in chest wall regions corresponding to the EIT regions during PEEP titration. We acquired EIT and LUS data in eight regions of interest at seven PEEP levels in 12 subjects. Therefore, 672 pairs of data were obtained for analysis. There were significant relationships between LUS score and tidal impedance variation and pixel compliance (Cpix). The Spearman's rho between LUS score vs. tidal impedance variation and LUS score vs. the Cpix were - 0.142, P < 0.001, and - 0.195, P < 0.001, respectively. The relationship between the LUS score and Cpix remained the same at every PEEP level but did not reach statistical significance. The individual's mean expected PEEP by LUS was similar to the EIT [10.33(± 1.67) vs. 10.33(± 1.44) cm H2O, P = 0.15]. Regarding the MLP, the LUS scores were associated with EIT parameters, and LUS scores might proof helpful for finding individual PEEP settings in MLP.

Weaning Outcomes in Patients with Brain Injury.

BACKGROUND: Despite the need for specific weaning strategies in neurological patients, evidence is generally insufficient or lacking. We aimed to describe the evolution over time of weaning and extubation practices in patients with acute brain injury compared with patients who are mechanically ventilated (MV) due to other reasons. METHODS: We performed a secondary analysis of three prospective, observational, multicenter international studies conducted in 2004, 2010, and 2016 in adults who had need of invasive MV for more than 12 h. We collected data on baseline characteristics, variables related to management ventilator settings, and complications while patients were ventilated or until day 28. RESULTS: Among the 20,929 patients enrolled, we included 12,618 (60%) who started the weaning from MV, of whom 1722 (14%) were patients with acute brain injury. In the acutely brain-injured cohort, 538 patients (31%) did not undergo planned extubation, defined as the need for a tracheostomy without an attempt of extubation, accidental extubation, and death. Among the 1184 planned extubated patients with acute brain injury, 202 required reintubation (17%). Patients with acute brain injury had a higher odds for unplanned extubation (odds ratio [OR] 1.35, confidence interval for 95% [CI 95%] 1.19-1.54; p < 0.001), a higher odds of failure after the first attempt of weaning (spontaneous breathing trial or gradual reduction of ventilatory support; OR 1.14 [CI 95% 1.01-1.30; p = 0.03]), and a higher odds for reintubation (OR 1.41 [CI 95% 1.20-1.66; p < 0.001]) than patients without brain injury. Patients with hemorrhagic stroke had the highest odds for unplanned extubation (OR 1.47 [CI 95% 1.22-1.77; p < 0.001]), of failed extubation after the first attempt of weaning (OR 1.28 [CI 95% 1.06-1.55; p = 0.009]), and for reintubation (OR 1.49 [CI 95% 1.17-1.88; p < 0.001]). In relation to weaning evolution over time in patients with acute brain injury, the risk for unplanned extubation showed a downward trend; the risk for reintubation was not associated to time; and there was a significant increase in the percentage of patients who underwent extubation after the first attempt of weaning from MV. CONCLUSIONS: Patients with acute brain injury, compared with patients without brain injury, present higher odds of undergoing unplanned extubated after weaning was started, lower odds of being extubated after the first attempt, and a higher risk of reintubation.

Evolution Over Time of Ventilatory Management and Outcome of Patients With Neurologic Disease.

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease.

Machine learning predicts mortality based on analysis of ventilation parameters of critically ill patients: multi-centre validation.

BACKGROUND: Mechanical Ventilation (MV) is a complex and central treatment process in the care of critically ill patients. It influences acid-base balance and can also cause prognostically relevant biotrauma by generating forces and liberating reactive oxygen species, negatively affecting outcomes. In this work we evaluate the use of a Recurrent Neural Network (RNN) modelling to predict outcomes of mechanically ventilated patients, using standard mechanical ventilation parameters. METHODS: We performed our analysis on VENTILA dataset, an observational, prospective, international, multi-centre study, performed to investigate the effect of baseline characteristics and management changes over time on the all-cause mortality rate in mechanically ventilated patients in ICU. Our cohort includes 12,596 adult patients older than 18, associated with 12,755 distinct admissions in ICUs across 37 countries and receiving invasive and non-invasive mechanical ventilation. We carry out four different analysis. Initially we select typical mechanical ventilation parameters and evaluate the machine learning model on both, the overall cohort and a subgroup of patients admitted with respiratory disorders. Furthermore, we carry out sensitivity analysis to evaluate whether inclusion of variables related to the function of other organs, improve the predictive performance of the model for both the overall cohort as well as the subgroup of patients with respiratory disorders. RESULTS: Predictive performance of RNN-based model was higher with Area Under the Receiver Operating Characteristic (ROC) Curve (AUC) of 0.72 (± 0.01) and Average Precision (AP) of 0.57 (± 0.01) in comparison to RF and LR for the overall patient dataset. Higher predictive performance was recorded in the subgroup of patients admitted with respiratory disorders with AUC of 0.75 (± 0.02) and AP of 0.65 (± 0.03). Inclusion of function of other organs further improved the performance to AUC of 0.79 (± 0.01) and AP 0.68 (± 0.02) for the overall patient dataset and AUC of 0.79 (± 0.01) and AP 0.72 (± 0.02) for the subgroup with respiratory disorders. CONCLUSION: The RNN-based model demonstrated better performance than RF and LR in patients in mechanical ventilation and its subgroup admitted with respiratory disorders. Clinical studies are needed to evaluate whether it impacts decision-making and patient outcomes. TRIAL REGISTRATION: NCT02731898 ( https://clinicaltrials.gov/ct2/show/NCT02731898 ), prospectively registered on April 8, 2016.

The Correlation Between Arterial Lactate and Venous Lactate in Patients With Sepsis and Septic Shock.

BACKGROUND: Applying peripheral venous lactate instead of arterial lactate in clinical practice is questionable because of deviation between both values. We aimed to find the relationship between the arterial lactate and the peripheral venous lactate before reasoned that the venous lactate could be used in substitution to the arterial lactate in sepsis. METHODS: We conducted a prospective, cross-sectional study at a university hospital. The patients with sepsis in ICU who required lactate level monitoring were enrolled in this research. The correlation and agreement between arterial lactate (A-LACT) and peripheral venous lactate (V-LACT) were the primary outcomes. RESULTS: A total of 63 paired samples were collected. The A-LACT and V-LACT were strongly correlated ( r = .934, P < .0001, r2 = .873). The regression equation was A-LACT = (0.934 × V-LACT) - 0.236. The mean difference between V-LACT and A-LACT was 0.66 ± 1.53 mmol/L. The 95% limits of agreement were between -3.66 and 2.33 mmol/L. The V-LACT ≥ 4 mmol/L can predict A-LACT level ≥ 4 mmol/L with 87.5% sensitivity and 91.5% specificity, and the area under receiver operating characteristic curve was 0.948. CONCLUSION: The present study demonstrated a strong correlation between A-LACT and V-LACT, but an agreement between both parameters was poor. We suggest not to use the V-LACT in substitution to the A-LACT in sepsis regarding the absolute value and clearance rate, but the V-LACT ≥ 4.5 mmol/L may be used for predicting the A-LACT ≥ 4 mmol/L.

Diaphragmatic parameters by ultrasonography for predicting weaning outcomes.

BACKGROUND: Diaphragmatic dysfunction remains the main cause of weaning difficulty or failure. Ultrasonographic measurement of diaphragmatic function can be used to predict the outcomes of weaning from mechanical ventilation. Our primary objective was to investigate the performance of various sonographic parameters of diaphragmatic function for predicting the success of weaning from mechanical ventilation. METHODS: We prospectively enrolled 68 adult patients requiring mechanical ventilation who were admitted to the intensive care unit from June 2013 to November 2013. The diaphragmatic inspiratory excursion, time to peak inspiratory amplitude of the diaphragm (TPIAdia), diaphragmatic thickness (DT), DT difference (DTD), and diaphragm thickening fraction (TFdi) were determined by bedside ultrasonography performed at the end of a spontaneous breathing trial. A receiver operating characteristic curve was used for analysis. RESULTS: In total, 62 patients were analyzed. The mean TPIAdia was significantly higher in the weaning success group (right, 1.27 ± 0.38 s; left, 1.14 ± 0.37 s) than in the weaning failure group (right, 0.97 ± 0.43 s; left, 0.85 ± 0.39 s) (P <  0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of a TPIAdia of > 0.8 s in predicting weaning success were 92, 46, 89, and 56%, respectively. The diaphragmatic inspiratory excursion, DTD, and TFdi were associated with reintubation within 48 h. The P values were 0.047, 0.021, and 0.028, and the areas under the receiver operating characteristic curve were 0.716, 0.805, and 0.784, respectively. CONCLUSION: Among diaphragmatic parameters, TPIAdia exhibits good performance in predicting the success of weaning from mechanical ventilation. This study demonstrated a trend toward successful use of TPIAdia rather than diaphragmatic inspiratory excursion as a predictor of weaning from mechanical ventilation.

Heat and moisture exchangers (HMEs) and heated humidifiers (HHs) in adult critically ill patients: a systematic review, meta-analysis and meta-regression of randomized controlled trials.

BACKGROUND: The aims of this systematic review and meta-analysis of randomized controlled trials are to evaluate the effects of active heated humidifiers (HHs) and moisture exchangers (HMEs) in preventing artificial airway occlusion and pneumonia, and on mortality in adult critically ill patients. In addition, we planned to perform a meta-regression analysis to evaluate the relationship between the incidence of artificial airway occlusion, pneumonia and mortality and clinical features of adult critically ill patients. METHODS: Computerized databases were searched for randomized controlled trials (RCTs) comparing HHs and HMEs and reporting artificial airway occlusion, pneumonia and mortality as predefined outcomes. Relative risk (RR), 95% confidence interval for each outcome and I 2 were estimated for each outcome. Furthermore, weighted random-effect meta-regression analysis was performed to test the relationship between the effect size on each considered outcome and covariates. RESULTS: Eighteen RCTs and 2442 adult critically ill patients were included in the analysis. The incidence of artificial airway occlusion (RR = 1.853; 95% CI 0.792-4.338), pneumonia (RR = 932; 95% CI 0.730-1.190) and mortality (RR = 1.023; 95% CI 0.878-1.192) were not different in patients treated with HMEs and HHs. However, in the subgroup analyses the incidence of airway occlusion was higher in HMEs compared with HHs with non-heated wire (RR = 3.776; 95% CI 1.560-9.143). According to the meta-regression, the effect size in the treatment group on artificial airway occlusion was influenced by the percentage of patients with pneumonia (ß = -0.058; p = 0.027; favors HMEs in studies with high prevalence of pneumonia), and a trend was observed for an effect of the duration of mechanical ventilation (MV) (ß = -0.108; p = 0.054; favors HMEs in studies with longer MV time). CONCLUSIONS: In this meta-analysis we found no superiority of HMEs and HHs, in terms of artificial airway occlusion, pneumonia and mortality. A trend favoring HMEs was observed in studies including a high percentage of patients with pneumonia diagnosis at admission and those with prolonged MV. However, the choice of humidifiers should be made according to the clinical context, trying to avoid possible complications and reaching the appropriate performance at lower costs.

Effects of ventilator settings, nebulizer and exhalation port position on albuterol delivery during non-invasive ventilation: an in-vitro study.

BACKGROUND: Few studies have investigated the factors affecting aerosol delivery during non-invasive ventilation (NIV). Our aim was to investigate, using a bench-top model, the effect of different ventilator settings and positions of the exhalation port and nebulizer on the amount of albuterol delivered to a lung simulator. METHODS: A lung model simulating spontaneous breathing was connected to a single-limb NIV ventilator, set in bi-level positive airway pressure (BIPAP) with inspiratory/expiratory pressures of 10/5, 15/10, 15/5, and 20/10 cmH2O, or continuous positive airway pressure (CPAP) of 5 and 10 cmH2O. Three delivery circuits were tested: a vented mask with the nebulizer directly connected to the mask, and an unvented mask with a leak port placed before and after the nebulizer. Albuterol was collected on a filter placed after the mask and then the delivered amount was measured with infrared spectrophotometry. RESULTS: Albuterol delivery during NIV varied between 6.7 ± 0.4% to 37.0 ± 4.3% of the nominal dose. The amount delivered in CPAP and BIPAP modes was similar (22.1 ± 10.1 vs. 24.0 ± 10.0%, p = 0.070). CPAP level did not affect delivery (p = 0.056); in BIPAP with 15/5 cmH2O pressure the delivery was higher compared to 10/5 cmH2O (p = 0.033) and 20/10 cmH2O (p = 0.014). Leak port position had a major effect on delivery in both CPAP and BIPAP, the best performances were obtained with the unvented mask, and the nebulizer placed between the leak port and the mask (p < 0.001). CONCLUSIONS: In this model, albuterol delivery was marginally affected by ventilatory settings in NIV, while position of the leak port had a major effect. Nebulizers should be placed between an unvented mask and the leak port in order to maximize aerosol delivery.

Tracheostomy procedures in the intensive care unit: an international survey.

INTRODUCTION: Percutaneous dilatational tracheostomy (PDT) is one of the most frequent procedures performed in the intensive care unit (ICU). PDT may add potential benefit to clinical management of critically ill patients. Despite this, no clinical guidelines are available. We sought to characterize current practice in this international survey. METHODS: An international survey, endorsed and peer reviewed by European Society of Intensive Care Medicine (ESICM), was carried out from May to October 2013. The questionnaire was accessible from the ESICM website in the 'survey of the month' section. RESULTS: 429 physicians from 59 countries responded to this survey. Single step dilatational tracheostomy was the most used PDT in ICU. Almost 75% of PDT's were performed by intensive care physicians. The main indication for PDT was prolonged mechanical ventilation. Tracheostomies were most frequently performed between 7-15 days after ICU admission. Volume control mechanical ventilation, and a combination of sedation, analgesia, neuromuscular blocking agents and fiberoptic bronchoscopy were used. Surgical tracheostomy was mainly performed in ICU by ENT specialists, and was generally chosen when for patients at increased risk for difficult PDT insertion. Bleeding controlled by compression and stoma infection/inflammation were the most common intra-procedural and late complications, respectively. Informed consent for PDT was obtained in only 60% of cases. CONCLUSIONS: This first international picture of current practices in regard to tracheostomy insertion demonstrates considerable geographic variation in practice, suggesting a need for greater standardization of approaches to tracheostomy insertion.

Management and outcome of mechanically ventilated patients after cardiac arrest.

INTRODUCTION: The aim of this study was to describe and compare the changes in ventilator management and complications over time, as well as variables associated with 28-day hospital mortality in patients receiving mechanical ventilation (MV) after cardiac arrest. METHODS: We performed a secondary analysis of three prospective, observational multicenter studies conducted in 1998, 2004 and 2010 in 927 ICUs from 40 countries. We screened 18,302 patients receiving MV for more than 12 hours during a one-month-period. We included 812 patients receiving MV after cardiac arrest. We collected data on demographics, daily ventilator settings, complications during ventilation and outcomes. Multivariate logistic regression analysis was performed to calculate odds ratios, determining which variables within 24 hours of hospital admission were associated with 28-day hospital mortality and occurrence of acute respiratory distress syndrome (ARDS) and pneumonia acquired during ICU stay at 48 hours after admission. RESULTS: Among 812 patients, 100 were included from 1998, 239 from 2004 and 473 from 2010. Ventilatory management changed over time, with decreased tidal volumes (VT) (1998: mean 8.9 (standard deviation (SD) 2) ml/kg actual body weight (ABW), 2010: 6.7 (SD 2) ml/kg ABW; 2004: 9 (SD 2.3) ml/kg predicted body weight (PBW), 2010: 7.95 (SD 1.7) ml/kg PBW) and increased positive end-expiratory pressure (PEEP) (1998: mean 3.5 (SD 3), 2010: 6.5 (SD 3); P <0.001). Patients included from 2010 had more sepsis, cardiovascular dysfunction and neurological failure, but 28-day hospital mortality was similar over time (52% in 1998, 57% in 2004 and 52% in 2010). Variables independently associated with 28-day hospital mortality were: older age, PaO2 <60 mmHg, cardiovascular dysfunction and less use of sedative agents. Higher VT, and plateau pressure with lower PEEP were associated with occurrence of ARDS and pneumonia acquired during ICU stay. CONCLUSIONS: Protective mechanical ventilation with lower VT and higher PEEP is more commonly used after cardiac arrest. The incidence of pulmonary complications decreased, while other non-respiratory organ failures increased with time. The application of protective mechanical ventilation and the prevention of single and multiple organ failure may be considered to improve outcome in patients after cardiac arrest.

How to minimise ventilator-induced lung injury in transplanted lungs: The role of protective ventilation and other strategies.

Lung transplantation is the treatment of choice for end-stage pulmonary diseases. In order to avoid or reduce pulmonary and systemic complications, mechanical ventilator settings have an important role in each stage of lung transplantation. In this respect, the use of mechanical ventilation with a tidal volume of 6 to 8 ml  kg(-1) predicted body weight, positive end-expiratory pressure of 6 to 8 cmH2O and a plateau pressure lower than 30 cmH2O has been suggested for the donor during surgery, and for the recipient both during and after surgery. For the present review, we systematically searched the PubMed database for articles published from 2000 to 2014 using the following keywords: lung transplantation, protective mechanical ventilation, lung donor, extracorporeal membrane oxygenation, recruitment manoeuvres, extracorporeal CO2 removal and noninvasive ventilation.

Ventilator-associated lung injury during assisted mechanical ventilation.

Assisted mechanical ventilation (MV) may be a favorable alternative to controlled MV at the early phase of acute respiratory distress syndrome (ARDS), since it requires less sedation, no paralysis and is associated with less hemodynamic deterioration, better distal organ perfusion, and lung protection, thus reducing the risk of ventilator-associated lung injury (VALI). In the present review, we discuss VALI in relation to assisted MV strategies, such as volume assist-control ventilation, pressure assist-control ventilation, pressure support ventilation (PSV), airway pressure release ventilation (APRV), APRV with PSV, proportional assist ventilation (PAV), noisy ventilation, and neurally adjusted ventilatory assistance (NAVA). In summary, we suggest that assisted MV can be used in ARDS patients in the following situations: (1) Pao(2)/Fio(2) >150 mm Hg and positive end-expiratory pressure ≥ 5 cm H(2)O and (2) with modalities of pressure-targeted and time-cycled breaths including more or less spontaneous or supported breaths (A-PCV [assisted pressure-controlled ventilation] or APRV). Furthermore, during assisted MV, the following parameters should be monitored: inspiratory drive, transpulmonary pressure, and tidal volume (6 mL/kg). Further studies are required to determine the impact of novel modalities of assisted ventilation such as PAV, noisy pressure support, and NAVA on VALI.

Transthoracic ultrasound assessment of B-lines for identifying the increment of extravascular lung water in shock patients requiring fluid resuscitation.

INTRODUCTION: Several studies have shown that the number of B-lines was related to the amount of extravascular lung water (EVLW). In our study, we aimed to demonstrate the magnitude of the incremental B-lines in shock patients with positive net fluid balance and the association with gas exchange impairment. MATERIALS AND METHODS: We performed trans-thoracic ultrasound at admission (T0) and at follow-up period (TFL) to demonstrate the change of B lines (ΔB-lines) after fluid therapy. We compared the total B-line score (TBS) at T0 and TFL and calculated the Pearson's correlation coefficient between the ΔB-lines and PaO2/FiO2 ratio. RESULTS: A total of 20 patients were analyzed. All patients had septic shock. Net fluid balance was + 2228.05 ± 1982.15 ml. The TBS at T0 and TFL were 36.6 ± 23.73 and 63.80 ± 29.25 (P < 0.01). The ΔB-lines along anterior axillary line (AAL) correlated to the ΔTBS (r = 0.90, P < 0.01). The ΔB-lines along AAL had inverse correlation to PaO2/FiO2 ratio (r = -0.704, P < 0.05). The increase of B-lines ≥ 10 was related to the decrease of PaO2/FiO2 ratio. The inter-observer reliability between two ultrasound readers was high (r = 0.92, P < 0.01). DISCUSSION: The number of B-lines increased in shock patients with positive net fluid balance and correlated to impaired oxygenation. These data supported the benefit of ultrasound for assessing the EVLW.

Effects of gabapentin on slow-wave sleep period in critically ill adult patients: A randomized controlled trial.

Sleep deprivation is a prevalent problem in critically ill patients, which leads to delayed recovery and delirium. Slow-wave sleep (SWS) is essential to energy restoration, tissue repair, and immune system strengthening. This study aimed to investigate the effects of gabapentin on SWS in critically ill patients. We performed a prospective open-label randomized controlled study to compare SWS and the clinical outcomes of gabapentin versus a control intervention in critically ill adult patients admitted to the intensive care unit (ICU) within 24 h. The patients' characteristics and sleep-related outcomes were recorded. The sleep-related outcomes, namely, bispectral analysis (BIS), the Richards-Campbell Sleep Questionnaire (RCSQ), and insulin-like growth factor-1 (IGF-1) levels, were evaluated. Furthermore, clinical outcomes and safety were assessed. Sixty patients from 348 cases were eligible for randomization. On day 3 of the study, patients in the gabapentin group had significantly increased SWS (66.79 vs. 0.00 min; p < 0.001), total sleep time (TST) (331.39 vs. 46.16 min; p = 0.001), RCSQ score (55.05 ± 20.18 vs. 32.80 ± 15.31; p < 0.001), and IGF-1 concentrations (84.33 ± 12.40 vs. 44.00 ± 10.20 ng/mL, p < 0.001) compared with the control group. Improvements in clinical outcomes, such as delirium, ICU-free days, and mechanical ventilator-free days, were observed; however, these differences did not reach statistically significant. Gabapentin at bedtime increased SWS, TST, and IGF-1 concentrations in critically ill patients. This regimen might be beneficial to critically ill patients for improving their sleep quality.

Remdesivir versus Favipiravir in Hospitalized Patients with Moderate to Severe COVID-19 Pneumonia: A Propensity Score-Matched Retrospective Cohort Study.

Background: Remdesivir treatment was associated with a reduced 28-day mortality and recovery time among patients hospitalized with severe COVID-19. Favipiravir is broadly used to treat COVID-19. However, various studies have had conflicting results on the efficacy of favipiravir for COVID-19. We hypothesized that remdesivir is more effective in clinical outcomes regarding the 29-day mortality rates, length of stay, and recovery rate than favipiravir in patients with moderate to severe COVID-19 pneumonia. Methods: We performed a retrospective cohort study that included adult hospitalized COVID-19 pneumonia patients with hypoxemia. Patients were classified into two groups according to the antiviral drugs. Age, oxygen saturation, fraction of inspired oxygen, and Charlson comorbidity index were used for propensity score matching. The primary objective was to determine whether the type of antiviral agent is associated with 29-day mortality. Other outcomes were the 15-day recovery rate and the length of intensive care unit or hospital stay. Results: A total of 249 patients with moderate to severe COVID-19 pneumonia were included. With an adjustment for propensity score-matched, there were 204 patients for further analysis (102 patients in each antiviral drug group). Remdesivir patients had higher Radiographic Assessment of Lung Edema (RALE) scores on Chest X-ray (14.32±9.08 vs 11.34±8.46; standardized mean difference =33.9%). The Charlson Comorbidity Index Scores were comparable. The prevalences of diabetes, obesity, hypertension, and non-HIV immunocompromised state were higher in the remdesivir group. Regarding the primary outcomes, after adjusting by diabetes, obesity, and RALE score, there was no difference in the 29-day mortality rate between both groups [26 patients (25.5%) in the remdesivir group vs 28 patients (27.5%) in the favipiravir group]. The Kaplan-Meier curve analysis at 29 days indicated no significant difference in cumulative survival rate. The two groups' adjusted hazard ratio was 0.72; 95% CI, 0.41 to 1.25, p=0.24. A Kaplan-Meier analysis on the 15-day cumulative survival rate observed a trend towards a higher survival rate in the remdesivir group (adjusted hazard ratio 0.41; 95% CI, 0.20 to 0.84; p= 0.02) The proportion of patients who recovered on day 15, the length of intensive care unit(ICU) stays, and the hospital stay were not different between remdesivir and favipiravir groups (62 patients (60.8%) vs 56 patients (54.9%), p=0.39; 11.48 ± 11.88 days vs 10.87 ± 9.31 days, p=0.69; and 16.64±14.28 days vs 16.59 ±11.31 days, p=0.98, respectively). Conclusion: In patients with moderate to severe COVID-19 pneumonia, Remdesivir did not demonstrate superior benefits over Favipiravir regarding 29-day mortality, 15-day recovery rates, or hospital and ICU stay lengths. However, further investigation into the 15-day cumulative survival rate revealed a trend towards improved survival in the Remdesivir group.

Implementing pain, agitation, delirium, and sleep deprivation protocol in critically ill patients: A pilot study on pharmacological interventions.

Critically ill patients frequently experience pain, agitation, delirium, and sleep deprivation, which have been linked to increased mortality and unfavorable clinical outcomes. To address these challenges, the Pain, Agitation, Delirium, and Sleep Deprivation (PADS) protocol was developed, aiming to mitigate mortality and improve clinical outcomes. This study focuses on assessing the protocol's impact using a robust before-and-after study design in the medical and surgical intensive care units (ICUs) at Ramathibodi Hospital. Using an observational approach, this study compares clinical outcomes before and after implementing the PADS protocol in the ICUs. Two patient cohorts were identified: the "before" group, comprising 254 patients with retrospective data collected between May 2018 and September 2019, and the "after" group, consisting of 255 patients for whom prospective data was collected from May to September 2020. Analysis reveals improvements in the after group. Specifically, there was a significant increase in 14-day ICU-free days (9.95 days vs. 10.40 days, p value = 0.014), a decrease in delirium incidence (18.1% vs. 16.1%, p value < 0.001), and a significant reduction in benzodiazepine usage (38.6% vs. 24.6%, p value = 0.001) within the after group. This study emphasizes the protocol's potential to improve patient care and highlights its significance in the ICU context.

High-frequency oscillatory ventilation with tracheal gas insufflation: the rescue strategy for brain-lung interaction.

The occurrence of moderate to severe acute respiratory distress syndrome due to traumatic brain injury is not uncommon and is associated with an extremely high incidence of morbidity and mortality. Owing to the complex interaction between the lung and brain, protective ventilation for the lung with lower tidal volume and higher positive end-expiratory pressure with or without mild hypercapnia might be harmful for the brain, and maintaining normocapnia or mild hypocapnia by increasing tidal volume or respiratory rate (or both) with lower positive end-expiratory pressure levels for protecting the brain might lead to ventilator-induced lung injury. Balancing the end-point between lungs and brain becomes a challenging issue, and non-conventional modes of mechanical ventilation might play a role in the more difficult clinical cases. In this commentary, the authors discuss the rationale, based on the physiologic principle of targeting both vital organs, of applying high-frequency oscillation and tracheal gas insufflation in acute respiratory distress syndrome patients with traumatic brain injury.

Effect of the Ramathibodi Rapid Response System Triggered by the Ramathibodi Early Warning Score and Clinical Warning Signs on in-Hospital Mortality and the Incidence of Cardiopulmonary Resuscitation in Adult Hospitalized Patients.

Purpose: The Ramathibodi Rapid Response System (RRRS), implemented in March 2017, aims to identify and respond to patients with deteriorating conditions outside the ICU. It employs the Ramathibodi early warning score and clinical signs to monitor all admitted patients, providing expert physician monitoring and early treatment for stabilization and appropriate care triage. This study assesses the RRRS's effectiveness in reducing in-hospital mortality and CPR events outside the ICU. Patients and Methods: We conducted a retrospective observational study from March 2014 to February 2020 in a tertiary care hospital's general wards. We included adult patients experiencing unplanned ICU admission, sudden cardiac arrest, or unexpected death. The study compared in-hospital mortality and CPR incidence outside the ICU between pre- and post-RRRS implementation groups. The associations between RRRS implementation and in-hospital mortality and the incidence of CPR outside the ICU were assessed using multiple logistic regression analyses. Results: We evaluated 17,741 admissions, with 9168 before RRRS implementation (1 March 2014 to 28 February 2017) and 8573 after RRRS implementation (1 March 2017 to 29 February 2020). The implementation of RRRS was associated with a significant reduction in in-hospital mortality, which decreased from 30.0% to 20.8% (odds ratio, 0.62; 95% confidence interval [CI], 0.57 to 0.66; P<0.0001). Even after adjusting for age, sex, and comorbidities, the reduction in in-hospital mortality remained significant (adjusted odds ratio, 0.58; 95% CI, 0.54 to 0.63; P<0.0001). The incidence of CPR outside the ICU also decreased from 1.8% to 1.1% (adjusted odds ratio, 0.6; 95% CI, 0.46 to 0.77; P<0.0001). Additionally, the rate of ICU transfer increased from 85.4% to 92.1% (risk difference, 6.7; 95% CI, 7.6 to 5.8; P<0.0001) after implementing the RRRS. Conclusion: Implementing the RRRS is associated with a reduction in in-hospital mortality and the incidence of CPR outside the ICU.