Breathing Index Research Articles

Correlation between Handgrip Strength and Rapid Shallow Breathing Index for Assessment of Weaning from Mechanical Ventilation.

Background Assessment of weaning from mechanical ventilation (MV) is an important process. Rapid shallow breathing index (RSBI) is a standard tool to evaluate a patient's readiness before the spontaneous breathing trial (SBT). Handgrip strength (HGS) is an alternative method for assessment of respiratory muscle strength. Relationship between HGS and RSBI has not been explored. This study aimed to determine the correlation between HGS and RSBI to predict successful extubation in mechanically ventilated patients. Methods A prospective study was conducted in screened 120 patients requiring MV with tracheal intubation >48 h. HGS was performed at 48 h after intubation, 10 min before and 30 min after SBT, and 1 h after extubation. RSBI was performed at 10 min before SBT. Results A total of 93 patients (58% men) were included in the final analysis. Mean age was 71.6 ± 15.2 years. Patients admitted in general medical wards were 84.9%. APACHE II score was 13.5 ± 4.7. Most patients were intubated from pneumonia (39.8%). Weaning failure was 6.5%. The main result shows that HGS was negatively correlated with RSBI (regression coefficient −0.571, P < 0.001). The equation for predicting RSBI, derived from the linear regression model, was predicted RSBI (breaths/min/L) = 39.285 + (age ∗ 0.138)–(HGS ∗ 0.571). Conclusions HGS had significantly negative correlation with RSBI for assessment of weaning from MV. A prospective study of the HGS cutoff value is needed to investigate the difference between patients who succeeded and those who failed extubation. This trial is registered with TCTR20180323004.

The role of diaphragmatic ultrasound as a predictor of successful extubation from mechanical ventilation in respiratory intensive care unit

BackgroundThe diaphragm muscle whose dysfunction may be very common in patients undergoing mechanical ventilation (Ferrari G, De Filippi G, Elia F, Panero F, Volpicelli G, Aprà F. Crit Ultrasound J 6:8, 2014). Aim: To evaluate real-time ultrasound in the evaluation of diaphragmatic thickening, thickening fraction, and/or excursion to predict extubation outcomes. We aimed to compare these parameters with other traditional weaning measures is a fundamental.ResultsOut of 80 included patients, 20 (25%) have failed extubation. Diaphragmatic thickening (DT), thickening fraction (DTF), and/or excursion (DE) were significantly higher in the successful group compared to those who failed extubation (p < 0.05). Cutoff values of diaphragmatic measures associated with successful extubation (during tidal breathing) were ≥ 17 mm for DE; ≥ 2.1 cm for DT inspiration; ≥ 15.5 mm for DT expiration, functional residual capacity (FRC); and ≥ 32.82% for DTF %, giving 68%, 95%, 62%, and 90% sensitivity, respectively, and 65%, 100%, 100%, and 75% specificity, respectively. Cutoff values of diaphragmatic parameters associated with successful extubation (during deep breathing) were > 28.5 mm DT Insp, total lung capacity (TLC); >22.5mm DT Exp (RV); >37 DTF %; and > 31 mm DE, giving 100%, 73%, 97%, and 75% sensitivity and 65%, 75%, 100%, and 55% specificity, respectively. Rapid shallow breathing index (RSBI) had 47% sensitivity but 90% specificity.ConclusionUltrasound evaluation of diaphragmatic parameters could be a good predictor of weaning in patients who passed the T-tube.

Abstract 6902: Heart Failure Measurements Using Heartlogic Directly Correlates with Increased Burden of Atrial Fibrillation

Introduction: Atrial Fibrillation (AF) is a risk factor for death in patients with heart failure (HF). Device sensor measurements from ICDs/CRT-Ds can provide detailed data on the impact of AF on HF. HeartLogic index, HF sensor monitoring can detect worsening HF with high sensitivity. Hypothesis: We hypothesize HeartLogic sensors would be able to detect worsening HF with increased AF burden. Methods: AF burden was measured as time greater than atrial tachyarrhythmia rate of 170 bpm. Each patient day was grouped into 7 groups based on daily AF burden: No AF/normal sinus rhythm (NSR), &gt;0min, &gt;6min, &gt;1hr, &gt;5.5hr, &gt;12hr, and 24hr. Total 15,533 US patients from ALTITUDE database with HeartLogic devices and a minimum of 365 days of data were analyzed, 754 patients with all 7 levels of AF burden were included. For each group, mean daily heart sounds (S3, S1), respiratory rate (RR), rapid shallow breathing index (RSBI), thoracic impedance (TI), daily and night heart rate (HR, NHR), patient time active, HeartLogic index, and the percent of in-alert days were evaluated. Sensors were compared during each AF burden and during NSR using paired T-test. Results: AF burden groups above 6min were associated to significant worsening in S1, RR, RSBI, NHR, HR and HeartLogic index (figure). Significant reduction in patient activity occurred above 5.5hr of AF burden. In-alert days (%) increased significantly during AF burden above 6min compared with NSR. Conclusions: This data suggests potential use of HeartLogic sensors to identify patients whose HF status is most impacted by development of AF and those who may benefit most from rhythm control. Additional studies using sensor based AF management may improve clinical outcomes.

Prediction of extubation outcome in critically ill patients: a systematic review and meta-analysis

BackgroundExtubation failure is an important issue in ventilated patients and its risk factors remain a matter of research. We conducted a systematic review and meta-analysis to explore factors associated with extubation failure in ventilated patients who passed a spontaneous breathing trial and underwent planned extubation. This systematic review was registered in PROPERO with the Registration ID CRD42019137003.MethodsWe searched the PubMed, Web of Science and Cochrane Controlled Register of Trials for studies published from January 1998 to December 2018. We included observational studies involving risk factors associated with extubation failure in adult intensive care unit patients who underwent invasive mechanical ventilation. Two authors independently extracted data and assessed the validity of included studies.ResultsSixty-seven studies (involving 26,847 participants) met the inclusion criteria and were included in our meta-analysis. We analyzed 49 variables and, among them, we identified 26 factors significantly associated with extubation failure. Risk factors were distributed into three domains (comorbidities, acute disease severity and characteristics at time of extubation) involving mainly three functions (circulatory, respiratory and neurological). Among these, the physiological respiratory characteristics at time of extubation were the most represented. The individual topic of secretion management was the one with the largest number of variables. By Bayesian multivariable meta-analysis, twelve factors were significantly associated with extubation failure: age, history of cardiac disease, history of respiratory disease, Simplified Acute Physiologic Score II score, pneumonia, duration of mechanical ventilation, heart rate, Rapid Shallow Breathing Index, negative inspiratory force, lower PaO2/FiO2 ratio, lower hemoglobin level and lower Glasgow Coma Scale before extubation, with the latest factor having the strongest association with extubation outcome.ConclusionsNumerous factors are associated with extubation failure in critically ill patients who have passed a spontaneous breathing trial. Robust multiparametric clinical scores and/or artificial intelligence algorithms should be tested based on the selected independent variables in order to improve the prediction of extubation outcome in the clinical scenario.

Resonant Voice: Perceptual and Acoustic Analysis After an Intensive Lessac Kinesensic Training Workshop

ObjectiveTo investigate whether actors’ and actresses’ voices post an Intensive Lessac Kinesensic Training Workshop – ILKTW can be perceptually identified as more resonant, and to assess if the Acoustic Voice Quality Index (AVQI), the Acoustic Breathing Index (ABI), and their acoustic measures are able to indicate the classified voices as more resonant. MethodsEight vocally healthy English first-language actors and actresses, participants of the same ILKTW, were asked to sustain the vowel /a/ and to read a piece of the Rainbow Passage, pre and postworkshop, at a self-selected habitual frequency and intensity. The readings were divided into initial and final parts, both with 34 syllables, and combined with the vowel /a/ (3s). The pre and postworkshop recordings (pairs of the initial and final parts followed by the /a/ vowel) of each participant were randomly presented to a voice expert who rated the samples as more resonant or similar. The same samples were analyzed using the AVQI and ABI scripts. Results87,5% of the initial parts and 100% of the final in postworkshop were rated by the voice expert as more resonant. Tilt was higher for the postworkshop initial parts (P = 0.036), but a correlation with the perceptual rating wasn't found. HNR was higher (P = 0.018) and jitter was lower (P = 0.017) for the postworkshop final parts. The statistical analysis comparing the perceptive and acoustic data for the final samples couldn't be applied. ConclusionIt seems that the ILKTW has a positive impact on the development of a resonant voice and that the perceptual auditory rating was more effective to describe resonant voices than the AVQI, ABI, and its acoustic measures.

Handgrip strength cutoff value predicting successful extubation in mechanically ventilated patients.

Handgrip strength (HGS) is an alternative tool to evaluate respiratory muscle function. HGS cutoff value indicating extubation success or failure has not been investigated. This study aimed to determine HGS cutoff value to predict successful extubation. A prospective study was conducted. Patients requiring intubated mechanical ventilation with intubation ≥ 48 hours in medical wards were recruited. HGS test was performed at 10 minutes before and 30 minutes after spontaneous breathing trial (SBT). Rapid shallow breathing index (RSBI) was measured at 10 minutes before SBT. Ninety-three patients (58% men) were included. Mean age was 71.6 ± 15.2 years. Weaning failure rate was 6.5%. The area under the ROC curve of 0.84 for the best HGS cutoff value at 10 minutes before SBT was 12.7 kg, with 75.9% sensitivity and 83.3% specificity (P = 0.005). The best HSG cutoff value at 30 minutes after SBT was 14.9 kg, with the area under the ROC curve of 0.82, with 58.6% sensitivity and 83.3% specificity (P = 0.009). The best RSBI cutoff value was 43.5 breaths/min/L, with the area under the ROC curve of 0.46, 33.3% sensitivity and 66.6% specificity (P = 0.737). HGS may be a predictive tool to guide extubation with better sensitivity and specificity than RSBI. A prospective study is needed to verify HGS test as adjunctive to RSBI in ventilator weaning protocol.

First Attempt at Using Electrical Impedance Tomography to Predict High Flow Nasal Cannula Therapy Outcomes at an Early Phase.

Objective: Spatial and temporal ventilation distributions in patients with acute respiratory failure during high flow nasal cannula (HFNC) therapy were previously studied with electrical impedance tomography (EIT). The aim of the study was to explore the possibility of predicting HFNC failure based on various EIT-derived parameters.Methods: High flow nasal cannula failure was defined reintubation within 48 h after HFNC. EIT was performed with the patients spontaneously breathing in the supine position at the start of HFNC. EIT-based indices (comprising the global inhomogeneity index, center of ventilation, ventilation delay, rapid shallow breathing index, minute volume, and inspiration to expiration time) were explored and evaluated at three time points (prior to HFNC, T1; 30 min after HFNC started, T2; and 1 h after, T3).Results: A total of 46 subjects were included in the final analysis. Eleven subjects had failed HFNC. The time to failure was 27.8 ± 12.4 h. The ROX index (defined as SpO2/FiO2/respiratory rate) for HFNC success patients was 8.3 ± 2.7 and for HFNC failure patients, 6.2 ± 1.8 (p = 0.23). None of the investigated EIT-based parameters showed significant differences between subjects with HFNC failure and success. Further subgroup analysis indicated that a significant difference in ventilation inhomogeneity was found between ARDS and non-ARDS [0.54 (0.37) vs. 0.46 (0.28) as evaluated with GI, p < 0.01]. Ventilation homogeneity significantly improved in ARDS after 60-min HFNC treatment [0.59 (0.20) vs 0.57 (0.19), T1 vs. T3, p < 0.05].Conclusion: Spatial and temporal ventilation distributions were slightly but insignificantly different between the HFNC success and failure groups. HFNC failure could not be predicted by changes in EIT temporal and spatial indexes of ventilation distribution within the first hour. Further studies are required to predict the outcomes of HFNC.

Validation of rapid shallow breathing index displayed by the ventilator compared to the standard technique in patients with readiness for weaning

BackgroundRapid shallow breathing index (RSBI) is the most commonly used parameter for predicting weaning outcome. Measurement of RSBI by Wright spirometer (RSBIstandard) is the standard method in routine clinical practice. Data specific to the accuracy and reliability of the RSBI value displayed by the ventilator (RSBIvent) are scarce. Accordingly, this study aimed to evaluate the association between the average value of RSBIvent at different time points and RSBIstandard, and to assess the accuracy and reliability of these two RSBI measurement techniques.MethodsThis prospective cohort study included mechanically ventilated patients who were ready to wean. At the beginning of spontaneous breathing trial using the flow-by method, RSBI was measured by two different techniques at the same time, including: (1) Wright spirometer (breathing frequency/average tidal volume in 1 min) (RSBIstandard), and (2) the values displayed on the ventilator at 0, 15, 30, 45, and 60 s (RSBIvent).ResultsForty-seven patients were enrolled. The RSBIvent value was significantly higher than the RSBIstandard value for every comparison. According to Spearman’s correlation coefficient (r) and intraclass correlation coefficient (ICC), the average value of RSBI from 5 time points (0, 15, 30, 45, and 60 s) showed the best correlation with the standard technique (r = 0.76 [P < 0.001], and ICC = 0.79 [95% CI 0.61–0.88], respectively). Bland–Altman plot also showed the best agreement between RSBIstandard and the RSBIvent value averaged among 5 time points (mean difference − 17.1 breaths/min/L).ConclusionsWe found that the ventilator significantly overestimates the RSBI value compared to the standard technique by Wright spirometer. The average RSBIvent value among 5 time points (0, 15, 30, 45, and 60 s) was found to best correlate with RSBIstandard.

STATIC LUNG COMPLIANCE AS A PREDICTOR OF EXTUBATION FAILURE IN NON-COVID-19 PATIENTS WITH ACUTE RESPIRATORY FAILURE

TOPIC: Critical Care TYPE: Original Investigations PURPOSE: Ventilator weaning protocols rely in part on objective indices to best predict extubation failure in the critically ill. In this study, we investigated static lung compliance (LC) as a predictor of extubation failure, in comparison to extubation readiness using rapid shallow breathing index (RSBI). METHODS: A cross-sectional, multi-institutional study of 2,334 mechanically ventilated patients admitted from 12/01/2017-12/01/2019. We included all older than 18 years with a documented spontaneous breathing trial and extubation trial. Static lung compliance and RSBI were calculated prior to extubation trial. The primary outcome was extubation failure - defined as need for reintubation within 24 hours from time of extubation. RESULTS: Of the 2,334 patients, 55.6% were males with a mean age of 66-years. The population consisted mostly of Caucasians (74%) and African Americans (20%). 183 of 2,334 (7.84%) patients required reintubation within 24 hours. There was a negative correlation between RSBI and lung compliance at time of extubation trial. The logLC of patients requiring reintubation was significantly lower than those who remained extubated with a mean of 3.58 ± 0.43 vs. 3.69 ± 0.49 (95% CI in difference:0.041 -0.17;p = 0.001). Whereas, log RSBI was not significant for 24-hour reintubation (p = 0.521). Patients were then dichotomized to a compliance of less or greater than 50 and RSBI of less or greater than 104. LC 104 was not associated with extubation failure (OR 1.53;98% CI:0.20 -11.57;p = 0.674). On multivariate logistic regression after adjusting for age, mode of ventilation, ventilator days, and P/F ratio, LC remained the strongest predictor for 24-hr reintubation (OR 1.56;95% CI: 1.14-2.13). CONCLUSIONS: Static lung compliance measured at the day of extubation is a promising physiological discriminant to evaluate extubation readiness. We recommend further validation studies in prospective cohorts. CLINICAL IMPLICATIONS: Static lung compliance may potentially be used as a discriminant to risk stratify patients with acute respiratory failure for extubation success. DISCLOSURES: No relevant relationships by Lauren Abplanalp, source=Web Response No relevant relationships by Girish Balachandran Nair, source=Admin input No relevant relationships by Enrique Calvo Ayala, source=Web Response No relevant relationships by Limin Yu, source=Web Response

The role of diaphragmatic rapid shallow breathing index and maximum inspiratory pressure in predicting outcome of weaning from mechanical ventilation

Introduction The rapid shallow breathing index (RSBI) is considered an accurate weaning predictor. The diaphragmatic excursion (DE) and maximum inspiratory pressure (MIP) can be used as weaning parameters. Substitution of the tidal volume by the DE in the RSBI, that is, calculating the diaphragmatic RSBI (DRSBI, RR/DE), might yield a more precise weaning predictor. Objective The aim of this research was to evaluate the predictive value of the DRSBI, MIP, and the ratio between them (MIP/DRSBI) in the weaning of mechanically ventilated patients. Patients and methods In our study, 64 mechanically ventilated patients were enrolled. At the time of their first spontaneous breathing trial, ultrasonographic assessment of the DE was done, MIP was measured, and RSBI, DRSBI, and MIP/DRSBI were calculated. A total of 36 (56.25%) patients had successful weaning, whereas 28 (43.75%) failed the weaning trial. The new composite parameter (MIP/DRSBI) with a cutoff value greater than or equal to 17 cmH2O/min/mm/breath was the best tool to predict successful weaning with area under the receiver operating characteristics curve of 0.982, with sensitivity and specificity of 100 and 96%, respectively. Conclusion Combining the MIP and DRSBI in one composite parameter (MIP/DRSBI) improved the sensitivity, specificity, and accuracy of both parameters when compared with either parameter alone.

The Role of Diaphragmatic Rapid Shallow Breathing Index and Maximum Inspiratory Pressure in Predicting Outcome of Weaning From Mechanical Ventilation

Abstract Background Mechanical ventilation is the defining event of intensive care unit (ICU) management. It is a lifesaving intervention in patients with acute respiratory failure and whose spontaneous ventilation is inadequate for subsequent development of life threatening hypoxia and/or respiratory acidosis. Many physicians simply look at the patient’s ability to tolerate a spontaneous breathing trial (SBT) without distress through the respiratory rate (RR) and TV during the SBT. The RR/TV ratio, i.e., the rapid shallow breathing index (RSBI), one of the most used clinical indices to predict weaning outcome, reflects the balance between mechanical load posed on the inspiratory muscles and the inspiratory muscles ability to face it during the weaning attempt. However, RSBI was found to have both variable sensitivity and specificity for predicting weaning outcome. Although the diaphragm plays a fundamental role in generating TV in healthy subjects, if the diaphragmatic efficiency is impaired the accessory inspiratory muscles mild contribute to the ventilation for a limited period of time, for example during a SBT. However, since they are by far less efficient and more fatigable than the diaphragm, their exhaustion was likely lead to weaning failure in subsequent hours. Hence, the contribution of the accessory muscles to TV could compromise the diagnostic accuracy of the RSBI by masking the underlying diaphragmatic dysfunction. Aim of the Work To assess the accuracy of Diaphragmatic Rapid shallow breathing index and Maximum inspiratory pressure in predicting the outcome of weaning from mechanical ventilation. Patients and Methods The study was conducted at Ain Shams University Hospitals over 6 months on Patients who were mechanically ventilated for more than 48 hrs who were ready for weaning. Inclusion Criteria Patients intubated &amp; mechanically ventilated for more than 48 hrs. Patients at their first SBT.Patients with adequate cough reflex. Patients fulfilling criteria of readiness for weaning from mechanical ventilation after resolution of cause of respiratory failure: Patients with score ranging between -1 and +1 on the Richmond Agitation and sedation scale (RASS). Exclusion criteria Age &amp;lt; 18 yrs. Patients with thoracotomy, pneumothorax, or pneumomediastinum. Patients with presence of flail chest or rib fractures. Patients with neuromuscular disease. Use of muscle-paralyzing agents within 48 hours before the study. History or new detection of paralysis or paradoxical movement of a single hemi diaphragm on diaphragmatic ultrasonography. Pregnant females. Unconscious noncooperative patients. Patients with intra-abdominal hypertension, Long term steroid therapy. Results I- Distribution of the studied patients regarding final outcome. II- Demographic data. III. Causes of MV. IV- Days on MV. V- Patients’ data and characteristics before start of weaning trial. VI- SBT Ventilator Breathing pattern after 30 min. VII- Study predictors. Conclusion D-RSBI is a new and promising tool that is superior to the traditional RSBI in predicting weaning outcome also MIP provides appreciated data with greater accuracy to assess inspiratory muscle strength and predicting weaning success in mechanically ventilated patients. Recommendations We could recommend the measurement of MIP and DRSBI as weaning predictors should be an integral part of evaluation of patients plan for weaning from MV. All intensivists should be acquitted with the use of U/S in the evaluation of diaphragmatic function.

The Effects of Manual Lung Hyperinflation on Pulmonary Function after Weaning from Mechanical Ventilation among Patients with Abdominal Surgeries: Randomized Clinical Trial.

Introduction: After abdominal surgery, the patients who are separated from mechanical ventilation and provided with oxygen therapy via a T-piece are at risk for respiratory complications. Therefore, they need additional respiratory support. This study aimed to evaluate the effects of manual hyperinflation (MHI) on pulmonary function after weaning. Methods: This randomized clinical trial included 40 patients who had undergone abdominal surgery and were receiving oxygen via a T-piece. Patients were selected from the intensive care units (ICU) of two hospitals in Mashhad, Iran. The subjects were randomly allocated to intervention (MHI) and control groups. Patients in the MHI group were provided with three 20-minute MHI rounds using the Mapleson C, while the control group received routine cares. Tidal volume (Vt), Rapid Shallow Breathing Index (RSBI), and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) were measured before the intervention, as well as 5 and 20 minutes after the intervention. Atelectasis prevalence was assessed before and 24 hours after the intervention. Data were analysed by SPSS software version 13. Results: At baseline, there were no significant differences between the groups regarding Vt, RSBI, P/F ratio, and atelectasis rate. No significant difference was also found between the groups regarding atelectasis rate 24 hours after the intervention. However, at both posttests, Vt, RSBI, and P/F ratio in the MHI group were significantly better than the control group. Conclusion: In patients with artificial airway and spontaneous breathing, MHI improves pulmonary function.

Comparative Assessment of the Effects of Two Methods of Pressure Support Adjustment on Respiratory Distress in Patients under Mechanical Ventilation Admitted to Intensive Care Units.

BackgroundIncorrect adjustment of the respiratory parameters of the mechanical ventilator increases respiratory distress and work of breathing (WOB) in mechanically ventilated patients. The accurate adjustment of pressure support increases thepatient's comfort and decreases respiratory distress and WOB, etc.; thus, the present study was conducted to compare the effects of two pressure support adjustment methods on respiratory distress in patients under mechanical ventilation to investigate whether the rapid shallow breathing index (RSBI)method can reduce patients’ respiratory distress more and faster than the tidal volume (VT) and respiratory rate (RR) methods.Patients and methodsThe study was conducted in 2020 on 56 mechanically ventilated patients with respiratory distress. The patients’ respiratory distress was first measured using RSBI and the respiratory distress observation scale (RDOS). The pressuresupport was then adjusted in the patients according to the RSBI (in the trial group, n = 33)and VT and RR (in the control group, n = 23). The patients’ respiratory distress was measured again in both groups 15 and 30 minutes after the pressure support adjustment.ResultsThe results showed no significant differences between the two groups in the mean RSBI and RDOS before (p = 0.374, p = 0.657 respectively) and 30 (p = 0.103, p = 0.218 respectively) minutes after the adjustment of the pressure support, but these mean values differed significantly (p = 0.025 for RSBI and p = 0.044 for RDOS) between the groups 15 minutes after the adjustment. Moreover, the interaction effect of the group * time for RDOS has become significant nonlinearly (p = 0.037), but none of the interaction effects of the group * time were significant for RSBI (linear: p = 0.531; nonlinear: p = 0.272).ConclusionThese two methods finally reduced the patients’ respiratory distress almost equally, but RSBI method can relieve the patients’ respiratory distress faster than the VT and RR methods.How to cite this articleBarati P, Ghafari S, Saghaei M. Comparative Assessment of the Effects of Two Methods of Pressure Support Adjustment on Respiratory Distress in Patients under Mechanical Ventilation Admitted to Intensive Care Units. Indian J Crit Care Med 2021;25(9):1026–1030.Key messageVT, RR, and RSBI methods finally reduced the patients’ respiratory distress almost equally, but RSBI method can relieve the patients’ respiratory distress faster than the VT and RR methods.

Physiological respiratory parameters in pre-hospital patients with suspected COVID-19: A prospective cohort study.

The COVID-19 pandemic has presented emergency medical services (EMS) worldwide with the difficult task of identifying patients with COVID-19 and predicting the severity of their illness. The aim of this study was to investigate whether physiological respiratory parameters in pre-hospital patients with COVID-19 differed from those without COVID-19 and if they could be used to aid EMS personnel in the prediction of illness severity. Patients with suspected COVID-19 were included by EMS personnel in Uppsala, Sweden. A portable respiratory monitor based on pneumotachography was used to sample the included patient's physiological respiratory parameters. A questionnaire with information about present symptoms and background data was completed. COVID-19 diagnoses and hospital admissions were gathered from the electronic medical record system. The physiological respiratory parameters of patients with and without COVID-19 were then analyzed using descriptive statistical analysis and logistic regression. Between May 2020 and January 2021, 95 patients were included, and their physiological respiratory parameters analyzed. Of these patients, 53 had COVID-19. Using adjusted logistic regression, the odds of having COVID-19 increased with respiratory rate (95% CI 1.000-1.118), tidal volume (95% CI 0.996-0.999) and negative inspiratory pressure (95% CI 1.017-1.152). Patients admitted to hospital had higher respiratory rates (p<0.001) and lower tidal volume (p = 0.010) compared to the patients who were not admitted. Using adjusted logistic regression, the odds of hospital admission increased with respiratory rate (95% CI 1.081-1.324), rapid shallow breathing index (95% CI 1.006-1.040) and dead space percentage of tidal volume (95% CI 1.027-1.159). Patients taking smaller, faster breaths with less pressure had higher odds of having COVID-19 in this study. Smaller, faster breaths and higher dead space percentage also increased the odds of hospital admission. Physiological respiratory parameters could be a useful tool in detecting COVID-19 and predicting hospital admissions, although more research is needed.

End-Expiratory Lung Volumes During Spontaneous Breathing Trials in Tracheostomized Subjects on Prolonged Mechanical Ventilation.

The role of end-expiratory lung volume (EELV) during a spontaneous breathing trial (SBT) in patients who were tracheostomized and on prolonged mechanical ventilation is unclear. This study aimed to assess EELV during a 60-min SBT and its correlation with weaning success. Enrolled subjects admitted to a weaning unit were measured for EELV and relevant parameters before and after the SBT. Of the 44 enrolled subjects, 29 (66%) were successfully liberated, defined as not needing mechanical ventilation for 5 d. The success group had fewer subjects with chronic kidney disease (41% vs 73%, P = .044), stronger mean ± SD maximum inspiratory pressure (41.6 ± 10.4 vs 34.1 ± 7.1 cm H2O; P = .02) and mean ± SD maximum expiratory pressure (46.9 ± 11.7 vs 35.3 ± 16.9 cm H2O; P = .01) versus the failure group. Toward the end of the SBT, the success group had a significant increase in the mean ± SD EELV (before vs after: 1,278 ± 744 vs 1,493 ± 867 mL; P = .040) and a decrease in the mean ± SD rapid shallow breathing index (83.8 ± 39.4 vs 66.3 ± 29.4; P = .02), whereas there were no significant changes in these 2 parameters in the failure group. The Cox regression analysis showed that, at the beginning of SBT, a greater difference between EELV with a PEEP of 0 cm H2O and with a PEEP of 5 cm H2O was significantly correlated to a higher likelihood of weaning success. Toward the end of the SBT, a greater EELV level at a PEEP of 0 cm H2O was also correlated with weaning success. Also, the greater difference of EELV at a PEEP of 0 cm H2O between the beginning and the end of the SBT was also correlated with a shorter duration to weaning success. The change in EELV during a 60-min SBT may be of prognostic value for liberation from prolonged mechanical ventilation in patients who had a tracheostomy. Our findings suggest a model to understand the underlying mechanism of failure of liberation from mechanical ventilation in these patients.

Predictors of Successful Weaning from Noninvasive Ventilation in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Single-Center Retrospective Cohort Study.

PurposeNoninvasive ventilation (NIV) is often required for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and it can significantly reduce the need for endotracheal intubation. Currently, there is no standard method for predicting successful weaning from NIV. Therefore, we aimed to evaluate whether a weaning index can predict NIV outcomes of patients with AECOPD.MethodsThis study was conducted at a single academic public hospital in northern Taiwan from February 2019 to January 2021. Patients with AECOPD admitted to the hospital with respiratory failure who were treated with NIV were included in the study. Univariate and multivariate logistic regression analyses were used to identify independent predictors of successful weaning from NIV. Receiver operating characteristic curve methodology was used to assess the predictive capacity.ResultsA total of 85 patients were enrolled, 65.9% of whom were successfully weaned from NIV. The patients had a mean age of 75.8 years and were mostly men (89.4%). The rapid shallow breathing index (RSBI) (P < 0.001), maximum inspiratory pressure (P = 0.014), and maximum expiratory pressure (P = 0.004) of the successful group were significant while preparing to wean. The area under the receiver operating characteristic curve for the RSBI was 0.804, which was considered excellent discrimination.ConclusionThe RSBI predicted successful weaning from NIV in patients with AECOPD with hypercapnic respiratory failure. This index may be useful for selecting patients with AECOPD that are suitable for NIV weaning.

Does diaphragm ultrasound improve the rapid shallow breathing index accuracy for predicting the success of weaning from mechanical ventilation?

BackgroundThis prospective study investigated whether taking into account diaphragmatic excursion (DE) measured by ultrasonography would improve the performance of the rapid shallow breathing index (RSBI) to predict extubation success or failure. ObjectivesThe aim of the study was to compare the new composite index named the rapid shallow diaphragmatic index (RSDI), and the RSBI measured during a spontaneous breathing trial regarding their ability to predict the need for re-intubation at 72 h. MethodsOne hundred mechanically ventilated patients underwent daily 30-min spontaneous breathing trials (SBTs) under pressure support ventilation of 6 cm H2O and end-expiratory pressure of 0 cm H2O until the SBT was considered successful and followed by extubation. The performances of RSBI (respiratory rate/tidal volume) and of the ratio RSBI/DE measured at 5 and 25 min of the successful SBT were compared in terms of area under the receiver operating characteristics curve (AUC), for predicting extubation success at 72 h. As secondary analysis, extubation and weaning success at 7 d were also considered. As exploratory analyses, predictive indices incorporating both clinical characteristics, the DE, and ultrasound diaphragm thickening fraction (DTF) were investigated. ResultsRSBI and RSBI/DE showed AUCs with 95% confidence intervals consistently extending below 0.50, either at the 5th (0.55 [0.36–0.74] and 0.55 [0.34–0.75], respectively) or at the 25th minute of SBT (0.49 [0.27–0.71] and 0.50 [0.29–0.68], respectively) for predicting weaning success at 72 h or at 7 d (5th min: 0.53 [0.37–0.70] and 0.54 [0.37–0.70], respectively; 25th min: 0.54 [0.37–0.71] and 0.55 [0.39–0.71], respectively). An exploratory index incorporating the accessory respiratory muscle activity, DE, DTF, and respiratory rate at 5th min of SBT showed AUCs for predicting extubation success at 7 d in the 78 patients with DTF measurement (0.77 [0.64–0.90]) that were significantly higher than that of the RSBI (P = 0.017) and RSBI/DE (P < 0.001) in the same respective populations. ConclusionsThe RSBI and the ratio RSBI/DE failed to predict weaning success when measured during an SBT performed under minimal pressure support. Predictive indices incorporating ultrasound DE and DTF may merit further investigation.

Effectiveness of Noninvasive Positive Pressure Ventilation in COVID-19 Patients with Severe Acute Respiratory Distress Syndrome

Results of invasive positive pressure ventilation (IPPV) in COVID-19 patients with Severe Acute Respiratory Distress Syndrome are discouraging despite its prompt use. However noninvasive positive pressure ventilation (NIPPV) is yet not a common practice internationally because of lack of global evidence advocating its effective use in severe cases of ARDS as well as dreadful concern about aerosol generation especially in patients having COVID-19 infection. Objective: To determine whether, NIPPV application is effective and safe in COVID-19 Patients. Methods: One hundred and thirty hemodynamically stable patients with severe CARDS as per Berlin definition (PaO2/FiO2 ratio ≤ 100mm Hg), having GCS &gt; 13, respiratory breathing index (RBI) &lt; 105, and without any systemic complication were selected. They were managed with NIPPV in Corona Intensive Care Unit of Mayo Hospital/King Edward Medical University Lahore. A little innovation was done with the application of a specific orofacial interface, fitted with heat and moist exchanger (HME) at the interface and viral/bacterial filters at the expiratory limb of ventilatory circuit. Favorable outcome has been observed in 64% of treated cases in terms of improvement in PaO2/FiO2 ratio, thus abating severity of ARDS from severe to mild category, in an average time span of 6 days. Remaining 36% of patients progressed to IPPV with definitive airway. During study period, 4.2% of healthcare workers (HCW) got infected with COVID-19. Associated complications of NIPPV application were claustrophobia (13.8%), nasal crusting (6.9%), aspiration (6.1%) and barotrauma (0.7%). Conclusion: In carefully selected patients, use of noninvasive positive pressure ventilation with the application of HME and viral/bacterial filters is an effective, preferable and safe modality of choice to provide respiratory support, thus obviating the need for IPPV. However further larger studies are needed to confirm our recommendations.

The Rothman Index Does Not Predict a Successful Extubation in the Neurosurgical Critical Care Unit.

BackgroundIdentification of risk factors associated with successful extubation in neurosurgical critical care units (NSICUs) has been elusive due to the complex nature of neurocritical care injuries and patient factors. Traditional risk factors for extubation were shown to have poor predictive value in neurocritical care patients as compared to mixed ICU patients. The aim of this study was to determine if any risk factors, including the Rothman Index, could reliably predict successful extubation in a large sample size of neurocritical care patients.MethodsWe retrospectively analyzed 610 consecutively intubated patients in an NSICU while collecting variables of interest in airway management. Furthermore, Rothman Indices were collected immediately after intubations and extubations. A paired t-test of the immediate changes in Rothman Indices after airway manipulation was compared in patients who needed reintubation. In a smaller cohort of 88 patients, in whom complete data points existed for airway management, we performed a principal component analysis (PCA) to determine which risk factors were associated with extubation success when indexed with the magnitude of the Rothman Index.ResultsIn 610 consecutively intubated patients, the mean pre-intubation Rothman Index average was 41.0 compared to the mean post-extubation Rothman Index was 35.4 (p<0.0001). Compared to those who were re-intubated, the Rothman Index did not correlate well with the prediction of extubation (p=0.355). Furthermore, an analysis of the PCA plot showed that a higher respiratory rate, longer length of stay, shorter length of intubation, and smaller cuff leak percentage were identified as risk factors associated with reintubation. Age and change in rapid shallow breathing index (RSBI) did not correlate with reintubation.ConclusionThe Rothman Index does not predict extubation success in patients in an NSICU. Risk factors associated with reintubation were respiratory rate, length of stay, length of intubation, and cuff leak percentage. Reintubation rates in our single-center NSICU are on par with general critical care populations.

Application of bedside ultrasound in predicting the outcome of weaning from mechanical ventilation in elderly patients

BackgroundWith the increased ageing of society, more and more elderly people are admitted to the intensive care unit, How to accurately predict whether elderly patients can successfully wean from the ventilator is more complicated. Diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) were measured by bedside ultrasound to assess diaphragm function. The lung ultrasound score (LUS) and the rapid shallow breathing index (RBSI) were used as indices of diaphragm function to predict the outcome of weaning from mechanical ventilation. The aim of this study was to examine the clinical utility of these parameters in predicting extubation success.MethodsThis prospective study included 101 consecutive elderly patients undergoing a trial of extubation in the ICU of Haidian Hospital between June 2017 and July 2020. Patients were divided into the successful weaning group (n = 69) and the failed weaning group (n = 32). Baseline characteristics, including RSBI, were recorded. Measurements of DE, DTF and LUS were made using ultrasound within 24 h before extubation.ResultsMedian DE was greater in patients with extubation success than in those with extubation failure (1.64 cm vs. 0.78 cm, p = 0.001). Patients with extubation success had a greater DTF than those with extubation failure (49.48% vs. 27.85%, p = 0.001). The areas under the receiver operating curves for the RSBI, LUS, DE and DFT were 0.680, 0.764, 0.831 and 0.881, respectively. The best cut-off values for predicting successful weaning were DTF ≥ 30%, DE ≥ 1.3 cm, LUS ≤ 11, and RSBI ≤ 102. The specificity of DTF (84%) in predicting weaning outcome was higher than that of RBSI (53%), that of LUS (55%), and that of DE (62%). The sensitivity of DTF (94%) was greater than that of RBSI (85%), that of LUS (71%), and that of DE (65%). The combination of RSBI, LUS, DE, and DTF showed the highest AUC (AUC = 0.919), with a sensitivity of 96% and a specificity of 89%.ConclusionsDTF has higher sensitivity and specificity for the prediction of successful weaning in elderly patients than the other parameters examined. The combination of RSBI, LUS, DE and DFT performed well in predicting weaning outcome. This has potentially important clinical application and merits further evaluation.