Autonomic Tone in Medical Intensive Care Patients Receiving Mechanical Ventilation and During a CPAP Weaning Trial

Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients ( n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation ( n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.

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Prevalence and Impact on Weaning of Pleural Effusion at the Time of Liberation from Mechanical Ventilation

Anesthesiology ◽

10.1097/aln.0000000000001621 ◽

2017 ◽

Vol 126 (6) ◽

pp. 1107-1115 ◽

Cited By ~ 14

Author(s):

Martin Dres ◽

Damien Roux ◽

Tài Pham ◽

Alexandra Beurton ◽

Jean-Damien Ricard ◽

...

Keyword(s):

Intensive Care Unit ◽

Mechanical Ventilation ◽

Intensive Care ◽

Pleural Effusion ◽

Spontaneous Breathing ◽

Odds Ratio ◽

Spontaneous Breathing Trial ◽

Ventilatory Support ◽

Weaning Failure ◽

Weaning Outcome

Abstract Background Pleural effusion is frequent in intensive care unit patients, but its impact on the outcome of weaning remains unknown. Methods In a prospective study performed in three intensive care units, pleural ultrasound was performed at the first spontaneous breathing trial to detect and quantify pleural effusion (small, moderate, and large). Weaning failure was defined by a failed spontaneous breathing trial and/or extubation requiring any form of ventilatory support within 48 h. The primary endpoint was the prevalence of pleural effusion according to weaning outcome. Results Pleural effusion was detected in 51 of 136 (37%) patients and was quantified as moderate to large in 18 (13%) patients. As compared to patients with no or small pleural effusion, their counterparts were more likely to have chronic renal failure (39 vs. 7%; P = 0.01), shock as the primary reason for admission (44 vs. 19%; P = 0.02), and a greater weight gain (+4 [0 to 7] kg vs. 0 [−1 to 5] kg; P = 0.02). The prevalence of pleural effusion was similar in weaning success and weaning failure patients (odds ratio, 1.23; 95% CI, 0.61 to 2.49; P = 0.56), as was the prevalence of moderate to large pleural effusion (odds ratio, 0.89; 95% CI, 0.33 to 2.41; P = 1.00). Duration of mechanical ventilation and intensive care unit length of stay were similar between patients with no or small pleural effusion and those with moderate to large pleural effusion. Conclusions Significant pleural effusion was observed in 13% of patients at the time of liberation from mechanical ventilation and was not associated with an alteration of weaning outcome. (Anesthesiology 2017; 126:1107–15)

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Usefulness of radiological signs of pulmonary congestion in predicting failed spontaneous breathing trials

Jornal Brasileiro de Pneumologia ◽

10.1590/s1806-37562016000000360 ◽

2017 ◽

Vol 43 (4) ◽

pp. 253-258 ◽

Cited By ~ 2

Author(s):

Ana Carolina Peçanha Antonio ◽

Cassiano Teixeira ◽

Priscylla Souza Castro ◽

Ana Paula Zanardo ◽

Marcelo Basso Gazzana ◽

...

Keyword(s):

Spontaneous Breathing ◽

Spontaneous Breathing Trial ◽

Area Under The Curve ◽

Intrathoracic Pressure ◽

Roc Curves ◽

X Rays ◽

Pulmonary Congestion ◽

Eligibility Criteria ◽

Weaning Failure ◽

Radiological Score

ABSTRACT Objective: Inspiratory fall in intrathoracic pressure during a spontaneous breathing trial (SBT) may precipitate cardiac dysfunction and acute pulmonary edema. We aimed to determine the relationship between radiological signs of pulmonary congestion prior to an SBT and weaning outcomes. Methods: This was a post hoc analysis of a prospective cohort study involving patients in an adult medical-surgical ICU. All enrolled individuals met the eligibility criteria for liberation from mechanical ventilation. Tracheostomized subjects were excluded. The primary endpoint was SBT failure, defined as the inability to tolerate a T-piece trial for 30-120 min. An attending radiologist applied a radiological score on interpretation of digital chest X-rays performed before the SBT. Results: A total of 170 T-piece trials were carried out; SBT failure occurred in 28 trials (16.4%), and 133 subjects (78.3%) were extubated at first attempt. Radiological scores were similar between SBT-failure and SBT-success groups (median [interquartile range] = 3 [2-4] points vs. 3 [2-4] points; p = 0.15), which, according to the score criteria, represented interstitial lung congestion. The analysis of ROC curves demonstrated poor accuracy (area under the curve = 0.58) of chest x-rays findings of congestion prior to the SBT for discriminating between SBT failure and SBT success. No correlation was found between fluid balance in the 48 h preceding the SBT and radiological score results (ρ = −0.13). Conclusions: Radiological findings of pulmonary congestion should not delay SBT indication, given that they did not predict weaning failure in the medical-surgical critically ill population. (ClinicalTrials.gov identifier: NCT02022839 [http://www.clinicaltrials.gov/])

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Product of driving pressure and respiratory rate for predicting weaning outcomes

Journal of International Medical Research ◽

10.1177/03000605211010045 ◽

2021 ◽

Vol 49 (5) ◽

pp. 030006052110100

Author(s):

Ju Gong ◽

Bibo Zhang ◽

Xiaowen Huang ◽

Bin Li ◽

Jian Huang

Keyword(s):

Mechanical Ventilation ◽

Respiratory Rate ◽

Spontaneous Breathing ◽

Spontaneous Breathing Trial ◽

Plateau Pressure ◽

Driving Pressure ◽

Failure Group ◽

Rapid Shallow Breathing Index ◽

Weaning Failure ◽

Shallow Breathing

Objective Clinicians cannot precisely determine the time for withdrawal of ventilation. We aimed to evaluate the performance of driving pressure (DP)×respiratory rate (RR) to predict the outcome of weaning. Methods Plateau pressure (Pplat) and total positive end-expiratory pressure (PEEPtot) were measured during mechanical ventilation with brief deep sedation and on volume-controlled mechanical ventilation with a tidal volume of 6 mL/kg and a PEEP of 0 cmH2O. Pplat and PEEPtot were measured by patients holding their breath for 2 s after inhalation and exhalation, respectively. DP was determined as Pplat minus PEEPtot. The rapid shallow breathing index was measured from the ventilator. The highest RR was recorded within 3 minutes during a spontaneous breathing trial. Patients who tolerated a spontaneous breathing trial for 1 hour were extubated. Results Among the 105 patients studied, 44 failed weaning. During ventilation withdrawal, DP×RR was 136.7±35.2 cmH2O breaths/minute in the success group and 230.2±52.2 cmH2O breaths/minute in the failure group. A DP×RR index >170.8 cmH2O breaths/minute had a sensitivity of 93.2% and specificity of 88.5% to predict failure of weaning. Conclusions Measurement of DP×RR during withdrawal of ventilation may help predict the weaning outcome. A high DP×RR increases the likelihood of weaning failure. Statement: This manuscript was previously posted as a preprint on Research Square with the following link: https://www.researchsquare.com/article/rs-15065/v3 and DOI: 10.21203/rs.2.24506/v3

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Practice Variation in Spontaneous Breathing Trial Performance and Reporting

Canadian Respiratory Journal ◽

10.1155/2016/9848942 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Stephanie Godard ◽

Christophe Herry ◽

Paul Westergaard ◽

Nathan Scales ◽

Samuel M. Brown ◽

...

Keyword(s):

Spontaneous Breathing ◽

Spontaneous Breathing Trial ◽

Ventilatory Support ◽

Standard Of Care ◽

Practice Variation ◽

Ventilator Support ◽

Physiological Variables ◽

Physiologic Parameters ◽

Spontaneous Breathing Trials ◽

Oxygen Requirements

Background. Spontaneous breathing trials (SBTs) are standard of care in assessing extubation readiness; however, there are no universally accepted guidelines regarding their precise performance and reporting.Objective. To investigate variability in SBT practice across centres.Methods. Data from 680 patients undergoing 931 SBTs from eight North American centres from the Weaning and Variability Evaluation (WAVE) observational study were examined. SBT performance was analyzed with respect to ventilatory support, oxygen requirements, and sedation level using the Richmond Agitation Scale Score (RASS). The incidence of use of clinical extubation criteria and changes in physiologic parameters during an SBT were assessed.Results. The majority (80% and 78%) of SBTs used 5 cmH2O of ventilator support, although there was variability. A significant range in oxygenation was observed. RASS scores were variable, with RASS 0 ranging from 29% to 86% and 22% of SBTs performed in sedated patients (RASS < −2). Clinical extubation criteria were heterogeneous among centres. On average, there was no change in physiological variables during SBTs.Conclusion. The present study highlights variation in SBT performance and documentation across and within sites. With their impact on the accuracy of outcome prediction, these results support efforts to further clarify and standardize optimal SBT technique.

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Evaluation of the spontaneous breathing trial in burn intensive care patients

Yearbook of Plastic and Aesthetic Surgery ◽

10.1016/s1535-1513(09)79410-x ◽

2011 ◽

Vol 2011 ◽

pp. 75-76

Author(s):

R.E. Salisbury

Keyword(s):

Intensive Care ◽

Spontaneous Breathing ◽

Spontaneous Breathing Trial ◽

Intensive Care Patients

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Mechanical power normalized to lung-thorax compliance indicates weaning readiness in prolonged ventilated patients

Scientific Reports ◽

10.1038/s41598-021-03960-y ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Alessandro Ghiani ◽

Joanna Paderewska ◽

Swenja Walcher ◽

Konstantinos Tsitouras ◽

Claus Neurohr ◽

...

Keyword(s):

Mechanical Ventilation ◽

Logistic Regression ◽

Respiratory System ◽

Spontaneous Breathing ◽

Characteristic Curve ◽

Spontaneous Breathing Trial ◽

Mechanical Power ◽

Binary Logistic Regression Model ◽

Weaning Failure ◽

Ventilated Patients

AbstractSince critical respiratory muscle workload is a significant determinant of weaning failure, applied mechanical power (MP) during artificial ventilation may serve for readiness testing before proceeding on a spontaneous breathing trial (SBT). Secondary analysis of a prospective, observational study in 130 prolonged ventilated, tracheotomized patients. Calculated MP’s predictive SBT outcome performance was determined using the area under receiver operating characteristic curve (AUROC), measures derived from k-fold cross-validation (likelihood ratios, Matthew's correlation coefficient [MCC]), and a multivariable binary logistic regression model. Thirty (23.1%) patients failed the SBT, with absolute MP presenting poor discriminatory ability (MCC 0.26; AUROC 0.68, 95%CI [0.59‒0.75], p = 0.002), considerably improved when normalized to lung-thorax compliance (LTCdyn-MP, MCC 0.37; AUROC 0.76, 95%CI [0.68‒0.83], p < 0.001) and mechanical ventilation PaCO2 (so-called power index of the respiratory system [PIrs]: MCC 0.42; AUROC 0.81 [0.73‒0.87], p < 0.001). In the logistic regression analysis, PIrs (OR 1.48 per 1000 cmH2O2/min, 95%CI [1.24‒1.76], p < 0.001) and its components LTCdyn-MP (1.25 per 1000 cmH2O2/min, [1.06‒1.46], p < 0.001) and mechanical ventilation PaCO2 (1.17 [1.06‒1.28], p < 0.001) were independently related to SBT failure. MP normalized to respiratory system compliance may help identify prolonged mechanically ventilated patients ready for spontaneous breathing.

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Influence of lung aeration on diaphragmatic contractility during a spontaneous breathing trial: an ultrasound study

Journal of Intensive Care ◽

10.1186/s40560-019-0409-x ◽

2019 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Jing Xia ◽

Chuan-Yun Qian ◽

Li Yang ◽

Mei-Ju Li ◽

Xiao-Xue Liu ◽

...

Keyword(s):

Mechanical Ventilation ◽

Spontaneous Breathing ◽

Spontaneous Breathing Trial ◽

Quiet Breathing ◽

Diaphragmatic Function ◽

Lung Aeration ◽

Ultrasound Study ◽

Weaning Failure ◽

Successful Weaning ◽

The Right

Abstract Background A spontaneous breathing trial (SBT) is a major diagnostic tool to predict successfully extubation in patients. Several factors may lead to weaning failure, including the degree of lung aeration loss and diaphragm dysfunction. The main objective was to compare the diaphragmatic contractility between patients with high lung aeration loss and low lung aeration loss during a 30-minute SBT by ultrasound. Methods This was a prospective single-center study. Lung ultrasound aeration score (LUS) and diaphragmatic thickening fraction (DTF) were measured during mechanical ventilation 1 h before SBT (T-1), 30 min (T1), and 120 min (T2) after the start of the SBT during quiet breathing. The right and left DTF were compared between patients with LUS ≥ 14 (high lung aeration loss), considered at high risk of post-extubation distress, and those with LUS < 14 (low lung aeration loss). The relationship between the LUS and DTF and the changes in LUS and DTF from T-1 to T2 in patients with LUS ≥ 14 were assessed. Results Forty-nine patients were analyzed; 33 had LUS ≥ 14 and 16 had LUS < 14 at T1. The DTF at T1 was significantly higher in patients with LUS ≥ 14 than in those with LUS < 14: the right median (IQR) DTF was 22.2% (17.1 to 30.9%) vs. 14.8% (10.2 to 27.0%) (p = 0.035), and the left median (IQR) DTF was 25.0% (18.4 to 35.0%) vs. 18.6% (9.7 to 24.2%) (p = 0.017), respectively. There was a moderate positive correlation between the LUS and the DTF (Rho = 0.3, p = 0.014). A significant increase in the LUS was observed from T-1 to T1, whereas no change was found between T1 and T2. The DTF remained stable from T-1 to T2. Conclusions During a SBT, diaphragmatic contraction acts differently depending on the degree of pulmonary aeration. In patients with high lung aeration loss, increased diaphragmatic contractility indicates an additional respiratory effort to compensate lung volume loss that would contribute to successful SBT. Further studies are needed to evaluate the combined evaluation of lung aeration and diaphragmatic function to predict the successful weaning of patients from mechanical ventilation.

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