Serial measurements of f/VT can predict extubation failure in patients with f/VT ≤ 105?

Development and validation of a mechanical power-oriented prediction model of weaning failure in mechanically ventilated patients: a retrospective cohort study

OBJECTIVE

To develop and validate a mechanical power (MP)-oriented prediction model of weaning failure in mechanically ventilated patients.

DESIGN

A retrospective cohort study.

SETTING

Data were collected from the large US Medical Information Mart for Intensive Care-IV (MIMIC-IV) V.1.0, which integrates comprehensive clinical data from 76 540 intensive care unit (ICU) admissions from 2008 to 2019.

PARTICIPANTS

A total of 3695 patients with invasive mechanical ventilation for more than 24 hours and weaned with T-tube ventilation strategies were enrolled from the MIMIC-IV database.

PRIMARY AND SECONDARY OUTCOME

Weaning failure.

RESULTS

All eligible patients were randomised into development cohorts (n=2586, 70%) and validation cohorts (n=1109, 30%). Multivariate logistic regression analysis of the development cohort showed that positive end-expiratory pressure, dynamic lung compliance, MP, inspired oxygen concentration, length of ICU stay and invasive mechanical ventilation duration were independent predictors of weaning failure. Calibration curves showed good correlation between predicted and observed outcomes. The prediction model showed accurate discrimination in the development and validation cohorts, with area under the receiver operating characteristic curve values of 0.828 (95% CI: 0.812 to 0.844) and 0.833 (95% CI: 0.809 to 0.857), respectively. Decision curve analysis indicated that the predictive model was clinically beneficial.

CONCLUSION

The MP-oriented model of weaning failure accurately predicts the risk of weaning failure in mechanical ventilation patients and provides valuable information for clinicians making decisions on weaning.

New integrated weaning indices from mechanical ventilation: A derivation-validation observational multicenter study

Background

To develop ten new integrated weaning indices that can predict the weaning outcome better than the traditional indices.

Methods

This retrospective-prospective derivation-validation observational multicenter clinical trial (Clinical Trial.Gov, NCT 01779297), was conducted on 1,175 adult patients admitted at 9 academic affiliated intensive care units (ICUs; 4 surgical and 5 medical), from Jan 2013 to Dec 2018. All patients, intubated and mechanically ventilated for at least 24 h and ready for weaning were enrolled. The study had two phases: at first, the threshold values of each index that best discriminate between a successful and an unsuccessful weaning outcome was determined among 208 patients in the derivation group. In the second phase, the predictive performance of these values was prospectively tested in 967 patients in the validation group. In the prospective-validation set we used Bayes’ theorem to assess the probability of each test in predicting weaning.

Results

In the prospective validation group, sensitivity, specificity, diagnostic accuracy, positive and negative predictive values, and finally area under the receiver operator characteristic curves and standard errors for each index (ten formulae) were calculated. Statistical values of ten formulae for aforesaid variables were higher than 87% (0.87–0.99).

Conclusion

The new indices can be used for hospitalized patients in intensive care settings for accurate prediction of the weaning outcome.

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

Background

Extubation 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.

Methods

We 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.

Results

Sixty-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.

Conclusions

Numerous 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03802-3.

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

BACKGROUND

This 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.

OBJECTIVES

The 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.

METHODS

One 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.

RESULTS

RSBI 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.

CONCLUSIONS

The 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.

Prediction of extubation failure in Intensive Care Unit: systematic review of parameters investigated

INTRODUCTION

Extubation failure (EF) refers to the inability to maintain spontaneous breathing after removal of endotracheal tube. The aim of this review is to identify the best parameter to predict EF in adult intensive care patients.

EVIDENCE ACQUISITION

We searched for publications in PubMed (2000-2016). Studies of patients intubated and mechanically ventilated for more than 24 hours were included and divided in groups basing on the extubation method. 2x2 tables were performed to evaluate the sensitivity, specificity and the predictive values only for those parameters investigated in more than three studies. Studies were divided in groups, basing on time required to define EF (<24 hours, <72 or >72 hours), and EF percentage was calculated for each group.

EVIDENCE SYNTHESIS

On 443 potentially studies, 26 were included. Rapid Shallow Breathing Index (RSBI) and cough strength parameters were found in more than three studies. RSBI or cough strength parameter showed a sensitivity of 20-88.8% or 55.5-85.2%, a specificity of 68.5-94.8% or 24-49%, a positive predictive value (PPV) of 39.5-66.6% or 24-49% and a negative predictive value of 98-82% or 89.5-96.4%, respectively. EF rate was 12.5%, 15.3% and 22% in patients evaluated within 24 hours, 72 hours and over 72 hours, respectively.

CONCLUSIONS

This review shows that all parameters used to predict EF have a low PPV. Therefore, the limitation of use of such predictive tests may prolong unnecessarily the intubation and increase the unfavorable outcome. A prospective study involving all variables could be useful to predict the EF in ICU.

Rapid shallow breathing index

Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed.

Weaning from mechanical ventilation: a cross-sectional study of reference values and the discriminative validity of aging

[Purpose] To evaluate pre-extubation variables and check the discriminative validity of age as well as its correlation with weaning failure in elderly patients. [Subjects and Methods] Two hundred thirty-nine consecutive patients (48% female) who were on mechanical ventilation and had undergone orotracheal intubation were divided into four subgroups according to their age: <59 years, 60-69 years, 70-79 years, and >80 years old. The expiratory volume (VE), respiratory frequency (f), tidal volume (VT), and respiratory frequency/tidal volume ratio (f/VT) were used to examine differences in weaning parameters between the four subgroups, and age was correlated with weaning failure. [Results] The rate of weaning failure was 27.8% in patients aged >80 years and 22.1% in patients aged <60 years old. Elderly patients presented higher f/VT and f values and lower VT values. The areas under the receiver operating characteristic curves for f/VT ratio were smaller than those published previously. [Conclusion] Our results indicate that aging influences weaning criteria without causing an increase in weaning failure.

Association between the rapid shallow breathing index and extubation success in patients with traumatic brain injury

Objective

To investigate the association between the rapid shallow breathing index and successful extubation in patients with traumatic brain injury.

Methods

This study was a prospective study conducted in patients with traumatic brain injury of both genders who underwent mechanical ventilation for at least two days and who passed a spontaneous breathing trial. The minute volume and respiratory rate were measured using a ventilometer, and the data were used to calculate the rapid shallow breathing index (respiratory rate/tidal volume). The dependent variable was the extubation outcome: reintubation after up to 48 hours (extubation failure) or not (extubation success). The independent variable was the rapid shallow breathing index measured after a successful spontaneous breathing trial.

Results

The sample comprised 119 individuals, including 111 (93.3%) males. The average age of the sample was 35.0±12.9 years old. The average duration of mechanical ventilation was 8.1±3.6 days. A total of 104 (87.4%) participants achieved successful extubation. No association was found between the rapid shallow breathing index and extubation success.

Conclusion

The rapid shallow breathing index was not associated with successful extubation in patients with traumatic brain injury.

Impacto de um protocolo de desmame de ventilação mecânica na taxa de falha de extubação em pacientes de difícil desmame

OBJETIVO: Determinar se a acurácia preditiva do julgamento clínico isolado pode ser melhorada com o uso suplementar de um protocolo de desmame objetivo como ferramenta de suporte para a tomada de decisão. MÉTODOS: Estudo prospectivo multicêntrico de coorte realizado em três UTIs clínicas/cirúrgicas. Foram incluídos no estudo todos os pacientes de difícil desmame (falha no primeiro teste de ventilação espontânea [TVE]), sob ventilação mecânica (VM) por mais de 48 h, admitidos em uma das UTIs entre janeiro de 2002 e dezembro de 2005. Os pacientes do grupo protocolo (GP) foram extubados após teste de tubo T de acordo com um protocolo de desmame e comparados com o grupo de pacientes extubados sem o uso do protocolo (GNP). O desfecho primário foi a taxa de reintubação em até 48 h após a extubação. RESULTADOS: Foram incluídos 731 pacientes - 533 (72,9%) no GP e 198 (27,1%) no GNP. A taxa global de reintubação foi de 17,9%. As taxas de sucesso da extubação no GP e no GNP foram 86,7% e 69,6%, respectivamente (p < 0,001). Não houve diferenças significativas entre os grupos quanto a idade, gênero, escore de gravidade e tempo de VM antes da inclusão. Entretanto, DPOC foi mais frequente no GNP que no GP (44,4% vs. 17,6%; p < 0,001), ao passo que pacientes sépticos e em pós-operatório foram mais comuns no GP (23,8% vs. 11,6% e 42,4% vs. 26,4%, respectivamente; p < 0,001 para ambos). O tempo de VM após a falha no primeiro TVE foi maior no GP que no GNP (9 ± 5 dias vs. 7 ± 2 dias; p < 0,001). CONCLUSÕES: Nesta amostra de pacientes de difícil desmame, o uso de um protocolo de desmame melhorou o processo decisório, reduzindo a possibilidade de falha na extubação.

Weaning predictors do not predict extubation failure in simple-to-wean patients

BACKGROUND

Predictor indexes are often included in weaning protocols and may help the intensive care unit (ICU) staff to reach expected weaning outcome in patients on mechanical ventilation.

OBJECTIVE

The objective of this study is to evaluate the potential of weaning predictors during extubation.

DESIGN

This is a prospective clinical study.

SETTINGS

The study was conducted in 3 medical-surgical ICUs.

PATIENTS

Five hundred consecutive unselected patients ventilated for more than 48 hours were included.

METHODS AND MEASUREMENTS

All patients were extubated after 30 minutes of successful spontaneous breathing trial and followed up for 48 hours. The protocol evaluated hemodynamics, ventilation parameters, arterial blood gases, and the weaning indexes frequency to tidal volume ratio; compliance, respiratory rate, oxygenation, and pressure; maximal inspiratory pressure; maximal expiratory pressure; Pao(2)/fraction of inspired oxygen; respiratory frequency; and tidal volume during mechanical ventilation and in the 1st and 30th minute of spontaneous breathing trial.

RESULTS

Reintubation rate was 22.8%, and intensive care mortality was higher in the reintubation group (10% vs 31%; P < .0001). The areas under the receiver operating characteristic curve showed that tests did not discriminate which patients could tolerate extubation.

CONCLUSION

Usual weaning indexes are poor predictors for extubation outcome in the overall ICU population.

Evolution of pattern of breathing during a spontaneous breathing trial predicts successful extubation

PURPOSE

Rapid shallow breathing may occur at any time during spontaneous breathing trials (SBT), questioning the utility of a single determination of the rapid shallow breathing index (RSBI). We hypothesize that change in RSBI during SBT may more accurately predict successful extubation than a single determination.

METHODS

Prospective observational study. Seventy-two subjects were extubated. At 24 h, 63/72 remained extubated (Extubation Success), and 9 were re-intubated (Extubation Failure). Respiratory rate (RR), tidal volume (VT) and RSBI were measured every 30 min during 2-h T-piece SBT. Change in respiratory parameters was assessed as percent change from baseline.

RESULTS

Initial RSBI was similar in Extubation Success and Extubation Failure groups (77.0 +/- 4.8, 77.0 +/- 4.8, p = ns). Nevertheless, RSBI tended to remain unchanged or decreased in the Extubation Success group; in contrast RSBI tended to increase in the Extubation Failure group because of either increased RR and/or decreased VT (p < 0.001 for mean percent change RSBI over time), indicating worsening of the respiratory pattern. Quantitatively, only 7/63 subjects of the Extubation Success group demonstrated increased RSBI >or=20% at any time during the SBT. In contrast, in the Extubation Failure group, RSBI increased in all subjects during the SBT, and eight of nine subjects demonstrated an increase greater than 20%. Thus, with a 2-h SBT the optimal threshold was a 20% increase (sensitivity = 89%, specificity = 89%). Similar results were obtained at 30 min (threshold = 5% increase). Percent change of RSBI predicted successful extubation even when initial values were >or=105.

CONCLUSION

Percent change of RSBI during an SBT is a better predictor of successful extubation than a single determination of RSBI.