The management of acute respiratory failure in a respiratory intensive care unit

Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress

Background

Recent studies suggest that isolated sonographic assessment of the respiratory, cardiac, or neuromuscular functions in mechanically ventilated patients may assist in identifying patients at risk of postextubation distress. The aim of the present study was to prospectively investigate the value of an integrated thoracic ultrasound evaluation, encompassing bedside respiratory, cardiac, and diaphragm sonographic data in predicting postextubation distress.

Methods

Longitudinal ultrasound data from 136 patients who were extubated after passing a trial of pressure support ventilation were measured immediately after the start and at the end of this trial. In case of postextubation distress (31 of 136 patients), an additional combined ultrasound assessment was performed while the patient was still in acute respiratory failure. We applied machine-learning methods to improve the accuracy of the related predictive assessments.

Results

Overall, integrated thoracic ultrasound models accurately predict postextubation distress when applied to thoracic ultrasound data immediately recorded before the start and at the end of the trial of pressure support ventilation (learning sample area under the curve: start, 0.921; end, 0.951; test sample area under the curve: start, 0.972; end, 0.920). Among integrated thoracic ultrasound data, the recognition of lung interstitial edema and the increased telediastolic left ventricular pressure were the most relevant predictive factors. In addition, the use of thoracic ultrasound appeared to be highly accurate in identifying the causes of postextubation distress.

Conclusions

The decision to attempt extubation could be significantly assisted by an integrative, dynamic, and fully bedside ultrasonographic assessment of cardiac, lung, and diaphragm functions.

Integrated use of bedside lung ultrasound and echocardiography in acute respiratory failure: a prospective observational study in ICU

BACKGROUND

It has been suggested that the complementary use of echocardiography could improve the diagnostic accuracy of lung ultrasonography (LUS) in patients with acute respiratory failure (ARF). Nevertheless, the additional diagnostic value of echocardiographic data when coupled with LUS is still debated in this setting. The aim of the current study was to compare the diagnostic accuracy of LUS and an integrative cardiopulmonary ultrasound approach (thoracic ultrasonography [TUS]) in patients with ARF.

METHODS

We prospectively recruited patients consecutively admitted for ARF to the ICU of a university teaching hospital over a 12-month period. Inclusion criteria were age ≥ 18 years and the presence of criteria for severe ARF justifying ICU admission. We compared both LUS and TUS approaches and the final diagnosis determined by a panel of experts using machine learning methods to improve the accuracy of the final diagnostic classifiers.

RESULTS

One hundred thirty-six patients were included (age, 68 ± 15 years; sex ratio, 1). A three-dimensional partial least squares and multinomial logistic regression model was developed and subsequently tested in an independent sample of patients. Overall, the diagnostic accuracy of TUS was significantly greater than LUS (P < .05, learning and test sample). Comparisons between receiver operating characteristic curves showed that TUS significantly improves the diagnosis of cardiogenic edema (P < .001, learning and test samples), pneumonia (P < .001, learning and test samples), and pulmonary embolism (P < .001, learning sample).

CONCLUSIONS

This study demonstrated for the first time to our knowledge a significantly better performance of TUS than LUS in the diagnosis of ARF. The value of the TUS approach was particularly important to disambiguate cases of hemodynamic pulmonary edema and pneumonia. We suggest that the bedside use of artificial intelligence methods in this setting could pave the way for the development of new clinically relevant integrative diagnostic models.

Usefulness of cardiothoracic chest ultrasound in the management of acute respiratory failure in critical care practice

BACKGROUND

This study investigated the clinical relevance of early general chest ultrasonography (ie, heart and lung recordings) in patients in the ICU with acute respiratory failure (ARF).

METHODS

We prospectively compared this diagnostic approach (ultrasound) to a routine evaluation established from clinical, radiologic, and biologic data (standard). Subjects were patients consecutively admitted to the ICU of a university teaching hospital during a 1-year period. Inclusion criteria were age ≥ 18 years and the presence of severe ARF criteria to justify ICU admission. We compared the diagnostic approaches and the final diagnosis determined by a panel of experts.

RESULTS

Seventy-eight patients were included (age, 70 ± 18 years; sex ratio, 1). Three patients given two or more simultaneous diagnoses were subsequently excluded. The ultrasound approach was more accurate than the standard approach (83% vs 63%, respectively; P &lt; .02). Receiver operating characteristic curve analysis showed greater diagnostic performance of ultrasound in cases of pneumonia (standard, 0.74 ± 0.12; ultrasound, 0.87 ± 0.14; P &lt; .02), acute hemodynamic pulmonary edema (standard, 0.79 ± 0.11; ultrasound, 0.93 ± 0.08; P &lt; .007), decompensated COPD (standard, 0.8 ± 0.09; ultrasound, 0.92 ± 0.15; P &lt; .05), and pulmonary embolism (standard, 0.65 ± 0.12; ultrasound, 0.81 ± 0.17; P &lt; .04). Furthermore, we found that the use of ultrasound data could have significantly improved the initial treatment.

CONCLUSIONS

The use of cardiothoracic ultrasound appears to be an attractive complementary diagnostic tool and seems able to contribute to an early therapeutic decision based on reproducible physiopathologic data.

A history of ethics and law in the intensive care unit

Because they provide potential benefit at great personal and public cost, the intensive care unit (ICU) and the interventions rendered therein have become symbols of both the promise and the limitations of medical technology. At the same time, the ICU has served as an arena in which many of the ethical and legal dilemmas created by that technology have been defined and debated. This article outlines major events in the history of ethics and law in the ICU, covering the evolution of ICUs, ethical principles, informed consent and the law, medical decision-making, cardiopulmonary resuscitation, withholding and withdrawing life-sustaining therapy, legal cases involving life support, advance directives, prognostication, and futility and the allocation of medical resources. Advancement of the ethical principle of respect for patient autonomy in ICUs increasingly is in conflict with physicians' concern about their own prerogatives and with the just distribution of medical resources.

Intrapulmonary haematoma complicating mechanical ventilation in patients with chronic obstructive pulmonary disease

Intrapulmonary haematomas occurred during mechanical ventilation of two patients with advanced chronic obstructive pulmonary disease and bullous dystrophy. In both cases, the haematomas were revealed by blood-stained aspirates, a fall in haemoglobin level, and the appearance of radiological opacities. Haematoma occurrence in the area of a bulla which recently has rapidly increased in size, suggests that the haematoma is due to the rupture of stretched vessels embedded in the wall of the bulla.

Chronic obstructive lung disease and acute respiratory failure

Patients with chronic obstructive lung disease (COLD) experience one or more episodes of acute respiratory failure in the late years of their illness. Initial evaluation is aimed at assessing the precipitating factor or factors as well as the severity of the acute episode and the need for intubation and mechanical ventilation. Specific treatment is directed toward the individual precipitating cause, as well as toward the general relief of hypoxemia and airflow obstruction. The prognosis for recovery from most episodes of acute respiratory failure is excellent and warrants an aggressive approach.