Antonio M. Esquinas

Use of a noninvasive ventilation device following tracheotomy: an alternative to facilitate ICU discharge?

Objective: We aimed to assess the use of noninvasive ventilation devices in pa- tients with prolonged weaning following tracheotomy.

To: Admission factors associated with intensive care unit readmission in critically ill oncohematological patients: a retrospective cohort study

We read the manuscript by Rodrigues et al. in the latest issue of Revista Brasileira de Terapia Intensiva Journal with great interest.(1) In this single-center, retrospective, observational cohort study, Rodrigues et al. aimed to identify risk factors associated with later readmission to the intensive care unit (ICU) among critically ill oncohematological patients by evaluating their first ICU admissions. They identified male sex, emergency surgery as the admission reason, longer length of hospital stay before ICU transfer and mechanical ventilation (MV) as independent risk factors for ICU readmissions. The hypothesis of this study was attractive because it evaluated a specific group of patients, “oncohematological patients,” who were followed in multiple critical care units and had different characteristics from the typical medical and surgical ICU populations. However, by evaluating only the admission factors of their first ICU stay, Rodrigues et al. limited their results to a narrow window. They disregarded evaluating other more important risk factors, some of which were mentioned in the manuscript’s discussion section. When evaluating readmission to ICU for a specific patient group, Gajic et al.(2) categorized the possible risk factors into 3 groups. These were (1) first ICU admission characteristics, (2) physiological characteristics, laboratory abnormalities and severity of illness at the time of ICU discharge and (3) functional status and need for nursing interventions at the time of ICU discharge. According to this categorization, Rodrigues et al.(1) should also have presented the first ICU admission characteristics of their patient group. They identified the length of hospital stay before ICU transfer as an independent predictor of readmission but did not take into consideration the length of ICU stay or the length of MV during patients’ first ICU admission. They also did not mention the type of MV applied, whether invasive MV (IMV) or noninvasive MV. Another risk factor that was excluded was ventilator-associated pneumonia development during the first ICU stay. Other relevant risk factors in oncohematological patients include immune suppression status and infections associated with this immune suppression, such as cytomegalovirus infections, pneumocystis carinii pneumonia, Aspergillus infections or invasive candidiasis. These infections are challenging to eradicate, and if not properly eradicated, can lead to readmissions in this group of patients. Second of all, physiological characteristics, laboratory abnormalities and severity of illness at the time of ICU discharge were not evaluated as risk factors of readmission by Rodrigues et al.(1) In assessing readmissions, it is important Conflicts of interest: None.

Practical Approach to the Use of Noninvasive Ventilation in Patients with ACPE

With regard to current noninvasive ventilation (NIV) practice, there are just four key A level indications supported by evidence-based medicine: chronic obstructive pulmonary disease (COPD) exacerbation, pulmonary infiltrates in immunocompromised patients, weaning with COPD, and, finally, cardiogenic pulmonary edema. These are what Nava [1] called “the fabulous four.” Acute-on-chronic cardiac failure exacerbation was not among those admitted to this club, but it is the only current indication among the cardiac diseases. The reason for the use of NIV in this clinical situation can be explained by the heart-lung interactions during mechanical ventilation (MV). When, how, and especially where to apply NIV are of major concern in achieving our therapeutic goals. The objective of this chapter is to answer these questions, why and where, based on current data in the literature.

To: Out-of-bed extubation: a feasible study

Weaning from mechanical ventilation represents one of the major challenges and concerns in intensive care units worldwide. The withdrawal time represents at least 40% of the overall mechanical ventilation period. Furthermore, in 30% of clinical cases some incidents will force the clinician to stop the attempt. Fortunately, there have been substantial improvements in mechanical ventilation weaning since release of the weaning and discontinuation ventilation guidelines in 2001,(1) standardizing the clinical practice of weaning protocols. Sedation control, adjusting doses to the minimum amount needed, daily spontaneous breathing trials after satisfying the respiratory assessment criteria and chest physical therapy (inspiratory muscle strength training) in the early stages of the illness, to avoid ventilator-induced diaphragm dysfunction (VIDD), are the cornerstones of current weaning protocols intended to avoid secondary wean failure (SWF). However, there remain many questions on this topic that merit further investigation. Dexheimer Neto et al. make progress in addressing these as yet unanswered questions.(2) The goal was to assess the advantages of extubating a patient after mobilization in an unusual position (seated in an arm chair) compared with the regular practice of extubation in the supine position. They concluded that there were no differences in the results for the two groups, (seated versus supine position).(1) With respect to the three main tools intended to prevent SWF mentioned above, the most poorly understood at present is chest physical therapy. Although controversy still exists because of limited data and a lack of multicenter trials on chest physical therapy,(3) it seems pathophysiologycally(4) that this therapy, in association with uncontrolled ventilator modalities, would significantly reduce the incidences of muscle atrophy, structural injury and respiratory muscle fiber remodeling, thereby preventing VIDD and failure to wean. However, the problem extends beyond the specific type of therapy, to when and how to use it. Chest physical therapy protocols are needed to solve this problem. These protocols should be tailored to address the main named causes of VIDD; however, we cannot forget cost effectiveness, respiratory secretion control and general motor muscle training. These are additional major concerns related to and causes of SWF that can interfere with weaning. Pharmacologic therapies such as expectorants, mucolytics, mucokinetics and mucoregulators and nonpharmacologic therapies such as humidification (active or passive), percussion Conflicts of interest: None.

Para: A realidade dos pacientes que necessitam de ventilação mecânica prolongada: um estudo multicêntrico

OBJECTIVE: The number of patients who require prolonged mechanical ventilation increased during the last decade, which generated a large population of chronically ill patients. This study established the incidence of prolonged mechanical ventilation in four intensive care units and reported different characteristics, hospital outcomes, and the impact of costs and services of prolonged mechanical ventilation patients (mechanical ventilation dependency ≥ 21 days) compared with non-prolonged mechanical ventilation patients (mechanical ventilation dependency < 21 days). METHODS: This study was a multicenter cohort study of all patients who were admitted to four intensive care units. The main outcome measures were length of stay in the intensive care unit, hospital, complications during intensive care unit stay, and intensive care unit and hospital mortality. RESULTS: There were 5,287 admissions to the intensive care units during study period. Some of these patients (41.5%) needed ventilatory support (n = 2,197), and 218 of the patients met criteria for prolonged mechanical ventilation (9.9%). Some complications developed during intensive care unit stay, such as muscle weakness, pressure ulcers, bacterial nosocomial sepsis, candidemia, pulmonary embolism, and hyperactive delirium, were associated with a significantly higher risk of prolonged mechanical ventilation. Prolonged mechanical ventilation patients had a significant increase in intensive care unit mortality (absolute difference = 14.2%, p < 0.001) and hospital mortality (absolute difference = 19.1%, p < 0.001). The prolonged mechanical ventilation group spent more days in the hospital after intensive care unit discharge (26.9 ± 29.3 versus 10.3 ± 20.4 days, p < 0.001) with higher costs. CONCLUSION: The classification of chronically critically ill patients according to the definition of prolonged mechanical ventilation adopted by our study (mechanical ventilation dependency ≥ 21 days) identified patients with a high risk for complications during intensive care unit stay, longer intensive care unit and hospital stays, high death rates, and higher costs.

Acute Effects of Continuous Positive Airway Pressure on Pulse Pressure in CHF

Today’s reality on non-invasive ventilation (NIV) use has nothing but four key A level indications supported by evidence-based medicine. These, which would be chronic obstructive pulmonary disease (COPD) exacerbation, cardiogenic pulmonary edema, pulmonary infiltrates in immunocompromised patients, and the weaning of already extubated COPD patients, are the so called “the fabulous four”1. But is this the maximum therapeutic potential of NIV? Probably not. If so, which would be the next one on this selected “fabulous four” group? Maybe it is stable chronic heart failure (CHF). If so, we would be facing a new frontier, yet unexplored, of those chronically stable not respiratory but cardiac patients, opening new applications, none existent up to today. Quintao et al.2 move on into the next step to conquer this new frontier, the NIV application on stable CHF. They do so, analyzing the NIV (Continuous Positive Airway Pressure - CPAP) effects on pulse pressure (PP), as a risk factor with independent negative predictive value for adverse cardiovascular events, followed by left ventricular dysfunction, especially type II, caused by acute myocardial ischemia. They prove not only to affect PP reduction, but also heart rate (HR), mean arterial pressure (MAP), systolic blood pressure (SBP) and respiratory rate (RR). The results will be explained through the relationship between positive pressure ventilation effects3 on the cardiorespiratory system. In the left heart, pulmonary vein compression followed to translung pressure increases, improving venous return and so the preload. In addition, this translung pressure increase contributes to squeeze the heart chambers and discharge them, this “dUp”4 effect increases the stroke volume (SV) and improves left systolic output. The afterload reduction is secondary to the systemic vasodilatation effect as a response to intrathoracic pressure elevation. As a final result, HR, MAP, SAP and PP decrease, protecting myocardial oxygenation and reducing the myocardial infarction risk. In the right heart, translung pressure reduces preload secondary to the vena cava squeeze and elevates afterload3 by the increase in pulmonary vascular resistances. As a result a “dDown”4 effect and right SV reduction occur, reducing vascular congestion and lung edema, and once again improving oxygenation and ventilation. Regarding respiratory effects, there will be direct oxygenation by O2 administration and also the alveolar recruitment effect. As a final result, PaO2 and mixed venous oxygen (SVO2) raise, and RR and HR decrease. In a study by Quintao et al.2, hemodynamic monitoring was not continuous, but manually measured (sphygmomanometer); thus, a continuous monitoring might offer more accurate and precise data. Actually additional monitoring with echocardiography will allow to expand data, calculate ejection fraction and SV, which will allow to establish the relationship between PP reduction and ventricular output improvement. The trial lasted 30 minutes, enough to confirm the hypothesis, but a longer time will allow maximum effect assessment to possibly define the best CPAP potential on this matter. Finally, although a CPAP pressure of 6 cm H20 is in fact the usual level used in those studies, a bigger pressure of 8 cm H20 will probably have a bigger effect, as we usually see in everyday work.