ABSTRACT
BACKGROUND: With increasing life expectancy and ICU admission of elderly patients, mechanical ventilation, and weaning trials have increased worldwide. METHODS: We evaluated a cohort with 479 subjects in the ICU. Patients younger than 18 y, tracheostomized, or with neurologic diseases were excluded, resulting in 331 subjects. Subjects ≥70 y old were considered elderly, whereas those <70 y old were considered non-elderly. Besides the conventional weaning indexes, we evaluated the performance of the integrative weaning index (IWI). The probability of successful weaning was investigated using relative risk and logistic regression. The Hosmer-Lemeshow goodness-of-fit test was used to calibrate and the C statistic was calculated to evaluate the association between predicted probabilities and observed proportions in the logistic regression model. RESULTS: Prevalence of successful weaning in the sample was 83.7%. There was no difference in mortality between elderly and non-elderly subjects (P = .16), in days of mechanical ventilation (P = .22) and days of weaning (P = .55). In elderly subjects, the IWI was the only respiratory variable associated with mechanical ventilation weaning in this population (P < .001). CONCLUSIONS: The IWI was the independent variable found in weaning of elderly subjects that may contribute to the critical moment of this population in intensive care.
Subject(s)
Geriatric Assessment/methods , Models, Statistical , Severity of Illness Index , Ventilator Weaning/statistics & numerical data , Aged , Aged, 80 and over , Critical Care/methods , Female , Humans , Intensive Care Units , Logistic Models , Male , Middle Aged , Risk , Risk Assessment/methods , Time Factors , Treatment Outcome , Ventilator Weaning/methodsABSTRACT
PURPOSE: The purpose of the study was to compare 2 alveolar recruitment maneuvers (ARMs) approaches in patients with subarachnoid hemorrhage (SAH) and acute respiratory distress syndrome (ARDS). MATERIAL AND METHODS: Sixteen SAH patients with ARDS were randomized in 2 similar groups. One received ARM with continuous positive airway pressure (CPAP) of 35 cm H(2)O for 40 seconds (CPAP recruitment), whereas the other received pressure control ventilation with positive-end expiratory pressure of 15 cm H(2)O and pressure control above positive end-expiratory pressure of 35 cm H(2)O for 2 minutes (pressure control recruitment maneuver [PCRM]). Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were measured before and after ARM. The ratio of arterial oxygen tension to fraction of inspired oxygen was measured before and 1 hour after the ARM. RESULTS: After ARM, ICP was higher in CPAP recruitment (20.50 ± 4.75 vs 13.13 ± 3.56 mm Hg; P = .003); and CPP was lower in CPAP recruitment (62.38 ± 9.81 vs 79.60 ± 6.8 mm Hg; P = .001). One hour after the ARM, the ratio of arterial oxygen tension to fraction of inspired oxygen increased significantly only in PCRM (108.5 to 203.6; P = .0078). CONCLUSION: In SAH patients with ARDS, PCRM did not affect ICP and decreased CPP in safe levels, besides improving oxygenation.
Subject(s)
Continuous Positive Airway Pressure/methods , Positive-Pressure Respiration/methods , Pulmonary Alveoli/physiopathology , Respiratory Distress Syndrome/therapy , Subarachnoid Hemorrhage/therapy , Aged , Brain Injuries/therapy , Cerebrovascular Circulation , Humans , Intracranial Pressure , Oxygen/administration & dosage , Oxygen/blood , Respiration, Artificial , Respiratory Distress Syndrome/complications , Subarachnoid Hemorrhage/complications , Treatment OutcomeABSTRACT
O presente artigo discute a avaliação dos índices de desmame da ventilação mecânica, suas aplicabilidades, limitações, acurácia e recomendações. Embora o teste de respiração espontânea seja recomendado antes do desmame e a impressão clínica seja importante, ambos não são suficientes para predizer o resultado do desmame. A maioria dos índices de desmame não é acurada; no entanto, ao menos cinco devem ser considerados para avaliar o seu prognóstico. O índice de desmame mais utilizado é a relação frequência respiratória/volume corrente, também conhecido como índice de respiração rápida e superficial. Os demais índices atualmente recomendados são frequência respiratória, pressão inspiratória máxima, volume corrente e capacidade vital. Em âmbito nacional, temos o índice integrativo de desmame, que tem mostrado alta acurácia em populações heterogêneas. As principais limitações dos índices de desmame são populações específicas, diferentes pontos de cortes utilizadose variações nas formas de mensuração. Como a impressão clínica e o teste de respiração espontânea não são 100% acurados, os índices de desmame podem ser úteis, principalmente em situações de difíceis decisões para a descontinuação da ventilação mecânica.
Subject(s)
Humans , Male , Female , Intensive Care Units , Respiration, Artificial , Ventilator Weaning , Respiratory TherapyABSTRACT
INTRODUCTION: Indexes predicting weaning outcome are frequently inaccurate. We developed a new integrative weaning index aimed at improving the accuracy of the traditional indexes. METHODS: Three hundred and thirty-one patients mechanically-ventilated for more than 24 hours were evaluated. Initially, the threshold values of each index that best discriminate between a successful and an unsuccessful weaning outcome were determined in 115 patients. In the second phase, the predictive performance of these values was tested prospectively in the other 216 patients. Frequency/tidal volume ratio (f/Vt ratio), tidal volume (Vt), tracheal airway occlusion pressure 0.1 s (P 0.1), the product of P 0.1 and f/Vt (P 0.1 x f/Vt), respiratory rate (f), static compliance of the respiratory system (Cst,rs), ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2 ratio) and the new integrative weaning index IWI (Cst,rs x arterial oxygen saturation/f/Vt ratio) were evaluated in all patients. The readiness for weaning and the decision to return to mechanical ventilation was made by the physician in charge, based on the signs of poor tolerance. The receiver operating characteristic (ROC) curves were calculated in order to evaluate the predictive performance of each index. The Bayes' theorem was used to assess the probability of each test of predicting weaning. RESULTS: In the prospective-validation set, successful weaning was observed in 183 patients (84.7%) and weaning failure in 33 (15.27%). IWI presented the highest accuracy, with the area under the ROC curves larger than that under the curves for the f/Vt ratio (0.96 x 0.85 respectively; P = 0.003), and also larger than that under the curves for the other indexes. IWI presented a higher probability of successful weaning when the test was positive (0.99) and a lower probability when the test was negative (0.14). Measurement of Cst,rs during the weaning process was considered one of the study limitations. CONCLUSIONS: IWI was the best predictive performance index of weaning outcome and can be used in the intensive care unit setting. TRIAL REGISTRATION: controlled-trials.com ISRCTN92117906.
Subject(s)
Ventilator Weaning/methods , Aged , Aged, 80 and over , Bayes Theorem , Biomarkers/analysis , Diffusion of Innovation , Humans , Middle Aged , Predictive Value of Tests , Prospective Studies , ROC Curve , Respiratory Physiological PhenomenaABSTRACT
PURPOSE: The objective of this study is to evaluate the predictive performance of maximal inspiratory pressure (Pimax), airway occlusion pressure (P 0.1), and its ratio (P 0.1/Pimax) in the weaning outcome. MATERIALS AND METHODS: Seventy patients on mechanical ventilation for more than 24 hours, who fulfilled weaning criteria, were prospectively evaluated. Pimax less than -25 cm H(2)O, P 0.1 less than 4.2 cm H(2)O, and P 0.1/Pimax less than 0.14 were evaluated in all patients before spontaneous breathing trials. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. RESULTS: Pimax presented the area under the ROC curves smaller than those for P 0.1 and P 0.1/Pimax (0.52 x 0.76 and 0.52 x 0.78; P = .004 and P = .0006, respectively), being the criteria of worst performance. P 0.1/Pimax presented excellent predictive performance in weaned patients, with sensitivity of 98.08, but with the area under the ROC curves only slightly larger than those for P 0.1 (0.78 x 0.76, respectively; P = .69). CONCLUSION: In our study, P 0.1 and P 0.1/Pimax ratio were moderately accurate, whereas Pimax was less accurate in predicting the weaning outcome.
Subject(s)
Airway Obstruction/physiopathology , Inhalation/physiology , Ventilator Weaning , Aged , Aged, 80 and over , Female , Humans , Inspiratory Capacity/physiology , Male , Middle AgedABSTRACT
Os efeitos da fisioterapia sobre a pressão intracraniana (PIC) não são totalmente esclarecidos. O objetivo deste estudo é avaliar os efeitos da fisioterapia respiratória e movimentação passiva sobre a PIC. Foram avaliados 70 pacientes com traumatismo cranioencefálico e acidente vascular cerebral com Escala de Coma de Glasgow ≤ 8. A cabeceira foi mantida em 30 graus durante o estudo. A PIC foi monitorizada durante as seguintes condutas: compressão torácica, vibração associada à compressão torácica, compressão torácica contínua unilateral, aspiração traqueal com circuito aberto e com circuito fechado, movimentação passiva de membros superiores e inferiores, rotação do quadril, mobilização escapular e flexão lateral do tronco inferior. A variação da PIC durante as condutas foi avaliada pelo teste de Wilcoxon. A PIC inicial foi de 14 ± 6,4 mm Hg. Quatro condutas alteraram a PIC de forma significativa: Flexão lateral do tronco inferior (19,1 ± 6,52 mmHg; p < 0,0001), compressão torácica unilateral contínua (19,09 ± 6,43 mmHg; p < 0,0001), aspiração traqueal com circuito aberto (19,06 ± 6,46 mmHg; p < 0,0001) e com circuito fechado (18,2 ± 7,61 mmHg; p < 0,0001). Compressão torácica unilateral contínua e flexão lateral do tronco inferior devem ser evitadas em pacientes com hipertensão intracraniana. A aspiração traqueal é inevitável, mas deve ser cautelosa.
The effects of physical therapy on intracranial pressure (ICP) are not totally clear. The aim of this study was to evaluate the effects of respiratory physical therapy and passive mobilization on ICP. Seventy patients with traumatic brain injury (TBI) and stroke with Glasgow Coma Scale (GCS) ≤ 8 were evaluated. Thirty degree head-up position was used during the study. ICP was monitored during the following procedures: chest compression, vibration associated to chest compression, unilateral continuous chest compression, tracheal suction with open circuit and closed circuit, passive mobilization of arms and legs, hip rotation, scapular mobilization and lateral flexion of the lower trunk. Wilcoxon test was used to evaluate changes on ICP during the procedures. Initial ICP was 14 ± 6.4 mmHg. Four procedures changed ICP expressively: lateral flexion of the lower trunk (19.1 ± 6.52 mmHg; p < 0.0001), unilateral continuous chest compression (19.09 ± 6.43 mmHg; p < 0.0001), tracheal suction with open circuit (19.06 ± 6.46 mmHg; p < 0.0001) and with closed circuit (18.2 ± 7.61 mmHg; p < 0.0001). Unilateral continuous chest compression and lateral flexion of the lower trunk should be avoided in patients with intracranial hypertension. Tracheal suction is unavoidable, but should be done carefully.
