Augusto Savi

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.

Central venous saturation is a predictor of reintubation in difficult-to-wean patients.

Objective: To evaluate the predictive value of central venous saturation to detect extubation failure in difficult-to-wean patients. Design: Cohort, multicentric, clinical study. Setting: Three medical-surgical intensive care units. Patients: All difficult-to-wean patients (defined as failure to tolerate the first 2-hr T-tube trial), mechanically ventilated for >48 hrs, were extubated after undergoing a two-step weaning protocol (measurements of predictors followed by a T-tube trial). Extubation failure was defined as the need of reintubation within 48 hrs. Interventions: The weaning protocol evaluated hemodynamic and ventilation parameters, and arterial and venous gases during mechanical ventilation (immediately before T-tube trial), and at the 30th min of spontaneous breathing trial. Measurements and Main Results: Seventy-three patients were enrolled in the study over a 6-mo period. Reintubation rate was 42.5%. Analysis by logistic regression revealed that central venous saturation was the only variable able to discriminate outcome of extubation. Reduction of central venous saturation by >4.5% was an independent predictor of reintubation, with odds ratio of 49.4 (95% confidence interval 12.1–201.5), a sensitivity of 88%, and a specificity of 95%. Reduction of central venous saturation during spontaneous breathing trial was associated with extubation failure and could reflect the increase of respiratory muscles oxygen consumption. Conclusions: Central venous saturation was an early and independent predictor of extubation failure and may be a valuable accurate parameter to be included in weaning protocols of difficult-to-wean patients.

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

OBJECTIVE: To determine whether the predictive accuracy of clinical judgment alone can be improved by supplementing it with an objective weaning protocol as a decision support tool. METHODS: This was a multicenter prospective cohort study carried out at three medical/surgical ICUs. The study involved all consecutive difficult-to-wean ICU patients (failure in the first spontaneous breathing trial [SBT]), on mechanical ventilation (MV) for more than 48 h, admitted between January of 2002 and December of 2005. The patients in the protocol group (PG) were extubated after a T-piece weaning trial and were compared with patients who were otherwise extubated (non-protocol group, NPG). The primary outcome measure was reintubation within 48 h after extubation. RESULTS: We included 731 patients-533 (72.9%) and 198 (27.1%) in the PG and NPG, respectively. The overall reintubation rate was 17.9%. The extubation success rates in the PG and NPG were 86.7% and 69.6%, respectively (p < 0.001). There were no significant differences between the groups in terms of age, gender, severity score, or pre-inclusion time on MV. However, COPD was more common in the NPG than in the PG (44.4% vs. 17.6%; p < 0.001), whereas sepsis and being a post-operative patient were more common in the PG (23.8% vs. 11.6% and 42.4% vs. 26.4%, respectively; p < 0.001 for both). The time on MV after the failure in the first SBT was higher in the PG than in the NPG (9 ± 5 days vs. 7 ± 2 days; p < 0.001). CONCLUSIONS: In this sample of difficult-to-wean patients, the use of a weaning protocol improved the decision-making process, decreasing the possibility of extubation failure.

Comportamento da mecânica pulmonar após a aplicação de protocolo de fisioterapia respiratória e aspiração traqueal em pacientes com ventilação mecânica invasiva

BACKGROUND AND OBJECTIVES: The chest physiotherapy (CP) in patients submitted to invasive support ventilation acts directly in the breathing system, and it could alter the lung mechanics through the dynamic lung compliance (DynC) and resistance of the breathing system (Rbs). However the alterations after the accomplishment of CP are still controversy. The objective of this study was to evaluate the alterations of the lung mechanics in patients in invasive mechanical ventilation (IMV). METHODS: It was a prospective, randomized, and controlled and crossover study, with patient with more than 48 hours in IMV. The protocol of chest physiotherapy and isolated tracheal aspiration they were randomized for the application order with a window of 24 hours among them. Data of lung mechanics and its varied cardiorespiratory were collected moments before the protocol, immediately after the application of the protocol, 30 minutes and 120 minutes after the application of the protocols. RESULTS: Twelve patients completed the study. Pneumonia was the mean cause respiratory failure (RF). There was not statistical difference among the groups in relation to Cdyn, volume tidal (Vt) and volume minute (Ve). Rbs decreased in a significant way immediately after (of 10.4 ± 3 cmH2O/L/seg for 8.9 ± 2 cmH2O/L/seg; p < 0.02), 30 minutes after (of 10.4 ± 3 cmH2O/L/seg for 9 ± 2 cmH2O/L/seg; p < 0.01) and 120 minutes after (of 10.4 ± 3 cmH2O/L/seg for 9 ± 2 cmH2O/L/seg; p < 0.03) application the protocol of chest physiotherapy. When compared with the protocol of isolated tracheal aspiration it was significantly smaller in the 30 (9 ± 2 cmH2O/L/seg versus10.2 ± 2 cmH2O/L/seg; p < 0.04) and 120 minutes (9 ± 2 cmH2O/L/seg versus 10.4 ± 3 cmH2O/L/seg; p < 0.04). CONCLUSIONS: The protocol of chest physiotherapy was effective in the decrease of Rsr when compared with the aspiration protocol. That decrease was maintained for two hours after its application, what did not happen when only the just accomplished the tracheal aspiration was performed isolated.

The Critical Illness Polyneuropathy in Septic Patients With Prolonged Weaning From Mechanical Ventilation: Is the Diaphragm Also Affected? A Pilot Study

BACKGROUND: Critical illness myopathy and/or neuropathy (CRIMYNE) is a common alteration seen in the ICU. The currently available bedside methods of measuring respiratory and peripheral muscle function in critically ill patients are somewhat inadequate. The objective of this study was to evaluate the presence of diaphragmatic and peripheral CRIMYNE in septic patients with prolonged weaning from mechanical ventilation (MV). METHODS: Cohort prospective study with an entry period of 6 months. In 2 Brazilian medical-surgical ICUs, septic patients ≥ 18 years of age, dependent on MV ≥ 14 days, requiring prolonged weaning from MV, awake (Richmond Agitation Sedation Scale ≥ –2), and with no previous history of polyneuropathy or myopathy were included. Electrophysiological studies of the limbs and also of the respiratory system by phrenic nerve conduction and needle electromyography of the diaphragm were performed in all subjects. RESULTS: Twelve subjects were enrolled during 6 months of study. The electrophysiological signs of peripheral CRIMYNE occurred in 9 subjects, 7 of whom died in the ICU. Three subjects developed critical illness polyneuropathy, 4 critical illness myopathy, and 2 both. Only one subject who developed peripheral CRIMYNE did not present diaphragmatic involvement, whereas no subject developed diaphragm involvement alone. Thus, electrophysiological signs of diaphragmatic CRIMYNE occurred in 8 of the 9 subjects with peripheral CRIMYNE. Upon clinical examination, 8 subjects were not able to moves their limbs against gravity, and these findings were related to the presence of peripheral and diaphragmatic dysfunction. CONCLUSIONS: Our pilot findings suggested that CRIMYNE is common in septic patients with prolonged weaning from MV (MV ≥ 14 d). The inability to move limbs against gravity is frequently associated with peripheral and diaphragmatic CRIMYNE, and the findings of CRIMYNE in peripheral electrophysiological tests are associated with diaphragmatic involvement.

The reality of patients requiring prolonged mechanical ventilation: a multicenter study

Objetivo: Na ultima decada ocorreu um aumento no numero de pacientes que necessitam manutencao de venti- lacao mecânica prolongada, resultando no surgimento de uma grande popula- cao de pacientes cronicos criticamen- te enfermos. Este estudo estabeleceu a incidencia de ventilacao mecânica pro- longada em quatro unidades de terapia intensiva e relatou as diferentes caracte- risticas, desfechos hospitalares e impacto nos custos e servicos de pacientes com ventilacao mecânica prolongada (depen- dencia de ventilacao mecânica por 21 dias ou mais) em comparacao a pacien- tes sem ventilacao mecânica prolongada (dependencia de ventilacao mecânica in- ferior a 21 dias).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.

Influence of FIO2 on PaCO2 during noninvasive ventilation in patients with COPD.

BACKGROUND: The administration of a high FIO2 to COPD patients breathing spontaneously may result in hypercapnia, due to reversal of preexisting regional hypoxic pulmonary vasoconstriction, resulting in a greater dead space. Arterial blood gas trends have not been reported in these patients. In a 31-bed medical ICU in a teaching hospital we prospectively investigated the response of 17 CO2-retaining COPD patients, after acute respiratory crisis stabilization with noninvasive ventilation, to an FIO2 of 1.0 for 40 min, after having been noninvasively ventilated with an FIO2 of ≤ 0.50 for 40 min. RESULTS: The mean ± SD baseline findings were: PaO2 101.4 ± 21.7 mm Hg, PaCO2 52.6 ± 10.4 mm Hg, breathing frequency 17.8 ± 3.7 breaths/min, tidal volume 601 ± 8 mL, and Glasgow coma score of 14.8 ± 0.3. PaO2 significantly increased (P < .001) when FIO2 was increased to 1.0, but there was no significant change in PaCO2, breathing frequency, tidal volume, or Glasgow coma score. CONCLUSIONS: During noninvasive ventilation with an FIO2 sufficient to maintain a normal PaO2, a further increase in FIO2 did not increase PaCO2 in our CO2-retaining COPD patients.

Spontaneous Breathing Trials With T-Piece or Pressure Support Ventilation

Spontaneous breathing trials (SBTs) are among the most commonly employed techniques to facilitate weaning from mechanical ventilation. The preferred SBT technique, however, is still unclear. To clarify the preferable SBT (T-piece or pressure support ventilation [PSV]), we conducted this systematic review. We then searched the MEDLINE, EMBASE, SciELO, Google Scholar, CINAHL, ClinicalTrials.gov, and Cochrane CENTRAL databases through June 2015, without language restrictions. We included randomized controlled trials involving adult subjects being weaned from mechanical ventilation comparing T-piece with PSV and reporting (1) weaning failure, (2) re-intubation rate, (3) ICU mortality, or (4) weaning duration. Anticipating clinical heterogeneity among the included studies, we compared prespecified subgroups: (1) simple, difficult, or prolonged weaning and (2) subjects with COPD. We summarized the quality of evidence for intervention effects using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology. We identified 3,674 potentially relevant studies and reviewed 23 papers in full. Twelve studies (2,161 subjects) met our inclusion criteria. Overall, the evidence was of very low to low quality. SBT technique did not influence weaning success (risk ratio 1.23 [0.94–1.61]), ICU mortality (risk ratio 1.11 [0.80–1.54]), or re-intubation rate (risk ratio 1.21 [0.90–1.63]). Prespecified subgroup analysis suggested that PSV might be superior to T-piece with regard to weaning success for simple-to-wean subjects (risk ratio 1.44 [1.11–1.86]). For the prolonged-weaning subgroup, however, T-piece was associated with a shorter weaning duration (weighted mean difference −3.08 [−5.24 to −0.92] d). In conclusion, low-quality evidence is available concerning this topic. PSV may be associated with lower weaning failure rates in the simple-to-wean subgroup. In contrast, in prolonged-weaning subjects, T-piece may be related to a shorter weaning duration, although this is at high risk of bias. Further study of the difficult-to-wean and COPD subgroups is required.

Functional and psychological features immediately after discharge from an Intensive Care Unit: prospective cohort study

Objective To assess the functional and psychological features of patients immediately after discharge from the intensive care unit. Methods Prospective cohort study. Questionnaires and scales assessing the degree of dependence and functional capacity (modified Barthel and Karnofsky scales) and psychological problems (Hospital Anxiety and Depression Scale), in addition to the Epworth Sleepiness Scale, were administered during interviews conducted over the first week after intensive care unit discharge, to all survivors who had been admitted to this service from August to November 2012 and had remained longer than 72 hours. Results The degree of dependence as measured by the modified Barthel scale increased after intensive care unit discharge compared with the data before admission (57±30 versus 47±36; p<0.001) in all 79 participants. This impairment was homogeneous among all the categories in the modified Barthel scale (p<0.001) in the 64 participants who were independent or partially dependent (Karnofsky score ≥40) before admission. The impairment affected the categories of personal hygiene (p=0.01) and stair climbing (p=0.04) only in the 15 participants who were highly dependent (Karnofsky score <40) before admission. Assessment of the psychological changes identified mood disorders (anxiety and/or depression) in 31% of the sample, whereas sleep disorders occurred in 43.3%. Conclusions Patients who remained in an intensive care unit for 72 hours or longer exhibited a reduced functional capacity and an increased degree of dependence during the first week after intensive care unit discharge. In addition, the incidence of depressive symptoms, anxiety, and sleep disorders was high among that population.

Public versus Private Healthcare Systems following Discharge from the ICU: A Propensity Score-Matched Comparison of Outcomes

Purpose. The long-term outcomes of patients after discharge from tertiary ICUs as they relate to the public versus private healthcare systems in Brazil have not yet been evaluated. Materials and Methods. A multicenter prospective cohort study was conducted to compare the all-cause mortality and the physical functional status (PFS) 24 months after discharge from the ICU between adult patients treated in the public and private healthcare systems. A propensity score- (PS-) matched comparison of all causes of mortality and PFS 24 months after discharge from the ICU was performed. Results. In total, 928 patients were discharged from the ICU including 172 (18.6%) patients in the public and 756 (81.4%) patients in the private healthcare system. The results of the PS-matched comparison of all-cause mortality revealed higher mortality rates among the patients of the public healthcare system compared to those of the private healthcare system (47.3% versus 27.6%, P = 0.003). The comparison of the PS-matched Karnofsky performance and Lawton activities of daily living scores between the ICU survivors of the public and private healthcare systems revealed no significant differences. Conclusions. The patients of private healthcare system exhibited significantly greater survival rates than the patients of the public healthcare system with similar PFS following ICU discharge.