Silvia Regina Rios Vieira

Serum neuron-specific enolase as early predictor of outcome after in-hospital cardiac arrest: a cohort study

IntroductionOutcome after cardiac arrest is mostly determined by the degree of hypoxic brain damage. Patients recovering from cardiopulmonary resuscitation are at great risk of subsequent death or severe neurological damage, including persistent vegetative state. The early definition of prognosis for these patients has ethical and economic implications. The main purpose of this study was to investigate the prognostic value of serum neuron-specific enolase (NSE) in predicting outcomes in patients early after in-hospital cardiac arrest.MethodsForty-five patients resuscitated from in-hospital cardiac arrest were prospectively studied from June 2003 to January 2005. Blood samples were collected, at any time between 12 and 36 hours after the arrest, for NSE measurement. Outcome was evaluated 6 months later with the Glasgow outcome scale (GOS). Patients were divided into two groups: group 1 (unfavorable outcome) included GOS 1 and 2 patients; group 2 (favorable outcome) included GOS 3, 4 and 5 patients. The Mann–Whitney U test, Students t test and Fishers exact test were used to compare the groups.ResultsThe Glasgow coma scale scores were 6.1 ± 3 in group 1 and 12.1 ± 3 in group 2 (means ± SD; p < 0.001). The mean time to NSE sampling was 20.2 ± 8.3 hours in group 1 and 28.4 ± 8.7 hours in group 2 (p = 0.013). Two patients were excluded from the analysis because of sample hemolysis. At 6 months, favorable outcome was observed in nine patients (19.6%). Thirty patients (69.8%) died and four (9.3%) remained in a persistent vegetative state. The 34 patients (81.4%) in group 1 had significantly higher NSE levels (median 44.24 ng/ml, range 8.1 to 370) than those in group 2 (25.26 ng/ml, range 9.28 to 55.41; p = 0.034).ConclusionEarly determination of serum NSE levels is a valuable ancillary method for assessing outcome after in-hospital cardiac arrest.

Effect of Lung Recruitment and Titrated Positive End-Expiratory Pressure (PEEP) vs Low PEEP on Mortality in Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial

Importance The effects of recruitment maneuvers and positive end-expiratory pressure (PEEP) titration on clinical outcomes in patients with acute respiratory distress syndrome (ARDS) remain uncertain. Objective To determine if lung recruitment associated with PEEP titration according to the best respiratory-system compliance decreases 28-day mortality of patients with moderate to severe ARDS compared with a conventional low-PEEP strategy. Design, Setting, and Participants Multicenter, randomized trial conducted at 120 intensive care units (ICUs) from 9 countries from November 17, 2011, through April 25, 2017, enrolling adults with moderate to severe ARDS. Interventions An experimental strategy with a lung recruitment maneuver and PEEP titration according to the best respiratory–system compliance (n = 501; experimental group) or a control strategy of low PEEP (n = 509). All patients received volume-assist control mode until weaning. Main Outcomes and Measures The primary outcome was all-cause mortality until 28 days. Secondary outcomes were length of ICU and hospital stay; ventilator-free days through day 28; pneumothorax requiring drainage within 7 days; barotrauma within 7 days; and ICU, in-hospital, and 6-month mortality. Results A total of 1010 patients (37.5% female; mean [SD] age, 50.9 [17.4] years) were enrolled and followed up. At 28 days, 277 of 501 patients (55.3%) in the experimental group and 251 of 509 patients (49.3%) in the control group had died (hazard ratio [HR], 1.20; 95% CI, 1.01 to 1.42; P = .041). Compared with the control group, the experimental group strategy increased 6-month mortality (65.3% vs 59.9%; HR, 1.18; 95% CI, 1.01 to 1.38; P = .04), decreased the number of mean ventilator-free days (5.3 vs 6.4; difference, −1.1; 95% CI, −2.1 to −0.1; P = .03), increased the risk of pneumothorax requiring drainage (3.2% vs 1.2%; difference, 2.0%; 95% CI, 0.0% to 4.0%; P = .03), and the risk of barotrauma (5.6% vs 1.6%; difference, 4.0%; 95% CI, 1.5% to 6.5%; P = .001). There were no significant differences in the length of ICU stay, length of hospital stay, ICU mortality, and in-hospital mortality. Conclusions and Relevance In patients with moderate to severe ARDS, a strategy with lung recruitment and titrated PEEP compared with low PEEP increased 28-day all-cause mortality. These findings do not support the routine use of lung recruitment maneuver and PEEP titration in these patients. Trial Registration clinicaltrials.gov Identifier: NCT01374022

Is hyperchloremia associated with mortality in critically ill patients? A prospective cohort study.

PURPOSE The aim of the study was to determine if acid-base variables are associated with hospital mortality. MATERIALS AND METHODS This prospective cohort study took place in a university-affiliated hospital intensive care unit (ICU). One hundred seventy-five patients admitted to the ICU during the period of February to May 2007 were included in the study. We recorded clinical data and acid-base variables from all patients at ICU admission. A logistic regression model was constructed using Sepsis-related Organ Failure Assessment (SOFA) score, age, and the acid-base variables. RESULTS Individually, none of the variables appear to be good predictors of hospital mortality. However, using the multivariate stepwise logistic regression, we had a model with good discrimination containing SOFA score, age, chloride, and albumin (area under receiver operating characteristic curve, 0.80; 95% confidence interval, 0.73-0.87). CONCLUSIONS Hypoalbuminemia and hyperchloremia were associated with mortality. This result involving chloride is something new and should be tested in future studies.

Noninvasive mechanical ventilation may be useful in treating patients who fail weaning from invasive mechanical ventilation: a randomized clinical trial

IntroductionThe use of noninvasive positive-pressure mechanical ventilation (NPPV) has been investigated in several acute respiratory failure situations. Questions remain about its benefits when used in weaning patients from invasive mechanical ventilation (IMV). The objective of this study was to evaluate the use of bi-level NPPV for patients who fail weaning from IMV.MethodsThis experimental randomized clinical trial followed up patients undergoing IMV weaning, under ventilation for more than 48 hours, and who failed a spontaneous breathing T-piece trial. Patients with contraindications to NPPV were excluded. Before T-piece placement, arterial gases, maximal inspiratory pressure, and other parameters of IMV support were measured. During the trial, respiratory rate, tidal volume, minute volume, rapid shallow breathing index, heart rate, arterial blood pressure, and peripheral oxygen saturation were measured at 1 and 30 minutes. After failing a T-piece trial, patients were randomly divided in two groups: (a) those who were extubated and placed on NPPV and (b) those who were returned to IMV. Group results were compared using the Student t test and the chi-square test.ResultsOf 65 patients who failed T-piece trials, 28 were placed on NPPV and 37 were placed on IMV. The ages of patients in the NPPV and IMV groups were 67.6 ± 15.5 and 59.7 ± 17.6 years, respectively. Heart disease, post-surgery respiratory failure, and chronic pulmonary disease aggravation were the most frequent causes of IMV use. In both groups, ventilation time before T-piece trial was 7.3 ± 4.1 days. Heart and respiratory parameters were similar for the two groups at 1 and 30 minutes of T-piece trial. The percentage of complications in the NPPV group was lower (28.6% versus 75.7%), with lower incidences of pneumonia and tracheotomy. Length of stay in the intensive care unit and mortality were not statistically different when comparing the groups.ConclusionThe results suggest that NPPV is a good alternative for ventilation of patients who fail initial weaning attempts. NPPV reduces the incidence of pneumonia associated with mechanical ventilation and the need for tracheotomy.Trial registrationCEP HCPA (02–114).

Measurement of alveolar derecruitment in patients with acute lung injury: computerized tomography versus pressure–volume curve

IntroductionPositive end-expiratory pressure (PEEP)-induced lung derecruitment can be assessed by a pressure–volume (P–V) curve method or by lung computed tomography (CT). However, only the first method can be used at the bedside. The aim of the study was to compare both methods for assessing alveolar derecruitment after the removal of PEEP in patients with acute lung injury or acute respiratory distress syndrome.MethodsP–V curves (constant-flow method) and spiral CT scans of the whole lung were performed at PEEPs of 15 and 0 cmH2O in 19 patients with acute lung injury or acute respiratory distress syndrome. Alveolar derecruitment was defined as the difference in lung volume measured at an airway pressure of 15 cmH2O on P–V curves performed at PEEPs of 15 and 0 cmH2O, and as the difference in the CT volume of gas present in poorly aerated and nonaerated lung regions at PEEPs of 15 and 0 cmH2O.ResultsAlveolar derecruitments measured by the CT and P–V curve methods were 373 ± 250 and 345 ± 208 ml (p = 0.14), respectively. Measurements by both methods were tightly correlated (R = 0.82, p < 0.0001). The derecruited volume measured by the P–V curve method had a bias of -14 ml and limits of agreement of between -158 and +130 ml in comparison with the average derecruited volume of the CT and P–V curve methods.ConclusionAlveolar derecruitment measured by the CT and P–V curve methods are tightly correlated. However, the large limits of agreement indicate that the P–V curve and the CT method are not interchangeable.

Inspiratory muscle training did not accelerate weaning from mechanical ventilation but did improve tidal volume and maximal respiratory pressures: a randomised trial.

QUESTION Does inspiratory muscle training accelerate weaning from mechanical ventilation? Does it improve respiratory muscle strength, tidal volume, and the rapid shallow breathing index? DESIGN Randomised trial with concealed allocation and intention-to-treat analysis. PARTICIPANTS 92 patients receiving pressure support ventilation were included in the study and followed up until extubation, tracheostomy, or death. INTERVENTION The experimental group received usual care and inspiratory muscle training using a threshold device, with a load of 40% of their maximal inspiratory pressure with a regimen of 5 sets of 10 breaths, twice a day, 7 days a week. The control group received usual care only. OUTCOME MEASURES The primary outcome was the duration of the weaning period. The secondary outcomes were the changes in respiratory muscle strength, tidal volume, and the rapid shallow breathing index. RESULTS Although the weaning period was a mean of 8 hours shorter in the experimental group, this difference was not statistically significant (95% CI -16 to 32). Maximal inspiratory and expiratory pressures increased in the experimental group and decreased in the control group, with significant mean differences of 10cmH2O (95% CI 5 to 15) and 8cmH2O (95% CI 2 to 13), respectively. The tidal volume also increased in the experimental group and decreased in the control group (mean difference 72 ml, 95% CI 17 to 128). The rapid shallow breathing index did not differ significantly between the groups. CONCLUSION Inspiratory muscle training did not shorten the weaning period significantly but it increased respiratory muscle strength and tidal volume.

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.

Leptospirosis as a cause of acute respiratory failure: clinical features and outcome in 35 critical care patients

Leptospirosis may have important complications, such as acute respiratory failure (ARF) associated or not with other organic dysfunction, with a high mortality rate. We report the characteristics and evolution of severe leptospirosis associated with ARF. During 10 years, 35 consecutive adult patients admitted in two general Intensive Care Units with severe leptospirosis and ARF, were followed up. Clinical characteristics, associated organic dysfunction and mortality were analyzed. Survivors were compared with non-survivors. The most frequent clinical manifestations were dyspnea, fever, myalgia, jaundice, hemoptysis and coughing. All patients presented ARF, needing mechanical ventilation, as well as other organic dysfunctions. The mortality rate was 51%. Non-survivors were older and had a higher incidence of organic dysfunction, mainly renal, cardiovascular and neurological failures, as well as a higher level of acidosis. In conclusion, leptospirosis should be considered as a cause of severe ARF and other associated organic dysfunctions.

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.