Survivors Of Mechanical Ventilation Research Articles

965: THE ASSOCIATION BETWEEN VENTILATORY EFFICIENCY, A NONINVASIVE DEAD SPACE METRIC, AND MORTALITY

Introduction: Higher dead space is associated with increased mortality and prolonged mechanical ventilation in children and adults with acute respiratory distress syndrome (ARDS). Dead space assessment typically requires measurement of PCO2. Ventilatory efficiency (minute ventilation/VCO2) may be a useful non-invasive continuous dead space surrogate with prognostic value. Methods: Prospective observational cohort study. Mechanically ventilated children with ARDS were monitored with volumetric capnography. The first simultaneous measurements of ventilatory efficiency, physiologic dead space (VD/VT=[PCO2-PeCO2]/PCO2), the end-tidal alveolar dead space fraction (AVDSf=[PCO2-PETCO2]/PCO2), and oxygenation index (OI) within the first 72h of mechanical ventilation were used in the analysis. Results: There were 80 enrolled children. Median VD/VT was 0.46 (IQR 0.38, 0.58) and OI was 7.5 (IQR 4.6, 14.2). Mortality was 19%. The correlation between VD/VT and ventilatory efficiency (rs=0.68, p< 0.001) and VD/VT and AVDSf (rs=0.74, p< 0.001) were high. The correlation between AVDSf and ventilatory efficiency was lower (rs=0.48, p< 0.001). After controlling for OI and severity of illness (PRISM III) in separate multivariable models, higher VD/VT (per 0.1 increase, OR 1.66 [95% CI 1.04, 2.64], p=0.035), ventilatory efficiency (per 0.01, OR 1.69 [95% CI 1.10, 2.59], p=0.017), and AVDSf (per 0.1, OR 1.88 (95% CI 1.05, 3.38), p=0.035) were all associated with increased mortality. However, VD/VT, ventilatory efficiency, and AVDSf were not independently associated with fewer 28-day ventilator free days (VFD) or longer length of mechanical ventilation in survivors (LMV) after controlling for OI and PRISM III. OI was not associated with mortality after controlling for any of the dead space terms (all p>0.15) and PRISM III, but was independently associated with fewer 28-day VFDs (all p< 0.03) and longer LMV (all p< 0.01). Conclusions: Higher ventilatory efficiency, a continuous non-invasive measure of dead space that does not rely on blood gas measurement, is highly correlated with VD/VT and is independently associated with increased mortality in children with acute hypoxemic respiratory failure. Dead space metrics appear more strongly associated with mortality while OI appears more strongly associated with length of ventilation.

Acute intensive care unit resuscitation of severely injured trauma patients: Do we need a new strategy?

Unlike recent advances in blood product resuscitation, intravenous crystalloid (IVF) use after intensive care unit (ICU) admission in hemorrhagic shock has received less attention and current recommendations are based on limited evidence. To address this knowledge gap, we aimed to determine associations between IVF administration during acute ICU resuscitation and outcomes. We hypothesized that larger IVF volumes are associated with worse outcomes. We linked our trauma registry with electronic health record data (2012-2015) to identify adults with an initial lactate level of ≥4 mmol/L and documented lactate normalization (≤2 mmol/L), excluding those with isolated head Abbreviated Injury Scale score ≥3. We focused on the period from ICU admission to lactate normalization, analyzing duration, volume of IVF, and proportion of volume as 1-L boluses. We used linear regression to determine associations with ICU length of stay and duration of mechanical ventilation in survivors, and logistic regression to identify associations with acute kidney injury and home discharge while adjusting for important covariates. We included 337 subjects. Median time to lactate normalization was 15 hours (interquartile range, 7-25 hours), and median IVF volume was 3.7 L (interquartile range, 1.5-6.4 L). The fourfold difference between the upper and lower quartiles of both duration and volume remained after stratifying by injury severity. Hourly volumes tapered over time but persistently aggregated at 0.5 and 1 L, with 167 subjects receiving at least one 0.5-L bolus for 6 hours after ICU admission. Administration of larger volumes was associated with longer ICU length of stay and duration of mechanical ventilation, as well as acute kidney injury. There is substantial variation in volume administered during acute ICU resuscitation, both absolutely and temporally, despite accounting for injury severity. Administration of larger volumes during acute ICU resuscitation is associated with worse outcomes. There is an opportunity to improve outcomes by further investigating and standardizing this important phase of care. Therapeutic/care management, level IV.

The Relationship between Frailty and Mechanical Ventilation: A Population-based Cohort Study.

Rationale: Frailty in critically ill patients is associated with higher mortality and prolonged length of stay; however, little is known about the impact on the duration of mechanical ventilation. Objectives: To identify the relationship between frailty and total duration of mechanical ventilation and the interaction with patients' age. Methods: This retrospective population-based cohort study was performed using data submitted to the Australian and New Zealand Intensive Care Society Adult Patient Database between 2017 and 2020. We analyzed adult critically ill patients who received invasive mechanical ventilation within the first 24 hours of intensive care unit admission. Results: Of 59,319 available patients receiving invasive mechanical ventilation, 8,331 (14%) were classified as frail. Patients with frailty had longer duration of mechanical ventilation compared with patients without frailty. Duration of mechanical ventilation increased with higher frailty score. Patients with frailty had longer intensive care unit and hospital stay with higher mortality than patients without frailty. After adjustment for relevant covariates in multivariate analyses, frailty was significantly associated with a reduced probability of cessation of invasive mechanical ventilation (adjusted hazard ratio, 0.57 [95% confidence interval, 0.51-0.64]; P < 0.001). Sensitivity and subgroup analyses suggested that frailty could prolong mechanical ventilation in survivors, and the relationship was especially strong in younger patients. Conclusions: Frailty score was independently associated with longer duration of mechanical ventilation and contributed to identifying patients who were less likely to be liberated from mechanical ventilation. The impact of frailty on ventilation time varied with age and was most apparent for younger patients.

Percutaneous Dilational Tracheostomy for Coronavirus Disease 2019 Patients Requiring Mechanical Ventilation.

To assess the impact of percutaneous dilational tracheostomy in coronavirus disease 2019 patients requiring mechanical ventilation and the risk for healthcare providers. Prospective cohort study; patients were enrolled between March 11, and April 29, 2020. The date of final follow-up was July 30, 2020. We used a propensity score matching approach to compare outcomes. Study outcomes were formulated before data collection and analysis. Critical care units at two large metropolitan hospitals in New York City. Five-hundred forty-one patients with confirmed severe coronavirus disease 2019 respiratory failure requiring mechanical ventilation. Bedside percutaneous dilational tracheostomy with modified visualization and ventilation. Required time for discontinuation off mechanical ventilation, total length of hospitalization, and overall patient survival. Of the 541 patients, 394 patients were eligible for a tracheostomy. One-hundred sixteen were early percutaneous dilational tracheostomies with median time of 9 days after initiation of mechanical ventilation (interquartile range, 7-12 d), whereas 89 were late percutaneous dilational tracheostomies with a median time of 19 days after initiation of mechanical ventilation (interquartile range, 16-24 d). Compared with patients with no tracheostomy, patients with an early percutaneous dilational tracheostomy had a higher probability of discontinuation from mechanical ventilation (absolute difference, 30%; p < 0.001; hazard ratio for successful discontinuation, 2.8; 95% CI, 1.34-5.84; p = 0.006) and a lower mortality (absolute difference, 34%, p < 0.001; hazard ratio for death, 0.11; 95% CI, 0.06-0.22; p < 0.001). Compared with patients with late percutaneous dilational tracheostomy, patients with early percutaneous dilational tracheostomy had higher discontinuation rates from mechanical ventilation (absolute difference 7%; p < 0.35; hazard ratio for successful discontinuation, 1.53; 95% CI, 1.01-2.3; p = 0.04) and had a shorter median duration of mechanical ventilation in survivors (absolute difference, -15 d; p < 0.001). None of the healthcare providers who performed all the percutaneous dilational tracheostomies procedures had clinical symptoms or any positive laboratory test for severe acute respiratory syndrome coronavirus 2 infection. In coronavirus disease 2019 patients on mechanical ventilation, an early modified percutaneous dilational tracheostomy was safe for patients and healthcare providers and associated with improved clinical outcomes.

Duration of Mechanical Ventilation and Extubation Success among Extremely Premature Infants

Objective: The objective of this study was to examine the duration of mechanical ventilation (MV) in days until the first successful extubation and the cumulative duration of MV until discharge of infants with gestational age (GA) <26 weeks. We also aimed to explore associations between early clinical variables and the cumulative duration of MV. Design and Setting: This population-based study analysed data reported to the Norwegian Neonatal Network on extremely premature infants admitted between January 1, 2013, and December 31, 2018. Results: A total of 406 infants were included, of which 293 (72%) survived to discharge. The proportion successfully extubated on their first attempt was 34% of the infants born at GA 22–23 weeks, 50% at GA 24 weeks, and 70% at GA 25 weeks. Median postmenstrual age (PMA) at the first successful extubation was 27 weeks. The median duration of MV was 35, 24, and 12 days for infants born at GA 22–23, 24, and 25 weeks, respectively. Male sex and low 5-min Apgar score were independent early predictors for prolonged MV duration adjusted for GA in regression analyses. Conclusions: Most of the infants born at GA 25 weeks were successfully extubated on the first attempt. However, half of the infants born <26 weeks experienced unsuccessful extubations, indicating a lack of useful clinical predictors of successful extubation. The median duration of MV in survivors was 4 weeks longer for infants at GA 22–23 weeks than for infants born at GA 25 weeks, while the difference in median PMA at the first successful extubation was 2 weeks.

Lupus anticoagulant and mortality in patients hospitalized for COVID-19.

Coronavirus disease 2019 (COVID-19) is characterized by a procoagulant state that can lead to fatal thromboembolic events. Several studies have documented a high prevalence of lupus anticoagulant that may at least partially explain the procoagulant profile of COVID-19. However, the association between lupus anticoagulant and thrombotic complications in COVID-19 is controversial and no study has specifically evaluated the impact of lupus anticoagulant on mortality. The aim of our study was to investigate the association between lupus anticoagulant and mortality in a large group of 192 consecutive patients hospitalized for COVID-19. Lupus anticoagulant was found in 95 patients (49.5%). No difference in the percentage of patients with lupus anticoagulant was observed between 130 survivors and 62 non-survivors (47.7 versus 53,2%; p = 0.4745). When the combined outcome of death or need for mechanical ventilation in survivors was taken into account, the difference in the prevalence of patients with lupus anticoagulant between the patients with the combined outcome (n = 76) and survivors who did not require mechanical ventilation (n = 116) was not significant (52.6% versus 47.4%; p = 0.4806). In multivariate analysis predictors of mortality or need for mechanical ventilation in survivors were obesity, low oxygen saturation and elevated troponin levels measured on admission. In conclusion, our study did not show any association of lupus anticoagulant with mortality and with need for mechanical ventilation in survivors. The role of obesity, low SaO2 and elevated troponin levels as predictors of a worse prognosis in patients hospitalized for COVID-19 was confirmed.

Impact of Bilateral Infiltrates on Inflammatory Biomarker Levels and Clinical Outcomes of Children With Oxygenation Defect.

The 2015 definition for pediatric acute respiratory distress syndrome did not require the presence of bilateral infiltrates. We tested the hypothesis that pediatric patients meeting oxygenation criteria for pediatric acute respiratory distress syndrome but without bilateral infiltrates would have different inflammatory biomarker levels and clinical outcomes than those with bilateral infiltrates. Secondary analysis of a prospective cohort study. Twenty-two PICUs. Four-hundred forty-six patients age 2 weeks to 17 years intubated for respiratory failure with oxygenation index greater than or equal to 4 or oxygenation saturation index greater than or equal to 5 on the day of intubation or the day after. None. Patients with bilateral infiltrates, either on the day of intubation or within the following 2 days, were compared with children who never developed bilateral infiltrates. Two analyses were performed to test 1) whether bilateral infiltrates are associated with elevated interleukin-1 receptor antagonist or interleukin-8 and 2) whether bilateral infiltrates are associated with worse clinical outcomes. Patients with bilateral infiltrates more often had a primary diagnosis of pneumonia (41% vs 28%; p = 0.02) and less often asthma (8% vs 23%; p < 0.01). After controlling for age, gender, and primary diagnosis, interleukin-1 receptor antagonist was higher on study days 1 and 2 in patients with bilateral infiltrates. There was no difference in interleukin-8 levels. After adjusting for age, gender, Pediatric Risk of Mortality score, and severity of oxygenation defect, presence of bilateral infiltrates was associated with longer duration of mechanical ventilation in survivors (hazard ratio, 0.64; 95% CI, 0.49-0.82; p < 0.01); this association was independent of primary diagnosis. Overall mortality was 9%; mortality was higher in those without bilateral infiltrates (14% vs 8%; p = 0.04). Children meeting pediatric acute respiratory distress syndrome oxygenation criteria with bilateral infiltrates on chest radiograph experience a more intense early inflammatory response. Bilateral infiltrates are associated with longer time on the ventilator independent of oxygenation defect severity.

Race, Ethnicity, Health Insurance, and Mortality in Older Survivors of Critical Illness.

To determine whether minority race or ethnicity is associated with mortality and mediated by health insurance coverage among older (≥ 65 yr old) survivors of critical illness. A retrospective cohort study. Two New York City academic medical centers. A total of 1,947 consecutive white (1,107), black (361), and Hispanic (479) older adults who had their first medical-ICU admission from 2006 through 2009 and survived to hospital discharge. None. We obtained demographic, insurance, and clinical data from electronic health records, determined each patient's neighborhood-level socioeconomic data from 2010 U.S. Census tract data, and determined death dates using the Social Security Death Index. Subjects had a mean (SD) age of 79 years (8.6 yr) and median (interquartile range) follow-up time of 1.6 years (0.4-3.0 yr). Blacks and Hispanics had similar mortality rates compared with whites (adjusted hazard ratio, 0.92; 95% CI, 0.76-1.11 and adjusted hazard ratio, 0.92; 95% CI, 0.76-1.12, respectively). Compared to those with commercial insurance and Medicare, higher mortality rates were observed for those with Medicare only (adjusted hazard ratio, 1.43; 95% CI, 1.03-1.98) and Medicaid (adjusted hazard ratio, 1.30; 95% CI, 1.10-1.52). Medicaid recipients who were the oldest ICU survivors (> 82 yr), survivors of mechanical ventilation, and discharged to skilled-care facilities had the highest mortality rates (p-for-interaction: 0.08, 0.03, and 0.17, respectively). Mortality after critical illness among older adults varies by insurance coverage but not by race or ethnicity. Those with federal or state insurance coverage only had higher mortality rates than those with additional commercial insurance.

Evaluation value of oxygenation index of mechanical ventilation on the prognosis of patients with ARDS: a retrospective analysis with 228 patients

To investigate the evaluation value of oxygenation index at different times of mechanical ventilation (MV) on the prognosis of patients with acute respiratory distress syndrome (ARDS). A retrospectively analysis was conducted. A total of 228 patients with ARDS admitted to Department of Emergency of China Medical University Affiliated First Hospital from February 2014 to June 2016 were enrolled. All patients underwent MV treatment, and recruitment maneuver (RM) was performed by pressure-controlled ventilation (PCV) 30 minutes after the implementation of the protective ventilation strategy. Arterial blood gas analysis was performed at MV immediately, after RM and at 6, 12, 24 hours of MV, and oxygenation index was calculated. Vital signs, laboratory data, ultrasonic echocardiography, sequential organ failure assessment (SOFA) score, duration of MV, and ventilator related parameters of patients were collected. The patients were divided into survivors and non-survivors according to the prognosis of 28 days. The survivors were subdivided into high and low oxygenation group (oxygenation index was ≥ 150 mmHg and < 150 mmHg, respectively, 1 mmHg = 0.133 kPa). Differences in clinical indicators between survivors and non-survivors were compared. The correlation between the oxygenation index after RM and the oxygenation index at each time after MV was analyzed by bivariate correlation analysis. Receiver operating characteristic (ROC) curve was plotted to analyze predictive value of oxygenation index measured at different times for the 28-day outcome of patients with ARDS. Among 228 patients, 99 patients died within 28 days, and 129 survived, with mortality rate of 43.4%. (1) The oxygenation index after RM and at 6, 12, 24 hours after MV in survivors and non-survivors showed a continuously increased tendency, which was significantly lower in non-survivors than that in survivors (all P < 0.05). There was no significant difference in the duration of MV between high oxygenation group and low oxygenation group at MV immediately and after RM, but the duration of MV in high oxygenation group was significantly shorter than that of the low oxygenation group at 6, 12, 24 hour of MV (all P < 0.01). (2) After ventilation for 24 hours, serum creatinine (SCr), brain natriuretic peptide (BNP), lactate (Lac), right ventricular internal diameter, and SOFA score in non-survivors were significantly higher than those of survivors, and arterial partial pressure of oxygen (PaO2), platelet (PLT) and right ventricular ejection fraction (RVEF) were significantly lower than those of survivors (all P < 0.05). (3) After 24 hours ventilation, positive end-expiratory pressure (PEEP), tidal volume (VT), and minute ventilation (VE) in non-survivors were significantly higher than those of survivors, and static compliance of thorax (Cdyn) was significantly lower than that of survivors (all P < 0.01). (4) It was shown by correlation analysis that the oxygenation index after RM was positively correlated with those at 6, 12, 24 hours of MV (r values were 0.856, 0.765, and 0.758, respectively, all P < 0.001). (5) It was shown by ROC curve that the area under the ROC curve (AUC) of the oxygenation index after RM for predicting 28-day prognosis was 0.688. When the cut-off value was 80.75 mmHg, the sensitivity was 97.7%, and the specificity was 42.4%, which could only be used for preliminary judgment of prognosis. The AUC of oxygenation index at 6, 12, 24 hours of MV for 28-day survival of ARDS patients were 0.719, 0.727, 0.754, respectively. When the cut-off values were 171.50, 192.14, and 161.75 mmHg, the sensitivity was 69.8%, 67.4%, 86.0%, and the specificity was 78.8%, 78.8%, and 63.6%, respectively. It indicated that the predictive value was higher, and no significant difference was found among the oxygenation index at different time points. The oxygenation index after the early stage of RM can preliminarily determine the prognosis of patients. The predictive value of oxygenation index after MV for 28-day survival of ARDS patients was higher, so the oxygenation index measured at 6 hours of MV may be considered to evaluate the prognosis of patients with ARDS.

The Acute Respiratory Distress Syndrome (ARDS) in mechanically ventilated burn patients: An analysis of risk factors, clinical features, and outcomes using the Berlin ARDS definition

BackgroundThe Berlin definition of Acute Respiratory Distress Syndrome (ARDS) has been applied to military burns resulting from combat-related trauma, but has not been widely studied among civilian burns. This study's purpose was to use the Berlin definition to determine the incidence of ARDS, and its associated respiratory morbidity, and mortality among civilian burn patients. MethodsRetrospective study of burn patients mechanically ventilated for ≥48h at an American Burn Association-verified burn center. The Berlin criteria identified patients with mild, moderate, and severe ARDS. Logistic regression was used to identify variables predictive of moderate to severe ARDS, and mortality. The outcome measures of interest were duration of mechanical ventilation and in-hospital mortality. Values are shown as the median (Q1–Q3). ResultsWe included 162 subjects [24% female, age 48 (35–60), % total body surface area (TBSA) burn 28 (19–40), % body surface area (BSA) full thickness (FT) burn 13 (0–30), and 62% with inhalation injury]. The incidence of ARDS was 43%. Patients with ARDS had larger %TBSA burns [30.5 (23.1–47.0) vs. 24.8 (17.1–35), p=0.007], larger FT burns [20.5(5.4–35.5) vs. 7 (0–22.1), p=0.001], but had no significant difference in the incidence of inhalation injury (p=0.216), compared to those without ARDS. The % FT burn predicted the development of moderate to severe ARDS [OR 1.034, 95%CI (1.013–1.055), p=0.001]. ARDS developed in the 1st week after burn in 86% of cases. Worsening severity of ARDS was associated with increased days of mechanical ventilation in survivors (p=0.001), a reduction in ventilator-free days/1st 30 days in all subjects (p=0.004), and a strong indication of increased mortality (0% in mild ARDS vs. 50% in severe ARDS, unadjusted p=0.02). Neither moderate ARDS nor severe ARDS were significant predictors of death. ConclusionsARDS is common among mechanically ventilated civilian burn patients, and develops early after burn. The extent of full thickness burn predicted development of moderate to severe ARDS. Increasing severity of ARDS based upon the Berlin definition was associated with a significantly greater duration of mechanical ventilation and a trend toward higher mortality.

The Relationship Between Obesity and Weaning From Prolonged Mechanical Ventilation in Survivors of Critical Illness

The Relationship Between Obesity and Weaning From Prolonged Mechanical Ventilation in Survivors of Critical Illness

Association Between Vitamin D Status and Weaning From Prolonged Mechanical Ventilation in Survivors of Critical Illness.

In this study, we examined the association between 25-hydroxyvitamin D (25(OH)D) concentration and successful weaning from mechanical ventilation in a cohort of ICU survivors requiring prolonged mechanical ventilation. This was a retrospective cohort study of ICU survivors admitted to a long-term acute care hospital. Demographic data were extracted from medical records, including 25(OH)D concentrations drawn on admission. Subjects were divided into 2 groups based on their 25(OH)D concentrations (deficient, < 20 ng/mL; not deficient, ≥ 20 ng/mL), and associations between 25(OH)D concentration and successful weaning were calculated. A total of 183 subjects were studied. A high prevalence of 25(OH)D deficiency was found (61%, 111/183). No association was found between 25(OH)D concentration and weaning from mechanical ventilation. Increased comorbidity burden (Charlson comorbidity index) was associated with decreased odds of weaning (odds ratio of 0.50, 95% CI 0.25-0.99, P = .05). Vitamin D deficiency is common in ICU survivors requiring prolonged mechanical ventilation. Surprisingly, there was no significant relationship between 25(OH)D concentration and successful weaning. This finding may be due to the low 25(OH)D concentrations seen in our subjects. Given what is known about vitamin D and lung function and given the low vitamin D concentrations seen in patients requiring long-term ventilatory support, interventional studies assessing the effects of 25(OH)D supplementation in these patients are needed.

Delirium in the ICU and Subsequent Long-Term Disability Among Survivors of Mechanical Ventilation*

Survivors of critical illness are frequently left with long-lasting disability. The association between delirium and disability in critically ill patients has not been described. We hypothesized that the duration of delirium in the ICU would be associated with subsequent disability and worse physical health status following a critical illness. Prospective cohort study nested within a randomized controlled trial of a paired sedation and ventilator weaning strategy. A single-center tertiary-care hospital. One hundred twenty-six survivors of a critical illness. Confusion Assessment Method for the ICU, Katz activities of daily living, Functional Activities Questionnaire (measuring instrumental activities of daily living), Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score, and Awareness Questionnaire were used. Associations between delirium duration and outcomes were determined via proportional odds logistic regression with generalized estimating equations (for Katz activities of daily living and Functional Activities Questionnaire scores) or via generalized least squares regression (for Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score and Awareness Questionnaire scores). Excluding patients who died prior to follow-up but including those who withdrew or were lost to follow-up, we assessed 80 of 99 patients (81%) at 3 months and 63 of 87 patients (72%) at 12 months. After adjusting for covariates, delirium duration was associated with worse activities of daily living scores (p = 0.002) over the course of the 12-month study period but was not associated with worse instrumental activities of daily living scores (p = 0.15) or worse Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score (p = 0.58). Duration of delirium was also associated with lower Awareness Questionnaire Motor/Sensory Factors scores (p 0.02). In the setting of critical illness, longer delirium duration is independently associated with increased odds of disability in activities of daily living and worse motor-sensory function in the following year. These data point to a need for further study into the determinants of functional outcomes in ICU survivors.

Diagnosis and treatment of post-extubation dysphagia: Results from a national survey

PurposeThis study sought to determine the utilization of speech-language pathologist (SLPs) for the diagnosis and treatment of post-extubation dysphagia in survivors of mechanical ventilation. MethodsWe designed, validated, and mailed a survey to 1,966 inpatient SLPs who routinely evaluate patients for post-extubation dysphagia. ResultsMost SLP diagnostic evaluations (60%; 95% CI, 59%-62%) were performed using clinical techniques with uncertain accuracy. Instrumental diagnostic tests (such as fluoroscopy and endoscopy) are more likely to be available at university than community hospitals. After adjusting for hospital size and academic affiliation, instrumental test use varied significantly by geographical region. Treatments for post-extubation dysphagia usually involved dietary adjustment (76%; 95% CI, 73-79%) and postural changes/compensatory maneuvers (86%; 95% CI, 84-88%), rather than on interventions aimed to improve swallowing function (24%; 95% CI, 21-27%). ConclusionsSLPs frequently evaluate acute respiratory failure survivors. However, diagnostic evaluations rely mainly upon bedside techniques with uncertain accuracy. The use of instrumental tests varies by geographic location and university affiliation. Current diagnostic practices and feeding decisions for critically ill patients should be viewed with caution until further studies determine the accuracy of bedside detection methods.

Acute Respiratory Distress Syndrome

The acute respiratory distress syndrome (ARDS) was defined in 1994 by the American-European Consensus Conference (AECC); since then, issues regarding the reliability and validity of this definition have emerged. Using a consensus process, a panel of experts convened in 2011 (an initiative of the European Society of Intensive Care Medicine endorsed by the American Thoracic Society and the Society of Critical Care Medicine) developed the Berlin Definition, focusing on feasibility, reliability, validity, and objective evaluation of its performance. A draft definition proposed 3 mutually exclusive categories of ARDS based on degree of hypoxemia: mild (200 mm Hg&lt;PaO2/FIO2≤300 mm Hg), moderate (100 mm Hg&lt;PaO2/FIO2≤200 mm Hg), and severe (PaO2/FIO2≤100 mm Hg) and 4 ancillary variables for severe ARDS: radiographic severity, respiratory system compliance (≤40 mL/cm H2O), positive end-expiratory pressure (≥10 cm H2O), and corrected expired volume per minute (≥10 L/min). The draft Berlin Definition was empirically evaluated using patient-level meta-analysis of 4188 patients with ARDS from 4 multicenter clinical data sets and 269 patients with ARDS from 3 single-center data sets containing physiologic information. The 4 ancillary variables did not contribute to the predictive validity of severe ARDS for mortality and were removed from the definition. Using the Berlin Definition, stages of mild, moderate, and severe ARDS were associated with increased mortality (27%; 95% CI, 24%-30%; 32%; 95% CI, 29%-34%; and 45%; 95% CI, 42%-48%, respectively; P&lt;.001) and increased median duration of mechanical ventilation in survivors (5 days; interquartile [IQR], 2-11; 7 days; IQR, 4-14; and 9 days; IQR, 5-17, respectively; P&lt;.001). Compared with the AECC definition, the final Berlin Definition had better predictive validity for mortality, with an area under the receiver operating curve of 0.577 (95% CI, 0.561-0.593) vs 0.536 (95% CI, 0.520-0.553; P&lt;.001). This updated and revised Berlin Definition for ARDS addresses a number of the limitations of the AECC definition. The approach of combining consensus discussions with empirical evaluation may serve as a model to create more accurate, evidence-based, critical illness syndrome definitions and to better inform clinical care, research, and health services planning.

Significant disability for older survivors of mechanical ventilation

Significant disability for older survivors of mechanical ventilation

Mild therapeutic hypothermia shortens intensive care unit stay of survivors after out-of-hospital cardiac arrest compared to historical controls

IntroductionPersistent coma is a common finding after cardiac arrest and has profound ethical and economic implications. Evidence suggests that therapeutic hypothermia improves neurological outcome in these patients. In this analysis, we investigate whether therapeutic hypothermia influences the length of intensive care unit (ICU) stay and ventilator time in patients surviving out-of-hospital cardiac arrest.MethodsA prospective observational study with historical controls was conducted at our medical ICU. Fifty-two consecutive patients (median age 62.6 years, 43 males, 34 ventricular fibrillation) submitted to therapeutic hypothermia after out-of-hospital cardiac arrest were included. They were compared with a historical cohort (n = 74, median age 63.8 years, 53 males, 43 ventricular fibrillation) treated in the era prior to hypothermia treatment. All patients received the same standard of care. Neurological outcome was assessed using the Pittsburgh cerebral performance category (CPC) score. Univariate analyses and multiple regression models were used.ResultsIn survivors, therapeutic hypothermia and baseline disease severity (Acute Physiology and Chronic Health Evaluation II [APACHE II] score) were both found to significantly influence ICU stay and ventilator time (all P < 0.01). ICU stay was shorter in survivors receiving therapeutic hypothermia (median 14 days [interquartile range (IQR) 8 to 26] versus 21 days [IQR 15 to 30] in the control group; P = 0.017). ICU length of stay and time on ventilator were prolonged in patients with CPC 3 or 4 compared with patients with CPC 1 or 2 (P = 0.003 and P = 0.034, respectively). Kaplan-Meier analysis showed improved probability for 1-year survival in the hypothermia group compared with the controls (log-rank test P = 0.013).ConclusionTherapeutic hypothermia was found to significantly shorten ICU stay and time of mechanical ventilation in survivors after out-of-hospital cardiac arrest. Moreover, profound improvements in both neurological outcome and 1-year survival were observed.

Pressure-Regulated Volume Control Ventilation vs Synchronized Intermittent Mandatory Ventilation for Very Low-Birth-Weight Infants

To test the hypothesis that pressure-regulated volume control (PRVC), an assist/control mode of ventilation, would increase the proportion of very low-birth-weight infants who were alive and extubated at 14 days of age as compared with synchronized intermittent mandatory ventilation (SIMV). Ventilated infants with birth weight of 500 to 1249 g were randomized at less than 6 hours of age either to pressure-limited SIMV or to PRVC on the Servo 300 ventilator (Siemens Electromedical Group, Danvers, Mass). Infants received their assigned mode of ventilation until extubation, death, or meeting predetermined failure criteria. Mean +/- SD birth weights were similar in the SIMV (888 +/- 199 g, n = 108) and PRVC (884 +/- 203 g, n = 104) groups. No differences were detected between SIMV and PRVC groups in the proportion of infants alive and extubated at 14 days (41% vs 37%, respectively), length of mechanical ventilation in survivors (median, 24 days vs 33 days, respectively), or the proportion of infants alive without a supplemental oxygen requirement at 36 weeks' postmenstrual age (57% vs 63%, respectively). More infants receiving SIMV (33%) failed their assigned ventilator mode than did infants receiving PRVC (20%). Including failure as an adverse outcome did not alter the overall outcome (39% of infants in the SIMV group vs 35% of infants in the PRVC group were alive, extubated, and had not failed at 14 days). In mechanically ventilated infants with birth weights of 500 to 1249 g, using PRVC ventilation from birth did not alter time to extubation.

Outcome of patients with acute myeloid leukemia and pulmonary infiltrates requiring invasive mechanical ventilation—a retrospective analysis

Purpose: To assess the prognosis of patients with acute myeloid leukemia (AML) and pulmonary infiltrates requiring mechanical ventilation. Design: A retrospective cohort study. Setting: A medical intensive care unit (ICU) in an academic tertiary care center. Patients and Methods: We identified 30 consecutive patients with acute myeloid leukemia and pulmonary infiltrates who received invasive mechanical ventilation and compared clinical and laboratory parameters between ICU survivors and ICU non-survivors using non-parametric statistics. Results: The overall mortality rate was 87% (26/30). The survival was 40 % (4/10) for patients aged 50 years or less while none (0/20) of the patients older than 50 years survived ( P < .02). The median time of mechanical ventilation in survivors was 23.5 (3–45) days. No differences between survivors and non-survivors were observed for the APACHE II score, oxygenation quotient, liver function tests, creatinine, blood urea nitrogen, or prognostic parameters of acute myeloid leukemia (presence of blasts on bone marrow aspirate, cytogenetic studies, and intensity of the chemotherapy regimen). Conclusions: Age seems to be an important prognostic parameter in our cohort of 30 consecutive patients with acute myeloid leukemia and pulmonary infiltrates requiring mechanical ventilation. Prolonged ventilation does not preclude survival.

The outcome of cardiac operations in infants weighing two kilograms or less

Objective: A review of our recent experience of operating on infants weighing 2 kg or less who had congenital heart disease was performed to determine the outcome of early surgical repair or palliation. Methods: A retrospective review of hospital records was performed for infants who weighed 2 kg or less and who were identified to have undergone cardiac operation at our institution January 1992 to June 1997. The data collected included age, weight, gestational age, cardiac diagnosis, surgical procedure, and outcome measures such as length of stay, morbidity, and mortality rate. Outpatient charts were reviewed for follow-up survival and cardiac status. Results: Thirty-three operations were performed on 30 patients. Median age at operation was 19.5 days (1 to 140 days), and median weight was 1.8 kg (1.1 to 2.0 kg). Cardiac diagnoses varied, with coarctation of the aorta and tetralogy of Fallot most common. Twenty-four patients were born at 37 or fewer weeks' gestation. Hospital survival was 83% with no difference in mortality rates based on age, weight, or type of surgical procedure. Premature infants tended to have worse hospital survival. Median postoperative length of stay was 39 days (6 to 122 days). Median duration of mechanical ventilation in survivors was 6 days (2 to 24 days). Neurologic complications were documented in eight patients. Of the 25 hospital survivors, 20 (80%) are alive with good cardiac status at a mean follow-up of 13 months. Conclusion: Cardiac operations in a selected group of infants weighing 2 kg or less can provide acceptable hospital survival. In most instances, complete repair is possible with good medium-term outcome in the survivors. Investigation into neurologic outcomes in these patients is warranted. (J Thoracic Cardiovasc Surg 1998;116:28-32)