Ventilated ICU Patients Research Articles

He survived thanks to a non-sedation protocol: Nurses’ reflections about caring for critically ill, non-sedated and mechanically ventilated patients

ObjectiveThe objective was to explore ICU nurses’ experiences of caring for non-sedated, critically ill mechanically ventilated patients, when following a study protocol as part of a clinical trial. DesignThe study had a qualitative design with twelve nurses participating in two focus groups. The interviews were analysed using a thematic approach. FindingsOne overall theme emerged, “Cautious optimism”, which suggests positive experiences but with a negative undertone. The most remarkable experiences were related to caring for the patient, but there were some disappointments with regard to the interprofessional teamwork. Three subthemes were identified: 1) Excitement and uncertainty 2) Inspiring but demanding nurse-patient relationship, and 3) Teamwork or working against the tide? ConclusionThe main findings reflect the remarkable and positive aspects of caring for awake and involved mechanically ventilated ICU patients, but also how nurses found it demanding to follow a weakly implemented study protocol that sometimes resulted in deviations from their nursing ethical standards of care. A more strategic implementation plan for the study and improved interprofessional teamwork might have improved their experiences.

S87. Sedation prediction using EEG spectrogram in ICU patients

Most mechanically ventilated ICU patients receive sedatives to relieve pain and anxiety, and to provide cardiopulmonary stability. Unfortunately, both excessive and insufficient sedation are common. Brain monitors that track electroencephalogram (EEG) features have been proposed as a real-time, physiologically-based alternative to clinical sedation assessments. However, existing monitors have been tested almost exclusively in the surgical setting, without being optimized for ICU patients. Patients: We analyzed prospectively collected data from 115 mechanically ventilated patients receiving usual ICU care. The Richmond agitation sedation scale (RASS), assessed every 2 h, provides reference sedation levels. In the present work, we consider only assessments with RASS −5 and −4 (deeply sedated) vs −1 and 0 (not sedated). In total, there are 664 RASS assessments. The dataset is split into 69 training, 23 validation and 23 testing patients. Label denoising: RASS assessments are sometimes recorded after a delay or in anticipation of a change in the level of consciousness following adjustment in sedative infusion rate. To reduce such “annotation noise”, before training a classifier we first “denoise” EEG segments whose spectra have a different label than the 10 most similar training segments.Classifier training and testing: We extract EEG power spectra from the 10 min period preceding each RASS assessment, using 10s windows sliding windows spaced 2s apart. The sequence of spectra is used to train a recurrent neural network (LSTM), which performs binary classification (RASS −5 and −4 vs −1 and 0). Performance is measured by area the under the receiver operator curve (AUC). The reported results are the average performance on the testing set from 10 random splits of patients. Strict separation of training and validation data from testing data is maintained throughout all experiments. The label denoising procedure alters 15% of RASS scores. The AUC in the testing set is 0.91 (SD 0.02). Visualization of the EEG spectrograms reveals lower total power and higher relative delta power for episodes of RASS −5 and −4; and higher total power and higher relative beta power for RASS −1 and 0. Despite heterogeneous medical conditions and varying severity of medical illness in our ICU cohort, our model learns to accurately discriminate deep sedation (RASS −5 and −4) from the awake state (RASS −1and 0). The classifier achieves AUC at 0.91 in a patient-independent manner. The use of recurrent network architecture allows our model to take advantage of long-range temporal information in the EEG, and will allow the extension to take pharmacokinetics and pharmacodynamics information into account, which may further enhance performance and robustness.

Reliability of respiratory pressure measurements in ventilated and non-ventilated patients in ICU: an observational study

BackgroundAssessment of maximum respiratory pressures is a common practice in intensive care because it can predict the success of weaning from ventilation. However, the reliability of measurements through an intubation catheter has not been compared with standard measurements. The aim of this study was to compare maximum respiratory pressures measured through an intubation catheter with the same measurements using a standard mouthpiece in extubated patients.MethodsA prospective observational study was carried out in adults who had been under ventilation for at least 24 h and for whom extubation was planned. Maximal respiratory pressure measurements were carried out before and 24 h following extubation.ResultsNinety patients were included in the analyses (median age: 61.5 years, median SAPS2 score: 42.5 and median duration of ventilation: 7 days). Maximum respiratory pressures measured through the intubation catheter were as reliable as measurements through a standard mouthpiece (difference in maximal inspiratory pressure: mean bias = − 2.43 ± 14.43 cmH2O and difference in maximal expiratory pressure: mean bias = 1.54 ± 23.2 cmH2O).ConclusionMaximum respiratory pressures measured through an intubation catheter were reliable and similar to standard measures.Clinical trial registration Retrospectively Registered in ClinicalTrials.gov (NCT02363231).

Respiratory Viruses in Invasively Ventilated Critically Ill Patients—A Prospective Multicenter Observational Study

The presence of respiratory viruses and the association with outcomes were assessed in invasively ventilated ICU patients, stratified by admission diagnosis. Prospective observational study. Five ICUs in the Netherlands. Between September 1, 2013, and April 30, 2014, 1,407 acutely admitted and invasively ventilated patients were included. None. Nasopharyngeal swabs and tracheobronchial aspirates were collected upon intubation and tested for 14 respiratory viruses. Out of 1,407 patients, 156 were admitted because of a severe acute respiratory infection and 1,251 for other reasons (non-severe acute respiratory infection). Respiratory viruses were detected in 28.8% of severe acute respiratory infection patients and 17.0% in non-severe acute respiratory infection (p < 0.001). In one third, viruses were exclusively detected in tracheobronchial aspirates. Rhinovirus and human metapneumovirus were more prevalent in severe acute respiratory infection patients (9.6% and 2.6% vs 4.5 and 0.2%; p = 0.006 and p < 0.001). In both groups, there were no associations between the presence of viruses and the number of ICU-free days at day 28, crude mortality, and mortality in multivariate regression analyses. Respiratory viruses are frequently detected in acutely admitted and invasively ventilated patients. Rhinovirus and human metapneumovirus are more frequently found in severe acute respiratory infection patients. Detection of respiratory viruses is not associated with worse clinically relevant outcomes in the studied cohort of patients.

Dysphagia in Mechanically Ventilated ICU Patients (DYnAMICS): A Prospective Observational Trial.

Swallowing disorders may be associated with adverse clinical outcomes in patients following invasive mechanical ventilation. We investigated the incidence of dysphagia, its time course, and association with clinically relevant outcomes in extubated critically ill patients. Prospective observational trial with systematic dysphagia screening and follow-up until 90 days or death. ICU of a tertiary care academic center. One thousand three-hundred four admissions of mixed adult ICU patients (median age, 66.0 yr [interquartile range, 54.0-74.0]; Acute Physiology and Chronic Health Evaluation-II score, 19.0 [interquartile range, 14.0-24.0]) were screened for postextubation dysphagia. Primary ICU admissions (n = 933) were analyzed and followed up until 90 days or death. Patients from an independent academic center served as confirmatory cohort (n = 220). Bedside screening for dysphagia was performed within 3 hours after extubation by trained ICU nurses. Positive screening triggered confirmatory specialist bedside swallowing examinations and follow-up until hospital discharge. Dysphagia screening was positive in 12.4% (n = 116/933) after extubation (18.3% of emergency and 4.9% of elective patients) and confirmed by specialists within 24 hours from positive screening in 87.3% (n = 96/110, n = 6 missing data). The dysphagia incidence at ICU discharge was 10.3% (n = 96/933) of which 60.4% (n = 58/96) remained positive until hospital discharge. Days on feeding tube, length of mechanical ventilation and ICU/hospital stay, and hospital mortality were higher in patients with dysphagia (all p < 0.001). The univariate hazard ratio for 90-day mortality for dysphagia was 3.74 (95% CI, 2.01-6.95; p < 0.001). After adjustment for disease severity and length of mechanical ventilation, dysphagia remained an independent predictor for 28-day and 90-day mortality (excess 90-d mortality 9.2%). Dysphagia after extubation was common in ICU patients, sustained until hospital discharge in the majority of affected patients, and was an independent predictor of death. Dysphagia after mechanical ventilation may be an overlooked problem. Studies on underlying causes and therapeutic interventions seem warranted.

Factors Associated With Pediatric Ventilator-Associated Conditions in Six U.S. Hospitals: A Nested Case-Control Study.

A newly proposed surveillance definition for ventilator-associated conditions among neonatal and pediatric patients has been associated with increased morbidity and mortality among ventilated patients in cardiac ICU, neonatal ICU, and PICU. This study aimed to identify potential risk factors associated with pediatric ventilator-associated conditions. Retrospective cohort. Six U.S. hospitals PATIENTS:: Children less than or equal to 18 years old ventilated for greater than or equal to 1 day. None. We identified children with pediatric ventilator-associated conditions and matched them to children without ventilator-associated conditions. Medical records were reviewed for comorbidities and acute care factors. We used bivariate and multivariate conditional logistic regression models to identify factors associated with ventilator-associated conditions. We studied 192 pairs of ventilator-associated conditions cases and matched controls (113 in the PICU and cardiac ICU combined; 79 in the neonatal ICU). In the PICU/cardiac ICU, potential risk factors for ventilator-associated conditions included neuromuscular blockade (odds ratio, 2.29; 95% CI, 1.08-4.87), positive fluid balance (highest quartile compared with the lowest, odds ratio, 7.76; 95% CI, 2.10-28.6), and blood product use (odds ratio, 1.52; 95% CI, 0.70-3.28). Weaning from sedation (i.e., decreasing sedation) or interruption of sedation may be protective (odds ratio, 0.44; 95% CI, 0.18-1.11). In the neonatal ICU, potential risk factors included blood product use (odds ratio, 2.99; 95% CI, 1.02-8.78), neuromuscular blockade use (odds ratio, 3.96; 95% CI, 0.93-16.9), and recent surgical procedures (odds ratio, 2.19; 95% CI, 0.77-6.28). Weaning or interrupting sedation was protective (odds ratio, 0.07; 95% CI, 0.01-0.79). In mechanically ventilated neonates and children, we identified several possible risk factors associated with ventilator-associated conditions. Next steps include studying propensity-matched cohorts and prospectively testing whether changes in sedation management, transfusion thresholds, and fluid management can decrease pediatric ventilator-associated conditions rates and improve patient outcomes.

Evaluation of critical care nurse's adherence to the principles of infection prevention and control when providing respiratory care to ventilated ICU patients

Evaluation of critical care nurse's adherence to the principles of infection prevention and control when providing respiratory care to ventilated ICU patients

Exploring the scope of communication content of mechanically ventilated patients

PurposeIneffective communication during mechanical ventilation (MV) and critical illness is distressing to many patients. This study aimed to describe the scope of communication content of ventilated critically ill patients. Materials and methodsWe performed a prospective qualitative interview study in a multidisciplinary intensive care unit. Ten alert, orientated adult patients who previously underwent MV for at least 24h and were able to speak at the time of interview were recruited. Semi-structured interviews with stimulated recall technique were conducted. A descriptive thematic analysis was performed of the patient-generated content using a free coding technique, where recurrent themes and subthemes were noted, coded and analyzed. ResultsPatients' communication content included medical discussions with clinicians; communication with family to provide advice or comfort, make requests and plans, express feelings and convey personal perspectives on medical care; and expression of their own psychoemotional needs. ConclusionsThe scope of communication content of ventilated ICU patients was broad, extending far beyond task-focused subject matter. Content ranged from conveying symptom-related messages to active participation in medical discussions, to conversing with family about a range of complex multi-dimensional issues, to sharing their own psychoemotional experiences. These patient-centered needs should be recognized and addressed in communication strategies.

Endothelial glycocalyx degradation is more severe in patients with non-pulmonary sepsis compared to pulmonary sepsis and associates with risk of ARDS and other organ dysfunction

BackgroundDisruption of the endothelial glycocalyx contributes to acute lung injury in experimental sepsis but has not been well studied in humans. To study glycocalyx degradation in sepsis-induced ARDS, we measured plasma levels of syndecan-1, a marker for glycocalyx degradation.MethodsThe present study is a retrospective observational study of 262 ventilated medical ICU patients at risk of ARDS due to severe sepsis and APACHE II ≥ 25. Plasma syndecan-1 was measured at study enrollment. Primary analysis focused on the association between syndecan-1 levels and the development of ARDS, other organ dysfunction (Brussels criteria), or in-hospital mortality.ResultsOverall, 135 (52%) patients developed ARDS. In patients with non-pulmonary sepsis, syndecan-1 levels were associated with ARDS (p = 0.05). Regardless of etiology of sepsis, higher syndecan-1 levels were associated with hepatic (p < 0.001), renal (p = 0.003), coagulation (p = 0.001), and circulatory (p = 0.02) failure as well as in-hospital mortality (p = 0.001), and there was a significant association between syndecan-1 levels and the number of vasopressors required in the first 24 h (p < 0.001). In addition, elevated syndecan levels were independently predictive of mortality in multivariable logistic regression adjusted for age and APACHE II score (odds ratio 1.85 per log increase in syndecan-1, 95% CI 1.056–3.241, p = 0.03).ConclusionThe extent of endothelial glycocalyx degradation is associated with non-pulmonary organ dysfunction in subjects with sepsis and is associated with ARDS but only in the subgroup with non-pulmonary sepsis. Measurement of syndecan-1 levels in sepsis patients might be useful for identifying patients at high risk of organ dysfunction and mortality as well as those who could benefit from therapies targeted at protecting or restoring the glycocalyx.

Adhesion of volatile propofol to breathing circuit tubing

Propofol in exhaled breath can be measured and may provide a real-time estimate of plasma concentration. However, propofol is absorbed in plastic tubing, thus estimates may fail to reflect lung/blood concentration if expired gas is not extracted directly from the endotracheal tube. We evaluated exhaled propofol in five ventilated ICU patients who were sedated with propofol. Exhaled propofol was measured once per minute using ion mobility spectrometry. Exhaled air was sampled directly from the endotracheal tube and at the ventilator end of the expiratory side of the anesthetic circuit. The circuit was disconnected from the patient and propofol was washed out with a separate clean ventilator. Propofol molecules, which discharged from the expiratory portion of the breathing circuit, were measured for up to 60 h. We also determined whether propofol passes through the plastic of breathing circuits. A total of 984 data pairs (presented as median values, with 95% confidence interval), consisting of both concentrations were collected. The concentration of propofol sampled near the patient was always substantially higher, at 10.4 [10.25–10.55] versus 5.73 [5.66–5.88] ppb (p < 0.001). The reduction in concentration over the breathing circuit tubing was 4.58 [4.48–4.68] ppb, 3.46 [3.21–3.73] in the first hour, 4.05 [3.77–4.34] in the second hour, and 4.01 [3.36–4.40] in the third hour. Out-gassing propofol from the breathing circuit remained at 2.8 ppb after 60 h of washing out. Diffusion through the plastic was not observed. Volatile propofol binds or adsorbs to the plastic of a breathing circuit with saturation kinetics. The bond is reversible so propofol can be washed out from the plastic. Our data confirm earlier findings that accurate measurements of volatile propofol require exhaled air to be sampled as close as possible to the patient.

Nonlinear Imputation of PaO2/FIO2 From SpO2/FIO2 Among Mechanically Ventilated Patients in the ICU: A Prospective, Observational Study.

In the contemporary ICU, mechanically ventilated patients may not have arterial blood gas measurements available at relevant timepoints. Severity criteria often depend on arterial blood gas results. Retrospective studies suggest that nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 is accurate, but this has not been established prospectively among mechanically ventilated ICU patients. The objective was to validate the superiority of nonlinear imputation of PaO2/FIO2 among mechanically ventilated patients and understand what factors influence the accuracy of imputation. Simultaneous SpO2, oximeter characteristics, receipt of vasopressors, and skin pigmentation were recorded at the time of a clinical arterial blood gas. Acute respiratory distress syndrome criteria were recorded. For each imputation method, we calculated both imputation error and the area under the curve for patients meeting criteria for acute respiratory distress syndrome (PaO2/FIO2 ≤ 300) and moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ≤ 150). Nine hospitals within the Prevention and Early Treatment of Acute Lung Injury network. We prospectively enrolled 703 mechanically ventilated patients admitted to the emergency departments or ICUs of participating study hospitals. None. We studied 1,034 arterial blood gases from 703 patients; 650 arterial blood gases were associated with SpO2 less than or equal to 96%. Nonlinear imputation had consistently lower error than other techniques. Among all patients, nonlinear had a lower error (p < 0.001) and higher (p < 0.001) area under the curve (0.87; 95% CI, 0.85-0.90) for PaO2/FIO2 less than or equal to 300 than linear/log-linear (0.80; 95% CI, 0.76-0.83) imputation. All imputation methods better identified moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ≤ 150); nonlinear imputation remained superior (p < 0.001). For PaO2/FIO2 less than or equal to 150, the sensitivity and specificity for nonlinear imputation were 0.87 (95% CI, 0.83-0.90) and 0.91 (95% CI, 0.88-0.93), respectively. Skin pigmentation and receipt of vasopressors were not associated with imputation accuracy. In mechanically ventilated patients, nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 seems accurate, especially for moderate-severe hypoxemia. Linear and log-linear imputations cannot be recommended.

The value of the excursion of diaphragm tested by ultrosonography to predict weaning from mechanical ventilation in ICU patients

Objective: To evaluate the excursion of the diaphragm and analyze the value in predicting weaning from mechanical ventilation in intensive care unit patients. Methods: The patients with mechanical ventilation (>48 hours) in ICU at Hebei Forth Medical University Hospital from June 2014 to December were classified into a success group or a failure group according to the weaning outcome. T-piece spontaneous breathing (SBT), airway occlusion pressure at 0.1 sec (P(0.1)) and maximal inspiratory pressure (MIP), rapid shallow breathing index (RSBI) and P(0.1)/MIP were measured or calculated. During the period of the 1st hour SBT, the excursion of diaphragm was measured with ultrasonography. The predictive value of each parameter to weaning was evaluated with ROC curve. Results: A total of 98 patients were enrolled in this study, including 74 successfully weaning and 24 failed. There were significant differences between two groups(success group and failure group) in P(0.1)[(2.00±2.00)cmH(2)O (1 cmH(2)O=0.098 kPa) vs (3.00±2.75)cmH(2)O, P<0.05], RSBI (39.14±16.81 vs 52.00±19.18, P<0.05), left diaphragmatic excursion [(1.12±0.97)cm vs (0.69±1.00)cm, P<0.001], right diaphragmatic excursion(1.87±0.75)cm vs (1.17±0.76)cm, P<0.001] and mean value of left and right diaphragmatic excursion [(1.57±0.52)cm vs (0.83±0.53)cm, and P<0.001]. The ventilation time [2.00(2.00-4.00)d vs 4.00(2.00-5.00)d], ICU hospital lengths of stay [4.50(3.00-7.25)d vs 8.50(6.25-15.25)d] and total hospital lengths of stay[20.00(15.00-25.25)d vs 25.00(20.25-37.25)d] were also statistically significant in success group and failure group respectively (all P<0.05). The cutoff value of diaphragmatic excursion for predicting successful extubation was determined to be 1.14 cm by ROC curve analysis. The sensitivity of diaphragmatic excursion to predict successful weaning was 89.2% and the specificity was 75.0%, the AUC(ROC) was 0.849. Conclusion: As an early predictor of diaphragmatic dysfunction, diaphragmatic excursion is probably superior to the traditional parameters in predicting weaning from ventilator in ICU patients.

Observational studies help us understand how to treat pandemic influenza and other emerging virus diseases

In his editorial, Zhang (1) comments on my earlier article that suggested inexpensive and widely available generic drugs might be used to reduce mortality from pandemic influenza, Ebola and other emerging virus diseases (2). He notes that several earlier studies explored the possibility that statins might be used to treat patients with sepsis and acute respiratory distress syndrome (ARDS) (1). Many individual observational studies [for example, (3)] and their meta-analyses (4) have suggested that statins might be effective in these patients, but several randomized controlled trials (RCTs) have failed to demonstrate their efficacy (5,6). Critical care specialists, many of them involved in these RCTs, have expressed different opinions on whether statins should still be considered potentially useful (7-9). In my view, the question is still open; the RCTs were conducted in mechanically ventilated ICU patients, and many of these patients were started on treatment late in the course of illness. Thus, statin treatment by itself may have been “too little, too late”. Nonetheless, the experimental and clinical rationale for this general approach to treating the host response in patients with critical illness is still persuasive. For many reasons, it must be further explored (2).

Comparison the Precision of Ear and Finger Pulse Oximetry with Finger Sensor in Mechanically Ventilated ICU Patients

Comparison the Precision of Ear and Finger Pulse Oximetry with Finger Sensor in Mechanically Ventilated ICU Patients

Hyperoxia: At what level of SpO2 is a patient safe? A study in mechanically ventilated ICU patients

BackgroundConcerns have been expressed regarding a possible association between arterial hyperoxia and adverse outcomes in critically ill patients. Oxygen status is commonly monitored noninvasively by peripheral saturation monitoring (SpO2). However, the risk of hyperoxia above specific SpO2 levels in critically ill patients is unknown. The purpose of this study was to determine a threshold value of SpO2 above which the prevalence of arterial hyperoxia distinctly increases. MethodsThis is a cross-sectional study in adult mechanically ventilated intensive care patients in a tertiary referral center. In 100 patients, we collected 200 arterial blood gases (ABG) and simultaneously registered SpO2 levels, as well as hemodynamic and ventilation parameters and vasoactive medication. Patients under therapeutic hypothermia were excluded. ResultsThe risk of arterial hyperoxia, defined as PaO2>100mmHg or >125mmHg, was negligible when SpO2 was ≤95% or ≤96%, respectively. The majority (89% and 54%, respectively for PaO2>100mmHg and 125mmHg) of ICU patients with SpO2 of 100% had arterial hyperoxia. The relation between SpO2 and PaO2 was not clearly affected by hemodynamic or other clinical variables (pH, pCO2, body temperature, recent blood transfusion). ConclusionIn critically ill patients, the prevalence of arterial hyperoxia increases when SpO2 is >95%. Above this saturation level, supplemental oxygen should be administered with caution in patients potentially susceptible to adverse effects of hyperoxia.

Long-term cognitive outcomes among unselected ventilated and non-ventilated ICU patients

BackgroundCognitive dysfunction is an important long-term complication of critical illness associated with reduced quality of life, increase in healthcare costs, and institutionalization. Delirium, an acute form of brain dysfunction that is common during critical illness has been shown to be associated with long-term cognitive dysfunction. The aim of this prospective cohort study was to estimate the prevalence and severity of cognitive dysfunction in an unselected population of medical and surgical ICU patients.MethodsThis prospective observational cohort study included all adult patients admitted to the surgical (13 beds) and medical (32 beds) ICUs of a tertiary hospital over a 12-month period. Patients with impaired cognition were excluded. At least 3 months after hospital discharge, patients were assessed for cognition using a validated battery of tests and were classified as having no cognitive impairment, mild to moderate cognitive impairment, or severe cognitive impairment.ResultsFour hundred thirteen patients were tested an average of 11 (3–18) months after discharge. Fifty-five (13.3%) patients included in the follow-up cohort had delirium. Cognitive impairment was identified in 206 (49.9%) patients, 120 (29.1%) patients had mild or moderate cognitive impairment, and 86 (20%) patients had severe cognitive dysfunction.ConclusionsThis investigation in an unselected and lower severity population of critically ill patients demonstrates that cognitive dysfunction is a frequent and severe long-term complication.

A randomized placebo-controlled phase II study of a Pseudomonas vaccine in ventilated ICU patients

BackgroundCurrently, no vaccine against Pseudomonas is available. IC43 is a new, recombinant, protein (OprF/I)-based vaccine against the opportunistic pathogen, Pseudomonas aeruginosa, a major cause of serious hospital-acquired infections. IC43 has proven immunogenicity and tolerability in healthy volunteers, patients with burns, and patients with chronic lung diseases. In order to assess the immunogenicity and safety of IC43 in patients who are most at risk of acquiring Pseudomonas infections, it was evaluated in mechanically ventilated ICU patients.MethodsWe conducted a randomized, placebo-controlled, partially blinded study in mechanically ventilated ICU patients. The immunogenicity of IC43 at day 14 was determined as the primary endpoint, and safety, efficacy against P. aeruginosa infections, and all-cause mortality were evaluated as secondary endpoints. Vaccinations (100 μg or 200 μg IC43 with adjuvant, or 100 μg IC43 without adjuvant, or placebo) were given twice in a 7-day interval and patients were followed up for 90 days.ResultsHigher OprF/I IgG antibody titers were seen at day 14 for all IC43 groups versus placebo (P < 0.0001). Seroconversion (≥4-fold increase in OprF/I IgG titer from days 0 to 14) was highest with 100 μg IC43 without adjuvant (80.6%). There were no significant differences in P. aeruginosa infection rates, with a low rate of invasive infections (pneumonia or bacteremia) in the IC43 groups (11.2-14.0%). Serious adverse events (SAEs) considered possibly related to therapy were reported by 2 patients (1.9%) in the group of 100 µg IC43 with adjuvant. Both SAEs resolved and no deaths were related to study treatment. Local tolerability symptoms were mild and rare (<5% of patients), a low rate of treatment-related treatment-emergent adverse events (3.1–10.6%) was observed in the IC43 groups.ConclusionThis phase II study has shown that IC43 vaccination of ventilated ICU patients produced a significant immunogenic effect. P. aeruginosa infection rates did not differ significantly between groups. In the absence of any difference in immune response following administration of 100 μg IC43 without adjuvant compared with 200 μg IC43 with adjuvant, the 100 μg dose without adjuvant was considered for further testing of its possible benefit of improved outcomes. There were no safety or mortality concerns.Trial registrationClinicalTrials.gov, NCT00876252. Registered on 3 April 2009.

Can calculation of energy expenditure based on CO2 measurements replace indirect calorimetry?

BackgroundMethods to calculate energy expenditure (EE) based on CO2 measurements (EEVCO2) have been proposed as a surrogate to indirect calorimetry. This study aimed at evaluating whether EEVCO2 could be considered as an alternative to EE measured by indirect calorimetry.MethodsIndirect calorimetry measurements conducted for clinical purposes on 278 mechanically ventilated ICU patients were retrospectively analyzed. EEVCO2 was calculated by a converted Weir’s equation using CO2 consumption (VCO2) measured by indirect calorimetry and assumed respiratory quotients (RQ): 0.85 (EEVCO2_0.85) and food quotient (FQ; EEVCO2_FQ). Mean calculated EEVCO2 and measured EE were compared by paired t test. Accuracy of EEVCO2 was evaluated according to the clinically relevant standard of 5% accuracy rate to the measured EE, and the more general standard of 10% accuracy rate. The effects of the timing of measurement (before or after the 7th ICU day) and energy provision rates (<90 or ≥90% of EE) on 5% accuracy rates were also analyzed (chi-square tests).ResultsMean biases for EEVCO2_0.85 and EEVCO2_FQ were -21 and -48 kcal/d (p = 0.04 and 0.00, respectively), and 10% accuracy rates were 77.7 and 77.3%, respectively. However, 5% accuracy rates were 46.0 and 46.4%, respectively. Accuracy rates were not affected by the timing of the measurement, or the energy provision rates at the time of measurements.ConclusionsCalculated EE based on CO2 measurement was not sufficiently accurate to consider the results as an alternative to measured EE by indirect calorimetry. Therefore, EE measured by indirect calorimetry remains as the gold standard to guide nutrition therapy.

ICUにおける人工呼吸器装着患者の睡眠の分断と看護ケアとの関連

ICUにおける人工呼吸器装着患者の睡眠の分断と看護ケアとの関連

ICU Clinicians Underestimate Breathing Discomfort in Ventilated Subjects.

Breathing discomfort (dyspnea) during mechanical ventilation in the ICU may contribute to patient distress and complicate care. Assessment of nonverbal cues may allow caregivers to estimate patient breathing discomfort. This study assesses the accuracy of those caregiver estimates. Thirty subjects were identified from ventilated, hemodynamically stable patients in the special care unit of Maine Medical Center. Those with impaired neurological function or too unstable to waken were excluded. Subjects provided a subjective score of breathing discomfort (0-10 using a modified Borg scale) during daily wake-up from sedation (sedation-agitation score of 3 or 4). Clinicians (physicians, respiratory therapists, and nurses) then provided a blinded estimate of subject breathing discomfort (0-10) through observation of the subject and inspection of ventilator parameters alone. Subject scores and caregiver estimates were compared. All subjects reported breathing discomfort with median score (interquartile range) of 4 (3-4). Caregiver estimates of breathing discomfort were significantly lower than subject scores (2 [0-3]), and the discrepancy was seen in all professions (physicians 1 point lower [0-2], P = .02; respiratory therapists 1 point lower [0-2], P = .01; nurses 2 points lower [1-3], P < .001). There was a positive correlation between subject breathing discomfort and degree of underestimation (ie, the degree of underestimation increased as the subject scores rose). The 3 most commonly used cues were subjects' facial expression, use of accessory muscles, and nasal flaring. Significant breathing discomfort is prevalent in mechanically ventilated ICU patients and is underestimated by caregivers, regardless of profession. The increasing disparity in caregiver estimate as breathing discomfort rises may expose patients to levels of dyspnea that promote anxiety and fear. This study demonstrates the need for further development and standardization of methods to assess dyspnea in nonverbal patients.