Local lung ventilation in critically ill patients using nonradioactive xenon-enhanced transmission computed tomography

Nonradioactive xenon is sufficiently radiodense to increase the density of gas-containing lung as seen in a computed tomography (CT) scan. Subtraction of a baseline CT scan from the xenon-enhanced CT scan can accentuate gas space differences by subtracting fixed tissue densities. The baseline scan and the scan obtained during wash-in of xenon (before equilibration) allow circulation of local ventilation. The xenon CT scan, thus, provides more precise information about distribution of ventilation than planar radiogas techniques. The technical aspects of application to a critically ill patient and the mathematical basis of the technique are presented.     

Assessment of muscle mass using ultrasound with minimal versus maximal pressure compared with computed tomography in critically ill adult patients

BackgroundPreserved skeletal muscle mass identified using computed tomography (CT) predicts improved outcomes from critical illness; however, CT imaging have few limitations such that it involves a radiation dose and transferring patients out of the intensive care unit. This study aimed to assess in critically ill patients the relationship between muscle mass estimates obtained using minimally invasive ultrasound techniques with both minimal and maximal pressure compared with CT images at the third lumber vertebra level.MethodsAll patients were treated in a single Australian intensive care unit. Eligible patients had paired assessments, within a 72-h window, of muscle mass by ultrasound (quadriceps muscle layer thickness in centimetres, with maximal and minimal pressure) and CT axial cross-sectional area (cm²). Data are presented as mean (standard deviation), median (interquartile range), and frequencies [n (%)].ResultsThirty-five patients [mean (standard deviation) age = 55 (16) years, median (interquartile range) body mass index = 27 (25–32) kg/m², and 26 (74%) men] contributed 41 paired measurements. Quadriceps muscle thickness measured using the maximal pressure technique was a strong independent predictor of lumbar muscle cross-sectional area. Within a multivariate mixed linear regression model and adjusting for sex, age, and body mass index, for every 1 cm increase in quadriceps muscle layer thickness, the lumbar muscle cross-sectional area increased by 35 cm² (95% confidence interval = 11–59 cm²). Similar univariate associations were observed using minimal pressure; however, as per multivariate analysis, there was no strength in this relationship [8 cm² (95% confidence interval = –5 to 22 cm²)].ConclusionUltrasound assessment of the quadriceps muscle using maximal pressure reasonably predicts the skeletal muscle at the third lumbar vertebra level of critically ill patients. However, there is substantial uncertainty within these regression estimates, and this may reduce the current utility of this technique as a minimally invasive surrogate for CT assessment of skeletal muscle mass.     

Hyperglycaemia and mortality in critically ill patients

Objective To describe hyperglycaemia as a possible marker of morbidity and mortality in critically ill medical and surgical patients admitted to a multidisciplinary ICU.Design Prospective cohort study.Setting A 13-bed non-cardiac multidisciplinary ICU in a university hospital.Patients and participants Adult patients consecutively admitted to the ICU in a 6-month period. Patients with fewer than 2 days stay in the ICU and patients with known diabetes were excluded.Measurements and results At admission a registration form was filled in including demographic data, first and second day APACHE II scores, infections and daily maximum blood glucose level. In surgical patients, high maximum blood glucose level during the stay in ICU was correlated with increased mortality, morbidity and frequency of infection. In medical patients, we found a non-significant trend towards a correlation between hyperglycaemia and morbidity and mortality, respectively.Conclusions High blood glucose level during the stay in ICU was a marker of increased morbidity and mortality in critically ill surgical patients. In medical patients the same trend was found, but non-significant. The population of patients in the present study are heterogeneous and the results from surgical critically ill patients should not be generalised to medical patients.     

The association between primary language spoken and all-cause mortality in critically ill patients

Purpose

The study objective was to investigate the association between primary language spoken and all-cause mortality in critically ill patients.

Materials and Methods

We performed a cohort study on 48?581 patients 18 years or older who received critical care between 1997 and 2007 in 2 Boston hospitals. The exposure of interest was primary language spoken determined by the patient or family members who interacted with administrative staff during hospital registration. The primary outcome was 30-day mortality. Associations between language and mortality were estimated by bivariable and multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both language and mortality. Adjustment included age, race, sex, Deyo-Charlson index, patient type (medical vs surgical), sepsis, creatinine, hematocrit, white blood count, and number of organs with acute failure.

Results

Validation showed that primary language spoken was highly accurate for a statement in the medical record noting the language spoken that matched the assigned language. Patients whose primary language spoken was not English had improved outcomes (odds ratio 30-day mortality, 0.69 [95% confidence interval, 0.60-0.81; P < .001), relative to patients with English as the primary language spoken, fully adjusted. Similar significant associations are seen with death by days 90 and 365 as well as in-hospital mortality. The improved survival in patients with a non-English primary language spoken is not confounded by indicators of severity of disease and is independent of the specific language spoken and neighborhood poverty rate, a proxy for socioeconomic status. There are significant limitations inherent to large database studies that we have acknowledged and addressed with controlling for measured confounding and evaluation of effect modification.

Conclusions

In a regional cohort, not speaking English as a primary language is associated with improved outcomes after critical care. Our observations may have clinical relevance and illustrate the intersection of several factors in critical illness outcome including severity of illness, comorbidity, and social and economic factors.     

Predictors of short-term mortality in critically ill patients with solid malignancies

Admission of cancer patients with serious medical complications to the ICU remains controversial primarily because of the high short-term mortality rates in these patients. However, the cancer patient population is heterogeneous regarding age, underlying conditions, and curability of their disease, suggesting that large variations may occur in the effectiveness of intensive care within this subgroup of critically ill patients.¶Objectives: To identify factors predicting 30-day mortality in patients with solid tumors admitted to a medical ICU.¶Patients and methods: We conducted a retrospective study in 120 consecutive cancer patients (excluding patients with hematological malignancies) admitted to the medical ICU of a 650-bed university hospital between January 1990 and July 1997. Medical history, physical and laboratory test findings at admission, and therapeutic interventions within the first 24 h in the ICU were recorded. The study endpoint was vital status 30 days after ICU admission. Stepwise logistic regression was used to identify independent prognostic factors.¶Results: The observed 30-day mortality rate was 58.7 % (n = 68), with most deaths (92 %) occurring in the ICU. Univariate predictors of 30-day mortality were either protective [prior surgery for the cancer (p = 0.01) and complete remission (p = 0.01)] or associated with higher mortality [Knaus scale C or D (p = 0.02), shock (p = 0.04), need for vasopressors (p = 0.0006) or for mechanical ventilation (p = 0.0001), SAPS II score greater than 36 (p = 0.0001), LOD score greater than 6 (p = 0.0001), and ODIN score > 2 (p = 0.0001)]. Three variables were independent predictors: previous surgery for the cancer (OR 0.20, 95 % CI 0.07–0.58), LOD score > 6 (OR 1.26, 95 % CI 1.09–1.44), and need for mechanical ventilation (OR 3.55, 95 % CI; 1.26–6.7). Variables previously thought to be indicative of a poor prognosis (i. e., advanced age, metastatic or progressive disease, neutropenia or bone marrow transplantation) were not predictive of outcome.¶Conclusion: When transfer to an ICU is considered an option by patients and physicians, 30-day mortality is better estimated by an evaluation of acute organ dysfunction than by the characteristics of the underlying malignancy.     

Assessment of candidemia-attributable mortality in critically ill patients using propensity score matching analysis

ABSTRACT: INTRODUCTION: Candidemia in critically ill patients is usually a severe and life-threatening condition with a high crude mortality. Very few studies have focused on the impact of candidemia on ICU patient outcome and attributable mortality still remains controversial. This study was carried out to determine the attributable mortality of ICU-acquired candidemia in critically ill patients using propensity score matching analysis. METHODS: A prospective observational study was conducted of all consecutive non-neutropenic adult patients admitted for at least seven days to 36 ICUs in Spain, France, and Argentina between April 2006 and June 2007. The probability of developing candidemia was estimated using a multivariate logistic regression model. Each patient with ICU-acquired candidemia was matched with two control patients with the nearest available Mahalanobis metric matching within the calipers defined by the propensity score. Standardized differences tests (SDT) for each variable before and after matching were calculated. Attributable mortality was determined by a modified Poisson regression model adjusted by those variables that still presented certain misalignments defined as a SDT > 10%. RESULTS: Thirty-eight candidemias were diagnosed in 1,107 patients (34.3 episodes/1,000 ICU patients). Patients with and without candidemia had an ICU crude mortality of 52.6% versus 20.6% (P < 0.001) and a crude hospital mortality of 55.3% versus 29.6% (P = 0.01), respectively. In the propensity matched analysis, the corresponding figures were 51.4% versus 37.1% (P = 0.222) and 54.3% versus 50% (P = 0.680). After controlling residual confusion by the Poisson regression model, the relative risk (RR) of ICU- and hospital-attributable mortality from candidemia was RR 1.298 (95% confidence interval (CI) 0.88 to 1.98) and RR 1.096 (95% CI 0.68 to 1.69), respectively. CONCLUSIONS: ICU-acquired candidemia in critically ill patients is not associated with an increase in either ICU or hospital mortality.     

Assessment of candidemia-attributable mortality in critically ill patients using propensity score matching analysis

Introduction

Endotracheal intubation in the ICU is a challenging procedure and is frequently associated with life-threatening complications. The aim of this study was to investigate the effect of the C-MAC^? video laryngoscope on laryngeal view and intubation success compared with direct laryngoscopy.

Methods

In a single-center, prospective, comparative before-after study in an anesthetist-lead surgical ICU of a tertiary university hospital, predictors of potentially difficult tracheal intubation, number of intubation attempts, success rate and glottic view were evaluated during a 2-year study period (first year, Macintosh laryngoscopy (ML); second year, C-MAC^?).

Results

A total of 274 critically ill patients requiring endotracheal intubation were included; 113 intubations using ML and 117 intubations using the C-MAC^? were assessed. In patients with at least one predictor for difficult intubation, the C-MAC^? resulted in more successful intubations on first attempt compared with ML (34/43, 79% vs. 21/38, 55%; P = 0.03). The visualization of the glottis with ML using Cormack and Lehane (C&L) grading was more frequently rated as difficult (20%, C&L grade 3 and 4) compared with the C-MAC^? (7%, C&L grade 3 and 4) (P < 0.0001).

Conclusion

Use of the C-MAC^? video laryngoscope improved laryngeal imaging and improved the intubating success rate on the first attempt in patients with predictors for difficult intubation in the ICU setting. Video laryngoscopy seems to be a useful tool in the ICU where potentially difficult endotracheal intubations regularly occur.     

Intensive insulin therapy and mortality in critically ill patients

Introduction  

Intensive insulin therapy (IIT) with tight glycemic control may reduce mortality and morbidity in critically ill patients and has been widely adopted in practice throughout the world. However, there is only one randomized controlled trial showing unequivocal benefit to this approach and that study population was dominated by post-cardiac surgery patients. We aimed to determine the association between IIT and mortality in a mixed population of critically ill patients.     

Post-ICU mortality in critically ill infected patients: an international study

Objective To determine the incidence and risk factors for post-ICU mortality in patients with infection.Design and setting International observational cohort study including 28 ICUs in eight countries.Patients All 1,872 patients discharged alive from the ICU over a 1-year period were screened for infection at ICU admission and daily throughout the ICU stay. Outcomes at ICU and hospital discharge were recorded.Measurements and results Post-ICU death occurred in 195 (10.4%) patients and was associated in the multivariable analysis with age, chronic respiratory failure, immunosuppression, cirrhosis, Simplified Acute Physiology Score II on the first day with infection, and LOD score at ICU discharge. Post-ICU death was more common among medical patients and patients with hospital-acquired infection or microbiologically documented infection and was less common in patients with pneumonia.Conclusions Post-ICU death in patients with infection was within previously reported ranges in overall ICU populations. The main risk factors were patient and infection characteristics, severity at ICU admission, and persistent organ dysfunction at ICU discharge. Further interventions such as further ICU management, discharge to a step-down unit, or follow-up by intensivists on the ward should be evaluated in patients with a high risk of post-ICU mortalityElectronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at .Supported by an educational grant from Roche.     

Clinically significant gastrointestinal bleeding in critically ill patients with and without stress-ulcer prophylaxis

Objective To compare the rates of clinically significant gastrointestinal bleeding and the number of blood units and endoscopies required for gastrointestinal hemorrhage between patients receiving or not receiving stress-ulcer prophylaxis.Design Historical observational study comparing two consecutive periods: with (phase 1) and without stress-ulcer prophylaxis (phase 2).Design and setting A 17-bed intensive care unit in a university teaching hospital.Patients In phase 1 there were 736 patients and in phase 2 737. Those in the two phases were comparable in age and reason for admission; clinically significant gastrointestinal bleeding rates did not differ between the two phases, but patients in phase 2 were more severely ill.Measurements and results Comparable numbers of blood units were transfused per bleeding patient in the two phases, especially for patients with significant gastrointestinal bleeding. During each phase 19 fibroscopies were performed for significant bleeding, and two patients required surgery. The clinically significant gastrointestinal bleeding rate and outcome did not differ in patients with at least one risk factor. Total expenditures directly related to gastrointestinal bleeding were similar during the two phases; the total cost incurred by stress-ulcer prophylaxis was estimated at €6700.Conclusions Our results suggest that stress-ulcer prophylaxis does not influence the clinically significant gastrointestinal bleeding rate in intensive care unit patients or the cost of its management.     

An evaluation on the association of vancomycin trough concentration with mortality in critically ill patients: A multicenter retrospective study

To determine the impact of initial vancomycin trough concentration (VTC) on mortality in adult patients in the intensive care unit (ICU) undergoing vancomycin therapy. During their first ICU stay, patients with initial VTC records after vancomycin treatment were recruited from the eICU Collaborative Research Database to this multicenter retrospective cohort study, and classified into four groups according to VTC: less than 10, 10–15, 15–20, and greater than 20 mg/L. Multivariable logistic regression and sensitivity analyses were performed to explore the association of VTC, as a continuous and categorical variable, with mortality. This study enrolled 7220 patients from 335 different ICUs at 208 hospitals. Multivariable logistic regression models indicated that VTC was positively correlated with ICU (odds ratio [OR], 1.028, 95% confidence interval [CI], 1.019–1.037) and hospital (OR 1.028, 95% CI, 1.020–1.036) mortalities. Moreover, compared with VTC less than 10 mg/L, VTCs of 10–15, 15–20, and greater than 20 mg/L were associated with a higher risk of ICU mortality (OR, 1.330, 95% CI, 1.070–1.653; OR, 1.596, 95% CI, 1.265–2.015; abd OR, 1.875, 95% CI, 1.491–2.357, respectively), and VTCs of 15–20 and greater than 20 mg/L were also correlated with increased hospital mortality (OR, 1.482, 95% CI, 1.225–1.793; and OR, 1.831, 95% CI, 1.517–2.210, respectively). Similar results persisted in patients with different Acute Physiology and Chronic Health Evaluation Ⅳ scores, creatinine clearance levels, ages, and body mass indexes. Our findings indicated a potential relationship of initial VTC with ICU and hospital mortalities in patients in the ICU. However, due to the retrospective nature of this study, future prospective studies or randomized controlled trials are needed to validate those results.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Although monitoring vancomycin trough concentration as a feasible pharmacokinetic method was recommended for personalized vancomycin dosing by the Infectious Diseases Society of America in 2009, it remains controversial regarding the association of trough concentration with treatment outcomes in patients with gram‐positive bacterial infection.

• WHAT QUESTION DID THIS STUDY ADDRESS?

A large‐scale multicenter cohort was performed to identify the association between initial trough concentration and prognosis in 7220 patients in the intensive care unit (ICU), aiming to evaluate the clinical value of trough concentration for ensuring vancomycin efficacy.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Our study demonstrated that trough concentration was positively related with ICU and hospital mortalities. Trough concentration greater than or equal to 10 mg/L was associated with increased ICU mortality. Moreover, hospital mortality failed to decrease at trough concentration 10–15 mg/L, even raised at trough concentration greater than 15 mg/L, compared with trough concentration less than 10 mg/L. The present study revealed that increased initial vancomycin trough concentration might not guarantee treatment success for critically ill patients.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

We found that high initial VTC might be associated with incremental ICU and hospital mortalities. However, due to the retrospective nature of this study, those findings are worth further investigation with prospective studies or randomized controlled trials.     

Insulin-treated diabetes is not associated with increased mortality in critically ill patients

Introduction  

This was a planned substudy from the European observational Sepsis Occurrence in Acutely ill Patients (SOAP) study to investigate the possible impact of insulin-treated diabetes on morbidity and mortality in ICU patients.     

Predicting in-hospital mortality among critically ill patients with end-stage liver disease

Purpose

Critically-ill patients with end-stage liver disease (ESLD) are at high risk for death during intensive care unit hospitalization, and currently available prognostic models have limited accuracy in this population. We aimed to identify variables associated with in-hospital mortality among critically ill ESLD patients and to develop and validate a simple, parsimonious model for bedside use.

Materials and methods

We performed a retrospective chart review of 653 intensive care unit admissions for ESLD patients; modeled in-hospital mortality using multivariable logistic regression; and compared the predictive ability of several different models using the area under receiver operating characteristic (AU-ROC) curves.

Results

Multivariable predictors of in-hospital mortality included Model for End-stage Liver Disease (MELD) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score, mechanical ventilation, and gender; there was also an interaction between MELD score and gender (P < .02). MELD alone had better discrimination (AU-ROC 0.83) than APACHE II alone (AU-ROC 0.76), and adding mechanical ventilation to MELD achieved the single largest increase in model discrimination (AU-ROC 0.85; P < .01). In a parsimonious, 2-predictor model, higher MELD scores (OR 1.14 per 1-point increase; 95% CI 1.11-1.16), and mechanical ventilation (OR 6.20; 95% CI 3.05–12.58) were associated with increased odds of death. Model discrimination was also excellent in the validation cohort (AU-ROC 0.90).

Conclusions

In critically ill ESLD patients, a parsimonious model including only MELD and mechanical ventilation is more accurate than APACHE II alone for predicting in-hospital mortality. This simple bedside model can provide clinicians and patients with valuable prognostic information for medical decision-making.     

Isolated diastolic dysfunction is associated with increased mortality in critically ill patients

PurposeLeft ventricular (LV) diastolic dysfunction is important in critically ill patients, but prevalence and impact on mortality is not well studied. We classified intensive care patients with normal left ventricular function according to current diastolic guidelines and explored associations with mortality.Material and methodsEchocardiography was performed within 24 h of intensive care admission. Patients with reduced LV ejection fraction, regional wall motion abnormality, or a history of cardiac disease were excluded. Patients were classified according to the 2016 EACVI guidelines, Recommendations for the Evaluation of LV Diastolic Function by Echocardiography.ResultsOut of 218 patients, 162 (74%) had normal diastolic function, 21 (10%) had diastolic dysfunction, and 35 (17%) had indeterminate diastolic function.Diastolic dysfunction were more common in female patients, older patients and associated with sepsis, respiratory and cardiovascular comorbidity as well as higher SAPS Score. In a risk-adjusted logistic regression model, patients with indeterminate diastolic dysfunction (OR 4.3 [1.6–11.4], p = 0.004) or diastolic dysfunction (OR 5.1 [1.6–16.5], p = 0.006) had an increased risk of death at 90 days compared to patients with normal diastolic function.ConclusionIsolated diastolic dysfunction, assessed by a multi-parameter approach, is common in critically ill patients and is associated with mortality.Trial registrationSecondary analysis of data from a single-center prospective observational study focused on systolic dysfunction in intensive care unit patients (Clinical Trials ID: NCT03787810     

Perioperative plasma melatonin concentration in postoperative critically ill patients: Its association with delirium

Purpose

Delirium is a common complication in postoperative critically ill patients. Although abnormal melatonin metabolism is thought to be one of the mechanisms of delirium, there have been few studies in which the association between alteration of perioperative plasma melatonin concentration and postoperative delirium was assessed.

Materials

We conducted a prospective observational study to assess the association of perioperative alteration of plasma melatonin concentration with delirium in 40 postoperative patients who required intensive care for more than 48 hours. We diagnosed postoperative delirium using Confusion Assessment Method for the intensive care unit and measured melatonin concentration 4 times (before the operation as the preoperative value, 1 hour after the operation, postoperative day 1, and postoperative day 2).

Results

Postoperative delirium occurred in 13 (33%) of the patients. Although there was no significant difference in preoperative melatonin concentration, Δ melatonin concentration at 1 hour after the operation was significantly lower in patients with delirium than in those without delirium (− 1.1 vs 0 pg/mL, P = .036). After adjustment of relevant confounders, Δ melatonin concentration was independently associated with risk of delirium (odds ratio, 0.50; P = .047).

Conclusions

Delta melatonin concentration at 1 hour after the operation has a significant independent association with risk of postoperative delirium.     

Predicted and measured aminoglycoside pharmacokinetic parameters in critically ill patients.

We conducted a prospective study to determine whether predicted aminoglycoside pharmacokinetic parameters (based on population averages) correlate with measured values in critically ill patients. There was wide interpatient variability for all pharmacokinetic parameters. Only predicted and measured volumes of distribution (18.7 +/- 6.5 versus 22.9 +/- 7.7 liters [mean +/- standard deviation], respectively), with a mean of 0.32 +/- 0.09 liter/kg of dosing body weight, were significantly different. There were no relationships between pharmacokinetic parameters and documented infection, death, or intubation status. The results indicate that volume of distribution is commonly underestimated in intensive care unit patients, whereas elimination rates may be adequately predicted based on population averages. We therefore recommend that aminoglycoside volume of distribution estimates for intensive care unit patients take fluid and adipose excess into account and be based on 0.32 liter/kg rather than the usual 0.25 liter/kg.