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OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease.

The incidence of thyroid disfunction has not been analyzed in critically ill COVID-19 patients. Our objective was to analyze the relationship of the thyroid profile and in-hospital mortality in critically ill COVID-19 patients. This was a prospective single-center study involving critically ill COVID-19 patients admitted to the ICU of a tertiary University Hospital. Thyroid hormones were measured through drawing blood samples from a central venous catheter at ICU admission and on the fifth day. A multiple logistic regression analysis was performed to analyze the variables associated with mortality. The ability of the different thyroid hormones to predict in-hospital mortality was evaluated by calculating the receiver operating characteristics (ROCs) and the area under the curve (AUC). A total of 78 patients were included in the study at ICU admission, 72 had their thyroid profile measured at day 5. In-hospital mortality reached 29.5%. Multiple logistic regression analysis showed that variables associated with mortality were age and prior beta-blocker therapy at ICU admission and age fT4 at day 5. The AUC for in-hospital mortality predictions of fT4 at day 5 was 0.69. Thyroid responses are commonly observed in critically ill COVID-19 patients. fT4 at day 5 after ICU admission was associated with mortality.

Resumen Objetivo Valorar el efecto de la FiO 2 sobre el sesgo y la precision en la medicion del consumo de oxigeno ( V ˙ O 2 ) y la produccion de dioxido de carbono ( V ˙ CO 2 ) con el monitor E-COVX en pacientes con ventilacion mecanica. Diseno Descriptivo de concordancia. Ambito Unidad de Cuidados Intensivos. Pacientes o participantes Pacientes con ventilacion mecanica. Intervenciones Se midieron el V ˙ O 2 y la V ˙ CO 2 con el monitor E-COVX. Los valores de V ˙ O 2 y V ˙ CO 2 fueron el promedio de 5 min. Dos grupos de 30 pacientes. Se analizo: 1) la reproducibilidad de la medicion del V ˙ O 2 y la V ˙ CO 2 con una FiO 2 de 0,4, y 2) el efecto de los cambios en la FiO 2 sobre el V ˙ O 2 y la V ˙ CO 2 . Analisis estadistico por el metodo de Bland y Altman. Variables de interes principales Sesgo y precision. Resultados 1) Reproducibilidad a una FiO 2 de 0,4: los sesgos en la medicion del V ˙ O 2 y la V ˙ CO 2 fueron de 1,6 y 2,1 mL/min, respectivamente, y los errores en la precision fueron de 9,7 a −8,3% y de 7,2 a −5,2%, respectivamente, y 2) efecto de la FiO 2 sobre el V ˙ O 2 : el sesgo del V ˙ O 2 medido a una FiO 2 de 0,4 y 0,6 fue de −4,0 mL/min y a FiO 2 de 0,4 y 0,8, de 5,2 mL/min. La precision entre FiO 2 de 0,4 y 0,6 fue de 11,9 a −14,1%, y entre FiO 2 de 0,4 y 0,8, de 43,9 a −39,7%. Conclusiones El monitor E-COVX mide el V ˙ O 2 y la V ˙ CO 2 en pacientes criticos con ventilacion mecanica con un sesgo y una precision clinicamente aceptables hasta una FiO 2 de 0,6.

Objective We evaluated the effect of changes in FiO2 on the bias and accuracy of the determination of oxygen consumption ( V ⋅ O 2 ) and carbon dioxide production ( V ⋅ CO 2 ) using the E-COVX monitor in patients with mechanical ventilation. Design Descriptive of concordance. Setting Intensive Care Unit. Patients or participants Patients with mechanical ventilation. Interventions We measured V ⋅ O 2 and V ⋅ CO 2 using the E-COVX monitor. Values recorded were the average in 5 min. Two groups of 30 patients. We analyzed: 1) the reproducibility in the measurement of V ⋅ O 2 and V ⋅ CO 2 at FiO2 0.4, and 2) the effect of the changes in FiO2 on the measurement of V ⋅ O 2 and V ⋅ CO 2 . Statistical analysis was performed using Bland and Altman test. Variables of main interest Bias and accuracy. Results 1) FiO2 0.4 reproducibility: The bias in the measurement of V ⋅ O 2 and V ⋅ CO 2 was 1.6 and 2.1 mL/min, respectively, and accuracy was 9.7 to −8.3% and 7.2 to −5.2%, respectively, and 2) effect of FiO2 on V ⋅ O 2 : The bias of V ⋅ O 2 measured at FiO2 0.4 and 0.6 was −4.0 mL/min and FiO2 0.4 and 0.8 was 5.2 mL/min. Accuracy between FiO2 0.4 and 0.6 was 11.9 to −14.1%, and between FiO2 0.4 and 0.8 was 43.9 to −39.7%. Conclusions The E-COVX monitor evaluates V ⋅ O 2 and V ⋅ CO 2 in critical patients with mechanical ventilation with a clinically acceptable accuracy until FiO2 0.6.

Our purpose was to assess the amino acids’ (AAs) profile in trauma patients and to assess the effect of the route of nutrition and the exogenous ALA-GLN dipeptide supplementation on plasma AAs’ concentration. This is a secondary analysis of a previous randomized controlled trial. On day 1 and day 6 after trauma, plasma concentration of 25 AAs was measured using reverse phase high-performance liquid chromatography. Results were analyzed in relation to the route of nutrition and supplementation of ALA-GLN dipeptide. Differences between plasma AAs’ concentrations at day 1 and day 6 were evaluated using the Student’s t test or Mann–Whitney–Wilcoxon test. One-way ANOVA and the Kruskal–Wallis test were used to compare groups. A two-sided p value less than 0.05 was considered statistically significant. Ninety-eight patients were analyzed. Mean plasma concentrations at day 1 were close to the lower normal level for most AAs. At day 6 we found an increase in the eight essential AAs’ concentrations and in 9 out of 17 measured non-essential AAs. At day 6 we found no differences in plasma concentrations for the sum of all AAs (p = .72), glutamine (p = .31) and arginine (p = .23) distributed by the route of nutrition. Administration of ALA-GLN dipeptide increased the plasma concentration of alanine (p = .004), glutamine (p

Objective To evaluate the effect of enteral nutrition volume, gastrointestinal function and the type of acid suppressive drug upon the incidence of lower respiratory tract infections in critically ill patients on mechanical ventilation (MV). Design A retrospective secondary analysis was carried out. Setting The Intensive Care Unit of a University Hospital. Patients or participants Patients ≥ 18-years-old expected to need MV for more than four days, and receiving enteral nutrition by nasogastric tube within 24 h of starting MV. Interventions We correlated enteral nutrition volume administered during the first 10 days, gastrointestinal function and the type of acid suppressive therapy with the episodes of lower respiratory tract infection up until day 28. Cox proportional hazards ratios in univariate and adjusted multivariate models were used. Statistical significance was considered for p Main variables of interest Lower respiratory tract infection episodes. Results Sixty-six out of 185 patients (35.7%) had infection; 27 patients had ventilator-associated pneumonia; and 39 presented ventilator-associated tracheobronchitis. Uninfected and infected groups were similar in terms of enteral nutrition volume (54 ± 12 and 54 ± 9 mL/h; p = 0.94) and caloric intake (19.4 ± 4.9 and 19.6 ± 5.2 kcal/kg/d; p = 0.81). The Cox proportional hazards model showed neurological indication of MV to be the only independent variable related to infection (p = 0.001). Enteral nutrition volume, the type of acid suppressive therapy, and the use of prokinetic agents were not significantly correlated to infection. Conclusions Enteral nutrition volume and caloric intake, gastrointestinal dysfunction and the type of acid suppressive therapy used were not associated to lower respiratory tract infection in patients on MV.

To evaluate whether patients with rhabdomyolysis and serum alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) higher than 1000 IU/L had higher mortality that patients with low aminotransferases. Retrospective analysis of intensive care unit patients with rhabdomyolysis [creatine kinase (CK) higher than 5000 IU/L]. Patients were classified in two groups: low aminotransferases group, when AST and ALT were equal or lower to 1000 IU/L, and elevated aminotransferases group, when AST or ALT was above 1000 IU/L. Forty-six out of 189 patients included in the analysis (24.3%) had elevated aminotransferases. The mortality of patients with rhabdomyolysis was 25.9 per cent, being higher in patients with elevated aminotransferases compared with patients with low aminotransferases (60.9% vs 14.7%; P < 0.001). Mortality stratified by quartiles of CK in patients with low aminotransferases was independent of the level of CK ( P = 0.67). Logistic regression analysis showed that the independent variables associated with mortality were Simplified Acute Physiology Score II [1.11 (1.07–1.16) for each point of increase, P < 0.001], the international normalized ratio value [4.2 (1.6–10.7) for each point of increase, P = 0.003], and the need of renal replacement therapy [5.4 (1.7–17.2), P = 0.004]. Patients with rhabdomyolysis with elevated serum aminotransferases had higher mortality than patients with low serum aminotransferase levels.

Purpose To identify risk factors of successful continuous renal replacement therapy (CRRT) weaning and to evaluate the effect of furosemide in the recovery of urine output after CRRT stop. Materials and methods Retrospective, observational study of critical patients treated with CRRT. Weaning tests (WT) were classified in two groups: successful (urine output was recovered and CRRT was not required again) and failed (CRRT was required again). A multiple logistic regression model was used to identify risk factors of successful CRRT WT. The prediction ability was assessed with the area under the receiver operating characteristic curves (AUC-ROC). Results Eighty-six patients underwent 101 CRRT WT. The multivariate model identified that the risk factors of successful CRRT weaning were sex and 6 h-urine output after CRRT stop. The AUC-ROC was 0.81 (0.72–0.90) for 6 h-urine output before and 0.91 (0.84–0.96) for 6 h-urine output after CRRT stop. The AUC-ROC for 6 h–urine output after WT to predict successful CRRT weaning were 0.94 (0.88–1.0) in patients who received furosemide and 0.85 (0.72–0.99) in patients who did not. Conclusions Urine output after CRRT stop was the main risk factor of successful CRRT weaning. Administration of furosemide increased the strength of this association.

Geriatric trauma constitutes an increasingly recognized problem. Aging results in a progressive decline in cellular function which leads to a loose of their capacity to respond to injury. Some medications commonly used in this population can mask or blunt the response to injury. Falls constitute the most common cause of trauma and the leading cause of trauma-related deaths in this population. Falls are complicated by the widespread use of antiplatelets and anticoagulants, especially in patients with brain injury. Under-triage is common in this population. Evaluation of frailty could be helpful to solve this issue. Appropriate triaging and early aggressive management with correction of coagulopathy can improve outcome. Limitation of care and palliative measures must be considered in cases with a clear likelihood of poor prognosis.

There is controversy about the effects of high plasma bicarbonate concentration ([HCO3(-)]) and the CO2 response test. We analyzed the relationship between [HCO3(-)] and the variation in hydrogen ion concentration (pH) for a given change in PaCO2, and its effects upon CO2 response.A retrospective study was carried out.Two intensive care units.Subjects with and without chronic obstructive pulmonary disease (COPD), at the beginning of weaning from mechanical ventilation.The CO2 response was evaluated by the re-inhalation of expired air method, measuring the hypercapnic ventilatory response (ΔVE/ΔPaCO2) and hypercapnic drive response (ΔP01/ΔPaCO2), where VE is minute volume and P0.1 is airway occlusion pressure 0.1s after the initiation of inspiration.[HCO3(-)] and CO2 response.A total of 120 patients in the non-COPD group and 48 in the COPD group were studied. COPD patients had higher mean [HCO3(-)] than non-COPD patients (33.2 ± 5.4 vs. 25.7 ± 3.7 mmol/l, p0.001). In both non-COPD and COPD patients we observed a significant inverse linear relationship between [HCO3(-)] and pH change per mmHg of PaCO2 (p0.001), ΔVE/ΔPaCO2 (p0.001) and ΔP0.1/ΔPaCO2 (p0.001).There is an inverse linear relationship between [HCO3(-)] and the variation of pH for a given change in PaCO2 and the CO2 response.

Purpose To evaluate the effect of the intravenous (i.v.) l-alanyl-l-glutamine dipeptide supplementation during 5 days on clinical outcome in trauma patients admitted to the intensive care unit (ICU).

The contribution of the central respiratory drive in the hypercapnic respiratory failure of neuromuscular diseases (NMD) is controversial.To compare the CO2 response and the duration of weaning of mechanical ventilation between a group of NMD patients and a group of quadriplegic patients due to ICU-acquired weakness (ICU-AW).We prospectively studied 16 subjects with NMD and 26 subjects with ICU-AW ready for weaning, using the method of the re-inhalation of expired air. We measured the hypercapnic drive response, defined as the ratio of change in airway occlusion pressure 0.1 second after the start of inspiration (ΔP0.1) to the change in Paco2 (ΔPaco2), and the hypercapnic ventilatory response, defined as the ratio of the change in minute ventilation (ΔVe) to ΔPaco2. We considered a value of ≤ 0.19 cm H2O/mm Hg as reduced hypercapnic drive response.Hypercapnic drive response (ΔP0.1/ΔPaco2 = 0.14 ± 0.08 cm H2O/mm Hg vs 0.37 ± 0.27 cm H2O/mm Hg, P = .002) and hypercapnic ventilatory response (ΔVe/ΔPaco2 = 0.21 ± 0.19 L/min/mm Hg vs 0.44 ± 0.40 L/min/mm Hg, P = .02) were lower in the NMD than in the ICU-AW subjects. Duration of weaning values, according to the Kaplan-Meier curves, were similar in both groups (Log-rank = 0.03, P = .96). Eleven NMD (69%) and 9 ICU-AW (35%) subjects had hypercapnic drive response ≤ 0.19 cm H2O/mm Hg. The duration of weaning was longer in subjects with hypercapnic drive response ≤ 0.19 cm H2O/mm Hg (log-rank = 15.4, P.001).Subjects with acute hypercapnic respiratory failure due to NMD had reduced hypercapnic drive response, compared to ICU-AW subjects. The duration of weaning was longer in subjects with reduced hypercapnic drive response.

Hypoxic hepatitis may be induced by hemodynamic instability or arterial hypoxemia in critically ill patients. We investigated the incidence, etiology, association with systemic ischemic injury and risk factors for mortality in this population. Retrospective analysis of patients with hypoxic hepatitis admitted to a multidisciplinary intensive care unit (ICU) of a university hospital. Hypoxic hepatitis was defined as the existence of a compatible clinical setting (cardiocirculatory failure or arterial hypoxemia) and aminotransferase levels higher than 1000 IU/L. During the 8-year study period, 182 out of the 7674 patients admitted presented hypoxic hepatitis (2.4%). The most common cause was septic shock. The rate of in-hospital mortality in hypoxic hepatitis was 61.5% (112 patients), and was higher in patients with septic shock (83.3%) and cardiac arrest (77.7%). Ischemic pancreatitis (25.6%), rhabdomyolysis (41.2%) and renal failure (67.2%) were common in these patients. Risk factors of mortality were prolonged INR (p = 0.005), need for renal replacement therapy (p = 0.001) and septic shock (p = 0.005). Hypoxic hepatitis was not a rare condition, and was frequently accompanied by multiorgan injury, with high mortality. Risk factors for increased mortality were prolonged INR, need for renal replacement therapy, and septic shock.

Traumatic brain injury (TBI) is commonly associated with disturbances of the hypothalamic–pituitary–adrenal axis secretion. Cerebral microdialysis techniques have been recently applied to measure brain interstitial cortisol levels. We evaluated for the first time the circadian rhythm of cortisol secretion at 08:00, 16:00, and 24:00 h in the acute phase of TBI by determination of total serum and brain interstitial cortisol levels (microdialysis samples) in 10 patients with TBI. Non-parametric Friedman’s two way analysis of variance test was used. Mean age was 29.8 ± 13.6 years. Median Glasgow Coma Scale score after resuscitation was 5 (range 3–10). No differences were found in total serum (P = 0.26) and brain interstitial cortisol (P = 0.77) in the whole sample. Intraindividual analysis showed that circadian variability was lost in all patients, both in serum and brain interstitial cortisol samples in the acute phase after TBI. In our series, circadian variability of cortisol evaluated by serum and cerebral microdialysis samples seems to be lost in TBI patients.

Background: There are reports with conflicting results on the expression of toll-like receptors (TLRs) in trauma patients. In addition, these studies analyzed TLR expression only at patients' hospital admission but not later when complications usually arise. Objectives: To analyze the surface expression of TLR2 and TLR4 on circulating monocytes from trauma patients during the hospitalization period and to correlate this with cytokine production after stimulation with TLR2 and TLR4 agonists. The phagocytic capacity of monocytes was analyzed at the same time points of TLR expression analysis; to correlate these molecular findings with the presence or absence of infections. Methods: Prospective and observational study from June 2005 to June 2007. In all analysis, a control group composed of healthy subjects was included. Results: We studied 70 trauma patients admitted to the intensive care unit (ICU) of a tertiary hospital, and 30 healthy volunteers. Blood samples were collected at hospital admission, on day 7 and 14. Forty-four patients (63%) developed at least one episode of infection. Monocytes from trauma patients expressed higher levels of TLR2 and TLR4 than monocytes from control subjects at all time points. Expression of TLR2 and TLR4 in monocytes from those patients who developed any infection was significantly lower than in those patients without infection but still significantly higher than in control subjects. Cellular responses to TLR4 agonist were impaired. Monocytes from traumatic patients phagocytosized less efficiently than monocytes from control subjects. Conclusions: These results indicate that trauma patients present a dysregulation of the innate immune system that persists during the first 14 days after hospital admission.

Objetivo El tratamiento con corticoides a dosis bajas (LDST) en los pacientes con shock septico tratados con soporte vasoactivo se ha asociado a una disminucion del tiempo de shock. Los pacientes con cortisol basal disminuido o con respuesta anormal a la estimulacion suprarrenal deberian tener un mayor beneficio con los LDST, por lo que hemos estudiado la respuesta hemodinamica precoz en pacientes con shock septico tratados o no con LDST. Diseno Estudio retrospectivo. Ambito Unidad de cuidados intensivos (UCI) en un hospital universitario de tercer nivel. Pacientes Estudiamos a 96 pacientes ingresado en la UCI, distribuidos en dos grupos de 48 pacientes segun hubieran recibido corticoids (grupo A) o no (grupo B), apareados segun los valores de cortisol basal y los requerimientos de noradrenalina. Intervenciones A todos los pacientes, se realizo un test de estimulacion suprarrenal con 250 μg de corticotrofina en las primeras 72 h del inicio del shock. Variables principales de interes Cortisol basal, incremento de cortisol, cortisol maximo, reduccion de la dosis de noradrenalina, duracion del shock. Resultados Ambos grupos fueron comparables. Las cifras de cortisol basal antes del test de estimulacion suprarrenal y el cortisol maximo fueron similares en ambos grupos. No hubo diferencias significativas entre ambos grupos en la dosis de noradrenalina antes y a las 24 h tras la estimulacion suprarrenal. La reduccion en la dosis de noradrenalina a las 24 h no se correlaciono con las cifras de cortisol basal ni con la respuesta a la estimulacion suprarrenal. Conclusiones El tratamiento con LDST no se asocio a una mejoria hemodinamica a las 24 h, independientemente de las cifras de cortisol basal y de la respuesta a la estimulacion suprarrenal.

Endocrine disturbances are common after traumatic brain injury (TBI). Hypothalamic-pituitary-adrenal (HPA) axis response in TBI patients may be related with hemodynamic status. However, its relationship with outcome is unclear. Our objective was to evaluate HPA axis response in the acute phase after TBI in patients with or without extracerebral trauma (ECT), and to investigate the impact of systemic injury and the mechanisms underlying HPA response.We prospectively studied 165 patients with moderate to severe TBI. Between 24 and 48 h after TBI, blood samples were taken for plasma adrenocorticotrophin hormone (ACTH) and baseline cortisol measurements. Afterwards, a short corticotrophin hormone test (250 mug Synacthen) was performed and samples were obtained at 30 and 60 min. We compared HPA response in TBI patients presenting with and without ECT and investigate potential mechanisms underlying this response.One hundred and eight patients presented with isolated TBI, whereas 57 patients presented associated ECT. Both groups were comparable. Overall, 23.6% of patients fulfilled adrenal insufficiency (AI) criteria. Patients with plasma ACTH9 pg/ml and patients presenting with hemorrhagic shock were more likely to present adrenal impairment. Variables associated with mortality were Injury Severity Score, Glasgow Coma Scale, Traumatic Coma Data Bank classification different than type II, need of second level measures to control intracranial pressure and plasma ACTH9 pg/ml.Patients with TBI presenting with or without associated ECT present similar acute HPA response. AI is present in 23.6% of patients. Risk is increased in patients with low plasma ACTH levels and in patients with hemorrhagic shock. Both primary and secondary mechanisms of HPA failure were found. However, AI did not affect outcome.

Objective We evaluated the expression of Toll-like receptors 2 and 4 (TLR-2 and TLR-4) in circulating monocytes from peripheral blood of critical care patients treated with and without glutamine. Because no research has been published to date on the effect of glutamine on TLR receptors in critical patients, it was determined in an initial sample of 30 patients. Methods This was a prospective, randomized, single-blind study with 15 patients assigned to receive parenteral nutrition with a daily glutamine supplement of 0.35 g/kg. The control group received isocaloric-isonitrogenous parenteral nutrition. Blood samples were extracted before beginning the treatment and at 5 and 14 d. Expressions of CD14, TLR-2, and TLR-4 were determined by flow cytometry. Levels of TLRs were expressed as mean fluorescence intensity (mfi). Results Basal characteristics were similar in both groups. The expressions of TLR-2 in the treatment group with glutamine were 4.67 ± 3.82 mfi before treatment, 3.91 ± 2.04 mfi at 5 d, and 4.28 ± 2.47 mfi at 14 d. The expressions of TLR-2 in the control group were 5.49 ± 3.20 mfi before treatment, 4.48 ± 2.15 mfi at 5 d, and 4.36 ± 2.36 mfi at 14 d. The expressions of TLR-4 in the treatment group were 1.65 ± 1.89 mfi before treatment, 1.23 ± 1.10 mfi at 5 d, and 1.77 ± 1.97 at 14 d. The expressions of TLR-4 in the control group were 1.51 ± 1.76 mfi before treatment, 1.36 ± 0.99 mfi at 5 d, and 1.26 ± 0.59 mfi at 14 d. Infections were detected in 11 patients who received glutamine and 13 control patients (P = 0.51). Conclusion In critical care patients, parenteral nutrition supplemented with glutamine does not increase the expression of TLR-2 or TLR-4 in peripheral blood monocytes.

"tight calorie control" concept arose to avoid over- and under-feeding of patients.to describe and validate a simplified predictive equation of total energy expenditure (TEE) in mechanically ventilated critically ill patients.this was a secondary analysis of measurements of TEE by indirect calorimetry in critically ill patients. Patients were allocated in a 2:1 form by a computer package to develop the new predictive equation TEE (prediction cohort) and the validation cohort. Indirect calorimetry was performed with three different calorimeters: the Douglas-bag, a metabolic computer and the CalorimetR. We developed a new TEE predictive equation using measured TEE (in kcal/kg/d) as dependent variable and as independent variables different factors known to influence energy expenditure: age, gender, body mass index (BMI) and type of injury.prediction cohort: 179 patients. Validation cohort: 91 patients. The equation was: TEEPE (kcal/Kg/d) = 33 - (3 x A) - (3 x BMI) - (1 x G). Where: A (age in years): ≤ 50 = 0;50 = 1. BMI (Kg/m2): 18.5 - 24.9 = 0; 25 - 29.9 = 1; 30 - 34.9 = 2; 35 - 39.9 = 3. G (gender): male = 0; female = 1. The bias (95% CI) was -0.1 (-1.0 - 0.7) kcal/kg/d and the limits of agreement (} 2SD) were -8.0 to 7.8 kcal/kg/d. Predicted TEE was accurate (within 85% to 115%) in 73.6% of patients.the new predictive equation was acceptable to predict TEE in clinical practice for most mechanically ventilated critically ill patients.Introducción: el concepto de “control calorico estricto” surgio para evitar la excesiva y la deficiente nutricion de los pacientes. Objetivo: describir y validar una ecuacion simplificada para el calculo del gasto energetico total (GET) en pacientes criticos con ventilacion mecanica. Métodos: analisis secundario de las mediciones de GET por calorimetria indirecta en pacientes criticos. Los pacientes fueron asignados de forma 2:1 por un paquete estadistico; el primer grupo se empleo para desarrollar la nueva ecuacion predictiva del GET (grupo predictivo) y el segundo para validarla (grupo validacion). La calorimetria indirecta se realizo con tres calorimetros diferentes: la bolsa de Douglas, un computador metabolico y el equipo CalorimetR. Hemos desarrollado la nueva ecuacion predictiva del GET utilizando el GET medido (en kcal/kg/d), como variable dependiente, y como variables independientes los diferentes factores que influyen en el gasto energetico: edad, genero, indice de masa corporal (IMC) y tipo de lesion. Resultados: el grupo de prediccion incluyo 179 pacientes y el de validacion 91 pacientes. La ecuacion predictiva fue: GETEP = 33 - (3 x E) - (3 x IMC) - (1 x G). Donde: E (edad en anos): ≤ 50 = 0;50 = 1. IMC (kg / m2): 18,5- 24,9 = 0; 25-29,9 = 1; 30-34,9 = 2; 35-39,9 = 3. G (genero): hombre = 0; mujer = 1. El sesgo (IC del 95%) entre el GET medido y el predicho fue de -0,1 (-1,0 a 0,7) kcal/ kg/dia y los limites de acuerdo (} 2SD) fueron -8,0 a 7,8 kcal/kg/d. El GET por la ecuacion predictiva fue preciso (entre el 85% y el 115%) en el 73,6% de los pacientes. Conclusiones: La nueva ecuacion predictiva fue aceptable para predecir el GET de la mayoria de pacientes criticos con ventilacion mecanica en la practica clinica.

Goals To evaluate the prevalence of lower gastrointestinal tract paralysis and to compare the success to achieve defecation between treatment and prophylaxis strategies. Background Laxatives use is commonly the first-level measure to achieve defecation in critically ill patients with lower gastrointestinal tract paralysis. Studies comparing prophylaxis versus treatment of lower gastrointestinal tract paralysis have not been performed yet. Study We designed 3 sequential phases of 4 months each: observational phase, treatment phase, and prophylaxis phase. First-level measure was intermittent polyethylene glycol (PEG) 4000 by nasogastric tube. Second-level measures were enema, neostigmine, and continuous PEG. Primary endpoints were the prevalence of constipation for the observational phase and the number of patients that failed to achieve defecation with first-level measures for the treatment and prophylaxis phases. Results Paralysis of lower gastrointestinal tract in the observational phase was found in 57 of 63 patients (90.5%). Failure to achieve defecation with the first-level measure occurred in 16 of 64 patients (25%) in the treatment phase and in 6 of 70 patients (8.6%) in the prophylaxis phase (P=0.01). Eighteen measures of second level were applied in the treatment phase and 6 in the prophylaxis phase. Conclusions Paralysis of the lower gastrointestinal tract in mechanically ventilated ICU patients is common. PEG given as prophylaxis on the first day after mechanical ventilation is associated with faster resolution of paralysis of gastrointestinal tract than PEG given as a treatment on day 4.

BACKGROUND: Hyperoxia-induced hypercapnia in subjects with COPD is mainly explained by alterations in the ventilation/perfusion ratio. However, it is unclear why respiratory drive does not prevent CO2 retention. Some authors have highlighted the importance of respiratory drive in CO2 increases during hyperoxia. The aim of the study was to examine the effects of hyperoxia on respiratory drive in subjects with COPD. METHODS: Fourteen intubated, ready-to-wean subjects with COPD were studied during normoxia and hyperoxia. A CO2 response test was then performed with the rebreathing method to measure the hypercapnic drive response, defined as the ratio of change in airway-occlusion pressure 0.1 s after the start of inspiratory flow (ΔP0.1) to change in PaCO2 (ΔPaCO2), and the hypercapnic ventilatory response, defined as the ratio of change in minute volume (ΔVE) to ΔPaCO2. RESULTS: Hyperoxia produced a significant increase in PaCO2 (55 ± 9 vs 58 ± 10 mm Hg, P = .02) and a decrease in pH (7.41 ± 0.05 vs 7.38 ± 0.05, P = .01) compared with normoxia, with a non-significant decrease in VE (9.9 ± 2.9 vs 9.1 ± 2.3 L/min, P = .16) and no changes in P0.1 (2.85 ± 1.40 vs 2.82 ± 1.16 cm H2O, P = .97) The correlation between hyperoxia-induced changes in VE and PaCO2 was r2 = 0.38 (P = .02). Median ΔP0.1/ΔPaCO2 and ΔVE/ΔPaCO2 did not show significant differences between normoxia and hyperoxia: 0.22 (0.12–0.49) cm H2O/mm Hg versus 0.25 (0.14–0.34) cm H2O/mm Hg (P = .30) and 0.37 (0.12–0.54) L/min/mm Hg versus 0.35 (0.12–0.96) L/min/mm Hg (P = .20), respectively. CONCLUSIONS: In ready-to-wean subjects with COPD exacerbations, hyperoxia is followed by an increase in PaCO2, but it does not significantly modify the respiratory drive or the ventilatory response to hypercapnia.

The metabolic rate of patients suffering severe head trauma (HT) is not well defined, and large variations of resting energy expenditure (REE) have been reported, suggesting an important nonuniformity of REE distribution in HT patients. The purpose of this clinical study was to assess the metabolic rate in mechanically ventilated patients suffering from severe isolated HT, or HT associated with other injuries, in the absence of gross motor activity.Eighty HT patients undergoing mechanical ventilation were studied between 48 and 72 hours after injury. Three groups of patients were studied in the following clinical settings: (group A) isolated HT, not receiving morphine (n = 34); (group B) isolated HT, receiving an intravenous perfusion of morphine (n = 26) to control gross motor activity; and (group C) HT associated with other serious injuries, receiving intravenous morphine (n = 20) to induce sedation and analgesia. REE was measured with the open-Douglas-bag method.No significant differences among the three groups were found in the metabolic rate expressed as the percentage of measured REE from predicted REE and REE expressed in terms of body weight. The mean percent measured REE was 123 +/- 16, and REE expressed in terms of body weight was 30 +/- 5 kcal/kg per day. Severe hypermetabolism was diagnosed if mean percent measured REE was greater than 130 and was present in 25 of 80 (31%) patients.Severe HT treated with or without morphine was characterized by a moderate state of hypermetabolism after the first days of trauma, but an important proportion of HT patients showed considerably elevated metabolic rates.

The CO2 response test measures the hypercapnic drive response (which is defined as the ratio of the change in airway-occlusion pressure 0.1 s after the start of inspiratory flow [ΔP(0.1)] to the change in P(aCO2) [ΔP(aCO2)]), and the hypercapnic ventilatory response (which is defined as the ratio of the change in minute volume to ΔP(aCO2)).In mechanically ventilated patients ready for a spontaneous breathing trial, to investigate the relationship between CO2 response and the duration of weaning.We conducted the CO2 response test and measured maximum inspiratory pressure (P(Imax)) and maximum expiratory pressure (P(Emax)) in 102 non-consecutive ventilated patients. We categorized the patients as either prolonged weaning (weaning duration7 d) or non-prolonged weaning (≤ 7 d).Twenty-seven patients had prolonged weaning. Between the prolonged and non-prolonged weaning groups we found differences in hypercapnic drive response (0.22 ± 0.16 cm H2O/mm Hg vs 0.47 ± 0.22 cm H2O/mm Hg, respectively, P.001) and hypercapnic ventilatory response (0.25 ± 0.23 L/min/mm Hg vs 0.53 ± 0.33 L/min/mm Hg, respectively, P.001). The optimal cutoff points to differentiate between prolonged and non-prolonged weaning were 0.19 cm H2O/mm Hg for hypercapnic drive response, and 0.15 L/min/mm Hg for hypercapnic ventilatory response. Assessed with the Cox proportional hazards model, both hypercapnic drive response and hypercapnic ventilatory response were independent variables associated with the duration of weaning. The hazard ratio of weaning success was 16.7 times higher if hypercapnic drive response was0.19 cm H2O/mm Hg, and 6.3 times higher if hypercapnic ventilatory response was0.15 L/min/mm Hg. Other variables (P(0.1), P(Imax), and P(Emax)) were not associated with the duration of the weaning.Decreased CO2 response, as measured by hypercapnic drive response and hypercapnic ventilatory response, are associated with prolonged weaning.

To demonstrate that blind insertion of the protected telescoping catheter (PTC-NB) through the orotracheal tube can provide reliable pulmonary samples for the diagnosis of nosocomial pneumonia (NP) in ventilated patients.We performed a random comparison between the protected telescoping catheter introduced through a bronchofiberscope (PTC-B) and the PTC-NB to diagnose NP.A general intensive care unit of a University Hospital.40 consecutive patients on mechanical ventilation and with suspicion of NP. The diagnosis of NP was suspected by clinical and chest X-ray findings.NP was confirmed microbiologically in 26 (65%) patients and maintained in 8 patients by clinical and radiological criteria. PTC-NB confirmed the microbiological diagnosis of PN in 21 (80%) patients. The use of antibiotics prior taking respiratory samples reduced the sensitivity of PTC-NB and PTC-B from 100-74% and from 94-70% (p = 0.001). Both techniques agreed in 24 of 33 (73%) patients but such agreement was better when PN was on the right lung. Two patients developed a self-limiting hemoptysis after the PTC-B procedure.PTC-NB is as sensitive as specific as PTC-B for diagnosing PN in mechanically ventilated patients, being a much easier technique to use.

In obesity-hypoventilation-syndrome patients mechanically ventilated for hypercapnic respiratory failure we investigated the relationship between CO₂ response, body mass index, and plasma bicarbonate concentration, and the effect of acetazolamide on bicarbonate concentration and CO₂ response.CO₂ response tests and arterial blood gas analysis were performed in 25 patients ready for a spontaneous breathing test, and repeated in a subgroup of 8 patients after acetazolamide treatment. CO₂ response test was measured as (1) hypercapnic drive response (the ratio of the change in airway occlusion pressure 0.1 s after the start of inspiratory flow to the change in P(aCO₂)), and (2) hypercapnic ventilatory response (the ratio of the change in minute volume to the change in P(aCO₂)).We did not find a significant relationship between CO₂ response and body mass index. Patients with higher bicarbonate concentration had a more blunted CO₂ response. Grouping the patients according to the first, second, and third tertiles of the bicarbonate concentration, the hypercapnic drive response was 0.32 ± 0.17 cm H₂O/mm Hg, 0.22 ± 0.15 cm H₂O/mm Hg, and 0.10 ± 0.06 cm H₂O/mm Hg, respectively (P = .01), and hypercapnic ventilatory response was 0.46 ± 0.23 L/min/mm Hg, 0.48 ± 0.36 L/min/mm Hg, and 0.22 ± 0.16 L/min/mm Hg, respectively (P = .04). After acetazolamide treatment, bicarbonate concentration was reduced by 8.4 ± 3.0 mmol/L (P = .01), and CO₂ response was shifted to the left, with an increase in hypercapnic drive response, by 0.14 ± 0.16 cm H₂O/mm Hg (P = .02), and hypercapnic ventilatory response, by 0.11 ± 0.22 L/min/mm Hg (P = .33).Patients with obesity-hypoventilation syndrome and higher bicarbonate concentrations had a more blunted CO₂ response. Body mass index was not related to CO₂ response. Acetazolamide decreased bicarbonate concentration and increased CO₂ response.

The incidence of gastroesophageal reflux (GER) in critically ill patients as well as the effect of a nasogastric tube (NGT) and body position as risk factors for GER were determined. Seventy patients with orotracheal intubation receiving enteral nutrition through a NGT for more than 48 hours were prospectively studied with two randomly assigned body positions: supine or semirecumbent. Detection of GER was achieved by scintigraphy after labeling gastric contents with 500 microCi of technetium-99m sulfur colloid administered through the NGT. In 50 patients scintigraphy was performed after subjects had remained in the randomized position for 2 hours with the NGT pinched. Twenty additional patients were studied after the NGT had been removed. In 50 patients with NGT, GER was present in 74% (37 of 50) and was higher in the supine position (81%, 21 of 26) than in the semirecumbent position (67%, 16 of 24), but this difference was not statistically significant (p = .26). In 20 patients without NGT, the incidence of GER was 35% (7 of 20) and it was also higher in the supine (50%, 6 of 12) than in the semirecumbent position (12%, 1 of 8, p = .16). There was a statistically significant difference between GER in patients with and without NGT (74% vs 35%, p = .0002). These data show that there is a high incidence of GER in patients with orotracheal intubation and NGT. The presence of a NGT is a risk factor for GER. Semirecumbency does not prevent GER, but there is less incidence than in the supine position.

Aim: The specific incidence of ischemic hepatitis in septic shock patients remains unknown. The aim of this study was to evaluate the incidence of ischemic hepatitis in septic shock and its relationship with mortality. Methods: We retrospectively studied 181 patients with septic shock admitted to the intensive care unit (ICU). We defined ischemic hepatitis as having a value of serum aminotransferases equal to or higher than 1000 IU/L. We recorded the age, sex, comorbidity, site of infection, the Sequential Organ Failure Assessment (SOFA) score on admission to the ICU, maximum SOFA score and inadequate antibiotic therapy. Results: Twenty-five (13.8%) patients developed ischemic hepatitis. In-hospital mortality was 57% (103 patients). In the ischemic hepatitis group, mortality increased up to 84.0% (21 patients) compared with 52.6% (82 patients) in patients without ischemic hepatitis (control group) (odds ratio [OR]: 4.7; 95% confidence interval [CI]: 1.6–14.4; P = 0.003). The development of ischemic hepatitis, age, maximum SOFA score and inadequate antibiotic therapy were independently associated with an increased risk of death. The odds of death increased by 247% in ischemic hepatitis (OR: 3.47; 95% CI: 1.02–11.8; P = 0.047). Conclusion: Ischemic hepatitis is a common complication in septic shock patients, associated with a high mortality.

BACKGROUND Hypothalamic pituitary adrenal response has been recently evaluated in patients with traumatic brain injury (TBI) with different results. Our objective was to study this response and its relationship with outcome in the early stage after TBI. METHODS We conducted a prospective observational clinical study in the intensive care unit of a tertiary level university hospital. The study included 50 consecutive patients who suffered isolated TBI. Intracranial pressure (ICP) was measured by an intraparenchymal probe. All patients were sedated and mechanically ventilated. Second-level measures were provided as per protocol, when needed. We measured plasma adrenocorticotropin hormone (ACTH) levels, as well as baseline and stimulated serum cortisol after a high-dose corticotrophin stimulation test, within 2 days after TBI for all patients. RESULTS Mean age was 36 +/- 18 (range 16-77) years. Forty-four (88%) were male. Median Glasgow Coma Scale score was 7. Mean ACTH was 15.4 +/- 19.8 pg/mL. Mean baseline cortisol was 14.8 +/- 9.0 microg/dL and mean stimulated cortisol was 27.1 +/- 7.3 microg/dL and 30.5 +/- 7.2 microg/dL at 30 and 60 minutes, respectively. Baseline and stimulated cortisol were not correlated with mortality. Logistic regression analysis revealed that, either plasma ACTH levels

Resting energy expenditure (REE) of critically ill patients is usually calculated according to basal energy expenditure obtained from Harris-Benedict equations traditionally corrected by different stress factors, resulting in a variable accuracy for the individual patient. The objective of this study was to investigate whether or not the type of lesion affects the metabolism level of critically ill patients treated with mechanical ventilation. We performed a retrospective study measuring the REE of critically ill patients with 3 different types of lesions (trauma, medical, surgical) who were treated with mechanical ventilation and sedation. Each lesion group of patients was matched with another group, differing in the type of lesion, according to gender, age, and weight.Eighty-seven from a database of 175 critically ill patients undergoing indirect calorimetry were necessary for matching. Twenty matched pairs of patients for each of the following different type of lesion were obtained: medical vs surgical, medical vs trauma, and surgical vs trauma.The mean REE difference was 52 kcal/d (95% confidence interval [CI] of -136 -241 kcal/d) for the medical vs surgical group, 5 kcal/d (95% CI -236 -247 kcal/d) for the medical vs trauma group and 43 kcal/d (95% CI of -132-219 kcal/d) for the surgical vs trauma group. No statistically significant differences between groups were found in the measured REE. We did not find statistically significant differences in the measured REE of patients with and without infection.Critically ill patients with different types of lesion treated with mechanical ventilation have similar measured REE.

Purpose Several studies showed that low-dose steroid therapy (LDST) in patients with septic shock leads to a significantly shorter duration of shock and a decreased mortality. However, these results have been criticized. Our purpose was to evaluate the effects of LDST on time to shock reversal and mortality in septic shock. Materials and Methods We retrospectively studied 203 patients with septic shock admitted to the intensive care unit of our tertiary hospital. A short corticotropin test was performed in all patients within 72 hours of septic shock onset. We performed a propensity score analysis through a logistic regression model with baseline relevant characteristics, and evaluated the influence of LDST on time to shock reversal and inhospital mortality. Results One hundred twenty-four patients were treated with LDST (steroid group) and 79 without LDST (control group). Patients treated with steroids presented higher Simplified Acute Physiology Score II and maximum Sepsis-Related Organ Failure Assessment scores. Both groups presented similar baseline and stimulated cortisol values. The hazard ratio of remaining on shock adjusted by severity of illness, inadequate antibiotic, and propensity score was 1.15 (95% confidence interval 0.71-1.86) for patients treated with steroids. Inhospital mortality was 62% in the steroid group and 52% in the control group (P = .84). Logistic regression analysis with propensity score neither showed differences between steroid and control group in the inhospital mortality. Predictors of inhospital mortality were age, maximum Sepsis-Related Organ Failure Assessment score, and inadequate antibiotics. Conclusion In our study, treatment with low-dose steroid therapy was not associated to a reduction in time to shock reversal or mortality.

There are no gold standards on the duration and frequency of the measurement of indirect calorimetry, a fact of importance in daily clinical practice. An assessment of is made of the degree of concordance between energy expenditure at rest (EER) measured over a short interval (10 minutes) versus another prolonged measurement (1 hour).Sixty critically-ill patients, under sedation and analgesia with connection to mechanical ventilation, were studied.EER values were determined by means of a metabolic computer analysis (Engström Eliza) at rest. The reproducibility and the degree of concordance were assessed in the measurements made with both periods.The mean values of the EER determinations at 10 and 60 minutes were 1,818 +/- 319 kilocalories/day and 1,815 +/- 318 Kcal/day. The limits of the concordance between both times were -101 and +117 kilocalories/day and the correlation was significant (r = 0.98, p0.0001).In critically-ill patients under sedation and with mechanical ventilation, the measurement of EER may be taken over short periods of time (10 minutes) providing that baseline examination conditions are met, thus giving greater availability of the resources used to study indirect calorimetry.

To evaluate the ability of the new, built-in occlusion pressure (P0.1) measurement to predict extubation failure. Prospective observational multicentre study in the ICU of five general hospitals. Hundred thirty patients on mechanical ventilation longer than 48 h when considered ready for weaning. Patients underwent a 30-min spontaneous breathing trial with simultaneous monitoring of occlusion pressure (P0.1) and breathing pattern (f/Vt). Sixteen patients (12%) failed the weaning trial and full ventilatory support was resumed, while 114 tolerated the trial and were extubated. Twenty-one (18%) required reintubation within 48 h. The area under the ROC curve for diagnosing extubation failure was 0.53 for f/Vt, 0.59 for P0.1 and 0.61 for P0.1*f/Vt (p=NS). Accordingly, P0.1*f/Vt more than 100 detected extubation failure with a sensitivity of 0.89, specificity of 0.35, positive predictive value of 0.21 and negative predictive value of 0.94. During a first trial of spontaneous breathing on pressure support ventilation (PSV), bedside P0.1 and P0.1*f/Vt are of little help, if any, for predicting extubation failure.

Background Use of a large-bore nasogastric tube (NGT) and patient position are considered key factors in promoting gastroesophageal reflux (GER) and pulmonary aspiration in critically ill patients. The objective of this study was to determine the incidence of GER and pulmonary aspiration of gastric contents in mechanically ventilated (MV) patients using small-bore NGTs. Methods We studied 30 patients on mechanical ventilation for acute respiratory failure who tolerated enteral nutrition through a small-bore NGT. Patients were randomly assigned to a group with (n = 16) or without (n = 14) a small-bore NGT and were maintained in a semirecumbent position during the study. GER and aspiration of gastric contents were assessed by a radioisotopic technique. Scans were done 24 hours after technetium-99m administration (n = 30). In 9 patients a dynamic scintigraphy was performed immediately after colloid administration, and samples of blood and tracheal and oropharyngeal secretions were obtained basally, 30 minutes, and 24 hours after technetium administration and analyzed for radioactivity using a gamma counter. Results Both groups were similar in age, underlying diagnosis, number of days of mechanical ventilation at the day of study, and mortality. There were no GER reaching the oropharynx and aspiration of gastric contents in both groups. Conclusions GER and aspiration of gastric contents were not detected in MV patients using small-bore NGTs and may be a simple measure to prevent ventilator-associated pneumonia.

Introduction: The use of glutamine as a dietary supplement is associated with a reduced risk of infection. We hypothesized that the underlying mechanism could be an increase in the expression and/or functionality of Toll-like receptors (TLR), key receptors sensing infections. The objective of this study was to evaluate whether glutamine supplementation alters the expression and functionality of TLR2 and TLR4 in circulating monocytes of trauma patients admitted to the intensive care unit (ICU). Methods: We designed a prospective, randomized and single-blind study. Twenty-three patients received parenteral nutrition (TPN) with a daily glutamine supplement of 0.35 g/kg. The control group (20 patients) received an isocaloric-isonitrogenated TPN. Blood samples were extracted before treatment, at 6 and 14 days. Expression of TLR2 and TLR4 was determined by flow cytometry. Monocytes were stimulated with TLR specific agonists and cytokines were measured in cell culture supernatants. Phagocytic ability of monocytes was also determined. Results: Basal characteristics were similar in both groups. Monocytes from patients treated with glutamine expressed the same TLR2 levels as controls before treatment (4.9 +/- 3.5 rmfi vs. 4.3 +/- 1.9 rmfi, respectively; P = 0.9), at Day 6 (3.8 +/- 2.3 rmfi vs. 4.0 +/- 1.7 rmfi, respectively; P = 0.7) and at Day 14 (4.1 +/- 2.1 rfim vs. 4.6 +/- 1.9 rmfi, respectively; P = 0.08). TLR4 levels were not significantly different between the groups before treatment: (1.1 +/- 1 rmfi vs 0.9 +/- 0.1 rmfi respectively; P = 0.9), at Day 6 (1.1 +/- 1 rmfi vs. 0.7 +/- 0.4 rmfi respectively; P = 0.1) and at Day 14 (1.4 +/- 1.9 rmfi vs. 1.0 +/- 0.6 rmfi respectively; P = 0.8). No differences in cell responses to TLR agonists were found between groups. TLR functionality studied by phagocytosis did not vary between groups. Conclusions: In trauma patients in the intensive care unit, TPN supplemented with glutamine does not improve the expression or the functionality of TLRs in peripheral blood monocytes., The ESPEN Peter Furst Research Prize was funded by Nestle Nutrition Institute and by Fresenius Kabi.; This work was funded by a grant from the ESPEN Peter Furst Research Prize awarded to JPB. All other authors declare that they have no competing interests.

The purpose of this study was to investigate the effect of ascites on the energy metabolism of patients with liver cirrhosis. The resting energy expenditure was determined in 10 patients with liver cirrhosis and ascites of moderate or large volume. The resting energy expenditure measurement was performed using indirect calorimetry and the resting energy expenditure predictive value was calculated with the Harris-Benedict equation, both before and after removal of ascitic fluid by paracentesis. Metabolic stress factors were absent in all cases. After an interval of 11.2 +/- 7.7 days between measurements, a weight loss of 16.6 +/- 10.3 kg was observed with paracentesis. The resting energy expenditure measured by indirect calorimetry showed a statistically significant decrease from 1682 +/- 291 to 1523 +/- 240 kcal/day (P less than 0.005) after removal of ascites. The repeatability of our indirect calorimetry method only allowed for the analysis of the results in 4 of 10 patients in whom ascites removal produced a consistent decrease in resting energy expenditure. There were no statistically significant differences between the measurements obtained by indirect calorimetry and those provided by the Harris-Benedict equation, but the latter had a moderate reliability in predicting the real resting energy expenditure of every patient. Our results suggest that, far from being an inert volume, ascites may be associated, at least in some patients, with an increased resting energy expenditure and therefore accelerate the appearance of protein energy malnutrition with corresponding complications.

The accuracy of pulse oximetry for the prediction of oxygen saturation of arterial blood in patients with shock has been hardly studied. This study was undertaken to determine if O2 arterial saturation estimated by the Biox 3700 pulse oximeter (SpO2) with an ear probe could reliably substitute for the measurements of O2 saturation (HbO2) with an IL-282 Co-Oximeter in samples of arterial blood obtained from 24 caucasian patients. All patients were mechanically ventilated and needed vasoactive drugs (dopamine and/or dobutamine). Of 24 patients 13 had shock: cardiogenic (n = 6) and septic (n = 7). The mean difference between HbO2 and SpO2 was 2.49% +/- 4.24, with a 95% confidence interval of 0.7% to 4.3% (p = 0.009). There were clinically important differences between both methods since in 9 of 24 patients (37%) SpO2 values were at least 4% lower or greater than HbO2. This disagreement was also apparent in patients with (6/13, 46%) or without shock (3/11, 27%). To conclude, pulse oximetry is not always a sufficiently reliable method to predict HbO2 in patients with or without shock treated with vasoactive drugs.

Introduction Experimental research has demonstrated that the level of neuroprotection conferred by the various barbiturates is not equal. Until now no controlled studies have been conducted to compare their effectiveness, even though the Brain Trauma Foundation Guidelines recommend that such studies be undertaken. The objectives of the present study were to assess the effectiveness of pentobarbital and thiopental in terms of controlling refractory intracranial hypertension in patients with severe traumatic brain injury, and to evaluate the adverse effects of treatment. Methods This was a prospective, randomized, cohort study comparing two treatments: pentobarbital and thiopental. Patients who had suffered a severe traumatic brain injury (Glasgow Coma Scale score after resuscitation 20 mmHg) first-tier measures, in accordance with the Brain Trauma Foundation Guidelines. Results A total of 44 patients (22 in each group) were included over a 5-year period. There were no statistically significant differences in ' baseline characteristics, except for admission computed cranial tomography characteristics, using the Traumatic Coma Data Bank classification. Uncontrollable intracranial pressure occurred in 11 patients (50%) in the thiopental treatment group and in 18 patients (82%) in the pentobarbital group (P = 0.03). Under logistic regression analysis -undertaken in an effort to adjust for the cranial tomography characteristics, which were unfavourable for pentobarbital -thiopental was more effective than pentobarbital in terms of controlling intracranial pressure (odds ratio = 5.1, 95% confidence interval 1.2 to 21.9; P = 0.027). There were no significant differences between the two groups with respect to the incidence of arterial hypotension or infection. Conclusions Thiopental appeared to be more effective than pentobarbital in controlling intracranial hypertension refractory to first-tier measures. These findings should be interpreted with caution because of the imbalance in cranial tomography characteristics and the different dosages employed in the two arms of the study. The incidence of adverse effects was similar in both groups. Trial Registration (Trial registration: US Clinical Trials registry NCT00622570.), This research was supported by a public grant from the Spanish government's Fondo de Investigacion Sanitaria (FIS PI020642), awarded to Dr J Perez Barcena. This public institution will not gain or lose financially from the publication of this manuscript in any way.

New equipment designed for the routine measurement of oxygen uptake (VO2) using a closed circuit method has been validated by comparing it with a standard Douglas bag method. The equipment (The Caloric Measurement Unit, CMU) has been tested in 10 critically ill patients during mechanical ventilation (MV) and in 10 spontaneously breathing healthy subjects. Determinations of VO2 and of the resting energy expenditure (REE) were measured in duplicate with the standard method and once with the CMU. Six additional patients receiving MV were studied with the CMU to evaluate the reproducibility and the effect of FIO2 = 1 vs FIO2 = 0.43 on VO2 measurements. Considering the whole group of 10 patients and 10 subjects, the mean difference of VO2 between both methods was -2 +/- 21 ml/min (95% confidence interval, -11.8 to 7.8 ml/min, p = 0.6) standard deviation. Both methods had a similar reproducibility and the mean difference of VO2 measured at the two different FIO2 with the CMU was -3.2 +/- 11 ml/min (95% confidence interval, -14.7 to 8.4 ml/min, p = 0.5). No statistically significant difference was found between derived REE values obtained from either method. These data show a good correlation between the two methods suggesting that CMU may be used in place of the standard method with the same accuracy in measurement of VO2 even at FIO2 = 1.

Wedge pulmonary angiography was done in 11 patients with acute respiratory failure, to assess the accuracy of pulmonary arterial wedge pressure (WP) as an estimation of left ventricular end-diastolic pressure (LVEDP). The pulmonary artery (PA) catheter tip was placed into a dependent position in the lungs. Although the pulmonary vein was not visualized in 7 of 11 patients, in no case was there a significant difference between WP and LVEDP. When WP is no greater than 15 mm Hg, wedge pulmonary angiography does not reflect the accuracy of WP; however, left ventricular filling pressure can be accurately estimated by WP in most of these patients.