Innate Lymphoid Cells Have Decreased HLA-DR Expression but Retain Their Responsiveness to TLR Ligands during Sepsis.

Sepsis, one of the leading causes of death in intensive care units, is caused by a dysregulated host response to infection that leads to life-threatening organ dysfunction. The proinflammatory and anti-inflammatory responses activated by the infecting microorganism become systemic, and the sustained anti-inflammatory response induces a state of immunosuppression that is characterized by decreased expression of HLA-DR on monocytes, T cell apoptosis, and reduced production of TNF-α by monocytes and macrophages in response to TLR ligands. Innate lymphoid cells (ILCs) are lymphocytes that lack Ag-specific receptors and lineage-specific markers; they express HLA-DR and are activated by cytokines and by direct recognition of microbial molecules. In this study, we evaluated if ILCs are affected by the anti-inflammatory response during sepsis. We found that the number of peripheral blood ILCs was decreased in septic patients compared with healthy volunteers; this decrease was caused by a reduction in ILC1 and ILC3 and is associated with apoptosis, because ILCs from septic patients expressed active caspase 3. ILCs from septic patients had decreased HLA-DR expression but increased expression of the activating receptors NKp46 and NKp44; they also showed a sustained expression of CD127 (IL-7R α-chain) and retained their capacity to produce TNF-α in response to TLR ligands. These results indicate that during sepsis, ILCs have decreased HLA-DR expression and die via apoptosis, similar to monocytes and T cells, respectively. However, other effector functions of ILCs (activation through NKp46 and NKp44, TNF-α production) may remain unaffected by the immunosuppressive environment prevailing in septic patients.

Healthcare-associated infections: Appropriate empirical antibiotic treatment / Infecciones asociadas a la atención de la salud: tratamiento antibiótico empírico apropiado

Background: Health-care Associated Infections (HAI) are one of the main causes of death in critically ill patients. The aim of this paper is to establish an appropriate empirical antibiotic treatment for the main HAI in an Intensive Care Unit (ICU). Methods: A retrospective, observational, descriptive and analytical study of the culture results from January, 2014 to December, 2015. The causative microorganisms were identified, as well as sensitivity and antibiotic resistance. Results: Of the three main HAI in the ICU were Ventilator Associated Pneumonia (VAP), whose most common germs were methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa; Urinary Tract Infection Associated with Urinary Catheter (IVU-CU), Escherichia coli BLEE and Pseudomonas aeruginosa were isolated in 70%, and 56% of the bloodstream infections of the germs that caused this infection were three, the most frequent being Escherichia coli, followed by Klebsiella oxytoca and methicillin-resistant Staphylococcus aureus. Conclusions: VAP was the most frequent HAI and resistant methicillin Staphylococcus aureus was the most prevalent in this type of infection. The proposed empiric antibiotic treatment was as follows: VAP (vancomycin plus amikacin plus meropenem), IVU-CU (meropenem) and STIs (vancomycin plus cefepime).

Introducción: Las infecciones asociadas a la atención de la salud (IAAS) son una de las principales causas de muerte en pacientes en estado crítico. El objetivo de este trabajo fue identificar los gérmenes más frecuentemente asociados a las IAAS en la Unidad de Cuidados Intensivos (UCI) y determinar el tratamiento antibiótico empírico apropiado. Métodos: Estudio retrospectivo, observacional, descriptivo y analítico de los cultivos de enero de 2014 a diciembre de 2015. Se identificaron los microorganismos causantes de las IAAS, la sensibilidad y la resistencia antibiótica. Resultados: Las tres principales IAAS en la UCI fueron: la neumonía asociada a ventilador (NAV), y los gérmenes más habituales fueron Staphylococcus aureus meticilino resistente, Acinetobacter baumannii y Pseudomonas aeruginosa; la infección de vías urinarias asociada a catéter urinario (IVUCU) la Escherichia coli BLEE y Pseudomonas aeruginosa fueron aisladas en el 70% y en las infecciones del torrente sanguíneo (ITS) el 56% de los gérmenes fueron Escherichia coli, Klebsiella oxytoca y Staphylococcus aureus meticilino resistente. Conclusiones: La NAV fue la IAAS más frecuente y el Staphylococcus aureus meticilino resistente fue el más prevalente en este tipo de infección. La propuesta de tratamiento antibiótico empírico es: para NAV (vancomicina más amikacina más meropenem), IVU-CU (meropenem) y las ITS (vancomicina más cefepime).

[Predictors of extubation failure in neurosurgical patients]. / Predictores de fracaso en la extubación de pacientes neuroquirúrgicos.

BACKGROUND: The information regarding the factors that affect the success of extubation in neurosurgical patients is limited; thus, it is necessary to determine the prevalence, and the associated factors, of extubation failure in neurosurgical patients. METHODS: It was performed a prospective, longitudinal, observational and comparative study in neurosurgical patients with criteria for extubation. In those who the number of endotracheal aspirations had failed 24 hours before extubation, it was analyzed the presence of cough reflex, length of stay and mechanical ventilation days. RESULTS: 70 patients were included in the study, of whom 11.4 % patients failed extubation and the associated factors were performing 6 events or more of endotracheal tube suction 24 hours prior to weaning (relative risk [RR] = 1.88, 95 % confidence interval [CI] = 1.14-3.09, p 0.01), 7 days of mechanical ventilation (RR = 1.31, 95 % CI = 1.08-1.57, p 0.005) and a length of hospital stay of 7.5 days (RR = 1.24, 95 % CI = 1.05-1.47, p 0.01). CONCLUSIONS: Performing 6 or more endotracheal tube suction events during the 24 hours before extubation is a risk factor for extubation failure in neurosurgical patients.

Introducción: la información con respecto a los factores que afectan el éxito de la extubación en pacientes neuroquirúrgicos es limitada; por lo tanto, es necesario determinar los factores que inciden en esta condición. Métodos: estudio prospectivo, longitudinal, observacional y comparativo en pacientes neuroquirúrgicos con criterios para la extubación. En aquellos que presentaron fracaso se analizó el número de aspiraciones endotraqueales en las 24 horas previas a la extubación, la presencia del reflejo de tos, los días de estancia y de ventilación mecánica. Resultados: se incluyeron 70 pacientes en el estudio, de los cuales el 11.4 % presentó fracaso de la extubación y los factores asociados fueron la realización de 6 aspiraciones de secreciones endotraqueales 24 horas previas a la extubación (con una razón de riesgo [RR] = 1.88, intervalo de confianza [IC] al 95 % = 1.14-3.09, p 0.01), 7 días de ventilación mecánica (RR = 1.31, IC 95 % = 1.08-1.57, p 0.005) y 7.5 días de estancia (RR = 1.24, IC 95 % = 1.05-1.47, p 0.01). Conclusión: hacer seis o más aspiraciones de secreciones endotraqueales durante las 24 horas previas a la extubación es un factor de riesgo para el fracaso de la extubación de pacientes neuroquirúrgicos.

Influenza A (H1N1pdm09)-Related Critical Illness and Mortality in Mexico and Canada, 2014.

OBJECTIVES: The 2009-2010 influenza A (H1N1pdm09) pandemic caused substantial morbidity and mortality among young patients; however, mortality estimates have been confounded by regional differences in eligibility criteria and inclusion of selected populations. In 2013-2014, H1N1pdm09 became North America's dominant seasonal influenza strain. Our objective was to compare the baseline characteristics, resources, and treatments with outcomes among critically ill patients with influenza A (H1N1pdm09) in Mexican and Canadian hospitals in 2014 using consistent eligibility criteria. DESIGN: Observational study and a survey of available healthcare setting resources. SETTING: Twenty-one hospitals, 13 in Mexico and eight in Canada. PATIENTS: Critically ill patients with confirmed H1N1pdm09 during 2013-2014 influenza season. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcome measures were 90-day mortality and independent predictors of mortality. Among 165 adult patients with H1N1pdm09-related critical illness between September 2013 and March 2014, mean age was 48.3 years, 64% were males, and nearly all influenza was community acquired. Patients were severely hypoxic (median PaO2-to-FIO2 ratio, 83 mm Hg), 97% received mechanical ventilation, with mean positive end-expiratory pressure of 14 cm H2O at the onset of critical illness and 26.7% received rescue oxygenation therapy with prone ventilation, extracorporeal life support, high-frequency oscillatory ventilation, or inhaled nitric oxide. At 90 days, mortality was 34.6% (13.9% in Canada vs 50.5% in Mexico, p < 0.0001). Independent predictors of mortality included lower presenting PaO2-to-FIO2 ratio (odds ratio, 0.89 per 10-point increase [95% CI, 0.80-0.99]), age (odds ratio, 1.49 per 10 yr increment [95% CI, 1.10-2.02]), and requiring critical care in Mexico (odds ratio, 7.76 [95% CI, 2.02-27.35]). ICUs in Canada generally had more beds, ventilators, healthcare personnel, and rescue oxygenation therapies. CONCLUSIONS: Influenza A (H1N1pdm09)-related critical illness still predominantly affects relatively young to middle-aged patients and is associated with severe hypoxemic respiratory failure. The local critical care system and available resources may be influential determinants of patient outcome.

[Constrictive pericarditis: the story of a constrained heart]. / Pericarditis constrictiva: historia de un corazón oprimido.

BACKGROUND: Symptoms of constrictive pericarditis may be nonspecific, misleading and may delay or lead to an incorrect diagnosis. CLINICAL CASE: We present the case of a 28-year-old male who was admitted to the hospital with progressive dyspnea, thoracic pain and a history of 25 kg of weight gain during the last 2 years. He was evaluated at another facility and his clinical presentation led to an erroneous diagnosis of primary hepatic disease (cirrhosis and portal hypertension). Physical examination showed that he was dyspneic, emaciated, had marked distention of his frontal cranial veins, diminished heart sounds, massive ascites and leg edema. Laboratory tests reported abnormal liver function tests and abdominal paracentesis chylous ascites. Electrocardiogram showed sinus rhythm with generalized low voltage and nonspecific repolarization changes. Heart size was normal on chest radiography. Doppler echocardiography reported bilateral atrial dilatation, a thickened pericardium and a short deceleration time of transmitral flow. A thickened and calcified pericardium was seen on CT scan. Pericardiectomy was performed. Spontaneous polyuria was observed during and after surgery with subsequent improvement of ascites and edema. The pericardium was found to be grossly thickened and inflamed. CONCLUSIONS: Clinician must be aware of the slow and progressive course of right ventricular failure, as well as to recognize constrictive pericarditis as a cause of chronic ascites.The hemodynamic aspects of the disease are of paramount importance for early diagnosis and opportune treatment.

[Ogilvie syndrome. Report of two cases]. / Pseudoobstrucción colónica aguda (síndrome de Ogilvie). Informe de dos casos.

Acute colonic pseudo-obstruction or "Ogilvie syndrome (OS)," is a gastrointestinal motility disorder characterized by marked dilatation of the colon in the absence of mechanical obstruction. It occurs most commonly in the postoperative state or with severe medical illness; it has been associated with a wide range of comorbidities, including trauma, pelvic surgery (orthopedic, gynecologic, urologic), metabolic disorders, central nervous system disorders, and prostaglandin abnormalities. OS may also be drug induced or idiopathic. Left untreated, it can progress to perforation, peritonitis, and death. Definitive management of OS traditionally has consisted of mechanical decompression. However, neostigmine, an acetyl-cholinesterase inhibitor, has recently emerged as a safe and effective pharmacologic alternative in the adult population. We present two cases of OS attended in the intensive care unit treated with colonoscopy and cecostomy respectively.

[Respiratory tract fluid microbiology in an intensive care unit]. / Microbiología de secreciones bronquiales en una unidad de cuidados intensivos.

OBJECTIVE: to know patterns of antimicrobial resistance of bacterial isolates from tracheal aspirates in an Intensive Care Unit and to evaluate the cases of ventilator-associated pneumonia. METHODS: antibiotic sensitivity test was done. A comparison was made between patients with nosocomial pneumonia reported by infection surveillance team against those reported by the attending physician with the infectious disease consultant. RESULTS: Pseudomonas aeruginosa was the bacteria most frequently reported with 134 isolates (26 %), 71 were multiple-drug-resistant; followed by Staphylococcus with 122 isolates (24 %), of which 88 were S. aureus with 62 of them (70 %) methicillin-resistant. Enterobacteriaceae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, as well as Acinetobacter sp. and S. maltophilia were occasionally isolated. Candida represented 17 % of the isolates. Three peaks of isolates of S. aureus and P. aeruginosa were identified during the two years of surveillance. There were differences in cases of ventilator associated pneumonia reported by the hospital based epidemiology team and the attending clinicians in collaboration with an Infectious disease consultant. CONCLUSIONS: prevalence of multiple-drug-resistant Pseudomonas aeruginosa (53 %) and methicillin resistant Staphylococcus (70 %) isolated from the airway is high in our Intensive Care Unit. Enterobacterias, Acinetobacter sp. and Stenotrophomonas maltophilia colonization are low in our Intensive Care Unit.

[Mean airway pressure during pressure-controlled ventilation with static vs. dynamic positive end-expiratory pressure]. / Presión media de la vía aérea con la aplicación de presión positiva al final de la espiración estática vs. dinámica.

BACKGROUND: Positive end-expiratory pressure increases mean airway pressure (Paw) in patients with mechanical ventilation. We undertook this study to compare mean airway pressure (Paw) generated with static PEEP (sPEEP) vs. dynamic PEEP (dPEEP) at the same level of total PEEP (tPEEP) in the same patient with pressure-controlled mechanical ventilation (PC). METHODS: We conducted a prospective clinical trial at the Intensive Care Unit of a university-affiliated hospital. Consecutive patients in PC with SaO2>90%; FiO2<50%; sPEEP of 4 cm H2O and inspiration-expiration ratio (I:E ratio) 1:2 were included in the study. After a basal period of time of 15 min, Paw was registered (phase one of the study protocol). In phase 2 with the ventilator settings constant, only the I:E ratio was switched to 2:1 to generate dPEEP, and after 15 min Paw and total PEEP (tPEEP) were registered (tPEEP=sPEEP+dPEEP). In phase 3, the I:E ratio was switched back to 1:2 substituting the dPEEP generated in the second phase of the study by sPEEP to maintain the same level of tPEEP of phase 2. After 15 min, Paw was again registered. Friedman and Wilcoxon's test were used, p value<0.05 was considered statistically significant. RESULTS: Thirty eight patients were admitted to the study protocol, tPEEP was 4, 8 and 8 cm H2O and median of the Paw 8.7, 13.8, and 11.4 cm H2O, respectively, with a p value<0.05 in the first, second and third phases of the study. CONCLUSIONS: During pressure control ventilation, mean airway pressure is affected by the level of total PEEP and its composition. Paw is higher when dynamic PEEP participates in the composition of total PEEP.

Presión media de la vía aérea con la aplicación de presión positiva al final de la espiración estática vs. dinámica / Mean airway pressure during pressure-controlled ventilation with static vs. dynamic positive end-expiratory pressure

Introducción: la presión positiva al final de la espiración (PEEP) incrementa la presión media de la vía aérea (Paw) en pacientes con ventilación mecánica. Con el objetivo de comparar la presión media de la vía aérea que se obtiene en un mismo paciente con ventilación mecánica controlada por presión al aplicar presión positiva al final de la espiración estática (PEEPe) y al aplicar presión positiva al final de la espiración dinámica (PEEPd), se realizó un estudio prospectivo, longitudinal, experimental, comparativo y de grupos relacionados. Material y métodos: se incluyeron pacientes con ventilación mecánica controlada por presión con SaO2 > 90 % y FiO2 < 50%, con PEEPe de 4 cm de H2O y relación inspiraciónespiración de 1:2. Después de 15 minutos se midió la presión media de la vía aérea (fase 1). Posteriormente se modificó la relación inspiración-espiración a 2:1 por 15 minutos, con el fin de generar PEEPd (fase 2). Una vez registrada la presión media de la vía aérea, en la fase 3 se regresó de nuevo a la relación inspiración-espiración 1:2, sustituyendo la PEEPd obtenida en la fase 2 por PEEPe para mantener la misma presión positiva al final de la espiración total (PEEPt) de la fase 2 (PEEPt = PEEPe + PEEPd). Concluidos los 15 minutos de estabilización, se registró de nuevo la presión media de la vía aérea y la PEEPt. Se utilizaron las pruebas de Friedman y Wilcoxon, considerando una p < 0.05 como estadísticamente significativa. Resultados: se estudiaron 38 pacientes. La PEEPt fue de 4, 8 y 8 cm de H2O, y las medianas de la presión media de la vía aérea fueron de 8.7, 13.8 y 11.4 cm de H2O en las fases 1, 2 y 3 respectivamente (p < 0.05). Conclusiones: en un mismo paciente con ventilación mecánica controlada por presión y con los mismos niveles de PEEPt, la presión media de la vía aérea es mayor al utilizar PEEPd que PEEPe.

BACKGROUND: Positive end-expiratory pressure increases mean airway pressure (Paw) in patients with mechanical ventilation. We undertook this study to compare mean airway pressure (Paw) generated with static PEEP (sPEEP) vs. dynamic PEEP (dPEEP) at the same level of total PEEP (tPEEP) in the same patient with pressure-controlled mechanical ventilation (PC). METHODS: We conducted a prospective clinical trial at the Intensive Care Unit of a university-affiliated hospital. Consecutive patients in PC with SaO2>90%; FiO2<50%; sPEEP of 4 cm H2O and inspiration-expiration ratio (I:E ratio) 1:2 were included in the study. After a basal period of time of 15 min, Paw was registered (phase one of the study protocol). In phase 2 with the ventilator settings constant, only the I:E ratio was switched to 2:1 to generate dPEEP, and after 15 min Paw and total PEEP (tPEEP) were registered (tPEEP=sPEEP+dPEEP). In phase 3, the I:E ratio was switched back to 1:2 substituting the dPEEP generated in the second phase of the study by sPEEP to maintain the same level of tPEEP of phase 2. After 15 min, Paw was again registered. Friedman and Wilcoxon's test were used, p value<0.05 was considered statistically significant. RESULTS: Thirty eight patients were admitted to the study protocol, tPEEP was 4, 8 and 8 cm H2O and median of the Paw 8.7, 13.8, and 11.4 cm H2O, respectively, with a p value<0.05 in the first, second and third phases of the study. CONCLUSIONS: During pressure control ventilation, mean airway pressure is affected by the level of total PEEP and its composition. Paw is higher when dynamic PEEP participates in the composition of total PEEP.

Efecto de diferentes niveles de presión positiva al final de la espiración sobre el gasto energético en reposo medido por calorimetría indirecta en pacientes con ventilación en presión control / Effects of Different Positive End Expiratory Pressure Levels on Resting Energy Expenditure Measured by Indirect Calorimeter in Patients with Pressure-Controlled Ventilation

Objetivo: determinar la variación del gasto energético en reposo (GER), consumo de oxígeno (VO2) y producción de CO2 (VCO2 por calorimetría indirecta (CI) al aplicar tres diferentes niveles de presión positiva al final de la espiración (PEEP) en pacientes con ventilación mecánica controlada por presión. Diseño: estudio prospectivo, longitudinal, experimental y comparativo. Material y método: se incluyeron nueve pacientes con ventilación mecánica controlada por presión internados en la unidad de cuidados intensivos. Se efectuó CIcon el propósito de medir el GER, VO2 y VCO2 así como el volumen minuto (VE) en tres diferentes niveles de PEEP. Para el análisis estadístico se utilizó la prueba de la t pareada y Wilcoxon se calcularon los coeficientes de variación de las variables en estudio. Resultados: se observó con el incremento de la PEEP disminución en el GER, VO2 y VCO2 que guarda relación con la disminución del VE y cuyo coeficiente de variación se mantiene alrededor del 6 %. En los tres casos en los que se mantuvo constante el VE durante la CI el coeficiente de variación fue menor de 6%. Conclusiones: la medición del GER por CI es confiable y útil cuando se incrementa la PEEP siempre que se mantenga el VE. El cálculo del cociente respiratorio (QR) en estas circunstancias no es confiable.

Objective: To identify variations during measurements of resting energy expenditure (REE), oxygen consumption (VO2 and CO production (VCO2 by indirect calorimetry (IC) in patients with pressure-controlled ventilation and different levels of positive end expiratory pressure (PEEP). Design: Prospective and comparative study. Setting: Intensive care unit (ICU) of a university-affiliated hospital. Measurements and Main Results: REE, VO2, and VCO2 were measured by IC in nine patients with pressure- controlled ventilation and different levels of PEEP. Paired t Wilcoxon and coeficient of variation tests for all measurements were carried out. Decrease in REE, VCO2, and VO2 was observed with increments in PEEP, these changes related with a concomitant reduction in VE. Coefficient of variation during IC was above 6%, and was lower in three patients who maintained the same VE throughout the study. Conclusions: Measurement of REE by Ids reliable atvarious levels of PEEP, and it improves if VE remains constant throughout measurement. Respiratory quotient (RQ) in this setting is not accurate.

[Effects of different positive end expiratory pressure levels on resting energy expenditure measured by indirect calorimeter in patients with pressure-controlled ventilation]. / Efecto de diferentes niveles de presión positiva al final de la espiración sobre el gasto energético en reposo medido por calorimetría indirecta en pacientes con ventilación en presión control.

OBJECTIVE: To identify variations during measurements of resting energy expenditure (REE), oxygen consumption (VO2) and CO2 production (VCO2) by indirect calorimetry (IC) in patients with pressure-controlled ventilation and different levels of positive end expiratory pressure (PEEP). DESIGN: Prospective and comparative study. SETTING: Intensive care unit (ICU) of a university-affiliated hospital. MEASUREMENTS AND MAIN RESULTS: REE, VO2, and VCO2 were measured by IC in nine patients with pressure-controlled ventilation and different levels of PEEP. Paired t Wilcoxon and coeficient of variation tests for all measurements were carried out. Decrease in REE, VCO2, and VO2 was observed with increments in PEEP, these changes related with a concomitant reduction in VE. Coefficient of variation during IC was above 6%, and was lower in three patients who maintained the same VE throughout the study. CONCLUSIONS: Measurement of REE by IC is reliable at various levels of PEEP, and it improves if VE remains constant throughout measurement. Respiratory quotient (RQ) in this setting is not accurate.

[Cerebral Blood flow velocity spectrum by transcranial doppler ultrasound in patients with brain death clinical criteria]. / Espectro de velocidad del flujo sanguíneo cerebral por ultrasonido Doppler transcraneal en pacientes con criterios clínicos de muerte cerebral.

OBJECTIVE: To evaluate cerebral blood flow (CBF) direction, speed, and shape of Doppler profile in patients with clinical criteria of brain death (BD). PATIENTS: A total of 42 consecutive patients with clinical criteria for BD were included. MEASUREMENTS AND INTERVENTIONS: After anemia, hypothermia and hypocapnia were ruled out; confirmatory electroencephalogram (EEG) and a complete transcranial Doppler ultrasonography (TCDU) profile of circle of Willis and basilar arteries were done in all patients. Patients continued with mechanical ventilation and support in the Intensive Care Unit. RESULTS: All EEG reported generalized theta and delta waves, which were associated with a TCDU profile showing small systolic peaks without diastolic wave. CBF velocities of < 10 cm/sec were recorded in all patients. Only four patients had reverberating flow. At follow-up, cardiac arrest occurred in all patients at a mean of 2 +/- 0.84 days. CONCLUSIONS: Patients with clinical criteria of BD frequently have slow wave neuronal electrical activity on EEG that anticipates cardiac arrest. In these patients, TCDU detects an early and severe drop in CFB that is incompatible with life. TCDU should be done when other confirmatory tests like EEG suggest some retention of brain function.

[Pulmonary mechanics, oxygenation index, and alveolar ventilation in patients with two controlled ventilatory modes. A comparative crossover study]. / Mecánica pulmonar, índice de oxigenación y ventilación alveolar en pacientes con dos modalidades de ventilación mecánica controlada. Un estudio comparativo de tipo cruzado.

OBJECTIVE: To compare in a crossover study pulmonary mechanics, oxigenation index (PaO(2)/FiO(2)), and partial pressure of CO(2) in arterial blood (PaCO(2)) in patients with mechanical ventilation in two controlled ventilatory modes. SETTING: Intensive care unit of a university affiliated hospital. DESIGN: Prospective crossover clinical trial. PATIENTS AND METHODS: A total 114 consecutive patients were admitted to the intensive care unit (ICU) under controlled mechanical ventilation with SaO(2) >90% and FiO(2) <0.5 and assigned by random allocation to either volume control (VC) and constant inspiratory flow (square flow curve) (group I) or pressure control mode (PC) (group II). Both groups were ventilated with tidal volume (Vt) of 7 ml/kg, respiratory rate (RR) 14/min, inspiratory-expiratory ratio 1:2 (I:E), PEEP 5 cm H(2)O, and FiO(2) 0.4. After 15 min of mechanical ventilation, pulmonary mechanics, oxygenation index (OI), and PaCO(2) were measured and registered, and ventilatory mode was switched to PC mode in group I and to VC in group II, maintaining the same ventilator settings. Pulmonary mechanics, OI, and PaCO(2) were again registered after 15 min of ventilation. RESULTS: Peak inspiratory pressure (PIP) was higher in VC than in PC (31.5 vs 26 cm H(2)O), which resulted in a significant increase in transpulmonary pressure amplitude difference (DP) (25 vs 19 cm H(2)O). Mean airway pressure (MAP) and OI were lower in VC than in PC (11.5 vs 12 cm H(2)O, and 198.5 vs 215, respectively). Dynamic compliance (DynC) was lower in VC than in PC (20 vs 26 ml/cm H(2)O), p < 0.05 for all values. At constant ventilator settings in the same patient, PC and not VC ventilation decreases PIP (which results in smaller transpulmonary pressure amplitude difference), increases MAP, and DynC and improves the oxygenation index.

Plasmaféresis en el síndrome de Guillain-Barré / Plasmapheresis in Guillain-Barre syndrome

OBJECTIVE: To evaluate the efficacy of early therapeutic plasmapheresis in severely affected patients with Guillain-BarrÚ syndrome (GBS). PATIENTS AND METHOD: Patients between 16 to 70 years of age, with GBS according to NINCDS criteria, in stage > or = 3 of Huges severity score and with less than 7 days of onset of symptoms were admitted for therapeutic plasmapheresis. All patients completed a total of five sessions of plasma exchange every other day using 25 albumin and saline in a 1:1 proportion. Follow-up was performed for 6 months. Friedman and Wilcoxon tests were done to establish differences within groups. RESULTS: A total of 34 patients were admitted to the study. The time span between onset of symptoms and admission to the study was 4 days (median). Fourteen (41) required mechanical ventilation. Clinical progression of the syndrome was observed during the first two sessions of plasma-pheresis. Improvement in motor function by Huges score was observed only after fourth session of plasma exchange (p < 0.05). Two patients did not improve, and one died. CONCLUSIONS: Clinical improvement in GBS during early therapeutic plasmapheresis occurs only after the fourth session of plasma exchange.

[Plasmapheresis in Guillain-Barre syndrome]. / Plasmaféresis en el síndrome de Guillain-Barré.

OBJECTIVE: To evaluate the efficacy of early therapeutic plasmapheresis in severely affected patients with Guillain-Barré syndrome (GBS). PATIENTS AND METHOD: Patients between 16 to 70 years of age, with GBS according to NINCDS criteria, in stage > or = 3 of Huges severity score and with less than 7 days of onset of symptoms were admitted for therapeutic plasmapheresis. All patients completed a total of five sessions of plasma exchange every other day using 25% albumin and saline in a 1:1 proportion. Follow-up was performed for 6 months. Friedman and Wilcoxon tests were done to establish differences within groups. RESULTS: A total of 34 patients were admitted to the study. The time span between onset of symptoms and admission to the study was 4 days (median). Fourteen (41%) required mechanical ventilation. Clinical progression of the syndrome was observed during the first two sessions of plasma-pheresis. Improvement in motor function by Huges score was observed only after fourth session of plasma exchange (p < 0.05). Two patients did not improve, and one died. CONCLUSIONS: Clinical improvement in GBS during early therapeutic plasmapheresis occurs only after the fourth session of plasma exchange.

Gasto energético y estado metabólico en pancreatitis aguda grave con y sin sepsis / Energy expenditure and metabolic status in patients with acute severe pancreatitis with or without sepsis

Objetivo: medir el estado metabólico, el gasto energético en reposo (GER) y el cociente respiratorio (CR) de pacientes con pancreatitis aguda grave (PAG) con y sin sepsis asociada. Material y métodos; Se evaluaron 10 pacientes con PAG; todos estaban con ventilación mecánica controlada y sedados. Para medir el GER y El CR se realizó calorimetría indirecta (CI). El estado metabólico de los pacientes se obtuvo comparando el gasto energético en reposo medido (GERm) con el gasto energético calculado (GERc), obtenido por la fórmula de harris-Benedict basal de acuerdo con la calsificación de Feurer y Foster. Se midió la excreción de nitrógeno ureico urinario (NUU) en orina de 24 horas. Resultados; siete pacientes estaban hipermetabólicos (Germ > 10 por ciento GERc). Al realizar el promedio del GERm éste fue 25 por ciento mayor que el GERc en cinco pacientes con PAG y sepsis (1958 ñ 170 versus 1568 ñ 138 Kcal/día) y 15 por ciento en dos de tres pacientes con PAG sin sepsis (1916 ñ 170 versus 1663 ñ 164 Kcal/día). El CR fue de 0.95 ñ 0.05 y de 0.85 ñ 0.04 en los pacientes con PAG con y sin sepsis respectivamente. Dos pacientes con PAG y sepsis se encontraron normometabólicos (Germ en tres 0 a 9 por ciento versus GERc), un paciente con PAG sin sepsis se encontró hipometabólico (GERm < 10 por ciento GERc). El promedio de la excreción de NUU fue de 15.5 g/día. Conclusión: la medición del GER por CI demostró que 70 por ciento de los pacientes con PAG se encontraban hipermetabólicos. En los pacientes con PAG el GERm se incrementa en promedio 15 por ciento; este incremento llega hasta 25 por ciento cuando existe sepsis asociada. Los resultados del CR sugieren una utilización de sustraro energético mixto. El catabolismo proteínico de pacientes con pancreatitis aguda grave es intenso

Procedimiento de reclutamiento alveolar en pacientes con insuficiencia respiratoria aguda y asistencia mecánica ventilatoria. Correlación entre mecánica pulmonar, el índice de oxigenación y la tomográfia computada de tórax / A ventilatory strategy for recruitment of partially collapsed lung in acute respiratory ailure. correlations of pulmonary mechanics and oxigenation index with chest computed tomography

Objetivo. Evaluar en los pacientes con insuficiencia respiratoria agua (PaO2/FiO2 < 150) los cambios en la mecanica pulmonar, el intercambio de gases y la distribución regional de gas intraalveolar al aplicar diferentes presiones en la vía aérea, para generar aumento en la presión inspiratoria pico (PIP) y la presión positiva al final de la espiración total (PEEPt) durante la ventilación mecánica controlada por presión con relación inspiración/espiración inversa (PC IRV), en la Unidad de Cuidados Intensivos y Medicina Crítica de un Hospital Universitario. Pacientes y métodos. Dos pacientes con insuficiencia respiratoria aguda y asistencia mecánica ventilatoria en la modalidad de volumen control, que fueron trasladados a la unidad de tomografía axial computada que se acondicionó previamente con un ventilador volumétrico, equipo de monitoreo hemodinámico y respiratorio, así como bombas de infusión intravenosa para ofrecer apoyo avanzado de vida. Una vez que se instaló el paciente y durante todo el estudio, se efectuaron mediciones seriadas de la mecánica pulmonar, intercambio de gases, así como de la distribución regional de gas por TAC de tórax. Una vez que se efectuaron los registros basales, y con la finalidad de recolectar alvéolos, se cambió la modalidad de ventilación a PC IRV y se aplicaron diferentes presiones a la vía aérea, se incrementó gradualmente la presión inspiratoria pico (PIP) y la presión positiva al final de la espiración (PEEP) para generar PEEP intrínseco. Se alcanzaron presiones de 60/25 cm H2O para PIP/PEEP total respectivamente por unos minutos. Resultados. El reclutamiento alveolar fue satisfactorio en ambos casos, pues al final del estudio se obtuvo incremento promedio de 86 puntos en el índice de oxigenación y la distensibilidad aumentó 9.5 mL/cm H2O en promedio. Conclusionesdurante la ventilación mecánica asistida con PC IRV, el incremento transitorio de las presiones en la vía aérea hasta 60/25 cm H2O de PIP/PEEPt por unos minutos recluta alvéolos de las zonas de atelectasia pulmonar. Al disminuir la PIP, estos alvéolos se mantienen abiertos con un PEEPt de aproximadamente 10 cm H2O