Two Cases of Arnold-Chiari Malformation with Respiratory Failure

Arnold–Chiari malformation is defined as downward displacement of the brainstem and cerebellum through the foramen magnum. It has different clinical presentations and four subtypes. It is known that downward migration of posterior fossa components through the foramen magnum and associated lower cranial nerve palsy and brainstem compression can cause respiratory failure. Acute respiratory failure could mark the onset of the disease. Posterior fossa decompression performed to treat primary disease can improve the central sleep abnormalities. As respiratory failure is rarely seen, this paper presents two cases of Arnold–Chiari malformation with respiratory failure.

The effects of prone position ventilation on experimental mild acute lung injury induced by intraperitoneal lipopolysaccharide injection in rats

The benefits of prone position ventilation are well demonstrated in the severe forms of acute respiratory distress syndrome, but not in the milder forms. We investigated the effects of prone position on arterial blood gases, lung inflammation, and histology in an experimental mild acute lung injury (ALI) model. ALI was induced in Wistar rats by intraperitoneal Escherichia coli lipopolysaccharide (LPS, 5 mg/kg). After 24 h, the animals with PaO2/FIO2 between 200 and 300 mmHg were randomized into 2 groups: prone position (n = 6) and supine position (n = 6). Both groups were compared with a control group (n = 5) that was ventilated in the supine position. All of the groups were ventilated for 1 h with volume-controlled ventilation mode (tidal volume = 6 ml/kg, respiratory rate = 80 breaths/min, positive end-expiratory pressure = 5 cmH2O, inspired oxygen fraction = 1). Significantly higher lung injury scores were observed in the LPS-supine group compared to the LPS-prone and control groups (0.32 ± 0.03; 0.17 ± 0.03 and 0.13 ± 0.04, respectively) (p < 0.001), mainly due to a higher neutrophil infiltration level in the interstitial space and more proteinaceous debris that filled the airspaces. Similar differences were observed when the gravity-dependent lung regions and non-dependent lung regions were analyzed separately (p < 0.05). The BAL neutrophil content was also higher in the LPS-supine group compared to the LPS-prone and control groups (p < 0.05). There were no significant differences in the wet/dry ratio and gas exchange levels. In this experimental extrapulmonary mild ALI model, prone position ventilation for 1 h, when compared with supine position ventilation, was associated with lower lung inflammation and injury.

Infección por virus sincitial respiratorio y su relación con valores de IGG en niños críticos

Antecedente: La infección por el virus sincitial respiratorio (VSR) representa una elevada morbimortalidad, y en algunos casos necesidad de manejo en unidades de cuidado intensivo pediátrico (UCIP). La respuesta inmunológica influye de manera directa en la expresión de la severidad y pronóstico de los pacientes con infección respiratoria. Metodología: Estudio de una cohorte retrospectiva de pacientes con infección respiratoria grave secundaria a VSR, sin historia de inmunodeficiencia, atendidos en la UCIP del Hospital Universitario Clínica San Rafael. Se realizó análisis descriptivoglobaly de acuerdo a la categorización de las prueba de IgG. Resultados: De 188 pacientes que ingresaron a la UCIP, 13% presentaron infección por VSR (24), con una edad promedio de 7,3 (DE=3,6) meses. Pertenecían al sexo masculino79,83%. Se encontró que 12,5% tenían un valor de IgGbajo para su edad, 58,33% tenían valores en límite inferior y el 29,17% dentro de rangos normales para su edad. En los pacientes con IgG baja, fue mayor la presentación de choque séptico que no responde a líquidos (100 vs 92 vs 86%), la mediana de días de ventilación mecánica fue mayor (8 vs 6 vs 5 respectivamente), así como la mortalidad (67 vs 7,1 vs 0%). Conclusión: Nuestra serie encontró que aquellos pacientes con niveles bajos o valores en el límite inferior de IgG sérica tuvieron mayor compromiso sistémico, mayor duración de ventilación mecánica y mayor mortalidad. Se necesitan estudios prospectivos que relaciones niveles bajos de IgG con severidad y pronostico en estos pacientes con infección grave por VSR.

Seguridad del monitoreo hemodinámico invasivo versus mínimamente invasivo en pacientes con choque cardiogénico en cuidado intensivo adultos. Revisión sistemática

Introducción: El monitoreo hemodinámico es una herramienta para diagnosticar el choque cardiogénico y monitorear la respuesta al tratamiento; puede ser invasivo, mínimamente invasivo o no invasivo. Se realiza rutinariamente con catéter de arteria pulmonar (CAP) o catéter de Swan Ganz; nuevas técnicas de monitoreo hemodinámico mínimamente invasivo tienen menor tasa de complicaciones. Actualmente se desconoce cuál técnica de monitoreo cuenta con mayor seguridad en el paciente con choque cardiogénico. Objetivo: Evaluar la seguridad del monitoreo hemodinámico invasivo comparado con el mínimamente invasivo en pacientes con choque cardiogénico en cuidado intensivo adultos. Diseño: Revisión sistemática de la literatura. Búsqueda en Pubmed, EMBASE, OVID - Cochrane Library, Lilacs, Scielo, registros de ensayos clínicos, actas de conferencias, repositorios, búsqueda de literatura gris en Google Scholar, Teseo y Open Grey hasta agosto de 2016, publicados en inglés y español. Resultados: Se identificó un único estudio con 331 pacientes críticamente enfermos que comparó el monitoreo hemodinámico con CAP versus PiCCO que concluyó que después de la corrección de los factores de confusión, la elección del tipo de monitoreo no influyó en los resultados clínicos más importantes en términos de complicaciones y mortalidad. Dado que se incluyeron otros diagnósticos, no es posible extrapolar los resultados sólo a choque cardiogénico. Conclusión: En la literatura disponible no hay evidencia de que el monitoreo hemodinámico invasivo comparado con el mínimamente invasivo, en pacientes adultos críticamente enfermos con choque cardiogénico, tenga diferencias en cuanto a complicaciones y mortalidad.

Ventilação oscilatória de alta freqüência em pediatria e neonatologia

Este trabalho teve por objetivo rever a literatura e descrever a utilização da ventilação oscilatória de alta freqüência em crianças e recém-nascidos. Revisão bibliográfica e seleção de publicações mais relevantes sobre ventilação de alta freqüência utilizando as bases de dados MedLine e SciElo publicadas nos últimos 15 anos. As seguintes palavras-chave foram utilizadas: ventilação oscilatória de alta freqüência, ventilação mecânica, síndrome do desconforto respiratório agudo, crianças e recém-nascidos. Descreveu-se o emprego da ventilação oscilatória de alta freqüência em crianças com síndrome do desconforto respiratório agudo, síndrome de escape de ar e doença pulmonar obstrutiva. Avaliou em recém-nascidos, síndrome do desconforto respiratório, displasia broncopulmonar, hemorragia peri-intraventricular, leucoencefalomalácia e extravasamento de ar. Também, abordou a transição da ventilação mecânica convencional para a ventilação de alta freqüência e o manuseio específico da ventilação de alta freqüência quanto à oxigenação, eliminação de gás carbônico, realização de exame radiológico, realização de sucção traqueal e utilização de sedação e bloqueio neuromuscular. Foram abordados o desmame deste modo ventilatório e as complicações. Em crianças maiores a ventilação oscilatória de alta freqüência é uma opção terapêutica, principalmente na síndrome do desconforto respiratório agudo, devendo ser empregada precocemente. Também pode ser útil em casos de síndrome de escape de ar e doença pulmonar obstrutiva. Em recém-nascidos, não há evidências que demonstram superioridade da ventilação oscilatória de alta freqüência em relação à ventilação convencional, sendo a síndrome de escape de ar a única situação clínica em que há evidência de melhores resultados com este modo ventilatório.

Emergence and disappearance of a virulent clone of Haemophilus influenzae biogroup aegyptius, cause of Brazilian Purpuric Fever

Summary: In 1984, children presented to the emergency department of a hospital in the small town of Promissão, São Paulo State, Brazil, with an acute febrile illness that rapidly progressed to death. Local clinicians and public health officials recognized that these children had an unusual illness, which led to outbreak investigations conducted by Brazilian health officials in collaboration with the U.S. Centers for Disease Control and Prevention. The studies that followed are an excellent example of the coordinated and parallel studies that are used to investigate outbreaks of a new disease, which became known as Brazilian purpuric fever (BPF). In the first outbreak investigation, a case-control study confirmed an association between BPF and antecedent conjunctivitis but the etiology of the disease could not be determined. In a subsequent outbreak, children with BPF were found to have bacteremia caused by Haemophilus influenzae biogroup aegyptius (H. aegyptius), an organism previously known mainly to cause self-limited purulent conjunctivitis. Molecular characterization of blood and other isolates demonstrated the clonal nature of the H. aegyptius strains that caused BPF, which were genetically distant from the diverse strains that cause only conjunctivitis. This led to an intense effort to identify the factors causing the unusual invasiveness of the BPF clone, which has yet to definitively identify the virulence factor or factors involved. After a series of outbreaks and sporadic cases through 1993, no additional cases of BPF have been reported

The impact of a 17-day training period for an international championship on mucosal immune parameters in top-level basketball players and staff members

This investigation examined the impact of a 17-d training period (that included basketball-specific training, sprints, intermittent running exercises, and weight training, prior to an international championship competition) on salivary immunoglobulin A (SIgA) levels in 10 subjects (athletes and staff members) from a national basketball team, as a biomarker for mucosal immune defence. Unstimulated saliva samples were collected at rest at the beginning of the preparation for the Pan American Games and 1 d before the first game. The recovery interval from the last bout of exercise was 4 h. The SIgA level was measured using enzyme-linked immunosorbent assay and expressed as absolute concentrations, secretion rate, and SIgA level relative to total protein. The decrease in SIgA levels following training was greater in athletes than in support staff; however, no significant differences between the two groups were detected. A decrease in SIgA level, regardless of the method used to express IgA results, was verified for athletes. Only one episode of upper respiratory tract illness symptoms was reported, and it was not associated with changes in SIgA levels. In summary, a situation of combined stress for an important championship was found to decrease the level of SIgA-mediated immune protection at the mucosal surface in team members, with greater changes observed in the athletes.

Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography

To present a novel algorithm for estimating recruitable alveolar collapse and hyperdistension based on electrical impedance tomography (EIT) during a decremental positive end-expiratory pressure (PEEP) titration. Technical note with illustrative case reports. Respiratory intensive care unit. Patients with acute respiratory distress syndrome. Lung recruitment and PEEP titration maneuver. Simultaneous acquisition of EIT and X-ray computerized tomography (CT) data. We found good agreement (in terms of amount and spatial location) between the collapse estimated by EIT and CT for all levels of PEEP. The optimal PEEP values detected by EIT for patients 1 and 2 (keeping lung collapse < 10%) were 19 and 17 cmH(2)O, respectively. Although pointing to the same non-dependent lung regions, EIT estimates of hyperdistension represent the functional deterioration of lung units, instead of their anatomical changes, and could not be compared directly with static CT estimates for hyperinflation. We described an EIT-based method for estimating recruitable alveolar collapse at the bedside, pointing out its regional distribution. Additionally, we proposed a measure of lung hyperdistension based on regional lung mechanics.

Image reconstruction affects computer tomographic assessment of lung hyperinflation

Objectives: Lung hyperinflation may be assessed by computed tomography (CT). As shown for patients with emphysema, however, CT image reconstruction affects quantification of hyperinflation. We studied the impact of reconstruction parameters on hyperinflation measurements in mechanically ventilated (MV) patients. Design: Observational analysis. Setting: A University hospital-affiliated research Unit. Patients: The patients were MV patients with injured (n = 5) or normal lungs (n = 6), and spontaneously breathing patients (n = 5). Interventions: None. Measurements and results: Eight image series involving 3, 5, 7, and 10 mm slices and standard and sharp filters were reconstructed from identical CT raw data. Hyperinflated (V-hyper), normally (V-normal), poorly (V-poor), and nonaerated (V-non) volumes were calculated by densitometry as percentage of total lung volume (V-total). V-hyper obtained with the sharp filter systematically exceeded that with the standard filter showing a median (interquartile range) increment of 138 (62-272) ml corresponding to approximately 4% of V-total. In contrast, sharp filtering minimally affected the other subvolumes (V-normal, V-poor, V-non, and V-total). Decreasing slice thickness also increased V-hyper significantly. When changing from 10 to 3 mm thickness, V-hyper increased by a median value of 107 (49-252) ml in parallel with a small and inconsistent increment in V-non of 12 (7-16) ml. Conclusions: Reconstruction parameters significantly affect quantitative CT assessment of V-hyper in MV patients. Our observations suggest that sharp filters are inappropriate for this purpose. Thin slices combined with standard filters and more appropriate thresholds (e.g., -950 HU in normal lungs) might improve the detection of V-hyper. Different studies on V-hyper can only be compared if identical reconstruction parameters were used.

Extrapolation from ten sections can make CT-based quantification of lung aeration more practicable

Clinical applications of quantitative computed tomography (qCT) in patients with pulmonary opacifications are hindered by the radiation exposure and by the arduous manual image processing. We hypothesized that extrapolation from only ten thoracic CT sections will provide reliable information on the aeration of the entire lung. CTs of 72 patients with normal and 85 patients with opacified lungs were studied retrospectively. Volumes and masses of the lung and its differently aerated compartments were obtained from all CT sections. Then only the most cranial and caudal sections and a further eight evenly spaced sections between them were selected. The results from these ten sections were extrapolated to the entire lung. The agreement between both methods was assessed with Bland-Altman plots. Median (range) total lung volume and mass were 3,738 (1,311-6,768) ml and 957 (545-3,019) g, the corresponding bias (limits of agreement) were 26 (-42 to 95) ml and 8 (-21 to 38) g, respectively. The median volumes (range) of differently aerated compartments (percentage of total lung volume) were 1 (0-54)% for the nonaerated, 5 (1-44)% for the poorly aerated, 85 (28-98)% for the normally aerated, and 4 (0-48)% for the hyperaerated subvolume. The agreement between the extrapolated results and those from all CT sections was excellent. All bias values were below 1% of the total lung volume or mass, the limits of agreement never exceeded +/- 2%. The extrapolation method can reduce radiation exposure and shorten the time required for qCT analysis of lung aeration.

Transfusion Requirements After Cardiac Surgery The TRACS Randomized Controlled Trial

Context Perioperative red blood cell transfusion is commonly used to address anemia, an independent risk factor for morbidity and mortality after cardiac operations; however, evidence regarding optimal blood transfusion practice in patients undergoing cardiac surgery is lacking. Objective To define whether a restrictive perioperative red blood cell transfusion strategy is as safe as a liberal strategy in patients undergoing elective cardiac surgery. Design, Setting, and Patients The Transfusion Requirements After Cardiac Surgery (TRACS) study, a prospective, randomized, controlled clinical noninferiority trial conducted between February 2009 and February 2010 in an intensive care unit at a university hospital cardiac surgery referral center in Brazil. Consecutive adult patients (n=502) who underwent cardiac surgery with cardiopulmonary bypass were eligible; analysis was by intention-to-treat. Intervention Patients were randomly assigned to a liberal strategy of blood transfusion (to maintain a hematocrit >= 30%) or to a restrictive strategy (hematocrit >= 24%). Main Outcome Measure Composite end point of 30-day all-cause mortality and severe morbidity (cardiogenic shock, acute respiratory distress syndrome, or acute renal injury requiring dialysis or hemofiltration) occurring during the hospital stay. The noninferiority margin was predefined at -8% (ie, 8% minimal clinically important increase in occurrence of the composite end point). Results Hemoglobin concentrations were maintained at a mean of 10.5 g/dL(95% confidence interval [CI], 10.4-10.6) in the liberal-strategy group and 9.1 g/dL (95% CI, 9.09.2) in the restrictive-strategy group (P<.001). A total of 198 of 253 patients (78%) in the liberal-strategy group and 118 of 249 (47%) in the restrictive-strategy group received a blood transfusion (P<.001). Occurrence of the primary end point was similar between groups (10% liberal vs 11% restrictive; between-group difference, 1% [95% CI, -6% to 4%]; P=.85). Independent of transfusion strategy, the number of transfused red blood cell units was an independent risk factor for clinical complications or death at 30 days (hazard ratio for each additional unit transfused, 1.2 [95% CI, 1.1-1.4]; P=.002). Conclusion Among patients undergoing cardiac surgery, the use of a restrictive perioperative transfusion strategy compared with a more liberal strategy resulted in noninferior rates of the combined outcome of 30-day all-cause mortality and severe morbidity. Trial Registration clinicaltrials.gov Identifier: NCT01021631 JAMA. 2010; 304(14):1559-1567 www.jama.com

Lung Pathology in Fatal Novel Human Influenza A (H1N1) Infection

Rationale: There are no reports of the systemic human pathology of the novel swine H1N1 influenza (S-OIV) infection. Objectives: The autopsy findings of 21 Brazilian patients with confirmed S-OIV infection are presented. These patients died in the winter of the southern hemisphere 2009 pandemic, with acute respiratory failure. Methods: Lung tissue was submitted to virologic and bacteriologic analysis with real-time reverse transcriptase polymerase chain reaction and electron microscopy. Expression of toll-like receptor (TLR)-3, IFN-gamma, tumor necrosis factor-alpha, CD8(+) T cells and granzyme B(+) cells in the lungs was investigated by immunohistochemistry. Measurements and Main Results: Patients were aged from 1 to 68 years (72% between 30 and 59 yr) and 12 were male. Sixteen patients had preexisting medical conditions. Diff use alveolar damage was present in 20 individuals. in six patients, diffuse alveolar damage was associated with necrotizing bronchiolitis and in five with extensive hemorrhage. There was also a cytopathic effect in the bronchial and alveolar epithelial cells, as well as necrosis, epithelial hyperplasia, and squamous metaplasia of the large airways. There was marked expression of TLR-3 and IFN-gamma and a large number of CD8(+) T cell sand granzyme B(+) cells within the lung tissue. Changes in other organs were mainly secondary to multiple organ failure. Conclusions: Autopsies have shown that the main pathological changes associated with S-OIV infection are localized to the lungs, where three distinct histological patterns can be identified. We also show evidence of ongoing pulmonary aberrant immune response. Our results reinforce the usefulness of autopsy in increasing the understanding of the novel human influenza A (H1N1) infection.

Bilevel vs ICU Ventilators Providing Noninvasive Ventilation: Effect of System Leaks A COPD Lung Model Comparison

Background: Noninvasive positive-pressure ventilation (NPPV) modes are currently available on bilevel and ICU ventilators. However, little data comparing the performance of the NPPV modes on these ventilators are available. Methods: In an experimental bench study, the ability of nine ICU ventilators to function in the presence of leaks was compared with a bilevel ventilator using the IngMar ASL5000 lung simulator (IngMar Medical; Pittsburgh, PA) set at a compliance of 60 mL/cm H(2)O, an inspiratory resistance of 10 cm H(2)O/L/s, an expiratory resistance of 20 cm H(2)O/L/s, and a respiratory rate of 15 breaths/min. All of the ventilators were set at 12 cm H(2)O pressure support and 5 cm H(2)O positive end-expiratory pressure. The data were collected at baseline and at three customized leaks. Main results: At baseline, all of the ventilators were able to deliver adequate tidal volumes, to maintain airway pressure, and to synchronize with the simulator, without missed efforts or auto-triggering. As the leak was increased, all of the ventilators (except the Vision [Respironics; Murrysville, PA] and Servo I [Maquet; Solna, Sweden]) needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation, and some transitioned to backup ventilation. Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators. Conclusions: The Vision and Servo I were the only ventilators that required no adjustments as they adapted to increasing leaks. There were differences in performance between these two ventilators, although the clinical significance of these differences is unclear. Clinicians should be aware that in the presence of leaks, most ICU ventilators require adjustments to maintain an adequate tidal volume. (CHEST 2009; 136:448-456)

Septic shock caused by Plesiomonas shigelloides in a patient with sickle beta-zero thalassemia

Invasive infection and extraintestinal complications are rarely caused by Plesiomonas shigelloides, a water-borne bacterium belonging to the Vibrionaceae family. We report a case of a 16-year-old female patient with sickle beta-zero thalassemia who survived septic shock caused by P. shigelloides associated with secondary acute respiratory distress syndrome and disseminated intravascular coagulation. Treatment with a carbapenem was successful, and the patient recovered without any sequelae. The previous reports of P. shigelloides sepsis are cited, and possible pathogenic mechanisms are discussed. (Heart Lung (R) 2010;39:335-339.)