Patricia Freitas Goes

Evaluation of the dead space to tidal volume ratio as a predictor of extubation failure.

OBJECTIVE The objective of this study was to evaluate the ratio of dead space to tidal volume (VD/VT) as a predictor of extubation failure of children from mechanical ventilation. METHODS From September 2001 to January 2003 we studied a cohort consisting of all children (1 day-15 years) submitted to mechanical ventilation at a pediatric intensive care unit who were extubated and for whom pre-extubation ventilometry data were available, including the VD/VT ratio. Extubation success was defined as no need for any type of ventilatory support, invasive or otherwise, within 48 hours. Patients who tolerated extubation, with or without noninvasive support, were defined as success-R and compared with those who were reintubated. Statistic analysis was based on a VD/VT cutoff point of 0.65. RESULTS During the study period 250 children received mechanical ventilation at the pediatric intensive care unit. Eighty-six of these children comprised the study sample. Twenty-one children (24.4%) met the criteria for extubation failure, with 11 (12.8%) of these requiring non-invasive support and 10 (11.6%) reintubation. Their mean age was 16.8 (+/-30.1) months (median = 5.5 months). The mean VD/VT ratio for all cases was 0.62 (+/-0.18). Mean VD/VT ratios for patients with successful and failed extubations were 0.62 (+/-0.17) and 0.65 (+/-0.21) (p = 0.472), respectively. Logistic regression failed to reveal any statistically significant correlation between VD/VT ratio and success or failure of extubation (p = 0.8458), even for patients who were reintubated (p = 0.5576). CONCLUSIONS In a pediatric population receiving mechanical ventilation due to a variety of etiologies, the VD/VT ratio was unable to predict the populations at risk of extubation failure or of reintubation.

Avaliação da relação entre espaço morto e volume corrente como índice preditivo de falha de extubação

OBJETIVO: O objetivo do estudo foi avaliar a relacao entre espaco morto e volume corrente (VD/VT) como preditivo de falha na extubacao de criancas sob ventilacao mecânica. METODOS: Entre setembro de 2001 e janeiro de 2003, realizamos uma coorte, na qual foram incluidas todas as criancas (1 dia-15 anos) submetidas a ventilacao mecânica na unidade de terapia intensiva pediatrica em que foi possivel realizar a extubacao e a ventilometria pre-extubacao com a medida do indice VD/VT. Considerou-se falha na extubacao a necessidade de reinstituicao de algum tipo de assistencia ventilatoria, invasiva ou nao, em um periodo de 48 horas. Para a analise dos pacientes que foram reintubados, definiu-se como sucesso-R a nao reintubacao. Para as analises estatisticas, utilizou-se um corte do VD/VT de 0,65. RESULTADOS: No periodo estudado, 250 criancas receberam ventilacao mecânica na unidade de terapia intensiva pediatrica. Destas, 86 compuseram a amostra estudada. Vinte e uma criancas (24,4%) preencheram o criterio de falha de extubacao, com 11 (12,8%) utilizando suporte nao-invasivo e 10 (11,6%) reintubadas. A idade media foi de 16,8 (±30,1) meses, e a mediana, de 5,5 meses. A media do indice VD/VT de todos os casos foi de 0,62 (±0,18). As medias do indice VD/VT para os pacientes que tiveram a extubacao bem sucedida e para os que falharam foram, respectivamente, 0,62 (±0,17) e 0,65 (±0,21) (p = 0,472). Na regressao logistica, o indice VD/VT nao apresentou correlacao estatisticamente significativa com o sucesso ou nao da extubacao (p = 0,8458), nem para aqueles que foram reintubados (p = 0,5576). CONCLUSOES: Em uma populacao pediatrica submetida a ventilacao mecânica, por etiologias variadas, o indice VD/VT nao possibilitou predizer qual a populacao de risco para falha de extubacao ou reintubacao.

Septic Shock, Necrotizing Pneumonitis, and Meningoencephalitis Caused by Mycoplasma pneumoniae in a Child: A Case Report

Mycoplasma pneumoniae is an important causative agent of respiratory infection in childhood. Although the infection caused by M. pneumoniae is classically described as benign, severe and life-threatening pulmonary and extrapulmonary complications can occur. This study describes the first case of septic shock related to M. pneumoniae in a child with necrotizing pneumonitis, severe encephalitis, and multiple organs involvement, with a favorable outcome after lobectomy and systemic corticosteroids

Fulminant Herpes Simplex Hepatitis Following a Short Course of Corticotherapy in a Child

Fulminant hepatitis (FH) is a rare condition defined by acute hepatocelular necrosis, coagulopathy, and encephalopathy, that develops within 8 weeks after the initial insult in a patient with no recognized previous liver disease. In children, encephalopathy may be of difficult recognition or late onset, and it is not essential for diagnosis of FH, but it may be useful for classification of severity of the disease. FH is a multisystem disorder. Besides impairment in liver function, hypotension, renal failure, higher susceptibility to infections, and multiple organ dysfunction may occur. Mortality ranges 29%, while the same number of patients requires liver transplantation. The etiology of FH differs around the world, according to social and economical features, prescription practices, and immunization status. In developed countries, acetaminophen overdose is the leading cause of acute liver failure, while in developing countries hepatitis A and B play a major role. Other causes of FH include idiosyncratic drug reactions, auto immune hepatitis, non-A non-B hepatitis, metabolic diseases, hypoperfusion secondary to shock, and undetermined causes. Herpes simplex virus (HSV) is a very unusual cause of FH. It comprises less than 1% cases of acute liver failure from viral etiology. It is a well known condition in pregnancy, newborns, and immunosupressed patients, and is very uncommon in immunocompetent ones. In all patient populations, the mortality rate is high. We report the first case of acute liver failure with a favorable outcome in an immunocompetent child who developed HSV FH following a short course corticosteroid therapy for treatment of status asthmaticus.

Ruptura traumática de via aérea em criança: um desafio diagnóstico

OBJETIVO: Relatar um caso de ruptura da via aerea em crianca vitima de trauma toracico decorrente de queda do tanque de lavar roupas. DESCRICAO: Relato de caso descritivo. O paciente pre-escolar de 34 meses, do sexo masculino foi atendido na unidade de terapia intensiva pediatrica de Hospital Universitario. Foram realizados os seguintes procedimentos: radiografia simples e tomografia de torax, endoscopia respiratoria, toracotomia, antibioticoterapia, ventilacao mecânica. A radiografia simples de torax, tomografia computadorizada de torax e endoscopia respiratoria foram necessarias para definir o diagnostico de ruptura traumatica da via aerea associada a contusao pulmonar, pneumotorax, pneumomediastino e enfisema subcutâneo. O paciente foi submetido a toracotomia para reparacao de lesao quase completa de bronquio principal esquerdo. Antibioticoterapia de largo espectro e suporte ventilatorio contribuiram para resolucao do caso sem sequelas a medio prazo. COMENTARIOS: Na vigencia de trauma toracico em crianca, a busca diagnostica por lesoes incomuns, mas potencialmente letais, como a ruptura da via aerea, deve ser incessante, particularmente naqueles pacientes com fortes evidencias clinicas. A complementacao diagnostica deve ser otimizada com a radiografia simples de torax, a tomografia de torax e o exame endoscopico que estabelece o diagnostico definitivo.

Hemophagocytic syndrome: a dilemma chasing the intensivists

Hemophagocytic lymphohistiocytosis or hemophagocytic syndrome is represented by an uncontrolled inflammatory response characterized by marked histiocyte activation and a cytokine storm. The entity may present a primary or genetic type, and the secondary type is usually triggered by infectious diseases of any kind, autoimmune disease, or neoplasia. This entity, although well described and with definite diagnostic criteria, still remains misdiagnosed because of the overlap presentation with other inflammatory processes. The authors present the case of a 13-year-old girl who was submitted to an appendicectomy complicated with a pericolic abscess, which required a second operation in order to be drained surgically. During the postoperative period of this second surgical procedure, the patient remained febrile, developing cytopenias, and multiple organ failure. Unfortunately, she died despite the efforts of the intensive care staff. The autopsy findings were characteristic of hemophagocytic syndrome. The authors report the case to call attention to this diagnosis whenever unexpected outcomes of infections are experienced.

Comparison of main trials of recombinant human activated protein C in sepsis-are we encouraging more bleeding in neonates?

To the Editor: Since the section in Pediatric Critical Care Medicine focused on neonatal intensive care was first announced in January 2006, we were pleasantly surprised by continued publication of high-quality manuscripts in this area, including the observational study of Beshlawy et al (1) about the physiologic coagulation inhibitors: proteins C, S, and antithrombin III. Regarding this study, we would like to make a few considerations. First, there was an unintentional oversight of aforementioned Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study(2), the most relevant published study about recombinant human activated protein C (rh-aPC), in the references. Since its publication in 2001, PROWESS (2, 3) has been counted with 2504 citations (ISI-Web.of.Science in April 22, 2010), and is the cornerstone for rh-aPC therapy in adults. In that study, an absolute decrease in mortality of 6% and a number-needed-to-treat of 16 were demonstrated (2, 3). Second, we noted the absence of mortality scores for comparison with the high reported mortality (57%) in septic fullterm neonates (shown in Beshlawy’s Table 3) (1) and intracranial hemorrhage rate (23.3%) (1), which is 11 times higher than the baseline risk of bleeding reported in PROWESS (2%) (2). Finally, the conclusion by Beshlawy’s group (1) encourages “further placebocontrolled clinical trials to investigate the role of activated protein C and antithrombin-III in severe neonatal sepsis, and specially, in the states of DIC [disseminated intravascular coagulation].” Such a conclusion seems controversial to us, for the reasons specified below. When a specific pharmacologic treatment is recommended, it should target clear advantages that outweigh the possible side effects. This is far from true for almost the totality of physiologic coagulation inhibitors studies. In Table 1 , we have compiled seven of the most relevant trials on physiologic coagulation inhibitors (2–4) (n 13,244 patients), alongside the study of Beshlawy et al (1) (n 60 patients). Randomized controlled trials which evaluated the use of rh-aPC in adults with Acute Physiology and Chronic Health Evaluation 25 (Administration of Drotrecogin Alfa [Activated] in Early Stage Severe Sepsis [ADDRESS]) (3) and in children (Safety and Efficacy of Ranibizumab in Diabetic Macular Edema With Center Involvement [RESOLVE]) (3) failed to show any benefit in mortality but demonstrated an increase in bleeding risks (3, 5) (Table 1). Similarly, randomized controlled trials on antithrombin III (High-Dose Antithrombin III in Severe Sepsis Trial) (4) and recombinant tissue factor pathway inhibitor (Tifacogin/ Optimized Phase 3 Tifacogin in Multicenter Sepsis Trial [OPTIMIST]) (6) showed no improvement in 28-day mortality. Interestingly, the Extended Evaluation of Recombinant Human Activated Protein C (ENHANCE) trial was a single arm study, and impact on mortality was determined by historical comparisons with PROWESS’s placebo. In contrast, analyzing the risk of hazard shows an increase in the number of bleeding and severe bleeding events (3.5% to 10%) (2–4) secondary to physiologic coagulation inhibitors treatments. The only randomized controlled trial (PROWESS, 1690 patients) showing a treatment benefit over placebo has also demonstrated more severe bleeding (3.5% 2.0%, p .06) and intracranial hemorrhage (2). An editorial published in 2009 (5) noticed that the prevalence of serious bleeding during infusion is lower in studies sponsored by the manufacturers (mean, 2.5% to 3.4% in PROWESS/ADDRESS/ ENHANCE/MERCURY/Xigris and Prophylactic Heparin Evaluation in Severe Sepsis Study [XPRESS]/Wheeler) (5) than in independent studies (mean, 7.2% in Gentry/Bertolini/Kanji/ Voluntary Health Association and University Health System Consortium) (5). We calculated that the number needed to harm for serious bleeding in PROWESS was 66, and it ranges from 22 (ENHANCE), 40 (RESOLVE-Intracranial hemorrhage), 58 (ADDRESS), 52 (XPRESS) sponsored trials (Table 1) to 9.7 (Gentry), 11 (Bertolini), 12 (Kanji), 37 (Voluntary Health Association and University Health System Consortium) independent trials . Studies with adequate statistical power and negative results have strongly suggested the nonindication of those lowefficacy treatments in low-risk adults (3) and in pediatric patients(3). Therefore, recommendations for further studies with rh-aPC, antithrombin III, and tifacogin (r-TFPI) in neonates—a wellknown high-risk population for severe bleeding (23.3%) (1)—should be cautious and, possibly, reconsidered. We thank Dr. Débora Cristina Raulik Shieh of Universidade Federal do Paraná for her assistance in the preparation of the manuscript. The authors have not disclosed any potential conflicts of interest.