Follow-up after acute respiratory distress syndrome caused by influenza a (H1N1) virus infection

BACKGROUND: There are no reports on the long-term follow-up of patients with swine-origin influenza A virus infection that progressed to acute respiratory distress syndrome. METHODS: Four patients were prospectively followed up with pulmonary function tests and high-resolution computed tomography for six months after admission to an intensive care unit. RESULTS: Pulmonary function test results assessed two months after admission to the intensive care unit showed reduced forced vital capacity in all patients and low diffusion capacity for carbon monoxide in two patients. At six months, pulmonary function test results were available for three patients. Two patients continued to have a restrictive pattern, and none of the patients presented with abnormal diffusion capacity for carbon monoxide. All of them had a diffuse ground-glass pattern on high-resolution computed tomography that improved after six months. CONCLUSIONS: Despite the marked severity of lung disease at admission, patients with acute respiratory distress syndrome caused by swine-origin influenza A virus infection presented a late but substantial recovery over six months of follow-up

First-year experience of a Brazilian tertiary medical center in supporting severely ill patients using extracorporeal membrane oxygenation

OBJECTIVES: The aim of this manuscript is to describe the first year of our experience using extracorporeal membrane oxygenation support. METHODS: Ten patients with severe refractory hypoxemia, two with associated severe cardiovascular failure, were supported using venous-venous extracorporeal membrane oxygenation (eight patients) or veno-arterial extracorporeal membrane oxygenation (two patients). RESULTS: The median age of the patients was 31 yr (range 14-71 yr). Their median simplified acute physiological score three (SAPS3) was 94 (range 84-118), and they had a median expected mortality of 95% (range 87-99%). Community-acquired pneumonia was the most common diagnosis (50%), followed by P. jiroveci pneumonia in two patients with AIDS (20%). Six patients were transferred from other ICUs during extracorporeal membrane oxygenation support, three of whom were transferred between ICUs within the hospital (30%), two by ambulance (20%) and one by helicopter (10%). Only one patient (10%) was anticoagulated with heparin throughout extracorporeal membrane oxygenation support. Eighty percent of patients required continuous venous-venous hemofiltration. Three patients (30%) developed persistent hypoxemia, which was corrected using higher positive end-expiratory pressure, higher inspired oxygen fractions, recruitment maneuvers, and nitric oxide. The median time on extracorporeal membrane oxygenation support was five (range 3-32) days. The median length of the hospital stay was 31 (range 3-97) days. Four patients (40%) survived to 60 days, and they were free from renal replacement therapy and oxygen support. CONCLUSIONS: The use of extracorporeal membrane oxygenation support in severely ill patients is possible in the presence of a structured team. Efforts must be made to recognize the necessity of extracorporeal respiratory support at an early stage and to prompt activation of the extracorporeal membrane oxygenation team

Estudo experimental sobre a eficiência e segurança da manobra de hiperinsuflação manual como técnica de remoção de secreção Experimental study on the efficiency and safety of the manual hyperinflation maneuver as a secretion clearance technique

OBJETIVO: Avaliar, em um modelo pulmonar simulando um paciente sob ventilação mecânica, a eficiência e a segurança da manobra de hiperinsuflação manual (HM) com o intuito de remover secreção pulmonar. MÉTODOS: Oito fisioterapeutas utilizaram um ressuscitador manual autoinflável para realizar HM com o objetivo de remover secreções, em duas condições: conforme rotineiramente aplicada durante sua prática clínica, e após receberem instruções verbais baseadas em recomendações de especialistas. Três cenários clínicos foram simulados: função pulmonar normal, doença pulmonar restritiva e doença pulmonar obstrutiva. RESULTADOS: Antes da instrução, o uso de duas compressões sequenciais do ressuscitador era comum, e a pressão proximal (Pprox) foi mais alta em relação à obtida após a instrução. Entretanto, a pressão alveolar (Palv) nunca excedeu 42,5 cmH2O (mediana, 16,1; intervalo interquartil [IQ], 11,7-24,5), mesmo com valores de Pprox de até 96,6 cmH2O (mediana, 36,7; IQ, 22,9-49,4). O volume corrente (VC) gerado foi relativamente pequeno (mediana, 640 mL; IQ, 505-735) e o pico de fluxo inspiratório (PFI) geralmente excedeu o pico de fluxo expiratório (PFE): 1,37 L/s (IQ, 0,99-1,90) e 1,01 L/s (IQ, 0,55-1,28), respectivamente. Uma relação PFI/PFE OBJECTIVE: To evaluate, in a lung model simulating a mechanically ventilated patient, the efficiency and safety of the manual hyperinflation (MH) maneuver as a means of removing pulmonary secretions. METHODS: Eight respiratory therapists (RTs) were asked to use a self-inflating manual resuscitator on a lung model to perform MH as if to remove secretions, under two conditions: as routinely applied during their clinical practice; and after receiving verbal instructions based on expert recommendations. In both conditions, three clinical scenarios were simulated: normal lung function, restrictive lung disease, and obstructive lung disease. RESULTS: Before instruction, it was common for an RT to compress the resuscitator bag two times, in rapid succession. Proximal pressure (Pprox) was higher before instruction than after. However, alveolar pressure (Palv) never exceeded 42.5 cmH2O (median, 16.1; interquartile range [IQR], 11.7-24.5), despite Pprox values as high as 96.6 cmH2O (median, 36.7; IQR, 22.9-49.4). The tidal volume (VT) generated was relatively low (median, 640 mL; IQR, 505-735), and peak inspiratory flow (PIF) often exceeded peak expiratory flow (PEF), the median values being 1.37 L/s (IQR, 0.99-1.90) and 1.01 L/s (IQR, 0.55-1.28), respectively. A PIF/PEF ratio < 0.9 (which theoretically favors mucus migration toward the central airways) was achieved in only 16.7% of the maneuvers. CONCLUSIONS: Under the conditions tested, MH produced safe Palv levels despite high Pprox. However, the MH maneuver was often performed in a way that did not favor secretion removal (PIF exceeding PEF), even after instruction. The unfavorable PIF/ PEF ratio was attributable to overly rapid inflations and low V T

Driving pressure and long-term outcomes in moderate/severe acute respiratory distress syndrome

Abstract Background Acute respiratory distress syndrome (ARDS) patients may present impaired in lung function and structure after hospital discharge that may be related to mechanical ventilation strategy. The aim of this study was to evaluate the association between functional and structural lung impairment, N-terminal-peptide type III procollagen (NT-PCP-III) and driving pressure during protective mechanical ventilation. It was a secondary analysis of data from randomized controlled trial that included patients with moderate/severe ARDS with at least one follow-up visit performed. We obtained serial measurements of plasma NT-PCP-III levels. Whole-lung computed tomography analysis and pulmonary function test were performed at 1 and 6 months of follow-up. A health-related quality of life survey after 6 months was also performed. Results Thirty-three patients were enrolled, and 21 patients survived after 6 months. In extubation day an association between driving pressure and NT-PCP-III was observed. At 1 and 6 months forced vital capacity (FVC) was negatively correlated to driving pressure (p < 0.01). At 6 months driving pressure was associated with lower FVC independently on tidal volume, plateau pressure and baseline static respiratory compliance after adjustments (r 2 = 0.51, p = 0.02). There was a significant correlation between driving pressure and lung densities and nonaerated/poorly aerated lung volume after 6 months. Driving pressure was also related to general health domain of SF-36 at 6 months. Conclusion Even in patients ventilated with protective tidal volume, higher driving pressure is associated with worse long-term pulmonary function and structure

Oxigenação extracorpórea por membrana na hipoxemia grave: hora de revermos nossos conceitos?

Em 2009, muitos casos de infecção pulmonar com hipoxemia grave refratária às estratégias ventilatórias habitualmente utilizadas e às manobras de resgate para a síndrome do desconforto respiratório agudo foram relatados durante a epidemia por influenza A (H1N1). Em muitos desses pacientes, o uso de extracorporeal membrane oxygenation (ECMO, oxigenação extracorpórea por membrana) foi necessário, fato que fez reacender o interesse na ECMO globalmente. O Grupo De Estudos em Suporte Extracorpóreo foi criado visando a aprender a técnica e a utilizar ECMO no tratamento de pacientes com hipoxemia grave. Neste artigo, são discutidas as indicações de ECMO e é relatado o caso de uma paciente com hipoxemia refratária que foi tratada através de ECMO de forma bem sucedida