Liberal red blood cell transfusions impair quality of life after cardiac surgery.

BACKGROUND: The optimal blood management after cardiac surgery remains controversial. Moreover, blood transfusions may have an impact on long-term outcomes. OBJECTIVE: The aim of this study is to characterize the impact of liberal red blood cell transfusions on Health-Related Quality of life (HRQoL) after cardiac surgery. METHODS: We studied a cohort of 205 consecutive patients after ICU discharge. Baseline characteristics and clinical data were recorded, and HRQoL was assessed using the EuroQoL-5D instrument, applied 6 months after ICU discharge. A specific question regarding the improvement in the quality of life after the surgical intervention was added to the HRQoL questionnaire. Risk factors related to impaired quality of life were identified using univariate comparisons and multivariate regression techniques. RESULTS: The median (interquartile range, IQR) of transfused red blood cells was 3 (1-4). Among 205 patients, 178 were studied 6 months after discharge. Impairment in at least one dimension of the EuroQoL-5D questionnaire was observed in 120 patients, with an overall score of 0.8 (IQR 0.61-1). The number of red blood cell transfusions was related to an impaired HRQoL (OR 1.17 per additional unit, 95% confidence interval 1.03-1.36, p=0.03), a trend to lower visual analog scale score (coefficient -0.75 per additional unit, 95% confidence interval -1.61 to 0.1, p=0.09) and an absence of improvement in HRQoL after surgery compared to the previous status (OR 1.13, 95% confidence interval 1.03-1.25, p=0.01). CONCLUSIONS: Liberal red blood cell transfusions increase the risk of impaired HRQoL after cardiac surgery.

Mechanical ventilation in acute respiratory distress syndrome: The open lung revisited.

Acute respiratory distress syndrome (ARDS) is still related to high mortality and morbidity rates. Most patients with ARDS will require ventilatory support. This treatment has a direct impact upon patient outcome and is associated to major side effects. In this regard, ventilator-associated lung injury (VALI) is the main concern when this technique is used. The ultimate mechanisms of VALI and its management are under constant evolution. The present review describes the classical mechanisms of VALI and how they have evolved with recent findings from physiopathological and clinical studies, with the aim of analyzing the clinical implications derived from them. Lastly, a series of knowledge-based recommendations are proposed that can be helpful for the ventilator assisted management of ARDS at the patient bedside.

[Monitorization of respiratory mechanics in the ventilated patient]. / Monitorización de la mecánica respiratoria en el paciente ventilado.

Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation.

[Inflammatory response and apoptosis in acute pulmonary injury]. / Respuesta inflamatoria y apoptosis en la lesión pulmonar aguda.

One of the principal mechanisms of pulmonary injury in acute respiratory distress is due to the effects of the precipitated inflammatory response. The damage produced to the alveolar epithelium and underlying endothelium depends on the sequestration and activation of inflammatory cells, which in turn exert their actions through mediators. On the other hand, apoptosis is a mechanism responsible for epithelial damage and regulation of inflammation. Response of the lung tissue subjected to mechanical ventilation stimulus is added to the previous mechanisms. All these processes flow into a series of common pathways of cellular activation. Knowledge of these mechanisms could serve to identify which patients would benefit from a specific treatment before applying therapies that act indiscriminately in the inflammatory response.

[The eternal promise of high frequency ventilation]. / La eterna promesa de la ventilación de alta frecuencia.

High frequency oscillatory ventilation (HFOV) is based on the application of continuous pressure in the respiratory system, which assures oxygenation, on which a small oscillation that permits ventilation is added. Although this ventilation form seems to comply with the requirements necessary to minimize the pulmonary lesion associated to mechanical ventilator-induced lung injury in acute lung injury, as several experimental studies suggest, its advantages in the clinical practice must still be demonstrated. Part of this lack of evidence is due to methodological problems of the studies published. However, the major limitation is that it has not been compared against a conventional ventilation strategy with low volumes/pressures. At present, it seems that high frequency ventilation is limited to cases refractory to conventional ventilation. A more extensive knowledge on how to optimize high frequency ventilation is needed before proposing clinical trials having greater scope.