Critical care : the official journal of the Critical Care Forum
-
Current protective lung ventilation strategies commonly involve hypercapnia. This approach has resulted in an increase in the clinical acceptability of elevated carbon dioxide tension, with hypoventilation and hypercapnia 'permitted' in order to avoid the deleterious effects of high lung stretch. ⋯ However, there are no clinical data evaluating the direct effects of hypercapnia per se in acute lung injury. This article reviews the current clinical status of permissive hypercapnia, discusses insights gained to date from basic scientific studies of hypercapnia and acidosis, identifies key unresolved concerns regarding hypercapnia, and considers the potential clinical implications for the management of patients with acute lung injury.
-
Review
Bench-to-bedside review: Ethical challenges for those in directing roles in critical care units.
Though much attention in the medical literature has focused on the ethics of critical care, it seems to be disproportionately weighted toward clinical issues. On the presumption that the operational management of an intensive care unit (ICU) also requires ethical considerations, it would be useful to know what these are. ⋯ We found that in addition to issues of resource allocation, there exist many areas of ethical importance to clinician-managers in the ICU that have been described only superficially. We argue that a renewed focus on ICU ethics is merited to shed light on these other, non-clinical, issues.
-
Review
Clinical review: Noninvasive ventilation in the clinical setting--experience from the past 10 years.
This brief review analyses the progress of noninvasive ventilation (NIV) over the last decade. NIV has gained the dignity of first line intervention for acute exacerbation of chronic obstructive pulmonary disease, assuring reduction of the intubation rate, rate of infection and mortality. ⋯ The infection rate reduction effect achieved by NIV application is crucial for immunocompromised patients for whom the endotracheal intubation represents a high risk. Improvements in skills acquired with experience over time progressively allowed successful treatment of more severe patients.
-
In patients with acute respiratory distress syndrome (ARDS), the lung comprises areas of aeration and areas of alveolar collapse, the latter producing intrapulmonary shunt and hypoxemia. The currently suggested strategy of ventilation with low lung volumes can aggravate lung collapse and potentially produce lung injury through shear stress at the interface between aerated and collapsed lung, and as a result of repetitive opening and closing of alveoli. An 'open lung strategy' focused on alveolar patency has therefore been recommended. ⋯ In animal studies, recruitment maneuvers clearly reverse the derecruitment associated with low tidal volume ventilation, improve gas exchange, and reduce lung injury. Data regarding the use of recruitment maneuvers in patients with ARDS show mixed results, with increased efficacy in those with short duration of ARDS, good compliance of the chest wall, and in extrapulmonary ARDS. In this review we discuss the pathophysiologic basis for the use of recruitment maneuvers and recent evidence, as well as the practical application of the technique.