Critical care : the official journal of the Critical Care Forum
-
Comparative Study
Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm.
Controlled mechanical ventilation (CMV) induces profound modifications of diaphragm protein metabolism, including muscle atrophy and severe ventilator-induced diaphragmatic dysfunction. Diaphragmatic modifications could be decreased by spontaneous breathing. We hypothesized that mechanical ventilation in pressure support ventilation (PSV), which preserves diaphragm muscle activity, would limit diaphragmatic protein catabolism. ⋯ PSV is efficient at reducing mechanical ventilation-induced proteolysis and inhibition of protein synthesis without modifications in the level of oxidative injury compared with continuous mechanical ventilation. PSV could be an interesting alternative to limit ventilator-induced diaphragmatic dysfunction.
-
Comparative Study
The influence of body composition on therapeutic hypothermia: a prospective observational study of patients after cardiac arrest.
Patients after out-of-hospital cardiac arrest (OHCA) benefit from therapeutic hypothermia for 24 hours. The time needed to reach hypothermia (target temperature of 32 degrees C to 34 degrees C) varies widely. In this study, we explore the relation between measures of body composition and the time needed to reach target temperature with hypothermia. ⋯ The body composition measures from single-frequency impedance and anthropometrics appear to be very concordant. Only TBF percentage (anthropometrics) showed a significant but clinically irrelevant influence on time needed to achieve target temperature with hypothermia. We conclude that there are no indications to adjust current cooling practice toward the body composition of patients.
-
The benefits of beta-adrenergic stimulation have been described in acute lung injury (ALI), but there is still no evidence of its anti-inflammatory effect in these patients. Biomarkers in exhaled breath condensate (EBC) were used to study the effects of salbutamol on lung inflammation in mechanically ventilated patients with ALI. ⋯ EBC analysis is a noninvasive technique that can be used to monitor ventilated patients. In EBC from a small cohort of patients with ALI, inhaled salbutamol significantly decreased airspace acidosis, a marker of inflammation, and was associated with a trend toward decreased markers of nitrosative and oxidative stress.
-
Optimal vasopressor support during resuscitation should theoretically enhance aortic diastolic and coronary perfusion pressure as well as coronary and cerebral blood flow/oxygen delivery without increasing cellular oxygen demand. Intravenous vasopressor support, using 1 mg doses of epinephrine every 5 minutes in adults or vasopressin 40 IU, is recommended by American Heart Association Advanced Cardiac Life Support Guidelines to maximize oxygen delivery to the heart and brain and increase cellular high energy phosphate levels. Vasopressin offers theoretical advantages over epinephrine in that it does not increase myocardial oxygen demand significantly and its receptors are relatively unaffected by acidosis. ⋯ Despite these differences in physiologic actions, two large randomized clinical trials yielded virtually identical overall survival to hospital discharge when these agents were compared during inhospital or out-of-hospital resuscitation in Canada and Europe, respectively. More recent clinical and experimental evidence suggests that a combination of vasopressin and epinephrine used during resuscitation can improve hemodynamics and perhaps survival. The verdict on a combination vasopressor strategy may soon come from a large (>2,000 patients) prospective clinical trial that is underway in France to clarify the role of combination vasopressin/epinephrine therapy in out-of-hospital resuscitation.