Abstract
Crit Care Sci. 2023;35(4):367-376
DOI 10.5935/2965-2774.20230069-pt
To assess the impact of different vertical positions on lung aeration in patients receiving invasive mechanical ventilation.
An open-label randomized crossover clinical trial was conducted between January and July 2020. Adults receiving invasive mechanical ventilation for > 24 hours and < 7 days with hemodynamic, respiratory and neurological stability were randomly assigned at a 1:1 ratio to the sitting position followed by passive orthostasis condition or the passive orthostasis followed by the sitting position condition. The primary outcome was lung aeration assessed using the lung ultrasound score (score ranges from 0 [better] to 36 [worse]).
A total of 186 subjects were screened; of these subjects, 19 were enrolled (57.8% male; mean age, 73.2 years). All participants were assigned to receive at least one verticalization protocol. Passive orthostasis resulted in mean lung ultrasound scores that did not differ significantly from the sitting position (11.0 versus 13.7; mean difference, -2.7; [95%CI -6.1 to 0.71; p = 0.11). Adverse events occurred in three subjects in the passive orthostasis group and in one in the sitting position group (p = 0.99).
This analysis did not find significant differences in lung aeration between the sitting and passive orthostasis groups. A randomized crossover clinical trial assessing the impact of vertical positioning on lung aeration in patients receiving invasive mechanical ventilation is feasible. Unfortunately, the study was interrupted due to the need to treat COVID-19 patients.
Abstract
Rev Bras Ter Intensiva. 2018;30(2):144-152
DOI 10.5935/0103-507X.20180028
To evaluate a novel physiological approach for setting the tidal volume in mechanical ventilation according to inspiratory capacity, and to determine if it results in an appropriate mechanical and gas exchange measurements in healthy and critically ill dogs.
Twenty healthy animals were included in the study to assess the tidal volume expressed as a percentage of inspiratory capacity. For inspiratory capacity measurement, the mechanical ventilator was set as follows: pressure control mode with 35cmH2O of inspired pressure and zero end-expiratory pressure for 5 seconds. Subsequently, the animals were randomized into four groups and ventilated with a tidal volume corresponding to the different percentages of inspiratory capacity. Subsequently, ten critically ill dogs were studied.
Healthy dogs ventilated with a tidal volume of 17% of the inspiratory capacity showed normal respiratory mechanics and presented expected PaCO2 values more frequently than the other groups. The respiratory system and transpulmonary driving pressure were significantly higher among the critically ill dogs but below 15 cmH2O in all cases.
The tidal volume based on the inspiratory capacity of each animal has proven to be a useful and simple tool when setting ventilator parameters. A similar approach should also be evaluated in other species, including human beings, if we consider the potential limitations of tidal volume titration based on the calculated ideal body weight.
Abstract
Rev Bras Ter Intensiva. 2007;19(1):74-84
DOI 10.1590/S0103-507X2007000100010
BACKGROUND AND OBJECTIVES: Organ transplantation is now an accepted option for end stage organ disease in well selected patients. This position is a result of great advances in the field of immunology, critical care medicine and pharmacology. However, organ transplantation is now suffering from its own success as the number of patients in waiting lists is dramatically increasing the same is not happening with organ availability results in increasing number of mortalities while waiting for transplantation. Transplant community responses to this situation consist of reviewing the criteria for organ acceptability and developing new strategies to get organs as the called non-heart beating organ donors. CONTENTS: However the physiopathology of brain death and its consequences are now better understood helping in such patients' management. The purpose of this review is to help to identify the most important clinical and therapeutic aspects related to its physiopathology as depletion of vasoactives substances and its importance in the management of cardio and respiratory systems. We also discuss endocrine and hidroelectrolytes disturbances. Organ specific data are also focused in order to offer a whole view of donor management. CONCLUSIONS: It is important to observe that new technologies will be available in the near future to diminish the low rate between organ availability and organ waiting patients. In conclusion, with the raising numbers in transplant waiting lists and scarce resources of organs make us believe that we have to improve the management of multi organ donors and the preservation technology in order to reduce the mortality in such waiting lists.