Evaluation of some pulmonary physiological and mechanical parameters as weaning criteeria

ABSTRACT

Simple protocols can help selecting patients capable of sustaining spontaneous breathing. To evaluate the utility of some pulmonary physiological and mechanical parameters as weaning predictors.Twenty four patients were included, the following data were assessed spontaneous respiratory frequency [/], spontaneous tidal volume [VT], peak inspiratory pressure [PIP],plateau airway pressure [P plat], maximum inspiratory pressure [PImax], rapid shallow breathing index [RSBI], dynamic compliance [Cdyn], static compliance [Cst], alveolar-arterial oxygen gradient [[A-a] O[2] and]], minute ventilation [VE], shunt fraction and arterial to inspired oxygen ratio [PaO[2]/FIO2].Eighteen patients were successfully weaned [GI] and six failed the T-piece trial [Gil]. Significant differences were found between both groups as regards RSBI, Cst, Cdyn, shunt fraction, p[A-a] O[2] Pplat and PaO2/FIO[2][p<0.05]. By testing cut off values for RSBI [49.78], PaO[2]/FIO[2][155].p [A-a] O[2] A [84] and shunt fraction [25%], they gave a diagnostic accuracy of 91.6%, 91.7%, 100% and 95.8% respectively. PImax, PIP and VE were not discriminating parameters.Simple bedside criteria can help triggering efficient weaning protocols which can be adopted in our intensive care units. The previous cut off values can also be helpful in taking weaning decisions