TY - JOUR
TI - The combination of the load/force balance and the frequency/tidal volume
can predict weaning outcome
AU - Vassilakopoulos, T
AU - Routsi, C
AU - Sotiropoulou, C
AU - Bitsakou, C and
AU - Stanopoulos, I
AU - Roussos, C
AU - Zakynthinos, S
JO - Intensive Care Medicine Experimental
PY - 2006
VL - 32
TODO - 5
SP - 684-691
PB - Springer-Verlag
SN - 2197-425X
TODO - 10.1007/s00134-006-0104-y
TODO - ventilator weaning; mechanical ventilation; muscle endurance
TODO - Objective: To examine whether an appropriately designed combination of
an index of ventilatory endurance and the frequency divided by tidal
volume ratio (f/V-T) provides prognostic information for weaning outcome
not offered by any index alone. Design and setting: Prospective study in
a multidisciplinary intensive care unit, university hospital. Patients:
124 consecutive mechanically ventilated patients. Interventions: We
designed an index of ventilatory endurance (load/force balance)
calculated as the mean inspiratory airway pressure (P-I) during
controlled mechanical ventilation/maximum inspiratory pressure (MIP)
[P-I equals the triplicate of mean airway pressure (Paw) displayed by
the ventilator] and tested its capacity in predicting weaning outcome at
48 h along with f/V-T and many other indices in 75 consecutive
mechanically ventilated patients ready to wean. A stepwise discriminant
function analysis was used to test the performance of appropriately
designed index combination. Threshold values of indices and their
combination were prospectively validated in another group of 45
consecutive patients. Results: Stepwise discriminant analysis showed
that P-I/MIP and f/V-T were the only indices that remained in the model
with the function D = 7.628 x mean Paw/MIP + 0.0158 x f/V-T - 2.374. The
cutoff point of D = 0.5 had 94% sensitivity, 67% specificity, and 87%
correct classifications. Prospective validation demonstrated similar
results. The simplified discriminant function D = 15 x mean Paw/MIP +
0.03 x f/V-T - 5 and the cut-off point of D = 1.0 had 89% sensitivity,
67% specificity, and 85% correct classifications. Conclusions: The
combination of mean Paw/MIP and f/V-T in a simplified discriminant
function is useful in predicting weaning outcome.
ER -