Page 554 - Clinical Application of Mechanical Ventilation

520 Chapter 16

WEANING CRITERIA

Weaning criteria are used to evaluate the readiness of a patient for a weaning trial
and the likelihood of weaning success. Weaning is more likely to succeed if a pa-
tient meets most of the criteria.
Both subjective and objective measurements have been developed to determine
a patient’s readiness for weaning. The common weaning criteria are summarized in
Table 16-2.

Ventilatory Criteria

The ventilatory status of a patient may be used to evaluate the readiness and out-
come of weaning attempts. Weaning success will be more likely if the patient can

TABLE 16-2 Common Weaning Criteria

Category Example Note

Clinical criteria Resolution of acute phase of disease
Adequate cough
Absence of excessive secretions
Cardiovascular and hemodynamic
stability

Ventilatory criteria Spontaneous breathing trial Tolerates 20 to 30 min
PaCO 2 ,50 mm Hg with normal pH
Vital capacity .10 mL/kg
Spontaneous V T .5 mL/kg
Spontaneous f ,35/min
f/V T ,100 breaths/min/L*
Minute ventilation ,10 L with satisfactory ABG

Oxygenation criteria PaO without PEEP .60 mm Hg at F O up to 0.4
I
2
2
PaO with PEEP (,8 cm H O) .100 mm Hg at F O up to 0.4
2
2
I
2
SaO 2 .90% at F O up to 0.4
I
2
PaO /F O (P/F) $150 mm Hg
2
2
I
Q /Q T ,20%
S
P(A-a)O 2 ,350 mm Hg at F O of 1.0
2
I
Pulmonary reserve Vital capacity .10 mL/kg
Max. insp. pressure . 230 cm H O in 20 sec
2
Pulmonary Static compliance .30 mL/cm H O
2
measurements Airway resistance Stable or improving
V /V T ,60% while intubated
D
*rounded from 105 breaths/min/L.
(Data from Boles et al., 2007; Burton et al., 1997; Caruso et al., 1999; Girault et al., 1994; Jabour et al., 1991; MacIntyre, 2004; Tobin et al., 1990;
Yang et al., 1991.)
© Cengage Learning 2014
Copyright 2013 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.