ISSN:
1432-1238
Keywords:
Key words Weaning
;
Extubation
;
Indices
;
Subjective
;
Critically ill
;
Mechanical ventilation
;
CPAP
;
Pressure support
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Objective: To assess the outcome of a clinical judgement-based approach to weaning and extubation and to adduce the predictive accuracy of various mechanical respiratory indices measured in parallel. Design: Prospective study. Setting: Multidisciplinary intensive care unit at a university teaching hospital. Patients: 163 consecutive mechanically ventilated patients, excluding tracheotomy, for weaning trial and extubation. Interventions: Using bedside clinical assessment, aided by arterial gas analysis, patients were weaned from mechanical ventilation to spontaneous ventilation via the continuous positive airway pressure (CPAP) circuit (with pressure support) of a microprocessor-controlled ventilator. Extubation occurred from the CPAP circuit at 7 cmH2O pressure support, fractional inspired oxygen (FIO2) ≤0.5 and CPAP level of ≤5 cmH2O, such that the partial pressure of oxygen in arterial blood (PaO2) was ≥65 mmHg. Before extubation, observation for a 1-h (T0 and T60) trial period allowed measurement of vital capacity (VC), expired minute volume (VE), respiratory rate/tidal volume (f/VT) and maximal inspiratory pressure (MIP) using a one-way valve technique over 25 s. Measurements and main results: Over 7 months, 163 patients (62 females and 101 males; mean(SD) age 64(15) years) were considered. There were 91 surgical (18 with chronic obstructive pulmonary disease; COPD) and 72 medical (28 with COPD) patients. Ventilation was for ≥1 day (median 5 days, range 1–31) in 115 [group I; APACHE II score 23(8)] and ≤1 day in 48 [Group II; APACHE II score 17(6)]. Three patients (all Group I: 2 surgical, 1 medical) were reintubated within 24 h, an overall extubation failure rate of 1.8%. In group I, at T0, PaO2/FIO2 was 238(65), f/VT 50(26), MIP 44(21) cmH2O, VE 10.6(3.7) l/min, VC 13(5) ml/kg. Cardiorespiratory variables did not change significantly in either group, T0 to T60. For prediction of reintubation (n=163), only VE (threshold 〉10 l/min) and f/VT (threshold 〉 100) demonstrated moderate sensitivity and specificity at T60: 67 and 52% and 33 and 94%, respectively. Conclusions: Bedside clinical judgement of weaning and extubation produces satisfactory outcomes. As a routine, mechanical predictive indices have limited utility.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01709517
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