Wednesday, March 22, 2006


Wednesday March 22, 2006
Spontaneous Breathing Trial (SBT) - how long - 30 minutes or 120 minutes?

Spontaneous Breathing Trial (SBT) remained one of the key clinical parameter for extubation from mechanical ventilation but there is always a debate about how long is good enough to predict successful extubation. Evidence-Based Guidelines for Weaning and Discontinuing Ventilatory Support published in chest 2001 recommends: "The tolerance of SBTs lasting 30 to 120 min should prompt consideration for permanent ventilator discontinuation."3

Earlier one study published 7 years ago in Am. J. Respir. Crit. Care Med, showed that successful extubation can be achieved equally effectively with trials targeted to last 30 and 120 minutes 1. This has been confirmed again in another study from Washington Hospital Center, Washington, DC. 164 consecutive medical ICU patients on mechanical ventilation have been evaluated. 90-minute CPAP trial has been given and RSBI was measured at 1, 30, 60, and 90 minutes of SBT. 141 patients were successfully extubated and the mean RSBI’s for successfully extubated patients were 65, 63, 64, and 65 at 1, 30, 60, and 90 minutes, respectively. It was concluded that there is little to be gained by extending the SBT beyond the first 30 minutes 2.

In this regard, read article with weaning protocols, strategies and numbers from FERNANDO FRUTOS-VIVAR, MD and ANDRÉS ESTEBAN, MD, PHD (Intensive Care Unit, Hospital Universitario de Getafe Madrid, Spain):
When to wean from a ventilator: An evidence-based strategy, published in CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 70, NUMBER 5 MAY 2003 page 389

1. Effect of Spontaneous Breathing Trial Duration on Outcome of Attempts to Discontinue Mechanical Ventilation - Am. J. Respir. Crit. Care Med., Volume 159, Number 2, February 1999, 512-518
Analysis of Rapid Shallow Breathing Index as a Predictor for Successful Extubation from Mechanical Ventilation - Chest 2004 126: 756S-757S.
Evidence-Based Guidelines for Weaning and Discontinuing Ventilatory Support- A Collective Task Force Facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine- Chest. 2001;120:375S-396S