Pressure Support Reduction Versus Spontaneous Breathing Trials in Weaning From Ventilation

• Occurence of ventilator associated pneumonia [ Time Frame: Until the date of discharge from hospital ] [ Designated as safety issue: Yes ]
• Reintubation rates [ Time Frame: 48 hours ] [ Designated as safety issue: Yes ]
• Mortality rates [ Time Frame: Until the time of discharge from hospital ] [ Designated as safety issue: Yes ]
• Duration from start of weaning to extubation [ Time Frame: In hospital stay ] [ Designated as safety issue: Yes ]
• Role of various factors that may influence the weaning outcome and hence predict the probability of successful weaning in a patient [ Time Frame: during ICU stay ] [ Designated as safety issue: Yes ]
• The influence of weaning outcome on mortality and the other complications of mechanical ventilation [ Time Frame: during hospital stay ] [ Designated as safety issue: Yes ]

• Occurence of ventilator associated pneumonia [ Time Frame: Till the date of discharge from hospital ] [ Designated as safety issue: Yes ]
• Reintubation rates [ Time Frame: 48 hours ] [ Designated as safety issue: Yes ]
• Mortality rates [ Time Frame: Till the time of discharge from hospital ] [ Designated as safety issue: Yes ]
• Duration from start of weaning to extubation [ Time Frame: In hospital stay ] [ Designated as safety issue: Yes ]

This study is a comparison of two most commonly used modes of weaning and the outcomes in the two groups.

Patients ventilated for more than 24 hours are randomized into two groups - one group of patients undergo gradual reduction of pressure support and in the other, T tube trials are used for weaning. The outcomes are compared in the two groups.

• Respiration, Artificial
• Ventilator Weaning

• Procedure: Pressure support ventilation
  These patients are weaned by gradual reduction of pressure support and extubated when they tolerate a pressure support of 7 cm of water for one hour.
  Other Name: weaning by reduction of pressure support
• Procedure: Spontaneous breathing trials
  These patients are weaned by giving a T piece trial with 8 cm of water pressure support and extubated when they tolerate it for one hour.
  Other Name: Weaning by T-piece trials

• Active Comparator: Pressure support ventilation
  Patients in this arm are weaned by gradual reduction of pressure support
  Intervention: Procedure: Pressure support ventilation
• Active Comparator: Spontaneous breathing trials
  Patients in this arm are weaned by T piece trials
  Intervention: Procedure: Spontaneous breathing trials

• Esteban A, Frutos F, Tobin MJ, Alía I, Solsona JF, Valverdú I, Fernández R, de la Cal MA, Benito S, Tomás R, et al. A comparison of four methods of weaning patients from mechanical ventilation. Spanish Lung Failure Collaborative Group. N Engl J Med. 1995 Feb 9;332(6):345-50.
• Brochard L, Rauss A, Benito S, Conti G, Mancebo J, Rekik N, Gasparetto A, Lemaire F. Comparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation. Am J Respir Crit Care Med. 1994 Oct;150(4):896-903.
• Esteban A, Alía I, Gordo F, Fernández R, Solsona JF, Vallverdú I, Macías S, Allegue JM, Blanco J, Carriedo D, León M, de la Cal MA, Taboada F, Gonzalez de Velasco J, Palazón E, Carrizosa F, Tomás R, Suarez J, Goldwasser RS. Extubation outcome after spontaneous breathing trials with T-tube or pressure support ventilation. The Spanish Lung Failure Collaborative Group. Am J Respir Crit Care Med. 1997 Aug;156(2 Pt 1):459-65. Erratum in: Am J Respir Crit Care Med 1997 Dec;156(6):2028.

Inclusion Criteria:

• Mechanically ventilated patients for more than 24 hours
• Satisfies weaning criteria
• RSBI < 80
• Ratio of PaO2/FiO2 > 250
• Arterial partial pressure of oxygen more than 60 mm Hg and carbon dioxide less than 50 mm Hg

Exclusion Criteria:

• Systolic blood pressure of less than 100
• Arterial partial pressure of oxygen less than 60 mm Hg
• Poor sensorium